Internal Neurolysis Research Articles

CARPAL TUNNEL RELEASE UNDER INTRAVENOUS REGIONAL OR LOCAL INFILTRATION ANAESTHESIA

Fifteen patients with bilateral carpal tunnel syndrome underwent surgery using intravenous regional anaesthesia (IVRA) on one hand and local infiltration anaesthesia (LA) on the other. All 30 carpal tunnel releases were performed without complication. Patient tolerance for IVRA and LA was similar. Six patients preferred the LA, eight preferred IVRA and one had no preference. Tourniquet time averaged 16 minutes when LA was used and 24 minutes with IVRA (P<0.05). Use of local anaesthesia allows more expeditious surgery and limits costs, but intravenous regional anaesthesia is recommended if epineurotomy, internal neurolysis or flexor tenosynovectomy are planned.

USE OF THE PALMARIS BREVIS FLAP FOR PREVENTING RECURRENT MEDIAN NERVE COMPRESSION IN MUCOLIPIDOSIS

In a patient with severe, recurrent bilateral carpal tunnel syndrome secondary to mucolipidosis, the ‘turnover’ palmaris brevis flap was used in conjunction with internal neurolysis. The procedure was effective in alleviating symptoms of recurrent carpal tunnel compression in both hands.

Functional results of low median and ulnar nerve repair with intraneural fascicular dissection and electrical fascicular orientation

Twenty-eight low median nerve injuries and 23 low ulnar nerve injuries were repaired using intraneural fascicular dissection and electrical fascicular orientation. Eleven freshly lacerated nerves were seen within 48 hours after injury; 40 nerve lacerations were chronic. Fascicular orientation between sensory and motor fascicles at the proximal nerve end could be accurately differentiated in 47 nerves (92%) independent of whether it was acute or chronic. At the distal nerve end in fresh lacerations, the motor fascicles could be determined conclusively by muscle contraction with sequential electrical stimulation of the fascicles. In chronic nerve lacerations, the distal fascicles could be estimated anatomically after internal neurolysis. After fascicular orientation, nerves were repaired with end-to-end group fascicular suture or interfascicular sural nerve grafting. Twenty-four nerves repaired with end-to-end suture and 13 nerves repaired with nerve grafting were monitored more than 25 months. Satisfactory sensory results (i.e., S3+ or S4 functions) were obtained in 29 nerves (78%) and M4 or M5 motor functions were achieved in 29 nerves (78%). There were no patients who needed additional tendon transfers to reconstruct thumb opposition or to correct claw finger deformity. These results suggest that low median or ulnar nerve lacerations, whether acute or chronic, partial or complete, may be successfully repaired with the aid of electrical fascicular orientation with or without intraneural fascicular dissection.

両側後骨間神経麻ひの一例

We report a case of bilateral posterior interosseous nerve (PIN) palsy. The subject was an 18 year-old female, working as a hotel maid, who developed severe pain in the lateral side of her left elbow after making beds for four hours daily over a three month period. Five days after onset of pain, she was unable to extend her left fingers. She received conservative treatment for PIN palsy but didn't show any improvement and was refered to us. Four months after the onset, internal neurolysis was performed. An hourglass-like constriction of PIN, 3cm proximal to the arcade of Frohse was found. Five months after surgery, she could extend her left fingers completely. One month after surgery of her left side, she started to show right sided PIN palsy after a few sets of dumbbell exercises. One and half months after the onset, internal neurolysis was performed. Operative findings was the same as the left side. Three months after surgery, she started to recover.

Value of nerve action potentials in the surgical management of traumatic nerve lesions.

