EComment: Brachial plexus injury in cardiac surgery

Abstract

I read with great interest the paper by Healey et al. [1]. The authors are to be commended for trying to answer an important question that frequently arises in clinical practice: what is the role of sternal retraction in brachial plexus injuries or peripheral neuropathies of upper extremities after median sternotomy? After reviewing the literature, they included in their results 12 relevant studies. Of particular concern is the finding that the incidence of brachial plexus injury following median sternotomy varies from 0.2% to 37.7% among hospitals. Many factors have been suggested as responsible for this injury, mainly: the time and amount of asymmetrical sternal retraction, especially with cephalad placement of sternal retractor. In worst case scenario, nerve injury by a fractured rib can explain more severe cases of brachial plexus injury. In a follow-up study by Ben-David and Stahl [2], post-sternotomy brachial plexus injury carries an excellent prognosis, with a full functional recovery in the majority of cases after 10 weeks. Patients with brachial plexopathy after cardiac surgery complain chiefly from sensory loss and tingling sensation in the lower root of the plexus. At the time of hospital discharge, the majority of these patients are already asymptomatic. In this valuable review, I think that there is yet another topic to be discussed. With the liberal use of axillary artery cannulation for complex heart surgery [3], direct injury to the nearby brachial plexus is expected to increase the number of patients with brachial plexopathy after cardiac surgery. Wong et al. [4] found that the incidence of postoperative peripheral neurologic injury appeared to be 4% (one patient still suffering from right arm motor deficit 2.5 years after the operation, and another one reported having right thumb numbness 3 months postoperatively). However, Strauch et al. [5] stated that only 0.7% of their patients had cannulation-related ipsilateral brachial plexus injury (one had complete recovery before hospital discharge, and one patient had permanent residual numbness and weakness in the right hand). Brachial plexus injuries occurring after sternal retraction or during axillary artery cannulation are two separate entities with a different mechanism of injury. The former is far more frequent than the latter, with an excellent prognosis for functional recovery. The prognosis of brachial plexopathy is worse in cases of direct lesions, especially in the presence of motor deficit. Conflict of Interest: none declared.