ACR Appropriateness Criteria ® imaging of mesenteric ischemia

[Epidemiology and diagnostics of mesenteric ischemia]

BACKGROUND

Mesenteric ischemia is a life-threatening condition with a complex etiology and diagnostics.

OBJECTIVE

Etiology, incidence, symptoms, and diagnostics of acute and chronic mesenteric ischemia.

MATERIAL AND METHODS

Literature search via PubMed with a focus on studies on the epidemiology and diagnostics of mesenteric ischemia and analysis of existing international guidelines.

RESULTS

The incidence of acute mesenteric ischemia is given as 0.63-12.9 per 100,000 people per year. There are no sufficiently reliable figures for chronic mesenteric ischemia, but an incidence of up to 3 per 100,000 inhabitants per year is generally assumed. The three-phase computed tomography has the highest diagnostic specificity and sensitivity.

CONCLUSION

In the presence of risk factors acute and chronic mesenteric ischemia should be considered as differential diagnoses in the presence of abdominal pain using three-phase computed tomography.

Could CT finding of gas in the sole mesenteric artery be a sign of a severe acute ischemia? Presentation of a rare fatal case and a literature review

Contrast-enhanced abdominal CT is the gold standard for the diagnosis of acute mesenteric ischemia (AMI). CT findings include several anomalies like bowel wall thickening, thinning, attenuation, decreased enhancement, dilated fluid-filled loops, pneumatosis, and portal venous gas. A rare case of gas found only in the superior mesenteric artery (SMA) is presented. A contrast-enhanced CT scan was performed in emergency on an 80-year-old man with vague and diffuse abdominal pain, which showed findings of occlusive AMI. Gas was found in the context of the SMA and its branches, but not in the mesenteric and portal veins. The patient underwent emergency surgery but he died the next day in the intensive care unit for complications. The rare CT finding of gas in SMA during an AMI should be considered a radiological sign of irreversible intestinal damage: surgical prompt intervention is needed, even if the mortality rate is high.

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.

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.

Antibiotic use in acute mesenteric ischemia: a review of the evidence and call to action

Acute mesenteric ischemia (AMI) is a life-threatening condition with a high mortality rate. The standard practice after making the diagnosis includes aggressive resuscitation, anticoagulation, followed by revascularization and resection of necrotic bowel. The role of empiric antibiotics in the management of AMI is not well defined in the literature. This review article aims to examine our current understanding on this matter, based on bench research and clinical studies. It is demonstrated in animal study model that the ischemia/reperfusion (I/R) injury damages intestinal epithelium, and subsequently lead to barrier dysfunction, a condition that can support bacterial translocation through a complex interplay between the intestinal epithelium, the intestinal immune system and the intestine's endogenous bacterial population. Based on this mechanism, it is possible that the use of antibiotics may help mitigate the consequences of I/R injury, which is examined in few animal studies. In clinical practice, many guidelines support the use of prophylactic antibiotics, based on a meta-analysis of randomized control trials (RCTs) demonstrating the benefit of antibiotics in multi-organ dysfunction syndrome. However, there is no direct reference to AMI in this meta-analysis. Most clinical studies that focus on AMI and mentions the use of antibiotics are retrospective and single institution, and very few comments on the role of antibiotics in their discussions. We conclude that there is limited evidence in literature to support the use of prophylactic antibiotic in AMI to improve outcome. More clinical studies with high level of evidence and basic science research are needed to improve our understanding on this topic and ultimately help build a better clinical pathway for patients with AMI.

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.

Review article: Acute superior mesenteric vessel ischaemia: A review of clinical practice and biomarkers

A patient with acute occlusion of the superior mesenteric vessels resulting in superior mesenteric vessel ischaemia (SMVI) who presents to the ED with abdominal pain and unremarkable abdominal examination risks delay in diagnosis and treatment with adverse outcome. A comprehensive literature search was performed, and the evidence was reviewed. To-date, there are no accurate biomarkers of SMVI and so, heightened awareness among ED staff and rapidly actioning diagnostic imaging and surgical referral will help fast-track the patient with SMVI to surgical management. Management of SMVI is challenging and requires ongoing communication. Prompt surgical intervention may help reduce mortality and morbidity in SMVI. SMVI is associated with significant mortality and morbidity. With the lack of accurate biomarkers, diagnosis and management is challenging and requires heightened awareness among ED staff for prompt surgical referral and intervention.

Epidemiology of Acute Mesenteric Ischemia: A Population-Based Investigation

BACKGROUND

There is a lack of population-based studies on acute mesenteric ischemia (AMI). We have therefore performed a nationwide epidemiological study in Estonia, addressing incidence, demographics, interventions and mortality of AMI.

METHODS

A retrospective population-based review was conducted of all adult cases of AMI accrued from the digital Estonian Health Insurance Fund and Causes of Death Registry for 2016-2020 based on international classification of diseases (ICD-10) diagnostic codes and procedure codes (NOMESCO).

RESULTS

Overall, 577 cases of AMI were identified-an annual incidence of 8.7 per 100,000. The median age was 79 (range 32-104) and 57% were female. Predominating comorbidities included hypertensive disease (81%), atherosclerosis (67%), and atrial fibrillation (52%). The majority of cases (60%) were caused by superior mesenteric artery occlusion (thrombosis 54%, embolism 12%, and unclear 34%). Inferior mesenteric artery occlusion occurred in 7%, non-occlusive mesenteric ischemia in 7%, venous thrombosis in 4%, whereas the type remained unclear in 21% of cases. 40% of patients received intervention (revascularization and/or intestinal resection) and 13% active non-operative treatment. In 21% an exploratory laparotomy or laparoscopy revealed unsalvageable bowel prompting end-of-life care, which was the only management in a further 25% of cases.

CONCLUSIONS

The population-based annual incidence of AMI in Estonia was 8.7 per 100,000 during the study period. The overall hospital mortality and 1 year mortality were 64% and 74%, respectively. In the 53% of patients who received active treatment hospital mortality was 32% and 1 year all-cause mortality was 51%.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier NCT04867499.

