An Observer Blinded Comparison of MACE and Conventional Upper Gastrointestinal Endoscopy in Upper GI Bleeding
Condition: Gastrointestinal Diseases
MeSH terms: Gastrointestinal Diseases; Digestive System Diseases
Study type: Interventional

Summary: 
      Gastroscopy (OGD) is a useful test for investigating a variety of suspected upper GI
      disorders. But it is uncomfortable for patients and incurs the risk of intubation and
      sedation, plus a large proportion of procedures reveal insignificant or no pathology. Capsule
      endoscopy (CE) is the investigation of choice for diseases of the small bowel. It is safe,
      non-invasive and well-tolerated. The use of CE is traditionally restricted to the small
      bowel, although newer capsules to image the oesophagus and colon are currently in use.
      Previous capsules have failed to adequately image the stomach due to its' large volume and
      rugal folds. Recently a magnetic capsule and handheld magnet has been developed (Mirocam
      Navi, Intromedic Ltd, Seoul, Korea) to enable an element of manoeuvrability of the capsule.
      This is unnecessary in the small bowel where the capsule is propelled along its' tubular
      structure by peristalsis, but in the capacious stomach this may allow the capsule to be
      steered to examine all areas of the stomach. We have already conducted two feasibility
      studies in porcine models with promising results and a trial has already evaluated the
      equipment to steer the small bowel capsule through the stomach into the duodenum. An ongoing
      study is comparing the ability of this technique to examine the stomach against conventional
      OGD, in patients with recurrent iron deficiency anaemia. The next stop would be to compare
      the two modalities under other different conditions.

      We wish to undertake a prospective single blind controlled trial comparing magnetically
      assisted capsule examination to conventional OGD in diagnosing upper gastrointestinal
      pathology in patients with gastrointestinal bleeding.
    

Detailed description: 
      Intubational endoscopy is uncomfortable for patients and incurs the risks of bleeding,
      perforation and sedation related complications. Gastroscopy is the 'gold-standard'
      investigation to identify upper gastrointestinal pathology but is poorly tolerated by
      patients. Moreover a large proportion of gastroscopies are normal or reveal insignificant
      pathology and despite efforts to produce pre-procedure scoring systems to grade the
      appropriateness of the procedure, correlation with diagnostic yield is poor. Capsule
      endoscopy is very well tolerated but is traditionally reserved for examination of the small
      bowel since it cannot be manipulated to view all areas of the capacious stomach. A capsule
      which could overcome this and be steered to examine all areas of the mucosal surface of the
      stomach as an alternative to intubational endoscopy would be advantageous to patients.
      Mirocam Navi (MC1000-WM, Intromedic Ltd, Seoul, Korea) is a small bowel capsule endoscope
      with an inclusion of magnetic material. Available accessories include a handheld magnet with
      which to gain some control over the capsule in the upper gastrointestinal tract. The capsule
      is CE marked (CE0120) with the handheld magnet classed as an accessory. In order to assess
      the feasibility of our hypothesis we conducted a study in an ex vivo porcine stomach model,
      commonly used for endoscopy training purposes. Different coloured/shaped beads were sewn into
      each major location of the stomach (cardia, fundus, greater and lesser curve, anterior and
      posterior wall, antrum and D1). The stomach was distended with 1000mls of water. Endoscopy
      was performed according to a set protocol. All stomach tags were identified in 87.2% (41/47)
      of examinations.

      This was followed by a double blind, randomised controlled trial comparing magnetically
      assisted capsule endoscopy (MACE) with conventional upper gastrointestinal endoscopy to
      detect coloured beads in a porcine stomach model. Gastroscopy correctly identified 88%
      (79/90) beads, MACE correctly identified 89% (80/90) beads and thus is noninferior to
      gastroscopy in this setting (95% CI 82.76%-95.24%). Mean examination times for gastroscopy
      and MACE were 3.34 minutes and 9.90 minutes respectively. Clearly there are significant
      differences between a porcine model and live human stomach. However, these studies provide
      proof of the principle that a small bowel capsule endoscope can be manipulated to make
      targeted movements within the stomach. We now also have one completed human trial assessing
      whether the magnetic controller can be utilised to manipulate the small bowel capsule through
      the stomach into the duodenum to improve the completion rate of small bowel capsule
      examinations. Another trial is also near completion comparing the diagnostic ability ,within
      the stomach, of MACE compared to conventional gastroscopy in the context of recurrent iron
      deficiency anaemia.

      In order to develop the protocol for our study, discussions were made with other health
      professionals (consultants, specialist nurses and ward nurses) who are involved in performing
      or reporting gastroscopy and small bowel capsule endoscopy examinations outside of the
      research team. Feedback was used to modify the study protocol so it could be as patient and
      user friendly as possible without compromising the overall aim to answer the research
      question.

      Additionally the protocol has been externally peer reviewed and subsequent modifications
      made.

      From our porcine and two human trials it is clear that to obtain reasonable views of the
      stomach to be able to guide the capsule the stomach needs to be distended. In our porcine
      study we achieved good results with 1000mls of water. We felt that this would be an
      acceptable amount for a patient to drink prior to magnetically assisted capsule endoscopy,
      and the two human trials we have completed to date have proven excellent tolerance to this
      volume of water.

      RECRUITMENT Patients will be offered information about the trial at the time of their initial
      clinical encounter in the outpatient clinic. Written information is provided at this stage
      and will be followed by confirmation of consent on the day of, but prior to, the procedure.
      The research team will be available when the patient attends for their procedures to answer
      any questions or concerns. Additionally a contact telephone number for the research team is
      provided on the patient information sheet for any other concerns or queries.

      INCLUSION/EXCLUSION We have made every effort to enable the study to be open to a wide range
      of patients however we have currently limited the study to patients with upper
      gastrointestinal bleeding to allow the highest possibility for pathology detection for either
      endoscopic modality and hence facilitate comparison of diagnostic ability. Specific
      considerations have been made to ensure that patients will be excluded from the study if
      there is to be any delay/interference to the standard management of upper gastroinstinal
      bleeding.

      CONSENT All participants will be consented as per the study consent form. All members of the
      research team are formally trained in consent procedures and assessment of capacity. Any
      participant without capacity to consent will not be included in the trial. The principal
      investigator is trained in the ethical principles underpinning informed consent and is bound
      to these principles as part of good medical practice.

      RISKS/BURDENS/BENEFITS The participant is subject to the risk of the procedures of
      gastroscopy and small bowel capsule endoscopy itself. Bleeding and perforation are the major
      risks of undergoing a gastroscopy and occur in 0.02% of procedures. There is also a risk of
      sedation related complications if the patient chooses this option. The main risk of SBCE is
      retention of the capsule, occurring in up to 2% of examinations. Since the participant is
      undergoing these procedures as part of their medical investigation these risks are discussed
      when the patient is offered the investigations at the time of booking, they are also formally
      consented by a trained individual when they attend for the procedure. Participants are not
      felt to be at any additional risk by undergoing magnetically steerable capsule examination of
      the stomach.
    

Intervention name(s): Magnetic Assisted Capsule Endoscopy
Intervention type(s): Device
Intervention description(s): Swallowed magnetic capsule for endoscopy purposes
Other intervention name(s): MACE
Intervention model: Single Group Assignment
Masking: None (Open Label)
Primary purpose: Treatment