Lower gastrointestinal bleeding: Role of 64-row computed tomographic angiography in diagnosis and therapeutic planning

The Accuracy of Computed Tomography Angiography Compared With Technetium-99m Labelled Red Blood Cell Scintigraphy for the Diagnosis and Localization of Acute Gastrointestinal Bleeding: A Systematic Review and Meta-Analysis

Imaging tests are commonly used as an initial or early investigation for patients presenting with suspected acute gastrointestinal bleeding (AGIB). However, controversy remains regarding which of two frequently used modalities, computed tomography angiography (CTA) or technetium-99m labelled red blood cell scintigraphy (RBCS), is most accurate. This systematic review and meta-analysis was performed to compare the accuracy of CTA and RBCS for the detection and localization of AGIB. Five electronic databases were searched with additional manual searching of reference lists of relevant publications identified during the search. Two reviewers independently performed screening, data extraction and methodological assessments. Where appropriate, the bivariate model was used for meta-analysis of sensitivities and specificities for the detection of bleeding and Freeman-Tukey double-arcsine transformation used for meta-analysis of proportions of correctly localized bleeding sites. Forty-four unique primary studies were included: twenty-two investigating CTA, seventeen investigating RBCS and five investigating both modalities. Meta-analysis produced similar pooled sensitivities; 0.83 (95% CI 0.74-0.90) and 0.84 (0.68-0.92) for CTA and RBCS respectively. Pooled specificity for CTA was higher than RBCS; 0.90 (0.72-0.97) and 0.84 (0.71-0.91) respectively. However, differences were not statistically significant. CTA was superior to RBCS in correctly localizing bleeding; pooled proportions of 1.00 (0.98-1.00) and 0.90 (0.83-0.96) respectively (statistically significant difference, P < 0.001). There is no evidence that CTA and RBCS have different diagnostic performance with respect to the detection of AGIB. However, CTA is superior to RBCS in terms of correctly localising the bleeding site, supporting usage of CTA over RBCS as the first line imaging investigation.

Multiphase photon counting detector CT data sets - Which combination of contrast phase and virtual non-contrast algorithm is best suited to replace true non-contrast series in the assessment of active bleeding?

PURPOSE

Aim of this study was to determine which virtual non-contrast (VNC) reconstruction algorithm, applied to which contrast phase of computed tomography angiography, best matches true non-contrast (TNC) images in the assessment of active bleeding.

METHOD

Patients who underwent a triphasic scan (pre-contrast, arterial, portal venous contrast) on a photon-counting detector CT (PCD-CT) (120 kV, image quality level 68) with suspected active (tumor, postoperative, spontaneous or other) bleeding were retrospectively included in this study. Conventional (VNCConv) and a calcium-preserving VNC algorithm (VNCPC) were derived from both arterial (art) and portal venous (pv) contrast scans, and analyzed quantitatively and qualitatively by two independent and blinded raters.

RESULTS

40 patients (22 female, mean age 76 years) were included. Measurements of CT values showed significant albeit small differences between TNC and VNC for most analyzed tissue regions without clear superiority of a VNC algorithm or contrast phase (e.g. ΔHU fat TNC to VNCPCpv 3.1 HU). However, qualitative analysis showed a preference to VNCPCpv in terms of image quality (on a 5-point Likert scale VNCConvart = 3.5 ± 0.8, VNCPCart = 3.7 ± 0.7, VNCConvpv = 3.7 ± 0.7, VNCPCpv = 3.8 ± 0.7) and residual calcium contrast (VNCConvart = 3.0 ± 0.8, VNCPCart = 3.5 ± 0.7, VNCConvpv = 3.6 ± 0.7, VNCPCpv = 3.9 ± 0.6).

CONCLUSIONS

When multiple post-contrast phases are available, VNCPC series based on portal venous phase are the most suitable replacement for an additional pre-contrast scan, with the prospect of a significant reduction in patient radiation dose.

How to manage lower gastrointestinal bleeding in 2022?

