the risk of rupture approximates 50% , most of which occur in the second trimester .
was then performed with fetal intracardiac potassium chloride and intraplacental methotrexate . magnetic resonance imaging ( mri ) of the pelvis was obtained .
while surgical resection of a rudimentary horn pregnancy is necessary , early diagnosis affords the opportunity to take steps that minimize surgical risks .
mri assists surgical planning by demonstrating the form of attachment of the uterine horn to the unicornuate uterus .
preoperative medical termination may decrease vascularity of the gestation , thereby decreasing operative blood loss .
a unicornuate uterus results from unilateral failure of normal mllerian system development . in most instances ,
the abnormal mllerian duct has partially developed into a rudimentary uterine horn . in one series of 42 patients with unicornuate uterus ,
the anatomic variations of a rudimentary horn serve as the basis for classification of unicornuate uterus by the american fertility society : rudimentary horn with cavity , communicating with unicornuate uterus ( class iia ) , rudimentary horn with cavity , not communicating with unicornuate uterus ( class ii - b , the most common ) , rudimentary horn without cavity ( class ii - c ) , or unicornuate uterus without rudimentary horn ( class ii - d ) .
pregnancy within a noncommunicating rudimentary uterine horn is a well - known complication , estimated to occur in 1 in 76,000 pregnancies .
migration of ovum with sperm can also occur , as evidenced by the 8% prevalence of a corpus luteum on the side contralateral to the rudimentary horn containing the pregnancy .
the prognosis for maternal and fetal outcome is poor , with a neonatal survival rate of 6% and uterine horn rupture risk of 50% . due to the high risk of this potentially catastrophic outcome
, the classical teaching has been that all uterine horn pregnancies should be surgically removed immediately upon diagnosis .
however , medical termination followed by delayed surgical resection is an option when diagnosis is obtained early and impending rupture seems unlikely , since most cases of rupture occur in the second trimester .
we describe a case of noncommunicating rudimentary horn pregnancy that was medically terminated and subsequently resected along with the uterine horn and fallopian tube 6 weeks later .
a 36-year - old female who had a known history of a left unicornuate uterus with a noncommunicating rudimentary horn presented to her obstetrician 8 weeks into her second pregnancy .
her uterine anomaly was detected in her first pregnancy during a cesarean delivery at 34 weeks for failure to progress .
however , an accurate description of the uterine anomaly was difficult given the gravid state .
several months later , a hysterosalpingogram revealed a small uterine cavity deviating towards the left side , along with a patent left fallopian tube .
an ultrasound at 8 weeks revealed a singleton pregnancy within the right uterine horn and a corpus luteum on the ipsilateral ovary ( figure 1 ) .
the crown - rump length and quantitative b - hcg ( approximately 89,000 miu / ml ) were consistent with the gestational age , and cardiac activity was observed .
the patient was referred to a perinatologist who confirmed the ectopic pregnancy diagnosis and counseled her about the risk of uterine horn rupture and poor prognosis for viability .
the patient was also counseled that surgery would be necessary to remove the ectopic gestation and noncommunicating rudimentary horn .
the perinatologist performed intracardiac injection of kcl along with intraplacental injection of methotrexate to prevent further gestational growth .
the patient was seen weekly to follow b - hcg levels , which had decreased to 653 miu / ml after 6 weeks .
four weeks after medical termination , we obtained an mri to further characterize the uterine anomaly and urinary system .
the mri revealed a rudimentary horn attached to the unicornuate uterus by a small band of tissue , and no urinary system abnormalities were detected ( figures 2 and 3 ) .
black arrow : right rudimentary horn containing pregnancy ; white arrow : left unicornuate uterus ; grey arrow : band of tissue connecting the rudimentary horn to the uterus .
black arrow : right rudimentary horn containing pregnancy ; white arrow : left unicornuate uterus ; grey arrow : band of tissue connecting the rudimentary horn to the uterus .
six weeks after medical termination , we performed laparoscopy with a 5-mm laparoscope in the umbilicus , a 10-mm trocar in the left lower quadrant , and a 5-mm trocar in the right lower quadrant .
