Microvascular decompression and percutaneous rhizotomy in trigeminal neuralgia

Repeat percutaneous rhizotomy for trigeminal neuralgia is not associated with an increased risk of postoperative complications

BACKGROUND AND OBJECTIVES

Patients undergoing percutaneous rhizotomy for trigeminal neuralgia (TN) may require several procedures to manage their pain. However, it is not fully understood whether repeat procedures influence postoperative complication rates.

METHODS

We retrospectively reviewed patients undergoing rhizotomy at our institution from 2011 to 2022. Patients were included only if they had no history of prior interventions including microvascular decompression (MVD) or radiosurgery. We collected baseline patient information, pain characteristics, and postoperative complications for each patient. Patients were dichotomized into those undergoing primary rhizotomy versus those undergoing a repeat rhizotomy. Potential drivers of postoperative complications were included in a multivariate logistic regression model.

RESULTS

Of the 1904 cases reviewed, 965 met our inclusion criteria. 392 patients underwent primary rhizotomy, and 573 patients underwent repeat rhizotomies. The repeat rhizotomy group was significantly older, p<0.001. Patients in the repeat rhizotomy group expressed higher frequencies of bilateral pain, p=0.01. Patients in the repeat rhizotomy group demonstrated a significantly higher rate of preoperative numbness and postoperative numbness, p<0.001. There were no significant differences in any of the considered complications between the single rhizotomy and repeat rhizotomy groups. On multivariate logistic regression, repeat rhizotomy did not predict an increased risk of any postoperative complications, p=0.14.

CONCLUSIONS

Patients undergoing repeat rhizotomy may be at risk of postoperative numbness but are not at increased risk for postoperative complications. These results are of use to patients who are poor surgical candidates, and thus may require multiple rhizotomies to effectively manage their pain over time.

Long-term follow-up of microvascular decompression for management of trigeminal neuralgia

Background

Trigeminal neuralgia (TN) is mostly caused by neurovascular compression of the trigeminal nerve and the root entry zone at the brain stem. Microvascular decompression (MVD) has been established as a standard treatment for trigeminal neuralgia in patients not adequately controlled by medications.

Objectives

Reporting the long-term outcome of MVD in our group of patients with follow-up period equal to or more than five years.

Patients and methods

Twenty-one patients operated by MVD for TN were followed up for at least five years, they were evaluated describing the patient criteria and operative findings, complications, and the long-term clinical outcome.

Results

Sixteen of the twenty-one patients had complete pain relief maintained for up to five years and three of them up to eight years. Two patients had significant improvement but with mild occasional pain not requiring medications only one of them had his occasional pain maintained till five years, three patients experienced persistent pain which was still there after five years one of them showed mild improvement in his pain after one year of follow-up. Complications were mild and/or transient most frequent were headache nausea and dizziness.

Conclusion

In the long-term follow-up, microvascular decompression still maintains its clinical benefit with most patients still pain free after at least five years and up to eight years. It is safe procedures and should be considered in every patient with failed medical treatment.

Dorsal root entry zone procedure and other surgeries for pain

Pain is a very common symptom that often serves a protective function. It is typically treated medically. When pain becomes chronic and intractable, it no longer serves a protective function and often requires more aggressive forms of treatment. Many types of surgeries can be performed for the management of pain. These surgeries can involve ablation (destruction) or augmentation (stimulation or facilitation) of some part of the nervous system. In many of these surgeries, neurophysiologic intraoperative monitoring (NIOM) is not needed, however, in others neuromonitoring serves a mapping and monitoring purpose. The prototype of pain surgery for this chapter is the dorsal root entry zone (DREZ) procedure. Both mapping and monitoring can help improve lesioning precision and outcomes in this surgery. In this chapter, the DREZ procedures and other surgeries for primarily pain relief in which NIOM is used are discussed. Surgeries, such as spinal stenosis, in which pain relief is important but not the sole purpose, are not discussed here and are covered elsewhere.

