RESUMO
OBJECTIVE: We examined the role of botulinum toxin (BTX) injections of anterior scalene (AS) and pectoralis minor (PM) muscles in patients undergoing surgery for neurogenic thoracic outlet syndrome (NTOS). We hypothesized that symptomatic improvement from BTX injections correlates with favorable long-term response to surgery for NTOS. MATERIALS AND METHODS: This Health Insurance Portability and Accountability Act compliant study was approved by the institutional review board and prior informed consent requirement was waived. We retrospectively analyzed prospectively acquired data in NTOS patients who underwent sonographically guided chemodenervation of AS and PM using BTX type A followed by scalenectomy and first rib resection. Overall responses to BTX injections and surgery were recorded after each procedure. Statistical analyses were performed to determine correlation between responses to BTX injections and surgery. RESULTS: In 157 patients, 178 BTX injections followed by surgery were identified (114 females; mean age 38 ± 13 years). Responders and non-responders to BTX injections and surgery had similar preoperative symptom duration and age (P > 0.14). Better response to BTX injections correlated positively with better response to surgery (P = 0.003), persisting after adjustment for age, gender, and symptom duration (P = 0.03). A high proportion of responders to BTX injections also responded to surgery (positive predictive value of 99%), and BTX injections showed high specificity (90%). BTX injections were moderately sensitive (66%) and accurate (67%) to determine surgical response and had low negative predictive value (14%). CONCLUSION: Response to BTX injections correlates positively with long-term surgical outcome in subjects with NTOS, potentially playing an important role in patient management.