Background and Purpose: We investigate a ureteral stent with radially expanding baskets producing passive dilation of the ureter for passage, capture, and removal of small ureteral stones.
Patients and Methods: Polyurethane ureteral stents were slit to open 15 to 17 baskets along the length. The baskets are designed to dilate the ureter passively and capture stones ≤5 mm. Forty-two patients had these stents placed for stones at nine medical centers. Stone size ranged from 2 to 30 mm, while fragment size ranged from 1 to 8 mm. The locations of the stones ranged from the kidney to the lower ureter. The Ureteral Expanding Stent was inserted in the closed position, similar to a standard ureteral stent, and left in place for an average of 11 days.
Results: The device was inserted and extracted safely in all patients. Most patients experienced pain at an average rating of 3.7 of 10 on a visual analog scale. All stents were removed without significant morbidity. In 36 patients (86%), stones were removed with the stent (n = 18) or passed while the stent was in place (n = 18). The largest stone captured was 6 mm.
Conclusions: The Ureteral Expanding Stent (OPEN-PassTM) was used safely in 42 patients with stones. The device captured ureteral stones and facilitated stone passage around it. Stent retention or ureteral injury as a result of stone entrapment did not occur. The Ureteral Expanding Stent represents a new stone-removal and ureteral-dilation tool worthy of further clinical study.
