Neurectomy | |
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Specialty | Neurology |
A neurectomy, or nerve resection is a neurosurgical procedure in which a peripheral nerve is cut or removed to alleviate neuropathic pain or permanently disable some function of a nerve. The nerve is not intended to grow back. For chronic pain it may be an alternative to a failed nerve decompression when the target nerve has no motor function and numbness is acceptable. [1] Neurectomies have also been used to permanently block autonomic function (e.g. excessive sweating in hands [2] or involuntary muscle movement causing cramps [3] ), and special sensory function not related to pain (e.g. vestibular nerve dysfunction causing vertigo [4] ).
A temporary nerve block with an anesthetic is usually performed before surgery to confirm the diagnosis of neuropathic pain. [1] Risks include numbness, neuroma, and complications due to lack of innervation.
A presacral neurectomy is typically conducted to decrease severe pain and menstrual cramps in the lower abdomen. Pain in this region is difficult to treat with noninvasive treatments. Endometriosis is the most common cause for this severe pain. One solution that doctors often mistakenly recommend as a cure is a hysterectomy, or removal of the uterus. However, this often does not relieve endometriosis pain because the disease is left behind on other organs such as the bladder, bowels, or pelvic side walls, and it can thrive on its own hormone supply. Another is to perform a presacral neurectomy. This is a procedure that interrupts the nerves going towards and/or around the uterus. [5] Pain located on either side of the lower abdomen (but not mid line) should not be treated with a neurectomy. Only individuals with pain that is not relieved by the use of NSAIDs should consider this procedure. Techniques have been developed for this procedure to be performed laparoscopically. [5]
The incision is typically directly under the navel. Normally three small holes are made in the lower abdomen to allow for the instruments and other various surgical tools. Nerve tissue that runs to the uterus is interrupted at the sacral promontory; a point at which spine and sacrum meet. This is the best area to access and obtain a clear view of the nerves in the uterus. Proper precautions must be taken as to avoid unnecessary complications with the major blood vessels surrounding the uterus. Some of the complications post-operation include urinary retention, as well as constipation. Neither has been reported to cause lasting effects. [5]
Recent technological advances have allowed this same procedure to be done robotically, a minimally invasive technique similar to laparoscopy. The outcome of the procedure is identical to an open approach (laparotomy), but the incisions are much smaller allowing for less post-operation pain. Less pain following this surgery allows for a quicker recovery period too; two weeks as opposed to six weeks, on average. [6]
A vestibular neurectomy is an operation that severs the vestibular nerve, which contributes to balance, while sparing the cochlear nerve, which contributes to hearing. The procedure has the potential to relieve vertigo, but may preserve the ability to hear. [7] It is important to note that this procedure will not reverse the effects of deafness. The risks include: hearing loss, tinnitus, dizziness, facial weakness, spinal fluid leak, and various infections. [8] There are several different surgical approaches that can be used to complete this procedure: the middle cranial fossa, retrolabrynthine, retrosigmoid, and translabrynthine. [9] The middle cranial fossa approach is one that most often requires neurosurgical expertise. The advantage of this procedure is that the vestibular nerve is clearly visible and can be sectioned without harming the cochlear nerve fibers. [7]
The general procedure begins by positioning the patient supine with the head turned to the side with surgical ear upright. An incision is made at the lower portion of the zygomatic root to the area of the temporal region for roughly seven centimeters. Precautions are taken by clamping flaps of tissue as to not impede further actions. To expose the IAC (Inner Auditory Canal) properly, portions of bone from the metal fundus and also the tegmen tympani must be removed. [8] The SVN (superior vestibular nerve) is then identified and cut at the point furthest from the vestibular crest. Along with the SVN, Scarpa's ganglion is also cut and removed. [8]
In cases of Ménière's disease, a neurectomy may be needed when no other medical treatment is sufficient for over six months. In bilateral Ménière's disease, the procedure is done on the worse-off ear. Some procedures are done on both ears, but the risk of hearing loss then becomes significantly greater. [8]
