The sigmoid mesocolon varies in length and depth between individuals.
The root of the sigmoid colon usually has a shallow, inverted V-shaped orly from the anterior surface of the rectum over the upper poles of
attachment; the apex of the V overlies the division of the left common the seminal vesicles and on to the posterior surface of the bladder,
iliac artery (see Fig. 63.2). Alternatively, the attachment may form a producing the rectovesical pouch. The pouch is limited laterally by
gentle curve. The left limb of the attachment runs over the left psoas sacrogenital folds of peritoneum, which extend posteriorly from the
major and along the external iliac vessels. The right limb passes over sides of the bladder to the anterior aspect of the sacrum. The perito-
the pelvic brim towards the midline at the level of the third sacral ver- neum covering the posterosuperior surface of the bladder forms a para-
tebra. The anteromedial peritoneal layer of the sigmoid mesocolon is vesical fossa on each side that is limited laterally by a ridge of peritoneum
continuous with the peritoneum of the lower left posterior abdominal containing the vas deferens; the depth of the paravesical fossae depends
wall, and its posterolateral layer is continuous with the peritoneum of on the volume of urine in the bladder. When the bladder is empty, a
the lateral abdominal wall. Bands of peritoneum may be present transverse vesical fold may be visible at laparoscopy; its medial portion
running from the proximal sigmoid colon to the posterior abdominal overlies the superior vesical artery or arteries (Boaz et al 2011). Between
wall. The sigmoid and superior rectal vessels run between its layers and the paravesical and pararectal fossae, the ureters and internal iliac
the left ureter descends into the pelvis behind its apex and anterior to vessels may cause slight elevations in the peritoneum. From the apex
the bifurcation of the left common iliac artery. of the bladder, the median umbilical fold extends superiorly on the
posterior surface of the lower anterior abdominal wall to the umbilicus.
Peritoneum of the lower anterior When the bladder distends, the overlying peritoneum is lifted so that
part of the anterior surface of the bladder comes into direct contact with
abdominal wall


the posterior surface of the lower anterior abdominal wall. This means
that a distended bladder can be punctured directly through the lower
The peritoneum of the lower anterior abdominal wall is raised into five anterior abdominal wall without traversing the peritoneal cavity
folds (sometimes referred to as ‘ligaments’), which diverge as they (suprapubic puncture).
descend from the umbilicus. They are the median, right and left medial,
and right and left lateral, umbilical folds (Fig. 63.7, see Fig. 75.9). The Peritoneum of the female pelvis
median umbilical fold extends from the umbilicus to the apex of the
bladder and contains the urachus or its remnant (Ch. 72). The medial
In females, peritoneum covers the anterolateral surface of the upper
umbilical fold overlies the obliterated umbilical artery, which ascends
rectum as it does in the male, but it descends further over the anterior
from the internal iliac artery in the pelvis to the umbilicus. The lateral
surface of the rectum. The pararectal and paravesical fossae are limited
umbilical fold covers the inferior epigastric vessels below their entry
laterally by the peritoneum that covers the uterosacral and round liga-
into the rectus sheath. The supravesical fossa lies between the medial
ments of the uterus, respectively (see Figs 77.14, 77.15, 77.18). The
and median umbilical folds on each side of the midline, and the medial
presence of the uterus and vagina means that there are two pelvic
and lateral inguinal fossae lie on either side of each lateral umbilical
pouches instead of the single rectovesical pouch seen in males. The
fold. The lateral inguinal fossa overlies the deep inguinal ring, and the
peritoneum from the rectum is reflected anteriorly on to the posterior
medial inguinal fossa overlies the femoral ring (Healy and Reznek
surface of the posterior fornix of the vagina and the uterus, forming the
1999).
recto-uterine pouch (of Douglas). The depth of the pouch – namely,
the extent to which it descends on the posterior surface of the vagina


– is variable (Baessler and Schuessler 2000). The peritoneum covers the
PERITONEUM OF THE PELVIS
fundus and body of the uterus, descending on its anterior surface as far
as the junction of the body and cervix; from here, it is reflected forwards
The parietal peritoneum of the abdominal wall is continuous with the
on to the posterosuperior surface of the bladder, forming a shallow
parietal peritoneum that lines the side walls of the pelvis. The arrange-
vesico-uterine pouch. As in males, the peritoneum over the dome of the
ment of the pelvic visceral peritoneum differs between the sexes.
bladder is reflected on to the posterior surface of the lower anterior
abdominal wall. Recto-uterine folds containing the uterosacral liga-
Peritoneum of the male pelvis
ments pass posteriorly from the sides of the cervix to the sacrum,
running lateral to the rectum. Peritoneum is also reflected from the
In males, the peritoneum of the left lower abdominal wall is reflected anterior and posterior uterine surfaces to the lateral pelvic walls as the
from the distal sigmoid colon and anterolateral surface of the upper broad ligament of the uterus (see Fig. 77.18). This consists of anterior
rectum to the side walls of the true pelvis, where it forms the right and and posterior layers that are continuous at the upper border of the liga-
left pararectal fossae (Fig. 63.8); these vary in size according to the ment. The broad ligament contains the uterine tubes in its free upper
degree of distension of the rectum. The peritoneum is reflected anteri- border; the ovaries are suspended from its posterior layer. Inferiorly, the


PERiTonEum And PERiTonEAl CAviTy
1106
8
noiTCES
Sacrum
Internal iliac vein
Sigmoid colon
Internal iliac artery
Rectum
External iliac vein
External iliac artery Pararectal fossa
Sacrogenital fold
Ureter
Rectovesical pouch
Ilium
Bladder Vas deferens
Transverse vesical fold
Paravesical fossa
Median umbilical fold Medial umbilical fold
Inferior epigastric vessels
Rectus abdominis
Fig. 63.8 The peritoneum of the male pelvis: anterosuperior view.
peritoneum at the base of the broad ligament merges with the pelvic the foregut is felt in the epigastric region, that from midgut structures
parietal peritoneum. The ovarian fossa is a shallow depression in the in the umbilical region, and that from hindgut structures in the
peritoneal lining of the lateral pelvic wall between the peritoneal ridges suprapubic region; none of these sensations is significantly lateralized.
formed by the obliterated umbilical arteries anteriorly, the ureter pos- Pain from the pancreas, gallbladder and even the small bowel may
teriorly, and the external iliac vessels above; it lies behind the lateral radiate to the back. Stretch or irritation of the visceral peritoneum
attachment of the broad ligament and usually contains the ovary in may also elicit profound reflex vasomotor and cardiac changes medi-
nulliparous females. ated by autonomic nerves, including a vasovagal response. This is of
considerable clinical relevance. Painful responses to manipulation of
the parietal peritoneum may be abolished by local or regional anaes-
VASCULAR SUPPLY AND LYMPHATIC DRAINAGE thesia. In marked contrast, the direct central connections of visceral
afferents, particularly via the vagus nerve, mean that stretching the
Parietal and visceral peritoneum develops from the somatopleural visceral peritoneum may induce profound effects, including acute
and splanchnopleural layers, respectively, of the lateral plate mesoderm haemodynamic instability, despite local or regional (including spinal)
(p. 1059). Parietal peritoneum is supplied by the somatic blood vessels anaesthesia.


of the abdominal and pelvic walls, and its lymphatics join those in the
body wall and drain to parietal lymph nodes. Visceral peritoneum is
best considered as an integral part of the viscus it covers: its blood
GENERAL ARRANGEMENT OF THE
supply and lymphatic drainage therefore correspond to those of the
associated viscus. PERITONEAL CAVITY
The peritoneal cavity is a single continuous space between the parietal
INNERVATION
peritoneum lining the abdominal wall and the visceral peritoneum
enveloping the abdominal organs. It consists of the greater sac, which
The parietal peritoneum is innervated by somatic efferent and afferent is the main peritoneal cavity surrounding most of the abdominal and
nerves that also supply the muscles and skin of the overlying body wall. pelvic viscera, and the lesser sac, or omental bursa, which is a small
The visceral peritoneum is innervated by afferent nerves that travel with diverticulum situated behind the stomach and lesser omentum and in
the autonomic supply to the underlying viscera. Sensations arising from front of the pancreas. These two sacs communicate via the epiploic
pathologies that affect the parietal or visceral peritoneum reflect these foramen.
different patterns of innervation. Well-localized pain is elicited by For clinical purposes, the peritoneal cavity can be divided into
mechanical, thermal or chemical stimulation of nociceptors in the pari- several ‘spaces’; pathological processes are often contained within these
etal peritoneum; the pain is usually well localized to the affected region. spaces and their anatomy may influence diagnosis and treatment. It is
Somatic nerves that innervate the parietal peritoneum also supply the useful to divide the peritoneal cavity into two main compartments,
corresponding segmental skin and muscles; when the parietal perito- supramesocolic (often simply called supracolic) and inframesocolic (or
neum is irritated, local reflex muscle contraction occurs, resulting in infracolic), which are partially separated by the transverse colon and its
clinical signs of guarding or even rigidity of the abdominal wall. The mesentery. The pelvic peritoneal spaces are described above.
parietal diaphragmatic peritoneum is supplied centrally by afferent


fibres from the phrenic nerves and peripherally by the lower intercostal
and subcostal nerves; peripheral irritation of the diaphragm may there-
fore result in pain localized in the distribution of the lower thoracic SUPRAMESOCOLIC COMPARTMENT
spinal nerves, while central irritation causes referred pain in the cutane-
ous distribution of the third to fifth cervical spinal nerves (the shoulder This lies between the diaphragm and the transverse mesocolon. It can
region). The innervation of the parietal peritoneum of the true pelvis be arbitrarily divided into right and left supramesocolic spaces. The
is poorly documented but the obturator nerve makes a significant right supramesocolic space can be subdivided into the right subphrenic
contribution. space, the right subhepatic space and the lesser sac. The left suprameso-
Irritation or stretch of the visceral peritoneum causes poorly local- colic space can be divided into two subspaces: the left subphrenic space
ized discomfort. The sensation of pain is referred to a diffuse area of and the left perihepatic space. These ‘spaces’ usually communicate but
the abdominal wall. Thus, discomfort from structures derived from may nevertheless be sites of localized fluid collections.


