P0380 - Combining Two Devices to Create a New Application: The Paracorporeal Lung Assist as a Bridge to Lung Transplant in an Infant

Introduction
Oxygenators are well known for their application in extracorporeal circulation. Berlin Heart silicone cannulae were specifically designed for use with ventricular assist devices. We describe a novel combination of these two devices for creation of a pumpless, paracorporeal system for bridging an infant to lung transplantation.

Case Description
A four-month-old baby, born at 36 weeks of gestation with refractory respiratory failure with components of both parenchymal lung disease and pulmonary hypertension, was referred from an outside institution. He had previously undergone ductal stenting at one month of age as a means of mitigating pulmonary hypertensive crises and then subsequently tracheostomy placement at two months old. The patient had been unresponsive to medical treatment, including bosentan, sildenafil, epoprostenol, methylprednisolone, inhaled nitric oxide, and maximal ventilatory support. Due to progression of his illness necessitating continuous chemical paralysis to allow for even minimal daily cares, the family agreed to proceed with creating a paracorporeal lung assist system, based on our past experience with alternative approaches. The presence of a stented ductus arteriosus introduced an additional layer of complexity for performing the procedure, which was carried out successfully using cardiopulmonary bypass. To allow proper functioning of the paracorporeal system, we also closed an atrial septal defect. The right middle lobe and lingula were resected to allow for proper placement of the cannulae. Following surgery, his chemical paralysis was discontinued. He has successfully weaned off bosentan, sildenafil, milrinone, morphine, and midazolam, and receiving minimal ventilator support with aggressive rehabilitation while awaiting transplantation.

Discussion
This case highlights the evolution of this unique approach to bridging infants with suprasystemic pulmonary hypertension to lung transplantation over the last 10 years. The technical details of the procedure, as well as the singular attributes of the paracorporeal system, are presented along with specific anticoagulation regimens necessary for its successful application. Extracorporeal membrane oxygenation has historically been the only option for bridging the sickest of children to lung transplantation. In comparison, our alternative approach, using the novel combination of devices outlined, has the potential to allow for a more significant reduction in overall medical and mechanical ventilatory support. These features, in turn, result in reduced morbidity and facilitate more effective physical rehabilitation, all features consistent with improving a child’s candidacy for transplantation.

Conclusion
Application of paracorporeal lung assist is readily feasible with the described combination of already approved devices for alternative indications. This approach shows promising results for bridging pediatric patients to lung transplantation.