[Ehlers-Danlos syndrome with impending ruptured thoracic descending aortic aneurysm in a young adult--a case report].

We here report on a rare case of Ehlers-Danlos syndrome type IV with impending ruptured thoracic aortic aneurysm in a young adult. A 38-year-old man complained of severe back pain and transient paralysis in both legs. He was diagnosed as having an impending ruptured thoracic descending aortic aneurysm. Emergency operation which was aneurysmectomy and reconstruction of the descending aorta was performed. The fact that the aneurysm (11 cm) in a patient was so large for his age and the abnormal subcutaneous fatty tissue suggested the existence of systemic metabolic disease. An analysis of collagen extracted from the patient revealed the absence of type III collagen. Furthermore, an electron microscopic analysis finding that the collagen fibrils was of non-uniform size lead to the diagnosis of Ehlers-Danlos syndrome, Type IV (arterial type). Postoperatively the patient suffered paralysis in both legs due to ischemia of the spinal cord. However, his general condition was stable. He was transferred to another hospital for rehabilitation of both legs 60 days after the operation. Although the physical signs usually associated with Ehlers-Danlos syndrome were absent in this case, diagnosis followed electrophoresis of collagen extracted from the patient. As a result of the above observation, we recommended analysis of collagen in cases where the size of the aneurysm or the age of the patient appear unusual even though physical signs of Ehlers-Danlos syndrome are absent.