Medical Student The University Of British Columbia Vancouver, British Columbia, Canada
Case background: A 61-year-old male with history of COPD, smoking, and alcohol use disorder was transferred from a remote hospital with severe chest pain radiating to the head, followed by progressive right arm pain and motor-sensory deficits. On arrival, approximately 8 hours after symptom onset, his right arm appeared dusky, cold, and pulseless with absent brachial, radial, and ulnar Doppler signals. There was complete motor and sensory loss below the shoulder, and fixed flexion at rest, consistent with Rutherford class III ischemia. Duplex ultrasound showed collapsed axillary and brachial arteries with suspected thrombosis. Computed tomography angiography (CTA) revealed type A aortic dissection originating near the left coronary ostium with brachiocephalic artery occlusion, near-occlusion of right carotid artery with distal recanalization, and complete right subclavian artery occlusion with no distal flow. The dissection extended to the left iliac artery with renal and inferior mesenteric arteries arising from the false lumen.
Endovascular intervention for limb revascularization was considered but deemed unsuitable due suspicion of extensive right subclavian artery thrombosis. The right upper limb had been ischemic for 10.5 hours at the time of operation, increasing the concern for limb viability. In a joint approach by cardiac and vascular surgery, emergent right brachial artery cannulation with simultaneous ascending aortic and zone 0 arch replacement, and aortic root bovine patch repair were performed. The brachial catheter was connected to the cardiopulmonary bypass (CPB) circuit, which was established via right femoral arterial and right atrial venous cannulation, to maintain intraoperative arm perfusion. Following repair and weaning from CPB, pulsatile brachial flow was restored with a mean arterial pressure of 60 mmHg, along with warmth and venous filling. Exploration by vascular surgery revealed dissection of the right axillary artery with true lumen perfusion and palpable pulse, eliminating the need for revascularization. This suggested static occlusion from a dissection flap as the etiology of limb ischemia, rather than thrombosis as initially suspected. On closure, all forearm and hand compartments were tense with absent radial and ulnar Doppler signals, necessitating emergent forearm fasciotomies. Postoperatively, the forearm remained in rigor mortis, but radial and ulnar arteries were now palpable, and the hand was warm with normal capillary refill. Postoperative CTA confirmed successful aortic repair with patent branch vessels and residual distal aortic dissection.
His recovery was complicated by acute renal failure requiring continuous renal replacement therapy (CRRT) and hypoxic respiratory failure necessitating reintubation. Three weeks postoperatively, he underwent forearm debridement and split-thickness skin grafting. While right shoulder and elbow motor function was preserved, electrophysiologic studies confirmed active denervation distal to the wrist with only trace wrist extension and partial ulnar sensation despite nerves remaining intact. He developed progressive neuropathic arm pain which suggested early sensory recovery, though several months are required before assessing full extent of recovery. He was otherwise ambulating independently and ready for discharge on post-operative day 44. Follow-up was arranged at the aortic and peripheral nerve clinics at 4 weeks. The patient provided consent for use of his case details and imaging.
Management Challenges: Acute type A aortic dissection (ATAAD) is a life-threatening surgical emergency with in-hospital mortality approaching 28% despite intervention. Peripheral malperfusion occurs in approximately one quarter of patients at initial presentation due to dynamic or static obstruction, thrombosis, or dissection leak or rupture. Upper limb ischemia, a rare complication of ATAAD, has been described in only 1.6-4% of cases and remains poorly characterized. Though CTA is the gold standard for diagnosing aortic dissection, the urgency of preoperative assessment may limit accurate diagnosis of the ischemic etiology, leading to delay in appropriate intervention. In our case, limb ischemia was initially attributed to thrombotic occlusion of the right subclavian artery based on Duplex ultrasound and CTA findings, influencing our decision against endovascular revascularization. However, intraoperative restoration of brachial perfusion following central aortic repair confirmed static occlusion by a dissection flap rather than thrombosis. This case highlights that dissection-related occlusion can mimic isolated arterial thrombosis on imaging.
There is no clear consensus on whether peripheral revascularization should precede central aortic repair. While few studies prioritized revascularization due to the high postoperative mortality from end-organ ischemia, delayed aortic repair in favour of limb revascularization has been associated with mortality rates of up to 33%. In 80% of patients, aortic repair restores true lumen perfusion and eliminates the need for revascularization, as observed in our case. In patients with prolonged arm ischemia, we propose intraoperative brachial perfusion with simultaneous central aortic repair and reassessment of arterial pulsatility to preserve limb viability without delaying definitive treatment. This approach likely contributed to the preservation of his proximal limb function, with expectation of further distal recovery. A similar limb perfusion technique has been well-described in reports of lower limb ischemia in ATAAD with favourable motor-sensory recovery.Limb ischemia with concomitant end-organ malperfusion reflects extensive dissection and portends increased mortality, underscoring the importance of comprehensive surveillance of malperfusion in other vascular beds2. Given persistent malperfusion despite surgical intervention, early involvement of vascular surgery and urgent extra-anatomic revascularization is indicated for optimal limb salvage.
