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What's New in Endoscope Technology
5 developments that may dramatically improvethe way physicians perform colonoscopies.
Jerome Waye
Publish Date: February 9, 2008   |  Tags:   Gastroenterology

We've seen a proliferation of endoscopic advances and instrumentation over the last few years as device manufacturers strive to keep pace with a continued industrywide emphasis on quick and effective colonoscopy. From navigating through the sigmoid colon more easily to speeding turnover times between cases, here's a look at a just a few innovations that could soon improve your GI service line in the near future.

1. Remote-controlled instruments
The Aer-O-Scope from GI View is a non-operator- dependent disposable scope propelled around the colon by air pressure. This device involves two balloons placed into the rectum. The distal-most balloon is inflated to maintain air in the colon. A port for air insufflation is located between the two balloons. As air is introduced, the inflated innermost balloon, tethered by a long flexible cord that transmits images from a small video chip on its tip, progresses through the twists and bends of the colon.

This system is said to provide a 360-degree angle of view and the operator can control both forward and backward propulsion. Visualization is in real time and the device carries its own lights and pressure-recording sensors. This system, due for commercial release later this year, is promising but might have difficulty passing through the sigmoid segment due to multiple twists, bends and angulations related to diverticular disease.

2. Computer-guided scope
NeoGuide Systems is scheduled to release its NeoGuide computer-guided scope system this summer. The technology is designed to eliminate pressure on the colon wall and excess looping with a "follow the leader" localization system. Multiple small-articulated segments in the instrument contain sensors that respond to a computer plot of each bend and twist of the tip. Information from the tip is transmitted to the computer, which directs successive segments to bend or twist at the same anatomic location as the prior segment.

If the tip goes through an "M" configuration, each segment will then traverse the same shape at the same points in the colon. This eliminates large loops in the colon, while an additional mechanism permits the instrument to be straightened before assuming that straight configuration for all successive segments. This scope is said to have performed well in clinical trials.

What Physicians Want in a Scope

Here's a look at the features your physicians will likely covet and some design developments that could dramatically improve their performance in the procedure room.

When choosing an endoscope, your physician will consider the degree of flexibility, the ability of the tip to bend in various angles, the length of its tip at the bending section and the scope's torque stability. Your physician will also judge his ability to clean the lens during a procedure — including the incorporation of an integral water jet into the scope's design — and his ability to view the colon with a light source other than white light.

Scopes must have adequate torque to remain stable as they are manipulated and twisted around the loops and bends of the colon. A physician's ability to control the bend in the scope's tip is also an essential aspect of the successful colonoscopy. The tip is capable of bending 160 degrees in four directions. The length of the tip's bending section and the radius of the bend greatly determine a scope's ease of use.

Adult scopes have a long tip and large bending radius, which may lead to difficult intubation of the sigmoid colon. The many bends and curves of the colon may be considerably more acute than the bending radius of the scope, particularly in post-pelvic surgery patients, in patients with diverticular disease and often in female patients. Using a pediatric colonoscope is a good choice in those cases. The even smaller radius and curvature at the tip of a gastroscope will always pass through the colon if an adult or pediatric scope can't.

Two modalities exist for enhancing the visualization of the colon: narrow (or multi-band) imaging and dye spray applied to the intestinal tract. As the light passes through a filter in the scope's processor, a narrow band of the normal light spectrum acts as a dye spray of sorts. The filtered light enhances the vascular appearance of the colon, letting physicians identify abnormalities more easily as they view the colon's surface in greater detail.

The sigmoid colon always makes instruments bend in a loop formation. A scope should stretch, but not overstretch, the colon. The more flexible a scope, the easier it passes through the colon. Conversely, more rigid instruments have an increased tendency to form into a large loop and pull on colon attachments. That pulling slows the scope's progress and causes pain and discomfort to the patient. Still, more rigid instruments are sometimes necessary to navigate certain areas of the colon. Scopes featuring variable stiffness controls are therefore helpful tools.

— Jerome D. Waye, MD, FACG

3. A retrograde view
Avantis Medical Systems' Third Eye Retroscope is a new tool that facilitates retrograde visualization as the scope is removed from the colon. The retroscope is designed to eliminate blind areas around various folds of the colon. This instrument passes through the channel of a standard-sized colonoscope and bends 180 degrees as it emerges from the instrument channel. The retroscope's tip contains light-emitting diodes and a small lens transmits the image to a special screen, which displays the conventional colonoscope view alongside the retrograde view. The light from the colonoscope is so bright that it would overwhelm the imaging capability of the retroscope. A polarizing filter is placed onto the colonoscope before it is introduced. The light from the retroscope is also polarized. By torquing the retroscope, the physician cancels the effects of the bright lights to achieve good visualization.

4. The colon capsule
The Pillcam Colon Capsule from Given Imaging is an evolution of the small bowel capsule. The Colon Capsule has a light and recording apparatus at each end and transmits images to a small computer on the subject's belt. Since the battery life is limited (although efforts are being made to prolong transmission time), the capsule turns off for several hours once swallowed so information is only transmitted once the capsule reaches the distal-most portion of the small bowel. The colon must be absolutely clean before the capsule can be used, meaning multiple doses of cathartic and prokinetic agents are required for purgative purposes. Multiple pictures are taken as the capsule tumbles its way through the large bowel and images can also be seen in realtime by a handheld monitor.

5. Disposable endoscopy system
The single most important part of reprocessing a scope involves the mechanical cleaning of the scope's inside and outside before using any of the disinfecting solutions, no matter if the disinfectant is employed in a basin or in an automated endoscope-reprocessing machine. The half-hour typically needed to properly disinfect and reprocess scopes between cases is a large hurdle for a GI center's colonoscopy efficiency.

Stryker's ProtectiScope CS, expected to hit the market this year, is a system that may eliminate a scope's downtime between cases and, some say, revolutionize the GI industry. The system is comprised of an endoscope skeleton which looks like a standard scope with a protective disposable sheath that unfolds from a fist-sized reservoir attached to a tethering device near the anus. When the scope is advanced, the sheath unravels from its container, then retracts into the device as the instrument is withdrawn. The biopsy channel is a part of the entire disposable sheath system.

Your physician would finish a colonoscopy, discard the disposable sheath that covered the scope during the procedure and attach a new sheath to ready the scope for the next case. I've trialed the system. Visualization is good and the handling is similar to a standard non-sheathed colonoscope. The protective sheath, its container and the biopsy channel are all disposable and cost around $70.

That price tag is comparable to the staffing and equipment costs of reprocessing scopes that the system's disposability would eliminate. Think about the other savings a disposable scope would help realize. The scope's system could be readied for the next case in minutes because the endoskeleton of the instrument does not need to be disinfected and the protective sheath can be changed quickly. You'd need only one upper and one lower scope in each procedure room instead of the three instruments many GI facilities employ to maintain case momentum. This product looks like it'll be cost-effective and a worthwhile option.