Efficacy of primary microvascular decompression versus subsequent microvascular decompression for trigeminal neuralgia

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

OBJECTIVE

Microvascular 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.

METHODS

Microsurgical 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.

RESULTS

The 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.

CONCLUSIONS

Posterior 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.

A Case Series of Stereotactic Radiosurgery First for Trigeminal Neuralgia: A History of Stereotactic Radiosurgery Does Not Complicate Microvascular Decompression

BACKGROUND AND OBJECTIVES

The influence of prior stereotactic radiosurgery (SRS) on outcomes of subsequent microvascular decompression (MVD) for patients with trigeminal neuralgia (TN) is not well understood. To directly compare pain outcomes in patients undergoing primary MVD vs those undergoing MVD with a history of 1 prior SRS procedure.

METHODS

We retrospectively reviewed all patients undergoing MVD at our institution from 2007 to 2020. Patients were included if they underwent primary MVD or had a history of SRS alone before MVD. Barrow Neurological Institute (BNI) pain scores were assigned at preoperative and immediate postoperative time points and at every follow-up appointment. Evidence of pain recurrence was recorded and compared via Kaplan-Meier analysis. Multivariate Cox proportional hazards regression was used to identify factors associated with worse pain outcomes.

RESULTS

Of patients reviewed, 833 met our inclusion criteria. Thirty-seven patients were in the SRS alone before MVD group, and 796 patients were in the primary MVD group. Both groups demonstrated similar preoperative and immediate postoperative BNI pain scores. There were no significant differences between average BNI at final follow-up between the groups. Multiple sclerosis (hazard ratio (HR) = 1.95), age (HR = 0.99), and female sex (HR = 1.43) independently predicted increased likelihood of pain recurrence on Cox proportional hazards analysis. SRS alone before MVD did not predict increased likelihood of pain recurrence. Furthermore, Kaplan-Meier survival analysis demonstrated no relationship between a history of SRS alone and pain recurrence after MVD ( P = .58).

CONCLUSION

SRS is an effective intervention for TN that may not worsen outcomes for subsequent MVD in patients with TN.

Meningitis after elective intracranial surgery: a systematic review and meta-analysis of prevalence

Meningitis is a potential complication of elective intracranial surgery (EIS). The prevalence of meningitis after EIS varies greatly in the literature. The objective of this study was to estimate the overall pooled prevalence of meningitis following EIS. Four databases (PubMed, Scopus, Web of Science, and Embase) were searched to identify relevant studies. Meta-analyses of proportions were used to combine data. Cochran's Q and I2 statistics were used to assess and quantify heterogeneity. Additionally, several subgroup analyses were conducted to investigate the source of heterogeneity and examine differences in the prevalence based on variables such as geographical regions, income level, and meningitis type. The meta-analysis included 83 studies (30 959 patients) from 26 countries. The overall pooled prevalence of meningitis after EIS was 1.6% (95% CI 1.1-2.1), with high heterogeneity present (I2 = 88%). The pooled prevalence in low- to middle-income countries and high-income countries was 2.7% (95% CI 1.6-4.1) and 1.2% (95% CI 0.8-1.7), respectively. Studies that reported only aseptic meningitis had a pooled prevalence of 3.2% (95% CI 1.3-5.8). The pooled prevalence was 2.8% (95% CI 1.5-4.5) in studies that reported only bacterial meningitis. Similar prevalence rates of meningitis were observed in the subgroups of tumor resection, microvascular decompression, and aneurysm clipping. Meningitis is a rare but not exceptional complication following EIS, with an estimated prevalence of 1.6%.

Outcome after microvascular decompression for trigeminal neuralgia in a single center-relation to sex and severity of neurovascular conflict

BACKGROUND

Trigeminal neuralgia (TN), a severe type of facial pain, is mainly caused by a neurovascular conflict (NVC). The severity of the NVC seems associated with the outcome following microvascular decompression (MVD) surgery. This study aimed to investigate the outcome after MVD and whether it is affected by NVC severity and sex.

METHODS

TN patients (n = 109) were followed for 5 to 10 years after MVD. Barrow Neurology Index (BNI), Patients Global Impression of Change (PGIC), complications, and time to relapse were evaluated. The NVC severity was retrospectively reviewed from presurgical MRI. Demographic and clinical factors and NVC severity were analyzed for potential association with outcome after MVD.

RESULTS

The success rate (BNI ≤ 2) was 80% after 5 to 10 years follow-up for TN patients with severe NVC (grade 2-3) and 56% for TN patients with mild NVC (grade 0-1, P = 0.003). No sex difference was observed in outcome for patients with both mild (P = 0.924) and severe NVC (P = 0.883) respectively. Three patients (2.8%) during the hospital stay, and two patients (1.8%) at 6 weeks, experienced a complication requiring invasive treatment. At long-term 52/109 patients (47.7%) reported some type of persistent adverse event, of which the majority were mild and required no treatment.