Lower gastrointestinal bleeding (LGIB), originating mainly in the colon, rectum and anus, occurs most often in older patients (7th decade) with co-morbidity, half of whom have coagulation abnormalities due to anti-coagulant or anti-aggregant therapy. In three cases out of four, bleeding regresses spontaneously but can recur in up to one third of patients. The main causes are diverticular disease, vascular disorders (hemorrhoids, angiodysplasia) and colitis. Ten to 15% of patients present in hypovolemic shock. The main problem is to determine the precise location and etiology of bleeding. First-line steps include correction of hemodynamics, correction of coagulation disorders and transfusion, as necessary. Rectal digital examination allows differentiation between melena and hematochezia. In patients with severe LGIB, upper endoscopy can eliminate upper gastro-intestinal bleeding (UGIB). Computerized tomography (CT) angiography can pinpoint the source. If contrast material extravasates, the therapeutic strategy depends on the cause of bleeding and the general status of the patient: therapeutic colonoscopy, arterial embolization and/or surgery. In the absence of severity criteria (Oakland score≤10), ambulatory colonoscopy should be performed within 14 days. Discontinuation of anticoagulant and/or antiplatet therapy should be discussed case by case according to the original indications.

Management of Acute Lower Gastrointestinal Bleeding: A Survey to Assess Adherence to Guidelines Across the United Kingdom and Ireland

Introduction: Acute gastrointestinal bleeding (GIB) is a common surgical problem requiring hospitalization in the United Kingdom (UK) and Ireland. The first UK lower gastrointestinal bleeding (LGIB) management guidelines were published in 2019 by the British Society of Gastroenterology (BSG). We aimed to evaluate self-reported adherence to BSG clinical guidance (CG) within the UK and Ireland.

Methods and materials: A Questionnaire was designed based on LGIB BSG CG 2019 using Google Forms (Google LLC, Mountain View, CA). This was distributed to surgical consultants and senior surgical practitioners (specialists, Trust grade registrars, and specialist registrars) across different centers in the UK and Ireland over four weeks (13th March to 5th April 2021). Data were analyzed using Statistical Package for Social Sciences (SPSS) version 27 (IBM Corp., Armonk, NY, USA).

Results: A total of 64 responses were recorded from 18 different centers in the UK and Ireland. The ratio of consultants and registrars was almost the same (34:30, 53.1%:46.9%). The majority of respondents were from colorectal surgery (65.6%, n=42) followed by general surgeons (23.4%, n=15). A total of 41 respondents (64.1%) admitted that BSG CG 2019 were practically applicable at their center. Approximately 75% of respondents did not use or were unaware of the Shock index or Oakland score to stratify patients. That translated into 59% opting to admit patients with a minor bleed. Around 36% wanted to perform a CT angiogram for a stable major bleed, while 37% were unaware of the interventional radiology (IR) referral pathway.

Conclusion: There is patchy adherence to the guidelines leading to significant variations in LGIB management practice and avoidable admissions.

[Lower Gastrointestinal Bleeding: Current State of Diagnosis and Treatment and Interpretation of the Clinical Guidelines]

Lower gastrointestinal bleeding (LGIB) is a common clinical emergency. However, most of the published findings on LGIB were of retrospective or observational studies, and the relevant clinical guidelines and consensuses were not published until quite recently. In clinical practice, LGIB treatment is not as standardized as the treatment of upper gastrointestinal bleeding. Herein, on the basis of the latest clinical research findings on and guidelines for LGIB, we summarized and analyzed the existent diagnosis and treatment of LGIB from the perspectives of patient assessment and endoscopic, interventional and medication treatment, intending to provide more references to support the clinical practice.