General arrangement of the peritoneal cavity
1107
36
RETPAHC
Right subphrenic space the posterior aspect of the fundus of the stomach and forms part of the
upper left border of the lesser sac. The two layers of the gastrophrenic
ligament diverge near the abdominal oesophagus, leaving part of the
The right subphrenic space lies between the diaphragm and the anterior,
posterior gastric surface devoid of peritoneum. The left gastric artery
superior and right lateral surfaces of the right lobe of the liver. It is
runs forwards here into the lesser omentum.
bounded on the left by the falciform ligament and posteriorly by the
The lesser sac is indented by a crescentic peritoneal fold that runs
upper layer of the coronary ligament (see Fig. 63.3). Because of the
from the upper border of the neck of the pancreas to the upper part of
clockwise flow of peritoneal fluid from the lower abdomen and pelvis,
the lesser curvature of the stomach. It is variably described but com-
it is a relatively common site for an infected fluid collection after a
monly known as the gastropancreatic fold. The upper part of this fold
perforated appendicitis or duodenal ulcer.
overlies the left gastric artery as it runs from the posterior abdominal
wall to the lesser curvature of the stomach. The lower part of the fold
Right subhepatic space (hepatorenal pouch)
overlies the common hepatic artery as it runs from the posterior abdom-
inal wall to the lesser omentum. When the fold is prominent, it divides
The right subhepatic space lies between the inferior surface of the right
the lesser sac into a smaller superior and a larger inferior recess. The
lobe of the liver and the upper pole of the right kidney. It is bounded
superior recess lies posterior to the lesser omentum and encloses
superiorly by the inferior layer of the coronary ligament, laterally by the
the caudate lobe of the liver; it extends superiorly into the fissure for
right lateral abdominal wall, posteriorly by the anterior surface of the
the ligamentum venosum and lies adjacent to the right crus of the
upper pole of the right kidney, and inferomedially by the hepatic
diaphragm posteriorly. The inferior recess of the lesser sac lies between


flexure, transverse mesocolon, second part of the duodenum, and part
the stomach and pancreas, and is contained within the double sheet of
of the head of the pancreas. In the supine position, the hepatorenal
the greater omentum.
pouch (of Morison) is more dependent than the right paracolic gutter.
Acute pancreatitis is probably the most common cause of a fluid
It is a site where a pathological fluid collection may develop.
collection within the lesser sac (or just behind its posterior peritoneal
lining) (p. 1182). Bleeding from trauma or a ruptured splenic artery
Lesser sac (omental bursa)
aneurysm and perforation of a posterior gastric ulcer are other causes
of lesser sac collections.
The lesser sac is a cavity lined with peritoneum and connected to the
Epiploic foramen
main peritoneal cavity (greater sac) by the epiploic foramen (of
Winslow). It is considered part of the right supramesocolic compart- The epiploic foramen (foramen of Winslow or aditus to the lesser sac)
ment because it develops in the embryo on the right side of the ventral is a short, vertical slit, about 3 cm in height in adults, behind the free
mesogastrium (p. 1059). It has posterior and anterior walls and superior, right border of the lesser omentum. It is the entrance to the lesser sac
inferior, right and left borders. The sac varies in size according to the from the greater sac. The hepatoduodenal ligament, formed by the
volume of the viscera making up its walls; it may be partially obliterated thickened free right margin of the lesser omentum and extending
by natural adhesions between the anterior and posterior walls. between the porta hepatis above and the upper border of the first part
The anterior wall of the lesser sac consists of the posterior peritoneal of the duodenum below, forms the anterior boundary of the foramen.
layer of the lesser omentum, the peritoneum over the posterior wall of Within this free border lie the bile duct (anteriorly on the right), the
the stomach and first part of the duodenum, and the posterior upper hepatic artery (anteriorly on the left) and the portal vein (posteriorly),


part of the anterior sheet of the greater omentum (see Fig. 63.5). At its together with nerves and lymphatics (see above). Rapid control of the
right border, the anterior wall is mostly formed by the lesser omentum hepatic artery and portal vein can be obtained by compression of the
but, towards the left, the lesser omentum becomes progressively shorter free edge of the lesser omentum (a ‘Pringle’ manœuvre), which is a
and more of the anterior wall is formed by the posterior surface of the potentially useful technique in liver trauma and surgery. Superiorly, the
stomach and greater omentum. peritoneum of the posterior layer of the hepatoduodenal ligament runs
The lower part of the posterior wall of the lesser sac is formed by the over the caudate process of the liver, forming the roof of the epiploic
anterior peritoneal layer of the posterior sheet of the greater omentum, foramen. This layer of peritoneum is then reflected on to the inferior
which overlies the transverse mesocolon. More superiorly, the perito- vena cava, which forms the posterior border of the foramen. The floor
neum of the posterior wall covers, from below upwards, a small part of of the foramen is formed by the peritoneal reflection overlying the
the head and the whole neck and body of the pancreas, the medial part upper border of the first part of the duodenum as it runs forwards above
of the anterior aspect of the upper pole of the left kidney, most of the the head of the pancreas. A narrow passage, the vestibule of the lesser
left suprarenal gland, the commencement of the abdominal aorta, the sac, may be formed to the left of the foramen between the caudate
coeliac trunk and part of the diaphragm (see Fig. 63.2). The inferior process above and the first part of the duodenum below. To the right,
phrenic, splenic, left gastric and common hepatic arteries lie partly the rim of the foramen is continuous with the peritoneum of the greater
behind the bursa. Many of these structures form the ‘bed’ of the stomach sac. The anterior and posterior walls of the foramen are normally
and are separated from it only by the linings of the lesser sac. apposed, which partly explains why patients can develop large fluid


The superior border of the lesser sac is narrow and lies between the collections isolated to the greater or lesser sac (Shrestha et al 2010).
right side of the oesophagus and the upper end of the fissure for the
Left subphrenic space
ligamentum venosum; it is sometimes referred to as the superior recess
of the omental bursa. Here, the peritoneum of the posterior wall of the
lesser sac is reflected anteriorly from the diaphragm to join the posterior The left subphrenic space lies between the diaphragm, the anterior and
layer of the lesser omentum. The inferior border runs along the line of superior surfaces of the left lobe of the liver, the anterosuperior surface
fusion of the layers of the greater omentum, which extends from the of the stomach and the diaphragmatic surface of the spleen. To the right
gastrosplenic ligament on the left to the peritoneal fold behind the first it is bounded by the falciform ligament. It is expanded in the absence
part of the duodenum on the right. If the layers of the greater omentum of the spleen and is a common site for fluid collection after splenec-
are not completely fused, the lesser sac may extend to the inferior limit tomy. The left subphrenic space is substantially larger than the right and
of this structure, but this is rarely demonstrable at surgery. can be divided into a left perihepatic space and anterior and posterior
The right border of the lesser sac is where the peritoneum overlying subphrenic spaces (see Fig. 63.6); these are in continuity in the absence
the head and neck of the pancreas is reflected on to the inferior aspect of disease. The definitions of the boundaries of these spaces vary.
of the first part of the duodenum. The line of this reflection ascends to The left anterior subphrenic space is large and lies between the
the left, along the medial side of the gastroduodenal artery. Near the superior and anterolateral surfaces of the spleen and the diaphragm.
upper duodenal border, the right border joins the floor of the epiploic Inferiorly and medially, this space is bounded by the phrenicocolic,


foramen round the hepatic artery proper. The epiploic foramen there- splenorenal and gastrosplenic ligaments. The phrenicocolic ligament
fore interrupts the right border. Above the epiploic foramen, the right partially obstructs the flow of fluid from the left paracolic gutter (Meyers
border is formed by the peritoneal reflection from the diaphragm to the 1973), which may explain why left subphrenic collections are less fre-
right margin of the caudate lobe of the liver, which then crosses the quent than right subphrenic collections after lower abdominal and
inferior vena cava. The left border of the lesser sac runs from the left pelvic surgery. Nevertheless, the left subphrenic space is a relatively
end of the root of the transverse mesocolon and is mostly formed by common site of fluid collection after upper abdominal surgery, particu-
the inner peritoneal layers of the splenorenal and gastrosplenic liga- larly surgery involving the spleen or distal pancreas. The left posterior
ments (see Fig. 63.6). The part of the lesser sac lying between the subphrenic space is small and lies between the fundus of the stomach
splenorenal and gastrosplenic ligaments is referred to as the splenic and the diaphragm above the origin of the splenorenal ligament.
recess. Above the spleen, the two ligaments merge to form the short The left perihepatic space is sometimes subdivided into anterior and
gastrophrenic ligament, which passes forwards from the diaphragm to posterior spaces. The left anterior perihepatic space lies between the


Peritoneum and peritoneal cavity
1107.e1
36
RETPAHC
Free tumour cells in the peritoneal cavity, especially from mucinous
tumours, may gain access to the lesser sac and settle by gravity into the
inferior recess of the lesser sac. This is more likely on the right side of
the lesser sac in an area recognized surgically as the ‘subpyloric space’.
Growth of tumour at this site may cause gastric outlet obstruction.
During surgical exploration of the abdomen, some peritoneal sur-
faces cannot be visualized without the aid of specific surgical manœu-
vres. One of these sites is the posterior aspect of the hepatoduodenal
ligament. The recess created by the posterior aspect of the hepatoduo-
denal ligament and the caudate process is an important site for muci-
nous peritoneal metastases. It can be visualized during cytoreductive
surgery by passing a tape around the structures in the free edge of the
lesser omentum and retracting them forwards.


PERiTonEum And PERiTonEAl CAviTy
1108
8
noiTCES
anterosuperior surface of the left lobe of the liver and diaphragm. The
Transverse
left posterior perihepatic space, also known as the gastrohepatic recess, mesocolon
lies inferior to the left lobe of the liver. It extends into the fissure for
the ligamentum venosum on the right. Posteriorly, it is separated from Inferior
mesenteric vein
the superior recess of the lesser sac by the lesser omentum.
Superior
Extraperitoneal subphrenic spaces duodenal fold
Superior
There are two potential subphrenic spaces that actually lie outside the
duodenal recess
peritoneum but are of clinical relevance because they may be sites of
fluid accumulation. The right extraperitoneal space is bounded by the Inferior
two layers of the coronary ligament, the bare area of the liver, and the duodenal recess
inferior surface of the right hemidiaphragm. The left extraperitoneal Inferior
space lies anterior to the left suprarenal gland and upper pole of the duodenal fold
left kidney. Left colic artery
Fig. 63.9 The superior and inferior duodenal recesses. Note that the
INFRAMESOCOLIC COMPARTMENT
transverse colon and jejunum have been displaced.
The inframesocolic compartment (also called the infracolic compart-
ment) lies below the transverse mesocolon and transverse colon, and
is divided into two unequal spaces by the root of the mesentery of the
a fossa or recess, the bowel may become obstructed or strangulate from
small intestine (see Fig. 63.2). It contains the right and left paracolic
a constriction at the entrance to the recess. The contents of the perito-
gutters lateral to the ascending and descending colon, respectively.
neal fold forming the fossa/recess must be considered when repairing
As a consequence of the mobility of the transverse mesocolon and
such a hernia.
mesentery of the small intestine, and the open boundaries of the
inframesocolic compartment, disease processes are rarely confined to
Lesser sac
the compartment. Continuous peristalsis of the small bowel may
explain the relative lack of peritoneal metastases on intestinal and


mesenteric surfaces. Although not usually classified as a peritoneal recess, the lesser sac may
be a site of internal herniation. There are reports of the small intestine,
caecum, transverse colon or gallbladder migrating through the epiploic
Right infracolic space
foramen into the lesser sac and causing acute abdominal symptoms
(Shrestha et al 2010).
The right infracolic space is a triangular space. It is smaller than its left-
sided counterpart and lies posterior and inferior to the transverse colon
Duodenal recesses
and mesocolon to the right of the small intestinal mesentery. The space
is narrowest inferiorly because the attachment of the root of the mesen-
tery of the small intestine lies well to the right of the midline. Several folds of peritoneum may exist around the fourth part of the
duodenum and the duodenojejunal junction, forming a number of
named recesses (Fig. 63.9). They probably arise during development as
Left infracolic space
a result of minor aberrations of duodenal rotation and fixation. Some
are potential sites of internal herniation (Zonca et al 2008).
The left infracolic space is larger than its right-sided counterpart and is
in free communication with the pelvis. It lies posterior and inferior to Superior duodenal recess
the transverse colon and mesocolon, and to the left of the mesentery The superior duodenal recess is occasionally present, often in associa-
of the small intestine. The sigmoid colon and its mesentery may par- tion with an inferior duodenal recess. It lies directly to the left of the
tially restrict the flow of fluid or blood from this space into the pelvis fourth part of the duodenum, adjacent to the second lumbar vertebra,
to the left of the midline. and behind a crescentic superior duodenal fold. The fold has a semilu-
nar free lower margin, which merges laterally with the peritoneum
Paracolic gutters overlying the left kidney. The inferior mesenteric vein lies under the
parietal peritoneum, directly behind the lateral end of this fold. The
The right and left paracolic gutters are peritoneal depressions on the recess extends superiorly and varies in size, but commonly admits a


