An ectopic or extrauterine pregnancy is one in which the blastocyst implants anywhere other than the endometrial lining of the uterine cavity. As such, they account for 1 to 2 percent of reported pregnancies in the United States (Zane, 2002). With the advent of a sensitive and specific radioimmunoassay for the β-subunit of human chorionic gonadotropin (β-hCG), combined with high-resolution transvaginal sonography (TVS), the initial presentation of a woman with an ectopic pregnancy is seldom as life threatening as in the past. Nevertheless, ectopic pregnancies remain an important cause of morbidity and mortality in the first trimester of pregnancy in the United States.

Reported ectopic pregnancy incidence rates are not as reliable as in the past. The dramatic improvements in diagnosis and outpatient treatment protocols render national hospital discharge statistics invalid. That said, one evaluation within the Kaiser Permanente system from 1997 to 2000 estimated a rate of 20.7 per 1000 pregnancies (Van Den Eeden, 2005). More recently, Hoover and colleagues (2010) queried a large claims database for women aged 15 to 44 years who were privately insured in the United States between 2002 and 2007 and calculated a rate of 6.4 per 1000 pregnancies. However, this reduction in ectopic pregnancy rate might not accurately reflect cases occurring in higher-risk, lower-socioeconomic, uninsured populations. Namely, Stulberg and associates (2014) reviewed 2004 to 2008 Medicaid claims data and confirmed that black women were 46 percent more likely to experience an ectopic pregnancy compared with white women. They reported a rate of 14.0 per 1000 pregnancies in the 14 states evaluated.

In modern gynecologic practice, several factors help explain the incidence of ectopic pregnancies:

1. 
   

   Greater prevalence of sexually transmitted diseases, specifically chlamydial infections (Ljubin-Sternak, 2014; Rajkhowa, 2000)

   
   
2. 
   

   Diagnostic tools with improved sensitivity

   
   
3. 
   

   Tubal factor infertility and corrective surgery to restore tubal patency (Ankum, 1996)

   
   
4. 
   

   Women with delayed childbearing and their accompanied use of assisted reproductive technologies (ART), which carry increased ectopic pregnancy risks (Li, 2014a)

   
   
5. 
   

   Increased intrauterine device (IUD) use and tubal sterilization, which predispose to ectopic pregnancy with method failure (Heinemann, 2015; Mol, 1995).

An appreciation of risk factors for ectopic pregnancy may lead to a more timely diagnosis. As summarized in Table 8-1, documented tubal pathology, surgery to restore tubal patency, and tubal sterilization carry the highest risks for fallopian tube obstruction and subsequent ectopic pregnancy. A woman with two prior ectopic pregnancies has a 10- to 16-fold increased chance for another (Barnhart, 2006; Skjeldestad, 1998).

Of other risks, recurrent chlamydial infection causes intraluminal inflammation and subsequent fibrin deposition with tubal scarring (Hillis, 1997). Moreover, despite subsequent negative culture results, chlamydial antigens can persist to trigger a delayed hypersensitivity reaction with continued scarring (Toth, 2000). In contrast to endotoxin-producing Neisseria gonorrhoeae, which causes rapid, virulent pelvic inflammation, chlamydial inflammatory response is chronic and peaks at 7 to 14 days. This chronic inflammation can lead to arrest of the descending embryo while providing a proimplantation signal for embryos within the fallopian tube (Shaw, 2010).

Smoking, which may be a surrogate marker for sexually transmitted infections, also increases the risk of ectopic pregnancy. This risk is three- to fourfold in women who consume more than one pack of cigarettes daily (Saraiya, 1998). The increased rate of ectopic pregnancy among smokers undergoing ART was verified in a metaanalysis by Waylen and associates (2009). In addition, animal studies show that the fallopian tube is directly affected by cigarette smoke. Smoking alters oocyte cumulus complex pick-up and embryo transport by its effects on ciliary function and smooth muscle contraction (Shaw, 2010; Talbot, 2005). Also, oviductal transport of embryos is mediated in part by the cannabinoid receptor (CB1), which is influenced by endocannabinoid signaling. Chronic exposure to nicotine can affect endocannabinoid levels and lead to fallopian tube dysfunction (Horne, 2008).

