NSAID injury to the small intestine

NSAID enteropathy: appearance at CT and MR enterography in the age of multi-modality imaging and treatment

CT and MR enterography and capsule endoscopy are increasingly used as routine diagnostic tests for patients with potential small bowel disorders and obscure gastrointestinal bleeding. Non-steroidal anti-inflammatory drugs (NSAIDs) are commonly used drugs that disrupt prostaglandin synthesis and result in a variety of localized complications within the small bowel ranging from ulcer formation to characteristic circumferential strictures, or diaphragms. NSAID enteropathy encompasses this spectrum of acute and chronic inflammatory sequelae, and is associated with typical findings at capsule endoscopy and surgery. Herein we review the typical clinical presentation of NSAID enteropathy, in addition to its endoscopic appearances, focusing on imaging findings at cross-sectional enterography. Multiple, short-segment strictures are the hallmarks of imaging diagnosis. Strictures may have minimal hyperenhancement or wall thickening, but these findings are typically symmetric and circumferential with respect to the bowel lumen. Multifocal Crohn's strictures, and occasionally radiation-induced strictures or adhesions, will mimic NSAID diaphragms. Multi-phase or multi-sequence imaging at CT and MR enterography increase diagnostic confidence in stricture presence. Strategies for subsequent workup and therapy after enterography are also discussed. Given the frequent use of NSAIDs and typical appearance of these strictures, knowledge of characteristic imaging findings can be particularly useful when evaluating patients with anemia and recurrent small bowel obstruction.

Double-contrast barium enteroclysis as a patency tool for nonsteroidal anti-inflammatory drug-induced enteropathy

BACKGROUND

Evaluating small bowel patency is recommended for capsule endoscopy in patients suspected of nonsteroidal anti-inflammatory drug-induced (NSAID) enteropathy.

AIMS

The aim of this investigation was to examine whether radiography is a candidate of patency tool in NSAID enteropathy.

METHODS

We reviewed double-contrast barium enteroclysis in 21 patients with NSAID enteropathy diagnosed either by capsule endoscopy or balloon-assisted endoscopy. The endoscopic findings were classified into circular ulcers, linear ulcers and small mucosal defects. The radiographic signs of the corresponding endoscopic findings were retrieved and the depiction rate was calculated.

RESULTS

Of the 21 patients, endoscopy detected circular ulcers, linear ulcers, and small ulcers in 12, 3 and 12 patients, respectively. Small bowel radiography depicted circular narrowing as pseudo-folds in 10 patients (83%) and linear ulcers as eccentric rigidity in 2 patients (67%). However, radiography was able to depict small mucosal defects in only 3 patients (17%). Two of 5 patients with pseudo-folds experienced retention of the capsule.

CONCLUSION

"Pseudo-folds" is a sign corresponding to circular ulcer in NSAID enteropathy, which may be predictive of capsule retention.

Special diaphragm-like strictures of small bowel unrelated to non-steroidal anti-inflammatory drugs

AIM: To summarize clinical, endoscopic, radiologic and pathologic features of special diaphragm-like strictures found in small bowel, with no patient use of non-steroidal anti-inflammatory drugs (NSAIDs).

METHODS: From January 2000 to December 2009, 5 cases (2 men and 3 women, with a mean age of 41.6 years) were diagnosed as having diaphragm-like strictures of small bowel on imaging, operation and pathology. All the patients denied the use of NSAIDs. The clinical, endoscopic, radiologic and pathologic findings in these 5 patients were retrospectively reviewed from the hospital database. Images of capsule endoscopy (CE) and small bowel follow-through (SBFT) obtained in 3 and 3 patients, respectively, and images of double-balloon enteroscopy and computed tomography enterography (CTE) obtained in all 5 patients were available for review.

RESULTS: All patients presented with long-term (2-16 years) symptoms of gastrointestinal bleeding and varying degrees of anemia. There was only one stricture in four cases and three lesions in one case, and all the lesions were located in the middle or distal segment of ileum. Circumferential stricture was shown in the small bowel in three cases in the CE image, but the capsule was retained in the small bowel of 2 patients. Routine abdomen computed tomography scan showed no other abnormal results except gallstones in one patient. The lesions were shown as circumferential strictures accompanied by dilated small bowel loops in the small bowel on the images of CTE (in all 5 cases), SBFT (in 2 cases) and double-balloon enteroscopy (in all cases). On microscopy, a chronic inflammatory infiltrate and circumferential diaphragm were found in all lesions.

