title: In vivo evaluation of a reverse thermosensitive polymer for ureteroscopy with laser lithotripsy: porcine model.
abstract: OBJECTIVE
  To evaluate the effects of a reverse thermosensitive polymer during ureteroscopy with laser lithotripsy in an in vivo porcine model.
  
  
  METHODS
  Six pigs underwent general anesthesia followed by bilateral ureteroscopy with laser lithotripsy of stone phantoms while measuring intrapelvic renal pressures through bilateral nephrostomy tubes. The procedures were performed in one ureter with the reverse thermosensitive polymer and in the contralateral, control ureter without the reverse thermosensitive polymer. Stone migration lengths, operative times, laser times, laser energy usage, intrapelvic pressures, and postnecropsy histologic examinations of the ureters were compared between the two groups.
  
  
  RESULTS
  Bilateral ureteroscopy with lithotripsy was successfully performed in five of six pigs. In one pig, only the unilateral control was performed, because the ureter was too narrow to complete the contralateral side. The mean laser time was 12.8 minutes shorter with the use of the reverse thermosensitive polymer group than in the controls (P=0.021). The procedure time, laser energy usage, and retropulsion length was shorter in the reverse thermosensitive polymer group, but did not reach significance. Between the two groups, there was no difference in mean renal pelvic pressures, peak renal pelvic pressures, or postprocedure histologic examinations of the ureters.
  
  
  CONCLUSIONS
  The use of a reverse thermosensitive polymer during ureteroscopy with lithotripsy may have greater advantages beyond preventing stone retropulsion. Here, the use of a reverse thermosensitive polymer during ureteroscopy with lithotripsy resulted in a significant decrease in laser times. Further clinical investigations could further delineate the advantages of using a reverse thermosensitive polymer during intracorporeal lithotripsy.
authors.affiliation: Division of Urology, Washington University School of Medicine , St. Louis, Missouri.
authors.forename: Jonathan M
authors.initials: JM
authors.lastname: Mobley
authors.forename: Goutham
authors.initials: G
authors.lastname: Vemana
authors.forename: Marshall
authors.initials: M
authors.lastname: Strother
authors.forename: Robert Sherburne
authors.initials: RS
authors.lastname: Figenshau
authors.forename: Joel M
authors.initials: JM
authors.lastname: Vetter
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Larson
authors.forename: Brian M
authors.initials: BM
authors.lastname: Benway
mesh_terms: D000818:Animals; D005260:Female; D007682:Kidney Pelvis; D017602:Lithotripsy, Laser / Q000295:instrumentation / Q000379:methods*; D023421:Models, Animal; D009403:Nephrostomy, Percutaneous / Q000295:instrumentation; D061646:Operative Time; D011108:Polymers / Q000737:chemistry / Q000627:therapeutic use*; D013552:Swine; D013696:Temperature; D014513:Ureter / Q000473:pathology; D014514:Ureteral Calculi / Q000628:therapy*; D018666:Ureteroscopy / Q000379:methods*
chemical_list: D011108:Polymers