posterior abdominal wall alongside the ascending and descending fingertip.
colon, respectively. The principal paracolic gutter lies lateral to the
Inferior duodenal recess
colon on each side. A less obvious medial paracolic gutter may be
present, more often on the right side, if the ascending or descending The inferior duodenal recess is usually present, often in association with
colon possesses a short mesentery for part of its length. The right a superior recess, with which it may share an orifice. It lies to the left
(lateral) paracolic gutter runs from the superolateral aspect of the of the fourth part of the duodenum, adjacent to the third lumbar ver-
hepatic flexure of the colon, down the lateral aspect of the ascending tebra, behind an avascular, triangular inferior duodenal fold, which has
colon and caecum. It is continuous with the peritoneum of the pelvic a sharp upper edge. It usually admits one or two fingertips and extends
cavity below. Superiorly, it is continuous with the peritoneum that lines inferiorly, sometimes behind the fourth part of the duodenum and to
the hepatorenal pouch and with the lesser sac through the epiploic the left, in front of the ascending branch of the left colic artery and the
foramen. Bile, pus, blood or other fluid may run along the gutter and inferior mesenteric vein.
collect in sites distant to the organ of origin. In supine patients, infected
Paraduodenal recess
fluid from the right iliac fossa may ascend in the gutter to the right
subphrenic space. In erect or semi-recumbent positions, fluid from the The paraduodenal recess may occur in conjunction with superior and
stomach, duodenum or gallbladder may run down the gutter to collect inferior duodenal recesses. It lies a little to the left and slightly behind
in the right iliac fossa (mimicking acute appendicitis) or pelvis to form the fourth part of the duodenum, behind a falciform fold of perito-
an abscess. The right paracolic gutter is deeper than the left, which, neum. The free right edge of this fold contains the inferior mesenteric


together with the partial barrier provided by the phrenicocolic ligament, vein and ascending branch of the left colic artery, and is part of the left
may explain why subphrenic collections are more common on the colic mesentery. This recess is the site of a ‘left paraduodenal hernia’
right. (Khan et al 1998).
Retroduodenal recess
RECESSES OF THE PERITONEAL CAVITY The retroduodenal recess is the largest of the duodenal recesses but is
rarely present. It lies behind the third and fourth parts of the duodenum
Peritoneal fossae or recesses within the peritoneal cavity are occasion- in front of the abdominal aorta, is up to 10 cm deep, and has a wide
ally sites of internal herniation. If a loop of intestine becomes stuck in orifice flanked by duodenoparietal peritoneal folds.


Peritoneum and peritoneal cavity
1108.e1
36
RETPAHC
The distribution of peritoneal metastases via the paracolic gutters is
not the same on each side. Peritoneal fluid usually tracks freely along
the right paracolic gutter, whereas the flow of peritoneal fluid running
down the left paracolic gutter from the upper abdomen will be impeded
by any attachments of the sigmoid colon to the left abdominal wall.
Cancer deposits at this site tend to invade the mesentery of the junction
between the sigmoid and descending colon, and therefore necessitate
sigmoid colectomy for tumour clearance.
The superior and inferior recesses of the duodenum may be sites of
occult peritoneal metastases and must be examined in patients having
surgery for peritoneal metastases.


General arrangement of the peritoneal cavity
1109
36
RETPAHC
In addition to these caecal recesses, one or more shallow paracae-
Ascending colon
cal or paracolic recesses may be present. These are simply depres-
Vascular
sions within the right paracolic gutter and are not sites of internal
fold of
caecum herniation.
Superior
Intersigmoid recess
iliocaecal
recess
Ileocaecal The intersigmoid recess is present in fetal life and infancy, but often
fold disappears subsequently. It lies behind and inferior to the apex of the
V-shaped attachment of the sigmoid mesocolon. It opens downwards
Ileum
and varies in shape from a slight depression to a shallow fossa. Its
posterior wall is formed by the parietal peritoneum of the posterior
abdominal wall, where it covers the left ureter as it crosses the bifurca-
tion of the left common iliac artery. It is a rare site for an internal hernia
(Harrison et al 2011).
Internal hernias
Inferior
Caecal fold ileocaecal An internal hernia is a protrusion of a viscus through a normal or
recess abnormal aperture (which includes a surgically created opening) within
Caecum
the confines of the peritoneal cavity (Martin et al 2006). It is possible
Retrocaecal recess Vermiform appendix Mesoappendix
for any of the peritoneal recesses, foramina or cul-de-sacs described in
Fig. 63.10 The peritoneal folds and recesses in the caecal region. this chapter to be associated with the development of an internal
hernia, but with a clinically apparent internal hernia the relevant peri-
toneal recess is usually enlarged and its aperture narrowed compared
to normal. Among the many potential sites for an internal hernia, the
Duodenojejunal recess most common are paraduodenal, followed by pericaecal, and hernias
through the epiploic foramen.
The duodenojejunal or mesocolic recess occurs in a minority of adults.
When present, it is almost never associated with other duodenal
recesses. It is approximately 3 cm deep and lies to the left of the abdom-


ADDITIONAL CLINICAL ASPECTS OF THE
inal aorta, between the duodenojejunal junction and the root of the
PERITONEAL CAVITY
transverse mesocolon. It is bounded above by the pancreas, on the left
by the kidney, and below by the left renal vein. Its circular opening lies
Peritoneal fluid collections
between two peritoneal folds and faces down and to the right.
Mesentericoparietal recess
Fluid collections frequently develop within the peritoneal cavity in
The mesentericoparietal recess or fossa is rarely present. It lies just response to a wide range of pathological processes. In the absence of
below the third part of the duodenum and invaginates the upper part inflammation, peritoneal adhesions or previous surgery, serous fluid
of the mesentery of the small intestine towards the right. Its orifice is tends to be distributed widely between the peritoneal spaces. Simple
large and faces to the left, behind a fold of mesentery raised by the ascites can therefore be drained freely from any convenient dependent
superior mesenteric artery. This recess is the site of the rare ‘right part of the peritoneal cavity; drainage is most commonly performed by
paraduodenal hernia’. blind puncture or ultrasound-guided insertion of a catheter into the
lower left or right paracolic gutters. The mobility of the small bowel
Caecal recesses makes it very unlikely to be injured during this procedure.
Fluid collections caused by inflammatory processes are often much
Peritoneal folds around the caecum may form a variety recesses (Fig. thicker because they contain pus, fibrin or blood. Furthermore, they are
63.10); these have the potential to become sites of internal herniation usually associated with peritoneal adhesions arising from peritoneal
(Rivkind et al 1986). Paracaecal recesses are common sites for abscess inflammation. These factors predispose to the formation of localized
formation after acute appendicitis. fluid collections, which may become walled-off as the inflammatory
process progresses. Any of the peritoneal spaces may develop a localized
Superior ileocaecal recess
collection, but the subphrenic, subhepatic and pelvic spaces are the


The superior ileocaecal recess is usually best developed in children and most common sites since they are well defined by peritoneal folds and
may be absent in the aged or obese. It is a narrow slit bounded in front organs forming their boundaries. These spaces are also the most
by a vascular fold of peritoneum containing the anterior caecal vessels, dependent regions within the peritoneal cavity.
behind by the ileal mesentery, below by the terminal ileum and on the Surgical access to the peritoneal spaces is less often needed today
right by the ileocaecal junction. Its orifice opens to the left. because of advances in radiologically guided percutaneous drainage
using fluoroscopy, ultrasound, computed tomography (CT) or magnetic
Inferior ileocaecal recess
resonance imaging (MRI) guidance. These techniques offer reliable and
The inferior ileocaecal recess is similarly well developed in the young versatile methods of accessing peritoneal spaces, including relatively
but frequently obliterated by fat in adults. It is formed by the ileocaecal inaccessible subhepatic, perihepatic or intermesenteric collections. Pos-
fold, which extends from the anteroinferior aspect of the terminal ileum terolateral translumbar or trans-sciatic approaches can also be used to
to the front of the mesoappendix (or to the appendix or caecum). It is access the retroperitoneum and pelvis, respectively. Occasionally, a sur-
also known as the ‘bloodless fold of Treves’, although it sometimes gical approach is necessary; thus, a subcostal or lateral intercostal inci-
contains blood vessels that bleed if divided during surgery. If inflamed, sion may be required to drain a subphrenic abscess or an inguinal
especially when the appendix and its mesentery are retrocaecal, it may incision to drain a pelvic abscess.
be mistaken for the mesoappendix. The recess is bounded in front by
the ileocaecal fold, above by the terminal ileum and its mesentery, to
Peritoneal dialysis
the right by the caecum, and behind by the upper part of the mesoap-
pendix. Its orifice opens downwards to the left.
The mean surface area of the peritoneum in the adult (female) has been


Retrocaecal recess estimated to be about 1.4 m2 (with the visceral peritoneum accounting
The retrocaecal recess lies behind the caecum. It ascends behind the for about 80% of the total) (Albanese et al 2009). Mesothelium resem-
ascending colon to a variable extent, often being large enough to admit bles vascular endothelium in that it allows the passage of ions and small
an entire finger. It is bounded in front by the caecum (and sometimes molecules. Normally, the volume of fluid transmitted by peritoneal
the proximal ascending colon), behind by the parietal peritoneum, and surfaces is small, but large volumes of fluid can be instilled into the
on each side by caecal folds (parietocolic folds) passing from the peritoneal cavity and then siphoned out, using the peritoneum as a
caecum to the posterior abdominal wall. The vermiform appendix fre- dialysing membrane. This can be used to support individuals with acute
quently occupies this retrocaecal recess (p. 1142). or chronic renal failure.


