stat of the art of different methods for peripheral nerve repair

2.  Neural cell
 Neural axon [Myelinated-Unmyelinated]
 Dendrites.
 Receptors.
 Motor end plates.
Structure of the nerves.

3. 1-Mechanical.
2-Thermal.
3-Chemical.
Types of nerve injury:

4.  Traumatic neuroma formation.
 Wallerian degeneration.
 Regeneration.
[Spontaneous-With medications].
Fate of nerve injury:

5.  Age.
 Nature of injury.
 Size of the gap between nerve stumps.
 Time lapse from injury.
 Type of nerve [sensory-Motor].
 Size of the nerve [thin-thick].
 Medications.
Factors affecting nerve regeneration:

8. Perineurial repairEpineurial repair

9. • Axons can’t regenerate in the absence of schwann cells.
• Proper apposition of nerve endings.
• No clot or debris is allowed to interpose between the coapted nerve
stumps.
• Avoid tension during anastomosis.
• Avoid angular or beveled cuts.
• Avoid handling or grasping the nerve with instruments.
• Avoid use of electrosurgery near the nerve stumps.
• Control of excessive swelling, hematoma, or edema.
• Delayed repair.
• Large numbers of sutures.
• Deep nerve location
• Small sized nerves.
Factors affecting prognosis of surgical nerve repair

12. Indication for nerve grafting:
• To avoid tension during anastomosis [large defect].
• In case of absence of schwann cells [unmyelinated
nerves].
• To avoid clot or debris to interpose between the
coapted nerve stumps.
• Delayed repair.

13. Most common nerves used in grafting:
 Superficial radial nerve.
 Medial cutaneous nerve.
 Lateral cutaneous nerve of the thigh.
 Sural nerve.
 Greater auricular nerve.

14. Problems[disadvantages] in nerve grafting:
• Donor site morbidity.
• More traumatic than nerve suturing [ 2 sides suturing + More
number of sutures.
• Synkinesis.
• Poor neovascularisation of the graft.
• Loss of function in the donor site.

15. The results of nerve grafting ranged
from satisfactory to poor. It considered
the alternative that exist for handling
large nerve defects.

17. Technique of nerve entubation guided repair
Proximal stump Distal stumpTube

18. Types of tubes used as nerve conduits
 Acrylic
 Silicone
 Silicone Mesh.
 Vein
 Polylactic acid.
 Polyglycolic acid.
 PTFE
 ePTFE [GoreTex].

19. Disadvantages of nerve conduits
Impermeable tubes prevents supply of oxygen and nutrients to
regenerated nerve.[acrylic-Silicone-PTFE]
Antigen antibody reaction increases inflammation and fibrous tissue
formation around the tube.[Meshed silicone]
Rigid or semi rigid tubes mechanically destruct the regenerated
nerve.[acrylic-silicone]
Natural tubes required donor site morbidity or enhanced necrosis and
phagocytosis.[Vein]
Resorpable tubes favors inflammation and fibrosis.[polyglycolic]
Motor nerve regeneration Requires muscle rehabilitation protocol

20. Advantages of nerve guided entubation repair
 Protection of the newly generated nerve stump.
 Healing of nerve gap without grafting procedure.
 Act as guidance of axons [proper orientation] without
synkinesis.
 Ingrowth of fibroblasts is prohibited.
 Factors favoring neural regeneration are
concentrated in the healing region.
 Help for administration of neural growth elements.
 Decrease number of sutures and excessive
manipulation of the nerve endings.