Spontaneous rupture of the subclavian artery in the Ehlers-Danlos syndrome

Multiple vascular and bowel ruptures in an adolescent male with sporadic Ehlers-Danlos syndrome type IV

Ehlers-Danlos syndrome (EDS) type IV is a heritable disorder resulting from mutations in the COL3A1 gene that cause deficient production of type III collagen. Clinical manifestations of EDS type IV include hypermobility of small joints, excessive bruisability, thin translucent skin, poor wound healing, bowel rupture, and vascular rupture that is often fatal. A 14-year-old male without a family history of EDS died following multiple bowel and abdominal blood vessel ruptures. Even in areas apart from rupture sites, the bowel wall was thin because of diminished submucosa and muscularis propria. Similarly, the walls of blood vessels in bowel submucosa and elsewhere in the abdomen varied in thickness, and contained frayed and fragmented elastic tissue fibers. Fibroblasts cultured from the patient's skin secreted reduced quantities of type III collagen that was explained by a point mutation in one copy of the COL3A1 gene. EDS type IV should be strongly suspected in any patient with otherwise unexplainable bowel and/or vessel rupture.

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.

Ehlers-Danlos syndrome IV due to a novel defect in type III procollagen

Ehlers-Danlos syndrome type IV (EDS IV) is characterized by variable changes in the skin, arterial fragility, bowel perforation, minimal joint involvement, and either autosomal recessive or autosomal dominant inheritance. The unifying biochemical abnormality is a deficiency of type III collagen; all patients studied thus far have shown a defect in either synthesis or in secretion of type III procollagen. We report on an adolescent boy who inherited EDS IV from his father and who developed a spontaneous subclavian artery aneurysm. In vitro studies of collagen production in dermal fibroblasts showed normal amounts of pro alpha 1 (III) messenger RNA and synthesis and secretion of nearly equal amounts of normal and of structurally abnormal pro alpha 1 (III) monomers. This patient is biochemically distinct from previous cases of EDS IV and is likely heterozygous for a mutation that results in an aberrant type III procollagen that is particularly susceptible to protease degradation.

Surgical complications of Ehlers-Danlos syndrome in children

The Ehlers-Danlos syndrome is a special challenge to the surgeon because of its relative infrequency and the late onset of overt symptoms, such as hyperelastic skin. We should consider this diagnosis in every child with recurrent inguinal herniae and search for its stigmata. A child with a known Ehlers-Danlos syndrome who requires an elective operation should be carefully studied for coagulation disorders. If there is a history of past injuries or operations in which there was poor healing, the benefits of the proposed operation must be carefully weighed against possible complications. Operations must be carried out with great care to avoid tearing the skin and fascia. Meticulous attention is given to hemostasis to prevent postoperative bleeding or hematomas. Inguinal hernias in these children resemble those seen in elderly patients. The transversalis fascia is thin and the internal ring is hugely dilated. An adult-type repair, with the use of mesh or felt may result in a lower incidence of recurrence. In addition, the Ehlers-Danlos syndrome may be yet another etiology for obscure gastrointestinal bleeding in children. Specific enzyme defects have been identified in 2 of the 7 subtypes of this disease. Further, biochemical study of connective tissue defects may contribute to our knowledge of normal collagen synthesis and wound healing.