Gastrointestinal haemorrhage from a second source in patients with colonic angiodysplasia

Endoscopic therapy for gastrointestinal angiodysplasia

OBJECTIVES

This is a protocol for a Cochrane Review (intervention). The objectives are as follows: To assess the benefits and harms of the different endoscopic management approaches for gastrointestinal angiodysplasia in symptomatic adults.

Diagnosis and treatment of malignant-appearing arteriovenous malformation

Arteriovenous malformations (AVM) are most commonly found in the gastrointestinal tract, and presentation can range from asymptomatic to massive gastrointestinal hemorrhage. This case highlights a unique presentation of AVMs. During a screening colonoscopy, a 5-cm mass was discovered in the transverse colon encompassing 25% to 50% of the circumference of the lumen. Biopsies showed polypoid AVM with overlying inflammatory polyps without evidence of malignancy or dysplasia. There are many treatment options for AVM removal. In this case, since suspicion for malignancy was high, the patient underwent surgery and will be closely monitored.

Therapeutic Opportunities for Intestinal Angioectasia- Targeting PPARγ and Oxidative Stress

Recurrent and acute bleeding from intestinal tract angioectasia (AEC) presents a major challenge for clinical intervention. Current treatments are empiric, with frequent poor clinical outcomes. Improvements in understanding the pathophysiology of these lesions will help guide treatment. Using data from the US Food and Drug Administration (FDA)'s Adverse Event Reporting System (FAERS), we analyzed 12 million patient reports to identify drugs inversely correlated with gastrointestinal bleeding and potentially limiting AEC severity. FAERS analysis revealed that drugs used in patients with diabetes and those targeting PPARγ-related mechanisms were associated with decreased AEC phenotypes (P < 0.0001). Electronic health records (EHRs) at University of Cincinnati Hospital were analyzed to validate FAERS analysis. EHR data showed a 5.6% decrease in risk of AEC and associated phenotypes in patients on PPARγ agonists. Murine knockout models of AEC phenotypes were used to construct a gene-regulatory network of candidate drug targets and pathways, which revealed that wound healing, vasculature development and regulation of oxidative stress were impacted in AEC pathophysiology. Human colonic tissue was examined for expression differences across key pathway proteins, PPARγ, HIF1α, VEGF, and TGFβ1. In vitro analysis of human AEC tissues showed lower expression of PPARγ and TGFβ1 compared with controls (0.55 ± 0.07 and 0.49 ± 0.05). National Center for Biotechnology Information (NCBI) Gene Expression Omnibus (GEO) RNA-Seq data was analyzed to substantiate human tissue findings. This integrative discovery approach showing altered expression of key genes involved in oxidative stress and injury repair mechanisms presents novel insight into AEC etiology, which will improve targeted mechanistic studies and more optimal medical therapy for AEC.

Definitive therapy of colonic angioectasia by submucosal coagulation

Background and study aims  Colonic angioectasia are the most common vascular lesions in the gastrointestinal tract and are among the most common causes for chronic or recurrent lower gastrointestinal bleeding. Endoscopic treatment involves a variety of techniques, all of which focus on destruction of the mucosal abnormality. However, recurrent bleeding after endoscopic treatment is common, with more than one treatment frequently necessary. We report a technique for definitive treatment of colonic angioectasia by targeting the feeding submucosal vessel. Patients and methods  Analogous to endoscopic mucosal resection, a submucosal injection is made beneath the target lesion which is then removed by electrocautery snare resection of the mucosal lesion. The exposed feeding vessel is then destroyed by application of coagulation current. The resection defect is closed by clips. Results  Six patients with a total of 14 colonic angioectasia were treated over the study period. All lesions were destroyed without adverse events. Conclusion  Elevation, hot snare resection and coagulation (ESC) of the visible vessel for treating colonic angioectasia appears safe and effective. Larger prospective comparative studies are required to assess its specific role.

