Agenesis of the left diaphragm: surgical repair and physiologic consequences.

Agenesis of the hemidiaphragm is an unusual congenital anomaly associated with a high mortality. This paper presents the fourth patient to survive the neonatal period with agenesis of the hemidiaphragm. He was an identical twin, weighing 1.5 kg and his clinical course was characterized by ipsilateral pulmonary hypoplasia, large alveolar-arterial gradient for oxygen, persistent fetal circulatory pattern and ventilator dependence. These abnormalities suggest a pathophysiology similar to that observed in patients with Bochdalek hernia. The surgical correction, postoperative care and observation of pulmonary function following repair of agenesis of the left diaphragm are described.