gms | German Medical Science

Objectives/Interrogation: Brachial plexus injury (BPI) is a rare complication after median sternotomy. However there are only few reports with small number of cases, which describes the clinical findings in detail. The purpose of this study was to investigate BPI cases retrospectively who underwent median sternotomy for open heart surgery.

Methods: During 2014 to 2018, 1062 patients underwent cardiac surgery with median sternotomy and 10 patients (0.94%) developed BPI after surgery. All ten patients were male with an average age of 65.6 (45~72) years old. The surgical time, the affected side, the level of paralysis and the period from onset to the recovery of paralysis were investigated in these ten patients. Motor function was evaluated using for Manual Muscle Testing (MMT).

Results and Conclusions: The mean surgical time was 457 (300~657) minutes. All patients had paralysis on left upper extremity. In all cases, sensory and motor nerve impairment developed in lower plexus. The average post-surgical muscle power was MMT 2.2 for extensor digitorium communis (EDC), 3.9 for flexor digitorum superficialis (FDS) and 2.7 for first dorsal interosseous muscle (IOD (1)). The average persistence of sensory deficit such as numbness or hypesthesia was 3.9 months. Two cases had persisted numbness for over a year after surgery. The average period for the recovery of motor weakness to at least MMT 4 was 4.2 months in EDC, 1.4 months in FDS and 5.6 months in IOD (1). In three cases which required 8 months for the recovery of IOD (1), the surgical time was over nine hours.

The mechanism of post-surgical BPI in cardiac surgery was reported to be due to compression of the plexus between first rib and clavicle during retraction of sternal halves and stretching of the plexus cord after median sternotomy. The risk factor of BPI after median sternotomy was reported that abduction of the arm to 90 degrees or more and the occurrence of first rib fracture. In this study, five out of ten patients' arms were fixed at abduction of over 90 degrees during operation, and two out of ten patients sustained first rib fracture during operation. Also, we found that longer surgical time was correlated with poor motor recovery.

BPI after median sternotomy is relatively infrequent complication, and not all patients recovered completely. It is necessary for the cardiothoracic surgeon should beaware of this complication.