Where Next for the Endoscope?

Ricardo A. Natalin; Jaime Landman

In This Article

Capsule Endoscopy

A new and promising technology in the urologic field is wireless capsule endoscopy (WCE), in which a camera and a wireless radio transmitter are contained in a small capsule that is inserted into the urinary tract. A capsule endoscope comprises the capsule device, an external receiving antenna with attached data recorder, and a computer workstation with the appropriate software for interpretation of images. The capsule has two main parts: optics, namely a lens with short focal length, a narrow aperture to increase the depth of field and illumination by LEDs; and an assembly of magnets to assist with device manipulation.

Capsule endoscopy is currently indicated after upper and lower gastrointestinal endoscopy has failed to identify the origin of obscure bleeding. Various other indications have been proposed for WCE, such as the investigation of unexplained anemia, evaluation of the small-bowel mucosa in patients with Crohn disease, as well as diagnosis and surveillance of patients with hereditary polyposis syndrome, protein-losing enteropathy, or irritable bowel syndrome. Within esophageal disease, WCE can evaluate the presence of reflux disease and portal hypertension.[33]

Limitations of WCE include that it is not recommended for patients with swallowing disorders owing to the risk of aspiration, the possibility of false-negative results and the inability of contemporary devices to obtain a biopsy specimen or to perform endoscopic treatment. Currently, the best applications for WCE are as a complement to conventional endoscopy, to avoid unnecessary examinations.[34]

WCE has only been used experimentally in urologic disorders. It has been successfully used to evaluate the urinary tract in a porcine model, where it produced continuous images and identified specific landmarks. In this setting, the device could be manipulated by means of an external magnet.[35]

In the future, WCE might be significantly enhanced by the development of capsules that can be actively steered, which would dramatically increase the sensitivity of this imaging modality. Similarly, capsules could be modified to enable tissue biopsy and treatment, and even to deliver medication such as bacillus Calmette–Guérin or chemotherapy after bladder tumor resection. We can speculate that a self-propelled 'untethered intracorporeal endoscope' could be developed, which could be introduced into the lower urinary tract and guided 'upstream' by a chemical signal derived from administration of an organ-specific targeting substance.

In the future, urologic imaging by virtual endoscopy or advanced WCE would certainly result in diminished discomfort for patients and decreased cost; these advances allow endoscopy to be performed effectively in the least invasive manner possible.