Nerve and Blood Vessel Wiring in Endometriotic Peritoneal Lesions

Detection of unique nerve fibres in the endometrium of women with endometriosis and subsequently in their peritoneal lesions has led to increased interest in studying their relationship with infertility and pain. Blood vessels and nerves fibres course throughout the body in an orderly pattern, often alongside one another. Although superficially distinct, the mechanisms involved in wiring neural and vascular networks seem to share similarities. We found that nerve fibres and blood vessels traverse the endometriotic peritoneal tissue in slightly different ways with variations in length densities (Lv), branch point density (Bv), segment length between branch points (Lv/Bv) and capillary radial diffusion distance r(diff). The capillary radial diffusion distance r(diff) and the spatial co-localisation distance in conjunction with nerve fibres fell within range for the facilitation of the physiological diffusion and transfer of molecular substances and the transmission of electrical signals to co-ordinate tasks within the endometriotic peritoneal lesion.Biological systems exist and operate in a three-dimensional environment and blood vessels and nerve trunks often travel in close apposition through many tissues; therefore, it was a priority to assess (CD31+) blood vessel and (PGP9.5+) nerve fibre three-dimensional structural features from qualitative and quantitative perspectives in peritoneal endometriotic lesions. Utilising laser scanning confocal microscopy allowed for considerable precision in the study of endometriotic peritoneal lesion blood vessel and nerve fibre co-localisation and three-dimensional relationships.