Predictors of the progression of immunoglobulin-G4-related abdominal aortic aneurysms after endovascular therapy

Abstract

Objective: Approximately half of inflammatory abdominal aortic aneurysms, defined by the prominent thickening adventitia, are immunoglobulin G4 (IgG4)related diseases characterized by elevated serum IgG4 and IgG4-positive-plasmacytes infiltration. IgG4-related AAAs (IgG4-AAAs) exhibit vasculitis with elevated inflammatory marker levels. Matrix metalloproteinases (MMPs) degrade the extracellular matrix to destroy the aortic structures to progress aneurysm. This report examined pre-and postoperative serum MMPs and inflammatory marker levels to evaluate the prognosis of IgG4-AAAs after endovascular aortic repair (EVAR).Methods: Among 25 patient with inflammatory abdominal aortic aneurysms (>2-mm-thick periaortic fibrosis) treated with EVAR, IgG4-AAA was diagnosed in 14 patients, and the remaining 11 patients were classified as non-IgG4-AAA. IgG4-AAAs were categorized into cases with increased (IgG4-AAA-up; n = 6) or decreased (IgG4-AAA-down; n=8) postoperative serum IgG4 levels. Before EVAR and after 24 months, we compared the serum MMP, inflammatory marker levels, periaortic fibrosis, and aneurysm diameter.Results: IgG4-AAAs patients showed higher preoperative IL-6 levels, increased postoperative MMP-9 levels, and enlarged postoperative aneurysmal diameters compared with non-IgG4-AAA patients. Among IgG4-AAAs, IgG4-AAA-up exhibited higher preoperative MMP-9, higher preoperative monocytes and eosinophils, increased postoperative MMP-9 and IL-6, and larger aneurysm diameter than IgG4-AAA-down. All patients in IgG4-AAA-down showed shrunk preoperative aneurysm, although almost all patients in IgG4-AAA-up showed enlarged. In IgG4-AAA-up, IgG4/IgG ratio was significantly higher consistently before and after EVAR. MMP-9 was significantly correlated with IgG4 and IL-6. MMP-2 was not significantly different between patients with and without as well as between IgG4-AAA-up and IgG4-AAA-down. Conclusion:Increased postoperative MMP-9 and IL-6 in IgG4-AAA may accelerate aneurysmal progression after EVAR. IgG4-AAA-up exhibited increased IL-6 levels and larger aneurysm diameters following EVAR than IgG4-AAA-down and were considered as the high-risk group with a tendency toward progression. Before surgery, a high IgG4/IgG ratio, high MMP-9 concentrations, a high ratio of monocytes and eosinophils might predict IgG4-AAA-up.

Immunoglobulin G4-related solitary aneurysm of the deep femoral artery

“…Regarding EVT of IgG4-related aneurysms, we have reported 14 cases of endovascular aneurysmal repair for abdominal aortic aneurysms. 22 However, in that study, we found that EVT did not improve lesions related to IgG4-RD. 22 Thus, open surgical repair has been recommended.…”

“… 22 However, in that study, we found that EVT did not improve lesions related to IgG4-RD. 22 Thus, open surgical repair has been recommended. 22 Furthermore, the number of reported cases of IgG4-related medium-size arterial aneurysms has been extremely small.…”

“… 22 Thus, open surgical repair has been recommended. 22 Furthermore, the number of reported cases of IgG4-related medium-size arterial aneurysms has been extremely small. Considering these issues, open surgical repair was performed for all cases.…”