Assessment of multi-modality evaluations of obscure gastrointestinal bleeding

The Role of Imaging for GI Bleeding: ACG and SAR Consensus Recommendations

Gastrointestinal (GI) bleeding is the most common GI diagnosis leading to hospitalization within the United States. Prompt diagnosis and treatment of GI bleeding is critical to improving patient outcomes and reducing high health care utilization and costs. Radiologic techniques including CT angiography, catheter angiography, CT enterography, MR enterography, nuclear medicine red blood cell scan, and technetium-99m pertechnetate scintigraphy (Meckel scan) are frequently used to evaluate patients with GI bleeding and are complementary to GI endoscopy. However, multiple management guidelines exist, which differ in the recommended utilization of these radiologic examinations. This variability can lead to confusion as to how these tests should be used in the evaluation of GI bleeding. In this document, a panel of experts from the American College of Gastroenterology and Society of Abdominal Radiology provide a review of the radiologic examinations used to evaluate for GI bleeding including nomenclature, technique, performance, advantages, and limitations. A comparison of advantages and limitations relative to endoscopic examinations is also included. Finally, consensus statements and recommendations on technical parameters and utilization of radiologic techniques for GI bleeding are provided. © Radiological Society of North America and the American College of Gastroenterology, 2024. Supplemental material is available for this article. This article is being published concurrently in American Journal of Gastroenterology and Radiology. The articles are identical except for minor stylistic and spelling differences in keeping with each journal's style. Citations from either journal can be used when citing this article. See also the editorial by Lockhart in this issue.

The Role of Imaging for Gastrointestinal Bleeding: Consensus Recommendations From the American College of Gastroenterology and Society of Abdominal Radiology

Gastrointestinal (GI) bleeding is the most common GI diagnosis leading to hospitalization within the United States. Prompt diagnosis and treatment of GI bleeding is critical to improving patient outcomes and reducing high healthcare utilization and costs. Radiologic techniques including computed tomography angiography, catheter angiography, computed tomography enterography, magnetic resonance enterography, nuclear medicine red blood cell scan, and technetium-99m pertechnetate scintigraphy (Meckel scan) are frequently used to evaluate patients with GI bleeding and are complementary to GI endoscopy. However, multiple management guidelines exist which differ in the recommended utilization of these radiologic examinations. This variability can lead to confusion as to how these tests should be used in the evaluation of GI bleeding. In this document, a panel of experts from the American College of Gastroenterology and Society of Abdominal Radiology provide a review of the radiologic examinations used to evaluate for GI bleeding including nomenclature, technique, performance, advantages, and limitations. A comparison of advantages and limitations relative to endoscopic examinations is also included. Finally, consensus statements and recommendations on technical parameters and utilization of radiologic techniques for GI bleeding are provided.

A Practical Guide to the Evaluation of Small Bowel Bleeding

Gastrointestinal bleeding is a common clinical problem encountered in both the inpatient and outpatient settings. Although the evaluation of upper and lower gastrointestinal bleeding is often straightforward, bleeding from the small bowel may pose a clinical challenge. In this article, we review the indications, modalities, and differential diagnoses of small bowel bleeding. On completion of the article, clinicians should be able to identify common causes of small bowel bleeding, understand the advantages and disadvantages of the modalities used to evaluate small bowel bleeding, and enact a stepwise management approach to the patient with presumed small bowel bleeding.

Role of 3D Volumetric and Perfusion Imaging for Detecting Early Changes in Pancreatic Adenocarcinoma

Purpose

There is a major shortage of reliable early detection methods for pancreatic cancer in high-risk groups. The focus of this preliminary study was to use Time Intensity-Density Curve (TIDC) and Marley Equation analyses, in conjunction with 3D volumetric and perfusion imaging to demonstrate their potential as imaging biomarkers to assist in the early detection of Pancreatic Ductal Adenocarcinoma (PDAC).

Experimental Designs

A quantitative retrospective and prospective study was done by analyzing multi-phase Computed Tomography (CT) images of 28 patients undergoing treatment at different stages of pancreatic adenocarcinoma using advanced 3D imaging software to identify the perfusion and radio density of tumors.

