The Male Pelvic Floor

Original Editor - Mandy Roscher Top Contributors - Mandy Roscher and Tarina van der Stockt

Introduction

The male pelvic floor is a complex structure made up of muscles, ligaments, nerves and fascia. The pelvic floor muscles form part of the pelvic floor and play a critical role in sexual function as well as the maintenance of  urinary and faecal continence,

Anatomy of the Prostate Gland

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Male genital system - Front view.svg.png
The prostate is a walnut-sized gland that is in the pelvis. Only men have prostate glands and its main function is to secrete prostatic fluid which lubricates and nourishes sperm. The prostate sits behind the pubic ramus and just below the bladder.[1] The urethra exits the bladder and passes through the prostate.

There is a complex neurovascular bundle found on either side of the prostate within its fascial sheath. These nerves are particularly responsible for erectile function. This neural plexus is often damaged during the surgical removal of the prostate. In 1982 two Surgeons Walsh and Donker pioneered the nerve-sparing surgical procedure when conducting a radical prostatectomy.[2] Before this, the neurovascular bundles were simply removed along with the prostate leading to complete, incurable erectile dysfunction and severe incontinence. Since then the procedure of performing a prostatectomy has been significantly refined and there are now 3 types of procedures, non-nerve-sparing (usually for severe cancers that have spread), unilateral nerve-sparing and bilateral nerve-sparing.[3]

The length of the urethra that runs through the prostate is surrounded by the sphincteric muscle.[1] The proximal sphincter is made up of smooth muscle as is responsible for closing the urethra during ejaculation to prevent retrograde ejaculation (sperm entering the bladder). The distal sphincter is made of more striated muscle and damage to this sphincter (through surgery) can lead to incontinence.[1]

Pelvic Floor Muscles

Superficial Layer

The male pelvic floor muscles make up a dome-shaped structure in the pelvis (similar to a hammock). They are responsible for the maintenance of continence, sexual function and pelvic organ support. The pelvic floor muscles are comprised of 3 layers and have a complex relationship with the surrounding bony pelvis, fascia, ligaments and nerves.[4]

The superficial perineal pouch is the most superficial of the layers and is made up of the bulbospongiosus, ischiocavernosus, superficial transverse perineal and external anal sphincter. This layer of muscles is particularly involved in ejaculation as well as urinary and faecal continence.[4][5]

The urogenital diaphragm comprises the next layer and is made up of the deep transverse perineals, the sphincter urethrae and the compressor urethrae.[4] This layer is particularly responsible for urinary continence when there is increased intraabdominal pressure (eg coughing or sneezing).

Deeper Layers
The deepest layer is the pelvic diaphragm, the muscles that make up the pelvic diaphragm are pubococcygeus, puborectalis, pubourethralis, iliococcygeus and ischiococcygeus. These muscles are particularly responsible for the support of pelvic organs and maintenance of continence.[4]

Nerve Supply to the Pelvic Region

The pelvic floor has parasympathetic, sympathetic and somatic nerve supply. This means there is both voluntary and involuntary control over the area.[4][5]

The pudendal, pelvic splanchnic and pre-sacral nerves (S2,3,4) are the nerves responsible for maintenance of urinary continence as well as erectile function in men.[3]

The pelvic splanchnic nerves provide motor function to the blood vessels of the penis and if damaged during surgery (Prostatectomy or other) will result in erectile dysfunction.

Erectile Function

An erection occurs due to a complex interaction between the vascular system, the parasympathetic, sympathetic, somatic and central nervous system with hormones and the muscular system also playing a significant role. An erection occurs when blood flows into the corpus cavernosa (tubes within the penis) faster than it can leave the penis and a closed hydraulic system maintains the erection.[4]

The bulbospongiosus and ischiocavernosus have been shown to have a significant effect on erectile function and pelvic floor muscle strengthening can result in an increase in rigidity of the penis.[4]

Alternatively, spasm of these muscles can result in limitation in blood flow and can cause erectile dysfunction.[4]

Cues for Muscle Activation

A correct pelvic floor muscle contraction combines the closure of sphincters as well as a general upward lift of the muscles (think of lifting the bladder towards the belly button)[3]

When activating specific areas of the pelvic floor to target continence and sexual function it can be helpful to divide the hammock into 3 sections a front, middle and back. Different cues can be used to activate the different areas. “Shorten your penis” and “stop the flow of urine” can be helpful activating the anterior and middle sections for erectile function and urinary continence while “tighten around the anus” is more helpful for the posterior region and faecal continence.[6]

References

  1. 1.0 1.1 1.2 Lee CH, Akin-Olugbade O, Kirschenbaum A. Overview of prostate anatomy, histology, and pathology. Endocrinology and Metabolism Clinics. 2011 Sep 1;40(3):565-75.
  2. Park YH, Jeong CW, Lee SE. A comprehensive review of neuroanatomy of the prostate. Prostate international. 2013 Dec 1;1(4):1-7.
  3. 3.0 3.1 3.2 Milios JE. Therapeutic interventions for patients with prostate cancer undergoing radical prostatectomy: A focus on urinary incontinence, erectile dysfunction and Peyronie’s disease. Thesis Document University of Western Australia. 2019
  4. 4.0 4.1 4.2 4.3 4.4 4.5 4.6 4.7 Cohen D, Gonzalez J, Goldstein I. The role of pelvic floor muscles in male sexual dysfunction and pelvic pain. Sexual medicine reviews. 2016 Jan 1;4(1):53-62.
  5. 5.0 5.1 Hodges PW, Stafford RE, Hall L, Neumann P, Morrison S, Frawley H, Doorbar-Baptist S, Nahon I, Crow J, Thompson J, Cameron AP. Reconsideration of pelvic floor muscle training to prevent and treat incontinence after radical prostatectomy. InUrologic Oncology: Seminars and Original Investigations 2019 Dec 25. Elsevier.
  6. Stafford RE, Ashton‐Miller JA, Constantinou C, Coughlin G, Lutton NJ, Hodges PW. Pattern of activation of pelvic floor muscles in men differs with verbal instructions. Neurourology and urodynamics. 2016 Apr;35(4):457-63.