Previous Microvascular Decompression Research Articles

Bipolar, high-voltage, long-duration pulsed radiofrequency ablation of the Gasserian ganglion for the treatment of trigeminal neuralgia in a patient with a cardiac implantable electronic device: illustrative case.

One of the common methods of treating trigeminal neuralgia (TN) nowadays is radiofrequency therapy. However, it has serious limitations in patients with a cardiac pacemaker because of electromagnetic interference. Therefore, it is crucial to select optimal radiofrequency ablation parameters to make this procedure safe with favorable outcomes for such patients. In this study, the authors present a case of a 70-year-old man with a history of cardiac pacemaker dependency and previous microvascular decompression with complaints of severe, constant facial pain. After reprogramming the cardiac implantable electronic device (CIED), the authors performed bipolar, high-voltage, long-duration pulsed radiofrequency therapy (PRFT) of the Gasserian ganglion under electrocardiography and pulse rate control in the pre-, intra-, and postoperative periods. There were no cardiovascular or neurological complications after PRFT. The patient reported relief of pain after the procedure, and at the 9-month follow-up, he was pain-free. This clinical case demonstrates that the use of bipolar, high-voltage PRFT for TN treatment in patients with a CIED can be safe and effective, provided that the rules and pacemaker instructions are followed. It is necessary to use ablative treatment with caution and to guide the patient in collaboration with a cardiac surgeon and an anesthesiologist resuscitator.

Microsurgical posterior fossa re-exploration for recurrent trigeminal neuralgia after previous microvascular decompression: common grounds—scarring, deformation, and the “piston effect”

ObjectiveMicrovascular decompression (MVD) is a well-accepted treatment modality for trigeminal neuralgia (TN) with high initial success rates. The causes for recurrence of TN after previously successful MVD have not been fully clarified, and its treatment is still a matter of debate. Here, we present the surgical findings and the clinical outcome of patients with recurrent TN after MVD who underwent posterior fossa re-exploration.MethodsMicrosurgical posterior fossa re-exploration was performed in 26 patients with recurrent TN (mean age 59.1 years) who underwent MVD over a period of 10 years. The trigeminal nerve was exposed, and possible factors for recurrent TN were identified. Arachnoid scars and Teflon granulomas were dissected meticulously without manipulating the trigeminal nerve. Outcome of posterior fossa re-exploration was graded according to the Barrow Neurological Institute (BNI) pain intensity score. Follow-up was analyzed postoperatively at 3, 12, and 24 months and at the latest available time point for long-term outcome.ResultsThe mean duration of recurrent TN after the first MVD was 20 months. Pain relief was achieved in all patients with recurrent TN on the first postoperative day. Intraoperative findings were as follows: arachnoid scar tissue in 22/26 (84.6%) patients, arterial compression in 1/26 (3.8%), venous contact in 8/26 (30.8%), Teflon granuloma in 14/26 (53.8%), compression by an electrode in Meckel’s cave used for treatment of neuropathic pain in 1/26 (3.8%), evidence of pulsations transmitted to the trigeminal nerve through the Teflon inserted previously/scar tissue (“piston effect”) in 15/26 (57.7%), and combination of findings in 18/26 (69.2%). At long-term follow-up (mean 79.5 months; range, 29–184 months), 21/26 (80.8%) patients had favorable outcome (BNI I-IIIa). New hypaesthesia secondary to microsurgical posterior fossa re-exploration occurred in 5/26 (19.2%) patients.ConclusionsPosterior fossa re-exploration avoiding manipulation to the trigeminal nerve, such as pinching or combing, may be a useful treatment option for recurrent TN after previously successful MVD providing pain relief in the majority of patients with a low rate of new hypaesthesia.

Treatment of postsurgical trigeminal neuralgia with Fu's subcutaneous needling therapy resulted in prompt complete relief: Two case reports.

