Ectopic Pregnancy

Management of cornual (interstitial) pregnancy - Faraj - 2007 - The Obstetrician & Gynaecologist - Wiley Online Library

Department of Obstetrics and Gynaecology, Blackpool Victoria Hospital, Whinny Heys Road, Blackpool FY3 8NR, UK Email: faraj68@hotmail.comAbstractKey content The Confidential Enquiry into Maternal and Child Health report for 2000 02 stated that cornual pregnancy is a rare but dangerous type of ectopic pregnancy. Four out of the 11 deaths from ruptured ectopic pregnancy were due to ruptured cornual pregnancy. In all four cases the diagnosis was made only after rupture. Haemorrhage can be severe because pregnancy is often more developed than extrauterine tubal pregnancy and because of the large blood supply to the uterus. Clinicians should be aware of the difficulties with both clinical and ultrasound diagnosis. Many case reports have been written about sporadic cases of intact and ruptured cornual pregnancy and several treatment modalities discussed. There are very few publications collecting all management strategies, including both surgical and medical treatment, for this dangerous type of ectopic pregnancy.Learning objectives To understand recent advances in diagnosis and conservative laparoscopic and medical treatment. To review the most reputable case reports discussing all modalities of treatment, including radical surgical and conservative laparoscopic methods and different types of medical treatment, with critical appraisal of each approach.Ethical issues How should a couple be counselled regarding future pregnancy risks and the optimum mode of delivery?

Please cite this article as: Faraj R, Steel M. Management of cornual (interstitial) pregnancy. The Obstetrician Gynaecologist 2007;9:249 255.Enhanced PDFStandard PDF (143.4 KB) Introduction

Cornual gestation is one of the most hazardous types of ectopic gestation. The diagnosis and treatment are challenging and frequently constitute a medical emergency. In general, the death rate associated with ectopic pregnancy has not declined since the Confidential Enquiry into Maternal and Child Health (CEMACH) report for 2000 02 and is increased on the rates for 1991 93. In the last report1 there were 11 deaths from ruptured ectopic pregnancy: 7 were located in the extrauterine tube and 4 in the interstitial portion of the tube (cornual pregnancy). Cornual pregnancy accounts for 2 4% of ectopic pregnancies and is said to have a mortality rate in the range of 2.0 2.5%.

The interstitial part of the fallopian tube is the proximal portion that lies within the muscular wall of the uterus. It is 0.7 mm wide and approximately 1 2 cm long, with a slightly tortuous course, extending obliquely upward and outward from the uterine cavity. Pregnancies implanted in this site are called interstitial (cornual) pregnancies.2 They pose a significant diagnostic and therapeutic challenge and carry a greater maternal mortality risk than ampullary ectopic pregnancy. Because of myometrial distensibility, they tend to present relatively late, at 7 12 weeks of gestation. Significant maternal haemorrhage leading to hypovolaemia and shock can rapidly result from cornual rupture.Diagnosis

Clinically, risk factors are as for other types of ectopic pregnancy: contralateral salpingectomy, previous ectopic pregnancy and in vitro fertilisation.2 Because of its location, early diagnosis of cornual pregnancy has historically been difficult. The eccentric position of the gestational sac and thinning of the myometrial mantle means that differentiation between eccentric intrauterine and cornual pregnancy is often difficult.3 The rate of diagnosis can be improved, however, with transabdominal or transvaginal ultrasound (Figure 1), using three criteria:Figure 1. Open FigureDownload Powerpoint slide

Coronal endovaginal image of right cornual region (complex cystic mass with an echogenic rim compatible with a gestational sac, located close to the uterus. The myometrium does not completely surround the gestational sac).1an empty uterus;2a gestational sac seen separately and 1 cm from the most lateral edge of the uterine cavity and;3a thin myometrial layer surrounding the sac.4

The gestational sac is usually in the lateral portion of the uterus early in gestation but in advanced cornual pregnancy it can be located above the uterine fundus and can be confused with an eccentric intrauterine pregnancy. This is referred to as the interstitial line sign.5 A thin echogenic line extends directly up to the centre of the cornual gestational sac: this represents either the endometrial cavity or the interstitial portion of the fallopian tube, depending on the size of the cornual pregnancy (Figure 2).Figure 2. Open FigureDownload Powerpoint slide

Transverse image of a cornual ectopic pregnancy. The uterus is outlined by arrowheads and the ectopic is outlined by arrows. There is a small pseudogestational sac in the endometrial cavity. (Reproduced by permission of the University of Florida.)

