Predicting conversion to open surgery in laparoscopic colorectal resections - A simple clinical model

Objective: The objective of this study was to develop a simple model for cl inical use in predicting the individual risk of conversion to open surgery in patients undergoing laparoscopic colorectal resections. Methods: A multiple logistic regression analysis of 367 laparoscopic colore ctal resections completed between 1991 and 1998 was performed. The followin g 13 factors were considered: patient-specific factors (age, gender, weight levels less than 60 kg 60-90 kg, 90 kg or more), disease-specific factors (Crohn's disease, diverticulitis, malignancy, fistula), and procedure-speci fic factors (resection of the hepatic flexure, splenic flexure, sigmoid, re ctum, perineum, experience with less than 50 cases). A scoring system was d eveloped on the basis of the three factors found to be predictive of the ri sk for conversion to open surgery: diagnosis of malignancy (odds ratio 3.23 ; p = 0.0037; one point), surgeon experience with 50 cases or less (odds ra tio 2.26; p = 0.0363; one point), and weight level (odds ratio 3.42; p = 0. 005; 60 to 90 kg, one point, 90 kg or more, two points). Results: The predicted conversion rates for the cumulative scores of 0 to 4 points were 1.1%, 3.3%, 9.8%, 25.4%, and 49.7%, respectively. No significa nt difference was found between predicted and actual conversion rates, indi cating a good fit of the model (chi square = 1.774; p > 0.5). Conclusions: This novel scoring system is simple, accurate, and readily app licable in an office setting. It represents the large experience of one sur gical group and remains to be validated by other centers.