Trigeminal neuralgia is a recurrent unilateral transient electroshock-like pain. Fu's subcutaneous needling (FSN), used to treat the musculoskeletal problems, has not been reported in this field. The pain extent of case 1 had no reduction after the previous microvascular decompression, the pain of case 2 relapsed 4 years after the microvascular decompression. Postsurgical trigeminal neuralgia. FSN therapy was applied on the muscles around the neck and face area, which the myofascial trigger points were palpated in these muscles. The FSN needle was inserted into the subcutaneous layer and the needle tip was pointed toward the myofascial trigger point. The following outcome measurements were observed before and after treatment, including numerical rating scale, Barrow Neurology Institute Pain Scale scores, Constant Face Pain Questionnaire scores, Brief Pain Inventory-Facial scores, Patient Global Impression of Change scores, and medication dosage. The follow-up surveys were made after 2 and 4 months respectively. The pain of Case 1 was significantly reduced after 7 times FSN treatments and the pain of Case 2 was even disappeared after 6 times FSN treatments. This case report suggested that FSN can relieve postsurgical trigeminal neuralgia safely and effectively. Clinical randomized controlled studies are needed to be further conducted.

Missed Culprits in Failed Microvascular Decompression Surgery for Hemifacial Spasm and Clinical Outcomes of Redo Surgery

To identify causes of recurrent hemifacial spasm (HFS) after initial microvascular decompression (MVD) and to assess the feasibility of redo MVD. The study included 21 patients who underwent redo MVD over the last 2 decades. Their medical charts were retrospectively reviewed for preoperative medical history, previous and redo MVD intraoperative findings, and previous and redo MVD postoperative outcomes. Redo MVDs were the second operation in 20 patients and the third operation in 1 patient. The median interval between previous and redo MVD was 46.3 months (range, 14.4-188.2 months). Compression of offending vessels such as a vein or perforating artery located medial to or at the cisternal segment of the facial nerve was found to be a possible cause of previous MVD failure. MVD failure resulted from neglect of offending vessels in 10 patients, insufficient decompression in 7 patients, and untouched neurovascular compression sites in 4 patients. Spasm-free rates after redo MVD were 80.5% at 1 year and 90.5% in the last year of follow-up (median, 15.8 months; range, 3.6-152.0 months). Permanent hearing loss and facial palsy were each observed in 2 patients (9.5%). In addition, 1 patient each experienced cerebellar infarction and vocal cord palsy. Redo MVD remains a feasible treatment option for patients with HFS who failed to benefit from previous MVD, but it is associated with an increased risk of cranial nerve and vascular injuries.

Gamma Knife Surgery for Recurrent Trigeminal Neuralgia in Cases with Previous Microvascular Decompression.

Microvascular decompression (MVD) and Gamma Knife surgery (GKS) are the primary treatments for trigeminal neuralgia (TN). However, many patients require further surgical treatment after initial surgery for recurrent TN. The aim of this study was to evaluate efficacy and safety of GKS for recurrent TN cases with prior MVD. From October 2008 to June 2015, 658 patients at West China Hospital underwent GKS as the only surgical treatment, and 42 patients underwent GKS with prior MVD. The single 4-mm isocenter was located at the cisternal portion of the trigeminal nerve in all patients. Median maximum prescription dose was 85 Gy (range, 70-90 Gy). Median follow-up time was 6.2 years (range, 1.1-10 years). The percentage of patients with or without previous MVD within 1 year was 56.81%, and the percentage of patients who were pain-free was 74.74%. The recurrence rates within 10 years were 49.11% and 43.74% for patients with and without MVD, respectively. Also, 9.52% and 11.04% of patients with and without previous MVD experienced complications as a result of GKS during the long-term follow-up period. Patients who underwent previous MVD showed a significantly lower pain-free rate compared with patients without previous MVD (P= 0.01). There was no statistical significance in the recurrence rate (P= 0.82) or the complications (P= 0.93) in the 2 groups during the long-term follow-up period. For patients with recurrent TN who previously underwent MVD, GKS remains an efficacious and safe mode of treatment.

Clinical analysis of hemifacial spasm patients with delay symptom relief after microvascular decompression of distinct offending vessels.

This study investigates symptom relief in patients whose hemifacial spasms (HFS) were completely relieved following microvascular decompression (MVD). Patients with HFS who were operated on from January 2007 to May 2011, at our department, were studied. The medical records and operation videos of each patient were reviewed. Follow-up was performed via telephone communication. A total of 410 patients with HFS were divided into two groups: Group A (277 cases): HFS caused by small vascular compression, and Group B (133 cases): HFS caused by vertebral artery compression. Magnetic resonance imaging (MRI) was performed on all the patients to rule out those with secondary HFS. Patients who had undergone previous MVD were also excluded at that time. In all, 462 patients underwent MVD for HFS in our center during the study period. Follow-up was available for 410 patients. In the small vascular compression cohort, 72 (72/277, 26.0 %) HFS patients achieved relief with delayed healing. While in the vertebral artery compression cohort, 52 (52/133, 39.1 %) HFS patients experienced relief with delayed healing. There was significant difference between these two cohorts (P < 0.05). 93.75% of delayed healing patients were cured and experienced spasm relief within 6 months. Surgeons should be aware that delayed symptom relief after MVD for HFS is more common than has been reported, and time course of symptom relief is various as well as unpredictable; however, most HFS patients are cured, and experience spasm relief within 6 months.

