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Potential Pitfalls in Pregnant Patients


 

Operative laparoscopy during pregnancy has been part of the growing field of minimally invasive surgery for more than 2 decades. As efforts during the 1980s to develop laparoscopic techniques unfolded, pregnant women were on the radar screen; one of the first textbooks of minimally invasive surgery, published in the 1980s, for instance, featured a chapter on laparoscopy in pregnancy.

A report on more than 150 patients undergoing laparoscopic appendectomy, including 6 pregnant patients, was published in 1990 (Surg. Endosc. 1990;4:100–2). The first laparoscopic cholecystectomy during pregnancy was reported in 1991 (Obstet. Gynecol. 1991;78[pt. 2]:958–9).

Through the 1990s, as technology improved and laparoscopy assumed a prominent place in gynecologic practice, and as general surgeons acquired more skill in laparoscopy, it became increasingly apparent that pregnant patients with appendicitis, cholecystitis, and other complications—both nonobstetric problems and problems of a more obstetric and gynecologic nature—were among the patients for whom laparoscopic surgery is often the treatment of choice.

Experience with the laparoscopic approach in pregnant patients increased, and anesthesiologists, surgeons, and obstetricians learned more about the effects of excessive intraabdominal pressure, other anesthesia-related problems, and the importance of prophylaxis for deep vein thromboses, among other issues.

Today, we can tell pregnant patients that laparoscopic surgery is a safe option. Data have shown that the second trimester is generally the safest time to intervene, and that most complications—when they do occur—seem to be related to the underlying disorder rather than the surgery per se. Overall, the complication rate for laparoscopic surgery during pregnancy is similar to that in the nonpregnant state.

It is important that we are aware of and knowledgeable about the unique presentation of certain problems during pregnancy, such as acute appendicitis and cholecystitis, and that we are ready to call upon a general surgeon with advanced minimally invasive skills.

Problems Requiring Surgery

Up to 2% of pregnancies are complicated by a surgical problem.

By far the most common surgical condition during pregnancy is acute appendicitis; its incidence is 0.5–1 per 1,000 pregnancies. Other surgical emergencies in pregnancy include acute cholecystitis (with an incidence of 5 per 10,000 pregnancies), intestinal obstruction, persistent ovarian cysts larger than 6 cm, and ovarian torsion and other adnexal problems. (The incidence of adnexal torsion is 1 in 5,000, and the incidence of any adnexal problem complicating pregnancy is 1 per 500–600 pregnancies.)

With the advent of assisted reproductive technologies, the incidence of heterotropic pregnancies is increasing, and growing numbers of successful laparoscopic surgeries for these pregnancies in hemodynamically unstable patients also are being reported. The extrauterine pregnancy can be addressed via salpingostomy or salpingectomy depending on the intraoperative findings. Minimal disturbance of the uterus and intrauterine gestation is the goal of intraoperative management.

The approach to laparoscopic surgery for these patients must take into account the physiological changes of pregnancy, including a 45% increase in plasma volume and a 10%-20% increase in cardiac volume, as well as increased oxygen consumption, decreased functional residual volume, and a theoretical predisposition to thromboembolic complications.

We must also be aware that the Trendelenburg position increases intrathoracic pressure, impairing venous return and accentuating the change in functional residual capacity. We may not, therefore, be able to achieve as steep a Trendelenburg position in pregnancy as in the nonpregnant state.

Because we are dealing with two passengers on these surgical journeys, we also must ensure that we not disturb the uteroplacental blood flow and oxygenation—that is, we must prevent fetal asphyxia and preterm labor—and that we are cognizant of the potential teratogenic effects of analgesics and other medications.

Medications and Assessment

Medications that have been recommended related to surgical intervention during pregnancy include indomethacin supplementation 25–50 mg preoperatively and a second dose 12 hours later. Unfortunately, however, there is a paucity of prospective data to support any one specific recommendation.

Progesterone supplementation—through a vaginal supplement of 25–100 mg postop for up to 7 days—has also been advocated after the procedure. Again, there are no well-designed studies to provide a firm basis for medication support.

Data from studies in ovariectomized rats supports the subcutaneous use of 3 mg of progesterone plus 200 ng of estradiol benzoate for 10–19 days with monitoring of serum progesterone levels (J. Reprod. Fertil. 1990;90:63–70).

Diagnostic procedures utilizing radiation should be limited to 5–10 rad during the first 25 weeks of gestation. Beyond that dosage, chromosomal mutations and neurologic abnormalities become concerns, as does the theoretical increased risk of childhood leukemia and other hematologic cancers.

Assessment CT scans generally are an appropriate test during pregnancy because the amount of radiation is relatively low—from 2 to 4 rad for a single study. MR imaging is appropriate, of course, as it does not involve ionizing radiation. Potentially concerning is the use of a contrast agent with CT or MR imaging. Gadolinium is commonly used in pregnancy; the use of this or other contrast agents should be discussed by the obstetrician and radiologist.

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