P E R I P H E R A L NERVE INJURIES: microsurgical repair with interfascicular autografts

J. J. R. Dreissen, M.D.*

"Special papers held at the combined meeting of the Netherlands Soci6ty of Neurosurgeons and the Soci6dad Luso Espagnola de Neurochirurgia.'"

SUMMARY

The technique of microsurgical interfascicular autografting and the arguments on which it is based are discussed. The advantages in comparison to conventional suture are pointed out. Preliminary results of 17 cases of nerve injury are presented from which can be concluded that nerve injuries treated by this technique show very promising recovery.

As far back as 1886 PHILLIPEAU and VULPIAN used a nerve graft taken from the lingual nerve to bridge a gap in the hypoglossal nerve. Cutaneous autografts were extensively used by Seddon to repair larger peripheral nerve trunk injuries and they reported in 1947 results equal or better than the best obtained by conventional

suture. In a symposion on peripheral nerve injuries in Kassel, Germany (February 1972)

the application of microsurgery and the use of grafts were discussed and results of several larger series of nerve injuries treated by various methods, old and new, were

available for comparison. We have adopted since a new technique for the surgical treatment of peripheral

nerve injuries and abandoned the time honoured conventional secondary epineural

suture. The drawback of the latter technique centers on problems related to gapclosure and

development of secondary scar tissue in the suture line. The technique of microsurgical interfascicular autografting was developed by

MILLESI (1967, 1969) and is based on the following arguments: - a nerve suture should be without any tension not only during but also after

operation; - most, if not all, of the secondary scar tissue originates from the epineurium which

consequently should be removed; - thin autografts are best suited for bridging a gap by virtue of the absence of ischa-

emic necrosis resulting in a normal Wallerian degeneration and preserved Schwann

tubes; - the grafts should be sutured interfascicularly and perineurally since the aim in

nerve repair is to reunite fascicles which, surrounded by perineurium, constitute

the functional nerve unit. The use of the operating microscope, bipolar coagulation and microsurgical dis-

secting instruments is essential in this technique. After a conventional dissection of the nerve towards the lesion the delicate resection

* Neurosurgical Department. Wilhelmina Gasthuis, University of Amsterdam.

Clin. NeuroI. Neurosurg. 1974 - 2

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Fig. 1. Glass injury of sciatic nerve.

of the epineurium is performed by using microsurgical techniques. The extent of the lesion can always be judged with certainty by following the individual fascicles from the anatomically normal regions into the lesion.

The fascicles are transected if found damaged, in which case they have lost their identity blending into a structure less mass.

Fig. 1 and 2 show this situation in a sciatic nerve injury (glass) in which the tibial division was found anatomically intact but the peroneal nerve fascicles disrupted.

After both stumps are thus prepared a cutaneous nerve is obtained via small multiple incisions, the choice depending on the extent of the gap. Grafts of generous length to allow for shrinkage are snugly adapted and held in place by one or two epineural ultrafine 10 zero sutures.

Fig. 3 shows the final aspect in a radial nerve injury after grafting. Extensive lesions can be treated by this technique: Patient A, an 11 year old boy fell off a shack, his arm being caught by a nail. The median nerve was not only completely severed in the cubital fossa but over a length of at least 10 cm it was altered into a scarred mass. After resection a gap of 13 cm was bridged by 4 interfascicular autografts with excellent recovery so far. Patient B, a 28 year-old lady, was injured by a matchet, cutting her left forearm and

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wrist. Six months later she was referred to us with a complete lower ulnar and median nerve paralysis. The extent of the lesion can be seen on fig. 4. Four autografts of 11 cm were used to repair the median division and 3 of 5 cm length for the ulnar division (Fig. 5).

RESULTS

From February 1972 through February 1974 nerve grafting was performed in 30 patients, presenting with various nerve injuries, excluding the brachial plexus.

In 17 the operation was sufficiently long ago to judge the preliminary results. All patients were seen at regular intervals but 2 lost to follow up after several months.

Tinel's sign was used to follow the axonal ingrowth and attention was paid to any possible neuroma formation. Motor function was evaluated and graded from M 0 to M 5 according to SEDDON (1972). Sensibility was tested by means of pin- prick, touch, cold and heat stimulus, as well as 2 point discrimination and the ability to localize a stimulus. SEDDON'S grading for sensory recovery was used ranging from SO for absence of sensibility to $4 for complete recovery. At suitable intervals

Fig. 2. After resection of scarred epineurium. T.N.: Tibial nerve (intact) P.N.: Peroneal nerve; proximal stump fascicles.

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Fig. 3. Radial nerve in- jury (elbow) aspect after interfascicular grafting. (4 cutaneous autografts in centre).

EMG'S were made and when signs of motor recovery appeared, nerve conduction and latency times across the grafts measured (Indirect stimulation).

The relevant data are shown in table I.

As yet we have not seen asingle case of neuroma formation, neither in the proximal, nor distal suture line. All cases showed smooth ingrowth of axons as judged from the Tinel's sign, gradually progressing in time.

Both ulnar nerve lesions, one in the forearm and one in the wrist show good recovery with gradings M4 $3 and M5 S3q- respectively and a near normal hand in function and appearance.

All 4 cases of median nerve injury appeared to have mixed innervation of the 0pponens pollicis and as such should be excluded for final comparative results. The third case in this group is the aforementioned patient A, who showed, after 13

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Fig. 4. Extensive injury of median and ulnar nerve in wrist. M.N. : Median nerve prox. s tump U.N. : Ulnar nerve prox. s tump.