Some ablations that have been previously performed laparoscopically are also now offered via the pulsed radiofrequency technique. Pulsed radiofrequency ablation relies on delivering an electrical field specifically to neural tissue in order to damage it while minimizing injury to the surrounding area. For example, this technique has been used in patients with chronic shoulder pain as a way to perform a neurectomy of the suprascapular nerve with less risk of damage to nearby muscles within the rotator cuff. [10] There is still a lack of evidence directly comparing the efficacy and safety of this technique compared to the traditional laparoscopic method, but there is evidence that it improves range of motion and pain compared to placebo [10] or sham surgery. [11]
Neurectomy can be an alternative to a nerve decompression for nerve entrapment, such as when the nerves have no motor function and numbness along the dermatome is acceptable. A neurectomy is not a mutually exclusive option to a decompression as a neurectomy can also be used after a failed decompression. [1]
There are many nerves in the human body that are purely sensory such as the cutaneous nerves, which provide innervation to all parts of the skin. The cutaneous nerves are especially susceptible to compression from wearables or injuries due to their superficial location. Some examples of wearable-induced irritation are supraorbital neuralgia from tight goggles, [12] superficial radial neuropathy from handcuffs, [13] and meralgia paresthetica from tight pants. [14] As cutaneous nerves cover all areas of the skin, and any surgery which requires incisions may inadvertently cause injury or scarring, now entrapping a cutaneous nerve. [15]
A common tradeoff when electing to a neurectomy is that numbness along the nerve distribution is expected. Studies that have measured how bothersome numbness is to patients have found that most patients are not bothered at all by the numbness, and the ones that are find the numbness minimally bothering. [16] [17]
Intercoastal neuralgia is a neuropathic condition that involves the intercoastal nerves. The primary symptom is pain and it may be localized to the distribution of one or more of the intercoastal nerves, manifesting as chest and abdominal pain. [18] No treatment modality prior to neurectomy (e.g. systemic medications, cryoablation, therapeutic nerve blocks, and radioablation) has given effective pain relief and none have been curative. [19]
The success outcome is typically measured as a 50% or more decrease in visual analog scale (VAS) scores, which are numerical pain scores from 0 - 10 or 0-100. Success rates are often reported as 70%. [20] [21] [22] Studies reporting on intercoastal neurectomy often report cure rates (100% reduction in symptoms), even though it's not the primary success outcome. For example, patients may say they are cured or report pain scores of zero. There is a wide span of the reported cure rates, ranging from 22 - 67%. [20] [21] [23] A double-blind, randomized, controlled surgery trial found a 22% cure rate for the surgery group and a 4% cure rate for the sham surgery group, suggesting that these cure rates cannot be purely attributable to the natural history of the disease or a placebo effect. [21]
Lateral femoral cutaneous neuralgia, often known as Meralgia Paresthetica, involves neuropathic pain on the outer thigh. The use of a nerve decompression or neurectomy to treat nerve pain along the lateral femoral cutaneous nerve is a firmly established surgical treatment. [24] [25] However, the more effective treatment between a decompression and neurectomy is still being researched.
Between a nerve decompression and a neurectomy, the neurectomy is associated with a higher success rate which has been validated by two Cochrane reviews. The reviews found decompressions beneficial in 88% of cases and neurectomy beneficial in 94% of cases. [26] [27] A German national cohort study found similar results where complete pain relief from decompression was seen in 63% of cases but complete pain relief from neurectomy was seen in 85%. [28]
Neurectomy is also used in equine medicine, primarily for cases of persistent lameness that is non-responsive to other forms of treatment. It is most commonly used for animals with navicular syndrome and suspensory ligament desmitis. [29]
Trigeminal neuralgia, also called Fothergill disease, tic douloureux, trifacial neuralgia, or suicide disease, is a long-term pain disorder that affects the trigeminal nerve, the nerve responsible for sensation in the face and motor functions such as biting and chewing. It is a form of neuropathic pain. There are two main types: typical and atypical trigeminal neuralgia.
Pudendal nerve entrapment (PNE), also known as Alcock canal syndrome, is an uncommon source of chronic pain in which the pudendal nerve is entrapped or compressed in Alcock's canal. There are several different types of PNE based on the site of entrapment anatomically. Pain is positional and is worsened by sitting. Other symptoms include genital numbness, fecal incontinence and urinary incontinence.
