Regarding “Molecular diagnosis of nonaneurysmal infectious aortitis”

Abstract

We read with great interest the case report by Kanemitsu et al1Kanemitsu S. Shimono T. Nakamura A. Yamamoto K. Wada H. Shimpo H. et al.Molecular diagnosis of nonaneurysmal infectious aortitis.J Vasc Surg. 2011; 53: 472-474Abstract Full Text Full Text PDF PubMed Scopus (19) Google Scholar showing the identification of bacterial species in infected, although not dilated, aortitis, which had been successfully treated surgically. Although the mortality rate of infected aortic aneurysm seems to have dropped in recent years,2Hsu R.B. Chen R.J. Wang S.S. Chu S.H. Infected aortic aneurysms: clinical outcome and risk factor analysis.J Vasc Surg. 2004; 40: 30-35Abstract Full Text Full Text PDF PubMed Scopus (185) Google Scholar infected aortic aneurysm is still a diagnostic and therapeutic challenge. Considering nonelective surgery or nonoperation increases the risk of aneurysm-related death,2Hsu R.B. Chen R.J. Wang S.S. Chu S.H. Infected aortic aneurysms: clinical outcome and risk factor analysis.J Vasc Surg. 2004; 40: 30-35Abstract Full Text Full Text PDF PubMed Scopus (185) Google Scholar and early diagnosis of infected aortitis, followed by timely surgical intervention is, without doubt, beneficial to the patient. In this case, however, Kanemitsu et al1Kanemitsu S. Shimono T. Nakamura A. Yamamoto K. Wada H. Shimpo H. et al.Molecular diagnosis of nonaneurysmal infectious aortitis.J Vasc Surg. 2011; 53: 472-474Abstract Full Text Full Text PDF PubMed Scopus (19) Google Scholar reported increased serum levels of immunoglobulin (Ig) G4 and high infiltration of IgG4-positive plasma cells in the adventitia of the descending aorta, both of which are characteristics of inflammatory aortic aneurysm and idiopathic retroperitoneal fibrosis. These disorders share similar clinical and histopathologic features and are both thought to result from an exaggerated inflammatory response to advanced atherosclerosis. In contrast to infected aortic aneurysm, inflammatory aortic aneurysm is presumed to be less susceptible to rupture, and corticosteroid therapy may be effective in controlling the perianeurysmal inflammation.3Yabe T. Hamada T. Kubo T. Okawa M. Yamasaki N. Matsumura Y. et al.Inflammatory abdominal aortic aneurysm successfully treated with steroid therapy.J Am Coll Cardiol. 2010; 55: 2877Abstract Full Text Full Text PDF PubMed Scopus (9) Google Scholar In the absence of definitive diagnostic criteria for inflammatory aortic aneurysm, however, the selection of immunosuppressive therapy is sometimes a challenging option, and thus overindication should be avoided. Results of blood culture can be negative in up to 50% of patients with an infected aortic aneurysm,4Bennett D.E. Primary mycotic aneurysms of the aorta Report of case and review of the literature.Arch Surg. 1967; 94: 758-765Crossref PubMed Scopus (74) Google Scholar and the prevalence of elevated serum IgG4 levels in patients with infected aortic aneurysm is not known. Despite these limitations, retroperitoneal fibrosis, rather than the infected aortitis, seems to be a more suitable diagnosis of the presented case, according to the serologic and immunohistochemical findings. Again, surgical intervention of the infected aorta, before it manifests apparent aneurysmal formation, may be an excellent choice for the management for this patient, especially considering that the aorta may show prominent enlargement over a short period of time and that arterial rupture can occur without aneurysm formation.5Oz M.C. Brener B.J. Buda J.A. Todd G. Brenner R.W. Goldenkranz R.J. et al.A ten-year experience with bacterial aortitis.J Vasc Surg. 1989; 10: 439-449PubMed Scopus (128) Google Scholar Nevertheless, this case presentation raises fundamental questions:1Did this patient have both IgG4-related chronic periaortitis and aortic wall infection?2Do the authors think that Ig4-related periaortic inflammation has a role in the development of bacterial infection-induced aortic wall remodeling, leading to aneurysmal formation, which is suggested in the pathogenesis of inflammatory aortic aneurysm? ReplyJournal of Vascular SurgeryVol. 54Issue 4PreviewWe thank Drs Ishizaka and Sakamoto for their interest in our article1 and are happy to reply to their comments. There is a close relationship between immunoglobulin (Ig) G4-related inflammation and fibrous sclerosing lesions. IgG4-related sclerosing disease is clinically characterized by high serum IgG4 concentrations and is associated with multiple lesions in different organs. It can occur in the cardiovascular system and can manifest as an inflammatory abdominal aortic aneurysm (AAA).2 Sclerosing inflammation in the aortic wall sometimes extends into fibroadipose connective tissue around the aorta, and these cases are known as inflammatory AAAs associated with retroperitoneal fibrosis. Full-Text PDF Open Archive