Objective: To investigate the changes of intrarenal pressure in response to continuous irrigation at different pressures during ureteroscopic lithotripsy.
Methods: Eleven patients with residual ureteral calculi after percutaneous nephrolithotomy (PCNL), 8 in the proximal section, 2 in the middle section, 1 in the distal section. And one patient with calculi in the distal ureteral section underwent ureteroscopic lithotripsy. Renal fistula tube was connected with a urine dynamic detector and irrigation was performed continuously through the ureteroscope at different pressures. The baseline intra-pelvic pressure (IPP(0)) and maximum intra-pelvic pressure (IPP(max)) were recorded.
Results: The average IPP(0) was (16.9 +/- 3.2) cm H(2)O. The IPP levels during the ureteroscopic lithotripsy [(172.6 +/- 32.2) cm H(2)O] were all significantly higher than the IPP(0) (all P < 0.01). In response to the irrigation pump pressure of 100 mmHg, the IPP(max) during the ureteroscopic lithotripsy in the distal, middle, and proximal ureter were 74.6, 93.5, and (110.3 +/- 2.4) cm H(2)O respectively. When the irrigation pump pressure levels were 50, 100, and 200 mm Hg respectively the IPP(max) levels during the ureteroscopic lithotripsy in the proximal ureter were (51.0 +/- 4.5), (110.3 +/- 2.4), and (193.2 +/- 5.9) cm H(2)O respectively (all P < 0.01).
Conclusion: The renal pelvic pressure is significantly increased during ureteroscopic lithotripsy. High renal pelvic pressure is associated with the irrigation pressure and the position of calculi.