The goals of the study were to investigate the value of intraoperative electrically evoked nerve action potentials (NAPs) in the surgical treatment of traumatic peripheral nerve injuries (nerve lesions in continuity). Sixty-four patients with 76 traumatic nerve lesions in continuity were investigated intraoperatively by stimulating and recording NAP from the whole nerve across the suspected lesion site. Among the 76 nerves (nerve lesions) were 43 with incomplete and 33 with complete loss of function. In cases (nerves) with complete loss of function (n = 33), the surgical procedure (external neurolysis, internal neurolysis, or nerve repair) was performed according to the microscopic aspect of the nerve and the result of the intraoperative electrophysiological testing. In cases (nerves) with incomplete loss of function (n = 43), the surgical procedure was performed solely according to the microscopic aspect of the nerve and independently from the result of the intraoperative electrophysiological testing. Of 43 nerves with incomplete loss of function, we were able to record reproducible NAPs in 41 (95%) across the lesion site, thus demonstrating a high reliability of the method. Of 33 nerves with complete loss of function, a reproducible NAP could be recorded only in 3. Assuming an axonotmetic lesion in regeneration, we did nothing else on the nerve with excellent clinical results (full recovery). Of the remaining nerves with no NAP, 24 showed a caliber shift of the nerve (in 20 cases a thickening of the nerve, suggesting a neuroma in continuity). A grafting procedure was performed, and the histological evaluation revealed a neurotmetic lesion. However, in six patients with no NAP, there was no clear caliber shift of the nerve. The epineurium was opened and an internal neurolysis performed showing fascicles in continuity. Three patients had good and three had partial (but useful) recovery. In nerve lesions in continuity with complete loss of nerve function, intraoperative NAPs are able to detect axonotmetic lesions in regeneration. Thus, unnecessary further surgical procedures can be avoided. On the other end of the spectrum, no recordable NAP together with a caliber shift of the nerve (suggesting a neuroma in continuity) may facilitate the surgeon's decision for a grafting procedure without a time-consuming internal neurolysis. But there is also evidence from our data that not every nerve lesion in continuity without a NAP needs to be grafted.

Pain after surgery for ulnar neuropathy at the elbow: a continuing challenge.

Fifty-eight percent of patients who had undergone surgery for ulnar neuropathy at the elbow experienced pain after surgery. Severe pain, mostly radiating from the elbow into the hand, is the main indication for subsequent surgery. During a period of 5.5 years, 25 patients underwent 28 operations for ulnar nerve entrapment at the elbow and experienced excruciating pain after surgery. Ten patients had undergone a simple decompression and 15 had undergone a nerve transposition. Seven patients underwent surgery at our hospital, whereas 18 patients underwent their primary surgery at other institutions. Various surgical techniques were used during the subsequent surgery, such as external or internal neurolysis, epineurectomy, anterior, transposition, and subsequent transfer of the nerve back into the sulcus. The average follow-up after the last procedure was 17 months (2-55 mo). All five patients with subsequent transfer of the ulnar nerve into the sulcus became pain-free, whereas only two of five patients who had secondary intramuscular transposition for subluxation became free of pain. Results after internal neurolysis were unsatisfactory. Only one of six patients was free of pain after secondary surgery. Results after three or four procedures are approximately similar to the results after the first subsequent surgery. Simple and less extensive techniques for subsequent surgery have relatively good results in this complicated condition. Although our small number of patients does not allow us to draw general conclusions, we think our report makes a contribution because of the few reports in the literature dealing with the results of subsequent surgery for ulnar nerve neuropathy.

O-20-290 - Internal neurolysis and neurotization in the treatment of brachial plexus injury

O-20-290 - Internal neurolysis and neurotization in the treatment of brachial plexus injury

Circumferential wrapping of a flap around a scarred peripheral nerve for salvage of end-stage traction neuritis

Nine patients with chronic severe pain due to end-stage traction neuritis of an intact peripheral nerve underwent external neurolysis and epineurectomy or epineurectomy and internal neurolysis followed by circumferential wrapping of the involved segment of nerve with a pedicle flap or free flap consisting of either subcutaneous fat tissue, fascia, or muscle. Seven patients (77%) followed for between 1 and 5 years had substantial relief of pain. Two patients (22%) had no decrease in their pain at all. Circumferential wrapping may cushion the nerve from external pressure on the overlying skin, may isolate the nerve from the traction forces of adjacent moving tendons to allow improved gliding of the nerve, and may promote revascularization of a scarred nerve. This surgery may be indicated for patients with persistent pain following multiple carpal tunnel or cubital tunnel surgeries.

Ulnar nerve decompression by transposing the nerve and Z-lengthening the flexor-pronator mass: Clinical outcome

Controversy surrounds the reliability of methods of treating ulnar nerve compression at the elbow. The effectiveness of submuscular anterior nerve transposition was evaluated in 33 limbs of 31 patients. The flexor-pronator Z-lengthening technique, without internal neurolysis, was used. Results were determined by patient chart reviews. Severity of preoperative nerve compression was measured using Dellon's classification. Of the 33 limbs, 6 had mild preoperative nerve compression; 7, moderate; and 20, severe. Overall outcome was evaluated using a modification of the Bishop rating system. At a mean follow-up period of 49 months, 12 limbs (36%) had excellent results, 20 limbs (61%) had good results, and 1 limb (3%) had a poor result. These findings indicate that submuscular ulnar nerve transposition using the flexor-pronator Z-lengthening technique without internal neurolysis is a reliable method of treating ulnar nerve compression at the elbow.