Microvascular decompression in trigeminal neuralgia: predictors of pain relief, complication avoidance, and lessons learned

OBJECTIVE

To analyze characteristics associated with long-term pain relief after microvascular decompression (MVD) for trigeminal neuralgia (TGN). Description of associated morbidity and complication avoidance.

METHODS

One hundred sixty-five patients with TGN underwent 171 MVD surgeries at the authors' institution. Patient characteristics and magnetic resonance imaging (MRI) datasets were obtained through the hospital's archiving system. Patients provided information about pre- and post-operative pain characteristics and neurologic outcome. Favorable outcome was defined as a Barrow Neurological Institute (BNI) pain intensity score of I to III with post-operative improvement of I grade.

RESULTS

Type of TGN pain with purely paroxysmal pain (p = 0.0202*) and TGN classification with classical TGN (p = 0.0372*) were the only significant predictors for long-term pain relief. Immediate pain relief occurred in 90.6% of patients with a recurrence rate of 39.4% after 3.5 ± 4.6 years. MRI reporting of a neurovascular conflict had a low negative predictive value of 39.6%. Mortality was 0% with major complications observed in 8.2% of patients. Older age was associated with lower complication rates (p = 0.0009***). Re-MVD surgeries showed improved long-term pain relief in four out of five cases.

CONCLUSIONS

MVD is a safe and effective procedure even in the elderly. It has the unique potential to cure TGN if performed on a regular basis, and if key surgical steps are respected. Early MVD should be offered in case of medical treatment failure and paroxysmal pain symptoms. The presence of a neurovascular conflict on MRI is not mandatory. In case of recurrence, re-MVD is a good treatment option that should be discussed with patients.

HIGHLIGHTS

• Long-term analysis of pain relief after MVD. • Positive predictors for outcome: classical TGN and purely paroxysmal pain. • Presence of neurovascular conflict in MRI is not mandatory for MVD surgery. • Analysis of complications and surgical nuances for avoidance. • MVD is a safe procedure also in the elderly.

Radiofrequency thermocoagulation for the treatment of trigeminal neuralgia

Although microvascular decompression (MVD) should be considered as the first-line treatment for classic trigeminal neuralgia (TN) owing to neurovascular compression of the trigeminal nerve, an increasing number of surgeons prefer radiofrequency thermocoagulation (RFT). RFT is a Gasserian ganglion-level ablative intervention that may achieve immediate pain relief for TN. It is used for emergency management when MVD is not suitable for the patient. As the gold surgical standard of classic trigeminal neuralgia, MVD has the advantage of longer efficacy. However, there are currently no high-quality controlled trials to evaluate the efficacy of MVD and RFT. For the present systematic review, the PubMed, Embase and Cochrane databases (all entries up until July 31, 2020) were searched to identify studies related to RFT in order to provide valuable information for clinical decision-making. The efficacy of the RFT method was evaluated in terms of the initial pain relief percentage, recurrence rate and follow-up time. Furthermore, the incidence rate of various postoperative complications was retrieved. RFT was used for a wider range of applications than MVD, including use for primary (owing to neurovascular compression of the trigeminal nerve), idiopathic and secondary (due to primary neurological diseases) TN, and provided a high rate of initial pain relief and long-term pain control. Although this method has several side effects, the incidence of complications could be reduced by precise cannulation. Furthermore, the complications that occurred were not permanent. Thus, RFT is a safe and effective minimally invasive method of pain relief for patients with TN.

