1. Central Cannulation Strategy Via Left Thoracotomy in the Treatment of Chronic or Residual Type B Dissection Extent I Thoracoabdominal + Distal Aortic Arch Aneurysms Prashanth Vallabhajosyula, MD, Tyler Wallen, BA, Joseph Bavaria, MD, Caroline Komlo, BS, Alberto Pochettino, MD The University of Pennsylvania Health System Philadelphia, PA

2. Background Extent I repair of thoracoabdominal (TAAA) aneurysms with chronic Type-B dissection is a technically complex operation typically requiring circulatory arrest for open proximal anastomosis in reverse hemiarch Standard methods of circulation management include femoral arterial-femoral venous, femoral arterial-right/left atrial cannulation We describe a novel central cannulation strategy performed entirely through the left chest for treatment of extent 1 TAAA with chronic type B dissection.

3. Central Cannulation Strategy Arterial cannulation: direct cannulation of the true lumen of the descending thoracic aorta using seldinger technique under transesophageal echocardiography guidance (18-20 Fr cannula) Venous cannulation: open pericardial sack for posterior exposure of RA-IVC junction (32-36 Fr right angle, single stage cannula) Placement of left ventricular vent via left inferior pulmonary vein

5. Purpose To evaluate the outcomes of TAAA extent I repairs for aneurysmal chronic type B dissection comparing central versus femoral cannulation.

6. Methods From 2000-20111, retrospective review of all aneurysmal TAAA with chronic type B dissections that underwent open operative repair at the Hospital of the University of Pennsylvania Extent I repairs were divided into 2 groups: central cannulation group versus femoral cannulation group Primary endpoints were death, paraplegia and stroke Secondary endpoints were reoperation for bleeding, MI, tracheostomy rate and length of stay (LOS) Early and midterm results are reported

7. Methods Chronic Type B TAA Repair (N=108) Open Extent II/III Repair (N=29) Open Extent I Repair (N=59) Central Cannulation (N=28)Femoral/standard Cannulation (N=31) TEVAR (N=20)

8. Patient Demographics FeatureCentralFemoralp N2831 Age (years)56+/-11.8861.5+/-7.080.009 Gender (M:F)18:1024:7 0.469 Aortic Diameter (cm) 6.5+/-0.797.03+/-1.150.088 HTN23 (82%)29 (94%) 0.278 History of Smoking5 (18%)7 (23%) 0.973 COPD6 (21%)6 (19%) 1.3 Renal Failure3 (11%)1 (3%) 0.382 LV Ejection Fraction (%) 60.41+/-10.9756.05+/-11.080.227 s/p Type A Repair 8 (29%)6 (19%)0.964

9. Operative/In-Hospital Outcomes OutcomeCentralFemoralp N2831 CPB Time 239.56+/-36.59173.69+/-68.240.001 Circulatory Arrest Time 43+/-5.3937+/-7.070.194 Emergent Operation 860.964 Death 0 (0%)2 (6.5%) 0.493 Stroke1 (3.6%)0 (0%) 0.475 Parapalegia 1 (3.6%) 1 (3.3%)1.22 MI 1 (3.6%)0 (0%) 0.475 Re-operation including Bleeding 2 (7.1%)1 (3.3%) 0.7 Tracheostomy 2 (7.1%)3 (9.7%) 1.21 LOS (days) 19+/-8.0417.23+/-14.50.235

10. Follow-Up Mean Follow-Up Median Follow-Up Central Cannulation: 3.61 +/-2.07 years Femoral Cannulation: 5.63+/-2.64 years Central Cannulation: 3.08 years Femoral Cannulation: 6.22 years Central Cannulation Femoral Cannulation 1 year mortality: 0% (N=0) 3 year mortality: 10.5% (N=4) 1 year mortality: 12.9% (N=4) 3 year mortality: 16.7% (N=5) *Mortality difference between the two groups was non-significant.

11. Conclusion Central cannulation strategy via the left thoracotomy incision in the treatment of extent I TAAA with chronic type B dissection is a safe approach, with equivalent early and midterm outcomes compared to more traditional cannulation techniques. This technique enables the entire extent type I repair to be performed via the left chest It may have applicability in patients with prohibitive ileofemoral disease or those with difficult groin exposure due to previous operations or radiation