Preoperative immunonutrition in patients undergoing liver resection:A prospective randomized trial

BACKGROUND Preoperative supplementation with immunonutrients, including arginine and n-3 fatty acids, has been shown in a number of systematic reviews to reduce infectious complications in patients who have undergone gastrointestinal surgery. Limited information, however, is available on the benefits of nutritional supplementation enriched with arginine and n-3 fatty acids in patients undergoing liver resection.AIM To evaluate the effects of preoperative nutritional supplementation enriched with arginine and n-3 fatty acids on inflammatory and immunologic markers and clinical outcome in patients undergoing liver resection.METHODS Thirty-four patients undergoing liver resection were randomized to either five days of preoperative Impact? [1020 kcal/d, immunonutrition(IMN) group], or standard care [no supplementation, standard care(STD) group]. Nutritional status was measured at study entry by subjective global assessment(SGA).Functional assessments(grip strength, fatigue and performance status) were carried out at study entry, on the day prior to surgery, and on postoperative day(POD) 7 and 30. Inflammatory and immune markers were measured at study entry, on the day prior to surgery, and POD 1, 3, 5, 7, 10 and 30. Postoperative complications were recorded prospectively until POD30.RESULTS A total of 32 patients(17 IMN and 15 STD) were analysed. All except four patients were SGA class A. The plasma ratio of(eicosapentaenoic acid plus docosahexaenoic acid) to arachidonic acid was higher in IMN patients on the day prior to surgery and POD 1, 3, 5 and 7(P < 0.05). Plasma interleukin(IL)-6 concentrations were elevated in the IMN group(P = 0.017 for POD7). No treatment effect was detected for functional measures, immune response(white cell count and total lymphocytes) or markers of inflammation(C-reactive protein,tumour necrosis factor-α, IL-8, IL-10). There were 10 patients with infectious complications in the IMN group and 4 in the STD group(P = 0.087). Median hospital stay was 9(range 4–49) d in the IMN group and 8(3-34) d in the STD group(P = 0.476).CONCLUSION In well-nourished patients undergoing elective liver resection, this study failed to show any benefit of preoperative immunonutrition.

Steatotic livers are susceptible to normothermic ischemiareperfusion injury from mitochondrial Complex-Ⅰ?dysfunction

AIM: To assess the effects of ischemic preconditioning(IPC, 10-min ischemia/10-min reperfusion) on steatotic liver mitochondrial function after normothermic ischemia-reperfusion injury(IRI).METHODS: Sixty male Sprague-Dawley rats were fed8-wk with either control chow or high-fat/high-sucrose diet inducing > 60% mixed steatosis. Three groups(n = 10/group) for each dietary state were tested:(1) the IRI group underwent 60 min partial hepatic ischemia and 4 h reperfusion;(2) the IPC group underwent IPC prior to same standard IRI; and(3) sham underwent t h e s a m e s u r g e r y w i t h o u t I R I o r I P C. H e p a t i c mitochondrial function was analyzed by oxygraphs. Mitochondrial Complex-Ⅰ, Complex-Ⅱ enzyme activity, serum alanine aminotransferase(ALT), and histological injury were measured.RESULTS: Steatotic-IRI livers had a greater increase in ALT(2476 ± 166 vs 1457 ± 103 IU/L, P < 0.01) and histological injury following IRI compared to the lean liver group. Steatotic-IRI demonstrated lower Complex-Ⅰ?activity at baseline [78.4 ± 2.5 vs 116.4 ± 6.0 nmol/(min.mg protein), P < 0.001] and following IRI [28.0 ± 6.2 vs 104.3 ± 12.6 nmol/(min.mg protein), P < 0.001]. Steatotic-IRI also demonstrated impaired Complex-Ⅰ?function post-IRI compared to the lean liver IRI group. Complex-Ⅱ activity was unaffected by hepatic steatosis or IRI. Lean liver mitochondrial function was unchanged following IRI. IPC normalized ALT and histological injury in steatotic livers but had no effect on overall steatotic liver mitochondrial function or individual mitochondrial complex enzyme activities. CONCLUSION: Warm IRI impairs steatotic liver Complex-Ⅰ?activity and function. The protective effects of IPC in steatotic livers may not be mediated through mitochondria.