The question of operative risk is one of great interest as well as concern to the surgeon, and justly deserves his consideration. At the present time, he must estimate the operative risk from the patient's general condition, age, obesity and blood pressure, from the type of lesion and from his own skill and experience. While these factors may at times furnish the basis for an accurate estimation of the risk, they often involve danger to the less experienced surgeon, and at times even to the most skilled, on account of their variability and the difficulty of interpretation. Various conditions, such as nasal and bronchial infections, and the like, may lie dormant and give no indication of their presence until the patient's resistance has been lowered sufficiently by operation to permit exacerbation. It is often impossible to anticipate such complications even from the most careful history.
In view of the fairly