Korean J Urol.  2010 Oct;51(10):719-723.

Use of NTrap(R) during Ureteroscopic Lithotripsy for Upper Ureteral Stones

• Lee MJ
• Lee ST
• Min SK

Abstract

PURPOSE
This study aimed to determine the value of the NTrap(R) (Cook Urological INC, USA), which was designed to block the upward movement of stones during ureteroscopic lithotripsy.
MATERIALS AND METHODS
We 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(R) were assigned to Group I and 76 patients who underwent ureteroscopic lithotripsy with the NTrap(R) 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.
RESULTS
The 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.
CONCLUSIONS
NTrap(R), 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.

Keyword

Ureteral calculi; Ureteroscopy

MeSH Terms

Humans
Lithotripsy
Postoperative Complications
Retrospective Studies
Sex Ratio
Ureter
Ureteral Calculi
Ureteroscopy

Figure

• 

  FIG. 1 The NTrap® in its packaging (A), before pushing the inner core (B), and after pushing the inner core (C).

Reference

1. Tawfiek ER, Bagley DH. Management of upper urinary tract calculi with ureteroscopic techniques. Urology. 1999. 53:25–31.

2. Denstedt JD, Clayman RV. Electrohydraulic lithotripsy of renal and ureteral calculi. J Urol. 1990. 143:13–17.

3. Denstedt JD, Eberwein PM, Singh RR. The Swiss Lithoclast: a new device for intracorporeal lithotripsy. J Urol. 1992. 148:1088–1090.

4. Scarpa RM, De Lisa A, Porru D, Usai E. Holmium:YAG laser ureterolithotripsy. Eur Urol. 1999. 35:233–238.

5. Desai MR, Patel SB, Desai MM, Kukreja R, Sabnis RB, Desai RM, et al. The Dretler stone cone: a device to prevent ureteral stone migration-the initial clinical experience. J Urol. 2002. 167:1985–1988.

6. Singal RK, Denstedt JD. Contemporary management of ureteral stones. Urol Clin North Am. 1997. 24:59–70.

7. Fuchs AMD, Fuchs GJ. Retrograde intra-renal surgery for calculus disease: new minimally invasive treatment approach. J Endourol. 1990. 4:337–345.

8. Scales CD, Kang D, Munver R, Auge BK, Ekeruo W, Haleblian GE, et al. Changing practice patterns for the surgical management of renal calculi. J Urol. 2006. 175:Suppl 4. 549.

9. Kim JH, Sung LH, Noh CH. Comparison between rigid ureteroscopic stone removal (URS) and extracorporeal shock wave lithotripsy (ESWL) for large (>10 mm) upper ureteral stones. Korean J Urol. 2006. 47:933–937.

10. Zheng W, Denstedt JD. Intracorporeal lithotripsy. Update on technology. Urol Clin North Am. 2000. 27:301–313.

11. Menezes P, Kumar PV, Timoney AG. A randomized trial comparing lithoclast with an electrokinetic lithotripter in the management of ureteric stones. BJU Int. 2000. 85:22–25.

12. Knispel HH, Klän R, Heicappell R, Miller K. Pneumatic lithotripsy applied through deflected working channel of miniureteroscope: results in 143 patients. J Endourol. 1998. 12:513–515.

13. Robert M, Bennani A, Guiter J, Avérous M, Grasset D. Treatment of 150 ureteric calculi with the Lithoclast. Eur Urol. 1994. 26:212–215.

14. Sun Y, Wang L, Liao G, Xu C, Gao X, Yang Q, et al. Pneumatic lithotripsy versus laser lithotripsy in the endoscopic treatment of ureteral calculi. J Endourol. 2001. 15:587–590.

15. Marguet CG, Sung JC, Springhart WP, L'Esperance JO, Zhou S, Zhong P, et al. In vitro comparison of stone retropulsion and fragmentation of the frequency doubled, double pulse nd:yag laser and the holmium:yag laser. J Urol. 2005. 173:1797–1800.

16. Bagley DH, Slotoroff CB, Zeltser IS. Evolution of ureteroscopy from 1996 to 2004: comparison of indications, endoscopes and instruments. J Endourol. 2005. 19:Suppl 1. 75.

17. Ouwenga MK, Sharma SK, Holley P, Turk TM, Perry KT. Load-release points of two novel ureteral stone-trapping devices. J Endourol. 2005. 19:894–897.

18. Olbert PJ, Keil C, Weber J, Schrader AJ, Hegele A, Hofmann R. Efficacy and safety of the Accordion stone-trapping device: in vitro results from an artificial ureterolithotripsy model. Urol Res. 2010. 38:41–46.

19. Chung HS, Park JY, Kim HK, Park CM. Efficacy of the Stone Cone for treatment of proximal ureteral stones: an initial clinical experience. Korean J Urol. 2006. 47:412–417.

20. Han DJ, Moon HY, Kim CS. Efficacy of the NTrap® for the treatment of ureteral stone: an initial clinical experience. Korean J Urol. 2007. 48:1161–1164.