Although 90% of patients with neurogenic thoracic outlet syndrome (NTOS) experience “excellent” or “good” results after thoracic outlet decompression, recurrent symptoms may develop in certain patients.

This is a retrospective review of patients with NTOS who developed recurrent symptoms of upper extremity/shoulder/neck pain, weakness and limitation of motion at least 3 months after initial relief of symptoms by surgical decompression. Diagnostic procedures and outcomes of reoperative surgery were assessed.

Among almost 500 patients undergoing initial successful thoracic outlet decompression for symptoms of NTOS during the last decade, 17 redeveloped classic NTOS symptoms (3 of them bilaterally) at intervals from 3 to 80 months (mean 18 months) after the initial operative procedure. Ultimate diagnoses included incomplete first-rib resection (n = 1), compression of the brachial plexus by an ectopic band (n = 1), persistent brachial plexus compression by an intact first (n = 2) or second (n = 1) rib, brachial plexus compression by the pectoralis minor tendon (n = 13) and adherent residual scalene muscle (n = 14). Anterior scalene muscle block was positive in 9 patients later found to have recurrent symptoms from adherent residual scalene muscle. Among these 20 cases of osseous or musculotendinous causes of recurrent NTOS, all had “excellent” or “good” results from repeat surgery to eliminate the underlying structural problem (removal of intact or residual rib, pectoralis minor tenotomy, brachial plexus neurolysis, or a combination of these).

Complete excision of cervical or first ribs and subtotal excision (instead of simple division) of the scalene muscles will decrease the incidence of recurrent NTOS. Pectoralis minor tenotomy should be considered part of complete thoracic outlet decompression. Anterior scalene muscle block accurately predicts outcome of reoperation for certain types of recurrent NTOS.