PERiTonEum And PERiTonEAl CAviTy
1110
8
noiTCES
Ventriculoperitoneal shunts chemotherapeutic agents (diluted in large volumes of fluid) directly
into the peritoneal cavity. Peritoneal access may be achieved via an
intraperitoneal catheter connected to a subcutaneous port or by repeated
The absorptive capabilities of the peritoneum can be exploited to
paracentesis. The infused chemotherapeutic agents may be retained
absorb excess transitional fluids from several sites in the body. The most
locally for longer than systemically administered agents. Targeting drugs
common of these is the absorption of cerebrospinal fluid diverted into
to the peritoneal space may improve the results of treatment if complete
the peritoneal cavity using a shunt (a fine catheter) from the cerebral
tumour resection is not possible.
ventricles or the intrathecal space. The catheter placed within the peri-
toneal cavity can be equipped with a one-way valve to prevent reflux of
peritoneal fluid into the cerebrospinal fluid. The cerebrospinal fluid is
continuously absorbed by the peritoneum, maintaining a low pressure
within the intraventricular or intrathecal space.
Bonus e-book video
Intraperitoneal cancer chemotherapy
In patients with peritoneal metastases, attempts to optimize the Video 63.1 Surgical exploration of the peritoneal cavity.
benefits of cytoreductive surgery may involve the administration of
KEY REFERENCES
Coakley FV, Hricak H 1999 Imaging of peritoneal and mesenteric disease: Pestieau SR, Wolk R, Sugarbaker PH 2000 Congenital pleuroperitoneal com-
key concepts for the clinical radiologist. Clin Radiol 54:563–74. munication in a patient with pseudomyxoma peritonei. J Surg Oncol
An explanation of the complex anatomy of the upper abdominal peritoneal 73:174–8.
fold suspending the stomach, liver and spleen. Platell C, Cooper D, Papadimitriou JM et al 2000 The omentum. World J
Healy JC, Reznek RH 1999 The anterior abdominal wall and peritoneum. Gastroenterol 6:169–76.


In: Butler P, Mitchell A, Ellis H (eds) Applied Radiological Anatomy. A comprehensive review of the greater omentum.
Cambridge: Cambridge University Press, pp. 189–200. Schnüriger B, Barmparas G, Branco BC et al 2011 Prevention of postoperative
A demonstration of the imaging anatomy of the peritoneal spaces and peritoneal adhesions: a review of the literature. Am J Surg 201:111–21.
reflections using cross-sectional imaging.
Simmons LE, Mir AR 1989 A review of management of pleuroperitoneal
Martin LC, Merkle EM, Thompson WM 2006 Review of internal hernias: communication in five CAPD patients. Adv Perit Dial 5:81–3.
radiographic and clinical findings. AJR 186:703–17. Stringer MD 2009 Eponyms in Surgery and Anatomy of the Liver, Bile Ducts
Meyers M 1994 Dynamic Radiology of the Abdomen: Normal and Patho- and Pancreas. London: Royal Society of Medicine Press.
logic Anatomy. New York: Springer. A short reference book that contains information and illustrations relating to
Meyers MA, Oliphant M, Berne AS et al 1987 The peritoneal ligaments and the original descriptions and the authors of many of the eponyms cited in
mesenteries: pathways of intraabdominal spread of disease. Radiology this chapter (e.g. Cullen, Winslow, Morison).
163:593–604.
A systematic application of anatomic and dynamic principles to the
understanding and diagnosis of intra-abdominal disease.


Peritoneum and peritoneal cavity
1110.e1
36
RETPAHC
REFERENCES
Albanese AM, Albanese EF, Mino JH et al 2009 Peritoneal surface area: Meyers MA, Oliphant M, Berne AS et al 1987 The peritoneal ligaments and
measurements of 40 structures covered by peritoneum: correlation mesenteries: pathways of intraabdominal spread of disease. Radiology
between total peritoneal surface area and the surface calculated by for- 163:593–604.
mulas. Surg Radiol Anat 31:369–77. A systematic application of anatomic and dynamic principles to the
Ashaolu JO, Ukwenya VO, Adenowo TK 2011 Cystoduodenal ligament as an understanding and diagnosis of intra-abdominal disease.
abnormal fold and the accompanying anatomical and clinical implica- Pestieau SR, Wolk R, Sugarbaker PH 2000 Congenital pleuroperitoneal com-
tions. Surg Radiol Anat 33:171–4. munication in a patient with pseudomyxoma peritonei. J Surg Oncol
Autio V 1964 The spread of intraperitoneal infection. Acta Chir Scand Suppl 73:174–8.
36:5–31. Platell C, Cooper D, Papadimitriou JM et al 2000 The omentum. World J
Baessler K, Schuessler B 2000 The depth of the pouch of Douglas in nulli- Gastroenterol 6:169–76.
parous and parous women without genital prolapse and in patients with A comprehensive review of the greater omentum.
genital prolapse. Am J Obstet Gynecol 182:540–4.
Rivkind AI, Shiloni E, Muggia-Sullam M et al 1986 Paracecal hernia: a cause
Boaz NT, Martin AH, Thompson K et al 2011 Structure and functional sig- of intestinal obstruction. Dis Colon Rectum 29:752–4.
nificance of the transverse vesical fold. Clin Anat 24:62–9.
Sanchez NC, Tenofsky PL, Dort JM et al 2001 What is normal intra-


Coakley FV, Hricak H 1999 Imaging of peritoneal and mesenteric disease: abdominal pressure? Am Surg 67:243–8.
key concepts for the clinical radiologist. Clin Radiol 54:563–74.
Schnüriger B, Barmparas G, Branco BC et al 2011 Prevention of postoperative
An explanation of the complex anatomy of the upper abdominal peritoneal
peritoneal adhesions: a review of the literature. Am J Surg 201:111–21.
fold suspending the stomach, liver and spleen.
Shimotsuma M, Shields JW, Simpson-Morgan MW et al 1993 Morpho-
Coulier B 2009 64-row MDCT review of anatomic features and variations physiological function and role of omental milky spots as omentum-
of the normal greater omentum. Surg Radiol Anat 31:489–500. associated lymphoid tissue (OALT) in the peritoneal cavity. Lymphology
Feldberg MA, van Leeuwen MS 1990 The properitoneal fat pad associated 26:90–101.
with the falciform ligament. Imaging of extent and clinical relevance. Shrestha BM, Brown PW, Wilkie ME et al 2010 The anatomy and pathology
Surg Radiol Anat 12:193–202. of the lesser sac: implications for peritoneal dialysis. Perit Dial Int 30:
Hagiwara A, Takahashi T, Sawai T et al 1994 Milky spots as the implantation 496–501.
site for malignant cells in peritoneal dissemination in mice. Cancer Res Simmons LE, Mir AR 1989 A review of management of pleuroperitoneal
54:687–92. communication in five CAPD patients. Adv Perit Dial 5:81–3.
Harrison OJ, Sharma RD, Niayesh MH 2011 Early intervention in intersig- Stringer MD 2009 Eponyms in Surgery and Anatomy of the Liver, Bile Ducts
moid hernia may prevent bowel resection – a case report. Int J Surg Case and Pancreas. London: Royal Society of Medicine Press.
Rep 2:282–4. A short reference book that contains information and illustrations relating to


Healy JC, Reznek RH 1999 The anterior abdominal wall and peritoneum. the original descriptions and the authors of many of the eponyms cited in
In: Butler P, Mitchell A, Ellis H (eds) Applied Radiological Anatomy. this chapter (e.g. Cullen, Winslow, Morison).
Cambridge: Cambridge University Press, pp. 189–200.
Sugarbaker PH 2012 An overview of peritonectomy, visceral resections,
A demonstration of the imaging anatomy of the peritoneal spaces and
and perioperative chemotherapy for peritoneal surface malignancy.
reflections using cross-sectional imaging.
In: Sugarbaker PH (ed) Cytoreductive Surgery and Perioperative Chemo-
Khan MA, Lo AY, Vande Maele DM 1998 Paraduodenal hernia. Am Surg therapy for Peritoneal Surface Malignancy. Textbook and Video Atlas.
64:1218–22. Woodbury, CT: Cine-Med Publishing, pp. 1–30.
Koninckx PR, Renaer M, Brosens IA 1980 Origin of peritoneal fluid in Wassilev W, Wedel T, Michailova K et al 1998 A scanning electron micros-
women: an ovarian exudation product. Br J Obstet Gynaecol 87: copy study of peritoneal stomata in different peritoneal regions. Ann
177–83. Anat 180:137–43.
Martin LC, Merkle EM, Thompson WM 2006 Review of internal hernias: Yoshikawa T, Hayashi N, Maeda E et al 2013 Peritoneal fluid accumulation
radiographic and clinical findings. AJR 186:703–17. in healthy men and postmenopausal women: evaluation on pelvic MRI.
Meyers MA 1973 Distribution of intra-abdominal malignant seeding: AJR 200:1181–5.
dependency on dynamics of flow of ascitic fluid. Am J Roentgenol Zonca P, Maly T, Mole DJ et al 2008 Treitz’s hernia. Hernia 2:531–4.
Radium Ther Nucl Med 119:198–206.
Meyers M 1994 Dynamic Radiology of the Abdomen: Normal and Patho-
logic Anatomy. New York: Springer.


SUBSECTION: Gastrointestinal tract
CHAPTER
64
Abdominal oesophagus and stomach
ous with the subpleural endothoracic fascia above the diaphragm; it is
ABDOMINAL OESOPHAGUS
thicker, contains more elastin than its inferior counterpart, and runs
cranially and obliquely to fuse firmly with the wall of the oesophagus.
The abdominal oesophagus is 1–2.5 cm in length, and is slightly A variable amount of adipose tissue lies in the triangular interval
broader at the cardiac orifice than at the diaphragmatic aperture. It lies between the two layers of the ligament. The phreno-oesophageal liga-
to the left of the midline and enters the abdomen through the oesopha- ment helps to anchor the oesophagus to the crural muscle fibres of the
geal aperture (formed by the two diaphragmatic crura) at the level of diaphragm and probably acts to limit upward and downward mobility
the eleventh thoracic vertebra (Mirjalili et al 2012). It runs obliquely to of the oesophagus within the hiatus (Kwok et al 1999). In the elderly,
the left and slightly posteriorly, and ends at the gastro-oesophageal the ligament tends to become attenuated and contain more adipose
junction, where it is continuous with the cardiac orifice of the stomach. tissue. The phreno-oesophageal ligament is denser anteriorly where it
The anterior wall of the abdominal oesophagus is effectively longer bridges between the outer layer of the oesophageal wall and the arching
than the posterior wall because of the obliquity of the crura. The fibres of the diaphragmatic crura.
abdominal oesophagus lies posterior to the left lobe of the liver, and The peritoneal reflection posterior to the abdominal oesophagus is
anterior to the left crus, the left inferior phrenic vessels and the left short and continues directly on to the posterior surface of the fundus
greater and lesser splanchnic nerves; its surface is covered by a thin layer of the stomach; it is sometimes referred to as the gastrophrenic liga-
of connective tissue and visceral peritoneum that contain the anterior ment. It encloses the oesophageal branches of the left gastric vessels


and posterior vagus nerves, as well as the oesophageal branches of the and the coeliac branches of the posterior vagus and can thus be con-
left gastric vessels. The anterior and posterior vagi may be single or sidered to form an extremely short, wide mesentery to the abdominal
composed of multiple trunks (Jackson 1949); the anterior is closely oesophagus. In adults, a fat pad may be visible beneath the peritoneum
applied to the anterior outer surface of the longitudinal muscle coat of over the anterior surface of the gastro-oesophageal junction and can be
the oesophagus while the posterior usually lies within loose connective a useful surgical marker of the gastro-oesophageal junction.
tissue immediately posterior and to the right of the oesophagus, making
its identification during surgery somewhat easier. Unlike the more Hiatus hernia
proximal parts of the oesophagus, the muscular wall of the abdominal
oesophagus is composed entirely of smooth muscle. Available with the Gray’s Anatomy e-book
The abdominal oesophagus is effectively tethered to the margins of
the muscular oesophageal hiatus in the diaphragm by the phreno-
oesophageal ligament (Fig. 64.1) (Kwok et al 1999). This is formed by VASCULAR SUPPLY AND LYMPHATIC DRAINAGE
two circumferential layers of elastin-rich connective tissue containing
some smooth muscle fibres. The inferior layer is an extension of the Arteries
subperitoneal transversalis fascia below the diaphragm; it is thin and
only loosely attached to the oesophagus. The superior layer is continu-
The abdominal oesophagus is supplied by numerous oesophageal
branches of the left gastric artery. These ascend beneath the visceral
Longitudinal oesophageal muscle peritoneum to supply perforating branches to the intramural and sub-
Circular oesophageal muscle mucosal plexuses. The posterior surface usually receives an additional
supply via branches of the upper short gastric arteries, reinforced by
Gradual slight muscular thickening
Oesophageal terminal arteries from the oesophageal branches of the thoracic aorta
mucosa Phreno-oesophageal ligament and occasionally an ascending branch of the posterior gastric artery
(ascending or upper limb) (Liebermann-Meffert et al 1987).
Submucosa Supradiaphragmatic
(endothoracic) fascia Veins
Diaphragm Diaphragm


