Chapter 11.5 Ectopic Pregnancy and Salpingectomy. Operative Techniques

 Chapter 11.5 Ectopic Pregnancy and Salpingectomy

GENERAL PRINCIPLES

Definition

■ An ectopic pregnancy is one in which the embryo implants outside of the endometrial cavity. Ectopic pregnancies account for 1.5% to 2% of all pregnancies.

Differential Diagnosis

■ The most common presenting symptoms of ectopic pregnancy include lower abdominal/pelvic pain (99%), delayed menses (74%), and vaginal bleeding (56%).1 As such, the differential diagnosis is broad and should include both gynecologic and nongynecologic etiologies.

■ For vaginal bleeding and/or pain in early pregnancy, the differential diagnosis includes:

■ Threatened, incomplete, complete and missed abortions

■ Subchorionic hematoma

■ Physiologic changes in early pregnancy

■ Gestational trophoblastic disease

■ For lower abdominal/pelvic pain with or without vaginal bleeding, consider:

■ Adnexal torsion

■ Degenerating leiomyoma

■ Dysmenorrhea

■ Endometriosis

■ Hemorrhagic corpus luteum cyst

■ Pelvic inflammatory disease, tubo-ovarian abscess

■ Appendicitis

■ Cystitis

■ Diverticulitis

■ Inflammatory bowel disease

■ Irritable bowel syndrome

■ Nephrolithiasis

Anatomic Considerations■ The vast majority of ectopic pregnancies, 98%, are located in the fallopian tube, with 70% in the ampulla, 12% in the isthmus, 11% in the fimbriated end, and 2% in the interstitial (cornual) segment.2 In these cases, the patient’s clinical picture and diagnostic workup will largely direct the management plan. This will be further discussed in the sections below.

■ Alternative locations of ectopic pregnancy, although rare, may require specialized treatment planning and can be associated with higher maternal morbidity. These include ovarian, cervical, abdominal, cesarean scar, rudimentary horn, and heterotopic pregnancies. Heterotopic pregnancies involve implantation of concurrent embryos in two separate locations, most commonly, an intrauterine and a tubal ectopic pregnancy.

■ A pregnancy of unknown location refers to one in which the patient has an elevated serum hCG without evidence of a pregnancy on ultrasound. A pregnancy of unknown location can occur up to 20% of the time in women with first trimester pain and/or bleeding. Upon further workup, 21% will be ectopic, 53% will be spontaneous abortions, and 26% will be intrauterine pregnancies.3 In a hemodynamically stable patient, one may trend hCG levels and perform repeat ultrasonography until the pregnancy location is determined; however, in a hemodynamically unstable patient or one with peritoneal signs, a diagnostic laparoscopy is warranted.

Nonoperative Management

■ There are two primary nonoperative options for managing ectopic pregnancy: expectant management and medical treatment.

■ Expectant management, which can be successful in nearly 20% of ectopic pregnancies, includes serial monitoring of hCG levels, follow up transvaginal ultrasonography if indicated, and cautious observation for changes in clinical status. Predicting the patients who will be best suited for expectant management can be difficult, so individuals who select this plan should be well counseled on the possibility for tubal rupture and the need for emergent surgery. Patients who can be considered for expectant management are asymptomatic and able to be compliant with the necessary follow-up. It has been suggested that expectant management outcomes are affected by the initial hCG level, with 90% of ectopic pregnancies spontaneously resolving when the baseline hCG is <1,000 IU/L and only 60% when the baseline hCG is <2,000 IU/L. Patients may continue to be followed expectantly as long as hCG levels are steadily decreasing and trending should continue until hCG becomes undetectable. If at any time hCG levels rise or plateau, medical or surgical management should be initiated.

