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A 23-year-old woman was seen in a vascular surgery clinic for a pulsatile mass over the calf for a few weeks' duration. She recollected sustaining a minor injury while she was horse riding. She also had a history of easy bruisability. Her brother also has similar history of skin bruising with hypermobile joints and thin skin.
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Further investigation suggested a pseudoaneurysm arising from the anterior tibial artery (Figure 36-1A). She was treated with retrograde coil embolization of the anterior tibial artery (Figure 36-1B) via a direct exposure of the artery at the ankle. The arteriotomy site was closed with pledgeted sutures. She did well in the postoperative period without any complications. Additional investigation with skin biopsy and collagen electrophoresis analysis that suggested a vascular Ehlers-Danlos syndrome (EDS). She was treated with vitamin C supplements and advised to avoid contact sports and of the need for continued follow-up.
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Heterogeneous group of inherited connective tissue disorders.
Six main forms of EDS identified with several rare variants.1
Majority are autosomal dominant inheritance; some less common forms are autosomal recessive or sex linked.2
Prevalence of 1/10,000 to 1/25,000.3
The vascular (AKA type IV or ecchymotic variant) accounts for 5% to 10% of all cases of EDS with a prevalence of less than 1/100,000 overall.3,4
The vascular form has the worst prognosis of all forms of EDS with median age of death at 48 years.2
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Genetic defects cause mutations in collagen synthesis.2
Vascular EDS is associated with type III procollagen deficiencies due to mutations in the COL3A1 gene, resulting in structural defects in the proalpha 1 (proα1) chain of type III collagen5,6 that leads to extreme vascular fragility.
The abnormal collagen III molecule cannot fold stably into a triple helix, and is degraded slowly in the rough endoplasmic reticulum of the fibroblast and is never secreted extracellularly. This instability or nonsecretion of mutant protein has been referred to as protein suicide.7
Incomplete penetrance and varying expressivity lead to variations in clinical presentation and symptoms.5
There is a diffuse thinning of the media with reduced elastin and fragmented internal elastic membranes in vessels.3
Patients with EDS have only a quarter of normal skin thickness so it appears translucent and reveals a network of subcutaneous veins, which is one of the major criterion of affected individuals.
Vessels have reduced collagen fibril cross-sectional area in the media of the vessel wall as well as reduced collagen ...