ACR Appropriateness Criteria® Radiologic Management of Lower Gastrointestinal Tract Bleeding: 2021 Update.

Diverticulosis remains the commonest cause for acute lower gastrointestinal tract bleeding (GIB). Conservative management is initially sufficient for most patients, followed by elective diagnostic tests. However, if acute lower GIB persists, it can be investigated with colonoscopy, CT angiography (CTA), or red blood cell (RBC) scan. Colonoscopy can identify the site and cause of bleeding and provide effective treatment. CTA is a noninvasive diagnostic tool that is better tolerated by patients, can identify actively bleeding site or a potential bleeding lesion in vast majority of patients. RBC scan can identify intermittent bleeding, and with single-photon emission computed tomography, can more accurately localize it to a small segment of bowel. If patients are hemodynamically unstable, CTA and transcatheter arteriography/embolization can be performed. Colonoscopy can also be considered in these patients if rapid bowel preparation is feasible. Transcatheter arteriography has a low rate of major complications; however, targeted transcatheter embolization is only feasible if extravasation is seen, which is more likely in hemodynamically unstable patients. If bleeding site has been previously localized but the intervention by colonoscopy and transcatheter embolization have failed to achieve hemostasis, surgery may be required. Among patients with obscure (nonlocalized) recurrent bleeding, capsule endoscopy and CT enterography can be considered to identify culprit mucosal lesion(s). The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

The Role of 68Ga-FAPI PET/CT for Patients with Malignancies of the Lower Gastrointestinal Tract: First Clinical Experience.

For oncologic management or radiotherapy planning, reliable staging tools are essential. The recent development of quinoline-based ligands targeting cancer-associated fibroblasts demonstrated promising preclinical and clinical results. The current study aimed to evaluate the role of fibroblast activation protein inhibitor (FAPI) PET/CT as a first clinical analysis for primary malignancies within the lower gastrointestinal tract (LGT). Methods:68Ga-FAPI PET/CT was performed on a cohort of 22 patients with LGT tumors, including 15 patients with metastatic disease, 1 patient with suspected local relapse, and 6 treatment-naïve patients. Uptake of 68Ga-FAPI-04 and 68Ga-FAPI-46 was quantified by SUVmax and SUVmean After comparison with standard imaging, changes in tumor stage or localization and in oncologic or radiooncologic management were recorded. Results: The highest uptake of FAPI tracer was observed in liver metastases and anal cancer, with an SUVmax of 9.1 and 13.9, respectively. Because of low background activity in normal tissue, there was a high tumor-to-background ratio of more than 3 in most lesions. In treatment-naïve patients, TNM was changed in 50%, whereas in patients with metastases, new findings occurred in 47%. In total, FAPI imaging caused a high, medium, and low change in oncologic or radiooncologic management in 19%, 33%, and 29%, respectively. For almost every patient undergoing irradiation, target volume delineation was improved by 68Ga-FAPI PET/CT. Conclusion: The present study demonstrated that both primary and metastatic LGT tumors were reliably detected by 68Ga-FAPI PET/CT, leading to relevant changes in TNM status and oncologic or radiooncologic management. 68Ga-FAPI PET/CT seems to be a highly promising imaging agent for the diagnosis and management of LGT tumors, potentially opening new applications for tumor staging or restaging.

Pelvic and Lower Gastrointestinal Tract Anatomical Characterization of the Average Male.

OBJECTIVE: Colorectal surgeons report difficulty in positioning surgical devices in males, particularly those with a narrower pelvis. The objectives of this study were to (1) characterize the anatomy of the pelvis and surrounding soft tissue from magnetic resonance and computed tomography scans from 10 average males (175 cm, 78 kg) and (2) develop a model representing the mean configuration to assess variability. METHODS: The anatomy was characterized from existing scans using segmentation and registration techniques. Size and shape variation in the pelvis and soft tissue morphology was characterized using the Generalized Procrustes Analysis to compute the mean configuration. RESULTS: There was considerable variability in volume of the psoas, connective tissue, and pelvis and in surface area of the mesorectum, pelvis, and connective tissue. Subject height was positively correlated with mesorectum surface area (P = .028, R2 = 0.47) and pelvis volume ( P = .041, R2 = 0.43). The anterior-posterior distance between the inferior pelvic floor muscle and pubic symphysis was positively correlated with subject height ( P = .043, r = 0.65). The angle between the superior mesorectum and sacral promontory was negatively correlated with subject height ( P = .042, r = -0.65). The pelvic inlet was positively correlated with subject weight ( P = .001, r = 0.89). CONCLUSIONS: There was considerable variability in organ volume and surface area among average males with some correlations to subject height and weight. A physical trainer model created from these data helped surgeons trial and assess device prototypes in a controllable environment.