CONCLUSIONS

MVD offers an 80% probability of long-term pain relief in TN patients with severe NVC, with low frequency of serious complications. NVC severity significantly affects outcome after MVD, while no sex differences in outcome were found. In consistency with previous work, the results stress the importance of adequate neuroradiological assessment of the NVC for preoperative patient selection.

Sequential onset of bilateral trigeminal neuralgia: clinical presentation and outcomes

PURPOSE

Sequential onset of bilateral trigeminal neuralgia (TN) is rare and not well-described in the literature. The objective of this study was to characterize demographic, clinical, and procedural characteristics of patients with sequential onset bilateral TN.

METHODS

We retrospectively reviewed patients presenting with sequential onset bilateral TN at our institution from 2007 to 2020. Patient demographics, clinical diagnoses, pain outcomes, and procedural characteristics were recorded and compared. Factors associated with pain recurrence were assessed using survival analyses and multivariate regressions.

RESULTS

We identified 34 patients who presented with sequential onset bilateral TN. The average age of onset for the index case was 49.9 ± 15.5 years, and 58.0 ± 16.8 years for the contralateral case. In total for our cohort, 91 surgical procedures were performed for the index case, and 70 for the contralateral case. With each additional surgical intervention, pain-free survival was more likely to decrease, p = 0.05. When controlled for order of intervention, glycerin rhizotomy (p = 0.01) and glycerin-radiofrequency rhizotomy (p = 0.05) were more likely associated with pain recurrence compared to microvascular decompression. While pain outcomes were significantly decreased in our cohort at final follow-up, 82.4% of patients were still dependent on medication for pain management after an average of 5.03 ± 7.74 years.

CONCLUSION

Our results represent one of the largest series of sequential onset bilateral TN in North America. Our study demonstrates the high treatment burden and chronicity of pain encountered in this population.

Microvascular decompression: Diversified of imaging uses, advantages of treating trigeminal neuralgia and improvement after the application of endoscopic technology

Classical trigeminal neuralgia (CTN) is a unilateral and severe facial pain disease, which seriously affects the patient's quality of life. Microvascular decompression (MVD) is currently the most effective surgical method, and it is the only treatment for the etiology of CTN. Imaging for MVD has been increasingly used, and the advantages and disadvantages of endoscopy-assisted vascular decompression surgery have been controversially debated. In this review, we aimed to discuss the advantages of MVD in the treatment of patients with CTN, the importance of using imaging in disease management, and the improvements of vascular decompression surgery through the application and maturity of endoscopic techniques. Compared with other surgical methods, MVD has more prominent short- and long-term treatment effects. Its selection depends on the accurate discovery of neurovascular compression by preoperative imaging. Moreover, magnetic resonance imaging plays a diverse role in MVD, not only in identifying the responsible vessels but also in determining the prognosis and as a tool for scientific research. The use of endoscopic techniques provides improved visualization of the MVD and additional benefits for vascular decompression surgery.

Surgical treatment for Trigeminal neuralgia

Various treatments for trigeminal neuralgia (TN) are known to yield initial satisfactory results; however, the surgical treatment has excellent long-term outcomes and a low recurrence rate. Surgical treatment addresses the challenge of vascular compression, which accounts for 85% of the causes of TN. As for surgical treatment for TN, microvascular decompression (MVD) has become the surgical treatment of choice after Peter J. Jannetta reported the results of MVD surgery in 1996. Since then, many studies have reported a success rate of over 90% for the initial surgical treatment. Most MVDs aim to separate (decompress) the culprit vessel from the trigeminal nerve. To increase the success rate of surgery, accurate indications for MVD and management of the offender vessels without complications are critical. In addition, if there is no vascular compression, partial sensory rhizotomy or internal neurolysis can be performed to improve surgical outcomes.

Treatment of redo-microvascular decompression or internal neurolysis plus microvascular decompression for recurrent trigeminal neuralgia: a review of long-term effectiveness and safety

Objective

We examined the clinical characteristics and outcomes of patients with recurrent trigeminal neuralgia (TN) and assessed the long-term efficacy and safety of microvascular decompression (MVD) to treat typical recurrent TN.

Methods

We identified 3024 patients who underwent MVD for treatment of TN at the China-Japan Friendship Hospital from March 2009 to December 2020. We retrospectively analyzed the data and outcomes of 137 patients who underwent redo-MVD and 74 patients who did not undergo redo-MVD as the control group. These outcomes were evaluated using the Barrow Neurological Institute scoring system.

Results

Recurrence in 68 of the 137 patients was due to incomplete or absent decompression or new responsible vessels. To ensure thorough pain relief, redo-MVD should include decompression of both the trigeminal root entry zone and the peripheral nerve segments, where blood vessels can cause symptoms. Factors associated with reduced effectiveness of redo-MVD were no period of initial pain relief after the first MVD and a longer duration of symptoms before the first MVD.

Conclusions

Redo-MVD should not be excluded as a treatment option for patients with refractory TN who develop recurrent pain after a first MVD procedure.

