Pectoralis minor obstruction of the axillary vein: report of six patients.

PURPOSE Although the usual site of nonthrombotic venous obstruction of the upper extremity is the subclavian vein, other sites may be the cause of such obstruction. This study describes the diagnosis and treatment of six patients with partial axillary vein obstruction by the pectoralis minor muscle, a condition that can mimic subclavian vein obstruction. METHODS A chart review of patients undergoing pectoralis minor tenotomies (PMT) between 2004 and 2006 revealed six patients (3 men and 3 women), aged 17 to 39, who underwent seven PMT procedures for symptoms of arm swelling, cyanosis, and pain or tightness. Diagnosis was suggested by history and physical examination and was confirmed by dynamic venography. Patients with paresthesia suggesting associated neurogenic pectoralis minor compression were given a pectoralis minor muscle block. As an outpatient, PMT was initially performed with an infraclavicular approach but later through the transaxillary route. Follow-up was by phone interview in five patients and a physical examination in one. RESULTS Venography demonstrated axillary vein compression under the pectoralis minor, which was more significant than the minor degree of subclavian vein compression seen on the same venogram. Follow-up was 1.5 years to 10 years in three patients and 3 months in the other three. All six patients experienced good-to-excellent relief of all symptoms. There were no surgical complications. CONCLUSION Axillary venous obstruction by the pectoralis minor must be distinguished from subclavian vein obstruction, which presents with similar symptoms. PMT is a simple, risk-free, outpatient procedure that has produced uniformly good results.