title: Perioperative outcomes of off-clamp vs complete hilar control laparoscopic partial nephrectomy.
abstract: OBJECTIVE
  To evaluate perioperative and 6-month renal functional outcomes of patients undergoing off-clamp vs complete hilar control laparoscopic partial nephrectomy (LPN).
  
  
  METHODS
  A retrospective review of 489 patients undergoing LPN was completed. Preoperative imaging assessed tumour characteristics. Patient demographics, perioperative parameters, and postoperative outcomes were documented. Multivariable regression analysis was used to assess factors contributing to changes in postoperative renal function between off-clamp and clamped LPN.
  
  
  RESULTS
  In all, 289 LPNs were performed on-clamp and 150 were performed off-clamp. Tumours in the on-clamp group were larger than those in the off-clamp group (mean [range] 3.3 [0.5-13.5] vs 2.7 [0.4-9] cm, P = 0.003). Univariable analysis comparing off-clamp to on-clamp cohorts showed that estimated glomerular filtration rate (eGFR) was better preserved in the off-clamp cohort at 6 months (-5.8% vs -11.4%, P = 0.046). Multivariable analysis of the groups showed that estimate blood loss (P = 0.015) and warm ischaemia time (WIT, P < 0.001) were the only significant predictors of decreased eGFR in the postoperative period. Difference in eGFR at 6 months was not significant when WIT was limited to 30 min. The complication rate was greater in the clamped cohort (10% vs 20%, P = 0.012). There was no difference in transfusion rate or positive margin status.
  
  
  CONCLUSIONS
  LPN without hilar clamping is feasible, safe and associated with less renal injury as assessed by postoperative GFR in select patients. With experience, it can be applied to complex renal lesions.
authors.affiliation: The Arthur Smith Institute for Urology, North Shore-Long Island Jewish Health System, New Hyde Park, NY 11040, USA. arvinkgeorge@gmail.com
authors.forename: Arvin K
authors.initials: AK
authors.lastname: George
authors.forename: Amin S
authors.initials: AS
authors.lastname: Herati
authors.forename: Arun K
authors.initials: AK
authors.lastname: Srinivasan
authors.forename: Soroush
authors.initials: S
authors.lastname: Rais-Bahrami
authors.forename: Nikhil
authors.initials: N
authors.lastname: Waingankar
authors.forename: Mostafa A
authors.initials: MA
authors.lastname: Sadek
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Schwartz
authors.forename: Zhamshid
authors.initials: Z
authors.lastname: Okhunov
authors.forename: Lee
authors.initials: L
authors.lastname: Richstone
authors.forename: Zeph
authors.initials: Z
authors.lastname: Okeke
authors.forename: Louis R
authors.initials: LR
authors.lastname: Kavoussi
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005500:Follow-Up Studies; D005919:Glomerular Filtration Rate / Q000502:physiology; D006801:Humans; D007680:Kidney Neoplasms / Q000503:physiopathology / Q000601:surgery*; D010535:Laparoscopy / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009392:Nephrectomy / Q000379:methods*; D011446:Prospective Studies; D012371:Robotics / Q000379:methods; D016896:Treatment Outcome; D052096:Warm Ischemia; D055815:Young Adult