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

[Imaging of pancreatic neuroendocrine tumors]

BACKGROUND

Neuroendocrine tumors of the pancreas have a broad biological spectrum. The treatment decision is based on an optimal diagnosis with regard to the local findings and possible locoregional and distant metastases. In addition to purely morphologic imaging procedures, functional parameters are playing an increasingly important role in imaging.

OBJECTIVES

Prerequisites for optimal imaging of the pancreas, technical principles are provided, and the advantages and disadvantages of common cross-sectional imaging techniques as well as clinical indications for these special imaging methods are discussed.

MATERIALS AND METHODS

Guidelines, basic and review papers will be analyzed.

RESULTS

Neuroendocrine tumors of the pancreas have a broad imaging spectrum. Therefore, there is a need for multimodality imaging in which morphologic and functional techniques support each other. While positron emission tomography/computed tomography (PET/CT) can determine the presence of one or more lesions and its/their functional status of the tumor, magnetic resonance imaging (MRI) efficiently identifies the location, relationship to the main duct and the presence of liver metastases. CT allows a better vascular evaluation, even in the presence of anatomical variants as well as sensitive detection of lung metastases.

CONCLUSIONS

Knowledge of the optimal combination of imaging modalities including clinical and histopathologic results and dedicated imaging techniques is essential to achieve an accurate diagnosis to optimize treatment decision-making and to assess therapy response.

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.

A Rare Case of Pancolonic Ischemia Complicated by Fusobacterium Necrophorum Bacteremia: A Review of Colonic Ischemia for Internists

The varied clinical presentation and objective findings associated with colonic ischemia (CI) overlap with multiple disease processes. A high index of suspicion is critical for timely diagnosis and prognostication to avoid delays in treatment. We present a case that highlights the challenges of diagnosing CI and the high morbidity associated with severe disease. Case report: A sixty-four-year-old female presented to our community hospital with acute onset abdominal pain, nausea, and diarrhea, complicated by septic shock. She was initially given a diagnosis of infectious colitis until a colonoscopy was performed revealing extensive pancolonic ulcerations. Histopathological features on biopsy were most consistent with colonic ischemia. Blood cultures grew Fusobacterium Necrophorum. Surgery was avoided due to the high morbidity and mortality of performing a total colectomy and ileostomy. The patient continued to struggle with abdominal pain, diarrhea, and hematochezia, consistent with continuous CI, leading to recurrent hospitalizations.

Acute ischemic colitis associated with oral decongestant use: a systematic review

Background and Aim

Acute ischemic colitis (IC) has been linked with the use of oral decongestants. However, clinical evidence on this association remains limited. We aim to evaluate the occurrence and clinical outcomes of acute IC following over-the-counter (OTC) use of pseudoephedrine and phenylephrine.

Methods

We conducted a systematic review of the MEDLINE, Google Scholar, Scopus, and Embase databases between inception and July 20, 2022. Specific search terms were used. The inclusion criteria consisted of English-language articles describing acute IC secondary to pseudoephedrine or phenylephrine.

Results

A total of 18 case reports (level of clinical evidence: IV) fulfilled our inclusion criteria. The mean age of patients was 51.6 ± 15.3 years, with 14 (77.8%) cases reported in women. The clinical presentation was mainly related to abdominal pain 16 (88.9%), hematochezia 15 (83.3%), and/or abdominal tenderness 10 (55.6%). The medical background showed that 5 (27.8%) patients were previously healthy. In the 13 (72.2%) patients with comorbidities, hypertension 6 (46.2%), a history of tobacco use 5 (38.5%), and psychiatric illnesses 4 (30.8%) were commonly reported. Leukocytosis was encountered in 13 (72.2%) patients. Diagnostic investigations included a combination of computed tomography scan and colonoscopy in 10 (55.6%), colonoscopy alone in 6 (33.3%), and flexible sigmoidoscopy in 1 (5.6%) patient. Colonoscopic biopsy was the mainstay of diagnosis in 15 (83.3%) patients. Treatment was based on supportive care in 18 (100%), concurrent antibiotic use in 2 (11.1%), and surgical intervention in 1 (5.6%) patient. Recurrent episodes of IC occurred in 4 (22.2%) patients.