Diagnostic and therapeutic challenges of gastrointestinal angiodysplasias: A critical review and view points

Gastrointestinal angiodysplasias (GIADs), also called angioectasias, are the most frequent vascular lesions. Its precise prevalence is unknown since most of them are asymptomatic. However, the incidence may be increasing since GIADs affect individuals aged more than 60 years and population life expectancy is globally increasing worldwide. They are responsible of about 5% to 10% of all gastrointestinal bleeding (GIB) cases. Most GIADs are placed in small bowel, where are the cause of 50 to 60% of obscure GIB diagnosed with video capsule endoscopy. They may be the cause of fatal severe bleeding episodes; nevertheless, recurrent overt or occult bleeding episodes requiring repeated expensive treatments and disturbing patient’s quality-of-life are more frequently observed. Diagnosis and treatment of GIADs (particularly those placed in small bowel) are a great challenge due to insidious disease behavior, inaccessibility to affected sites and limitations of available diagnostic procedures. Hemorrhagic causality out of the actively bleeding lesions detected by diagnostic procedures may be difficult to establish. No treatment guidelines are currently available, so there is a high variability in the management of these patients. In this review, the epidemiology and pathophysiology of GIADs and the status in the diagnosis and treatment, with special emphasis on small bowel angiodysplasias based on multiple publications, are critically discussed. In addition, a classification of GIADs based on their endoscopic characteristics is proposed. Finally, some aspects that need to be clarified in future research studies are highlighted.

Acquired von Willebrand Syndrome Associated with Cardiovascular Diseases

The blood glycoprotein von Willebrand factor (VWF) plays an important role in hemostasis and thrombosis. VWF is produced and secreted as large multimers by endothelial cells and megakaryocytes. It is then cleaved in a sheer-stress dependent manner by a specific protease, ADAMTS13, into multimers consisting of 2–80 subunits. Among VWF multimers, high molecular weight (HMW) multimers play important roles in platelet aggregation. Therefore, their loss induces a hemostatic disorder known as von Willebrand disease (VWD) type 2A. Various cardiovascular diseases, such as aortic stenosis, hypertrophic obstructive cardiomyopathy (HOCM), and several congenital structural diseases, as well as mechanical circulatory support systems, generate excessive high shear stress in the bloodstream. These cause excessive cleavage of VWF multimers resulting in a loss of HMW multimers, known as acquired von Willebrand syndrome (AVWS), a hemostatic disorder similar to VWD type 2A. Bleeding often occurs in the gastrointestinal tract since a fragile angiodysplasia develops associated with these diseases. Radical treatment for AVWS is to remove the pathological high shear causing AVWS.

Nonisolated Small Bowel Gastrointestinal Angiodysplasias are Associated With Higher Rebleeding Rates When Compared With Isolated Small Bowel Gastrointestinal Angiodysplasia on Video Capsule Endoscopy

BACKGROUND

Gastrointestinal angiodysplasias (GIAD) are commonly diagnosed in the small bowel but can be located in other areas of the gastrointestinal tract. About half of patients diagnosed with GIAD have more than 1 lesion and 20% of patients have GIAD in both the small bowel and a source outside of the small bowel (nonisolated to small bowel GIAD or NISGIAD). The remaining patients with GIAD have lesions isolated to the small bowel (ISGIAD). Complications including rebleeding, hospitalization and mortality rates have not been previously analyzed between these 2 groups.

AIM

To compare rebleeding, hospitalization and mortality rates between ISGIAD and NISGIAD. The secondary goals were to evaluate comorbidities that may be associated with ISGIAD and/or NISGIAD, and to determine if any of these comorbidities are associated with a higher risk of rebleeding from GIAD.

MATERIALS AND METHODS

This was a retrospective study that included 425 patients who underwent video capsule endoscopy between 2006 and 2013. Patients underwent esophagogastroduodenoscopy and colonoscopy before video capsule endoscopy. The primary indications for workup included obscure gastrointestinal bleeding. After exclusion criteria, 87 patients diagnosed with GIAD remained, 57 patients with ISGIAD and 30 with NISGIAD. Categorical variables were compared by the Fisher exact test or χ test and continuous data were compared using the Student T test.

RESULTS

Risk factors associated with rebleeding rates included coronary artery disease, chronic kidney disease, and congestive heart failure on multivariate analysis. Odds ratios for rebleeding was found in patients with NISGIAD (odds ratio, 4.222; P=0.036). There was no difference in hospitalization rates between patients with ISGIAD and NISGIAD. There was no statistically significant difference in mortality from any cause at 30, 60, and 90 days in patients with ISGIAD and NISGIAD.

CONCLUSIONS

In this retrospective analysis of GIAD at a single institution, patients with NISGIAD compared with ISGIAD had a 4 times odds of rebleeding within 1 year after capsule endoscopy. This is a novel study, as the distribution of GIAD has not been previously described as being a risk factor for rebleeding.

