Aust NZ J Obstet Gynaecol
1992; 32: 4: 371
Ultrasound Diagnosis and Laparoscopic Excision of an Interstitial Ectopic Pregnancy Carl Wood’ and Victor Hurley’ Department of Obstetrics and Gynaecologj Monash University’and Ultrasound Services, Infertility Medical Centre2,Melbourne
EDITORIAL COMMENT: We accepted this case report as readers may well marvel at the elegant details of careful removal of an interstitialpregnancy at laparoscopy. The procedure seems brave since the editor can recall being called by the junior author of this paper to lend a hand in a case of ruptured interstitial pregnancy with frightening haemorrhage at laparotomy - in this case ergometrine lessened the bleeding that was then controlled by a mattress suture in the uterine wall. Dr Eric Bieber from Chicago delivered an interesting account of laparoscopic management of ectopic pregnancy in Melbourne in May, 1992, and strongly emphasized a point about the pathology of tubal ectopic pregnancy which seems important and was new to his audience - namely that the pregnancy usually lies outside the tubal lumen having distended not the tube but the outer layer of the tubal wall beneath the peritoneum. This apparently explains how an ectopic pregnancy can be incised and evacuated without affecting tubal patency in a high proportion of cases. Our editorial committee would welcome a contribution giving details of this concept and its relevance to the success of conservative treatment of unruptured ectopic pregnancy.
Summary: Interstitial tubal pregnancy occurs in about 5% of ectopic tubal pregnancies and is associated with an increased risk of severe haemorrhage (1). Diagnosis prior to rupture of the pregnancy into the peritoneal cavity is very important to avoid haemorrhage. Its presence has been considered to be a contraindication to laparoscopic surgery (2), although most ectopic pregnancies can be managed laparoscopically by an experienced endoscopist. We report the diagnosis of a n interstitial pregnancy by ultrasound before rupture and treatment by laparoscopic excision of the pregnancy. CASE REPORT A 27-year-old patient presented at approximately 6 weeks amenorrhoea with mid right-sided pelvic pain. The patient’s history included an ectopic pregnancy 10 years ago, which was treated by removal of the left tube. A diagnostic laparoscopy 7 years ago showed no abnormalities and a patent right tube. Two years ago, menstrua1 pain led to a provisional diagnosis of endometriosis which was confirmed by laparoscopy; the endometriosis was treated by electrocautery, danazol and other progestogens. A further laparoscopy one year ago revealed a patent right tube, the tubal opening pressure being above normal, 200 mmHg, and no endometriosis. A 2 cm cyst of the distal end of the tube was removed at laparoscopy. Quantitative plasma HCG assay was performed (first IRP) and the level was found 1. Chairman. 2. Director. Address for correspondence: Professor C. Wood, Department of Obstetrics and Gynaecology, Monash Medical Centre, 246 Clayton Road, Clayton, Victoria, 3168.
to be 1.1 IU/L. A transvaginal ultrasound examination was performed (Acuson, Mountain View, California). The uterus contained a 9 mm prominent endometrium but no intrauterine gestation sac was identified. No ectopic gestation was identified and there was no corpus luteum seen in either ovary. A small quantity of free fluid was noted adjacent to the left ovary. In view of continuing pain and the concern that an ectopic pregnancy might be present, diagnostic laparoscopy was performed. The Fallopian tubes, uterus and adnexa were reported as normal. The patient presented to 1 of the authors (CW) 2 weeks later with persistent pregnancy symptoms and right-sided pelvic pain. The level of plasma HCG had risen to 24 IU/L. A transvaginal ultrasound examination was performed and this identified a right interstitial ectopic pregnancy and intact gestation sac with surrounding trophoblast ring in the region of the interstitial portion of the right Fallopian tube. There was marked distortion of the outline of the uterus with a prominent bulging of the pregnancy into the right adnexa. Only 3 mm of myometrium separated the trophoblast from the serosal surface of the uterus (figure 1). The patient was noted to be extremely tender in the
372
AUST.AND N.Z. J O U R N AOF L OBSTETRICS A N D
Figure 1. Transverse ultrasonogram at the level of the uterine fundus. The upper uterine body and cavity are seen on the right with the bulging interstitial pregnancy on the left.
