Ectopic Pregnancy—Laparotomy Case File

Ectopic Pregnancy—Laparotomy Case File

Eugene C. Toy, MD, Konrad P. Harms, MD, Keith O. Reeves, MD, Cristo Papasakelariou, MD, FACOG

Case 15

A 29-year-old G4P1021 Hispanic woman at 11 weeks’ gestation presents to the ED with a complaint of abdominal pain and vaginal bleeding that began 4 hours ago. She has a past obstetrical history significant for pelvic inflammatory disorder 10 years prior (treated as an outpatient) and two spontaneous first-trimester miscarriages both treated with dilation and curettage of the uterus. The patient reports an uneventful spontaneous vaginal delivery of her son 18 months ago. She has not seen a physician yet for this pregnancy, but reports no abnormalities before this morning. The pain started this morning abruptly along with the vaginal bleeding. She reports dizziness, but denies syncope. Vaginal bleeding is the same as her menses. The vital signs taken at intake in the ED were BP 80/40 mm Hg and HR 110 beats/min. Her hemoglobin level was 6.7 g/dL and quantitative β human chorionic gonadotropin (β-hCG) level was 16,000 mIU/mL. Pelvic transvaginal ultrasound reveals an empty uterine cavity, possible chorionic sac near the cornual region of the uterus, and a moderate amount of free fluid in the cul-de-sac.

➤ What is the most likely diagnosis?

➤ What is your next step?

➤ What interventions are undertaken with this diagnosis?

ANSWER TO CASE 15:

Ectopic Pregnancy—Laparotomy

Summary: This is a 29-year-old G4P1021 woman at 11 weeks’ gestation with abdominal pain and vaginal bleeding. She is hypotensive, and has ultrasonographic and clinical evidence of an abnormal pregnancy and intra-abdominal hemorrhage.

➤ Most likely diagnosis: Ruptured interstitial pregnancy.

➤ Next step: Surgical intervention.

➤ Interventions: Exploratory laparotomy versus operative laparoscopy.

ANALYSIS

Objectives

1. Be able to diagnose an interstitial pregnancy.
2. Be familiar with management options for interstitial pregnancy.
3. Be familiar with the surgical techniques employed to treat this condition.

Considerations

This is a 29-year-old G4P1021 Hispanic woman at 11 weeks’ gestation presents with a complaint of abdominal pain and vaginal bleeding. Suspicion of an abnormal pregnancy was confirmed by pelvic ultrasound. Ultrasound demonstrated an empty uterine cavity and a separate chorionic sac near the cornual region of the uterus. The patient’s vital signs and ultrasound finding of free fluid in the posterior cul-de-sac suggest a ruptured ectopic pregnancy.

Initially, it is crucial for the physician to assess the hemodynamic stability of the patient. This is generally screened by orthostatic blood pressure readings, J-V distension, capillary refill time, skin turgor, and laboratory readings. In cases such as acute hemorrhage, the complete blood (cell) count (CBC) level of hemoglobin may not have equilibrated with the actual blood loss amount since the patient is bleeding whole blood. A normal hemoglobin in this patient may be falsely reassuring. Internal bleeding is suggested by the free fluid seen in the posterior cul-de-sac on ultrasound as well as the patient’s stating that she feels light-headed. Abdominal examination may reveal tenderness to palpation and rebound tenderness suggestive of peritoneal irritation from blood in the abdominal cavity.

Identifying the location of the pregnancy in a patient presenting with abdominal complaints and a positive pregnancy test is essential. In the case of this patient, a pelvic ultrasound was performed. No intrauterine pregnancy was visualized, and a separate chorionic sac near the cornual region was seen. These findings suggest an abnormal pregnancy in the interstitial region. Ruptured interstitial (cornual) ectopic pregnancy in a patient who demonstrates hemodynamic instability necessitates operative management. The patient’s wishes for future fertility must be addressed before proceeding with surgical management. Surgical options include laparoscopic management, but are reserved for the more stable patient and dependent on surgeon experience. Generally, in an unstable patient, time is of the essence and exploratory laparotomy is the method of choice.

