ASGE guideline: endoscopy in the diagnosis and treatment of inflammatory bowel disease

Enteroscopy in the diagnosis and management of Crohn disease

Crohn disease is a chronic disorder that can affect any part of the gastrointestinal tract, and is characterized by mucosal and transmural inflammation of the bowel wall. The disease most commonly involves the small bowel. Evaluation of patients with suspected Crohn disease has traditionally involved the use of ileocolonoscopy, push enteroscopy, and barium small bowel radiography. A large proportion of patients with mild small bowel disease or involvement of the mid small bowel can potentially be missed if only these tests are utilized. Enteroscopy is defined as direct visualization of the small bowel using a fiber optic or wireless endoscope. Following recent advances in technology, enteroscopy currently plays a pivotal role not only in the diagnosis of small bowel Crohn disease but also in the management of its complications, such as bleeding and strictures. Enteroscopy may have additional roles in the future, including the objective assessment of mucosal response to therapy, and surveillance for small bowel malignancy. This article focuses on the utility of enteroscopy, and its advantages and limitations in the evaluation and longterm management of Crohn disease.

Use of double-balloon enteroscopy in the management of patients with Crohn's disease: feasibility and diagnostic yield in a high-volume centre for inflammatory bowel disease

BACKGROUND

Double-balloon enteroscopy (DBE) is theoretically useful in Crohn's disease (CD) since it is potentially able to investigate the whole small intestine, but sparse data are available.

AIM

To assess the feasibility, safety, and diagnostic yield of DBE in CD.

METHODS

The study was conducted in a tertiary care centre for inflammatory bowel disease. Thirty-seven patients with CD (18/19 male/female, mean age 42 years, range 13-77 years) were considered. Thirty-two DBEs from the oral approach and 18 from the anal (in 6 patients from both ways with a complete exploration in 4, 10.8%) were performed. Indications were: first diagnosis/staging in 16 cases, diagnosis of stenosis in 7, obscure bleeding in 10, suspected neoplasia in 2, and postsurgical evaluation in 2. One hundred and thirty-three other procedures (3.7 per patient) were performed with the same indication.

RESULTS

Insertion depth from the oral route was 266.5 ± 100 cm and from the anal route 72.5 ± 60 cm. Ileocecal valve was passed in 8/13 patients, but in 4 DBE explored less than 50 cm of ileum. Diagnostic yield was 59.4% but changed according to indication (40% in obscure bleeding, 100% in case of strictures) and was higher when DBE was conducted on the basis of previous investigations (77.8% versus 40%, p = 0.037).

CONCLUSION

DBE is a feasible, useful, but technically demanding method in CD. Definition of the proper introduction route by means of previous investigations is associated with a higher efficacy of DBE.

Magnetic resonance imaging of experimental inflammatory bowel disease: quantitative and qualitative analyses with histopathologic correlation in a rat model using the ultrasmall iron oxide SHU 555 C

OBJECTIVES

To quantitatively and qualitatively characterize the MR findings of inflammatory bowel disease in a rat model after i.v. injection of the reticuloendothelial system cell specific ultrasmall iron oxide SHU 555 C.

MATERIALS AND METHODS

Colitis was induced in 15 rats using dinitrobenzene sulfonic acid instillation. Five rats served as controls. T1- and T2-weighted spin-echo- and T2*-weighted gradient-echo-sequences were acquired at 2.4 Tesla before and immediately, 15, 45, 60, and 90 minutes, and 24 hours after i.v.-injection of SHU 555 C (0.1 mmol Fe/kg). MR images were evaluated quantitatively regarding thickness and signal-to-noise ratio (SNR) of the bowel wall and qualitatively regarding overall bowel wall signal intensity and the occurrence of bowel wall ulcerations. MR findings were correlated to histology.