■ Medical management involves treatment with methotrexate, a folic acidantagonist that inactivates dihydrofolate reductase and thereby disrupts DNA and RNA synthesis. Similar to expectant management, patients best suited for medical management are lacking symptoms, hemodynamically stable and able to be compliant with follow-up. Absolute contraindications to methotrexate use include active pulmonary or peptic ulcer disease, alcoholism, breastfeeding, hematologic abnormalities, hepatic or renal dysfunction, immunodeficiency, and intolerance to the medication. In order to evaluate for eligibility, all patients should have a complete blood count, blood type, Rh antibody screen, serum creatinine, liver function panel, and transvaginal ultrasound prior to initiating methotrexate therapy. Use of methotrexate is thought to be most successful when the initial hCG level is less than 5,000 IU/L, the ectopic sac is less than 3 to 4 cm and there is no fetal cardiac activity.4 There are several regimens of methotrexate dosing, including single, double, and multi-dose (Table 11.5.1). Numerous studies have compared efficacies of the different methotrexate regimens, and although both single and multi-dose regimens are effective in the treatment of ectopic pregnancy (88% vs. 93% success rate, respectively), a metaanalysis suggested that at least two doses are generally needed for successful ectopic management.5 Regardless of the chosen regimen, all patients with properly decreasing serum hCG levels require measuring values weekly until hCG becomes undetectable. This on average takes 5 weeks, but may require up to 15 weeks of monitoring. A patient is considered to have failed methotrexate therapy if hCG levels rise or plateau any time after the initial measurements between days 4 and 7. Similar to expectant management, patients should understand warning signs and symptoms of tubal rupture, and the possible need for emergent surgery.

Patients should be counseled to refrain from folic acid–containing supplements, NSAIDs, alcohol, excessive sunlight exposure, sexual intercourse, and strenuous physical activities while undergoing treatment with methotrexate. Lastly, patients should be provided with contraception for 3 to 6 months after successful treatment with methotrexate, as studies have shown that a single dose can take up to 8 months to be systemically cleared.

■ In some circumstances, such as cervical, abdominal, cesarean scar, or interstitial ectopic pregnancies, one may chose to perform a more localized treatment by injecting an agent directly into the gestational sac under ultrasound or laparoscopic guidance. Methotrexate (50 mg/mL), potassium chloride (2 mEq/mL), and hyperosmolar (50%) glucose have all been successfully utilized, and function by delivering a high concentration of drug directly to the ectopic pregnancy. To perform localized injection, one must first aspirate the gestational sac contents and then inject ∼10 mL of one of the aforementioned agents. In heterotopic pregnancies, directinjection with agents such as potassium chloride or hyperosmolar glucose provides a unique opportunity to manage the ectopic while decreasing the risk of interrupting the viable intrauterine pregnancy. Methotrexate injection should be avoided due to its known teratogenicity.

Table 11.5.1 Dosing Regimens for Methotrexate

■ Although limited data exists, uterine artery embolization, either alone or combined with medical or surgical management, has been safely and successfully used for the treatment of interstitial, cervical, and cesarean scar ectopic pregnancies.

IMAGING AND OTHER DIAGNOSTICS

■ For the majority of ectopic pregnancies, the diagnosis can be quickly made with a quantitative hCG level and a transvaginal ultrasound. A serum progesterone level may provide additional information in cases where the viability of the pregnancy is uncertain.

■ A quantitative hCG level can be assessed through a simple blood draw, and elevations in the maternal serum can be appreciated as early as 8 days after the LH surge. In normal pregnancies, hCG is produced by the syncytiotrophoblasts in a predictable manner, and levels increase in a linear fashion during the timeframe when an ectopic pregnancy may occur. A rise of at least 53% to 66% every 48 hours should be appreciated in normal pregnancies. Levels will continue to increase in this manner until they peak at approximately 100,000 IU/L, around 8 to 10 weeks of gestation.

Pregnancies deviating from this trend on serial hCG monitoring are only indicative of an abnormal pregnancy and require further evaluation.

■ Serum hCG assays are both highly sensitive and specific, with detection limits below 5 IU/L. Both false-negative and false-positive results are rare; however, in the case of a static and consistently elevated serum hCG level, one must evaluate for the presence of heterophilic antibodies. This diagnosis is made by obtaining a negative urine hCG. An additional consideration for cautious hCG interpretation is for individuals with an increased likelihood of a multifetal gestation, such as those who haveconceived with the help of assisted reproductive technologies. In these cases, hCG levels will likely be elevated beyond that expected for the gestational age and may not be reliable for directing the expected findings on ultrasonography.

■ Transvaginal ultrasonography can detect evidence of a pregnancy as early as 4.5 to 5 weeks gestational age, with the visualization of the gestational sac. At 5 to 6 weeks, a yolk sac can be seen, and between 5.5 to 6 weeks, a fetal heartbeat can be appreciated. Correlating the hCG level with ultrasonography helps to interpret the findings. Generally, sonographic evidence of an intrauterine pregnancy should be seen by day 24 if conception date is known, or with hCG levels between 1,500 and 2,000 IU/L, also known as the discriminatory zone.6 A definitive diagnosis of an ectopic pregnancy is made when a gestational sac with yolk sac and/or fetal pole is appreciated outside of the endometrial cavity. Findings which are concerning for ectopic pregnancy include a complex adnexal mass, tubal ring, and free fluid in the posterior cul-de-sac; however, these alone are insufficient to diagnose an ectopic pregnancy. Color and pulsed Doppler ultrasonography can be helpful when a diagnosis is unclear. As arterial and venous blood flow is increased to a developing pregnancy, this technique may help differentiate an intrauterine pseudosac from an intrauterine pregnancy and an ectopic pregnancy from an ovarian or paratubal cyst.