ART for sub- or infertile couples is another risk. It has an associated 0.8-percent incidence of ectopic pregnancy per transfer and 2.2-percent per clinical pregnancy (Coste, 2000). Interestingly, recent series are finding significant reductions in ectopic pregnancy rates associated with in vitro fertilization (IVF) if frozen-thawed embryos are used instead of those derived from fresh cycles (2.22 versus 4.62 percent) (Fang, 2015; Huang, 2014). In women undergoing IVF, the main risk factors for ectopic pregnancy are tubal factor infertility and hydrosalpinges (Strandell, 1999; Van Voorhis, 2006). Moreover, “atypical” implantation is more common following ART. These include interstitial, abdominal, cervical, ovarian, or heterotopic pregnancies. A heterotopic pregnancy is an intrauterine pregnancy (IUP) coexistent with an extrauterine pregnancy.

Age also increases the ectopic pregnancy rate. Women aged 35 to 44 years have a threefold risk of ectopic pregnancy compared with those aged 15 to 25 years (Goldner, 1993). These have been attributed to age-related hormonal changes that alter tubal function (Coste, 2000).

When considering a contraceptive’s role in ectopic pregnancy, the absolute risk (the risk of any women experiencing an ectopic pregnancy) and the conditional risk (the risk a given pregnancy will be an ectopic pregnancy) are both weighed. Most contraceptives effectively prevent pregnancies and thereby lower the absolute risk of an ectopic pregnancy. However, if pregnancy does occur, some methods increase the conditions that favor ectopic implantation. For example, the contraceptive failure rates of the levonorgestrel-releasing intrauterine system (LNG-IUS) and the copper IUD are extremely low and have an adjusted hazard ratio for ectopic pregnancy of 0.26 (Heinemann, 2015). However, the IUD mechanisms of action are more effective in preventing intrauterine implantation. Thus, if an IUD fails, a higher proportion of resulting pregnancies are likely to be ectopic (Furlong, 2002). Of other methods, progestin-only contraceptive pills have a slightly increased rate because of their effects to diminish tubal motility. Tubal sterilization can be followed by an ectopic pregnancy and is also discussed in Chapter 33 (p. 527). This risk is doubled in women younger than 30 years at the time of sterilization, partially because of age-related fecundity.

As described in Chapter 3 (p. 43), the fallopian tube contains interstitial, isthmic, ampullary, and infundibular portions. Of these, the interstitial portion is the most proximal, and muscle of the tubal wall merges with the myometrium. This segment has a lumen with a simple, stellate cross-section (Fig. 3-13, p. 44). The isthmic portion of the fallopian tube has a narrow lumen with a thick wall. It is approximately 2 cm in length and has few longitudinal mucosal folds. The ampulla has thin walls and makes up most of the fallopian tube. It contains primary, secondary, and tertiary longitudinal mucosal folds throughout, and these folds favor ovum fertilization. Logically, this is where ectopic pregnancies typically implant. The infundibulum is the distal, trumpet-shaped end lined by fimbriae and connected to the ovary.

Lack of a submucosal layer within the fallopian tube provides easy access for the fertilized ovum to burrow through the epithelium and allow implantation within the muscular wall. Moreover, absent resistance allows early trophoblast penetration. As the rapidly proliferating trophoblast erodes the muscularis layer, maternal blood pours into the spaces within the trophoblastic or adjacent tissue.

With this pattern of invasion, the anatomic location of a tubal pregnancy may predict the extent of damage. Senterman and coworkers (1988) studied histologic samples from 84 isthmic and ampullary pregnancies and reported that half of the ampullary pregnancies were intraluminal, and the muscularis was preserved in 85 percent of these. Conversely, isthmic gestations were found both intra- and extraluminally with greater disruption of the tubal wall.

Nearly 95 percent of ectopic pregnancies implant in the fallopian tube (Bouyer, 2002). Other uncommon sites are individually described later in the chapter. Bilateral simultaneous ectopic pregnancies are rare, and their estimated prevalence is 1 of every 200,000 pregnancies (al-Awwad, 1999).

Symptoms

Many women with a small, unruptured ectopic pregnancy have unremarkable clinical findings. In these instances, early diagnosis of ectopic pregnancy is aided by a high index of suspicion.

Classic symptoms of ectopic pregnancy are amenorrhea followed by vaginal bleeding and abdominal pain on the affected side. Other pregnancy discomforts such as breast tenderness, nausea, and urinary frequency may accompany more ominous findings. Of these, shoulder pain worsened by inspiration can be caused by phrenic nerve irritation from subdiaphragmatic blood. Vasomotor disturbances such as vertigo and syncope may reflect hemorrhagic hypovolemia.

