Common Bile Duct Pressures in Patients With and Without Cholelithiasis
Common Bile Duct Pressures in Patients With and Without Cholelithiasis
Objective. To measure the pressures of the common bile duct in patients with and without
 cholelithiasis and relating them to the presence of pancreatobiliary reflux.

 Summary Background Data. The reflux of pancreatic enzymes into the epithelium of the bile
 duct and mainly of the gallbladder is an abnormal phenomenon that plays a role in the
 lithogenesis and carcinogenesis of this epithelium. It has been suggested that the cause of
 this reflux is the dysfunction of the sphincter of Oddi. Because the pressure of the common
 bile duct depends on the pressures of the sphincter of Oddi, this dysfunction would be
 reflected in an increase in the pressure of the common bile duct in patients with
 cholelithiasis.

 Methods. A prospective case-control study was designed. The universe was constituted by a
 convenience sample in which all patients undergoing gastrectomy for gastric cancer during 30
 months in our institution were included. The primary outcome measure was to establish
 differences between common bile duct pressures in patients with and without cholelithiasis.

 Results. Common bile duct pressures in patients with gallstones showed a significant
 elevation (Mean 16.9 mmHg) compared to those of patients without gallstones (Mean 3.3 mm Hg)
 (p<0.0001). These pressures correlated with the values of amylase and lipase in gallbladder
 bile; higher levels of these enzymes were found in patients with gallstones compared to
 patients without gallstones (p<0.0001).

 Conclusions. Common bile duct pressures in patients with cholelithiasis were significantly
 elevated above the parameters previously considered normal.
A prospective study of cases and controls was designed using a previously validated model for
 the study of occult pancreatobiliary reflux in patients undergoing gastrectomy for gastric
 cancer, in which cholecystectomy is routine according to the oncological surgery protocol for
 gastric cancer of our institution. The study universe was constituted by a convenience sample
 in which all patients undergoing gastrectomy for gastric cancer during the period between
 January 2015 and June 2017 the investigators included. All patients included in this study
 signed a detailed informed consent regarding the interventions to be performed and the
 objectives of the study.

 Cholecystectomy was performed in all patients after the section of the duodenum. Before the
 manipulation and dissection of the Calot triangle, a sample of 5 to 10 cc of bile was taken
 directly from the gallbladder. The sample was stored in a sterile tube at room temperature
 and immediately sent for processing. The technicians of our institutional laboratory that
 processed the sample did not know the details of the study. The cholecystectomy was then
 carried out until the cystic was reached and was cut as proximally as possible to the
 gallbladder. Through the cystic duct, a 4 French feeding tube equivalent to 1.35 mm in
 diameter (Well Lead®, Hamburg, Germany) was introduced until reaching a distance of 3 cm
 distal to the junction of the cystic duct and the common bile duct. Once tested for patency,
 this probe was connected to a standard pressure transducer used to measure intra-arterial
 pressure (Edwards Lifesciences™, Irvine, California, USA) and this was connected to a B40
 monitor (General Electric® Medical Systems, Milwaukee, WI, USA) with the ability, among other
 functions, to perform pressure measurements in millimeters of mercury. The level of the
 junction of the cystic duct and the common bile duct was taken as a zero point, as previously
 described. Once the whole system was irrigated with 0.9% physiological solution and the zero
 point was established on the monitor with the system closed, the system was opened and
 pressures were measured. The minimum, maximum and mean pressures were recorded for one
 minute. After the procedure was completed, the gastrectomy was performed.
Inclusion Criteria:

 -  All patients with normal values of amylase, lipase, and liver function tests measured
 24 hours before the intervention

 Exclusion Criteria:

 -  Patients previously cholecystectomized

 -  Patients with clinical, radiological and laboratory evidence of common bile duct
 stones