Navigational Capsule Endoscopy as a Triage Tool in the Management of Hemodynamically Stable Patients With Acute Upper Gastrointestinal Bleeding a Single Center Prospective Cohort Study

INTRODUCTION Background/ rationale Acute upper gastrointestinal bleeding (AUGIB) is a common emergency. The incidence varies from 50 to 110 per 100,000 population. In the majority of patients with AUGIB, bleeding is self-limiting and often has stopped spontaneously on presentation. Traditionally patients undergo early endoscopy (within 24 hours) for the purpose of finding the source of bleeding and if actively bleeding is seen from a lesion, endoscopy hemostatic treatment is then applied.

The NaviCam (ANKON) is a miniaturised wireless endoscope in a single use capsule. It can be remotely controlled with the patient in a magnetic console. The operator to the magnetic-driven NaviCam sits in a computer workstation and manipulates the capsule suspended in a waterfilled stomach. After careful examination of the stomach, the capsule is then allowed to passed through the pylorus into duodenum and small bowel. The patient wears harness with small bowel imaging capabilities. In patients with AUGIB, NaviCam has been compared to conventional esophago-gastro-duodenoscopy (EGD) in their diagnostic yields. NaviCam has been shown to detect more lesions including those in the small bowel. There are therefore several theoretical advantages to the use of NaviCam in the management of patients with AUGIB. First, the NaviCam procedure is well tolerated and in fact preferred by many patients. It is convenient to administer. Second, NaviCam can in addition examine small bowel. About 20% of patients with overt signs of AUGIB bleed from small bowel or colon. An initial NaviCam examination allows triaging of patients. Those with low risk lesions can be discharged without EGD and hospital admission. These represent substantial reduction in resource utilisation. In the diagnosis of small bowel lesions, the yield from a video capsule examination is higher closer to the time of index bleed.

Objectives The primary objective of the study is to determine the diagnostic yield of NaviCam in patients who present with overt signs of AUGIB. In addition, the investigators aim to determine if NaviCam examinations can reduce hospital resource utilisation and compare the use of NaviCam as a triage tool to the use of risk scores such as the Glasgow Blatchford Score (GBS). The investigators hypothesize that early NaviCam examination can allow safe discharge of more patients when compared to GBS.

METHODS Study design The investigators plan to conduct a prospective cohort study at the Prince of Wales Hospital, Shatin. The investigators enrol patients who present to the Accident and Emergency Department with overt signs of AUGIB (hematemesis or melena) and are hemodynamically stable (systolic blood pressure > 100 mmHg and pulse less than 100 per minute). The investigators intend to keep a log of all patients who present with AUGIB and are being referred for EGD. The investigators record their admission Glasgow Blatchford Score. The investigators exclude patients who are below the age of 18 and above 80 years, those with permanent pacemakers and other metallic implants that preclude magnetic resonance examinations, those with pharyngeal dysfunction that render them difficult to swallow, those with poor conscious state with the concern of aspiration and patients known to have risks of capsule retention e.g. previous gastric surgery, inflammatory bowel disease, patients who are unable to provide an informed consent and those in pregnancy.

Patients are required to fast for 6 hours. Before the examination, the patient ingests 400 mg simethicone dissolved in 100 ml of water to distend the stomach. He then drinks an addition of one liter of water 10 minutes before the examination. An activated NaviCam (ANKON) is then swallowed with the patient in a supine position in the MR console. This allows examination of the esophagus and the squamo-columnar junction. An operator then drives the magnetic robot and actively controls the capsule.