Activation of monocytes and endothelial cells depends on the severity of surgical stress

Surgical injury not only induces a systemic endocrine-metabolic response hu t also influences the function of the leukocytes and endothelial cells lead ing to various systemic responses. These responses appear to depend on the severity of surgical stress, which differs according to the surgical proced ures. In this study, ae investigated the response of monocytes and endothel ial cells, and the development of systemic inflammatory response syndrome ( SIRS) in relation to the severity of surgical stress. The postoperative cli nical course was evaluated between patients undergoing an esophagectomy (ER group) and a distal gastrectomy (DG group). The tumor necrosis factor alph a (TNF alpha) production of monocytes, the serum interleukin 6 (IL-6) level s, the CD11b expression on either monocytes or granulocytes, and the interc ellular adhesion molecule-1 (ICAM-1) expression on human umbilical vein end othelial cells (HU-VECs) stimulated with culture supernatants of monocytes were compared between the 2 groups. The development of SIRS was observed in all patients in the ER group, whereas no patients demonstrated SIRS in the DG group. The serum IL-6 levels, TNF alpha production of monocytes, and CD 11b intensity on monocytes or granulocytes in the ER group were higher than those in the DG group. In the ER group, the ICAM-1 intensity on HUVECs wit h monocytes immediately after operation significantly increased compared wi th before the operation. In conclusion, both the CD11b expression on monocy tes and the TNF alpha production of monocytes are considered to reflect the degree of surgical stress, and the activation of endothelial cells stimula ted with these activated leukocytes may therefore lead to both tissue and o rgan injury.