Development of a Novel Scoring Model to Estimate the Severity Grade of Mesenteric Artery Stenosis

Objective: This study aimed to derive a new scoring model from estimating the severity grade of mesenteric artery stenosis. We sought to analyze the relationship between the new scoring model and the development, treatment, and mortality of chronic mesenteric ischemia (CMI). Methods: This retrospective study included 242 patients (128 (53%) women and 114 (47%) men) with suspected CMI from January 2011 to December 2020. A weighted sum six-point score (CSI-score; the celiac artery is abbreviated by “C”, superior mesenteric artery by “S”, and inferior mesenteric artery by “I”) based on the number of affected vessels and the extent and grade of the stenosis or occlusion of the involved visceral arteries was derived by maximizing the area under the ROC curve. The calculated CSI-score ranged from 0 to 22. The patients were divided according to the best cut-off point into low-score (CSI-score < 8) and high-score (CSI-score ≥ 8) groups. Results: The area under the receiver operating characteristic curve (AUC) of the CSI-score was 0.86 (95% CI, 0.82−0.91). The best cut-off point of “8” represented the highest value of Youden’s index (0.58) with a sensitivity of 87% and specificity of 72%. The cohort was divided according to the cut-off point into a low-score group (n = 100 patients, 41%) and high-score group (n = 142 patients, 59%) and according to the clinical presentation into a CMI group (n = 109 patients, 45%) and non-CMI group (n = 133 patients, 55%). The median CSI-score for all patients was 10 (range: 0 -22). High-scoring patients showed statistically significant higher rates of coronary artery disease (54% vs. 36%, p = 0.007), chronic renal insufficiency (50% vs. 30%, p = 0.002), and peripheral arterial disease (57% vs. 16%, p < 0.001). A total of 109 (45%) patients underwent invasive treatment of the visceral arteries and were more often in the high-score group (69% vs. 11%, p < 0.001). Of those, 79 (72%) patients underwent primary endovascular treatment, and 44 (40%) patients underwent primary open surgery or open conversion after endovascular treatment. Sixteen (7%) patients died during the follow-up, with a statistically significant difference between high- and low-scoring patients (9% vs. 0%, p = 0.008). The score stratification showed that the percentage of patients treated with endovascular and open surgical methods, the recurrence of the stenosis or failure of the endovascular treatment, the need for a bypass procedure, and the mortality rates significantly increased in the subgroups. The CSI-score demonstrated an excellent ability to discriminate between patients who needed treatment and those who did not, with an AUC of 0.87 (95% CI, 0.82−0.91). Additionally, the CSI-score’s ability to predict the patients’ mortality was moderate, with an AUC of 0.73 (95% CI, 0.62−0.83). Conclusions: The new scoring model can estimate the severity grade of the stenosis of the mesenteric arteries. Our study showed a strong association of the score with the presence of chronic mesenteric ischemia, the need for treatment, the need for open surgery, and mortality.

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.

Acute mesenteric ischemia secondary to oral contraceptive-induced portomesenteric and splenic vein thrombosis: A case report

BACKGROUND

Mesenteric ischemia represents an uncommon complication of splanchnic vein thrombosis, and it is less infrequently seen in young women using oral contraceptives. Diagnosis is often delayed in the emergency room; thus, surgical intervention may be inevitable and the absence of thrombus regression or collateral circulation may lead to further postoperative ischemia and a fatal outcome.

CASE SUMMARY

We report a 28-year-old female patient on oral contraceptives who presented with acute abdominal pain. Her physical examination findings were not consistent with her symptoms of severe pain and abdominal distention. These findings and her abnormal blood tests raised suspicion of acute mesenteric ischemia (AMI) induced by splanchnic vein thrombosis. Contrast-enhanced abdominal computed tomography revealed ischemia of the small intestine with portomesenteric and splenic vein thrombosis (PMSVT). We treated the case promptly by anticoagulation after diagnosis. We then performed delayed segmental bowel resection after thrombus regression and established collateral circulation guided by collaboration with a multidisciplinary team. The patient had an uneventful postoperative course and was discharged 14 d after surgery and took rivaroxaban orally for 6 mo. In subsequent follow-up to date, the patient has not complained of any other discomfort.

CONCLUSION

AMI induced by PMSVT should be considered in young women who are taking oral contraceptives and have acute abdominal pain. Prompt anticoagulation followed by surgery is an effective treatment strategy.

Diabetic Ketoacidosis and Acute Mesenteric Ischemia in Adults: An Underreported Association

Acute mesenteric ischemia (AMI) is a rapidly fatal abdominal process that has been associated with diabetic ketoacidosis (DKA). This association has been reported among pediatric patients but has rarely been reported in adult patients. This case series presents two adult patients who presented with DKA and were subsequently found to have AMI. The first case is that of a 60-year-old male with a history of insulin-dependent type II diabetes mellitus who had a presentation and laboratory values consistent with DKA. He developed hypovolemic shock and worsening acidosis, and computed tomography angiography (CTA) revealed superior mesenteric artery occlusion. The second case is that of a 41-year-old male with a history of type I diabetes mellitus who presented with DKA and had no improvement despite aggressive resuscitation with fluids and insulin therapy. Computed tomography (CT) imaging of the abdomen revealed pneumatosis of the small bowel, indicative of ischemia. Both patients underwent bowel resection in the operating room. Given the high mortality and morbidity of AMI, it is an important diagnosis to consider in patients with DKA who have unresolving acidosis.

Radiology of the Mesentery

The recent description and re-classification of the mesentery as an organ prompted renewed interest in its role in physiological and pathological processes. With an improved understanding of its anatomy, accurately and reliably assessing the mesentery with non-invasive radiological investigation becomes more feasible. Multi-detector computed tomography is the main radiological modality employed to assess the mesentery due to its speed, widespread availability, and diagnostic accuracy. Pathologies affecting the mesentery can be classified as primary or secondary mesenteropathies. Primary mesenteropathies originate in the mesentery and subsequently progress to involve other organ systems (e.g., mesenteric ischemia or mesenteric volvulus). Secondary mesenteropathies describe disease processes that originate elsewhere and progress to involve the mesentery with varying degrees of severity (e.g., lymphoma). The implementation of standardized radiological imaging protocols, nomenclature, and reporting format with regard to the mesentery will be essential in improving the assessment of mesenteric anatomy and various mesenteropathies. In this article, we describe and illustrate the current state of art in respect of the radiological assessment of the mesentery.

Non-invasive assessment of mesenteric hemodynamics in patients with suspected chronic mesenteric ischemia using 4D flow MRI

PURPOSE

Chronic mesenteric ischemia (CMI) is a rare disease with a particularly difficult diagnosis. In this study, 4D flow MRI is used to quantitatively evaluate mesenteric hemodynamics before and after a meal in patients suspected of having CMI and healthy individuals.