■ Serum progesterone levels should rise progressively throughout pregnancy. Assessment of this level can be helpful in distinguishing a normal from an abnormal pregnancy when the previous workup is inconclusive. Generally, a progesterone level of <5 ng/mL is suggestive of a nonviable pregnancy, whereas a level >20 ng/mL is consistent with a viable pregnancy. The limitation of this test, however, is that it cannot aid in elucidating the pregnancy location.

■ Historically, culdocentesis was performed in the setting of an indeterminate ultrasound and a high clinical suspicion. A large bore spinal needle was inserted through the posterior vaginal fornix to aspirate the contents of the posterior cul-de-sac. An aspirate of blood is consistent with hemoperitoneum, a common sequela of tubal rupture. This test has largely fallen out of favor, not only because of its invasiveness, but also because it has an inferior sensitivity and specificity for hemoperitoneum as compared to transvaginal ultrasound.

■ Special considerations for difficult diagnoses:

■ The diagnosis of extratubal ectopic pregnancies can be especially challenging given their rare incidence and sometimes unusual presentations. Specific criteria have been developed to assist with diagnosing interstitial, ovarian, cervical, and cesarean scar pregnancies(Table 11.5.2). The use of additional imaging modalities, such as MRI, may be helpful in establishing the pregnancy location.

■ Gracia and Barnhart7 developed a helpful algorithm for the workup of a pregnancy of unknown location. If the hCG level is above the discriminatory zone and a pregnancy cannot be identified on ultrasound, a dilation and curettage can be performed. The absence of chorionic villi in the curettage and a continued rise in hCG confirms the presence of an ectopic pregnancy. If the hCG level is below the discriminatory zone, repeat hCG levels and a follow-up transvaginal ultrasound should be performed.

PREOPERATIVE PLANNING

■ Since most patients have ready access to the above diagnostic testing, ectopic pregnancies are diagnosed early and fertility-preserving surgery can be performed in a controlled manner. It is very rare to see a hemodynamically unstable patient from massive hemoperitoneum due to a ruptured ectopic.

■ If the patient is unstable, obtain a complete blood count and type and cross for the potential administration of blood products. Obtain venous access with two peripheral large-bore IVs for fluid resuscitation and place an indwelling Foley catheter to monitor urine output.

■ For stable patients with an early unruptured ectopic pregnancy, a fertilitysparing salpingostomy may be planned. However, the patient should be consented for possible salpingectomy if the fallopian tube is significantly damaged or hemostasis cannot be achieved.

SURGICAL MANAGEMENT

■ When deciding the best course for surgical management, one must consider the patient’s clinical status, laboratory results, ultrasound findings, and fertility desire.

Table 11.5.2 Criteria for the Diagnosis of Interstitial, Ovarian, Cervical, and Cesarean Scar Ectopic Pregnancies

In cases of tubal rupture, the fallopian tube is often damaged beyond repair and will require a complete salpingectomy. A salpingectomy should also be performed in the setting of recurrent ectopic pregnancy or prior surgery on the ipsilateral fallopian tube, uncontrollable intraoperative hemorrhage, or completed childbearing. In the latter case, the contralateral tube may be ligated for contraception.

■ In patients who are clinically stable, but do not meet the criteria for medical management, a salpingostomy may be performed for individuals who desire future fertility, especially when the contralateral fallopian tube is surgically absent or appears functionally compromised.Procedures and Techniques (Videos 11.5.1 and 11.5.2)

Examination under anesthesia

■ After general anesthesia is obtained, a gentle pelvic examination should be performed to ascertain the size, mobility, and positioning of the uterus, as well as to evaluate for fullness in the adnexa. Extreme care must be taken during adnexal palpation, as tubal rupture may occur if excessive pressure is exerted on the affected fallopian tube. Patient positioning and creation of a sterile surgical field

■ The patient should be placed in the low dorsal–lithotomy position using Allentype stirrups with the legs in neutral position and the weight on the soles of the feet. The arms should be tucked at the patient’s sides using a draw sheet. If the patient is obese, arm sleds may be indicated. The extremities are padded at pressure points to prevent neuropathy. Shoulder braces should be avoided, as these have the potential to cause a brachial plexus injury.

