The inside view

Wireless capsule video-endoscopy, a recently-developed diagnostic tool principally useful for small intestine imaging, comes to India.

NANOTECHONOLOGY, the science of the small or the minute, has applications in areas as diverse as space research and medicine. It has revolutionary potential, especially in medicine, as the recent development of the procedure of capsule endoscopy is proved. A simple, non-invasive, ambulatory procedure, capsule endoscopy has hailed as one of the technological marvels of the millennium. It has revolutionised gastroenterological diagnosis and treatment. For the first time, doctors are able to see the inside of the entire six-metre-long small intestinal tract, which had previously remained beyond the reach of any diagnostic device.

Every year millions of people are affected by gastrointestinal (G.I.) diseases. The G.I. tract, which is the longest tract in the human body, has several organs attached to it. It is the cause of many diseases. Most of them remain undetected until it is too late as the intestinal tract frustrates radiology, ultrasound, enteroscopy, and even endoscopy. But now capsule endoscopy has changed all that.

As a concept, endoscopy was developed nearly a hundred years ago in Germany by Dr. Adolf Kussmaul to look into patients' stomachs. He used a rigid stainless steel tube, a rather crude instrument, causing a lot of discomfort to patients. The very thought of endoscopy was scary because over half of those undergoing the procedure would end up with major complications such as a perforated food pipe or stomach. Sometimes it was even fatal. It took another 50 years for the flexible fibre-optic endoscope to be developed by Basil Hirschowitz. For the last half century, flexible fibre-optic video endoscopes have been used to look into the upper gastrointestinal system. However, the six metres of the small bowel remained unreached and unexplored.

But that changed in 2001, when Gavriel Iddan, an engineer who works for the Israeli Defence Agency, developed capsule endoscopy. Twenty years earlier, on a sabbatical in Boston, United States, Iddan was pained to find his neighbour ironically, a gastroenterologist himself suffering from undiagnosed stomach pain. Iddan decided to develop a small rocket with a camera that could get into the small intestinal tract and send images of the six mysterious metres. In 1998, after working on the idea for two decades, Iddan came out with a prototype of the capsule endoscope, which was showcased at the 11th World Congress on Gastroenterology in Vienna. Given Diagonistic Imaging System, a small Israeli company, showed interest in commercialising the invention. After trial at several levels in many countries, capsule endoscopy became a reality by the end of 2001. It was launched commercially after it was approved by the U.S. Food and Drug Administration.

The capsule is swallowed and it sends images of the entire G.I. tract from the mouth to the anus in eight and a half hours. These images can be recorded on a compact disc and then analysed by a computer. This technological marvel is especially useful in detecting inconspicuous gastrointestinal bleeds. For example, angiodysplastic lesions or drug-induced ulcers and erosions in the small intestine, ulcers caused by colitis or ileitis, bleeding due to polyps in the small intestine, recurrent abdominal pain of obscure iteology caused by polyps or worms in the small intestine, can all now be detected by capsule endoscopy.

This procedure can also be done on moribund patients who cannot be shifted for diagnosis and treatment. The patient need not even come to the hospital; he or she can remain at home or at the work place while undergoing this test. What the patient has to do is just swallow the capsule and at the end of eight and half hours go to a hospital where the images recorded in the compact disc recorder placed in a belt-pouch strapped to the waist are downloaded for analysis and diagnosis.

This revolutionary technology is now available in India in Chennai, Hyderabad and Coimbatore. India was the first Asian country to introduce the product. Capsule endoscopy has been used as a life-saving device and in routine master health check-ups in order to diagnose obscure small-intestinal problems, which are common in the country. Dr. V.G. Mohan Prasad, who brought capsule endoscopy to Coimbatore (K.G. Hospital) and Chennai (Bharat Scans) says: "In May 2002, we had a patient with a dilated heart who was on cardiac drugs, including aspirin. He was passing blood and his haemoglobin count dropped from 14 gm to 4 gm within a span of 48 hours. He needed repeated blood transfusions and resuscitation. The cardiologist would not allow endoscopy or colonoscopy to locate the bleed because the patient had an enlarged heart and risked developing arrethmia during the procedure which could prove fatal. Luckily, capsule endoscopy arrived on time for use on the patient. The patient had erosions in the stomach and the small bowel from where he had been bleeding. Aspirin was stopped and the patient was resuscitated with blood transfusions and anti-acid drugs. He is living today, thanks to this technology."

Or take the case of a patient from Bangalore, who suffered from a recurrent abdominal pain that remained undiagnosed for two years despite two master health check-ups, which included endoscopy, colonoscopy, and Endoscopic Retrograde Cholangiopancreatography (ERCP) which is done to examine the bile and pancreatic ducts. All parameters appeared normal. But capsule endoscopy found a live round worm or ascaris swimming in the small intestine, which had previously remained undetected. After treatment for round worm, the patient has remained asymptomatic, without even a single episode of pain, for the last six months.

The capsule, now manufactured commercially by, Given Diagnostic Imaging System, is expensive; it costs $500 (about Rs.25,000) apiece. The CD recording and analysis costs another Rs.10,000. But according to Dr. Mohan Prasad, the cost is likely to fall in the next few months as the manufacturing volume increases. Also, a few other companies are in the trial stage of making the capsule, which would further reduce the price. Developments in electronics are also expected to reduce its price.

The development of the capsule has opened up a world of wonders. Several variants of the capsule, on which research and trials are in advanced stages, offer exciting possibilities in the diagnosis and treatment of several diseases. For instance, the rocket-propelled version of the capsule can be controlled using a joy-stick. It can be halted, moved and directed, and its progress can be seen on a monitor. As it is jet-propelled, the entire G.I. tract can be screened in less than the eight and a half hours that are required now. A therapeutic capsule that can treat a lesion is also in an advanced stage of trial. If there is a bleed from an ulcer or a lesion, such a capsule can be made to remain at that spot and emit microwaves so that thermal cooking of the lesion can be done to stop the bleeding.

Capsules with extensions like, say, an injection needle can also be used. For instance, a capsule can be loaded with a drug and can be sent to the site of cancerous tissues. The needle can be extended to inject the drug and can then be retracted into the capsule, which would remain in the patient's body until it comes out naturally. Similarly, it can be used to deliver genes and other therapeutic agents directly to disease sites. Biopsies can be done using retractable arms and the collected tissue can be retrieved after the capsule comes out. Capsules are also being developed to obtain a magnified view of lesions so that detailed examinations can be carried out.

The possibilities are endless, and this capsule is certain to revolutionise medical diagnosis and treatment.