Multislice computed tomography vs. intravenous urography for planning supine percutaneous nephrolithotomy: A randomised clinical trial

Objective:
To compare the outcome of treatment planning using multislice computed tomography (CT) or intravenous urography (IVU) for supine percutaneous nephrolithotomy (PCNL).

Patients and methods:
The study included 60 patients with renal stones, all treated by supine PCNL, between March 2011 and October 2012. The patients were divided randomly into two equal groups; in group 1 30 patients had the PCNL access planned based on IVU findings, and in group 2 the PCNL access was planned based on multislice CT images. All patients were suitable for PCNL, based on a plain abdominal film and ultrasonography, and with a body mass index of <30 kg/m2. The exclusion criteria were renal anomalies and bleeding diathesis. All data from both groups for the mean time taken to gain percutaneous access, operative duration, fluoroscopic time, access difficulty, stone-free rate and intraoperative morbidity were collected and analysed statistically.

Results:
The mean (SD) time taken to gain percutaneous access was longer in group 1 than group 2, at 22.2 (1.76) vs. 13.1 (1.62) min (P < 0.001), as were the operative duration, at 81.9 (14.9) vs. 58.8 (7.6) min (P < 0.001), and fluoroscopic time, at 3.5 (1.7) vs. 2.2 (1.3) min (P = 0.002). In group 1 there were four cases (13%) in which there were difficulties in establishing percutaneous access, while in group 2 there were none (P = 0.003). There was intraoperative morbidity in three patients (10%) in group 1 and two (7%) in group 2.

Conclusion:
Multislice CT is a safer, more accurate and noninvasive imaging technique than IVU for mapping the pelvicalyceal system. It saves time and is essential in choosing the optimal percutaneous access into the pelvicalyceal system for a safe and successful PCNL.