Aortic Surgery

Cerebral Protection

Our complex aortic program has allowed our team to take on patients that may not have been offered therapy in the past, due to innovations and improvements in cardiovascular anesthesia, surgical techniques and post-operative intensive care.  Surgery to correct pathology of the ascending aorta and aortic arch often requires deep hypothermic circulatory arrest to allow reconstruction of the aorta at the level of the distal ascending aorta or proximal aortic arch.  Since cold temperature alone is insufficient to provide adequate protection to the brain, previous investigators have demonstrated that perfusing cold blood to the brain may improve neurological protection and improve outcomes following aortic surgery.

These techniques, known collectively as cerebral protection, refer to blood delivery to the brain during the period of circulatory arrest, in either an antegrade or retrograde manner.  Our publication, demonstrates the effective use of a small cannula that is inserted over a wire directly into the innominate artery, to allow delivery of antegrade cerebral protection. 

Aortic Dissection

Dr Mark Peterson is the Principal Investigator for the International Registry of Acute Aortic Dissection (IRAD) since 2008.  The IRAD group is a research consortium comprised primarily of cardiologists and cardiovascular surgeons from over 30 international academic centers in 11 countries.  As one of the primary investigators for IRAD, which is based out of the University of Michigan, Dr. Peterson has the opportunity to participate and contribute to original research on all aspects of patients with Type A and B acute aortic dissections.  The clinical and imaging database on patients who present with acute dissections allows for study on all aspect of the disease process:  natural history, presentation, outcomes with medical, surgical and endovascular therapy, response to medical therapy.  Late outcomes can also be study as a result of active longitudinal follow-up.

Aortic Pathology

The Toronto Aortic Collaborative (TAC) was conceived and founded by Dr. Peterson in conjunction with colleagues in the University of Toronto (U of T), Drs. Bradley, Dueck and Caldarone.  The TAC is comprised of Cardiac and Vascular Surgeons, Cardiologists, Radiologists, Basic and Clinical Scientists and Geneticists interested in improving the care and science related to patients with aortic pathology.  The TAC  bring together specialists from across the Academic Hospitals who meet regularly to discuss complex clinical aortic cases, as well as to advance multiple research initiatives in Aortic Diseases.  The TAC has received funding to study the management of patients with acute aortic syndromes, and to design a U of T wide management system for effective triage and improve care for these patients.   

Global Clinical Trials led by the Cardiac Surgery Reseach Program Include:

Cardiothoracic Surgical Trials Network [CTSN]

Principal Investigator: Dr David A Latter

The CTSN is the co-creation of the Canadian Institutes for Health Research (CIHR), National Heart, Lung, and Blood Institute (NHLBI), and National Institute of Neurologic Disorders and Stroke (NINDS).  The mission of the Network is to design, conduct, and analyze multiple, collaborative clinical trials that evaluate surgical interventions, and related management approaches, for the treatment of cardiovascular disease in adult patients.  The latest publication from the CTSN focussed on surgical ablation of atrial fibrillation during mitral-valve surgery (N Engl J Med. 2015 Apr 9;372(15):1399-409)

Cardiovascular Inflammation Reduction Trial [CIRT]

Steering Committee Member and site lead: Dr Subodh Verma

The CIRT will determine if low-doses of the anti-folate methotrexate reduce heart attacks, strokes, or death in people with type 2 diabetes or metabolic syndrome who have had a heart attack or multiple coronary blockages.

Improving the Results of Heart Bypass Surgery Using New Approaches to Surgery and Medication [SUPERIORSVG]

Site lead: Dr Subodh Verma

This study is designed to compare traditional and emerging interventions for harvesting saphenous vein grafts with the goal of reducing the incidence of blockages in the veins used for heart bypass surgery