APPROACH TO

Ectopic Pregnancy—Laparotomy

DEFINITIONS

INTERSTITIAL PREGNANCY: Also known as cornual ectopic pregnancy. Pregnancy implantation within the tubal segment that penetrates the uterine wall.

INTERSTITIAL LINE SIGN: Ultrasonographic term used to describe the visualization of an echogenic line extending from the endometrial cavity into the cornual region and abutting the interstitial mass or gestational sac.

ANGULAR PREGNANCY: Embryo implantation in the lateral angle of the uterine cavity medial to the internal ostium of the fallopian tube.

CLINICAL APPROACH

Interstitial pregnancy (cornual ectopic pregnancy) is an implantation of a pregnancy within the tubal portion piercing the wall of the uterus. This form of ectopic pregnancy accounts for only 2% to 3% of all ectopic locations.1 Overlooking this form of ectopic pregnancy due to the rarity is dangerous due to the rich arterial blood supply from the ovarian and uterine arteries at this location.

Differentiation between an interstitial and angular pregnancy must be determined. Angular pregnancy occurs when an embryo implants in the lateral angle of the uterine cavity medial to the internal ostium of the fallopian tube. Angular pregnancies may lead to asymmetric and symptomatic enlargement of the uterus that may be misinterpreted as a cornual ectopic pregnancy. Differentiation may further be clouded by a pregnancy in a septated or bicornuate uterus. Laparoscopy may be needed to further evaluate the anatomy.

As compared to other ectopic pregnancies, interstitial pregnancies are associated with a high maternal morbidity. This is largely because presentation of an interstitial pregnancy generally occurs later than a classic ectopic pregnancy, they are difficult to diagnose, and they frequently present with massive intraperitoneal hemorrhage when ruptured. The delayed rupture is due to the denser tissue (myometrium) surrounding the gestation in the interstitium as compared to the thinner tubal segment allowing greater distensibility. Thus, diagnosis generally occurs around 10 to 14 weeks. Rupture may not occur until 16 weeks. Because of the unfortunate location of the interstitial segment of the tube in a richly vascularized location, initial presentation may be profound shock. Vaginal bleeding may be a presenting symptom with or without abdominal pain in women presenting with an unruptured cornual ectopic pregnancy. Evidence of acute-onset abdominal pain combined with a positive pregnancy test necessitates an evaluation of the location of the pregnancy in most instances.2,3

Risk factors for interstitial pregnancies are generally the same as for all ectopic pregnancies. These include a history of PID, previous pelvic surgery, previous ectopic pregnancy, and the use of assisted reproductive technology (ART) (ovulation induction or in vitro fertilization). PID and prior pelvic surgery may damage the tubes and create areas of blockage or stricture that may predispose improper implantation.2,3 A unique risk factor for interstitial implantation is ipsilateral salpingectomy. This occurs in 25% to 37.5% of patients with cornual ectopics.4

Diagnosis

Diagnosis of interstitial pregnancies is similar to that with other tubal ectopic pregnancies. Ultrasonographic evidence along with clinical clues often suggests the diagnosis. Symptoms seen include acute abdominal pain, intraperitoneal bleeding, low hematocrit, and a positive pregnancy test. Further testing includes pelvic ultrasound and quantitative β-hCG. Timor-Tritsch et al.5 described the following transvaginal ultrasound criteria for interstitial pregnancy:

1. An empty uterine cavity

2. A chorionic sac seen separately and measuring less than 1 cm from the most lateral edge of the uterine cavity

3. A thick myometrial layer surrounding the chorionic sac

Specificity for these criteria was 88% to 93%, while sensitivity was only 40%. The “interstitial line sign” has been used by some in diagnosis of cornual ectopic and differentiation from angular pregnancies.6 This term refers to the visualization of an echogenic line extending from the endometrial cavity into the cornual region and abutting the interstitial mass or gestational sac. Ackerman et al.7 have claimed 80% sensitivity and 98% specificity, using the “interstitial line sign” in diagnosis of interstitial pregnancy. Tulandi and Al-Jaroudi8 demonstrated diagnosis by ultrasound in 71.4% of patients.

