The role of warm ischemia time on functional outcomes after robotic partial nephrectomy: a radionuclide renal scan study from the clock randomized trial.

PURPOSE: To evaluate the relationship between warm ischemia time (WIT) duration and renal function after robot-assisted partial nephrectomy (RAPN). METHODS: The CLOCK trial is a phase 3 randomized controlled trial comparing on- vs off-clamp RAPN. All patients underwent pre- and postoperative renal scintigraphy. Six-month absolute variation of eGFR (AV-GFR), rate of relative variation in eGFR over 25% (RV-GFR > 25), absolute variation of split renal function (SRF) at scintigraphy (AV-SRF). The relationships WIT/outcomes were assessed by correlation graphs and then modeled by uni- and multivariable regression. RESULTS: 324 patients were included (206 on-clamp, 118 off-clamp RAPN). Correlation graphs showed a threshold on WIT equal to 10 min. The differences in outcome measures between cases with WIT < vs ≥ 10 min were: AV-GFR - 3.7 vs - 7.5 ml/min (p < 0.001); AV-SRF - 1% vs - 3.6% (p < 0.001); RV-GFR > 25 9.3% vs 17.8% (p = 0.008). Multivariable models found that AV-GFR was related to WIT ≥ 10 min (regression coefficient [RC] - 0.52, p = 0.019), age (RC - 0.35, p = 0.001) and baseline eGFR (RC - 0.30, p < 0.001); RV-GFR > 25 to WIT ≥ 10 min (odds ratio [OR] 1.11, p = 0.007) and acute kidney injury defined as > 50% increase in serum creatinine (OR 19.7, p = 0.009); AV-SRF to WIT ≥ 10 min (RC - 0.30, p = 0.018), baseline SRF (RC - 0.76, p < 0.001) and RENAL score (RC - 0.60. p = 0.028). The main limitation was that the CLOCK trial was designed on a different endpoint and therefore the present analysis could be underpowered. CONCLUSIONS: Up to 10 min WIT had no consequences on functional outcomes. Above the 10-min threshold, a statistically significant, but clinically negligible impact was found.

"Bordeaux Neobladder": First Evaluation of the Urodynamic Outcomes.

Background: The intracorporeal orthotopic modified-Y "Bordeaux" neobladder (iYNB) was first described in 2016. No urodynamic evaluation of this neobladder has yet been performed. Objective: To present the urodynamic features of the iYNB and incontinence-specific health-related quality of life (HRQoL) outcomes. Design setting and participants: We prospectively assessed 26 patients operated between September 2018 and November 2020. Surgical procedure: Robotic radical cystectomy for malignant disease of the bladder and iYNB, performed by a single surgeon, were used. Measurements: Three months after surgery and in November 2021, consenting patients underwent clinical evaluation and multichannel urodynamic study (UDS). The incontinence quality of life (I-QoL) questionnaire was used to evaluate HRQoL. Continence was classified into day- and nighttime, and clinically defined as the use of zero pads. A descriptive statistical analysis was performed. Results and limitations: The mean age at surgery was 65.4 yr. The mean follow-up period was 27 mo (12-38). The mean time for the neobladder reconstruction was 192 min (110-340). The mean maximum capacity was 431 cm3 (range 200-553). The mean postvoid residual was 101.6 ml (0-310), and the rate of clean intermittent catheterization was 17.6%. With the exception of a significant reduction in the volume of the first sensation of bladder fullness, no other statistically significant changes in the UDS parameters of both the storage and the voiding phase were observed over time. Day- and nighttime continence rates were 58.8% and 23.5%, respectively. The mean postoperative I-QoL score was 103.3 (89-110). Limitations include the small number of patients and short follow-up. Conclusions: The UDS evaluation of iYNB demonstrates that both the volumetric and the pressure characteristics are acceptable and may enhance quality of life. Prospective studies with larger numbers of patients and longer follow-up are needed to further evaluate the iYNB. Patient summary: The "Bordeaux" neobladder provides acceptable urodynamic outcomes. It is associated with high levels of health-related quality of life and good rates of continence in patients.

Is off-clamp robot-assisted partial nephrectomy beneficial for renal function? Data from the CLOCK trial.

OBJECTIVES: To compare the functional outcomes of on- vs off-clamp robot-assisted partial nephrectomy (RAPN) within a randomized controlled trial (RCT). MATERIALS AND METHODS: The CLOCK study (CLamp vs Off Clamp the Kidney during robotic partial nephrectomy; NCT02287987) is a multicentre RCT including patients with normal baseline function, two kidneys and masses with RENAL scores ≤ 10. Pre- and postoperative renal scintigraphy was prescribed. Renal defatting and hilum isolation were required in both study arms; in the on-clamp arm, ischaemia was imposed until the completion of medullary renorraphy, while in the off-clamp condition it was not allowed throughout the procedure. The primary endpoint was 6-month absolute variation in estimated glomerular filtration rate (AV-GFR); secondary endpoints were: 12, 18 and 24-month AV-GFR; 6-month estimated glomerular filtration rate variation >25% rate (RV-GFR >25); and absolute variation in ipsilateral split renal function (AV-SRF). The planned sample size was 102 + 102 cases, after taking account crossover of cases to the alternate study arm; a 1:1 randomization was performed. AV-GFR and AV-SRF were compared using analysis of covariation, and RV-GFR >25 was assessed using multivariable logistic regression. Intention-to-treat (ITT) and per-protocol analyses (PP) were performed. RESULTS: A total of 160 and 164 patients were randomly assigned to on- and off-clamp RAPN, respectively; crossover was observed in 14% and 43% of the on- and off-clamp arms, respectively. We were unable to find any statistically significant difference between on- vs off-clamp with regard to the primary endpoint (ITT: 6-month AV-GFR -6.2 vs -5.1 mL/min, mean difference 0.2 mL/min, 95% confidence interval [CI] -3.1 to 3.4 [P = 0.8]; PP: 6-month AV-GFR -6.8 vs -4.2 mL/min, mean difference 1.6 mL/min, 95% CI -2.3 to 5.5 [P = 0.7]) or with regard to the secondary endpoints. The median warm ischaemia time was 14 vs 15 min in the ITT analysis and 14 vs 0 min in the PP analysis. CONCLUSION: In patients with regular baseline function and two kidneys, we found no evidence of differences in functional outcomes for on- vs off-clamp RAPN.

