Fate of Residual Aorta After Surgery for Type A Aortic Dissection

Abstract

Introduction: Surgical treatment of type A aortic dissection is essentially palliative. Many patients who undergo the procedure still have a dissection flap in the residual aorta, with a persistent patent or partially thrombosed false lumen leaving them susceptible to the dilatation of distal aorta and aneurysm formation.

Methods: Patients who had undergone surgery for type A aortic dissection from January 2015 till December 2022 were recruited into the study. Two follow-up computed tomography scans were performed at least six months apart, the first one at least one month after the surgery.

Results: A persistent dissection flap was found in 34 (68%) patients. All segments of residual distal aorta showed dilatation with time. Growth rate was maximum for abdominal aorta - 3.1 (1.6 - 5.4) mm/year. Patency of false lumen was the only significant factor associated with growth of lower descending thoracic aorta and abdominal aorta (P<0.05). Maximum growth was seen in the patients with partial thrombosis of the false lumen, followed by those with patent false lumen. Two patients with partially thrombosed false lumens required reintervention in the form of endovascular stenting.

Conclusion: Patients after surgery for type A aortic dissection with partially thrombosed false lumens are more prone to aortic dilatation. Regular follow-up of these patients with computed tomography aortogram can lead to timely detection of these sequalae and intervention as needed.

Keywords: Abdominal Aorta; Aneurysm; Aortic Dissection; Pathologic Dilatation; Thoracic Aorta; Thrombosis; Tomography.

Fig. 1

Sagittal section from postoperative computed tomography aortograms of two patients showing dissection flap in descending thoracic aorta with a) partially thrombosed false lumen and b) patent false lumen.