Category: Laparoscopic/ Robotic: Other

MP16-17 - On-clamp versus Off-clamp Partial Nephrectomy: Propensity Score Matched Comparison of Long Term Functional Outcomes.

Sat, Sep 22
10:00 AM - 12:00 PM

Introduction & Objective :

To compare renal functional outcomes after either off-clamp (Off-C) or on-clamp (On-C) PN in patients with cT1- 2/N0 M0 renal tumors and baseline estimated eGFR >60 ml/min.


Methods :

A prospective “renal cancer” database of two high volume centers was queried for “cT1-2/N0/M0” tumors and “baseline eGFR>60 mL/min”. Overall 1073 patients met the inclusion criteria, 588 of which underwent On-C PN and 485 Off-C PN. A 1:3 propensity score-matched (PSM) analysis was                 employed to minimize the selection bias of non-random assignment of patients to the two groups.                                                                           Joinpoint regression analysis was used to plot the 2 to 8 yrs probabilities of experiencing eGFR decreases of 0%, < 25% and between 25 and 50% in both PSM cohorts and therefore to compare the trends for each of these 3 subgroups.                                                                                             Kaplan–Meier method was used to compare the risk of developing a CKD stage≥3b (eGFR<45mL/min) during follow-up in the PSM cohorts. Univariable and multivariable Cox regression analyses were performed to identify independent predictors of developing a CKD stage≥3b during follow-up. 


 


Results :

In the whole cohort  On-C patients were significantly younger (p=0.001), less frequently smokers (p=0.01), with a lower incidence of diabetes (p=0.001) and hypertension (p=0.001), lower ASA scores (p<0.001), higher baseline eGFR values (p=0.003), smaller tumor sizes (p<0.001), longer warm ischemia time (17 minutes vs 0, p<0.001) and higher incidence of positive surgical margins (p=0.021). After applying the PSM analysis, the two cohorts of 157 On-C and 471 Off-C PN cases did not differ for all clinical and pathologic covariates (Table 1;all ≥0.08), except for mean warm ischemia time (p<0.001).
At Joinpoint regression analysis Off-C group displayed significantly higher probabilities of maintaining unmodified eGFR after surgery (p=0.02), and significantly lower probabilities of experiencing eGFR decrease >25% in the first 8-yr follow-up (p=0.02) The probability of developing a CKD stage ≥3b was significantly higher (log rank p=0.006) in the On-C cohort (2, 5 and 8yr risk 0.9%, 5.1% and 12.8% versus 0.6%, 1.2% and 1.2% in the Off-C cohort, respectively.                                                                                                                                                                                                                At multivariable Cox regression analysis, eGFR at discharge (HR 0.94 [95% CIs 0.91–0.98]; p=0.002) and Off-clamp approach (HR .33 [95% CIs 1.8-29.4]; p=0.005) were independent predictors of improved renal functional outcomes.


Conclusions :

Off-C PN is associated with a significantly higher probability of maintaining 100% eGFR after surgery compared with On-C PN in patients with cT1-2/N0/MO renal tumors and good baseline renal function candidate to elective PN. 

Gabriele Tuderti

Fellow
"Regina Elena" National Cancer Institute, Dept. of Urology
Roma, Lazio, Italy

Giuseppe Simone

Consultant
“Regina Elena” National Cancer Institute, Dept. of Urology
Roma, Lazio, Italy

Umberto Capitanio

Unit of Urology, Division of Oncology, Urological Research Institute, IRCCS Ospedale San Raffaele, Milan, Italy
Milan, Lombardia, Italy

Alessandro Larcher

Hospital San Raffaele, University Vita Salute, Department of Urology
Milan, Lombardia, Italy

Mariaconsiglia Ferriero

MD, PhD
"Regina Elena" National Cancer Institute, Dept. of Urology
Rome, Lazio, Italy

Leonardo Misuraca

Fellow
"Regina Elena" National Cancer Institute, Dept. of Urology
Rome, Lazio, Italy

Manuela Costantini

"Regina Elena” National Cancer Institute, Dept. of Urology
Rome, Lazio, Italy

Francesco Minisola

"Regina Elena" National Cancer Institute, Dept. of Urology
Roma, Lazio, Italy

Salvatore Guaglianone

"Regina Elena" National Cancer Institute, Dept. of Urology
Roma, Lazio, Italy

Fabio Muttin

"Hospital San Raffaele, University Vita Salute, Department of Urology
Milan, Lombardia, Italy

Alessandro Nini

Hospital San Raffaele, University Vita Salute, Department of Urology
Milan, Lombardia, Italy

Francesco Trevisani

Hospital San Raffaele, University Vita Salute, Department of Urology
Milan, Lombardia, Italy

Francesco Montorsi

Unit of Urology, Division of Oncology, Urological Research Institute, IRCCS Ospedale San Raffaele, Milan, Italy
Milan, Lombardia, Italy

Roberto Bertini

Hospital San Raffaele, University Vita Salute, Department of Urology
Milan, Lombardia, Italy

Michele Gallucci

Roma, Lazio, Italy