Damaged peripheral nerves are usually surgically repaired in an attempt to optimize recovery. The patient is stabilized and other potential life-threatening problems are managed. The wound area is thoroughly cleaned and devitalized tissue debrided, and any vascular injuries repaired. The nerve ends are trimmed, and if possible, sutured together using fine sutures using standard microsurgical techniques, provided there is no tension. There is often a gap between the ends of a damaged nerve, because of loss of nerve substance by the injury or resection of tumour, as well as retraction of the stumps because of the inherent elasticity of nerves. In certain circumstances, the nerve stumps may be mobilized to gain extra length, or sutured to other neighbouring nerves (see end-to side repair), but generally, a conduit is required to bridge the gap. Various different conduits have been used to bridge this gap in an attempt to allow axons to regenerate across the gap to the distal nerve stump, align and enter the endoneurial tubes of the distal stump, elongate down these tubes, and finally assume a connection with the end-organs (e.g. motor end-plates, sensory receptors, etc.) of their previous peripheral targets.