Neil A Ray, BS, Dillon Kwiat, BS, Stanley J Rogers, MD, Matthew Y Lin, MD. UCSF Department of Surgery
Surgical endoscopy has gained expertise and popularity over the past several decades and is a viable option for minimally invasive removal of benign and early malignant lesions in the gastrointestinal tract. Surgical endoscopy utilizes natural orifice access which shortens hospital stay, minimizes patient discomfort, and decreases overall healthcare costs. However, the inability to effectively retract and position target tissue is a significant limitation of these procedures. Endoscopic “biopsy” working channels, ranging from 2.8mm to 6.0mm in diameter, are the surgeon’s only access for intervention, and dual channel endoscopes allow two instruments to be used simultaneously. Current instruments are unable to triangulate and can only be manually withdrawn or advanced through the channels. As a result, the surgeon must manipulate the endoscope itself to create an appropriate dissection plane, often obscuring visualization of the plane in the process. There is a tangible need to provide better access and control of soft tissue to be able to perform more complex and complete endoscopic resections.
We have developed a three-dimensional (3D)-printed prototype of a novel retractor to provide optimal tissue retraction for endoscopic procedures. Our device consists of an articulating tissue retractor and a specialized handle that allows for single-hand operation. We created two “joints” that can manipulate the position and direction of the retractor tip by attaching wires to two different articulation points on the retractor (see Figure). Each joint is independently adjusted by locking thumb sliders on an intuitively designed handle, allowing for increased range of motion and retraction independent of endoscope position. With a diameter of 2.8mm, the proposed device can be used in standard endoscopic channels. Increased control of tissue manipulation significantly improves visualization and allows for triangulation. It will expedite simple procedures and make complex cases amenable to endoscopic surgery.
We are currently in the design stage of our device and are collaborating with UCSF surgeons to finalize the prototype. A 3D printer is utilized for mass production and injection molding will be used to make the final prototype device. There are no preliminary results at this time. We will conduct a head-to-head comparative trial with current techniques using porcine and cadaveric models to evaluate the device’s ability to safely and effectively resect lesions in the gastrointestinal tract. Several lesions will be created in the esophagus using electrocautery and then resected using currently available retractors and our novel instrument. Factors such as operative time and margin adequacy will be assessed for both techniques.
Surgical endoscopy has considerable popularity but remains limited in complexity by insufficient retraction and limited visualization. With our device, tissue can be retracted in multiple planes independent of endoscope position, allowing for complete visualization of the dissection plane. In addition, our device will be disposable and have minimal moving components, ensuring sterility. The number and complexity of endoscopic procedures will likely increase as a result of our device. A grasper that can better triangulate and preserve visualization of the dissection plane will overcome the most significant barrier restricting endoscopic surgery.