METHODS

Nineteen patients suspected of CMI and twenty control subjects were analyzed. Subjects were scanned using a radially undersampled 4D flow MR sequence (PC-VIPR). Flow rates were assessed in the supraceliac (SCAo) and infrarenal aorta, celiac artery, superior mesenteric artery (SMA), left and right renal arteries, superior mesenteric vein (SMV), splenic vein, and portal vein (PV) in a fasting state (preprandial) and 20 min after a 700-kcal meal (postprandial). Patients were subcategorized into positive diagnosis (CMI+, N = 6) and negative diagnosis (CMI-, N = 13) groups based on imaging and clinical findings. Preprandial, postprandial, and percent change in flow rates were compared between subgroups using a Welch t test.

RESULTS

In controls and CMI- patients, SCAo, SMA, SMV, and PV flow increased significantly after meal ingestion. No significant flow increases were observed in CMI+ patients. Percent changes in SMA, SMV, and PV flow were significantly greater in controls compared to CMI+ patients. Additionally, percent changes in flow in the SMV and PV were significantly greater in CMI- patients compared to CMI+ patients.

CONCLUSIONS

4D flow MRI with large volumetric coverage demonstrated significant differences in the redistribution of blood flow in SMA, SMV, and PV in CMI+ patients after a meal challenge. This approach may assist in the challenging diagnosis of CMI.

Errors in MDCT diagnosis of acute mesenteric ischemia

The causes of diagnostic errors during daily medical practice can be several, mainly attributable to perceptual, interpretive and communication factors. The eventuality of radiological error is much more amplified in the emergency setting where a high number of complex multidetector-row computed tomography (MDCT) images must be evaluated quickly and critical time decisions need to be taken. In particular, in this context, the diagnosis of vascular intestinal diseases represents a crucial and difficult challenge in case of acute abdominal pain given the importance of being able to identify patient with high suspicious for intestinal ischemia and for a specific patient to judge if his ischemia is reversible or irreversible. Awareness of potential biases which can lead to diagnostic errors together with an extensive knowledge of the imaging features of these pathologies can lead to promptly recognize them with fewer mistakes, improving patients' outcome. This article reviews the MDCT findings of acute intestinal ischemia and acute colonic ischemia and analyzes the main types of diagnostic errors, underlining the importance of being familiarized with them to avoid misdiagnosis.

Colonic involvement in acute mesenteric ischemia: prevalence, risk factors, and outcomes

OBJECTIVES

This study aimed to investigate the prevalence, risk factors, and outcomes of colonic involvement in patients with acute mesenteric ischemia (AMI).

METHODS

CT scans from a prospective cohort of 114 AMI patients treated in an intestinal stroke center between 2009 and 2018 were blindly reviewed by two radiologists. Colon involvement was defined on CT scan by the presence of at least one of the following CT colonic features: wall thickening, pneumatosis, decreased wall enhancement, dilatation, or perforation. In addition, the clinical, biological, and radiological characteristics of patients with and without colonic involvement were compared to identify risk factors for colonic involvement on CT and its impact on morbidity and mortality.

RESULTS

Colonic involvement was identified in 32/114 (28%) patients with AMI, the right colon being more frequently involved (n = 29/32, 91%). Wall thickening (n = 27/32) was the most common CT finding. Occlusion of the inferior mesenteric artery was the only statistically significant risk factor for colonic involvement (35% vs. 15%, p = 0.02). Patients with colonic involvement on CT vs. those without had more frequently transmural colonic necrosis (13% vs. 0%, p = 0.006), short bowel syndrome (16% vs. 4%, p = 0.04), need for long-term parenteral support (19% vs. 5%, p = 0.03), and death during follow-up (22% vs. 10%, p = 0.03).

DISCUSSION

In patients with AMI, colonic involvement is associated with increased morbidity and mortality and should be carefully searched for during initial CT scan assessment.

KEY POINTS

• In a prospective cohort of acute mesenteric ischemia patients from an intestinal stroke center, 28% had an associated colonic involvement on CT. • Colonic involvement on CT most commonly affected the right colon, and the occlusion of the inferior mesenteric artery was the only risk factor. • Colonic involvement on CT was associated with increased morbidity and mortality and should be carefully searched for during initial CT scan assessment.

Contrast-Enhanced Ultrasound in Small Intestinal Ischemia: Proof of Concept

BACKGROUND

Small intestinal ischemia is a challenging diagnosis to make, even with the combination of imaging, laboratory analysis, and physical exam. This pilot study investigated the role of CEUS in evaluating small bowel wall vascularity in participants with suspected ischemia.

METHODS

In this IRB-approved pilot study, CEUS using perflutren lipid microspheres (DEFINITY®; Lantheus Medical Imaging Inc., N. Billerica, MA) was performed on participants determined by the clinical surgical team to have concerns for small intestinal ischemia. CEUS interpretations were performed at both the bedside and later by a blinded radiologist and compared to clinical imaging, surgical findings, or long-term clinical outcomes.

RESULTS

Fifteen CEUS examinations were performed on 14 participants. Five of the participants underwent exploratory laparotomy. Of these, one had small intestinal ischemia (without necrosis). Point of care CEUS demonstrated no evidence of bowel necrosis in any case, and delayed enhancement (indicative of intestinal ischemia) in three cases, resulting in a sensitivity of 100% (95% CI 2.5-100%) and specificity of 85.7% (95% CI 57.2-98.2%). CEUS correctly ruled out ischemia in 91.7% of cases with CT suspicion of small bowel obstruction and 60% of cases that underwent surgical intervention. Additionally, the rate of agreement between bedside interpretation and later radiologist read was high (93%).

CONCLUSIONS

CEUS is uniquely positioned for evaluating the small intestine, because of its high temporal resolution and immediacy of results. Combined with multi-sectional imaging for focal areas of ischemia and/or clinical suspicion for pan ischemia, CEUS may be a useful rule out test for small intestinal ischemia.

Diagnostic approach to small-bowel wall thickening: Beyond Crohn's disease and cancer

Although small-bowel wall thickening is a common manifestation of Crohn's disease and tumors, many other entities can give rise to similar imaging findings. The small bowel is difficult to access by endoscopy, so radiologic imaging tests play an essential role in the diagnosis of conditions involving the small bowel. The main objectives of this paper are to explain the definition of small-bowel wall thickening, analyze the patterns of involvement seen in multidetector computed tomography (MDCT) with intravenous contrast administration, and provide an image-based review of the different causes of small-bowel wall thickening. The differential diagnosis must include many entities because wall thickening can result from immune-mediated, infectious, or vascular causes, as well as from toxicity and other lesser-known entities. As the imaging appearance of many of these conditions overlap, clinical and laboratory findings are necessary to support the imaging diagnosis.

