Role of preoperative sonography in predicting conversion from laparoscopic cholecystectomy to open surgery

Background: Laparoscopic cholecystectomy is the first step treatment in cholelithiasis. The purpose of this study was to establish a radiologic view on prediction of conversion from laparoscopic cholecystectomy to open surgery.

Methods: This study included 176 patients who had undergone laparoscopic cholecystectomy. Preoperative ultrasonographic findings were assessed and we gave points to each finding according to results from correlation analysis. After the scoring we investigated the relationship between ultrasonographic findings and conversion from laparoscopic cholecystectomy to open surgery.

Results: Scoring significantly predicted failure in laparoscopic approach (AUC=0.758, P=0.003,). Optimal cut off score was found to be 1.95 with 67% sensitivity and 78% specificity. Score>1.95 was a risk factor for failure in laparoscopic approach [odds ratio=7.1(95% CI,2-24.9, P=0.002)]. There were 8 subjects out of 36(22%) with high score underwent open surgery while 4 out of 128 (3%) subjects with low score needed open surgery (p=0.002). Negative predictive value of 128/132=97%. Mean score of whole study population was 1.28 (range 0-8.8) and mean score of subjects underwent open surgery was 3.6 while it was 1.1 in successful laparoscopic approach group (p<0.001). Mean Age and BMI were similar between groups (p>0.05). Sex of subjects did not affect the success of surgery (p>0.05).

Conclusion: The contribution of preoperative ultrasonography is emphasized in many studies. Our study suggests quantitative results on conversion from laparoscopic cholecystectomy to open surgery. We believe that radiologists have to indicate the risk of conversion in their ultrasonography reports.