CONCLUSION: Diaphragm-like strictures of small bowel might be a special consequence of unclear damaging insults to the intestine, having similar clinical, endoscopic, radiologic and pathologic features.

Drug-induced Injury of the Gastrointestinal Tract

The effects of drugs on the gastrointestinal tract are diverse and depend on numerous factors. Diagnosis is centered on histologic findings, with mostly nonspecific patterns of injury that must be interpreted in the correct clinical context. Nonsteroidal antiinflammatory drugs are a common cause of drug-induced gastrointestinal injury, with effects primarily in the gastric mucosa but also throughout the gastrointestinal tract. Another common class of drugs causing a variety of pathologic findings in the gut is chemotherapeutic agents. This article discusses the differential diagnosis of the various patterns of injury, including ischemic damage, and the histologic findings specific for certain drugs.

Intermittent obstruction resulting from multiple intestinal webs

Intestinal webs are a rare cause of bowel obstruction. A case of a 32-year-old man with multiple intestinal webs causing intermittent, partial bowel obstruction is described. The webs were initially detected with capsule endoscopy. The patient was treated with intraoperative endoscopy and balloon dilation. At early follow-up, no recurrence of his symptoms was evident.

Randomized, double-blind, pilot study of geranylgeranylacetone versus placebo in patients taking low-dose enteric-coated aspirin. Low-dose aspirin-induced small bowel damage

OBJECTIVE

Low-dose enteric-coated aspirin is increasingly being used for prevention of cardiovascular disease. The aim of this study was to evaluate whether geranylgeranylacetone (GGA) could prevent aspirin-induced small bowel injury.

MATERIAL AND METHODS

This was a prospective, randomized, double-blind, pilot study of GGA versus placebo in subjects taking low-dose enteric-coated aspirin. Young healthy volunteers were enrolled and each received 100 mg of enteric-coated aspirin per day plus either GGA (150 mg/day) or matching placebo for 7 days. Video capsule endoscopy of the small bowel and the Gastrointestinal Symptom Rating Scale (GSRS) questionnaire were performed before and after the administration of aspirin.

RESULTS

Twenty volunteers were evaluated. There was no significant difference in the number of lesions in any category between those receiving or not receiving GGA. Large erosions or ulcers were observed in 12 (60%; 95% confidence interval 36%- 80%) aspirin users. Mucosal breaks were most frequently found in the latter half of the proximal small bowel.

CONCLUSIONS

Short-term administration of low-dose enteric-coated aspirin was associated with visible small bowel damage in the majority of users. We could not prove that aspirin-induced small bowel mucosal injury was prevented by GGA.

Assessment and prevention of gastrointestinal toxicity of non-steroidal anti-inflammatory drugs

Non-steroidal anti-inflammatory drugs (NSAIDs) are widely used for analgesic, anti-inflammatory and, in the case of aspirin, for anti-thrombotic actions. The serious gastrointestinal side-effects associated with these drugs are of concern and pose a significant obstacle to their use. This review discusses the pathogenic mechanisms by which the conventional acidic NSAIDs induce gastrointestinal toxicity, with particular emphasis on non-prostaglandin effects. Methods of assessment of NSAID-induced enteropathy are reviewed, with particular emphasis on the use of functional measurement of NSAID-induced changes in the gastrointestinal tract. The advances in our knowledge of the pathogenesis of these effects have resulted in the development of a range of novel NSAIDs. Where functional assessment of the effects of NSAIDs has been employed, it appears to be more useful as an indicator of early-stage changes rather than a predictor of the effects of long-term NSAID exposure. Successful pharmaceutical strategies now offer considerable promise for reducing the severity of NSAID damage to the gastrointestinal tract. The utility of intestinal permeability measurements for selection and assessment of these strategies is discussed.

Non-steroidal anti-inflammatory drug-induced small bowel injuries identified by double-balloon endoscopy

AIM: To clarify clinical features of the NSAID-induced small bowel lesions using a new method of endoscopy.