A case report of an isolated superior mesenteric artery dissection caused by childbirth

Background

The isolated superior mesenteric artery dissection (SMAD) is a rare and sporadic cause of acute abdominal pain. It most frequently affects male patients in their fifth to sixth decades, while our patient was a young woman who delivered a baby before the onset of abdominal pain. Possible risk factors for SMAD include hypertension, arteriosclerosis, abnormalities in elastic fibres, trauma, and pregnancy. In our case, delivery was suggested as a risk factor, which has not been reported previously.

Case presentation

A 27-year-old woman complained of acute severe upper abdominal pain and vomiting for 2 days after delivery. The patient had no significant medical history. Physical examination revealed epigastric mild tenderness. All routine blood tests, blood coagulation analysis, liver function tests and abdomen computed tomography showed no remarkable findings. Computed tomography angiography revealed a marked dissection 3.5 cm below the superior mesenteric artery ostium. Since distal blood flow existed and the patient was in a puerperal state with no evidences of mesenteric ischemia, she was managed conservatively, including intestinal rest by fasting, parenteral nutritional support and antibioticis, without anticoagulants or antiplatelet agents. Fortunately, she recovered smoothly and had no recurrence.

Conclusions

SMAD is a rare and sporadic cause of acute abdominal pain that occurs in young women after delivery.

The role of adropin, HIF-1α and apelin biomarkers in the diagnosis of acute mesentaric ischemia

OBJECTIVE

The absence of a specific biomarker for acute mesenteric ischemia diagnosis results in a delay in diagnosis and treatment, as well as a high mortality rate. The current research examined whether the proteins adropin, HIF-1α, and apelin may be used to help in the early detection of acute mesenteric ischemia.

MATERIALS AND METHODS

A total of 20 patients with acute mesenteric ischemia, 20 patients with abdominal pain, and 20 healthy controls were included in the study. The levels of adropin, HIF-1, and apelin in the serum were determined using the ELISA method.

RESULTS

Adropin concentrations were significantly higher in the acute mesenteric ischemia group than in the abdominal pain and healthy control groups (p < 0.05). HIF-1α levels were considerably greater in patients with acute mesenteric ischemia compared to both the abdominal pain group and the healthy control group (p < 0.05). There was no difference in apelin levels between the acute mesenteric ischemia and abdominal pain groups (p > 0.05). HIF-1α was found to be moderate (AUC: 0.705) and adropin was found to be a weak biomarker (AUC: 0.692) in the ROC analysis for acute mesenteric ischemia.

CONCLUSION

In this study of 20 patients with acute mesenteric ischemia, we found adropin and HIF-1α levels to be increased compared to patients with abdominal pain who did not have acute mesenteric ischemia.

Mesenteric Vessel Thrombosis Treatment Experience

BACKGROUND: One of the most serious diseases among all emergency abdominal pathology is an acute violation of the mesenteric blood circulation. The rapid development of intestinal ischemia results in its infarction and necrosis. AIM: The study aims to assess the survival rate of patients with mesenteric vascular thrombosis, taking into account, the predictor characteristics influence of disease development factors. METHODS: The study presents a retrospective analysis of mesenteric vascular thrombosis clinical cases for 2016–2019. During this period, there were 147 patients with an established diagnosis at the Irkutsk Clinical Hospital No. 1, 21 of them met the study criteria. RESULTS: According to the type of thrombosis, there were two groups – occlusive (Group I, n = 11) and non occlusive (Group II, n = 10). Four patients (36.3%) of Group I and 7 patients (70%) of Group II (p = 0.388) recovered from the disease. Three patients (27.2%) of Group I and 4 patients (40%) of Group II (p = 0.662) received conservative therapy, 2 of them (66.6%) in Group I and 4 (100%) in Group II (p = 0.724) recovered from the disease. In addition, the authors performed a mortality assessment, according to the timing of the visit to a medical institution. Four (50%) out of eight patients who applied in the first 12 h, 2 (66%) out of three – in the first 12–24 h, and 5 (50%) out of 10 for more than 24 h of illness had a positive treatment result in the combined group. CONCLUSION: The patients over 70 years old with peritoneal symptoms and established intestinal necrosis have an extremely unfavorable prognosis. The primary mesenteric vessel thrombosis with additional contrast angiography still gives a moderate treatment prognosis.

Ischemic bowel disease in 2021

Ischemic bowel disease (ISBODI) includes colon ischemia, acute mesenteric ischemia (AMI) and chronic mesenteric ischemia (CMI). Epidemiologically, colon ischemia is the most common type followed by AMI and CMI. There are various risk factors for the development of ISBODI. Abdominal pain is the common presenting symptom of each type. High clinical suspicion is essential in ordering appropriate tests. Imaging studies and colonoscopy with biopsy are the main diagnostic tests. Treatment varies from conservative measures to surgical resection and revascularization. Involvement of multidisciplinary team is essential in managing ISBODI. Although open surgery with revascularization plays an important role, recently there is an increasing interest in percutaneous endovascular treatment.

Problem-solving with MRI in acute abdominopelvic conditions, part 2: gynecological, obstetric, vascular, and renal diseases

The purpose of this article is to illustrate the benefits of magnetic resonance imaging (MRI) in the setting of abdominopelvic emergencies. Owing to intrinsically high soft-tissue contrast resolution, and ability to resolve different soft tissue, MRI holds notable advantages over other imaging modalities and can be used as a problem-solving tool. Additional advantages of MRI include lack of radiation-related risks to children and pregnant women, and the ability to acquire detailed diagnostic information even without intravenous contrast which can be beneficial in patients with contrast allergy and end-stage renal disease. In the part 2, the authors focus on MRI features of female pelvic gynecological diseases, pregnancy- related complications, abdominal vascular complications, and renal diseases.

Large Bowel Ischemia/Infarction: How to Recognize It and Make Differential Diagnosis? A Review

Ischemic colitis represents the most frequent form of intestinal ischemia occurring when there is an acute impairment or chronic reduction in the colonic blood supply, resulting in mucosal ulceration, inflammation, hemorrhage and ischemic necrosis of variable severity. The clinical presentation is variable and nonspecific, so it is often misdiagnosed. The most common etiology is hypoperfusion, almost always associated with generalized atherosclerotic disease. The severity ranges from localized and transient ischemia to transmural necrosis of the bowel wall, becoming a surgical emergency, with significant associated morbidity and mortality. The diagnosis is based on clinical, laboratory suspicion and radiological, endoscopic and histopathological findings. Among the radiological tests, enhanced-CT is the diagnostic investigation of choice. It allows us to make the diagnosis in an appropriate clinical setting, and to define the entity of the ischemia. MR may be adopted in the follow-up in patients with iodine allergy or renal dysfunctions, or younger patients who should avoid radiological exposure. In the majority of cases, supportive therapy is the only required treatment. In this article we review the pathophysiology and the imaging findings of ischemic colitis.