Infradiaphragmatic Mucosal and submucosal veins drain via plexuses to the left gastric and
(transversalis) fascia
upper short gastric veins in the abdomen and to the azygos/hemiazygos
Phreno-oesophageal system of veins in the thorax. The distal oesophagus is an important
ligament site of portosystemic anastomosis where oesophageal varices develop
(descending limb)
in portal hypertension (see below).
Phreno-oesophageal Lymphatic drainage
ligament
(descending limb)
The oesophagus has a freely anastomosing plexus of lymphatics in the
lamina propria, submucosa and muscularis propria. The lower third
Subhiatal fat ring
primarily drains caudally to left gastric and left and right paracardial
Zigzag (Z) line: nodes, and from there to coeliac nodes. In lower oesophageal cancer,
juncture of lymph also drains cranially to mediastinal lymph nodes (Aikou et al
oesophageal and Peritoneum 1987).
gastric mucosa
Cardiac notch
Cardiac region of INNERVATION
stomach (cardia)
Gastric folds (rugae)
The oesophagus has a well-developed intrinsic nervous system consist-
Fig. 64.1 The anatomical structures around the abdominal oesophagus. ing of a ganglionated myenteric plexus and a sparsely ganglionated
(Reprinted from Netter Anatomy Illustration Collection, © Elsevier Inc. All submucosal plexus, modulated by extrinsic autonomic nerves. Parasym-
Rights Reserved.) pathetic innervation of the abdominal oesophagus is derived directly 1111


Abdominal oesophagus and stomach
1111.e1
46
RetpAhc
Hiatus hernia is a relatively common condition involving expansion of
the oesophageal hiatus and herniation of the stomach through the
diaphragm into the mediastinum. It is more common in the elderly
and the obese. There are two types of hiatus hernia: the sliding type,
which accounts for at least 90%, and the para-oesophageal or mixed
type, which makes up the remainder (Roman and Kahrilas 2014). A
hiatus hernia may not cause any symptoms or it may be associated with
symptoms of gastro-oesophageal reflux. Para-oesophageal hernias can
cause obstruction and/or ischaemia of the herniated stomach. Treat-
ment of a symptomatic sliding hiatal hernia is directed at managing
associated gastro-oesophageal reflux, which may require anti-reflux
surgery.


AbdominAl oesophAgus And stomAch
1112
8
noitces
from the thoracic peri-oesophageal plexus and, to a lesser extent, from drawn from the angular incisure to an inconstant indentation on the
the anterior and posterior vagi. These nerves are motor to the distal greater curvature defines the lower boundary of the body. The pyloric
oesophagus and both stimulatory and inhibitory to the lower oesopha- antrum extends from this line to where the stomach narrows to become
geal sphincter, maintaining basal tone and coordinating distal oesopha- the pyloric canal (1–2 cm long), which terminates at the pyloric orifice
geal peristalsis with relaxation of the sphincter during swallowing (the (Didio and Anderson 1968).
latter being mediated by intrinsic nitrergic inhibitory neurones under
vagal control). Sympathetic supply of the distal oesophagus originates
from the fifth to twelfth thoracic spinal segments mainly via the greater GASTRIC RELATIONS
and lesser splanchnic nerves and the coeliac plexus. Nociceptive signals
are conveyed by afferent nerves accompanying sympathetic nerves and Gastric curvatures
by vagal afferents, which are also involved in mechanosensory signal-
ling (Neuhuber et al 2006). Lesser curvature
The lesser curvature extends between the cardiac and pyloric orifices
STOMACH and forms the medial border of the stomach. It descends from the
medial side of the oesophagus in front of the decussating fibres of the
right crus of the diaphragm, curves downwards and to the right, and
The stomach is the widest part of the alimentary tract and lies between
lies anterior to the superior border of the pancreas (Fig. 64.3). It ends
the oesophagus and the duodenum. It performs numerous functions,
at the pylorus, just to the right of the midline. In the most dependent
including the temporary storage of ingested nutrients; mechanical
breakdown of solid food; chemical digestion of proteins; regulation of
the passage of chyme into the duodenum; secretion of intrinsic factor
for vitamin B absorption; secretion of gut hormones; and secretion of Cardiac notch
12
acid to aid digestion (including the absorption of iron). It is also impor-
tant in microbial defence.


The stomach is situated in the upper abdomen, extending from the
left upper quadrant downwards, forwards and to the right, lying in the Abdominal part Fundus
left hypochondrium, epigastrium and umbilical regions. It occupies a of oesophagus
recess beneath the diaphragm and anterior abdominal wall bounded
by the upper abdominal viscera on either side. The mean capacity of Cardiac region
the stomach increases from approximately 20–30 ml at birth to approx-
imately 1000–1500 ml in adults. The peritoneal surface of the stomach Lesser curvature Body
is interrupted by the attachments of the greater and lesser omenta,
which define the greater and lesser curvatures and separate the anterior Angular incisure
and posterior surfaces.
Greater
PARTS OF THE STOMACH curvature
For descriptive purposes, the stomach can be divided into a fundus,
body, pyloric antrum and pylorus by artificial lines drawn on its external
surface (Fig. 64.2). The internal appearance and microstructure of these
regions vary. The fundus is dome-shaped and projects above and to the
left of the oesophageal opening (cardiac (cardial) orifice) to lie in Duodenum Pyloric antrum
contact with the left dome of the diaphragm; it lies above a horizontal
line from the cardiac notch to the greater curvature. The body extends Pylorus Intermediate sulcus
from the fundus to the angular incisure (incisura angularis), a constant
external notch at the lower end of the lesser curvature. The cardia is the Pyloric canal
region of the stomach adjacent to the oesophageal opening. A line Fig. 64.2 The parts of the stomach.
Fig. 64.3 The posterior relations
of the stomach.
Left hemidiaphragm
Left inferior phrenic artery
Decussating fibres
of the right crus
Left suprarenal gland
Spleen
Splenic artery
Origin of mesentery of
transverse colon
Body of pancreas
Left kidney
Duodenojejunal flexure


stomach
1113
46
RetpAhc
part, there is typically a notch, the angular incisure, whose position and crus and sometimes the left suprarenal gland. The left gastric vessels
appearance vary with gastric distension. The lesser omentum is attached reach the lesser curvature at the right extremity of this bare area. The
to the lesser curvature and contains the right and left gastric vessels. gastrophrenic ligament passes from the lateral aspect of this bare area
to the inferior surface of the diaphragm. The posterior surface of the
Greater curvature
stomach lies anterior to the left crus and lower fibres of the diaphragm,
The greater curvature is two to three times longer than the lesser the left inferior phrenic vessels, the left suprarenal gland, the superior
(Csendes and Burgos 2005). It starts from the cardiac notch, formed pole of the left kidney, the splenic artery, the anterior surface of the
between the lateral border of the abdominal oesophagus and the pancreas, and the upper layer of the transverse mesocolon (see Fig.
fundus of the stomach, and arches upwards, posterolaterally and to the 64.3). Together, these form the shallow stomach bed, which is separated
left. Its highest convexity, the apex of the fundus, is approximately level from the stomach by the lesser sac (over which the stomach slides as it
with the left sixth rib anteriorly but varies between individuals and with distends). The upper left part of the posterior surface curves anterolater-
respiration (Mirjalili et al 2012). From this point, it sweeps inferiorly ally and lies in contact with the visceral surface of the spleen. The
and anteriorly, slightly convex to the left, almost as far as the tenth transverse mesocolon separates the stomach from the duodenojejunal
costal cartilage in the supine position, where it turns medially to end flexure and proximal jejunum.
at the pylorus in the transpyloric plane at the lower border of the first
lumbar vertebra. There is frequently a groove, the intermediate sulcus,
in the curvature close to the pyloric canal. The start of the greater cur- GASTRIC ORIFICES
vature is covered by peritoneum, which continues over the anterior
surface of the stomach. Laterally, the greater curvature gives attachment
Cardiac orifice and gastro-


to the gastrosplenic ligament and, below this, to the greater omentum,
oesophageal junction
which contains the gastroepiploic vessels. The gastrosplenic ligament
and the greater omentum, together with the gastrophrenic and spleno-
renal ligaments, are continuous derivatives of the original dorsal meso- The oesophagus opens into the stomach at the cardiac orifice (see Fig.
gastrium; their names merely indicate regions of the same continuous 64.1). It is usually situated to the left of the midline behind the seventh
sheet of peritoneum and its associated connective tissue. costal cartilage at the level of the eleventh thoracic vertebra (Mirjalili
et al 2012). It is, on average, about 40 cm from the incisor teeth in the
Gastric volvulus
adult. The right side of the abdominal oesophagus is continuous with
the lesser curvature and the left side with the greater curvature.
Available with the Gray’s Anatomy e-book Internally, the transition between the oesophagus and stomach is
difficult to define because gastric fundal mucosal folds extend a variable
Gastric surfaces distance up the abdominal oesophagus. For practical purposes, the
gastro-oesophageal junction is usually identified by a circumferential
‘zigzag’ line (‘Z line’) between the pale pink oesophageal squamous
When the stomach is empty and contracted, the anterior and posterior
epithelium above and the red columnar epithelium below. In the
surfaces tend to face superiorly and inferiorly, but as the stomach
healthy oesophagus, the Z line is located at the proximal extent of the
distends, they face progressively more anteriorly and posteriorly
gastric mucosal folds. When metaplastic columnar epithelium extends
(Fig. 64.4).
above the gastric folds into the lower oesophagus, it is regarded
Anterior (superior) surface as pathological and termed Barrett’s oesophagus. The presence of a
The entire anterior (superior) surface of the stomach is covered by peri- sliding hiatus hernia with or without Barrett’s oesophagus can make
toneum. The lateral part of the anterior surface lies posterior to the left
costal margin in contact with the diaphragm, which separates it from
the left pleura, the base of the left lung, the pericardium and the left


seventh to ninth ribs and costal cartilages (Fig. 64.5). It also lies pos-
terior to the costal attachments of the upper fibres of transversus Spleen Transversus abdominis Left lobe of liver
abdominis. The upper left part of this surface curves posteriorly and lies
in contact with the visceral surface of the spleen. The right half of the
anterior surface is related superiorly to the left lobe of the liver and
inferiorly to the anterior abdominal wall, through which it can be
accessed by a needle for placement of a gastrostomy tube (see below).
When the stomach is empty, the transverse colon may lie adjacent to
the anterior surface.
Posterior (inferior) surface
The posterior surface is covered by peritoneum, except near the cardiac
orifice, where a small, triangular area contacts the left diaphragmatic
Axis
Posterior rectus sheath
Axis
Anterior/ Anterior
superior surface
surface
Posterior/
inferior
surface
Greater curvature/
line of attachment of Diaphragm Stomach Transverse colon
Empty Full gastrocolic omentum
Fig. 64.5 Anterior relations of the stomach, viewed from behind. The
Fig. 64.4 Axes of the empty and full stomach. As the stomach distends, fibres of the diaphragm (oblique), transversus abdominis (transverse) and
the greater curvature ‘rolls’ downwards and the anterosuperior surface rectus abdominis (vertical) can be seen through the outlines of the
comes to lie almost completely vertical as the anterior surface. stomach and its visceral relations.


