Morphometric analysis of the fibroadipose tissue of the female pelvis.

PURPOSE: The structure of the retroperitoneal connective tissue of the female pelvis was evaluated to determine whether its spatial arrangement may have a role in supporting the pelvic viscera. MATERIALS AND METHODS: After in situ formalin fixation the pelvic viscera with the surrounding connective tissue were removed together with the pelvic floor from 18 female cadavers 48 to 68 years old. Serial macrosections of the bladder base, cervix, lower rectum and pelvic floor complex, cut in coronal (4 cases) and horizontal (10 cases) planes, were stained with azan-Mallory, and the remaining 4 were cut in the horizontal plane and plastinated using von Hagens E12 technique. Morphometry of the retroperitoneal connective tissue was performed using a computerized system for image analysis connected through a black and white television camera to an optic microscope. The diameters of the adipose lobules and density of the connective tissue were evaluated in the proximity of the visceral adventitia and the parietal pelvic fascia, respectively. RESULTS: The retroperitoneal connective tissue of the female pelvis consists of varying amounts of adipose tissue divided into small lobules by thin connective laminae. These laminae are connected to the visceral and parietal layers of the pelvic fascia, and are closely connected to the vascular and nervous bundle sheaths crossing the pelvis. At the level of the sacrouterine and cardinal ligaments we were unable to find any connective ligamentous structure. Only an areolar tissue was seen, which after removal of the lipids demonstrated a fibrillar structure. The mean area of the adipose lobules was smaller (average of 1.41 mm.2) near the viscera with respect to the lateral retroperitoneal connective tissue (average of 1.73 mm.2) due to greater ramification of the connective laminae. CONCLUSIONS: In the absence of real connective ligaments the retroperitoneal connective tissue forms a 3-dimensional network of thin connective laminae that are connected to the visceral adventitia, parietal layer of the pelvic fascia and neurovascular bundles crossing the pelvis. These connective laminae are bounding adipose lobules of different size (smaller near the viscera, larger at the periphery). Overall, the retroperitoneal connective tissue constitutes an anatomical structure that, beyond the functional limits of any individual ligament, may have supporting properties.