incisional ( postoperative ventral ) hernia is an iatrogenic abdominal wall defect that occurs at the site of previous incision following breakdown in the continuity of the fascia closure . it has been described as a bulge visible and palpable when the patient is standing and often requiring support and repair .
it is a very common complication of abdominal surgeries and is associated with considerable morbidity and mortality [ 3 , 4 ] .
as many as 11% of laparotomies are complicated by the development of incisional hernias [ 57 ] .
the figure rises to 26% in those who develop wound infection . despite increased understanding of abdominal wound closure
, it is worrisome that the frequency has not diminished appreciably in the past 75 years [ 9 , 10 ] .
an incisional hernia occurs due to biochemical failure of the acute fascial wound early in the healing process when wound tensile strength is very low or absent ( days 030 ) .
it is during this time , when wound strength depends entirely on suture integrity , that recovering patients start returning to increased levels of activity and thereby place increasing loads across their acute wounds [ 11 , 12 ] .
however , the hernia may not be obvious for days or even years [ 13 , 14 ] .
various factors have been identified to be responsible for the failure , including obesity and wound infection ; other contributory factors include initial closure of fascia with catgut , drainage tube through the index incision , senility , early wound dehiscence , immunosuppressant therapy , anaemia , diabetes mellitus , malnutrition , jaundice , and azotaemia , [ 1517 ] .
occurrence of incisional hernia has also been attributed to the disturbance of collagen metabolism at the microscopic level .
this entails the use of mesh , either open or laparoscopic [ 15 , 21 ] , but this material is not available in most poor countries such as ours .
this study was carried out to identify the factors associated with incisional hernia in our region as well as factors affecting recurrence .
forty - four women who presented with ventral incisional hernia at obafemi awolowo university teaching hospital ( o.a.u.t.h.c ) , ile - ife , osun state , nigeria , between january 1996 and december 2005 were included in the study .
o.a.u.t.h.c is a tertiary health facility located in southwest nigeria and serves as the referral hospital for patients from osun , ondo , ekiti and part of oyo state of nigeria .
people from these areas are mostly farmers and the others are either self - employed or government workers .
a standard form was used during the initial evaluation of the patient to obtain the indication for the pre - hernia operations and the possible predisposing factors .
surgeons ' skill and level of experience for the pre - hernia surgery were not assessed because most were patients referred from other hospitals .
all hernias were in the midline of the abdomen , but they were characterised as being supraumbilical , periumbilical or infraumbilical . wound infection as a risk factor was arrived at if the patient gave a history of a pussy discharge from the wound after the pre - hernia surgery .
this was corroborated by the length of hospital stay and the scar of the pre - hernia operation .
prolonged ileus was defined as delay of return of the bowel sound 72 hours after surgery .
all patients with body mass index of > 25 kg / m whose weight was the same or greater before the pre - hernia surgery were considered overweight or obese .
scars with no sutures in the wound were assumed to have been repaired with absorbable sutures ( chromic catgut is a common absorbable suture used in our region ) .
the operation notes of the few patients who were operated on in this hospital were also reviewed .
all the patients had general anaesthesia . either mayo 's or keel 's repair were offered to the patient ; mayo 's repair was used for the smaller defects .
a relaxing incision was made on the rectus sheath to relieve tension on the repair .
post - operative complications were classified as superficial or deep wound infection , seroma , or haematoma .
superficial wound infection was defined as the presence of signs or symptoms of inflammation at the wound , which was treated with antibiotics ; this may or may not have included the development of systemic evidence of infection or the presence of purulent discharge from the wound .
deep wound infection was defined as the presence of a sub - fascial collection of purulent fluid that may or may not have been associated with systemic or local evidence of inflammation .
seroma was defined as the presence of a symptomatic prefascial collection of sterile fluid requiring drainage .
categorical data was compared with recurrence using chi square ( pearson chi square and fischer 's exact test ) where appropriate .
two - tailed student 's t - test was used to compare the continuous data with recurrence .
about three - quarters of the incisional hernias ( 34 , 77.4% ) occurred within the first year of pre - hernia surgery .
most patients ( 32 , 72.7% ) had mayo 's repair and the remainder had keel 's repair .
only four patients ( 8.2% ) had recurrence of the lesion within the study period .
