Current status on plasma biomarkers for acute mesenteric ischemia

Mesenteric Ischemia after Cardiac Surgery

BACKGROUND

 Mesenteric ischemia (Me-Is) after cardiac surgery is underreported in present literature but has still earned the bad reputation of a dismal prognosis. This study adds clinical outcomes in a large patient cohort.

METHODS

 Between 2009 and 2019 of the 22,590 patients undergoing cardiac surgery at our facility 106 (0.47%) developed Me-Is postoperatively. Retrospective patient data was analyzed. Additionally, patients were stratified by outcome-survivors and nonsurvivors.

RESULTS

 Patients were predominantly male (n = 68, 64.2%), mean age was 71.2 ± 9.3 years. Most procedures were elective (n = 85, 80.2%) and comprised of more complex combined procedures (50.9%) and redos (17.9%). Mean EuroSCORE II averaged 10.9 ± 12.2%. Survival at 30 days was 49.1% (n = 52). Clinical baseline and procedural characteristics did not differ significantly between survivors and nonsurvivors. The median postoperative interval until symptom onset was 5 days in both groups. Survivors were more frequently diagnosed by computed tomography and nonsurvivors based on clinical symptoms. Me-Is was predominantly nonocclusive (n = 84, 79.2%). Laparotomy was the main treatment in both groups (n = 45, 78.8% vs. n = 48, 88.9%, p = 0.94). Predictors of mortality were maximum norepinephrine doses (hazard ratio [HR] 8.29, confidence interval [CI] 3.39-20.26, p < 0.0001), lactate levels (HR 1.06, CI 1.03-1.09), and usage of inotropes (HR 2.46, CI 1.41-4.30).

CONCLUSION

 The prognosis of Me-Is following cardiac surgery is poor-independently from diagnostic or treatment patterns. There exists a significant asymptomatic time period postoperatively, in which pathophysiologic processes seem to cross the Rubicon. After clinical demarcation, the further course can almost no longer be influenced.

Irreversible Transmural Intestinal Necrosis in Acute Mesenteric Ischemia: Retrospective Cohort Study from a High-Volume Hospital

Background: Owing to the low incidence rate and nonspecific symptoms of acute mesenteric ischemia (AMI), the identification and prediction of irreversible transmural intestinal necrosis (ITIN) and extensive bowel resection (≥100 cm) (EBR) are difficult and critical. This study aimed to investigate the risk factors for ITIN and EBR in patients with AMI. Methods: The clinical data of 254 AMI patients were retrospectively analyzed. Furthermore, the incidence of ITIN and EBR were set as dependent variables, and relevant risk factors were screened using univariate and multivariate logistic regression analyses. The comparisons of surgical characteristics and postoperative recovery outcomes between the EBR and control group were also conducted. Results: The presence of hemorrhagic (odds ratio [OR] = 28.356, P < .001) or other types ascites (OR = 13.051, P = .003), peritonitis (OR = 8.463, P = .005), intestinal diameter >2.35 cm (OR = 5.493, P = .020), and serum creatinine (CREA) >95 μmol/L (OR = 4.866, P = .048) were identified as independent risk factors for ITIN in patients with AMI. In addition, serum C-reactive protein (CRP) >15 mg/L (OR = 38.023, P = .006), and CREA >100 μmol/L (OR = 6.248, P = .035) were proved to be independently associated with EBR for ITIN cases. Compared to the control group, EBR significantly increased the likelihood of requiring enterostomy (P = .001), blood transfusion (P = .002), and transfer to intensive care unit (P = .016), while also prolonging the recovery time for intestinal function (P = .014). Conclusions: The presence of ascites, peritonitis, intestinal diameter >2.35 cm, and serum CREA >95 μmol/L were independently correlated with ITIN for AMI cases, while serum CRP >15 mg/L and CREA >100 μmol/L independently increased the risk of EBR.

Is there a faster and easier method for assessing the severity of acute mesenteric ischemia?

Acute mesenteric ischemia (AMI) is a potentially fatal abdominal emergency. The estimation of the severity of AMI is of great importance since changes in disease severity may have different impacts on the treatment options. This study aims to define laboratory and radiological parameters that can successfully predict the severity of AMI. Data from 100 patients who were treated conservatively and underwent an operation with a diagnosis of AMI between the years 2010 and 2019 were reviewed. The patients were divided into 3 groups as those treated with a conservative approach (group 1), those with partial intestinal ischemia (group 2), and those with complete intestinal ischemia (group 3) according to the pathology results. Laboratory findings of the patients were recorded and matched with radiological findings. The white blood cell (WBC) count, neutrophil (NEUT) count, neutrophil/lymphocyte ratio, and C-reactive protein/albumin ratios were the considered distinctive parameters for distinguishing the third group from the first group. However, the same result cannot be applied to the first and the second groups since only the WBC and NEUT counts showed distinctive performance. The measurement of neutrophil/lymphocyte ratio, WBC, NEUT, and albumin levels can be used to predict the severity of AMI. We believe that evaluating these laboratory parameters will greatly prevent possible morbidity and mortality in the patient. Also, we were able to observe that the parameters used in predicting AMI severity can be verified with rapid and low-cost radiological imaging techniques.

Exploring D-Lactate as a Biomarker for Acute Intestinal Necrosis in 2958 Patients: A Prospective Cross-Sectional Study

BACKGROUND

Timely diagnosis of acute intestinal necrosis (AIN) is lifesaving, but challenging due to unclear clinical presentation. D-lactate has been proposed as an AIN biomarker.

OBJECTIVES

We aimed to test the diagnostic performance in a clinical setting.

METHODS

We performed a cross-sectional prospective study, including all adult patients with acute referral to a single tertiary gastrointestinal surgical department during 2015-2016 and supplemented by enrollment of high-risk in-hospital patients suspected of having AIN during 2016-2019. AIN was verified intraoperatively, and D-lactate was analyzed using an automatic spectrophotometric set-up. A D-lactate cut-off for AIN was estimated using the receiver operating characteristic curve. The performance according to patient subgroups was estimated using the area under the receiver operating characteristic curve (AUC). Given the exploratory nature of this study, a formal power calculation was not feasible.

RESULTS

Forty-four AIN patients and 2914 controls were enrolled. The D-lactate cut-off was found to be 0.0925 mM. Due to lipemic interference, D-lactate could not be quantified in half of the patients, leaving 23 AIN patients and 1456 controls for analysis. The AUC for the diagnosis of AIN by D-lactate was 0.588 (95% confidence interval 0.475-0.712), with a sensitivity of 0.261 and specificity of 0.892. Analysis of high-risk patients showed similar results (AUC 0.579; 95% confidence interval 0.422-0.736).

CONCLUSION

D-lactate showed low sensitivity for AIN in both average-risk and high-risk patients. Moreover, lipemic interference precluded valid spectrophotometric assessment of D-lactate in half of the patients, further disqualifying the clinical utility of D-lactate as a diagnostic marker for AIN.

The Diagnostic Value of Biomarkers in Acute Mesenteric Ischaemia Is Insufficiently Substantiated: A Systematic Review

OBJECTIVE

There is an urgent need for accurate biomarkers to support timely diagnosis of acute mesenteric ischaemia (AMI) and thereby improve clinical outcomes. With this systematic review, the aim was to substantiate the potential diagnostic value of biomarkers for arterial occlusive AMI.

DATA SOURCES

The Pubmed, Embase, and the Cochrane Library electronic databases were searched.

REVIEW METHODS

A systematic review of the literature has been conducted to define the potential diagnostic value of biomarkers for arterial occlusive AMI. All studies including ≥ 10 patients describing biomarkers for macrovascular occlusive AMI between 1950 and 17 February 2023 were identified within the Pubmed, Embase, and the Cochrane Library electronic databases. There were no restrictions to any particular study design, but letters and editorials were excluded. The QUADAS-2 tool was used for the critical appraisal of quality. The study protocol was registered on Prospero (CRD42021254970).

RESULTS

Fifty of 4334 studies were eligible for inclusion in this review. Ninety per cent of studies were of low quality. A total of 60 biomarkers were identified, with 24 in two or more studies and 15 in five or more studies. There was variation in reported units, normal range, and cut off values. Meta-analysis was not possible due to study heterogeneity. Biomarkers currently recommended by the European Journal of Vascular and Endovascular Surgery, European Society for Trauma and Emergency Surgery 2016, and World Society of Emergency Surgery 2017 guidelines also had heterogeneous low quality data for use in the diagnosis of AMI.

CONCLUSION

This systematic review demonstrates high heterogeneity and low quality of the available evidence on biomarkers for arterial occlusive AMI. No clinical conclusions can be drawn on a biomarker or combination of biomarkers for patients suspected of arterial occlusive AMI. Restraint is advised when rejecting or determining AMI solely based on biomarkers.

