THE EFFECT OF MINOCIN ON THE PERICARDIUM

The purpose of this study was to evaluate in a dog model whether intra pericardial instillation of tetracycline is superior to the effect of drainage alone in causing pericardial adhesions and cavity obliteratio n. Twelve mongrel dogs were randomly divided into two experimental gro ups. All dogs received a pericardial drain through a sterile thoracoto my. Group A dogs (n = 6) received minocycline hydrochloride, 20 mg/kg, group B received normal saline. All dogs were sacrificed 1 month late r. Echocardiograms performed 1 week postsurgery were normal in all dog s. Macroscopic evaluation disclosed that all group A dogs had over 25% cavity obliteration whereas group B dogs had no adhesions or had obli teration of less than 25% of the cavity area. Microscopic evaluation s howed that group A dogs had severe pericardial fibrosis and thickening with slight focal lymphoplasmocytic infiltration. Myocardial damage w as not seen. Our results support the clinical use of injecting tetracy cline into the pericardium (in addition to drainage) to cause cavity o bliteration in patients with persistent pericardial effusion.