Renal function is the same 6 months after robot-assisted partial nephrectomy regardless of clamp technique: analysis of outcomes for off-clamp, selective arterial clamp and main artery clamp techniques, with a minimum follow-up of 1 year.
OBJECTIVE
To compare the renal functional outcomes, with >1 year of follow-up, of patients who underwent robot-assisted partial nephrectomy (RAPN) performed with different clamping techniques.


METHODS
The peri-operative data of patients undergoing RAPN performed with different clamping techniques were retrospectively analysed (group 1: off-clamp, n = 23; group 2: selective clamp, n = 25; group 3: main artery clamp, n = 114). The main outcome measures were postoperative serum creatinine level, estimated glomerular filtration rate (eGFR) and percentage change in eGFR, the data for which were collected at periodic intervals during the first 12 months and annually thereafter, in addition to late eGFR value. Only patients with >1 year of follow-up were included in the analysis.


RESULTS
The baseline characteristics of groups 2 and 3 were similar, while patients in group 1 had smaller sized tumours and lower tumour complexity. The median follow-up periods were 45 (group 1), 20 (group 2) and 47 (group 3) months. The median clamping times were 24.8 min in the main artery clamp and 18 min in the selective artery clamp groups. Group 2 had greater median blood loss volume (100 vs 500 vs 200 mL for groups 1, 2 and 3, respectively; P < 0.01) and a longer length of hospital stay (3 vs 4 vs 3 days for groups 1, 2 and 3, respectively; P = 0.02). No significant differences were found among the groups with regard to transfusion rates, positive surgical margin rates, complications, recurrence or mortality rates. Groups 1 and 2 had significantly less deterioration of postoperative renal function during the first 3 months after surgery (P = 0.04; percent change in eGFR -1.5, -2 and -8% for groups 1, 2 and 3, respectively), but this beneficial outcome was not observed after 6 months or for the latest eGFR measurement (P = 0.48; latest percent change in eGFR -3, -6 and -3.5% for groups 1, 2 and 3, respectively). In regression analysis, baseline eGFR, type of clamp procedure and tumour complexity score were predictive of normal renal function 7 days after surgery, while only baseline eGFR and age could predict it 1 year postoperatively.


CONCLUSIONS
Off-clamp and selective artery clamp techniques result in superior short-term renal functional outcomes compared with the main artery clamp approach; however, after the 6th postoperative month, there were no significant differences regarding the functional outcome among the above surgical techniques, as long as the warm ischaemia time was 20-30 min.
Department of Urology and Urological Science Institute, Yonsei University College of Medicine, Seoul.|Department of Urology, General Hospital of Nikaia 'St. Panteleimon', Athens, Greece.
Christos
C
Komninos
Department of Urology, Chuncheon Sacred Hospital, Hallym Medical College, Chuncheon, Korea.
Tae Young
TY
Shin
Department of Urology and Urological Science Institute, Yonsei University College of Medicine, Seoul.
Patrick
P
Tuliao
Department of Urology and Urological Science Institute, Yonsei University College of Medicine, Seoul.
Woong Kyu
WK
Han
Department of Urology and Urological Science Institute, Yonsei University College of Medicine, Seoul.
Byung Ha
BH
Chung
Department of Urology and Urological Science Institute, Yonsei University College of Medicine, Seoul.
Young Deuk
YD
Choi
Department of Urology and Urological Science Institute, Yonsei University College of Medicine, Seoul.
Koon Ho
KH
Rha
D000328:Adult; D000368:Aged; D005260:Female; D005919:Glomerular Filtration Rate; D006488:Hemostasis, Surgical / Q000009:adverse effects / Q000379:methods*; D006801:Humans; D007668:Kidney / Q000098:blood supply / Q000502:physiology* / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D009392:Nephrectomy / Q000009:adverse effects / Q000379:methods*; D012189:Retrospective Studies; D065287:Robotic Surgical Procedures / Q000009:adverse effects / Q000379:methods*; D016896:Treatment Outcome; D055815:Young Adult
partial nephrectomy; selective clamping; warm ischemia time; zero ischemia