Effect of physical protection on the mesothelial integrity of the pericardium

Background. Mesothelial integrity is essential for the prevention of pericardial adhesions. This study was performed to determine the effect of physical protection of the pericardium on mesothelial integrity. Methods. A pericardial biopsy specimen was obtained at the time of pericardiotomy (0 minutes) in 10 patients undergoing a cardiac operation for the first time. The left free edge of the pericardiotomy was plicated inward to protect the mesothelium. Biopsy specimens were obtained from the protected and unprotected pericardium at 45 and 90 minutes after the start of extracorporeal circulation. Mesothelial integrity and the local inflammatory response were then assessed and graded histologically. Results. The mesothelium was found to be present in the protected specimens at 0, 45, and 90 minutes, but it was found to be denuded in the unprotected specimens (p = 0.003 at 45 minutes; p = 0.004 at 90 minutes). Local inflammation was totally established in both the protected and unprotected specimens at 45 minutes. Conclusions. Physical agents appear to be the main factor that is damaging to the pericardial mesothelium, and this is an important concept to be taken into consideration when designing a method to prevent pericardial adhesions.