The immunologic changes during different phases of intestinal anastomotic healing

Higher Cardiovagal Baroreflex Sensitivity Predicts Increased Pain Outcomes After Cardiothoracic Surgery

Excessive postoperative pain can lead to extended hospitalization and increased expenses, but factors that predict its severity are still unclear. Baroreceptor function could influence postoperative pain by modulating nociceptive processing and vagal-mediated anti-inflammatory reflexes. To investigate this relationship, we conducted a study with 55 patients undergoing minimally invasive cardiothoracic surgery to evaluate whether cardiovagal baroreflex sensitivity (BRS) can predict postoperative pain. We assessed the spontaneous cardiovagal BRS under resting pain-free conditions before surgery. We estimated postoperative pain outcomes with the Pain, Enjoyment, and General Activity scale and pressure pain thresholds on the first (POD1) and second (POD2) postoperative days and persistent pain 3 and 6 months after hospital discharge. We also measured circulating levels of relevant inflammatory biomarkers (C-reactive protein, albumin, cytokines) at baseline, POD1, and POD2 to assess the contribution of inflammation to the relationship between BRS and postoperative pain. Our mixed-effects model analysis showed a significant main effect of preoperative BRS on postoperative pain (P = .013). Linear regression analysis revealed a significant positive association between preoperative BRS and postoperative pain on POD2, even after adjusting for demographic, surgical, analgesic treatment, and psychological factors. Moreover, preoperative BRS was linked to pain interfering with general activity and enjoyment but not with other pain parameters (pain intensity and pressure pain thresholds). Preoperative BRS had modest associations with postoperative C-reactive protein and IL-10 levels, but they did not mediate its relationship with postoperative pain. These findings indicate that preoperative BRS can independently predict postoperative pain, which could serve as a modifiable criterion for optimizing postoperative pain management. PERSPECTIVE: This article shows that preoperative BRS predicts postoperative pain outcomes independently of the inflammatory response and pain sensitivity to noxious pressure stimulation. These results provide valuable insights into the role of baroreceptors in pain and suggest a helpful tool for improving postoperative pain management.

The Influence of Apremilast-Induced Macrophage Polarization on Intestinal Wound Healing

There is compelling evidence suggesting a pivotal role played by macrophages in orchestrating intestinal wound healing. Since macrophages display significant plasticity and heterogeneity, exhibiting an either classically activated (M1-like) or alternatively activated (M2-like) phenotype, they can aggravate or attenuate intestinal wound healing. Growing evidence also demonstrates a causal link between impaired mucosal healing in inflammatory bowel disease (IBD) and defects in the polarization of pro-resolving macrophages. By targeting the switch from M1 to M2 macrophages, the phosphodiesterase-4 inhibitor Apremilast has gained recent attention as a potential IBD drug. However, there is a gap in our current knowledge regarding the impact of Apremilast-induced macrophages' polarization on intestinal wound healing. The THP-1 cells were differentiated and polarized into M1 and M2 macrophages, and subsequently treated with Apremilast. Gene expression analysis was performed to characterize macrophage M1 and M2 phenotypes, and to identify possible target genes of Apremilast and the involved pathways. Next, intestinal fibroblast (CCD-18) and epithelial (CaCo-2) cell lines were scratch-wounded and exposed to a conditioned medium of Apremilast-treated macrophages. Apremilast had a clear effect on macrophage polarization, inducing an M1 to M2 phenotype switch, which was associated with NF-κB signaling. In addition, the wound-healing assays revealed an indirect influence of Apremilast on fibroblast migration. Our results support the hypothesis of Apremilast acting through the NF-κB-pathway and provide new insights into the interaction with fibroblast during intestinal wound healing.

Comparative early histologic healing quality of magnetic versus stapled small bowel anastomosis

BACKGROUND

Successful anastomotic healing is critical to preventing complications after intestinal surgery. We aimed to compare the early healing of end-to-end small bowel anastomosis by self-forming magnets with surgical stapling in a porcine model.