Care must be exercised to avoid misinterpreting a normal intrauterine pregnancy in an anomalous (bicornuate or septate) uterus as a cornual pregnancy. With 2 dimensional scanning in a sagittal plane, the endometrial cavity will appear shorter and then longer for a bicornuate uterus but will remain the same length for cornual ectopic pregnancy. It is also important to count the number of corpora lutea. Heterotopic pregnancy is not possible when there is a single corpus luteum. Asymmetrically increased low resistance flow in a uterine cornu can also be a secondary sign of cornual pregnancy.

Features that are helpful with the use of 3 dimensional TVS include a live embryo in a gestational sac, surrounded by myometrium below the cornu lying outside the endometrium.6

One study7 has shown that early diagnosis of cornual pregnancy with TVS allows for first trimester conservative management with methotrexate. If the diagnosis is made later in gestation, however, surgical treatment with cornual resection, or even hysterectomy, may be required.

Tulandi et al.2 reviewed the management of 32 reported cases of cornual pregnancy. Ultrasound revealed an ectopic cornual gestational sac in 40.6% of the women and a hyperechoic mass in the cornual region in another 25%. The diagnosis was established in 71.4% of the 32 women. A sensitivity of 80% and specificity of 99% have been reported.

Four dimensional volume contrast imaging with coronal plane technology provides scan planes inaccessible by conventional 2 dimensional scanning, with enhanced tissue contrast resolution in the region of interest. This new ultrasound technique, although not yet widely available, has the potential to provide a more accurate image, particularly when 2 dimensional TVS fails to differentiate between cornual and angular pregnancy.8 In angular pregnancy the embryo is implanted in the lateral angle of the uterine cavity, medial to the uterotubal junction and round ligament. Angular pregnancy must be distinguished from cornual pregnancy, in which the embryo is implanted lateral to the round ligament.

Another diagnostic aid is laparoscopy, which has the advantage of allowing both diagnosis and treatment.

Petersen et al.9 reported a case of uterine cornual rupture following attempted mid trimester induced abortion for (presumed) intrauterine pregnancy. They stated that physicians should consider ectopic pregnancy when attempts at induced abortion do not succeed. Similarly, the CEMACH report (1994 96)10 supplied details of maternal death from a ruptured cornual pregnancy at 9 weeks of gestation. The woman underwent suction curettage for termination of pregnancy twice. With improved ultrasound facilities, combined with clinical expertise, these cases of missed or delayed diagnosis should become less frequent.Treatment

Traditionally, the treatment of cornual pregnancy has been hysterectomy or cornual resection at laparotomy. As all surgical management has been associated with morbidity and unfavourable effects on fertility, more conservative approaches have been introduced into clinical practice. Medical treatment (as with other types of tubal pregnancy) has been introduced with generally satisfactory results. See Box 1.(Box 1 )

Surgical treatment consists of conservative techniques, such as laparoscopic cornual resection, laparoscopic cornuostomy or hysteroscopic removal of interstitial ectopic tissue, and radical operations such as hysterectomy. Radical surgery is necessary in cases where haemorrhage is life threatening.11 Surgical treatment involving resection of the involved cornual region is associated with decreased fertility rates and increased rates of uterine rupture in future pregnancies.12

Because of the abundant blood supply in the cornual region from both uterine and ovarian vessels, rupture occurring after 12 weeks of gestation often leads to severe haemorrhage and even death. Laparotomy used to be the preferred approach for treatment of ruptured cornual pregnancy, especially when it happens in advanced gestation (Table 1).9,15,19 22 Khawaja et al.21 reported a unique method of management for ruptured cornual gestation, using uterine artery ligation to conserve the uterus. The authors suggested that ipsilateral uterine artery ligation should be performed before attempting to repair a ruptured uterine cornu. This will help to achieve haemostasis and allow time to repair the cornu.Table 1. Outcome of ruptured cornual pregnancyLaparoscopic techniques

In general, laparoscopic techniques involve cornual resection, cornuostomy, salpingostomy or salpingectomy. Even in women with ectopic pregnancy with a significant haemoperitoneum, laparoscopic surgery has been safely conducted by experienced laparoscopists, with intraoperative autologous blood transfusion if haemodynamic stability is achieved by perioperative management.11,23

Initial laparoscopic procedures involved loss of tubal continuity by cornual excision. Hill et al.23 described a woman who presented at 10 weeks of gestation with a large unruptured cornual pregnancy. After placing an Endoloop (Ethicon Endosurgery, Edinburgh, UK) around the cornu, the authors were able to evacuate the pregnancy using unipolar current and blunt dissection. Both Tulandi et al.24 and Reich et al.25 used laparoscopic cornual excision to manage cornual pregnancy. Cornual excision has also been useful for the treatment of ruptured cornual pregnancy.13

