Background: Laparoscopic appendectomy(LA) has been increasingly adopted for its advantages over the open technique, but there is a possibility of conversion to open appendectomy(OA) if complications occur or the extent of inflammation prohibits successful dissection. This study was designed to identify preoperative indicators that may be useful in predicting conversion.
Methods: Medical records of 705 consecutive patients with suspected appendicitis between 1996 and 2000 in a single university hospital were reviewed retrospectively. LA was attempted in 595 patients by 27 different surgeons. Factors evaluated were demographic data (age and sex), clinical parameters (previous abdominal surgery, previous appendicitis attack, pain, nausea, vomiting, fever, duration of symptoms, local or diffuse tenderness), laboratory data (leukocyte count) and surgeon's experience in LA. Univariate analysis was performed using chi-square, Fisher's exact and Students ttest, as appropriate. Multiple stepwise logistic regression was then performed to evaluate those significant predictors found in the univariate analysis.
Results: Conversion to OA occurred in 58 out of 595(9.7%) patients. The most common reason for conversion was dense adhesions due to inflammation (36.2%), followed by localized perforation (12.1%) and diffuse peritonitis (10.3%). Significant factors associated with conversion to OA were age, diffuse tenderness on physical examination, and surgeons with less experience in LA(£operations). In 261 patients evaluated by CT scan preoperatively, the presence of significant fat stranding, free fluid, or free air significantly increased the possibility of conversion (Odds ratio 2.78, 95% CI of 1.24-6.20).
Conclusion: Advanced age, diffuse tenderness on exam, specific findings on CT scan, and surgeon inexperience are factors associated with the need for conversion from laparoscopic to open appendectomy.