Principles_and_Techniques_of_Nerve_Repair_and_Reconstruction_AGP.pptx

Principles_and_Techniques_of_Nerve_Repair_and_Reconstruction_

1. Principles and Techniques of Nerve Repair and Reconstruction Dr. Akshai George Paul

2. Contents Repair of Nerve in a total/Partial transection Repair of a nerve in a delayed setting Management of Neuroma in continuity Management of Nerve gap

3. Basic requirements Good anesthesia Good illumination Good magnification with loupe or microscope Generous operative field Good hemostasis

4. PRIMARY NERVE REPAIR Exposure :Liberal incision over the proximal and distal course of the nerve. Identification and Dissection: Then identify and dissect both the proximal and distal ends of injured nerves. Observation :Determine whether there is a complete or partial transection of the nerve.

5. Evaluation : Ensuring the ends of nerve are good ,evaluate the injured fascicles and trim the fascicles until there is bright red bleeding from both ends of the nerve.Assess the distance between two ends only now!! It can be no gap, slight gap(1 – 2 cm) and more gap (>2cm)

6. NO GAP If the ends of nerve come together easily Nerve ends can be brought together with no tension, with full range of movements Usually possible only in clean, sharp lacerations treated shortly after injury.

7. P rimary suture when the operation is performed within 5 days of injury D elayed primary suture when up to 3 weeks has passed. Some resection, of a millimeter or so, of the nerve stump is always necessary after a few days, even in cases of clean sectioning with a knife or razor. S econdary suture is used for repairs performed 3 weeks or longer after injury, and it involves resection of neuroma proximally and glioma distally.

8. SLIGHT GAP (1-2CM) Gentle mobilisations of injured nerve ends to shorten the gap Manipulating the distal and proximal joints can be done Course of nerve can be shortened ( Ulnar nerve transposition)

9. MORE GAP ( >2CM) Treated as nerve gap

10. TECHNIQUES OF PRIMARY NERVE REPAIR Suturing techniques Sutureless technique

11. SUTURING TECHNIQUE Epineural repair Epineural sleeve repair Group fascicular repair Fascicular repair

12. NERVE REPAIR IN DELAYED SETTING More than 3 weeks Amount of dissection will be more because of scarring Proximal neuroma and distal glioma will be present There will be gap between nerve ends after preparation

13. PREPARATION OF NERVE BED The repaired nerve must not be left to lie against a naked tendon, synovium must be drawn together The repaired nerve must not be left to lie against a lacerated muscle belly

14. SUTURELESS REPAIR DEVICES Fibrin Cyanoacrylate Laser tissue welding Albumin solder laser welding Photochemical tissue bonding

15. MANAGEMENT OF NERVE GAP Nerve autograft Nerve allograft Nerve conduits End to side transfer Distal nerve transfer / vascularised nerve transfer

16. A) NERVE AUTOGRAFT Specialised nerve conduit containing Schwann cells Indications : Direct repair is not possible Advantages : Gold standard , Schwann cells and extracellular matrix Disadvantages : Donor site morbidity, Limited availability We must reverse the nerve while grafting – There is no loss of axons into the branches of the nerve

17. B) NERVE ALLOGRAFT Donor related or cadaveric allograft Contain both viable donor Schwann cells and endoneurial microstructure Requires systemic immunosuppression Clinical protocol : ABO matching, small diameter donor graft, cold preservation Advanatges : Functional recovery equal to autograft, no donor site morbidity Disadvantages : Requires systemic immunosuppression, opportunistic infections

18. C) NERVE CONDUIT Proximal and distal nerve segments are enclosed in ends of the conduits ( tubes) Axons regenerating from growth cone sprout towards the distal stem, proceeding within the original path avoiding misdirection problems The conduits also precludes the entrance of the surrounding tissues into the gap

19. BIOLOGIC Superficial veins, <30 mm SYNTHETIC – Non degradeable or degradeable - Sialastic or polyvinyl alcohol - Polyglycolic acid, Caprolactone, Collagen

20. D) END TO SIDE REPAIR Advantages : No length limitation Disadvantages : Poor sensory results, Motor require donor neurectomy Coaptation of distal stump of transected nerve to side of an intact nerve Involves creation of an epineural window on the donor nerve

21. E) NERVE TRANSFER T ransferring an uninjured nerve to the distal stump of an injured nerve Proximal nerve transfers – Brachial plexus Distal nerve transfers – Radial, Median, Ulnar nerve palsies

22. Hara, Nagano, and their colleagues refined intercostal nerve transfer for the treatment of avulsion injuries of the brachial plexus and achieved very good results Oberlin and colleagues’ operation has been successful in our hands in more than 70% of cases.The spinal accessory nerve is a very powerful motor when transferred without an interposed graft to the suprascapular nerve. Gu and coworkers have used the contralateral seventh cervical nerve to reinnervate the limb after complete avulsion of the brachial plexus.

23. Direct Muscular Neurotization This is useful for lesions of the axillary or musculocutaneous nerves in which the nerve has been avulsed directly from the muscle, or if the distal stump of the nerve is wrecked. The proximal stump is prepared in the usual way and two lengths of graft, usually from the medial cutaneous nerve of the forearm,are united to the proximal stump and then implanted into the muscle through short incisions in its epimysium. About 10 portals of entry are fashioned to implant the terminal branches of the graft. These may be sutured or secured with fibrin clot glue