Intestinal Ischemia: US-CT findings correlations

Abdominal Emergencies in Cancer Patients

Abdominal emergencies in cancer patients encompass a wide spectrum of oncologic conditions caused directly by malignancies, paraneoplastic syndromes, reactions to the chemotherapy or often represent the first clinical manifestation of an unknown malignancy. Not rarely, clinical symptoms are the tip of an iceberg. In this scenario, the radiologist is asked to exclude the cause responsible for the patient's symptoms, to suggest the best way to manage and to rule out the underlying malignancy. In this article, we discuss some of the most common abdominal oncological emergencies that may be encountered in an emergency department.

Abdominal compartment syndrome: what radiologist needs to know

The intra-abdominal hypertension (IAH) and the abdominal compartment syndrome (ACS) are life-threatening conditions with a significant rate of mortality; therefore, early detection is paramount in their optimal management. IAH is diagnosed when the intra-abdominal pressure (IAP) is more than 12 mmHg. It can occur when the intra-abdominal volume increases (ileus, ascites, trauma, pancreatitis, etc.) and/or the abdominal wall compliance decreases. IAH can cause decreased venous flow, low cardiac output, renal impairment, and decreased respiratory compliance. Consequently, these complications can lead to multiple organ failure and induce the abdominal compartment syndrome (ACS) when IAP rises above 20 mmHg. The diagnosis is usually made with intravesical pressure measurement. However, this measurement was not always possible to obtain; therefore, alternative diagnostic techniques should be considered. In this setting, computed tomography (CT) may play a crucial role, allowing the detection and characterization of pathological conditions that may lead to IAH. This review is focused on the pathogenesis, clinical features, and radiological findings of ACS, because their presence allows radiologists to raise the suspicion of IAH/ACS in critically ill patients, guiding the most appropriate treatment.

Outcome of laparotomy and conservative treatment of patients with acute mesenteric venous ischemia with viable bowel

BACKGROUND

Acute mesenteric ischemia (AMI) is one of the most serious abdominal emergencies. Predicting the onset of bowel necrosis that warrants surgical intervention is of paramount importance in AMI. The present study aimed to investigate the outcome of patients with AMI secondary to mesenteric venous occlusion (MVO) and the consequence of non-therapeutic exploratory laparotomy.

METHODS

The records of 132 patients with AMI were retrospectively reviewed. The outcome of patients with acute mesenteric venous ischemia (AMVI) and viable bowel was analyzed based on the method of treatment: conservative versus surgical. The impact of non-therapeutic laparotomy on the outcome of patients with AMVI in terms of morbidity, readmission, and mortality was analyzed.

RESULTS

Forty-seven patients (34 male) with AMVI had viable bowel. Of the 47 patients with viable bowel, 8 (17%) had an exploratory non-therapeutic laparotomy, whereas 39 patients were treated conservatively. Patients who had non-therapeutic laparotomy had significantly higher complication (50 vs 5.1%, p = 0.005) and readmission rates (37.5 vs 5.1%, p = 0.03) and longer hospital stay (8.5 vs 7 days, p = 0.02) than those treated conservatively. Patients with bowel necrosis who had a therapeutic laparotomy had slightly lower rates of morbidity and mortality as compared to patients with viable bowel who underwent a non-therapeutic laparotomy.

CONCLUSION

Careful assessment and informed decision-making in patients with AMVI are crucial to avoid unnecessary surgical intervention that can result in higher rates of complications and readmission and extended hospital stay.

A Pictorial Essay Describing the CT Imaging Features of COVID-19 Cases throughout the Pandemic with a Special Focus on Lung Manifestations and Extrapulmonary Vascular Abdominal Complications

With the Omicron wave, SARS-CoV-2 infections improved, with less lung involvement and few cases of severe manifestations. In this pictorial review, there is a summary of the pathogenesis with particular focus on the interaction of the immune system and gut and lung axis in both pulmonary and extrapulmonary manifestations of COVID-19 and the computed tomography (CT) imaging features of COVID-19 pneumonia from the beginning of the pandemic, describing the typical features of COVID-19 pneumonia following the Delta variant and the atypical features appearing during the Omicron wave. There is also an outline of the typical features of COVID-19 pneumonia in cases of breakthrough infection, including secondary lung complications such as acute respiratory distress disease (ARDS), pneumomediastinum, pneumothorax, and lung pulmonary thromboembolism, which were more frequent during the first waves of the pandemic. Finally, there is a description of vascular extrapulmonary complications, including both ischemic and hemorrhagic abdominal complications.

Abdominal Sonographic Evaluation: In the Field, at the Hospital, and After Surgery

Abdominal sonography is currently a routine procedure in the evaluation of colic in the horse. This imaging technique is used in both the assessment of the horse presented in the emergency setting with acute colic and the assessment of the horse presented for chronic or recurrent colic in the nonemergency setting. Sonography for colic evaluation is used by specialists in different disciplines and by general practitioners in the ambulatory and hospital settings. In this review, we will focus on indications and clinical interpretation of findings as well as recent developments in abdominal sonography.

Gastrointestinal Ultrasound in Emergency Setting

Acute bowel diseases are responsible for more than one third of subjects who were referred to the emergency department for acute abdominal pain and gastrointestinal evaluation. Gastrointestinal ultrasound (GIUS) is often employed as the first imaging method, with a good diagnostic accuracy in the setting of acute abdomen, and it can be an optimal diagnostic strategy in young females due to the radiation exposure related to X-ray and computed tomography methods. The physician can examine the gastrointestinal system in the area with the greatest tenderness by ultrasound, thus obtaining more information and data on the pathology than the standard physical examination. In this comprehensive review, we have reported the most relevant indications and advantages to using ultrasound in the investigation of abdominal acute pain.

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.

Neutrophil-lymphocyte ratio and platelet-lymphocyte ratio use in detecting bowel ischaemia in adhesional small bowel obstruction

BACKGROUND

Bowel ischaemia significantly increases morbidity and mortality from adhesional small bowel obstruction. Current biomarkers and clinical parameters have poor predictive value for ischaemia. Our study investigated whether neutrophil-lymphocyte ratio (NLR) and platelet-lymphocyte ratio (PLR) could be used to predict bowel ischaemia in adhesional small bowel obstruction.

