Acute Mesenteric Ischemia: A Challenge for the Acute Care Surgeon

CT of acute abdomen in the elderly

Abdominal disorders represent 10 to 15% of all Emergency Department visits in elderly patients. This educational review focuses on acute abdomen pathologies specific to the elderly and on their imaging patterns and proposes a strategy for performing CT scans in this population. Bowel obstruction is the most common cause of emergency surgery in the elderly with a higher proportion of colonic obstructions, in particular obstructive colorectal cancer and sigmoid volvulus. Concerning abdominal inflammatory processes, such as cholecystitis, appendicitis, and diverticulitis, gangrenous cholecystitis and complicated appendicitis are relatively frequently encountered due to delayed diagnoses. Bowel ischemia, which includes acute mesenteric ischemia (AMI) and ischemic colitis (IC), is also much more common after the age of 80. Although ischemic colitis is mainly related to cardiovascular risk factors, it can also result from a persistent distension above a colonic cancer or from fecal impaction. Finally, extra-abdominal pathologies responsible for acute abdominal pain, such as inferior myocardial infarction, should not be overlooked. In clinical practice, when possible thanks to sufficient and appropriate radiological resources, we recommend a scan without injection of contrast and an injection depending on the results of the unenhanced scan, decided by the radiologist present at the CT scan room during the examination. CRITICAL RELEVANCE STATEMENT: CT is critical in the diagnosis and management of patients over 75 years old with an acute abdomen, given the difficulty of clinico-biological diagnosis, the frequency of complicated forms, and the morbidity induced by delayed diagnosis. KEY POINTS: The most common site and cause of bowel obstruction in the elderly is large bowel obstruction due to colon cancer. Discrepancy between a poor clinical examination and complicated forms on imaging, particularly for inflammation and infections, is responsible for late diagnosis and increased morbidity. Ischemia, including of the small bowel, colon, and gallbladder are common cause of acute abdomen in elderly. In patients with upper quadrant pain, consider extra-abdominal causes such as pneumonia or myocardial infarction.

Performance of open versus endovascular approaches in swine modeling of acute mesenteric ischemia

ObjectivesTraditionally, acute mesenteric ischemia studies are performed by utilizing an open superior mesenteric artery (SMA) occlusion, which is an invasive technique with potentially devastating effects. A new endovascular technique for SMA occlusion using a catheter-balloon system was designed and compared to the open SMA occlusion to test its efficacy and animal safety.MethodsAll animals underwent open instrumentation of the superior mesenteric vein (SMV) for blood flow monitoring. The animals were grouped into an open SMA occlusion technique group and an endovascular SMA occlusion group. The open SMA occlusion technique group involved exposure of the SMA via left medial visceral rotation with vascular clamping. In the endovascular group, an endovascular balloon was placed in the SMA and inflated to produce occlusion.ResultsComplete cessation of flow to the SMV was observed in the endovascular group, compared to the residual SMV flow in the open occlusion group. Following a 30-min post-occlusion period, the MAP in the endovascular group increased, compared to a decline of MAP in the open occlusion group.ConclusionsThis study indicates the endovascular technique provides a more potent SMA occlusion, with insignificant consequences on the overall health of the animal, in contrast to the open vascular clamping.

A predictive clinical-radiomics nomogram for early diagnosis of mesenteric arterial embolism based on non-contrast CT and biomarkers

PURPOSE

Mesenteric artery embolism (MAE) is a relatively uncommon abdominal surgical emergency, but it can lead to catastrophic clinical outcomes if the diagnosis is delayed. This study aims to build a prediction model of clinical-radiomics nomogram for early diagnosis of MAE based on non-contrast computed tomography (CT) and biomarkers.

METHOD

In this retrospective study, a total of 364 patients confirmed as MAE (n = 131) or non-MAE (n = 233) who were randomly divided into a training cohort (70%) and a validation cohort (30%). In the training cohort, the minimum redundancy maximum relevance (mRMR) and the least absolute shrinkage and selection operator (LASSO) algorithms were used to select optimal radiomics features from non-contrast CT images for calculating Radscore which was utilized to establish the radiomics model. Logistic regression analysis was performed to screen clinical factors, and then generate the clinical model. A predictive nomogram model was built using Radscore and the selected clinical risk factors, which was evaluated through the receiver operating characteristic (ROC) curve, calibration curve and decision curve analysis (DCA).