Abdominal oesophagus and stomach
1113.e1
46
RetpAhc
Volvulus of the stomach is much less common than volvulus of either
the sigmoid colon or the caecum. Two types of gastric volvulus may
occur. The first, organoaxial volvulus, occurs about an axis of rotation
running from below the cardiac orifice to the pylorus. The antrum, body
and fundus rotate upwards, such that the greater curvature comes to lie
above the lesser curvature. The second type, mesenteroaxial volvulus,
occurs about an axis drawn ‘across’ the body of the stomach, usually
just above the angular incisure. This type of volvulus is perpendicular
to the axis of organoaxial volvulus. The distal body and antrum rotate
anteriorly, superiorly and laterally while the upper body and fundus
rotate posteriorly, medially and inferiorly. Although it is relatively
mobile within the upper abdomen, the stomach is normally tethered
at the gastro-oesophageal junction and the pylorus, to the spleen by the
gastrosplenic ligament, and to the liver by the lesser omentum. The
attachment to the transverse colon via the gastrocolic omentum also
restrains the stomach but it is the most mobile attachment. For either
type of gastric volvulus to occur, some or all of these points of tethering
must be loosened either by previous surgical division or by chronic
lengthening and laxity of their connective tissue. Organoaxial volvulus
is most common because the lesser omentum, gastrosplenic ligament
and gastrocolic omentum are more likely to undergo chronic lengthen-
ing by traction than the other attachments of the stomach. Mesentero-
axial volvulus requires the gastro-oesophageal junction and pylorus to
be sufficiently mobile as to come into close approximation, which is
much less common. Despite the rich arterial supply of the stomach,
either type of volvulus may cause a strangulating obstruction.
Provided the detorted stomach is viable, gastric volvulus is typically
managed by fixation of the anterior surface of the stomach to the ante-
rior abdominal wall (‘gastropexy’) (García et al 2013). Gastric volvulus
of the organoaxial type is frequently associated with a para-oesophageal


hiatus hernia, which must also be repaired. This surgery can usually be
carried out laparoscopically.


AbdominAl oesophAgus And stomAch
1114
8
noitces
endoscopic identification of the gastro-oesophageal junction particu- releasing nitric oxide leads to relaxation of the sphincter. Muscle tone
larly difficult. is reduced in advance of the oesophageal peristaltic wave during swal-
Externally, a fat pad is often present in adults beneath the perito- lowing and raised again after the food bolus has passed. During inspira-
neum over the anterior surface of the gastro-oesophageal junction. The tion, the greater negative intrathoracic pressure increases the
junction is also demarcated by a sling of longitudinal and oblique gastro-oesophageal pressure gradient, but this is offset by increased
gastric muscle fibres that forms a loop on the superior, left, side of the pressure in the HPZ from contraction of the peri-oesophageal fibres of
gastro-oesophageal junction between the oesophagus and the stomach. the right diaphragmatic crus. Activation of the crural muscle slightly
before the rest of the diaphragmatic muscle facilitates this anti-reflux
Lower oesophageal sphincter and gastro-
mechanism.
oesophageal reflux Reflux of gastric contents into the lower oesophagus as a result of
At rest, there is a pressure gradient across the gastro-oesophageal junc- transient relaxation of the lower oesophageal sphincter occurs as a
tion, reflecting the negative intrathoracic pressure transmitted to the normal event in most individuals on a daily basis. Prolonged episodes
thoracic oesophagus and the positive intra-abdominal pressure trans- of acid reflux as a result of a weak lower oesophageal sphincter or
mitted to the stomach (augmented by any contraction of the stomach). sliding hiatus hernia may cause oesophagitis and its associated compli-
Several anatomical and physiological factors normally prevent gastro- cations. Surgical procedures to prevent abnormal reflux aim to restore
oesophageal reflux. The two major anti-reflux mechanisms are the toni- a normal length of intra-abdominal oesophagus, repair any hiatus
cally contracted, specialized, thickened intrinsic circular smooth muscle hernia and increase the pressure surrounding the intra-abdominal
of the lower oesophagus, which is reinforced by the extrinsic encircling oesophagus; this is usually achieved by wrapping the fundus of the


fibres of the right diaphragmatic crus. Together, they exert a radial pres- stomach around the intra-abdominal oesophagus (fundoplication).
sure on the lower 2–4 cm of oesophagus, creating an effective high- The converse type of lower oesophageal sphincter dysfunction occurs
pressure zone (HPZ) that can be measured by electromyography or in achalasia, which is characterized by reduced or absent ganglion cells
manometry (Paterson 2001, Mittal and Goyal 2006, Hershcovici et al in the myenteric plexus of the distal oesophagus and gastro-oesophageal
2011). The description of the intrinsic muscles of the lower oesophageal junction. Loss of inhibitory innervation of the sphincter leads to
sphincter can be refined further to include clasp-like semicircular impaired relaxation, causing dysphagia and proximal oesophageal dila-
smooth muscle fibres on the right side of the oesophagus and sling-like tion. Management of this condition involves disruption of the hyper-
oblique gastric muscle fibres on the left side (Preiksaitis and Diamant tonic muscle fibres by balloon dilation or surgical myotomy (‘Heller’s
1997, Stein et al 1995). The distribution of these muscle fibres corre- cardiomyotomy’).
sponds to the anatomical and functional asymmetry of the HPZ.
At and just below the level of entry of the abdominal oesophagus Barrett’s oesophagus
into the stomach, the circular fibres of the intermediate layer of the The squamous epithelium lining the lower oesophagus may be patho-
muscularis externa lying over the upper lesser curvature are particularly logically replaced by a metaplastic ‘intestinalized’ columnar epithelium
pronounced; they are sometimes referred to as ‘clasp’ fibres and exert known as ‘Barrett’s oesophagus’ (see Commentary 1.4). This process
fairly constant myogenic tone (Fig. 64.6). Since the oesophagus passes results from chronic episodic reflux of gastric acid and bile into the
obliquely into the stomach, the tone in the clasp fibres rises with lower oesophagus (Dvorak et al 2007). The abnormal intestinal meta-
increasing gastric distension and they may act to draw the anterior and plasia may extend proximally for a variable length from the gastro-


posterior surfaces together, increasing the tone at the gastro-oesophageal oesophageal junction and associated macroscopic mucosal changes can
junction and contributing to the HPZ. Several minor anti-reflux factors be seen on endoscopy. The presence of Barrett’s oesophagus confers a
also exist: the folds of gastric mucosa present at the gastro-oesophageal significantly increased risk of oesophageal adenocarcinoma, although
junction form a mucosal rosette that helps to create a fluid- and gas- the condition can remain stable or even regress with appropriate
tight seal from the basal tonic contraction of the muscular wall of the medical therapy (Yousef et al 2008).
lower oesophagus; the angle of the cardiac orifice (angle of His),
formed, in part, by the pull of the oblique fibres of the innermost layer
Pyloric orifice
of gastric smooth muscle, thereby constituting a type of ‘flap valve’; and
the length of the abdominal oesophagus, which is buttressed externally
by pads of adipose tissue at and below the level of the oesophageal The pyloric orifice is the opening from the stomach into the duodenum.
hiatus. These anatomical and physiological features are collectively When the body is supine and the stomach empty, it typically lies
referred to as the lower oesophageal sphincter. The oesophageal part of 1–2 cm to the right of the midline in the transpyloric plane (the lower
the lower oesophageal sphincter is controlled by the intramural plex- border of the body of the first lumbar vertebra). The pyloric sphincter
uses of the enteric nervous system; activation of inhibitory neurones is formed by a circumferential thickening of circular muscle interlaced
with connective tissue septa and some longitudinal muscle fibres, and
is palpably thicker than the adjacent stomach and duodenum. The
circular pyloric constriction on the surface of the stomach usually indi-
cates the location of the pyloric sphincter, and may be marked by a
prepyloric vein that crosses the anterior surface in a caudal direction.
Infantile hypertrophic pyloric stenosis is due to idiopathic hypertro-
Longitudinal oesophageal muscle (cut)
phy of the circular muscle of the pylorus and causes gastric outlet
Cardiac notch obstruction in early infancy. It is readily treated by dividing the thick-


Circular oesophageal muscle ened pyloric muscle (pyloromyotomy).
Fundus of
(shown here as spiral)
stomach
GASTRIC FORM AND INTERNAL APPEARANCES
Numerous factors influence both the form and the position of the
Circular ‘clasp’ fibres below the stomach, including the posture and build of the individual, the extent
gastro-oesophageal junction to which the stomach is filled, the position of the surrounding viscera,
and the tone of the abdominal wall and gastric musculature. The empty
Window cut in middle circular
muscle layer of stomach stomach is most commonly J-shaped, the fundus usually contains gas,
and, in the erect posture, the pylorus descends to the level of the second
Innermost oblique muscle or third lumbar vertebra. The lowest part of the antrum may lie below
layer of stomach (forms sling)
the level of the umbilicus, and the overall axis of the organ is slightly
Outer longitudinal muscle inclined from the vertical (Fig. 64.7). In short, obese individuals, the
layer of stomach (cut) axis of the stomach lies more towards the horizontal as a ‘steer-horn’
shape.
The extent of filling mainly affects the shape and position of the
body of the stomach. As the stomach fills, it expands forwards and
downwards but, when the colon or small bowel is distended, the fundus
Fig. 64.6 Detail of the arrangements of the muscle layers of the enlarges towards the liver and diaphragm. As stomach capacity increases,
oesophageal and gastric walls. (Reproduced and modified from Netter the pylorus is displaced to the right and the axis of the whole organ lies
Anatomy Illustration Collection, © Elsevier Inc. All Rights Reserved.) in a more oblique direction (see Fig. 64.4).


