Hybrid Left Heart Bypass Circuit for Repair of the Descending Aorta in an 8-kg Williams Syndrome Patient.

A 1-year old male patient with Williams syndrome and multiple prior interventions presented for surgical repair of his descending aorta (DA) through a left thoracotomy. Concerns for significant bleeding and spinal cord protection led the care team to consider a left heart bypass (LHB) circuit with options for pump sucker use, heat exchange capacity, and the possibility of converting to traditional cardiopulmonary bypass (CPB). A traditional CPB circuit with a roller-head arterial pump was assembled with a bypass line around the cardiotomy venous reservoir (CVR). Excluding the CVR with this line allowed for a closed LHB circuit. A second pump head was integrated to both recirculate the CVR volume and to serve as a means for controlled volume administration to the closed LHB circuit. Pump sucker return directed to the CVR could easily be transfused back to the patient. The patient was placed on the hybrid LHB circuit and cooled to 32°C. DA clamps were placed. Upper body dynamic blood pressure was managed for a target mean of 50 mmHg, the left atrial pressure (LAP) was maintained in the 5-7 mmHg range, and the nonpulsatile lower body blood pressure was targeted at 40-50 mmHg. Cerebral near-infrared spectroscopy (NIRS) helped guide volume and pressure management. The surgeons placed two long-segment patches on the DA, moving clamps as needed. The patient was rewarmed and separated from the hybrid LHB circuit after 82 minutes. Closed circuit LHB can be provided with a roller-head hybrid circuit incorporating an oxygenator for gas exchange, central cooling and warming, and arterial line filtration along with a CVR for pump sucker use and controlled transfusion to the patient.

A Modified EXIT-to-ECMO with Optional Reservoir Circuit for Use during an EXIT Procedure Requiring Thoracic Surgery.

A 34 year old mother with a history of polyhydraminos and premature rupture of membranes presented for an ex utero intrapartum treatment (EXIT) procedure to deliver her 34 week gestation fetus. The fetus had been diagnosed with a large cervical mass which significantly extended into the right chest. The mass compressed and deviated the airway and major neck vessels posteriorly. Imaging also revealed possible tumor involvement with the superior vena cava and right atrium. The plan was for potential extracorporeal membrane oxygenation (ECMO) during the EXIT procedure (EXIT-to-ECMO) and the potential for traditional cardiopulmonary bypass (CPB) for mediastinal tumor resection. A Modified EXIT-To-ECMO with Optional Reservoir (METEOR) circuit was devised to satisfy both therapies. A fetal airway could not be established during the EXIT procedure and so the EXIT-to-ECMO strategy was utilized. The fetus was then delivered and transferred to an adjoining operating room (OR). Traditional cardiopulmonary bypass with a cardiotomy venous reservoir (CVR) was utilized during the establishment of an airway, tumor biopsy and partial resection. The patient was eventually transitioned to our institution's standard ECMO circuit and then transferred to the intensive care unit. The patient was weaned from ECMO on day of life (DOL) eight and had a successful tumor resection on DOL 11. The patient required hospitalization for numerous interventions including cardiac surgery at 4 months of age. She was discharged to home at 5 months of age.