a 446-cm rudimentary horn was attached to the unicornuate uterus by a 15-mm diameter band of tissue ( figure 4 ) .
we transected the right round ligament and opened the broad ligament by using a 5-mm ligasure ( valleylab , boulder , co ) .
the anterior leaf of the broad ligament was dissected from the edge of the uterine horn , and a right salpingectomy was performed .
the posterior leaf of the broad ligament was dissected off the edge of the uterine horn ( figure 5 ) , and the utero - ovarian ligament was transected .
two pds endoloops ( ethicon endo - surgery , inc , cincinnati , oh ) were placed over the rudimentary horn and ligated around the fibrous band before it was transected with the ligasure . once the uterine horn and tube were free , the specimen was removed by using an endopouch ( ethicon endo - surgery , inc , cincinnati , oh ) .
uterine horn ( black arrow ) is attached to the unicornuate uterus ( white arrow ) by a small band of tissue ( grey arrow ) .
superficial lesions of endometriosis in the posterior culde - sac and on the left uterosacral ligament were fulgurated using bipolar cautery . estimated blood loss was less than 50ml and there were no complications .
the patient was aware of the poor prognosis for carrying a pregnancy to term , yet she continued to express a strong desire for future childbearing .
when ectopic pregnancy within a rudimentary uterine horn occurs , surgical resection is requisite due to the high risk of rupture . because most cases of uterine horn rupture occur in the second trimester , early diagnosis in the first trimester provides some time to take measures that can minimize surgical risks . in this case ,
medical termination was performed before surgery to decrease the vasculature to the ectopic gestation . for the nongravid patient , elective surgical removal of a rudimentary horn
the patient was asymptomatic from the ectopic pregnancy and displayed no signs of impending rupture .
termination with intracardiac kcl and intraplacental methotrexate was successful in reducing further development of the ectopic gestation , and the b - hcg levels decreased rapidly .
single - dose intramuscular methotrexate has also been reported to terminate rudimentary horn pregnancy , which requires a larger dose of medication due to systemic adminstration .
we delayed surgical resection until b - hcg levels declined significantly , hoping this would signify a decrease in blood flow to the rudimentary horn .
the use of preoperative gnrh agonists to render the surgical field less vascular has been reported in cases without pregnancy . however ,
this was not used in our patient because we did not feel that a gnrh agonist would have a significant effect during pregnancy .
characterizing the anatomic relation between the uterine horn and the unicornuate uterus with mri is helpful for planning the surgical approach .
a rudimentary horn can be attached to the unicornuate uterus by either a band of tissue or a broad , firm attachment . a band of tissue is easily transected while a broad attachment requires much more dissection .
separation is more difficult without a pedicle , and there is a higher risk of dissecting into the cavity of the uterus .
an mri is also useful to determine whether any urinary abnormalities are present , given that approximately 38% of patients have coexisting renal abnormalities .
unilateral renal agenesis is most commonly found , which is always ipsilateral with the rudimentary horn .
mri is helpful for making this diagnosis and understanding the anatomy to plan the surgical approach for resection .
when diagnosis is obtained early , medical termination before surgery can be used to potentially decrease blood flow to the gestation , facilitating surgical removal with limited blood loss .
 background : pregnancy within a noncommunicating rudimentary horn is a known complication of unicornuate uterus . 
 the risk of rupture approximates 50% , most of which occur in the second trimester.case:a rudimentary horn pregnancy was discovered at 8 weeks gestation . 
 medical termination was then performed with fetal intracardiac potassium chloride and intraplacental methotrexate . magnetic resonance imaging ( mri ) of the pelvis was obtained . 
 laparoscopic uterine horn resection 6 weeks after medical termination was performed.discussion:while surgical resection of a rudimentary horn pregnancy is necessary , early diagnosis affords the opportunity to take steps that minimize surgical risks . 
 mri assists surgical planning by demonstrating the form of attachment of the uterine horn to the unicornuate uterus . 
 preoperative medical termination may decrease vascularity of the gestation , thereby decreasing operative blood loss . 
Background:
Case:
Discussion:
INTRODUCTION
CASE REPORT
DISCUSSION
CONCLUSION