title: Optical clearing of vaginal tissues, ex vivo, for minimally invasive laser treatment of female stress urinary incontinence.
abstract: Near-infrared laser energy in conjunction with applied tissue cooling is being investigated for thermal remodeling of the endopelvic fascia during minimally invasive treatment of female stress urinary incontinence. Previous computer simulations of light transport, heat transfer, and tissue thermal damage have shown that a transvaginal approach is more feasible than a transurethral approach. However, results were suboptimal, and some undesirable thermal insult to the vaginal wall was still predicted. This study uses experiments and computer simulations to explore whether application of an optical clearing agent (OCA) can further improve optical penetration depth and completely preserve the vaginal wall during subsurface treatment of the endopelvic fascia. Several different mixtures of OCA’s were tested, and 100% glycerol was found to be the optimal agent. Optical transmission studies, optical coherence tomography, reflection spectroscopy, and computer simulations [including Monte Carlo (MC) light transport, heat transfer, and Arrhenius integral model of thermal damage] using glycerol were performed. The OCA produced a 61% increase in optical transmission through porcine vaginal wall at 37°C after 30 min. The MC model showed improved energy deposition in endopelvic fascia using glycerol. Without OCA, 62%, 37%, and 1% of energy was deposited in vaginal wall, endopelvic fascia, and urethral wall, respectively, compared with 50%, 49%, and 1% using OCA. Use of OCA also resulted in 0.5-mm increase in treatment depth, allowing potential thermal tissue remodeling at a depth of 3 mm with complete preservation of the vaginal wall.
authors.affiliation: University of North Carolina at Charlotte, Department of Physics and Optical Science, 9201 University City Boulevard, Charlotte, North Carolina 28223, United States.
authors.forename: Chun-Hung
authors.initials: CH
authors.lastname: Chang
authors.affiliation: Carolinas Medical Center, Women's Center for Pelvic Health, 2001 Vail Avenue, Suite 360, Charlotte, North Carolina 28207, United States.
authors.forename: Erinn M
authors.initials: EM
authors.lastname: Myers
authors.affiliation: Carolinas Medical Center, Women's Center for Pelvic Health, 2001 Vail Avenue, Suite 360, Charlotte, North Carolina 28207, United States.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Kennelly
authors.affiliation: University of North Carolina at Charlotte, Department of Physics and Optical Science, 9201 University City Boulevard, Charlotte, North Carolina 28223, United StatesbCarolinas Medical Center, Women's Center for Pelvic Health, 2001 Vail Avenue, Suite 360, Charlotte, North Carolina 28207, United States.
authors.forename: Nathaniel M
authors.initials: NM
authors.lastname: Fried
mesh_terms: D005260:Female; D006801:Humans; D053685:Laser Therapy / Q000379:methods*; D019060:Minimally Invasive Surgical Procedures / Q000379:methods; D016896:Treatment Outcome; D014550:Urinary Incontinence, Stress / Q000601:surgery*; D014621:Vagina / Q000601:surgery*