METHODS

This single-centre retrospective study collected clinical, biochemical and radiological data from patients with adhesional small bowel obstruction between 2017 and 2020 who underwent operative management. The presence or absence of bowel ischaemia/infarction was used to distinguish two populations. Biochemical markers on admission and immediately prior to operation were collected to give platelet-lymphocyte ratio (PLR₀ and PLR_PRE-OP , respectively) and neutrophil-lymphocyte ratio (NLR₀ and NLR_PRE-OP , respectively). SAS 9.4 (SAS Institute Inc., Cary, NC) software was used for data analysis with Mann-Whitney U testing for continuous variables and Pearson Chi-square test for categorical variables. Sensitivity and specificity for PLR and NLR were calculated by means of receiver operating characteristic (ROC) curve analysis.

RESULTS

Twenty-seven patients had intra-operative bowel ischaemia whilst the remaining 73 had no evidence of bowel ischaemia. Both median PLR_PRE-OP and NLR_PRE-OP were significantly higher in patients with bowel ischaemia compared to those without (PLR_PRE-OP 272 [IQR 224-433] and 231 [IQR 146-295] respectively, P = 0.027; NLR_PRE-OP 12.5 [IQR 8.6-21.3] v. 5.5 [IQR 3.5-10.2] respectively, P ≤ 0.001). Area under the receiver operator characteristic curve (AUC) was 0.762 for NLR_PRE-OP , with a sensitivity of 85.1% and specificity of 63% for NLR 7.4.

CONCLUSION

Raised NLR is predictive of bowel ischaemia in patients with adhesional small bowel obstruction.

Use of Translational, Genetically Modified Porcine Models to Ultimately Improve Intestinal Disease Treatment

For both human and veterinary patients, non-infectious intestinal disease is a major cause of morbidity and mortality. To improve treatment of intestinal disease, large animal models are increasingly recognized as critical tools to translate the basic science discoveries made in rodent models into clinical application. Large animal intestinal models, particularly porcine, more closely resemble human anatomy, physiology, and disease pathogenesis; these features make them critical to the pre-clinical study of intestinal disease treatments. Previously, large animal model use has been somewhat precluded by the lack of genetically altered large animals to mechanistically investigate non-infectious intestinal diseases such as colorectal cancer, cystic fibrosis, and ischemia-reperfusion injury. However, recent advances and increased availability of gene editing technologies has led to both novel use of large animal models in clinically relevant intestinal disease research and improved testing of potential therapeutics for these diseases.

Small bowel obstruction and intestinal ischemia: emphasizing the role of MDCT in the management decision process

The objective of this article is to assess the computed tomography (CT) findings of small bowel obstruction (SBO) complicated by ischemia. SBO is a frequent clinical entity characterized by high morbidity and mortality. The radiologic aim is not just to diagnose the obstruction itself but to rule out the presence of complications related to SBO. This is crucial for differentiating which patients can be safely treated non-operatively from the ones who may need an urgent surgical approach. The main complication of SBO is intestinal ischemia. In the emergency setting, CT imaging is the modality of choice for SBO because of its ability to assess the bowel wall, the supporting mesentery and peritoneal cavity all in one. On the other hand, the radiologist who documents an intestinal ischemia should think about SBO as possible cause. In this case, the main finding which helps the radiologist in the identification of SBO is the presence of multiple and packed valvulae conniventes in the dilated bowel wall and the "transition zone" that indicates the passage between compressed and decompressed small bowel, otherwise the localization of the obstruction cause. Once the site of obstruction has been recognized, the other issue is to assess the cause of obstruction, considering that the most common cause of SBO remains "unidentified" and related to intra-abdominal adhesions. After that, the following most important point is to rule out the presence of an ischemic bowel and mesenteric changes associated to SBO. CT signs of bowel ischemia include reduced or increased bowel wall enhancement, mesenteric edema or engorgement, fluid or free air in the peritoneal cavity. This condition usually leads to an urgent laparotomy and, in some cases, to a surgical resection.

Contrast-enhanced ultrasonographic findings of non-occlusive mesenteric ischemia: a case series

PURPOSE

Diagnosis of non-occlusive mesenteric ischemia (NOMI) is difficult, with diagnostic imaging being mainly performed using angiography or contrast-enhanced computed tomography. Contrast-enhanced ultrasonography (CEUS) offers an alternative diagnostic method, although diagnosis of NOMI using CEUS is not common. In this report, we review CEUS findings in a series of patients with NOMI.

METHODS

The records of patients diagnosed with NOMI who underwent a surgical procedure in our institution between January 2015 and February 2020 were retrospectively assessed. Grayscale ultrasonography and CEUS findings were evaluated.

RESULTS

Ten patients (mean age 65 ± 25 years, 7 men) were studied. Grayscale ultrasonography revealed bowel dilatation, the presence of intestinal pneumatosis, portal venous gas, bowel wall thickening, and no or decreased peristalsis. A CEUS finding of note was a partial lack of enhancement of the bowel wall.

CONCLUSION

In a small case series of 10 patients with surgically/histopathology confirmed NOMI, partial lack of ultrasound contrast-enhancement of the bowel wall was observed.