Endovascular therapy in acute mesenteric ischemia after coronary artery bypass grafting: a case report and literature review

In the pattern of abdominal complications after cardiac surgery, acute mesenteric ischemia is rare but high-mortality pathology. In the initial stages, the disease has no specific signs, which makes it difficult to perform early multislice computed tomography to diagnose it. Risk stratification and an individual approach to the choice of diagnostic and therapeutic measures aimed at early restoration of mesenteric blood flow will reduce the mortality in this complication.

Many faces of acute bowel ischemia: overview of radiologic staging

Acute bowel ischemia (ABI) can be life threatening with high mortality rate. In spite of the advances made in diagnosis and treatment of ABI, no significant change has occurred in the mortality over the past decade. ABI is potentially reversible with prompt diagnosis. The radiologist plays a central role in the initial diagnosis and preventing progression to irreversible intestinal ischemic injury or bowel necrosis. The most single imaging findings described in the literature are either non-specific or only present in the late stages of ABI, urging the use of a constellation of features to reach a more confident diagnosis. While ABI has been traditionally categorized based on the etiology with a wide spectrum of imaging findings overlapped with each other, the final decision for patient’s management is usually made on the stage of the ABI with respect to the underlying pathophysiology. In this review, we first discuss the pathologic stages of ischemia and then summarize the various imaging signs and causes of ABI. We also emphasize on the correlation of imaging findings and pathological staging of the disease. Finally, a management approach is proposed using combined clinical and radiological findings to determine whether the patient may benefit from surgery or not.

Influence of clinical suspicion on CT accuracy of acute mesenteric ischemia: Retrospective study of 362 patients

PURPOSE

Acute mesenteric ischemia (AMI) may be underdiagnosed when not clinically suspected before CT is performed. We assessed the influence of a clinical suspicion of AMI on the CT accuracy.

METHOD

This retrospective single-centre study included patients who underwent CT in 2014-2019 and had clinically suspected AMI and/or confirmed AMI. CT protocols were adapted based on each patient's presentation and on findings from unenhanced images. The CT protocol was considered optimal for AMI when it included arterial and portal venous phases. CT protocols, accuracy of reports, and outcomes were compared between the groups with and without suspected AMI before CT.

RESULTS

Of the 375 events, 337 (90 %) were suspected AMI and 66 (18 %) were AMI, including 28 (42 %) with and 38 without suspected AMI. These two groups did not differ significantly regarding the medical history, clinical presentation, or laboratory tests. The CT protocol was more often optimal for AMI in the group with suspected AMI (26/28 [93 %] vs. 28/38 [74 %], p = 0.046). Diagnostic accuracy was not different between groups with and without suspected AMI (26/28 [93 %] vs. 34/38 [90 %], p = 1.00). However, it was lower in the group without suspicion of AMI when the CT protocol was not optimal for AMI (27/28 [96 %] vs 7/10 [70 %], p = 0.048).

CONCLUSIONS

The negative influence of not clinically suspecting AMI can be mitigated by using a tailored CT protocol.

Chronic mesenteric ischaemia presenting as possible large bowl malignancy: an easily overlooked differential diagnosis

An 80-year-old woman presented to a regional emergency department with postprandial pain, weight loss and diarrhoea for 2 months and a Computed Tomography (CT) report suggestive of descending colon malignancy. Subsequent investigations revealed the patient to have chronic mesenteric ischaemia (CMI) with associated bowel changes. She developed an acute-on-chronic ischaemia that required emergency transfer, damage control surgery and revascularisation. While the patient survived, this case highlights the importance of considering CMI in elderly patients with vague abdominal symptoms and early intervention to avoid potentially catastrophic outcomes.

Diagnostic approach to small-bowel wall thickening: beyond Crohn's disease and cancer

Although small-bowel wall thickening is a common manifestation of Crohn's disease and tumors, many other entities can give rise to similar imaging findings. The small bowel is difficult to access by endoscopy, so radiologic imaging tests play an essential role in the diagnosis of conditions involving the small bowel. The main objectives of this paper are to explain the definition of small-bowel wall thickening, analyze the patterns of involvement seen in multidetector computed tomography (MDCT) with intravenous contrast administration, and provide an image-based review of the different causes of small-bowel wall thickening. The differential diagnosis must include many entities because wall thickening can result from immune-mediated, infectious, or vascular causes, as well as from toxicity and other lesser-known entities. As the imaging appearance of many of these conditions overlap, clinical and laboratory findings are necessary to support the imaging diagnosis.

Predictors and risk factors for intestinal necrosis in patients with mesenteric ischemia

Background

Mesenteric ischemia results in blood flow that is insufficient to meet metabolic demands and subsequent dysfunction of visceral organs, including arterial obstruction and venous thrombosis. Sustained mesenteric ischemia exhausts the ability of capillaries to provide oxygen and initiate an inflammatory reaction, and eventually leads to intestinal mucosal necrosis, a serious and potentially life-threatening condition. Therefore, it is essential that the predictors and risk factors for intestinal necrosis in patients with mesenteric thrombus are explored.

Methods

This study retrospectively enrolled 41 patients with mesenteric ischemia (including mesenteric vein embolism, mesenteric artery thrombosis, and portal vein thrombosis) who were admitted to the Department of Gastrointestinal Surgery, Beijing Tsinghua Changgung Hospital between May 2016 and October 2019; of the patients, 18 were further diagnosed with intestinal necrosis. Comparisons of symptoms, computed tomography angiography (CTA) features, and laboratory examination results were performed between mesenteric ischemia patients with and without intestinal necrosis.

Results

White blood cell count showed an excellent predictive ability for intestinal necrosis in patients with mesenteric ischemia, with an area under the receiver operating characteristic (ROC) curve of 0.772 (P=0.009). The four CTA features [pneumatosis (P=0.016), intestinal swelling (P=0.006), ascitic fluid (P<0.001), and decreased intestinal wall enhancement (P=0.004)] differed significantly between patients with and without intestinal necrosis. Peritonitis showed a strong association with intestinal necrosis (P=0.006) in the univariate analysis, and multivariate analysis further showed their association [odds ratio (OR): 8.53; 95%CI: 1.46-49.81; P=0.017].

