The impact of preoperative percutaneous nephrostomy as a treatment strategy before flexible ureteroscopy for impacted upper ureteral stones with hydronephrosis

Abstract

Background: The treatment of impacted upper ureteral stones with hydronephrosis remains a challenge for urologists. The current study aimed to evaluate the impact of preoperative percutaneous nephrostomy (PNS) as a treatment strategy before flexible ureteroscopy (f-URS) of asymptomatic impacted upper ureteral stones with hydronephrosis.Methods: This multicenter retrospective study included patients who underwent PNS (group A, n=61) and those who did not (group B, n=75) before f-URS for asymptomatic impacted upper ureteral stones with hydronephrosis. Impacted ureteral stones are defined as those that remain in one position for >2 months.Operative outcomes, including stone-free rate, operation time, postoperative hospital days, and complication rate, were evaluated.Results: There were no significant differences in age, sex, and stone size between the two groups except in the grade of hydronephrosis, with group A having more cases of advanced hydronephrosis than group B. The stone-free rate was significantly higher in group A than in group B [95% vs. 77% (P=0.004)]. However, there were no significant differences between the groups in operation time [55 vs. 55 min (P=0.84)], postoperative fever [5% vs. 5% (P=1.00)], and postoperative hospital days [2 vs. 2 days (P=0.44)]. In group A, preoperative PNS placement was performed 4 days before f-URS, and the PNS was removed postoperatively on the same day of the f-URS. Additionally, subgroup analysis was performed in cases of grade 2 and 3 hydronephrosis. A total of 110 patients, 60 who underwent f-URS with PNS and 50 who underwent f-URS without PNS, were included. The stone-free rate was significantly higher in f-URS with PNS than in f-URS without PNS [95% vs. 76% (P=0.005)]. However, no significant differences were found between the groups in operation time, ureteral injury, postoperative fever, and postoperative hospital days.Conclusions: At grade 2 or 3 hydronephrosis, preoperative PNS as a treatment strategy for a few days prior to f-URS for impacted upper ureteral stones improved the stone-free rate without increasing the operation time and postoperative length of hospital stay.

Area of hydronephrosis is a useful predictive factor of impacted ureteral stones

“…Moreover, if impacted stones can be predicted, it may be possible to plan certain treatment strategies preoperatively. Anan et al showed that preoperative percutaneous nephrostomy would improve the stone-free rate in patients who underwent URSL for impacted stones [ 14 ]. Other papers also revealed that antegrade URSL in large impacted upper ureteral calculi was a safe and efficient treatment option [ 9 , 10 ].…”

“…It seems that the more severe the obstruction of the ureter becomes, the worse the degree of hydronephrosis will be. Hydronephrosis, which is evaluated by grading system (e.g., SFU grade), has often been apparent in previous reports [ 2 , 12 , 14 ]. However, the grading system is based upon qualitative factors.…”

Area of hydronephrosis is a useful predictive factor of impacted ureteral stones

“…If impacted stones can be predicted, some treatment strategies may be able to be planned preoperatively. Anan et al showed that preoperative percutaneous nephrostomy would improve the stone-free rate in patients who underwent URSL for impacted stones [14]. Other papers also revealed that antegrade URSL in large impacted upper ureteral calculi was a safe and e cient treatment option [9,10].…”

“…It seems that the more severe the obstruction of the ureter becomes, the worse the degree of hydronephrosis will be. Hydronephrosis, which is evaluated by grading system (e.g., SFU grade), has often been apparent in previous reports [2,12,14].…”

What are the predictors of residual stone after ureteroscopy for urolithiasis?

“…Second, there are differences in terms of surgical methods (rigid or flexible URS) and surgical equipment (laser device or basket catheters). In addition, the presence of a preoperative ureteral stent and impacted stone has a significant impact on surgical outcomes (17). As patient background, a relatively large number of patients in some nomograms had a ureteral stent inserted before the URS procedure (18).…”