Concept for a retractor with force indicator for reduction of tissue trauma in abdominal surgery

Abstract

Retractors are used in surgery for the displacement of tissue and organs and to keep the surgical area open. The retraction can lead to a tissue compression that can cause irritation on nerves, perfusion deficits, hematoma or late sequelae like wound healing disorders, pain and numbness. The retraction force and thus the load on the tissue can not be measured with retraction systems today. We present a new concept for a retractor with an integrated spring element and an indicator to visualize retraction force and allow an adjustment of the organ compression. The new retractor was designed considering organ compression limits, requirements on sterility and easy manufacturing. Two retractors were built up as a prototype by 3D printing and tested in a distinguished test setup. The first test of the retractors was performed on a force measurement test bench using a fixed retractor, and in a second test, a liver specimen in a bowl. Tests were repeated for both retractor variants. The tests showed how different spring characteristics could be realized with the new retractor design. Depending on the spring characteristics, the compression could be limited to a certain level and flexibility that can compensate for unwanted patient motion. An indicator is integrated into the design showing the applied load on the retraction system. The presented concept can help to increase patient safety and reduce tissue trauma and late sequelae. The indicator is an easy way to visualize applied forces and allow adaption of the setup to the surgeon's needs.

Keywords

• surgery
• retractor
• spring
• organ damage
• trauma
• soft tissue