There was a set made in the U.S. with what they called a Horse-hair Retractor. It was a metal tube with a horse hair loop that could be pulled tight from the top of the tube, and then manipulated to work as a saw. Low tech, but same tool. Horse hair is strong, flexible, and has a rough enough surface to cut through the membrane holding the testicle in place. The operator pulls the horse hair ends individually after the loop is around the testicle, which cuts through the membrane releasing the testicle. The pulling of the horse hair, first left, then right, then left... works like the Chinese wire tool.
With the tool above, you'd need a spoon under the testicle to keep it from disappearing into the intestines. The problem I see with this type of tool is the stress on the surrounding tissue. Instead of just cutting, you'll be pulling and tearing once you've worked the loop around the testicle. The testicle will be smashed against the end of the tool as the wire is pulled tight. If anyone makes/uses this type of retractor, I'd be interested to know if the testicle becomes torn as part of it gets pulled against the end of the metal tube.