Identification of Perioperative Procedural and Hemodynamic Risk Factors for Developing Colonic Ischemia after Ruptured Infrarenal Abdominal Aortic Aneurysm Surgery: A Single-Centre Retrospective Cohort Study

(1) Background: This retrospective study evaluated perioperative and intensive care unit (ICU) variables to predict colonic ischemia (CI) after infrarenal ruptured abdominal aortic aneurysm (RAAA) surgery. (2) Materials and Methods: We retrospectively analyzed the data of the patients treated for infrarenal RAAA from January 2011 to December 2020 in our hospital. (3) Results: A total of 135 (82% male) patients were admitted to ICU after treatment of infrarenal RAAA. The median age of all patients was 75 years (IQR 68-81 years). Of those, 24 (18%) patients developed CI, including 22 (92%) cases within the first three postoperative days. CI was found more often after open repair compared to endovascular treatment (22% vs. 5%, p = 0.021). Laboratory findings in the first seven PODs revealed statistically significant differences between CI and non-CI patients for serum lactate, minimum pH, serum bicarbonate, and platelet count. Norepinephrine (NE) was used in 92 (68%) patients during ICU stay. The highest daily dose of norepinephrine was administered to CI patients at POD1. Multivariable analysis revealed that NE > 64 µg/kg (RD 0.40, 95% CI: 0.25-0.55, p < 0.001), operating time ≥ 200 min (RD 0.18, 95% CI: 0.05-0.31, p = 0.042), and pH < 7.3 (RD 0.21, 95% CI: 0.07-0.35, p = 0.019), significantly predicted the development of CI. A total of 23 (17%) patients died during the hospital stay, including 8 (33%) patients from the CI group and 15 (7%) from the non-CI group (p = 0.032). (4) Conclusions: CI after RAAA is a sever complication occurring most frequently within the first 3 postoperative days. Our study identified many surrogate markers associated with colonic ischemia after aortic RAAA, including norepinephrine dose > 64 µg/kg, operating time ≥ 200 min, and PH < 7.3. Future studies are needed to support these results.

Contribution of Blood Vessel Activation, Remodeling and Barrier Function to Inflammatory Bowel Diseases

Inflammatory bowel diseases (IBDs) consist of a group of chronic inflammatory disorders with a complex etiology, which represent a clinical challenge due to their often therapy-refractory nature. In IBD, inflammation of the intestinal mucosa is characterized by strong and sustained leukocyte infiltration, resulting in the loss of epithelial barrier function and subsequent tissue destruction. This is accompanied by the activation and the massive remodeling of mucosal micro-vessels. The role of the gut vasculature in the induction and perpetuation of mucosal inflammation is receiving increasing recognition. While the vascular barrier is considered to offer protection against bacterial translocation and sepsis after the breakdown of the epithelial barrier, endothelium activation and angiogenesis are thought to promote inflammation. The present review examines the respective pathological contributions of the different phenotypical changes observed in the microvascular endothelium during IBD, and provides an overview of potential vessel-specific targeted therapy options for the treatment of IBD.

Global trend and future landscape of intestinal microcirculation research from 2000 to 2021: A scientometric study

BACKGROUND

The intestinal microcirculation functions in food absorption and metabolic substance exchanges. Accumulating evidence indicates that intestinal microcirculatory dysfunction is a significant source of multiple gastrointestinal diseases. To date, there has not been a scientometric analysis of intestinal microcirculatory research.

AIM

To investigate the current status, development trends, and frontiers of intestinal microcirculatory research based on bibliometric analysis.

METHODS

VOSviewer and CiteSpace 6.1.R2 were used to identify the overall characteristics and knowledge map of intestinal microcirculatory research based on the core literature published from 2000 to 2021 in the Web of Science database. The characteristics of each article, country of origin, institution, journal, cocitations, and other information were analyzed and visualized.