■ Throughout the positioning process, one must communicate with the anesthesia provider to ensure that the patient’s IV, pulse oximeter, and ventilation are not compromised.

■ Intermittent pneumatic compression stockings should be placed on the lower extremities to help prevent deep vein thrombosis.

■ The abdomen, upper thighs, and vagina are prepped and draped.

■ Generally, prophylactic antibiotics are not indicated.

Insertion of a uterine manipulator

■ A uterine manipulator may be inserted to facilitate exposure of the fallopian tubes. First, a bivalve speculum is inserted into the vagina. The anterior surface of the cervix is grasped with a single-toothed tenaculum to stabilize the cervix and straighten the uterine axis. A uterine sound may be used to assess the length and direction of the endometrial cavity. Gentle cervical dilation is performed if needed. A uterine manipulator is inserted, and the tenaculum and speculum are removed. No manipulator is placed in cases of heterotopic pregnancy so as not to disrupt the intrauterine pregnancy.

■ An indwelling Foley catheter is placed to avoid bladder distention during surgery.

■ A nasogastric or orogastric tube, placed by anesthesia, helps to ensure the stomach is decompressed during trocar insertion.

Abdominal entry

■ The technique utilized for initial trocar placement is largely dependent onsurgeon preference and expertise.

■ Traditionally, initial entry through the umbilicus is chosen, as it is the thinnest portion of the abdominal wall. Mindfulness of the anatomical structures below is critical and vary based on the patient’s habitus. This also determines the safest angle for trocar entry. Insert the trocar at a 45-degree angle in thin patients and 90 degrees in obese patients. There is no evidence that using a Veress needle or optical trocars reduces the incidence of complications with initial abdominal entry. Also, injecting local anesthesia at the trocar sites has not been shown to significantly reduce postoperative discomfort.

■ Consider a left upper quadrant entry for patients at risk for having bowel adherent to the anterior abdominal wall beneath the umbilicus. These would include those with prior abdominopelvic surgery (especially with a midline laparotomy) or pelvic infection from pelvic inflammatory disease, Crohn’s disease, or ruptured appendix. A 5-mm trocar is placed under the lowest rib in the mid-clavicular line. Again, an oro- or nasogastric tube must be inserted to decompress the stomach. An umbilical port may be safely placed under direct vision after assuring that it is free from adherent bowel. A 10-mm trocar is placed transumbilically to facilitate tissue extraction. After the initial trocar is inserted and intraperitoneal placement is confirmed, pneumoperitoneum is established with carbon dioxide gas and the patient placed in Trendelenburg positioning.

■ A survey of the peritoneal cavity is important prior to inserting accessory ports. One should evaluate for any adhesive disease, inspect the anatomy, and identify the course of the inferior epigastric vessels. Also, transilluminate the abdominal wall with the laparoscope from within the pelvis to identify and avoid superficial vessels in the abdominal wall.

■ Two accessory 5-mm ports should then be placed under direct laparoscopic visualization, one in each lower quadrant.

Salpingostomy versus salpingectomy

■ For a salpingostomy, one can begin by grasping the affected fallopian tube with an atraumatic grasper and then injecting dilute vasopressin (20 units in 100 mL of injectable saline) into the mesosalpinx inferior to the pregnancy sac (Tech Fig. 11.5.1). A linear incision, 1 to 2 cm in length, can be made using monopolar needlepoint cautery on the antimesenteric side of the fallopian tube (Tech Figs. 11.5.2 and 11.5.3). Any instrument may be used to apply gentle pressure beneath the ectopic to help extrude the products of conception (POC) (Tech Figs. 11.5.4 and 11.5.5). This is preferred to manually removing the POC with graspers, which tends to cause more bleeding. Once the POC is out, the tubal defect is irrigated and bipolar cautery is used sparingly to achieve hemostasis while limiting thermal damage (Tech Figs. 11.5.6 to 11.5.9). With the exception of the POC protruding though the fimbria, “tubal milking” should be avoided as it causes more damageto the fallopian tube than salpingostomy. Salpingectomy involves coagulating and dividing the proximal isthmic segment and serially coagulating and cutting the mesosalpinx. A bipolar grasper, such as a Kelppinger, may be used with scissors as well as any vessel-sealing device. The procedure can be performed from proximal to distal or distal to proximal depending on which is technically easier. It is of utmost importance to stay as close as possible to the fallopian tube to avoid compromising the ovarian vascular supply, which may lead to diminished ovarian reserve.