Usefulness of damage control approach in patients with limited acute mesenteric ischemia: a prospective study of 85 patients

To evaluate the efficacy of the damage control approach by two-step surgical procedure in not critical patients (without sepsis or septic shock) with peritonitis from limited acute mesenteric ischemia. From April 2013 to April 2020, 85 patients [49 (57.7%) women and 36 (42.3%) men, median age 69.5 (range 38-92)] were enrolled in this study and underwent emergency surgery. After resection of ischemic bowel, basing on the individual decision of the single surgeon, the patients underwent primary end-to-end anastomosis (Group 1) or damage control approach (Group 2) including primary laparotomy with resection of ischemic bowel, temporary abdominal closure and a second-look procedure at 48 h with re-evaluation of bowel vitality. Forty-seven (55.3%) patients underwent one-stage surgical treatment and 38 (44.7%) patients received a two-step procedure. In the latter group, at second exploration, 8 (21%) patients required a further intestinal resection, due to mesenteric ischemia progression. Both anastomosis dehiscence rate and need for ileostomy in Group 1 patients were significantly higher than in Group 2 (23.4% vs 5.3%: p = 0.03 and 19.1% vs 2.6%: p = 0.03; Fisher's exact test). No significative differences in mortality and morbidity rate were found between the two groups. The damage control approach by two-step surgical procedure may represent a valid innovative option in the management of not critical patients with limited acute mesenteric ischemia, achieving a better clinical outcome if compared with surgical treatment by one-step procedure.

Imaging spectrum of abdominal manifestations of COVID-19

Coronavirus disease 2019 (COVID-19) has posed a serious threat to global public health with its rapid spread, high fatality, and severe burden on health care providers all over the world. Although COVID-19 has been established as a respiratory tract infection, it can manifest with gastrointestinal symptoms as a consequence of direct infection by the virus or due to inflammation-mediated cytotoxicity. It has been observed that COVID-19 patients presenting with gastrointestinal symptoms tend to progress to a severe form of disease with increased morbidity and mortality, thus indicating the need for timely management. COVID-19 manifests with a wide spectrum of radiologic findings on gastrointestinal tract imaging, encompassing bowel abnormalities, hepato-biliary and pancreatic involvement, vascular occlusion, and solid organ infarction. Early recognition of these imaging features can facilitate timely treatment of COVID-19 associated gastrointestinal tract complications and may prompt the diagnosis of COVID-19 in patients with atypical disease manifestations. The aim of this article is to provide an overview of the various gastrointestinal imaging manifestations that can be encountered in patients with COVID-19, with an emphasis on early diagnosis of the disease as well as treatment related complications.

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.

Ultrasound of Small Bowel Obstruction: A Pictorial Review

Small bowel obstruction (SBO) is a common condition requiring urgent attention that may involve surgical treatment. Imaging is essential for the diagnosis and characterization of SBO because the clinical presentation and results of laboratory tests may be nonspecific. Ultrasound is an excellent initial imaging modality for assisting physicians in the rapid and accurate diagnosis of a variety of pathologies to expedite management. In the case of SBO diagnosis, ultrasound has an overall sensitivity of 92% (95% CI: 89–95%) and specificity of 93% (95% CI: 85–97%); the aim of this review is to examine the criteria for the diagnosis of SBO by ultrasound, which can be divided into diagnostic and staging criteria. The diagnostic criteria include the presence of dilated loops and abnormal peristalsis, while the staging criteria are represented by parietal and valvulae conniventes alterations and by the presence of free extraluminal fluid. Ultrasound has reasonably high accuracy compared to computed tomography (CT) scanning and may substantially decrease the time to diagnosis; moreover, ultrasound is also widely used in the monitoring and follow-up of patients undergoing conservative treatment, allowing the assessment of loop distension and the resumption of peristalsis.

Bowel ultrasonography in acute abdomen: beyond acute appendicitis

Acute abdomen is a common reason for consultation in the emergency department. A broad spectrum of entities, including diverse diseases of the gastrointestinal tract, can cause acute abdomen. Although computed tomography is the technique most widely used to evaluate acute abdomen in the emergency department, abdominal ultrasound is often performed first and allows bowel disease to be suspected. This article describes the ultrasound features of diverse bowel diseases that can cause acute abdomen, such as acute diverticulitis, bowel obstruction, gastrointestinal perforation, bowel ischemia, intraabdominal fat necrosis, and miscellaneous processes such as endometriosis, foreign bodies, or vasculitis. Radiologists must be familiar with the different features of abnormal bowel that can be detected incidentally in patients without clinical suspicion of bowel disease. This article focuses on ultrasonographic signs of bowel disease; other articles in this series cover the ultrasonographic signs of acute appendicitis, inflammatory bowel disease, and infectious diseases.

Superior Mesenteric Arterial and Venous Thrombosis in COVID-19

Background

Patients with coronavirus disease 2019 (COVID-19) commonly present with fever, constitutional symptoms, and respiratory symptoms. However, atypical presentations are also well known. Though isolated mesenteric arterial occlusion associated with COVID-19 has been reported in literature, combined superior mesenteric arterial and venous thrombosis is rare. We report a case of combined superior mesenteric arterial and venous occlusion associated with COVID-19 infection.

Case Report

We report a case of a 45-year-old man who was a health care worker who presented to the emergency department with severe abdominal pain. The clinical examination was unremarkable, but imaging revealed acute mesenteric ischemia caused by superior mesenteric artery and superior mesenteric vein occlusion. Imaging of the chest was suggestive of COVID-19 infection, which was later confirmed with reverse transcription polymerase chain reaction of his nasopharyngeal swab. To date, only 1 case of combined superior mesenteric artery and superior mesenteric vein thrombosis caused by COVID-19 has been reported.

Why Should an Emergency Physician Be Aware of This?

During the COVID-19 pandemic it is important to keep mesenteric ischemia in the differential diagnosis of unexplained abdominal pain. Routinely adding high-resolution computed tomography of the chest to abdominal imaging should be considered in patients with acute abdomen because it can help to identify COVID-19 immediately. © 2020 Elsevier Inc.

Gastrointestinal Ultrasound (GIUS) in Intestinal Emergencies - An EFSUMB Position Paper

An interdisciplinary group of European experts summarizes the value of gastrointestinal ultrasound (GIUS) in the management of three time-critical causes of acute abdomen: bowel obstruction, gastrointestinal perforation and acute ischemic bowel disease. Based on an extensive literature review, statements for a targeted diagnostic strategy in these intestinal emergencies are presented. GIUS is best established in case of small bowel obstruction. Metanalyses and prospective studies showed a sensitivity and specificity comparable to that of computed tomography (CT) and superior to plain X-ray. GIUS may save time and radiation exposure and has the advantage of displaying bowel function directly. Gastrointestinal perforation is more challenging for less experienced investigators. Although GIUS in experienced hands has a relatively high sensitivity to establish a correct diagnosis, CT is the most sensitive method in this situation. The spectrum of intestinal ischemia ranges from self-limited ischemic colitis to fatal intestinal infarction. In acute arterial mesenteric ischemia, GIUS may provide information, but prompt CT angiography is the gold standard. On the other end of the spectrum, ischemic colitis shows typical ultrasound features that allow correct diagnosis. GIUS here has a diagnostic performance similar to CT and helps to differentiate mild from severe ischemic colitis.

