Use of NTrap® during Ureteroscopic Lithotripsy for Upper Ureteral Stones

Abstract

PurposeThis study aimed to determine the value of the NTrap® (Cook Urological INC, USA), which was designed to block the upward movement of stones during ureteroscopic lithotripsy.Materials and MethodsWe reviewed the data of 144 patients who underwent ureteroscopic lithotripsy for an upper ureteral stone from June 2006 to May 2010. Sixty-eight patients who underwent ureteroscopic lithotripsy without the use of the NTrap® were assigned to Group I and 76 patients who underwent ureteroscopic lithotripsy with the NTrap® were assigned to Group II. The size of the stones, operation time, success rate, and pre- and postoperative complications were compared retrospectively between the two groups.ResultsThe mean age of the patients (Group I: 35.8 years; Group II: 32.6 years) and the sex ratios were not significantly different between the two groups. The mean size of the stones was 6.9 mm and 7.4 mm, which also was not significantly different between the two groups. The mean operation time was 82.7 minutes and 78.7 minutes. The operation time was shorter in Group II, but the difference was not significant. The success rate of stone removal was 89.7% and 98.7% in Groups I and II, respectively; Group II showed a significantly higher success rate. Two cases of ureteral perforation and one case of ureteral avulsion occurred in Group I, and one case of ureteral perforation occurred in Group II.ConclusionsNTrap®, which is an instrument used to assist during ureteroscopic lithotripsy, can be considered to be an effective tool that blocks the upward movement of the stone and aids in safe stone removal.

The Efficacy and Safety of Simultaneous Use of Wire Stone Basket and Pneumatic Lithotripter Probe in the Treatment of Ureteral Stones: Randomized Control Trial

“…The need to perform ESWL and ESWL with DJ was significantly higher in the control group (p <0.05). Several studies in the treatment of ureteroscopic lithotripsy have shown that the most common cause of failure of lithotripsy can be attributed to stone retropulsion and the movement of stone pieces into the pelvis or kidney calyx during lithotripsy [11]. This can increase costs due to secondary interventions and morbidity [12,[16][17][18].…”

“…The risk of stone retropulsion or the escaping of the stone is affected by factors such as washing fluid pressure, the energy source type of transurethral lithotripsy, the location and the amount of stone compression in the ureter, and the proximal ureter dilatation severity. The rate of stone migration in pneumatic and electrohydraulic lithotripters is higher than that of a laser lithotripter [11]. Stone upward migration may increase the time of lithotripsy due to time waste of trapping stones fragments that have migrated to the back.…”

“…Desai MR, et al reported 5-40% rates of stone retropulsion during ureteroscopic lithotripsy of proximal and distal ureteral stone cases [7]. Its rate for all types of pneumatic lithotripter is 15 to 48 percent [8][9][10].Several studies in the treatment of ureter stones have shown that the most common cause of stone removing failure can be attributed to the migration of stone parts [11]. Retropulsion rate is more common in proximal ureter stones and often the failure of lithotripsy is due to inability to recapture the stone in a hydronephrotic ureter [2].…”

“…Different mechanical tools for preventing stone retropulsion include: 1-Lithovac suction device 2-Stone basket 3-N-Trap 4-stone cone 5-Accordion 6-Passport balloon [2,8,11,[13][14][15]. Also, the use of the lubricant gel and back stone gel have been reported and this substance is injected into the proximal part of the stone and prevents stone retropulsion [11].…”

Use of XenX™, the latest ureteric occlusion device with guide wire utility: results from a prospective multicentric comparative study

“…Most significant results have been published in a recent meta-analysis [17] including 2 randomized controlled trials [18,19] and 1 case-control study [20]: stonefree rate for N-Trap™ ranged from 83 to 100 %, which was significantly higher than controls also at the pooled analysis [OR = 3.08, 95 % CI (1.45-6.53)].…”