Efficacy and safety of radiofrequency in the treatment of trigeminal neuralgia: a systematic review and meta-analysis

To assess the effectiveness of radiofrequency (RF) versus other percutaneous strategies (balloon compression, glycerol rhizotomy [GR], and microvascular decompression [MVD]) in patients with trigeminal neuralgia. We systematically searched the electronic databases of PubMed, Embase, and the Cochrane Library to identify eligible studies throughout October 2020. The odds ratio (OR) with 95% confidence interval (CI) was applied to assess effect estimates using the random-effects model. Eighteen retrospective cohort studies that enrolled 6391 patients with trigeminal neuralgia were included. We noted that RF was associated with an increased incidence of immediate pain relief compared with GR (OR 2.65; 95% CI 1.29-5.44; P = 0.008). Moreover, RF was associated with an increased risk of pain recurrence compared with MVD (OR 3.80; 95% CI 2.00-7.20; P < 0.001). Furthermore, RF was associated with an increased incidence of postoperative anesthesia compared with GR (OR 3.01; 95% CI 1.11-8.13; P = 0.030) or MVD (OR 4.62; 95% CI 2.15-9.93; P < 0.001). This study found that RF was superior to GR for the improvement in immediate pain relief; whereas, RF yielded an excess risk of pain recurrence compared with MVD. Moreover, the incidence of postoperative anesthesia in patients treated with RF significantly increased compared with the incidence after treatment with GR and MVD.

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

OBJECTIVE Trigeminal neuralgia (TN) is characterized by intermittent, paroxysmal, and lancinating pain along the distribution of the trigeminal nerve. Microvascular decompression (MVD) directly addresses compression of the trigeminal nerve. The purpose of this study was to determine whether patients undergoing MVD as their first surgical intervention experience greater pain control than patients who undergo subsequent MVD. METHODS A retrospective review of patient records from 1998 to 2015 identified a total of 942 patients with TN and 500 patients who underwent MVD. After excluding several cases, 306 patients underwent MVD as their first surgical intervention and 175 patients underwent subsequent MVD. Demographics and clinicopathological data and outcomes were obtained for analysis. RESULTS In patients who underwent subsequent MVD, surgical intervention was performed at an older age (55.22 vs 49.98 years old, p < 0.0001) and the duration of symptoms was greater (7.22 vs 4.45 years, p < 0.0001) than for patients in whom MVD was their first surgical intervention. Patients who underwent initial MVD had improved pain relief and no improvement in pain rates compared with those who had subsequent MVD (95.8% and 4.2% vs 90.3% and 9.7%, respectively, p = 0.0041). Patients who underwent initial MVD had significantly lower rates of facial numbness in the pre- and postoperative periods compared with patients who underwent subsequent MVD (p < 0.0001). The number of complications in both groups was similar (p = 0.4572). CONCLUSIONS The results demonstrate that patients who underwent other procedures prior to MVD had less pain relief and a higher incidence of facial numbness despite rates of complications similar to patients who underwent MVD as their first surgical intervention.

Surgical Management of Trigeminal Neuralgia

BACKGROUND:

Trigeminal neuralgia is a relatively common neurosurgical pathology with multiple management options. Microvascular decompression (MVD) is nonablative and is considered the gold standard. However, stereotaxic radiosurgery (SRS) and percutaneous stereotaxic rhizotomy (PSR) are 2 noninvasive but ablative options that have rapidly gained support.

OBJECTIVE:

To use Medicare claims data in conjunction with a literature review to assess the usage, effectiveness, and cost-effectiveness of the 3 different invasive treatments for trigeminal neuralgia.

METHODS:

All of the claims of trigeminal neuralgia treatment were extracted from the 2011 5% Inpatient and Outpatient Limited Data Set. Current Procedural Terminology, 4th Edition/International Classification of Diseases, Ninth Revision codes for the 3 different surgical treatment modalities were used to further classify these claims. Kaplan-Meier survival curves in key articles were used to calculate quality-adjusted life years and cost-effectiveness for each procedure.

RESULTS:

A total of 1582 claims of trigeminal neuralgia were collected. Ninety-four (6%) patients underwent surgical intervention. Forty-eight (51.1%) surgical patients underwent MVD, 39 (41.5%) underwent SRS, and 7 (7.4%) underwent PSR. The average weighted costs for MVD, SRS, and PSR were $;40 434.95, $;38 062.27, and $;3910.64, respectively. The quality-adjusted life years were 8.2 for MVD, 4.9 for SRS, and 6.5 for PSR. The cost per quality-adjusted life year was calculated as $;4931.1, $;7767.8, and $;601.64 for MVD, SRS, and PSR, respectively.