However, no constellation of symptoms secures the diagnosis with reliability (Dart, 1999). Thus, every sexually active reproductive-aged woman who has abdominal pain or vaginal bleeding should be screened for pregnancy. The diagnosis is considered strongly in those with risk factors.

Rarely, ectopic pregnancies have been the source of abdominal pain in women who previously underwent hysterectomy (Fylstra, 2009). Presumably, postoperative fistulous connections allow sperm to access an ovulated ovum. Possibilities include a nonobliterated cervical stump after supracervical hysterectomy, fistula following vaginal cuff infection, or prolapsed fallopian tube.

Physical Findings

Although some women have orthostatic findings, normal vital signs are unreliable to exclude a ruptured ectopic pregnancy. Birkhahn and associates (2003) employed the shock index to evaluate the possibility of ruptured ectopic pregnancy. This index reflects heart rate divided by systolic blood pressure (HR ÷ SBP) and is used to evaluate trauma patients for hypovolemic or septic shock. The normal range lies between 0.5 and 0.7 for nonpregnant patients. A shock index >0.85 and a systolic blood pressure <110 mm Hg are highly suggestive of a potentially life-threatening gynecologic emergency, such as a ruptured ectopic pregnancy (Polena, 2015).

Abdominal and pelvic findings are notoriously scarce in many women before tubal rupture. With rupture, however, nearly three fourths will have marked tenderness during both abdominal and pelvic examination. Pain is aggravated with cervical manipulation, which most likely reflects posterior cul-de-sac peritoneal irritation from blood. A pelvic mass, including fullness posterolateral to the uterus, can be palpated in approximately 20 percent of women. Initially, an ectopic pregnancy may feel soft and elastic, whereas extensive hemorrhage produces a firmer consistency. Many times, discomfort precludes palpation of the mass, and limiting examinations may help avert iatrogenic rupture.

Laboratory Findings

Serial serum β-hCG measurements and TVS are the most valuable diagnostic aids to confirm clinical suspicions of an ectopic pregnancy (Fig. 8-1). Human chorionic gonadotropin is a glycoprotein produced by syncytiotrophoblast and can be detected in serum as early as 8 days after the luteinizing hormone surge. In normal pregnancies, serum β-hCG levels rise in a log-linear fashion until 60 or 80 days after the last menses, at which time values plateau at approximately 100,000 IU/L. Given the variability between assays of 5 to 10 percent, interpretation of serial values is more reliable when performed by the same laboratory. With a robust uterine pregnancy, serum β-hCG levels should increase at least 53 to 66 percent every 48 hours (Barnhart, 2004; Kadar, 1982). In hemodynamically stable women, adding a third serum β-hCG level on day 4 or 7 could correct the diagnosis of a pregnancy of unknown location in an additional 7 to 13 percent of patients (Zee, 2014). This additional time and data may better ascertain the location and viability of the pregnancy. However, the value of this added data point should be weighed against the increased chance of ectopic pregnancy rupture in the interim. Nevertheless, inadequately rising serum β-hCG levels indicate only a dying pregnancy, not its location.

Frequently, women present with an unsure last menstrual period, and an educated guess of gestational age is made. In these cases, correlation between the serum β-hCG concentration and TVS findings becomes especially important, as discussed in the next section.

As an adjunctive test, determination of a serum progesterone concentration is used by some when serum β-hCG determinations and sonographic findings are inconclusive (Carson, 1993; Stovall, 1992). Serum progesterone concentrations vary minimally between 5 and 10 weeks’ gestation, thus a single value is sufficient. Mol and colleagues (1998) performed a metaanalysis of 22 studies to assess the accuracy of a single serum progesterone level to differentiate ectopic from uterine pregnancy. They found that results were most accurate when approached from the viewpoint of healthy versus dying pregnancy. With serum progesterone levels <5 ng/mL, a dying pregnancy was detected with near perfect specificity and with a sensitivity of 60 percent. Conversely, values >20 ng/mL had a sensitivity of 95 percent with specificity approximating 40 percent to identify a healthy pregnancy. Ultimately, serum progesterone levels can be used to buttress a clinical impression, but they alone cannot reliably differentiate between an ectopic and uterine pregnancy (Guha, 2014).