THE USE OF THE PALMARIS BREVIS FLAP IN RECURRENT CARPAL TUNNEL SYNDROME

In failed cases of primary carpal tunnel release, the addition of the highly vascular palmaris brevis turnover flap as an adjunct to internal neurolysis discourages scarring and provides a nutrient bed for axonal regeneration. In fact, the palmaris muscle flap actually may suppress the growth of nerve fibers into the overlying scar. Experimentally, classic neuromas do not form when a severed nerve is placed in an innervated muscle, particularly those with minimal excursion, as is the case with the turned over palmaris cushion. Major advantages of the palmaris turnover muscle are (1) proximity of the muscle to the operative field, obviating the need for a distant graft source; (2) negligible functional motor loss as a result of forfeiting this muscle; (3) no separate scar is created in raising this flap; and (4) adequate padding of the subcutaneous fat is still left at the donor site to protect the ulnar neurovascular bundle. Although postoperative healing and rehabilitation time are relatively lengthened by the more extensive dissection, subjective assessments of pain relief and clinical improvements in grip strength, pinch strength, and sensory parameters justify the use of the palmaris brevis turnover flap in recalcitrant carpal tunnel cases.

Long-termresults of carpal tunnel release

To determine the long-term results of carpal tunnel release, we retrospectively reviewed 60 cases, an average of 5.5 years after surgery. 87% reported a good or excellent overall outcome; the average time to maximum improvement of symptoms was 9.8 months. However, 30% reported poor to fair strength and long-term scar discomfort, and 57% noted a return of some pre-operative symptoms, most commonly pain, beginning an average of 2 years after surgery. We found no correlation between pre-operative symptoms or extent of surgical dissection (internal neurolysis) and outcome. Carpal tunnel syndrome was job related in 42%; of these, 26% changed from heavy to lighter work following surgery. Although occupational cases were slower to improve and remained off work longer, the long-term subjective results were the same for both groups. We found significant morbidity from the surgical scar and decreased strength, and often considerable delay until ultimate improvement, especially in patients with job-related carpal tunnel syndrome.

重度手根管症候群の手術例の検討 神経内剥離術例と手根管開放術単独例の比較

Adjunctive internal neurolysis of the median nerve followed by release of the transverse carpal ligament is widely performed for treating carpal tunnel syndrome. However, the efficacy of internal neurolysis is still controversial. In this series, eleven hands in eleven patients had internal neurolysis of the median nerve and carpal tunnel release, twelve hands in eleven patients had standard ligament release alone.Thenar muscle strength and bulk were recorded in all hands. Median nerve function was evaluated using the two-point discrimination test and electromyography. Preoperatively, all hands had severe thenar muscle atrophy with no motor response to stimulation.Analysing the postoperative data, the majority of hands in both groups achieved satisfactory results and there was no significant difference between the results of the two groups. Results of this study indicate that standard surgical release of the transverse carpal ligament is equally effective in patients with severe carpal tunnel syndrome. Therefore, it can be suggested that internal neurolysis is not necessary in the treatment of carpal tunnel syndrome.

Pathogenesis and treatment of cubital tunnel syndrome caused by osteoarthrosis of the elbow joint.

We consider the primary cause of cubital tunnel syndrome caused by osteoarthrosis of the elbow joint to be degenerative osteophytes originating in the humeroulnar joint underneath the ulnar nerve. In the operative procedure the ulnar nerve in the cubital tunnel is fully exposed by cutting the soft tissues covering the nerve, because some of the soft tissues often seem to compress the nerve. Internal neurolysis is performed with microscopy in cases where the constriction is severe. Osteophytes in the humeroulnar joint underneath the nerve are removed. The osteophytes and loose bodies in the anterior and the posterior parts of the joint are also removed to increase joint motion. In 75 of 77 cases recovery of the ulnar nerve palsy and improvement in the range of joint motion were obtained.

Surgical management of recurrent carpal tunnel syndrome

An approach to the surgical management of recurrent carpal tunnel syndrome was evaluated in 30 patients with 35 involved wrists. This includes internal neurolysis of the median nerve and early post-operative mobilization of the wrist and fingers. The preferred surgical approach is through a second, more ulnar incision. Clinical assessment of sensorimotor function was converted into a numerical score ranging from zero (normal) to 9 (anaesthesia) and 10 (atrophy, severe). The average pre-operative score was mean 6.5 and median 7. At a mean follow-up of 23.5 months, the average post-operative score was mean 1.8 and median 0, a statistically significant improvement ( P < 0.001).

