Type A aortic dissection with leg malperfusion

The working diagnosis is acute type A aortic dissection, complicated by left leg malperfusion and atrial fibrillation. The inter-arm blood pressure difference, widened mediastinum, tearing interscapular pain, and pulse deficit are classic. The elevated lactate and creatinine suggest malperfusion and end-organ ischaemia.

In the first 30 minutes I would:

• Call for senior cardiothoracic and anaesthetic help immediately and activate the aortic dissection pathway.
• Secure large-bore IV access, take crossmatch, arterial blood gas, coagulation screen, and send troponin and lactate.
• Give effective IV analgesia, usually an opioid, because pain drives sympathetic tone.
• Start rate and blood pressure control with an IV beta-blocker such as esmolol or labetalol, targeting a heart rate around 60/min and a systolic pressure around 100–120 mmHg, provided there is no tamponade or critical coronary malperfusion. A vasodilator alone can cause reflex tachycardia and increase shear stress, so beta-blockade comes first.
• Avoid thrombolysis and avoid anticoagulation beyond what is needed for theatre.
• Arrange urgent CT angiography if it can be done without delaying surgery; if he becomes unstable, proceed on bedside transoesophageal echocardiography.

The leg is ischaemic but not yet fully threatened with fixed mottling, so aortic repair remains the priority; restoring the true lumen may reperfuse the leg.

I would send him for CT only if he remains stable and the scan can be completed and interpreted without materially delaying surgery. CT angiography defines the intimal flap, extent of dissection, aortic root involvement, pericardial effusion, and the mechanism of leg malperfusion. It also helps the surgeon plan the proximal repair and decide whether a vascular bypass or fenestration may be needed. In a stable patient with a 90-minute theatre delay, a rapid CT is reasonable use of that otherwise idle time.

I would not send him if he develops hypotension, tamponade, worsening chest pain, or a falling conscious level. In that situation the diagnosis is already strongly suspected and he should go directly to theatre, with transoesophageal echocardiography confirming the diagnosis on the table. The CT request must be marked urgent, the anaesthetist must accompany him, and the surgical team must be ready to receive him immediately. The CT must not become a reason to defer surgery. Consent and crossmatch should proceed in parallel, not sequentially.

The left leg is ischaemic because the dissection flap or false-lumen compression has compromised iliac or femoral flow. The priority is proximal aortic repair, which often restores true-lumen flow to the leg. I would involve vascular surgery in theatre so that a femorofemoral crossover or iliofemoral bypass can be performed if the leg remains critically ischaemic after the aortic repair. I would not perform a blind embolectomy before the aorta is repaired, because the problem is not an embolus and heparinisation plus manipulation may worsen the dissection.

Postoperatively I would monitor closely for reperfusion injury: hyperkalaemia, metabolic acidosis, myoglobinuria, acute kidney injury, and compartment syndrome. Creatine kinase, potassium, creatinine, urine output, and urine colour should be checked frequently. Fasciotomy is indicated for clinical compartment syndrome or a compartment pressure delta of less than 30 mmHg, not routinely. Other major risks are bleeding, stroke, spinal cord ischaemia, renal failure, arrhythmia, and death. The family should be counselled that surgery is life-saving but carries a high risk of major morbidity.