Johnson, Brett A.

Purpose: We report the first multicenter, prospective, randomized noninferiority controlled trial of steerable ureteroscopic renal evacuation (SURE) for nephrolithiasis treatment. Materials and Methods: Candidates for laser lithotripsy ≥18 years with ≥1 renal stone ≥7 mm and 7–20 mm stone burden were randomized 1:1 SURE vs ureteroscopy (URS). SURE was performed using the CVAC Aspiration System, a novel steerable irrigation–aspiration catheter. The primary efficacy end point was noninferiority in stone-free rate (SFR) based on zero residual fragments (RFs) 30 days postprocedure on noncontrast computed tomography. Secondary end points were superiority tests, stone clearance (percent stone volume reduction), residual stone volume (RSV), SFR (no RF >2 mm), and SFR (no RF >4 mm) 30 days postprocedure. Results: Of the subjects, 123 were randomized and 101 qualified for efficacy analysis (SURE 46 vs URS 55). Despite randomization, baseline URS stone volume was higher (SURE 485.0 ± 432.5 mm 3 vs URS 713.3 ± 558.5 mm 3 ). The primary noninferiority end point was achieved (SURE SFR 48% vs URS SFR 49%, p = 0.027, −1.3% [90% confidence interval; −18%, 15%]). Stone clearance was significantly higher for SURE vs URS subjects (SURE 96.9 ± 5.6% vs URS 92.9 ± 11.6%, p = 0.036); RSV was significantly lower (SURE 14.3 ± 3 0.9 mm 3 vs URS 70.2 ± 144.9 mm 3 , p = 0.012). SURE stone clearance and RSV were independent of baseline stone volume, but for URS degraded with increasing baseline stone volume. Safety was comparable between groups. Conclusions: SFR for SURE subjects was noninferior compared with URS subjects; stone clearance and RSV were significantly better with SURE, independent of baseline stone volume.

Introduction: Tissue retraction during minimally invasive surgery has been achieved to date with patient positioning or additional instrumentation. The Levita™ Magnetic Surgical System (San Mateo, CA), a novel, noninvasive, magnetic retraction device for minimally invasive surgery, has been used to facilitate reduced-port robotic prostatectomy using a multiport robotic platform. With the release of the da Vinci SP robotic system (Intuitive, Sunnyvale, CA), we now report a multi-institutional initial case series of magnet-assisted robotic prostatectomy using the single-port robotic platform. Materials and Methods: An IRB-approved, retrospective chart review was performed of all patients undergoing robot-assisted radical prostatectomy using the da Vinci SP surgical system and a single Levita magnetic retractor in treatment of prostatic adenocarcinoma at two institutions from November 2018 to January 2019. Preoperative, intraoperative, and postoperative data were collected for descriptive analysis. Results: A total of 15 men, median age 62 years (range 57–71), with mean PSA 7.0 ± 2.3 underwent surgery. The robotic cannula and a single 12-mm assistant port were utilized in all cases, the latter for suction, suture passage, and clip placement; the magnetic retractor aided with posterior dissection, dorsal venous complex stitch placement, bladder neck dissection, and lymphadenectomy. No cases required conversion to a multiport robotic platform, laparoscopy, or open surgery, nor placement of additional assistant ports. No intraoperative or postoperative complications occurred. Average operative time was 224 ± 43 minutes and blood loss was 198 ± 115 mL. All patients were discharged home within 2 days of surgery. Conclusions: Robotic prostatectomy utilizing the da Vinci SP system is feasible, safe, and effective. Use of the magnetic retractor facilitates tissue exposure and improves procedure ergonomics, mimicking the conventional multiport technique. Further exploration of magnet utilization in robotic surgery and optimization of assistant port placement for true single-site surgery is warranted.