Sonography

High-resolution sonography has revolutionized the clinical management of women with a suspected ectopic pregnancy. However, routine sonography without a clinical suspicion of ectopic pregnancy does not improve diagnostic and triage efficiency. With TVS, a gestational sac is usually visible between 4½ and 5 weeks after the last menstrual period, the yolk sac appears between 5 and 6 weeks after the last menstrual period, and a fetal pole with cardiac activity is first detected at 5½ to 6 weeks after the last menstrual period. With transabdominal sonography, these structures are visualized slightly later. The sonographic diagnosis of ectopic pregnancy rests on visualization of an adnexal mass separate from the ovary (Fig. 8-2).

When the last menstrual period is unknown, serum β-hCG testing is used to define expected sonographic findings. Each institution must define a β-hCG discriminatory value, that is, the lower limit at which an examiner can reliably visualize pregnancy. At most institutions, this value is a concentration between 1500 and 2000 IU/L. Accurate IUP diagnosis by TVS is three times more likely if the initial β-hCG level is above this value. A fetal pole is usually recognized when the serum β-hCG concentration has reached 5000 IU/L, and embryonic cardiac activity is usually recognized when the serum β-hCG level has reached 17,000 IU/L. Technical challenges include coexisting leiomyomas, adenomyosis, or intrauterine devices, which can visually hinder the ability to accurately diagnose an intrauterine gestation. Moreover, multifetal gestations may have sufficient trophoblast to produce β-hCG levels above the discriminatory value when they have not yet reached structural development to be seen sonographically (Gurel, 2007; Ko, 2014).

In addition to these exceptional cases, the absence of a uterine pregnancy when β-hCG levels are above the discriminatory value may suggest an abnormal pregnancy that is an ectopic, an incomplete abortion, or a resolving completed abortion. For example, despite total passage of products of conception with complete abortion, β-hCG testing may still be positive while original circulating β-hCG is metabolized and cleared. Conversely, sonographic findings obtained when β-hCG values lie below the discriminatory value are not diagnostic in nearly two thirds of cases (Barnhart, 1999).

In an attempt to unify the language used with sonographic diagnosis of early pregnancies, a consensus statement was published. The following five categories were agreed upon for diagnosis based upon sonographic findings: (1) definitive ectopic pregnancy (extrauterine gestational sac with yolk sac and/or embryo, with or without cardiac activity), (2) probable ectopic pregnancy (inhomogeneous adnexal mass or extrauterine saclike structure), (3) pregnancy of unknown location (PUL) (no signs of either an ectopic pregnancy or IUP), (4) probable IUP (intrauterine echogenic saclike structure), and (5) definite IUP (intrauterine gestational sac with yolk sac and/or embryo, with or without cardiac activity) (Barnhart, 2011).

Systematic sonographic evaluation is critical to establish the correct diagnosis. Most begin with the endometrial cavity. In pregnancies conceived spontaneously, identification of a uterine pregnancy effectively excludes the possibility of an ectopic implantation. When ART is employed, however, careful examination of the tube and ovary is performed even with an intrauterine pregnancy because heterotopic pregnancy rates may be as high as 1 per 100 (Tal, 1996).

An intracavitary fluid collection caused by partial breakdown of the decidua can create a pseudogestational sac, or pseudosac. This small, anechoic collection lies typically in the midline of the uterine cavity. In contrast, a normal gestational sac is eccentrically located (Dashefsky, 1988). Another intracavitary finding is a trilaminar endometrial pattern, which represents two adjacent edematous proliferative-phase endometrial layers (Lavie, 1996). For the diagnosis of ectopic pregnancy, this finding’s specificity is 94 percent but with a sensitivity of only 38 percent (Hammoud, 2005). Endometrial stripe thickness has not been well correlated with ectopic pregnancies. However, Moschos and Twickler (2008b) determined that in women with a PUL at presentation, no normal IUPs had a stripe thickness <8 mm.

The fallopian tubes and ovaries are also inspected. Visualization of an extrauterine yolk sac or embryo clearly confirms a tubal pregnancy, although such findings are present in only 15 to 30 percent of cases (Paul, 2000). In some cases, a halo or tubal ring surrounded by a thin hypoechoic area caused by subserosal edema can be seen. According to Burry and associates (1993), this has a positive predictive value of 92 percent and a sensitivity of 95 percent. Brown and coworkers (1994) conducted a metaanalysis of 10 studies to ascertain the best transvaginal sonographic criteria to diagnose ectopic pregnancy. They reported that the finding of any adnexal mass, other than a simple ovarian cyst, was the most accurate, with a sensitivity of 84 percent, specificity of 99 percent, positive predictive value of 96 percent, and negative predictive value of 95 percent. However, not all adnexal masses represent an ectopic pregnancy, and integration of sonographic findings with other clinical information is necessary.