RESULTS

Thirteen radiomics features were chosen to calculate Radscore. Age, white blood cell (WBC) count, creatine kinase (CK) and D-dimer were determined as the independent clinical factors. The clinical-radiomics nomogram model showed the best performance in training cohort. The nomogram model was with higher area under curve (AUC) value of 0.93, compared to radiomics model with AUC value of 0.90 or clinical model with AUC value of 0.78 in the validation cohort. The calibration curve showed that nomogram model achieved a good fit in both cohorts (P  = 0.59 and 0.92, respectively). The DCA indicated that nomogram model was significantly favorable for clinical usefulness of MAE diagnosis.

CONCLUSIONS

The nomogram provides an effective tool for the early diagnosis of MAE, which may play a crucial role in shortening the time for therapeutic decision-making, thereby reducing the risk of intestinal necrosis and death.

[Endovascular treatment and selection criteria for acute mesenteric ischemia]

OBJECTIVE

To demonstrate the results of endovascular intervention in patients with acute arterial mesenteric ischemia, while observing the indications developed in the clinic.

MATERIAL AND METHODS

In total, endovascular approach in the treatment of acute mesenteric ischemia were used in 49 patients in the clinic. In compliance with the developed indications and criteria, endovascular intestinal revascularization was performed in 27 patients. Various endovascular intervention techniques were used (aspiration, balloon dilation, artery stenting and their combinations). Extracorporeal filtration techniques were used as a treatment for reperfusion syndrome after intestinal revascularization in 10 patients.

RESULTS

Angiographic success in the form of complete restoration of the main blood flow in the basin of the superior mesenteric artery and its large branches was obtained in 85% of cases. Intestinal viability was preserved in 15 (56%) patients. After successful endovascular surgery, intestinal necrosis was diagnosed on laparoscopy in the remaining 12 (44%) patients, which required extensive (n=2) or non-extensive (n=10) resection. Postoperative mortality was 48% (13 patients).

CONCLUSION

Endovascular surgery in acute mesenteric ischemia is an effective method of intestinal revascularization. To optimize the indications for these interventions, it is necessary to gain experience and conduct large-scale studies.

Outcomes after open and endovascular treatment for mesenteric artery embolism patients: a retrospective inverse probability of treatment-weighted analysis

PURPOSE

This study aims to evaluate outcomes in patients with mesenteric artery embolism (MAE) who received primary endovascular therapy (EVT) or laparotomy, and investigate risk factors for 30-day mortality.

METHODS

A retrospective analysis of 94 MAE patients who underwent two different treatment strategies was undertaken. An inverse probability of treatment weighting (IPTW) method was used to balance the confounding effects of baseline clinical data. Logistic regression analysis was performed to compare the outcomes according to type of treatment regimens before and after IPTW. Univariate and multivariable analysis were conducted to determine the risk factors for 30-day mortality.

RESULTS

Twenty-eight MAE patients received primary EVT, and 66 Open Surgery (OS). Logistic regression analysis showed that there was no significant difference between the EVT and OS group in 30-day mortality rate before (odds ratio [OR] 0.477, 95% confidence interval [CI] 0.170 to 1.340, P = 0.160), and after IPTW (OR 0.647, 95% CI 0.210 to 1.993, P = 0.449). After IPTW, it revealed that the rates of second-look surgery (OR 36.727, 95% CI 5.407 to 249.458, P < 0.001) and hospital stay [> 30 days] (OR 0.006, 95% CI 0.000 to 0.363, P = 0.014) were different in the two groups. D-dimer (> 4 mg/L) and procalcitonin (> 0.5 ng/mL) were the independent risk factors for 30-day mortality in MAE patients postoperatively (P < 0.05).

CONCLUSION

In this retrospective study, MAE patients who performed primary EVT had no obvious difference in 30-day mortality rate compared to those who received OS; but it was conducive to reducing prolonged hospital stays. An increase in procalcitonin level and higher D-dimer were associated with short-term poor prognosis in patients with MAE.