Results

TIDC and the Marley Equation proved useful in quantifying tumor aggressiveness. Perfusion delays in the venous phase can be linked to Vascular Endothelial Growth Factor (VEGF)-related activity which represents the active part of the tumor. 3D volume analysis of the multiphase CT scan of the patient showed clear changes in arterial and venous perfusion indicating the aggressive state of the tumor.

Conclusion

TIDC and 3D volumetric analysis can play a significant role in defining the response of the tumor to treatment and identifying early-stage aggressiveness.

Revising the European Society of Gastrointestinal Endoscopy (ESGE) research priorities: a research progress update

BACKGROUND

One of the aims of the European Society of Gastrointestinal Endoscopy (ESGE) is to encourage high quality endoscopic research at a European level. In 2016, the ESGE research committee published a set of research priorities. As endoscopic research is flourishing, we aimed to review the literature and determine whether endoscopic research over the last 4 years had managed to address any of our previously published priorities.

METHODS

As the previously published priorities were grouped under seven different domains, a working party with at least two European experts was created for each domain to review all the priorities under that domain. A structured review form was developed to standardize the review process. The group conducted an extensive literature search relevant to each of the priorities and then graded the priorities into three categories: (1) no longer a priority (well-designed trial, incorporated in national/international guidelines or adopted in routine clinical practice); (2) remains a priority (i. e. the above criterion was not met); (3) redefine the existing priority (i. e. the priority was too vague with the research question not clearly defined).

RESULTS

The previous ESGE research priorities document published in 2016 had 26 research priorities under seven domains. Our review of these priorities has resulted in seven priorities being removed from the list, one priority being partially removed, another seven being redefined to make them more precise, with eleven priorities remaining unchanged. This is a reflection of a rapid surge in endoscopic research, resulting in 27 % of research questions having already been answered and another 27 % requiring redefinition.

CONCLUSIONS

Our extensive review process has led to the removal of seven research priorities from the previous (2016) list, leaving 19 research priorities that have been redefined to make them more precise and relevant for researchers and funding bodies to target.

Role of Video Capsule Endoscopy as a Prelude to Deep Enteroscopy

Video capsule endoscopy and device-assisted enteroscopy are complementary technologies. Capsule endoscopy is a highly acceptable technology with high diagnostic yield that can guide a subsequent enteroscopy approach. This article aims to focus on the role of video capsule endoscopy as a prelude to deep enteroscopy with a focus on the strengths and limitations of either approach.

Non-small-bowel lesions identification by capsule endoscopy: A single centre retrospective study

BACKGROUND

Capsule endoscopy has been considered the first-line approach for the investigation of obscure gastro-intestinal bleeding since its approval in 2001. Our study aims to evaluate the diagnostic yield of capsule endoscopy in the investigation of this condition. We also analyse the incidence of non-small-bowel lesions missed after conventional endoscopy and later detected by capsule endoscopy in patients with suspected obscure bleeding.

METHODS

A total of 290 patients with negative conventional endoscopy referred to our centre to undergo a capsule endoscopy examination for the investigation of obscure gastro-intestinal bleeding. We considered as non-small-bowel lesions those outside the tract between the second duodenal portion and the ileocecal valve. We also looked for actively bleeding lesions at the time of the exam.

RESULTS

Intestinal preparation was good, adequate or poor in 74.1%, 8.4%, and 17.5% of the tests, respectively. Caecum was reached in 92.4%. Capsule retention occurred in 0.7%. Mean small bowel transit time was 5hours and 13minutes. Diagnostic yield was 73.8%. An actively bleeding lesion was noticed in 39.3% of positive tests. Capsule endoscopy revealed clinically significant non-small-bowel lesions missed at gastroscopy or colonoscopy in 30.3% of patients, 43.2% of which were bleeding.

CONCLUSIONS

Capsule endoscopy has high diagnostic yield and safety in the investigation of obscure gastro-intestinal bleedings. Given the high percentage of non-small-bowel lesions detected, it may be appropriate to consider an endoscopic second look before performing a capsule endoscopy study.