region of the pregnancy raising the concern of an imminent rupture. No yolk sac, fetal pole or fetal heart movements were present. A corpus luteum was noted in the left ovary. The patient was offered ultrasound-guided needling with methotrexate injection into the gestation sac (4) but because certainty of cure could not be offered, the patient preferred surgical removal. The pregnancy was excised laparoscopically. Vasopressin, 1 A O O dilution, was injected into the myometrium and broad ligament surrounding the pregnancy. Because severe bleeding may be associated with removal of interstitial pregnancy, the right ascending uterine vessels were cauterized with bipolar diathermy after mobilizing the inner isthmic portion of the Fallopian tube. The pregnancy was excised using needle unipolar and bipolar diathermy. Pathology confirmed the operative diagnosis. One litre of Hartmann solution was placed in the peritoneal cavity. Blood loss was < 50 ml. The patient left hospital 24 hours later and returned to work 1 week after surgery. DISCUSSION The combination of transvaginal ultrasound techniques and sensitive quantitative HCG assays has increased the sensitivity of detection of ectopic pregnancy. Previously, using abdominal full bladder ultrasound techniques, the diagnosis was presumed when no intrauterine pregnancy was demonstrated in a patient known to be 6 weeks pregnant or more. Only rarely was the ectopic pregnancy actually visualized ultrasonographically and the definitive diagnosis made. The diagnosis was generally made at laparoscopy or laparotomy. Many authors have now reported sensitivities in the range of 8599% for the detection and positive identification of
GYNAEC'OIOGY
tubal ectopic pregnancy using the combination of sensitive assays and vaginal ultrasound. Moreover, the diagnosis is now made more frequently at an earlier preclinical stage prior to rupture enabling more conservative treatment modalities to be employed such as the case presented here (4,5). Laparoscopic removal of ectopic pregnancy has become the recommended surgical treatment, but some authors have stated that interstitial pregnancies should not be treated in this way because of the added risks of excessive bleeding. The use of Vasopressin does markedly reduce uterine or tubal bleeding and allow surgery with minimal blood loss. Because a large branch of the ascending uterine vessels may be involved in an interstitial pregnancy, postoperative bleeding would be likely after the effect of Vasopressin disappeared. Ligation of the ascending uterine vessels by bipolar cautery or suture would avoid such a hazard. The usual laparoscopic method of removing an ectopic pregnancy is to cut over the outer surface of the tube, irrigate and aspirate the ectopic pregnancy, and obtain haemostasis by laser or cautery (3). This method may be suitable for an interstitial pregnancy but was not used in the present case because of the serious risk of severe bleeding if a portion of the ectopic pregnancy remained in the tube. Laparoscopic suction removal has a small chance of failure and may not be suitable for routine removal of interstitial pregnancies. It is suggested that laparoscopic excision removal may be the optimal surgical method, copying the technique of laparoscopy but avoiding the morbidity associated with laparotomy. A similar operation has been reported in 1 other patient with interstitial ectopic pregnancy (6). The cause of the interstitial pregnancy was probably tubal stenosis as the tubal opening pressure at previous hydrotubation was high.
References 1. Paavonen J, Varjonen-Toivonen H, Kosulaines M, Heinones K. Diagnosis and management of tubal pregnancy. Int J Gynecol Obstet 1985; 23: 129. 2. O'Shea R. Ectopic pregnancy removal by laparoscopy. Presentation, New Gynaecological Operations, Hands-on Workshop. Monash Medical Centre, Monash University, Melbourne, February, 1991. 3. Verniesh M. Conservative management of ectopic gestation. Fertil Steril 1989; 51: 559-567. 4. Menard A, Crequat J, Mandelbrot L, Hanny J, Mandelenat P. Treatment of unruptured tubal pregnancy by local injection of methotrexate under transvaginal sonographic control. Fertil Steril 1990; 54: 47-50. 5. Meyer W, Mitchell D. Hysteroscopic Removal of an Interstitial Ectopic Gestation. A case report. J Reprod Med 1989; 34: 928-929. 6. Reich H, McGlynn F, Budin R, Tsoutsoplides C, DeCaprio J. Laparoscopic treatment of ruptured interstitial pregnancy. J Gynecol Surg 1990; 6: 135-138.
