Venovenous perfusion in ECMO for newborn respiratory insufficiency. A clinical comparison with venoarterial perfusion

Extracorporeal membrane oxygenation (ECMO) in neonatal respiratory failure. 100 cases

Extracorporeal membrane oxygenation (ECMO) was used in the treatment of 100 newborn infants with respiratory failure in three phases: Phase I (50 moribund patients to determine safety, efficacy, and risks); Phase II (30 high risk patients to compare ECMO to conventional ventilation); and Phase III (20 moderate to high risk patients, the current protocol). Seventy-two patients survived including 54% in Phase I, 90% in Phase II, and 90% in Phase III. The major complication was intracranial bleeding, which occurred in 89% of premature infants (less than 35 weeks) and 15% of full-term infants. Best survival results were in persistent fetal circulation (10, 10 survived), followed by congenital diaphragmatic hernia (9, 7 survived), meconium aspiration (44, 37 survived), respiratory distress syndrome (26, 13 survived), and sepsis (8, 3 survived). There were seven late deaths; in follow-up, 63% are normal or near normal, 17% had moderate to severe central nervous system dysfunction, and 8% had severe pulmonary dysfunction. ECMO is now used in several neonatal centers as the treatment of choice for full-term infants with respiratory failure that is unresponsive to conventional management. The success of this technique establishes prolonged extracorporeal circulation as a definitive means of treatment in reversible vital organ failure.

Pulmonary hypertension postventricular septal defect repair treated by extracorporeal membrane oxygenation

Severe pulmonary hypertension complicating the correction of congenital cardiac defects is an unusual cause of early postoperative mortality. We present a case of a nine-month-old infant who developed paroxysmal pulmonary hypertension associated with severe hypoxemia after the successful repair of a large perimembranous ventricular septal defect (VSD). The pulmonary hypertension was refractory to all medical and pharmacologic therapy but was successfully treated with extracorporeal membrane oxygenation (ECMO). On ECMO, pharmacologic support was removed, pulmonary artery pressure reduced, and ECMO support withdrawn. To date, ECMO has been applied to pulmonary hypertension of the newborn, neonatal respiratory insufficiency, and for primary cardiac pump failure. Our experience with this case leads us to believe it is an effective therapy for acute pulmonary hypertension occurring after the repair of congenital cardiac anomalies.

The current status of mechanical circulatory support

In summary, techniques for support of a failing circulation have advanced steadily over the past thirty years. Just as the use of the intra-aortic balloon pump has permitted successful treatment of certain groups of high-risk patients, so increasing application of more invasive techniques of mechanical circulatory support has extended the range of surgical endeavour. Nevertheless, it is evident that further advances in the design and construction of mechanical circulatory support devices are most likely to occur in conjunction with developments in bioengineering technology. These advances will in turn demand analysis by means of careful animal and clinical investigations. Although the general clinical use of an off-the-shelf mechanical ventricular support will give rise to major financial and ethical problems it is likely that application of these devices may herald a new era in the field of artificial organ replacement.

Congenital diaphragmatic hernia

Congenital diaphragmatic hernia continues to be a critical problem in neonatal surgery. Despite the apparent simplicity of the anatomic defect, the physiology is complex, and survival remains uncertain. Surgical success has been achieved, but we recognize that the barrier to survival is pulmonary parenchymal and vascular hypoplasia as well as the complex syndrome of persistent fetal circulation. In many ways the problem of diaphragmatic hernia is as much of an enigma to today's physician-scientist as it was to Bochdalek in the nineteenth century. The treatment of respiratory distress after repair of congenital diaphragmatic hernia has brought out the most creative and innovative efforts of pediatric surgeons in both the laboratory and the intensive care unit.