RESULTS

The inflamed bowel wall was significantly thicker than the noninflamed bowel wall and 90 minutes after contrast injection it showed a significant reduction of SNR in T1- (94 +/- 27 vs. 61 +/- 29; P < 0.01), T2- (67 +/- 26 vs. 28 +/- 17; P < 0.05), and T2*- (92 +/- 57 vs. 10 +/- 7; P < 0.05) weighted images as compared with unenhanced images. At 24 hours, the respective SNR values remained significantly reduced. The signal loss was homogeneous in 12 and focal in 3 of the 15 rats with colitis. Nine rats showed colonic wall ulcerations. In all but one animal (missed focal ulceration) MR findings correlated to the histologic findings.

CONCLUSIONS

SHU 555 C leads to a significant signal intensity loss of the inflamed bowel wall in T1-, T2- and T2*-weighted images. SHU 555 C enhanced MRI findings correlate well with histologic findings.

Indications and techniques for lower intestinal endoscopy

The search for inflammatory and neoplastic lesions are the main indications for colonoscopy. A high rate of detection of polyps has become a quality criterion that depends on skilled handling of the colonoscope, on expertise and concentration during the examination, on excellent bowel preparation, and on a high standard of technical equipment. The diagnostic benefits outweigh the risk of bleeding, perforation and infection in almost all situations. Contraindications are signs of perforated intestine or imminent perforation due to deep ulcerations, necroses, or fulminant colitis. The patient's comorbidity must be considered to assess the physical stress of bowel preparation, colonoscopy and sedation. Informed consent is necessary and must be documented in all cases. It is advisable to explain planned therapeutic manoeuvres before the examination, since all non-invasive polyps must be removed completely. Total colonoscopy is possible in 95-99% of cases, but technical efforts are under way to solve the problem of looping and fixed colon angulations. Optimising optical imaging is another main focus of industrial development. The combination of narrow-band imaging, zoom magnification, and high-definition processor technology is currently the most promising tool for identifying small and flat lesions in the colon.

Small-bowel imaging in Crohn's disease: a prospective, blinded, 4-way comparison trial

BACKGROUND

With the introduction of new techniques to image the small bowel, there remains uncertainty about their role for diagnosing Crohn's disease.

OBJECTIVE

To assess the sensitivity and specificity of capsule endoscopy (CE), CT enterography (CTE), ileocolonoscopy, and small-bowel follow-through (SBFT) in the diagnosis of small bowel Crohn's disease.

METHODS

Prospective, blinded trial.

SETTING

Inflammatory bowel disease clinic at an academic medical center.

PATIENTS

Known or suspected Crohn's disease. Exclusion criteria included known abdominal abscess and non-steroidal anti-inflammatory drug (NSAID) use. Partial small-bowel obstruction (PSBO) at CTE excluded patients from subsequent CE.

INTERVENTIONS

Patients underwent all 4 tests over a 4-day period.

MAIN OUTCOME MEASUREMENTS

Sensitivity, specificity, and accuracy of each test to detect active small-bowel Crohn's disease. The criterion standard was a consensus diagnosis based upon clinical presentation and all 4 studies.

RESULTS

Forty-one CTE examinations were performed. Seven patients (17%) had an asymptomatic PSBO. Forty patients underwent colonoscopy, 38 had SBFT studies, and 28 had CE examinations. Small-bowel Crohn's disease was active in 51%, absent in 42%, inactive in 5%, and suspicious in 2% of patients. The sensitivity of CE for detecting active small-bowel Crohn's disease was 83%, not significantly higher than CTE (83%), ileocolonoscopy (74%), or SBFT (65%). However, the specificity of CE (53%) was significantly lower than the other tests (P < .05). One patient developed a transient PSBO due to CE, but no patients had retained capsules.

LIMITATION

Use of a consensus clinical diagnosis as the criterion standard-but this is how Crohn's disease is diagnosed in practice.

CONCLUSIONS

The sensitivity of CE for active small-bowel Crohn's disease was not significantly different from CTE, ileocolonoscopy, or SBFT. However, lower specificity and the need for preceding small-bowel radiography (due to the high frequency of asymptomatic PSBO) may limit the utility of CE as a first-line test for Crohn's disease.