Acute Upper Non-variceal and Lower Gastrointestinal Bleeding

Acute gastrointestinal (GI) bleeding is a common surgical emergency requiring hospital admission and associated with high morbidity and mortality. Appropriate decision-making is essential to make a prompt diagnosis, accurate risk assessment, and proper resuscitation of patients with gastrointestinal bleeding. Despite multiple randomized trials and meta-analyses, there is still controversy on various management issues like appropriate risk stratification, the timing of endoscopy, choosing an appropriate endoscopic, and radiological intervention in these groups of patients. As the usage of nonsteroidal anti-inflammatory drugs, antiplatelet, and antithrombotic agents is common in patients with gastrointestinal bleeding, the physician is challenged with proper management of these drugs. The present review summarizes the current strategies for risk stratification, localization of bleeding source, endoscopic and radiological intervention in patients with acute nonvariceal upper GI, middle GI, and lower GI bleeding.

CT angiograms for lower GI bleeding: the experience of a large UK teaching hospital

INTRODUCTION

The clinical presentation of lower gastrointestinal bleeding (LGIB) is variable in severity, cause and potential investigations. The British Society of Gastroenterology recently published LGIB guidelines, recommending CT angiography (CT-A) for haemodynamically unstable patients, defined by shock index (SI) greater than 1. The aim of this study was to assess the use and role of CT-A in diagnosing LGIB, by assessing the pickup rate of active LGIB defined by contrast extravasation or 'blush' and to determine any association between positive CT-A with various patient and clinical characteristics.

METHODS

A retrospective analysis was carried out of 4 years of LGIB admissions. Demographics, inpatient observations and use of blood products were acquired. Vital signs nearest the time of CT-A plus abnormal vital signs preceding imaging were used to calculate SI, Age SI, National Early Warning Score 2 (NEWS2) and Standardised Early Warning Score (SEWS). A consultant gastrointestinal radiologist further reviewed all consultant-reported scans.

RESULTS

In total, 930 patients were admitted with LGIB. Median age was 71 years and 51% were male; 179 (19.2%) patients received red blood cell transfusion and 93 patients (10%) underwent CT-A, who were older and were likely to be hypotensive and receive red cell transfusions. Following exclusions, 92 CT-As were included in the analysis. Nine (9.8%) were positive. Univariate analysis showed no association between positive CT-A and any scoring system. A multivariate analysis, including age and gender, showed association between both NEWS2 and SEWS scores with positive CT-A.

CONCLUSION

In our analysis of the typical LGIB population, CT-A has shown relatively low pick up rate of active bleeding. CT-A clearly has a role in the investigation of LGIB, but selection remains challenging.

Hemosuccus Pancreaticus: A Comprehensive Review of Presentation Patterns, Diagnostic Approaches, Therapeutic Strategies, and Clinical Outcomes

Hemosuccus pancreaticus is a rare but potentially torrential and life-threatening cause of acute upper gastrointestinal bleeding. It is described as an intermittent hemorrhage from the major duodenal papilla via the main pancreatic duct. Peripancreatic pseudoaneurysm following chronic pancreatitis is a common underlying etiology. However, gastroduodenal artery pseudoaneurysm-related hemosuccus pancreaticus remains exceedingly rare in the etiological spectrum of upper gastrointestinal bleeding. We hereby delineate a rare case of hemosuccus pancreaticus associated with gastroduodenal artery pseudoaneurysm in a patient who initially presented with abdominal pain and hematochezia. He was successfully managed with coil embolization without recurrence or sequelae. Furthermore, we conducted a search of the MEDLINE (PubMed and Ovid) database for relevant studies on hemosuccus pancreaticus published between inception and September 15, 2021. The available clinical evidence on causes, presentation patterns, diagnosis, and management was analyzed and summarized. This article highlights the rarity, the intermittent nature of hemorrhage, and the lack of a standardized diagnostic approach for this elusive disease. Clinicians should remain cognizant of hemosuccus pancreaticus, especially in patients presenting with symptoms and signs of intermittent gastrointestinal bleeding and abdominal pain. Prompt diagnosis carries paramount importance in saving patients from repeat hospital admissions and disease-associated morbidity and mortality. Conventional angiography with coil embolization may constitute an effective treatment strategy.

