Pre-operative Diet: Effect of Wound Healing After Bariatric Surgery

This study is a randomised control trial comparing the effects of a pre-operative very low calorie diet (VLCD) on wound healing in the morbidly obese patients undergoing bariatric surgery. The benefits and disadvantages of a very low calorie pre-operative diet are not clear. Some centres ask their patients to take a VLCD 2-6 weeks before bariatric surgery with the aim of shrinking the liver to make surgery easier. Studies have shown that after this diet the liver does shrink and therefore operating may be easier but this did not necessary translate into significant lesser operative times. The effects of operating during a catabolic phase have not been evaluated. Theoretically a low calorie diet before surgery is similar to starving a patient and can potentially create a state of malnutrition. This is rarely advisable before surgery and can lead to poor wound healing and poor healing of bowel anastomosis. This study will ascertain if there is any difference in wound healing rates in these morbidly obese patients (BMI\>40kg/m2)undergoing a Laparoscopic Roux en Y gastric by pass in groups who have taken the preoperative diet compared to those who were not on a special diet. Skin wounds will be evaluated. This will potentially reflect the general state of healing of the patient which includes the healing of bowel anastomosis. Surrogate markers will be employed to evaluate the pre-morbid nutritional state, effectiveness of dieting, subsequent wound healing (collagen production, markers for the different aspects of wound healing) and impact on liver cell death .This study will be able to tell us how safe this calorie deficient diet is in these morbidly obese patients before surgery.