To clamp or not to clamp? Long-term functional outcomes for elective off-clamp laparoscopic partial nephrectomy.
OBJECTIVE
To evaluate whether elective off-clamp laparoscopic partial nephrectomy (LPN) affords long-term renal functional benefit compared with the on-clamp approach.


METHODS
This is a retrospective review of patients who underwent elective LPN between 2006 and 2011. Patients were followed longitudinally for up to 5 years. In all, 315 patients with radiographic evidence of a solitary renal mass and normal-appearing contralateral kidney underwent elective LPN; 209 were performed on-clamp vs 106 off-clamp. One patient who required conversion from LPN to open PN was excluded from the study. Additionally, four patients in the on-clamp cohort who underwent subsequent radical nephrectomy for local-regional recurrence were excluded from longitudinal functional evaluation after their procedure. The primary objective was to evaluate differences in postoperative estimated glomerular filtration rate (eGFR) between hilar clamping groups. Subgroup analyses were performed for patients with clamp times >30 min and those with baseline renal insufficiency (eGFR <60 mL/min/1.73m(2) ). Risk of developing worsened or new-onset renal insufficiency was also compared.


RESULTS
The mean preoperative eGFR was similar between the on-clamp and off-clamp cohorts (80.7 vs 84.1 mL/min/1.73m(2) , P > 0.05). Univariable and multivariable analyses did not show significant differences in postoperative eGFR between both groups among all-comers, those with clamp times >30 min, and patients with baseline renal insufficiency. Risk of chronic kidney disease was not diminished by the off-clamp approach with up to 5 years of follow-up.


CONCLUSIONS
Progressive recovery of renal function after hilar clamping in the elective setting eclipses short-term functional benefit achieved with off-clamp LPN by 6 months; there was no significant difference in eGFR or the percentage incidence of chronic kidney disease between the on-clamp and off-clamp cohorts with up to 5 years follow-up. As such, eliminating transient ischaemia during elective LPN does not confer clinical benefit.
Department of Urology, Smith Institute for Urology, New Hyde Park, NY, USA.
Paras H
PH
Shah
Department of Urology, Smith Institute for Urology, New Hyde Park, NY, USA.|National Cancer Institute - Urologic Oncology Branch, Bethesda, MD, USA.
Arvin K
AK
George
Department of Urology, Smith Institute for Urology, New Hyde Park, NY, USA.|Department of Urology, Mayo Clinic, Rochester, MN, USA.
Daniel M
DM
Moreira
Department of Urology, Smith Institute for Urology, New Hyde Park, NY, USA.
Manaf
M
Alom
Department of Urology, Smith Institute for Urology, New Hyde Park, NY, USA.|Department of Urology, University of California, Irvine, CA, USA.
Zhamshid
Z
Okhunov
Department of Urology, Smith Institute for Urology, New Hyde Park, NY, USA.
Simpa
S
Salami
Department of Urology, Smith Institute for Urology, New Hyde Park, NY, USA.|Division of Urologic Oncology, Fox Chase Cancer Center, Philadelphia, PA, USA.
Nikhil
N
Waingankar
Department of Urology, Smith Institute for Urology, New Hyde Park, NY, USA.
Michael J
MJ
Schwartz
Department of Urology, Smith Institute for Urology, New Hyde Park, NY, USA.
Manish A
MA
Vira
Department of Urology, Smith Institute for Urology, New Hyde Park, NY, USA.
Lee
L
Richstone
Department of Urology, Smith Institute for Urology, New Hyde Park, NY, USA.
Louis R
LR
Kavoussi
D003250:Constriction; D005260:Female; D005500:Follow-Up Studies; D005919:Glomerular Filtration Rate; D006801:Humans; D007680:Kidney Neoplasms / Q000401:mortality / Q000503:physiopathology / Q000601:surgery*; D010535:Laparoscopy / Q000379:methods* / Q000401:mortality; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000401:mortality*; D009392:Nephrectomy / Q000379:methods* / Q000401:mortality; D051436:Renal Insufficiency, Chronic / Q000401:mortality*; D012189:Retrospective Studies; D016896:Treatment Outcome
glomerular filtration rate; ischaemia; laparoscopy; nephrectomy; renal neoplasms