Endovascular Repair of an Aortic Arch Aneurysm in a Patient with a Hypoplastic Left Vertebral Artery Terminating into the Posterior Inferior Cerebellar Artery

Transposition of Anomalous Left Vertebral to Carotid Artery During the Management of Thoracic Aortic Dissections and Aneurysms

OBJECTIVES

Preservation of antegrade flow to the left vertebral artery is often achieved by transposition or bypass to the left subclavian artery during zone 2 thoracic endovascular aortic repair (TEVAR). An anomalous left vertebral artery (aLVA) originating directly from the aortic arch is a common arch variant with a reported incidence of 4-6%. In addition, 6-10% of vertebral arteries terminate in a posterior inferior cerebellar artery (PICA), increasing the risk of stroke if not revascularized. Few series of aLVA to carotid transposition have been reported. The aim of this study was to evaluate the outcomes of patients who underwent aLVA to carotid transposition for the management of aortic disease.

METHODS

A retrospective review of all aLVA-carotid transpositions performed for the management of thoracic aortic dissection or aneurysm at a single center from 2018 to 2021 was performed. The primary outcomes were postoperative stroke and patency of the transposed aLVA. Secondary outcomes were spinal cord ischemia, postoperative cranial nerve injury (CNI), and Horner's syndrome.

RESULTS

Seventeen patients underwent aLVA to carotid transposition as an adjunct to management of aortic disease during the study period. Most were men (14) and the mean age was 54 (±16 years). The primary indication for aortic repair was dissection in 10, aneurysm in 6, and Kommerell diverticulum in 1. Nine patients underwent zone 2 TEVAR, seven received open total arch repair and there was one attempted total endovascular arch repair which was aborted due to unfavorable anatomy. Twelve transpositions were performed prior to or concomitant with planned aortic repair due to high-risk cerebrovascular anatomy (3 PICA termination, 6 dominant aLVA, 4 intracranial left vertebral artery stenosis), and two were performed postoperatively for treatment of type II endoleak. LVA diameter ranged from 2 - 6mm (mean 3.3 mm). Mean operative time for transposition was 178 (±38) minutes, inclusive of left subclavian artery revascularization and mean estimated blood loss was 169 (±188) mL. No patients experienced 30-day postoperative spinal cord ischemia, stroke, or mortality. There were two cases of postoperative hoarseness, presumably due to recurrent laryngeal nerve palsy, both of which resolved within 4 months. There were no cases of Horner's syndrome. At follow-up (mean 306 days [6-714 days]), all transpositions were patent.

CONCLUSIONS

Vertebral-carotid transposition is a safe and effective adjunct in the management of aortic disease with anomalous origin of the LVA.