A Case of High-Risk Acute Stanford Type B Aortic Dissection in a Right-Sided Aortic Arch Presenting With Transient Hemiparesis.

Acute aortic dissection usually presents with abrupt chest or back pain, but neurological symptoms may dominate the presentation and mimic acute ischemic stroke. We report a case of a 50-year-old woman who presented with recurrent transient left-sided weakness. The initial episode persisted during early hospital assessment and resolved as brain magnetic resonance imaging was initiated. A second episode occurred during subsequent aortic computed tomography angiography and lasted approximately 20 minutes. Brain computed tomography and diffusion-weighted magnetic resonance imaging showed no acute abnormality, while magnetic resonance angiography of the head and neck showed no large-vessel occlusion or cervical arterial involvement. A marked inter-arm blood pressure difference prompted computed tomography angiography of the chest, abdomen, and pelvis, which demonstrated an acute Stanford type B aortic dissection extending from the proximal descending thoracic aorta to the infrarenal abdominal aorta. The dissection occurred in a Type I right-sided aortic arch with mirror-image branching, consisting of a left brachiocephalic trunk followed by the right common carotid and right subclavian arteries. The dissected descending thoracic aorta measured up to 6.7 × 5.4 cm. The patent false lumen supplied the right renal artery, with delayed right renal enhancement suggesting impaired perfusion despite preserved serum creatinine. These high-risk imaging findings supported early intervention after multidisciplinary evaluation. On hospital day 3, the patient underwent a single-session hybrid repair consisting of bilateral carotid-subclavian bypasses, proximal embolization of both subclavian arteries, and thoracic endovascular aortic repair using two overlapping stent grafts. Completion angiography showed exclusion of antegrade false-lumen flow through the treated proximal entry region and preserved right renal perfusion through distal false-lumen re-entry. Cerebrospinal fluid drainage and perioperative pressure augmentation were used for spinal cord protection. The patient was discharged without neurological deficit or major postoperative complication. Clinical evaluation and surveillance computed tomography angiography were planned at the one-month post-repair interval. Completion angiography documented immediate procedural success, while durable technical success remained to be confirmed by surveillance computed tomography angiography because of the residual focal graft malapposition and continued false-lumen-dependent right renal perfusion. This case highlights the importance of considering acute aortic disease in patients with recurrent focal neurological deficits, normal cerebral imaging, and marked inter-arm blood pressure asymmetry, even in the absence of typical thoracic pain. It also illustrates how Type I right-sided aortic arch anatomy and severe arch angulation can complicate proximal landing-zone planning and require an individualized hybrid repair strategy.