Microsurgical neurolysis: Its anatomical and physiological basis and its classification

Neurolysis is a procedure which has to be performed if the gliding apparatus of a peripheral nerve does not function, and consequently, adhesions and fibrosis develop. The gliding tissue has to provide the ability for the nerve to adapt to the different position of the extremity by longitudinal passive movement. The paraneurium provides movements between the nerve and the surrounding tissue; the interfascicular epineurium provides the possibility of the movement within the nerve. Internal neurolysis is defined as surgery within the nerve if the epifascicular epineurium is completely transected. A classification of different degrees of fibrosis is given with special reference to the procedure which has to be done in each case. Neurolysis is a step-wise procedure with the aim to decompress the fascicles and which is immediately stopped if this aim is achieved. In very severe cases, if the gliding tissue does not regenerate, a gliding tissue flap to envelope the nerve may solve the problem.

Walking Track Analysis

Functional recovery following sciatic, tibial, and peroneal nerve injury was assessed over a 1-year period using walking track analysis in the rat. Internal neurolysis did not affect nerve function. Crush injury induced a temporary, but complete, loss of function that recovered to control levels by 4 weeks. Nerve transection resulted in complete loss of function without any evidence of recovery. After nerve repair, functional recovery occurred, reaching near-optimal recovery by 12 weeks. The degree of functional recovery varied with the specific nerve involved. The sciatic nerve recovered 41 percent of function, whereas the tibial nerve recovered 54 percent of function. The peroneal nerve exhibited the highest degree of recovery, achieving functional levels similar to control values. Assessment of neural regeneration using walking track analysis appears to be a valuable addition to the traditional methods of histology and electrophysiology.

Intraoperative electroneurography during median nerve decompression in carpal tunnel syndrome

In 17 patients with the diagnosis of carpal tunnel syndrome, orthodromic sensory nerve conduction measurements during ligament division and internal neurolysis were performed without the use of a pneumatic tourniquet. While ligament division led to an increase in conduction velocity (p < 0.05; median increase 0.7 m/s), it did not result in a significant change of the amplitude. During internal neurolysis, an increase of the sensory nerve potential (p<0.01; median increase 0.9 μV) and no significant change in conduction velocity were observed. We conclude that internal neurolysis does not cause a disruption of nerve function during the operation.

Internal neurolysis fails to improve the results of primary carpal tunnel decompression

This prospective, randomized study compares two treatment methods in patients with primary carpal tunnel syndrome. Decompression of the transverse carpal ligament was done in thirty-two hands (thirty patients) and decompression of the transverse carpal ligament with the addition of an internal neurolysis of the median nerve was done in thirty-one hands (twenty-nine patients). Relief of symptoms was described in eighty-eight percent of the patients with carpal ligament release and eighty-one percent of patients with carpal ligament release plus internal neurolysis. Improvement in hand sensibility testing, in thenar muscle strength, and atrophy was noted in both treatment groups with no statistical difference between groups. The addition of an internal neurolysis to division of the transverse carpal ligament does not add significant improvement in the sensory or motor outcome of patients with primary carpal tunnel syndrome.

Palmaris brevis turnover flap as an adjunct to internal neurolysis of the chronically scarred median nerve in recurrent carpal tunnel syndrome

Thirteen hands in 11 patients with previous carpal tunnel releases were treated by microscopic internal neurolysis and palmaris brevis "turnover" flaps. All patients in the series had positive electrodiagnostic testing, dysesthetic wrist pain, and numbness in the median nerve distribution before operation. Average age was 41.9 years (range, 27 to 62 years). Ten were male and 3 were female. Range of follow-up after the procedure was from 1 to 1 1/2 years. All hands with abnormal preoperative two-point discriminations or Semmes-Weinstein measurements showed numerical improvement in their sensory parameters. Thenar strength and bulk improved at least one grade in all six cases of thenar atrophy. Mean grip strength was 15.2% greater than before operation. Key pinch increased 5.5% and pulp pinch 31.9%. Subjective assessment of improvement ranged from 25% to 100%. All patients returned to their former jobs or to vocational retaining except the oldest patient who is semiretired.

Peripheral nerves compressions

The application of microsurgical neurolytic techniques in cases of peripheral nerve entrapments offers greater advantages than other techniques, as it allows a better understanding of the neural alterations. In most cases, a longitudinal epineurectomy is necessary to free the fascicles of the epineural fibrosis. Less frequently, internal neurolysis is needed for removal of interfascicular scarring. Fifty cases of elbow ulnar neuropathy and 58 of the carpal tunnel syndrome were treated with this technique: 72% of the results were satisfactory.