Peripheral Nerve Surgery
Issues with peripheral nerves, including entrapment or compression, can result in significant pain or disability. Many patients often see a spine surgeon, or even undergo a spine surgery, without recognizing it may be their peripheral nerves in the arms or legs that are triggering pain or weakness! An experienced neurosurgeon is able to triage and discern what the source of a patient's disability may be from.
Peripheral Nerve Decompressions
The most typical peripheral nerves in the body to be compressed include the median nerve at the carpal tunnel, ulnar nerve at the cubital tunnel, radial nerve in the forearm, common peroneal nerve at the fibular head, and tarsal tunnel at the ankle. However, many other nerves may be entrapped at various points at other locations. Dr. Faraji completed a second fellowship in peripheral nerve surgery to decipher and treat issues with peripheral nerves and is available for consultation regarding these procedures. While these entrapment disorders may respond to conservative measures and bracing, some patients may require surgical decompression. Typically, nerve decompressions are short outpatient surgeries with the patient under moderate sedation or general anesthesia. Dr. Faraji uses mechanomyography for most decompressions to assess nerve function intra-operatively (see below).
Peripheral Nerve Repairs
Nerves may be injured due to prolonged compression, sharp or blunt injury, or other forms of trauma. Scar tissue may even form following a prior surgery done as well. Nerve repair involves inspecting the nerves with direct repair if there is a discontinuity or performing a decompression to free it from surrounding tissues. Sometimes a nerve transfer may be used as well to improve function.
Peripheral Nerve Transfers
Nerve transfers utilize the body's natural capacity for repair following nerve injury. If function is lost due to trauma or other disorder, adjacent and redundant nerve function may be used to "bypass" and restore this lost function. This approach uses typical donor nerves and the nerve is cut and re-routed to recipient nerves. The nerve axons grow down these new paths to re-innervate the target muscles in the areas of lost function. This technique is not experimental and has several decades of scientific, clinical, and outcomes research supporting it. The outcomes following nerve transfer may depend on the type of injury, length of time since injury, distance the nerves must regrow, viability of the donor and recipient targets, and even age of the patient. Dr. Faraji is the site principal investigator (Houston Methodist) of a multi-center clinical trial funded by the Department of Defense to evaluate outcomes following upper extremity nerve transfers for patients experiencing quadriplegia after spinal cord injury. For more information, please visit the clinicaltrials.gov website.
Peripheral Nerve Tumors
Peripheral nerve tumors are typically benign and non-cancerous, however rarely may be malignant or cancerous. Surgical resection is often indicated for benign tumors in situations with documented growth, significant pain, neurological deficit, or worsening quality of life. Surgery to remove these tumors involves separating intact and viable parts of the nerve from portions where the tumor grows from. This is almost like separating a single strand away from an intertwined rope. Dr. Faraji uses sophisticated nerve stimulation and neurophysiological monitoring techniques in the operating room to minimize the chances of inadvertent injury of an intact portion of the nerve while trying to preserve function.
Targeted Muscle Reinnervation (TMR)
TMR is a technique to reflect and transfer nerves, such as from an amputated limb, to reinnervate new muscle targets that have otherwise lost function. This is a strategy used in amputated limbs to reduce pain and avoid neuroma growth, but also is involved in improving the control of neural prosthetics for clinical research purposes.
MMG is a technique to directly assess nerve function in the operating room. It does not cause pain or injury to the nerve and the ability of this technique to prognosticate outcomes is currently being explored through research. Dr. Faraji was one of the first adopters of this technology in the world for peripheral nerve surgery and has developed and optimized a workflow for its use in the operating room.
Electromyography & Nerve Conduction Study (EMG/NCS)
An EMG/NCS is a diagnostic test that may be ordered to assess nerve function and to localize a point in the nerve where conduction may be interrupted, such as a site needing a decompression or nerve release. It may also provide some evidence for nerve and muscle viability and can even assist in providing a prognosis after a peripheral nerve surgery. It is typically performed as an outpatient procedure and involves the placement of small needles through the skin with a brief electrical current applied to assess nerve function. Parts of the procedure are not comfortable, but most patients do tolerate it without issues.