Management of biliary tract disease during pregnancy: a decision analysis

Abstract

The appropriate management of biliary tract disease during pregnancy is uncertain. Although laparoscopic cholecystectomy can be performed safely during pregnancy, the timing and indications for this surgical intervention have not been firmly established. We constructed a Markov decision analytic model that incorporates maternal well-being and fetal outcome into a choice between nonoperative management (NM) and laparoscopic cholecystectomy (LC) for pregnant women with biliary tract disease (BTD). Our model cycles through weeks of pregnancy for a cohort of 200 gravid women presenting with biliary tract disease in both the first and second trimesters. Weekly state probabilities and utilities for fetal outcome were derived from the literature, while weekly utilities for disease and operative states were estimated in consultation with obstetricians. We cycled the model from 6 to 42 weeks and from 19 to 42 weeks to simulate first and second trimester presentations. Outcomes are expressed in quality pregnancy weeks (QPWs). One QPW is the utility of a normal healthy week of pregnancy. A comprehensive search of the literature yielded a fetal death rate following LC for biliary tract disease of 2.2% and following NM of 7%. Relapse rates were found to be trimester dependent and estimated to be 55%, 55%, and 40% in the first, second, and third trimester, respectively. For a hypothetical cohort of 100 women presenting with biliary tract disease in their first trimester, LC generated 12,800 QPWs compared with 12,400 QPWs for NM, an average gain of 4 QPWs per woman. For the cohort of women entering the model in the second trimester, 11,600 QPWs were accrued by the LC group and 11,400 QPWs by the NM group, an average gain of 2 QPWs per woman. These findings were sensitive only to changes in fetal death rates under the two treatment arms. Laparoscopic cholecystectomy is superior to nonoperative management for pregnant women presenting in the first or second trimester with biliary tract disease.