Nerve compression syndrome surgery

Nerve compression syndrome develops when the nerves, which run in the passages (tunnels) between the muscles, ligaments, bones, and connective tissue of the body, are compressed for some reason. Therefore, these nerves that are under pressure may cause numbness, and pain. If other treatments do not alleviate the symptoms, then surgery is necessary to improve the quality of life.

The role of the peripheral nervous system is the transmission of information as the extension of the centrally located (brain, spine) nerve cells. This could be a sensory, motor (movement), or vegetative message. The structure and location of the nerves are well defined. Nerves mostly run between soft-tissue structures, in protected places. However, during their pathway it could still occur that they run close to bones, on boney surfaces. This precipitates that spatial disproportionality may develop at the places of predilection in case of an increased compression caused by scarring, misalignment after a healed fracture, bone spurs, bursa, or tendonitis. When this happens, the nerves do not have enough space to run freely, because of which they are pressed to the hard surface. Its supply with nutrients, oxygen, and blood is reduced in that area, the impulse conduction gets slower, the electric potential of the impulse is reduced, and the function could even stop if the compression remains for a long time. This is mostly temporary i.e., the process is reversible; the injury sometimes could cause permanent nerve damage.

Typical locations of nerve compression syndromes:

• In the area of the wrist
• In the area of the forearm
• Elbow region
• In the area of the upper arm
• Compressions caused by a lymph node scar in the underarm. (This could affect all three upper limb nerves.)
• Thoracic outlet syndrome (TOS) – in the triangle formed by the clavicle and the scalene muscles.
• In one sense, the narrowing of the nerve root canals in the spine could also be considered as a nerve compression syndrome, but this does not cause a group of symptoms, which is typical for one nerve, it could induce a complaint that affects multiple nerves (this disease is not included in this notice).

The symptom of nerve compression syndrome is the disturbed function of the affected nerve – sensory, movement, vegetative innervation disturbance (sweating, the regulation of circulation). These could often come in waves, and other times it could be accompanied by constant pain, feeling of numbness, and clumsiness.

Nerve compression syndrome could be classified as mild, moderate, and severe based on the level of severity. Compression causes a measurable change in the nerves; the disease is classified, and the treatment principles are determined based on this. Primarily, neurosonography (ultrasound scan) is the suitable imaging study, but in some regions, an opinion could be formed based on an MRI. Electroneurography (ENG) provides reliable information on the functions of the nerves, and their ability of impulse conduction and its changes. Out of physical examinations, the Phallen test and the Tynnel sign could be highlighted in addition to two point discrimination test, strength measurement and ranking. Based on the international standard, the results of ENG and neurosonography are also suitable on their own to determine the disease’s level of severity.

If the examinations were performed, the treating physician proves a recommendation for therapy. It is recommended to make a decision by considering the opinions of both parties, given that the results of risk evaluation and the expectable results of the planned therapy are known.  It is recommended to start the treatment after providing full information to the patient. In case of severe tunnel syndrome, surgical treatment may be necessary, while conservative treatment can be performed with good results in milder cases.

What are the treatment options?

Conservative treatment option: pain relief, relaxation exercises, long term administration of a vitamin that supports nerve function, electrical stimulation, non hormonal anti inflammatory agents in case of inflammatory enlargement of bursae. Attempts were made to the application of local treatments such as local cremes (e.g., Carpal acut), or infiltration of steroid injection. An asymptomatic state could often temporarily be achieved by exclusively applying these local treatments. Occasionally, calcified lumps, or scars develop in the location of the steroid injection, which may worsen the case further.

Surgical treatment: exploration of the involved nerve segment, finding the healthy segment both centrally and peripherally, release of the compressions and scars between these two areas, removing bursae, shaving down bone spurs, removing neoplasms, if necessary. The original length of the neural pathway could be reduced by nerve transposition, so e.g., in case of an ulnar nerve compression in the area of the elbow, the nerve will be transposed anteriorly. The patient must always be aware of the transposition, because later if an unexpected accident or injury occurs, the colleagues who provide care will not find the nerve at its original anatomical locations.

What happens before surgery?

• Specifying and finalizing the diagnosis and the indication.
• Investigation, a consultation with an anesthesiologist, if necessary.
• Admittance to the department, where the preoperative actions take place. Checking the aseptic state of the surgical site, ingrown nails, chronic wound, sign of inflammation, insect or spider bites.
• As a direct preparation for surgery, it is checked whether jewelry, nail polish, and built artificial nails were removed (it is useful to do these at home).
• Cleansing with an antiseptic soap. Changing everyday clothing to surgery clothing: gown, hat, facemask. Changing the previously given anticoagulants to LMWH treatment, thrombosis prophylaxis in other cases e.g., prolonged surgery, or intervention on the lower limb.
• In each case, the patient is transferred to the operation room by a patient transfer with an identification code and the full documentation.

How is the surgery performed for nerve compression syndrome?

As a condition for good visibility, it is necessary to achieve blood flow blockage in the limbs, which is a safe and practiced solution.  In the significant period of the surgery, the circulation is temporarily blocked for the purpose of the accurate visibility of the nerve by using tourniquet cuffs which occlude blood flow, (blood pressure monitor), or elastic band.

What happens in the operating room?

• The patient is positioned on the operating table; in lying (shaving depending on the body region and the presence of hair); anesthesia depending on its type, its preparation; starting an infusion, monitoring the blood pressure and the heart function.
• Sterilizing the surgical site with an antiseptic solution; isolation the surgical site from its environment.
• Performing blood flow blockage after anesthesia but before the surgical entry.
• Surgical entry; preparation; searching the nerve, releasing it; performing other necessary actions.
• After blood flow blockage is released, accurate hemostasis is performed with bipolar electrocautery devices.
• In the need of wound closing, a drain is built in; covering bandages are placed over wound; fixation with elastic bandages or plaster casting.

What kind of posttreatments are recommended?

The conservative methods, which are used in the treatment of nerve compression syndromes, may have a positive effect in the postsurgical period too, so in addition to taking vitamin B, doing exercises, and starting to use the limb for everyday tasks as soon as possible, physical therapy treatments, e.g., nerve stimulation (in case of weakened muscles), electrical stimulation. These are given based on individual evaluation; they are not routinely applied treatments.

What could be expected from the surgical treatment?

• Cessation of nerve compression, normalization of blood supply.
• Decrease and cessation of numbness and pain (in the long term, severe cases, the function is not completely restored, symptoms may partially remain).
• Improvement may already be noticed on the first day after surgery, but very often the final state changes depending on the speed of nerve regeneration, even after multiple weeks, mostly until the 100th day.
• The improvement of movement function could be expected with the increased muscle strength: grip strength, gripping ability, resilience.
• Gradual return of fine, coordinated movements
• Improvement in the movement function is expected with the increasing muscle strength, along with the grip strength, grasping ability, and load capacity.