Trends in population-based incidence, diagnostics, and mortality of acute superior mesenteric artery occlusion

Acute occlusion of the superior mesenteric artery (SMA) results in lethal intestinal ischemia. Results from two previous population-based studies in Malmö, Sweden, suggest a decreasing incidence of acute SMA occlusion. This study aimed to evaluate trends in the epidemiology of acute SMA occlusion in Malmö. The report was a retrospective population-based study conducted from 2014 to 2019 on patients with acute SMA occlusion residing in Malmö municipality. Patient data were retrieved from Skåne University Hospital and postmortem examinations. Epidemiological data were compared to those of the two earlier studies, in particular to the one conducted from 2000 to 2006. Sixteen patients with acute SMA occlusion resided in Malmö municipality. The incidence of acute SMA occlusion significantly decreased from 5.4/100,000 person-years to 0.8/100,000 person-years. The ratio of acute SMA occlusion to non-occlusive mesenteric ischemia (NOMI) decreased from 12.5:1 to 0.9:1 (p < 0.0001), the proportion of inhabitants aged 80 years or above in the population decreased from 6.0% to 4.3% (p < 0.0001), and the autopsy rate decreased from 25% to 14% (p < 0.0001). The in-hospital mortality rate decreased from 63% to 44% (p = 0.14). The incidence of acute SMA occlusion seems to have decreased significantly in Malmö, probably due to high-resolution computed tomography angiographies being available around the clock to distinguish acute SMA occlusion from NOMI, a reduced proportion of elderly individuals, improved control of medical risk factors, and a decrease in autopsy rates.

Acute Mesenteric Ischemia: The Diagnostic Value of QT Parameters and their Relationship with CT Findings

BACKGROUND

One of the greatest challenges in the diagnosis of acute mesenteric ischemia (AMI) is the lack of specific laboratory tests that support multidetector computed tomography (CT). Our aim is to investigate the diagnostic value of electrocardiographic QT parameters in AMI and their relationship with CT findings.

MATERIALS AND METHODS

Patients who were admitted to the emergency department with abdominal pain were recruited retrospectively from the hospital information system. Grouping was carried out on the basis of AMI (n=78) and non-AMI (n=78). In both groups, the corrected QT (QTc) and QT dispersion (QTD) were measured on electrocardiographs, and the qualitative and quantitative CT findings were evaluated on CT examinations.

RESULTS

The QTc and QTD values were higher in the AMI group. The median QTc values were 456.16 (IQR: 422.88-483.16) for the AMI group and 388.83 (IQR: 359.74-415.83) for the control group (p<0.001), and the median QTD values were 58 (IQR: 50.3-68.25) for the AMI group and 46 (IQR: 42-50) for the control group (p<0.001). In the CT analysis, the QTc values were significantly higher among AMI patients, with images of paper-thin bowel walls and the absence of bowel wall enhancement (p=0.042 and p=0.042, respectively). Meanwhile, the QTD values were significantly higher among patients with venous pneumatosis findings on CT (p=0.005). In the regression analysis, a significant relationship was found between the QT parameters and AMI (p<0.001). For QTc, an AUC of 0.903 (95% CI: 0.857-0.950, p<0.001), a sensitivity of 80.8%, and a specificity of 82.3% were found. For QTD, an AUC of 0.821 (95% CI: 0.753-0.889, p<0.001), a sensitivity of 73.1%, and a specificity of 82.3% were found.

CONCLUSION

We found the QTc and QTD values to be significantly higher among AMI patients. Furthermore, we found a significant relationship between the CT findings and QTc and QTD and a significant relationship between survival and QTc in the AMI group.

Diagnostic accuracy of biomarkers to detect acute mesenteric ischaemia in adult patients: a systematic review and meta-analysis

BACKGROUND

Acute mesenteric ischaemia (AMI) is a disease with different pathophysiological mechanisms, leading to a life-threatening condition that is difficult to diagnose based solely on clinical signs. Despite widely acknowledged need for biomarkers in diagnosis of AMI, a broad systematic review on all studied biomarkers in different types of AMI is currently lacking. The aim of this study was to estimate the diagnostic accuracy of all potential biomarkers of AMI studied in humans.

METHODS

A systematic literature search in PubMed, The Cochrane Library, Web of Science and Scopus was conducted in December 2022. Studies assessing potential biomarkers of AMI in (at least 10) adult patients and reporting their diagnostic accuracy were included. Meta-analyses of biomarkers' sensitivity, specificity, and positive and negative likelihood ratios were conducted. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed, and the study quality was assessed with the QUADAS-2 tool.

RESULTS

Seventy-five studies including a total of 9914 patients assessed 18 different biomarkers in serum/plasma and one in urine (each reported in at least two studies), which were included in meta-analyses. None of the biomarkers reached a conclusive level for accurate prediction. The best predictive value overall (all studies with any type and stage of AMI pooled) was observed for Ischaemia-modified albumin (2 studies, sensitivity 94.7 and specificity 90.5), interleukin-6 (n = 4, 96.3 and 82.6), procalcitonin (n = 6, 80.1 and 86.7), and intestinal fatty acid-binding protein (I-FABP) measured in serum (n = 16, 73.9 and 90.5) or in urine (n = 4, 87.9 and 78.9). In assessment of transmural mesenteric ischaemia, urinary I-FABP (n = 2, 92.3 and 85.2) and D-dimer (n = 3, 87.6 and 83.6) showed moderate predictive value. Overall risk of bias was high, mainly because of selected study populations and unclear timings of the biomarker measurements after onset of symptoms. Combinations of biomarkers were rarely studied, not allowing meta-analyses.

CONCLUSIONS

None of the studied biomarkers had sufficient sensitivity and specificity to diagnose AMI, although some biomarkers showed moderate predictive accuracy. Future studies should focus on timing of measurements of biomarkers, distinguishing between early stage and transmural necrosis, and between different types of AMI. Additionally, studies on combinations of biomarkers are warranted. PROSPERO registration: CRD42022379341.

Results after intraoperative open and endovascular revascularization of acute mesenteric ischemia requiring a laparotomy

BACKGROUND

Acute mesenteric ischemia (AMI) is a dreaded condition with a difficult diagnosis and high mortality. Due to different baseline situations, the frequently performed comparison between endovascular and open surgical treatment is interfered with selection bias. The purpose of this study was to review outcomes in AMI treatment with an open or endovascular approach in association with laparotomy and to evaluate the endovascular-first strategy in similar clinical situations.

METHODS

The clinical data of 74 patients treated for AMI from 2007 to 2021 were retrospectively reviewed and compared. In-hospital mortality was appointed as the primary study endpoint. Risk factors for mortality were identified by using univariate and multivariate analysis.

RESULTS

In total, 61 patients (82%) were treated open surgically (OT) and, 13 patients (18%) with an endovascular approach (ET) in combination with laparatomy. The etiology of AMI was 49% arteriosclerotic and 51% thromboembolic occlusions. The total in-hospital mortality manifested at 43% (n =32) (OT 41% vs. ET 53.8%; P=0.54). As independent risk factors for in-hospital mortality, pneumatosis intestinalis (P=0.01), increased lactate concentration (P=0.04), and ischemic intestinal sections (P=0.01) were identified. Additionally, on univariate analysis patient age, congestive heart failure (> NYHA II) and atrial fibrillation were related with higher mortality.

CONCLUSIONS

Morbidity and mortality of AMI remains at a high level. Conventional open or intraoperative endovascular therapy achieved similar results in patients with indication for laparotomy. Advanced disease stage with ischemic intestinal sections at presentation and cardiovascular comorbidities were associated with adverse outcome.

Impairment of Mesenteric Perfusion as a Marker of Major Bleeding in Trauma Patients

The majority of potentially preventable mortality in trauma patients is related to bleeding; therefore, early recognition and effective treatment of hemorrhagic shock impose a cardinal challenge for trauma teams worldwide. The reduction in mesenteric perfusion (MP) is among the first compensatory responses to blood loss; however, there is no adequate tool for splanchnic hemodynamic monitoring in emergency patient care. In this narrative review, (i) methods based on flowmetry, CT imaging, video microscopy (VM), measurement of laboratory markers, spectroscopy, and tissue capnometry were critically analyzed with respect to their accessibility, and applicability, sensitivity, and specificity. (ii) Then, we demonstrated that derangement of MP is a promising diagnostic indicator of blood loss. (iii) Finally, we discussed a new diagnostic method for the evaluation of hemorrhage based on exhaled methane (CH₄) measurement. Conclusions: Monitoring the MP is a feasible option for the evaluation of blood loss. There are a wide range of experimentally used methodologies; however, due to their practical limitations, only a fraction of them could be integrated into routine emergency trauma care. According to our comprehensive review, breath analysis, including exhaled CH₄ measurement, would provide the possibility for continuous, non-invasive monitoring of blood loss.

