For surgical residents presentation

1. By
Dr Olofin K E
Registrar
Dept of Surgery
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2. Introduction
Anatomy of the nerve
Nerve injuries
Classification of nerve injuries
Clinical features
Investigations
Treatment
Techniques of nerve repair
Follow up
Complications
Prognosis
Conclusion
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3. Paulus Aegineta: 1ST to repair nerve in 17th century
others Rhazes, Evicenna
Repair was not attempted again until mid 19th
century
Nerves were thought not to regenerate or may cause
convulsion
Techniques refined following world war 1
Seddon & Woodhall further defined several methods
of repair during world war 2
Nerve repair was refined by Millesi with the
introduction of the operating microscope and
nerve improved staining technique.
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4.  The term “Nerve” is often used erroneously to
describe what in fact is a bundle of nerve fibers.
 The actual nerve fiber or axon is an anatomic
process of a single nerve cell.
 Nerve fiber is the functional component of
peripheral nerve responsible for transmitting
stimuli.
 The Axon is an extension of a neuron and can be
characterized by morphology, conduction velocity
and function
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5.  FIGURE 1. Schematic drawing of a peripheral
nerve.
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FIGURE 1. Schematic drawing of a peripheral nerve.

6. Nerve
 Nerves are solid white cords made up of bundles
of axons. Each nerve fibre is known as an axon
and each axon is bound together by fibrous tissue
into small bundles.
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7. Axon
 An axon is a direct extension of a cell body. The
most important component of the peripheral nerve
is the nerve fibre that transmits the stimuli.
 All other components of the nerve simply provide
the optimal conditions for the nerve fibre to
function.
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8. Nerve morphology
 The nerve trunk is
composed of four
connective tissue
sheath. They are as
follows from outside
inward,
◦ Mesoneurium
◦ Epineurium
◦ Perineurium
◦ Endoneurium
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9. Mesoneurium
 Is a connective tissue sheath that suspends the
nerve trunk within the soft tissue, contains the
segmental blood supply of the nerve and is
continuous with the second layer – the epineurium.
Epineurium
 Is the loose connective tissue sheath that defines
the nerve trunk and protects it against mechanical
stress.
 Composed of longitudinally oriented collagen fibres
that resist both compressive forces and stretch.
Nerve trunks are fairly mobile except where
branches and blood vessels enter the epineural
sheath.
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10. Perineurium
•It delineates the fascicles. In a living nerve, it is
a white glistening layer devoid of blood vessels.
•This is a continuation of the pia-arachnoid
mater of the central nervous system.
•It is composed of two layers
•Blood vessels transverse the perineurium to
connect the vasa nervosum and endoneurial
capillaries.
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11. Endoneurium
•It surrounds the individual nerve fibre and their
schwann cells.
•Endoneurium and perineurium together give
elasticity to the nerve.
•Endoneurium is composed of two layers
•The capillaries of the endoneurial space are
connected to vasa nervosum through the
perineurium.
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12.  Each individual nerve fibre and their Schwann
cell are surrounded by endoneurium.
 Group of nerve fibres – fasciculi
 Each fasciculi is surrounded by perineurium
 Group of fasciculi forms a nerve trunk
 Fascicules are surrounded by epineurium.
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13. Etiology of peripheral nerve injuries
• Metabolic or collagen diseases.
• Malignancies.
• Endogenous or exogenous toxins.
• Thermal, mechanical or chemical injuries.
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14. • Mechanical injuries to peripheral nerves are most
common.
• Among this lacerating wounds resulting from road
traffic accidents, interpersonal violence including
stabs, war injuries such as bullet injuries are more
common.
• Iatrogenic nerve injuries are very common in
maxillofacial region.
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15.  Seddon (1943) classification
 Sunderland classification
 Physiologic conduction block symptomatic
classification
 Anatomic classification
 Histopathologic classification
 Pathophysiologic classification
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22. Always test for nerve injuries following any
significant trauma.
 numbness,
 paraesthesia
 abnormal posture (e.g. a wrist drop in radial
nerve palsy),
 weakness in specific muscle groups and
changes in sensibility.
