title: Intermediate-term results of retroperitoneoscopy-assisted cryotherapy for small renal tumours using multiple ultrathin cryoprobes.
abstract: OBJECTIVE
  To evaluate outcome after retroperitoneoscopic cryotherapy for small renal tumours.
  
  
  METHODS
  Fourteen patients underwent cryoablation performed with six ultrathin 1.5-mm cryoprobes. Retroperitoneoscopic access was used for any tumour location. A double freeze-thaw cycle was performed under simultaneous retroperitoneoscopic visual control and real-time ultrasound monitoring.
  
  
  RESULTS
  Mean tumour size was 2.8 cm (range: 2.0-4.0), mean patient age was 68 yr (range: 49-83), and six left and eight right kidneys were treated. The mean operative time was 167 min (range: 120-200); mean blood loss was 93 ml (range: 0-300). Cryosurgery was successfully performed in all 14 patients, with 13 patients undergoing assisted retroperitoneoscopy and one patient, after previous open nephropexy, undergoing an open approach. Intraoperative biopsy specimens revealed renal cell cancer (RCC) in 10 (71%) patients. The only intraoperative complication was bleeding after removal of the cryoprobes in four (29%) patients, necessitating one intracorporeal stitch in each. Two (14%) of the first four patients presented postoperatively with superficial skin frostbite, which healed with conservative treatment. During mean follow-up of 21 mo (range: 2-42), 2 (14%) patients died from unrelated disease, and 12 patients remained without evidence of local recurrence. One patient with previous contralateral nephrectomy for RCC developed retroperitoneal lymph node metastasis on that side without recurrence in the cryoablated kidney.
  
  
  CONCLUSIONS
  Retroperitoneoscopic cryotherapy using multiple ultrathin cryoprobes is safe and effective with encouraging oncologic results on intermediate-term follow-up. Prospective clinical trials and long-term oncologic data are needed to define its definitive role in treatment of renal tumours.
authors.affiliation: Department of Urology, University Hospital Basel, Basel, Switzerland.
authors.forename: Stephen F
authors.initials: SF
authors.lastname: Wyler
authors.forename: Tullio
authors.initials: T
authors.lastname: Sulser
authors.forename: Robin
authors.initials: R
authors.lastname: Ruszat
authors.forename: Boris
authors.initials: B
authors.lastname: Weltzien
authors.forename: Thomas H
authors.initials: TH
authors.lastname: Forster
authors.forename: Maurizio
authors.initials: M
authors.lastname: Provenzano
authors.forename: Thomas C
authors.initials: TC
authors.lastname: Gasser
authors.forename: Alexander
authors.initials: A
authors.lastname: Bachmann
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D017679:Cryotherapy / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007680:Kidney Neoplasms / Q000473:pathology* / Q000628:therapy*; D010535:Laparoscopy; D008297:Male; D008875:Middle Aged; D012187:Retroperitoneal Space; D013997:Time Factors