Bile duct injury during laparoscopic cholecystectomy: results of a national survey

Abstract

Objective: To determine whether surgical residency training has influenced the occurrence of common bile duct injuries during laparoscopic cholecystectomy, and to asses the anatomic and technical details of bile duct injuries from the practices of surgeons trained in laparoscopic cholecystectomy after residency versus surgeons trained in laparoscopic cholecystectomy during residency.

Summary background data: Shortly after the introduction of laparoscopic cholecystectomy, the rate of injury to the common bile duct increased to 0.5%, and injuries were more commonly reported early in each surgeon's experience. It is not known whether learning laparoscopic cholecystectomy during surgery residency influences this pattern.

Methods: An anonymous questionnaire was mailed to 3,657 surgeons across the United States who completed an Accreditation Council for Graduate Medical Education (ACGME)-approved residency between 1980 and 1990 (group A) or 1992 and 1998 (group B). All surgeons in group A learned laparoscopic cholecystectomy after residency, and all those in group B learned laparoscopic cholecystectomy during residency. Information obtained included practice description, number of laparoscopic cholecystectomies completed since residency, postgraduate training in laparoscopy, and annual volume of laparoscopic cholecystectomy in the surgeon's hospital. In addition, technical details queried included the completion of a cholangiogram, the interval between injury and identification, the method of repair, and the site of definitive treatment. The primary endpoint was the occurrence of a major bile duct injury during laparoscopic cholecystectomy (bile leaks without a major bile duct injury were not tabulated).

Results: Forty-five percent (n = 1,661) of the questionnaires were completed and returned. Mean practice experience was 13.6 years for group A and 5.4 years for group B. At least one injury occurrence was reported by 422 surgeons (37.6%) in group A and 143 surgeons (26.5%) in group B. Forty percent of the injuries in group A occurred during the first 50 cases compared with 22% in group B. Thirty percent of bile duct injuries in group A and 32.9% of all injuries in group B occurred after a surgeon had performed more than 200 laparoscopic cholecystectomies. Independent of the number of laparoscopic cholecystectomies completed since residency, group A surgeons were 39% more likely to report one or more biliary injuries and 58% more likely to report two or more injuries than their counterparts in group B. Bile duct injuries were more likely to be discovered during surgery if a cholangiogram was completed than if cholangiography was omitted (80.9% vs. 45.1%). Sixty-four percent of all major bile duct injuries required biliary reconstruction, and most injuries were definitively treated at the hospital where the injury occurred. Only 14.7% of injuries were referred to another center for repair.

Conclusions: Accepting that the survey bias underestimates the true frequency of bile duct injuries, residency training decreases the likelihood of injuring a bile duct, but only by decreasing the frequency of early "learning curve" injuries. If one accepts a liberal definition of the learning curve (200 cases), it appears that at least one third of injuries are not related to inexperience but may reflect fundamental errors in the technique of laparoscopic cholecystectomy as practiced by a broad population of surgeons in the United States. Intraoperative cholangiography is helpful for intraoperative discovery of injuries when they occur. Most injuries are repaired in the hospital where they occur and are not universally referred to tertiary care centers.

Figure 1. Number of bile duct injuries reported by all respondents. In group A, 422 surgeons reported 533 biliary injuries. In group B, 143 surgeons reported 171 biliary injuries. In group A, 75 surgeons reported two biliary injuries, 17 reported three injuries, and 1 reported four injuries. In group B, 22 surgeons reported two biliary injuries and 3 reported three injuries.

Figure 2. Respondents from group A and group B reported the estimated number of laparoscopic cholecystectomies completed at the time of their first bile duct injury. A higher percentage of surgeons in group A reported injuries early in their experience compared with group B; however, the frequency of reported first injuries equalized in the category “more than 200 cases.” Approximately one third of surgeons reporting an injury in either group reported that the injury occurred after having completed 200 cases. Although it appears that the incidence of injury is increasing in group B, correction for the size of the category reveals a decreasing injury rate. Beyond 200 cases, the incidence cannot be calculated because the total experience (denominator) is unknown.

Figure 3. Number of laparoscopic cholecystectomies completed at the time of first reported bile duct injury, combining response categories of surgeons reporting at least one injury. More surgeons in group A than group B reported injuries within the first 50 cases completed. This observation was also true when calculating the number of surgeons reporting their first injury in the first 100 cases. The percentage of surgeons reporting their first injury within 200 cases, however, was similar between groups.