In considering the value of any operative procedure, critical analysis of several factors is necessary. The mortality of the operation must be compared with the mortality of the disease for which it is performed, and the complications of the operation must be compared with the complications of the untreated disease. In a review of any series of operations it may be seen that both fatal and nonfatal complications arise, which are not inherent in the type of operation but may be sequelae of any surgical procedure. These include wound infections and pulmonary lesions. It is this group of postoperative complications that I wish to discuss in this paper. It has been said that all surgical procedures, no matter how simple, are attended by some risk of complications. As surgical science advances, the number of such complications will be reduced toward the minimum. During this evolutionary process, however, many prophylactic and