In the treatment of pulmonary tuberculosis, under the old regimen of watchful waiting, in which patients were kept at bed rest until their disease had advanced so far that only the more drastic surgical procedures were of benefit, phrenic nerve operations were not often employed.
Since it has become clear to all physicians that early compression of some sort should be used in unilateral lesions to assist in their arrest before the disease has spread to the other lung, phrenic crushing and exeresis have taken their places along with artificial pneumothorax as valuable and necessary methods of treatment.
Operations on the phrenic nerve are performed to cause a paralysis of the diaphragm, this paralysis being made temporary or permanent by the choice of procedure. Paralysis of the diaphragm will be caused by simple cutting or crushing of the phrenic nerve and its accessory, which exists in about 20 per cent