ten patients ( 22.7% ) had other complications , including superficial wound infection ( 3 , 6.8% ) , deep wound infection ( 2 , 4.5% ) , haematoma ( 2 , 4.5% ) , seroma ( 1 , 2.3% ) , hypertrophic scar ( 3 , 6.8% ) and cough ( 1 , 2.3% ) .
age distribution and the outcome of surgery in the 44 women with incisional hernia the pre - hernia ( index ) operations of the patients are as shown in table 2 . by using the chi square test
, we found that the index operation was significantly associated ( p < 0.0001 ) with the nature of the surgery : emergency or elective .
twenty - eight patients ( 63.6% ) had caesarean section , 26 of whom were on emergency basis .
obstructed labour ( 18 , 69.2% ) was the most common indication for emergency caesarean sections , followed by foetal distress ( 4 , 15.4% ) and eclampsia ( 4 , 15.4% ) .
the six emergency exploratory laparotomies were done for two typhoid perforations , one appendiceal abscess , and three uterine perforations from septic abortion .
the elective surgeries included total abdominal hysterectomy with bilateral salpingoophorectomy , herniorrhaphies cholecystectomy , bilateral truncal vagotomy with pyloroplasty , and right hemicolectomy .
only six hernias were periumbilical ( 13.6% ) and two ( 4.5% ) were supraumbilical .
prehernia ( index ) operations among incisional hernia patients p  0.0001 - the incidence of incisional hernia are more common in patients who had emergency surgeries than elective surgeries .
tah - bso = total abdominal hysterectomy and bilateral salpingoophorectomy recurrent i.h . recurrent inguinal hernia
the sizes of the hernias ranged from 2.5 to 15 cm long with a median of 10.0 cm , and from 2.5 to 12 cm wide with a median of 6.0 cm .
the area of the defect ranged from 6.25 to 180 cm2 with a median of 75 cm2 .
the major predisposing factors included midline incision ( 44 , 100.0% ) , wound sepsis ( 35 , 71.4% ) , absorbable suture ( 34 , 69.4% ) , overweight ( 12 , 24.5% ) , and prolonged post operative ileus ( 10 , 20.4% ) ( table 4 ) .
other factors included multiparity , wound attrition from old age , drain from original wound , cough , haematoma , difficult extubation , diabetes mellitus , cigarette smoking , and cancer .
patients were followed up for 18 to 60 months . of the four patients with recurrence ,
two were overweight and had wound infection , and the other two had difficult extubation associated with wound infection .
recurrence was significantly affected by the pre - hernia surgery ( p = 0.012 ) .
recurrence was seen in the repair of incisional hernia resulting from umbilical hernia and emergency caesarean section .
pre - hernia surgeries were pregnancy - related in 28/44 ( 63.6% ) cases . this age group is always subjected to prolonged or repeated stretching and weakness of the abdominal muscular tendinous structure .
it is therefore not surprising that incisional hernia was more prevalent in this group twenty - six patients ( 59.1% ) had emergency caesarean section before the incisional hernia .
this is in agreement with previous observations [ 13 , 23 ] ; the pregnant abdomen , attendant obesity , and emergency nature of surgery can all predispose to incisional hernia .
the major possible predisposing factors identified in this study ( tables 2 , 3 , 4 ) are not much different from those reported elsewhere [ 13 , 18 , 23 , 24 ] .
thirty - two patients ( 72.7% ) had emergency operations , where nothing could have been done about the weight of overweight patients .
hence , obesity as a causative factor was prominent in 12 ( 27.3% ) of our patients .
surgeons ' lack of experience and inappropriate surgical technique could also be factors leading to incisional herniation .
this could not be ascertained in many of our patients who had presented from various hospitals , without access to their previous operation records .
anatomical location of hernia defect factors associated with incisional hernia in 44 patients wound sepsis has continued to be an important risk factor .
perhaps the usual reduced immune state of pregnancy and the occasional undetected gestational diabetes , combined with the emergency nature of the surgeries could account for this frequent involvement of sepsis .
the constant mutations of the contaminating genital microbes and consequent development of antibiotic resistance do not make matters any better .
the least resistance to stress by intra - abdominal forces is offered by vertical incision , which transversely divides the oriented fascia fibers of the anterior abdominal wall [ 1 , 13 ] .
incisional hernia is expected in patients who have absorbable suture for fascia repair [ 1 , 26 ] .
