Schwartz, Michael J.

The PRESERVE study (NCT04972097) aims to evaluate the safety and effectiveness of the NanoKnife System to ablate prostate tissue in patients with intermediate-risk prostate cancer (PCa). The NanoKnife uses irreversible electroporation (IRE) to deliver high-voltage electrical pulses to change the permeability of cell membranes, leading to cell death. A total of 121 subjects with organ-confined PCa ≤ T2c, prostate-specific antigens (PSAs) ≤ 15 ng/mL, and a Gleason score of 3 + 4 or 4 + 3 underwent focal ablation of the index lesion. The primary endpoints included negative in-field biopsy and adverse event incidence, type, and severity through 12 months. At the time of analysis, the trial had completed accrual with preliminary follow-up available. Demographics, disease characteristics, procedural details, PSA responses, and adverse events (AEs) are presented. The median (IQR) age at screening was 67.0 (61.0–72.0) years and Gleason distribution 3 + 4 (80.2%) and 4 + 3 (19.8%). At 6 months, all patients with available data (n = 74) experienced a median (IQR) percent reduction in PSA of 67.6% (52.3–82.2%). Only ten subjects (8.3%) experienced a Grade 3 adverse event; five were procedure-related. No Grade ≥ 4 AEs were reported. This study supports prior findings that IRE prostate ablation with the NanoKnife System can be performed safely. Final results are required to fully assess oncological, functional, and safety outcomes.

Objective To evaluate whether elective off‐clamp laparoscopic partial nephrectomy ( LPN ) affords long‐term renal functional benefit compared with the on‐clamp approach. Patients and 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.