Identification of preoperative risk factors associated with the conversion of laparoscopic to open appendectomies.

Our goals were to (1) identify risk factors associated with conversion from laparoscopic to open appendectomies and (2) establish criteria that predict the possibility of conversion to an open technique. We did a retrospective chart review of all patients who underwent laparoscopic appendectomies during a 5-year period (2004-2008). Preoperative risk factors, intraoperative findings, and postoperative complications were compared. We found that of 763 patients who had undergone laparoscopic appendectomy, 44 patients were converted to open technique (conversion rate of 5.8%). For these 44 patients, the male to female ratio was 2 to 1, and the men were older (45 versus 37 years of age, P < 0.001). Conversion rates decreased with time (8.7% in 2004 versus 3.5% in 2008). Past surgical history was insignificant. However, a duration of symptoms of >5 days as well as a white blood cell count >20,000 were found to have a direct correlation. Incidence of postoperative complications did not increase in converted patients. The conversion rate is highest in male patients above 45 years of age, with over 5 days' duration of symptoms, leukocytosis >20,000, and ruptured appendicitis on computed tomography scan. The presence of 3 to 4 of these risk factors should lower the threshold for consideration of conversion to open appendectomy.