High risk and low prevalence diseases: Mesenteric ischemia

INTRODUCTION

Mesenteric ischemia is a rare, frequently misdiagnosed, serious condition that carries with it a high rate of morbidity and mortality.

OBJECTIVE

This review highlights the pearls and pitfalls of mesenteric ischemia, including presentation, diagnosis, and management in the emergency department (ED) based on current evidence.

DISCUSSION

Mesenteric ischemia is an abdominal vascular emergency that includes superior mesenteric arterial embolism, arterial thrombosis, venous mesenteric ischemia, and non-occlusive mesenteric ischemia. It is associated with a variety of risk factors including older age, cardiovascular disease, hypercoagulable state, and end-stage renal disease. The presentation depends on the underlying pathophysiology. While arterial embolic disease may present with sudden, severe pain, the early stages of the disease and other forms can present with vague symptoms, including generalized abdominal pain, weight loss, vomiting, and diarrhea. Laboratory testing can suggest the disease with leukocytosis and elevated lactate, but normal values should not be used to exclude the diagnosis. The imaging modality of choice is triple phase computed tomography with non-contrast, arterial, and delayed phases. The initial ED management includes fluid resuscitation, symptomatic therapy, broad-spectrum antibiotics, and anticoagulation. Emergent consultation with a multidisciplinary team including diagnostic and interventional radiologists and cardiovascular and general surgeons is necessary for definitive treatment.

CONCLUSIONS

An understanding of mesenteric ischemia can assist emergency clinicians in diagnosing and managing this disease.

Intra-Arterial Urokinase for Acute Superior Mesenteric Artery Occlusion: A Retrospective 12-Year Report of 13 Cases

This retrospective study aimed to evaluate the outcomes of 13 patients with acute superior mesenteric artery (SMA) occlusion who underwent intra-arterial urokinase thrombolysis between 2008 and 2020. On angiography, seven presented with complete SMA occlusion versus six with incomplete occlusion. The median time from abdominal pain to attempting urokinase thrombolysis was 15.0 h (interquartile range, 6.0 h). After urokinase therapy, bowel perfusion was restored with bowel preservation in six patients; however, treatment failed in the other seven patients. The degree of SMA occlusion (complete vs. incomplete, p = 0.002), degree of recanalisation (p = 0.012), and length of stay (p = 0.032) differed significantly between groups. Of the seven patients with complete SMA occlusion, six underwent bowel resection, of whom three died, and the remaining patient died of shock due to delayed surgery. Among the six patients with incomplete SMA occlusion, no bowel resection was performed. In our experience, intra-arterial urokinase thrombolysis may serve as an adjunctive treatment modality, being a potential replacement for open thrombectomy that is able to preserve the bowel and obviate surgery in cases of incomplete SMA occlusion; however, its use is unsuitable in cases of complete SMA occlusion, for which surgery is warranted.

Biomarkers of Intestinal Injury in Colic

Biomarkers are typically proteins, enzymes, or other molecular changes that are elevated or decreased in body fluids during the course of inflammation or disease. Biomarkers pose an extremely attractive tool for establishing diagnoses and prognoses of equine gastrointestinal colic, one of the most prevalent causes of morbidity and mortality in horses. This topic has received increasing attention because early diagnosis of some forms of severe colic, such as intestinal ischemia, would create opportunities for rapid interventions that would likely improve case outcomes. This review explores biomarkers currently used in equine medicine for colic, including acute phase proteins, proinflammatory cytokines, markers of endotoxemia, and tissue injury metabolites. To date, no single biomarker has been identified that is perfectly sensitive and specific for intestinal ischemia; however, L-lactate has been proven to be a very functional and highly utilized diagnostic tool. However, further exploration of other biomarkers discussed in this review may provide the key to accelerated identification, intervention, and better outcomes for horses suffering from severe colic.

Plasma α-Glutathione S-Transferase in Patients with Chronic Mesenteric Ischemia and Median Arcuate Ligament Syndrome

Background

Chronic mesenteric ischemia (CMI) due to either atherosclerosis of the mesenteric arteries or median arcuate ligament syndrome (MALS) is an underdiagnosed entity. The etiology of MALS and its existence have been debated and questioned. We aimed to identify plasma biomarkers indicating mesenteric ischemia in patients with CMI and MALS.

Methods

Plasma α-glutathione S-transferase (α-GST), intestinal fatty acid-binding protein (I-FABP), citrulline, and ischemia modified albumin (IMA) were analyzed in fifty-eight patients with CMI (Group A, n=44) and MALS (Group B, n=14) before and after revascularization. The plasma levels of these potential biomarkers were compared with those of healthy individuals (Group C, n=16). Group comparison was performed with the Mann–Whitney U-test. Cross-tabulation and its derivatives were obtained. Receiver operating characteristic (ROC) curves and area under the curve (AUC) were calculated.

Results

Plasma levels of α-GST were significantly raised in the patients with CMI (7.8 ng/mL, p<0.001) and MALS (8.4 ng/mL, p<0.001), as compared with the control Group C (3.3 ng/mL). The threshold for normal median plasma α-GST levels of 4 ng/mL yielded a sensitivity of 93% and 86%, specificity of 86% and 88%, respectively, for the diagnosis of CMI due to atherosclerosis and MALS. AUC of ROC curves was 0.96 (p<0.0001) for CMI and 0.85 (p<0.002) for MALS. The patient groups did not differ from the healthy controls in any other biomarkers.

Conclusion

Plasma α-GST levels are elevated in CMI and MALS patients. Elevated plasma levels of α-GST suggest ischemia as the etiology of MALS.

The Prognostic Value of C-Reactive Protein/Albumin Ratio in Acute Mesenteric Ischemia

Background

Diagnosis of acute mesenteric ischemia (AMI) in its early stages is important for reversing ischemic damage. The CRP to albumin (CRP/Alb) ratio has been defined as an inflammatory indicator and is associated with the severity of inflammation and mortality rates. However, the prognostic value of CRP/Alb has not been evaluated in patients with AMI. Here, we aimed to examine the prognostic significance of CRP/Alb and compare it with other inflammatory markers.

Materials and Methods

In this retrospective, case-control study, we included patients diagnosed with AMI at the emergency department between January 1, 2016, and December 31, 2020. In addition to demographic characteristics, lactate, D-dimer, white blood cell (WBC), CRP/Alb, and neutrophil/lymphocyte ratio (NLR) were recorded. Testing characteristics of CRP/Alb in predicting in-hospital mortality were studied.

Results

The mean age of 132 patients was 66.48 ± 15.95 years and 71 (53.8%) of them were male. The cut-off value obtained using the receiver operating characteristic (ROC) curve for in-hospital mortality was a CRP/Alb ratio of >1.32 (sensitivity, 93.65%; specificity, 69.57%; +LR, 3.08; −LR, .091; AUC, .782; 95% CI, .70-.85; P < .0001). The comparison of ROC curves between CRP/Alb and WBC, NLR, and lactate revealed a statistically significant difference ( P < .05), whereas there was not any statistically significant difference between the ROC curves of CRP/Alb and D-dimer ( P = .47).

Conclusion

C-reactive protein/albumin ratio is a powerful predictor of in-hospital mortality for AMI patients. It was superior to WBC, NLR, and lactate. It could be used to determine low-risk patients and help clinicians with treatment options.

Acute Mesenteric Ischemia in Patients with COVID-19: Review of the literature

The coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has resulted in a global health emergency. In addition to common respiratory symptoms, some patients with COVID-19 infections may experience a range of extra-pulmonary manifestations, such as digestive system involvement. Patients with COVID-19 have been reported to suffer from acute mesenteric ischemia (AMI) that is associated with disease-related severity and mortality. However, in the context of COVID-19, the exact cause of AMI has yet to be clearly defined. This review provides a comprehensive overview of the available data and elucidates the possible underlying mechanisms linking COVID-19 to AMI, in addition to highlighting therapeutic approaches for clinicians. Finally, given the severe global impact of COVID-19, we emphasize the importance of coordinated vaccination programs.

Tick-Tock Consider the Clock: The Influence of Circadian and External Cycles on Time of Day Variation in the Human Metabolome-A Review

The past decade has seen a large influx of work investigating time of day variation in different human biofluid and tissue metabolomes. The driver of this daily variation can be endogenous circadian rhythms driven by the central and/or peripheral clocks, or exogenous diurnal rhythms driven by behavioural and environmental cycles, which manifest as regular 24 h cycles of metabolite concentrations. This review, of all published studies to date, establishes the extent of daily variation with regard to the number and identity of 'rhythmic' metabolites observed in blood, saliva, urine, breath, and skeletal muscle. The probable sources driving such variation, in addition to what metabolite classes are most susceptible in adhering to or uncoupling from such cycles is described in addition to a compiled list of common rhythmic metabolites. The reviewed studies show that the metabolome undergoes significant time of day variation, primarily observed for amino acids and multiple lipid classes. Such 24 h rhythms, driven by various factors discussed herein, are an additional source of intra/inter-individual variation and are thus highly pertinent to all studies applying untargeted and targeted metabolomics platforms, particularly for the construction of biomarker panels. The potential implications are discussed alongside proposed minimum reporting criteria suggested to acknowledge time of day variation as a potential influence of results and to facilitate improved reproducibility.

