Capsules are going where no-one has been before…

Dr John P Wright

Updated: 21 September 2006

Since Dr McCoy in “Star Trek” was able to diagnose common and esoteric diseases with a non-invasive hand held probe we have all been waiting for the magic gadget. The hand held ultrasound probe was perhaps the first step in this direction. Its utility continues to improve. Each iteration has more inbuilt intelligence, diagnostic ability and stability. As in all diagnostic equipment this elimination of operator variability is central to the process. As the price falls and the diagnostic return increases the role of the specialist technician falters and falls. This development of technical skills by intelligent machines is progressing relentlessly. A good example is abdominal ultrasound which in some European countries has joined endoscopy as a basic tool of the gastroenterologist. There is little doubt that non-invasive diagnostic machines are the future.

In clinical gastroenterology advancing technology is rapidly moving us to the ultimate goal of non invasive ambulant diagnosis. The initial revolution was the birth of the flexible endoscope. At first fiberoptic equipment took us to the duodenum and caecum. Less invasive than the radiology and open surgery of a previous period but nevertheless invasive and often uncomfortable. This plumbing phase of gastroenterology is fortunately passing although some specialist technicians continue to defend their turf vigorously.

Endoscopic Retrograde Cholangio-Pancreatography (ERCP) is moving from a diagnostic to a highly specialized interventional discipline. The diagnostic value of the current CAT and MRI scans in demonstrating small pancreatic and hepatic ducts is making diagnostic ERCP a back up option only.

Diagnostic colonoscopy is similarly threatened by the new CAT scan equipment. A persistent problem for both techniques however is the cleansing of the colon required prior to examination and the need for filling the colon with air or liquid to enable visualization by eye or X ray. Both procedures can be uncomfortable although usually preferable to an upper gastrointestinal endoscopy.

The latest surge in technology is in the development of electronic capsules that can be swallowed. They then transmit information to an exterior recording device as they travel down the gastrointestinal tract from stomach through small bowel to colon and out in the traditional manner. Capsule endoscopy which photographs the gastrointestinal mucosa is now well established as the preferred technique to examine the small bowel. Although often used to identify sources of blood loss from the small bowel the detailed view of the mucosa and villi is creating a new paradigm of intestinal assessment that is not yet fully understood.

The recent arrival of the “SmartPill™” has moved the goal posts further along the road to Star Trek medicine. These capsules register pH and pressure continuously for 3 or more days. This is intended to give insight into the motility and pressures associated with functional disorders of the gut in particular. Understanding these pH/pressure recordings and their relevance to gastrointestinal symptoms is the next challenge. On the horizon are capsules that can be maneuvered and take samples. Whether these developments will enhance our detection of treatable conditions remains to be seen but as surely as direct vision of the gastrointestinal mucosa replaced barium radiology so the new technology will open a new physiological and diagnostic world.

Bring on the future…