Energy source comparison in en-bloc resection of bladder tumors: subanalysis of a single-center prospective randomized study

PURPOSE: Different energy sources are employed to perform en-bloc transurethral resection of bladder tumor (ERBT). No study compared different energy sources in ERBT. The aim is to compare the different ERBT sources in terms of pathological, surgical and postoperative outcomes. METHODS: This is a sub-analysis of a prospective randomized trial enrolling patients submitted to ERBT vs conventional TURBT from 03/2018 to 06/2021 (NCT04712201). 180 patients enrolled in ERBT group were randomized 1:1:1 to receive monopolar (m-ERBT), bipolar (b-ERBT) or thulium laser (l-ERBT). Endpoints were the comparison between energies in term of pathological analysis, intra, and post-operative outcomes. RESULTS: 49 (35%) m-ERBT, 45 (32.1%) b-ERBT, and 46 (32.9%) l-ERBT were included in final analysis. The rate of detrusor muscle (DM) presence was comparable between the energies used (p = 0.796) or the location of the lesion (p = 0.662). Five (10.2%), 10 (22.2%) and 0 cases of obturator nerve reflex (ONR) were recorded in m-ERBT, b-ERBT and I-ERBT groups, respectively (p = 0.001). Conversion to conventional TURBT was higher for lesions located in the anterior wall/dome/neck (p < 0.001), irrespective from the energy used. The presence of artifact in the pathological specimen was higher for lesions at the posterior wall (p = 0.03) and trigone (p = 0.03). CONCLUSIONS: In our study, no difference in staging feasibility among energies was found. Laser energy might be beneficial in lateral wall lesions to avoid ONR. Since there is an increased risk of ERBT conversion to conventional TURBT for lesions of the anterior wall, electrocautery might be preferred over laser to avoid waste of material. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s00345-022-04042-y.