CONGENITAL absence of the sternum, or a complete sternal cleft, is a rare chest wall malformation resulting from failed midline fusion during embryonic development. This abnormality can cause significant morbidity and, like other congenital anomalies, can have associated defects. We present such a patient here, first encountered at 2 days of life in anticipation of chest wall closure (fig.).
Absence of the sternum introduces multiple risks, most obviously mediastinal injury, hypothermia, and insensible fluid losses.1,2 Equally important, however, are the respiratory and hemodynamic sequelae that can occur. Viewable in the accompanying video, one can observe the pattern of paradoxical breathing present in all complete sternal clefts (Supplemental Digital Content 1, http://links.lww.com/ALN/A920). This abnormal movement can lead to cyanosis and recurrent chest infections through impaired gas exchange and secretion clearance.1,2 Moreover, the resulting alterations in intrathoracic pressure can decrease venous return to the heart.2
Anomalies associated with sternal clefts include other defects of midline fusion, most significantly Cantrell’s pentalogy, an abnormality involving the sternum, pericardium, heart, diaphragm, and abdominal wall.1,3 Seemingly unrelated processes such as PHACES syndrome, consisting of Posterior fossa malformations, Hemangiomas, Arterial lesions, and Cardiac and Eye disease, can also be present.1,2
Repair of sternal clefts is ideally undertaken in the neonatal period when the chest wall is highly compliant and primary closure can thus be achieved without significant cardiopulmonary compression.1,2 As the patient ages and chest wall compliance decreases, closure can become progressively difficult as venous return and lung compliance are increasingly compromised.1,2 Anesthetic goals in this scenario entail maintaining adequate preload and right heart function, and manipulating ventilation and oxygenation to account for decreases in lung compliance.