LAUSR

BACKGROUND En-bloc resection of bladder tumors achieves complete tumor removal, improves the quality of resection, decreases perioperative complication, and potentially improves recurrence rates. OBJECTIVE To assess the efficacy and safety of holmium laser en-bloc resection (HolERBT) versus conventional transurethral resection of bladder tumor (cTURBT). DESIGN, SETTING, AND PARTICIPANTS Between September 2015 and September 2018, 100 patients with non-muscle-invasive bladder cancer were randomly allocated to cTURBT or HolERBT. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS The primary endpoint was detection of residual tumor in reTURBT specimens at 4 wk after the primary resection. Operative parameters, specimen quality, perioperative complications, and recurrence-free survival (RFS) were compared. Independent sample t tests, χ2 tests, and Kaplan-Meier curves were used, as appropriate. RESULTS AND LIMITATIONS The patient and tumor baseline characteristics were comparable between the groups. Residual tumors were detected in 7% and 27.7% of cases after HolERBT and cTURBT, respectively (p=0.01). Detrusor muscle was sampled in 98% of HolERBT and 62% of cTURBT cases (p<0.001). Lamina propria invasion substaging was feasible in only 68.2% of HolERBT and 18.4% of cTURBT cases (p<0.001). Following HolERBT, catheterization time (p<0.001) and hospital stay (p=0.001) were shorter when compared to cTURBT. Immediate postoperative instillation of chemotherapy in indicated cases was feasible for 100% of the HolERBT group and 91.5% of the cTURBT group (p=0.04). After follow-up of 20 ± 9.9 mo (13-36), RFS was 31.76 mo (95% confidence interval [CI] 28.67-34.86) in the HolERBT group and 28.25 mo (95% CI 24.87-31.64) in the cTURBT group (hazard ratio 0.43, 95% CI 0.17-1.1; p=0.07). However, this study was not powered to detect a difference in RFS. CONCLUSIONS Compared to cTURBT, HolERBT is a safer procedure for bladder tumor resection. It fulfills the oncological criteria of optimized resection with less residual tumor and better specimen quality. PATIENT SUMMARY En-bloc resection of bladder cancer tumors using a holmium laser is safer than the conventional technique. It has the advantages of less residual tumor and better specimen quality, with a similar tumor recurrence rate. This study is registered at ClinicalTrials.gov as NCT02555163.