Diagnosis and management of acute lower gastrointestinal bleeding: European Society of Gastrointestinal Endoscopy (ESGE) Guideline

1: ESGE recommends that the initial assessment of patients presenting with acute lower gastrointestinal bleeding should include: a history of co-morbidities and medications that promote bleeding; hemodynamic parameters; physical examination (including digital rectal examination); and laboratory markers. A risk score can be used to aid, but should not replace, clinician judgment.Strong recommendation, low quality evidence. 2 : ESGE recommends that, in patients presenting with a self-limited bleed and no adverse clinical features, an Oakland score of ≤ 8 points can be used to guide the clinician decision to discharge the patient for outpatient investigation.Strong recommendation, moderate quality evidence. 3 : ESGE recommends, in hemodynamically stable patients with acute lower gastrointestinal bleeding and no history of cardiovascular disease, a restrictive red blood cell transfusion strategy, with a hemoglobin threshold of ≤ 7 g/dL prompting red blood cell transfusion. A post-transfusion target hemoglobin concentration of 7-9 g/dL is desirable.Strong recommendation, low quality evidence. 4 : ESGE recommends, in hemodynamically stable patients with acute lower gastrointestinal bleeding and a history of acute or chronic cardiovascular disease, a more liberal red blood cell transfusion strategy, with a hemoglobin threshold of ≤ 8 g/dL prompting red blood cell transfusion. A post-transfusion target hemoglobin concentration of ≥ 10 g/dL is desirable.Strong recommendation, low quality evidence. 5: ESGE recommends that, in patients with major acute lower gastrointestinal bleeding, colonoscopy should be performed sometime during their hospital stay because there is no high quality evidence that early colonoscopy influences patient outcomes.Strong recommendation, low quality of evidence. 6 : ESGE recommends that patients with hemodynamic instability and suspected ongoing bleeding undergo computed tomography angiography before endoscopic or radiologic treatment to locate the site of bleeding.Strong recommendation, low quality evidence. 7 : ESGE recommends withholding vitamin K antagonists in patients with major lower gastrointestinal bleeding and correcting their coagulopathy according to the severity of bleeding and their thrombotic risk. In patients with hemodynamic instability, we recommend administering intravenous vitamin K and four-factor prothrombin complex concentrate (PCC), or fresh frozen plasma if PCC is not available.Strong recommendation, low quality evidence. 8 : ESGE recommends temporarily withholding direct oral anticoagulants at presentation in patients with major lower gastrointestinal bleeding.Strong recommendation, low quality evidence. 9: ESGE does not recommend withholding aspirin in patients taking low dose aspirin for secondary cardiovascular prevention. If withheld, low dose aspirin should be resumed, preferably within 5 days or even earlier if hemostasis is achieved or there is no further evidence of bleeding.Strong recommendation, moderate quality evidence. 10: ESGE does not recommend routinely discontinuing dual antiplatelet therapy (low dose aspirin and a P2Y12 receptor antagonist) before cardiology consultation. Continuation of the aspirin is recommended, whereas the P2Y12 receptor antagonist can be continued or temporarily interrupted according to the severity of bleeding and the ischemic risk. If interrupted, the P2Y12 receptor antagonist should be restarted within 5 days, if still indicated.Strong recommendation, low quality evidence.

Endoscopic hemostasis makes the difference: Angiographic treatment in patients with lower gastrointestinal bleeding

BACKGROUND

The large majority of gastrointestinal bleedings subside on their own or after endoscopic treatment. However, a small number of these may pose a challenge in terms of therapy because the patients develop hemodynamic instability, and endoscopy does not achieve adequate hemostasis. Interventional radiology supplemented with catheter angiography (CA) and transarterial embolization have gained importance in recent times.

AIM

To evaluate clinical predictors for angiography in patients with lower gastrointestinal bleeding (LGIB).

METHODS

We compared two groups of patients in a retrospective analysis. One group had been treated for more than 10 years with CA for LGIB (n = 41). The control group had undergone non-endoscopic or endoscopic treatment for two years and been registered in a bleeding registry (n = 92). The differences between the two groups were analyzed using decision trees with the goal of defining clear rules for optimal treatment.