midline abdominal fascia is poorly vascularised and hence is slow to heal , consolidate and regain its tensile strength [ 1 , 27 , 28 ]
. it therefore requires suture materials whose tensile strength will still hold until the fascia heals . as noted by previous workers [ 24 , 29 ] , herniation through
this is anatomical , due to the thinner anterior sheath with virtually no posterior sheath support of the linea alba .
it has also been attributed to the orientation of the incision , which is parallel to the line of forces acting on it .
the sizes of our patients ' hernial defects allowed re - apposition without significant tension .
hence two main techniques ( mayo 's and keel ) were employed [ 30 , 31 , 32 ] .
this suture has been used successfully by other workers [ 8 , 23 , 27 , 33 ] .
surgical treatment of incisional hernia include suture repair ( which may incorporate relaxing incision ) , internal suture retention techniques , muscle flap rotation , autodermal hernioplasty , and prosthetic implantation using onlay and sublay techniques [ 5 , 34 ] .
concluded that suture repair was safe for small incisional hernias ; both autoplastic and alloplastic hernia repair yielded comparably low recurrence rates , but led to a high rate of wound infection .
laparascopic herniorrhaphy is a promising technique with all the advantages of minimally - invasive surgery [ 5 , 22 , 36 , 37 ] .
incisional hernia repair is associated with high cumulative rates of re - operative repairs ; and important measures of adverse outcomes have not improved .
the recurrence rate among the 44 patients was 4/44 ( 9.1% ) , after a period of follow - up ranging from 18 to 60 months .
this should not be discouraging because two of the cases are thought to have been due to wound sepsis and overweight .
therefore , we suggest that whenever possible , reduction of weight should be encouraged before laparotomies and incisional hernia repair in overweight patients . transverse incisions , unless contraindicated , should be used more frequently .
judicious use of perioperative antibiotics in all emergency laparatomies , particularly caesarean section , with meticulous attention to asepsis at all times should be encouraged .
there is a need to continue insisting on appropriate nonabsorbable suture materials in closure of abdominal wounds during laparatomy .
the well - established surgical principles remain valid : wound closure should be free of excessive tension , the sutures should be placed in healthy tissue , and strong suture material should be used to support the wound through the critical period of healing .
despite the relatively small number of patients , we confidently conclude that the major clinical attributes with possible risk factors for incisional hernia are using the wrong type of sutures , midline incisions , wound sepsis , and overweight .
a further study of a large population to compare patients with similar attributes but no incisional hernia would be shed light on this . however , we recommend that whenever possible , reduction of overweight be encouraged before laparatomies and that transverse or oblique incision be used instead of vertical incision when practicable .
prophylactic antibiotics should be used in all emergency laparatomies , especially caesarean sections for obstructed labour .
absorbable sutures ( especially chromic catgut ) should not have a place in repair of fascia of midline incision .
if these suggestions are adhered to , the incidence and morbidity of incisional hernia will definitely diminish .
it is noteworthy that in our centre we started repairing incisional hernias and other defects with mesh .
this forms the thrust of an ongoing prospective study on the management of fascial defects .
 background / aim : incisional hernia is still relatively common in our practice . the aim of the study was to identify risk factors associated with incisional hernia in our region . 
 the setting is the obafemi awolowo university teaching hospitals complex , ile - ife , nigeria during a period when prosthetic mesh was not readily available . 
 patients and methods : all the women who presented with incisional hernia between 1996 and 2005 were prospectively studied using a standard form to obtain information on pre - hernia ( index ) operations and possible predisposing factors . 
 they all had open surgical repair and were followed up for 1860 months . 
 results : forty - four women were treated during study period . 
 the index surgeries leading to the hernias were emergency caesarian section 26/44 ( 59.1% ) , emergency exploratory laparotomy 6/44 ( 13.6% ) , and elective surgeries 12/44 ( 27.3% ) . 
 major associated risk factors were the use of wrong suture materials for fascia repair , midline incisions , wound sepsis , and overweight . 
 conclusion : for elective surgeries , reduction of weight should be encouraged when appropriate , and transverse incisions are preferred . 
 absorbable sutures , especially chromic catgut , should be avoided in fascia closure . 
 antibiotics should be used for complicated obstetric cases . 
Introduction
Methods and patients
Results
Discussion
Conclusion