CONCLUSION:

This study shows that the most frequently used surgical management of trigeminal neuralgia is MVD, followed closely by SRS. PSR, despite being the most cost-effective, is by far the least utilized treatment modality.

Trigeminal neuralgia occurs and recurs in the absence of neurovascular compression

Object

Vascular compression of the trigeminal nerve is the most common factor associated with the etiology of trigeminal neuralgia (TN). Microvascular decompression (MVD) has proven to be the most successful and durable surgical approach for this disorder. However, not all patients with TN manifest unequivocal neurovascular compression (NVC). Furthermore, over time patients with an initially successful MVD manifest a relentless rate of TN recurrence.

Methods

The authors performed a retrospective review of cases of TN Type 1 (TN1) or Type 2 (TN2) involving patients 18 years or older who underwent evaluation (and surgery when indicated) at Oregon Health & Science University between July 2006 and February 2013. Surgical and imaging findings were correlated.

Results

The review identified a total of 257 patients with TN (219 with TN1 and 38 with TN2) who underwent high-resolution MRI and MR angiography with 3D reconstruction of combined images using OsiriX. Imaging data revealed that the occurrence of TN1 and TN2 without NVC was 28.8% and 18.4%, respectively. A subgroup of 184 patients underwent surgical exploration. Imaging findings were highly correlated with surgical findings, with a sensitivity of 96% for TN1 and TN2 and a specificity of 90% for TN1 and 66% for TN2.

Conclusions

Magnetic resonance imaging detects NVC with a high degree of sensitivity. However, despite a diagnosis of TN1 or TN2, a significant number of patients have no NVC. Trigeminal neuralgia clearly occurs and recurs in the absence of NVC.

Comparative evaluation of surgical procedures for trigeminal neuralgia

Trigeminal neuralgia (TN) is a debilitating ailment. Pharmacotherapy still remains the first line therapy for the management of TN. However, often the patients become refractory to the pharmacotherapy and need surgical interventions. There is a wide array of surgical treatment modalities available for TN and it is important to select the most appropriate surgery for a patient. This review evaluates the various surgical modalities by employing a comparative analysis with respect to patient selection, success rate, complications and cost effectiveness. For the evaluation, a critical review of literature was done with predefined search terms to obtain the details of individual procedures, which were then compared, under similar parameters. The results suggested that microvascular decompression seem to be the most effective treatment in terms of patient satisfaction and long term cost effectiveness. However, if patient factors do not permit, then the peripheral procedures may be employed as a substitute, though they have higher recurrence rate and complications and have relatively lower long term cost effectiveness. The newer modalities like stereotactic radiosurgery and botulinum injections have promising results and further refinement in these procedures will provide additional options for the patients suffering from TN.

Long-term follow-up of microvascular decompression for trigeminal neuralgia

We conducted a study to evaluate the follow-up characteristics of patients with trigeminal neuralgia (TN) and to evaluate the factors affecting long-term outcome of microvascular decompression (MVD) in TN. Between 1983 and 2003, 156 patients with TN treated with MVD by 4 neurosurgeons at University Medical Centre Groningen/the Netherlands were evaluated. Baseline data from operative outcome were evaluated using univariate and multivariate analysis. The group consisted of 156 patients with TN: 90 females and 66 males with a median follow-up period of 9.7 years. The average age of initial symptoms was 51 years. The average duration of symptoms was 58 months. Postoperative 22 patients had a facial hyperpathia or hyperesthesia. Postoperatively, 137 patients had immediate relief. Postoperatively 1 year, 140 patients still had a good outcome of the operation. Twenty-seven patients with good immediate postoperative results had recurrent pain. From the group of patients with typical TN, 82% had good long-term results after operation. Patients with typical TN and immediate postoperative remission, in univariate analysis, had significantly more often an excellent/good postoperative outcome. Immediate postoperative remission is an independent predictive factor for a good long-term outcome. The long-term results of MVD in majority of patients were good with no mortalities and no major morbidities. Patients with typical TN had better long-term outcomes and less recurrence.

