(057) Destabilising Evidence: A Micro-Anatomical Investigation of Penile Suspensory Ligaments (PSL) Using Epoxy Sheet Plastination and Confocal Microscopy
Authors: Calopedos R , Rashid P , Zhang M 
Published: February 2024

Introduction

Precise anatomy of the PSL remains controversial. It is routinely described as having 3 components: The fundiform (FL), Suspensory (SL) and Arcuate Ligaments (AL). Proponents of penile enlargement surgery (PES) ensure that division of the “superficial” PSL (FL, SL), allows desired distraction between phallus and pubic symphysis (PS) without risking instability. Seemingly in support of this rationale, many publications imply the FL and SL provide less structural integrity as they connect only superficial fascias (Origin: Scarpa’s fascia or linea alba; Insertion: Penile Dartos or Buck’s fascia). AL is reported to be the primary support structure as it connects the corporal tunica albuginea (TA) directly to the bone and preserved in PES given its deeper location. Despite this, significant sexual dysfunction (SD) from PSL deficiency after PES has been reported. An improved understanding of this anatomy is paramount for quality surgical care in both pre-operative counselling and rectification of adverse functional outcomes.

Objective

(1) To present initial findings of the in-situ PSL anatomy (2) To propose a new anatomical classification system

Methods

Data from six male cadavers (46-87 years; mean 75) were used in present study. There was no history of genitourinary operations and cause of death were either respiratory or vascular. Following deep-freeze and 0.9mm whole-mount sectioning, specimens were impregnated with epoxy-resin mixture (E12/E1/AE10/AE30). Without specific labelling, this process allows endogenous autofluorescence of collagen/elastin/myofilaments when excited using 488nm-confocal-laser microscope. Select areas were examined using stereoscopic microscopy and scanned at high-resolution. This technique ensures preservation of anatomy in-situ and allowed enhanced examination at both macroscopic and microscopic levels (Figure 1).

Results

Proposed classification divides PSL by anatomical location: Prepubic, Subpubic, Retropubic. While corresponding to the same distinct structures, it avoids the misnomers and discrepancies that are embedded in existing nomenclature. Findings are summarised in Table 1. The AL does not appear to the PSL apparatus. It fuses with the interosseus fibrocartilaginous lamina deep to it and attaches laterally to the inferior pubic rami. Inferiorly, its semicircular free edge rounds off the apex of the pubic arch but has no corporal attachment.

Conclusions

Findings of the present study do not support an anatomical rationale for PES, without risking instability. Contrary to previous reports, the subpubic PSL (or suspensory ligament) is the only component that directly connects TA with PS. The purported role of AL appears unfounded. Furthermore, perpendicular fibrous orientation of the subpubic and retropubic PSL suggests a dynamic support mechanism, not dissimilar to the knee’s cruciate ligaments. To the author’s knowledge, this is the first description of the musculotendinous origin of the retropubic PSL, whose fibres extend anteriorly from the urogenital diaphragm. Further studies are required to better characterise the retropubic PSL insertion and may lead to new insights into the origin and architecture of deep penile fascia. Based on present findings, the TA likely consists of multiple fibrous components originating from the musculotendinous aponeuroses of superficial perineal musculature.

Disclosure

No.