Acute and Chronic Ischemic Disorders of the Small Bowel

A Case of Chronic Mesenteric Ischemia Due to Celiac and Mesenteric Artery Thrombosis

Chronic mesenteric ischemia (CMI) is uncommon and accounts for approximately 5% of cases. CMI presents with non-specific symptoms, making it difficult to diagnose, and requires complex management involving interprofessional teams. We present the case of a 66-year-old female who presented with postprandial abdominal pain, vomiting, sitophobia, and weight loss. Investigations showed raised inflammatory markers, and plain film X-ray and endoscopy showed no significant findings. CT angiogram showed celiac and mesenteric artery thrombosis. The patient proceeded to have endovascular revascularization. With this case, we highlight the importance of considering CMI in an elderly patient with a history of microvascular disease or risk factors presenting with postprandial abdominal pain and weight loss. Early diagnosis and timely intervention are imperative for a good prognosis.

Risk of Ischemic Bowel Disease in Patients With Atrial Fibrillation Receiving Warfarin or Non-vitamin K Antagonist Oral Anticoagulants

Background

Although atrial fibrillation (AF) is a risk factor for ischemic bowel disease, data regarding the incidence of ischemic bowel disease in patients with anticoagulated AF were limited.

Methods

The present study used the Taiwan NHIRD and included newly diagnosed patients with AF aged ≥ 20 years without ischemic bowel disease from 2012 to 2018. A total of 69,549 patients taking warfarin or non-vitamin K antagonist oral anticoagulants (NOACs) constituted the final study group. We aimed to study the incidence of ischemic bowel disease in patients with AF receiving warfarin or NOACs. Secondary endpoints were also analyzed, including ischemic stroke, systemic embolism, myocardial infarction, mortality, intracranial hemorrhage (ICH), major bleeding, and composite adverse events (ischemic bowel disease or ICH or major bleeding).

Results

There were 43,787 patients taking NOACs and 25,762 patients taking warfarin. The overall incidence rate of ischemic bowel disease was 0.036% per year and increased with the CHA2DS2-VASc scores [0.013% for patients with a CHA2DS2-VASc score of 0 (men) or 1 (women), 0.022% for those with a CHA2DS2-VASc score of 1 (men) or 2 (women), and 0.039% for those with a CHA2DS2-VASc score ≥ 2 (men) or ≥ 3 (women)]. The risk of ischemic bowel disease was similar between NOAC and warfarin groups (0.036%/year vs. 0.037%/year; adjusted hazard ratio 0.802, p = 0.430), whereas the NOAC group had a significantly lower risk of secondary endpoints compared to the warfarin group.

Conclusion

We reported the incidence of ischemic bowel disease in patients with anticoagulated AF from a nationwide cohort database and observed a positive correlation between the increase of CHA2DS2-VASc scores and the incidence rate. Moreover, NOAC was as effective as warfarin for the risk of ischemic bowel disease.

Translational Application of Fluorescent Molecular Probes for the Detection of Reactive Oxygen and Nitrogen Species Associated with Intestinal Reperfusion Injury

Acute mesenteric ischemia, caused by an abrupt interruption of blood flow in the mesenteric vessels, is associated with high mortality. When treated with surgical interventions or drugs to re-open the vascular lumen, the reperfusion process itself can inflict damage to the intestinal wall. Ischemia and reperfusion injury comprise complex mechanisms involving disarrangement of the splanchnic microcirculatory flow and impairment of the mitochondrial respiratory chain due to initial hypoxemia and subsequent oxidative stress during the reperfusion phase. This pathophysiologic process results in the production of large amounts of reactive oxygen (ROS) and nitrogen (RNS) species, which damage deoxyribonucleic acid, protein, lipids, and carbohydrates by autophagy, mitoptosis, necrosis, necroptosis, and apoptosis. Fluorescence-based systems using molecular probes have emerged as highly effective tools to monitor the concentrations and locations of these often short-lived ROS and RNS. The timely and accurate detection of both ROS and RNS by such an approach would help to identify early injury events associated with ischemia and reperfusion and increase overall clinical diagnostic sensitivity. This abstract describes the pathophysiology of intestinal ischemia and reperfusion and the early biological laboratory diagnosis using fluorescent molecular probes anticipating clinical decisions in the face of an extremely morbid disease.

Avoiding Misdiagnosis of Abdominal Vascular Catastrophes

Abdominal vascular emergencies are an uncommon entity in emergency medicine, but when they present, they are often catastrophic. These time-sensitive and life-threatening diagnoses are often hidden in nonspecific complaints such as nausea, vomiting, or flank pain, so the emergency physician must remain diligent and consider these in the differential diagnoses. The following is an overview of the more common of these abdominal vascular emergencies, in the hope that they help the Emergency Physician avoid the misdiagnosis and subsequent vascular catastrophe that would follow.