Features

Growing obesity rates, aging populations, poor diets, and other factors have fueled a tremendous increase in the number of patients seeking gastrointestinal treatments and caused greater demand for both diagnostic and interventional endoscopic procedures.

Fig. 1 – The strength and pliability of Dyneema Purity® fiber provides the high-tension forces required to apply the superelastic Nitinol clips in an over-the-scope-clip endoscopic clipping system.
Endoscopic procedures, however, are highly complex and have the potential to introduce significant medical complications. For example, one complication known to occur as a result of snare resection or biopsy of gastrointestinal tissues is iatrogenic lesions of gastrointestinal organs, and can involve deep injury or perforation to the GI wall. Snare resections have also been known to induce hemorrhage in the GI tract — which can be a critical condition for patients.

Growing Patient Demand

As demand for both diagnostic and interventional endoscopic procedures grows, so too does the need for sophisticated new technologies and techniques that have the ability to mitigate the risks associated with traditional endoscopic practices and the potential to improve patient outcomes across a range of procedures.

In December 2010, Ovesco Endoscopy USA (Campbell, CA), a subsidiary of Germany’s Ovesco AG, announced FDA approval of its over-the-scope-clip endoscopic clipping system (OTSC®), for the treatment of gastrointestinal hemorrhage and for endoscopic digestive organ wall closure. The OTSC system® represents a new class of endoscopic clips that provide significantly more strength and better tissue capture compared to conventional clips delivered through the working channel of the flexible endoscope.

The increased strength is produced through the unique design of the OTSC system, which includes a medical-grade UHMWPE fiber, Dyneema Purity®, developed by DSM; the OTSC clip; and the OTSC applicator mechanism with respective accessories and specific OTSC application aids.

At the core of the system is the OTSC clip, a superelastic Nitinol device for compression and approximation of tissues in the human digestive tract. The OTSC clip is delivered by means of an applicator cap mounted to the tip of gastroscopes or colonoscopes. Different sizes are available for different scopes. The clip is preinstalled on the cap and is released at the target site by means of a Dyneema Purity® thread connected to the hand wheel at the handle of the scope and pulled under high tension to release the clip on the target tissue. The strength and pliability of the fiber provides the high tension forces required to apply the superelastic Nitinol clips. The fiber won’t stretch under tension, allowing for the low elongation of the fiber that provides the surgeon with optimal control of the release mechanism.

In this unique design, the clip closes itself and firmly anchors the tissue to be compressed for hemorrhage or closure of a GI organ wall lesion. The fiber can be used as a raw material for applications inside the human body, during surgery, or over the lifespan of an implant. Fifteen times stronger than cable steel, it is also soft and highly pliable, and its near-zero stretch enhances fixation in orthopedic applications, such as knee and shoulder arthroscopy. The fiber’s resistance to fatigue and abrasion is advantageous in cardiovascular applications that require thin structures, lowering the risk of complications due to internal or external stressors. The fiber has been through extensive biocompatibility and hemocompatibility testing and is backed by a Master File on record with the FDA.

Clinical Kudos

Fig. 2 – The OTSC® clip is a superelastic Nitinol device for compression and approximation of tissues in the human digestive tract.
The OTSC is available in three different versions, an a version with blunt teeth for tissue compression, a t version with pointed teeth featuring increased anchoring capabilities, and a gc version with longer pointed teeth for gastric closure.

Positive clinical results, as well as the system’s ease of use, have contributed to its success. In terms of clinical results, the March issue of the journal Endoscopy, R. Manta et al., report about a case series of 12 consecutive patients treated with OTSC for closure of post-surgical gastrointestinal fistula in a tertiary referral center (S. Agostino Estense Hospital, Modena, Italy). Researchers found that fistula closure with OTSC clipping was successful in 11 out of 12 cases. Healing was confirmed by radiographic control or endoscopy. No device-related complications occurred.

The authors conclude that OTSC clipping is an effective and technically simple technique for the closure of wall defects. (For additional clinical results, please visit the publication section of the Ovesco Web site at www.ovesco.com).

Surgeons report that the system is intuitive, easy to use, and similar to other devices based on the application cap principle. It is compatible with all commercially available endoscopes. A variety of different sizes and types is available.

Through partnerships like that between Ovesco and DSM, medical device companies are increasingly able to meet the growing demand of innovative new endoscopic technologies that provide superior therapeutic effectiveness and to allow endoscopists to deal with complex conditions in the digestive tract or gastrointestinal organs.

This article was written by Carina Snijder, Business Manager Dyneema Purity® of DSM (Geleen, the Netherlands) and Gunnar Anhoeck, R&D Manager of Ovesco Endoscopy AG (Tubingen, Germany). For more information, visit http://info.hotims.com/34456-161.