Positive Fecal Occult Blood Test is a Predictive Factor for Gastrointestinal Bleeding after Capsule Endoscopy in Patients with Unexplained Iron Deficiency Anemia: A Korean Multicenter CAPENTRY Study

BACKGROUND/AIMS

Capsule endoscopy (CE) is recommended as the primary method for the evaluation of unexplained anemia. This study aimed to assess the diagnostic yield of CE in patients with unexplained iron deficiency anemia (IDA) without overt bleeding, and to evaluate their long-term outcomes and related clinical factors.

METHODS

Data of patients who underwent CE for the evaluation of IDA were reviewed from a CE registry in Korea. Additional clinical data were collected by the involved investigators of each hospital through a review of medical records.

RESULTS

Among a total of 144 patients, the diagnostic yield of CE was 34%. Gastrointestinal (GI) bleeding was found in 6.3% (n=9) of the patients (occult bleeding in four patients and overt bleeding in five patients) during a mean follow-up of 17.8 months. Patients with a positive fecal occult blood test (FOBT) result at the initial diagnosis had a higher rate of GI bleeding after CE (p=0.004). In addition, a positive FOBT result was the only independent predictive factor for GI bleeding (hazard ratio, 5.30; 95% confidence interval, 1.41-19.85; p=0.013).

CONCLUSION

Positive FOBT is a predictive factor for GI bleeding during follow-up after CE in patients with unexplained IDA without overt bleeding. Thus, patients with positive FOBT need to be more closely followed up.

Quality indicators in enteroscopy. Enteroscopy procedure

Within the project "Quality Indicators in Gastrointestinal Endoscopy," under the leadership of the Sociedad Española de Patología Digestiva (SEPD), our goal is to propose the procedures and the structure, process, and outcome indicators required for the application and assessment of quality in enteroscopy. To this end a search was performed for quality indicators in enteroscopy. Quality of evidence was measured by using the GRADE (Grading of Recommendations Assessment, Development and Evaluation) system, and classified as high, moderate, low, and very low. A total of 10 process indicators (one preprocedure, eight procedure, one postprocedure) were identified for enteroscopy, with appropriate indication and choice of most efficient route being most significant.

The evolving role of imaging for small bowel neuroendocrine neoplasms: estimated impact of imaging and disease-free survival in a retrospective observational study

PURPOSE

To determine how small bowel neuroendocrine neoplasms (SBNEN's) are diagnosed and examine the effect of CT enterography (CTE) on diagnosis and rates of disease-free survival.

METHODS

Histopathologically-confirmed SBNEN's diagnosed at our institution between 1996 and 2016 were identified. Clinical presentation, radiology, endoscopy, surgery, and pathology reports were reviewed and compared between consecutive 5-year periods.

RESULTS

Of the 178 SBNEN initially diagnosed at our institution, the incidence increased 12-fold from 9 (during 1996-2000) to 114 (during 2011-2016). Comparing the first 5 to the last 5 years, GI bleeding and abdominal pain increased significantly as indications (with both increasing from 0 to > 25%, p ≤ 0.023). Initial diagnosis by radiology increased 2-fold [from 33% (n = 3) to 66% (n = 75); p = 0.263]. Detection of a small bowel mass and the suggestion that SBNEN was present varied significantly between imaging modalities (p < 0.0001; CTE - 95% (52/55) and 91% (50/55) vs. abdominal CT 45% (37/85) and 35% (29/85), respectively). Recurrence rates increased with SBNEN size (p = 0.012; e.g., of SBNEN diagnosed by endoscopy, 18% of SBNEN measuring 0.6 ± 0.3 cm recurred vs. 75% measuring 3.7 ± 1.0 cm). Rates of disease-free survival, and the incidence of local and liver metastases were decreased when tumors were first identified by CTE rather than other CT/MR imaging modalities (p = 0.0034, 0.0475, and 0.0032, respectively).

CONCLUSION

There has been a dramatic increase in SBNENs detected by CTE and endoscopy over the last 20 years. SBNEN's detected by CTE and small tumors detected at endoscopy have longer disease-free survival after surgical resection.