Treatment Options

Treatment options include medical management and surgical resection (laparoscopic vs laparotomy). The patient’s wishes for future childbearing and the amount of damage to the uterus must be taken into account when deciding on a treatment course. First reported by Tanaka et al.9 and subsequently by Lau and Tulandi,10 methotrexate has been utilized to treat unruptured interstitial pregnancies. Lau and Tulandi10 reported an 83% success rate with this modality. Local administration via laparoscopic or hysteroscopic administration versus systemic administration of methotrexate have been described. Success with local administration is reported to be 91% versus 79% for systemic. Treatment with methotrexate also requires a compliant patient who will follow up in order to follow serum β-hCG levels.11

Medical management with methotrexate and laparoscopic surgical treatment options have a common variable of a hemodynamically stable patient. Moon et al.12 demonstrated that vasopressin and electric cauterization methods for bleeding control and cornual incision, encircling suture before evacuation of the conceptus methods, and endoloop before evacuation of the conceptus method, were similar in effectiveness in treating both ruptured and unruptured cornual pregnancies via laparoscopy. Traditional laparoscopic procedures have used cornual excision or a combination of approaches to remove the interstitial pregnancy. Hemostasis may be achieved by ligating the ascending branches of the uterine vessels via intra- or extracorporeal suturing or the gastrointestinal anastomosis (GIA) stapler.

Surgical Therapy

Surgical management of the hemodynamically unstable patient generally requires laparotomy. Two large bore IVs, availability of blood products, and fluid resuscitation are critical. Cornual resection and repair of the defect by laparotomy is the standard conservative surgical procedure for the interstitial pregnancy with an unruptured uterus. Hysterectomy may be necessary if a large uterine rupture has occurred or if the interstitial pregnancy is very large. If the pregnancy is deemed to be so advanced that repair of the cornu would be technically difficult or medically dangerous, hysterectomy may be the only option.13

The classic technique for excision of the interstitial pregnancy is via cornual resection and salpingectomy via laparotomy (Figure 15–1). Patients with extensive rupture may require an emergency hysterectomy for definitive treatment. The classic cornual resection would be the treatment of choice in the patient described in the above case presentation. There are numerous ways to perform a cornual resection, but all follow similar principles:

1. The ipsilateral tube must be removed from the mesosalpinx attempting to spare the ovary if possible (see see Figure 15–1, the ectopic is too large and involving the ovary necessitating oophorectomy; in Figure 15–2 and 15–3, the ovary is spared).

Figure 15–1. Salpingo-oophorectomy with resection of interstitial pregnancy.

2. Vasopressin may or may not be utilized to further help with hemostasis at the cornu. 

A mixture of 20 U of vasopressin with 30 mL of saline injected in the myometrial incision site may be performed.

3. The ascending uterine vessels are ligated nearest the cornu via a figure-of-eight suture (see Figure 15–1B).

4. In a V-shaped incision, the pregnancy is incised and the myometrium is approximated with a figure-of-eight closure utilizing an O delayed absorbable suture. Note the optional placement of a figure-of-eight suture below the cornual pregnancy prior to resection, allowing quick hemostasis when resection performed as suture is already present and only needs to be tied (Figure 15–3).5 If necessary, the round ligament may be cut and resutured to the cornu and uterine serosa using interrupted sutures. Mattress

Figure 15–2. Resection tube from mesosalpinx.

sutures are utilized to bring the round and broad ligaments over the incision. Additional interrupted 2-O or 3-O delayed absorbable sutures are then utilized to secure the serosa of the round ligament to the serosa of the uterus. This last maneuver maintains the operative site in a permanent retroperitoneal position (see Figure 15–1C and D).