METHOD

Six Yorkshire pigs underwent 2 simultaneous small bowel anastomoses using a circular stapler and self-forming magnet technique. The primary outcome was healing quality, measured by 4 histologic features: inflammatory cell infiltration, collagen formation, grade of inflammation, and bacterial infiltration at the anastomosis. The samples were evaluated at days 1, 3, and 7. Gross evaluation of anastomotic integrity was a secondary outcome.

RESULTS

The self-forming magnet group displayed significant differences at each time point. On day 1, the stapled group displayed dense inflammatory cell infiltration and extensively ulcerated intestinal layers with significant edema. The self-forming magnet group showed less inflammatory infiltrate, and all intestinal layers remained compressed in direct apposition. By day 3, the self-forming magnet group already exhibited neovascularization with scant bacterial colonies. By contrast, stapled anastomoses had large areas of inflammation separating collagen fibers with prevalent bacterial infiltrations. On day 7, self-forming magnet anastomoses were characterized by robust neovascularization, maturing granulation tissue, and mucosal re-epithelization without significant inflammation. Meanwhile, stapled samples had persisting dense inflammation, tissue cavities with hemorrhage, and immature fibrous tissue. Grossly, the self-forming magnet created a patent lumen without defect, whereas stapled anastomoses demonstrated focal areas of serosal separation.

CONCLUSION

Bowel anastomosis by self-forming magnets is associated with superior early histologic healing metrics, including early seal generation through mechanical compression, decreased inflammation, early neovascularization, lower bacterial infiltration, and faster re-epithelization.

Laparoscopic single-layer running "trapezoid-shaped" suture versus mechanical stapling for esophagojejunostomy after total gastrectomy for gastric cancer: cost-effect analysis of propensity score-matched study cohorts

OBJECTIVES

Totally laparoscopic total gastrectomy has been developed with difficulty in intracorporeal esophagojejunostomy. Although mechanical stapling has been widely used for intracorporeal esophagojejunostomy, manual suture holds great promise with the emergence of high-resolution 3D vision and robotic surgery. After exploration of how to improve the safety and efficiency of intracorporeal suture for esophagojejunostomy, we recommended the technique of single-layer running "trapezoid-shaped" suture. The cost-effectiveness was analyzed by comparing with conventional mechanical stapling.

METHODS

The study retrospectively reviewed the patients undergoing laparoscopic gastrectomy for gastric cancer from January 2010 to December 2021. The patients were divided into two cohorts based on the methods of intracorporeal esophagojejunostomy: manual suture versus stapling suture. Propensity score matching was performed to match patients from the two cohorts at a ratio of 1:1. Then group comparison was made to determine whether manual suture was non-inferior to stapling suture in terms of operation time, anastomotic complications, postoperative hospital stay, and surgical cost.

RESULTS

The study included 582 patients with laparoscopic total gastrectomy. The manual and stapling suture for esophagojejunostomy were performed in 50 and 532 patients, respectively. In manual suture cohort, the median time for the whole operation and digestive tract reconstruction were 300 min and 110 min. There was no anastomotic bleeding and stenosis but two cases of anastomotic leak which occurred at 3 days after surgery. The median length of postoperative hospital stay was 11 days. After propensity score matching, group comparison yielded two variables with statistical significance: time for digestive tract reconstruction and surgery cost. The manual suture cohort spent less money but more time for esophagojejunostomy. Intriguingly, the learning curve of manual suture revealed that the time for digestive tract reconstruction was declined with accumulated number of operations.

CONCLUSIONS

Laparoscopic single-layer running "trapezoid-shaped" suture appears safe and cost-effective for intracorporeal esophagojejunostomy after total gastrectomy. Although the concern remains about prolonged operation time for beginners of performing the suture method, adequate practice is expected to shorten the operation time based on our learning curve analysis.

[Evaluation of resistance to transient occlusion of anterior mesenteric artery under the influence of the course of mineral water enriched with selenium (experimental research)]

OBJECTIVE

To evaluate the effect of the preventive course of drinking mineral water enriched with selenium on the processes of resistance to the damaging action of reversible occlusion of the anterior mesenteric artery based on the comparison of intestinal morphological changes in the experiment.

