Off-the-shelf bilateral antegrade cerebral perfusion: The "brain-bridge" technique.

Central MessageThe “brain bridge” should be integrated in a global approach aiming for improved clinical outcomes in complex arch surgery, especially regarding neurologic events. The “brain bridge” should be integrated in a global approach aiming for improved clinical outcomes in complex arch surgery, especially regarding neurologic events. Total arch replacement (TAR) is still associated with significant morbidity. Antegrade cerebral perfusion (ACP) has greatly improved neurologic outcomes during moderate hypothermic circulatory arrest. Unilateral ACP has been shown to be as effective as bilateral ACP, provided competent intracranial collateralization. However, the status of the circle of Willis is not systematically known, especially in the acute setting. In this article, we report the description of an original approach, allowing prompt conversion from unilateral to bilateral ACP when required in TAR. Intraoperative monitoring involved: (1) left radial and femoral arterial pressures; (2) central nasopharyngeal, bladder, and rectal temperatures; and (3) cerebral oxygenation through near-infrared spectroscopy (NIRS). The procedure was performed through median sternotomy, and cardiopulmonary bypass (CPB) was conducted between the right atrium and the right axillary artery. Myocardial protection was performed by continuous retrograde infusion of cold blood cardioplegia in the coronary sinus, and the left ventricle was unloaded through the right superior pulmonary vein. CPB was initiated and the central temperature was cooled. Once moderate hypothermia (25-28 °C) was achieved, the neck vessels were snared, unilateral ACP was initiated (10 mL/kg/min), and moderate hypothermic circulatory arrest was performed. Ascending aorta and arch were resected. During arch reconstruction, effectiveness of ACP was assessed both by NIRS and back-flow in the left common carotid (LCC) and subclavian arteries. If suboptimal cerebral perfusion was likely, bilateral ACP was considered. In this setting, we usually performed direct insertion of a retroplegia cannula (Edwards Lifesciences) in the LCC lumen. Alternatively, we proposed a homemade shunt directly introduced in the innominate and LCC arteries, allowing to perfuse the latter from the former, which we called the “brain-bridge” technique (Figure 1). This shunt is made from the connection of 2 venous canulae (16Fr and 14Fr, respectively), shortened and positioned in the opposite way. Once the arch reconstruction was completed, deairing was performed, the prosthesis was clamped proximally to the innominate artery branch, the systemic CPB was resumed, and rewarming was performed. Finally, proximal repair was performed as usual and CPB was weaned. Among the 3 patients who underwent the “brain-bridge technique,” none experienced neurologic event or death (Video 1 and Table E1).Table 1Respective advantages and drawbacks of the different techniques of cerebral protectionTechniquesAdvantagesDrawbacksDeep hypothermia•Simple•Deep hypothermia•Hazardous cerebral protectionRetrograde cerebral perfusion•Simple CPB circuit•No manipulation of the arch vessels•Deep hypothermia•Randomization of cerebral perfusionUnilateral ACP•Moderate/mild hypothermia•Simple CPB circuit•Potential unique incision if IA cannulation•Decreased embolic risk in the left hemisphere•Hazardous in case of nonfunctional circle of Willis, especially in the acute setting (no preoperative assessment)Bilateral ACP•Moderate/mild hypothermia•More homogeneous perfusion in case of incomplete circle of Willis•Increased embolic risk in the left hemisphere•Crowding of the operative field“Brain-bridge” technique•Moderate/mild hypothermia•Simple CPB circuit•Intraoperative tailor-made strategy, especially in case of unavailable preoperative assessment of the circle of Willis•Low cost•Additional manipulation of the arch vessels•Crowding of the operative field, especially in case of separate reimplantation of the arch vesselsCPB, Cardiopulmonary bypass; ACP, antegrade cerebral perfusion; IA, innominate artery. Open table in a new tab CPB, Cardiopulmonary bypass; ACP, antegrade cerebral perfusion; IA, innominate artery. ACP is widely considered a safe option for brain protection during TAR while allowing moderate hypothermia.1Cefarelli M. Murana G. Surace G.G. Castrovinci S. Jafrancesco G. Kelder J.C. et al.Elective aortic arch repair: factors influencing neurologic outcome in 791 patients.Ann Thorac Surg. 2017; 104: 2016-2023Abstract Full Text Full Text PDF PubMed Scopus (31) Google Scholar, 2Englum B.R. He X. Gulack B.C. Ganapathi A.M. Mathew J.P. Brennan J.M. et al.Hypothermia and cerebral protection