Evolution in the Presentation, Treatment, and Outcomes of Patients with Acute Mesenteric Ischemia

OBJECTIVES

Acute mesenteric ischemia (AMI) is a life-threatening condition associated with dismal outcomes. This study sought to evaluate the evolution of presentation, treatment, and outcomes of AMI over the past two decades.

METHODS

AMI patients presenting at a single institution were reviewed (1993-2016). Venous thrombosis patients were excluded. Primary outcome was 30-day mortality. Patients were stratified by etiology and diagnosis date (before 2004 versus 2004 and later). Ordered logistic regression was performed for longitudinal temporal analysis.

RESULTS

303 patients were identified. AMI mechanisms included: embolic (49%), thrombotic (29%), and non-occlusive (NOMI) (22%). The majority were women (55%), 50% had atrial fibrillation, and 23% were on anticoagulation (AC) therapy. Mean age was 72±13 years. 345 procedures were performed in 242 patients: 321 open and 24 hybrid/endovascular. Among the 189 embolic/thrombotic patients who were managed operatively, 45% (n=85) underwent mesenteric revascularization while 39 (21%) had findings of non-survivable bowel necrosis (NSBN). Among the 104 patients who did not undergo revascularization, 64 (62%) died within 30-days compared to 36 out of 85 (42%) patients who were revascularized (P=0.01). 30-day mortality was 61% and stable over time (P=0.91); when stratified by AMI etiology, the thrombotic cohort had worse survival than embolic and NOMI patients (P=0.04). Since 2000, there was a significant decrease in the percentage of embolic AMI events (P=0.04). The percentage of patients who underwent operative management decreased also over time (P=0.01, 81% → 61%), which was correlated with an increasing number of patients being made comfort measures only (CMO) prior to surgical intervention (50% → 70%, P=0.02). The majority of patients (55%) were ultimately made CMO during their hospitalization. Predictors of 30-day mortality included a preoperative white blood cell count (WBC) ≥ 25 K/ µL. (OR 3.0, P=0.002) and lactate ≥ 2.3 mmol/L (OR 2.8, P=0.045). NSBN predictors included WBC ≥ 24 K/ µL. (OR 3.4 P=0.03) and lactate ≥ 3.8 mmol/L (OR 3.6, P=0.04).

CONCLUSIONS

Despite advances in critical care over the past 25 years, AMI continues to be associated with poor prognosis. The survival benefit observed in patients who undergo revascularization supports an aggressive approach towards early vascular intervention, although this requires further study. The importance of early diagnosis, prognostication and advanced directives is highlighted given the high morbidity, mortality and use of comfort measures associated with AMI.

Synergistic Effect of β-alanine and Aprotinin on Mesenteric Ischemia

BACKGROUND

Acute mesenteric ischemia arises through sudden interruption of mesenteric blood flow, mostly due to an occlusion of the superior mesenteric artery and is associated with a high mortality of approximately 50% to 90%. In previous studies, the single application of β-alanine or aprotinin caused an ameliorated intestinal damage but without any systemic effects.

METHODS

To analyze the combined effect of β-alanine and aprotinin on acute ischemia and reperfusion of the small intestine, a model with anesthetized rats was used. Ischemia and reperfusion were initiated by occluding and reopening the superior mesenteric artery. After 120 min of ischemia and 180 min of reperfusion, the intestine was analyzed for tissue damage, the activity of the saccharase, and accumulation of granulocytes. In addition, systemic and metabolic as well as inflammatory parameters were measured in blood at certain points in time.

RESULTS

The combination of β-alanine and aprotinin resulted in a clearly stabilized mean arterial blood pressure and blood glucose level during the reperfusion period. Furthermore, the combined administration resulted in significantly reduced tissue damage parameters, cytokine and cell-free hemoglobin concentrations in blood plasma. In addition, the damage to the small intestine was significantly attenuated, so that the animals ultimately survived the entire test period because of the administration of both substances.

CONCLUSIONS

Overall, the simultaneous application of both substances leads to a synergistic protection without the occurrence of undesirable side effects. The combined usage of β-alanine and aprotinin can be seen as a promising approach to inhibit the onset of acute mesenteric ischemia.

D-Lactate and intestinal fatty acid-binding protein are elevated in serum in patients with acute ischemic stroke

Experimental studies suggest that the intestinal barrier is affected in ischemic stroke. D-Lactate and intestinal fatty acid-binding protein (IFABP) are markers of intestinal mucosa integrity and barrier function. Our purpose was to evaluate the serum concentrations of these markers in patients with acute ischemic stroke (AIS). We included patients with AIS and used healthy subjects as controls. Clinical, demographic and outcome measures were recorded. Blood was drawn within 24 h of symptom onset. Serum concentrations of D-Lactate and IFABP were determined using commercially available colorimetric and ELISA kits, respectively. We included a total of 61 patients (median age of 64 years). The majority of patients were male (57.4%). The most common cause of stroke was atherosclerosis (34.4%), followed by small-vessel disease and cardioembolic (32.7% each). Mean admission NIHSS score was 8. Median IFABP and D-Lactate concentrations were significantly higher in patients than in controls. Concentrations were not associated with stroke severity or 3-month outcome. Patients with large-artery atherosclerosis and cardioembolic etiology had higher D-Lactate values than patients with small-vessel disease. D-Lactate and IFABP were significantly elevated in patients with AIS. This suggests that there is disruption of the intestinal barrier in patients with AIS.

Early transcatheter thrombectomy and thrombolytic therapy in acute non-cirrhotic and non-malignant mesenteric vein thrombosis: Case report of two cases and literature review

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Non-cirrhotic non malignant acute mescenteric thrombosis could lead to massive bowel ischaemia and is challenging to manage.

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Conventional PV or SMV exploration is associated with significant blood lost, physiological disturbances and may need repeated procedures.

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Catheter directed thrombolysis and thrombectomy provide minimal invasive option to restore patency of PV or SMV.

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Literature review found high success rate and favourable outcome.

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Catheter directed therapy should be the first line therapy.

Aim

To present two cases of acute non-cirrhotic and non-malignant mesenteric vein thrombosis (MVT) treated with early transcatheter thrombectomy and thrombolysis with tissue plasminogen activator (tPA) and to review the literature on transcatheter thrombectomy and thrombolytic therapy of such condition.

Methods

Two cases of acute MVT treated with transhepatic transcatheter thrombectomy and thrombolysis in addition to systemic anticoagulation upon diagnosis are presented. In addition, a Pubmed literature search was undertaken using keywords acute mesenteric vein thrombosis, thrombolysis and thrombectomy. The inclusion criteria were studies examining the impacts of transcatheter thrombolysis and thrombectomy in the management of acute MVT.

Results

Early transcatheter thrombectomy and thrombolysis achieves technical success in both patients and result in nearly complete recanalization of the venous system, with no recurrent thrombosis to date in follow up. Both patients do not require extensive bowel resection despite extensive thrombus on presentation. However, both patients develop intra-abdominal bleeding requiring blood transfusion and embolization of the transcatheter tract.

Conclusion

Catheter-directed first approach provides a minimal invasive approach for management of non-malignant and non-cirrhotic acute mesenteric thrombosis. It offers the benefits of rapid venous recanalization and avoid massing bowel resection despite extensive thrombosis. Subsequent progression into chronic MVT was also reduced. However, the procedure could lead to bleeding from puncture site and hence embolization of the catheter tract is advised during catheter removal.

The value of potassium, pH and D-dimer levels in early diagnosis of acute mesenteric ischemia: an experimental study on rats

INTRODUCTION

The aim of this randomized controlled experimental study was to evaluate the efficacy of potassium, pH and D-dimer levels in blood, as well as potassium and pH levels in peritoneal lavage fluid, in the early diagnosis of acute mesenteric ischemia.

MATERIAL AND METHODS

This study was conducted at the Istanbul University Center of Experimental Medicine after having received approval from the Istanbul University animal testing ethics committee. Male albino Wistar rats (n = 24; 250 to 350 g) were divided into two control groups and two ischemic groups. Levels of potassium, pH, and D-dimer in blood and levels of potassium and pH in peritoneal lavage fluid were analyzed for 1 h and 2 h after the induced acute mesenteric ischemia procedure. The degree of ischemic injury was determined using the histopathological damage score in tissue samples taken from the terminal ileum.