Conclusions

White blood cell count is a potential predictor of intestinal necrosis. Peritonitis is a possible risk factor for intestinal necrosis in patients with mesenteric ischemia. A multi-center prospective study with a larger sample size needs to be performed to further investigate these findings.

Early and Midterm Outcomes of Open and Endovascular Revascularization of Chronic Mesenteric Ischemia

Background

Revascularization strategies for chronic mesenteric ischemia (CMI) include open (OR) and endovascular (ER) modalities. The primary objective of this study was to analyze the safety and effectiveness of OR and ER and the impact of clinical and morphological variables on early and midterm outcomes in a consecutive series of CMI patients in a tertiary referral center.

Patients and methods

From 2004 to 2017, all CMI patients treated with OR and ER were retrospectively identified. Patient records, preoperative imaging, as well as peri- and postoperative outcomes were analyzed. Univariable and multivariable analysis was performed to identify clinical or morphological variables affecting reintervention rates within 2 years.

Results

In total, 63 patients (33% male; mean age 71, range 60–76 years) were treated by ER (41 patients) or OR (22 patients) for CMI. Mean follow-up was 26 (10–71) months. 30-day mortality was 0.0% after ER and 4.5% after OR (p = 0.069); 30-day morbidity was 9.8% vs. 31.8%, respectively (p = 0.030). Length of stay was significantly longer after OR (14 vs. 4 days; p < 0.001). Freedom from reintervention rate after 2 years was 82% after OR and 73% after ER (p = 0.14). Overall survival did not differ after 2 years (OR 85% vs. ER 86%; p = 0.35). Multivariable analysis revealed that smoking was associated with higher risk of reintervention (hazard ratio, HR: 4.14; 95% confidence interval, CI 1.11–15.53; p = 0.03). Additionally, a nonsignificant trend of lower reintervention rates after OR was detected (HR 0.23 95% CI 0.05–1.08; p = 0.06).

Conclusion

Due to a lower invasiveness, despite the higher reintervention rate, an “endovascular first” strategy is justified and recommended.

Chronic mesenteric ischemia: Clinical practice guidelines from the Society for Vascular Surgery

BACKGROUND

Chronic mesenteric ischemia (CMI) results from the inability to achieve adequate postprandial intestinal blood flow, usually from atherosclerotic occlusive disease at the origins of the mesenteric vessels. Patients typically present with postprandial pain, food fear, and weight loss, although they can present with acute mesenteric ischemia and bowel infarction. The diagnosis requires a combination of the appropriate clinical symptoms and significant mesenteric artery occlusive disease, although it is often delayed given the spectrum of gastrointestinal disorders associated with abdominal pain and weight loss. The treatment goals include relieving the presenting symptoms, preventing progression to acute mesenteric ischemia, and improving overall quality of life. These practice guidelines were developed to provide the best possible evidence for the diagnosis and treatment of patients with CMI from atherosclerosis.

METHODS

The Society for Vascular Surgery established a committee composed of vascular surgeons and individuals experienced with evidence-based reviews. The committee focused on six specific areas, including the diagnostic evaluation, indications for treatment, choice of treatment, perioperative evaluation, endovascular/open revascularization, and surveillance/remediation. A formal systematic review was performed by the evidence team to identify the optimal technique for revascularization. Specific practice recommendations were developed using the Grading of Recommendations Assessment, Development, and Evaluation system based on review of literature, the strength of the data, and consensus.

RESULTS

Patients with symptoms consistent with CMI should undergo an expedited workup, including a computed tomography arteriogram, to exclude other potential causes. The diagnosis is supported by significant arterial occlusive disease in the mesenteric vessels, particularly the superior mesenteric artery. Treatment requires revascularization with the primary target being the superior mesenteric artery. Endovascular revascularization with a balloon-expandable covered intraluminal stent is the recommended initial treatment with open repair reserved for select younger patients and those who are not endovascular candidates. Long-term follow-up and surveillance are recommended after revascularization and for asymptomatic patients with severe mesenteric occlusive disease. Patient with recurrent symptoms after revascularization owing to recurrent stenoses should be treated with an endovascular-first approach, similar to the de novo lesion.

CONCLUSIONS

These practice guidelines were developed based on the best available evidence. They should help to optimize the care of patients with CMI. Multiple areas for future research were identified.

The radiologist's guide to duplex ultrasound assessment of chronic mesenteric ischemia

OBJECTIVE

This article reviews the relevant anatomy and physiology of the mesenteric vasculature, familiarizes the radiologist with the accepted diagnostic criteria for mesenteric artery stenosis and its role in the diagnosis of chronic mesenteric ischemia, describes Doppler imaging techniques, and provides protocols for the assessment and surveillance of the mesenteric vasculature before and after revascularization. It also discusses expected changes following revascularization and reviews common post-procedural complications.

RESULTS

Duplex sonography plays an important role in the diagnosis and management of chronic mesenteric ischemia (CMI). Establishing a successful diagnosis is dependent upon knowledge of mesenteric arterial anatomy and physiology as well as sufficient expertise in image optimization and scanning techniques. Although there has been a trend toward utilization of other noninvasive [computed tomographic angiography (CTA), magnetic resonance angiography (MRA), and invasive (digital subtraction angiography (DSA)] imaging modalities for assessment of the mesenteric vasculature, a new era of "imaging wisely" raises legitimate concerns about the effects of ionizing radiation as well as potential effects of CT and MR contrast agents. These concerns are obviated by the use of ultrasound, and recently developed techniques, such as contrast-enhanced ultrasound and vascular applications focused on the evaluation of slow flow, have revealed the vast potential of vascular ultrasound in the evaluation of chronic mesenteric ischemia.

CONCLUSION

Duplex sonography is a cost-effective and powerful tool that can be utilized for the accurate assessment of mesenteric vascular pathology, specifically mesenteric arterial stenosis, and for the evaluation of mesenteric arterial system post revascularization.

Amphetamine-induced small bowel ischemia - A case report

Nonocclusive mesenteric ischemia is most common in elderly patients with multiple comorbidities. Nevertheless, there are some reports of acute bowel ischemia in young patients with a history of recreational drug abuse. We describe the case of a 33-year-old patient who presented with acute abdominal pain following amphetamine consumption. Multidetector computed tomography showed nonocclusive segmental ischemia of the distal ileum, and the patient underwent emergency surgery with ileocecal resection. The patient recovered quickly and was discharged without any postoperative complications. An early and precise diagnosis of patients with intestinal ischemia having a history of amphetamine abuse is of utmost importance for prompt and proper treatment. Especially in younger patients, multidetector computed tomography should be tailored to use with less radiation. A single portal venous scan proved sufficient in our case.

