Baseline erectile function alters the cavernous nerve quantity and distribution around the prostate.

Area of Science:

• Urology
• Neuroscience
• Surgical Pathology

Background:

• Radical prostatectomy can impact erectile function due to disruption of the cavernous nerve supply.
• Neuronal nitric oxide synthase (nNOS) is a key marker for evaluating the integrity of the cavernous nerves responsible for penile erection.

Purpose of the Study:

• To map the distribution of nNOS-positive nerve fibers in the prostate.
• To identify factors influencing the quantity of these nerve fibers, correlating with erectile function outcomes.

Main Methods:

• Analysis of 46 prostatectomy specimens from patients with pre-operative erectile function data (International Index of Erectile Function, IIEF) and penile change measurements.
• Immunohistochemical staining for nNOS to quantify nerve fibers in six prostatic zones.
• Multivariate analysis to assess the correlation between nNOS fiber quantity and patient/clinical variables.

Main Results:

• nNOS-positive nerve fibers were predominantly located in the 3 to 5 o'clock sextant (65%) of the prostate.
• Maximum penile circumferential change, an indicator of erectile function, was the sole significant predictor of nNOS fiber quantity (p=0.019).
• Patients with objective erectile dysfunction had a significantly higher count of nNOS-positive nerve fibers compared to those without (p=0.009), particularly in the apical region.

Conclusions:

• Pre-operative erectile function status is a critical determinant of cavernous nerve quantity and distribution.
• Preservation of the neurovascular bundle, especially at the prostate apex, remains vital for maintaining erectile function post-surgery.