title: Increasing dwell time of mitomycin C in the upper tract with a reverse thermosensitive polymer.
abstract: Abstract Background and Purpose: Topical chemotherapy for urothelial cancer is dependent on adequate contact time of the chemotherapeutic agent with the urothelium. To date, there has not been a reliable method of maintaining this contact for renal or ureteral urothelial carcinoma. We evaluated the safety and feasibility of using a reverse thermosensitive polymer to improve dwell times of mitomycin C (MMC) in the upper tract.
  
  
  METHODS
  Using a porcine model, four animals were treated ureteroscopically with both upper urinary tracts receiving MMC mixed with iodinated contrast. One additional animal received MMC percutaneously. The treatment side had ureteral outflow blocked with a reverse thermosensitive polymer plug. MMC dwell time was monitored fluoroscopically and intrarenal pressures measured. Two animals were euthanized immediately, and three animals were euthanized 5 days afterward.
  
  
  RESULTS
  In control kidneys, drainage occurred at a mean of 5.3±0.58 minutes. Intrarenal pressures stayed fairly stable: 9.7±14.0 cm H20. In treatment kidneys, dwell time was extended to 60 minutes, when the polymer was washed out. Intrarenal pressures in the treatment kidneys peaked at 75.0±14.7 cm H20 and reached steady state at 60 cm H20. Pressures normalized after washout of the polymer with cool saline. Average washout time was 11.8±9.6 minutes. No histopathologic differences were seen between the control and treatment kidneys, or with immediate compared with delayed euthanasia.
  
  
  CONCLUSIONS
  A reverse thermosensitive polymer can retain MMC in the upper urinary tract and appears to be safe from our examination of intrarenal pressures and histopathology. This technique may improve the efficacy of topical chemotherapy in the management of upper tract urothelial carcinoma.
authors.affiliation: Department of Surgery, Division of Urology, Duke University Medical Center, Durham, NC 27713, USA.
authors.forename: Agnes J
authors.initials: AJ
authors.lastname: Wang
authors.forename: Zachariah G
authors.initials: ZG
authors.lastname: Goldsmith
authors.forename: Andreas
authors.initials: A
authors.lastname: Neisius
authors.forename: Gaston M
authors.initials: GM
authors.lastname: Astroza
authors.forename: Olugbemisola
authors.initials: O
authors.lastname: Oredein-McCoy
authors.forename: Muhammad W
authors.initials: MW
authors.lastname: Iqbal
authors.forename: W Neal
authors.initials: WN
authors.lastname: Simmons
authors.forename: John F
authors.initials: JF
authors.lastname: Madden
authors.forename: Glenn M
authors.initials: GM
authors.lastname: Preminger
authors.forename: Brant A
authors.initials: BA
authors.lastname: Inman
authors.forename: Michael E
authors.initials: ME
authors.lastname: Lipkin
authors.forename: Michael N
authors.initials: MN
authors.lastname: Ferrandino
mesh_terms: D000818:Animals; D003287:Contrast Media; D004322:Drainage; D005260:Female; D005471:Fluoroscopy; D007668:Kidney / Q000000981:diagnostic imaging / Q000187:drug effects; D016685:Mitomycin / Q000494:pharmacology*; D011108:Polymers / Q000494:pharmacology*; D011312:Pressure; D034421:Sus scrofa; D013696:Temperature; D013997:Time Factors; D014513:Ureter / Q000000981:diagnostic imaging / Q000187:drug effects* / Q000473:pathology
chemical_list: D003287:Contrast Media; D011108:Polymers; D016685:Mitomycin