Predictors of bowel necrosis in patients with acute mesenteric ischemia: systematic review and meta-analysis

Acute mesenteric ischemia (AMI) is a serious medical condition that can progress to transmural bowel necrosis. Prediction of the onset of bowel necrosis in AMI is crucial to justify surgical intervention before more severe consequences supervene. This systematic review aimed to identify the significant predictors of bowel necrosis in AMI in the current literature. In adherence to the PRISMA guidelines, electronic databases were searched for studies that reported significant independent predictors of bowel necrosis in AMI. The quality of the studies was assessed with MINORS score. The main outcomes of the review were the incidence and predictors of bowel necrosis in patients with AMI and the mortality rate. This systematic review comprised nine articles that included 963 patients of a median age of 57 years. Irreversible bowel necrosis was found in 402 (41.7%) patients. The significant predictors of bowel necrosis were subdivided into eight clinical, seven biochemical, and six radiologic parameters. Eight parameters were reported by two or more studies, whereas 13 were reported by a single study. Based on the weight and odds ratio of the predictive parameters, a prognostic scoring system, Emile-Khan Score, was proposed. Several clinical, biochemical, and radiologic predictors of bowel necrosis were reported in the literature. Pooling of odds ratios was feasible for eight factors that were reported by more than one study. Further studies are needed to ascertain the utility of the other predictive factors.Level of evidence: Level II (systematic review and meta-analysis).

Two-dimensional and contrast-enhanced ultrasound of intestinal ischaemia in cats: four cases

OBJECTIVES

The aim of this study was to describe the results of two-dimensional (2D) and contrast-enhancement ultrasound (CEUS) in four cats with intestinal ischaemia.

METHODS

Data were collected from hospital records of all cats that had intestinal ischaemia between January 2012 and August 2018. The inclusion criteria were complete abdominal ultrasound examination, colour flow Doppler and CEUS of lesions, confirmation of intestinal ischaemia detected by visual assessment of avascular intestinal segment at surgery, and/or necropsy and histopathology. All images and video clips were reviewed by the same experienced operator.

RESULTS

Four cats with different intestinal ischaemic lesions were included in the study: duodenal perforating ulcer, jejunal necrotising enteritis, necrosis secondary to jejunojejunal intussusception and iatrogenic damage of jejunal arteries. On the 2D ultrasound, all intestinal lesions were characterised by non-specific findings: focal hypoechoic wall thickening with loss of normal layering associated with hyperechoic mesentery surrounding the intestinal tract. CEUS showed a reduced or absent enhancement of the intestinal lesions in comparison to the surrounding perfused wall.

CONCLUSIONS AND RELEVANCE

Intestinal ischaemia is a potentially fatal disorder. Grey-scale, colour and power Doppler ultrasonography are not sensitive for evaluating this condition. Our preliminary findings illustrate the usefulness of CEUS for the detection of intestinal wall impaired perfusion in cats.

An unusual cause of bowel ischemia in an intensive care unit patient with herpes simplex virus encephalitis

We present a case of an unexpected cause of bowel ischemia in an intensive care unit patient with herpes simplex virus encephalitis who required an operation. A 79-year-old lady was being worked up and treated for encephalitis with antibiotics and an antiviral. On Day 13, she developed abdominal pain, and an ultrasound showed cholelithiasis but no cholecystitis; thus conservative treatment was advocated. By Day 18, pain localized to the right iliac fossa, and she had an emergency laparotomy that showed bowel ischemia and perforation of the caecum with the cause being a terminal ileal adhesional band. An extended right hemicolectomy and ileostomy was performed. Patients with significant comorbidities who are intensive care unit-dependent may still have unexpected clinical challenges. We advocate an increased clinical vigilance in this cohort for unexpected life-threatening presentations such as bowel ischemia and more specifically the cause of the bowel ischemia.

Outcomes and clinical characteristics of transmural intestinal necrosis in acute mesenteric ischemia

Background: Acute mesenteric ischemia (AMI) is a rare life-threatening condition, especially for the patients with transmural intestinal necrosis (TIN). However, the optimal time for surgical intervention is controversial. As a series study, this study aimed to identify the outcomes and clinical characteristic of patients with TIN. Methods: Clinical data of 158 patients with AMI from January 2010 to December 2017 were retrospectively analyzed in a national gastrointestinal referral center in China to confirm the outcomes and identify predictors for TIN. Results: According to the results of pathological assessment and follow-up, 62 patients were TIN and 96 were non-TIN. Patients with TIN have a higher mortality and incidence of severe complications. The significant independent predictors for TIN were arterial lactate level (OR: 4.76 [2.29 ∼ 9.89]), free intraperitoneal fluid (OR: 9.49 [2.56 ∼ 35.24]) and pneumatosis intestinalis (OR: 7.08 [1.68 ∼ 29.82]) in computed tomography (CT) scan imaging. The overall area under the receiver operating characteristics (ROC) curve of the model was 0.934 (95% confidence interval: 0.893 ∼ 0.974). Using ROC curve, the cutoff value of arterial lactate level predicting the onset of TIN was 2.65 mmol/L. Conclusions: Patients concomitant with TIN manifest a higher risk of poor prognosis. The three predictors for TIN were arterial lactate level >2.65 mmol/L, free intraperitoneal fluid and pneumatosis intestinalis. Close monitoring these predictors would help identify AMI patients developed TIN and in urgent need for bowel resection.