Advanced diagnostic endoscopy in the lower gastrointestinal tract: A review of JGES core sessions.

At each of the 89th to the 92nd congresses of the Japan Gastroenterological Endoscopy Society, a series of featured discussion sessions concerning advanced diagnostic endoscopy in the lower gastrointestinal tract were presented. In total, 45 lectures were presented in this subject area. It was shown that, in recent years, several convenient and less invasive colonoscopic modalities have been developed. This review article summarizes these core sessions and the efficacy of the techniques discussed.

Diagnosis of lower gastrointestinal bleeding by multi-slice CT angiography: A meta-analysis.

PURPOSE: To estimate the diagnostic value of multi-slice spiral CT angiography (CTA) in lower gastrointestinal bleeding by a meta-analysis. METHODS: The relevant clinical studies on the diagnostic value of CTA were searched on PubMed, Embase and other electronic documents databases with the deadline of 2016 September. Language was limited to English. A diagnostic meta-analysis was performed by using Meta-DiSc software. The effect sizes included sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), and diagnostic odds ratio (DOR) and 95% confidence interval (CI). The Cochran-Q test and I2 statistic based on χ2 test were used for estimation of the heterogeneity. Meta-regression was performed to explore the source of heterogeneity. SROC curve was established. RESULTS: A total of 14 articles including 549 patients with lower gastrointestinal bleeding were enrolled in the meta-analysis. The combined PLR, NLR and DOR were respectively 8.149, 0.158 and 56.213. There were significant heterogeneities in all estimations but we could not find the sources by meta-regression based on study design, study location, CT slices and sample size. The AUC and Q index under the fixed effect model was respectively 0.9463 and 0.8856. CONCLUSIONS: The multi-slice CTA has high diagnostic value for lower gastrointestinal bleeding.

[Indications, diagnoses and quality markers in upper and lower endoscopies in 2010 and 2011 at the 1st Department of Medicine, Semmelweis University, Budapest]. / A felso és alsó endoszkópiák indikációja, a diagnózisok megoszlása és minoségi mutatók 2010­2011-ben a Semmelweis Egyetem I. Belgyógyászati Klinikáján.

INTRODUCTION AND AIM: The aim was to assess the incidence of endoscopic findings based on the indication of the procedures in upper/lower endoscopies, and measuring quality indicators of colonoscopies at the 1st Department of Medicine, Semmelweis University, Budapest. METHOD: Data of 2987 patients (male/female:1361/1626, mean age: 60.7 years(y), SD: 16.7y) between 01.01.2010 and 31.12.2011 were analyzed. Both inpatient and outpatient records were collected. RESULTS: Incidence of peptic ulcer disease, esophageal varices, gastric polyps and gastric cancer were 10.8%, 4.5%, 6.1%, 2.9% in upper endoscopies, respectively. In colonoscopies colorectal polyps, diverticulosis, colorectal cancer and IBD were found in 29.9%, 22.4%, 6.9%, 9.7%, respectively. In patients having upper endoscopy with GI bleeding indication, older age (p<0.001), male gender (p<0.001, OR: 1.64), acenocoumarol/heparin use (p<0,001, peptic ulcers and esophageal varices were more frequent (p<0.001, OR: 2.83 and p<0.001, OR: 2.79), while in colonoscopies colorectal cancer had higher incidence (p<0.001, OR:3.27). 81% of colonoscopies were complete. Causes of incomplete procedures were ineffective bowel preparation (38.2%), technical difficulties (25.1%) and strictures (20.5%). CONCLUSION: The endoscopic findings and quality indicators (adenoma detection rate, coecal intubation rate) were in line with that reported in published series. Orv. Hetil., 2016, 157(52), 2074-2081.

Elasticity mapping of murine abdominal organs in vivo using harmonic motion imaging (HMI).