RESULTS

Ischemic groups had statistically significant differences in potassium and pH in blood and peritoneal lavage fluid compared to non-ischemic groups (p < 0.05). There was no significant difference between control and ischemic groups in terms of D-dimer and histologic grading results after 1 h (p = 0.132, p = 0.475 respectively), while there was a significant difference between control and ischemic groups after 2 h (p < 0.05).

CONCLUSIONS

The levels of potassium, pH, and D-dimer could be useful in daily practice for the early diagnosis of acute mesenteric ischemia.

Faecal cytokine profiling as a marker of intestinal inflammation in acutely decompensated cirrhosis

BACKGROUND & AIMS

Gut dysbiosis and inflammation perpetuate loss of gut barrier integrity (GBI) and pathological bacterial translocation (BT) in cirrhosis, contributing to infection risk. Little is known about gut inflammation in cirrhosis and how this differs in acute decompensation (AD). We developed a novel approach to characterise intestinal immunopathology by quantifying faecal cytokines (FCs) and GBI markers.

METHODS

Faeces and plasma were obtained from patients with stable cirrhosis (SC; n = 16), AD (n = 47), and healthy controls (HCs; n = 31). A panel of 15 cytokines and GBI markers, including intestinal fatty-acid-binding protein-2 (FABP2), d-lactate, and faecal calprotectin (FCAL), were quantified by electrochemiluminescence/ELISA. Correlations between analytes and clinical metadata with univariate and multivariate analyses were performed.

RESULTS

Faecal (F) IL-1β, interferon gamma, tumour necrosis factor alpha, IL-21, IL-17A/F, and IL-22 were significantly elevated in AD vs. SC (q <0.01). F-IL-23 was significantly elevated in AD vs. HC (p = 0.0007). FABP2/d-lactate were significantly increased in faeces in AD vs. SC and AD vs. HC (p <0.0001) and in plasma (p = 0.0004; p = 0.011). F-FABP2 correlated most strongly with disease severity (Spearman's rho: Child-Pugh 0.466; p <0.0001; model for end-stage liver disease 0.488; p <0.0001). FCAL correlated with plasma IL-21, IL-1β, and IL-17F only and none of the faecal analytes. F-cytokines and F-GBI markers were more accurate than plasma in discriminating AD from SC.

CONCLUSIONS

FC profiling represents an innovative approach to investigating the localised intestinal cytokine micro-environment in cirrhosis. These data reveal that AD is associated with a highly inflamed and permeable gut barrier. FC profiles are very different from the classical innate-like features of systemic inflammation. There is non-specific upregulation of TH1/TH17 effector cytokines and those known to mediate intestinal barrier damage. This prevents mucosal healing in AD and further propagates BT and systemic inflammation.

LAY SUMMARY

The gut barrier is crucial in cirrhosis in preventing infection-causing bacteria that normally live in the gut from accessing the liver and other organs via the bloodstream. Herein, we characterised gut inflammation by measuring different markers in stool samples from patients at different stages of cirrhosis and comparing this to healthy people. These markers, when compared with equivalent markers usually measured in blood, were found to be very different in pattern and absolute levels, suggesting that there is significant gut inflammation in cirrhosis related to different immune system pathways to that seen outside of the gut. This provides new insights into gut-specific immune disturbances that predispose to complications of cirrhosis, and emphasises that a better understanding of the gut-liver axis is necessary to develop better targeted therapies.

Lactate and intestinal fatty acid binding protein as essential biomarkers in neonates with necrotizing enterocolitis: ultrasonographic and surgical considerations

BACKGROUND

Necrotizing enterocolitis (NEC) is a neonatal disease with its pathogenesis still not well understood, although it is hypothesized to be related to decreased perfusion of the intestinal wall. The current study aimed to evaluate the plasma lactate levels and assess the validity of plasma and urinary intestinal fatty acid binding protein (I-FABPp and I-FABPu/Cru respectively) in NEC.

METHODS

The study included 55 neonates with variable Bell's stages who were comparable with 23 matched controls. Colorimetric assays of plasma lactate and ELISA assays of I-FABP in both serum and urine of the included neonates have been performed.

RESULTS

There were significantly higher median levels of I-FABPp, I-FABPu and lactate among cases (2.84 ng/ml, 1.74 ng/g creat. and 32.34 mg/dl, respectively) compared with controls (0.16 ng/ml, 0.60 ng/g creat. and 15.33 mg/dl, respectively) with p ˂ 0.05 for all. I-FABPp at cut-off point >3.24 ng/ml showed 90% sensitivity, 72% specificity, PPV = 52.6%, NPP = 94.7%, while for I-FABPu (at cut-off point > 2.93 ng/g creat.) those values were 90%, 92%, 81.8% and 95.8% respectively, in discriminating stage IIIA from stage II with p = 0.001. In predicting surgical NEC, I-FABPp at the cut-off point of 6.95 ng/ml revealed 75% sensitivity, 100% specificity, PPV = 100%, NPP = 95%, while for I-FABPu (cut-off point>4.13 ng/g creat.) they were 100%, 76.19%, 44.4 %and 100%, p = 0.04.

CONCLUSION

s: In addition to clinical judgment, sonographic data and plasma lactate, I-FABPp was shown to be a specific marker for early identification of surgical NEC, while I-FABPu could be more useful for differentiating Bell's stage II from stage III.

Impaired intestinal barrier in patients with obstructive sleep apnea

BACKGROUND

Obstructive sleep apnea (OSA) is often associated with multisystem damage. The gut is a pivotal organ that initiates the pathophysiological processes of multisystem diseases. Intermittent hypoxia resulting from OSA may impair the intestinal barrier prior to the induction of systemic inflammation. We hypothesize that the intestinal barrier markers D-lactic acid (D-LA) and intestinal fatty acid-binding protein (I-FABP) levels would be higher in patients with OSA.

METHODS

Consecutive snoring and nonsnoring adults were included in this study and were grouped based on their apnea-hypopnea index (AHI) scores: the control group (AHI < 5) and the OSA group (AHI ≥ 5). Plasma D-LA and I-FABP levels were measured using colorimetry and ELISA, respectively. Other parameters, such as fasting levels of lipids, routine blood tests, and glucose were also assessed.

RESULTS

Of 76 participants, patients in the OSA group accounted for 73% (55/76). Plasma D-LA and I-FABP levels were significantly higher in patients with OSA [7.90 (7.42) (IQR) vs. 0.88 (2.79) (IQR) mmol/L, p < 0.001 and 1851.99 ± 754.23 (SD) vs. 1131.98 ± 383.38 pg/mL, p < 0.001, respectively]. Increased glucose, triglycerides (TGs), leukocytes, neutrophils, and monocytes but decreased high density lipoprotein (HDL) were also found in patients with OSA. It was also observed that the increase in D-LA and I-FABP exhibited the strongest positive association with AHI (r = 0.443, p < 0.001; r = 0.645, p < 0.001), followed by the lowest SaO2 (p ≤ 0.001), BMI (p ≤ 0.017), glucose (p ≤ 0.011), and TGs (p ≤ 0.025). Moreover, multivariate regression analysis showed that D-LA (B = 0.823, p < 0.001) and I-FABP (B = 0.002, p = 0.017) were independently associated with OSA.

CONCLUSIONS

The systemic expression of D-LA and I-FABP is dramatically higher in OSA patients, suggesting that hypoxia resulting from OSA might have the capacity to impair the intestinal barrier prior to the induction of multisystem dysfunction.

Mesenteric vascular disease: A population-based cohort study

OBJECTIVES

Mesenteric vascular disease carries a high risk of mortality and morbidity; however, due to obscure clinical presentation, it can be under-recognized. Currently, epidemiology of mesenteric vascular disease remains poorly defined. The aim of this study is to analyze changes in Scottish mortality rates from mesenteric vascular disease overtime.

METHODS

This is a retrospective, longitudinal population-based cohort study using data extracted from death certificates and Scottish Index of Multiple Deprivation. All deaths related to a vascular disorder of the intestines recorded as an underlying cause of death between 1979 and 2014 were identified using International Classification of Disease-9 or International Classification of Disease-10 code groups. Data included demographics and location of death. The residence postcodes were used to classify socio-economic status using the Scottish Index of Multiple Deprivation.

RESULTS

From 2,142,921 deaths over 36 years, 14,530 (0.7%) were due to mesenteric vascular disease with a median (interquartile range) age of 77 and a 2:1 female to male gender ratio. The mean ± standard deviation age significantly increased from 72.6 ± 12.1 in 1979 to 76.8 ± 11.1 in 2014 (p < 0.001, R² = 0.772). Males were consistently younger than females at the time of death. The two lowest Scottish Index of Multiple Deprivation categories accounted for half of the cohort, throughout the study period (p = 0.068). The adjusted death rate per 100,000 population increased from 7.6 in 1979 to 12.1 in 2014.

