Numerical analysis for laser endoluminal treatment of stress urinary incontinence

Résumé fourni par la source

Stress urinary incontinence (SUI) is a sudden urine-leaking condition during physical activities due to weakened pelvic floor muscles or sphincter malfunction. Recently, a balloon-integrated diffusing applicator (DA) with 980 nm laser wavelength at 20W showed promising results for SUI treatment in light of urethral sphincter tightening and regeneration [1]. However, a large divergence beam emitted from DA can surpass a short treatment length of the sphincter (~16 mm) causing injury to the surrounding healthy tissue. A radial fiber (RF) emits a narrow beam width circumferentially around the fiber tip [2]. The current study aims to numerically compare the laser emission profiles from various angle fiber tips (β) in the balloon-integrated RF for SUI treatment. ZEMAX software was utilized for the numerical simulation. 0.22 NA 400-μm core diameter fibers with three β values were chosen for the simulation (i.e., β = 74°, 58°, and 42°) [2]. 980 nm laser at 20W was delivered by RFs. No significant difference was found among the output beam widths from RFs at the balloon surface (approximately 2 mm). The divergence angles (α) of the output beam from the tips decreased (α = 88°, 59°, and 33°) as β values decreased (β = 74°, 58°, and 42°), respectively. The starting position of the laser beam relative to the fiber tip (d) at the balloon surface was affected by the α values (i.e., d = 0, 1, and 2 mm for α = 88°, 59°, and 33°, respectively). According to the longitudinal emission, the normalized intensity peak for β = 74° was higher than those for β = 58° and 42° (i.e., 10% and 17%, respectively). Therefore, RF with β = 74° can control the position of the laser output beam more accurately and provide more effective energy than the other β values for the laser endoluminal treatment of SUI. Further studies will investigate the performance of RF with β = 74° in both ex vivo and in vivo models in terms of temperature distribution and wound healing.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.