RESULTS

There were 1364 publications enrolled in the bibliometric analysis, exhibiting an upward trend from 2000 to 2021 with increased participation worldwide. The United States and Dalhousie University took the lead among countries and institutions, respectively. Shock was the most prolific journal, and Nature Reviews Microbiology Clinical had the most citations. The topical hotspots and frontiers in intestinal microcirculatory research were centered on the pathological processes of functional impairment of intestinal microvessels, diverse intestinal illnesses, and clinical treatment.

CONCLUSION

Our study highlights insights into trends of the published research on the intestinal microcirculation and offers serviceable guidance to researchers by summarizing the prolific areas in intestinal disease research to date.

General anesthesia bullies the gut: a toxic relationship with dysbiosis and cognitive dysfunction

Perioperative neurocognitive disorder (PND) is a common surgery outcome affecting up to a third of the elderly patients, and it is associated with high morbidity and increased risk for Alzheimer's disease development. PND is characterized by cognitive impairment that can manifest acutely in the form of postoperative delirium (POD) or after hospital discharge as postoperative cognitive dysfunction (POCD). Although POD and POCD are clinically distinct, their development seems to be mediated by a systemic inflammatory reaction triggered by surgical trauma that leads to dysfunction of the blood-brain barrier and facilitates the occurrence of neuroinflammation. Recent studies have suggested that the gut microbiota composition may play a pivotal role in the PND development by modulating the risk of neuroinflammation establishment. In fact, modulation of gut microbiome composition with pre- and probiotics seems to be effective for the prevention and treatment of PND in animals. Interestingly, general anesthetics seem to have major responsibility on the gut microbiota composition changes following surgery and, consequently, can be an important element in the process of PND initiation. This concept represents an important milestone for the understanding of PND pathogenesis and may unveil new opportunities for the development of preventive or mitigatory strategies against the development of these conditions. The aim of this review is to discuss how anesthetics used in general anesthesia can interact and alter the gut microbiome composition and contribute to PND development by favoring the emergence of neuroinflammation.

Malaria-induced bacteremia as a consequence of multiple parasite survival strategies

Globally, malaria continues to be an enormous public health burden, with concomitant parasite-induced damage to the gastrointestinal (GI) barrier resulting in bacteremia-associated morbidity and mortality in both adults and children. Infected red blood cells sequester in and can occlude the GI microvasculature, ultimately leading to disruption of the tight and adherens junctions that would normally serve as a physical barrier to translocating enteric bacteria. Mast cell (MC) activation and translocation to the GI during malaria intensifies damage to the physical barrier and weakens the immunological barrier through the release of enzymes and factors that alter the host response to escaped enteric bacteria. In this context, activated MCs release Th2 cytokines, promoting a balanced Th1/Th2 response that increases local and systemic allergic inflammation while protecting the host from overwhelming Th1-mediated immunopathology. Beyond the mammalian host, recent studies in both the lab and field have revealed an association between a Th2-skewed host response and success of parasite transmission to mosquitoes, biology that is evocative of parasite manipulation of the mammalian host. Collectively, these observations suggest that malaria-induced bacteremia may be, in part, an unintended consequence of a Th2-shifted host response that promotes parasite survival and transmission. Future directions of this work include defining the factors and mechanisms that precede the development of bacteremia, which will enable the development of biomarkers to simplify diagnostics, the identification of therapeutic targets to improve patient outcomes and better understanding of the consequences of clinical interventions to transmission blocking strategies.

ECOG and BMI as preoperative risk factors for severe postoperative complications in ovarian cancer patients: results of a prospective study (RISC-GYN-trial)

BACKGROUND

Accompanying co-morbidities in patients with ovarian cancer are of major relevance for scheduling debulking surgery, especially in the anesthesiological consultations. Aim of this study was to evaluate the impact of co-morbidities and patient characteristics on postoperative complications.

METHODS

Patients undergoing maximal cytoreductive surgery were prospectively enrolled from October 2015 to January 2017. Various variables were recorded, such as the Charlson comorbidity index, Eastern cooperative oncology group scale of performance status (ECOG PS) and the American society of anesthesiologists physical status classification system (ASA PS). Surgical complications were graded using the Clavien-Dindo criteria. Logistic regression models were used to analyze risk factors for severe postoperative complications.

