Surgical complications of Ehlers-Danlos syndrome type IV: Case report and review of the literature

Ehlers-Danlos syndrome (EDS) is a hereditary disorder of the connective tis sue. The phenotypical variance that characterizes this syndrome often makes recognition difficult, and failure to recognize the disease is not uncommo n. The diagnosis may be missed until catastrophic vascular or gastrointesti nal complications occur and point the way to the diagnosis.(1,2) In 1899, Edward Ehlers reported a patient who demonstrated a constellation of symptoms including recurrent hematomas, lax digits, and extensible skin. Nine years later, Henri-Alexandre Danlos described the classic triad of sk in hyperelasticity, skin fragility, and joint hypermobility. He associated posttraumatic tumors with the manifestations presented by Ehlers.(1,2) Currently, the term Ehlers-Danlos syndrome describes a group of disorders c lassified according to the presenting clinical manifestations. Ten types of EDS have been described, most of which are associated with skin hyperflexi bility and joint hypermobility (Table 1).(2-7) The type most frequently encountered by surgeons is the arterial-ecchymotic type, or type IV, which represents 4% of all cases. This type was first de scribed by Sacks in 1936,(6) and was later recognized as a distinct clinica l entity in 1966 by Barabas.(3) There are five types of collagen in humans that are distinguished by the composition of their three subunits. Type I c ollagen constitutes approximately 90% of total body collagen and is found i n structures such as tendons, ligaments, and bone. Type II is a constituent of hyaline cartilage, and type III can be found in highly vascular structu res such as liver and blood vessels. The remaining types, IV and V, are loc ated in the basement membrane and the connective tissue matrix. Type IV Ehlers-Danlos syndrome (vascular or ecchymotic type) is a rare form of EDS with a prevalence of less than I per 100,000.(7) It is caused by a defect in the pro-alpha -1 III collagen chain, which results in reduced or abnormal secretion of type III collagen. Type III collagen composition is a triple helix composed of three procollagen molecules, each containing 1,02 9 amino acids. Critical to the stability of the triple helix is a glycine a mino acid located at every third position on the helix. Larger amino acids can disrupt the helical stability and therefore interfere with normal extra cellular transport of collagen. Any mutation that changes the ability of co llagen to form triple helixes or fibrils affects the stabilization of the c ollagen molecule, and thus interferes with normal tissue strength. It is im portant to differentiate type IV EDS because of the unique complications of arterial, colonic, and uterine rupture. Patients usually die before their fourth decade of life, and survival beyond 50 years is rare.(7).