Differentiation of an ectopic pregnancy from a corpus luteum cyst can be challenging. However, Swire and coworkers (2004) observed that the corpus luteum wall is less echogenic compared with both the halo and the endometrium. They found that a spongelike, lacelike, or reticular pattern seen within the cyst is classic for hemorrhage (Fig. 14-4, p. 228). Moreover, a corpus luteum is found within the parenchyma of an ovary, whereas an asymmetric ovary should raise suspicion of an ectopic pregnancy (Gurel, 2007). With transvaginal color Doppler imaging, placental blood flow within the periphery of the complex adnexal mass—the ring of fire—can be seen (Fig. 8-3). Although this finding can aid ectopic pregnancy diagnosis, it also can be seen with a corpus luteum of pregnancy (Pellerito, 1992). Finally, to help characterize a suspicious mass, an examiner can gently palpate an adnexum that is placed between the vaginal probe and the examiner’s abdominal hand during real-time scanning. A mass that moves separately from the ovary suggests a tubal pregnancy, whereas a mass that moves synchronously more likely represents a corpus luteum cyst (Levine, 2007).

During sonographic evaluation of the pelvis, a small amount of free fluid, as little as 10 mL, is commonly present in the posterior cul-de-sac (Khalifé, 1998). Free fluid that contains low-level echoes or echogenic debris is consistent with hemoperitoneum with clot. If free fluid is seen extending to the fundus of the uterus, it is considered to be moderate in amount. Once identified, moderate free fluid should prompt further evaluation of the paracolic gutters and Morison pouch in the right upper quadrant to assess the fluid’s extent (Fig. 17-10, p. 287). Blood in the paracolic gutters and Morison pouch indicates significant hemorrhage. Specifically, free fluid in Morison pouch typically is not seen until a hemoperitoneum reaches 400 to 700 mL (Branney, 1995; Rodgerson, 2001). Detection of peritoneal fluid in conjunction with an adnexal mass is highly predictive of ectopic pregnancy (Nyberg, 1991).

Despite technologic advances, the absence of suggestive findings does not exclude an ectopic pregnancy. In addition, TVS has not decreased the prevalence of tubal rupture or need for transfusions at the time of surgery (Atri, 2003). However, sonography has decreased the need for diagnostic laparoscopy or curettage or both to establish the diagnosis of ectopic pregnancy.

Endometrial Sampling

Several endometrial changes accompany ectopic pregnancy, and all lack coexistent trophoblast. Decidual reaction is found in 42 percent of samples, secretory endometrium in 22 percent, and proliferative endometrium in 12 percent (Lopez, 1994). Many recommend that the absence of trophoblastic tissue be confirmed by curettage before methotrexate (MTX) treatment is given (Barnhart, 2002; Chung, 2011; Shaunik, 2011). Investigators found that the presumptive diagnosis of ectopic pregnancy is inaccurate in nearly 40 percent of cases without histologic exclusion of a spontaneous pregnancy loss. Nevertheless, the need for and method of endometrial sampling must carefully be weighed against the limited maternal risks of MTX.

Endometrial biopsy with a Pipelle catheter was studied as an alternative to curettage and found inferior. The sensitivity of obtaining chorionic villi ranged from 30 to 63 percent (Barnhart, 2003b; Ries, 2000). By comparison, frozen section of curettage fragments to identify products of conception is accurate in more than 90 percent of cases (Barak, 2005; Li, 2014b; Spandorfer, 1996).

Without intervention, an ectopic tubal pregnancy can lead to tubal abortion, to tubal rupture, or to spontaneous resolution. Tubal abortion is the expulsion of products through the fimbrial end of the fallopian tube. This tissue can then either regress or reimplant in the abdominal cavity. With reimplantation, bleeding or pain necessitating surgical intervention is a common complication. Tubal rupture is usually associated with significant intraabdominal hemorrhage. With spontaneous resolution, small ectopic pregnancies die and are resorbed without adverse patient effects.

Reductions in morbidity and mortality rates are directly related the early diagnosis of ectopic pregnancies prior to rupture and catastrophic hemorrhage. Early diagnosis also may allow for conservative therapeutic approaches, preserved reproductive capacity, and reduced overall treatment costs.

