The diagnostic specificity of creatine kinase isoenzymes after transurethral operations.

It has been suggested recently that increases in the concentration of the MB isoenzyme of creatine kinase after transurethral operations could result from release of creatine kinase-MB by prostatic or bladder tissues and, therefore, that creatine kinase-MB is not specific for myocardial damage. Our study of 53 patients undergoing transurethral operations and 37 undergoing urethral dilations showed that creatine kinase-MB is not released in significant quantities from the prostate or bladder. Therefore, we believe that an elevated creatine kinase-MB concentration is specific for myocardial infarction in these patients. We also concluded that the increase in total serum creatine kinase activity in these patients probably results from release of the creatine kinase-MM isoenzyme from periurethral muscle damage by electrocautery.