Conclusions

Acute IC secondary to oral decongestants remains a rare but important clinical phenomenon. Clinical suspicion and imaging findings are important for the early diagnosis.

Relevance to Patients

In unexplained cases of IC, clinicians should specifically inquire about oral decongestants since they are OTC and patients commonly fail to reveal their usage. These drugs should be avoided for transient cold symptoms, especially in women.

Imaging in Non-Traumatic Emergencies

"Emergency" is a scenario that every medical professional must face since the first day of her/his career [...].

A case report of transmural rectosigmoid ischemia in an elderly patient

INTRODUCTION AND IMPORTANCE

While acute colonic ischemia is frequently observed in the elderly, rectal ischemia is a rare occurrence. We presented a case of transmural rectosigmoid ischemia in a patient who had not undergone any significant interventions and had no underlying diseases. Conservative treatment methods were unsuccessful, and surgical resection was necessary to prevent the development of gangrene or sepsis.

CASE PRESENTATION

Upon arrival at our health center, a 69-year-old man reported experiencing left lower quadrant pain and rectorrhagia. The CT scan revealed thickening in the sigmoid and rectum. Subsequent colonoscopy revealed circumferential ulcers, severe edema, erythema, discoloration, and ulcerative mucosa in both the rectum and sigmoid. Due to persistent severe rectorrhagia and worsening pathologic parameters, another colonoscopy was performed three days later.

CLINICAL DISCUSSION

Initially, conservative treatments were administered, but as the tenderness worsened, surgical exploration of the abdomen was necessary. During the procedure, a large ischemia from the sigmoid to the rectal dentate line was observed, and the lesion was resected. A stapler was then inserted into the rectum, followed by the use of the Hartman pouch method to deviate the tract. Finally, colectomy, sigmoidectomy, and rectal resection were performed.

CONCLUSION

Due to the worsening pathological condition of our patient, surgical resection was necessary. It is important to note that rectosigmoid ischemia, although rare, can develop without a known underlying cause. Therefore, it is crucial to consider and evaluate potential causes beyond the most common ones. Furthermore, any pain or rectorragia should be assessed immediately.

[Computed tomography and magnetic resonance imaging of colonic diseases]

BACKGROUND

Early diagnosis of a luminal colonic disease is of essential clinical importance to start timely optimised therapy and detect complications early.

OBJECTIVES

This paper aims to provide an overview of the use of radiological methods in diagnosing neoplastic and inflammatory luminal diseases of the colon. Characteristic morphological features are discussed and compared.

MATERIALS AND METHODS

Based on an extensive literature review, the current state of knowledge regarding the imaging diagnosis of luminal pathologies of the colon and their importance in patient management is presented.

RESULTS

Technological advances in imaging have made the diagnosis of neoplastic and inflammatory colonic diseases using abdominal computed tomography and magnetic resonance imaging the established standard. Imaging is performed as part of the initial diagnosis in clinically symptomatic patients, to exclude complications, as a follow-up assessment under therapy and as an optional screening method in asymptomatic individuals.

CONCLUSIONS

Accurate knowledge of the radiological manifestations of the numerous luminal disease patterns, the typical distribution pattern and characteristic bowel wall changes are essential to improve diagnostic decision-making.

Diagnostic Management of Gastroenteropancreatic Neuroendocrine Neoplasms: Technique Optimization and Tips and Tricks for Radiologists

Gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) comprise a heterogeneous group of neoplasms, which derive from cells of the diffuse neuroendocrine system that specializes in producing hormones and neuropeptides and arise in most cases sporadically and, to a lesser extent, in the context of complex genetic syndromes. Furthermore, they are primarily nonfunctioning, while, in the case of insulinomas, gastrinomas, glucagonomas, vipomas, and somatostatinomas, they produce hormones responsible for clinical syndromes. The GEP-NEN tumor grade and cell differentiation may result in different clinical behaviors and prognoses, with grade one (G1) and grade two (G2) neuroendocrine tumors showing a more favorable outcome than grade three (G3) NET and neuroendocrine carcinoma. Two critical issues should be considered in the NEN diagnostic workup: first, the need to identify the presence of the tumor, and, second, to define the primary site and evaluate regional and distant metastases. Indeed, the primary site, stage, grade, and function are prognostic factors that the radiologist should evaluate to guide prognosis and management. The correct diagnostic management of the patient includes a combination of morphological and functional evaluations. Concerning morphological evaluations, according to the consensus guidelines of the European Neuroendocrine Tumor Society (ENETS), computed tomography (CT) with a contrast medium is recommended. Contrast-enhanced magnetic resonance imaging (MRI), including diffusion-weighted imaging (DWI), is usually indicated for use to evaluate the liver, pancreas, brain, and bones. Ultrasonography (US) is often helpful in the initial diagnosis of liver metastases, and contrast-enhanced ultrasound (CEUS) can solve problems in characterizing the liver, as this tool can guide the biopsy of liver lesions. In addition, intraoperative ultrasound is an effective tool during surgical procedures. Positron emission tomography (PET-CT) with FDG for nonfunctioning lesions and somatostatin analogs for functional lesions are very useful for identifying and evaluating metabolic receptors. The detection of heterogeneity in somatostatin receptor (SSTR) expression is also crucial for treatment decision making. In this narrative review, we have described the role of morphological and functional imaging tools in the assessment of GEP-NENs according to current major guidelines.

The Role of CT-Angiography in the Acute Gastrointestinal Bleeding: A Pictorial Essay of Active and Obscure Findings

Gastrointestinal bleeding is a potentially life-threatening abdominal emergency that remains a common cause of hospitalisation. Although 80–85% of cases of gastrointestinal bleeding resolve spontaneously, it can result in massive haemorrhage and death. The presentation of gastrointestinal bleeding can range from asymptomatic or mildly ill patients requiring only conservative treatments to severely ill patients requiring immediate intervention. Identifying the source of the bleeding can be difficult due to the wide range of potential causes, the length of the gastrointestinal tract and the intermittent nature of the bleeding. The diagnostic and therapeutic approach is fully dependent on the nature of the bleeding and the patient’s haemodynamic status. Radiologists should be aware of the appropriate uses of computed tomography angiography and other imaging modalities in patients with acute gastrointestinal bleeding, as well as the semiotics of bleeding and diagnostic pitfalls in order to appropriately diagnose and manage these patients. The learning objective of this review is to illustrate the computed tomography angiography technique, including the potential role of dual-energy computed tomography angiography, also highlighting the tips and tricks to identify the most common and uncommon features of acute gastrointestinal bleeding and its obscure form.

Non-occlusive mesenteric ischemia (NOMI) and prognostic signs at CT: reperfusion or not reperfusion that is the question!

PURPOSE

Non-occlusive mesenteric ischemia (NOMI) is a misdiagnosed and dangerous condition. To our knowledge, a comprehensive evaluation of CT parameters that can predict the outcome of patients suffering from NOMI is still missing.

MATERIALS AND METHODS

Contrast-enhanced CT examination of 84 patients with a confirmed diagnosis of NOMI (37 with clinical and laboratory confirmation and 47 biopsy or surgery proven) was retrospectively reviewed by assessing vessels, mesentery, bowel, and peritoneal cavity CT quantitative and dichotomous parameters, and data were analyzed with Fisher's test. Diameter of superior mesenteric artery (SMA), celiac trunk (CT), inferior vena cava (IVC), superior mesenteric vein (SMV), and differences in CT HU (Delta HU) of the bowel wall before and after intravenous contrast media (ICM) administration were correlated to the patients' outcome using ANOVA test. Receiver operating characteristic (ROC) curves were elaborated after a binary logistic regression was performed.

