User:Jgore3/sandbox

‘’’Thesis’’’: What is epinuerial nerve repair and how does it differ from other nerve repair procedures

Description
Repair to the epineurium, the connective tissue surrounding nerve fibers originating from the spinal cord, is intended to allow the restoration of sensory function. When a nerve is cut, repair is done by sewing the cut ends together to increase the potential proximal part growing correctly, along the route the degrading distal part leaves behind. Usual sensation and mobility will not be an immediate result because nerves grow at a rate of 1 mm/day so it will take a few months to notice the final outcome.

When do you need it?
More severe nerve injury like axonotmesis or neurotmesis warrant the repair of the epineurium because the connective tissue is damaged. A typical indications for surgery is if the patient who presented with a laceration and no conduction along the axon, signal transmitted across the nerve, does not recover within a week.

Procedure
Note: Avoid tension on the repair. Note: If you bend the body part in any position to bring the nerve ends together, the patient should be instructed to maintain this position for 10–14 days in order not to disrupt the repair.
 * 1) Trim the nerve to healthy parts of the bundle in order to minimize scarring.
 * 2) Free nerve from surrounding soft tissues to avoid tension or change position to allow ends to meet more easily.
 * 3) Place the needle through the epineurium to the lateral side and a little of the subepineurial neural structure.
 * 4) Repeat on the other side 180 degrees from the first suture.
 * 5) Simultaneously tie the knots in surgeon's knots  by the assistant and surgeon in surgeon's knots.
 * 6) Place sutures halfway between each lateral suture in between. Note: Depending on the size of the nerves the amount of sutures needed could range from 2 to as many as is needed to get a smooth repair.
 * 7) Repeat suturing between that suture and the lateral suture.
 * 8) Reverse the position of the lateral sutures to expose the opposite side and suture the same way.

Nerves applied to
Any nerve epineurium

Perineurial
This is the repair of the individual fascicles and placing sutures through the perineurium. Trauma to the nerve by cutting out each fascicle and fibrosis that develops due to the dissections and number of sutures is a problem.

Group Funicular
Involves suturing group fascicles in the intraneural epineurium to line up the groups of fascicles. This is only applicable when fascicles are grouped.

Interviewee’s opinion

 * 1.	Advantages
 * Regain motor function
 * Using glue instead of not all sutures reduces scarring
 * Allows for repair of different sized fascicles
 * Allows for repair of non grouped fascicles
 * 2.	Disadvantages
 * Cannot guarantee results
 * The larger the gap, the less likelihood of recovery
 * Takes too long for regeneration

Research results of comparisons
In acute nerve laceration in cats, epineurial repair was shown to be as good as perineurial repair by evaluating the ambulation pattern, fanning of claws and sensation. The objective measures where efficiency, absolute strength and weight of the flexor carpi ulnaris muscle. The anterior tibial nerves of dogs were cut to determine which of fascicular, interfascicular and epineural suture techniques were best. There was not a significant difference between the results of fascicular and eipneural, but a significant difference between the two and interfascicular. In a study of 18 children with a 2:1 ratio of male to female, the children showed a recovery of motor and sensory functions assessed by the Bruininks-Oseretsky test.

Growth Factors
Current research involves the use of neurotrophic factors such as N-acetylmuramyl-L-alanyl-D-isoglutamine (MDP) to aide in the nerve regeneration. Assessments using a grasp test were performed weekly for 12 weeks in order to know functional recovery of the flexor muscle in fingers along with median nerve regeneration. The results showed that MDP with fibrin tissue adhesive (FTA) and epineurial sutures were the best performing group among the sutures along and sutures combined with FTA.

Stem Cells
Cell therapy to improve nerve regeneration is also being researched. In one study mononuclear cells were used to repair the sciatic nerve followed by epineurial repair. Wistar rats were divided into groups of a control, epineurial sutures, medium after suture and injection of 10 microliters of medium into the nerve to allow for growth of cells still there, and mononuclear cells combined with medium after in the epineurium region. Results of sciatic functional index, histological and morphometric analyzes showed that the mononuclear group was the best.

Artificial Nerve Grafts
Alloplastic nerve graft research is being conducted for nerve repair. Silicone has been used previously, but long-term use of tubes produces compression and decreased conduction requiring surgery to remove the tube. Polyglocolic acid conduits, a bioabsorbable substance used for dissolvable sutures, reduces the problems associated with Silicone combined with the elimination of problems associated with nerve grafts taken from donors show promise. In a study on nerve repair comparing nerve grafts and polyglocolic acid materials, there was no statistical differences, but 2-point discrimination showed that the conduit group was better eliminating donor-site morbidity.