CONCLUSIONS

The reported death rates of mesenteric vascular disease in Scotland between 1979 and 2014 have nearly doubled. Mesenteric vascular disease affects twice as many women as men and is associated with social deprivation. The increased reporting of mesenteric vascular disease is likely due to increased recognition and incidence. These implications should be considered when planning healthcare provision in Scotland.

Comparison of diagnostic accuracy for nonocclusive mesenteric ischemia in models with biomarkers including intestinal fatty acid-binding protein in addition to clinical findings

BACKGROUND

Nonocclusive mesenteric ischemia (NOMI) is an acute and life-threatening gastrointestinal disorder, requiring rapid therapeutic intervention for ischemic bowel. However, its rapid detection remains challenging. This retrospective, observational study was aimed at comparing the diagnostic accuracy for NOMI in models of biomarkers, including intestinal fatty acid-binding protein (I-FABP), and clinical findings.

METHODS

All consecutive patients who presented to the emergency department of the study hospital with suspected NOMI were prospectively enrolled. Receiver operating characteristic analysis compared the diagnostic accuracy of I-FABP with traditional biomarkers (white blood cell count, C-reactive protein, lactate, creatine kinase, and D-dimer) alone and in combination with the baseline model established from clinical findings.

RESULTS

Of 96 patients with suspected NOMI, 25 (26.0%) were clinically diagnosed with NOMI. In-hospital mortality was higher in patients with NOMI than those with other conditions (56.0% vs. 4.2%, p < 0.001). Receiver operating characteristic analyses revealed that the I-FABP model had the highest area under the curve (0.805) in the diagnosis of NOMI, compared with other biomarkers. The diagnostic model of clinical findings including age, cardiovascular disease history, undergoing hemodialysis, hypotension, and consciousness disturbance in combination with I-FABP showed the best discrimination (area under the curve, 0.883), compared with other biomarkers. The bootstrap optimism estimate showed the lowest discrimination among the other models with other biomarkers (0.006).

CONCLUSION

The usefulness of I-FABP for final diagnosis of NOMI in patients with clinically suspected NOMI at the emergency department was internally validated. Further external validation study is warranted.

LEVEL OF EVIDENCE

Diagnostic test, level III.

European guidelines on chronic mesenteric ischaemia - joint United European Gastroenterology, European Association for Gastroenterology, Endoscopy and Nutrition, European Society of Gastrointestinal and Abdominal Radiology, Netherlands Association of Hepatogastroenterologists, Hellenic Society of Gastroenterology, Cardiovascular and Interventional Radiological Society of Europe, and Dutch Mesenteric Ischemia Study group clinical guidelines on the diagnosis and treatment of patients with chronic mesenteric ischaemia

Chronic mesenteric ischaemia is a severe and incapacitating disease, causing complaints of post-prandial pain, fear of eating and weight loss. Even though chronic mesenteric ischaemia may progress to acute mesenteric ischaemia, chronic mesenteric ischaemia remains an underappreciated and undertreated disease entity. Probable explanations are the lack of knowledge and awareness among physicians and the lack of a gold standard diagnostic test. The underappreciation of this disease results in diagnostic delays, underdiagnosis and undertreating of patients with chronic mesenteric ischaemia, potentially resulting in fatal acute mesenteric ischaemia. This guideline provides a comprehensive overview and repository of the current evidence and multidisciplinary expert agreement on pertinent issues regarding diagnosis and treatment, and provides guidance in the multidisciplinary field of chronic mesenteric ischaemia.

Review Article: Mesenteric Ischemia

PURPOSE OF REVIEW

Mesenteric ischemia (MI), both acute (AMI) and chronic (CMI), is a challenging diagnosis to make, and early diagnosis and treatment are vital to improve outcomes. This manuscript summarizes the most up to date information on diagnosis and treatment of these disorders.

RECENT FINDINGS

There have been several significant advancements in the computed tomography (CT) diagnostic imaging as well as medical and endovascular management of AMI and CMI. In appropriate populations, endovascular interventions appear superior to open surgical management with lower mortality, morbidity, and cost of care. Efficient clinical identification and targeted testing are essential to diagnose AMI and CMI. Aggressive resuscitation and early endovascular (or in select cases, surgical) intervention improve outcomes in those with AMI. In those with CMI, considering this on the differential diagnosis and imaging appropriately can identify those that might benefit from intervention and halt progression to acute episodes.

Itaconate modulates tricarboxylic acid and redox metabolism to mitigate reperfusion injury

OBJECTIVES

Cerebral ischemia/reperfusion (IR) drives oxidative stress and injurious metabolic processes that lead to redox imbalance, inflammation, and tissue damage. However, the key mediators of reperfusion injury remain unclear, and therefore, there is considerable interest in therapeutically targeting metabolism and the cellular response to oxidative stress.

METHODS

The objective of this study was to investigate the molecular, metabolic, and physiological impact of itaconate treatment to mitigate reperfusion injuries in in vitro and in vivo model systems. We conducted metabolic flux and bioenergetic studies in response to exogenous itaconate treatment in cultures of primary rat cortical neurons and astrocytes. In addition, we administered itaconate to mouse models of cerebral reperfusion injury with ischemia or traumatic brain injury followed by hemorrhagic shock resuscitation. We quantitatively characterized the metabolite levels, neurological behavior, markers of redox stress, leukocyte adhesion, arterial blood flow, and arteriolar diameter in the brains of the treated/untreated mice.

RESULTS

We demonstrate that the "immunometabolite" itaconate slowed tricarboxylic acid (TCA) cycle metabolism and buffered redox imbalance via succinate dehydrogenase (SDH) inhibition and induction of anti-oxidative stress response in primary cultures of astrocytes and neurons. The addition of itaconate to reperfusion fluids after mouse cerebral IR injury increased glutathione levels and reduced reactive oxygen/nitrogen species (ROS/RNS) to improve neurological function. Plasma organic acids increased post-reperfusion injury, while administration of itaconate normalized these metabolites. In mouse cranial window models, itaconate significantly improved hemodynamics while reducing leukocyte adhesion. Further, itaconate supplementation increased survival in mice experiencing traumatic brain injury (TBI) and hemorrhagic shock.

CONCLUSIONS

We hypothesize that itaconate transiently inhibits SDH to gradually "awaken" mitochondrial function upon reperfusion that minimizes ROS and tissue damage. Collectively, our data indicate that itaconate acts as a mitochondrial regulator that controls redox metabolism to improve physiological outcomes associated with IR injury.

Serological biomarkers for acute mesenteric ischemia

Acute mesenteric ischemia (AMI) defines a complex of conditions characterized by an interruption of the splanchnic circulation, leading to insufficient oxygen delivery or utilization to fill the metabolic needs of the visceral organs. Early diagnosis and immediate therapy are the cornerstones of early ischemia to reach a successful outcome and are necessary to reduce the high mortality. Although there is still lack of specific biomarkers to assist the diagnosis of AMI in clinical practice, there are several biomarkers with high specificity, may become a potential tools in early diagnosis of AMI, including intestinal fatty acid binding protein (I-FABP), a-glutathione S-transferase (a-GST), D-dimer, L- and D-lactate, citrulline, ischemia modified albumin, procalcitonin (PCT). However, they use in clinical limited duo to the many studies about these makers finished with small patient populations, and heterogeneous among these populations. This review describes the etiology of AMI, the current most studied promising biomarkers, the current research situation and future of biomarker research.

Screening and combining serum biomarkers to improve their diagnostic performance in the detection of intestinal barrier dysfunction in patients after major abdominal surgery

Background

The aim of this prospective study was to screen and combine effective biomarkers to improve their diagnostic performance in detecting intestinal barrier dysfunction in patients after major abdominal surgery.

Methods

Patients undergoing major abdominal surgery were enrolled after signing informed consent in this study. The serum concentrations of α-GST, DAO, D-lactate, citrulline and I-FABP were detected 24 hours before and after surgery. The diagnostic performance of five biomarkers on intestinal barrier dysfunction was assessed using logistic regression models and receiver operating characteristic (ROC) curve analyses.

Results

Thirty-nine patients with major abdominal surgery were enrolled in and successfully completed this study. ROC analysis revealed that the sensitivities of D-lactate, citrulline and I-FABP were very high (0.91, 0.91 and 1.00, respectively), but the specificities of these biomarkers were less than 0.70. The sensitivity of DAO was very low [0.25; 95% confidence interval (CI), 0.05-0.57], but its specificity was high (0.92; 95% CI, 0.75-0.99). The accuracies of D-lactate and I-FABP were very high, and the areas under the curves (AUCs) of the biomarkers were 0.84 (95% CI, 0.68-0.93) and 0.81 (95% CI, 0.65-0.92), respectively. Different combinations of five biomarkers were also analysed. The sensitivity, specificity and AUC values of the combination of I-FABP, citrulline and D-lactate were 1.00, 0.74 and 0.89, respectively. These results were similar to those derived from the combination of α-GST, DAO, D-lactate, citrulline and I-FABP (P=1.000).

