Non-invasive assessment of pulmonary blood supply after staged repair of pulmonary atresia

S Del Torso, M J Kelly, V Kalff, G Stellin, R B Mee, A W Venables
1985 Heart  
Radionuclide studies were performed to determine pulmonary blood flow in six children who had undergone surgery for pulmonary atresia, ventricular septal defect, and hypoplastic pulmonary arteries with or without major aortopulmonary collateral arteries. Lung blood flow was assessed from both particle perfusion lung scans and the pulmonary and systemic phase of a radionuclide dynamic flow study. Five patients had perfusion defects identified on the particle perfusion lung scan. In three of
more » ... , abnormal areas were perfused only during the systemic phase of the flow study, a combination of findings that indicate the presence of perfusion by collateral arteries. In one patient no systemic perfusion was noted and in one an initial particle perfusion study indicated the presence of a lung segment perfused by a collateral artery. In this last patient the particle perfusion scan after total correction showed a reduction in the size of the lung perfusion defect and no evidence of lung perfusion during the systemic phase of the flow study. The particle perfusion lung scan in the sixth patient showed pronounced asymmetry in blood flow to the lungs with no segmental perfusion defect on the particle perfusion scan and no abnormalities on the systemic flow study. It is concluded that radionuclide lung perfusion and flow studies provide useful information on lung perfusion and merit further evaluation to define their role in the management of these patients. There is still debate regarding the surgical management of patients with pulmonary atresia, ventricular septal defect, and hypoplastic pulmonary arteries with or without major aortopulmonary collateral arteries.' It is, however, generally agreed that the long term results of surgery depend on achieving maximal direct segmental perfusion of the lungs and satisfactory relief of right ventricular outflow tract obstruction.24 After each staged palliative operation haemodynamic and angiographic investigations are usually performed. The numbers of invasive investigations should be reduced if possible as each adds morbidity and discomfort for the patient. Non-invasive radionuclide assessment of lung blood flow has the potential for this. We report our experience with radionuclide studies Requests for reprints to Dr Alex Venables, in determining pulmonary blood flow in six patients with this complex abnormality. Six underwent studies postoperatively and one was also investigated preoperatively. Patients and method Six patients were studied (age range 6-15 years). Each had pulmonary atresia, ventricular septal defect, and hypoplastic pulmonary arteries, five with and one without collateral arteries. Table 1 shows the past history and clinical data of each patient at the time of radionuclide investigation. RADIONUCLIDE DATA ACQUISITION After informed consent was obtained an intravenous cannula was inserted into a brachial vein. A two stage scintigraphic procedure was then performed. Firstly, a standard multiple view lung particle perfusion scan was performed using a small field of view gammacamera fitted with a general all purpose low energy 209 on 26 April 2019 by guest. Protected by copyright.
doi:10.1136/hrt.54.2.209 fatcat:w6lgo4azjjbhtil7ssanpgecwq