Clinical characteristics and outcomes of 61 patients with chronic periaortitis including IgG4‐related and non‐IgG4‐related cases.

Abstract: Aim: Chronic periaortitis (CP) is a disease characterized by a fibro‐inflammatory periaortic cuff and adventitia‐predominant fibrosis. CP encompasses idiopathic retroperitoneal fibrosis and inflammatory abdominal aortic aneurysm (AAA), and recent studies have documented overlap between CP and immunoglobulin G4‐related disease (IgG4‐RD). This study aimed to investigate clinical characteristics and treatment outcomes of patients with CP. Method: CP patients were identified by retrospective review of 1245 patients with International Classification of Diseases 10th edition code of aortitis or aortic disease. Patients were further classified into IgG4‐related and non‐IgG4‐related CP according to the criteria proposed by a Japanese study. Results: A total of 61 CP patients were identified. Patients showed a male predominance (70%) with median age of 61 at diagnosis. The abdominal aorta was most commonly involved (84%), while the thoracic aorta was affected in 46% of patients. Twenty‐three (38%) patients had accompanying aortic aneurysm. Approximately 60% of patients achieved remission without further relapse during the course. Ten patients were classified as IgG4‐related and 25 as non‐IgG4‐related. There was no significant difference in clinical features and outcomes between groups, with the exception of older age and greater pancreas involvement in IgG4‐related patients. Conclusion: We documented 61 CP patients including 10 IgG4‐related cases. CP involved the abdominal aorta in most patients and the thoracic aorta in approximately 50% of patients. IgG4‐related CP patients were older and had greater pancreas involvement, but disease outcomes appeared to be similar between IgG4‐related and non‐IgG4‐related CP. [ABSTRACT FROM AUTHOR]