stomach
1115
46
RetpAhc
B C
Areae gastricae
Fig. 64.7 Double contrast barium meal films. A, In the erect position, the stomach has a more
‘J’-shaped configuration. B, Initial stomach filling demonstrates a horizontally lying stomach with
A prominent gastric rugal folds. C, The areae gastricae within the antrum are clearly identified on
distension of the stomach.
Fig. 64.8 Endoscopic appearances of the
stomach. A, The cardiac orifice and fundus from
below, showing the pronounced lateral mucosal
fold at the cardiac orifice. B, The body and greater
curvature, showing mucosal folds (‘magenstrasse’).
C, The antrum, showing the internal appearance
of the incisura angularis. D, The prepyloric antrum
and opening of the pyloric canal.
A B
C D
Internal appearances
In the partially distended stomach, the mucosa of the body and, to
a lesser extent, the fundus is thrown into longitudinal folds (rugae) (see
During endoscopic examination (Fig. 64.8), the stomach is typically at Fig. 64.7). These are most obvious on the anterolateral, lateral and
least partially distended by air. The cardiac orifice and the lowest portion posterolateral parts of the stomach, towards the greater curvature. The
of the abdominal oesophagus viewed from above are typically closed smoother mucosa along the lesser curvature forms a ‘gastric canal’ or
at rest by tonic contraction of the lower oesophageal sphincter. The ‘magenstrasse’ that enables liquids entering the stomach to be fast-
transition between the pale pink squamous epithelium of the oesopha- tracked to the pylorus (see Fig. 64.8).
gus and the red columnar epithelium of the stomach, the ‘Z line’, is The areae gastricae within the antrum are small undulations of the
usually clearly visible at the proximal extent of the gastric mucosal folds mucosal surface that give a subtle cobblestone-type appearance on
(Silverstein and Tytgat 1991). Viewed retrogradely from within the dis- double contrast barium meal examination (see Fig. 64.7) (Mackintosh


tended stomach, the cardiac orifice lies medial to the fundus, with a and Kreel 1977). The few folds present in the antrum when the stomach
mucosal fold between the two corresponding to the acute angle at this is relaxed disappear with distension. The antrum adjacent to the pyloric
orifice. The mucosa also appears slightly thickened, forming part of the canal, the prepyloric antrum, has a smooth mucosal surface that culmi-
‘mucosal rosette’ that lines the orifice and contributes to its closure (see nates in a slight puckering of the mucosa at the pyloric orifice, caused
above). by contraction of the pyloric sphincter.


AbdominAl oesophAgus And stomAch
1116
8
noitces
Short gastric arteries Right hepatic Right medial sectoral Left hepatic Right gastric Left gastric Splenic
Oesophageal branch artery artery artery artery artery artery
Left gastric artery
Common hepatic artery
Gastroduodenal artery
Hepatic artery
Right gastric artery Epiploic branch
Gastric branch A
Right gastroepiploic artery
Left gastroepiploic artery
Cystic artery Gastroduodenal Common hepatic Right gastroepiploic
Fig. 64.9 The arterial supply of the stomach. A posterior gastric artery is
artery artery artery
not shown in this illustration.
Gastrostomy Left gastric
artery
Available with the Gray’s Anatomy e-book
Splenic artery
VASCULAR SUPPLY AND LYMPHATIC DRAINAGE
Common hepatic
Arteries
artery
The arterial supply to the stomach comes predominantly from the
coeliac trunk, although intramural anastomoses exist with arteries of Coeliac trunk
other origins at the two ends of the stomach (Figs 64.9–64.11). The left B
gastric artery usually arises directly from the coeliac trunk. The short
gastric arteries, left gastroepiploic artery and, when present, the poste-
rior gastric artery are branches of the splenic artery. The right gastric
artery and right gastroepiploic artery arise from the hepatic artery and Coeliac trunk
its gastroduodenal branch, respectively.
left gastric artery
The left gastric artery is the smallest branch of the coeliac trunk. It Common hepatic
ascends to the left of the midline and crosses over the lower end of the artery
left crus of the diaphragm beneath a fold of peritoneum in the upper
posterior wall of the lesser sac (the gastropancreatic fold). Here, it lies
Splenic artery
adjacent to the left inferior phrenic artery and medial or anterior to the
left suprarenal gland. It runs forwards into the superior portion of the
lesser omentum adjacent to the upper end of the lesser curvature, and
then turns anteroinferiorly to run along the lesser curvature between
C
the two peritoneal leaves of the lesser omentum. At the highest point
of its course, it gives off one or more oesophageal branches. In its course


along the lesser curvature, it gives off multiple branches that run on to Fig. 64.10 The coeliac trunk and its branches. A, Digital subtraction
the anterior and posterior surfaces of the stomach, after which it anas- angiogram. B–C, Digital reformatted multislice CT angiograms. (A,
tomoses with the right gastric artery in the region of the angular incisure. Courtesy of Dr James McCall, Chelsea & Westminster Hospital, London.
The left gastric artery (replaced or accessory) may rarely arise from B and C, Courtesy of GE Worldwide Medical Systems.)
the common hepatic artery or its left branch, or directly from the
abdominal aorta (Panagouli et al 2013). The most common of these
variations is an origin from the left branch of the hepatic artery, when anastomose with branches of the left gastric and left gastroepiploic
the left gastric artery passes between the peritoneal layers of the upper arteries. Rarely, an accessory left gastric artery may arise with these
lesser omentum to reach the lesser curvature of the stomach. However, vessels from the distal splenic artery.
a replaced/accessory left hepatic artery arising from the left gastric artery
is more common than a replaced/accessory left gastric artery origin. left gastroepiploic artery
The left gastroepiploic artery is the largest branch of the splenic artery.
short gastric arteries It arises near the splenic hilum and runs anteroinferiorly between the
For practical purposes, the short gastric arteries may be defined as those layers of the gastrosplenic ligament into the upper gastrocolic omentum.
arteries arising above the level of the splenic artery and supplying the Here, it descends between the layers of peritoneum close to the greater
fundus of the stomach on its greater curvature. The short gastric arteries curvature and often anastomoses with the right gastroepiploic artery. It
are variable in number: commonly, between five and seven. They arise gives off gastric branches to the fundus of the stomach through the
from the splenic artery or its terminal divisions, or from the proximal gastrosplenic ligament, and to the body of the stomach through the
left gastroepiploic artery, and pass between the layers of the gastro- gastrocolic omentum. These are necessarily longer than the gastric


splenic ligament to supply the gastric fundus and cardiac orifice. They branches of the right gastroepiploic artery and may be up to 8 cm long.


Abdominal oesophagus and stomach
1116.e1
46
RetpAhc
Since the lower half of the anterior surface of the stomach lies adjacent
to the anterior abdominal wall in the left upper quadrant, it may be
readily accessed to form a gastrostomy. The mobility of the stomach
allows it to be approximated to the parietal peritoneum on the upper
anterior abdominal wall, and a communication can then be established
between the lumen of the stomach and the skin surface. This may be
performed as an open surgical procedure but is much more commonly
undertaken by percutaneous puncture of the stomach, guided by an
endoscope within the gastric lumen or by radiological or laparoscopic
visualization of the stomach. Caution is needed to avoid inadvertent
transfixion of the transverse colon, which may be interposed between
the stomach and anterior abdominal wall.


stomach
1117
46
RetpAhc
Posterior gastric Extramural arteries Pyloric artery Submucous plexus
artery
Left gastric artery origin:
Left hepatic artery
Abdominal aorta
(not shown)
Mucosal arteries Duodenum Pyloric sphincter Pyloric antrum
Fig. 64.12 The blood supply of the stomach and the proximal duodenum:
Right gastric artery origin: Incomplete gastroepiploic a scheme of arterial arrangements at the gastroduodenal junction. Dotted
Common hepatic artery arcade lines indicate sites where the submucous plexus may be non-continuous.
Fig. 64.11 Principal variations in the gastric arterial supply. Accessory Shaded areas represent the muscular layer of the visceral wall. (Redrawn
vessels or possible replaced origins of vessels are shown by pale pink courtesy of C Piasecki, Department of Anatomy, Royal Free Hospital
lines. School of Medicine, London, and the Journal of Anatomy.)
Epiploic (omental) branches arise along the course of the vessel and supplying the stomach form extensive arterial anastomoses throughout
descend between the layers of the gastrocolic omentum into the greater the wall of the stomach but particularly in the submucosa. The right
omentum. A particularly large epiploic branch commonly originates and left gastroepiploic arteries and left and right gastric arteries anasto-
close to the origin of the left gastroepiploic artery, descends in the mose along the greater and lesser curvatures, respectively. Anastomoses
lateral portion of the greater omentum and provides a large arterial also exist in the fundus between the short gastric and left gastric arteries,
supply to the lateral half of the omentum. and in the antrum between the right gastric and right gastroepiploic
arteries. The rich arterial supply to the stomach ensures that the high
posterior gastric artery mucosal blood flow required for physiological functioning is main-
A posterior gastric artery supplying the posterior wall of the upper part tained even if one or more vessels become occluded; the stomach shows
of the gastric body is commonly present but there has been a lack of considerable resistance to ischaemia, even when multiple arterial sup-
consensus regarding its origin, course and distribution. It usually arises plies are lost.


from the splenic artery (usually from its mid section), posterior to the The pyloric arteries are branches of the right gastric and right gastro-
body of the stomach (see Fig. 64.11), and ascends behind the perito- epiploic arteries. They pierce the duodenal wall around its entire cir-
neum of the lesser sac towards the fundus to reach the posterior surface cumference just distal to the sphincter and reach the submucosa. Here,
of the stomach. It may also arise from the left gastric artery or coeliac they divide into two or three rami that run towards the stomach in the
trunk (Loukas et al 2007). submucosa of the pyloric canal and terminate in the mucosa of the
pyloric antrum (Fig. 64.12) (Piasecki 1974). The pyloric arteries anas-
Right gastric artery
tomose with submucosal arteries in the duodenum and gastric antrum
The right gastric artery is a relatively small artery that usually arises from close to their origin and termination, respectively. The pyloric sphincter
the hepatic artery proper and runs forwards into the lesser omentum muscle is supplied by gastric and pyloric arteries via branches that leave
just above the first part of the duodenum. It then travels within the their parent vessels in the subserosal and submucosal levels to penetrate
lesser omentum along the lesser curvature of the stomach, giving off the sphincter.
multiple branches to the anterior and posterior surfaces of the stomach,
before anastomosing with the left gastric artery. In a significant minority dieulafoy lesions
of individuals, it may originate from the common hepatic artery, left
hepatic artery or gastroduodenal artery (Yamagami et al 2010).
Available with the Gray’s Anatomy e-book
Right gastroepiploic artery
The right gastroepiploic artery usually originates from the gastroduode- Veins
nal artery behind the first part of the duodenum, anterior to the head
of the pancreas. It passes inferiorly towards the midline just below the The veins draining the stomach ultimately empty into the portal vein.
pylorus and then runs laterally along the greater curvature between the A rich submucosal and intramural venous network gives rise to veins


layers of the gastrocolic omentum about 1–2 cm from the greater cur- that usually accompany the corresponding named arteries and drain
vature of the stomach. It ends by anastomosing with the left gastroepi- into either the splenic or superior mesenteric veins, although some pass
ploic artery (although this anastomosis is variably developed (Ndoye directly into the portal vein. The course and distribution of the veins is
et al 2006) and may be absent). The right gastroepiploic artery gives off highly variable even up to the level of the major named vessels.
gastric branches that ascend on to the anterior and posterior surfaces
of the antrum and lower body of the stomach; epiploic branches that short gastric veins
descend into the greater omentum; and branches that contribute to the Three to five short gastric veins drain the gastric fundus and the upper
supply of the inferior aspect of the first part of the duodenum. part of the greater curvature into the splenic vein or one of its large
tributaries.
Arterial anastomoses of the stomach
Oesophageal arteries originating from the thoracic aorta anastomose left gastroepiploic vein
with vessels supplying the fundus of the stomach in the region of the The left gastroepiploic vein drains both anterior and posterior surfaces
cardiac orifice. At the pyloric orifice, the extensive network of vessels of the body of the stomach and the adjacent greater omentum via
supplying the duodenum allows for some anastomosis between multiple tributaries. It runs superolaterally along the greater curvature,
branches of the superior mesenteric artery and pyloric vessels derived between the layers of the gastrocolic omentum, and drains into the
from arteries arising from the coeliac trunk. The major named vessels splenic vein within the gastrosplenic ligament.