Review article: gastrointestinal angiodysplasia - pathogenesis, diagnosis and management

BACKGROUND

Angiodysplasia (AD) of the gastrointestinal (GI) tract is an important condition that can cause significant morbidity and -rarely - mortality.

AIM

To provide an up-to-date comprehensive summary of the literature evaluating this disease entity with a particular focus on pathogenesis as well as current and emerging diagnostic and therapeutic modalities. Recommendations for treatment will be made on the basis of the current available evidence and consensus opinion of the authors.

METHODS

A systematic literature search was performed. The search strategy used the keywords 'angiodysplasia' or 'arteriovenous malformation' or 'angioectasia' or 'vascular ectasia' or 'vascular lesions' or 'vascular abnormalities' or 'vascular malformations' in the title or abstract.

RESULTS

Most AD lesions (54-81.9%) are detected in the caecum and ascending colon. They may develop secondary to chronic low-grade intermittent obstruction of submucosal veins coupled with increased vascular endothelial growth factor-dependent proliferation. Endotherapy with argon plasma coagulation resolves bleeding in 85% of patients with colonic AD. In patients who fail (or are not suitable for) other interventions, treatment with thalidomide or octreotide can lead to a clinically meaningful response in 71.4% and 77% of patients respectively.

CONCLUSIONS

Angiodysplasia is a rare, but important, cause of both overt and occult GI bleeding especially in the older patients. Advances in endoscopic imaging and therapeutic techniques have led to improved outcomes in these patients. The choice of treatment should be decided on a patient-by-patient basis. Further research is required to better understand the pathogenesis and identify potential therapeutic targets.

Radiological features of Meckel's diverticulum and its complications

Meckel's diverticulum is the most common congenital abnormality of the small bowel. The majority of patients with this anomaly will remain asymptomatic; however, several complications may occur, including obstruction, intussusception, perforation, diverticulitis, and gastrointestinal haemorrhage. These complications may produce a variety of different clinical features and radiological appearances. The purpose of this article is to review the potential imaging manifestations of Meckel's diverticulum and its complications and discuss the advantages and disadvantages of the imaging techniques available.

Long-term outcome of argon plasma ablation therapy for bleeding in 100 consecutive patients with colonic angiodysplasia

PURPOSE

Angiodysplasia is a frequent cause of colonic bleeding. Argon plasma coagulation was reported to be useful in endoscopic hemostasis. However, the long-term outcomes have been poorly evaluated. This study was designed to assess the long-term outcomes of bleeding patients with colonic angiodysplasia treated by argon plasma coagulation.

METHODS

A cohort of 100 patients with gastrointestinal bleeding caused by colonic angiodysplasia was studied prospectively. The endoscopic intervention was considered successful if there was no further overt bleeding and hemoglobin concentration was stabilized (primary end point). Secondary end points were the requirement of blood transfusions, the need for surgery, bleeding-related mortality, and overall mortality.

RESULTS

Overt bleeding resolved and hemoglobin levels were stabilized without transfusions or iron therapy in 85 of 100 patients (85 percent) after a median follow-up of 20 (range, 6-62) months. Transfusion requirements ceased in 90 percent of patients and only one required surgery. No patient died because of hemorrhage. In the subgroup of patients with anemia, mean hemoglobin levels increased from 9.3 (range, 5.5-12.2) g/dl before treatment to 12.6 (range, 7.4-16.7) g/dl after treatment (P < 0.01). The probability of remaining free of rebleeding at one and two year follow-up was 98 percent (95 percent confidence interval, 96-100) and 90 percent (95 percent confidence interval, 83-97), respectively. Among 118 procedures, only two complications were observed (1.7 percent).

CONCLUSIONS

Endoscopic argon plasma ablation therapy is useful in the management of bleeding from colonic angiodysplasia.

Intraoperative enteroscopy for diagnosis and management of unexplained gastrointestinal bleeding

BACKGROUND

The aim of this study was to evaluate the diagnostic and therapeutic yield of intraoperative enteroscopy in patients with obscure gastrointestinal (GI) bleeding.

METHODS

Complete intraoperative enteroscopy was performed in 25 patients with GI bleeding (overt hemorrhage 21, occult blood loss 4). The cause of GI bleeding was unknown before intraoperative enteroscopy in 20 patients and presumed in 5 (colon 4, duodenum 1).