RESULTS

Patients in the CA group had a higher shock index, a higher Glasgow-Blatchford bleeding score (GBS), lower serum hemoglobin levels, and more rarely achieved hemostasis in primary endoscopy. These patients needed more transfusions, had longer hospital stays, and had to undergo subsequent surgery more frequently (P < 0.001).

CONCLUSION

Endoscopic hemostasis proved to be the crucial difference between the two patient groups. Primary endoscopic hemostasis, along with GBS and the number of transfusions, would permit a stratification of risks. After prospective confirmation of the present findings, the use of decision trees would permit the identification of patients at risk for subsequent diagnosis and treatment based on interventional radiology.

A novel concept on volumetric assessment and quantification of gastrointestinal bleed on computed tomography angiography: Observations based on a case series

Department of Radiology, Mazumdar Shaw Medical Centre - Narayana Multispecialty Hospital, Narayana Health, Estimation of quantity and rate of bleeding is of great value in the management of patients with acute GI bleed. Endoscopy and multiphase contrast enhanced computed tomography (MCECT) are the presently employed two important methods for this purpose. Still there is a lacuna in the methods of precise estimation of amount of bleed, which at the moment are somewhat unreliable and subjectively evaluated. We present the value of dynamic contrast-enhanced CT examination in quantitatively estimating the amount of extravasated blood with the help of three illustrative clinical examples. Technique CT examination, the methodology for assessment of quantity of bleed is presented and the discussion of existing literature regarding the estimation methods is presented.Bommasandra, Bengaluru, India

Analysis of time delay between computed tomography and digital subtraction angiography on the technical success of interventional embolisation for treatment of lower gastrointestinal bleeding

INTRODUCTION

A retrospective study was undertaken to determine a potential relationship, based on the time delay, between a positive lower gastrointestinal bleed demonstrated on computed tomography (CT) and a positive digital subtraction angiographic (DSA) study and the impact on technical success.

METHODS

This study investigated the correlation of time delays between imaging modalities and technical success with endovascular embolisation procedures over a 10-year period.

RESULTS

A total of 110 patient events were analysed, and it was observed that the greater the time delay between modalities (up to 7 h), the weaker the correlation between a bleed observed on CT and DSA. This was also reflected by the technical success of the embolisation treatment. Patients experienced shorter delays when the event occurred out of normal business hours, however with decreased rates of technical success.

CONCLUSIONS

There is a suggestion patients should be escalated to the angiography suite for DSA imaging as soon as possible to maximise the ability to angiographically observe acute bleeding and treat appropriately with interventional embolisation. More research in this area is required to statistically confirm this.

Society of abdominal radiology gastrointestinal bleeding disease-focused panel consensus recommendations for CTA technical parameters in the evaluation of acute overt gastrointestinal bleeding

PURPOSE

To formulate consensus recommendations for CT angiography technical parameters used to evaluate overt gastrointestinal (GI) bleeding.

METHODS

An electronic questionnaire consisting of 17 questions was sent to a panel of 16 radiologists with expertise on the imaging of GI bleeding from the Society of Abdominal Radiology GI Bleeding disease-focused panel to obtain consensus agreement on issues related to CTA technical parameters for imaging overt GI bleeding. A multi-round Delphi method of voting was performed to obtain consensus which was defined as ≥ 80% agreement.

RESULTS

Consensus agreement was reached in 15/17 (89%) of the questions including the technique for the administration of IV contrast, the number of phases, scan timing, and image reconstruction.

CONCLUSIONS

A panel of experts on the imaging of GI bleeding from the Society of Abdominal Radiology was able to reach consensus on the majority of technical parameters used for CTA of overt GI bleeding. These recommendations should improve the quality of patient care by adopting these minimal technical requirements for optimal exam performance and lead to less variation in the performance of these exams which will facilitate collecting and comparing published data from different centers. These recommendations will need revisions as additional scientific data become available.