METHODS: This is a retrospective study and we analyzed seven patients with small bowel lesions while taking NSAIDs among 61 patients who had undergone double-balloon endoscopy because of gastro-intestinal bleeding or anemia between September 2000 and March 2004, at Jichi Medical School Hospital in Japan. Neither conventional EGD nor colonoscopy revealed any lesions of potential bleeding sources including ulcerations. Double-balloon endoscopy was carried out from oral approach in three patients, from anal approach in three patients, and from both approaches in one patient.

RESULTS: Ulcers or erosions were observed in the ileum in six patients and in the jejunum in one patient, respectively. The ulcers were multiple in all the patients with different features from tiny punched out ulcers to deep ulcerations with oozing hemorrhage or scar. All the patients recovered uneventfully and had full resolution of symptoms after suspension of the drug.

CONCLUSION: NSAIDs can induce injuries in the small bowel even in patients without any lesions in both the stomach and colon.

Diaphragm disease: complete small bowel obstruction after long-term nonsteroidal anti-inflammatory drugs use

Diaphragm-like stricture of the small bowel is an infrequent complication of the treatment of patients with nonsteroidal anti-inflammatory drugs (NSAIDs) and is part of the spectrum of diseases associated with NSAIDs injury. We report a patient with this condition who had used various forms of NSAIDs for over 20 years. Patient presented with abdominal pain and indigestion. Plain abdominal film revealed small bowel obstruction. Surgical resection of jejunum and proximal part of ileum identified dilated thickened hyperemic mucosa alternating with areas of small bowel fibrotic constriction. The mucosal surface showed multiple pink-tan mucosal folds (circumferential ridges) with focal hemorrhage and edema. Our findings support the local stimulation and damage and reparative process seen with NSAIDs use. A high degree of suspicion and awareness of diaphragm disease is necessary in those patients.

Determining small bowel integrity following drug treatment

Intestinal integrity is maintained by a delicate balance between mucosal defence and luminal aggressors that cause damage if exposed to the mucosa. The intestinal barrier function appears to be the gatekeeper for controlling this balance. It is becoming increasingly clear that if the intestinal barrier is disrupted the consequences are low grade intestinal inflammation which carry with it the risk of significant blood and protein loss both of which may cause clinical management problems. We review the strength and weaknesses of methods for assessing small bowel function that are useful for assessing drug-induced intestinal toxicity. There are a number of imaging methods for assessing intestinal integrity but these do not provide functional information. Intestinal permeability measurements have been optimized for specificity and there are now ways of measuring intestinal permeability regionally, but marker analyses continue to be cumbersome. Recent developments of faecal inflammatory markers make it a matter of routine to assess this in any routine chemical pathology laboratory. Bleeding, protein loss and other complications of inflammation can also be measured with good specificity, but again the methods are cumbersome. Using a combination of functional and imaging techniques it is now possible to characterize and define with precision, the small bowel side-effects of drugs, the best example being the small bowel side-effects of nonsteroidal anti-inflammatory drugs (NSAIDs).

Gastrointestinal mucosal injury following repeated daily oral administration of conventional formulations of indometacin and other non-steroidal anti-inflammatory drugs to pigs: a model for human gastrointestinal disease

