A device and method in accordance with the invention for generating a signal indicative of a property of a subject tissue in contact with the working surface of a surgical instrument. The invention describes a sensing adjunct to surgical staplers. The adjunct can take the form of an optionally coupled accessory to a surgical stapler, or a stand-alone substitutive component acting to serve as a replacement for a component of the surgical stapler such as an anvil, housing or cartridge. Embodiments include a sensing anvil serving to act in place of a non-sensing surgical stapler anvil to monitor tissue properties of an anastomosis for the purpose of avoiding anastomotic failure.