Nitinol stone retrieval-assisted ureteroscopic management of lower pole renal calculi

Duke University, Durham, North Carolina, United States
Urology (Impact Factor: 2.13). 01/2001; DOI: 10.1016/S0090-4295(00)00821-9

ABSTRACT Objectives. Current ureteroscopic intracorporeal lithotripsy devices and stone retrieval technology allow for the treatment of calculi located throughout the intrarenal collecting system. Difficulty accessing lower pole calculi, especially when the holmium laser fiber is used, is often encountered. We retrospectively reviewed our experience with cases in which lower pole renal calculi were ureteroscopically managed by holmium laser fragmentation, either in situ or by first displacing the stone into a less dependent position with the aid of a nitinol stone retrieval device.Methods. Thirty-four patients (36 renal units) underwent ureteroscopic treatment of lower pole renal calculi between April 1998 and November 1999. Lower pole stones less than 20 mm were primarily treated by ureteroscopic means in patients who were obese, in patients who had a bleeding diathesis, in patients with stones resistant to shock wave lithotripsy, and in patients with complicated intrarenal anatomy, or as a salvage procedure after failed shock wave lithotripsy. Lower pole calculi were fragmented with a 200-μm holmium laser fiber by way of a 7.5F flexible ureteroscope. For those patients in whom the laser fiber reduced the ureteroscopic deflection, precluding re-entry into the lower pole calix, a 3.2F nitinol basket or a 2.6F nitinol grasper was used to displace the lower pole calculus into a more favorable position, allowing easier fragmentation.Results. In 26 renal units, routine in situ holmium laser fragmentation was successfully performed. In the remaining 10 renal units, a nitinol device was passed into the lower pole, through the ureteroscope, for stone displacement. Only a minimal loss of deflection was seen. Irrigation was significantly reduced by the 3.2F nitinol basket, but improved with the use of the 2.6F nitinol grasper. This factor did not impede stone retrieval in any of the patients. At 3 months, 85% of patients were stone free by intravenous urography or computed tomography.Conclusions. Ureteroscopic management of lower pole calculi is a reasonable alternative to shock wave lithotripsy or percutaneous nephrolithotomy in patients with low-volume stone disease. If the stone cannot be fragmented in situ, nitinol basket or grasper retrieval, through a fully deflected ureteroscope, allows one to reposition the stone into a less dependent position, thus facilitating stone fragmentation.

  • [Show abstract] [Hide abstract]
    ABSTRACT: Extracorporeal Shock Wave Lithotripsy (ESWL) is currently the recommended treatment for intra-renal calculi smaller than 2 cm. However the low Stone Free Rate (SFR) in lower pole calculi gives rise to new techniques, such us retrograde intrarenal surgery (RIRS), for improve the surgery outcomes.Objective To compare the efficacy of a treatment with ESWL with RIRS, in terms of SFR after surgery, in patients with kidney stones up to 15 mm in the lower pole.Material and methodsA prospective study was carried out in order to assess the results of ESWL and RIRS in patients with lower pole stones less than 15 mm. Among a total of 55 patients, 31 were underwent to ESWL (Group 1) and the remaining 24 to RIRS (Group 2). Clinical data recorded, including general characteristics of each patient, were: calculi size, side, operative time, complications according to Clavien scale, SFR and the presence of residual fragments at 2 months post-treatment assessed by a CT scan. STATA 11 was used to perform the statistical analysis.ResultsThere were no differences for general descriptors among groups with the exception of a significantly longer operative time for RIRS. The rates of SFR and residual fragments lesser than 3 mm. were lower in the RIRS group than in ESWL ones. RIRS also showed a lower rate of clinically significant fragments (0% vs 42.3%. P < .05). In the subgroup of patients with stones between 10/15 mm RIRS showed higher SFR (75% vs. 41.2%) and a lower rate of stones > 3 mm (0% vs. 58.8%), being statistically significant (P < .05). Clavien III or higher complications were not reported in any of the groups.Conclusions In the treatment of lower pole stone RIRS has the same results than ESWL in terms of SFR. Regarding absence of a clinically significant residual fragment, RIRS was superior to ESWL. A bigger sample size is required in order to confirm this results.
    Actas urologicas españolas 11/2014; DOI:10.1016/j.acuro.2014.08.003 · 1.15 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: OBJECTIVE Flexible ureterorenoscopy (f-URS) for lower pole stones (LPS) compared to other renal locations can be challenging, due to anatomical and technical considerations. We aimed to compare stone free rate (SFR) and surgical complication rate with f-URS for LPS vs other renal locations. PATIENTS AND METHODS We carried out a retrospective, single-centre study including 371 f-URS for renal stone retrieval performed in our institution between January 2004 and December 2010. Among the 371 procedures included in this analysis, 139 were performed for stones located in a single renal location other than the lower pole (Group 1), and 232 for at least one stone located in the lower pole (Group 2). We compared the efficacy (SFR) and the morbidity of f-URS between the 2 groups. The success of the procedure was defined as a complete SFR 6 months after f-URS. RESULTS Age, gender, history of urolithiasis, body mass index and pre-operative stenting did not differ between the 2 groups. No differences in stone characteristics were observed between both groups except stone size under 10 mm that was significantly higher in Group 2 (p=0.018). Technical aspects of the procedure did not differ between the groups, except for more frequent use of access sheath in group 2 (p=0.007). SFR was comparable between groups (p=0.774). The complication rate was similar in both groups, as was the severity of complications. By multivariate analysis, stone size >10 mm (p<0.0001) and multiple stone locations (p=0.001) were associated with f-URS failure, but lower pole location did not impact on SFR. CONCLUSION In our study, stone location, in particular LPS, did not have any impact on efficacy and morbidity of f-URS. Only multiple locations and stone size >10 mm seemed to significantly decrease the SFR, without impacting morbidity.
    Journal of endourology / Endourological Society 05/2014; DOI:10.1089/end.2014.0286 · 2.10 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The optimal management of lower pole renal calculi is controversial. We compared shock wave lithotripsy (SWL) and ureteroscopy (URS) for the treatment of patients with small lower pole stones in a prospective, randomized, multicenter trial.Materials and Methods:A total of 78 patients with 1 cm or less isolated lower pole stones were randomized to SWL or URS. The primary outcome measure was stone-free rate on noncontrast computerized tomography at 3 months. Secondary outcome parameters were length of stay, complication rates, need for secondary procedures and patient derived quality of life measures.Results:A total of 67 patients randomized to SWL (32) or URS (35) completed treatment. The 2 groups were comparable with respect to age, sex, body mass index, side treated and stone surface area. Operative time was significantly shorter for SWL than URS (66 vs 90 minutes). At 3 months of followup 26 and 32 patients who underwent SWL and URS had radiographic followup that demonstrated a stone-free rate of 35% and 50%, respectively (p not significant). Intraoperative complications occurred in 1 SWL case (unable to target stone) and in 7 URS cases (failed access in 5 and perforation in 2), while postoperative complications occurred in 7 SWL and 7 URS cases. Patient derived quality of life measures favored SWL.Conclusions:This study failed to demonstrate a statistically significant difference in stone-free rates between SWL and URS for the treatment of small lower pole renal calculi. However, SWL was associated with greater patient acceptance and shorter convalescence.
    The Journal of Urology 06/2005; 173(6):2005-2009. DOI:10.1097/01.ju.0000158458.51706.56 · 3.75 Impact Factor