NS-AUA 2024 Annual Meeting Abstracts – Trauma

Introduction: Red and near-infrared light (NIR) were shown to provide positive photobiomodulation (PBMT) in multiple injury models.Such biostimulatory effects were utilized to promote wound healing by dampening inflammation, which plays a vital role in the early phase of tissue repair.We aimed to investigate light therapy in urethral stricture repair.Our hypothesis was that those rabbits treated with direct vision internal urethrotomy (DVIU) followed by light therapy have higher rates of stricture resolution on imaging and decreased inflammation on histologic specimen.Methods: A previously developed rabbit stricture model was used.After successful stricture induction, the subjects were randomized into three groups: control, red light, and NIR group.All subjects underwent DVIU followed by catheter insertion.The control group received catheters without any modification.The red light group received an engineered catheter with red light source inside the catheter.The NIR light group received an engineered catheter with NIR light source.Each day for seven days, 5.4J/cm 2 of energy was delivered to the treatment arms.Catheters were then removed.The animals were sacrificed at 24 weeks after retrograde urethrograms (RUG) and urethroscopy by a surgeon blinded to the treatment arm.Radiographic images and histological specimens were reviewed by a radiologist and a pathologist, respectively, blinded to the treatment arm.Detectable radiographic improvement was defined as at least 10% of improvement in the percentage of stenosed lumen after treatment.Histological specimens were assessed for inflammation.Results: Stricture was successfully induced on 24 rabbits, which were then randomized, eight per arm.The control group had a mean of 41% stenosis, while the red light group had a mean of 47% and the NIR group, of 37%.Seven of the eight rabbits in the red light group (87.5%) and eight of eight (100%) in the NIR group had detectable improvement.In contrast, six of eight subjects (75%) in the control group had detectable improvement.In the control group, two (25%) had worsening strictures, and one had a complete obliteration.No worsening stricture was found in either treatment arm.Four of eight (50%) in the control group had >50% improvement, compared to two of eight (25%) and five of eight (62.5%) in the NIR and red light groups, respectively.Chronic inflammation was significantly more pronounced in the control group, when compared to the NIR group (p=0.04).Conclusions: This pilot study successfully demonstrated feasibility of utilizing red or NIR light energy via engineered catheters.Such a method may allow for a wide application of this novel concept to use light therapy to augment DVIU.