The Value of Phrenic Exairesis in the Treatment of Pulmonary Tuberculosis

nerve is found in the medial aspect of the muscle; very occasionally the nerve is in very close apposition to the brachial plexus and then it may lie on the lateral aspect of the muscle and may cross it only at the point of insertion of the muscle. The accessory fibres to the phrenic nerve follow the first part of the brachial plexus taking their origin usually from the fifth or sixth cervical roots. They may arise as a single bundle or as a series of 2 or 3 nerves, which run obliquely downwards and inwards from the brachial plexus joining the main trunk of the phrenic nerve occasionally in the neck but more often below the level of the clavicle (Morriston-Davies, 1933). Sometimes the phrenic nerve may be found to be bound down by adhesions and it may not be possible to evulse the whole nerve. In such cases it is dangerous to pull it violently. Our technique usually is to expose the nerve in the neck, dissect it out free from under the fascia of the anterior scalene muscle and then use slow traction. If the nerve comes easily, the whole nerve is evulsed. If there is considerable