Percutaneous nephrolithotomy of patients with staghorn stone and incidental purulent fluid suggestive of infection

Background and Purpose: Patients undergoing percutaneous nephrolithotomy (PCNL) sometimes have purulent fluid in the puncture site in spite of having no signs or symptoms of infection preoperatively. We report the safety and effectiveness of PCNL in 45 patients with staghorn renal stones and incidental purulent fluid in the pelvicaliceal system. Patients and Methods: Of 1264 patients who underwent PCNL at our medical center from February 2002 to May 2006, 45 patients had purulent fluid in the initial puncture. These patients were asymptomatic, and the preoperative work-up did not suggest infection. In 29 patients (group 1), stone removal was accomplished during the first session, while for 16 patients (group 2), a nephrostomy tube remained in place and stone removal occurred 3 to 5 days later when results of urine and nephrostomy fluid cultures were negative. We studied preoperative findings, stone-free rate, intraoperative and postoperative complications, and final outcome of these patients. Results: The stone-free rate was almost similar in the two groups (86.2% v 81.25%, P = 0.9). In groups I and 2, three (10.3%) and two (12.5%) patients experienced low-grade fever for 12 to 24 hours (P = 0.179). In group 1, urine cultures revealed Escherichia coli in three patients and Pseudomonas aeruginosa in two patients, while 24 (82.7%) patients had negative fluid cultures. In group 2, results of urine cultures showed E coli in two patients and Klebsiella pneumoniae in one patient; results of urine cultures of 13 (81.2%) patients were negative (P = 0.78). Mean operative time was 70 minutes in both groups. No intraoperative or postoperative complications other than fever were seen in both groups. Conclusion: In patients who undergo PCNL, purulent fluid may be found incidentally in the puncture site. PCNL may be performed with full antibiotic coverage at the same session.