Neuropathic pain is pain caused by a lesion or disease of the somatosensory nervous system. Neuropathic pain may be associated with abnormal sensations called dysesthesia or pain from normally non-painful stimuli (allodynia). It may have continuous and/or episodic (paroxysmal) components. The latter resemble stabbings or electric shocks. Common qualities include burning or coldness, "pins and needles" sensations, numbness and itching.
Neuralgia is pain in the distribution of a nerve or nerves, as in intercostal neuralgia, trigeminal neuralgia, and glossopharyngeal neuralgia.
Occipital neuralgia (ON) is a painful condition affecting the posterior head in the distributions of the greater occipital nerve (GON), lesser occipital nerve (LON), third occipital nerve (TON), or a combination of the three. It is paroxysmal, lasting from seconds to minutes, and often consists of lancinating pain that directly results from the pathology of one of these nerves. It is paramount that physicians understand the differential diagnosis for this condition and specific diagnostic criteria. There are multiple treatment modalities, several of which have well-established efficacy in treating this condition.
Microvascular decompression (MVD), also known as the Jannetta procedure, is a neurosurgical procedure used to treat trigeminal neuralgia, a pain syndrome characterized by severe episodes of intense facial pain, and hemifacial spasm. The procedure is also used experimentally to treat tinnitus and vertigo caused by vascular compression on the vestibulocochlear nerve. As the goal of the Jannetta procedure is to relieve (vascular) pressure on the trigeminal nerve, it is a specific type of a nerve decompression surgery.
Tarsal tunnel syndrome (TTS) is a nerve compression syndrome or nerve entrapment syndrome causing a painful foot condition in which the tibial nerve is entrapped as it travels through the tarsal tunnel. The tarsal tunnel is found along the inner leg behind the medial malleolus. The posterior tibial artery, tibial nerve, and tendons of the tibialis posterior, flexor digitorum longus, and flexor hallucis longus muscles travel in a bundle through the tarsal tunnel. Inside the tunnel, the nerve splits into three segments. One nerve (calcaneal) continues to the heel, the other two continue on to the bottom of the foot. The tarsal tunnel is delineated by bone on the inside and the flexor retinaculum on the outside.
Nerve block or regional nerve blockade is any deliberate interruption of signals traveling along a nerve, often for the purpose of pain relief. Local anesthetic nerve block is a short-term block, usually lasting hours or days, involving the injection of an anesthetic, a corticosteroid, and other agents onto or near a nerve. Neurolytic block, the deliberate temporary degeneration of nerve fibers through the application of chemicals, heat, or freezing, produces a block that may persist for weeks, months, or indefinitely. Neurectomy, the cutting through or removal of a nerve or a section of a nerve, usually produces a permanent block. Because neurectomy of a sensory nerve is often followed, months later, by the emergence of new, more intense pain, sensory nerve neurectomy is rarely performed.
Meralgia paresthetica or meralgia paraesthetica is pain or abnormal sensations in the outer thigh not caused by injury to the thigh, but by injury to a nerve which provides sensation to the lateral thigh.
Morton's neuroma is a benign neuroma of an intermetatarsal plantar nerve, most commonly of the second and third intermetatarsal spaces, which results in the entrapment of the affected nerve. The main symptoms are pain and/or numbness, sometimes relieved by ceasing to wear footwear with tight toe boxes and high heels. The condition is named after Thomas George Morton, though it was first correctly described by a chiropodist named Durlacher.
Radiofrequency ablation (RFA), also called fulguration, is a medical procedure in which part of the electrical conduction system of the heart, tumor, sensory nerves or a dysfunctional tissue is ablated using the heat generated from medium frequency alternating current. RFA is generally conducted in the outpatient setting, using either a local anesthetic or twilight anesthesia. When it is delivered via catheter, it is called radiofrequency catheter ablation.
The lateral cutaneous nerve of the thigh is a cutaneous nerve of the thigh. It originates from the dorsal divisions of the second and third lumbar nerves from the lumbar plexus. It passes under the inguinal ligament to reach the thigh. It supplies sensation to the skin on the lateral part of the thigh by an anterior branch and a posterior branch.
The superior hypogastric plexus is a plexus of nerves situated on the vertebral bodies anterior to the bifurcation of the abdominal aorta. It bifurcates to form the left and the right hypogastric nerve. The SHP is the continuation of the abdominal aortic plexus.
