Capsule endoscopy and imaging tests in the elective investigation of small bowel disease

Gastrointestinal bleeding of undetermined origin: What diagnostic strategy to propose?

Gastrointestinal bleeding of undetermined origin (GBUO) is defined as gastrointestinal bleeding without an identified cause or location despite an endoscopic assessment including an esogastroduodenal endoscopy (EOGD) and a total colonoscopy. A distinction is made between exteriorized GBUO and non-exteriorized occult GBUO. The causes in the majority of cases (vascular, inflammatory and tumoral) are located in the small intestine. The diagnostic strategy aiming to locate the origin of the GBUO is a real challenge. Innovation in endoscopic and imaging techniques has enabled minimally invasive exploration of the small intestine. In Europe, there is a strong consensus to recommend a video-capsule endoscopy (VCE) as the first-intention study. If there is reason to suspect intestinal obstruction, VCE is contraindicated and a CT-enteroscopy is then performed as first intention. Enteroscopy is performed as a second-line treatment, either for therapeutic purposes after a positive VCE or CT-enteroclysis, or for diagnostic purposes after a negative VCE. Finally, intraoperative enteroscopy (IOE) coupled with surgical exploration should be reserved either for therapeutic purposes in the event of impossibility or failure of preoperative enteroscopy, or for diagnostic purposes in the event of recurrent GBUO after failure of all other studies and explorations of the small intestine.

The management of lower gastrointestinal bleeding

Lower gastrointestinal (LGI) bleeding is generally less severe than upper gastrointestinal (UGI) bleeding with spontaneous cessation of bleeding in 80% of cases and a mortality of 2-4%. However, unlike UGI bleeding, there is no consensual agreement about management. Once the patient has been stabilized, the main objective and greatest difficulty is to identify the location of bleeding in order to provide specific appropriate treatment. While upper endoscopy and colonoscopy remain the essential first-line examinations, the development and availability of angiography have made this an important imaging modality for cases of active bleeding; they allow diagnostic localization of bleeding and guide subsequent therapy, whether therapeutic embolization, interventional colonoscopy or, if other techniques fail or are unavailable, surgery directed at the precise site of bleeding. Furthermore, newly developed endoscopic techniques, particularly video capsule enteroscopy, now allow minimally invasive exploration of the small intestine; if this is positive, it will guide subsequent assisted enteroscopy or surgery. Other small bowel imaging techniques include enteroclysis by CT or magnetic resonance imaging. At the present time, exploratory surgery is no longer a first-line approach. In view of the lesser gravity of LGI bleeding, it is most reasonable to simply stabilize the patient initially for subsequent transfer to a specialized center, if minimally invasive techniques are not available at the local hospital. In all cases, the complexity and diversity of LGI bleeding require a multidisciplinary collaboration involving the gastroenterologist, radiologist, intensivist and surgeon to optimize diagnosis and treatment of the patient.

Clinicopathological features and treatment of primary small intestinal lymphoma: recent advances

Primary small intestinal lymphoma (PSIL) is an extra-nodal lymphoma whose clinical and histological presentations are usually heterogeneous depending on the site of the lesion. Proper staging criteria are important for clinicopathological diagnosis. Although there is no consensus regarding the role of surgery and chemotherapy in the treatment of PSIL, surgery followed by chemotherapy and radiotherapy is still the main treatment. This review summarizes the clinicopathological features, diagnosis, therapy and prognosis of PSIL.

Can capsule endoscopy be used as a diagnostic tool in the evaluation of nonbleeding indications in daily clinical practice? A prospective study

OBJECTIVE

To evaluate the diagnostic yield of capsule endoscopy (CE) and its impact on treatment and outcome in patients without bleeding indications.

SUBJECTS AND METHODS

One hundred and sixty-five nonbleeding patients were enrolled in the study. The most common indications for CE were chronic abdominal pain alone (33 patients) or combined with chronic diarrhea (31 patients) and chronic diarrhea alone (30 patients). Among the 165 patients, 129 underwent CE for evaluation of gastrointestinal symptoms and 36 for surveillance or disease staging.

RESULTS

CE findings were positive, suspicious and negative in 73 (44.2%), 13 (7.9%) and 79 (47.9%) of cases, respectively. The diagnostic yield was highest in patients with refractory celiac disease (10/10, 100%) and suspected Crohn's disease (5/6, 83.3%), followed by patients with chronic abdominal pain and chronic diarrhea (13/31, 41.9%), established Crohn's disease (2/6, 33.3%), chronic diarrhea alone (8/30, 26.7%), chronic abdominal pain alone (8/33, 24.2%) and other indications (3/13, 23.1%) (p < 0.005). The CE findings led to a change of medication in 74 (47.7%) patients, surgery in 15 (9.7%), administration of a strict gluten-free or other special diet in 13 (8.4%) and had other consequences in 11 (6.7%). Management was not modified in 42 (27.1%) patients. Among symptomatic patients (n = 129), 29 (22.5%) were lost to follow-up. The remaining 100 patients were followed up for 8.7 ± 4.0 months (range 2-19). Among the latter, resolution or improvement of symptoms was observed in 86 (86%) patients, no change in 11 (11%) and 3 (3%) died. All 86 patients who experienced resolution or improvement of their symptoms had a modification of their management after CE; only 7/11 patients whose symptoms did not change (63.6%) and 2/3 patients who died (66.7%) had a modification of management (p < 0.001).

CONCLUSIONS

CE appears to be a useful tool in the evaluation of patients with nonbleeding indications. The outcome of most patients with negative findings was excellent.

The future of endoscopic esophageal therapy--what comes next

The diagnosis and treatment of esophageal diseases have undergone major changes over the last several years, and these are expected to continue. This article highlights these changes.

Finite-difference modeling of micromachine for use in gastrointestinal endoscopy

An on-going research project is to develop a micromachine driven actively and wirelessly by external magnetic field. The micromachine has great potential for being used in medical fields such as gastrointestinal endoscopy. The ultimate goal is to develop a control mechanism capable of moving the wireless endoscope through the human's gastrointestinal tract in any direction with minimum level of harm to human body. This paper establishes fluid dynamics model suitable for micromachine's movement in intestinal tract, simulates pressure distributions of micromachine's surface, and further calculates driving and load torques. Based on the fluid simulation results, parameters for generating appropriate rotating magnetic field can be calculated. This fluid dynamics simulation method provides a novel approach to analyze biomedical micromachine's mechanical properties under external electromagnetic equipment.

Role of MRI in Crohn's disease

The traditional imaging of Crohn's disease has relied on barium and computed tomography (CT) examinations. In recent years magnetic resonance imaging (MRI) has emerged as an imaging method that can be used in the diagnosis and assessment of Crohn's disease. The advantages of MRI include lack of ionizing radiation and its superior tissue contrast resolution. The clinical progression of Crohn's disease can be variable, and MRI can be used to assess inflammatory status, disease progression, and complications of Crohn's disease. MRI of the small bowel is an evolving technique and it has the potential to become the preferred technique for imaging of small bowel Crohn's disease in the future.

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.