RESULTS

Increased number and diameter of vessels, bowel wall thickening, and hypervascularity were more frequent in patients with good prognosis. Conversely, pale mesentery, paper thin, hypovascularity, and aeroportia were more frequent in patients with bad prognosis. A significant correlation between diameters of SMA, CT, IVC, IMA, and SMV and outcome was found at univariate analysis. Also Delta HU resulted to be correlated with the outcome. At multivariate analysis only IVC and Delta HU were significant (p = 0.038 and 0.01) and the combined AUC resulted in 0.806 (CI 0.708-0.903).

CONCLUSION

Dichotomous signs of reperfusion and quantitative CT parameters can predict the outcome of patients with NOMI. In particular the combination of IVC diameter and Delta HU of bowel wall allows to predict the prognosis with the highest accuracy.

Development and validation of a composite score to predict severe forms of ischemic colitis

OBJECTIVE

To develop a simple scoring system in order to predict the risk of severe (death and/or surgery) ischemic colitis METHODS: In this retrospective study, 205 patients diagnosed with ischemic colitis in a tertiary hospital were consecutively included over a 6-year period. The study sample was sequentially divided into a training cohort (n = 103) and a validation cohort (n = 102). In the training cohort, multivariable analysis was used to identify clinical, biological, and CT variables associated with poor outcome and to build a risk scoring system. The discriminative ability of the score (sensitivity, specificity, positive predictive value, negative predictive value) was estimated in the two cohorts to externally validate the score, and a receiver operating characteristic curve was established to estimate the area under the curve of the score. Bootstrapping was used to validate the score internally.

RESULTS

In the training cohort, four independent variables were associated with unfavorable outcome: hemodynamic instability (2 pts), involvement of the small bowel (1 pt), paper-thin wall pattern (3 pts), no stratified enhancement pattern (1 pt). The score was used to categorize patients into low risk (score: 0, 1), high risk (score: 2-3), and very high risk (score: 4-7) groups with sensitivity and specificity of 97% and 67%, respectively, and a good discriminating capability, with a C-statistic of 0.94. Internal and external validation showed good discrimination capability (C-statistics of 0.9 and 0.84, respectively).

CONCLUSION

A simple risk score can stratify patients into three distinct prognosis groups, which can optimize patient management.

CLINICAL TRIAL NUMBER

NCT04662268 KEY POINTS: • Simple scoring system predicting the risk of severe ischemic colitis • First study to include CT findings to the clinical and biological data used to determine a severity score.

Phlebosclerotic colitis: an analysis of clinical and CT findings in 29 patients with long-term follow-up

Background

Phlebosclerotic colitis (PC) is a rare form of nonthrombotic colonic ischemia. This retrospective study analyzed the clinical findings and temporal CT changes in 29 PC patients with long-term follow-up.

Methods

Twenty-nine patients with characteristic CT features of PC collected between 1997 and 2020 were stratified into the acute abdomen group (AA-group) (n = 10), chronic-progressive group (CP-group) (n = 14) and chronic-stable group (CS-group) (n = 5). Clinical and CT changes during follow-up, comorbidities and final outcomes were compared.

Results

The AA-group exhibited a significantly thicker colonic wall and more involved segments and pericolic inflammation than the CP-group and CS-group on initial CT (p =  < 0.001–0.031). Seven patients in the AA-group who underwent right hemicolectomy had no recurrence during follow-up (mean ± SD, 7.1 ± 3.3 years), and the remaining three patients with renal or hepatic comorbidities who underwent conservative treatment died within 14 days. The CP-group showed significantly higher frequencies of chronic renal failure, urinary tract malignancies and liver cirrhosis than the AA-group (p = 0.005–0.008). In addition, CT follow-up (7.9 ± 4.3 years) showed significant increases in mesenteric venous calcifications, colonic wall thickening and involved colonic segments (p = 0.001–0.008) but conservative treatments were effective. The CS-group remained unchanged for years (8.2 ± 3.9 years).

Conclusions

Early surgery offered excellent prognosis in PC-related acute abdomen denoted by marked right colonic wall thickening and pericolic inflammation on CT. Conservative treatments with a wait-and-watch strategy were appropriate for CP-PC and CS-PC, albeit CP-PC harbored significant increases in calcifications, colonic wall thickening and affected segments in long-term CT follow-up.

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.