RESULTS

Of 106 enrolled patients, 19 (17.9%) developed severe postoperative complications grade ≥ IIIb according to Clavien-Dindo criteria. In the multivariable regression analysis impaired (ECOG PS) > 1 (odds ratio OR) 13.34, 95% confidence interval (CI) 1.74-102.30, p = 0.01), body mass index (BMI) > 25 kg/m² (OR 10.48, 95% CI 2.38-46.02, p = 0.002) along with the use of intraoperative norepinephrine > 0.11 µg/kg/min (OR 4.69, 95% CI 1.13-19.46, p = 0.03) and intraoperative fresh frozen plasma (FFP) > 17 units (OR 4.11, 95% CI 1.12-15.14, p = 0.03) appeared as significant predictors of severe postoperative complications.

CONCLUSION

We demonstrated that neither the presence of a certain comorbidity nor the summation of the co-morbidities were associated with adverse outcome. Patient characteristics, such as ECOG PS > 1 and obesity (BMI > 25 kg/m²), are highly predictive factors for severe postoperative complications. The analysis of intraoperative data showed that the need for more than > 0.11 µg/kg/min of norepinephrine and transfusions of FFPs more than 17 units were strongly associated with severe postoperative complications.

Role of predictive markers for severe postoperative complications in gynecological cancer surgery: a prospective study (RISC-Gyn Trial)

BACKGROUND

Surgery for gynecological cancer involves highly invasive and complex procedures potentially associated with various complications, which can cause extended hospital stays and delay of subsequent therapy, with a detrimental effect on the prognosis. The aim of this study was to explore and define the predictors of severe postoperative complications in patients undergoing surgery for gynecologic cancer.

METHODS

Patients undergoing surgery for gynecologic cancers were analyzed prospectively from October 2015 through January 2017. Using validated assessment tools preoperatively, we assessed comorbidities, performance status, quality of life, nutritional and body composition by bioelectrical impedance analysis, and the surgical data of each patient. Surgical complications were graded using the Clavien-Dindo criteria. Using stepwise logistic regression models, we identified predictive markers for postoperative complications.

RESULTS

Of the 226 enrolled patients, 40 (17.7%) experienced a grade ≥IIIb complication according to the Clavien-Dindo criteria. In the regression analysis, overweight/obesity (body mass index >25) (OR 6.41, 95% CI 2.38 to 17.24; p<0.001) and impaired physical functioning defined by a quality of life questionnaire (OR 4.19, 95% CI 1.84 to 9.50; p=0.001) emerged as significant predictors of postoperative complications. Moreover, postoperative complications were predicted by phase angle of bioelectrical impedance analysis <4.75° (OR 3.11, 95% CI 1.35 to 7.16; p=0.008) and Eastern Cooperative Oncology Group (ECOG) performance status >1 (OR 2.51, 95% CI 1.06 to 5.92; p=0.04). Intraoperative factors associated with higher risk of postoperative complications were increased use of norepinephrine (>11 µg/kg/min) (OR 5.59, 95% CI 2.16 to 14.44; p<0.001) and performance of large bowel resection (OR 4.28, 95% CI 1.67 to 10.97; p=0.002).

CONCLUSION

In patients undergoing surgery for gynecological cancer, preoperative evaluation of performance status according to ECOG, domains of quality of life and nutritional status, as well as intraoperative monitoring of risk factors, might help to identify patients at high risk for severe postoperative complications, and thus reduce surgical morbidity and mortality.