Uterine rupture is a possibility at the site of a prior interstitial pregnancy. The rates of rupture are currently not established. Maternal mortality rates attributed to cornual ectopic pregnancy are estimated at 2% to 2.5 % with the vast majority due to rupture and extensive hemorrhage. The risk of rupture with a subsequent pregnancy must be discussed with the patient when conservative (ie, nonhysterectomy) methods are employed.13-15

Figure 15–3. Cornual resection preserving the ovary.

Comprehension Questions

15.1 Which patient is most likely to have an interstitial pregnancy?

A. A 22-year-old African American G2P1001 woman at 6 weeks’ gestation with a history of Chlamydia treated 3 years ago

B. A 30-year-old Hispanic G1P0 woman at 22 weeks’ gestation with vaginal spotting

C. A 37-year-old Caucasian G2P1001 woman at 12 weeks’ gestation who has undergone ART

D. A 19-year-old Hispanic G2P0101 woman at 15 weeks’ gestation with a history of cocaine usage

15.2 A 30-year-old Caucasian G3P1102 woman at 8 weeks’ gestation has a transvaginal ultrasound showing evidence of an interstitial pregnancy measuring less than 1.5 cm. She is hemodynamically stable. Which is the best treatment for this patient?

A. Methotrexate

B. Wedge resection of uterus

C. Hysterectomy

D. Diagnostic peritoneal lavage

15.3 In which patient would laparoscopic treatment be a viable option?

A. A 17-year-old G2P0010 woman with sonographic evidence of free fluid in the posterior cul-de-sac and BP of 80/40.

B. A hemodynamically stable 33-year-old G3P0020 woman at 12 weeks’ gestation with no evidence of intrauterine pressure (IUP) on ultrasound and a 3-cm cornual gestational sac with a heartbeat.

C. An unstable 27-year-old G2P0100 woman at 10 weeks’ gestation who presents with a complaint of syncope and abdominal pain.

D. A 25-year-old G3P1102 woman at 14 weeks’ gestation with profuse vaginal bleeding, abdominal pain, and free fluid seen on ultrasound.

15.4 A hypotensive 38-year-old at woman 12 weeks’ gestation who has undergone ART presents to the ED with complaints of severe abdominal pain and vaginal bleeding. Exploratory laparotomy shows evidence of rupture of the uterus and extensive hemorrhage. What intervention may be necessary in this patient?

A. Uterine artery embolization

B. Cornual wedge resection

C. Hysterectomy

D. B-Lynch stitch

ANSWERS

15.1 C. Assisted reproductive technology has been the latest risk factor for interstitial pregnancies. IVF as well as ovulation induction techniques have been associated with cornual pregnancies. The incidence of heterotopic pregnancy in the ART population has been estimated at 1 in 100. Though controversial, conservative medical and surgical management approaches have been used in small published

series; Lau and Tulandi.10 followed nine cases conservatively resulting in two-thirds (six out of nine) of the intrauterine pregnancies delivering at term. Certainly, this should not be viewed as standard treatment, since massive hemorrhage has been described with these ectopic pregnancies. With increasing number of embryos transferred, the rate of interstitial heterotopic pregnancies climbs as well.

15.2 A. Methotrexate has been demonstrated as a viable option in the patient without evidence of uterine rupture. Systemic and direct administration via laparoscopy or hysteroscopy of methotrexate has been performed with an overall success rate of 83%. The patient must be counseled about the risks of uterine rupture with subsequent pregnancies if she opts for a conservative approach. Reliability of the patient must also be assessed. The patient must follow up for serial draws of β-hCG levels in order to monitor the response to methotrexate.

15.3 B. When choosing the correct surgical modality, the patient must be assessed as a whole. In each case an ectopic pregnancy is suspected. The patient in option B is hemodynamically stable and thus it would be a more suitable option for laparoscopic management. Uterine rupture is a relative contraindication to laparoscopic management. The extent of the rupture site is difficult to assess via ultrasound. Laparoscopic management has been described for cases of minimal rupture at the site of the cornual gestation. As with any surgical technique, the skill of the surgeon and the overall state of the patient must be fully taken into account before a modality is decided upon.

