Aorto-Right Atrial Fistula Associated With Acute Type A Aortic Dissection

A 63-year-old man who had presented with chest pain was referred for further evaluation. Both contrast-enhanced computed tomography and transesophageal echocardiography showed a type A aortic dissection and shunt flow from the false lumen of the sinus of Valsalva to the right atrium (Figure A–D; Supplementary Movie). Having established a diagnosis of acute type A aortic dissection complicated by an aorto-right atrial fistula, we performed emergency surgery. During surgery, we noted the torn adventitia of the right sinus of Valsalva rupturing into the right atrium (Figure E), so we performed direct closure of the atrial shunt, and aortic root replacement for the aortic dissection.

Figure.

(A–C) Computed tomography images showing shunt flow from the false lumen of the sinus of Valsalva to the right atrium (red arrows). (D) Transesophageal echocardiography image showing the shunt flow from the sinus of Valsalva to the right atrium. (E) Intraoperative image of the mouth of the right atrial shunt, indicated by the metal probe.

Aorto-right atrial fistula is a rare disorder that is generally attributable to long-term compression or adhesion by the aortic root as a result of rupture or enlargement of a sinus of Valsalva aneurysm, infectious endocarditis, or prior cardiac surgery involving the proximal aorta.¹ When the fistula is attributable to a type A aortic dissection, the aortic dissection is generally chronic, which makes this condition extremely rare. Acute type A aortic dissection that requires surgery is inevitably fatal if untreated, and the patient’s condition will deteriorate further if an aorto-right atrial fistula develops. In such cases, atrial shunt closure in addition to aortic dissection repair is mandatory. Clinicians should consider the possibility of an aorto-right atrial fistula associated with acute type A aortic dissection, and perform preoperative screening using imaging modalities to detect unexpected abnormalities.

Disclosures

The authors declare no conflicts of interest.

Supplementary Files

Supplementary Movie. Preoperative transesophageal echocardiography.

Please find supplementary file(s);

https://doi.org/10.1253/circj.CJ-23-0830

Reference

• 1.   Jainandunsing JS, Linnemann R, Maessen J, Natour NE, Lorusso R, Gelsomino S, et al. Aorto-atrial fistula formation and therapy. J Thorac Dis 2019; 11: 1016–1021.