Metabolites of Tryptophane and Phenylalanine as Markers of Small Bowel Ischemia-Reperfusion Injury

Ischemic-reperfusion injury of the small intestine is an acute clinical condition with high mortality rate. This study describes the changes in levels of phenylalanine and tryptophan metabolites in intestinal homogenates and urine samples of Wistar male rats after 60 minutes of mesenteric ischemia and different reperfusion periods (1, 24, 30 hours) in comparison with a control group without the ischemia. The ischemic-reperfusion injury was quantified by the histopathological injury index. The levels of serotonin, epinephrine, and norepinephrine were determined in the intestinal homogenate and epinephrine, vanillylmandelic acid, and the 5-hydroxyindoleacetic acid was analyzed in urine using the HPLC method. The statistically significant increased level of serotonin, epinephrine and norepinephrine were detected in the intestinal samples after 24 hours of reperfusion (p<0.01); even the most elevated serotonin level was observed after one hour of reperfusion (p<0.001). A statistically significant decreased level of vanillylmandelic acid was observed after one hour of reperfusion, but it significantly increased after 24 hours (p<0.05) in urine. The elevated level of the 5-hydroxyindoleacetic acid after one hour and 24 hours after reperfusion (p<0.05) were determined in the urine. The most significant elevated epinephrine level was observed after 24 hours of reperfusion (p<0.001) in urine. Results showed a potential role of serotonin as an early biomarker (after one hour of reperfusion) of small intestinal damaged homogenate, while the best predictor of intestinal injury in urine was epinephrine, which was elevated after 24 hours.

Peripheral corticotropin-releasing factor receptor type 2 activation increases colonic blood flow through nitric oxide pathway in rats

BACKGROUND

Corticotropin-releasing factor (CRF) peptides exert profound effects on the secretomotor function of the gastrointestinal tract. Nevertheless, despite the presence of CRF peptides and receptors in colonic tissue, their influence on colonic blood flow (CBF) is unknown.

AIM

To determine the effect and mechanism of members of the CRF peptide family on CBF in isoflurane-anesthetized rats.

METHODS

Proximal CBF was measured with laser-Doppler flowmetry simultaneously with mean arterial blood pressure (MABP) measurement. Rats were injected with intravenous human/rat CRF (CRF1 > CRF2 affinity), mouse urocortin 2 (mUcn2, selective CRF2 agonist), or sauvagine (SVG, CRF2 > CRF1 affinity) at 1-30 µg/kg. The nitric oxide (NO) synthase inhibitor, L-NAME (3 mg/kg, iv), the cyclooxygenase inhibitor, indomethacin (Indo, 5 mg/kg, ip), or selective CRF2 antagonist, astressin2-B (Ast2B, 50 µg/kg, iv) was given before SVG injection (10 µg/kg, iv).

RESULTS

SVG and mUcn2 dose-dependently increased CBF while decreasing MABP and colonic vascular resistance (CVR). CRF had no effect on CBF, but increased CVR. The hyperemic effect of SVG was inhibited by L-NAME but not by Indo, whereas hypotension was partially reduced by L-NAME. Sensory denervation had no effect on SVG-induced changes. Ast2B inhibited SVG-induced hyperemia and decreased CVR, and partially reduced the hypotension.

CONCLUSIONS

Peripheral CRF2 activation induces colonic hyperemia through NO synthesis, without involving prostaglandin synthesis or sensory nerve activation, suggesting a direct action on the endothelium and myenteric neurons. Members of the CRF peptide family may protect the colonic mucosa via the activation of the CRF2 receptor.

Necrotizing enterocolitis and the role of anemia of prematurity

Necrotizing enterocolitis (NEC) is one of the most common surgical diseases of preterm infants, with significant short- and long-term morbidity and mortality. Although the etiology of NEC remains elusive, multiple factors adversely affecting the intestinal mucosal integrity of preterm infants are known to be associated with NEC. Anemia and red blood cell (RBC) transfusion-related gut injury have been shown to have strong correlation with NEC. Anemia potentially compromises mucosal integrity with subsequent poor healing, and this injury may be augmented by yet unknown factors associated with RBC transfusions. Although convincing evidence is lacking, there is a need for guidelines to keep the hematocrit within clinically and physiologically relevant limits by appropriate interventions. Further investigations need to focus on assessing the interplay between anemia, chronically hypoxemic/hypoperfused intestines, and early iron therapy or other pharmacologic approaches for prevention/treatment of anemia and RBC transfusions.