Attaching nerves is trickiest part of surgery

FIRST Mark Cahill with new hand in 2012 ARM transplant surgery can take as long as 12 hours and is followed by months of intensive rehabilitation.

The hardest element is attaching the donor’s nerves to the recipient without the body rejecting them.

The highly skilled surgery requires an incredible amount of planning. The bones are attached first with titanium plates. Tendons and muscles are reconnected, then the blood vessels.

Major nerves are reattached, and the large and small veins connected. With blood circulating in the remaining muscles, tendons and nerves are reconnected and the skin stitched closed.

The hand alone has 27 bones, 28 muscles, two major arteries, three major nerves, tendons, veins and soft tissue.

The limb should regain nerve signals within three to 18 months. However, results are never guaranteed.

The first person in the UK to have a hand transplant was Mark Cahill, of Halifax, West Yorks, at Leeds General Infirmary in December 2012.