Vascular collagen fibril morphology in type IV Ehlers-Danlos syndrome.

Morphometric analysis of transmission electron micrographs of blood vessel, skin and dura mater collagen fibers were performed on postmortem tissues taken from 28-year-old female with Ehlers-Danlos type IV syndrome (EDS IV). Vascular tissue from this patient was compared to 5 age- and sex-matched controls (age range 26-28 years). Our study revealed significant variation in collagen fibril diameter in the walls of almost all the vessels studied. In general, the EDS IV tissue showed a net decrease in average collagen fibril cross sectional area in arterial wall samples. This decrease was significant (p less than .05) across the entire wall of the renal artery, in the media of the carotid artery, and in the media and adventitia of the common iliac artery. Samples from the vena cava show significant increases in collagen fibril cross sectional area across the vessel wall (p less than .005). The only areas studied which did not show significant changes were the intimal and adventitial regions of the common carotid artery. The observed changes may be contributory to the decreased arterial wall strength typical of the syndrome.