Surgical management of medically refractory trigeminal neuralgia

The role of surgery for patients with medically refractory trigeminal neuralgia (TN) is well established. High-quality magnetic resonance imaging, including gadolinium-enhanced and volume acquisition sequences, should be performed to exclude intracranial tumors or demyelinating disease as the cause of the pain, as well as to clearly demonstrate the trigeminal nerve and adjacent blood vessels. For physiologically healthy patients with Type 1 TN, a microvascular decompression (MVD) is the preferred surgical approach because of its high rate of complete pain relief, the durability of the pain relief, and the fact that trigeminal injury is not required for pain relief. Patients with recurrent TN after a failed MVD, patients with significant medical comorbidities, and patients with multiple sclerosis-related TN are generally recommended to undergo less invasive, destructive surgical techniques aimed at providing pain relief by damaging the trigeminal nerve.

Long term outcomes of gamma knife radiosurgery for typical trigeminal neuralgia-minimum 5-year follow-up

Objective

Gamma knife radiosurgery (GKRS) is the least invasive surgical option for patients with trigeminal neuralgia (TN). However, the indications and long term outcomes of GKRS are still controversial. Additionally, a series with uniform long-term follow-up data for all patients has been lacking. In the present study, the authors analyzed long-term outcomes in a series of patients with TN who underwent a single GKRS treatment followed by a minimum follow-up of 60 months.

Methods

From 1994 to 2009, 40 consecutive patients with typical, intractable TN received GKRS. Among these, 22 patients were followed for >60 months. The mean maximum radiation dose was 77.1 Gy (65.2-83.6 Gy), and the 4 mm collimator was used to target the radiation to the root entry zone.

Results

The mean age was 61.5 years (25-84 years). The mean follow-up period was 92.2 months (60-144 months). According to the pain intensity scale in the last follow-up, 6 cases were grades I-II (pain-free with or without medication; 27.3%) and 7 cases were grade IV-V (<50% pain relief with medication or no pain relief; 31.8%). There was 1 case (facial dysesthesia) with post-operative complications (4.54%).

Conclusion

The long-term results of GKRS for TN are not as satisfactory as those of microvascular decompression and other conventional modalities, but GKRS is a safe, effective and minimally invasive technique which might be considered a first-line therapy for a limited group of patients for whom a more invasive kind of treatment is unsuitable.

Effectiveness of Repeat Glycerol Rhizotomy in Treating Recurrent Trigeminal Neuralgia

BACKGROUND:

Percutaneous glycerol rhizotomy (GR) is used to treat trigeminal neuralgia (TN), with satisfactory pain relief lasting 2 to 3 years in most patients after the first intervention. The efficacy of subsequent GRs, however, has not been studied.

OBJECTIVE:

To compare the pain relief and durability achieved by the first GR with those obtained after subsequent GRs in a retrospective cohort of TN patients.

METHODS:

Between 1998 and 2010, 548 patients with TN underwent 708 GRs. After exclusions, 430 initial GRs (GR1) and 114 subsequent GRs (GR2+) were compared in terms of initial pain relief, durability, sensory change, and complications. Durability was assessed by determining median time to treatment failure for all GRs achieving complete pain relief without medications (n = 375: 264 failures, 111 censored). Predictors of initial pain relief were assessed by logistic regression, and predictors of failure were assessed by Cox regression analysis.

