Peripheral neurectomies: A treatment option for trigeminal neuralgia in rural practice

Abstract

Background:Trigeminal neuralgia is a commonly diagnosed neurosensory disease of head, neck and face region, involving 5th cranial nerve. Carbamazepine is the first line drug if there is decrease in efficacy or tolerability of medication, surgery needs to be considered. Factors such as pain relief, recurrence rates, morbidity and mortality rates should be taken in to account while considering which technique to use. Peripheral neurectomy is a safe and effective procedure for elderly patients and in rural and remote centers where neurosurgical facilities are not available. It is also effective in those patients who are reluctant for major neurosurgical procedures. Although loss of sensation along the branches of trigeminal nerve and recurrence rate are associated with peripheral neurectomy, we consider it as the safe and effective procedure in rural practice, which can be done under local anesthesia.Aims:The aim of this prospective study is to evaluate the long term efficacy of peripheral neurectomy with and without the placement of stainless steel screws in the foramina and to calculate the mean remission period after peripheral neurectomies for different branches of trigeminal nerve.Setting and Design:The sample was divided into 2 groups by selecting randomly the patients, satisfying inclusion criteria. Both groups were operated under local anesthesia by regional nerve blocks. In one group of patients after peripheral neurectomy, the proximal nerve stump was left alone in the foramina, and in another group of patients, obturation of foramina was done with stainless steel screws after peripheral neurectomy.Materials and Methods:Peripheral neurectomy was done on the terminal branches of trigeminal nerve in 14 patients. We selected only those cases that were experiencing pain after Carbamazepine therapy, all our patients were from rural and remote areas where facilities to neurosurgical centers are limited. Elderly patients who were unfit for surgical procedures and those patients who were reluctant for major neurosurgical treatments were considered for the study.Results:Post-surgical pain relief varied from 15 months to 24 months in cases where neurectomy was done without placing stainless steel screws in the foramina. Those cases where peripheral neurectomy was done along with the placement of stainless steel screws in the foramina, none of the patient had painful symptoms even after minimum 2 years of follow-up. Student's `t`-test of 2 groups showed the remission period to be statistically highly significant in patients with stainless steel screw obturation, having P-value <0.0005.Obturating the foramen with stainless steel screws can prevent nerve regeneration. Thus, remission of pain can be prolonged.Conclusion:Peripheral neurectomy is thus a safe and effective procedure for elderly patients, for those patients living in remote and rural places that cannot avail major neurosurgical facilities, and for those patients who are reluctant for major neurosurgical procedures.

Interventional Treatment Options for Trigeminal Neuralgia

“…Often, patients electing these auxiliary interventions have major contraindications for neurosurgery, are unfit for general anesthesia, or simply prefer less invasive procedures [14][15][16]. However, the effectiveness, duration of pain relief, rate of relapse and complication, and overall patient satisfaction with auxiliary interventions are generally based on case reports and studies with small sample sizes; thus, overall impression of such modalities is less favorable compared to MVD, rhizotomy, and GKRS [17].…”

“…Contraindications: peripheral neurectomy may be contraindicated in those unable to tolerate general anesthesia, as other approaches are more invasive (e.g., maxillary sinus route) [49]. Decreased corneal sensation 6.3-15 [40] Facial hematoma 7 [42] Aseptic meningitis 0.12-3 [42] Hearing loss 1.9 [42] Bacterial meningitis 1.5-1.7 [42] Buccal mucosa penetration 1.5 [42] Carotid puncture 0.77 [42] PBC Hyperesthesia; persistent symptoms 89-100; 4.6-40 [41] Masseter weakness 1.2-12 [39] Facial hematoma 3.5-6.7 [43] Hearing loss 2.4-6.3 [44] Anesthesia dolorosa 0-3.4 [39] Decreased corneal sensation 0-3.1 [40] Pseudoaneurysm 1 [44] Bacterial meningitis 0.7-1 [43] Aseptic meningitis 0.7 [43] Trigeminal reflex bradycardia Hypotension GKRS Hyperesthesia 6-42 [33] Anesthesia dolorosa 0.2 [33] MVD Trigeminal nerve deficit 1.6-22 [45] Facial weakness 0.6-10.6 [45] Hearing loss 1.2-6.8 [45] Anesthesia dolorosa 0-4 [46] Aseptic meningitis 2 [47] Hydrocephalus 0.15 [48] Mortality 0.15-0.8 [24] Cerebellar infarct or hematoma 0.075-0.68 [45] Approach: for procedures done under local anesthesia, a diagnostic nerve block with 2% lidocaine HCl plus adrenaline 1:200,000 concentration must completely resolve symptoms prior to neurectomy [14]. Infraorbital, inferior alveolar, and mental neurectomies usually require the following incisions: vestibular, Ginwalla's, and crevicular incision, respectively.…”

“…After further blunt and sharp dissection on its medial aspect, the temporalis and medial pterygoid muscles are split, facilitating the clamping and avulsing of the mental nerve at the mental foramen. Sealing the infraorbital foramen with stainless steel screws is the final step [14].…”

“…Outcome: pain relief from peripheral neurectomies has been reported to an average of 26.5 months when obturated with fatty tissues [50] and greater than 24 months when obturated with stainless steel screws [14]. One case report from India of a 65-year-old female who underwent a mental neurectomy endorsed pain reduction from 8 to 1 on VAS score from pre-procedure to 2 years postoperatively, respectively [11].…”

Trigeminal neuralgia: recent approach in classification, diagnosis and management

“…Overall, PN is a safe procedure without any major complications reported and can be repeated for pain recurrence. 31…”