Perioperative outcomes of off-clamp vs complete hilar control laparoscopic partial nephrectomy


Arvin K. George, The Arthur Smith Institute for Urology, North Shore-Long Island Jewish Health System, 450 Lakeville Rd, Suite M-41, New Hyde Park, NY 11040, USA. e-mail:


What's known on the subject? and What does the study add?

Off-clamp laparoscopic partial nephrectomy (LPN) is thought to preserve renal function by limiting warm ischaemia time (WIT) and consequently reperfusion injury. To date, studies using the off-clamp technique represent a heterogeneous group, with limited follow-up showing feasibility and safety in a restricted number of cases.

We report the largest experience of off-clamp vs on-clamp LPN with perioperative outcomes and intermediate follow-up of renal functional outcomes with stratification by WIT.


  • • To evaluate perioperative and 6-month renal functional outcomes of patients undergoing off-clamp vs complete hilar control laparoscopic partial nephrectomy (LPN).


  • • 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.


  • • 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.


  • • 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.