Conclusions

The combination of serum D-lactic acid, citrulline and I-FABP greatly improved the diagnostic performance for identifying intestinal barrier dysfunction in patients after major abdominal surgery.

Review: Acute superior mesenteric artery embolism: A vascular emergency cannot be ignored by physicians

BACKGROUND

Acute mesenteric ischemia (AMI) is a life-threatening medical condition that occurs when a sudden decreased perfusion to the intestines which leads to bowel infarction, and acute superior mesenteric artery embolism (ASMAE) is the main cause of AMI. Unfortunately, with the improvement of diagnosis and treatment technology, the mortality remains high due to less frequent clinical suspicion resulted from the unclear clinical manifestation and non-specific laboratory findings.

METHODS

Relevant studies published were identified by searching the PubMed, Embase and Cochrane Library databases. This review presented the literatures to introduce the research progress of ASMAE in recent years.

RESULTS

Patients with the history of atrial fibrillation, heart valve disease and atherosclerosis should be considered as ASMAE. Laboratory findings are insensitive and unspecific, however, angiography and Computed tomography angiography (CTA) can provide a clear diagnosis sensitively and specifically. Endovascular approaches have been increasingly reported in multiple case series. The key to successful treatment of AMI involves early clinical recognition and early intervention to move the embolus, which can reduce the rate of misdiagnosis and save the precious time and lives of patients.

CONCLUSIONS

Loss of time eventually leads to progression of ischemia to transmural bowel necrosis with peritonitis and septicemia, which may further worsen patients' outcomes. It is important for physicians to make a timely and accurate diagnosis, which can save precious time and reduce the mortality.

Mesenteric Ischemia: Concepts of Care for the Bedside Nurse

Bedside nurses require excellent observational and assessment skills. Being knowledgeable about common diseases that often affect the population is essential; however, it is often more challenging to be informed about life-threatening conditions that rarely develop. Such is the case with mesenteric ischemia, a rare but complicated condition, which is difficult to diagnose, carries a degree of mortality of about 40%-70%, and is more common in people older than 50 years. Mesenteric ischemia requires that nurses be aware of the different etiologies and presentations of this uncommon disease to alert physicians of changes in a patient's condition and detect clues that may assist with an accurate and prompt diagnosis. Being educated about the diagnostic procedures, possible outcomes, and anticipated care and needs of patients affected by this medical complication is imperative to maintain the health status and well-being of these patients and their families.

Serum markers for early detection of patients with mesenteric ischemia after cardiac surgery

Objective

Mesenteric ischemia (MESI) is a rare but often fatal complication in patients after cardiac surgery. Non-specific clinical symptoms and lack of specific laboratory parameters complicate the diagnosis. We evaluated potential serum markers for MESI in cardiac surgery patients.

Methods

Between March and October 2012, serial serum samples of 567 elective cardiac surgery patients were collected 1, 24, and 48 h after the operation, and concentrations of potential markers for MESI [α-glutathione-S-transferase (αGST), intestinal fatty-acid-binding protein (iFABP), and D-lactate] were measured retrospectively. In patients requiring laparotomy, blood samples obtained 72, 48, 24, and 12 h before the laparotomy were additionally measured and compared to all other patients (control group).

Results

Laparotomy was performed in 18 patients at 11±7 days after cardiac surgery. MESI was found in 9/18 patients. Already 1 h after cardiac surgery, the serum concentrations of D-lactate (37±18 vs. 25±20 nmol/mL, p<0.01) and αGST (82±126 vs. 727±1382 μg/L, p<0.01) in patients undergoing laparotomy were increased compared to the control group. Between patients with and without MESI, differences were only found for iFABP 24 h after cardiac surgery (1.1±0.4 vs. 2.9±0.6 ng/mL, p=0.04) and up to 72 h before laparotomy (0.56±0.72 vs. 2.51±1.96 ng/mL, p=0.01).

Conclusions

D-lactate and αGST were early markers for gastrointestinal complications after cardiac surgery. Before laparotomy, lowered iFABP levels indicated MESI. Routinely used, these markers can help identify patients with gastrointestinal complications after cardiac surgery early, and might be useful for the evaluation of new therapeutic or preventive strategies.

Biochemical markers of acute intestinal ischemia: possibilities and limitations

Acute intestinal ischemia is a relative rare abdominal emergency, associated with considerably high morbidity and mortality rates. Although the conventional diagnostic approach to acute intestinal ischemia entails a preliminary evaluation of signs and symptoms, followed by radiological and laboratory investigations, a definitive diagnosis is can usually be made after laparotomy, which still remains the gold standard diagnostic (and therapeutic) procedure. Several potential laboratory biomarkers have been investigated over the past decades, but none of these seems to reach a suitable diagnostic accuracy for an early and reliable diagnosis of intestinal ischemia. The aim of this narrative review is to provide an overview on traditional laboratory tests for diagnosing acute intestinal ischemia (i.e., complete blood count, D-dimer, blood gas analysis, total lactic acid, C-reactive protein and procalcitonin), and summarize current evidence regarding some emerging and potentially useful biomarkers such as D-lactate, intestinal fatty acid-binding protein (I-FABP), ischemia modified albumin (IMA), α-glutathione S-transferase (α-GST), interleukin-6 (IL-6), citrulline and smooth muscle protein of 22 kDa (SM22). Among the various tests, D-lactate, IMA and I-FABP are perhaps the most promising, since they are characterized by optimal sensitivity and relatively good specificity, early kinetics, and can be measured with assays suited for a rapid diagnosis.

Acute mesenteric ischaemia: a pictorial review

Abstract

Acute mesenteric ischaemia (AMI) is an uncommon cause of acute hospital admission with high mortality rates (50–90%) that requires early diagnosis and treatment. With the increase in average life expectancy, AMI represents one of the most threatening abdominal conditions in elderly patients. Untreated, AMI will cause mesenteric infarction, intestinal necrosis, an overwhelming inflammatory response and death. Early intervention can reverse this process leading to a full recovery, but the diagnosis of AMI is difficult. The failure to recognise AMI before intestinal necrosis has developed is responsible for the high mortality of the disease. Unfortunately, common CT findings in bowel ischaemia are not specific. Therefore, it is often a combination of nonspecific clinical, laboratory and radiological findings that helps most in the correct interpretation of CT findings. The purpose of this article is to provide an overview of the anatomy, physiology of mesenteric perfusion and discussions of causes, pathogenesis and CT findings in various types of acute bowel ischaemia. Familiarity with various imaging features of mesenteric injury is essential to make a timely diagnosis that will lead to improved patient outcomes.

Teaching Points

• AMI is a potentially life-threatening disorder whose prognosis depends on early recognition, accurate diagnosis and timely intervention.

• Arterial inflow occlusion due to thrombosis or embolisation is the most common cause of AMI.

• Four aetiological types of AMI have been associated with different characteristics and risk factors (EAMI, TAMI, VAMI and NOMI).

• Physical examination and laboratory findings are not sensitive or specific for diagnosing AMI; therefore, MDCT is still the first-line imaging method in suspected AMI.

• Although a number of scoring systems for prognosis have been proposed, these have not been validated in large-scale studies.

Predictive Factors for Intestinal Transmural Necrosis in Patients with Acute Mesenteric Ischemia

BACKGROUND

Acute mesenteric ischemia (AMI) is a serious and potentially fatal condition. No definite parameter can predict transmural bowel necrosis in patients with AMI to justify early surgical intervention. The current study aimed to identify the clinical, laboratory, and radiologic parameters that can successfully predict the onset of intestinal transmural necrosis in patients with AMI.

PATIENTS AND METHODS

Records of patients with AMI in the period of January 2013 to October 2017 were reviewed. Clinical parameters as patients' symptoms, vital signs, and signs of peritonitis along with the results of laboratory and radiologic investigations were analyzed to identify predictive factors for intestinal transmural necrosis using binary logistic regression analysis.

RESULTS

One hundred and one patients (70 males) with mean age of 55 years were included. Venous occlusion was the cause of AMI in 78 (77.3%) patients and arterial occlusion in 23 (22.7%) patients. Twenty-two patients completed conservative treatment successfully, whereas 79 patients required exploratory laparotomy. On laparotomy, six patients were found to have viable bowel. Overall, 28 patients had viable bowel and 73 had bowel necrosis. The significant independent predictors for transmural bowel necrosis were mesenteric arterial occlusion (OR: 26.5, p = 0.02), leukocytosis (OR: 1.3, p < 0.0001), acidosis (OR: 3.8, p = 0.04), free intraperitoneal fluid (OR: 4.21, p = 0.005), and combined portal vein and SMV thrombosis in CT scan (OR: 3.4, p = 0.026).

