Use of antioxidants in surgery: a measure to reduce postoperative complications

This review highlights recent research into the causes and prevention of free radical (particularly reactive oxygen species)-induced surgical complications. Experimental and clinical studies have contributed new understanding of the sources of free radical attack, modalities to counter these and newer approaches developed with the aid of molecular biology.

Most work has centred on cardiac bypass surgery, other surgery involving ischaemia and reperfusion, and transplant surgery. In cardiac bypass surgery, recent work using spin trap techniques has shown extracorporeal bypass to be the major source of free radical production. This has emphasized the need for a multifaceted approach, initially directed against the stress of bypass and secondly against the reperfusion phenomenon. Experimental work in the rat in partial hepatectomy has provided evidence of the synergistic effect of vitamin E and the flavonoid silibinin on cellular immunoresponse. In transplant surgery, the possible use of lecithinized superoxide dismutase to protect donor organs against cold ischaemic and reperfusion injury has been reported, and work with a rat model showed that blockade of caspase-3 can ameliorate reperfusion injury by upregulating bcl-2 and inhibiting TNF-alpha.

The combined approaches of patient preconditioning with free radical scavengers such as ascorbate and vitamins E and A, additional measures directed against the further challenge of the ischaemia/reperfusion cycle (antioxidant additions to cardioplegia solutions, the use of chelating agents and preservation of the immune response), and the maximization of resistance of donor organs or substitutes (skin culture) may provide an integrated approach to minimize free radical-induced surgical complications.