Radical prostatectomy - Surgical anatomy

Surgical anatomy of Radical prostatectomy

1. RADICAL PROSTATECTOMY SURGICAL ANATOMY - Dr. Abhishek Pandey

2. Prostatic relations Pyramidal shape – Base against bladder Apex joining membranous urethra Deep in pelvis – difficult surgical exposure Anterior – Pubic symphysis Lateral – Levator ani (wedged b/w levators ) Posterior – Rectal ampulla separated by denonvillier’s fascia

3. Postero -superior Seminal vesicles Ampullae of the vasa Normal – 18-20g 70% glandular 30% Fibromuscular stroma

4. Zonal Anatomy – McNeal (1988)

5. Prostatic Capsule Surgical capsule – relevant to TURP Compressed prostate gland remaining after procedure Anatomic Prostatic Capsule – relevant to RP Non-glandular fibromuscular stromal portion of prostatic parenchyma distributed over surface Non-discrete with indistinct margin with strands mingling in periprostatic fascia 2-3mm thick Microscopically integral part of prostate

6. Prostaic Sheath AKA Peri -Prostatic Fascia – Loose areolar tissue encasing prostate Derived from intermediate stratum of retroperitoneal fascia Fuses anterolaterally with endopelvic fascia (lateral pelvic fascia) continuous with obturator & transversalis fasciae Lateral pelvic fascia – derived from outer stratum

7. Three parts of periprostatic fascia Anterior leaf – encloses dorsal venous complex Lateral leaf – most important surgically Extends from anterolateral to posterolateral area Encloses the Neurovascular bundle Posterior leaf – fuses with denonvillier’s fascia

8. Denonvillier’s Fascia Between posterior wall of prostate & rectum Loose areolar connective tissue – more condensed than periprostatic fascia Two Lamellae Anterior lamella – single layer fusion-fascia Arises by distal-to-proximal fusion of mesothelial layers of two layers of pelvic peritoneum in rectovesical pouch Derived from inner stratum

9. A Adherent to posterior prostatic surface Limited laterally – merges with periprostatic fascia Shield shaped Posterior lamella – rectal fascia Overlies anterolateral wall of rectum over lamina propria Derived from inner stratum Both layers taken with specimen in RP No surgically separable plane between them

10. Pearly Gates – Hugh Young Combined layers of denonvillier’s fascia appearing glistening white on perineal exposure Signify safe passage past rectum Beware – Rectourethralis

11. Puboprostatic Ligaments AKA median puboprostatic ligaments Paired ligaments each 4.5mm wide Attached to perichondrium near inferior border of symphysis pubis lateral to synchondrosis Each deviates slightly medially towards prostate Becomes continuous with prostatic sheath Branches of deep dorsal vein that run beneath & b/w puboprostatic ligaments

12. Dorsal Venous Complex Deep Dorsal Vein of Penis Under Buck’s fascia between corpora cavernosa Penetrates Urogenital diaphragm to enter Retzius space Three major branches Superficial branch – Single median Travels between puboprostatic lig . Lies outside peri -prostatic fascia Lateral branches – Right & Left Travel posterolaterally peri -prostatic fascia

13. Prostatic Venous Plexus of Santorini Lies over anterior fibromuscular stroma & lateral surface Embeded in peri -prostatic fascia Main input – Deep dorsal vein Empty in vesical venous plexus & Inferior Vesical Vein Thin-walled valve-less veins Intercommunication with all deep pelvic veins

14. Striated Sphincter Vertically oriented tubular sheath Horseshoe shaped fibers at apex Close to apex fibers fuse posteriorly in midline Innervation – Pudendal N. DVC travels through it Fuse with Ant. FMS Insert on perineal body

15. Prostatic Innervation Sympathetic – L1 & L2 → Sup. hypogastric plexus → Inferior hypogastric plexus Parasympathetic - Pelvic Splanchnic nerves from S2, 3, 4 via Inferior hypogastric plexus Somatic – from sacral nerves S2, 3, 4 → supply EUS via Pudendal N.

16. Inferior Hypogastric (Pelvic) Plexus Located retroperitoneally besides rectum 5-11cm from the anal verge Form a fenestrated rectangular plate in sagittal plane Midpoint at the level of tip of seminal vesicles Input from sacral centers & hypogastric nerves Gives rise to Neurovascular Bundle (NVB)

17. Neurovascular Bundle of Walsh Runs within periprostatic fascia at the postero -lateral junction 1.5mm from prostate at base 3.0mm from prostate at apex Contains fibres of Prostatic nerves & Cavernous N. Prostatic nerve fibres closely associated with prostatic capsular vessels Nerve-sparing – lateral displacement of NVB

18. Arterial Supply Anterior div. of Internal Iliac A. → Gluteo - pudendal trunk → Prostatovesical A. → Inf. Vesicle & Prostatic A. Prostatic A. Urethral A. – Proximal branch – Transition zone (4 & 8 o’ clock position near bladder neck) Capsular branches – Posterolateral offshoots – Peripheral & central zones Superior vesicle A. → Vesiculodeferential A. → Seminal vesicles & vasa

19. Lymphatic Drainage Three lymphatic routes of nodal spread Route 1 – along Prostatic pedicle – major lymphatic vessels - obturator and internal iliac nodes Route 2 – along Vesiculodeferential A. – Central zone – external iliac nodes Route 3 – along capsular vessels – capsular lymphatic vessels – sacral nodes Primary drainage – Obturator & External Iliac nodes

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