1. Does Operative Technique of Performing Distal Anastomosis in Acute type A Dissection Affect Early And Late Clinical Outcomes? Sotiris C. Stamou, MD, Ph.D, Nicholas T. Kouchoukos, MD, Robert C. Hagberg, MD, Kamal Khabbaz, MD, Robert M. Stiegel, MD, Mark K. Reames, MD, Eric Skipper, MD, Marcy Nussbaum, MS, Francis Robicsek, MD, Kevin W. Lobdell, MD Divisions of Thoracic and Cardiovascular Surgery Missouri Baptist Medical Center, St. Louis, MO Beth Israel Deaconness Medical Center, Harvard Medical School, Boston, MA Sanger Heart and Vascular Institute, Carolinas Medical Center, Charlotte, NC Sotiris C. Stamou, MD, Ph.D, Nicholas T. Kouchoukos, MD, Robert C. Hagberg, MD, Kamal Khabbaz, MD, Robert M. Stiegel, MD, Mark K. Reames, MD, Eric Skipper, MD, Marcy Nussbaum, MS, Francis Robicsek, MD, Kevin W. Lobdell, MD Divisions of Thoracic and Cardiovascular Surgery Missouri Baptist Medical Center, St. Louis, MO Beth Israel Deaconness Medical Center, Harvard Medical School, Boston, MA Sanger Heart and Vascular Institute, Carolinas Medical Center, Charlotte, NC

2. Objective To evaluate the early and late clinical outcomes of two different surgical techniques for repair of acute type A dissection: 1.open distal anastomosis under deep hypothermic circulatory arrest (DHCA) and 2.distal aortic clamping on moderate hypothermic cardiopulmonary bypass (ACPB) To evaluate the early and late clinical outcomes of two different surgical techniques for repair of acute type A dissection: 1.open distal anastomosis under deep hypothermic circulatory arrest (DHCA) and 2.distal aortic clamping on moderate hypothermic cardiopulmonary bypass (ACPB)

3. Acute Aortic Dissection Type A (Stanford) Inspection of the arch for additional intimal tear Yes Patient Exclusion No Study Group DHCA (n=82) ACPB (n=42)

4. Preoperative Characteristics DHCAACPBP N(n=82)(n=42) Females35%29%0.55 Diabetes10% 5%0.49 Hypertension83%81%0.81 Renal Failure15% 3%0.06 Instability 21% 10%0.18 DHCAACPBP N(n=82)(n=42) Females35%29%0.55 Diabetes10% 5%0.49 Hypertension83%81%0.81 Renal Failure15% 3%0.06 Instability 21% 10%0.18

5. Operative Characteristics I DHCAACPBP N(n=82)(n=42) CABG17%21%0.63 Aortic Valve Procedure Resuspension 58% 68%0.33 Replacement17% 5%0.09 Composite root 6% 19% 0.06 Nothing19% 7% 0.11 DHCAACPBP N(n=82)(n=42) CABG17%21%0.63 Aortic Valve Procedure Resuspension 58% 68%0.33 Replacement17% 5%0.09 Composite root 6% 19% 0.06 Nothing19% 7% 0.11

6. Operative Characteristics II DHCAACPBP N(n=82)(n=42) Arterial Cannulation Axillary a16%10%0.70 Femoral a76%83% Other 8% 7% ACP22%------ RCP10%------ Circ Arrest Time 23+15<1min <0.001 (Mean/SD) DHCAACPBP N(n=82)(n=42) Arterial Cannulation Axillary a16%10%0.70 Femoral a76%83% Other 8% 7% ACP22%------ RCP10%------ Circ Arrest Time 23+15<1min <0.001 (Mean/SD) (ACP= Antegrade cerebral perfusion, RCP= retrograde cerebral perfusion)

7. Postoperative Characteristics DHCAACPBP N(n=82)(n=42) Reop for Bleeding 20%34%0.16 Renal Failure 20%19% 0.99 Atrial Fibrillation 27%36%0.31 Stroke 16%24%0.33 Length of Stay 16+13 18+150.68 Operative mortality 17%21%0.63 DHCAACPBP N(n=82)(n=42) Reop for Bleeding 20%34%0.16 Renal Failure 20%19% 0.99 Atrial Fibrillation 27%36%0.31 Stroke 16%24%0.33 Length of Stay 16+13 18+150.68 Operative mortality 17%21%0.63

8. Time to Death (in years) 1.0 0.8 0.7 0.5 245 Freedom from Death at 5 Years Death Free Probability Log Rank p = 0.99 30 day 1 year 2 years 3 years 4 years 5 years DHCA (N=42) 34 (81%) 31 (74%) 31 (74%) 31 (74%) 31 (74%) 31 (74%) ACPB (N=82) 67 (82%) 62 (76%) 61 (74%) 60 (73%) 60 (73%) 60 (73%) 0.6 13 0.9 DHCA ACPB

9. Conclusion No significant differences in operative mortality, major morbidity and actuarial 5-year survival were observed between DHCA and ACPB. However, there are some practical technical advantages if the distal anastomosis is performed with an open manner More studies are required to determine the fate of the false lumen and the incidence of dissecting aneurysms with the two techniques. No significant differences in operative mortality, major morbidity and actuarial 5-year survival were observed between DHCA and ACPB. However, there are some practical technical advantages if the distal anastomosis is performed with an open manner More studies are required to determine the fate of the false lumen and the incidence of dissecting aneurysms with the two techniques.