Thoracic outlet syndrome in a child--transaxillary resection of anomalous first rib

Thoracic outlet syndrome (TOS) is extremely rare in children. Only several pediatric cases have been reported, and all presented with neurologic symptoms. The authors report on a 6-year-old boy with an asymptomatic left subclavian artery aneurysm caused by compression of the subclavian artery by an anomalous first rib with poststenotic aneurysmal dilatation. This was successfully managed by transaxillary resection of the anomalous rib. This represents the youngest reported case of TOS and the first description of a vascular manifestation of TOS in the pediatric population. Access to the costoscalene triangle utilizing a transaxillary approach was straightforward and afforded excellent exposure, even in a child.