Recently, ultrasonic imaging of soft tissue mechanics has been increasingly studied to image otherwise undetectable pathologies. However, many underlying mechanisms of tissue stiffening remain unknown, requiring small animal studies and adapted elasticity mapping techniques. Harmonic motion imaging (HMI) assesses tissue viscoelasticity by inducing localized oscillation from a periodic acoustic radiation force. The objective of this study was to evaluate the feasibility of HMI for in vivo elasticity mapping of abdominal organs in small animals. Pathological cases, i.e. chronic pancreatitis and pancreatic cancer, were also studied in vivo to assess the capability of HMI for detection of the change in mechanical properties. A 4.5 MHz focused ultrasound transducer (FUS) generated an amplitude-modulated beam resulting in 50 Hz harmonic tissue oscillations at its focus. Axial tissue displacement was estimated using 1D-cross-correlation of RF signals acquired with a 7.8 MHz diagnostic transducer confocally aligned with the FUS. In vitro results in canine liver and kidney showed the correlation between HMI displacement and Young's moduli measured by rheometry compression testing. HMI was capable of providing reproducible elasticity maps of the mouse abdominal region in vivo allowing the identification of, from stiffest to softest, the murine kidney, pancreas, liver, and spleen. Finally, pancreata affected by pancreatitis and pancreatic cancer showed HMI displacements 1.7 and 2.2 times lower than in the control case, respectively, indicating higher stiffness. The HMI displacement amplitude was correlated with the extent of fibrosis as well as detecting the very onset of stiffening even before fibrosis could be detected on H&E. This work shows that HMI can produce reliable elasticity maps of mouse abdominal region in vivo, thus providing a potentially critical tool to assess pathologies affecting organ elasticity.

Lower Gastrointestinal Hemorrhage.

Lower gastrointestinal bleeding (LGIB) is a frequent reason for hospitalization especially in the elderly. Patients with LGIB are frequently admitted to the intensive care unit and may require transfusion of packed red blood cells and other blood products especially in the setting of coagulopathy. Colonoscopy is often performed to localize the source of bleeding and to provide therapeutic measures. LGIB may present as an acute life-threatening event or as a chronic insidious condition manifesting as iron deficiency anemia and positivity for fecal occult blood. This article discusses the presentation, diagnosis, and management of LGIB with a focus on conditions that present with acute blood loss.

Visceroptosis of the bowel in the hypermobility type of Ehlers-Danlos syndrome: presentation of a rare manifestation and review of the literature.

Gastrointestinal complications are common in patients with Ehlers-Danlos syndrome, affecting up to 50% of individuals depending on the subtype. The spectrum of gastrointestinal manifestations is broad and ranges from life threatening spontaneous perforation of the visceral organs to a more benign functional symptoms. Here we describe the clinical and radiographic manifestations of visceroptosis of the bowel, a rare complication of Ehlers-Danlos syndrome that is characterized by prolapse of abdominal organs below their natural position. We further review the literature on gastrointestinal complications in the different forms of Ehlers-Danlos syndrome.

Acute lower intestinal bleeding: feasibility and diagnostic performance of CT angiography.

PURPOSE: To assess the diagnostic performance of computed tomographic (CT) angiography as the initial diagnostic examination for patients presenting to the emergency room with acute lower intestinal bleeding. MATERIALS AND METHODS: The study was reviewed and approved by the ethics committee, and written informed consent was obtained from each patient or their closest relative when the clinical condition precluded consent by the patient. This prospective study comprised 47 patients (27 men, 20 women; mean age, 68 years) with acute lower gastrointestinal tract bleeding who were referred to undergo emergency colonoscopy for evaluation. CT angiography was performed in all patients shortly after arrival to the emergency room. Findings identified at CT angiography included active extravasation (ongoing hemorrhage) or hyperattenuating intraluminal contents on noncontrast material-enhanced images (recent hemorrhage). Presence and location of bleeding and likely cause of hemorrhage were determined and compared with the standard of reference (angiography, colonoscopy, or surgical findings). Data collected were analyzed with a statistical software package. Sensitivity, specificity, and positive and negative predictive values of CT angiography in depicting ongoing or recent hemorrhage were calculated and compared with those of standard of reference. RESULTS: CT angiography demonstrated active bleeding in 14 patients and intraluminal hyperattenuating material in six patients. The sensitivity, specificity, positive predictive value, and negative predictive value of CT angiography in depicting active or recent bleeding were 100% (19 of 19), 96% (27 of 28), 95% (19 of 20), and 100% (27 of 27), respectively. Findings of CT angiography and the standard of reference were concordant for determining definite or potential cause of bleeding in 44 of 47 patients (93% accuracy). CONCLUSION: CT angiography performed in the emergency setting in patients with acute lower intestinal bleeding is feasible and correctly depicts the presence and location of active or recent hemorrhage, as well as the potential cause, in the majority of patients.

