Impact of Stone Location on Success Rates of Endoscopic Lithotripsy for Nephrolithiasis

Division of Urology, West Virginia University, Morgantown, West Virginia 26506, USA.
Urology (Impact Factor: 2.19). 03/2008; 71(2):214-7. DOI: 10.1016/j.urology.2007.09.023
Source: PubMed


To determine whether stone location affects the stone-free rates of endoscopic lithotripsy for nephrolithiasis.
From January 2002 to August 2006, 245 patients with 272 stones, ranging from 4 to 20 mm in size, underwent ureteroscopy (URS) with laser lithotripsy at West Virginia University Hospital. The patients were followed up postoperatively with noncontrast spiral computed tomography, abdominal plain radiography, renal ultrasonography, or retrograde pyelography. Patients were considered to have been treated successfully if they had no residual stones. All pediatric patients were excluded, as were all patients with stones greater than 2 cm. Also, patients who had undergone previous shock wave lithotripsy, percutaneous nephrolithotripsy, or URS by an outside urologist were excluded.
A total of 86 kidney stones were treated with URS and laser lithotripsy. Of these, 81 (94.2%) were successfully treated. Five patients (5.8%) had persistent stones. All 18 upper pole stones (100%) were cleared, 23 (95.8%) of 24 middle pole stones were cleared, and 40 (90.9%) of 44 lower pole stones were cleared (P = 0.338).
URS is an important tool for treating nephroureterolithiasis with excellent success rates and minimal morbidity. The results of our study have shown that stone location does not significantly affect stone clearance rates when performing endoscopic lithotripsy for intrarenal calculi.

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    • "Breda et al. evaluated 51 patients with 161 renal stones (mean stone size of 6.6 mm) and they found the overall stone-free rate after single and second procedures was 64.7% and 92.2%, respectively [8]. In a different study, Perlmutter et al. evaluated the impact of stone location on success rates of flexible URS [28]. A total of 86 renal stones were treated, and the stone-free rates for upper-, middle-, and lower-caliceal stones were 100%, 95.8%, and 90.9%, respectively. "
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    ABSTRACT: Today, shock wave lithotripsy (SWL), percutaneous nephrolithotomy (PCNL), and flexible ureterorenoscopy (URS) are the most widely used modalities for the management of renal stones. In earlier series, treatment success of renal calculi assessed with KUB radiography, ultrasound, or intravenous pyelography which are less sensitive than CT that leads to be diversity of study results in reporting outcome. Residual fragments (RFs) after interventional therapies may cause pain, infection, or obstruction. The size and location of RFs following SWL and PCNL are the major predictors for clinical significant symptoms and stone events requiring intervention. There is no consensus regarding schedule for followup of SWL, PCNL, and flexible URS. Active monitoring can be recommended when the stones become symptomatic, increase in size, or need intervention. RFs <4 mm after SWL and <2 mm after PCNL and flexible URS could be actively monitored on an annual basis with CT. Early repeat SWL and second-look endoscopy are recommended after primary SWL and PCNL, respectively. There is insufficient data for flexible URS, but RFs can be easily treated with repeat URS. Finally, medical therapy should be tailored based on the stone analysis and metabolic workup that may be helpful to prevent regrowth of the RFs.
    Advances in Urology 07/2012; 2012(6):813523. DOI:10.1155/2012/813523
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    • "In the present study, stone position did not affect the SFR. This is consistent with another study by Perlmutter et al., who found no significant differences in the SFR between stones in different positions (10). When lower-pole stones were analyzed separately, the SFR was 44.4%. "
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    ABSTRACT: Retrograde intra-renal surgery (RIRS) has been used to remove stones of less than 2 cm in the kidney. However, its role is not well defined. The objective of this study was to evaluate the outcomes and safety of RIRS, used either as a primary or secondary procedure, and to analyze factors predicting the stonefree rate (SFR). A retrospective analysis was performed on data from patients who underwent RIRS over a 10-year period (2002-2012). Stone size was measured as the surface area and was calculated according to the EAU guidelines. In cases of multiple stones, the total stone burden was calculated as the sum of each stone size. Stone burden was then classified as ≤ 80 mm(2) or > 80 mm(2). RIRS was classified as primary procedure or secondary procedure (after failed extracorporeal shockwave lithotripsy or percutaneous nephrolithotripsy).Stone clearance was defined as a complete absence of stones or stones < 4 mm, which were deemed insignificant on ultrasonography and plain radiography. The overall SFR for renal stones treated with RIRS in our center was 55.4%, and the complication rate was 1.5%, which consisted of one case of sepsis. The only factor affecting SFR in this study was the indication for RIRS. When performed as a primary operation, RIRS showed a significantly better SFR (64.3%). The SFR for lower pole stones was only 44.4%. There were no statistically significant effects of stone burden, radio-opacity, or combination with ureteral stones on SFR. RIRS should be used as the primary treatment for renal stones whenever possible.
    03/2012; 4(2):454-7. DOI:10.5812/numonthly.2211
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    • "In 1990, indications for retrograde ureteroscopic techniques were broadened to include intrarenal stones [9]. With improvements to endoscopic instruments and techniques, retrograde intrarenal surgery (RIRS) using ureteroscopy and laser lithotripsy for the treatment of renal stones is being used as a minimally invasive treatment modality, and a wide range of stone-free rates, from 50% to 94.2%, has been reported for this procedure [10-13]. RIRS may offer an alternative to ESWL or PCNL; however, to date, good scientific evidence is lacking to support the efficacy of this modality, which is not recommended as a first-line treatment for renal stones [1]. "
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    ABSTRACT: The aim of this study was to evaluate the efficacy and safety of retrograde intrarenal surgery (RIRS) for the treatment of renal stones and to analyze the predictive factors for stone-free. We retrospectively reviewed the records of patients who underwent RIRS for renal stones from January 2000 to July 2009. We identified 66 RIRSs (63 patients with 3 bilateral renal stones) and collected data. Stone-free and success were respectively defined as no visible stones and clinically insignificant residual stones less than 3 mm on postoperative imaging; predictive factors for stone-free were evaluated. Of the 66 renal stones, 18 stones (27.3%) were located in the upper pole or midpole or renal pelvis and 48 (72.7%) in the lower pole with or without others, respectively. The mean cumulative stone burden was 168.9±392.5 mm(2). The immediate postoperative stone-free rate was 69.7%, and it increased to 72.7% at 1 month after surgery. The success rate was 80.3% both immediately after the operation and 1 month later. In the multivariate analysis, stone location except at the lower pole (p=0.049) and small cumulative stone burden (p=0.002) were significantly favorable predictive factors for the immediate postoperative stone-free rate. The overall complication rate was 6%. RIRS is a safe and effective treatment for renal stones. The stone-free rate of RIRS was particularly high for renal stones with a small burden, except for those located in the lower pole. RIRS could be considered in selective patients with renal stones.
    Korean journal of urology 11/2010; 51(11):777-82. DOI:10.4111/kju.2010.51.11.777
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