ECMO for Pediatric Lung Transplantation.

Extracorporeal membrane oxygenation (ECMO) has been reported as an alternative to cardiopulmonary bypass during lung transplantation. The reports in the literature have been limited to adult practice and associated with decreased pulmonary and renal complications, lower mortality, and lower in-hospital mortality. We present four pediatric lung transplantations performed on ECMO and discuss relevant perfusion management.

Mechanically assisted bidirectional cavopulmonary shunt in neonates and infants: An acute human pilot study.

OBJECTIVE: Poor survival following surgical palliation for hypoplastic left heart syndrome (HLHS) raises the question of the need for a paradigm shift. This is the first human study to investigate the possibility of primary "in-series" palliation in neonates and infants with HLHS in an acute setting with the aid of 2 types of mechanical assist: superior vena cava (SVC)-to-pulmonary artery (PA) pump assist and SVC-to-right atrium (RA) oxygenation assist. METHODS: By rearranging the cannula sites and flow rates for modified ultrafiltration, 2 types of mechanically assisted bidirectional cavopulmonary shunt (BCPS) circulation were simulated for 20 minutes. Three neonates undergoing a stage I Norwood procedure were assigned to SVC-PA pump assist, and 3 infants undergoing stage II BCPS were assigned to SVC-RA oxygenation assist. Hemodynamic parameters, blood gas values, and arterial (SaO2) and regional cerebral tissue (rCTO2) saturations were analyzed. RESULTS: All 6 patients completed the study without hemodynamic compromise. In the SVC-PA pump assist group, a mean arterial pressure >40 mm Hg was maintained. SVC pressure was lower (P = .01) and cerebral perfusion pressure (CPP) was higher (P = .03) during the last 10 minutes of assist compared with Norwood physiology. SaO2 >80%, rCTO2 >60%, and mixed venous saturation ≥59% were maintained, comparable to values with Norwood physiology. In the SVC-RA oxygenation assist group, with full or 50% support, mean blood pressure >50 mm Hg, SVC pressure <15 mm Hg, mixed venous saturation >50%, and CPP >40 mm Hg were maintained, which were comparable to BCPS physiology. CONCLUSIONS: Two types of mechanical assist to support primary in-series palliation are feasible in the acute setting. Both modes of mechanical assist maintained oxygenation, as well as systemic and cerebral perfusion.

Mechanical cavopulmonary assist maintains pulmonary and cerebral blood flow in a piglet model of a bidirectional cavopulmonary shunt with high pulmonary vascular resistance.

OBJECTIVES: We tested mechanical cavopulmonary blood flow assist by incorporating a novel miniature centrifugal pump into a 1(1/2)-ventricle type cavopulmonary connection in neonatal pigs. METHODS: Nine 3-week-old piglets (mean body weight, 10.2 kg) were used: mechanical cavopulmonary assist (n = 6) and controls (n = 3). A bidirectional cavopulmonary connection between the superior vena cava and the main pulmonary artery was created. The superior vena cava and pulmonary artery were also connected by cannulas with an interposed centrifugal pump. The cavoarterial mechanical cavopulmonary assist was performed at pump speeds of 1500, 2000, 2500, and 3000 rpm. Retrograde superior vena caval flow was limited by a band on the superior vena cava. A bidirectional cavopulmonary connection was created in the control animals, which then had a pure 1(1/2)-ventricle repair physiology without mechanical support. Hemodynamics, blood gas, and cerebral blood flow measured by ultrasound were analyzed. Catheter-based dilatation of the surgically created superior vena cava obstruction was tested. RESULTS: Incremental increases in pump speed augmented bidirectional cavopulmonary shunt blood flow (P =.03) and diminished superior vena caval pressure (P =.03), thereby improving cerebral perfusion pressure. Pump flow of 3000 rpm was equivalent to baseline superior vena caval flow (before caval flow, 392 +/- 48 mL/min vs MCPA, 371 +/- 120 mL/min; mean +/- SD; P = not significant). The mechanical cavopulmonary assist group had higher Doppler velocities of the middle cerebral artery and higher transcerebral oxygen difference(P < .05) than controls. Balloon dilatation of the superior vena cava band was successful. CONCLUSIONS: Mechanical cavopulmonary assist maintained bidirectional cavopulmonary shunt flow, thereby sustaining primary bilateral cavopulmonary shunt physiology in a neonatal pig model of high pulmonary vascular resistance. The mechanical cavopulmonary assist maintained cerebral blood flow and metabolism with an adequate transcerebral pressure gradient.