Scintigraphic evaluation of acute lower gastrointestinal hemorrhage: current status and future directions.

This review examines the role and limitations of scintigraphic evaluation in acute lower gastrointestinal hemorrhage. A detailed discussion of methods for improving diagnostic outcomes is provided. Techniques and recommendations are offered for optimization of red blood cell scintigraphy for earlier detection and more accurate localization of acute lower gastrointestinal hemorrhage.

Provocative mesenteric angiography for lower gastrointestinal hemorrhage: results from a single-institution study.

PURPOSE: To determine the diagnostic capability, complication rate, and potential predictors of success for provocative mesenteric angiography in patients with obscure and recurrent lower gastrointestinal (GI) hemorrhage. MATERIALS AND METHODS: Thirty-four patients (age, 7-92 years; 22 men) underwent 36 provocative mesenteric angiograms between January 2002 and December 2008. Provocative mesenteric angiography consisted of systemic anticoagulation with heparin followed by selective transcatheter injection of vasodilator and tissue plasminogen activator into the arterial distribution of highest suspicion. Medications were administered incrementally until active extravasation was visualized or until the operator deemed the outcome negative. The pertinent clinical, radiologic, surgical, laboratory, and pathologic notes were retrospectively reviewed. RESULTS: Among 36 provocative mesenteric angiograms, 11 resulted in angiographically visible extravasation (31%) and an additional procedure resulted in angiographic visualization of an undiagnosed hypervascular mass, resulting in the identification of a source of a hemorrhage in 33% overall. In 10 of the 11 cases with visualized extravasation, transcatheter embolization successfully controlled recurrent hemorrhage, while the hypervascular mass without extravasation was successfully resected. Therefore, a total of 11 of 36 studies (31%) resulted in successful definitive treatment of recurrent hemorrhage. One embolization-related complication occurred, resulting in surgical resection of perforated ischemic bowel. No hemorrhagic complications were identified. Patients with melena and patients admitted for reasons other than acute lower GI hemorrhage were significantly less likely to benefit from provocative mesenteric angiography. CONCLUSIONS: In this series, provocative mesenteric angiography was safe and effective for eliciting the source of occult lower GI hemorrhage, leading to definitive therapy in about one third of patients.

Ultrasonographic appearance of canine parvoviral enteritis in puppies.

The ultrasonographic appearance of the gastrointestinal tract of puppies suffering from parvoviral enteritis was characterized. Forty puppies between 6 and 24 weeks of age with confirmed canine parvoviral enteritis were examined ultrasonographically within 24 h of admission. Sonographic findings included fluid-filled small intestines in 92.5% of subjects, and stomach and colon in 80% and 62.5% of subjects, respectively. Generalized atony was present in 30 subjects and weak peristaltic contractions indicative of functional ileus observed in the remaining 10 subjects. The duodenal and jejunal mucosal layer thicknesses were significantly reduced when compared with normal puppies with mean duodenal mucosal layer measuring 1.7 mm and jejunal mucosal layer 1.0 mm. Additionally, a mucosal layer with diffuse hyperechoic speckles was seen in the duodenum (15% of subjects) and the jejunum (50% of subjects). The luminal surface of the duodenal mucosa was irregular in 22.5% of subjects and the jejunal mucosa in 42.5% of subjects. In all of these subjects, changes were accompanied by generalized indistinct wall layering. Small intestinal corrugations were seen within the duodenum in 35% of subjects and within the jejunum in 7.5%. A mild amount of anechoic free peritoneal fluid was observed in 26 subjects and was considered within normal limits and a moderate amount of anechoic free peritoneal fluid was observed in six subjects. The jejunal lymph node size was within normal limits. None of the above changes are pathognomonic for canine parvoviral enteritis but finding them in combination is highly suggestive.

Normal canine pediatric gastrointestinal ultrasonography.

