1. Ipsilateral Lower Extremity Complications in Patients Undergoing Emergent Common Femoral Arteriovenous ECMO Therapy Prashanth Vallabhajosyula, MD MS, Matthew Kramer, BS, Sofiane Lazar, BS, Fenton McCarthy, MD, Eduardo Rame, MD, Joyce Wald, MD, Wilson Szeto, MD, Pavan Atluri, MD, Nimesh Desai, MD PhD, Michael Acker, MD Division of Cardiovascular Surgery University of Pennsylania, Philadelphia, PA

2. Disclosures Michael Acker : consultant Thoratec, Inc., Heartware, Inc. Wilson Y. Szeto : grant/ research support Edwards Lifesciences

3. Background Arteriovenous (AV) ECMO therapy is being increasingly used as a mechanical support strategy in patients with severe cardiopulmonary compromise Peripheral AV ECMO employed through the common femoral artery (CFA) and vein is the most common surgical AV ECMO strategy Ipsilateral lower limb ischemia remains one of the major complications associated with femoral AV ECMO To our knowledge, there is no common algorithmic approach put forth by the cardiac surgical community for preventing and addressing this complication

4. Background At our institution, the management of ipsilateral limb perfusion has evolved from expectant monitoring to preemptive cannulation of the superficial femoral artery (SFA) for antegrade limb perfusion We report our institutional outcomes with ipsilateral limb perfusion strategies for peripheral AV ECMO

5. Methods Retrospective review, single institution experience (2008 to 2013) 105 (42%) out of 250 ECMO cases were peripheral AV ECMO cases with femoral arterial cannulation (16 – 20 Fr). Patients were divided into 3 groups based on ipsilateral limb perfusion strategy (7 Fr cannula): - expectant monitoring [No SFA group, n=35 (33%)] - percutaneous SFA cannulation [PSFA group, n=23 (21%)] - open femoral cut-down with SFA cannulation under direct visualization [Open SFA group, n=47 (45%)] Primary end point: ipsilateral limb ischemia

6. Demographics and preoperative parameters Characteristics TotalNo SFAPercutaneous SFA Open SFA Number105352347 Age50 ± 1649 ± 1850 ± 1447 ± 16 Male67 (63%)24 (69%)13 (57%)30 (64%) Body Mass Index30 ± 8 Cardiac Arrest32 (30%)8 (23%)5 (22%)19 (40%) Transfer72 (68%)29 (83%)15 (65%)28 (59%) Diabetes24 (23%)7 (20%)6 (26%)11 (23%) Hypertension39 (37%)14 (40%)8 (34%)17 (36%) Smoking22 (21%)7 (20%)4 (17%)11 (23%)

7. Indications for ECMO Myocarditis, 2(2%) N=92 N=13

8. Limb ischemia by SFA cannulation strategy Total Patients: n=105 PSFA n= 23 (22%) Open SFA n= 47 (45%) Ischemia n= 7 (20%) Ischemia n=6 (26%) Ischemia n=1 (2.1%) No SFA n=35 (33%) Open SFA vs. No SFA= 0.02 NO SFA vs. PSFA = 0.7 PSFA vs. Open SFA = 0.004

9. Interventions for limb ischemia - Thromboembolectomy (n=2) - Fasciotomy (n=3) - SFA cannulation (n=2) - Expired in ICU (n=1) - Thromboembolectomy (n=2) - Expired in ICU (n=1) - Below knee amputation (n=1) - Fasciotomy (n=1) - Revision of SFA cannula (n=1) No SFA group (n=7) PSFA group (n=6) No SFA group (n=1)

10. Postoperative outcomes TotalNo SFAPercutaneous SFA Open SFA Number105352347 ECMO duration (hours) 89 ± 12088 ± 12088 ± 12189 ± 120 Length of stay (days) 18 ± 2118 ± 22 IABP22 (21%)8 (23%)4 (17%)10 (21%) Bridge to long term assist device 22 (21%)9 (26%)2 (9%)11 (23%) Heart Transplant 7 (6%)2 (5%)1 (4%)4 (8%) 30-Day/ In- hospital Mortality 67 (63%)21 (60%)14 (61%)32 (68%)

11. Limb ischemia versus without CharacteristicNo IschemiaIschemia P value Number91 (87%)14 (13%) Male54 (59%)13 (93%) 0.01 Age (yrs) 49 ± 1648 ± 15 0.5 CPR29 (32%)3 (21%) 0.7 IABP21 (23%)1 (7%) 0.3 Duration of support (hours) 89 ± 12088 ± 122 0.2 Body mass index 30 ± 8 0.2 Pre-ECMO renal failure 19 (21%)4 (29%) 0.5 Location of ECMO setup (OR/ICU/OSH) 44/40/75/7/2 0.6

12. Conclusions Ipsilateral limb ischemia remains a major complication associated with femoral AV ECMO (13% in this series) Expectant monitoring without preemptive ipsilateral limb perfusion is associated with high limb ischemia rates (20% in this series) Percutaneous SFA cannulation strategy without angiographic confirmation can be associated with high limb ischemic complications (26% in this series) Open SFA cannulation is a safe strategy. Chimney graft may also be a safe option More algorithmic and programmatic approach to ipsilateral limb perfusion may be warranted to minimize limb ischemia

13. Current institutional practice LOCATIONFloorICUOutside hospital ECMO transfer Operating room : percutaneous/ open SFA cannulation ICU : percutaneous SFA cannulation SFA cannula Yes No Operating room : percutaneous/ open SFA cannulation ICU or Operating room SFA cannula angiography: lower extremity perfusion Yes No ICUOperating room: surgical correction of SFA cannula

14. Study limitations Retrospective review, single institution experience SFA cannulation strategy was based on surgeon preference Evolving practice in terms of SFA cannulation strategies

15. Thank you