Ex vivo and animal study of the blue diode laser, Tm fiber laser, and their combination for laparoscopic partial nephrectomy

Background and objectives: To evaluate the feasibility of using a novel blue diode laser (blue laser), a thulium fiber laser (Tm laser), and their combination as a directed-energy surgical tool in laparoscopic partial nephrectomy (LPN).

Study design/materials and methods: The blue laser emitting at 442 nm, the Tm laser emitting at 1,940 nm wavelengths, and the combination of them were tested. First, cutting and coagulative abilities of the lasers were characterized ex vivo on porcine kidney in air and CO₂ . Histological staining was performed to assess the efficiency of ablation and coagulation. Next, experimental LPN was performed on a porcine model at zero ischemia. Upper and lower segments of both kidneys were resected. Total operation time and resection time were measured; bleeding and carbonization were evaluated.

Results: Ex vivo data show that laser-induced ablation and coagulation processes do not differ substantially between CO₂ and air environments. Histological analysis of ex vivo incisions demonstrates that the blue laser produced deep ablation with relatively narrow coagulation zone, whereas Tm laser was less efficient in terms of ablation but possessed excellent coagulative properties. Experimental LPN revealed that the blue laser provided fast cutting with minimal carbonization, whereas Tm laser induced slow cutting with strong carbonization. The combination of the blue and Tm lasers provided the most promising results demonstrating the highest resection rate, almost carbonization free resection surface and clinically acceptable hemostasis enabling LPN without the need for vessel clamping.

Conclusions: The blue laser can be efficiently utilized in LPN. Furthermore, the combination of the blue and Tm lasers into a single modality may be beneficial for further development of successful laser-assisted LPN. Lasers Surg. Med. © 2019 Wiley Periodicals, Inc.