strategies in aortic arch surgery: a comparative effectiveness analysis from the STS Adult Cardiac Surgery Database.Eur J Cardio-Thoracic Surg. 2017; 52: 492-498Crossref PubMed Scopus (0) Google Scholar, 3Abjigitova D. Veen K.M. van Tussenbroek G. Mokhles M.M. Bekkers J.A. Takkenberg J.J.M. et al.Cerebral protection in aortic arch surgery: systematic review and meta-analysis.Interact Cardiovasc Thorac Surg. 2022; 35ivac128Crossref PubMed Scopus (3) Google Scholar, 4Montagner M. Kofler M. Pitts L. Heck R. Buz S. Kurz S. et al.Matched comparison of 3 cerebral perfusion strategies in open zone-0 anastomosis for acute type A aortic dissection.Eur J Cardio-Thoracic Surg. 2022; 62ezac214Crossref Scopus (2) Google Scholar Unilateral ACP has been proven to be as effective as bilateral ACP while potentially decreasing injuries to the LCC artery and subsequent iatrogenic embolisms in the left hemisphere.3Abjigitova D. Veen K.M. van Tussenbroek G. Mokhles M.M. Bekkers J.A. Takkenberg J.J.M. et al.Cerebral protection in aortic arch surgery: systematic review and meta-analysis.Interact Cardiovasc Thorac Surg. 2022; 35ivac128Crossref PubMed Scopus (3) Google Scholar, 4Montagner M. Kofler M. Pitts L. Heck R. Buz S. Kurz S. et al.Matched comparison of 3 cerebral perfusion strategies in open zone-0 anastomosis for acute type A aortic dissection.Eur J Cardio-Thoracic Surg. 2022; 62ezac214Crossref Scopus (2) Google Scholar, 5Norton E.L. Wu X. Kim K.M. Patel H.J. Deeb G.M. Yang B. Unilateral is comparable to bilateral antegrade cerebral perfusion in acute type A aortic dissection repair.J Thorac Cardiovasc Surg. 2019; Google Scholar Multimodal (both anatomical and functional) assessment and more accurate stratification of different risk-profile patients should be critical to reduce the cerebral complications, either as the result of malperfusion in patients with insufficient intracranial collateralization or iatrogenic embolism related to undue manipulations of the arch vessels.6Smith T. Jafrancesco G. Surace G. Morshuis W.J. Tromp S.C. Heijmen R.H. A functional assessment of the circle of Willis before aortic arch surgery using transcranial Doppler.J Thorac Cardiovasc Surg. 2019; 158: 1298-1304Abstract Full Text Full Text PDF PubMed Scopus (14) Google Scholar,7Lewis C. Parulkar S.D. Bebawy J. Sherwani S. Hogue C.W. Cerebral neuromonitoring during cardiac surgery: a critical appraisal with an emphasis on near-infrared spectroscopy.J Cardiothorac Vasc Anesth. 2018; 32: 2313-2322Abstract Full Text Full Text PDF PubMed Scopus (47) Google Scholar Moreover, cannulation of the LCC artery and bilateral ACP should be considered when intraoperative NIRS points out inadequate regional oxygenation in the left cerebral hemisphere under unilateral ACP.6Smith T. Jafrancesco G. Surace G. Morshuis W.J. Tromp S.C. Heijmen R.H. A functional assessment of the circle of Willis before aortic arch surgery using transcranial Doppler.J Thorac Cardiovasc Surg. 2019; 158: 1298-1304Abstract Full Text Full Text PDF PubMed Scopus (14) Google Scholar,7Lewis C. Parulkar S.D. Bebawy J. Sherwani S. Hogue C.W. Cerebral neuromonitoring during cardiac surgery: a critical appraisal with an emphasis on near-infrared spectroscopy.J Cardiothorac Vasc Anesth. 2018; 32: 2313-2322Abstract Full Text Full Text PDF PubMed Scopus (47) Google Scholar Our original technique allows an easy switch to bilateral ACP, especially in the acute setting, where a reliable preoperative assessment of the circle of Willis functionality is rarely available. Moreover, this is a simple and reproducible technique that does not require any modification of our standard CPB circuit and does not excessively overstock the operative field, especially in the setting of “en-bloc” arch vessel reimplantation or hemiarch reconstruction. Nevertheless, such canulae are quite bulky compared with available smaller and smoother balloon-expandable catheters; thus, they must be manipulated cautiously. Moreover, the management of the shunt is more challenging in case of separate arch vessel reimplantation, requiring additional manipulations during LCC and innominate arteries anastomoses. Finally, this technique is precluded when femoral artery canulation is mandatory (Table 1). Aortic arch reconstruction is challenging and still associated with significant morbidity. Thus, developing simple and reproducible techniques to avoid procedural pitfalls and prevent adverse events remains pivotal. Our off-the-shelf bilateral ACP approach is safe and easily reproducible. Obviously, the “brain bridge” should not be seen as a perfect technique that avoids all complications but as part of global approach aiming for improved clinical outcomes in complex arch surgery.