RESULTS

Complete inspection of the small bowel was achieved in all cases. Mucosal-based lesions of the small bowel were identified in 16 of the 20 patients in whom the source of bleeding was unknown preoperatively (angiodysplasia 12, other causes 4). These lesions were treated by segmental small bowel resection (15) or medical therapy (1). With a mean 19-month follow-up, the rebleeding rate was 30% (6 of 20), and 2 of them in whom enteroscopy was negative died of massive hemorrhage. Intraoperative enteroscopy was normal in the 5 patients with bleeding of presumed GI origin preoperatively.

CONCLUSIONS

Intraoperative enteroscopy remains a valuable tool for exploring obscure GI bleeding in selected patients.

AGA technical review on the evaluation and management of occult and obscure gastrointestinal bleeding

This literature review and the recommendations therein were prepared for the American Gastroenterological Association Clinical Practice and Practice Economics committee. The paper was approved by the committee on May 16, 1999, and by the AGA governing board on July 18, 1999.

Prospective evaluation of gastrointestinal tract in patients with iron-deficiency anemia

Gastrointestinal bleeding is believed to cause iron-deficiency anemia (IDA). The information concerning ideal evaluation of the gastrointestinal tract and exact findings in patients with IDA is scant. The aim of this study was to prospectively evaluate patients with IDA for gastrointestinal lesions potentially causing IDA at a US Army Teaching Medical Center with Gastroenterology Fellowship. Seventy patients with IDA had esophagogastroduodenoscopy (EGD) and colonoscopy, and if this evaluation was unremarkable, then small bowel biopsy was obtained at EGD to evaluate for celiac disease. Enteroclysis was done if endoscopic evaluation was negative. At endoscopy, at least one lesion potentially accounted for the IDA in 50 (71%) patients. At colonoscopy, 21 (30%) patients had 22 lesions (four colon cancer, seven adenoma > 1 cm, six vascular malformation, four severely bleeding hemorrhoids, one ileal Crohn's); at EGD, 39 (56%) patients had 43 lesions (11 gastric erosion, 10 esophagitis, four vascular malformation, four celiac disease, three gastric cancer, three gastric ulcer, three duodenal ulcer, two gastric polyp > 1 cm, one duodenal lymphoma, one esophageal cancer, and one duodenal Crohn's). Twelve (17%) patients had both upper and lower gastrointestinal tract lesions. Twenty-four of 32 (75%) patients with positive fecal occult blood test had potentially bleeding lesions compared to 24 of 38 (63%) patients with negative fecal occult blood test (P > 0.05). Six of nine patients with malignancy had positive fecal occult blood test. Twenty patients with normal endoscopy and small bowel biopsy had normal enteroclysis.(ABSTRACT TRUNCATED AT 250 WORDS)

Diffuse microscopic angiodysplasia--a previously unreported variant of angiodysplasia. Report of a case

PURPOSE

The entity of diffuse microscopic angiodysplasia is described, and a patient with severe gastrointestinal hemorrhage because of this submucosal source of bleeding is reported.

METHOD

Case records of a patient with severe gastrointestinal hemorrhage were reviewed, and histologic findings were compared with colonoscopic and operative findings. The patient received 51 units of packed red blood cells over 3.5 months and remained undiagnosed, despite an exhaustive evaluation, until autopsy.

RESULTS

Ectatic veins, venules, and capillaries were present within the submucosa in virtually every section of the small and large intestine examined (79 of 86 sections). Histologic evidence of bleeding from these submucosal vessels was identified in three sites (colon, jejunum, and ileum). The absence of endoscopically visible lesions was explained by findings that vessels did not traverse the muscularis mucosa and that mucosal depth was normal. This case of diffuse microscopic angiodysplasia, therefore, represents a unique variant, because the vascular findings were so diffuse and the mucosa remained histologically and endoscopically uninvolved, despite severe bleeding.

CONCLUSION

Gastrointestinal bleeding from angiodysplasia is generally assumed to arise from endoscopically recognizable vascular ectasia within the mucosa. Thus, this case helps provide an explanation for some cases in which occult or massive bleeding is assumed to be secondary to angiodysplasia, even when endoscopic verification is not possible. Recognition of this disease process may require segmental resection or deep biopsy of endoscopically normal intestine.

