Case Report
A full-term 16 day old and 3,5 kg weight newborn boy was admitted our department with absence of femoral pulses and suspected coarctation of the aorta. Echocardiography(ECHO) revealed an arcus aorta hypoplasia with important aortic coarctation (35- 40 mm hg gradient with diastolic extension) and the diameter of proximal transvers arch was 4,9 mm (z-score -3,27), the diameter of distal transvers arch was 4 mm (z score -2,62), and the diameter of isthmic arch was 2,8 mm (z-score -4,29). She also had restrictive muscular outlet ventricular septal defect with no evidence of left ventricular volume overload, bicuspid aortic valve with mild stenosis, left aortic arch, systemic pulmonary hypertension. There was no abnormality in the patient’s preoperative laboratory values, and the neonate did not have a fever or cough preoperatively.
Surgical repair was performed with median sternotomy and cardiopulmonary bypass (CPB) was performed. During the arch repair, the antegrade cerebral perfusion was initiated (ASCP) and the del Nido cardioplegia was given. Aortic arch was reconstructed with anterior patch augmentation technique and VSD was closed with pericardial patch via right atriotomy. After the cessation of CPB, modified ultrafiltration was performed and the skin was closed with a patch, leaving the sternum open. The patient was transferred to the intensive care unit with moderate doses of inotropic supports, and in stable hemodinamic condition. The CPB, the aortic cross-clamping time, and the ASCP time were 152 min ,75 min, and 35 min respectively. In the control ECHO examination, no significant gradient was observed on arkus, and no residual VSD was detected. Peritoneal dialysis was started in the postoperative period. Sternum was closed on the postoperative day 2 uneventfully. Laboratory tests included normal white blood cell (WBC) count (6.2 ku/ul, ref range <= 4 ku/ul) with elevated 77,9% polymorphonuclear neutrophils, with low lymphocyte count of 750 cells/mm3 (ref range <=800 cells/mm3) on the postoperative day 2. The lymphocyte count (570 cells/mm3) was lower than the previous day, and C-reactive protein (CRP) levels (7.7 mg / dL, ref interval <= 0.5 mg / dL) were higher on the postoperative day 3.
Acute respiratory deteriation was occurred with refractory hypoxemia and worsening hypercapnia despite lung protective ventilation and high positive end-expiratory presssure (PEEP) theraphy on the postoperative day 3 (Figure 1). Extracorporeal membrane oxygenation (ECMO) support was used because of acute respiratory dysfunction on the postoperative day 4. Venoarterial ECMO support was initiated via 14 Fr venous cannula into the right atrium and 8 Fr arterial cannula into the ascending aorta. ECMO support was started at flow rate of 100 ml/kg/min (80-140 ml/kg/min) and arterial waveform demonstrated normal pulsatility. WBC count decreased to 4 ku/ul with elevated 72% polymorphonuclear neutrophils, and with low lymphocyte count of 690 cells/mm3. The patient’s reverse transcription-polymerase chain reaction (RT-PCR) testing for SARS-CoV-2 was positive with the sample taken from the endotracheal tube on the postoperative day 4. Hydroxychloroquine and favipiravir theraphy was started immediately and given during 7 days. Heparin infusion was started and activated clotting time was maintained with in the goal range of 180-220. We did not see major complications as thrombosis or bleeding during the ECMO support. The initial echocardiogram on ECMO showed normal LV systolic function. The patient weaned from ECMO after 6 days support. Since oxygen saturation decreased and respiratory functions deteriorated 7 days after leaving ECMO, the ECMO support was applied again. After 18 days of care including hydroxychloroquine and favipiravir theraphy RT-PCR testing for SARS-CoV-2 was changed negative; however, there was no significant improvement in the patient’s clinical condition. During these periods, the patient’s sternum being open also made the patient vulnerable to infections in addition to Covid 19. Candida parapsilosis mediastinitis was occurred, and Sterotrophomonas maltophilia reproduced in blood culture during second ECMO support. Unfortunately, the patient could not survive and died on ECMO due to sepsis and multiorgan failure despite extended antibiotic theraphy on the postoperative day 28.