Electromyographic evaluation of the spared serratus anterior after postero-lateral thoracotomy

Postero-lateral thoracotomy is the standard access in thoracic surgery, and can be carried out dividing or preserving the serratus anterior muscle. This last method, besides its advantages, is still a matter of discussion, in fact traction has been claimed to cause severe muscular damage equal to section. We have studied 20 patients (16 males and 4 females, mean age 63 years), who underwent postero-lateral thoracotomy sparing the serratus anterior, after 6 months from surgery, both clinically and by means of electromyography (EMG), to evaluate the functional status of the spared muscles. In 4 cases (20%) there wasn't any neurogenic damage nor clinical evidence of winging scapula; 3 cases (15%) had medium neurogenic damage. The remaining 13 (65%) cases had a medium neurogenic damage and only one patient showed a winging scapula, neverthless being able to lift the arm to shoulder level. Our data confirmed that retraction during surgery does not damage the serratus anterior, leaving a functionally valid muscle.