Upper extremity neuropathies after cardiac surgery

Although coronary artery bypass grafting is a common procedure, there can be significant postoperative morbidity. The occasional finding of unexplained postoperative neuropathy in these patients prompted this study. Fifty-three patients who had cardiac surgery that used the standard median sternotomy were studied prospectively. Detailed sensory and motor testing and intraoperative measurement of the distance of sternal retraction and duration of cardiopulmonary bypass were recorded. Twenty patients (37.7%) exhibited postoperative motor and sensory neuropathies, all of which involved the ulnar nerve. Five patients who were studied with electromyography and nerve conduction evaluations exhibited evidence of brachial plexus injury. The average duration of symptoms was 2.3 months, but several patients have long-term unresolved symptoms. Previous neuropathies, wide retraction of the sternum, and long cardiopulmonary pump runs seem to predispose to such injury, which appears to involve the brachial plexus. Anatomic reasons for such findings are offered.