Post herniorrhaphy pain syndrome, or inguinodynia is pain or discomfort lasting greater than 3 months after surgery of inguinal hernia. Randomized trials of laparoscopic vs open inguinal hernia repair have demonstrated similar recurrence rates with the use of mesh and have identified that chronic groin pain (>10%) surpasses recurrence (<2%) and is an important measure of success.
The superior cluneal nerves are pure sensory nerves that innervate the skin of the upper part of the buttocks. They are the terminal ends of the L1-L3 spinal nerve dorsal rami lateral branches. They are one of three different types of cluneal nerves. They travel inferiorly through multiple layers of muscles, then traverse osteofibrous tunnels between the thoracolumbar fascia and iliac crest.
Migraine surgery is a surgical operation undertaken with the goal of reducing or preventing migraines. Migraine surgery most often refers to surgical nerve decompression of one or several nerves in the head and neck which have been shown to trigger migraine symptoms in many migraine sufferers. Following the development of nerve decompression techniques for the relief of migraine pain in the year 2000, these procedures have been extensively studied and shown to be effective in appropriate candidates. The nerves that are most often addressed in migraine surgery are found outside of the skull, in the face and neck, and include the supra-orbital and supra-trochlear nerves in the forehead, the zygomaticotemporal nerve and auriculotemporal nerves in the temple region, and the greater occipital, lesser occipital, and third occipital nerves in the back of the neck. Nerve impingement in the nasal cavity has additionally been shown to be a trigger of migraine symptoms.
Nerve compression syndrome, or compression neuropathy, or nerve entrapment syndrome, is a medical condition caused by chronic, direct pressure on a peripheral nerve. It is known colloquially as a trapped nerve, though this may also refer to nerve root compression. Its symptoms include pain, tingling, numbness and muscle weakness. The symptoms affect just one particular part of the body, depending on which nerve is affected. The diagnosis is largely clinical and can be confirmed with diagnostic nerve blocks. Occasionally imaging and electrophysiology studies aid in the diagnosis. Timely diagnosis is important as untreated chronic nerve compression may cause permanent damage. A surgical nerve decompression can relieve pressure on the nerve but cannot always reverse the physiological changes that occurred before treatment. Nerve injury by a single episode of physical trauma is in one sense an acute compression neuropathy but is not usually included under this heading, as chronic compression takes a unique pathophysiological course.
Anterior cutaneous nerve entrapment syndrome (ACNES) is a nerve entrapment condition that causes chronic pain of the abdominal wall. It occurs when nerve endings of the lower thoracic intercostal nerves (7–12) are 'entrapped' in abdominal muscles, causing a severe localized nerve (neuropathic) pain that is usually experienced at the front of the abdomen.
A nerve decompression is a neurosurgical procedure to relieve chronic, direct pressure on a nerve to treat nerve entrapment, a pain syndrome characterized by severe chronic pain and muscle weakness. In this way a nerve decompression targets the underlying pathophysiology of the syndrome and is considered a first-line surgical treatment option for peripheral nerve pain. Despite treating the underlying cause of the disease, the symptoms may not be fully reversible as delays in diagnosis can allow permanent damage to occur to the nerve and surrounding microvasculature. Traditionally only nerves accessible with open surgery have been good candidates, however innovations in laparoscopy and nerve-sparing techniques made nearly all nerves in the body good candidates, as surgical access is no longer a barrier.
Deep gluteal syndrome describes the non-discogenic extrapelvic entrapment of the sciatic nerve in the deep gluteal space. In simpler terms this is sciatica due to nerve irritation in the buttocks rather than the spine or pelvis. It is an extension of non-discogenic sciatic nerve entrapment beyond the traditional model of piriformis syndrome. Where sciatic nerve irritation in the buttocks was once thought of as only piriformis muscle, it is now recognized that there are many other causes. Symptoms are pain or dysthesias in the buttocks, hip, and posterior thigh with or without radiating leg pain. Patients often report pain when sitting. The two most common causes are piriformis syndrome and fibrovascular bands, but many other causes exist. Diagnosis is usually done through physical examination, magnetic resonance imaging, magnetic resonance neurography, and diagnostic nerve blocks. Surgical treatment is an endoscopic sciatic nerve decompression where tissue around the sciatic nerve is removed to relieve pressure.