Zone 2 Aortic Arch Debranching for the Treatment of Type A Aortic Dissection
Surgical repair of type A aortic dissection (TAAD) carries a hospital mortality of 18% (1). The authors use bilateral upper extremity arterial monitoring and a Swan-Ganz catheter (Edwards Lifesciences, Irvine, USA) in all patients. They prefer central cannulation including direct true lumen cannulation of the aorta under transesophageal echocardiography guidance. A single stage cannula is used to cannulate the superior vena cava (SVC) for retrograde cerebral perfusion (RCP). A cardioplegia line is connected to SVC cannula through a Y-connector when used for retrograde perfusion. They use Near infrared spectroscopy (NIRS), continuous electroencephalogram (EEG), and all extremities somatosensory evoked potential (SSEP) in all the cases. The patient was cooled for five more minutes after electrocerebral silence is confirmed on EEG, and then the patient was cooled to three degrees below this temperature before instituting circulatory arrest (2).
In cases with complex arch repair, the authors use a combination of RCP and antegrade cerebral perfusion (ACP). Direct cannulation of the brachiocephalic vessels with balloon tipped catheters is done for this purpose. For re-approximation of delaminated aortic layers, they use Teflon felt (DuPont, Wilmington, Del) for reconstruction of neomedia in a felt neomedia technique (3). The authors believe this gives strength due to its profibrotic effect and prevents late degeneration. Neomedia also helps with hemostasis by sealing the needle holes and preventing new tears in the weak aortic wall.
References
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- Sultan I, McGarvey J, Vallabhajosyula P, Desai ND, Bavaria JE, Szeto WY. Routine use of hemiarch during acute type A aortic dissection repair. Ann Cardiothorac Surg. 2016 May;5(3):245-724.
- Bojko MM, Suhail M, Bavaria JE, Habertheuer A, Hu RW, Harmon J, et al. Fate of the preserved sinuses of valsalva after emergency repair for acute type a aortic dissection. Ann Thorac Surg. 2020 Mar;7:S0003-4975(20)30352-2.
