Pilot study of a device for measuring instrument forces during endoscopic sinus surgery.

ESS is a form of minimal access surgery that includes different tasks and manoeuvres requiring sophisticated psychomotor coordination with varying levels of force application. The avoidance of complications is partially dependent upon reducing surgical force application when operating against vital barriers such as the skull base and the medial orbital wall. The study of the surgical forces in endoscopic sinus surgery offers the potential for surgeons to identify the appropriate application of the instrument forces and torques necessary to conduct safe surgery. We have developed Sinoforce, a sinus surgery force-measuring instrument, which comprises modified Blakesley forceps fitted with specialized force sensors The instrument produces a real-time visual display of the various forces applied by the surgeon to the forceps during endoscopic ethmoidectomy. A pilot study was conducted using four cadaveric head specimens. We measured the force needed to break through the different parts of the ethmoidal bony labyrinth and skull base. Comparable forces were needed to break through the ethmoidal bulla and uncinate process. However, a force of > 2 kg, exceeding the forceps calibration, was needed to break through the different parts of the skull base. In this article we describe the new forceps, present our preliminary results and explore the potential benefits of this new instrument.