MATERIAL AND METHODS

There has been modeled ischemic reperfusion injury of the intestinal wall according to H. Ikeda and co-authors using reversible occlusion of the anterior mesenteric artery with 33 outbred male rats. The rats were divided into four groups by block randomization: the 1^st group - intact animals (n=7) - without an exposure; the control group - sham operated animals (n=6); the group of comparison (n=7) - with a model-operation; the experimental group (n=11) - animals with a model operation that had courses of intragastric watering of bottled sulfate-chloride-hydrocarbonate-sodium low-mineralized (2.2 g/l) drinking mineral water «Psyzh» enriched with selenium. Biopsies of the small intestine were taken for histological examination.

RESULTS

Histological examination of the small intestine of experimental animals determines various degrees of severity of damage: on average, the animals of the experimental group on the scale of C.J. Chiu (1970) had the lowest degree of severity of pathological changes, the animals of the group of comparison - 1.4 times higher (p=0.02). That is, the effect of a preventive course of mineral water «Psyzh» enriched with selenium was manifested in the formation of resistance to the damaging effect of reversible occlusion of the anterior mesenteric artery; in the presence of ischemic reperfusion damage to the intestinal wall, comparable in severity to changes with the animals without prevention, the most significant positive effect was realized in the containment of reactive changes.

CONCLUSION

The effect of the preventive course of drinking mineral water «Psyzh» enriched with selenium manifested itself in the formation of resistance to the damaging effect of reversible occlusion of the anterior mesenteric artery, which is the basis for introducing this technique into clinical practice in order to prevent the development of reperfusion injuries of the intestine.

Detrimental effect of intraoperative hypothermia on pancreatic fistula after pancreaticoduodenectomy: A single-centre retrospective study

BACKGROUND

Although perioperative hypothermia was found to be associated with gastrointestinal anastomotic leakage in preclinical studies, its association with postoperative pancreatic fistula (POPF) following pancreaticoduodenectomy was never evaluated. We investigated the association between intraoperative hypothermia and clinically relevant (CR)-POPF following pancreaticoduodenectomy.

METHODS

We retrospectively reviewed 2163 consecutive patients who underwent pancreaticoduodenectomy during 2007-2019. Based on intraoperative time-weighted average core temperature, patients were grouped into normothermia (36.0-37.5°C), mild hypothermia (35.0-<36.0°C), and severe hypothermia (<35°C). We conducted multivariable logistic regression analysis for CR-POPF, a propensity score analysis using inverse probability of treatment weighting (IPTW) to adjust the baseline differences between the three groups, followed by multivariable logistic regression with IPTW for CR-POPF.

RESULTS

Among the 2008 patients analysed, 1118 (55.7%) and 120 (6.0%) had mild and severe hypothermia, respectively, and 14.2% overall incidence of CR-POPF. Severe intraoperative hypothermia was significantly associated with CR-POPF before and after IPTW (before: odds ratio [OR] 1.79, 95% confidence interval [CI]: 1.03-3.09, P = .038; after: OR 2.48, 95% CI: 1.28-4.81, P = .007); however, mild hypothermia had no significant associations.

CONCLUSION

Severe intraoperative hypothermia is significantly associated with the occurrence of CR-POPF following pancreaticoduodenectomy, suggesting that hypothermia is deleterious on pancreaticojejunal anastomotic healing.

The immunologic changes during different phases of intestinal anastomotic healing

Intestinal anatomosis is a complex and multicellular process that involving three overlapped phases: exudative phase, proliferative phase, and reparative phase. Undisturbed anastomotic healings are crucial for the recovery of patients after operations but unsuccessful healings are linked with a considerable mortality. This time, we concentrate on the immunologic changes during different phases of intestinal anastomotic healing and select several major immune cells and cytokines of each phase to get a better understanding of these immunologic changes in different phases, which will be significant for more precise therapy strategies in anastomoses.