Predictive Risk Factors of Intestinal Necrosis in Patients with Mesenteric Venous Thrombosis: Retrospective Study from a Single Center

PURPOSES

Mesenteric venous thrombosis (MVT) is a serious condition. The current study aimed to identify risk factors of intestinal necrosis (IN) in patients with MVT to predict the onset of patients.

METHODS

Data pertaining to patients diagnosed with MVT between 2014 and May 2018 were reviewed. Patients' characteristics and risk factors of IN were assessed.

RESULTS

Seventy-eight patients were included in our study, of whom all cases were diagnosed as superior mesenteric venous thrombosis. There were fifty-eight cases (74%) with intestinal necrosis and twenty cases (26%) without intestinal necrosis. Multivariate analysis of factors associated with IN was organ failure (odds ratio (OR): 4.1; 95% confidence interval (95%CI): 1.26-8.59; P=0.028), elevated serum lactate (OR:3.6; 95% CI: 1.51-5.47; P=0.024), bowel loop dilation on computerized tomography (CT) scan (OR: 2.8; 95% CI: 1.32-7.23; P=0.031), and the time between onset of symptoms and operation (OR: 4.8; 95% CI: 1.36-9.89; P=0.012). Area under the receiver operating characteristics curve for the diagnosis of IN with MVT was 0.901 (95%CI: 0.809-0.993; P=0.000) depending on the different number of predictive factors.

CONCLUSION

Predictive risk factors for IN with MVT were organ failure, elevated serum lactate level, bowel loop dilation on CT, and the time between onset of symptoms and operation. However, this result is from a retrospective study and further long-term, large-sample prospective studies are required to confirm this finding.

Duplex ultrasound in the early diagnosis of acute mesenteric ischemia: a longitudinal cohort multicentric study

OBJECTIVE

Acute mesenteric ischemia (AMI) is a life-threatening condition requiring time-dependent treatment; thus, early recognition may improve outcomes. We hypothesized that clinician-performed mesenteric vessels duplex ultrasound (DUS) could facilitate early identification of patients with AMI in high-risk patients presenting with abdominal pain.

METHODS

This was a single-operator, observational, prospective cohort study. Patients aged at least 65 presenting to Emergency Departments with acute abdominal pain and no clear diagnosis after an initial work-up were enrolled. All patients underwent multidetector computed tomography and these findings provided the reference standard in this study. DUS of the celiac artery and superior mesenteric artery (SMA) were obtained to measure the peak systolic velocity (PSV) and were performed within 24 h of admission. PSVs outside the normal range were considered to indicate AMI.

RESULTS

Of 49 patients identified, 47 were consented to enrollment and diagnostic images were obtained in 45 (96%). Fifteen patients (33%) had AMI (six occlusive, nine nonocclusive disease). Among these, 12 (80%) had abnormal DUS velocities. SMA PSV showed a sensitivity of 78.57% [95% confidence interval (CI): 49.2-95.34], a specificity of 64.52% (95% CI: 45.37-80.77), a positive predictive value of 50% (95% CI: 28.22-71.78), and a negative predictive value of 86.96% (95% CI: 66.41-97.22) for AMI. DUS had a sensitivity of 100%, a specificity of 64%, and a negative predictive value of 100% for occlusive AMI. Assessment of celiac artery PSV did not improve diagnostic performance.

CONCLUSION

In this single-operator pilot study, mesenteric vessel DUS was performed successfully in the Emergency Department, with a high proportion of diagnostic images obtained. A normal SMA PSV was associated with a low risk of occlusive AMI.

Role of contrast-enhanced ultrasound in evaluation of the bowel

Contrast-enhanced ultrasound (CEUS) of the gastrointestinal tract provides vascular information helpful for characterizing masses and other pathologies in and around the bowel, similar to contrast applications in other solid organs. However, the use of microbubble contrast agents for the bowel provides additional unique contributions as it gives both subjective and objective information about mural and mesenteric blood flow, invaluable for the determination of disease activity in those many patients affected by inflammatory bowel disease (IBD). IBD is a lifelong chronic disease and has its peak age of onset in adolescence or young adult life. Today, we have moved away from treating patient’s symptoms and strive instead to alter the course of disease by obtaining mucosal healing. Expensive and aggressive biologic therapies and lack of agreement of patient’s symptoms with their disease activity and complications necessitate frequent imaging surveillance, which must be safe, readily available, inexpensive, and effective. Ultrasound with the benefit of contrast enhancement meets these requirements and is shown in meta-analysis to be equivalent to CT and MRI scans for these indications.

Imaging of Oncologic Emergencies

Oncologic emergencies can be either the result of the primary tumor, its metastasis, a paraneoplastic syndrome or reaction to the chemotherapy. Imaging plays a crucial role in ensuring a prompt diagnosis as well as assisting in the therapeutic management. In this article, we discuss the common thoracic and abdominal oncological emergencies that may be encountered in an emergency department.

Small Bowel Ultrasound beyond Inflammatory Bowel Disease: An Updated Review of the Recent Literature

The use of bowel ultrasonography (US) for the evaluation of gut diseases has increased in recent years and has been proven to provide a widely available, non-invasive and inexpensive method for the initial work-up and follow-up of different intestinal diseases, limited mostly by technical challenges posed by the patient's anatomy. The present review aims to provide an extensive overview of the main pathologic features at US examination of intestinal diseases other than inflammatory bowel disease, both acute (e.g., acute appendicitis, colonic diverticulitis, infectious diseases and ischemic conditions) and chronic (e.g., celiac disease, cystic fibrosis and other enterocolites). The identification of typical US features may help in the diagnostic process and guide the treatment approach. Therefore, the application of knowledge of the US appearance of gastrointestinal diseases is of relevance in enabling greater diagnostic performance and better patient management.

Diagnostic value of arterial blood gas lactate concentration in the different forms of mesenteric ischemia

PURPOSE

The role of serum lactate measurement in patients with intestinal ischemia still remains unclear. The aim of this study was to prospectively evaluate the diagnostic performance of arterial blood gas lactate concentrations in the patients with acute mesenteric ischemia and its different forms.

