Insufficient venous drainage following axillary approach to brachial plexus blockade.

Progressive obstruction of an axillary vein following an axillary approach to brachial plexus blockade is described. At surgical exploration, the axillary vein was narrowed with an aneurysm of its wall. It is likely that, during the performance of the block, the needle penetrated the adventitia of the vein, causing a sub-adventitial haematoma and an aneurysm of the vein wall. Normal venous drainage was re-established surgically and the patient recovered completely.