CD is a chronic inflammatory disease that can involve the whole digestive tract but especially involves the terminal ileum and right colon. The etiology of CD remains unknown, and there is still no specific radical treatment. Aminosalicylic acid preparations, glucocorticoids, and thiopurine drugs can be used for maintenance therapy during the active period and after drug-induced remission. However, surgical treatment is often needed. As reported previously, approximately 78% of patients who have CD for more than 20 years need surgical treatment1,21−23. Surgical treatment can only address complications, such as obstructions, bleeding, perforations, abscesses, inflammatory masses, and internal and external intestinal fistulas; it cannot cure the primary disease. In addition, postoperative complications are still major problems after colorectal surgery that cause prolonged in-hospital stays, increase treatment costs, and worsen long-term survival. Malnutrition, preoperative drugs use, preoperative intestinal fistulas and abdominal abscesses can all increase the risk of postoperative complications24–26. Hence, reliable treatments are needed to reduce postoperative complications in order to enable early and safe patient discharge, especially under the Enhanced Recovery after Surgery program.
In the current study, we analyzed the protective effects of ω-3 PUFA-supplemented PN after surgery against postoperative complications for patients with CD. The results revealed that CD patients who did not receive ω-3 PUFA after surgery were at higher risk of postoperative complications, exhibited higher postoperative serum CRP levels and experienced longer postoperative hospital stays after enterotomy than those who did receive ω-3 PUFAs. These findings indicate that ω-3 PUFA-supplemented PN after surgery can reduce the postoperative inflammatory response and reduce the incidences of postoperative complications, especially major complications, thus accelerating the recovery of CD patients. This study is the first to focus on the relationship between ω-3 PUFA-supplemented PN and postoperative rehabilitation for CD patients.
ω-3 PUFAs have been shown to be effective in enhancing nutritional status and immune function in gastrointestinal patients who have undergone surgery. ω-3 PUFA-supplemented PN has been proven to be successful, safe, and effective and has good clinical applications and clinical value for CD patients without surgery27–28. However, little is known about the relationship between the use of ω-3 PUFAs after surgery and clinical outcomes. The effects of ω-3 PUFAs in surgical patients are still controversial. One prospective randomized controlled study showed that ω-3 PUFAs could significantly ameliorate the postoperative inflammatory response in 48 patients with gastric cancer29. Zhang et al.30 found that ω-3 PUFA-supplemented PN could improve postoperative recovery, reduced postoperative complications, and shorten hospital stays after hepatectomy in patients with liver cirrhosis or liver cancer. A meta-analysis by Zhao et al.31 revealed that early application of ω-3 PUFAs in patients with gastrointestinal cancer could improve immunity, reduce the postoperative stress response, and attenuate metastasis or recurrence. However, other studies have shown that there is no significant correlation between ω-3 PUFAs and postoperative complications in colorectal or esophageal cancer patients12,32−33. Our study suggests that ω-3 PUFA-supplemented PN can reduce the postoperative inflammatory response, promote the recovery of intestinal function, reduce the incidence of anastomotic leakage, and reduce the incidences of abdominal abscesses and other major postoperative complications in CD patients after enterotomy. However, the incidence of postoperative incision infection was not revealed to be significantly reduced in our study. CD is characterized by abnormal activation of the intestinal immune system and a major inflammatory response; however, application of ω-3 PUFAs after surgery can reduce the inflammatory response caused by surgical trauma stress, and further control the inflammatory response caused by CD itself34.
The postoperative rehabilitation improvement mediated by ω-3 PUFAs may be due to regulation of the arachidonic acid pathway and control of the release of prostaglandins, thromboxanes, leukotrienes and other molecules, which reduces the levels of inflammatory molecules such as IL-6, IL-8, and TNF-ɑ35–37; regulation of sterol regulatory element binding protein (SREBP-1), protein acylation reactions and calcium ion release, which maintains cell membrane integrity, stability, and fluidity, thus reducing the production and release of cytokines and ameliorating, the postoperative inflammatory response38; alteration of the phospholipid composition and function of T-cell membranes, which enhances the function of antigen-presenting cells and the cytotoxicity of natural killer cells and regulates the function of dendritic cells to affect immune function39; and regulation of the intestinal flora and their metabolites, such as short chain fatty acids40.
The current study had several limitations. First, it was a retrospective observational analysis, and the effects of residual confounding factors could not be fully excluded. Second, as this was a single-center study, the perioperative management strategies were dependent on our local experience, which may have influenced the outcomes41. Large multicenter prospective studies must be performed to verify the conclusions of the current study.