The Human Penile Fibro-Vascular Assembly Requires the Integrity of Ten Fibro-Ligaments

Introduction: Penile fibro-ligaments have been extensively studied for many centuries; however, there is, unfortunately, a lack of thorough understanding. We aimed to bridge the research gap between anatomy and surgical reconstruction. Methods: We excluded cadaveric penises, already dissected and disassembled by medical students, that had damaged the corpora cavernosa (CC) or corpus spongiosum (CS). However, penises were included if both the ischiocavernosus and bulbospongiosus muscles were undamaged. A total of 8 out of 52 penises were meticulously examined. Our dissection findings were supplemented with 101 cadaveric photos, 255 penile vascular surgeries, 11 CT imaging scans, and 8 MRI imaging scans. The combined understanding was reprocessed with radiographic imaging, and patients underwent penile surgeries, notably eight hypospadias surgeries, and eight penile elongation surgeries were performed elsewhere. Results: Bilaterally, the penile CC is primarily anchored to the pelvic wall through the cavernosal ligament (CL = 2), while the CS is connected to the urinary sphincter. The suspensory, fundiform, and arcuate pubic ligament (two anatomically and one functionally) assist in stabilizing and holding the penile shaft to the pelvic wall. Distally, a distal ligament (DL = 1) and spongiosal ligament (SL = 1) extend the CC and CS to the glans penis and frenulum, ensuring urethral patency when necessary. The CC is encircled by a bi-layered tunica consisting of a 360° inner circular and a 300° outer longitudinal tunica. The ischiocavernosus muscle wraps around the penile crus and envelops the CL, connecting to the ischial tuberosity. The CS is partially surrounded by the bulbospongiosus muscle proximally and receives the SL distally. The entire penis interconnects with the skeletal muscle of the urogenital diaphragm. Conclusion: The physiological integrity of the human penis relies on ten anatomically and six functionally fibro-muscular ligaments.