What is the best drainage method for a perinephric abscess?

Purpose: To compare the results of percutaneous and open drainage for perinephric abscess. Materials and Methods: The files of 86 patients who underwent drainage for perinephric abscesses from April 2001 through March 2008 were evaluated. The method of drainage for each patient was performed according to the clinical decision of the treating physician. Percutaneous tube drain (PCD) was used for drainage of the abscess in 43 patients (group 1), while the other 43 patients were managed with open drainage (group 2). Cure was defined as complete obliteration of the abscess cavity. The cure rates, complications, and hospital stay were compared between both groups. Results: The study included 50 males and 36 females with mean age 44.2 ± 17.3. The most common predisposing factors were diabetes mellitus and/or stones. Open drainage of perinephric abscesses resulted in a statistically significant higher cure rate (98% versus 69%, p < 0.001) and shorter hospital stay than PCD (3.6 versus 6 days, p < 0.001). Failure of complete drainage of multilocular abscess was observed in 8 of 13 cases (61.5%) in group 1 and one of 38 cases (2.6%) in group 2 (P < 0.001). Complications were observed in 7% of group 1 and 11.5% in group 2 (P = 0.45). After mean follow-up of 19 months, 9 of 46 patients (19.6%) had recurrence; 7 of them were in group 1. Conclusion: Percutaneous drainage of perinephric abscess is an effective minimally invasive treatment. However, PCD is not the optimal method for drainage of multilocular abscess because open surgical drainage provided higher cure rates and shorter hospitalization than PCD.