During an 8-month period, 86 consecutive infants and children under 2 years of age underwent palliative or corrective cardiac surgery, of whom 11 subsequently developed phrenic nerve injury (PNI). This was seen most frequently following classic or modified Blalock-Taussig shunts. The diagnosis was established by ultrasound screening of the diaphragm, and patients were initially managed expectantly with ventilatory support. In nine patients no further management was necessary with demonstrated return of diaphragmatic function. The remaining two patients underwent plication of the diaphragm. The mean time to diaphragmatic recovery was 40.8 days and was more prolonged in patients with paradoxical, as opposed to absent, diaphragmatic movement. There were no deaths in the series. A further retrospective review of 241 patients of similar age undergoing similar surgery over the preceding 2 years revealed evidence of PNI in 11 (4.6%). Recovery of diaphragmatic function was documented in all except one patient who died. Based on these results we believe that although PNI is associated with considerable morbidity, and frequently a long stay in Intensive Care, there is evidence of spontaneous recovery of diaphragmatic function in 90% of the patients. Consequently, plication of the diaphragm can usually be avoided. Ultrasound scanning is extremely useful in establishing the diagnosis and offers assistance in predicting prognosis and deciding management.

The new technique described here has a potential to reduce or eliminate bronchial compression by pulmonary artery. Translocation of pulmonary artery anterior to the aorta takes the dilated pulmonary artery away from the trachea and bronchial tree. This approach was found to be technically feasible and can be useful especially in symptomatic newborns and infants.

Phrenic nerve palsy is a recognised complication of operation for congenital heart disease in children. The accuracy of ultrasound in assessing diaphragmatic motion was prospectively compared with fluoroscopy in 16 patients in whom phrenic nerve palsy was suspected. Ultrasound successfully identified the five patients with phrenic nerve palsy; there were no false positive or false negative diagnoses. Ultrasound was as effective as fluoroscopy in the diagnosis of abnormalities of diaphragmatic motion.