ECMO vs. CPB for Intraoperative Support: How do you Choose?

ECMO vs. CPB for Intraoperative Support: How do you Choose? Shaf Keshavjee MD MSc FRCSC FACS Director, Toronto Lung Transplant Program Surgeon-in-Chief, University Health Network James Wallace McCutcheon Chair in Surgery Professor, Division of Thoracic Surgery Vice Chair, Innovation, Department of Surgery University of Toronto

DISCLOSURE No conflicts to disclose

Terminology CPB = Cardiopulmonary Bypass ECMO = Extracorporeal Membrane Oxygenator ECLS = Extracorporeal Lung Support (Extracorporeal Life Support)

PHASES IN THE TECHNIQUE OF LUNG PROTECTION 1. In the multi-organ donor, preservation 2. Ex vivo ex vivo perfusion and repair 3. Intra-operative 4. Post-operative in the recipient

Intra-operative Lung Protection Single or Bilateral Sequential Lung Transplant Lung cooling jacket during implantation Clear blood/secretions from donor lung Gently re-inflate lung (25 cm H 2 0); FiO 2 < 0.5 Gradually release PA clamp (over 10 min) De-air through atrial anastomosis Avoids need for CPB most of the time

Selective use of cardiopulmonary support Don t persist unduly if problems with hypoxia or hypotension pump support Sequential SLT technique stresses the first lung CPB/ECMO has pros Maintain protective ventilation of first lung once reperfused Decrease pump flow / allow gentle ejection to reperfuse lung allows (longer) modified reperfusion Maintain low pressure perfusion - ejection into first lung (3/4 full flow- target spap 10-15mmHg)

INTRAOPERATIVE CARDIOPULMONARY SUPPORT ~35% pts require intra-operative cardiopulmonary support usually standard CPB Improvements in ECLS (ECMO) technology, increased experience with ECLS as bridge to transplant/recovery Some centers have increasingly used intraop ECLS Recent literature suggests VA-ECMO appears to be associated with superior outcomes compared to CPB Concomitant cardiac surgery and/or circumstances of canulation (emergent vs. planned) may be confounding factors

Cardiopulmonary Support: The Equipment CPB ECMO Pump Centrifugal (roller) Centrifugal Oxygenator PMP coated (0.5-7.0L) Same Heat Exchanger Yes Yes Coated Tubing Carmeda /Heparin Coated Same Anticoagulation (ACT) >400 180-200 Tubing (circuit) length Standard SHORTER Priming volume 1.2L 0.8L Venous Reservoir Yes NO Cardiotomy Sucker Yes NO Cell Saver Sucker Optional YES

THEORETICAL ADVANTAGES OF ECMO Less anticoagulation less bleeding Miniaturized circuit smaller priming volume No cardiotomy suction and No venous reservoir less air-blood interface Less inflammation (SIRS), less consumptive coagulopathy

SO HOW AND WHAT DO YOU CHOOSE? What is the optimal mode of intraoperative cardiorespiratory support in lung transplantation? Machuca et al. J Thorac Cardiovasc Surg 2015

METHODS Cohort study: adult patients, lung transplantation from 2007 to 2013, required intra-op cardiopulmonary support Patients were matched 1 ECMO : 2 CPB based on: 1. Transplant Indication 2. Single vs. Bilateral 3. Age (± 10 years) Excluded: bridged with ECLS, emergent cannulation, concomitant cardiac surgery, pediatric transplants, lungliver/heart-lung and B. cepacia

Toronto Lung Transplant Program 2007 to 2013 697 lung transplants 673 adults 24 pediatric 267 (39.7%) cardiopulmonary support 406 (60.3%) no support 39 ECMO 228 CPB 6 excluded 39 excluded cases 33 ECMO 66 CPB

CHANGE IN PRACTICE

DONOR DEMOGRAPHICS Variable CPB ECMO p Age 44.7±16 41.8±19.8 0.42 Gender (M) 28 (42%) 21 (63%) 0.056 Smoking 37 (56%) 15 (45%) 0.39 Positive BAL 45 (68%) 17 (51%) 0.12 EVLP 8 (12%) 9 (27%) 0.08

33 ECMO : 66 CPB RECIPIENT DEMOGRAPHICS Variable CPB n (%) ECMO n (%) p Indication 1 IPF 36 (54%) 18 (54%) CF 10 (15%) 5 (15%) Emphysema 6 (9%) 3 (9%) Scleroderma 6 (9%) 3 (9%) Redo 4 (6%) 2 (6%) Others 4 (6%) 2 (6%) Double 56 (85%) 27 (82%) 0.77 Age (years) 53.4±13.5 55.8±12.5 0.38 Gender (M) 41 (62%) 19 (57%) 0.66 BMI 24±4 23±4 0.67

INTRA-OPERATIVE VARIABLES Variable CPB ECMO p Pump Time (min) 199±90 210±84 0.38 Warm ischemic time L (min) 69±17 73±23 0.37 Warm ischemic time R (min) 64±14 70±20 0.123 Warm ischemic time SLTx (min) 74±9 74±19 0.94 Blood Transfusion RBC (units) 7.7±8 3.6±3.3 <0.001 Platelets (units) 0.8±1 0.3±0.7 0.007 FFP (units) 5.1±4.8 3.2±5.1 0.006 Cryoprecipitate (units) 1±3.5 1.3±4.3 0.97

INTRAOPERATIVE VARIABLES Variable CPB ECMO p Pump Time (min) 199±90 210±84 0.38 Warm ischemic time L (min) 69±17 73±23 0.37 Warm ischemic time R (min) 64±14 70±20 0.123 Warm ischemic time SLTx (min) 74±9 74±19 0.94 Blood Transfusion RBC (units) 7.7±8 3.6±3.3 <0.001 Platelets (units) 0.8±1 0.3±0.7 0.007 FFP (units) 5.1±4.8 3.2±5.1 0.006 Cryoprecipitate (units) 1±3.5 1.3±4.3 0.97

EARLY OUTCOMES Outcome CPB ECMO p Length of MV (days) 7.5 (2-18) 3 (2.5-5) 0.005 ICU stay (days) 9.5 (3-210 5 (3-9) 0.026 Hospital Stay (days) 27 (17-42) 19 (14-30) 0.029 ECLS post-op 5 (7.5%) 0 0.166 Dialysis requirement 12 (18%) 3 (9%) 0.37 Reoperation (bleeding) 18 (27%) 3 (9%) 0.04 90-day mortality 10 (15%) 2 (6%) 0.32

12-MONTH SURVIVAL

SO WHEN DO YOU NEED CPB? Combined cardiac repair and lung transplant Anaesthesiologist experience ECLS requires active participation Situations where you might anticipate high volume bleeding or air Difficult atrial anastomosis requiring cardiac arrest If you need emergently clamp and switch circuits

CONCLUSIONS ECMO appears to have significant advantages over CPB for cardiopulmonary support in lung transplantation Less blood product transfusion, less reoperation for bleeding Better early outcomes ventilator days, ICU and hospital stay Option for prolonged postoperative support CPB still has a role in emergent situations (bleeding, heart arrest) and concomitant cardiac surgery ECMO has become our first choice for intra-operative support