Mesenteric venous thrombosis complicating acute appendicitis: A case series

INTRODUCTION

Acute appendicitis is one of the most common surgical conditions. In the current era it rarely presents in association with mesenteric venous thrombosis. We present 4 cases of mesenteric venous thrombosis occurring in the setting of acute appendicitis.

METHODS

We performed a retrospective review of Mayo Enterprise clinical database for inpatients with a diagnosis of acute appendicitis and venous thrombosis related ICD-10 codes. Charts for patients with a diagnosis of mesenteric venous thrombosis and acute appendicitis were reviewed to identify demographic data, findings at presentation, and management patterns.

RESULTS

A total of 1,615 inpatients were identified with a principle diagnosis of acute appendicitis across the Mayo Enterprise from October 1st, 2015- March 31st, 2019. Four inpatients with a diagnosis of acute appendicitis were also noted to have a mesenteric venous thrombosis at presentation resulting in an incidence of 0.25 %. Mean duration of symptoms at presentation was 12.25 days. All patients with acute appendicitis and mesenteric venous thrombosis were initially managed with a heparin drip, antibiotics, and intravenous fluids. Ultimately, 3 of 4 patients underwent appendectomy.

CONCLUSION

Mesenteric venous thrombosis complicating acute appendicitis is rare and typically presents in a delayed fashion. Patients without evidence of non-viable bowel are typically treated initially with intravenous fluid resuscitation, antibiotics, bowel rest, and anticoagulation with a heparin drip.

Non-occlusive Mesenteric Ischemia as a Fatal Complication in Acute Pancreatitis: A Case Series

BACKGROUND

Vascular complications of severe acute pancreatitis are well known and largely described unlike non-occlusive mesenteric ischemia, which is a rare and potentially fatal complication. Non-occlusive mesenteric ischemia is an acute mesenteric ischemia without thrombotic occlusion of blood vessels, poorly described as a complication of acute pancreatitis.

METHODS

We retrospectively reviewed a prospectively maintained registry of all pancreatic diseases referred to our center from 2013 to 2018, in order to determine the causes of early death. We identified three patients who died within 48 h after hospital admission from severe acute pancreatitis complicated by irreversible non-occlusive mesenteric ischemia. Their clinical presentation, management, and outcomes were herein reported.

RESULTS

Three consecutive patients with severe acute pancreatitis developed non-occlusive mesenteric ischemia within the first 5 days after onset of symptoms and died 48 h after non-occlusive mesenteric ischemia diagnosis despite optimal intensive care management and surgery, giving a prevalence of 3/609 (0.5%). Symptoms were unspecific with consequently potential delayed diagnosis and management. High doses of norepinephrine required for hemodynamic support (n = 3) potentially leading to splanchnic vessels vasoconstriction, transient hypotension (n = 3), and previous severe ischemic cardiomyopathy (n = 1) could be involved as precipitating factors of non-occlusive mesenteric ischemia.

CONCLUSION

Non-occlusive mesenteric ischemia can be a fatal complication of acute pancreatitis but is also challenging to diagnose. Priority is to reestablish a splanchno-mesenteric perfusion flow. Surgery should be offered in case of treatment failure or deterioration but is still under debate in early stage, to interrupt the vicious circle of intestinal hypoperfusion and ischemia.

[Diagnosing acute organ ischemia : A practical guide for the emergency and intensive care physician]

Ischemia refers to a reduction or interruption of the blood flow to one or more organs. Early recognition of shock, a global ischemic state of the body, is of key importance in emergency and intensive care medicine. The physical examination and point-of-care laboratory diagnostics (i.e. lactate, base deficit, central/mixed venous oxygen saturation, venous-arterial carbon dioxide partial tension) are the methods of choice to diagnose shock in clinical practice. Importantly, a state of shock can also be present in patients with normo- or hypertensive arterial blood pressures. In shock, hypoperfusion of vital and visceral organs occurs. In the second part of this article, physical examination techniques, laboratory and diagnostic methods to detect shock-related hypoperfusion of the brain, heart, kidney and gastrointestinal tract are reviewed.

Ischemic Gut in Critically Ill (Mesenteric Ischemia and Nonocclusive Mesenteric Ischemia)

Ischemic gut or splanchnic hypoperfusion is a life-threatening emergency and it is associated with high mortality. It requires prompt diagnosis and intervention to establish the mesenteric blood flow, hence an attempt to avoid gut necrosis. Despite the understanding of pathogenesis of acute mesenteric ischemia and advanced treatment and revascularization techniques, it still remains a big diagnostic dilemma for the clinicians. Any delay in diagnosis and appropriate treatment affects the overall outcome of the patient. The high incidence of sepsis and multiorgan failure requires high-quality intensive care management.

How to cite this article: Gupta S, Tomar DS. Ischemic Gut in Critically Ill (Mesenteric Ischemia and Nonocclusive Mesenteric Ischemia). Indian J Crit Care Med 2020;24(Suppl 4):S157–S161.

Superior mesenteric artery endarterectomy for chronic mesenteric ischemia: A viable alternative in poor candidates for endovascular interventions

Background

Chronic mesenteric ischemia can be treated with either endovascular approaches or surgical revascularization. Recent data suggest that surgery leads to more durable symptom relief with similar long-term survival compared to transcatheter angioplasty. Splanchnic vessel endarterectomy has been shown to lead to longer freedom from recurrence compared to the more commonly used surgical bypass procedure.

Methods

We retrospectively reviewed the medical records of patients with chronic mesenteric ischemia who were considered poor candidates for endovascular repair and therefore underwent superior mesenteric artery endarterectomy in our institution. Study period was April 2016 to April 2018.

Results

A 73-year-old female and a 69-year-old male patient fulfilled our inclusion criteria. Extensive stenosis of the celiac axis and the superior mesenteric artery was found in both patients. superior mesenteric artery endarterectomy was performed in both cases. Endarterectomy was closed using a polytetrafluoroethylene patch. Both patients are alive and symptom-free at one year postoperatively with no signs of restenosis.

Conclusions

Our institutional outcomes are in line with recent literature supporting superior mesenteric artery endarterectomy as a viable alternative to surgical bypass in patients with chronic mesenteric ischemia who are suboptimal candidates for endovascular angioplasty and stenting.

Necessity of revascularization for acute mesenteric ischemia in symptomatic patients with spontaneous isolated dissection of the superior mesenteric artery

Objectives

We evaluated the necessity of revascularization for acute mesenteric ischemia in symptomatic patients with spontaneous isolated dissection of the superior mesenteric artery.