METHODS

All the patients reporting abdominal pain associated with risk factors for mesenteric ischemia underwent arterial blood gas and contrast enhanced abdominal computer tomography (CT).

RESULTS

At CT, 201 patients (70.7%) showed a nonischemic disease (group 1) and 83 patients (29.2%) showed findings of mesenteric ischemia. Out of these, 35 patients (42.1%) showed bowel ischemia secondary to non vascular causes (group 2) and 48 (57.8%) had a vascular intestinal ischemia (group 3). Out of these, 20 showed small bowel arterial occlusion (group 3a), 13 a small bowel nonocclusive ischemia (group 3b), 7 a venous small bowel occlusion (group 3c) and 8 showed isolated colonic ischemia (group 3d). The median lactate serum level was significantly higher in patients with vascular ischemia if compared with patients with nonischemic disease and secondary mesenteric ischemia (p < 0.0001; Kruskal-Wallis test). The areas under ROC curves for the lactate serum levels in the groups 2, 3, 3a, 3b, 3c and 3d were, respectively, 0.61, 0.85, 0.93, 0.93, 0.68 and 0.67.

CONCLUSIONS

Arterial blood gas lactate levels seem to show good diagnostic accuracy in diagnosing small bowel arterial and nonocclusive ischemia and poor accuracy in diagnosing secondary mesenteric ischemia, small bowel venous ischemia and ischemic colitis.

Non-occlusive mesenteric ischaemia in out of hospital cardiac arrest survivors

BACKGROUND AND AIM OF THE STUDY

Non-occlusive mesenteric ischaemia (NOMI) is characterised by hypoperfusion of the intestines without evidence of mechanical obstruction, potentially leading to extensive ischaemia and necrosis. Low cardiac output appears to be a major risk factor. Cardiopulmonary resuscitation aims at restoring blood flow after cardiac arrest. However, post restoration of spontaneous circulation, myocardial stunning limits immediate recovery of sufficient cardiac function. Since after successful cardiopulmonary resuscitation patients are often ventilated and sedated, NOMI might be underdiagnosed and potentially life-saving treatment delayed.

MATERIAL AND METHODS

A prospectively maintained multi-purpose cohort of out of hospital cardiac arrest survivors, who had successful restoration of spontaneous circulation, was used for this retrospective database analysis. Patients' charts were screened for clinical, radiological or pathological evidence of NOMI and clinical data were collected.

RESULTS

Between 2000 and 2014, 1780 patients who were successfully resuscitated after out of hospital cardiac arrest were screened for NOMI. Twelve patients (0.68 %) suffered from NOMI and six of those died (50 %). Patients suffering from NOMI tended to have a longer duration until restoration of spontaneous circulation (27 vs. 20 min, p=0.128) and had significantly higher lactate (14 mmol/l vs. 8 mmol/l, p=0.002) and base deficit levels at admission (-17 vs. -10, p=0.012). Median leukocyte counts in NOMI patients peaked at the day of diagnosis.

CONCLUSION

NOMI is a rare but life-threatening and potentially curable complication following successful cardiopulmonary resuscitation. Lactate and base deficit at admission could help to identify patients at risk for developing NOMI who might benefit from increased clinical attention.

Ischemic Colitis Diagnosed by Magnetic Resonance Imaging during Lenalidomide Treatment in a Patient with Relapsed Multiple Myeloma

Introduction

Multiple myeloma is the second most common hematological neoplasm that also affects young patients. The progression-free survival after autologous stem cell transplant has improved with the introduction of several novel agents such as lenalidomide, which may, however, increase the risk of adverse events.

Methods

We describe the case of a 54-year-old woman with relapse of multiple myeloma 3 years after myeloablative allogeneic stem cell transplant who developed abdominal pain and bloody diarrhea following 7 months of lenalidomide therapy.

Results

Abdominal plain x-ray and magnetic resonance imaging (MRI) without intravenous contrast material showed left-sided and splenic flexure acute ischemic colitis with reperfusion phenomena. Continuous intravenous infusion of unfractionated heparin was given with metronidazole and meropenem and the patient improved within a few days. MRI performed 15 days later confirmed complete recovery of ischemic colitis.

Conclusions

To our knowledge there have been no previously reported cases of ischemic colitis during lenalidomide therapy as a single agent in relapsed or refractory multiple myeloma, in particular promptly diagnosed by MRI.

Ischemic Colitis Diagnosed by Magnetic Resonance Imaging during Lenalidomide Treatment in a Patient with Relapsed Multiple Myeloma

Introduction

Multiple myeloma is the second most common hematological neoplasm that also affects young patients. The progression-free survival after autologous stem cell transplant has improved with the introduction of several novel agents such as lenalidomide, which may, however, increase the risk of adverse events.

Methods

We describe the case of a 54-year-old woman with relapse of multiple myeloma 3 years after myeloablative allogeneic stem cell transplant who developed abdominal pain and bloody diarrhea following 7 months of lenalidomide therapy.

Results

Abdominal plain x-ray and magnetic resonance imaging (MRI) without intravenous contrast material showed left-sided and splenic flexure acute ischemic colitis with reperfusion phenomena. Continuous intravenous infusion of unfractionated heparin was given with metronidazole and meropenem and the patient improved within a few days. MRI performed 15 days later confirmed complete recovery of ischemic colitis.

Conclusions

To our knowledge there have been no previously reported cases of ischemic colitis during lenalidomide therapy as a single agent in relapsed or refractory multiple myeloma, in particular promptly diagnosed by MRI.

Computed Tomography Perfusion Imaging Detection of Microcirculatory Dysfunction in Small Intestinal Ischemia-Reperfusion Injury in a Porcine Model

Objective

To evaluate multi-slice computed tomography (CT) perfusion imaging (CTPI) for identifying microcirculatory dysfunction in small intestinal ischemia−reperfusion (IR) injury in a porcine model.