Mesenteric venous thrombosis in a young adult: A case report and review of the literature

BACKGROUND

Acute mesenteric vein thrombosis (MVT) accounts for only 2%-10% of all cases of acute mesenteric ischaemia, with an incidence rate of ~0.1% in Europe and the United States. It represents < 10% of mesenteric infarction cases and is seen predominantly in older adults. In younger individuals, MVT is uncommon, with 36% of cases having unidentified mechanisms and causes.

CASE SUMMARY

A 27-year-old man presented to the emergency department on February 29, 2024, with a chief complaint of intermittent abdominal pain for 3 day. He was previously in good health. As the abdominal pain was not alleviated by conventional treatment, an abdominal computed tomography (CT) scan was performed, which showed increased density in the portal and mesenteric veins. Further imaging, including portal vein ultrasound, mesenteric CT angiography, and enhanced abdominal CT, revealed widespread thrombosis of the portal vein system (including the main portal vein, left and right branches, proximal mesenteric vein, and splenic vein). After 10 day of thrombectomy and anticoagulation therapy, the patient's abdominal pain had improved significantly. Follow-up assessments indicated that portal venous blood flow had largely returned to normal. He was discharged on March 9, 2024. During a follow-up exam 2 months later, repeat abdominal enhanced CT showed that the previously detected thrombi were no longer visible.

CONCLUSION

Clinicians should remain vigilant for acute MVT in young patients presenting with abdominal pain, to prevent misdiagnosis of this fatal condition.

Germacrone ameliorates acute lung injury induced by intestinal ischemia-reperfusion by regulating macrophage M1 polarization and mitochondrial defects

Intestinal ischemia-reperfusion (I/R) injury severely affects the lungs. Germacrone (Ger) possesses anti-inflammatory and antioxidant properties. However, it is unclear whether it protects the lungs from I/R injury. In this study, we elucidate the mechanisms by which Ger protects lungs from I/R injury. C57BLKS/J male mice are subjected to I/R injury via complete clamping of the superior mesenteric artery. Ger is administered before intestinal I/R. Mitochondrial morphology is observed via electron microscopy. The histopathology of the lung tissues is monitored via hematoxylin-eosin and immunofluorescence staining. The mitochondrial oxygen consumption rate is measured via an XF96 extracellular flux analyzer. In the I/R mouse model, lung specimens present significant lung damage accompanied by increases in the levels of collagen III, vimentin, and α-SMA in lung tissues. After treatment with Ger, lung impairment and fibrosis in I/R-induced acute lung injury (ALI) model mice are restored, suggesting that Ger improves I/R-ALI. In addition, Ger administration decreases the release of inflammatory factors such as IL-1β, IL-6, and COX2, as well as the expressions of M1 macrophage markers, facilitating cell survival in the I/R-ALI model. Additionally, Ger (EC50: 47.16 μM) ameliorates mitochondrial dysfunction by increasing I/R-ALI-induced apoptosis, increasing the expression of SIRT1, and reducing the levels of HIF1-α, Nrf2, and OGG1 in MLE-12 cells. Ger may affect macrophage polarization and improve subsequent mitochondrial defects through the SIRT1-HIF1α-Nrf2 signaling pathway in MLE-12 cells, which ultimately improves lung function and lung inflammation in the I/R-ALI model.

Hyperspectral imaging combined with blood oxygen saturation for in vivo analysis of small intestinal necrosis tissue

Acute mesenteric ischemia (AMI) is a clinically significant vascular and gastrointestinal condition, which is closely related to the blood supply of the small intestine. Unfortunately, it is still challenging to properly discriminate small intestinal tissues with different degrees of ischemia. In this study, hyperspectral imaging (HSI) was used to construct pseudo-color images of oxygen saturation about small intestinal tissues and to discriminate different degrees of ischemia. First, several small intestine tissue models of New Zealand white rabbits were prepared and collected their hyperspectral data. Then, a set of isosbestic points were used to linearly transform the measurement data twice to match the reference spectra of oxyhemoglobin and deoxyhemoglobin, respectively. The oxygen saturation was measured at the characteristic peak band of oxyhemoglobin (560 nm). Ultimately, using the oxygenated hemoglobin reflectance spectrum as the benchmark, we obtained the relative amount of median oxygen saturation in normal tissues was 70.0 %, the IQR was 10.1 %, the relative amount of median oxygen saturation in ischemic tissues was 49.6 %, and the IQR was 14.6 %. The results demonstrate that HSI combined with the oxygen saturation computation method can efficiently differentiate between normal and ischemic regions of the small intestinal tissues. This technique provides a powerful support for internist to discriminate small bowel tissues with different degrees of ischemia, and also provides a new way of thinking for the diagnosis of AMI.