Decreased Probability of Initial Pain Cessation in Classic Trigeminal Neuralgia Treated With Gamma Knife Surgery in Case of Previous Microvascular Decompression: A Prospective Series of 45 Patients With >1 Year of Follow-up.

Microvascular decompression (MVD) is the reference technique for pharmacoresistant trigeminal neuralgia (TN). To establish whether the safety and efficacy of Gamma Knife surgery for recurrent TN are influenced by prior MVD. Between July 1992 and November 2010, 54 of 737 patients (45 of 497 with >1 year of follow-up) had a history of MVD (approximately half also with previous ablative procedure) and were operated on with Gamma Knife surgery for TN in the Timone University Hospital. A single 4-mm isocenter was positioned in the cisternal portion of the trigeminal nerve at a median distance of 7.6 mm (range, 3.9-11.9 mm) anterior to the emergence of the nerve. A median maximum dose of 85 Gy (range, 70-90 Gy) was delivered. The median follow-up time was 39.5 months (range, 14.1-144.6 months). Thirty-five patients (77.8%) were initially pain free in a median time of 14 days (range, 0-180 days), much lower compared with our global population of classic TN (P = .01). Their actuarial probabilities of remaining pain-free without medication at 3, 5, 7, and 10 years were 66.5%, 59.1%, 59.1%, and 44.3%. The hypoesthesia actuarial rate at 1 year was 9.1% and remained stable until 12 years (median, 8 months). Patients with previous MVD showed a significantly lower probability of initial pain cessation compared with our global population with classic TN (P = .01). The toxicity was low (only 9.1% hypoesthesia); furthermore, no patient reported bothersome hypoesthesia. However, the probability of maintaining pain relief without medication was 44.3% at 10 years, similar to our global series of classic TN (P = .85).

Microvascular decompression for trigeminal neuralgia using the 'Stitched Sling Retraction' technique in recurrent cases after previous microvascular decompression.

Microvascular decompression is a well-known therapeutic option for trigeminal neuralgia. It is considered safe and effective, and is the surgical treatment of choice for the malady. However, there is no standard technique for it and different authors have proposed different techniques of performing it. In this study, we observe the clinical results of the so-called 'stitched sling retraction' technique for recurrent cases of trigeminal neuralgia. Twelve consecutive patients with recurrent trigeminal neuralgia after previous microvascular decompression(s) were admitted to our institution form February 2009 to February 2011 and underwent microvascular decompression of the trigeminal nerve using the 'stitched sling retraction' technique. In this technique, the offending loop of the superior cerebellar artery is retracted from the nerve and, using a silk thread loop around it, is suspended to the adjacent tentorium. All patients experienced pain resolution during the immediate post-operative period or within the first 6 months after surgery. They were followed for 24 to 38 months. No recurrence occurred. The 'stitched sling retraction' technique shows promising preliminary results in recurrent cases of trigeminal neuralgia after previous microvascular decompression(s). Since it is a 'transposing' technique, it might be associated with less recurrence rates (due to resuming of the neurovascular conflict) than the classic interposing technique, which uses a prosthesis between the offending vessel and the trigeminal nerve.

Decreased Rate of CSF Leakage Associated with Complete Reconstruction of Suboccipital Cranial Defects

Background Cerebrospinal fluid (CSF) leakage represents a major source of morbidity following microvascular decompression (MVD) surgery. The objective of this study was to retrospectively assess whether complete versus incomplete reconstruction of the suboccipital cranial defect influences the incidence of CSF leakage following MVD. Methods We reviewed the charts of 100 patients who consecutively underwent MVD for trigeminal neuralgia by two attending neurosurgeons between July 2004 and April 2010. Operative variables including incomplete or complete calvarial reconstruction, primary dural closure or dural closure with adjunct, and use of lumbar drainage were recorded. The effect of complete calvarial reconstruction on the incidence of postoperative CSF leakage was examined using a multivariate logistic regression model. Results Of the 36 patients whose wound closure was reconstructed with a complete cranioplasty, 2 (5.6%) patients experienced a postoperative CSF leak. Of the 64 patients whose wound closure was augmented with an incomplete cranioplasty, 15 (23.4%) experienced a postoperative CSF leak. There was suggestive but inconclusive evidence that the risk of CSF leakage following MVD was smaller with complete reconstruction of calvarial defect than with incomplete reconstruction (two-sided p value = 0.059), after accounting for age, dural closure method, use of lumbar drainage, and previous MVD. Conclusion Complete reconstruction of the suboccipital cranial defect decreases the risk of CSF leakage.

