Conversions during laparoscopic cholecystectomy: risk factors and effects on patient outcome.

In view of the substantial, at times conflicting, literature on conversion to open surgery during laparoscopic cholecystectomy (LC), we have considered it timely to review the subject to identify the risk factors for conversion and its consequences. The review is based on a complete literature search covering the period 1990 to 2005. The search identified 109 publications on the subject: 68 retrospective series, 16 prospective nonrandomized studies, 8 prospective randomized clinical trials, 5 prospective case-controlled studies, 5 reviews and 7 others (3 observational, 2 population-based studies, 1 national survey, and 1 editorial). As the majority of reported studies are retrospective, firm conclusions cannot be reached. Single factors that appear to be important include male gender, extreme old age, morbid obesity, cirrhosis, previous upper abdominal surgery, severe/advanced acute and chronic disease, and emergency LC. The combination of patient- and disease-related risk factors increases the conversion risk. In the training of residents, the number of cases needed for reaching proficiency exceeds 200 cases. The value of predictive scoring systems is important in the selection of cases for resident training. Conversion exerts adverse effects on operating time, postoperative morbidity, and hospital costs, especially when it is enforced. There appears to be no absolute contraindication to LC that is agreed upon by all. There is consensus on certain individual risk factors and their additive effect on the likelihood of conversion. Predictive systems based on these factors appear to be useful in selection of cases for resident training.