Non-steroidal anti-inflammatory drugs (NSAIDs) vary in their propensity to cause damage in different regions of the gastrointestinal (GI) tract in laboratory animals and humans. This may depend on the type of drug formulation as well as the intrinsic pharmacological properties of the drugs. The purpose of this study was to determine the effects of NSAIDs, with cyclooxygenase 1 and 2 inhibitory activity but with different potency as inhibitors of prostaglandin production, when given orally as tablet/capsule formulations of NSAIDs for 10 days to pigs, a species that has close resemblance in structure and function of the tract to that in humans. Three capsule or tablet formulations of NSAIDs were given orally to pigs for 10 days. GI bleeding was measured by determination of radioactive iron in the faeces from (59)Fe-pre-labelled red blood cells. The blood loss was compared with the pathological changes in the GI mucosa observed at autopsy, mucosal myeloperoxidase (MPO) activity as an index of leucocyte infiltration, and plasma and mucosal concentrations of the drugs at termination assayed by high-performance liquid chromatography. Mucosal damage and bleeding varied according to the type of NSAID. Gastroduodenal ulcers and lesions occurred with the cyclooxygenase inhibitors indometacin (indomethacin) (Indocid capsules 10 or 5 mg kg(-1) day(-1) b.i.d.), aspirin (USP tablets 150 mg kg(-1) day(-1) b.i.d) and naproxen (Apotex tablets 50 or 75 mg kg(-1) day(-1) b.i.d.), and there was an increase in the cumulative (i.e. 10-day) blood loss at higher doses of indometacin and naproxen, and with aspirin. There was no statistically significant increase in gastric or intestinal mucosal MPO activity in the non-damaged mucosa with these drugs and this was confirmed by histological observations in non-lesioned areas of the mucosa. Indometacin produced focal ulcers in the caecum but this was not observed with the other drugs. All the NSAIDs produced significant blood loss coincident with gastric ulceration but no increase in gastric or intestinal MPO activity. Plasma concentrations of the non-aspirin NSAIDs were within the range encountered therapeutically in humans. The mucosal concentrations of indometacin in the gastric and intestinal mucosa correlated with mucosal injury. These findings show that: (i) NSAIDs vary in their propensity to produce mucosal injury in different regions of the GI tract according to their pharmacological properties and formulation; (ii) mucosal injury from some NSAIDs may not directly relate to blood loss at low doses of NSAIDs and this may depend on inhibition of platelet aggregation; and (iii) the occurrence of caecal ulcers uniquely observed with indometacin treatment may be relevant to the development of intestinal pathology (e.g. diaphragm-like structures) seen occasionally in humans. These results suggest that the pig model employed in the present studies may be useful for investigations of GI damage from NSAID tablets/capsules, especially in regions that are generally inaccessible to routine endoscopic investigations in humans (e.g. the proximal regions of the large intestine).

Clinical implications of prostaglandin inhibition in the small bowel

NSAID-induced intestinal toxicity is more common than previously recognized and may have clinically significant sequelae, especially in elderly arthritic patients. Increased awareness of the potential intestinal complications associated with prostaglandin inhibition is required for early recognition and appropriate management. An increase in the level of suspicion by physicians may lead to earlier diagnosis and subsequent discontinuation of the offending NSAID; this is important in that discontinuation of the offending agent may be preferable to multiple endoscopic radiologic and surgical procedures in the patient with obscure blood loss and anemia. Appropriate diagnosis in selected patients may prevent the increased morbidity and mortality associated with small intestinal surgery. The emergence of selective COX-2 inhibitors likely will bring this issue to the forefront because it will become increasingly important to determine the effects of these agents on the small intestine and colon, in addition to their effects on the gastroduodenal mucosa. The new generation of selective COX-2 inhibitors may offer a potential therapeutic advantage over the nonselective NSAIDs with respect to their intestinal toxicity. Well-designed safety trials that have intestinal injury as a predefined end point will provide important information as to the overall gastrointestinal safety of these compounds. These agents must be evaluated with respect to their overall safety profile and not just by their gastrointestinal safety. Nevertheless, these agents are continuing to provide new directions for exciting basic and clinical scientific investigation.

Palliative care in inflammatory bowel disease: an evidence-based approach

The management of the patient with inflammatory bowel disease (IBD) is challenging for both the physician and the patient. IBD imposes both a physical and emotional burden on patients' lives. Palliative care is important for IBD patients because it focuses on improving quality of life. While palliative care does not change the natural history of the disease, it provides relief from pain and other distressing symptoms. This article focuses on various aspects of care for IBD patients including pain control, management of oral and skin ulcerations, stomal problems in IBD patients, control of nausea and vomiting, management of chronic diarrhea and pruritus ani, evaluation of anemia, treatment of steroid-related bone disease, and treatment of psychological problems associated with IBD. Each of these areas is reviewed using an evidence-based approach. Evidence in category A refers to evidence from clinical trials that are randomized and well controlled. Category B Evidence refers to evidence from cohort or case-controlled studies. Category C is evidence from case reports or flawed clinical trials. Evidence from category D is limited to the clinical experience of the authors. Evidence labelled as category E refers to situations where there is insufficient evidence available to form an opinion. Algorithms for management of pain and nausea in IBD patients are presented.