Pharmacological treatment of gastrointestinal bleeding due to angiodysplasias: A position paper of the Italian Society of Gastroenterology (SIGE)

Tranexamic acid may be a useful pharmacotherapy for endoscopically resistant small bowel angiodysplasia

Small bowel angiodysplasia (SBAD) is reported to account for nearly 50% of cases of small bowel bleeding. When SBAD occurs frequently, it is difficult to treat all the angiodysplasias endoscopically, and gastrointestinal bleeding often recurs. Hormone therapy, somatostatin analogs, thalidomide and vascular endothelial growth factor (VEGF)-neutralizing antibodies have been reported to reduce gastrointestinal angiodysplasia (GIAD) bleeding. However, there is no strong evidence to recommend them. Also, there are no guidelines for their use. Hereditary hemorrhagic telangiectasia (HHT) is a hereditary disease caused by abnormalities in VEGF, resulting in multiple GIADs. A treatment guideline has been created for GIAD in HHT, and the use of tranexamic acid, an antifibrinolytic agent, is the first recommendation pharmacotherapy for GIAD with gastrointestinal bleeding that is difficult to treat endoscopically. It has been reported that fibrinolysis is accelerated in GIAD patients who are not HHT, similar to HHT patients. The use of tranexamic acid for gastric antral vascular ectasia in GIAD has been reported to be useful. However, there are very few reports of its use for SBAD. There are concerns with tranexamic acid use regarding the development of thrombosis/embolism, but there are few reports of such side effects. Future clinical trials including tranexamic acid for SBAD are desired.

Efficacy of pharmacologic treatment for treating gastrointestinal angiodysplasias-related bleeding: a systematic review and meta-analysis

INTRODUCTION

We evaluated the efficacy of pharmacologic treatments for patients with overt or occult bleeding due to gastrointestinal angiodysplasias (GIADs).

METHODS

A systematic computer-aided literature search across Medline, Cochrane, Scopus and Embase databases was performed. Studies evaluating pharmacologic treatments for patients presenting with GIADs-related overt or occult bleeding were included. Post-treatment rebleeding was the primary outcome. Need for red blood cells (RBC) transfusion, post-treatment hemoglobin levels and adverse events rate comprised secondary outcomes. Results are presented as odds ratio (OR), mean difference (MD) or pooled rates (%) with 95% confidence intervals (95%CI).

RESULTS

Four types of pharmacologic treatment were identified (25 studies): somatostatin analogs, hormonal therapy, thalidomide and angiogenesis inhibitors. Pharmacologic treatment of any kind led to significantly reduced bleeding episodes [OR (95% CI), 0.08 (0.04-0.18)]. No pharmacologic treatment was superior to others ( P  = 0.46). Overall, pooled rebleeding rate post-treatment was 34% (26-43%). Similarly, significantly fewer patients required RBC transfusion during the post-treatment period [0.03 (0.03-0.07)], with no differences among various treatments ( P  = 0.83), yielding an overall pooled transfusion rate of 33% (19-46%). Administration of pharmacological treatment led to significant improvement in terms of hemoglobin levels [MD (95% CI), 3.21 g/dL (2.42-3.99)]. The pooled rate of adverse events was 32% (22-42%).

CONCLUSION

In patients with GIADs administration of any pharmacologic treatment significantly decreases rebleeding episodes and transfusions leading to higher hemoglobin values. One-third of them experience at least one adverse event related to the treatment.

A comprehensive systematic review and meta-analysis of risk factors for rebleeding following device-assisted enteroscopy therapy of small-bowel vascular lesions

INTRODUCTION

the aim of this study was to determine the risk factors for rebleeding following device-assisted enteroscopy therapy of small bowel vascular lesions.

METHODS

this is a systematic review and meta-analysis. A literature search was performed from January 2003 to October 2019. All studies reporting on at least one risk factor for bleeding recurrence after endoscopic therapy of small bowel vascular lesions were included. A meta-analysis of those risk factors reported in at least three studies was performed to assess their association with rebleeding. The OR and 95 % CI were used for binary outcome data. Heterogeneity analysis was performed using the Tau and I2 index. If I2 > 20 %, potential sources of heterogeneity were identified by sensitivity analyses and a random-effect model was used.

