Pubourethral ligaments in women: anatomical and clinical aspects

The anatomy and histological structure of the proximal (PPUL), distal (DPUL) and intermediate (IPUL) pubourethral ligaments in women was examined to improve the understanding of their roles in female urethral physiology. An anatomical study of the pelvis was carried out in 10 adult female cadavers (60-102 years), the pelvis being removed and frozen prior to dissection. The pubourethral ligaments (PUL) were dissected in sagittal sections in seven specimens and in a frontal section in one specimen; the remaining two pelves were dissected using a hypogastric approach. The location, insertion, direction and histological structure of the ligamentous structures were studied. The PUL were identified in all 10 dissections, being paired, symmetrical, pearly-white, fibrous and resistant to stretching. The bony (parietal) insertion was variable on the posterior surface of the pubis, while the visceral insertion was located on the dorsal aspect of the proximal third of the urethra and neck of the bladder for the PPUL and on the distal third of the urethra for the DPUL. Histologically, the ligaments were composed of dense collagen fibres and bundles of axially orientated smooth muscle fibres. The PPUL was closely associated with the sphincter urogenitalis muscle, whereas the DPUL appeared to reinforce the role of the compressor urethra. It is suggested that the PUL plays an effective role in passive and active suspension of the urethra. The pubourethral ligaments are a constant anatomical entity which should be spared in urethral surgery in women in order to ensure an intact urogenital sphincter.