In the 15 years since its approval by the Food and Drug Administration, video capsule endoscopy (VCE) has become a first-line diagnostic tool at Penn Medicine for visualizing the small bowel mucosa.
Video Capsule Endoscopy at Penn Medicine
Under the new directorship of Laurel Fisher, MD, the video capsule endoscopy (VCE) program at the Penn Division of Gastroenterology is now entering its second decade, and the small bowel team has grown to include Jan Michal Klapproth, MD, Octavia Pickett-Blakely, MD, and Anna Buchner, MD. Originally introduced at Penn Medicine as an adjunctive tool, VCE has proved to be an effective and increasingly comprehensive means of evaluating the small intestine, where it has largely supplanted barium radiography and push enteroscopy to become a diagnostic modality of choice.
Approximately the size of a large vitamin pill (11 x 24 mm), VCE devices travel through the gastrointestinal tract via peristalsis much as a bolus of food would. Each device contains a camera that, aided by white-light-emitting diodes, transmits 50,000-60,000 high-resolution digital images by radio telemetry or microwave to an external sensor array and data recording device worn by the patient. These images are then collected and processed to create a complete video picture of the small bowel.
Improvements in Technology and Technique
To many endoscopists, the early VCE devices had the aura of novelty about them. “There was some concern early on about the VCE’s capacity to produce consistent and reliable documentation of the small bowel, and some apprehensions about pill retention,” Dr. Fisher explains.
However, the technology of VCE devices has improved substantially in the last decade. The latest generation of devices, for example, employs lighting technology based upon automated adaptive illumination of the GI mucosa to ensure uniform illumination of the mucosa, and multi-element lenses that eliminate distortion. Battery life has increased dramatically, as well, to 12 hours or more in some devices, and precision optics have standardized image resolution to 0.07 mm.
Improvements in bowel preparation and efforts to define patient populations at risk for capsule retention have enhanced both the safety and efficacy of the VCE procedure. Superior visualization has been attributed to preparation with polyethylene glycol solutions versus no cleansing in most studies, and at least one meta-analysis suggests that bowel preparation significantly improves diagnostic yields—if not small bowel transit or VCE completion rates to the caecum.
The safety of any endoscopic procedure at Penn Medicine is a paramount consideration, and VCE is no exception, according to Dr. Pickett-Blakely, an expert in celiac disease. “We now know that a history of stricture, Crohn’s disease, opioid use or abdominal surgery increases the risk of capsule retention,” she observes. “And as much as we value imaging studies for the exclusion of patients with stricture or obstruction, we know they alone can’t eliminate the possibility of capsule retention.”
While no patient at Penn has experienced capsule retention, Penn Gastroenterology is prepared for every eventuality. “We’re fortunate in having both the equipment and the expertise to perform double-balloon endoscopy or other device assisted enteroscopy here at Penn,” says Dr. Fisher. Double-balloon endoscopy, or DBE, has been reported to be an effective instrument for the retrieval of VCE devices in the rare event of long term capsule retention.
At Penn Medicine, VCE is used primarily to evaluate the small bowel for obscure gastrointestinal bleeding (OGIB) of presumed small bowel origin, Crohn’s disease, neoplasms and polyps. In these indications, VCE has generally been found to be equivalent or superior to the established approaches to small bowel investigation, including push enteroscopy, small bowel barium radiography, double balloon endoscopy, and in some instances, CT enterography and 64-section CT.
Obscure Gastrointestinal Bleeding
VCE demonstrates a substantial diagnostic yield in patients with obscure gastrointestinal bleeding, effectively characterizing common sources of blood loss, including ileal and jejunal arteriovenous malformations, angiodysplasias, ulcers, neoplasms and other small bowel etiologies. According to Dr. Fisher, the devices can also help determine the need for more invasive procedures in the presence of bleeding following negative upper endoscopy and colonoscopy.
VCE is useful for the diagnosis of suspected or confirmed Crohn’s enteritis and to characterize anatomical distribution and severity in established disease. New proximal small bowel lesions have been detected in 50% of patients with established Crohn’s disease. The devices have also been used to establish the diagnosis of Crohn’s in patients with suspected or indeterminate ulcerative colitis and to facilitate appropriate medical management.
Small Bowel Tumors
Neoplasms and lesions visible and detected by VCE include lymphomas, neuroendocrine tumors, sarcomas, gastrointestinal stromal tumors, adenocarcinomas, carcinoids and small bowel polyps in polyposis and hereditary cancer syndromes. VCE can be used for interval surveillance in patients with polyposis syndromes.
“An increasing benefit of VCE is its capacity to detect small intestinal tumors during tests for other conditions, including GI bleeding and iron deficiency,” notes Dr. Fisher.
Specially designed VCE devices have been used outside the United States, and more recently in this country for colon cancer screening and to assess the mucosal abnormalities and complications of celiac disease. While an esophageal VCE is approved in the US for screening of patients with esophagitis and Barrett's esophagus, concerns about accuracy and the inability of the devices to obtain biopsy samples or provide treatment have limited its use in this indication.
Research is ongoing to continue improvements in the accuracy of VCE image interpretation and recording, as well as ways to expand the utility and indications for the devices. It is likely that future developments in information technology and nanotechnology will result in further diagnostic and therapeutic advances for VCE technology.