Abdominal oesophagus and stomach
1117.e1
46
RetpAhc
In patients requiring replacement of the oesophagus for severe con-
genital anomalies or after resection for cancer, a gastric tube supplied
by the left gastroepiploic artery can be fashioned from the greater cur-
vature of the stomach and anastomosed to the cervical oesophagus
(Arul and Parikh 2008).
The right gastroepiploic artery has been used for coronary artery
revascularization in some centres and this may pose a particular hazard
if the patient subsequently requires surgery for gastric cancer.
Abnormalities of the intramural vascularity of the stomach are a rare
cause of acute upper gastrointestinal haemorrhage. The so-called ‘Dieu-
lafoy’ lesion occurs most often near the lesser curvature within a few
centimetres of the gastro-oesophageal junction and consists of an
abnormally large artery that penetrates the muscular coat of the
stomach, runs a tortuous course in the submucosa, and protrudes
through a small mucosal defect, where it is vulnerable to rupture (Baxter
and Aly 2010).


AbdominAl oesophAgus And stomAch
1118
8
noitces
Right gastroepiploic vein gastrectomy and gastric lymphadenectomy
The right gastroepiploic vein drains the greater omentum, distal body
and antrum of the stomach. It runs medially along the greater curvature Available with the Gray’s Anatomy e-book
in the upper part of the gastrocolic omentum. Just proximal to the
pylorus, it passes posteriorly to drain into the superior mesenteric vein
INNERVATION
below the neck of the pancreas. The right gastroepiploic vein may
receive the right colic vein (forming a ‘gastrocolic trunk’) and/or supe-
rior pancreaticoduodenal vein close to its entry into the superior The stomach is innervated by sympathetic and parasympathetic nerves.
mesenteric vein (Yamaguchi et al 2002). A variety of neurotransmitters have been identified within pyloric
muscle, including acetylcholine, nitric oxide, enkephalins and vasoac-
left gastric vein tive intestinal polypeptide. Inhibition of the sphincter is mediated by
The left gastric vein drains the upper body and fundus of the stomach. nitrergic fibres whilst basal tone is mostly cholinergic (although it
It ascends along the lesser curvature to the oesophageal opening, where should be noted that many other factors, including acid and luminal
it receives several lower oesophageal veins. It then curves posteriorly nutrients, influence pyloric contraction; Ramkumar and Schulze (2005)).
and medially behind the posterior peritoneal surface of the lesser sac,
Sympathetic innervation
passing either anterior or posterior to the common hepatic artery. It
usually drains into the portal vein at the level of the upper border of The sympathetic supply to the stomach originates from the fifth to
the first part of the duodenum, which corresponds to 1–2 cm from the twelfth thoracic spinal segments, and is mainly distributed via the
origin of the portal vein (Rebibo et al 2012). In up to one-third of greater and lesser splanchnic nerves and the coeliac plexus. Peri-arterial
individuals, the left gastric vein terminates in the splenic vein. On rare plexuses form along the arteries arising from the coeliac trunk. Addi-


occasions, it drains into the left portal vein within the liver (Ohkubo tional innervation comes from fibres of the hepatic plexus, which pass
2000), which may be clinically important in portal hypertension. to the upper body and fundus via the lesser omentum and by direct
branches from the greater splanchnic nerves.
Right gastric vein Sympathetic activity causes vasoconstriction, inhibits gastric motility
The right gastric vein is typically small and runs along the medial end and constricts the pylorus. Afferent sensory pathways, including pain,
of the lesser curvature, passing under the peritoneum as it is reflected travel with sympathetic efferent nerves.
from the posterior aspect of the pylorus and first part of the duodenum
Parasympathetic innervation
on to the posterior wall of the lesser sac. It drains directly into the portal
vein at the level of the first part of the duodenum. It receives the pre- The parasympathetic supply to the stomach is from the vagus nerves
pyloric vein as it ascends anterior to the pylorus at the level of the (Fig. 64.15). The anterior vagal trunk (formed mainly from fibres from
pyloric opening. Rarely, the right gastric vein drains directly into a the left vagus nerve within the oesophageal plexus) is often double or
branch of the portal vein within the liver. even triple, and supplies filaments to the cardiac orifice. The nerve is
closely applied to the anterior surface of the outer muscle of the abdom-
posterior gastric veins inal oesophagus and usually divides near the gastro-oesophageal junc-
One or more distinct posterior gastric veins may be present, draining tion into gastric, pyloric and hepatic branches (Jackson 1949). Upper
the middle of the posterior surface of the stomach into the splenic vein. gastric branches radiate on the anterior surface of the upper body and
They may become particularly prominent in portal hypertension fundus but the main gastric branch (also known as the anterior nerve
(Kimura et al 1990). of the lesser curvature or greater anterior gastric nerve) lies in the lesser
omentum near the lesser curvature. It supplies branches to the body
oesophageal and gastric varices and antrum, and usually terminates near the angular incisure in a crow’s


Blood from the oesophageal mucosa normally drains into a submu- foot type of pattern (Shanthi and Sudhayesshayyan 2011). The hepatic
cosal venous plexus, then into a deeper intrinsic venous plexus and branch runs almost transversely between the peritoneal layers of the
finally into peri-oesophageal veins via perforating veins. In the abdomi- lesser omentum towards its free edge to reach the hilum of the liver,
nal oesophagus, the perforating veins drain into tributaries of the left where hepatic branches ramify. From here, some fibres descend adjacent
gastric vein, whereas, in the lower thoracic oesophagus, they drain into to the hepatic artery to supply the pylorus, duodenum and pancreas.
tributaries of the azygos and hemiazygos systems. Bidirectional flow is An additional pyloric branch often arises from the greater anterior
possible in this region, and accommodates pressure changes that occur gastric nerve during its course; this runs inferomedially to the pyloric
during breathing and Valsalva manœuvres. antrum, where it gives off branches to the pylorus before running supe-
Oesophageal and gastric varices are abnormally dilated veins that riorly to contribute to the hepatic plexus. Variations in the anterior
occur in the submucosal plexus of the distal oesophagus and gastric nerve include accessory pyloric branches and high and low courses of
fundus when portal venous pressure is chronically elevated (typically the hepatic and pyloric branches in the lesser omentum.
greater than 15 mmHg). This may develop as a consequence of liver The posterior vagal trunk usually lies within loose connective tissue
fibrosis or cirrhosis, or portal vein thrombosis, or from a variety of other immediately posterior and to the right of the oesophagus. It divides
causes. Portal hypertension leads to the recanalization of occluded into gastric branches and one or more coeliac branches. Gastric branches
embryonic venous channels between venous tributaries of the portal run behind the cardiac orifice and body of the stomach and extend to
system and the systemic venous circulation (e.g. the ligamentum teres) the proximal antrum, but do not normally reach the pyloric sphincter.


and progressive dilation of small, naturally occurring venous anasto- The largest gastric branch (also known as the posterior nerve of the
moses between portal and systemic venous tributaries (Paquet 2000). lesser curvature or the greater posterior gastric nerve) descends posteri-
Valves within these veins become incompetent, permitting retrograde orly near the lesser curvature. The coeliac branch arises from the poste-
flow and causing the development of varices. Varices in the distal rior vagal trunk and carries the majority of fibres contributing to the
oesophagus are readily visible at endoscopy because they are situated coeliac plexus. One or two small hepatic branches may also originate
superficially and protrude into the oesophageal lumen (Fig. 64.13); from the coeliac division of the nerve.
they are vulnerable to rupture and a source of major gastrointestinal The parasympathetic nerve supply is secretomotor to the gastric
bleeding. Gastric varices may also be present on the inferior aspect of mucosa and motor to the gastric musculature. It is responsible for
the cardiac orifice. coordinated relaxation of the pyloric sphincter during gastric emptying.
However, the majority of fibres within the vagus nerves are afferent;
Lymphatic drainage these convey gut sensation, including fullness, nausea and probably
pain.
The stomach has a rich network of lymphatics that connect with lym- Referred pain
phatics draining other viscera within the upper abdomen. At the gastro-
Pain sensation from the stomach is poorly localized and, in common
oesophageal junction, the lymphatics are continuous with those
with other structures of foregut origin, is referred to the epigastrium.
draining the lower oesophagus; in the region of the pylorus, they are
Pain arising from the gastro-oesophageal junction is commonly referred
continuous with those draining the duodenum and pancreas. In
to the lower retrosternal and subxiphoid areas.
general, lymphatics follow the course of the arteries supplying the
stomach. However, many separate groups of nodes are now recognized
(Fig. 64.14) and their relationship to the specific regions and vascular MICROSTRUCTURE
territories of the stomach is of great importance during resection of the
stomach, particularly for malignancy. Pancreatic and hepatic lymphatics The gastric wall consists of the major layers found elsewhere in the gut,


play a significant role in draining the stomach during disease. i.e. mucosa, submucosa, muscularis externa and serosa, together with


Abdominal oesophagus and stomach
1118.e1
46
RetpAhc
A B C
Fig. 64.13 The endoscopic appearance of oesophageal and gastric varices in portal hypertension. A, Oesophageal varices. B, Fundal varices seen
from within the stomach after retroflexion of the gastroscope. C, Portal gastropathy (gastric antrum) due to venous congestion of the gastric mucosa.
(Courtesy of Professor Mark Stringer.)
Surgery for gastro-oesophageal malignancy involves varying degrees of (wider-draining nodes, including para-aortic nodes). Gastrectomies can
radical resection of lymph nodes that drain the tumour. Locoregional be classified according to the node groups excised with the tumour: D1
lymphatic spread can occur in the absence of haematogenous spread (removal of the affected portion of the stomach and en bloc resection
and gastric cancer may therefore remain a localized disease, even when of N1 nodes); D2 (total gastrectomy, including all N1 and N2 nodes);
lymph nodes are involved (UICC et al 1997). Hence, gastrectomy with and D3 (total gastrectomy plus extensive lymphadenectomy that
meticulous lymphadenectomy can be curative in a proportion of includes the associated upper abdominal lymph nodes: namely, pan-
patients with gastric cancer and nodal involvement. creatic, superior mesenteric, coeliac, hepatic and transverse colic) (Japa-
The extent of potential/actual nodal involvement by the tumour is nese Gastric Cancer Association 1998, Japanese Research Society for
classified as N1 (locoregional nodes specific to the tumour site); N2 Gastric Cancer 1998).
(regional and major named vessel nodes draining the tumour); and N3