145. Outcomes of Early Extracorporeal Membrane Oxygenation following the Norwood Procedure – Analysis of Consecutive Operations over 20 Years

OBJECTIVE: Extracorporeal membrane oxygenation (ECMO) is often required following infant cardiac surgery. We assessed if the severity of intraoperative residual lesions is associated with the need for ECMO postoperatively, and if early institution of ECMO improves in-hospital outcomes following the Norwood operation.

METHODS: This was a retrospective review of all patients who underwent the Norwood operation from 01/1997-11/2017 at a single institution. Previously published criteria were used to assign a residual lesion score (RLS) based on the intraoperative post-repair echocardiogram (class 1, no residua; class 2, minor residua; class 3, major residua requiring intraoperative revision) for all patients. In the primary analysis, associations between RLS and need for postoperative ECMO (primary outcome) were assessed with logistic regression, adjusting for age, prematurity, presence of non-cardiac anomalies or genetic syndromes, need for a second cardiopulmonary bypass (CPB) run, and any preoperative or procedure-specific risk factor (ascending aorta <2 mm, at least moderate atrioventricular valve regurgitation, aortic atresia, and intact atrial septum or obstructed pulmonary venous return). In the secondary analysis involving the subpopulation of patients who required ECMO, the association between early institution of ECMO (defined as ≤2 days following the index operation) and in-hospital mortality or transplant (secondary outcome) was similarly evaluated.

RESULTS: Of 500 patients who underwent the Norwood operation, 78 (15.6%) required ECMO postoperatively. There were 66 (13.2%) in-hospital deaths or transplants in the entire cohort. On univariable analysis, both RLS class 2 and 3 were significantly associated with the primary outcome (class 2: odds ratio [OR] 2.9, 95% confidence interval [CI] 1.2-7.2, p=0.023; class 3: OR 27; 95% CI 7.9-89, p<0.001). On multivariable analysis, RLS class 3 (OR 22, 95% CI 5.9-83, p<0.001), prematurity (OR 3.1, 95% 1.5-6.8, p=0.004), and need for a second CPB run (OR 4.5, 95% CI 2.1-9.8, p<0.001) were significantly associated with postoperative ECMO (Table). Among patients who required ECMO following surgery, there were 44 (56.4%) deaths or transplants. Median time to ECMO was 1 day (interquartile range 0-5 days). On univariable analysis, early institution of ECMO resulted in a significantly reduced risk of in-hospital mortality or transplant (OR 0.13, 95% CI 0.037-0.48, p=0.002). This finding was robust even after adjusting for RLS class and various patient- and procedure-related variables (Table).

CONCLUSIONS: Major intraoperative residual lesions are significantly associated with the need for ECMO following the Norwood operation. If mechanical circulatory support is required, early institution of ECMO, ideally within two postoperative days, may improve in-hospital transplant-free survival in this high-risk cohort.

Aditya Sengupta (1), Kimberlee Gauvreau (1), Aditya Kaza (1), Katherine Kohlsaat (1), Pedro del Nido (1), Meena Nathan (1), (1) Boston Children's Hospital, Boston, MA

David Kalfa

Invited Discussant

David Kalfa, MD, PhD, is a Associate Professor of Surgery, in the Section of Pediatric & Congenital Cardiac Surgery at Columbia University Medical Center and Site Director, Pediatric cardiac Surgery, Weill-Cornell Medical Center. He is the Director of the Pediatric Heart Valve Center at Columbia and Surgical Director of the Initiative for Pediatric Cardiac Innovation at Columbia University. He is a NIH and AHA-funded surgeon scientist and an Irving Scholar at Columbia University. His clinical interests center around neonatal cardiac surgery, congenital valve repair, biventricular intracardiac reconstruction and minimally invasive surgery. Dr Kalfa also leads  international research programs, focusing on development of innovative medical devices, tissue and mechanical engineering, computational modeling studies and precision medicine. Dr Kalfa's clinical and research expertise has been recognized and honored by many awards and grants. He is a AATS, STS, CHSS, EACTS, AHA member and a NIH reviewer.

Meena Nathan

Abstract Presenter

I am a pediatric cardiac surgeon at Boston Children’s Hospital, primarily involved in clinical research. I have over 15 years of research experience encompassing the period of my residency training and current faculty position. Having successfully graduated with an MPH from the Harvard TH Chan School of Public Health in clinical effectiveness, my area of excellence is clinical investigation. After early work in basic science examining the role of mitochondria in cardiac hypertrophy and failure, supported by the Thoracic Surgery Foundation's Nina Braunwald research fellowship, I transitioned to clinical outcomes research, particularly validation of the Residual Lesion Score (RLS) as a quality assessment initiative in congenital cardiac surgery. This 17-center project was supported by the Braunwald Research Award, a K23 grant from the NHLBI and a UO1 grant through the Pediatric Heart Network. My primary research focus remains clinical outcomes and quality improvement in congenital cardiac surgery, particularly in understanding residual lesions and their impact on outcomes after congenital cardiac surgery. I have collaborated with researchers in my hospital and across centers in the US and internationally to understand modifiable factors that determine outcomes after pediatric heart surgery.

Specialties: Congenital, Mechanical Circulatory Support, Procedures, Anatomy and Conditions, Hypoplastic Left Heart Syndrome, Single Ventricle, Treatment/Procedure/Operation/Surgery