15.4 C. Conservative surgical management may be detrimental to the patient if a situation presents with severe uterine rupture. The rich blood supply to the uterus may necessitate removal of the uterus in order to achieve lifesaving hemostasis. The patient from question 15.4 has a uterine rupture and severe hemorrhage. The extent of damage to the uterus must be assessed as well as future childbearing wishes. Hysterectomy is viewed as a last resort, but may be necessary if bleeding is unable to be controlled via conservative efforts. The decision to proceed with laparotomy is the correct choice because of the hemodynamic instability.

Clinical Pearls

(See Table 1-2 for definition of level of evidence and strength of recommendation)

➤ Methotrexate is an option for management in the appropriately selected patient (Level B).

➤ Laparoscopic methods are viable options for treatment of both ruptured and unruptured interstitial pregnancies in the hemodynamically stable patient (Level B).

➤ Uterine rupture is a potential complication for subsequent pregnancies when conservative methods of treatment are utilized (Level C).

REFERENCES

1. Breen JL. A 21-year survey of 654 ectopic pregnancies. Am J Obstet Gynecol. 1970;106:1004. 

2. Cunningham FG, Leveno KJ, Bloom SL, Gilstrap III LC, Wenstrum KD. Ectopic pregnancy. In: Williams Obstetrics. 22nd ed. New York, NY: McGraw-Hill; 2005:253-272. 

3. Katz VL, Lentz GM, Lobo RA, Gershenson DM. Ectopic pregnancy. In: Comprehensive Gynecology. 5th ed. Philadelphia, PA: Mosby; 2007:389-415. 

4. Society for Assisted Reproductive Technology and American Society for Reproductive Medicine. Assisted reproduction technology in the United States: 2000 results generated from the American Society for Reproductive Medicine/ Society for Reproductive Technology Registry. Fertil Steril. 2004;81:1207. 

5. Timor-Tritsch IE, Monteagudi A, Matera C, et al. Sonographic evolution of cornual pregnancies treated without surgery. Obstet Gynecol. 1992;79:1044-1049. 

6. Auslender R, Arodi J, Pascal B, et al. Interstitial pregnancy: early diagnosis by ultrasonography. Am J Obstet Gynecol. 1983;146:717-718. 

7. Ackerman TE, Levi CS, Dashfesky SM. Interstitial line: sonographic finding in interstitial (cornual) ectopic pregnancy. Radiology. 1993;189:83-87. 

8. Tulandi T, Al-Jaroudi D. Interstitial pregnancy: results generated from the Society of Reproductive Surgeons registry. Obstet Gynecol. 2004;103:47-50. 

9. Tanaka T, Hayashi J, Kutsuzawa T, et al. Treatment of interstitial ectopic pregnancy with methotrexate: report of a successful case. Fertil Steril. 1982;37:851-852. 

10. Lau S, Tulandi T. Conservative medical and surgical management of interstitial ectopic pregnancy. Fertil Steril. 1999;72:207-215. 

11. Weissman A, Fishman A. Uterine rupture following conservative surgery for interstitial pregnancy. Eur J Obstet Gynecol Reprod Biol. 1992;44:237-239. 

12. Moon HS, Choi YJ, Park YH, et al. New simple endoscopic operations for interstitial pregnancies. Am J Obstet Gynecol. 2000;182:114-121. 

13. Rock J, Jones H. Ectopic pregnancy. In: Te Linde’s Operative Gynecology. 10th ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2008:798-824. 

14. Baggish MS, Karram MM. Surgical management of ectopic pregnancy. In: Atlas of Pelvic Anatomy and Gynecologic Surgery. 2nd ed. Philadelphia, PA: Elsevier Saunders; 2006:279-282. 

15. Gilstrap III LC, Cunningham FG, Vandorsten JP. Ectopic pregnancy. In: Operative Obstetrics. 2nd ed. New York, NY: McGraw-Hill; 2002:355-378.

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