Nonhereditary colonic angiodysplasias: histomorphometric approach to their pathogenesis

Treatment of gastrointestinal angiodysplasia and unmet needs

BACKGROUND

Gastrointestinal angiodysplasia (GIAD) may either be asymptomatic or induce overt or obscure bleeding with a high risk of recurrence. Numerous therapeutic options are available but evidence bases are lacking.

AIM

We conducted a comprehensive review of pharmacological and endoscopic treatments for previous or active bleeding GIAD and established the unmet needs of the clinicians.

METHODS

Clinical trials, series, and reports, having been selected through PubMed inquiry, manual searching, and reference list reviewing, were classified by levels of evidence.

RESULTS

Controlled studies focusing on GIAD treatment, excluding other GI vascular malformations, are rare. Endoscopic destruction, preferably using non-contact endoscopic techniques, is most often proposed as a first-line treatment for GIAD (expert level). In addition, APC is preferred over Nd:Yag laser due to the lower risk of perforation (expert level). Pharmacological treatments for GIAD are considered either when endoscopy fails to access the AD or in order to prevent rebleeding for "chronic bleeding patients." Octreotide and oestroprogestative treatments are the best evaluated drugs; however, no appropriate comparison on cost-effectiveness and tolerance has been performed.

CONCLUSIONS

The most effective therapeutic strategy for bleeding GIAD is currently inconclusive, and new trials should be performed to address unmet needs.

Colonic mucosa in patients with portal hypertension

BACKGROUND AND AIMS

To do a histomorphometric study of vascular changes in colonic mucosa of patients with portal hypertension (PHT) and to find their association with clinical and upper and lower gastrointestinal endoscopic observations.

METHODS

Full length colonoscopy was carried out in 55 patients with portal hypertension and 25 controls. Hemorrhoids, anorectal varices and colopathy were carefully looked for and recorded. Two biopsies each were taken from the caecum, ascending colon, transverse colon, descending colon and rectum. Sections from all the five sites were examined for histopathological changes with special reference to changes in mucosal capillaries. Morphometric assessment of the diameter of the capillary and thickness of the capillary wall was performed. These histomorphometric changes were correlated with clinical parameters and findings of upper and lower gastrointestinal endoscopic findings.

RESULTS

Dilated and congested capillaries as well as capillaries with irregular thickening of the wall were seen in a significantly higher number of sections from patients than controls in biopsies from all the five sites from caecum to rectum. On morphometry, the diameter of the capillaries and the thickness of the capillary wall in biopsies from all the five sites in patients was significantly higher than that in the control group. Apart from vascular changes, edema and inflammatory infiltrate in lamina propria were the other significant histological features noted. No significant association between clinical and endoscopic features and histomorphometric assessment was found.

CONCLUSION

Dilated tortuous mucosal capillaries with irregular thickening of wall, edema of lamina propria and mild chronic inflammatory infiltrate are the major histopathological changes seen in colonic biopsies of patients with PHT, showing that PHT produces changes in the colonic mucosa similar to those seen in the mucosa of upper GI tract. However, the histological changes had no correlation with the clinical or endoscopic findings except that the thickness of the capillary wall was higher in patients who had undergone endoscopic sclerotherapy as opposed to those who had not received sclerotherapy.

A multicenter, randomized, clinical trial of hormonal therapy in the prevention of rebleeding from gastrointestinal angiodysplasia

BACKGROUND & AIMS

The efficacy of hormonal therapy for recurrent bleeding from gastrointestinal angiodysplasia remains uncertain. We investigated the efficacy of long-term estrogen-progestagen therapy in the prevention of rebleeding from gastrointestinal angiodysplasia.

METHODS

Seventy-two noncirrhotic patients bleeding from gastrointestinal angiodysplasia confirmed by endoscopy or angiography were randomized to receive in double-blind conditions treatment with ethinylestradiol (0.01 mg) plus norethisterone (2 mg) (1 tablet/d), or placebo (1 tablet/d) for a minimum period of 1 year (range: 1-2 years).

RESULTS

Four patients could not be assessed because they did not attend the first follow-up visit. Failure of treatment occurred in 13 of 33 (39%) patients in the treatment group and in 16 of 35 (46%) patients in the placebo group (P = NS). No significant differences between groups were found according to number of bleeding episodes (0.7 +/- 1.0 vs. 0.9 +/- 1.5) and transfusional requirements (0.9 +/- 1.9 vs. 0.7 +/- 1.5 units). Treatment received was not an independent predictor for rebleeding prevention in the multivariate regression analysis. Severe adverse events (2 vs. 1) and mortality (0 vs. 1 patient, respectively) were similar between the treatment and placebo groups.