RESULTS

the search identified a total of 572 articles and 35 full-text records were assessed for eligibility after screening. Finally, eight studies that included 548 patients were selected. The overall median rebleeding rate was 38.5 % (range: 10.9-53.3 %) with a median follow-up of 24.5 months. Female sex (OR: 1.96, 95 % CI: 1.14-3.37, p = 0.01, I2 = 0 %), Osler-Weber syndrome (OR: 4.35, 95 % CI: 1.22-15.45, p = 0.02, I2 = 0 %) and cardiac disease (OR: 1.89, 95 % CI: 1.12-2.97, p = 0.005, I2: 0 %) were associated with rebleeding. According to the sensitivity analysis, overt bleeding (OR: 2.13, 95 % CI: 1.22-3.70, p = 0.007, I2 = 0 %), multiple lesions (OR: 4.57, 95 % CI: 2.04-10.22, p < 0.001, I2 = 0 %) and liver cirrhosis (OR: 2.61, 95 % CI: 1.11-6.13, p = 0.03, I2 = 0 %) were also predictors for rebleeding.

CONCLUSIONS

patient characteristics and comorbidities should be considered for follow-up patient management after effective device-assisted endoscopic therapy, as they can predict rebleeding.

Thalidomide for refractory gastrointestinal bleeding from vascular malformations in patients with significant comorbidities

BACKGROUND

Refractory gastrointestinal bleeding (GIB) secondary to gastrointestinal vascular malformations (GIVM) such as gastrointestinal angiodysplasia (GIAD) and gastric antral vascular ectasia (GAVE) remains challenging to treat when endoscopic therapy fails. Recently thalidomide has been suggested as a treatment option for refractory GIB.

AIM

To determine the outcome of patients treated with thalidomide for refractory GIB due to GIVM.

METHODS

IRB approved, single center, retrospective review of electronic medical records from January 2012 to November 2018. Patients age > 18 years old, who had > 3 episodes of GIB refractory to medical or endoscopic therapy, and who had been treated with thalidomide for at least 3 mo were included. The primary endpoint was recurrence of GIB 6 mo after initiation of thalidomide.

RESULTS

Fifteen patients were included in the study, all with significant cardiac, hepatic, or renal comorbidities. The cause of GIB was GIAD in 10 patients and GAVE in 5 patients. Two patients were lost to follow up. Of the 13 patients followed, 38.5% (n = 5) had no recurrent GIB or transfusion requirement after treatment with thalidomide. Furthermore, 84.6% (n = 11) of patients had a reduction in transfusion requirements and hospitalizations for GIB. Thalidomide was discontinued in 2 patients due to cost (n = 1) and medication interaction (n = 1). Reported adverse reactions included fatigue (n = 3), neuropathy (n = 2), dizziness (n = 1), and constipation (n = 1). Six patients died during follow up due to unknown cause (n = 4) and sepsis (n = 2).

CONCLUSION

Thalidomide appears to be an effective treatment for refractory GIB due to GIAD or GAVE in a Western population with significant comorbidities.

Thalidomide for the treatment of angiodysplasia-related recurrent gastrointestinal hemorrhage: Is low dose a safe and viable option?

Thalidomide is often used for the management of refractory gastrointestinal angiodysplasia (GIAD). The tolerance, toxic profile, and compliance of thalidomide are dose-dependent. The low-dose thalidomide (50 mg) is safe and a viable option for bleeding related to GIAD.

Long-Acting Somatostatin Analogue Safety Monitoring Protocol for Outpatients With Neuroendocrine Tumors

Somatostatin analogues (SSAs) are widely used in the long-term treatment of neuroendocrine tumors (NETs) and have a relatively favorable safety profile. However, SSAs are associated with specific side effects that are important to monitor. Currently, there is no standardized safety monitoring protocol for health-care professionals to use as a reference when initiating patients on long-acting SSAs. With the expansion of SSA use from symptomatic control to include antiproliferative tumor treatment in patients with NETs, it is increasingly important that patients taking these medications are properly monitored. The purpose of this analysis was to develop a comprehensive, practical SSA safety monitoring protocol for patients with NETs in the outpatient setting. This strategy was based on side effect frequencies that were reported and the monitoring parameters used in influential clinical and safety trials. Based on our assessment, we consider monitoring gallbladder imaging, laboratory tests (including blood chemistry, thyroid-stimulating hormone, hemoglobin A1c, and stool studies), vital signs, and physical examinations as the most important parameters when evaluating the safety of long-term SSA therapy. Due to the frequency at which patients experienced diarrhea as a side effect in clinical trials, questions about urgency, frequency, timing, consistency, odor, and color of bowel movements should be asked as part of the follow-up visits every 6 months to help differentiate between drug-induced vs. disease-associated causes. This broad monitoring strategy for patients receiving long-term SSAs was developed specifically for patients with NETs; however, the use of this protocol could be expanded to other indications in the future.

