Clearance of lower-pole stones following shock wave lithotripsy: effect of the infundibulopelvic angle

• Published in: European urology Vol. 36; no. 5; p. 371
• Main Authors: Keeley, Jr, F X, Moussa, S A, Smith, G, Tolley, D A
• Format: Journal Article
• Language: English
• Published: Switzerland 01.11.1999
• Subjects: Adolescent; Adult; Aged; Aged, 80 and over; Analysis of Variance; Female; Follow-Up Studies; Humans; Kidney Calculi - diagnosis; Kidney Calculi - therapy; Kidney Pelvis - anatomy & histology; Kidney Pelvis - diagnostic imaging; Lithotripsy - methods; Male; Middle Aged; Observer Variation; Predictive Value of Tests; Treatment Outcome; Urography
• ISSN: 0302-2838
• DOI: 10.1159/000020016

To assess the effect of anatomic factors, especially the angle of the lower-pole infundibulum, on stone clearance following shock wave lithotripsy (SWL) in order to determine selection criteria for percutaneous nephrolithotomy. We retrospectively analyzed 116 patients with single lower-pole stones measuring 11-20 mm treated with SWL. Intravenous urograms were reviewed to measure the infundibulopelvic angle, the angle of the infundibulum to the vertical, and the anatomy of lower-pole calyces. The overall stone-free rate was 52%. Factors most closely associated with a stone-free status were obtuse infundibulopelvic angle, lack of calyceal distortion, and a large infundibular diameter. The infundibulopelvic angle was the only factor to attain significance in predicting stone-free status (p = 0.012). The size of the stone did not predict eventual stone-free status (p = 0.911), but larger stones were more likely to require intervention after SWL. For solitary lower-pole stones 11-20 mm in size, the angle of the lower-pole infundibulum as it relates to the pelvis plays a role in eventual stone clearance and should be taken into account before choosing a mode of treatment.