CONCLUSIONS

Continuous estrogen-progestagen treatment is not useful in the prevention of rebleeding from gastrointestinal angiodysplasia.

Long-acting octreotide is effective in controlling rebleeding angiodysplasia of the gastrointestinal tract

BACKGROUND

Management of bleeding angiodysplasia of the gastrointestinal tract is often a major clinical problem. Lesions are frequently multiple, not detectable or missed during conventional endoscopy and patients are sometimes at high risk for complications because of advanced age and serious concomitant disorders.

AIMS

To determine the efficacy of a new formulation of somatostatin analogue (octreotide long-acting) in management of recurrent bleeding angiodysplasia in patients resistant to endoscopic treatment and not suitable for surgery.

PATIENTS AND METHODS

Three patients with recurrent bleeding angiodysplasia of gastrointestinal tract were treated with long-acting octreotide administered intramuscularly 20 mg monthly to each individual. The number of admissions for acute bleeding, hospital stay and number of blood units transfused before and after treatment (followup: 15-17 months) were regularly monitored.

RESULTS

In each patient, a relevant decrease in number of hospital admissions, duration of hospital stay, number of administered blood units was seen and mean haemoglobin values significantly increased in all of them after introducing long-acting octreotide therapy.

CONCLUSIONS

This is the first report on use of long-acting octreotide in bleeding angiodysplasia of gastrointestinal tract. Data suggest that long-acting octreotide is a safe drug and is successful in controlling recurrent gastrointestinal bleeding due to angiodysplasia in elderly patients not eligible for surgical or endoscopic therapy.

The efficacy of octreotide therapy in chronic bleeding due to vascular abnormalities of the gastrointestinal tract

BACKGROUND

The treatment of angiodysplasia and watermelon stomach, vascular abnormalities implicated in gastrointestinal bleeding of obscure origin, is a major clinical problem.

AIM

To determine the efficacy of octreotide in patients with long-standing gastrointestinal bleeding due to acquired angiodysplasia and watermelon stomach, resistant to previous treatments and not suitable for surgery because of old age and/or concomitant disorders.

PATIENTS AND METHODS

We treated 17 patients (seven had isolated angiodysplasia, seven had multiple upper and lower gastrointestinal angiodysplasia, and three had watermelon stomach) with octreotide (0. 1 mg subcutaneous t.d.s. for 6 months). Six of the patients had liver cirrhosis, one had Glanzmann-type platelet derangement, two had cardiovascular diseases and one had chronic uraemia.

RESULTS

Octreotide treatment stopped bleeding in 10 patients. A transient improvement was observed in four, who needed subsequent cyclical retreatment to correct low haemoglobin levels. No effect was observed in three, probably due to the severity of the concomitant disorders.

CONCLUSIONS

Octreotide is a safe drug that may be useful to control the recurrent gastrointestinal bleeding due to acquired angiodysplasia and watermelon stomach, especially in patients who are not candidates for surgery due to old age and/or concomitant disorders.

Alterations in colonic mucosal vessels in patients with cirrhosis and noncirrhotic portal hypertension

Changes in intestinal mucosal microvasculature as a cause of lower gastrointestinal hemorrhage in patients with portal hypertension have been well documented clinically, but the analogous histomorphological changes have not been well characterized. The goal of this study was to evaluate qualitative and quantitative changes in colonic mucosal vessels in patients with cirrhosis or clinically evident portal hypertension and to correlate these changes with endoscopic and clinical findings. Colon biopsy or resection specimen slides from 46 patients with biopsy-proven cirrhosis (44 patients) or noncirrhotic portal hypertension (two patients) were reviewed. Immunoperoxidase stain for CD34 antigen was used to facilitate visualization of mucosal vessels, and vessel diameter was measured with a micrometer. Patients with inflammatory bowel disease were excluded. Twenty-four normal colon biopsy specimens served as controls. Mucosal vessels were divided into superficial, intermediate, and deep layers. As a group, the cirrhotic patients had a significantly higher mean diameter of vessels in all three layers. Qualitatively, increased numbers of small vessels and prominent branching were noted, especially in the superficial and intermediate layers. Tortuous, thick-walled vessels, suggesting arterialization of venules, were present in some cases. Eleven patients had endoscopic findings suggestive of vascular abnormalities, including erythematous mucosal patches, red macules, and telangiectasias. Eighteen had esophageal varices, and five had portal gastropathy. Nineteen patients had gastrointestinal (GI) bleeding, localized to the lower GI tract in 11. These qualitative and quantitative findings suggest that colonic mucosal vascular lesions are common in portal hypertension and may represent a potential source of clinically significant lower GI hemorrhage in these patients.