1992; 32: 4: 371
Ultrasound Diagnosis and Laparoscopic Excision of an Interstitial Ectopic Pregnancy Carl Wood’ and Victor Hurley’ Department of Obstetrics and Gynaecologj Monash University’and Ultrasound Services, Infertility Medical Centre2,Melbourne
EDITORIAL COMMENT: We accepted this case report as readers may well marvel at the elegant details of careful removal of an interstitialpregnancy at laparoscopy. The procedure seems brave since the editor can recall being called by the junior author of this paper to lend a hand in a case of ruptured interstitial pregnancy with frightening haemorrhage at laparotomy - in this case ergometrine lessened the bleeding that was then controlled by a mattress suture in the uterine wall. Dr Eric Bieber from Chicago delivered an interesting account of laparoscopic management of ectopic pregnancy in Melbourne in May, 1992, and strongly emphasized a point about the pathology of tubal ectopic pregnancy which seems important and was new to his audience - namely that the pregnancy usually lies outside the tubal lumen having distended not the tube but the outer layer of the tubal wall beneath the peritoneum. This apparently explains how an ectopic pregnancy can be incised and evacuated without affecting tubal patency in a high proportion of cases. Our editorial committee would welcome a contribution giving details of this concept and its relevance to the success of conservative treatment of unruptured ectopic pregnancy.
Summary: Interstitial tubal pregnancy occurs in about 5% of ectopic tubal pregnancies and is associated with an increased risk of severe haemorrhage (1). Diagnosis prior to rupture of the pregnancy into the peritoneal cavity is very important to avoid haemorrhage. Its presence has been considered to be a contraindication to laparoscopic surgery (2), although most ectopic pregnancies can be managed laparoscopically by an experienced endoscopist. We report the diagnosis of a n interstitial pregnancy by ultrasound before rupture and treatment by laparoscopic excision of the pregnancy. CASE REPORT A 27-year-old patient presented at approximately 6 weeks amenorrhoea with mid right-sided pelvic pain. The patient’s history included an ectopic pregnancy 10 years ago, which was treated by removal of the left tube. A diagnostic laparoscopy 7 years ago showed no abnormalities and a patent right tube. Two years ago, menstrua1 pain led to a provisional diagnosis of endometriosis which was confirmed by laparoscopy; the endometriosis was treated by electrocautery, danazol and other progestogens. A further laparoscopy one year ago revealed a patent right tube, the tubal opening pressure being above normal, 200 mmHg, and no endometriosis. A 2 cm cyst of the distal end of the tube was removed at laparoscopy. Quantitative plasma HCG assay was performed (first IRP) and the level was found 1. Chairman. 2. Director. Address for correspondence: Professor C. Wood, Department of Obstetrics and Gynaecology, Monash Medical Centre, 246 Clayton Road, Clayton, Victoria, 3168.
to be 1.1 IU/L. A transvaginal ultrasound examination was performed (Acuson, Mountain View, California). The uterus contained a 9 mm prominent endometrium but no intrauterine gestation sac was identified. No ectopic gestation was identified and there was no corpus luteum seen in either ovary. A small quantity of free fluid was noted adjacent to the left ovary. In view of continuing pain and the concern that an ectopic pregnancy might be present, diagnostic laparoscopy was performed. The Fallopian tubes, uterus and adnexa were reported as normal. The patient presented to 1 of the authors (CW) 2 weeks later with persistent pregnancy symptoms and right-sided pelvic pain. The level of plasma HCG had risen to 24 IU/L. A transvaginal ultrasound examination was performed and this identified a right interstitial ectopic pregnancy and intact gestation sac with surrounding trophoblast ring in the region of the interstitial portion of the right Fallopian tube. There was marked distortion of the outline of the uterus with a prominent bulging of the pregnancy into the right adnexa. Only 3 mm of myometrium separated the trophoblast from the serosal surface of the uterus (figure 1). The patient was noted to be extremely tender in the
372
AUST.AND N.Z. J O U R N AOF L OBSTETRICS A N D
Figure 1. Transverse ultrasonogram at the level of the uterine fundus. The upper uterine body and cavity are seen on the right with the bulging interstitial pregnancy on the left.
