M. Sippey1, A. Mozer1, M. Grzybowski1, M. Manwaring1, J. Pender IV1, W. Chapman1, W. Pofahl1, W. Pories1, K. Spaniolas1 1East Carolina University Brody School Of Medicine,General Surgery,Greenville, NC, USA
Introduction: Laparoscopic cholecystectomy is one of the most common general surgical procedures performed. Conversion to an open procedure (CTO) is associated with increased morbidity and length of stay. Patients presenting with acute cholecystitis (AC) are at higher risk for CTO. Studies have attempted to examine risk factors for CTO in patients who undergo laparoscopic cholecystectomy for AC, but are limited by small sample size. The aim of this study was to identify pre-operative variables that predict higher risk for CTO in patients presenting with AC.
Methods: Patients undergoing laparoscopic cholecystectomy for AC from 2005 to 2011 were identified from the ACS-NSQIP database. Patients who underwent successful laparoscopic surgery were compared with those who required CTO. Demographics, co-morbidities, and 30-day outcomes were analyzed. Multivariable logistic regression was used for variables with p-value <0.1, with CTO used as the dependent variable.
Results: A total of 7,242 patients underwent laparoscopic cholecystectomy for AC. CTO was reported in 436 (6.0%) patients. Those who required conversion were older (60.7 ± 16.2 vs 51.6 ± 18.0, p = 0.0001) and mean BMI was greater (30.8 ± 7.55 vs 30.0 ± 7.31, p = 0.028) compared to those whose procedure was completed laparoscopically. Vascular, cardiac, renal, pulmonary, hepatic disease, diabetes and bleeding disorders were more prevalent in CTO patients. Mortality (2.1% vs 0.7%, p = 0.001), overall morbidity (21.2% vs 6.0%, p<0.0001), serious morbidity (14.4% vs 3.8%, p<0.0001), reoperation (3.2% vs 1.4%, p = 0.002), and SSI (9.1% vs 1.8%, p<0.0001) rates, as well as LOS (8.52 ± 12.58 vs 3.41 ± 5.60, p<0.0001) were greater in those requiring CTO. Our model showed the following factors were independently associated with CTO: age (OR 1.01, p = 0.015), male gender (OR 1.77, p = 0.005), BMI (OR 1.04, p<0.0001), pre-operative alkaline phosphatase (OR 1.01, p = 0.0005), WBC count (OR 1.06, p = 0.0001), and albumin (OR 0.52, p = 0.0001). The overall model had a strong ability to discriminate between patients who did and did not require CTO (c=0.74, p<0.0001).
Conclusion: CTO for AC remains low, but not clinically negligible. After controlling for confounding baseline characteristics, for each unit increase in BMI, risk of CTO increases by 4%. The identified risk factors can potentially guide management and patient selection for delayed intervention for AC.