title: Efficacy of semirigid ureteroscopy with pneumatic lithotripsy for ureteral stone surface area of greater than 30 mm2.
abstract: OBJECTIVE
  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.
  
  
  METHODS
  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.
  
  
  RESULTS
  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%.
  
  
  CONCLUSIONS
  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).
authors.affiliation: Department of Surgery, Aga Khan University, Karachi, Pakistan. hammad.ather@aku.edu
authors.forename: M Hammad
authors.initials: MH
authors.lastname: Ather
authors.forename: Syed M
authors.initials: SM
authors.lastname: Nazim
authors.forename: M Nasir
authors.initials: MN
authors.lastname: Sulaiman