MD, FACS, ABU/FPMRS University of California Irvine
Introduction: The sub trigonal peri-vesical nerve plexus has a considerable proportion of the bladder afferent and autonomic innervation. It has been a targeted area to treat Overactive Bladder (OAB) and Bladder Painful Syndrome (BPS). The transurethral approach for radiofrequency ablation (RFA) of this region has been successful in denervating it to alleviate symptoms. However, there were some adverse effects because of the induced scarring. Here, we report a novel transvaginal approach of low-temperature RFA device (DENERA) and assess its feasibility and efficacy and safety of transvaginal ablation of peri-vesical nerve plexus in Vivo ovine model. Methods: We used 14 adult female sheep in this prospective study. They were divided into control (n=4) without ablation. Post-ablation groups were: 1 week (n=3), 4 weeks (n=4), and 12 weeks (n=3). RFA probe inserted into the vagina aiming to deploy RFA needles through the anterior vaginal wall into the sub trigonal peri-vesical plexus. Pulsed RF energy is applied for three cycles of 4 minutes with 30 seconds rest between each cycle, maintaining the tissue temperature at 45 °C. After termination, the bladder and proximal urethra were harvested and subjected to gross and histological assessment, including neural histopathology analysis with H&E, S100, TH, and VAcht immunostaining. To quantify the tissue's neural density and neural vacuolization, they were graded on a 0-3 scale proportional to the number of vacuoles or nerves counted on the microscope slide, with higher scores being a greater effect of ablation (more vacuoles and fewer nerves) vice versa. Results: The ablation effects were most pronounced as neural vacuolization at one week and decreased neural density the most at four weeks (Figure 1). Both variables displayed a slight rebound towards baseline at 12 weeks. The pathology analysis also showed that the needles penetrated deep into the sub trigonal detrusor muscle. There was no urothelium damage or injury reported in the post-ablation group. The sheep recovered from the DENERA procedure with no signs of pain or complications. Conclusions: This study shows that DENERA device can cause sub trigonal perivesical nerve denervation, with some rebound at 12 weeks. The ease of the procedure and using low temperature offers DENERA as an encouraging new office treatment option for OAB and or BPS. Future clinical data is needed. SOURCE OF Funding: University of California Innovation grant