Optimizing Outcomes for Acute Mesenteric Ischemia in the Context of Hypogammaglobulinemia: A Detailed Analysis of Surgical and Medical Strategies

Acute mesenteric ischemia is a critical condition marked by a sudden loss of blood supply to the intestines, often leading to rapid tissue necrosis and severe clinical outcomes if untreated. In the context of hypogammaglobulinemia, an immunodeficiency characterized by decreased levels of immunoglobulins, this vascular emergency becomes even more daunting. Hypogammaglobulinemia can impair the immune system's response to both infection and ischemic injury, intensifying the severity of intestinal damage. This report describes the case of a 52-year-old female with hypogammaglobulinemia who presented with severe abdominal pain. Surgical exploration revealed 100 cm of necrotic small bowel extending from 150 cm distal to the ligament of Treitz to within 10 cm of the ileocecal valve. The necrotic section was surgically removed, and primary anastomosis was performed. This instance highlights the significant impact of immunodeficiency on the progression and management of acute mesenteric ischemia, demonstrating the critical need for early intervention and tailored management strategies, especially in immunocompromised patients, to prevent severe outcomes. The case illuminates the importance of recognizing immunodeficiency as a complicating factor in acute gastrointestinal emergencies, stressing the necessity for prompt and effective medical and surgical interventions to improve prognosis and patient outcomes in complex clinical scenarios.

Complex Traumatic Jejunal Perforation With Mesenteric Tear and Intussusception: A Case Report

Blunt abdominal trauma can result in a spectrum of injuries, ranging from superficial contusions to severe hollow viscus perforations. We present the case of a 52-year-old male involved in a bicycle-truck collision, leading to complex intra-abdominal injuries. The patient presented with acute abdominal pain and signs of peritonitis, prompting urgent diagnostic workup and surgical intervention. Imaging studies revealed pneumoperitoneum, free fluid, and multiple rib fractures indicative of significant trauma. Exploratory laparotomy unveiled a perforated jejunal loop with an associated mesenteric tear and intussusception, necessitating segmental bowel resection and repair. Histopathological analysis confirmed acute hemorrhagic inflammation consistent with traumatic perforation. This case highlights the challenges and complexities associated with blunt abdominal trauma, emphasizing the importance of prompt recognition, multidisciplinary management, and surgical intervention in optimizing patient outcomes.

Study of ischemic progression in different intestinal tissue layers during acute intestinal ischemia using swept-source optical coherence tomography angiography

In acute intestinal ischemia, the progression of ischemia varies across different layers of intestinal tissue. We established a mouse model and used swept-source optical coherence tomography (OCT) to observe the intestinal ischemic process longitudinally in different tissue layers. Employing a method that combines asymmetric gradient filtering with adaptive weighting, we eliminated the vessel trailing phenomenon in OCT angiograms, reducing the confounding effects of superficial vessels on the imaging of deeper vasculature. We quantitatively assessed changes in vascular perfusion density (VPD), vessel length, and vessel average diameter across various intestinal layers. Our results showed a significant reduction in VPD in all layers during ischemia. The mucosa layer experienced the most significant impact, primarily due to disrupted capillary blood flow, followed by the submucosa layer, where vascular constriction or decreased velocity was the primary factor.

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.

[Modern biochemical markers of acute mesenteric ischemia]

OBJECTIVE

To analyze modern literature data on biochemical markers of critical mesenteric ischemia.

MATERIAL AND METHODS

We analyzed the most promising, highly specific and sensitive biochemical markers of total and segmental intestinal damage following acute mesenteric ischemia. Analysis included domestic and foreign literature data between 2015 and 2023.

