Thoracic Outlet Syndrome: Minimally Invasive Surgery Works

Norra MacReady

February 12, 2013

Minimally invasive surgery can help selected patients with disabling neurogenic thoracic outlet syndrome (NTOS), according to results from a new study published online February 4 in the Journal of Vascular Surgery.

In a second study, published in the January issue of the journal, the same investigators showed that NTOS surgery is especially helpful to adolescents compared with adults.

Although relatively uncommon, NTOS "most frequently occurs in relatively young, active, and otherwise healthy individuals," senior author Robert W. Thompson, MD, professor of surgery and director of the Washington University Center for Thoracic Outlet Syndrome at Barnes-Jewish Hospital in St. Louis, Missouri, and colleagues write in the first study. Symptoms include pain, numbness, and paresthesia of the arm, neck, or hand. Different physicians and specialties vary in their approach to treatment, making it hard to identify factors associated with optimal surgical outcomes.

NTOS results from compression of the brachial plexus nerves running either through the neck just above the collarbone or down into the upper chest and just under the collarbone near the shoulder, an area known as the interscalene triangle. In some patients, nerve compression occurs within the subcoracoid space underlying the pectoralis minor muscle tendon near the shoulder, prompting the development of a minimally invasive procedure called pectoralis minor tenotomy (PMT), consisting of detachment of the pectoralis minor tendon. The efficacy of this operation is still unclear. In the first study, Dr. Thompson and coauthors compared PMT with traditional open surgery, which combines PMT with supraclavicular decompression (SCD+PMT).

They studied 200 patients referred to the hospital for treatment of disabling NTOS from February 2008 to October 2011. The diagnosis was made mostly through clinical criteria, with infraclavicular, axillary, and anterior chest wall pain most suggestive of pectoralis minor compression. At baseline, all patients completed the Disabilities of Arm, Shoulder, and Hand survey, the Cervical-Brachial Symptom Questionnaire, and a 10-point visual analog scale for pain. The results of these 3 instruments were combined to produce the NTOS index, a composite measure scored on a scale of 0 to 100, with higher scores indicating more severe disability.

Fifty-seven patients underwent PMT, and the remaining 143 patients underwent SCD+PMT. In both groups, the most common symptoms were pain in the arms, neck, and shoulders, as well as pain, weakness, and paresthesias of the hands. The mean baseline NTOS index scores (±standard error of the mean [SEM]) were 54.5 ± 3.4 in the isolated PMT group, derived from 35 patients, and 62.7 ± 2.3 in the SCD+PMT group, derived from 113 patients. These differences were insignificant.

After surgery, 163 of the 200 patients (82%) reported significant and progressive improvement at the 3-month follow-up, including 43 of the patients who underwent isolated PMT (75%) and 120 who underwent the combined procedure (84%). The mean 3-month NTOS index scores were 36.8 ± 3.8 from 26 patients undergoing isolated PMT and 41.3 ± 2.5 from 84 patients who underwent SCD+PMT (P > .05). The difference in the proportion of patients taking opiate painkillers in each group also was insignificant (35% and 27%, respectively).

Younger Patients Fare Better

These findings suggest that "selected patients with disabling NTOS can improve substantially after surgical treatment by isolated PMT, as well as by more conventional SCD+PMT, compared with their condition before the operation," the authors write.

In addition, the data "confirm that isolated PMT is successful in treating disabling NTOS with physical examination findings confined to the subcoracoid space."

In the second study, the authors compared outcomes in 35 adolescents with a mean age of 17.3 ± 0.3 years with those of 154 patients whose mean age was 40.0 ± 0.7 years (P < .0001). Hand pain was reported by 79% of adults and 56% of adolescents (P = .0118); otherwise, the prevalence of most symptoms was similar between groups. All patients underwent SCD, with PMT added if indicated.

The mean preoperative NTOS index scale was 46.5 ± 3.6 for the adolescents and 58.5 ± 1.7 for the adults (P = .0089). At 3 months, the scores were 18.4 ± 4.1 and 41.0 ± 2.3, respectively (P < .0001), and at 6 months, they were 10.4 ± 3.1 and 39.3 ± 3.3, respectively (P < .0001).

The 35 adolescents in this analysis make up the largest group of pediatric or adolescent patients with NTOS studied to date, the authors write. The younger patients had a lower incidence of depression, history of motor vehicle injuries, use of opiate painkillers, symptom duration, and a higher incidence of repetitive motion injuries and sports participation.

"These favorable clinical features in adolescent patients can thereby be expected to predict improved outcomes after surgical treatment compared with adults," the authors write. However, they caution that younger age may simply be a surrogate for earlier diagnosis and treatment of symptoms, rather than an independent prognostic factor. They also warn that symptoms can recur up to 2 years after surgery, which is well past the 6-month follow-up period in this study.

These studies were supported in part by a research grant from the Thoracic Outlet Syndrome Research and Education Fund of the Barnes-Jewish Hospital Foundation. The authors have disclosed no relevant financial relationships.

J Vasc Surg. Published online February 4, 2013, and 2013;57:149-157. Abstract