Multiphase Computed Tomographic Enterography: Diagnostic Yield and Efficacy in Patients With Suspected Small Bowel Bleeding

Objective

To estimate the diagnostic yield and efficacy of multiphase computed tomographic enterography (mpCTE) for suspected small bowel bleeding in routine clinical practice.

Patients and Methods

All mpCTEs performed between January 1, 2006, and December 31, 2014, for suspected small bowel bleeding were included and classified by a gastroenterologist and an abdominal radiologist. The reference standard for a definitive diagnosis was balloon-assisted enteroscopic, angiographic, surgical, or pathologic results. Overall and lesion-specific diagnostic yield (DY), sensitivity, and positive predictive value were calculated. The relationship of mpCTE diagnosis and continued bleeding or iron supplementation was examined using logistic regression in patients with at least 1 year of follow-up.

Results

We identified 1087 patients who had an initial mpCTE indication of small bowel bleeding. The overall DY was 31.6% (344 of 1087 patients; 95% CI, 29.0%-35.0%), higher for an indication of small bowel bleeding that was overt or occult with heme-positive stool vs occult with only iron-deficiency anemia (DY, 35.0% [170 of 486] and 35.3% [66 of 187] vs 26.1% [108 of 414]; P=.004 and P=.02, respectively). The highest sensitivity and positive predictive value were for small bowel masses (90.2% [55 of 61] and 98.2% [55 of 56], respectively). Higher risk of future bleeding and iron supplementation was seen with a negative result on mpCTE (odds ratio [OR], 1.91; 95% CI, 1.28-2.86), lack of surgical intervention (OR, 4.37; 95% CI, 2.31-8.29), or discrepant balloon-assisted enteroscopic findings (OR, 2.50; 95% CI, 1.03-6.09).

Conclusion

Multiphase computed tomographic enterography has a higher rate of detection in patients with overt bleeding or heme-positive stool. The procedure provides actionable targets for further intervention and leads to substantially reduced rates of rebleeding in long-term follow-up.

The Small Bowel Cancer Incidence Enigma

Although the small bowel is a vast organ with a highly proliferative epithelium, the incidence of small bowel cancers is surprisingly low. Many factors could be involved in this unexpected cancer incidence, including difficult access to the exploration of the small bowel mucosa, which might lead to missed diagnoses of non-obstructive and non-bleeding small tumours. Moreover, possible factors that influence the low incidence include more efficient machinery of DNA replication and DNA repair enzymes, peculiarities in microbiota components, competence of the immune system, and the speed of intestinal transit. Importantly, the answer for the enigmatic risk of driver mutations caused by replication errors may be hidden in the small bowel, which is an obscure part of digestive tract that is usually inaccessible by endoscopic or colonoscopic conventional investigations. These observations warrant the necessity of an urgent exploration of small bowel features, including the evaluation of DNA replication controls and expression of DNA repair genes, in order to shed light on these obscure events.

Diagnosis of chronic anaemia in gastrointestinal disorders: A guideline by the Italian Association of Hospital Gastroenterologists and Endoscopists (AIGO) and the Italian Society of Paediatric Gastroenterology Hepatology and Nutrition (SIGENP)

Anaemia is a common pathologic condition, present in almost 5% of the adult population. Iron deficiency is the most common cause; other mechanisms can be involved, making anaemia a multi-factorial disorder in most cases. Anaemia being a frequent manifestation in the diseases of the gastrointestinal tract, patients are often referred to gastroenterologists. Furthermore, upper and lower endoscopy and enteroscopy are pivotal to the diagnostic roadmap of anaemia. In spite of its relevance in the daily clinical practice, there is a limited number of gastroenterological guidelines dedicated to the diagnosis of anaemia. For this reason, the Italian Association of Hospital Gastroenterologists and Endoscopists and the Italian Society of Paediatric Gastroenterology, Hepatology and Nutrition commissioned a panel of experts to prepare a specific guideline on anaemia and its diagnostic roadmap in the gastroenterological scenario. The panel also discussed about the potential involvement of gastroenterologists and endoscopists in the management of patients with anaemia, with particular attention to the correct use of investigations. The panel paid particular attention to practical issues with the aim to support gastroenterologists in their clinical practice when dealing with patients with anaemia.