Background/Purpose: Erdheim-Chester disease (ECD) is a rare histiocytosis of the “L” (Langerhans) group with multisystem involvement that can affect the large and medium sized arteries mimicking vasculitis. Aortic involvement is common but the frequency and outcome of aortic branch vessel abnormalities are less well described.

Methods: Patients diagnosed with ECD from January 1, 1998 to July 31, 2016 were retrospectively identified. Images containing information of arterial involvement within six months of diagnosis were considered baseline and compared to last follow-up studies. Two physicians independently reviewed the studies to evaluate for presence of abnormalities attributable to ECD. Age and sex adjusted logistic regression models were used to examine associations between patient characteristics and vessel involvement at baseline.

Results: Among a cohort of 64 patients with ECD, 63 had baseline imaging of vascular structures. ECD involvement of at least one segment of the aorta was observed in 56%. Abnormalities were also observed in aortic arch branches (26%), visceral branch arteries (40%), iliofemoral arteries (31%), coronary (5%) and pulmonary (3%) arteries. Perinephric fibrosis was strongly associated with the identification of abnormalities in the thoracic aorta [OR 4.92 (1.54, 15.75); p=0.007], abdominal aorta [OR 7.57 (2.28, 25.07); p=0.001] and visceral branch arteries [OR 6.05 (1.52, 24.03); p=0.01] but not pelvic/lower extremity arteries.

A total of 47 patients had follow-up imaging of arterial structures. The majority of arterial segments affected at baseline did not have significant radiographic change during the follow-up evaluation. Partial response was observed in 11% of patients with baseline abnormalities seen in the infra-renal abdominal aorta and 6% of patients with baseline aortic arch, descending thoracic aorta, and supra-renal abdominal aorta involvement, respectively. The remainder of arterial segments had partial response detected at a frequency of less than 5%. Complete normalization of arterial abnormalities at follow-up was only observed in 9% or less of arterial segments involved at baseline. Development of arterial involvement after diagnosis in patients with normal baseline arteries was similarly infrequent but occurred most often in the pulmonary arteries (11%), celiac artery (9%), right iliac (7%), left iliac (7%) and right femoral (5%). Eight patients required intervention with arterial endovascular stenting or bypass. At last follow-up 12 (19%) patients were deceased. Of the 9 patients for which cause of death was known, only 3 patients died from cardiovascular causes.

Conclusion: Aortic and aortic branch vessel abnormalities are frequently observed in patients with ECD and are often asymptomatic. Partial and/or complete resolution of arterial findings is uncommon.

ACR Meeting Abstracts - https://acrabstracts.org/abstract/arterial-involvement-in-erdheim-chester-disease-a-retrospective-cohort-study/