 Dry skin
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23. • Smooth and shiny
• Evidence of diminished sensibility such as
cigarette burns of the thumb in median nerve
palsy or foot ulcers with sciatic nerve palsy
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24. Diagnostic Tests/Assessment Of Nerve Recovery
History
• Nerve conduction studies ( NCS )
• Electromyography ( EMG )
 They demonstrate fibrillations and denervation
potential in a completely denervated muscle
 They help find the presence, location, and extent
of damage done to the nerves and muscles.
 They distinguish neuropraxia from neurotmesis.
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25.  A nerve conduction study
(NCS)— also called a
nerve conduction velocity
(NCV) test.
 measures how fast an
electrical impulse moves
through the nerve using
percutaneous current to
stimulate the nerve
 NCV can identify nerve
damage.
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26. Electromyography (
EMG )
• A resting muscle is
normally electrically
silent
• Records the
depolarization
potential of active
muscle movement
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27. • Muscle distal to injury may appear normal for
several days after injury(14 to 21 days) ,hence in
root avulsion the result is not reliable until after 3
wks when Wallerian degeneration in the post-
ganlionic lesion will block the nerve conduction.
• Best time for EMG is 3 to 4 wks post injury
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28.  Tinel test:
◦ peripheral tingling or dysaesthesia provoked by
percussing the nerve – is important.
◦ In a neurapraxia, it is negative.
◦ In axonotmesis, it is positive at the site of injury
because of sensitivity of the regenerating axon
sprouts.
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29.  Assessment of nerve function
◦ Two-point discrimination
◦ Threshood test
◦ Locognosia
◦ Moberg pick-up test
◦ Motor power
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30.  Short inversion recovery MRI
 A unique form of MRI that returns
pictures that can highlight nerve trauma.
 Not as sensitive as NCS
Indications
1. Px wt non classic or ambiguous findings
e.g Dm
2. To visualize neuromas
3. To determine the length of damaged nerve
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31.  MRI: shows ganglion, lipoma or bone spurs
in osseofibrous tunnel
 CT myelography :
◦ Pseudomenigocele in brachial plexus inj.
◦ May show leakage of contrast medium
 Doppler study: A- V fistular or aneurism
may cause nerve compression
 X-ray: fracture or dislocation, may show
bone fragment in soft tissue
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32.  Intradermal inj of histamine:
◦ If flare persists in an anaesthetic skin, suspect root
avulsion
 Williams test; if immersed in water at 40
deg, normally innervated skin wrinkles
witthin 4 mins
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33.  E/U/CR+ URIC ACID
 SER ALB;>2.5mg/dl
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34. Choice of treatment depend on complete
patient assessment.
Treatment options includes
 Non-operative
 Operative
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35. Non-operative.
When awaiting for spontaneous recovery in
a close low energy injury
While waiting
 Wound care
 Physiotherapy
 Dynamic splint
 Opt for operative rx if no spontaneous
response in 3 mths
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36. Associated injuries should be managed before nerve
is repaired
Nerve must be handled gently
Operating microscope is ideal for nerve repair
Nerve exploration indications
• If nerve is seen to be divided and needs to be
repaired
• If type of injury (e.g. a knife wound or a high
energy injury) suggests that the nerve has been
divided or severely damaged
• If recovery is inappropriately delayed and the
diagnosis is in doubt.
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37. Primary repair
Divided nerve is best repaired ASAP
Prerequisites :
• Sharply incised nerve
• Minimal wound contamination
• No skeletal instability
• Patient is medically stable
• Facility is available
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38. Nerve is approximated end to end using 10/0
suture tension-free
Sufficient relaxation of soft tissue
Ensure homeostasis before closing the
wound.
Wound is splinted for 2-3 wks
Physiotherapy.
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39. Delayed repair
Indication;
• Close wound without sign of recovery after
3mths
• Diagnosis missed and patient present late
• Failed primary repair.
 Excision is done if the neuroma is hard and
there is no conduction on nerve stimulation.
 Stump sutured end to end tension-free
 Splint application for 4 to 6 wks
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40. Nerve grafting
 Free autogenous nerve grafts can be used
to bridge gaps too large for direct suture.
 The sural nerve is most commonly used; up
to 40 cm can be obtained from each leg.
 Graft is routed through a vascular bed.
 A vascularised graft is used in special
situation like Volkmann ischemic
contracture.
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41.  nerves require only one.