Diagnosis and therapeutic strategies for small bowel vascular lesions

Small bowel vascular lesions, including angioectasia (AE), Dieulafoy’s lesion (DL) and arteriovenous malformation (AVM), are the most common causes of obscure gastrointestinal bleeding. Since AE are considered to be venous lesions, they usually manifest as a chronic, well-compensated condition. Subsequent to video capsule endoscopy, deep enteroscopy can be applied to control active bleeding or to improve anemia necessitating blood transfusion. Despite the initial treatment efficacy of argon plasma coagulation (APC), many patients experience re-bleeding, probably because of recurrent or missed AEs. Pharmacological treatments can be considered for patients who have not responded well to other types of treatment or in whom endoscopy is contraindicated. Meanwhile, a conservative approach with iron supplementation remains an option for patients with mild anemia. DL and AVM are considered to be arterial lesions; therefore, these lesions frequently cause acute life-threatening hemorrhage. Mechanical hemostasis using endoclips is recommended to treat DLs, considering the high re-bleeding rate after primary APC cauterization. Meanwhile, most small bowel AVMs are large and susceptible to re-bleeding therefore, they usually require surgical resection. To achieve optimal diagnostic and therapeutic approaches for each type of small bowel lesion, the differences in their epidemiology, pathology and clinical presentation must be understood.

Diagnosis and management of acute lower gastrointestinal bleeding: guidelines from the British Society of Gastroenterology

This is the first UK national guideline to concentrate on acute lower gastrointestinal bleeding (LGIB) and has been commissioned by the Clinical Services and Standards Committee of the British Society of Gastroenterology (BSG). The Guidelines Development Group consisted of representatives from the BSG Endoscopy Committee, the Association of Coloproctology of Great Britain and Ireland, the British Society of Interventional Radiology, the Royal College of Radiologists, NHS Blood and Transplant and a patient representative. A systematic search of the literature was undertaken and the quality of evidence and grading of recommendations appraised according to the GRADE(Grading of Recommendations Assessment, Development and Evaluation) methodology. These guidelines focus on the diagnosis and management of acute LGIB in adults, including methods of risk assessment and interventions to diagnose and treat bleeding (colonoscopy, computed tomography, mesenteric angiography, endoscopic therapy, embolisation and surgery). Recommendations are included on the management of patients who develop LGIB while receiving anticoagulants (including direct oral anticoagulants) or antiplatelet drugs. The appropriate use of blood transfusion is also discussed, including haemoglobin triggers and targets.

Predicting the need for transfer and interventional angiography for patients with acute colonic haemorrhage in a regional setting

BACKGROUND

Radiological angioembolization is an important strategy in management of acute colonic bleeding. Due to requirement for specialized interventional radiology, many hospitals rely on transfer for this service. This study aimed to identify patient and clinical factors associated with positive (blush) computed tomography mesenteric angiogram (CTMA) or need for invasive angiography. The secondary aim was to identify a patient population who may forego transfer and be safely managed in a regional centre.

METHODS

All presentations to Central Coast Local Health District with colonic bleeding from June 2013-June 2017 were included. A guideline for transfer of patients with positive CTMA from Central Coast Local Health District to Royal North Shore Hospital had been established prior to the study period. Demographics, medical background, transfusion requirement, presentation details and mortality data were collected on all patients.

RESULTS

Of 2378 patients presenting with colonic bleeding, 71 of 247 patients investigated with CTMA had a blush. Forty-six patients were transferred to Royal North Shore Hospital. Of these, 28 proceeded to interventional angiography with 19 undergoing angioembolization. Acute transfusion ≥5 units (odds ratio 6.78, P < 0.01) was the only significant predictor of needing interventional angiography. There was no association between age, bleeding site (right or left), use of antiplatelet or anticoagulation, diverticular disease or chronic kidney disease and identification of arterial bleeding on interventional angiography. There was no mortality or significant procedure-related morbidity.

CONCLUSION

A patient's medical background demonstrates a lack of correlation to identification of active bleeding on interventional angiography. Patients requiring ≥5 units blood transfusion should be considered for transfer and interventional angiography.

