Preoperative Evaluation:
Despite continuous improvements in diagnostic techniques and refinements in management strategies, surgical mortality for Type-A dissection patients remains high, and is mostly influenced by the patient’s clinical status at presentation. 8 Without surgical intervention, the mortality of type-A dissection has been reported to be approximately 1 to 2% per hour after symptom onset, with up to 90% of patients dying within 30days 5. Time is therefore of paramount importance. A high degree of clinical suspicion for Type-A dissection should be maintained for any patient who presents with sharp chest or back pain, pulse deficit or waxing and waning of peripheral pulses, and any hemodynamic instability.9
Once suspected, imaging options such as computed tomography (CT), transthoracic and/or transesophageal echocardiography (TEE), and magnetic resonance imaging can be utilized for confirmation.10, 11 Definition of anatomic details are important to achieve true lumen cannulation when establishing cardiopulmonary bypass. A multislice ECG-gated CT angiography will best define the anatomic details about true and false lumens, extent of dissection, and status of the intimal-medial flap.12 However, if hemodynamic instability precludes definitive CT imaging, intra-operative TEE may provide relevant details about the anatomy. Intra-operative echocardiographic guidance should always be available to confirm true lumen cannulation. 13 14