The incidence of postoperative cerebrospinal fluid leakage after elective cranial surgery: a systematic review

Cerebrospinal fluid (CSF) leakage is a major complication after elective neurosurgical procedures. The aim of this systematic literature review is to summarize the incidence rates of postoperative cerebrospinal fluid leakage for neurosurgical procedures, classified by surgical approach. The Pubmed, Cochrane, Embase, and Web of Science databases were searched for studies reporting the outcome of patients undergoing elective neurosurgical procedures. The number of patients, surgical approach, and indication for surgery were recorded for each study. Outcomes related to CSF leakage such as clinical manifestation and treatment were reported as well. One hundred and thirteen studies were included, reporting 94,695 cases. Overall, CSF leaks were present in 3.8% of cases. Skull base surgery had the highest rate of CSF leakage with 6.2%. CSF leakage occurred in 5.9% of anterior skull base procedures, 6.4% of middle fossa, and 5.2% of transpetrosal surgeries. 5.8% of reported infratentorial procedures were complicated by CSF leakage versus 2.9% of supratentorial surgeries. CSF leakage remains a common serious adverse event after cranial surgery. There exists a need for standardized procedures to reduce the incidence of postoperative CSF leakage, as this serious adverse event may lead to increased health care costs.

Personal experience with microvascular decompression and partial sensory rhizotomy for trigeminal neuralgia

Background

Trigeminal neuralgia (TN) is a severe, paroxysmal pain in the distribution of the fifth cranial nerve. Microvascular decompression (MVD) is the most widely used surgical treatment for TN. We undertook this study to analyze the effects of and complications of MVD and to refine the surgical procedure for treating TN.

Methods

A total of 88 patients underwent for TN underwent surgery at our hospital. Among them, 77 patients underwent MVD alone, and 11 underwent partial sensory rhizotomy (PSR) with or without MVD. The medical records of these patients were retrospectively analyzed for patient characteristics, clinical results, offending vessels, and complications if any.

Results

The mean follow-up duration was 43.2 months (range, 3–216 months). The most common site of pain was V2+V3 territory (n=27), followed by V2 (n=25) and V3 (n=23). The most common offending vessels were the superior cerebellar artery and anterior inferior cerebellar artery in that order. The overall rate of postoperative complications was 46.1%; however, most complications were transient. There were two cases of permanent partial hearing disturbance. In the MVD alone group, the cure rate was 67.5%, and the improvement rate was 26.0%. Among 11 patients who underwent PSR with or without MVD, the cure rate was 50.0%, and the improvement rate was 30.0%.

Conclusion

The clinical results of MVD were satisfactory. Although the outcomes of PSR were not as favorable as those of pure MVD in this study, PSR can be considered in cases where there is no significant vascular compressive lesion or uncertainty of the causative vessel at the surgery.

Intraoperative monitoring of sensory part of the trigeminal nerve using blink reflex during microvascular decompression for trigeminal neuralgia

Intraoperative monitoring during cerebellopontine angle surgery is widely accepted. While techniques which monitor cranial motor nerves are commonly used, monitoring the sensory afferents has been challenging. Considering the reflex arc, blink reflex (BR) might be useful in monitoring the sensory part of the trigeminal nerve, the brainstem connections and the facial nerve. We describe the case of a patient who developed hemifacial hypoesthesia after microvascular decompression surgery for trigeminal neuralgia. Intraoperative BR showed a severe loss of R1 amplitude. BR might be a useful intraoperative technique to monitor the sensory part of the trigeminal nerve.

Outcomes of Two-Isocenter Gamma Knife Radiosurgery for Patients with Typical Trigeminal Neuralgia: Pain Response and Quality of Life

OBJECTIVE

To evaluate the effectiveness and safety of 2-isocenter Gamma Knife surgery (GKS) by reviewing patients with trigeminal neuralgia (TN) from the last 10 years.

METHODS

A total of 247 patients were followed up and the Barrow Neurological Institute scale was used to evaluate pain degree. Patients' age, gender, pain duration and location, preoperative/postoperative Barrow Neurological Institute scale score, time to initial pain relief, recurrence time, and complications were documented and analyzed.

RESULTS

Patients who underwent a 2-isocenter GKS achieved earlier initial pain relief. The median time of initial pain relief was 2.0 months. Kaplan-Meier analysis showed that the patients with a shorter history of TN and the patients without preoperative surgery achieved earlier initial pain relief. During the 122.8 months of follow-up, the median time of recurrence-free pain relief was 49.7 months. Age was found to be a risk factor of recurrence. Patients who underwent 2-isocenter GKS had a higher rate of postoperative facial numbness, but only 9 cases reported bothersome facial numbness. Multibranch involvement was a risk factor for postoperative facial numbness.

CONCLUSIONS

Compared with other modalities, 2-isocenter GKS was a safe and highly effective option for patients with TN. However, more data need to be collected to verify its long-term effect.