Department of Gastroenterology, Yangon General Hospital
Video Capsule endoscopy as been available since 2014 in Myanmar civil government hospitals and diagnoses of small bowel pathology.The small bowel is the most difficult part to examine and conventional endoscopic techniques for examination is limited by its length and its multiple, complex, looped configurations.VideoCapsule endoscopy entered the domain of clinical gastroenterology in2001 and is a noninvasive method to evaluate theentire length of the small bowel.After an overnight fast, the patient swallows the capsule, which travels through the GI tract by normal peristaltic action. Images are transmitted by a digital radio frequency communication channel to an external data recorder unit. The noninvasive nature of capsule endoscopy makes it an attractive option over traditional endoscopy.
There are four CE systems: the PillCam SB2 (Given Imaging,Yoqneam, Israel), the Endo Capsule (Olympus America, CenterValley, PA), the OMOM capsule (Jinshan Science and Technology,Chongqing, China), and the MiroCam(IntroMedic, Seoul, Korea).All capsule endoscopes have similar components: adisposable plastic capsule, a complementary metal oxide semiconductor or high-resolution charge-coupled deviceimage capture system, a compact lens, white-light emittingdiode illumination sources, and an internal battery source.
VCE has been approved for a number of indications and the most common applications include evaluation for : (1) obscure GI bleeding (OGB), both overt and occult, including iron deficiency anemia (2) suspected Crohn’s Disease (3) surveillance in patients with polyposis syndromes (4) suspected small-intestine tumors and (5) suspected or refractory malabsorptive syndromes (e.g. celiac disease).
Absolute contraindications include :
Clinical or radiographic evidence of relevant bowel obstruction
Extensive and active Crohn’s disease of the small bowel, with or without obstruction
Intestinal pseudo-obstruction
Young children (< 10 years)
Relative contraindications include :
Cardiac pacemakers or other implanted electro medical devices
Dysphagia
Previous abdominal or pelvic surgery
Pregnancy
Extensive intestinal diverticulosis
VCE administration can be performed using two methods: swallowing the VCE bymouth or endoscopic deployment of the VCE into the small bowel. Oral VCE administrationis more common and endoscopic deployment should be considered in patients with known or anticipateddifficulty of the VCE passing from the mouth to the small bowel in a safe and timelymanner to enable maximal small bowel mucosal visualization and to ensure a completecapsule study.
Capsule endoscopy is a relatively simple test for the patient, provided the patient can swallow the capsule. Oncethe capsule is ingested, the patient can continue normaldaily activities as the pill traverses the alimentary tract.It is expected that the entire small bowel can bevisualized within the lifespan of the standard 8-hour battery.
At the time of the procedure, the sensing system (e.gpadsor a belt) is applied to the abdominal wall and connectedto the data recorder that is worn by the patient.After ingestion of the capsule, patients are instructedto keep a diary of symptoms and monitor thelights on the data recorder to confirm that the signal is beingreceived. Patients are encouraged to avoid exercise oractivities that may cause the sensors to detach. A diet of clear liquids is allowed after two hours and a light meal after4 hours.
The capsule usually leaves the stomach within 30 min and it has reached the caecum in 85% of cases. On completion of the procedure, the data from the recorder is downloaded onto a computer workstation which allows approximately 50,000 images to be viewed as a video. The average reading time of the video images takes between 40 and 60 minutes depending on the experience of the endoscopist. The yield of CE can be affected by two problems: firstly, the presence of dark intestinal contents in the distal small bowel which may impair visualization of the mucosa, and secondly the rate of gastric emptying and small bowel transit which could lead to the exhaustion of the capsule batteries before the capsule reaches the ileo-caecal valve.
The most commonly detected lesions in the small bowel suspicious of being responsible for bleeding, that can be found on VCE are angioectasia, fresh blood, ulceration, polypoid or tumoral lesions and varices.
Despite its obvious advantages, CE has some limitations.Image quality is not as good as that of flexiblevideoendoscopy.A lesion cannot be washed or examined repeatedly. In some patients, CE fails to visualize the entire small bowelbecause of intestinal content.During CE, progressivedarkening of the images may be observed as the capsulemoves toward the distal small bowel. This is probablybecause of the presence of bile and unabsorbed foodmaterial. In patients prepared with a colonoscopy-typepreparation, the images from the distal small intestine aresignificantly brighter, and the bowel contains less obscuringmaterial.
Informed consent to patients undergoing CE would be made by the researcher and it will include a discussion of the potential risk, including a failedprocedure (capsule fails to exit the stomach or otherwisefails to provide definitive visualization of the small bowel);retention (capsule becomes impacted); or missed smallbowellesion (i.e. false-negative result).
The primary risk in capsule endoscopy is that of capsule entrapment within the GI tract (variously referred to as impaction and non-natural excretion). Entrapment occurs in 0.75% to 5% of cases and most capsule entrapment occurs in the small intestine. High-risk factors for entrapment include use of nonsteroidal anti-inflammatory drugs, prior abdominal radiation, Crohn’s enteritis, and prior major abdominal surgery.
Images of possible wireless video capsule endoscopy in 2020
Development of new technology makes our lives more convenient and improvements may include wireless video capsule endoscopy in near future.
References
Adler, S.N. The history of time for capsule endoscopy.AnnTransl Med2017, 5 (9), 194-196.
Enns, R.A., Hookey, L. & Armstrong, D. et al. Clinical Practice Guidelines for the Use of Video Capsule Endoscopy.Gastroenterology 2017, 152, 497–514.
Barkin, J.A. &Barkin , J.S. Video Capsule Endoscopy Technology, Reading, and Troubleshooting. Gastrointest Endoscopy Clin N Am 2017, 2 (7), 15–27.
Wang, A., Banerjee, S. & Barth, B.A. et al. Wireless capsule endoscopy. Gastrointestinal Endoscopy 2013,78(6), 805-815.
- Professor and Head, Department of Gastroenterology, Yangon General Hospital
- Professor, Department of Gastroenterology, Yangon General Hospital
- Associate Professor, Department of Gastroenterology, Yangon General Hospital
- Consultant Gastroenterologist, Department of Gastroenterology, Yangon General Hospital
- Doctorate student, Department of Gastroenterology, University of Medicine 1, Yangon
Thein Myint1, Moe Myint Aung2, Tin Moe Wai3, Swe Mon Mya4, MyaThet Nwe4, Sandar Win4, Thida Soe4, Than Than Aye5
