Introduction and objectives
Outcomes of 2 dedicated randomized controlled trials (RCTs) comparing on-clamp versus off-clamp robot-assisted (RPN) or pure laparoscopic partial nephrectomy (LPN) (CLOCK I and II RCTs, respectively) have been published. Both in the LPN and in the RPN RCTs, shift from planned off-clamp to on-clamp approach occurred in some patients. We performed a cross-analysis between the trials, comparing perioperative outcomes of RPN vs LPN in these specific subgroups of patients.
Methods
For the purpose of the study, patients randomized to off-clamp and who were shifted to on-clamp RPN and LPN were extracted from CLOCK I and II RCTs, respectively (ClinicalTrials.gov NCT02287987). Univariate analysis of baseline data and perioperative outcomes was performed. Multivariable models were used to balance the effect of potential confounders on the results.
Results
69 out of 164 (42.1%) and 41 out of 126 (32.5%) patients were shifted from off-clamp to on-clamp RPN and LPN (p=0.1) and extracted from the CLOCK I and II RCTs. At baseline, cohorts had comparable age, gender, BMI, comorbidities/performance status, hemoglobin, platelets count, PT/PTT, creatinine, eGFR, tumor size and RENAL score. Median tumor size was 3.5 vs 4 cm (IQR 2.7-4.4 vs 2.5-5, RPN vs LPN, respectively, p=0.4) and RENAL score 7 vs 7 (IQR 6-8 vs 5-8, p=0.6). No significant differences were noted as regarding approach (trans- versus retroperitoneal), resection technique as assessed by the SIB score and renorrhaphy technique. During RPN, AirSeal was more likely used (78% vs 2.4%, p<0.001). Hemostatic agents were more likely used during LPN (85.5% vs 100%, p=0.01). At univariate analysis, operative time, renorrhaphy time, drainage removal day, length of stay, and Clavien >2 complications favored RPN. 5thpostoperative day hemoglobin was higher after LPN (12 g/dl, IQR 10.9-12.8 vs 13 g/dl, IQR 12-13.7, p=0.01) although no significant differences were found in blood loss. No significant differences in renal function and positive surgical margins (4.5% vs 2.6%, p=1) were found. At multivariable analysis, AirSeal and hemostatic agents use mitigated for differences in operative time (p=0.02), suture time (p=0.001), drainage removal day (p<0.001), 5th postoperative day hemoglobin (p=0.002) and length of stay (p=0.01).
Conclusions
Cross-analysis of two RCTs showed that robotics allows for more favorable perioperative outcomes when shifting from a planned off-clamp to an on-clamp approach during partial nephrectomy. Use of AirSeal and hemostatic agents seemed impacting on such differences.
Source of Funding
None