RESULTS:

After GR1, pain relief results were as follows: 285 patients (66%) were pain free without medications, 26 (6%) were pain free with medications, 66 (15%) improved, and 53 (12%) were unchanged. After GR2+, results were as follows: 90 patients (79%) were pain free without medications, 6 (5%) were pain free with medications, 7 (6%) improved, and 11 (10%) were unchanged (P = .03). Median time to treatment failure was 26 months after GR1 and 25 months after GR2+ (P = .34). On multivariate analysis, prior GR was a positive predictor of initial pain relief (odds ratio, 2.067; 95% confidence interval, 1.243-3.437; P = .005) and had no effect on durability.

CONCLUSION:

TN patients experienced greater pain relief and equivalent durability after GR2+ beyond the initial treatment.

Pharmacological versus microvascular decompression approaches for the treatment of trigeminal neuralgia: clinical outcomes and direct costs

In idiopathic trigeminal neuralgia (TN) the neuroimaging evaluation is usually normal, but in some cases a vascular compression of trigeminal nerve root is present. Although the latter condition may be referred to surgery, drug therapy is usually the first approach to control pain. This study compared the clinical outcome and direct costs of (1) a traditional treatment (carbamazepine [CBZ] in monotherapy [CBZ protocol]), (2) the association of gabapentin (GBP) and analgesic block of trigger-points with ropivacaine (ROP) (GBP+ROP protocol), and (3) a common TN surgery, microvascular decompression of the trigeminal nerve (MVD protocol). Sixty-two TN patients were randomly treated during 4 weeks (CBZ [n = 23] and GBP+ROP [n = 17] protocols) from cases of idiopathic TN, or selected for MVD surgery (n = 22) due to intractable pain. Direct medical cost estimates were determined by the price of drugs in 2008 and the hospital costs. Pain was evaluated using the Numerical Rating Scale (NRS) and number of pain crises; the Hospital Anxiety and Depression Scale, Sickness Impact Profile, and satisfaction with treatment and hospital team were evaluated. Assessments were performed at day 0 and 6 months after the beginning of treatment. All protocols showed a clinical improvement of pain control at month 6. The GBP+ROP protocol was the least expensive treatment, whereas surgery was the most expensive. With time, however, GBP+ROP tended to be the most and MVD the least expensive. No sequelae resulted in any patient after drug therapies, while after MDV surgery several patients showed important side effects. Data reinforce that, (1) TN patients should be carefully evaluated before choosing therapy for pain control, (2) different pharmacological approaches are available to initiate pain control at low costs, and (3) criteria for surgical interventions should be clearly defined due to important side effects, with the initial higher costs being strongly reduced with time.

Prospective Comparison of Posterior Fossa Exploration and Stereotactic Radiosurgery Dorsal Root Entry Zone Target as Primary Surgery for Patients With Idiopathic Trigeminal Neuralgia

BACKGROUND

Trigeminal neuralgia (TN) is the most common facial pain syndrome, with an incidence of approximately 27 per 100 000 patient-years.

OBJECTIVE

To prospectively compare facial pain outcomes for patients having either a posterior fossa exploration (PFE) or stereotactic radiosurgery (SRS) as their first surgery for idiopathic TN.

METHODS

Prospective cohort study of 140 patients with idiopathic TN who had either PFE (n = 91) or SRS (n = 49) from June 2001 until September 2007. The groups were similar with regard to sex, pain location, and pain duration. Patients who had SRS were older (67.1 vs 58.2 years; P &lt; .001). The median follow-up after surgery was 38 months.

RESULTS

Patients who had PFE more commonly were pain free off medications (84% at 1 year, 77% at 4 years) compared with the SRS patients (66% at 1 year, 56% at 4 years; hazard ratio = 2.5; 95% confidence interval, 1.4–4.6; P = .003). Additional surgery for persistent or recurrent face pain was performed in 14 patients after PFE (15%) compared with 17 patients after SRS (35%; P = .009). Nonbothersome facial numbness occurred more frequently in the SRS group (33% vs 18%; P = .04). No difference was noted in other complications between patients who had PFE (12%) (dysesthetic facial pain, n = 3; cerebrospinal fluid leakage, n = 3; hearing loss, n = 2; wound infection, n = 1; pneumonia, n = 1; deep vein thrombosis, n = 1) and patients who had SRS (8%) (dysesthetic facial pain, n = 4; P = .47).

