Poster W5 - The Wolverine Tube: An Improved Gastroesophageal Balloon Tamponade

Introduction: Esophageal bleeding occurs in patients with ruptured esophageal varices, which is a common side effect of cirrhosis and is an often deadly scenario. Today’s current solution, the gastroesophageal balloon tamponade, involves the insertion of a dual balloon catheter down the esophagus and inflating the balloons to place pressure on the bleed. Current gastroesophageal balloon tamponades are outdated and it is a time-consuming and dangerous procedure that leaves a significant percentage of patients dead in the emergency room. This result can be attributed to various factors: supplies being scattered throughout the ER instead of being packaged together, the tube being difficult to insert due to flimsiness, difficulty finding the esophageal entrance, reliance on time-consuming X-rays for placement confirmation, indistinguishable ports, and lack of reliable securement methods. Hence, we propose the Wolverine Tube: an improved gastroesophageal balloon tamponade that addresses these issues. All relevant supplies for this procedure will ultimately be packaged into one box. Through conducting clinician interviews to identify key problems with the existing solutions and procedure, our team has researched, developed, and tested our design, ultimately hoping to improve patient outcomes.

Materials and

Methods: Prototype fabrication was in-house due to the steep costs and inaccessibility of injection molding, the only viable manufacturing method for our design. Our design consists of variously sized catheter tubing, 3D-printed visually and tactilely distinguishable ports, balloons sourced from an existing balloon tamponade (specifically, the latest model: the Minnesota Tube), a built-in securement appliance, and a mechanism to locate the esophageal entrance. Verification and validation testing was performed on a human airway mannequin and a SynDaver synthetic esophagus in a simulated hospital bedside setting to mimic emergency room conditions. The usefulness of the unique and novel aspects of our design, as well as the timing of the procedure, were tested by the mannequin. Test subjects consisted of ER physicians as well as biomedical engineering graduates. Each tester was directed to insert the device into the mannequin, as well as other aspects of the procedure we aimed to improve upon. They were recorded for time and were asked for feedback regarding their experience. The risk for rupture with the device was evaluated by having testers insert the device into the synthetic esophagus with varying degrees of force and subsequently inspecting the synthetic esophagus for any tears.

Results, Conclusions, and Discussions: Our design proved successful in our usability testing. While the Minnesota Tube takes over 15 minutes to insert, the Wolverine Tube takes under 2 minutes due to its stiffer catheter tubing. In addition, it did not puncture or tear our esophageal simulators during insertion. Securement testing, indistinguishable ports, and difficulty finding the esophageal entrance have all been addressed, resulting in faster procedure time and increased efficiency. So far, it has garnered the support of six stakeholders: five ER (emergency room) physicians and one ER nurse. However, we need to pursue further manufacturing and clinical testing. We would ideally invest in injection molds for our future iterations, complete with balloons. Further testing will be done with more ER physicians and nurses on higher fidelity testbeds consisting of porcine or human cadaver esophagi. We also plan to test the device in conjunction with other medical devices (e.g. an endotracheal tube or laryngoscope). The ultimate goal is to pursue a patent to retain device innovation and intellectual property, as well as seek additional funding for more specialized fabrication methods.

Acknowledgements (Optional): Thank you to our clients Drs. Ashley Cohen, Mitchell Hooyer, and Jordan Sell from Michigan Medicine's Emergency Department for your clinical expertise and support, as well as Dr. Malie Kopplin for being our primary end-user for testing. We would also like to thank Drs. Rachael Schmedlen, John Gosbee, Stephanie Sheffield, and DeAndre Jamison from the University of Michigan Biomedical Engineering Department.