Malignant 'angiodysplasia'

Four patients with chronic gastrointestinal blood loss of obscure aetiology were investigated by visceral angiography. All showed angiographic abnormalities in the caecum with characteristic features seen in angiodysplasia as well as other conditions such as inflammatory bowel disease, carcinoma. All four patients had a malignant cause for their angiographic appearance. This paper stresses the importance of reviewing previous examinations before accepting a diagnosis of angiodysplasia. The angiographic features of contrast pooling on the anti-mesenteric border of the caecum or ascending colon, a dilated intramural vein and early filling of a draining vein imply that serious pathology is present.

Colonoscopic diagnosis and treatment of lower gastrointestinal bleeding

Methods of diagnosis and treatment of lower gastrointestinal bleeding depend on the rate of bleeding and the amount of blood lost. If bleeding is occult, colonoscopy is the single best way to determine the source, if bleeding is gross but mild, causing melena or small amounts of hematochezia, colonoscopy or a combination of flexible sigmoidoscopy and double-contrast barium enema should be used to evaluate the colon. In most patients with melena, the upper tract must be examined endoscopically. Acute lower gastrointestinal bleeding stops spontaneously in 75 to 90 per cent of patients, permitting preparation of the colon before colonoscopy. If bleeding is continuing, diagnostic options include colonoscopy with no preparation of the colon, relying on the cathartic effect of blood, or a red cell radionuclide scan followed by angiography if the scan is positive. A bleeding lesion seen on angiography is usually treated by infusion of vasopressin. Colonoscopic treatment of a bleeding site uses the BICAP probe, heater probe, or argon laser. Patients who bleed severely and those who do not respond to treatment or rebleed after treatment are candidates for operation. Segmental resection is preferred if the bleeding site is known. If not, total colectomy with ileorectal anastomosis may be necessary. A mortality rate of 10 to 15 per cent in patients with severe bleeding reflects the advanced age of many of these patients and the difficulty of managing gastrointestinal bleeding in the presence of associated medical conditions.

Angiodysplasia as a cause of iron deficiency anaemia

Angiodysplasia, a condition of unknown aetiology, is thought to represent the commonest cause of obscure gastrointestinal bleeding, particularly in the elderly population. The lesions of angiodysplasia, which are small (less than 5 mm) and usually multiple, consist of microvascular abnormalities in the mucosa and submucosa of the bowel wall. They are most commonly found in the caecum and right side of the colon, but have been observed in the stomach, ileum and elsewhere in the colon. The diagnosis is made by either selective visceral angiography and/or colonoscopy, but the lesions cannot be detected on barium studies or with the naked eye at laparotomy. Localisation of the abnormalities by the histopathologist is greatly facilitated by special injection techniques demonstrating the blood vessels of resected colonic specimens prior to fixation and section. Treatment may be conservative (iron replacement) if the anaemia is not severe, by endoscopic fulguration or by colonic resection. Other common causes of gastrointestinal blood loss should always be excluded before the final diagnosis of angiodysplasia is accepted. Although the condition is well recognised as a significant cause of gastrointestinal blood loss a number of questions remain to be answered. The true incidence of angiodysplasia in the population is not known, the aetiology of the condition remains a mystery, although many theories abound.

Localization of lower gastrointestinal bleeding using in vivo technetium-99m-labelled red blood cell scintigraphy

Technetium-99m-labelled red blood cell scintigraphy was used in the investigation of 41 patients with major rectal haemorrhage. Red cells were labelled in vivo with technetium-99m pertechnetate and serial scans (0-36 h) were taken using a large field gamma camera. Twenty-two men and 15 women, mean age 71.3 years (range 32-91 years), and four children were studied. Forty-three scans were performed in all and there were 31 positive and 12 negative results. In each case the accuracy of the scan in localizing the bleeding site was checked either by independent investigations or at laparotomy. A definite bleeding site was identified in 30 cases and red cell scintigraphy correctly localized 29 of these (sensitivity 97 per cent). In the remaining 13 cases a bleeding site was not identified by any of the independent investigations and in this group there were two false positive scans (specificity 85 per cent). The investigation had a high predictive value when both positive (94 per cent) and negative (92 per cent). These data suggest that technetium-99m-labelled red cell scintigraphy should be used more widely in the investigation of patients with suspected lower gastrointestinal haemorrhage.

Management of major colonic haemorrhage

Major colonic haemorrhage remains a difficult diagnostic and therapeutic problem. We propose that those patients who continue to bleed after resuscitation are best served by immediate laparotomy. High flow antegrade irrigation and intra-operative colonoscopy can then be used to localize the site of bleeding and allow appropriate excisional surgery rather than blind colonic resection.

Angiodysplasia: current concepts

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