Vascular Ehlers-Danlos syndrome

Clinical History

A 30-year-old male patient presented with acute right loin pain radiating to the right testis accompanied by vomiting.
Past medical history included sigmoid colectomy for "perforated diverticular disease."
On examination he was haemodynamically normal with right renal angle tenderness.
Bloods and urinalysis reveal an elevated CRP (95), mild leucocytosis and microscopic haematuria.

Imaging Findings

Initial contrast-enhanced CT abdomen (portal venous phase) demonstrated a right renal infarct and probable hypoperfusion in the remainder of the kidney with occlusive thrombus in the proximal right renal artery. There was aneurysmal dilatation at the origins of both common iliac arteries.
Subsequent CT angiography (arterial phase) demonstrated an abnormal right renal artery with circumferential thickening from the origin all the way along its length. The bifurcations of both common iliac arteries were abnormally enlarged at 25 mms. The right external iliac artery contained a thrombus with a focal segment of dissection. The rest of the arterial tree was unremarkable.
Transthoracic echocardiogram revealed good biventricular systolic function with trivial mild aortic regurgitation and no thrombus.
Possible diagnoses of connective tissue disease such as Ehlers-Danlos or a vasculitis were raised.
Follow-up CT angiography showed further evolution with new dissection within the left external iliac artery and thrombus/dissection within the left hepatic artery.

Discussion

This patient presented with a renal tract infarct and an unusual pattern of vascular ectasia, thrombus and dissection, and the reporting radiologist raised the possibility of Ehlers-Danlos syndrome (EDS).

EDS is used to describe a heterogeneous group of connective tissue disorders which demonstrate one or more of skin hyper-extensibility, joint hypermobility, and tissue fragility. The disease is caused by alterations in genes used in processing collagen.
The Villefranche classification scheme for EDS defines six subtypes based upon clinical features, mode of inheritance, biochemical and genetic factors:
●Classic
●Hypermobility
●Vascular
●Kyphoscoliosis
●Arthrochalasia
●Dermatosparaxis

The hypermobile type has the highest incidence but it remains a rare disease [1].

Diagnoses are traditionally based upon major and minor criteria, however, patients often exhibit characteristics from multiple subtypes. The historical classification of EDA is largely replaced by the use of genetic testing, with increasing acceptance that there are not individual subtypes, but the different systems involved are more or less prevalent in individuals.

'Vascular' EDS has been described as an autosomal dominant condition, although some 50% of causes are thought to arise from spontaneous mutations [2]. This patient did not have any antecedent family history of significance.

Individuals with vascular EDS have potentially life-threatening events with increased risk of vascular, muscle or organ rupture (typically bowel or uterus). Pseudoaneurysm formation or arterial rupture involving the aorta, iliac, splenic, or renal arteries can occur, however, the pseudoaneurysms tend to be rarely detected prior to rupture.

EDS is associated with an increased mortality and median age of death of 48 years – 80% of patients experience a major vascular event/rupture of an internal organ by age 40 [1].

Large joint hyper-extensibility appears to be generally absent in patients with vascular EDS, however, laxity of the smaller more distal joints has been reported. The skin can be thin and translucent with prominent veins [1].

Diagnosis of EDS has traditionally been from history & 'classical' examination findings, although in this case the imaging findings were crucial in raising suspicion for the disease. Definitive diagnosis is now obtained by genetic testing. In the above case, mutations were identified in the COL3A1 gene, which encodes typeIII procollagen and is the genetic abnormality most typically found in vascular EDS [2].

This patient was found to have joint hypermobility (Beighton score 5) but did not have any skin manifestations such as “Cigarette Paper Scars” or skin hyperelasticity.

The history of bowel resection seven years previously due to perforation is also consistent with the diagnosis of EDS.

Differential Diagnosis List

Final Diagnosis

Vascular Ehlers-Danlos Syndrome

URL:	https://eurorad.org/case/15551
DOI:	10.1594/EURORAD/CASE.15551
ISSN:	1563-4086