Materials and Methods

Fifty-two pigs were randomly divided into 4 groups: (1) the IR group (n = 24), where intestinal ischemia was induced by separating and clamping the superior mesenteric artery (SMA) for 2 h, followed by reperfusion for 1, 2, 3, and 4 h (IR-1h, IR-2h, IR-3h, and IR-4h; n = 6, respectively); (2) the sham-operated (SO) group (n = 20), where the SMA was separated without clamping and controlled at postoperative 3, 4, 5, and 6 h (SO-3h, SO-4h, SO-5h, and SO-6h; n = 5, respectively); (3) the ischemia group (n = 4), where the SMA was separated and clamped for 2 h, without reperfusion, and (4) baseline group (n = 4), an additional group that was not manipulated. Small intestinal CTPI was performed at corresponding time points and perfusion parameters were obtained. The distal ileum was resected to measure the concentrations of malondialdehyde (MDA) and superoxide dismutase (SOD) and for histopathological examination.

Results

The perfusion parameters of the IR groups showed significant differences compared with the corresponding SO groups and the baseline group (before ischemia). The blood flow (BF), blood volume (BV), and permeability surface (PS) among the 4 IR groups were significantly different. BF and BV were significantly negatively correlated with MDA, and significantly positively correlated with SOD in the IR groups. Histopathologically, the effects of the 2-h ischemic loops were not significantly exacerbated by reperfusion.

Conclusion

CTPI can be a valuable tool for detecting microcirculatory dysfunction and for dynamic monitoring of small intestinal IR injury.

Sonography of Gastrointestinal Tract Diseases: Correlation With Computed Tomographic Findings and Endoscopy

Sonographic evaluation of the gastrointestinal (GI) tract may be difficult because of overlying intraluminal bowel gas and gas-related artifacts. However, in the absence of these factors and with the development of high-resolution scanners and the technical experience of radiologists, sonography can become a powerful tool for GI tract assessment. This pictorial essay focuses on sonographic findings of GI tract lesions compared with endoscopic, computed tomographic, and magnetic resonance imaging findings. Neoplastic and non-neoplastic diseases and postoperative complications are illustrated, and the distinctive sonographic characteristics of these entities are highlighted.

MDCT in ischaemic colitis: how to define the aetiology and acute, subacute and chronic phase of damage in the emergency setting

Ischemic colitis (IC) is the most common vascular disorder of the gastrointestinal tract with a reported incidence of 6.1-44 cases/100,000 person years with confirmatory histopathology. However, the true incidence of IC poses some difficulty, and even vigilant clinicians with patients at high risk often miss the diagnosis, since clinical presentation is non-specific or could have a mild transient nature. Detection of IC results is crucial to plan the correct therapeutic approach and reduce the reported mortality rate (4-12%). Diagnosis of IC is based on a combination of clinical suspicion, radiological, endoscopic and histological findings. Some consider colonoscopy as a diagnostic test of choice; however, preparation is required and it is not without risk, above all in patients who are severely ill. There are two manifestations of vascular colonic insult: ischaemic and reperfusive. The first one occurs above all during ischaemic/non-occlusive mesenteric ischaemia; in this case, the colonic wall appears thinned with dilated lumen and fluid appears in the paracolic space. When reperfusion occurs, the large bowel wall appears thickened and stratified, because of subepithelial oedema and/or haemorrhage, with consequent lumen calibre reduction. Shaggy contour of the involved intestine and misty mesentery are associated with the pericolic fluid. The pericolic fluid results are a crucial finding for IC diagnosis since its evidence suggests the presence of an ongoing damage thus focusing the attention on other pathological aspects which could be otherwise misdiagnosed, such as thinned or thickened colonic wall. Moreover, the pericolic fluid may increase or decrease, depending on the evolution of the ischaemic damage, suggesting the decision of medical or surgical treatment. Radiologists should not forget the hypothesis of IC, being aware that multidetector CT could be sufficient to suggest the diagnosis of IC, allowing for early identification and grading definition, and in a short-term follow-up, discriminating patients who need urgent surgery from patients in whom medical treatment and follow-up can be proposed.

Intestinal ultrasonography in infants with moderate or severe hypoxic-ischemic encephalopathy receiving hypothermia

BACKGROUND

Infants with hypoxic-ischemic encephalopathy (HIE) may develop multiorgan dysfunction, but assessment of intestinal involvement is imprecise and based on nonspecific clinical signs that may occur several days later. Ultrasound imaging has been described as a helpful tool in assessing intestinal involvement in many gastrointestinal disorders.

OBJECTIVE

Describe abdominal ultrasonography findings in infants receiving therapeutic hypothermia and investigate its association with the severity of the hypoxic-ischemic insult and death.

MATERIALS AND METHODS

Studies were performed within the first 36 h of life to assess intestinal appearance (normal bowel, bowel wall echogenicity and thickness, and sloughed mucosa), free fluid, peristalsis and intramural perfusion. These findings were compared between infants with moderate and severe encephalopathy. Ultrasound findings were also categorized in three major groups and compared with markers of severity of the hypoxic-ischemic insult and with mortality.

RESULTS

Nineteen infants with moderate and 9 with severe HIE at admission were studied (17.7 ± 9.5 h of life). Major ultrasonography findings were increased bowel wall echogenicity (78%), free fluid (75%), decreased or absent peristalsis (50%) and sloughing of the intestinal mucosa (21%). Abnormal intestinal findings such as increased bowel wall echogenicity in all quadrants and presence of sloughed mucosa were associated with more severe hypoxic-ischemic insult. All 12 patients with normal bowel appearance or increased bowel wall echogenicity restricted to only one quadrant survived, whereas 7/15 (47%) patients with increased bowel wall echogenicity in all four quadrants died during hospitalization. The presence of sloughed mucosa was associated with increased mortality (P < 0.001).

CONCLUSION

In infants receiving therapeutic hypothermia, a high prevalence of intestinal involvement was noted by using ultrasonographic assessment. An association between intestinal findings and severity of hypoxic-ischemic insult was observed. The presence of sloughed mucosa is a potential ultrasonographic sign of severity.

Imaging of acute superior mesenteric artery embolus using spectral CT in a canine model

OBJECTIVE

To explore the diagnostic value of single-source dual-energy spectral CT (sDECT) imaging in an acute superior mesenteric artery embolus (SMAE) canine model.