RESULTS

We identified the most easy-to-use for any hospitals biochemical markers with at least 90% sensitivity and specificity for further practical research.

CONCLUSION

Further prospective research will provide a new step in solving the problem of timely diagnosis of acute mesenteric circulatory disorders.

Superior Mesenteric Artery Stenosis Presenting as Chest Pain: Danger in Disguise

Chronic mesenteric ischemia (CMI), often known as abdominal angina, is a syndrome caused by a severe reduction in arterial flow to the digestive loops. It is an uncommon and underdiagnosed entity with potential severe adversities, such as acute mesenteric ischemia (AMI). Patients with coronary artery disease (CAD) are shown to also have mesenteric artery stenosis (MAS). By identifying risk variables, it may be possible to screen for mesenteric artery involvement in patients with CAD who exhibit an elevated risk. Here, we present a unique case of a person with severe retrosternal chest pain with postprandial angina, which turned out to be superior mesenteric artery (SMA) ostial stenosis.

Long-term outcome after implementation of endovascular-first strategy to treat acute mesenteric ischemia

OBJECTIVE

To evaluate the rationale of an aggressive endovascular-first strategy to treat elderly patients with acute mesenteric ischemia (AMI) by studying long-term survival, readmissions, and patients' discharge to home vs nursing facility a decade after an episode of AMI.

METHODS

The retrospective study cohort included 66 consecutive patients (all-comers) treated for arterial occlusive AMI between 2009 and 2013. Endovascular revascularization (EVR) was attempted in 50 patients (EVR+), whereas 16 patients were treated without attempted revascularization (EVR-). All patients were followed until death or September 2022. Studied outcomes included discharge status, long-term survival and cause of death and readmissions related to AMI.

RESULTS

The mean age of all 66 patients was 78 ± 10 years: 79 ± 9 years in the EVR+ group and 76 ± 12 years in the EVR- group. EVR was technically successful in 44 patients (88%); three patients underwent subsequent open revascularization after EVR failure. One-third required bowel resection after EVR. The 30-day mortality for all patients was 44%; 32% in the EVR+ group and 81% in the EVR- group. Only two survivors were permanently institutionalized, whereas all others were discharged to the same place they lived prior to the AMI episode. There were four AMI-related readmissions during the follow-up; all were in the EVR+ group. Two patients underwent reinterventions for recurrent AMI. One-year survival was 52% for EVR+ and 19% for EVR- patients. Five-year survival rates were 18% and 13%, respectively. The causes of deaths were mesenteric ischemia in 22, other cardiovascular event in 21, and non-cardiovascular cause in 19 patients. Four patients were alive at the end of the follow-up.

CONCLUSIONS

In this unselected elderly population with AMI, the aggressive strategy to attempt EVR resulted in a high revascularization rate and favorable outcomes. The high proportion of patients returning to their prior living status and low readmission rate after survival from AMI encourages active treatment of high-functioning elderly patients.

Acute management of mesenteric emergencies: Tailoring the solution to the problem

Acute mesenteric ischemia (AMI) constitutes a life-threatening problem that can result in death, multiorgan failure, and severe nutritional disability. Although AMI is a rare cause of acute abdominal emergencies, ranging between 1 and 2 individuals per 10,000, the morbidity and mortality rates are high. Arterial embolic etiology composes nearly one-half of AMIs, with a sudden onset of severe abdominal pain considered the most common symptom. Arterial thrombosis is the second most common cause of AMI, which presents similarly to arterial embolic AMI, although often more severe due to anatomic differences. Veno-occlusive causes of AMI are the third most common and are associated with an insidious onset of vague abdominal pain. Each patient is unique, and the treatment plan should be tailored to their individual needs. This may include considering the patient's age, comorbidities, and overall health, as well as their preferences and personal circumstances. A multidisciplinary approach involving specialists from different fields, such as surgeons, interventional radiologists, and intensivists, is recommended for the best possible outcome. Potential challenges in tailoring an optimal treatment plan for AMI may include delayed diagnosis, limited availability of specialized care, or patient factors that make some interventions less feasible. Addressing these challenges requires a proactive and collaborative approach, with regular review and adjustment of the treatment plan as needed to ensure the best possible outcome for each patient.

