How are the ends prevented from rejoining?
After the vas is divided, the lower end is allowed to slide back down into the sheath, while the upper end is held outside the sheath. A tiny hemoclip (the size of a grain of rice) is then used to close the empty portion of the sheath between the 2 ends. It would be like making a lengthwise opening in a wire’s insulation, reaching in and dividing the wire, lifting one cut end out through the insulation, then putting a clip on the empty portion of the insulation, thereby holding one end outside and one end inside, the insulation itself serving as a barrier between the two ends. Most hemoclips are made of titanium, a non-ferromagnetic metal used for many types of implanted medical devices such as dental implants, heart valves, and joint replacement.
