Short-term preoperative supplementation of an immunoenriched diet does not improve clinical outcome in well-nourished patients undergoing abdominal cancer surgery

Abstract

Objective

A recent study suggested that the anti-inflammatory effect of immunonutrition starts after only two d. We therefore investigated the effect of an immunoenriched oral diet administered for three d preoperatively.

Methods

In this prospective, randomized, double-blind, placebo-controlled study, well-nourished patients (Nutrition Risk Screening 2002 <3) with gastrointestinal cancer who were scheduled for major elective abdominal cancer surgery were randomly assigned to either 750 mL of an immunoenriched formula (IEF group) or 750 mL of an isocaloric, isonitrogenous placebo diet (Con group) for 3 consecutive d preoperatively.

Results

A total of 108 patients (IEF group: n = 55; Con group: n = 53) were randomized. The two groups were comparable for all baseline and surgical characteristics. The overall mortality was 2.8% and not significantly different between the two groups (IEF group: 3.6% vs. Con group: 1.9%, P = 1.00). Intention-to-treat analysis showed no difference for the incidence of postoperative overall (IEF group: 29% vs. Con group: 30%; P = 1.00) and infectious (IEF group: 15% vs. Con group: 17%; P = 0.79) complications. Length of hospital stay was 12 ± 4.9 d in the IEF group and 11.6 ± 5.3 d in the Con group (P = 0.68).

Conclusions

Preoperative oral supplementation with an immunoenriched diet for 3 d preoperatively did not improve postoperative outcome compared with the placebo in well-nourished patients with elective gastrointestinal cancer surgery.

Introduction

Major surgery is a powerful stimulus for systemic inflammatory response, which represents, if excessive and uncontrolled, a risk factor for a state of hypermetabolism with rapid consumption of endogenous energy stores and immunological dysfunction, eventually leading to postoperative complications, including deterioration of organ function [1], [2]. Patients undergoing surgery for gastrointestinal or pharyngeal cancer are often malnourished, rendering them vulnerable for postoperative complications, prolonged hospitalization, and increased health care costs. Among the proposed strategies to reduce such sequelae is the use of enteral diets enriched with specific nutritional compounds such as arginine, glutamine, omega-3 fatty acids (fish oil), and/or ribonucleic acid (RNA), which has been defined as immunonutrition. Immunonutrition is supposed to alter immune function and cytokine production, thereby limiting the undesirable perioperative excessive stimulation of the immune and inflammatory cascades [3]. Several randomized studies found that the perioperative (before and after surgery) use of such diets in malnourished cancer patients significantly decreases the incidence of infectious complications, length of hospital stay (LOS), and hospital costs compared with a control enteral formula [4], [5], [6], [7]. Preoperative oral feeding with an immune-enhancing diet for 5 d in well-nourished cancer patients undergoing abdominal surgery has been shown to decrease postoperative infectious complications, length of hospital stay, and health care costs [8]. Although guidelines recommend supplementation with an immunoenriched diet for 5 consecutive d before visceral surgery [9], there is neither clear evidence about the exact length of preoperative supplementation, nor about the required minimum amount of immunonutrients needed for improving clinical outcome.

In a recent pilot study, we have shown that the positive effect an immunoenriched diet on markers of inflammation starts after only 2 d of preoperative supplementation [10]. On the basis of this observation, we performed a trial in well-nourished visceral cancer patients to find out whether preoperative supplementation with an immunoenriched diet for 3 d is superior to placebo concerning postoperative outcome.