Do Carbamazepine, Gabapentin, or Other Anticonvulsants Exert Sufficient Radioprotective Effects to Alter Responses From Trigeminal Neuralgia Radiosurgery?

Laboratory studies have documented radioprotective effects with carbamazepine. We sought to determine whether carbamazepine or other anticonvulsant/neuroleptic drugs would show significant radioprotective effects in patients undergoing high-dose small-volume radiosurgery for trigeminal neuralgia. We conducted a retrospective review of 200 patients undergoing Gamma Knife (Elekta Instrument AB, Stockholm, Sweden) stereotactic radiosurgery for trigeminal neuralgia between February 1995 and May 2008. We selected patients treated with a maximum dose of 80 Gy with 4-mm diameter collimators, with no previous microvascular decompression, and follow-up ≥6 months (median, 24 months; range, 6-153 months). At the time of radiosurgery, 28 patients were taking no anticonvulsants, 62 only carbamazepine, 35 only gabapentin, 21 carbamazepine plus gabapentin, 17 carbamazepine plus other anticonvulsants, and 9 gabapentin plus other anticonvulsants, and 28 were taking other anticonvulsants or combinations. Pain improvement developed post-radiosurgery in 187 of 200 patients (93.5%). Initial complete pain relief developed in 84 of 200 patients (42%). Post-radiosurgery trigeminal neuropathy developed in 27 of 200 patients (13.5%). We could not significantly correlate pain improvement or initial complete pain relief with use of carbamazepine, gabapentin, or use of any anticonvulsants/neuroleptic drugs or other factors in univariate or multivariate analysis. Post-radiosurgery numbness/paresthesias correlated with the use of gabapentin (1 of 36 patients with gabapentin vs. 7 of 28 without, p = 0.017). In multivariate analysis, decreasing age, purely typical pain, and use of gabapentin correlated (p = 0.008, p = 0.005, and p = 0.021) with lower risks of developing post-radiosurgery trigeminal neuropathy. New post-radiosurgery numbness/paresthesias developed in 3% (1 of 36), 5% (4 of 81), and 13% (23 of 187) of patients on gabapentin alone, with age ≤70 years, and Type 1 typical trigeminal neuralgia pain compared with 25% (7 of 28), 20% (23 of 114), and 33% (4 of 12) of patients taking no anticonvulsants, age >70 years, and partly atypical Type 2 trigeminal neuralgia, respectively. The use of carbamazepine or gabapentin at the time of radiosurgery does not decrease the rates of obtaining partial or complete pain relief after radiosurgery, but gabapentin may reduce the risks of developing post-radiosurgery trigeminal neuropathy.

Unusual recurrence of trigeminal neuralgia after microvascular decompression by muscle interposal

SummaryBackgroundPatients with trigeminal neuralgia (TN) and persistent or recurrent facial pain after microvascular decompression (MVD) typically undergo less invasive procedures in the hope of providing pain relief. However, re-operation should be considered in selected patients.Case ReportA 48-year-old woman presented with recurrent trigeminal neuralgia (TN) 3 years following microvascular decompression (MVD). The patient underwent brain magnetic resonance angiography (MRA), which did not reveal neurovascular compression; therefore surgical re-exploration was carried out. During the operation, the fifth cranial nerve was seen without impingement from any blood vessels; however, a very firm tissue was observed and identified as the muscle fragment from the previous MVD procedure. The fifth cranial nerve was carefully separated from the muscle. Thereafter, the right SCA was dissected out from the muscle and suspended by a periosteum tape sutured to the nearby dura.ConclusionsOur findings, along with similar cases reported in the literature, support the development of new inert materials and alternative surgical strategies that can limit TN recurrence.

