Experimental study to assess the impact of vasopressors administered during maintenance of the brain-dead donation in the quality of the intestinal graft

The role of sex hormones in the intestinal injury after brain death using a surgical menopause model in rats

Among transplantable organs, the intestine is one of the most challenging organs to transplant. While there is considerable research on the effects of brain death (BD), little is known about the specific intestinal changes that occur, particularly in females. Here we investigated the role of female sex hormones in the BD-induced intestinal inflammation, using an ovariectomy (OVx) model for sex hormones depletion. Wistar rats (female) were divided into four experimental groups: Control non-OVx - non-manipulated; Control-OVx -ovariectomized; BD non-OVx - animals submitted to BD (6h); BD-OVx -ovariectomized animals submitted to BD. OVx was performed 10 days before BD induction. non-OVx groups were chosen during proestrus phase (heat period). Inflammatory mediators and white blood cell count were quantified in the blood. Intestine tissue was sampled for histopathological analysis, myeloperoxidase (MPO) activity, Evans blue dye extravasation assay and immunohistochemistry. Results show higher intestinal injury in BD-OVx than BD non-OVx animals, presenting reduced crypt depth and increased serum inflammatory mediators. Independently from the previous hormonal status, BD increased intestinal inflammation, with higher leukocyte infiltration, MPO activity, ICAM-1 expression, and higher serum MIP-1α. In summary, BD modulates intestinal inflammation by increasing leukocyte mobilization. Whereas OVx, and its consequences on the female hormonal profile, influences homeostasis and BD-induced inflammation, increasing inflammatory mediators and altering intestinal morphology.

Intraoperative Initial Intracranial Pressure Demonstrates High Diagnostic Efficacy for Postoperative Intestinal Mucosal Barrier Dysfunction Following Severe Traumatic Brain Injury

OBJECTIVE

To investigate the risk factors and their diagnostic efficacy for postoperative intestinal mucosal barrier dysfunction (IBD) following severe traumatic brain injury (sTBI).

METHODS

There were 140 patients with sTBI enrolled in this study. Univariate and multivariate logistic regression analyses were conducted to assess the relationship between the clinical data and postoperative IBD in sTBI patients and determine the independent risk factors. The diagnostic efficacy of each risk factor was evaluated using the receiver operating characteristic curve and the area under the curve.

RESULTS

According to the diagnostic criteria for IBD, the 140 enrolled patients were classified into the IBD group (n = 60) and the non-IBD group (n = 80). The levels of intraoperative initial intracranial pressure (iICP) of patients with IBD were significantly higher compared with those of patients without IBD (P < 0.001). Furthermore, intraoperative iICP presented high diagnostic efficacy for postoperative IBD (area under the curve = 0.91, 95% confidence interval 0.85-0.96, P < 0.001). Patients with higher intraoperative iICP were more prone to suffering unfavorable neurological outcomes.

CONCLUSIONS

Intraoperative iICP could act as an independent and quantifiable predictor with high diagnostic efficacy for IBD in patients with sTBI after emergency surgery.

Intestinal transplantation: Significance of immune responses

Intestinal allografts, with many resident immune cells and as a destination for circulating lymphocytes of the recipient, appear to be the most challenging solid organ transplants. The high incidence of acute rejection and frequent reports of fatal graft-versus-host disease (GvHD) after intestinal transplantation call for more research to describe the molecular mechanisms involved in the immunopathogenesis of post-transplant complications to define new therapeutic targets. In addition, according to the rapid development of immunosuppressive agents, it is time to consider novel therapeutic approaches in managing treatment-refractory patients with rejection or severe GvHD. Herein, the main immunological challenges before and after intestinal transplant including, brain-dead donor inflammation, acute rejection, antibody-mediated, and chronic rejections, as well as GvHD have been described. Besides, the new immune-based therapies used in experimental and clinical settings to improve tolerance toward intestinal allograft, and cases of operational tolerance have been reviewed.

Luminal Preservation Protects the Small Intestine in a Brain-dead Rat Model

Intestinal transplantation depends on donation after brain death (DBD). Luminal preservation (LP) has been beneficial against preservation injury in previous studies in animal models, but none include DBD. This study aims to investigate whether these benefits occur also with DBD.