Outcomes analysis of percutaneous antegrade endopyelotomy

INTRODUCTION AND OBJECTIVES: Factors that play a role in endopyelotomy failure are thought to include high grade hydronephrosis and the presence of crossing vessels. We sought to evaluate the role of primary versus secondary obstruction, hydronephrosis, renal function, type of stent used for postoperative drainage, and surgeon experience in determining endopyelotomy outcome. METHODS: The last 401 percutaneous antegrade endopyelotomies with at least 6 month follow-up were analyzed retrospectively. Hydronephrosis was graded based on the degree of dilation seen on preand post-operative intravenous pyelograms (massive, severe, moderate, and mild). Renal function was assessed by the means of split renal function on nuclear scintigraphy (>40%-good, 25-40%-moderate, <25%-poor). The outcome was considered successful if the patient remained completely asymptomatic at the time of most recent follow-up and had no evidence of obstruction in follow-up radiographic studies. Equivocal cases (persistent symptoms or possible obstruction) were usually evaluated by means of a Whitakertest. RESULTS: Success rates were 85% overall, 89% for secondary obstruction, and 82% for primary obstruction, 87% in men, and 84% in women. The average age of successful patients was 42, and for failed patients 37. Patients with high grade hydronephrosis and poor initial renal function were much less likely to have successful outcome than patients without these factors (50% vs. 96% and 54% vs. 92%, p< 0.001). The type of stent used for drainage and the experience of the surgeon had no statistically significant impact on success. CONCLUSIONS: Degree of hydronephrosis and initial renal function play important roles in determinig the outcome following percutaneous antegrade endopyelotomy.