The operative findings in re-do microvascular decompression for recurrent trigeminal neuralgia

Background. Re-do microvascular decompression (MVD) of the trigeminal nerve occasionally becomes necessary following recurrence of symptoms after a previous MVD. The indications include failure or contraindication of less invasive treatment options such as medication or trigeminal nerve lesioning and when supported by vascular compression on brain MRI scans.Purpose. To report on our findings following re-do MVD in the National Hospital for Neurology and Neurosurgery, Queen Square London from July 1995 to July 2008.Methods. Case note review of all patients who underwent re-do MVD for the above reasons in the senior author's series in the above institution and stated period. The parameters of study interest were pre-operative MRI features, operative findings, and complete pain-free period with regards to the first and re-do MVD.Results. Data analysis showed that 6 underwent a re-do MVD. Neurovascular conflict was confirmed in 5 cases (83.3%) involving the superior cerebellar artery and anterior inferior cerebellar artery in 2 cases each (33.3%) and ectatic basilar artery in 1 case (16.6%). Arachnoid adhesions around the previous teflon felt were also found in 5 cases (83.3%) mostly in association with other findings. Neo-arachnoid cyst formation in the corresponding cerebello-pontine angle, was an unexpected finding in 2 cases (33.3%), though of uncertain significance.Conclusion. Redo MVD should be considered as a safe and effective treatment option in recurrent trigeminal neuralgia, which fails to respond to non-surgical means.

NONISOCENTRIC RADIOSURGICAL RHIZOTOMY FOR TRIGEMINAL NEURALGIA

Although stereotactic radiosurgery is an established procedure for treating trigeminal neuralgia (TN), the likelihood of a prompt and durable complete response is not assured. Moreover, the incidence of facial numbness remains a challenge. To address these limitations, a new, more anatomic radiosurgical procedure was developed that uses the CyberKnife (Accuray, Inc., Sunnyvale, CA) to lesion an elongated segment of the retrogasserian cisternal portion of the trigeminal sensory root. Because the initial experience with this approach resulted in an unacceptably high incidence of facial numbness, a gradual dose and volume de-escalation was performed over several years. In this single-institution prospective study, we evaluated clinical outcomes in a group of TN patients who underwent lesioning with seemingly optimized nonisocentric radiosurgical parameters. Forty-six patients with intractable idiopathic TN were treated between January 2005 and June 2007. Eligible patients were either poor surgical candidates or had failed previous microvascular decompression or destructive procedures. During a single radiosurgical session, a 6-mm segment of the affected nerve was treated with a mean marginal prescription dose of 58.3 Gy and a mean maximal dose of 73.5 Gy. Monthly neurosurgical follow-up was performed until the patient became pain-free. Longer-term follow-up was performed both in the clinic and over the telephone. Outcomes were graded as excellent (pain-free and off medication), good (>90% improvement while still on medication), fair (50-90% improvement), or poor (no change or worse). Facial numbness was assessed using the Barrow Neurological Institute Facial Numbness Scale score. Symptoms disappeared completely in 39 patients (85%) after a mean latency of 5.2 weeks. In most of these patients, pain relief began within the first week. TN recurred in a single patient after a pain-free interval of 7 months; all symptoms abated after a second radiosurgical procedure. Four additional patients underwent a repeat rhizotomy after failing to respond adequately to the first operation. After a mean follow-up period of 14.7 months, patient-reported outcomes were excellent in 33 patients (72%), good in 11 patients (24%), and poor/no improvement in 2 patients (4%). Significant ipsilateral facial numbness (Grade III on the Barrow Neurological Institute Scale) was reported in 7 patients (15%). Optimized nonisocentric CyberKnife parameters for TN treatment resulted in high rates of pain relief and a more acceptable incidence of facial numbness than reported previously. Longer follow-up periods will be required to establish whether or not the durability of symptom relief after lesioning an elongated segment of the trigeminal root is superior to isocentric radiosurgical rhizotomy.

Imaging the trigeminal nerve and pons before and after surgical intervention for trigeminal neuralgia.