 FIGURE 6. Sural nerve that is being used as a
cable graft to reconstruct a 6-cm defect in
the median nerve. The distal end of the nerve
graft is attached to the proximal nerve
stump.
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nerves require only one.

42. Nerve conduits
 Prevents mechanical block
 Provides suitable environment in which
neurotropic hormones can operate.
 Maximum gap for conduit is 3cm
 The inner diameter should be 30% >nerve
Indications:
 Gap too big for end-to-end repair
 Desire to achieve improved functional
outcome
 To secure nerve ends pending definitive
repair.
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43. Options
 Silicone
 PGA
 ePTFE ,(expanded polytetrafluoroethylene)
 Amnion
 Veins
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45. Nerve transfer
• Scarifying less important function to restore
a function of greater significance
• Root avulsion of upper Brachial plexus too
proximal for direct repair e.g. Spinal
accessory nerve to suprascaular nerve,
intercostal nerve to musculocutaneous nerve
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46. 
Surg Can appx Vascular
bed
Prox end
intact
Distal
end
intact
End – end Yes Yes Yes Yes
Nerve
graft
No Yes Yes Yes
Vascular
graft
No No Yes Yes
Conduit No No Yes Yes
Nerve
transfer
No No No Yes
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47. Epineural repair
• Most commonly used
• End to end epineural repair done under
magnification with the nerve fascicles
aligned
• Use size 11 scalpel blade in trimming of
nerve ends
• Stitch pierces the epineurium
• Repair not under tension
• Repair should not violate the fascicles
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48.  FIGURE 4. Drawing of a suture that is being
placed in an epineurial end-to-end repair.
The first stitch should be placed to align the
corresponding anatomic landmarks, such as
longitudinal landmarks and easily visualized
fascicles.
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49. Fascicular repair
 Grouped fascicles are repaired in similar
manner to epineural repair
 9-0 or 10-0 suture used to pick the internal
epineurium
 Largest identifiable grp is repaired first.
 Indication for single fascicular repair are
limited; Incomplete transection
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50. Conduit repair
 Dissect nerve free of surrounding tissue for 5mm
 Measure the diameter of the nerve, if<2.2mm a PGA
conduit is use
 End of the nerve is brought into the conduit for
5mm
 Minimum gap btw nerve ends is 5mm to allow the
internal environment exert its neurotropic effect
 Conduit is sutured to the epineurium using 8/0
suture
 The tube is infiltrated wt 1000u of heparin
in100mls of n/saline
 Distal end of the nerve is now inserted into the tube
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52.  Splint in safe position for post op
physiotherapy
 Sensory re-education; patient learn to
interpret the pattern of abnormal stimulus in
a meaningful way.
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53.  Medically unstable patient from other injuries
and/or illnesses
 Presence of a grossly contaminated wound
bed
 Active soft tissue infection in the region of
the nerve injury
 Severely compromised nutrition
 Patient unable and/or unwilling to comply
with required activity restrictions
 Patient with unrealistic expectations
 Presence of underlying skeletal instability
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54. This depends on the following
 Type of lesion
• Neuropraxia always recover fully.
• Axonopmesis may or may not recover.
• Neuropmesis will not recover unless the nerve is
repair
 Level of lesion
• The higher the lesion ,the worst the prognosis.
 Type of nerve
• Pure motor or pure sensory nerve recover better.
 Size of gap
• With size greater than two 2cm,end to end suturing is
not successful
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55.  Age
• Children do better than adult,
 Delay
• Most important factor, best result is achieved with
early nerve repairs.
 Associated lesions
• damage to vessel, tendon may make recover of
useful function impossible.
 Importance of use of suitable facilities can
not be over emphasized
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57.  Nerve repair and grafting have benefited from the
development of microsurgical techniques and
advances in the neurosciences.
 State-of-the-art nerve repair requires not only
precision techniques but also additional measures
to direct nerve regeneration to its original function.
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58.  Although nerve grafting remains the
standard for reconstruction of the nerve
gap, synthetic conduits, allografts, and
nerve transfers now play a limited role in
the peripheral nerve surgeon's
armamentarium.
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59.  Apley’s System of Orthopaedics and Fractures
Ninth Edition
 GRABB AND SMITH'S PLASTIC SURGERY Seventh
Edition
 https://www.orthobullets.com/hand/6066/periphe
ral-nerves-injury-and-repair
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60. Thank you
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