Abstract
Abstract
Introduction
Case
A 31-year-old woman's first pregnancy in 2004 was a left tubal ectopic pregnancy, for which she underwent a laparoscopic partial left salpingectomy in France. This was followed by two early spontaneous miscarriages. In 2006, she was had an interstitial ectopic pregnancy in her left tubal stump. Laparoscopic excision of the ectopic fetus was done, using bipolar diathermy. The interstitial area was not sutured as was the authors' practice at that time, and histology confirmed the diagnosis of an ectopic pregnancy.
She became pregnant again a few months later, and presented with bleeding in early pregnancy. A scan confirmed a normal viable intrauterine pregnancy. In January of 2007, she was admitted to the hospital at 24 weeks' gestation with acute abdominal pain and vomiting. Ultrasound examination suggested a uterine rupture with no fetal heart activity. An urgent midline laparotomy showed a rupture of the uterus over the site of the previous left interstitial ectopic with a hemoperitoneum. The fetus was within the abdominal cavity with an intact amniotic sac, which was removed and the uterus was closed in three layers using Vicryl sutures.
In November of 2007, she was pregnant again, and a scan at 6 weeks' gestation showed a gestational sac high in the uterine cavity close to the left interstitium, with a rim of myometrium surrounding the pregnancy. The patient chose to continue the pregnancy under close supervision but, 2 weeks later, presented with abdominal pain and vomiting. In view of her previous history, an emergency laparoscopy was performed. This revealed a hemoperitoneum, and a subsequent laparotomy revealed a recurrent rupture at the left interstitium, which was then sutured with Vicryl in two layers.
Results
At a follow-up scan in January of 2008, the interstitial region appeared to have healed well, with the myometrium measuring 14.3 mm near the fundus and 11.8 mm laterally with no obvious adhesions.
She subsequently had a subsequent intrauterine pregnancy in 2008, which was very closely monitored with serial scan measurements of her myometrial thickness. The left interstitium measured between 4 and 5 mm in thickness for the duration of the pregnancy. In view of her previous uterine rupture, following administration of steroids for lung maturity, she was delivered by elective caesarean section at 32 weeks' gestation. At caesarean section, dehiscence of the interstitial site was noted, which was sewn over with Vicryl. She and her child remain in good health.
Discussion
Uterine rupture occurs mostly during the intrapartum period and is potentially catastrophic for both mother and fetus. Although much attention is paid to scar rupture following caesarean section and myomectomy, uterine rupture following interstitial ectopic pregnancy has not been studied properly.
Rupture of the uterus in cases of interstitial pregnancy may occur in 20% of pregnancies that progress beyond 12 weeks' gestation. 1 There is probably no direct association between tubal ectopic pregnancy and uterine rupture. However, partial resection of the Fallopian tube in an ectopic pregnancy can pose the risk of development of a subsequent ectopic pregnancy in the stump or interstitial region, with a subsequent risk of uterine horn rupture. 2 In a series of 32 interstitial pregnancies, the most common risk factors were tubal damage from previous ectopic pregnancy (40.6%), previous ipsilateral or bilateral salpingectomy (37.5%), conception after in vitro fertilization (34.4%), and history of sexually transmitted disease (25.0%). 3 There are also numerous cases of ipsilateral stump pregnancies following salpingectomy following laparoscopic management of ectopic pregnancy.4–6 In view of this risk, total salpingectomy with resection of the interstitial portion of the tube is recommended to prevent implantation in the interstitial stump. 7 However in some cases, particularly following the use of an ENDOLOOP,® suture this principle is not necessarily followed, leaving a stump with resulting higher risk for future interstitial pregnancy.
Management of interstitial pregnancy remains a challenge because of the risk of rupture. Laparotomy still remains the mainstay of management in cases of ruptured interstitial ectopic pregnancies because of the rapid and massive haemorrhaging that can occur, but different laparoscopic techniques have been used for the treatment of interstitial pregnancy. Cornuostomy, which is analogous to linear salpingostomy, is used for some cornual ectopic pregnancieswithout removing the surrounding myometrium, and the defect is closed with a variety of methods to achieve hemostasis.8–10 Laparoscopic cornual resection is the most common approach; this is the endoscopic version of the traditional cornual wedge resection.11,12 Laparoscopic mini-cornual excision on the other hand is relatively new technique which involves deroofing of the interstitial pregnancy by excision of the thinned-out myometrial mantle through an elliptical incision along the long axis of the interstitial pregnancy. The interstitial pregnancy is evacuated without creating a myometrial defect and need for sutures, which preserves the architecture and vascularity of the uterus by leaving the base intact. 13
The cumulative success rate with the use of various laparoscopic techniques from the available case reports and series in the literature is 85%, 7 but no long-term data are available to assess the risk of uterine rupture in subsequent pregnancies. The risk of rupture exists because of the presence of a weakened cornual region following different techniques of repair. It can be argued that suturing may decrease the risk of future uterine rupture, and, as such, many institutions have adopted this practice, but, however, overzealous suturing may compromise adequate, blood supply resulting in tissue ischemia. This, in turn, can impair healing and compromise the tensile strength of the interstitial region, potentially leading to uterine rupture. There are no randomized trials to assess the usefulness of suturing in interstitial ectopic pregnancy, although a few studies have compared linear salpingotomy with or without suturing. In contrast, excessive use of electrocautery may also cause significant damage to the myometrium that can weaken the interstitial region further and increase the risk of uterine rupture in future pregnancies. 13 All surgical techniques have had high rates of success claimed for these techniques, but more-objective assessment in terms of subsequent successful pregnancies and rates of uterine rupture should be used to determine effectiveness of of any kind of management. Ideally, a randomized trial needs to be conducted to determine the long-term outcome and risk of uterine rupture with different surgical techniques. Organizing such a trail is a likely to be a daunting task because of the numbers of subjects needed to assess risk of uterine rupture. In the interim, a retrospective review of interstitial ectopic pregnancies may perhaps provide some answers until more direct evidence is available.
This particular case was unusual, in that there were two episodes of uterine rupture following laparoscopic treatment of interstitial pregnancy. While it is possible that the technique used, resection without suturing, may have contributed directly to the subsequent rupture, the interpregnancy interval may also be a crucial factor. With respect to caesarean sections, it is known that a short interpregnancy interval is associated with a higher risk of rupture. The uterus requires a certain length of time to develop strong scar tissue, a process that is likely to be impeded by the distension that follows a subsequent pregnancy. It is therefore possible that the short interpregnancy interval in this case between the interstitial ectopic pregnancy and the subsequent pregnancies, that led to rupture, did not provide adequate time for the uterus to develop a strong scar.
Conclusions
In response to this case, the authors have also modified the surgical approach to such ectopic pregnancies, which now involves laparoscopic suturing after resection. It is hoped that this approach will produce a stronger scar than one where the resected area has not been approximated. While the authors are aware that there is little evidence to support such a change, the dramatic nature of the recurrent ruptures in this case have suggested a need for this change.
This case highlights the risk of uterine rupture following a previous interstitial ectopic pregnancy but also demonstrates that, despite recurrent ruptures, a successful pregnancy outcome can be achieved.
Disclosure Statement
No competing financial conflicts exist.