• Nussenzweig SC, Verma S, Finkel T. The role of autophagy in vascular biology. Circ Res. 2015 Jan 30;116(3):480-8. doi: 10.1161/CIRCRESAHA.116.303805.
• Peterson MD, Mazine A, El-Hamamsy I, Manlhiot C, Ouzounian M, MacArthur RG, Wood JR, Bozinovski J, Apoo J, Moon MC, Boodhwani M, Hassan A, Verma S, Dagenais F, Chu MW; Canadian Thoracic Aortic Collaborative Investigators. Knowledge, attitudes, and practice preferences of Canadian cardiac surgeons toward the management of acute type A aortic dissection. J Thorac Cardiovasc Surg. 2015 Jul 14. pii: S0022-5223(15)01236-2. doi: 10.1016/j.jtcvs.2015.07.026.
• Yanagawa B, Puskas JD. State-of-the-art surgical coronary revascularization: Multiple arterial conduits, minimal aortic manipulation. J Thorac Cardiovasc Surg. 2015 Jul;150(1):259-61. doi: 10.1016/j.jtcvs.2015.02.030.
• Kotha VK, Yan AT, Prabhudesai V, Kirpalani A, Connelly K, Peerani R, Hill SJ, Streutker CJ, Latter DA, Pinter A, Deva DP. Benign intramyocardial mesothelial cyst in the right ventricular outflow tract: computed tomography and cardiovascular magnetic resonance imaging appearances. Circulation. 2014 Dec 9;130(24):e275-7.
• Teo KK, Cohen E, Buller C, Hassan A, Carere R, Cox JL, Ly H, Fedak PW, Chan K, Légaré JF, Connelly K, Tanguay JF, Ye J, Gupta M, John Mancini GB, Dagenais G, Williams R, Teoh K, Latter DA, Townley R, Meyer SR. Canadian Cardiovascular Society/Canadian Association of Interventional Cardiology/Canadian Society of Cardiac Surgery position statement on revascularization–multivessel coronary artery disease. Can J Cardiol. 2014 Dec;30(12):1482-91.
• Garg V, Tsirigotis DN, Dickson J, Dalamagas C, Latter DA, Verma S, Peterson MD. Direct innominate artery cannulation for selective antegrade cerebral perfusion during deep hypothermic circulatory arrest in aortic surgery. J Thorac Cardiovasc Surg. 2014 Dec;148(6):2920-4.
• Di Eusanio M, Trimarchi S, Peterson MD, Myrmel T, Hughes GC, Korach A, Sundt TM, Di Bartolomeo R, Greason K, Khoynezhad A, Appoo JJ, Folesani G, De Vincentiis C, Montgomery DG, Isselbacher EM, Eagle KA, Nienaber CA, Patel HJ. Root replacement surgery versus more conservative management during type A acute aortic dissection repair. Ann Thorac Surg. 2014 Dec;98(6):2078-84.
• Verma S, Siu SC. Aortic dilatation in patients with bicuspid aortic valve. N Engl J Med. 2014 May 15;370(20):1920-9. doi: 10.1056/NEJMra1207059.
• Yanagawa B, Algarni KD, Singh SK, Deb S, Vincent J, Elituv R, Desai ND, Rajamani K, McManus BM, Liu PP, Cohen EA, Radhakrishnan S, Dubbin JD, Schwartz L, Fremes SE. Clinical, biochemical, and genetic predictors of coronary artery bypass graft failure. J Thorac Cardiovasc Surg. 2014 Aug;148(2):515-520.
• Verma S, Farkouh ME, Yanagawa B, Fitchett DH, Ahsan MR, Ruel M, Sud S, Gupta M, Singh S, Gupta N, Cheema AN, Leiter LA, Fedak PW, Teoh H, Latter DA, Fuster V, Friedrich JO. Comparison of coronary artery bypass surgery and percutaneous coronary intervention in patients with diabetes: a meta-analysis of randomised controlled trials. Lancet Diabetes Endocrinol. 2013 Dec;1(4):317-28. doi: 10.1016/S2213-8587(13)70089-5.
• Teman NR, Peterson MD, Russo MJ, Ehrlich MP, Myrmel T, Upchurch GR Jr, Greason K, Fillinger M, Forteza A, Deeb GM, Montgomery DG, Eagle KA, Isselbacher EM, Nienaber CA, Patel HJ. Outcomes of patients presenting with acute type A aortic dissection in the setting of prior cardiac surgery: an analysis from the International Registry of Acute Aortic Dissection. Circulation. 2013 Sep 10;128(11 Suppl 1):S180-5.
• Teoh H, Quan A, Creighton AK, Annie Bang KW, Singh KK, Shukla PC, Gupta N, Pan Y, Lovren F, Leong-Poi H, Al-Omran M, Verma S. BRCA1 gene therapy reduces systemic inflammatory response and multiple organ failure and improves survival in experimental sepsis. Gene Ther. 2013 Jan;20(1):51-61. doi: 10.1038/gt.2011.214.
• Lovren F, Pan Y, Quan A, Singh KK, Shukla PC, Gupta N, Steer BM, Ingram AJ, Gupta M, Al-Omran M, Teoh H, Marsden PA, Verma S. MicroRNA-145 targeted therapy reduces atherosclerosis. Circulation. 2012 Sep 11;126(11 Suppl 1):S81-90.
• Shukla PC, Singh KK, Quan A, Al-Omran M, Teoh H, Lovren F, Cao L, Rovira II, Pan Y, Brezden-Masley C, Yanagawa B, Gupta A, Deng CX, Coles JG, Leong-Poi H, Stanford WL, Parker TG, Schneider MD, Finkel T, Verma S. BRCA1 is an essential regulator of heart function and survival following myocardial infarction. Nat Commun. 2011 Dec 20;2:593. doi: 10.1038/ncomms1601.
• Verma S, Mesana TG. Mitral-valve repair for mitral-valve prolapse. N Engl J Med. 2009 Dec 3;361(23):2261-9. doi: 10.1056/NEJMct0806111.
• Lovren F, Pan Y, Shukla PC, Quan A, Teoh H, Szmitko PE, Peterson MD, Gupta M, Al-Omran M, Verma S. Visfatin activates eNOS via Akt and MAP kinases and improves endothelial cell function and angiogenesis in vitro and in vivo: translational implications for atherosclerosis. Am J Physiol Endocrinol Metab. 2009 Jun;296(6):E1440-9. doi: 10.1152/ajpendo.90780.2008.
• Verma S, Kuliszewski MA, Li SH, Szmitko PE, Zucco L, Wang CH, Badiwala MV, Mickle DA, Weisel RD, Fedak PW, Stewart DJ, Kutryk MJ. C-reactive protein attenuates endothelial progenitor cell survival, differentiation, and function: further evidence of a mechanistic link between C-reactive protein and cardiovascular disease. Circulation. 2004 May 4;109(17):2058-67.