The Tumor: A Simulator for Open Surgery

Abstract

Few simulation tools for practicing open surgical skills have been developed. We have built and tested a device that allows a learner to practice careful dissection, hemostasis, tying off blood vessels with suture in deep locations, and control of massive hemorrhage. The device is inexpensive, applicable to a wide range of surgical specialties, and can produce robust measurement of skills. The Tumor is a device that represents a generic vascularized growth in a non-specific tissue medium. It is constructed of readily available materials and can be discarded after each use. The tumor model is constructed from a pluot (a cross between a plum and an apricot, approximately 5 cm in diameter) that has been pitted, frozen and thawed. Gelatin tinted with food coloring in a plastic food bowl represents the surrounding tissue. The pluot is imbedded in the gelatin so that 25% of the fruit is exposed. Four lengths of Silastic rubber (1.47 mm ID, 1.96 mm ID) tubing are threaded through the pluot to represent blood vessels. A fifth length of tubing of greater diameter is located under the core of the pluot to enable simulation of massive hemorrhage. Solenoid valves are used to control the pulsatile flow of red fluid from a pressure bag through the rubber blood vessels. The model must be refrigerated prior to use, but remains stable for approximately two hours at room temperature. Surgical exposure can be adjusted by cutting a hole in the cover of the food bowl to a desired size. At any time, the controller can produce bleeding from one of the minor or from the major blood vessel via the solenoid valves. A learner is instructed to resect the tumor carefully using a limited set of basic surgical instruments so that the margin is maintained with as little damage to the tumor body and surrounding tissue as possible. The tumor is described as vascular, friable, and that bleeding may occur as it is manipulated. Blood vessels must be cut and tied with 3–0 silk sutures to keep blood loss to a minimum. We have used the tumor model to engage surgeons during simulations centered on team training as a means to more closely replicate surgical tasks in the actual operating room. The nature of the model requires coordination with assistants and scrub nurses and also makes their jobs during simulation more realistic. The ability to create massive hemorrhage also allows for the creation of simulation scenarios based on the surgical field itself, a departure from scenarios that are often anesthesia based. We hope to expand the use of the model in the future as a training device and possibly as a measure of surgical skill and judgment after validation studies to correlate surgical experience with technical performance on the model. Conflict of Interest: Authors indicated they have nothing to disclose.