Tech Figure 11.5.1. Injecting vasopressin into the ectopic pregnancy.Tech Figure 11.5.2. Coagulating the superficial vessels.

Tech Figure 11.5.2. Coagulating the superficial vessels

Tech Figure 11.5.3. Sharply incising the fallopian tube.

Tech Figure 11.5.4. Expressing the products of conception (POC).

Tech Figure 11.5.5. POC ready for removal.

Tech Figure 11.5.6. Removing the POC from the fallopian tube.

Tech Figure 11.5.7. Extracting the specimen.

Tech Figure 11.5.8. Irrigating the fallopian tube.

Tech Figure 11.5.9. Performing the final visual inspection of the fallopian tube at the end of the case.

Retrieval of the specimen

■ A 5-mm laparoscope is placed through one of the lower ports, or left upper quadrant port if used, and the specimen is extracted though the 10-mm umbilical port, with or without endoscopic bag. The key point is to avoid leaving any POC,which may develop a collateral blood supply and continue to grow.

Case completion

■ The abdomen and pelvis should be copiously irrigated and the fluid aspirated. Bipolar cautery may be used if needed to assure complete hemostasis. Again, all POC should be removed, as failure to do so may result in persistent trophoblastic implants. The insufflation pressure can be decreased to ensure that no bleeding occurs under lower intra-abdominal pressures.

■ The fascia of the 10-mm umbilical port must be closed with a delayed absorbable suture. This can be accomplished by placing the 5-mm laparoscope through one of the lower ports, removing the 10-mm port, and using an endoclose (Grice) needle or a Carter–Thomason device to suture the defect. Alternatively, it can be closed with a UR-6 needle on a conventional needle holder after all of the ports have been removed. The fascia should be closed with a delayed absorbable suture for any other port sites of 8 mm or greater to prevent a potential incisional hernia.

■ The pneumoperitoneum is released, taking care to ensure that as much of the carbon dioxide gas is removed from the abdomen as possible for patient comfort postoperatively. All of the instruments are removed.

■ The skin incisions can be closed with a delayed absorbable suture in a subcuticular fashion or with tissue adhesive.

POSTOPERATIVE CARE

■ Same-day discharge to home may be appropriate if the surgical procedure was uncomplicated and the patient is doing well during the postoperative recovery. If a significant amount of blood loss occurred, observation overnight to follow vital signs and serial blood counts may be more appropriate.

■ A patient may return to her preoperative diet and activities when she feels ready.

■ Rh(D) immune globulin should be administered if indicated.

■ Quantitative hCG levels should be followed weekly until negative if a salpingostomy is performed. Consider administering a dose of methotrexate (50 mg/m2 BSA) to reduce the risk of persistent trophoblastic disease.

■ Contraception should be provided if the pregnancy was unplanned. If pregnancy was planned, the patient should be instructed not to attempt to conceive until her hCG is negative and her menses resume.

■ The patient should be informed that she is now at a higher risk for another ectopic and to call as soon as she conceives for close follow-up.

OUTCOMES

■ A history of an ectopic pregnancy is a significant risk factor for recurrence, and approximately 15% of individuals will have a subsequent ectopic pregnancy. When stratified by treatment regimens, salpingostomy had a higher recurrence rate compared to salpingectomy and single-dose methotrexate (15%, 10%, and 8%, respectively).8 It has been estimated that ∼60% of individuals will have a successful pregnancy after an ectopic, regardless of the utilized surgical technique.9

COMPLICATIONS

■ The primary complications in the management of ectopic pregnancies are related to the inherent risks associated with surgery. These include reaction to anesthesia, bleeding, infection, and unintentional injury to other organs, such as the bowel or bladder.

■ The risk of incomplete removal of ectopic tissue is higher when surgery is performed at an early gestational age, the gestational sac diameter is small, tubal rupture occurred, salpingostomy is technically difficult, or insufficient irrigation is performed at the end of the procedure.10 For salpingostomy, the risk of persistent ectopic pregnancy was estimated to be 3% to 20%. If a remnant of trophoblastic tissue remains in the abdomen, hCG levels may be persistently elevated. This can often be ameliorated with a dose of methotrexate postoperatively.