Imaging of cholelithiasis: what does the surgeon need?

Abstract

Laparoscopic cholecystectomy (LC) has become the standard approach for cholecystectomy despite relatively scant evidence that it is superior to open cholecystectomy (OC) in several prospective randomized studies [1‐ 4]. The overwhelmingly fast spread of the laparoscopic technology and the purported lower invasiveness and quicker recovery after LC as opposed to OC have led to important modifications in the management of biliary disease and especially in the attitude of many surgeons toward common bile duct (CBD) stones. Despite consensus that only symptomatic gallbladder stones require surgery [5], the general enthusiasm for laparoscopic surgery has lowered the threshold for LC. In most developed countries, the total number of cholecystectomies performed has increased by 14 ‐24% during 1991‐1993 [6, 7]. Data from Scandinavia suggest that the number of procedures has remained stable [6]. When cholecystectomy was performed for symptomatic cholelithiasis, the prevalence of CBD stones was 8 ‐15% in patients younger than 60 years and 15‐ 60% in patients older than 60 [5]. Performing LC in an increasing number of patients with little or only short-lasting symptoms has decreased the prevalence of CBD stones in the surgical population. Because the predictive values of any diagnostic test are directly related to the prevalence of the disease in the population tested, it is more than likely that the currently available preoperative diagnostic tools have lower positive predictive values than in populations with truly symptomatic cholelithiasis. Although LC is relatively safe (mortality rate ,0.1%), it is associated with a 0.36 ‐ 0.7% incidence of CBD injuries, which is almost twice the incidence for OC [6 ‐ 8]. Obviously, the increasing absolute number of cholecystectomies has increased the overall number of operative CBD injuries. The increasing number of cholecystectomies has also been responsible for the rising number of preoperative biologic and radiologic tests currently performed for the detection of CBD stones. A large variety of morphologic diagnostic investigations are available to the present-day clinician: conventional or endoscopic ultrasound, intravenous cholangiography, spiral computed tomographic (CT) cholangiography, magnetic resonance (MR) cholangiography, endoscopic retrograde cholangiography (ERC), and laparoscopic ultrasound. In addition to their variable efficiency for the detection of CBD stones, these techniques differ in terms of invasiveness, cost, and availability. Standardized and cost-efficient diagnostic strategies for CBD stones are required more than ever to limit the performance of diagnostic tests that may not only be noncontributive for most patients referred for cholecystectomy but also potentially harmful.