The effects of subclinical malnutrition and refeeding on the healing of experimental colonic anastomoses.

The effects of dietary protein deprivation on he healing of colonic anastomosis in the rat have been investigated. Nutritional status was assessed both before and after operation using body weight, nitrogen balance studies and serum albumin estimations. Healing of colonic anastomosis was assessed by bursting pressure measurements. Rats fed a protein-depleted diet throughout the study were compared both with rats restored to a full diet after surgery and rats receiving a full diet throughout. Although protein depletion caused a 12.5 per cent weight loss and a negative nitrogen balance, serum albumin remained normal in all rats at the time of operation. After operation, all rats were in negative nitrogen balance, although this was greater in the protein-depleted group. Similarly, in comparison to control animals, the protein-depleted group had significantly lower colonic bursting pressures and significantly lower serum albumin concentrations. Rats returned to a full diet after operation had smaller losses of nitrogen and normal colonic bursting pressures. The results indicate that a commonly encountered degree of malnutrition, insufficient to affect nutritional indices used in clinical assessment, may interfere with colonic healing. Early re-introduction of nutrition in the postoperative period may be able to reverse this effect.