Clinical features of acute lower gastrointestinal bleeding and its diagnostic strategy with emergency enteroscopy

AIM

To investigate the clinical features of acute lower gastrointestinal bleeding and its diagnostic strategy with emergency enteroscopy.

METHODS

Two hundred and ten patients with acute lower gastrointestinal bleeding at our hospital from January 2014 to December 2017 were selected, and the clinical features of acute lower gastrointestinal bleeding were analyzed. The patients were then divided into two groups based on the bowel preparation method used: a cleansing enema group (169 cases) and an oral cathartic group (41 cases). The influence of intestinal tract cleanliness on emergency enteroscopy diagnosis was then analyzed.

RESULTS

The ratio of males to females in 210 patients was 1.50:1. The elderly, middle-aged, and young patients accounted for 45.71% (96/210), 29.05% (61/210), and 25.24% (53/210), respectively. There were 10.48% of hidden blood loss and 89.52% of overt blood loss. The hemorrhage was mostly common with melena, bright red bloody stools, and dark red bloody stools. The bleeding was mostly caused by intestinal inflammation or infection (35.71%) and polyps of the rectum and colon (20.95%). Colorectal cancer, intestinal inflammation or infection, and polyps of the rectum and colon were main causes in the elderly group. Intestinal inflammation or infection, polyps of the rectum and colon, and colorectal cancer were main causes in the middle-aged group. Intestinal inflammation or infection, polyps of the rectum and colon, and vascular disease were main causes in the young group. The excellent rate of intestinal tract cleanliness in the cleansing enema group was lower than that of the oral cathartic group (P < 0.05). The diagnostic accuracy of enteroscopy with excellent, good, and poor cleanliness was 91.04% (61/67), 80.85% (38/47), and 52.42% (65/124), respectively. The diagnostic accordance rate of enteroscopy with excellent or good cleanliness was higher than that of enteroscopy with poor cleanliness (P < 0.05). There was no statistical difference in the diagnostic accordance rate between enteroscopy with excellent and good cleanliness (P > 0.05).

CONCLUSION

Acute lower gastrointestinal hemorrhage is common in males and the elderly population. Main causes are intestinal inflammation and polyps of the rectum and colon, and there is certain difference in the causes of bleeding in patients of different ages. Hemorrhage is mostly common with melena, bright red bloody stools, and dark red bloody stools. Good intestinal tract cleanliness can increase the diagnostic rate of emergency enteroscopy, and the intestinal tract cleanliness associated with oral cathartic is better than that of cleansing enema. Therefore, based on patient's hemodynamic stability, using bowel preparation with oral cathartic can improve the diagnostic accordance rate.

CT for Evaluation of Acute Gastrointestinal Bleeding

Acute gastrointestinal (GI) bleeding is common and necessitates rapid diagnosis and treatment. Bleeding can occur anywhere throughout the GI tract and may be caused by many types of disease. The variety of enteric diseases that cause bleeding and the tendency for bleeding to be intermittent may make it difficult to render a diagnosis. The workup of GI bleeding is frequently prolonged and expensive, with examinations commonly needing to be repeated. The use of computed tomography (CT) for evaluation of acute GI bleeding is gaining popularity because it can be used to rapidly diagnose active bleeding and nonbleeding bowel disease. The CT examinations used to evaluate acute GI bleeding include CT angiography and multiphase CT enterography. Understanding the clinical evaluation of acute GI bleeding, including the advantages and limitations of endoscopic evaluation, is necessary for the appropriate selection of patients who may benefit from CT. Multiphase CT enterography is used primarily to evaluate stable patients who have undergone upper and lower endoscopy without identification of a bleeding source. CT angiography is used to examine stable and unstable patients who respond to resuscitation, are believed to be actively bleeding, and are considered unlikely to have an upper GI source of hemorrhage. In the emergent setting, CT may yield critical information regarding the presence, location, and cause of active bleeding-data that can guide the choice of subsequent therapy. Recent developments in the use of and techniques for performing CT angiography have made it a potential first-line tool for evaluating acute GI bleeding. ^©RSNA, 2018.