ERCP in Pregnancy

Indication

It is essential to have a strong indication before performing an ERCP during pregnancy. ERCP in pregnancy is most commonly performed for management of choledocholithiasis. Strong suspicion for the presence of a CBD stone is necessary before considering ERCP. For asymptomatic and minimally symptomatic patients, it may be reasonable to manage expectantly, understanding that there remains a risk for development of cholangitis and gallstone pancreatitis if stones are left untreated. There is no place for diagnostic ERCP, given the advancements in diagnostic imaging. ERCP has also been performed during pregnancy for cholangitis, biliary pancreatitis, and bile duct injury. There have been a few reports of performing ERCP in pregnant patients for management of choledochal cysts, parasitic infestation of the biliary tree, and pancreatic adenocarcinoma. Unusual situations such as these warrant careful evaluation on a case-by-case basis with a thorough assessment of the risks and benefits before pursuing ERCP. Serious obstetric complications such as placental abruption, eclampsia, rupture of membranes, and imminent delivery are contraindications to endoscopy. Rapid pregnancy testing before endoscopy is now commonplace and should be considered the standard of care before ERCP in women of childbearing age. Box 30.1 lists the indications for ERCP in pregnancy.

Diagnostic Imaging Modalities

Advances in diagnostic imaging have enabled endoscopists to often confirm a diagnosis before proceeding with ERCP, yielding the highest probability of therapeutic intervention. This is especially important in the pregnant patient, as these imaging modalities can often prevent unnecessary ERCP procedures.

Transabdominal ultrasonography is commonly used because of its safety profile and low cost. It is a sensitive method of detecting gallstones but has a low sensitivity for detecting CBD stones. It should still be used as an initial test, as a dilated CBD in the appropriate clinical setting (e.g., cholangitis) is often sufficient evidence to pursue ERCP. It is important to keep in mind that the symptoms of biliary disease (e.g., nausea, vomiting, abdominal pain) can often be encountered as a part of normal pregnancy, potentially obscuring the clinical picture.

Computed tomography scan is not recommended in the pregnant patient because of radiation exposure and poor sensitivity for choledocholithiasis. Magnetic resonance cholangiopancreatography (MRCP) is an excellent imaging tool for detection of CBD stones, with a reported sensitivity of 92%. There are no known deleterious effects of magnetic fields on the fetus. Magnetic resonance imaging is indicated in pregnancy with diagnostic-therapeutic urgency when the information needed cannot be obtained by other nonionizing imaging. It should be kept in mind that paramagnetic contrast agents (gadolinium) cross the placenta. Although there are no reports of harmful effects on the fetus, the molecule theoretically remains in the fetoplacental system, and for this reason these agents are generally not recommended for use in the pregnant patient. Fortunately, MRCP does not require paramagnetic contrast to image the biliary and pancreatic ductal systems, although imaging of other structures is limited without contrast. It should be noted that MRCP is less sensitive for detection of smaller stones (<6 mm).

Endoscopic ultrasonography (EUS) has emerged as a highly sensitive and specific test for choledocholithiasis ( Fig. 30.2 ) and can reduce the need for intervention in cases with low or moderate probability. Only a few cases of EUS in pregnancy have been reported. The risk of diagnostic EUS during pregnancy is believed to be minimal. It is reasonable to consider EUS immediately before ERCP in indeterminate cases of biliary obstruction if MRCP is not available, is contraindicated, or is nondiagnostic in the setting of high clinical suspicion for CBD stones.

Timing

The optimal time to perform ERCP is during the second trimester, although it has been performed safely throughout gestation. ERCP during the first trimester should be avoided if possible because of fetal exposure to ionizing radiation during the period of organogenesis and the risk of spontaneous abortion. In the general population, 15% to 20% of clinical pregnancies end in spontaneous abortion, with most of these occurring during the first trimester. This may represent a confounding factor if miscarriage occurs after an ERCP performed in the first trimester. ERCP during the third trimester may be complicated by distortion of anatomy by the gravid uterus and the risk of preterm labor and therefore should be preferably delayed beyond 36 weeks or ideally after delivery. In the presence of an urgent indication, ERCP should be performed regardless of the stage of pregnancy. It is advisable to have an obstetrician involved in the care of these patients. In some centers, fetal monitoring is performed preprocedurally and postprocedurally and, in some cases, intraprocedurally.

Surgery for gallbladder disease during pregnancy is controversial. Some surgeons favor early surgical management, whereas others prefer to wait until after delivery. If possible, surgery should be avoided in the first trimester during the period of organogenesis. Laparoscopy in the third trimester may be problematic because of the enlarged uterus, which can obscure surgical anatomy and limit access to the gallbladder fossa. The second trimester and early third trimester provide the best window should surgery be necessary. Recent reports suggest that laparoscopic cholecystectomy can be performed safely throughout gestation.