title: Enhanced renal cryoablation with hilar clamping and intrarenal cooling in a porcine model.
abstract: OBJECTIVE
  To evaluate the effects of renal vascular control and intrarenal cooling on the size of renal lesions attainable with a 3.4-mm cryoprobe.
  
  
  METHODS
  Three groups of pigs underwent unilateral laparoscopic renal cryoablation with a 3.4-mm cryoprobe inserted to a depth of 1 cm. An 8-minute double-freeze cycle was used. One week later, an acute contralateral cryolesion was created before killing the animal. In group 1 (n = 6), bilateral cryolesions were created without hilar clamping or intrarenal cooling. In group 2 (n = 6), the cryolesions were created after hilar clamping alone. In group 3 (n = 6), the cryolesions were created after both hilar clamping and application of intrarenal cooling with saline ice-slush infused into the renal pelvis. After nephrectomy, the gross diameters were determined for each cryolesion. The mean diameters of the zones of complete and partial necrosis were determined by histopathologic examination.
  
  
  RESULTS
  In group 3, the cortex cooled from 36.9 degrees C to a mean of 24.8 degrees C. Acutely, no statistically significant difference was found between the lesions produced with clamping alone (37.6 mm) and intrarenal cooling (40.4 mm); however, both were significantly larger than the control cryolesions (28.7 mm). At 1 week, the area of complete necrosis produced with intrarenal cooling (34.3 mm) was significantly larger than the areas of necrosis produced by clamping alone (27.8 mm) or conventional cryoablation (23.9 mm; alpha = 0.05, Tukey's honestly significantly different [HSD] test).
  
  
  CONCLUSIONS
  Enhanced cryolesion necrosis was achieved with intrarenal cooling with a 3.4-mm cryoprobe. Intrarenal cooling may be a valuable adjunct to cryoablation in selected cases.
authors.affiliation: Division of Urology, Washington University School of Medicine, St. Louis, Missouri 63110, USA.
authors.forename: William
authors.initials: W
authors.lastname: Collyer
authors.forename: Ramakrishna
authors.initials: R
authors.lastname: Venkatesh
authors.forename: Richard
authors.initials: R
authors.lastname: Vanlangendonck
authors.forename: Kevin
authors.initials: K
authors.lastname: Morissey
authors.forename: Peter
authors.initials: P
authors.lastname: Humphrey
authors.forename: Yan
authors.initials: Y
authors.lastname: Yan
authors.forename: Jaime
authors.initials: J
authors.lastname: Landman
mesh_terms: D000818:Animals; D003452:Cryosurgery / Q000295:instrumentation / Q000379:methods*; D007668:Kidney / Q000473:pathology* / Q000601:surgery*; D010535:Laparoscopy / Q000379:methods*; D023421:Models, Animal; D009336:Necrosis; D013552:Swine