Objective Assessment of Residual Nerve Tissues in Radical Prostatectomy Specimens by Immunohistochemical Staining of Neuronal Nitric Oxide Synthase–positive Nerves and Its Impact on Postoperative Erectile Function

Preservation of Denonvilliers' fascia for nerve-sparing laparoscopic total mesorectal excision: A neuro-histological study

Urogenital complications due to pelvic autonomic nerve damage frequently occur following rectal surgery. We investigated whether total mesorectal excision (TME) with preservation of the Denonvilliers' fascia (DVF) can effectively prevent the removal of pelvic autonomic nerves through microscopy. Twenty consecutive male patients with mid-low rectal cancer who received TME with preservation or resection of the Denonvilliers' fascia (P and R groups, respectively) were included. Serial transverse sections from surgical specimens were studied histologically. Nerve fibers at the surfaces of the mesorectum were counted. Clinical correlation between the amount of nerve fibers removed and post-operative sexual function was analyzed. Nerve fibers closely localized to the DVF in the R group displaying rich erectile activity (positive anti-nNOS immunostaining). At the anterior surface of the mesorectum, the mean numbers of nNOS-positive nerve fibers per specimen in the P group were significantly lower than the R group (3.0 ± 1.8 vs. 5.0 ± 2.3, P < 0.05). Compared to the R group, patients in the P group had higher IIEF scores and better erectile function at 3 and 6 months post-operatively. The DVF is a key risk zone for pelvic denervation during laparoscopic TME. Preservation of the DVF can prevent the removal of autonomic nerves and protect post-operative erectile function. Clin. Anat. 32:439-445, 2019. © 2019 Wiley Periodicals, Inc.

The impact of nerve-sparing robot-assisted radical prostatectomy on lower urinary tract function: Prospective assessment of patient-reported outcomes and frequency volume charts

AIMS

To elucidate the effects of a nerve-sparing (NS) procedure on lower urinary tract symptoms (LUTS) and urinary function after robot-assisted radical prostatectomy (RARP), the associations between the NS procedure and LUTS and urinary function were investigated.

METHODS

The participants in this study were 200 consecutive patients who underwent RARP. These patients were categorized into unilateral and bilateral NS groups and the non-NS group. The International Prostate Symptom Score (IPSS), quality of life (QOL) index, frequency-volume chart, uroflowmetry, 1-h pad test, and the 5-item International Index of Erectile Function (IIEF-5) questionnaire were evaluated before and after RARP.

RESULTS

The total IPSS score was significantly lower in the unilateral (P = 0.03) and bilateral NS groups (P = 0.03) than in the non-NS group after RARP. Diurnal maximum voided volume (MVV) values were significantly greater in the bilateral NS group than in the non-NS group after RARP (P = 0.002). Nocturnal frequency was significantly decreased in the unilateral NS group than in the non-NS group after RARP (3 months P = 0.01, 12 months P = 0.01). Erectile function was significantly better in both the unilateral NS group (P < 0.0001) and the bilateral NS group (P = 0.02) than in the non-NS group 12 months after RARP.

CONCLUSIONS

The NS procedure in RARP has the possibility to improve not only erectile function, but also LUTS, owing to both the increase of MVV and the decrease of nocturia. Therefore, the NS procedure is also recommended from the viewpoint of early improvement of LUTS and lower urinary tract dysfunction after RARP.

Low-energy Shock Wave Therapy Ameliorates Erectile Dysfunction in a Pelvic Neurovascular Injuries Rat Model

INTRODUCTION

Erectile dysfunction (ED) caused by pelvic injuries is a common complication of civil and battlefield trauma with multiple neurovascular factors involved, and no effective therapeutic approach is available.

AIMS

To test the effect and mechanisms of low-energy shock wave (LESW) therapy in a rat ED model induced by pelvic neurovascular injuries.

METHODS

Thirty-two male Sprague-Dawley rats injected with 5-ethynyl-2'-deoxyuridine (EdU) at newborn were divided into 4 groups: sham surgery (Sham), pelvic neurovascular injury by bilateral cavernous nerve injury and internal pudendal bundle injury (PVNI), PVNI treated with LESW at low energy (Low), and PVNI treated with LESW at high energy (High). After LESW treatment, rats underwent erectile function measurement and the tissues were harvested for histologic and molecular study. To examine the effect of LESW on Schwann cells, in vitro studies were conducted.

MAIN OUTCOME MEASUREMENTS

The intracavernous pressure (ICP) measurement, histological examination, and Western blot (WB) were conducted. Cell cycle, Schwann cell activation-related markers were examined in in vitro experiments.

RESULTS

LESW treatment improves erectile function in a rat model of pelvic neurovascular injury by leading to angiogenesis, tissue restoration, and nerve generation with more endogenous EdU(+) progenitor cells recruited to the damaged area and activation of Schwann cells. LESW facilitates more complete re-innervation of penile tissue with regeneration of neuronal nitric oxide synthase (nNOS)-positive nerves from the MPG to the penis. In vitro experiments demonstrated that LESW has a direct effect on Schwann cell proliferation. Schwann cell activation-related markers including p-Erk1/2 and p75 were upregulated after LESW treatment.

CONCLUSION

LESW-induced endogenous progenitor cell recruitment and Schwann cell activation coincides with angiogenesis, tissue, and nerve generation in a rat model of pelvic neurovascular injuries.