Efficacy of semirigid ureteroscopy with pneumatic lithotripsy for ureteral stone surface area of greater than 30 mm2.

Department of Surgery, Aga Khan University, Karachi, Pakistan.
Journal of endourology / Endourological Society (Impact Factor: 1.75). 04/2009; 23(4):619-22. DOI: 10.1089/end.2008.0182
Source: PubMed

ABSTRACT To study the outcome and safety of semirigid ureteroscopy (URS) using pneumatic lithotripsy for treatment of ureteral stones of surface area >30 mm2 and to assess the impact of size and location on stone-free (SF) rate.
In this study, 265 patients with >30 mm2 isolated ureteral stones treated by semirigid URS were included. URS was performed using an 8F, 7F, or 6.4F semirigid ureteroscopes with pneumatic lithotripsy (Swiss Lithoclast). Stones were fragmented to approximately 2-3 mm particles, and removed. The outcome parameters assessed at 3-month follow-up were SF rate and efficiency quotient (EQ); impact of stone size and site on SF/EQ was also analyzed. The patient demographics, stone, procedure, and patient-related parameters and complications were noted.
At 3-month follow-up overall SF was 74% and EQ 59.2%. SF for 30-100 mm2 and >100 mm2 was 79.2% and 68.5%, respectively (p < 0.003). The SF/EQ for upper, middle, and lower ureteral stones were 59/40.7, 53/37.5, and 92/84.5, respectively (p < 0.001). There was no major complication; the minor complication rate was 12.5%.
Semirigid URS using pneumatic lithotripsy for treatment of stones >30 mm2 is a safe and highly efficacious procedure particularly in the distal ureter. There is a significant difference in the SF and EQ between upper/middle ureteral stone and lower ureteral stone. Stone size has a direct relation with the SF and EQ. Upper ureteral stones have a longer time to SF compared to middle and lower ureteral stones (p < 0.001).

  • [Show abstract] [Hide abstract]
    ABSTRACT: We investigated whether previous intraureteral manipulations had an effect on the stone-free rates (SFR) after semi-rigid ureteroscopy (URS) with pneumatic lithotripsy. A retrospective review of all patients who were treated for ureteral stones at two different institutions from June 2003 through January 2010 was performed. Data of 161 URS procedures were analyzed. Stone size, location (distal, mid and proximal) and number (single and multiple), patient demographics and previous intraureteral manipulations were recorded. Patients were grouped as having undergone a previous ipsilateral intraureteral manipulation (Group 1) or not (Group 2). Stone location and number, stone clearance and ancillary procedures were compared. There were no significant differences between Group 1 versus Group 2 for age (p > 0.05), gender (p > 0.05), stone site (p > 0.05) and stone size (p > 0.05). Stones with multiple locations were more frequent in Group 1 (18.5%); however, the difference did not reach statistical significance between the two groups. Similarly, the frequency of multiple stones was also higher in Group 1 (29.6%). Stone site, diameter and gender were comparable in both groups. Stone-free rate of all patients was 84.6% after the first intervention. This rate increased to 98.1% after secondary procedures. Univariate analysis revealed that SFR after URS were low in patients who underwent previous intraureteral manipulations (Group 1:55.6% vs. Group 2:89.1%). SFR after the first intervention were related with stone size, location and number. Additionally, multiple logistic regression analysis indicated a relationship between previous intraureteral manipulations and initial stone clearance rates. Spontaneous passage of stone fragments after URS was associated with stone burden, location, number and previous intraureteral manipulations. Further multiple logistic regression analysis showed that only previous intraureteral manipulations were associated with the expulsion of the stones left for passage.
    Urological Research 09/2011; 40(4):365-71. · 1.59 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: To examine which parameters should be measured to preoperatively determine the stone burden as predictors of stone-free (SF) status after a single flexible ureteroscopy (URS). Although several stone parameters reportedly influence the outcome of treatment for urinary stones, the most reliable indicators of stone burden remain unclear. Patients with renal stones treated by flexible URS with holmium laser lithotripsy between October 2009 and December 2011 at a single institute were retrospectively evaluated. The SF status was determined by kidney-ureter-bladder (KUB) films at postoperative day 1. Correlations of possible predictors with the SF status were analyzed using a logistic regression model. According to the univariate analysis, the following variables were significantly associated with failed treatment: number of stones (P = .001), cumulative stone diameter (CSD) (P < .001), stone surface area (SA) (P < .001), stone volume (P < .001), and presence of lower pole calculi (P = .008). According to the multivariate analysis, the stone volume (P < .001) and the CSD (P = .015) were found to be independent predictors of SF status. The SA (P = .598) had no significant independent influence on the SF status. Among the several parameters regarding the renal stone burden, the stone volume determined by noncontrast computed tomography and the CSD of the KUB were significantly and independently inversely related to the success rate of URS. Among the 3 parameters of stone burden, the SA was found to have a lower clinical utility and priority as a predictor of a SF status after URS.
    Urology 05/2012; 80(3):524-8. · 2.42 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Objectives: To investigate the utility and limitations of stone surface area (SA) as a predictor of stone-free (SF) status after a single semirigid ureteroscopy (URS), with or without a flexible component, for the treatment of urinary stones. Patients and Methods: Cases of patients with urinary stones treated by combined ureteroscopy with holmium laser lithotripsy at a single institute were retrospectively evaluated. Correlations of possible predictors with SF status were analyzed using a logistic regression model. Two types of stone surface area were measured, "traced stone surface area" (tSA) and "calculated stone surface area" (cSA). Results: According to the univariate analysis, the following variables were significantly associated with non-SF: stone number (P<0.001), ureteral stone location (P=0.045), presence of renal stones (P<0.001), tSA (P<0.001), cSA (P<0.001), stone volume (P<0.001), and operator experience (P=0.02). According to multivariate analysis, stone volume (P=0.016) was an independent predictor of SF status. The scatter diagrams for tSA and cSA showed strong correlations between these parameters, and Spearman's ρ was 0.975. Conclusions: Stone volume and SA were highly indicative of stone status after single semirigid URS, with or without a flexible component. The formula for cSA, maximum diameter x width x π x 1/4, was demonstrated to accurately represent SA in this study. SA, however, indicated a lower clinical priority and utility as a predictor of stone status than stone volume. The combination of semirigid and flexible URS could access any ureteral stones, including those that semirigid URS alone could not treat. The cut-off points for these predictors of outcome were 110.0 mm2 for cSA, 125.0 mm2 for tSA, and 840.0 mm3 for stone volume.
    Journal of endourology / Endourological Society 02/2013; · 1.75 Impact Factor


Available from
May 27, 2014