METHODS

Pre-contrast and double-phase contrast-enhanced sDECT were performed before and after embolization in eight SMAE dog models. Monochromatic images of embolized intestine with the best contrast-to-noise ratio (CNR) were obtained and compared with the polychromatic images. CT parameters including attenuation value, iodine content, water content and thickness of the embolized intestinal segments were obtained, and normalized difference in iodine concentration (NDIC) was calculated.

RESULTS

The CNR in pre-contrast, arterial phase and portal venous phase at 4 h after embolization was 1.11 ± 1.23, 13.50 ± 1.54 and 10.63 ± 3.75, respectively, significantly higher than those of the polychromatic images (p < 0.05). The iodine-based images clearly revealed the embolized intestinal segments, which were highly consistent with the gross findings. The difference in attenuation values between the embolization area and non-embolization area in the monochromatic images was 105.06 ± 35.35 HU, higher than that in the polychromatic images (p < 0.001). The attenuation values and NDIC were significantly decreased at 2 h after embolization, relatively increased at 4 h and gradually decreased at 6 and 8 h. The changing pattern of thickness was similar to that of NDIC over time after embolization.

CONCLUSION

sDECT can provide the optimal monochromatic images and allow increased detection rates of lesions. sDECT is a very promising tool for quantitative diagnosis of SMAE.

ADVANCES IN KNOWLEDGE

Our research provides more quantitative parameters for the assessment of SMAE by sDECT.

Porcine models of digestive disease: the future of large animal translational research

There is increasing interest in nonrodent translational models for the study of human disease. The pig, in particular, serves as a useful animal model for the study of pathophysiological conditions relevant to the human intestine. This review assesses currently used porcine models of gastrointestinal physiology and disease and provides a rationale for the use of these models for future translational studies. The pig has proven its utility for the study of fundamental disease conditions such as ischemia-reperfusion injury, stress-induced intestinal dysfunction, and short bowel syndrome. Pigs have also shown great promise for the study of intestinal barrier function, surgical tissue manipulation and intervention, as well as biomaterial implantation and tissue transplantation. Advantages of pig models highlighted by these studies include the physiological similarity to human intestine and mechanisms of human disease. Emerging future directions for porcine models of human disease include the fields of transgenics and stem cell biology, with exciting implications for regenerative medicine.

Radiology and mesenteric ischaemia

This review focuses on the radiology of mesenteric ischaemia. Covering the acute and chronic presentations, both of which result from impaired vascularisation of the gastrointestinal tract, we evaluate the role of radiographs, ultrasound, CT, MRI, and catheter angiography in the diagnosis of these conditions. Looking to the future, we also assess some of the emerging imaging techniques. Across medicine and surgery there has been a significant shift towards minimally invasive interventions. Although percutaneous revascularisation of chronic mesenteric ischaemia has been performed for some time, there has been a developing trend for the use of such techniques in acute mesenteric ischaemia. We evaluate the available evidence for the use of these percutaneous interventions and assess how they compare with or in some instances compliment traditional surgical alternatives.

Imaging assessment of gunshot wounds

Gunshot injuries occur when someone is shot by a bullet or other sort of projectile from a firearm. Wounds are generally classified as low velocity (less than 609.6m/s) or high velocity (more than 609.6m/s). Those with higher velocity may be expected, on this basis, to dissipate more energy into surrounding tissue as they are slow and cause more tissue damage, but this is only a very approximate guide. However, these terms can be misleading; more important than velocity is the efficiency of energy transfer, which is dependent on the physical characteristics of the projectile, as well as the kinetic energy, stability, entrance profile and path traveled through the body, and the biological characteristics of the tissues injured. Hemodynamically stable patients and patients who stabilized after simple immediate resuscitation were evaluated with a careful history and physical examination. A routine x-ray is performed in patients with gunshot wounds. Indication for total body computed tomography (CT) is based on the presence of signs and symptoms of vascular damage at clinical examination. Patients are immediately transferred in the operating room for surgery if more serious injuries that require immediate surgical care are not diagnosed, or hemostasis may be preliminary reached in the emergency room. Hemodynamically stable patients with no history and clinical examination showing suspected vascular damage are allowed in the radiology department for obtaining a total body CT scan with intravenous contrast medium and then transferred to the surgical ward trauma for observation. After 24 hours without the complications, patient can be discharged. CT is the procedure of choice to identify hemorrhage, air, bullet, bone fragments, hemothorax, nerve lesion, musculoskeletal lesions, and vessels injuries and is useful for assessing medicolegal aspects as trajectory and the anatomical structures at risk.

Automated CT detection of intestinal abnormalities and ischemia for decision making in emergency medicine

Background

Evaluation of computed tomography (CT) for the diagnosis of intestinal wall abnormalities and ischemia is important for clinical decision making in patients with acute abdominal pain to which if surgery should be performed in the emergency department. Interpretation of such information on CT is usually based on visual assessment by medical professionals and still remains a challenge in a variety of settings of the medical emergency care. This paper reports a pilot study in the implementation of image processing methods for automated detection of intestinal wall abnormalities and bowel ischemia, which can be of a potential application for CT-based detection of the intestinal disease.

Methods

CT scans of 3 patients of ischemia, one benign and one control subjects were used in this study. Statistical and geometrical features of the CT scans were extracted for pattern classification using two distance measures and the k-nearest neighbor algorithm. The automated detection of intestinal abnormalities and ischemia was carried out using labeled data from the training process with various proportions of training and testing samples to validate the results.

Results

Detection rates of intestinal ischemia and abnormalities are promising in terms of sensitivity and specificity, where the sensitivity is higher than the specificity in all test cases. The overall classification accuracy between the diseased and control subjects can be as high as 100% when all CT scans were included for measuring the difference between a cohort of three patients of ischemia and a single control subject.

Conclusion

The proposed approach can be utilized as a computer-aided tool for decision making in the emergency department, where the availability of expert knowledge of the radiologist and surgeon about this complex bowel disease is limited.