Perioperative arginine supplementation in mastectomy patients undergoing immediate breast reconstruction.
BACKGROUND Immediate reconstruction after mastectomy is a major surgical procedure of the breast associated with a significant risk of postoperative complications. To date, there is very little evidence supporting nutritional intervention as a potential risk-reducing factor. This study aimed to assess the effect of perioperative arginine supplementation on postoperative recovery. MATERIALS AND METHODS This was an open-label, non-randomised pilot cohort study including 94 patients. The intervention group received one oral supplement daily providing 5 g of arginine, 20 g of protein, and 100 kcal for 14 days before surgery and postoperatively until complete wound healing or for a maximum of 14 days; controls continued their usual diet without additional supplementation. Postoperative complications and wound-healing outcomes were assessed for 90 days. RESULTS Analyses showed no statistically significant difference in overall complication occurrence or severity between groups. In exploratory unadjusted analyses, the median time to complete wound healing was 22 days in the intervention group and 35 days in the control group (log-rank p = 0.016; HR for control versus intervention, 0.38; 95% CI, 0.17-0.83). Among patients who developed any complication, long-lasting complications were observed in 12.5% of the intervention group and 50.0% of controls (OR for control versus intervention 6.50, 95% CI 1.13-37.50; Fisher's exact p = 0.034). CONCLUSIONS Exploratory secondary analyses suggested shorter observed wound-healing times and fewer long-lasting complications among patients receiving perioperative arginine-containing oral nutritional supplementation; however, these findings were attenuated after multivariable adjustment and cannot be interpreted causally due to the non-randomised design, baseline imbalances, limited sample size, and potential residual confounding. Because the administered supplement also contained protein and energy, the observed findings cannot be attributed to an arginine-specific effect. Adequately powered randomised controlled trials are required to confirm these preliminary hypothesis-generating results.