Login to Access Video or Poster Abstract: MP50-02
Sources of Funding: None

Introduction

Impacted ureteral stones have been variably defined as stones that have not moved for 2 months or that are not bypassable with a guidewire or with contrast. Impaction has been reported to lead to stricture rates as high as 24%, but the factors that predict for stricture formation, persistent hydronephrosis, or renal dysfunction have not been described in the literature.

Methods

A prospective series of 54 newly diagnosed consecutive patients with impacted ureteral calculi who were treated by a single surgeon between August 2014 and July 2016 with retrograde ureteroscopy and laser lithotripsy (URSLL) were assessed for preoperative (imaging and labs) and intraoperative (OR time, difficulty of case, need for stent, complications) factors. These factors were then correlated with outcome parameters including stone-free rates, complications such as stricture development, resolution of hydronephrosis, and change in serum creatinine.

Results

The average age of patients was 54 +/- 13 including 21 females and 33 males. Preoperative hydronephrosis was noted in 39 of the 49 patients (mild 19, moderate 14, severe 6). Serum creatinine was normal in 43 patients and elevated in 11. Site of impaction was proximal ureter in 18, mid ureter in 22, and distal ureter in 14. Mean stone size was 7.7 +/- 3.3 mm. Measured mean serum creatinine improved from 1.11 +/- 0.29 preoperatively to 0.97 +/- 0.18 post-operatively. Three patients had postoperative hydronephrosis, with a stricture diagnosed in the mid ureter in two patients. Both patients with strictures had failed initial URSLL at an outside institution which resulted in a severe inflammatory response with residual fragments likely embedded in the ureteral wall. Strictures were amenable to laser incision.

Conclusions

Impacted ureteral stones are successfully managed in 94% of patients with resolution of hydronephrosis and normal serum creatinine post treatment with URSLL. Preoperative factors such as hydronephrosis, elevated serum creatinine, stone size, and stone location do not reliably predict outcomes of URSLL for impacted stones. Intraoperative factors and technique are the most important factors affecting outcome. Silent obstruction can occur and all patients with impacted stones should have routine postoperative imaging to rule out hydronephrosis regardless of symptoms.

Funding

None