region of the pregnancy raising the concern of an imminent rupture. No yolk sac, fetal pole or fetal heart movements were present. A corpus luteum was noted in the left ovary. The patient was offered ultrasound-guided needling with methotrexate injection into the gestation sac (4) but because certainty of cure could not be offered, the patient preferred surgical removal. The pregnancy was excised laparoscopically. Vasopressin, 1 A O O dilution, was injected into the myometrium and broad ligament surrounding the pregnancy. Because severe bleeding may be associated with removal of interstitial pregnancy, the right ascending uterine vessels were cauterized with bipolar diathermy after mobilizing the inner isthmic portion of the Fallopian tube. The pregnancy was excised using needle unipolar and bipolar diathermy. Pathology confirmed the operative diagnosis. One litre of Hartmann solution was placed in the peritoneal cavity. Blood loss was < 50 ml. The patient left hospital 24 hours later and returned to work 1 week after surgery. DISCUSSION The combination of transvaginal ultrasound techniques and sensitive quantitative HCG assays has increased the sensitivity of detection of ectopic pregnancy. Previously, using abdominal full bladder ultrasound techniques, the diagnosis was presumed when no intrauterine pregnancy was demonstrated in a patient known to be 6 weeks pregnant or more. Only rarely was the ectopic pregnancy actually visualized ultrasonographically and the definitive diagnosis made. The diagnosis was generally made at laparoscopy or laparotomy. Many authors have now reported sensitivities in the range of 8599% for the detection and positive identification of
GYNAEC'OIOGY
tubal ectopic pregnancy using the combination of sensitive assays and vaginal ultrasound. Moreover, the diagnosis is now made more frequently at an earlier preclinical stage prior to rupture enabling more conservative treatment modalities to be employed such as the case presented here (4,5). Laparoscopic removal of ectopic pregnancy has become the recommended surgical treatment, but some authors have stated that interstitial pregnancies should not be treated in this way because of the added risks of excessive bleeding. The use of Vasopressin does markedly reduce uterine or tubal bleeding and allow surgery with minimal blood loss. Because a large branch of the ascending uterine vessels may be involved in an interstitial pregnancy, postoperative bleeding would be likely after the effect of Vasopressin disappeared. Ligation of the ascending uterine vessels by bipolar cautery or suture would avoid such a hazard. The usual laparoscopic method of removing an ectopic pregnancy is to cut over the outer surface of the tube, irrigate and aspirate the ectopic pregnancy, and obtain haemostasis by laser or cautery (3). This method may be suitable for an interstitial pregnancy but was not used in the present case because of the serious risk of severe bleeding if a portion of the ectopic pregnancy remained in the tube. Laparoscopic suction removal has a small chance of failure and may not be suitable for routine removal of interstitial pregnancies. It is suggested that laparoscopic excision removal may be the optimal surgical method, copying the technique of laparoscopy but avoiding the morbidity associated with laparotomy. A similar operation has been reported in 1 other patient with interstitial ectopic pregnancy (6). The cause of the interstitial pregnancy was probably tubal stenosis as the tubal opening pressure at previous hydrotubation was high.
References 1. Paavonen J, Varjonen-Toivonen H, Kosulaines M, Heinones K. Diagnosis and management of tubal pregnancy. Int J Gynecol Obstet 1985; 23: 129. 2. O'Shea R. Ectopic pregnancy removal by laparoscopy. Presentation, New Gynaecological Operations, Hands-on Workshop. Monash Medical Centre, Monash University, Melbourne, February, 1991. 3. Verniesh M. Conservative management of ectopic gestation. Fertil Steril 1989; 51: 559-567. 4. Menard A, Crequat J, Mandelbrot L, Hanny J, Mandelenat P. Treatment of unruptured tubal pregnancy by local injection of methotrexate under transvaginal sonographic control. Fertil Steril 1990; 54: 47-50. 5. Meyer W, Mitchell D. Hysteroscopic Removal of an Interstitial Ectopic Gestation. A case report. J Reprod Med 1989; 34: 928-929. 6. Reich H, McGlynn F, Budin R, Tsoutsoplides C, DeCaprio J. Laparoscopic treatment of ruptured interstitial pregnancy. J Gynecol Surg 1990; 6: 135-138.