Laparotomy versus Laparoscopy

An ectopic pregnancy can be surgically removal via either of these routes. At least three prospective studies have compared laparotomy with laparoscopic surgery for this indication (Lundorff, 1991; Murphy, 1992; Vermesh, 1989). Their findings are summarized as follows:

1. 
   

   Overall, tubal patency determined at second-look laparoscopy did not differ between these routes. However, higher rates of ipsilateral adhesions were found in the laparotomy group.

   
   
2. 
   

   Each method was followed by a similar number of subsequent uterine pregnancies.

   
   
3. 
   

   Subsequent ectopic pregnancies were less frequent in women treated laparoscopically, although this difference in rate was not significant.

   
   
4. 
   

   Laparoscopy resulted in shorter operative times, less blood loss, fewer analgesic requirements, and shorter hospital stays.

   
   
5. 
   

   Laparoscopic surgery was significantly less successful in resolving a tubal pregnancy. However, this was balanced by the just-mentioned benefits of laparoscopy.

   
   
6. 
   

   The costs for laparoscopy were significantly lower than for laparotomy, although some argue that costs are similar when cases converted to laparotomy are considered (Foulk, 1996).

Thus, with modern instrumentation and improved laparoscopic skills, most pelvic surgeons now select minimally invasive surgery (MIS) to treat ectopic pregnancies in suitable candidates. A general discussion of laparoscopy in pregnancy is found in Chapter 15 (p. 240). Even for a clinically stable patient with hemoperitoneum, ruptured ectopic pregnancies may be treated via MIS (Sagiv, 2001). Among experienced surgeons, shorter operating times and expedited hemorrhage control were both advantages of laparoscopic intervention for ruptured ectopic pregnancies (Cohen, 2013). Although an unstable patient was previously considered a contraindication to laparoscopic surgery, many skilled surgeons feel they can safely and quickly enter the abdomen laparoscopically. That said, the lowered venous return and cardiac output associated with the pneumoperitoneum of laparoscopy must be factored into the decision to select MIS for hypovolemic patients.

Laparotomy offers a potential advantage to laparoscopy if salpingostomy is planned. A metaanalysis using data from two trials concluded that compared with laparotomic salpingostomy, laparoscopic salpingostomy leads to one case of persistent trophoblastic disease for every 12 women undergoing a laparoscopic approach (Mol, 2008). However, residual tissue responds well to MTX, and this is weighed against the risks of laparotomy.

Conservative versus Radical Surgery

Two multicenter, randomized controlled trials have been completed to date to guide the choice between conservative surgery—laparoscopic salpingostomy, and definitive treatment—laparoscopic salpingectomy. The European Surgery in Ectopic Pregnancy (ESEP) study randomized women with a healthy contralateral fallopian tube to salpingectomy (n = 231) or salpingostomy (n = 215). After surgery, the cumulative rates of ongoing pregnancy by natural conception did not differ significantly between groups (56 versus 61 percent, respectively) (Mol, 2014). In the DEMETER trial, patients with “active ectopic pregnancies” were randomly assigned to either salpingectomy or salpingostomy. Similar to the ESEP study, the subsequent 2-year rate for achieving an IUP did not differ between groups (64 versus 70 percent, respectively) (Fernandez, 2013).

Salpingectomy, performed for ectopic pregnancy, either by laparotomy or laparoscopy, should resolve ectopic pregnancy 100 percent of the time, because the fallopian tube containing the ectopic implantation is completely removed. One hazard of conservative surgery and medical therapy for ectopic pregnancy is the possibility of residual trophoblastic tissue in the tube continuing to proliferate, causing symptoms, and even resulting in tubal rupture. To summarize the literature, this risk of incomplete removal of the trophoblastic tissue from the tube is 2 to 11 percent with laparotomy and 5 to 20 percent with laparoscopy. A prophylactic postoperative dose of MTX to prevent persistent trophoblasts would need to be given to 10 women to prevent one case (Mol, 2008). Therefore, close observation with serial measurement of β-hCG levels is the preferred option.

Salpingectomy

If the contralateral fallopian tube appears normal, then salpingectomy is a reasonable treatment option that avoids the 5- to 8-percent complication rate caused by persistent or recurrent ipsilateral ectopic pregnancies (Rulin, 1995).

