Bipolar versus thulium-YAG laser en bloc resection of bladder tumors: a prospective randomized controlled trial.

BACKGROUND: En bloc resection of bladder tumors (ERBT) has gained increasing acceptance as an alternative to conventional TURBT because it enables intact specimen retrieval while minimizing tissue fragmentation and thermal distortion. However, the optimal energy source for ERBT remains controversial. In this study, the perioperative, pathological, and short-term oncological outcomes of bipolar versus thulium-YAG laser ERBT were evaluated. METHODS: This prospective, randomized controlled trial included 140 patients with resectable bladder tumors (< 4 cm) treated between July 2023 and July 2025 at Menoufia University hospital. Patients were randomly assigned (1:1) to undergo en bloc resection using either bipolar energy or a thulium-YAG laser. The primary endpoint was perioperative hemoglobin drop. Secondary outcomes included intraoperative complications, hemostatic quality, detrusor muscle retrieval, histopathological thermal artifact, perioperative recovery, and 12 month recurrence. Histopathological assessment was performed by a blinded senior uropathologist, and all patients underwent standardized postoperative follow-up. RESULTS: Perioperative hemoglobin decline was comparable between the bipolar and thulium-YAG groups. Thulium-YAG ERBT was associated with significantly fewer intraoperative complications (1.4% vs. 20.0%, p < 0.001), better hemostatic quality, significantly lower histopathological thermal artifact, and a higher rate of detrusor muscle retrieval (94.3% vs. 67.1%, p = 0.001). Operative time, catheterization duration, postoperative pain scores, hospital stay, and 12 month recurrence rates were comparable between the two groups, although recurrence was numerically lower after thulium-YAG ERBT (7.8% vs. 14.3%, p =0.244). CONCLUSION: Thulium-YAG and bipolar ERBT are effective techniques for appropriately selected NMIBC. Thulium-YAG provided less thermal artifact, higher detrusor muscle retrieval, and fewer intraoperative complications, with comparable perioperative outcomes and short-term oncological results. Bipolar ERBT remains a viable alternative where laser technology is unavailable.