Recent advances of endoscopy in inflammatory bowel diseases

Endoscopy plays a key role in the diagnosis and treatment in inflammatory bowel disease (IBD). The most valuable tool for distinguishing different types of IBD is a complete ileocolonoscopy with mucosal biopsy. Endoscopic localization of the disease not only aids in determining prognosis and appropriateness of medical therapies but also aids decision-making in those undergoing surgical therapy. With regard to therapeutic applications, obstructive symptoms caused by benign fibrotic strictures can be treated adequately by endoscopic balloon dilation. Epidemiological studies have demonstrated an increased risk of colorectal cancer in patients with both ulcerative colitis and colonic Crohn's disease (CD). Colonoscopy is currently considered to be the gold standard for cancer surveillance. Published guidelines recommend that two to four biopsy samples should be obtained every 10 cm in the colorectum, necessitating 20-50 samplings per examination. This may result in standard colonoscopy - which is also very time-consuming and laborious - missing significant numbers of small lesions. Various novel techniques have been applied to reduce the required number of biopsy samples and the duration of examinations, including chromoendoscopy with or without magnification, fluorescence endoscopy, narrow-band imaging, optical coherence tomography, and confocal laser endomicroscopy. Until recently the only way to evaluate the small-bowel mucosa in a patient with CD was by barium small-bowel radiographs and intubation of the distal terminal ileum. Both wireless-capsule endoscopy (WCE) and double-balloon enteroscopy (DBE) allow light to be used in the inspection of the small bowel and may replace radiological methods. WCE is more convenient than DBE for probing small-bowel mucosal changes, but only DBE allows a biopsy sample to be obtained from the deep small bowel, and these two examinations can be considered complementary. The wider application of new techniques in the near future might increase the role played by endoscopy in the management of IBD.

Crohn's disease-associated colorectal cancer in Japan: report of four cases

PURPOSE

We report four cases of Crohn's disease (CD)-associated colorectal cancer (CRC) in our department. CASE 1: A 42-year-old Japanese man had a 14-year history of ileocolon CD. He had a history of an ileocecal resection and a stricture plasty. At the age of 42, sigmoid colostomy was performed because of the deterioration of the anal stenosis. After this operation, the perianal pain had remained, and a magnetic resonance imaging scan revealed a rectal tumor. CASE 2: A 30-year-old Japanese man had a 13-year history of ileocolon CD. He had a history of an ileostomy, a subtotal colectomy, and ileo-rectal anastomosis. At the age of 30, he had perianal pain, and a colonoscopy revealed a rectal cancer. An abdomino-perineal resection of the remnant rectum was performed. CASE 3: A 46-year-old Japanese man had a 9-year history of ileocolon CD. He experienced abdominal fullness. Colonoscopy revealed an ascending colon cancer. He underwent a subtotal colectomy and ileo-rectal anastomosis. CASE 4: A 33-year-old Japanese woman had a 16-year history of ileocolon CD. She had no changes in symptoms of CD. Surveillance colonoscopy revealed a transverse colon cancer. She underwent a subtotal colectomy and ileo-rectal anastomosis.

CONCLUSION

As the number of patients with CD and with CD-associated CRC has increased in Japan, CD-associated CRC, as noted in these patients, should be kept in mind in the management of patients with CD. In addition, a surveillance system of patients with CD should be established and should prompt further study about CD-associated CRC.

Diagnosis of colitis: making the initial diagnosis

The evaluation of patients with colitis of recent onset is a relatively common clinical challenge. The main considerations are infectious colitides, idiopathic IBD, ie, ulcerative and Crohn's colitis, and colonic ischemia. An initial risk assessment on the basis of such factors as concurrent symptoms in contacts, travel history, medications, and human immunodeficiency virus risk factors should be followed by a thorough clinical history, physical examination, stool studies, blood tests, and, in selected cases, endoscopic examination and serologic tests. Biopsies can be decisive in distinguishing among the different types of acute colitis and might help identify specific etiologies. The diagnostic yield of biopsies is maximized by appropriate sampling of the colonic mucosa and by sharing the clinical and endoscopic findings with the pathologist, eg, via a copy of the endoscopy report.