Exploring Outcomes Related to Residential Determinants in Acute Mesenteric Ischemia Patients

INTRODUCTION

To access the relationship between residential status and outcomes in surgical acute mesenteric ischemia (AMI) patients.

METHODS

Retrospective chart review of 153 AMI patients admitted to our institution between 2007 and 2021. Residential median income and Rural-Urban Commuting Area (RUCA) code were used as residential proxies.

RESULTS

Being of the female sex (odds ratio [OR] = 3.116 [1.276-7.609] P = 0.013) and having a vascular intervention performed (OR = 2.927 [1.087-7.883] P = 0.034) were both associated with a threefold increase in the risk of mortality. Increased age (OR = 1.037 [1.002-1.073] P = 0.039), elevated blood urea nitrogen (OR = 1.032 [1.012-1.051] P = 0.001), and living in higher residential income area (OR = 1.049 [1.009-1.091] P = 0.017) had a small, but statistically significant, increased risk of mortality. Patients in higher median income areas were less likely to undergo colonic resection (OR = 0.953 [0.911-0.997] P = 0.038) and tended to have a lower likelihood of receiving an ostomy (OR = 0.963 [0.927-1] P = 0.051). Being from urban or rural areas was not associated with mortality (OR = 1.565 [0.647-3.790] P = 0.321, although rural patients were more likely to undergo colon resection (OR = 2.183 [0.938-5.079] P = 0.070). Furthermore, rural patients were much more likely to be readmitted than urban dwellers (OR = 4.700 [1.022-21.618] P = 0.047).

CONCLUSIONS

AMI patients living in rural or small-town areas were more likely to be readmitted and tended to undergo colonic resection. Patients residing in higher income areas had a slightly higher risk of mortality but tended to be less likely to require ostomy or colonic resection. These findings suggest a potential need for postoperative care initiatives focused on AMI patients living in rural and lower income areas.

Plasma riboflavin fluorescence as a diagnostic marker of mesenteric ischemia-reperfusion injury in rats

Due to the delayed and vague symptoms, it is difficult to early diagnose mesenteric ischemia injuries in the dynamics of acute illness, leading to a 60-80 % mortality rate. Here, we found plasma fluorescence spectra can rapidly assess the severity of mesenteric ischemia injury in animal models. Ischemia-reperfusion damage of the intestine leads to multiple times increase in NADH, flavins, and porphyrin auto-fluorescence of blood. The fluorescence intensity ratio between blue-fluorophores and flavins can reflect the occurrence of shock. Using liquid chromatography and mass spectroscopy, we confirm that riboflavin is primarily responsible for the increased flavin fluorescence. Since humans absorb riboflavin from the intestine, its increase in plasma may indicate intestinal mucosa injury. Our work suggests a self-calibrated and reagent-free approach to identifying the emergence of fatal mesenteric ischemia in emergency departments or intensive care units.

Imaging of Bowel Ischemia: An Update, From the AJR Special Series on Emergency Radiology

Acute mesenteric ischemia is a life-threatening condition that results from abrupt reduction in or cessation of blood flow to the bowel. Characterized by nonspecific abdominal symptoms, mesenteric ischemia is infrequently encountered and commonly misdiagnosed, with potentially catastrophic consequences. Prompt clinical diagnosis and early implementation of therapeutic interventions are critical to improving patient outcomes. Because cross-sectional imaging plays a key role in the diagnosis of mesenteric ischemia, radiologists must be familiar with the varied imaging manifestations of intestinal ischemia. Thus, the objectives of this article are to review the various types and common causes of mesenteric ischemia and to describe its spectrum of multimodality imaging findings, with special attention to novel imaging techniques and emerging diagnoses.

