Background and purpose: Objective parameters for the classification of ureteral injuries and resulting indications for ureteral stent placement after ureteroscopy are lacking. We hereby present a new classification system including proof of interrater reliability and validation of recommendations for postoperative ureteral stent placement.
Patients and methods: The Postureteroscopic Lesion Scale (PULS) was applied in 435 patients undergoing ureteroscopy. Interrater reliability between three surgeons (junior resident, senior resident, and specialist) was evaluated in 112 patients. Postoperative ureteral stent placement was performed according to PULS. For follow-up with ultrasonography, we assumed hydronephrosis to be an indirect sign for significant postoperative ureteral obstruction.
Results: No ureteral lesion was seen in 46.2% of patients (grade 0). A grade 1, 2, or 3 lesion was seen in 30.8%, 19.1%, and 3.9% of patients, respectively. No grade 4 or 5 lesions were observed in our series. Interrater reliability was high (Kendall W=0.91; mean Spearman Rho=0.86). This was particularly true between senior resident and specialist (Rho=0.95), compared with junior resident and senior resident or specialist (Rho=0.83, Rho=0.79, respectively). All patients with documented lesions had a Double-J stent placed. Indwelling time varied according to PULS. Results of a postoperative ultrasonographic follow-up could be obtained in 95.6% of cases. No patient showed clinical or sonographic signs of upper urinary tract obstruction.
Conclusions: According to these preliminary data for the clinical application of PULS, interrater reliability is high. Standardized empiric recommendations for the use and duration of postoperative stent placement after ureteroscopy might be useful in guiding urologists in this conversely discussed issue, ultimately preventing ureteral strictures as a late complication of ureteroscopy. These will have to be confirmed, however, by controlled trials in the future.