Search

Abstract: The objective of this study was to explore the influence of ureteral stent on renal pelvic pressure by urodynamic study. 41 patients (with unilateral renal and/or ureteral calculi) after minimally invasive percutaneous nephrolithotomy (MPCNL) were placed a 4.7-Fr ureteral stent and 16-Fr nephrostomy tube. Renal pelvic pressure of these patients was measured by urodynamic study at the 5–7 days after MPCNL. Renal pelvic pressure (RPP), intraabdominal pressure (IAP), and vesical pressure (VP) during the filling and voiding phases were detected by urodynamic study with intravesical perfusion. At the baseline, intraabdominal pressure (IAP0) was 27.52 ± 7.03 cmH2O, renal pelvic pressure (RPP0) was 33.07 ± 7.04 cmH2O; at the maximum cystometric bladder capacity (MCBC) during the filling phase, vesical pressure (VPvol) was 41.61 ± 10.34 cmH2O, renal pelvic pressure (RPPvol) was 39.44 ± 7.33 cmH2O; at the maximum vesical pressure during the voiding phase, vesical pressure (VPmax) was 74.95 ± 12.79 cmH2O, renal pelvic pressure (RPPmax) was 65.68 ± 17.03 cmH2O. (1) There was a strong relationship between RPP0 and IAP0 (P = 0.0001); (2) There was statistical significance among RPP0, RPPvol and RPPmax (P = 0.0001); (3) RPP was higher than 40 cmH2O during the voiding phase, and it was obviously relevant to the VP (P = 0.0001) but not to the MCBC (P = 0.2696). RPP increased mildly during the filling phase and dramatically during the voiding phase after stenting. RPP increased higher than the level required for a backflow (40 cmH2O) during the voiding phase. So it was encouraged to remove the stent at earlier stage or decrease using the ureteral stent if possible.

Abstract: We conducted a prospective, randomized study to evaluate whether postoperative ureteral stenting is necessary after ureteroscopic holmium laser lithotripsy. A total of 115 consecutive patients with distal or middle ureteral calculi amenable to ureteroscopic holmium laser lithotripsy were prospectively randomized into stented group (n = 58) and nonstented group (n = 57). The stent was routinely placed in the treated ureter for 2 weeks. The outcomes were measured with postoperative patient symptoms, stone-free rates, early and late postoperative complications, and cost-effectiveness. The postoperative symptoms were measured with Ureteral Stent Symptom Questionnaire (USSQ). All patients completed a 12-week follow-up. There was no significant difference between two groups with respect to the patient age, stone size, stone location and mean operative time. According to the USSQ, the symptoms of the stented group were significantly worse compared to the nonstented group (P = 0.0001). In the stented group, two patients had high fever for 1 week after the operation, stent migration was found in two patients, and the stents had to be removed earlier in five patients because of severe pain or hematuria. The cost of the stented group was significantly higher than the nonstented group. The stone-free rate was 100% in both groups. No hydronephrosis or ureteral stricture was detected by intravenous pyelogram in the 12th week postoperative follow-up. In conclsion, we believe that routine stenting after ureteroscopic intracorporeal lithotripsy with the holmium laser is not necessary as long as the procedure is uncomplicated for distal or middle ureteral calculis less than 2 cm.