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.

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.

Diagnostic yield of capsule endoscopy for small bowel arteriovenous malformations in patients with hereditary hemorrhagic telangiectasia: a systematic review and meta-analysis

Background and study aims  Small bowel arteriovenous malformations (AVMs) pose a bleeding risk and have traditionally been diagnosed by invasive enteroscopic procedures in patients with hereditary hemorrhagic telangiectasia (HHT). Capsule endoscopy (CE) is emerging as a safe and non-invasive alternative for small intestinal evaluation, but its diagnostic yield and utility in diagnosing small bowel AVMs in HHT patients are understudied. The aim of this study was to meta-analyze the utility of CE for diagnosing AVMs in HHT patients. Methods  A meta-analysis and systematic review of the literature on CE in HHT patients identified in the PubMed, EMBASE, Scopus, and Cochrane databases from inception to March 2018 were conducted. Summary effects were estimated using a random effects model. Results  After applying exclusion criteria, five studies (n = 124 patients) were eligible for meta-analysis. The pooled diagnostic yield for visualization of small bowel AVMs by CE was 77.0 % (95 % CI 65.8 - 85.4 %, P  < 0.001). Conclusions  CE has a good diagnostic yield for small bowel AVMs in HHT. It can be regarded as a sufficient, noninvasive diagnostic modality for identifying small bowel AVMs in HHT patients.

Long-term results with lanreotide in patients with recurrent gastrointestinal angiodysplasias bleeding or obscure gastrointestinal bleeding. Benefits in efficacy and procedures consumption

BACKGROUND

Gastrointestinal angiodysplasias (GIAD) bleeding and obscure gastrointestinal bleeding (OGIB) are increasing health problems. Somatostatin analogues have been proposed as rescue therapy, but data for lanreotide are scarce.

OBJECTIVE

To determine the efficacy, safety and resource saving of long-acting lanreotide for GIAD and OGIB.

METHODS

Retrospective study including adults with GIAD bleeding or OGIB and lanreotide treatment for at least 6 consecutive months. Demographics, comorbidities and treatments were collected. Anaemia and health resource consumption were analysed and compared between the year before and three years after starting lanreotide. Complete response was defined as a lack of new blood transfusion or endovenous iron dose need.

RESULTS

Twenty-seven patients (mean age 76.8 years) were included, 63% taking anticoagulants/antiplatelets. The bleeding was attributable to angiodysplasia in 85.2%, of whom half had multi-site lesions. Lanreotide was administered for a median of 27.1 months. During follow-up of up to 3 years (mean 32.5 months), 18.5% of patients achieved complete response and around 60% a 50% reduction of health resource consumption. Haemoglobin values improved (p = .007), while admission time, blood/iron infusions, and the number of endoscopies decreased significantly (p<.05) at least up to the second year. There were no relevant side effects during the follow-up period.

CONCLUSION

Long-term treatment with lanreotide significantly improves anaemia and decreases health resource consumption in patients with recurrent GIAD bleeding or OGIB.

von Willebrand factor regulation of blood vessel formation

Several important physiological processes, from permeability to inflammation to hemostasis, take place at the vessel wall and are regulated by endothelial cells (ECs). Thus, proteins that have been identified as regulators of one process are increasingly found to be involved in other vascular functions. Such is the case for von Willebrand factor (VWF), a large glycoprotein best known for its critical role in hemostasis. In vitro and in vivo studies have shown that lack of VWF causes enhanced vascularization, both constitutively and following ischemia. This evidence is supported by studies on blood outgrowth EC (BOEC) from patients with lack of VWF synthesis (type 3 von Willebrand disease [VWD]). The molecular pathways are likely to involve VWF binding partners, such as integrin αvβ3, and components of Weibel-Palade bodies, such as angiopoietin-2 and galectin-3, whose storage is regulated by VWF; these converge on the master regulator of angiogenesis and endothelial homeostasis, vascular endothelial growth factor signaling. Recent studies suggest that the roles of VWF may be tissue specific. The ability of VWF to regulate angiogenesis has clinical implications for a subset of VWD patients with severe, intractable gastrointestinal bleeding resulting from vascular malformations. In this article, we review the evidence showing that VWF is involved in blood vessel formation, discuss the role of VWF high-molecular-weight multimers in regulating angiogenesis, and review the value of studies on BOEC in developing a precision medicine approach to validate novel treatments for angiodysplasia in congenital VWD and acquired von Willebrand syndrome.