Laparoscopy and the Pregnant Patient

Evert A. Eriksson, MD*
Assistant Professor of Surgery
Department of Surgery
Division of Trauma / Acute Care Surgery
Medical University of South Carolina
Charleston, South Carolina, USA

Early in the development of laparoscopy, many argued that it was contraindicated in pregnancy due to concern for the safety of the fetus, physiologic effects of carbon dioxide insufflation on both the mother and fetus, and the technical ability of surgeons to obtain optimal exposure given the gravid uterus. Data supporting the use of minimally invasive techniques have increased over the past few decades, and laparoscopy increasingly has been applied and accepted in pregnancy.(1)

Approximately 0.2% of women will require nonobstetrical abdominal surgery during pregnancy.(2-3) Acute appendicitis, cholecystitis and bowel obstruction are the three most common nonobstetrical emergencies.(2) Other diseases commonly treated using laparoscopy also have been described in pregnant patients, including ovarian cysts, masses or torsions, symptomatic cholelithiasis, adrenal tumors, splenic disorders, hernias, complicated inflammatory bowel disease, and abdominal pain of unknown etiology.(4)

Workup and Diagnosis
The evaluation of the pregnant patient often presents challenges due to the altered physiology of pregnancy and the displacement of abdominal structures by the gravid uterus. History and physical examination remain critically important in the evaluation of these patients. Often the differential diagnosis is broad and radiologic evaluation is helpful in determining the underlying pathology. Ultrasound is considered safe for the mother and fetus, with high sensitivity and specificity for several intra abdominal processes without the risk of ionizing radiation.(5) Computed tomography (CT) scans and radiography may be used in pregnancy, but a risk/benefit assessment should be undertaken for each examination. The radiation risk is highest in the first 25 weeks, and the total exposure should not exceed 5 to 10 rads.(5) Exposure in a standard CT scan of the abdomen and pelvis is usually 2 to 4 rads.(6-7) Non-contrast enhanced magnetic resonance imaging may be performed safely, but gadolinium crosses the systemic-placental border.(8-9) Further studies are needed to determine the safe, allowable exposure for the fetus. Intraoperative and endoscopic cholangiography may be useful adjuncts in pregnancy and often allow for shielding of the fetus.(4) Nuclear medicine studies and cholangiography may be accomplished with low fetal exposure, often less than 0.5 rad, which is within the safe range for fetal exposure.(10) Although fetal safety is of utmost importance, careful evaluation of the mother with appropriate radiologic evaluations is appropriate given the high risk to the fetus when the mother presents with a surgical emergency.

Operative Planning
Indications for operative intervention are the same in the pregnant and nonpregnant patient. Fetal outcome is improved with early recognition and operative therapy for some diseases, whereas delays in diagnosis result in increased rates of fetal loss and preterm labor.(4) Generally, laparoscopy may be performed safely in any trimester without increased risk to mother or fetus.(11) Historically, laparoscopy use has been limited to the second trimester due to concerns over spontaneous abortion and preterm labor, but recent studies have refuted this recommendation and have demonstrated that laparoscopy may be performed in any trimester without increased risk to mother or fetus.(11-12) Surgical exposure becomes more complicated the larger the gravid uterus, but several studies have demonstrated that laparoscopic appendectomy and cholecystectomy may be performed safely in the third trimester.(12) Laparoscopy offers several postoperative advantages in the pregnant patient, including decreased fetal depression due to lower narcotic use, earlier mobilization, shortened length of stay, reduced maternal hypoventilation, and decreased uterine irritability resulting in lower rates of spontaneous abortion and preterm labor.(4) Ultimately, the experience of the surgeon, as well as the availability of appropriate equipment and staff, determine the best operative approach in each patient.

Operative Treatment
The pregnant woman presents several unique operative challenges. Gravid patients should be placed in a left lateral recumbent position to avoid uterine compression of the inferior vena cava, which can decrease cardiac output by 10% to 30% and result in decreased perfusion to the placenta.(13) The location of port placement must also be considered, and often adjusted, based on the size of the gravid uterus. Initial access may be obtained safely by open Veress needle or by the optical trocar technique, provided the location and technique are adjusted for fundal height and surgeon experience.(4) Several authors have advocated using only an open technique for surgical access to the abdomen in pregnancy.(14) Once access to the abdominal cavity has been obtained, carbon dioxide insufflation pressure should be maintained at the lowest level that provides adequate visualization. An insufflation pressure of 10 to 15 mm Hg can be used safely without adverse outcomes to either patient or fetus.(4) Venous return may be compromised by abdominal insufflation, which also can result in a decrease in cardiac output. In patients with preexisting restrictive pulmonary physiology, lower insufflation pressures should be considered. Intraoperative carbon dioxide monitoring should be performed to ensure that maternal levels are not rising to critical levels. Animal models have demonstrated fetal acidosis and instability with carbon dioxide insufflation, although no long-term effects have been documented.(15) Several studies have confirmed that capnography provides adequate monitoring during laparoscopy, so routine arterial blood gas measurements of carbon dioxide levels are not necessary.(12,16) Increasing the abdominal compartment pressure may predispose patients for development of deep venous thrombosis (DVT), especially in pregnant women who are hypercoagulable.(17) Intraoperative and postoperative use of pneumatic compression devices and early mobilization are recommended for DVT prophylaxis.(4) Unfortunately, research on chemical prophylaxis for DVT in the pregnant population is lacking. However, because it is recommended in major abdominal surgery in the general population, it should be considered in pregnant surgical patients.

Obstetrical Care
If available, obstetrical consultation, as well as maternal and fetal monitoring, should be included in the treatment plan for pregnant surgical patients. Treatment of a pregnant woman who develops an acute abdominal process should not be delayed because of the risk of increased morbidity and mortality for both mother and fetus.(4) Pre- and postoperative monitoring will be determined by the patient’s condition and gestational age. Intraoperative fetal heart monitoring was once thought to be required to detect fetal distress during laparoscopic procedures; however, no reports of abnormal heart rate have been reported, leading to the use of only pre- and postoperative monitoring of fetal heart rate.(4) Perioperative tocolytics should not be administered prophylactically, but threatened preterm labor can be managed with tocolytic therapy.(18) Great debate exists over the preferred agent for such use.

Conclusion
The utilization of laparoscopy to diagnose and treat nonobstetrical surgical problems has increased without evidence of adverse outcomes. The safety of the mother and fetus must be considered when determining the optimal surgical approach. Pregnancy presents unique diagnostic and therapeutic challenges to surgeons, making laparoscopy a useful tool in the care of pregnant patients.

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