Infected Takayasu's arteritis presenting with aortic perforation

Abstract

We want to remind Physicians that unusual conditions can present in unusual ways and to keep an open mind always.

Introduction

We would like to remind physicians that unusual conditions can present in very strange ways. Takayasu arteritis is a rare large vessel vasculitis predominantly affecting young Asian females. Aortic regurgitation and heart failure are well described, and are usually proceeded by constitutional symptoms, pulse discrepancies, and features of organ/limb ischaemia.

Materials and methods

A 39 years old African female with a 2 years history of vague aches presented with chest pain and shortness of breath. A transthoracic echocardiogram showed severe aortic regurgitation with a 3 mm defect in the posterior aortic wall, communicating with a space in the transverse sinus. Computerised tomographic (CT) aortogram confirmed the defect showing contrast in a cavity in the transverse sinus (Figure 1). The patient was taken for emergency surgery due to the rupture.

Figure 1.

CT sagittal section: contrast in a cavity behind the aorta (red arrow), with tiny connection visible (blue arrow). 3D-CT Reconstruction showing the cavity behind the aorta (red arrow).

At operation the aortic wall was inflamed and grossly thickened (>10 mm, the texture of cheddar cheese), with a 3 mm hole at the commissure between left and non-coronary sinuses with a friable, oedematous aortic wall. The defect was closed with pledgeted sutures, but the aorta was so fragile an aortic valve replacement was not attempted (the sutures were cutting through). Aortic wall biopsy showed granulomatous inflammation with central micro-abscess formation (necrotising granulomas) (Figure 2). Fungal and Ziehl-Neelsen stains were negative. Aortic wall biopsy culture in enrichment medium grew Acinetobacter baumannii and Clostridium species (identified as Paeniclostridium sordelli). Rheumatoid factor was 10 IU/mL, anti-CCP antibody <8 μ/mL, ANCA, antimeyloperoxidase, antiproteinase 3 antibody, anticardiolipin antibody IgM, anti-B2 Glycoprotein IgG, anti-B2 Glycoprotein IgM, ANA CTD were all negative, and C3 and C4 levels were normal. Syphilis RPR and treponema pallidum antibody were non-reactive, and treponema pallidum hemagglutination and HIV were negative. The C-reactive protein (CRP) was 148 μg/mL and the erythrocyte sedimentation rate (ESR) was 59 mm/hr. The diagnosis of infected Takayasu Arteritis was made, and she was treated with meropenem and metronidazole for 6 weeks, as well as prednisolone (60 mg for 2 weeks, then gradually reduced to 5 mg maintenance) and azathioprine 50 mg maintenance. The CRP decreased from 148 to 3 μg/mL.

Figure 2.

Haematoxylin and Eosin staining revealed aortic wall infiltrated by several nodules (×20, left) consisting of ill-defined epithelioid granulomas formed by mixtures of lymphocytes, histiocytes and multi nucleated Langhans giant cells with central necrosis and micro abscess formation (×400, right). Ziehl-Neelsen stain for acid fast bacilli and GMS stain for fungi were negative.

The rheumatologists advised us to wait until the inflammation in the aorta had resolved, with serial positron emission tomography (PET) eventually confirming this. Due to delays related to the COVID-19 Pandemic it took 1 year to confirm the resolution, by which time she had dropped her ejection fraction (EF) from 45% to 38% (end diastolic diameter [EDD]: 6 cm, end systolic diameter [ESD]: 4.3 cm). CT coronary showed no evidence of coronary artery disease. She underwent mechanical aortic valve replacement (21 mm), where the aortic wall quality was vastly improved. Aortic wall biopsy showed ill-defined necrotising granuloma and the aortic valve leaflets showed degenerative changes only. She made an uneventful recovery, and at 6 months her EF had returned to 58% (EDD: 4.2 cm, ESD: 2.1 cm). She remains under review (rheumatological and cardiac surgical) initially undergoing 6 monthly CT scans but this will now be done annually.

Discussion

Aortic valve regurgitation can result from aortic dilation, cusp perforation, prolapse, or restriction, and aortitis (inflammatory or infectious). Non-infectious aortitis includes the large-vessel vasculitides: giant-cell arteritis and Takayasu arteritis affecting the aorta and its primary branches. ¹ Infectious aortitis includes syphilis, bacterial and mycobacterial infections. ¹ The presentation of aortitis varies from abdominal/back pain to aneurysms and aortic regurgitation. Acute complications include dissection, rupture, thrombosis, acute coronary syndrome, and valve regurgitation. ²

Multimodal imaging, including echocardiography, cardiac CT, and cardiac magnetic resonance imaging (MRI) show homogenous circumferential thickening of the aortic wall, but it is uniform with a smooth lumen that differentiates aortitis from atherosclerosis. ³

Patients with Takayasu's arteritis can present with a long history of vague symptoms, in addition to cardiovascular/cardiac manifestations. The diagnosis is confirmed on operative findings and aortic biopsy, in addition to CT/MR imaging study. PET CT scan can follow regression of aortic thickening, as well as the intensity of tracer uptake. Conventional angiogram is a risk for aortic perforations and dissections. ²

Although infection has been considered to have a role in the pathogenesis of Takayasu's arteritis, no specific organism has been found to be the trigger.^1,2 In this patient, the combination of active inflammation and active infection may have predisposed the aorta to perforation.

Conclusion

This patient gave a vague history of aches and pains, but her diagnosis came after a dramatic and unusual presentation. We think that the infective process on top of untreated Takayasu's arteritis may have caused the aortic perforation. Following treatment, she safely underwent aortic valve replacement, with an excellent outcome.