To study the various imaging changes occurring in the trigeminal nerve and brainstem in patients before or after trigeminal neuralgia surgery. During a 7-year period, 275 patients with trigeminal neuralgia underwent high-resolution, contrast-enhanced magnetic resonance imaging (MRI) of the pons during gamma knife radiosurgery. Ninety-seven patients had no previous surgical intervention for trigeminal neuralgia, and 178 patients had undergone one or more previous procedures. Two independent observers, one of whom was blinded to patients' clinical details, reviewed MRI scans retrospectively. The analysis of the independent observers was then correlated with all previous therapeutic interventions. One hundred one MRI scans demonstrated no radiological changes related to trigeminal neuralgia, and 174 MRI scans exhibited some radiological abnormality. The average axial plane diameter of the nerve for all patients was 4 mm (range, 2-6 mm). In the group that had not undergone previous surgery, 65 patients (67%) exhibited vascular compression. In the 88 patients who had undergone previous microvascular decompression, 21 (24%) had evidence of a pontine infarction. Twenty-six patients experienced facial sensory loss, 22 (88%) of whom had undergone previous surgery with evidence of a pontine infarction (n = 11) or perineural scarring (n = 6). The majority of patients who had undergone previous trigeminal neuralgia surgery demonstrated readily identifiable abnormalities of the trigeminal nerve or brainstem. The frequency of such changes correlated with the type and number of procedures. Evidence of vascular compression was detected in the majority of patients. Most patients with postoperative facial sensory loss demonstrate changes in the nerve or pons on MR images.

Findings and long-term results of subsequent operations after failed microvascular decompression for trigeminal neuralgia.

To evaluate the indication of subsequent operations after failed microvascular decompression (MVD) for the treatment of trigeminal neuralgia, the intraoperative findings and long-term results of 16 subsequent operations are reported. Subsequent exploration of the posterior fossa was performed for lack of pain relief (3 patients) and recurrent neuralgia (13 patients) after an average of 17 months (range, 4-62 mo). In all patients, typical arterial compression patterns at the root entry zone of the trigeminal nerve were found in the first procedure. The mean follow-up period after subsequent operation was 90 months (range, 78-104 mo). New arterial neurovascular conflicts were found in nine patients. After subsequent MVD procedures, seven patients were pain-free (with one recurrence after 6 mo), one had constant marked relief, and one was unchanged. Second exploration revealed no abnormalities in the other seven patients who experienced continued or recurrent pain; only careful neurolysis of the trigeminal nerve was performed in those patients. Initially, all seven patients obtained complete pain relief, but two experienced late recurrences after 64 and 68 months, respectively. Thus, subsequent operations failed in all 4 patients who had undergone prior destructive procedures but were successful in those 12 patients who had undergone only previous MVD. Two patients developed severe sequelae, and the other nine had minor complications, especially permanent (four patients) or transitory (three patients) ipsilateral trigeminal hypoesthesia. Subsequent MVD seems to have good long-term results. However, because of the significantly high incidence of complications, the indication for subsequent operations should be restricted to younger patients to avoid destructive procedures. In general, glycerol rhizolysis or radiofrequency rhizotomy may be the treatment of choice after failed MVD.

Findings and Long-term Results of Subsequent Operations after Failed Microvascular Decompression for Trigeminal Neuralgia

OBJECTIVE: To evaluate the indication of subsequent operations after failed microvascular decompression (MVD) for the treatment of trigeminal neuralgia, the intraoperative findings and long-term results of 16 subsequent operations are reported. METHODS: Subsequent exploration of the posterior fossa was performed for lack of pain relief (3 patients) and recurrent neuralgia (13 patients) after an average of 17 months (range, 4-62 mo). In all patients, typical arterial compression patterns at the root entry zone of the trigeminal nerve were found in the first procedure. The mean follow-up period after subsequent operation was 90 months (range, 78-104 mo). RESULTS: New arterial neurovascular conflicts were found in nine patients. After subsequent MVD procedures, seven patients were pain-free (with one recurrence after 6 mo), one had constant marked relief, and one was unchanged. Second exploration revealed no abnormalities in the other seven patients who experienced continued or recurrent pain; only careful neurolysis of the trigeminal nerve was performed in those patients. Initially, all seven patients obtained complete pain relief, but two experienced late recurrences after 64 and 68 months, respectively. Thus, subsequent operations failed in all 4 patients who had undergone prior destructive procedures but were successful in those 12 patients who had undergone only previous MVD. Two patients developed severe sequelae, and the other nine had minor complications, especially permanent (four patients) or transitory (three patients) ipsilateral trigeminal hypoesthesia. CONCLUSION: Subsequent MVD seems to have good long-term results. However, because of the significantly high incidence of complications, the indication for subsequent operations should be restricted to younger patients to avoid destructive procedures. In general, glycerol rhizolysis or radiofrequency rhizotomy may be the treatment of choice after failed MVD.