What structures need to be identified during a laparoscopic radical prostatectomy (LRP)?

Anatomical Structures to Identify During Laparoscopic Radical Prostatectomy

During laparoscopic radical prostatectomy, surgeons must systematically identify and preserve the neurovascular bundles, external urethral sphincter complex, dorsal venous complex, puboprostatic ligaments, prostatic fascias, and when indicated, perform extended pelvic lymph node dissection with specific anatomic boundaries. 1, 2

Critical Neurovascular Structures

Neurovascular Bundles (NVB)

• The NVB runs along the posterolateral surface of the prostate between fascial layers, composed of nerve fibers superimposed on veins, arteries, and adipose tissue, surrounding almost the entire lateral and posterior prostate surfaces 3
• The bundles originate from the pelvic plexus and course distally along the urethra, with three critical zones of potential injury 2:
  • Near the seminal vesicles where the pelvic plexus ganglions are vulnerable to thermal, electrical, or crush injury during seminal vesicle dissection 2
  • Along the lateral prostatic surface where the NVB is enclosed between the lateral pelvic fascia and Denonvillier's fascia 2
  • At the prostato-urethral junction (apex) where the bundles are in precarious distal location 4, 2
• Additional fine neural plexuses exist along the posterior and anterolateral prostatic surfaces that must be preserved 2

Sphincteric Complex

• The external urethral sphincter is a complex structure in close anatomic relationship to the pelvic floor, with fragile innervation closely associated with the prostatic apex 3
• The sphincter can be injured during dissection of the dorsal venous complex and during urethral transection at the apex 4
• Preservation of urethral length beyond the prostatic apex and avoiding damage to the distal sphincter mechanism reduces urinary incontinence 5

Vascular and Ligamentous Structures

Dorsal Venous Complex

• The dorsal vein complex requires careful control to reduce blood loss during prostatectomy 5
• Improper handling during ligation can damage the underlying external urethral sphincter 1

Puboprostatic Ligaments

• These ligaments play a critical role in maintaining urinary continence postoperatively 1
• Their correct handling is necessary to avoid urogenital system malfunction 1

Fascial Anatomy

Prostatic Fascias

• The fascia surrounding the prostate is multilayered and can be either fused with the prostatic capsule or clearly separated, with substantial interindividual variation 3
• The relationship between lateral pelvic fascia and Denonvillier's fascia is critical, as both enclose the neurovascular bundles 2
• When performing intrafascial nerve-sparing, the dissection plane is as close to the prostatic capsule as possible, though this eliminates periprostatic tissue and prevents detection of pT3a disease 1

Pelvic Lymph Node Dissection Landmarks (When Indicated)

Extended PLND Template Boundaries

When extended PLND is performed, all node-bearing tissue must be removed from the area bounded by 5, 6:

• External iliac vein (anteriorly)
• Pelvic sidewall (laterally)
• Bladder wall (medially)
• Floor of the pelvis (posteriorly)
• Cooper's ligament (distally)
• Internal iliac artery (proximally)

Risk-Stratified Approach

• Extended PLND should be performed in appropriately risk-selected patients using nomogram-predicted probability of lymph node involvement 5, 6
• Extended PLND provides superior staging accuracy with higher lymph node counts and greater positive lymph node yield compared to limited dissection 5, 6

Additional Anatomical Considerations

Seminal Vesicles

• The seminal vesicles have a cage-like relationship with the neurovascular bundles, making them vulnerable during dissection 3

Bladder Neck

• Bladder neck preservation may decrease the risk of incontinence 5
• Understanding bladder neck anatomy is key for better functional results 1

Laparoscopic-Specific Advantages

The laparoscopic approach provides magnified visualization of anatomic structures and decreased venous bleeding, allowing more accurate dissection of the prostate and neurovascular bundles 7

• The visual angles, magnification, and sometimes three-dimensional visualization differ significantly from open surgery, requiring reexamination of pelvic anatomy in this surgical context 2