Safety of on- vs off-clamp robotic partial nephrectomy: per-protocol analysis from the data of the CLOCK randomized trial.

PURPOSE: To compare the safety of on- vs off-clamp robotic partial nephrectomy (RAPN). METHODS: 302 patients with RENAL masses ≤ 10 were randomized to undergo on-clamp (150) vs off-clamp (152) RAPN (CLOCK trial-ClinicalTrials.gov NCT02287987) at seven institutions by one experienced surgeon per institution. Intra-operative data, complications, and positive surgical margins were compared. RESULTS: Due to a relevant rate of shift from the assigned treatment, the per-protocol analysis only was considered and the data from 129 on-clamp vs 91 off-clamp RAPNs analyzed. Tumor size (off-clamp vs on-clamp, 2.2 vs 3.0 cm, p < 0.001) and RENAL score (5 vs 6, p < 0.001) significantly differed. At univariate analysis, no differences were found regarding intra-operative estimated blood loss (off- vs on-clamp, 100 vs 100 ml, p = 0.7), post-operative complications rate (19% vs 26%, p = 0.2), post-operative anemia (Hb decrease > 2.5 g/dl 26% vs 27%, p = 0.9; transfusion rate 3.4% vs 6.3%, p = 0.5; re-intervention due to bleeding 1.1% vs 4%, p = 0.4), acute kidney injury (4% vs 6%, p = 0.8), and positive surgical margins (3.5% vs 8.2%, p = 0.1). At multivariate analysis accounting for tumor diameter and complexity, considering the on-clamp group as the reference category, a significant difference was noted in the off-clamp group exclusively for blood loss (OR 0.3, 95% CI 0.09-0.52, p = 0.008). CONCLUSIONS: The on-clamp and off-clamp approaches for RAPN showed a comparable safety profile.

Predictors of the Transition from Off to On Clamp Approach during Ongoing Robotic Partial Nephrectomy: Data from the CLOCK Randomized Clinical Trial.

PURPOSE: We sought to identify predictive factors of the transition from off clamp to on clamp robotic partial nephrectomy following an intraoperative decision. MATERIALS AND METHODS: In the multicenter, randomized, prospective CLOCK (CLamp vs Off Clamp the Kidney during robotic partial nephrectomy) trial 152 and 149 of the 301 patients with a localized renal mass were assigned to undergo off clamp and on clamp robotic partial nephrectomy, respectively. Surgery was done at a total of 7 referral institutions by 1 surgeon per institution. A localized renal mass was defined as having a R.E.N.A.L. (radius, exophytic/endophytic, nearness to collecting system or sinus, anterior/posterior, location relative to polar lines, hilar) score less than 10. Surgeons had similar experience with at least 100 previous robotic partial nephrectomies. All patients underwent a preoperative and a 6-month renal scan. The current study deals with one of the secondary end points of the trial, comparing cases finalized as clampless (off robotic partial nephrectomy group) with those which were converted (shift robotic partial nephrectomy group). RESULTS: Of the 152 patients randomized to off clamp 61 (40%) were shifted to clamp with a median ischemia time of 15 minutes. In the shift robotic partial nephrectomy group the masses were larger (3.5 vs 2.2 cm) and more complex (R.E.N.A.L. score 7 vs 6). A significant association with transition was found for tumor diameter (OR 1.4) and the R.E.N.A.L. score continuously (OR 1.4) and when recoded in groups, including 4-no risk (referent OR 1), 5-6-low risk (OR 1.8), 7-8-intermediate risk (OR 3.6) and 9 or greater-high risk (OR 6.6). The shift robotic partial nephrectomy group had longer operative time, higher blood loss and increased performance of 2-layer renorrhaphy. No significant differences were noted in postoperative complications or renal function after 6 months. CONCLUSIONS: The transition from off to on clamp robotic partial nephrectomy is associated with renal mass diameter and complexity. Under the specific conditions of the current trial no harm was related to this decision.

The role of vascular clamping during robot-assisted partial nephrectomy for localized renal cancer: rationale and design of the CLOCK randomized phase III study.

To outline the design and rationale of clock, a large, phase III randomized controlled trial which examines the role vascular clamping during robot-assisted partial nephrectomy (RAPN) for localized renal cancer. To be eligible for study entry, patients must have normal coagulative function, preoperative estimated glomerular filtration rate (eGFR) >60 mL/min, normal contralateral kidney and a single renal mass with RENAL Score ≤10. Eligible patients are to be randomized in a 1:1 ratio between two arms. Randomized allocation was assigned by a permuted block design, stratified by center. Allocation arm was notified by the study internet-based e-form, managed by an independent software house. Arm A=RAPN with ischemia; Arm B=RAPN without ischemia. At any moment, from randomization to the end of the procedure, the investigators could amend the indication given by randomization and shift to the alternative clamping option, detailing the timing and reasons of their decision. CLOCK is a randomized controlled trial, which addresses two questions relating to the management of localized renal cancer treated by RAPN with or without ischemia: 1) what is the impact of the surgical technique on long-term renal function; 2) what are the factors influencing the shift from one technique to the other. The study will be completed 24 months after the last enrollment.