Many laparoscopic techniques have been described to perform salpingectomy, and two options are presented here. First, following abdominal entry, the affected fallopian tube is identified, and atraumatic forceps grasp, elevate, and extend the tube. The most proximal portion of the fallopian tube is desiccated and transected using the surgeon’s preference of energy source. The mesosalpinx under the fallopian tube is sequentially coagulated and transected until the fallopian tube is freed (Fig. 8-4).

As a second option, the vascular supply to the fallopian tube within the mesosalpinx can instead be suture ligated. Figure 8-5 shows an endoscopic suture loop encircling the involved fallopian tube segment. Absorbable and delayed-absorbable suture loops are available, and either is suitable for ligation. Two or three suture loops are sequentially placed, and the tube distal to these ligatures is then cut free with scissors. The most proximal portion of the affected fallopian tube is desiccated to help prevent ipsilateral recurrence. Lim and associates (2007) compared electrosurgical coagulation of the tube and mesosalpinx during laparoscopic salpingectomy with laparoscopic suture-loop (Endoloop) ligation. Endoloop use was associated with significantly shorter operating times (48 versus 61 minutes) and lower postoperative pain scores.

Following excision, most tubal ectopic pregnancies are small and pliant. Thus, they can be held firmly by grasping forceps and drawn up into one of the accessory site cannulas. The laparoscopic cannula, grasping forceps, and ectopic tissue can then be removed together. Larger tubal ectopic pregnancies may be placed in an endoscopic sac to prevent fragmentation as they are removed through the laparoscopic port site. Alternatively, larger ectopic pregnancies can be morcellated with scissors within an enclosed bag. Tissue removal techniques are also presented and illustrated in Chapter 14 (p. 234), which discusses treatment of other adnexal masses in pregnancy.

Salpingostomy

The woman who is hemodynamically stable and strongly desires to preserve fertility is an appropriate candidate for salpingostomy. However, if a treating surgeon has neither the laparoscopic skills nor the instrumentation needed to atraumatically remove trophoblastic tissue via linear salpingostomy, then salpingectomy by laparoscopy or laparotomy is preferred. Leaving a scarred, charred fallopian tube behind after removing an ectopic pregnancy does not preserve reproductive potential.

In addition, serum β-hCG levels may be a factor in patient selection. A retrospective study by Milad and colleagues (1998) found that ectopic-pregnancy resolution rates following salpingostomy were lower in women in whom the initial serum β-hCG level was >8000 IU/L. Supportive evidence for this comes from Natale and associates (2003), who reported that serum β-hCG levels >6000 IU/L indicate a high risk of implantation into the tubal muscularis. This greater degree of invasion may leave trophoblast behind during extraction of the conceptus.

When performing salpingostomy, the fallopian tube surrounding the ectopic complex is first grasped with atraumatic forceps. To aid hemostasis, dilute vasopressin (Pitressin) is injected into the mesosalpinx beneath the ectopic pregnancy and also in the serosal layer overlying the mass. Dilutions of 20 U of vasopressin in 30 to 100 mL of saline are suitable. Approximately 10 mL of solution is typically sufficient. Vasopressin has potential systemic vasoconstrictive effects. Aspiration with the syringe prior to and during injection helps avoid intravascular injection.

A 1- to 2-cm long incision is made on the anti-mesosalpinx border and on the maximally distended portion of the tube that holds the pregnancy (Fig. 8-6). Suitable tools for incision include a monopolar needle tip electrode, scissors, bipolar needle, or Harmonic scalpel. The products of conception are then carefully removed using a combination of blunt and hydrodissection. Electrosurgical coagulation of bleeding points can aid hemostasis. Finally, the abdomen and pelvis are thoroughly irrigated and suctioned free of all tubal placental tissue. Subsequent intraabdominal implantation of trophoblastic tissue can explain some cases of persistent serum β-hCG levels (Bucella, 2009).

A novel approach to the conservative surgical treatment of a distal fallopian tube ectopic pregnancy involves a device called the fallopian tube stripping forceps (FTSF). The laparoscopic instrument has two clamp plates that, when closed, form a narrow ellipse to milk the fallopian tube free of products. In their observational trial with 102 women, Liu and coworkers (2014) found the rates of intraoperative bleeding and of recurrent ectopic pregnancy to be lower in the stripping-forceps group compared with a group undergoing salpingostomy. The rates of persistent ectopic pregnancy or subsequent spontaneous IUP did not differ. This method awaits additional investigation.