How small is small? The latest digital camera takes images of a patient's 'inner space.'
The 1966 movie “Fantastic Voyage” took us on a trip through the human body. Today, a device called the PillCam is capturing the essence of that travel. The PillCam, a small digital camera about the size of a large vitamin tablet, is allowing direct visualization of the small intestine. Until recently, the small intestine, a hollow tube nearly 18 feet long, has been a diagnostic black hole. Traditional endoscopy allows visualization of both ends, leaving the greater part in the middle unseen. The various radiological imaging technologies are less than perfect in diagnosing small bowel disorders.
The PillCam, manufactured by Given Imaging, appears to be filling part of the void with its unique ability to capture images of the small intestine as it transits.
To perform a study using the PillCam, there are no special recommended bowel preparations. Patients should drink clear liquids from noon the day before the procedure, and from 10 p.m. should be NPO (nothing by mouth) except for sips of water for needed medication.
The capsule weighs less than four grams, is 11 mm x 26 mm in size, and has a field of view of 140 degrees. The PillCam is tested, activated, and then swallowed with one glassfull of water.
The PillCam generates two images per second and comes complete with its own miniature flash. It normally takes eight hours to transit the small intestine. PillCam can record as many as 57,000 images, which are transmitted to a sensor array taped to the patient's abdomen, which in turn is connected to a small data recorder carried by the person. When the recording is over, the recorder uploads the images to a workstation where the physician can view the images in about 30 or 40 minutes.
The manufacturer provides training for physicians interested in performing this procedure. The majority of the devices are purchased directly by physicians and billed to insurance carriers. Institutions such as hospitals also are involved with this device but to a lesser extent. The majority of the clinical studies are available only as abstracts.
The PillCam is indicated for observation of the small bowel mucosa in adults and children age 10 and up. Typically, physicians will order the PillCam for people with suspected cancer of the small intestine, Crohn's disease, obscure GI bleeding, iron deficiency anemia, malabsorptive diseases such as celiac/sprue disease, irritable bowel syndrome, or intestinal injury. Currently it is not meant to replace direct endoscopy or radiological evaluations, but increasing comfort with the results coupled with an ever increasingly available bibliography of world wide literature is likely to lead to physicians using it as a stand-alone procedure, especially as a follow up examination after treatment has been implemented.
For obvious reasons, the PillCam is contraindicated in patients with known or suspected gastrointestinal obstruction, strictures, or fistulas based upon the clinical evaluation or pre-procedural testing. It is also currently contraindicated in patients with cardiac pacemakers or other implanted electromedical devices. Another contraindication includes patients with swallowing disorders.
There are few other instructions for proper use. If the patient is on a medication that slows transit time, the physician may choose to withhold the drug the day of the test. Regular medication can be taken until two hours before the test and resumed two hours after the PillCam is ingested. Physicians may wish to withhold medications that coat the small bowel, such as sulcrafate, for five days prior to the test.
After ingestion, the patient should remain NPO for two hours, at which time water is fine. After four hours, a light snack is allowed, and after eight hours, normal diet may return. The PillCam then ends up at the local sewage treatment plant!
As amazing as the pill cam is, it does have limitations: It is good at demonstrating what the problem is, but it cannot determine where the lesion is, exactly.
The manufacturer has mechanisms for estimating the location(s) of lesions, including labeled anatomic landmarks such as the pylorus and ileocecal valve, a capsule timebar, typical gastric and small bowel transit times, and models, but the exact location will require other testing if a surgical procedure is required for lesions such as a malignancy. PillCam is untested for visualizing the large intestine.
The billing consists of two different components, professional and technical, leading to two bills or a "global bill" if billed together. It is recognized by both Medicare and commercial payers as acceptable and covered for suspected Crohn's disease and GI bleed that remain undiagnosed after a traditional workup.
Undiagnosed iron deficiency anemia and abdominal pain are typically not covered indications but common reasons for physicians to consider this tool. For approved indications, Medicare global reimbursement is in the $900–$1,000 range (varying by locale) with the professional being about $200 and the technical being the rest. The list price of the actual capsule is $450. It is sold in packs of 10. About a quarter of a million studies have been performed so far worldwide.
The use of this technology is expanding with the more recent approval by the FDA of an esophageal version of the device, the PillCam ESO. This device has two video cameras, one on each end, that can take four images per second during the less-than-five-second transit through the esophagus. The device continues to transmit images for 20 minutes until the battery dies. The manufacturer has performed comparison trials against the gold standard, — upper endoscopy — reporting a comparative 92 percent sensitivity and 95 percent specificity.
Obviously the PillCam does not have the capability to be maneuvered or to acquire tissue samples as does an endoscopy. Its use in the total management of upper GI disorders still remains to be established in formal evidence-based guidelines, but given the convenience, the lack of need for sedation and the rather benign nature of the patient experience, MCOs will probably face increased demand from patients and physicians in the coming years. This device takes us one step closer to what was once science fiction, again reminding us of the coming attractions of Tomorrow's Medicine!