Infundibular stenosis after percutaneous nephrolithotomy.

PURPOSE: Acquired infundibular stenosis can develop after percutaneous nephrolithotomy. We review our experience with infundibular stenosis after this procedure. MATERIALS AND METHODS: We evaluated the records of patients diagnosed with infundibular stenosis after percutaneous nephrolithotomy was performed at our institution between 1995 and 2000. Analysis included medical history, urinary stone type, stone removal procedure technique, length and number, postoperative course, stenosis time to development location, severity and treatment, and treatment outcome. RESULTS: Infundibular stenosis developed in 5 of 223 percutaneous nephrolithotomy cases (2%) performed during this period. Medical history in affected patients included previous ipsilateral open pyelolithotomy, diabetes and morbid obesity in 2 each. Percutaneous nephrolithotomy were done through a standard 30Fr nephrostomy tract and all cases were terminated before complete stone removal. Mean operative time was 258 minutes, which was significantly greater than the mean operative time of 207 minutes in all cases of unilateral percutaneous nephrolithotomy (p = 0.03). Postoperatively nephrostomy tube drainage was done for a mean of 33 days (range 16 to 51). All patients underwent at least 1 additional percutaneous stone removal procedure after primary percutaneous nephrolithotomy and before stenosis was detected. The mean time to stenosis detection was 9 months (range 2 to 24). Stenosis generally developed in areas corresponding to previous sites of percutaneous access and the degree of narrowing ranged from mild to severe. Mild and moderate stenosis was managed by observation and endoscopic dilation in 2 each. Severe stenosis in 1 patient was associated with significantly impaired ipsilateral renal function. CONCLUSIONS: Infundibular stenosis is a rare complication of percutaneous nephrolithotomy. In this series it was associated with prolonged operative time, a large stone burden requiring multiple removal procedures and extended postoperative nephrostomy tube drainage. In most cases stenosis developed at previous access sites within 1 year of initial percutaneous nephrolithotomy. Mild and moderate cases may be treated with observation and endoscopic dilation, respectively, while severe cases may result in renal impairment.