Three-dimensional analysis of increased vasculature around the glomerular vascular pole in diabetic nephropathy.

In diabetic nephropathy, several small vessels are frequently observed around the glomerular vascular pole in addition to the usual afferent and efferent arterioles. To elucidate the morphology of these abnormal small vessels, a three-dimensional study was performed by using computer-aided reconstruction techniques. In the present study, the renal tissue samples of 21 biopsy and 73 autopsy cases of diabetic glomerulonephropathy were examined. In addition to ordinary light microscopic observations, three series of serial sections from one autopsy and two biopsy cases were analysed. Five glomeruli with increased numbers of vessels around the vascular pole were reconstructed three-dimensionally. The vasculature in and around the glomerulus was analysed in detail by rotating and viewing in different planes via computer-generated three-dimensional images. These vessels anastomose to the lobular structure of the intraglomerular capillary network, mainly to the afferent branches through the widened vascular hilus. The distal end of the vessels anastomoses to the peritubular capillary. The increased vasculature is interpreted as neoangiogenesis resulting from diabetes, which may have a functional role in facilitating efferent blood flow from the glomerulus.