Trends toward less extensive laparoscopic procedures are evident in further case reports using cornuostomy (Table 2).26,27 Most authors agree that the size of cornual gestation determines the best laparoscopic approach. Tulandi24 reported that salpingostomy is appropriate for gestations of 3.5 cm, whereas cornual excision was recommended by Grobman et al.29 for gestations of 4 cm. In an uncontrolled retrospective study, Moon et al.32 reported that The endoloop method and the encircling suture method are simple, safe, effective, and nearly bloodless . There were no uterine ruptures in the pregnancies following these methods of endoscopic management.Table 2. Summary of reported cases of laparoscopic treatment of cornual pregnancy

A laparoscopic approach should only be attempted if the surgeon is skilled in laparoscopic techniques and has the ability to convert the operation quickly to a laparotomy.29 If these conditions are met, laparoscopy provides several advantages over laparotomy: fewer postoperative hospital days, a faster return to normal activity and decreased healthcare costs. In many centres laparoscopic surgery alone is quicker than laparoscopy followed by laparotomy. However, in general, laparoscopic surgery requires more overall theatre time because of the need to set up the equipment.Hysteroscopic management

The rationale behind this approach is to avoid more extensive surgery. It can be particularly suitable for women who are reluctant to undergo medical treatment with methotrexate or in whom this treatment fails or is unavailable.33

Minelli et al.34 stated that, in expert hands, resection of the cornual endometrium, including the tubal ostium, can be successfully performed without perforation of the uterus. The authors concluded that operating interstitially was safe because the resection was performed under laparoscopic control.

A search of the literature revealed three cases of cornual pregnancy managed using a hysteroscopic approach. In one case,35 the products of conception were removed with forceps using an operating hysteroscope under laparoscopic guidance. In the second case,36 the sac was perforated under hysteroscopic control and the products of conception removed with polyp forceps under sonographic guidance. This procedure was done following the failure of systemic methotrexate. The third case33 used a combination of all three modalities of hysteroscopy, laparoscopy and ultrasound. The management here consisted of identifying and perforating the sac under hysteroscopic control and injecting dilute vasopressin solution into the uterine cornu around the pregnancy through a laparoscopic accessory port to reduce the risk of haemorrhage. To minimise the possibility of leaving retained products of conception in the cornu, a laparoscopically controlled suction evacuation of the pregnancy was performed. A flexible suction cannula was inserted under ultrasound control and the pregnancy aspirated under direct laparoscopic vision to prevent perforation.Medical treatment

See Box 2. Systemic methotrexate is a safe and highly effective treatment for cornual pregnancy. Surgery can be avoided in the majority of women. Early recognition of the cornual pregnancy is essential.(Box 2 )

In a prospective observational study7 at St George's Hospital Medical School in London, 17 out of 20 women with cornual pregnancy were treated with single dose intramuscular methotrexate, which was administered on day 0. A second dose of methotrexate was given if the human chorionic gonadotrophin (hCG) levels had not fallen by 15% between days 4 and 7. Sixteen (94%) were treated successfully, including all of the 4 cases with fetal heart activity present. A second methotrexate dose was given to 6 women.

Many studies have focused on the use of local injection of methotrexate into the interstitial gestation, either transvaginally or laparoscopically, and both provide highly effective methods of administration. One of the arguments for the local administration of methotrexate has been its favourable side effect profile. However, this has been based on comparisons with multiple systemic dose regimes. The effectiveness of single dose systemic methotrexate and, more importantly, its side effect profile, was demonstrated by Stovall and Ling37 in the treatment of tubal gestations. Of 120 women receiving single dose systemic methotrexate, side effects were virtually eliminated, while the efficacy was equal to that of multiple systemic dose regimes. The systemic route of administration offers advantages over local injection of the ectopic gestation in that it is less invasive and not operator dependent. Follow up may need to be prolonged after medical treatment of cornual pregnancy, as initial hCG values tend to be higher than those encountered with tubal ectopic pregnancy.

The Royal College of Obstetricians and Gynaecologists recommends38 that the women with tubal pregnancy who are most suitable for methotrexate therapy are those with a serum hCG level of 3000 iu/l and with minimal symptoms. In the previously discussed series, all women with cornual pregnancy presenting with initial hCG values of 5000 iu/l were treated successfully with single dose methotrexate, but almost all women with an initial hCG of 5000 iu/l required two doses. These data help with counselling women regarding the likelihood of needing a second dose of methotrexate to achieve a successful outcome. Alternatively, this latter group may benefit from alternative dose strategies from the outset or from local administration of methotrexate.

In those cases with higher hCG values there is controversy over whether inpatient or outpatient follow up should be used. The latter is suitable in a dedicated early pregnancy unit with clear guidelines and open access for admission when indicated.