Methods

This retrospective study included 28 consecutive, symptomatic patients with spontaneous isolated dissection of the superior mesenteric artery treated at our hospital between December 2005 and December 2017. Patients with concomitant aortic dissection were excluded. We reviewed the patients’ clinical presentation; laboratory evaluations; computed tomography findings, including the true lumen residual ratio (i.e., the minimum true lumen size compared to the diameter of the transverse section of the dissected artery) at the time of admission; the number of patients who were suspected of having bowel ischemia; and the number of patients who required surgical or endovascular treatment and their outcomes. Additionally, to evaluate the true lumen residual ratio in symptomatic patients with bowel ischemia, the true lumen residual ratio in those with abnormal laboratory data were compared with that in those without abnormal laboratory data. Initial true lumen residual ratio values were also compared with final values. Furthermore, we assessed the clinical details of patients who had bowel necrosis. Categorical variables were compared using the χ2 test or Fisher’s exact test, and continuous values were presented as either the mean ± standard deviation or median (interquartile range 25–75%). Variables were analyzed using Student’s t-test or the Mann–Whitney U test.

Results

The patients’ age ranged between 41 and 85 years, and 25 were men. Although nine patients were suspected of having acute mesenteric ischemia, only one underwent bowel resection. None of the patients had an indication for revascularization. The true lumen residual ratio of the nine patients with abnormal laboratory data were significantly lower than those of the 19 without abnormal laboratory data (10 [0–25]% vs. 40 [20–50]%, p = 0.005). The patient who underwent bowel resection had a true lumen residual ratio of 10%; however, there was no obvious abnormal laboratory data suggestive of bowel necrosis. Dissections were managed conservatively in all patients. True lumen residual ratio increased from initial value of 30 (10–48)% to 98 (60-100)%at the final imaging study ( p < 0.0001). There were no adverse events related to the mesenteric circulation during the follow-up period of 2–11 years.

Conclusions

Reintervention is rarely required for spontaneous isolated dissection of the superior mesenteric artery, even in symptomatic patients, and spontaneous resolution of the luminal compromise is the rule.

Aorto-mesenteric Bypass for the Treatment of Chronic Mesenteric Ischemia

Chronic mesenteric artery disease has a much lower incidence than the acute one, but it raises the same problems in terms of patient survival. The long-term outcomes for open surgery are crucial for the right choice of a particular technique. We present the case of a 39-year-old female patient with a history of total nephrectomy, chronic kidney failure, and hypertension, who presented in the Emergency Department with abdominal pain with high intensity, for which she was admitted to the General Surgery Department. Abdominal computed tomography angiography was performed, which indicated the diagnosis of partial upper mesenteric artery stenosis. The patient underwent surgery, during which a retrograde aorto-mesenteric bypass with a Gore-Tex 5 mm diameter prosthesis was performed. In situations where the endovascular approach fails or has no indication (multiple incidence lesions from the origin of the superior mesenteric artery), open surgery is the indication in chronic mesenteric ischemia.

Mesenteric ischemia: what the radiologist needs to know

Acute mesenteric ischemia (AMI) is a life-threatening condition that often presents with abdominal pain. Early diagnosis with contrast-enhanced computed tomography and revascularization can reduce the overall mortality in AMI. This article reviews practical etiological classification, pathophysiology of imaging manifestations and common pitfalls in intestinal ischemia.

Acute mesenteric ischaemia: imaging and intervention

Acute mesenteric ischaemia (AMI) is an abdominal emergency in which an acute reduction in mesenteric arterial supply threatens bowel viability and may result in bowel infarction, perforation, and death. Despite improvements in diagnosis and treatment over recent decades, mortality rates in AMI remain very high. This article discusses the aetiological classification, pathophysiology, and clinical aspects of AMI. The specific imaging characteristics of each aetiological type of AMI are detailed and the role of different imaging methods in the diagnosis of AMI is discussed. Surgery is the established treatment of choice for AMI, but there is increasing use of endovascular techniques in treating AMI in cases where there are no clinical features of peritonism or radiological evidence of irreversible ischaemia. This article reviews the evidence for different diagnostic and management strategies for patients with AMI and discusses the advantages and disadvantages of surgical and endovascular treatments. Endovascular techniques have been reported to have high technical success rates and favourable outcomes when compared to open surgery; however, patient selection bias and a paucity of data limit the conclusions that can be drawn.

Detection of Intestinal Tissue Perfusion by Real-Time Breath Methane Analysis in Rat and Pig Models of Mesenteric Circulatory Distress

OBJECTIVES

Methane (CH4) breath test is an established diagnostic method for gastrointestinal functional disorders. Our aim was to explore the possible link between splanchnic circulatory changes and exhaled CH4 in an attempt to recognize intestinal perfusion failure.

DESIGN

Randomized, controlled in vivo animal study.

SETTING

University research laboratory.

SUBJECTS

Anesthetized, ventilated Sprague-Dawley rats (280 ± 30 g) and Vietnamese minipigs (31 ± 7 kg).

INTERVENTIONS

In the first series, CH4 was administered intraluminally into the ileum before 45 minutes mesenteric ischemia or before reperfusion in non-CH4 producer rats to test the appearance of the gas in the exhaled air. In the porcine experiments, the superior mesenteric artery was gradually obstructed during consecutive, 30-minute flow reductions and 30-minute reperfusions achieving complete occlusion after four cycles (n = 6), or nonocclusive mesenteric ischemia was induced by pericardial tamponade (n = 12), which decreased superior mesenteric artery flow from 351 ± 55 to 182 ± 67 mL/min and mean arterial pressure from 96.7 ± 18.2 to 41.5 ± 4.6 mm Hg for 60 minutes.

MEASUREMENTS AND MAIN RESULTS

Macrohemodynamics were monitored continuously; RBC velocity of the ileal serosa or mucosa was recorded by intravital videomicroscopy. The concentration of exhaled CH4 was measured online simultaneously with high-sensitivity photoacoustic spectroscopy. The intestinal flow changes during the occlusion-reperfusion phases were accompanied by parallel changes in breath CH4 output. Also in cardiac tamponade-induced nonocclusive intestinal ischemia, the superior mesenteric artery flow and RBC velocity correlated significantly with parallel changes in CH4 concentration in the exhaled air (Pearson's r = 0.669 or r = 0.632, respectively).

CONCLUSIONS

we report a combination of in vivo experimental data on a close association of an exhaled endogenous gas with acute mesenteric macro- and microvascular flow changes. Breath CH4 analysis may offer a noninvasive approach to follow the status of the splanchnic circulation.