The base of the prostate is at the bladder-prostate junction
The narrowed apex is the most inferior portion of the prostate gland, reaching the urogenital diaphragm. The apex of the prostate is continuous with the striated urethral sphincter
The prostate is fixed to the pubic bone anteriorly by the puboprostatic ligaments near the apex of the prostate
≈70% of the prostate's compositionMikael Häggström, M.D. Author info - Reusing images- Conflicts of interest: NoneMikael Häggström, M.D., CC0, via Wikimedia Commons
Divided into anatomic zones (largest to smallest) (3):
Peripheral zone
≈70% of the glandular prostate tissue
Most (≈70%) prostate cancers occur in the peripheral zone
Central zone
≈25% of the glandular prostate tissue
Surrounds the opening of the ejaculatory ducts
Transitional zone
≈3-5% of the glandular prostate tissue
In the young adult male, only constitutes about 5-10% of male prostate; with age and the development of BPH, the TZ can occupy a large part of the glandular prostate[3]
Anterior to the peripheral zone
Separatedfrom the rest of the glandular compartments of the prostate by a distinct fibromuscular band
Benign prostatic hyperplasia most commonly occurs in the transitional zone
≈20% of prostate cancers occur in the transitional zone
Anteriorly/anterolaterally: prostatic fascia (also inappropriately called the capsule of the prostate; recall no true histologic capsule)
Laterally: prostatic fascia fuses with endopelvic fascia
See Figures 1 and 2
Denonvilliers fascia
A filmy, delicate layer of connective tissue
Located between the anterior wall of the rectum and prostate
There is a plane of loose, areolar tissue between Denonvilliers fascia and the rectum
Most prominent and dense near the base of the prostate and the seminal vesicles and thins dramatically as it extends caudally to its termination at the striated urethral sphincter
Impossible to discern posterior and anterior layers of this fascia on microscopic examination; for this reason, this must be excised fascia completely to obtain an adequate surgical margin
Prostatic fascia
In direct continuity with the parenchyma of the prostate anteriorly and anterolaterally
Fuses with the levator fascia laterally to form the lateral pelvic fascia
Endopelvic fascia
Also known as levator fascia, lateral prostatic fascia, and lateral pelvic fascia§
Lines the inner surface of pelvic muscles
Continuous with the transversalis fascia
The cavernosal nerves (neurovascular bundles) travel between the levator/endopelvic and prostatic fascia, posterolateral to the prostate (See Figure 1, same as above)
The blood supply to the prostate enters at the 4 and 8 o'clock positions.
The prostate receives arterial blood supply from the inferior vesical artery, which is a branch of the anterior branch of the internal iliac artery
After the inferior vesical artery provides small branches to the seminal vesicle and the base of the bladder and prostate, the artery terminates in 2 large groups of prostatic vessels:
Urethral vessels
Enter the prostate at the posterolateral vesicoprostatic junction and supply the vesical neck and periurethral portion of the gland.
Capsular branches
Run along the pelvic sidewall in the lateral pelvic fascia posterolateral to the prostate, providing branches that course ventrally and dorsally to supply the outer portion of the prostate.
These capsular arteries and veins are intimately associated with the branches of the pelvic plexus forming the neurovascular bundle (NVB), which is used as the macroscopic landmark to aid in the identification of the microscopic branches of these nerves.
Branches from the internal pudendal artery and the middle rectal (hemorrhoidal) artery also contribute a supply to the prostate
The veins of the prostate drain into the Santorini/periprostatic plexus
The periprostatic plexus anastomoses with the deep dorsal vein of the penis and the internal iliac (hypogastric) veins
The deep dorsal vein leaves the penis under the Buck fascia between the corpora cavernosa and penetrates the urogenital diaphragm, with the common trunk dividing into 3 major branches:
Superficial branch
Right lateral venous plexuses
Left lateral venous plexuses
Superficial branch
The centrally located vein overlying the bladder neck and prostate
Lies in the retropubic fat outside the anterior prostatic fascia.
Travels between the puboprostatic ligaments
Easily visualized early in retropubic operations and has communicating branches over the bladder itself and into the endopelvic fascia.
Right and left lateral venous plexuses
Traverse posterolaterally
Communicate freely with the pudendal, obturator, and vesical plexuses, which form the inferior vesical vein, which empties into the internal iliac vein.
The common trunk (including deep dorsal vein complex) and lateral venous plexuses are covered by the prostatic and endopelvic/levator fascia.
See Figure for representation of DVC in relationship to other surrounding veins
In males, the pelvic plexus is located retroperitoneally beside the rectum 5 to 11 cm from the anal verge
The nerves innervating the prostate travel outside the fascia of the prostate and Denonvilliers fascia until they perforate the fascia where they enter the prostate
TRUS uses probes with frequency ranging from 6-8 MHz
Prostate volume can be calculated using an ellipsoid formula where volume = π/6 x L x W x H (0.52) (some use spheroid formula where volume = 4/3 x π × length × width × height or "bullet" formula described with volume calculator); this is accurate to within 5% of its true weight