Fig. 5. Same as fig. 4 after interfascicular autografting.

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NERVE NAME AGE

~LNAR

Forearm C h . e . 27

I r t s t M.Z. 12

~EDIAN

I r l s t H , S . 24

# f i s t P . V , 26

Forearm A.B. 11

i r i s t E.G. 25

3OMBINED

I r i s t E . S . 27

Forearm J . F . 43

RADIAL

krm R.H. 30

Lrm E . P . 10

~rn s. d. 59

DIGITAL

~ndex a . s . 20

)ERONEAL

PERIFERAL NERVE LESIONS TREATED BY CUTANEOUS AUTOGRAFTS

INJURY INTERVAL

NUHBER LENGTH

Ccu)

FOLLOW UP TIRE

( m o n t h )

c u t 3 no 4 x 4 , 5 24

c u t 5 no 3 x 4 , 5 19

c u t 6½ me

o u t 8 y r s

t r a c t i o n 3 me

c u t 4 mo

c u t 6 mo

o u t 11 mo

c u t 4 mo

f r a c t u r e 4 so

CUt 2 Re

o u t 2½ no

Knee c u t ~½ mo

Upper l i m b o u t 2 mo

Knee t ~ r a o t i o n 6 me

Knee t r a o t i o n 4 no

Knee t r a c t i o n mo

11x4,5

4,5,5

3x14 l x 1 0 l x 8

~x2,5

med 4xll uln )x5

msd 3x4,5 u lo 4x5

l x 7 2 x 9

4x4

:,x4 3x5

l x 1 . 8

3x3

3 x 4

~xl 1

4 x 1 7

]~x l l

T A B L E I

24 16

5"

17

14,5

20

14

6"

19

16

19

19

18

RECOVERY GRADING (SEDDON) 2pd EMG motor sensory cn AP IS

M4 S3 MP +

M5 $3+ 10 RP +

$2 - +

$3+ 20 +

M2 SO I P +

S2

R3 S3+ 6-10 + R4 S4 5 +

R2 Sl - M2-} S l - 2 - MP +

M4-5 S2 - RIP +

R5 S4 15 HIP +

R1

S4

IP ÷

RIP ",

SAP ÷

8 0 MEP ÷

In this table the EMG results are tabulated simplified in abbreviated form. ( A P stands for action poten- tial, Me = mixed pattern, SAP = solitary action potential, ~e = interferance pattern. Is = indirect stimulation).

months, nearly complete recovery of forearm muscles while the abductor pollicis brevis was still weak. Sensory recovery had started in the palm.

The first case in the combined ulnar and median nerve group is patient B, mentioned

before: She has after 17 months a fair to good recovery o f both nerves.

The results in radial nerve injuries are all good: graded M 4 to M 5. All injuries were at the level of the epicondylus.

The third patient graded M 1, was lost to follow up after 6 months but then had regained a firm dorsiflexion of the wrist.

One digital nerve injury, treated with a single autograft , has full sensory recovery with a 2 point descrimination o f 5 ram,

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Of the 5 peroneal nerve injuries 2 were inflicted by glass and 3 suffered traction injuries.

In the 1st case the fascicles of the superficial branch appeared undamaged after

dissection. The severed profundus branch was grafted. Motor recovery of the pro-

fundus branch began after I1 months and powerful, dorsiftexion of the foot was regained after a further 8 months.

In the second case with peroneal paralysis and tibial nerve weakness, the tibial

nerve fascicles could be freed from a large sciatic swelling and the common peroneal was grafted (fig. 1 and 2).

His motor recovery could be graded as M4.

All 3 traction injuries with grafts varying from 11 to 17 cm show no useful re-

covery as yet but do have signs of reinnervation on recent EMG'S: action potentials

could be recorded when stimulating the peroneal nerve proximal of the graft.

DISCUSSION

Since the plateau of recovery is reached only after a time interval of 2 to 3 years,

depending on the site of the injury, these results do not permit firm conclusions as

yet but seem promising. They seem to sustain the opinion that interfascicular auto-

grafting is a rewarding technique with the following advantages in comparison to

the conventional epineural suture:

- delicate handling of tissue;

- certainty in judging the extent of lesions;

- feasability to treat extensive lesions; - no joint flexure with secondary stretching of nerve tissue;

- early mobilisation and institution of electrotherapy.

The final results of course depend on good after-care as well as surgical technique.

REFERENCES

MILLESI, H. (1969) Wiederherstellung durchtrennter peripherer Nerven und Nerventransplantation. Mfinch. reed. Wschr. 111,2669.

MmLESl, H., GAN6LBERCER, J. and BERCER, A. (1967) Erfahrungen mit der Mikrochirurgie peripherer Nerven. Chir. plast, reconstr. 3, 47.

PnILLIPEAV, J. M. and VOLPIAN, A. (1970) Note sur des essais de greffe d'un trongon du nerf lingual entre les deux bouts du nerf hypoglosses. Arch. Physiol. norm. path. 3,618.

SEDDON, H. J. (1947) The use of autogenous grafts for the repair of large gaps in peripheral nerves. Brit. J. Surg. 35, 151.

SEOOON, H. J. (1972) Surgical disorders of the peripheral nerves. Edinburgh, Churchill Livingstone 299.