Thulium fiber laser as a novel technique with shallow and accurate cutting,high-quality hemostasis,and no ballistic effect in the treatment of non-muscle invasive bladder cancer

Dear Editor,

We read the article by Choudhury and colleagues analyzing the safety and efficacy of Thulium laser en bloc enucleation of bladder tumor (ThuLEBT) compared to transurethral resection of bladder tumor (TURBT) for non-muscle invasive bladder cancer (NMIBC) treatment, with great interest. ¹

The surgical management of non-muscle invasive bladder tumors has come a long way, thanks in particular to the development of new lasers. As reflected by this article’s findings, transurethral resection is no longer the gold standard. Indeed, the EAU recommends, “Whenever possible, TURBT should be performed by a monobloc technique, known as ‘en-bloc’, whereby the tumor is removed with the muscle.” ² “En bloc” enucleation of the tumor results in muscle present in 96%–100% of cases. ³

Transurethral vesical resection has certainly progressed thanks to the development of bipolar energy and plasma. However, many drawbacks remain, including the risk of bladder perforation during reflex contractions induced by the obturator nerve. A significant advantage of the use of lasers is that there is no risk of obturator reflexes. With the wide range of lasers available today, a key element for successful treatment is to find the best energy for each pathology. For bladder tumor enucleation, we expect the laser to deliver a clean and efficient section, excellent hemostasis, and little or no ballistic effect which tends to vaporize tumors, making anatomopathological analysis impossible. Although interesting, holmium lasers could benefit from improved hemostasis, and a major ballistic effect means that they do not meet the above-mentioned requirements.

The thulium laser is divided into several types: the classic thulium (Yag) laser—the topic of Choudhury et al., the pulsed thulium Yag laser, and the thulium fiber laser. The classic thulium (Yag) laser delivers superficial, high-quality hemostasis with no ballistic effect. Although a superficial carbonization effect can hamper correct visualization of the planes, it represents a valuable tool for enucleation of NMBIC. However, it is associated with vaporization requiring sectioning with a 5 mm safety margin, which seems impossible for some tumors such as those located close to the ureteral meatus. The pulsed thulium Yag laser has close characteristics to those of the Holmium laser including a ballistic effect, which is less than ideal for NMIBC enucleation. Finally, the thulium fiber laser meets all the required characteristics and therefore seems to be the laser of choice in this indication.

After ThuLEBT (and after TFL enucleation), en-bloc extraction is not limited to small-size tumors, contrary to what is suggested by the authors: using a nephroscope and tripod forceps, also large tumors can be extracted “en bloc.”

Lastly, the quality of hemostasis induced by the lasers may yield early bladder catheter removal and shorter hospitalization time, but further studies are necessary to confirm this outcome. In this study, the average hospitalization length of stay for ThuLEBT was 2.1 days versus 3.5 days for TURBT. With removal of the bladder catheter at home the day after the operation, the development of outpatient surgery for this indication may be achievable.