The normal sonographic appearance of the adult canine gastrointestinal tract has been described. Interpretation of abdominal ultrasonographic findings in puppies is difficult due to the lack of information on normal ultrasonographic findings. The gastrointestinal tract, jejunal lymph node size and the presence and appearance of abdominal fluid were investigated in 23 normal, 7-12-week-old Beagle puppies. The duodenal wall thickness was greater than in other parts of the gastrointestinal tract (mean 3.8 +/- standard deviation [SD] 5 mm, range 3.2-4.8 mm). The mean stomach wall thickness was 2.7 +/- SD 0.4 mm (range 2.2-3.7 mm), the mean jejunal wall thickness was 2.5 +/- SD 0.5 mm (range 1.2-3.4 mm), and the mean colonic wall thickness was 1.3 +/- SD 0.3 mm (range 0.7-2.0 mm). In addition, mean duodenal and jejunal mucosal layer thicknesses measured 2.7 +/- SD 0.5 mm (range 2.0-3.8 mm) and 1.5 +/- SD 0.4 mm (range 0.6-2.5 mm), respectively. Homogenous, hypoechoic jejunal lymph nodes were easily found and the mean thickness was 7.1 +/- SD 2.2 mm (range 1.5-12.5 mm). A mild amount of anechoic free peritoneal fluid was present in all puppies.

Initial experience using N-butyl cyanoacrylate for embolization of lower gastrointestinal hemorrhage.

PURPOSE: To report initial experience using N-butyl cyanoacrylate (n-BCA) to control lower gastrointestinal hemorrhage (LGIH). MATERIALS AND METHODS: From May 2005 to March 2009, 14 patients with LGIH underwent mesenteric angiography and transcatheter arterial embolization using n-BCA. Candidacy was primarily based on the patient's hemodynamic stability and the risk for future LGIH, determined by the presence of at least one of the following risk factors: more than one arterial feeder supplying the bleeding vessel, underlying coagulopathy, or need to resume anticoagulation after embolization. Outcome measures included technical success (immediate postembolic hemostasis confirmed with completion angiography showing no further extravasation of contrast medium), clinical success (postembolic hemostasis in the absence of complications 30 days after the procedure), and clinical failure (recurrence of LGIH necessitating repeat embolization or surgical treatment). RESULTS: Fourteen patients with active LGIH were treated with n-BCA, with 100% technical success. Two patients had rebleeds resulting in bowel resection. One patient experienced a minor rebleed that spontaneously resolved. One patient died secondary to multiorgan failure in the setting of multiple medical problems. The remaining 10 patients had complete clinical success, experiencing no signs of rebleeding or infarction. CONCLUSIONS: The results suggest that n-BCA can be a useful alternative embolic agent for the treatment of hemodynamically unstable patients with LGIH when standard microcoiling techniques fail or are not feasible and in patients with coagulopathy.

Delayed, life-threatening lower gastrointestinal hemorrhage in an infant after serial transverse enteroplasty: treatment with transcatheter n-butyl-2-cyanoacrylate embolization.

We report a case of n-butyl-2-cyanoacrylate glue embolization of life-threatening lower gastrointestinal (LGI) hemorrhage in a 10-month-old boy. The child had a history of gastroschisis and short-bowel syndrome. Six months prior to the LGI bleed, he had undergone a serial transverse enteroplasty (STEP) to lengthen his intestine. To the best of our knowledge this is both the first report of successful glue embolization for LGI bleeding in a child and also the first report of severe hemorrhage after the STEP procedure.

Investigation of acute lower gastrointestinal bleeding with 16- and 64-slice multidetector CT.

We evaluated the usefulness of 16- and 64-slice multidetector CT (MDCT) in the detection of a bleeding site in acute lower gastrointestinal tract (GIT) haemorrhage by conducting a retrospective study of cases of presumed acute lower GIT haemorrhage imaged with CT in two teaching hospitals in an 11-month period. The patients underwent contrast enhanced CT using either a 16 or 64 MDCT. No oral contrast was used. One hundred milliliters of non-ionic intravenous contrast agent was injected at 4.5 mL/s, followed by a 60 mL saline flush at 4 mL/s through a dual head injector. Images were acquired in arterial phase with or without non-contrast and portal phase imaging with 16 x 1.5 mm or 64 x 0.625 mm collimation. Active bleeding was diagnosed by the presence of iodinated contrast extravasation into the bowel lumen on arterial phase images with attenuation greater than and distinct from the normal mucosal enhancement or focal pooling of increased attenuation contrast material within a bowel segment on portal-venous images. Further management and final diagnosis was recorded. Fourteen patients and 15 studies were reviewed. CT detected and localized a presumed bleeding site or potential causative pathology in 12 (80%) of the patients. Seven of these were supported by other investigations or surgery, while five were not demonstrated by other modalities. Eight patients had mesenteric angiography, of which only four corroborated the site of bleeding. CT did not detect the bleeding site in three patients, of which two required further investigation and definitive treatment. We propose that MDCT serves a useful role as the initial rapid investigation to triage patients presenting with lower GIT bleeding for further investigation and management.