Diseño y validación de una herramienta para la predicción de desenlaces adversos en pacientes con obstrucción intestinal por bridas: La escala HALVIC

Introducción. La obstrucción intestinal por bridas representa una causa común de consulta a los servicios de urgencias, pero hay poca claridad sobre qué pacientes tienen mayor riesgo de desarrollar complicaciones. El objetivo de este estudio fue diseñar y validar una escala de predicción de riesgo de desenlaces adversos en pacientes con obstrucción intestinal por bridas. Métodos. Estudio de cohorte retrospectivo realizado a partir de la base de datos MIMIC-IV. Se incluyeron pacientes adultos admitidos al servicio de urgencias entre 2008 y 2019, con diagnóstico de obstrucción intestinal por bridas. El desenlace principal fue el compuesto de resección intestinal, ingreso a unidad de cuidados intensivos y mortalidad por cualquier causa. Se diseñó una escala de predicción de riesgo asignando un puntaje a cada variable. Resultados. Se incluyeron 513 pacientes, 63,7 % hombres. El desenlace compuesto se presentó en el 25,7 % de los casos. La edad, historia de insuficiencia cardiaca y enfermedad arterial periférica, nivel de hemoglobina, recuento de leucocitos e INR constituyeron el mejor modelo de predicción de estos desenlaces (AUC 0,75). A partir de este modelo, se creó la escala simplificada HALVIC, clasificando el riesgo del desenlace compuesto en bajo (0-2 puntos), medio (3-4 puntos) y alto (5-7 puntos). Conclusión. La escala HALVIC es una herramienta de predicción simple y fácilmente aplicable. Puede identificar de manera precisa los pacientes con obstrucción intestinal por bridas con alto riesgo de complicaciones, permitiendo el ajuste individualizado de las estrategias de manejo para mejorar los desenlaces.

Advances in the diagnosis of non-occlusive mesenteric ischemia and challenges in intra-abdominal sepsis patients: a narrative review

Non-occlusive mesenteric ischemia (NOMI) is a type of acute mesenteric ischemia (AMI) with a high mortality rate mainly because of a delayed or misdiagnosis. Intra-abdominal sepsis is one of the risk factors for developing NOMI, and its presence makes early diagnosis much more difficult. An increase in routine abdominal surgeries carries a corresponding risk of abdominal infection, which is a complication that should not be overlooked. It is critical that physicians are aware of the possibility for intestinal necrosis in abdominal sepsis patients due to the poor survival rate of NOMI. This review aims to summarize advances in the diagnosis of NOMI, and focuses on the diagnostic challenges of mesenteric ischemia in patients with intra-abdominal sepsis.

Acute Mesenteric Ischemia in COVID-19 While Receiving Prophylactic Enoxaparin

COVID-19 infection is known to cause thromboembolic complications. This is why patients hospitalized with COVID-19 are put on prophylactic anticoagulation. We present the case of a Caucasian woman, aged 71 years, with risk factors of class 1 obesity, hyperlipidemia, and hypertension, initially admitted for COVID-19 pneumonia, and later developed acute mesenteric ischemia followed by pulmonary embolism. These incidents occurred while the patient was receiving high-dose prophylactic enoxaparin (40 mg twice daily). COVID-19 associated acute mesenteric ischemia is a complication with high mortality. Therefore, high suspicion, early recognition, and surgical management is necessary. Apart from that, this case emphasizes the question of whether there is a need for proactively administering therapeutic anticoagulation for high thrombotic risk COVID-19 patients to prevent deadly complications.

Acute mesenteric ischemia: updated guidelines of the World Society of Emergency Surgery

Acute mesenteric ischemia (AMI) is a group of diseases characterized by an interruption of the blood supply to varying portions of the intestine, leading to ischemia and secondary inflammatory changes. If untreated, this process may progress to life-threatening intestinal necrosis. The incidence is low, estimated at 0.09-0.2% of all acute surgical admissions, but increases with age. Although the entity is an uncommon cause of abdominal pain, diligence is required because if untreated, mortality remains in the range of 50%. Early diagnosis and timely surgical intervention are the cornerstones of modern treatment to reduce the high mortality associated with this entity. The advent of endovascular approaches in parallel with modern imaging techniques is evolving and provides new treatment options. Lastly, a focused multidisciplinary approach based on early diagnosis and individualized treatment is essential. Thus, we believe that updated guidelines from World Society of Emergency Surgery are warranted, in order to provide the most recent and practical recommendations for diagnosis and treatment of AMI.

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.