V05-02: Technical aspects of transurethral thulium laser en bloc resection of bladder cancer.
The safety and efficacy of laser en bloc resection (LERB) of non-muscle-invasive bladder cancer (NMIBC) are confirmed by several studies. En bloc resection of bladder cancer has basic advantages compared to TURB, namely: higher specimen quality, lower recurrence rate and cancer progression risks. Utilizing a laser energy during en bloc resection may help to reduce obturator nerve stimulation and avoid complications.
LERB were performed with Thulium fiber laser with diode laser pumping operating at wavelength 1.94 µm Urolase (IRE-Polus, Russia), 1J x 10 Hz settings. The distance from the tumor base to the resection line must be not less than 5 mm. According to our findings, the evaluation of resection margin was 91% when the distance from the tumor to the edge of resection was 10 mm. LERB provides relatively clear vision of muscle fibers and allows to dissect precisely within a deep muscular layer. Random cold forceps biopsy of tumor ground is needed to control the surgical margin. You can see that thulium en bloc resection of the bladder tumor is a specimen-oriented surgical procedure, that l provides specimen of excellent quality. In case of big tumors routinely we use a two-step approach. First we cut off the exophytic part of the tumor from the bladder wall afterwards tumor is morcellated. Samples of morcellated tissues are well-suitable for histopathological examination and G grading. Then we excise en-bloc the tumor base and this specimen is appropriate for T staging. Laser makes it feasible to completely remove tumors that are located in close proximity to the ureter orifice without its injury. If ureter orifice is difficult to detect because tumor covers it, aggressive en bloc resection of tumor and the ureter orifice can be performed. In such a case a ureteral stent should be placed. In this case the tumor is located in the bladder neck. As for laser settings, we use the same ones as for thulium enucleation of BPH. We carried out the comparative analysis of patients with non-muscle invasive bladder cancer after TURB and thulium laser en bloc resection. Patients groups were comparable.
According to our data, detrusor muscle was detected in 58,62% of specimens after TURB, and in 91,55% after thulium laser en bloc resection. There were no cases of the obturator nerve stimulation, perforation and/or bleeding in thulium laser en bloc resection group which made it possible to early instillate mitomycin. The recurrence rate in laser en bloc resection group was significantly lower. .
Thulium LERB of bladder cancer is an effective, feasible and safe surgical option for NMIBC.