Methotrexate has been given by intramuscular injection in most studies in the literature. However, the intravenous route has also been used successfully.39

Medical treatment is not free of complications: it can be associated with uterine rupture and catastrophic haemorrhage. A large ectopic pregnancy and the presence of a heartbeat are relative contraindications to medical treatment.Ultrasound or laparoscopic guided medical treatment

The main advantages of local injection of methotrexate include smaller drug dosage, fewer systemic side effects and higher tissue concentration. Many types of unruptured live ectopic pregnancy can be successfully managed without surgical intervention through TVS guided local injection of potassium chloride or methotrexate. In a series of consecutive cases (4 of cornual pregnancy out of a total of 18 different ectopic sites), Monteagudo et al.40 described immediate cessation of fetal cardiac activity with potassium chloride or methotrexate injection. The mean initial hCG level was 33 412 iu/l. There was no difference in time to resolution of the ectopic pregnancies between those treated with potassium chloride and those treated with methotrexate. The same group reported a 100% success rate. They used a TVS guided route of local methotrexate injection by traversing the myometrium and approaching the gestational sac from the medial aspect, a technique that may enable the wider use of this treatment modality by lowering the complication rate caused by bleeding at the puncture site if the lateral approach is used.41

Heterotopic pregnancy remains an indication for local injection of potassium chloride.7 Both transvaginal and transabdominal ultrasound can be used for guided medical treatment. This ablates the ectopic pregnancy, permitting normal continuation of a concomitant intrauterine pregnancy and preserving the uterus for subsequent pregnancies.42

Many studies43,44 have reported the use of laparoscopy for local methotrexate injection into a cornual pregnancy. Onderoglu et al.44 reported the successful management of a cornual pregnancy with a single high dose laparoscopic methotrexate injection (100 mg). Considering the rarity of cornual pregnancy, a comparative study between systemic and laparoscopic methotrexate would be difficult. The best medical treatment regimen, therefore, remains unknown.

Further non surgical interventions after medical treatment have been advocated to abolish or minimise any risk of bleeding or rupture. Selective uterine artery embolisation associated with methotrexate (or after methotrexate failure) can be used successfully in treating selected cases of early cornual pregnancy.45 This procedure, combined with methotrexate, could reduce haemorrhagic risk.Expectant management

Few reports in the literature contemplate this approach, although Kok Min Seow et al.46 reported a case of cornual pregnancy followed up by serial transvaginal colour power Doppler angiography and serum beta hCG levels.

In contrast with other types of ectopic pregnancy, this management is out of favour with most authorities. The high risk of complications, which include uterine rupture and massive internal bleeding, make expectant management an unsafe approach.Future pregnancy

One of the concerns of future pregnancy is rupture of the interstitial portion of the tube (uterine rupture). The postulated mechanism is through a defective area of uterine wall.47

Uterine rupture was described at 20 weeks of gestation in a woman who had cornual pregnancy treated by salpingectomy and at 24 weeks in another after spontaneous resolution of the interstitial pregnancy.48,49 Some authorities, therefore, suggest suturing the uterine wall after surgical management to reinforce the defective area in the uterine wall. Term deliveries have, however, been reported following laparoscopic treatment of cornual pregnancy without reinforcing sutures.27,32 If myomectomy (open or laparoscopic) is performed, suturing the uterine wound may not prevent uterine rupture in subsequent pregnancy.50

There is general agreement that suturing the uterine wall should be performed in cases where the cornual pregnancy sac extends into the endometrial cavity. Long term follow up studies of women without endometrial cavity involvement treated by laparoscopic surgery may reveal the optimum way to manage the uterine wound after cornual resection and cornuostomy. Most authors are agreed that caesarean section should be the optimum mode of delivery for all pregnancies following cornual pregnancy.11

The second concern after conservative management of cornual pregnancy is recurrence of ectopic pregnancy, particularly cornual pregnancy on the same side. This risk continues even after a good anatomical result (whether assessed by hysterosalpingography or direct laparoscopic visualisation) following laparoscopic conservative surgery.27

Tubal pathology is often the primary factor blamed for recurrence. Weiden and Karsdorp51 reported a case of recurrence after previous heterotopic pregnancy in which the cornual pregnancy was treated by selective feticide. Tubal pathology, together with assisted conception and non invasive management of cornual pregnancy, have been shown to contribute to a higher risk of recurrence of cornual pregnancy.51 Wittich52 reported an association of recurrent ectopic pregnancy with uterine fibroids. In general, the available literature provides conflicting guidance as to appropriate counselling regarding future pregnancy risks and optimum mode of delivery.Conclusion

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