CONCLUSION

The independent predictors for transmural bowel necrosis were mesenteric arterial occlusion, leukocytosis, acidosis, free intraperitoneal fluid, and combined portal vein and SMV thrombosis in CT scan.

The value of endoplasmic reticulum stress markers (GRP78 and CHOP) in the diagnosis of acute mesenteric ischemia

AIM

To evaluate levels of the endoplasmic reticulum (ER) stress markers GRP78 and CHOP in acute mesenteric ischemia (AMI) and to examine relations with degrees of AMI-related intestinal injury.

MATERIALS AND METHODS

Twenty-four rats were divided into four groups. Group I and Group III represented the control groups, from which blood and tissue specimens were collected 2 and 6 h after laparotomy without superior mesenteric artery (SMA) ligation. Group II and Group IV constituted the ischemia groups, from which blood and tissue specimens were collected 2 and 6 h after SMA ligation. The ER stress markers GRP78 and CHOP, total oxidant status (TOS), total antioxidant status (TAS), and the oxidative stress index (OSI) were investigated in each group. Ileum specimens were assessed in terms of ischemic injury, and appropriate comparisons were performed.

RESULTS

Significantly higher GRP78, CHOP, TOS, and TAS values were determined in the ischemia groups (groups II and IV) compared to the control groups (groups I and III). This elevation was greater in the 6 h ischemia group, the group exposed to the greatest ischemic injury (Group IV). Significant and powerful correlation was present between histopathological damage and levels of the ER stress markers and oxidative markers.

CONCLUSION

According to our results, ER stress markers (GRP78 and CHOP) increase significantly following ischemic injury. This elevation has the potential to be used diagnostically and also in prognostic terms due to the powerful correlation it exhibits with AMI-related ischemic injury.

Experimental Hemorrhagic Shock Protocol in Swine Models: The Effects of 21-Aminosteroid on the Small Intestine

Background

The protective potential of lazaroids has been reported in previous studies on ischemia/reperfusion and induced hemorrhagic shock protocols.

Objectives

The present study is the first experimental protocol on the effects of the antioxidant factor U-74389G on the small intestine of swine models in a hemorrhagic shock protocol and resuscitation with 3 different types of fluids.

Methods

The study included 49 Landrace breed swine that were divided into groups of 7 each. Hemorrhage was provoked 45 minutes after starting the surgical protocol (0 minutes), followed by resuscitation starting 30 minutes after haemorrhage ceased by using 3 different fluids. Three groups (Group A, resuscitation using blood; Group B, resuscitation with Ringer’s lactate solution; and Group C, resuscitation with hypertonic saline solution) underwent resuscitation with fluid alone, and another 3 groups (named A', B,' and C') were administered lazaroid U-74389G in addition to fluid. Control Group S underwent all the surgical procedures without hemorrhagic shock. Vital signs, complete blood count, and biochemical markers were analyzed, and tissue samples of the small intestine were collected from all animals. Further, malondialdehyde, tumor necrosis factor-α, and levels of inflammation in the tissue sample were measured.

Results

In Group S-A-A' and Group S-C-C', the analysis did not show statistically significant differences in the percentage changes of histopathology, malondialdehyde, and tumor necrosis factor-α through time. In Group S-B-B', the malondialdehyde levels in the small intestine were reduced in both the B and B' groups, without lazaroid (Group B) (P = 0.038) and lazaroid (Group B') (P = 0.011), compared with Group S (control), but the group without lazaroid (Group B) had greater reduction in malondialdehyde levels than the group treated with lazaroid (Group B'). With regard to the biochemistry results, 24% reduction was observed for alkaline phosphatase (P = 0.022) in Group A' treated with lazaroid compared with that in the untreated group. Lastly, for the complete blood count parameters, a 14% reduction in white blood cells was observed in Group B', which was treated with lazaroid in all phases (P = 0.015) (absolute value = 6.23) compared with Group B (absolute value = 13.74).

Conclusions

Despite few initial findings of this study suggesting that administration of lazaroid U-74389G may have some potential in attenuation of the effects of hemorrhagic shock in the small intestine of swine models, no differences remained after correction for multiple comparisons was made. Therefore, further research is required to investigate this result thoroughly.

Diagnosis biomarkers in acute intestinal ischemic injury: so close, yet so far

Acute intestinal ischemic injury (i3) is a life-threatening condition with disastrous prognosis, which is currently difficult to diagnose at the early stages of the disease; a rapid diagnosis is mandatory to avoid irreversible ischemia, extensive bowel resection, sepsis and death. The overlapping protein expression of liver and gut related to the complex physiopathology of the disease, the heterogeneity of the disease and its relative rarity could explain the lack of a useful early biochemical marker of i3. Apart from non-specific biological markers of thrombosis, hypoxia inflammation, and infection, several more specific biomarkers in relation with the gut barrier dysfunction, the villi injury and the enterocyte mass have been used in the diagnosis of acute i3. It includes particularly D-lactate, intestinal fatty acid-binding protein (FABP) and citrulline. Herein, we will discuss leading publications concerning these historical markers that point out the main limitations reagrding their use in routine clinical practice. We will also introduce the first and limited results arising from omic studies, underlying the remaining effort that needs to be done in the field of acute i3 biological diagnosis, which remains a challenge.

A Novel Scoring System for Diagnosing Acute Mesenteric Ischemia in the Emergency Ward

BACKGROUND

Early diagnosis of acute mesenteric ischemia (AMI) based on clinical judgment has been proved to be too difficult. Therefore, it is important for identifying clinical parameters that can differentiate AMI from other acute abdomen upon presentation.

METHODS

We analyzed a database of 106 consecutive patients admitted to the emergency ward for suspected AMI in whom diagnosis of AMI was confirmed by laparotomy, CT angiography or mesenteric angiography. The patients' demographics, previous history, clinical signs, results of laboratory investigations and ultrasonography were collected. Diagnostic cutoff value of quantitative indexes was derived from the receiver operating curve. Multivariate logistic regression was used to identify risk factors for AMI and formulated these risk factors into a scoring system.

RESULTS

A total of 45 patients (42.5%) were confirmed to have AMI. Compared with other acute abdomen, AMI had significantly increased level of white blood cell (Odds ratio (OR) 16.11, 95% confidence interval (CI) 1.10-235.34), red cell distribution width (OR 27.65, 95% CI 1.53-501.02), mean platelet volume (OR 16.06, 95% CI 1.48-174.50) and D-dimer (OR 42.91, 95% CI 2.56-718.09). A diagnostic score was calculated by adding points assigned to the four parameters, and a cutoff score of four best identified patients with AMI, with sensitivity, specificity, positive and negative predictive values of 97.8, 91.8, 89.8 and 98.2%, respectively.

CONCLUSION

This scoring system based on easily available parameters could be used as a useful tool for differentiating AMI from other acute abdomen in the emergency ward. Prospective studies with large sample remain needed for validating the results.

Effect of Remote Ischemic Preconditioning on Intestinal Ischemia-Reperfusion Injury in Adults Undergoing On-Pump CABG Surgery: A Randomized Controlled Pilot Trial

OBJECTIVE

Cardiopulmonary bypass (CPB) surgery commonly threatens the heart and remote organs with ischemia-reperfusion injury. Transient episodes of ischemia to nonvital tissue, known as remote ischemic preconditioning (RIPC), is thought to help local and remote vital organs to withstand subsequent ischemic insults.

DESIGN

Prospective, randomized, double-blinded control trial.

SETTING

Tertiary referral academic teaching hospital.

PARTICIPANTS

Thirty patients undergoing elective CPB surgery INTERVENTION: RIPC was achieved via three 5-minute cycles of upper limb ischemia using a blood pressure cuff or control (sham cuff).

MEASUREMENTS AND MAIN RESULTS

Primary outcome was the occurrence of intestinal injury, as measured by an increase in intestinal fatty acid binding protein (I-FABP). Secondary outcomes included incidence of gastrointestinal complications and duration of intensive care unit (ICU) stay. RIPC did not affect serum IFABP levels at the end of surgery and on the first postoperative day (p = 0.697 and p = 0.461, respectively). For all patients, mean I-FABP levels significantly increased at the end of surgery and decreased to under baseline levels on the first postoperative day (from a mean [± standard deviation] baseline value of 764 ± 492 pg/mL to 2,002 ± 974 pg/mL and decreased to 568 ± 319 pg/mL, p < 0.001). All patients remained clinically absent of gastrointestinal complications until hospital discharge. Duration of ICU stay was not correlated with I-FABP levels at the end of surgery. Neither duration of CPB nor duration of aortic clamping significantly correlated with postoperative I-FABP levels.

CONCLUSIONS

These findings suggest that RIPC does not affect intestinal injury in patients undergoing CPB surgery. In patients undergoing cardiac surgery, intestinal injury appears to be moderate and transient without any clinical relevant complication.