Rigi10™ Malleable Penile Prosthesis
Also Known As
Alcock's canal nerve (in reference to its passage through Alcock's canal/pudendal canal)
Definition
The pudendal nerve is a bilateral, paired nerve originating from the ventral rami of the sacral spinal nerves S2, S3, and S4.¹ It carries both motor and sensory axons.¹ Its name is derived from the Latin word “pudendum,” reflecting the regions it innervates, which include the rectal canal, anus, perineum, and external genitalia of both sexes.¹ The pudendal nerve is crucial for providing sensation to the penis and clitoris, the labia minora, the vaginal vestibule, the lower portion of the vaginal canal, and the posterior aspects of the scrotum and labia majora.¹ It plays a significant role in controlling somatic muscles involved in penile and clitoral erection, as well as ejaculation in males.¹ Furthermore, this nerve innervates the external anal sphincter and the external urethral sphincter, contributing to voluntary control over defecation and micturition.¹ The pudendal nerve typically gives off three main branches: the inferior rectal nerve, the perineal nerve, and the dorsal nerve of the penis or clitoris.¹
Clinical Context
The pudendal nerve is of significant clinical importance due to its extensive innervation of the perineum and pelvic structures. It is commonly implicated in various conditions and procedures:
Pudendal Neuralgia: This is a chronic and often debilitating pain condition that occurs in the distribution of the pudendal nerve.¹ Symptoms can include burning, stabbing, or aching pain in the genitals, perineum, or anorectal region, often exacerbated by sitting.³ Pudendal nerve entrapment, where the nerve is compressed along its course (e.g., between ligaments or in Alcock’s canal), is a common cause.³
Childbirth: The pudendal nerve can be susceptible to injury during childbirth, particularly during vaginal delivery, due to stretching or compression.¹ Such injuries can lead to sensory loss, fecal or urinary incontinence, and sexual dysfunction.¹
Pudendal Nerve Block: This is an anesthetic procedure used to provide analgesia for obstetric procedures (e.g., during the second stage of labor, episiotomy repair), anorectal surgery, or to diagnose and treat pudendal neuralgia.¹ The anesthetic is typically injected near the ischial spine, where the nerve can be palpated.&sup4;
Urinary and Fecal Continence: The pudendal nerve provides motor innervation to the external urethral sphincter and the external anal sphincter, playing a crucial role in the voluntary control of urination and defecation.¹ Damage to the nerve or its branches can result in urinary and/or fecal incontinence.² Electrostimulation of the pudendal nerve has been shown to increase intraurethral closure pressure, highlighting its role in continence mechanisms.²
Sexual Function: The pudendal nerve is vital for normal sexual function in both males and females. It carries sensory information from the external genitalia (penis and clitoris) and provides motor control to muscles involved in erection and ejaculation.¹ Damage can lead to sexual dysfunction, including decreased sensation, erectile dysfunction, or pain during intercourse.¹
Surgical Considerations: Knowledge of the pudendal nerve’s anatomy is critical during surgical procedures in the pelvic and perineal regions to avoid iatrogenic injury.¹ Variations in its course and branching patterns must be considered by surgeons.&sup4;
Diagnostic Evaluation: Electrophysiological studies, such as pudendal nerve motor latency tests, can be used to assess pudendal nerve function and diagnose neuropathy.¹ Imaging techniques like MRI may also be employed to identify potential sites of nerve entrapment or injury.³