Prospective Evaluation of Risk Factors Concerning Intraoperative Conversion from Laparoscopic to Open Cholecystectomy

Background: The surgical approach of choice in the treatment of symptomatic cholecystolithiasis is considered to be elective laparoscopic cholecystectomy (CCE) as the established gold standard. Today, approximately 80-90% of CCE are performed using a laparoscopic approach whereas the remaining portion undergoes primary conventional CCE, however, in 6% conversion is necessary. Aim: Since pathological aspects found intraoperatively and finally requiring conversion are correlated to an increased risk for complications, it appears reasonable to assess the risk factors prior to operation. Patients and Methods: Through a well defined study period of 9 years, all consecutive patients who underwent CCE for cholecystolithiasis at the Municipal Hospital "HELIOS Klinikum Aue" were enrolled in a registry comparing laparoscopic and conversion CCE. Diverse parameters were tested as to whether they increase significantly the risk for conversion. The intensity of each factor-associated impact on a possible conversion was determined. Results: From 2001 to 2009 1477 patients underwent CCE at the Municipal Hospital "Helios Klinikum Aue", out of them 131 (8.9%) cases were primarily treated by conventional CCE whereas in the vast majority (1346 subjects [91.1%]), laparoscopic CCE was the initial approach. However, conversion became necessary in 106 individuals resulting in a conversion rate of 7.9%. Comparing data obtained from laparoscopic CCE with those from open procedure after conversion, there were significant differences in operating time, complication rate and postoperative hospital stay (p = 0.01). Over the study period, there were 5 cases (0.37%) with iatrogenic injuries of the biliary system. Hospital mortality was 0.08% in the laparoscopic and 2.8% in the conversion group.The following parameters were found to have a significant impact on the risk for conversion (univariate analysis): elevation of CRP, preoperative ERCP, renal insufficiency, previous laparotomy, histological gradeM3 (ulcerous, haemorrhagic necrotising cholecystitis, perforation of the gall bladder) and M4 (carcinoma of the gall bladder). While in the spectrum of preoperative factors former ERCP, elevation of CRP and terminal renal insufficiency were most relevant (2- to 3-fold each), histological grade M3 and M4, 7- and 14-fold, respectively, showed the greatest impact on conversion rate highlighting the profile of postoperative parameters. Conclusion: The main focus is directed to keep the conversion rate low. In case of diagnosing a severely inflamed gall bladder, a primarily open procedure or an early decision for conversion should be considered.