CONCLUSION

PFE is more effective than SRS as a primary surgical option for patients with idiopathic TN.

[Treatment of trigeminal neuralgia with microvascular decompression]

Pure microvascular decompression (MVD) can cure (that is, no pain, no medication) primary trigeminal neuralgia (TN) caused by vascular compression in 75% of patients (90% when compression is pronounced), according to a Kaplan-Meier survival study at 15 years. MRI with high resolution evidences neurovascular conflicts with good reliability. The results were found to be significantly better when the prosthesis implanted to maintain the compressive vessel away was not touching the nerve. This argues in favor of a real decompressive mechanism of the MVD procedure, rather than a conduction block. Because pure MVD generally does not produce hypoesthesia in the painful territory, MVD is the first surgical therapeutic option for patients with neuralgia resistant to anticonvulsive medications.

Operative treatment of trigeminal neuralgia: review of current techniques

Surgical approaches to pain management are performed when medication cannot control pain or patients cannot tolerate the adverse effects of the medication. Microvascular decompression (MVD) is generally performed when the patient is healthy and relatively young. Partial sensory rhizotomy is performed in addition to, or instead of MVD, in patients in whom significant compression of the trigeminal sensory root does not exist or in whom MVD is technically not feasible. Three percutaneous ablative procedures and gamma knife radiosurgery (GKS) are also performed when MVD cannot be performed. The result of MVD is superior to that of the 3 ablative procedures. GKS is inferior to the 3 ablative procedures in terms of initial pain relief and recurrence, but superior in terms of complications. Peripheral procedures are usually performed in patients not suitable for or not wishing to have other procedures. However, no strict rules exist and each patient should be evaluated individually.

Perioperative and long-term operative outcomes after surgery for trigeminal neuralgia: microvascular decompression vs percutaneous balloon ablation

Objectives

Numerous medical and surgical therapies have been utilized to treat the symptoms of trigeminal neuralgia (TN). This retrospective study compares patients undergoing either microvascular decompression or balloon ablation of the trigeminal ganglion and determines which produces the best long-term outcomes.

Methods

A 10-year retrospective chart review was performed on patients who underwent microvascular decompression (MVD) or percutaneous balloon ablation (BA) surgery for TN. Demographic data, intraoperative variables, length of hospitalization and symptom improvement were assessed along with complications and recurrences of symptoms after surgery. Appropriate statistical comparisons were utilized to assess differences between the two surgical techniques.

Results

MVD patients were younger but were otherwise similar to BA patients. Intraoperatively, twice as many BA patients developed bradycardia compared to MVD patients. 75% of BA patients with bradycardia had an improvement of symptoms. Hospital stay was shorter in BA patients but overall improvement of symptoms was better with MVD. Postoperative complication rates were similar (21% vs 26%) between the BA and MVD groups.

Discussion

MVD produced better overall outcomes compared to BA and may be the procedure of choice for surgery to treat TN.

Cost-effectiveness analysis for trigeminal neuralgia: Cyberknife vs microvascular decompression

BACKGROUND/AIMS

We present the preliminary results of a cost-effectiveness analysis of cyberknife radiosurgery (CKR) versus microvascular decompression (MVD) for patients with medically unresponsive trigeminal neuralgia.

METHODS

Direct healthcare costs from hospital's perspective attributable to CKR and MVD were collected. Pain level caused by trigeminal neuralgia was measured through the Barrow Neurological Institute pain intensity scoring criteria, at admission and after an average of 6 months follow-up.

RESULTS

20 patients for both arms were enrolled, for a total of 40 patients. The two procedures resulted equally effective at 6 month follow-up, with different resources consumption: CKR reducing hospital costs by an average of 34% per patient. The robustness of these results was confirmed in appropriate sensitivity analyses.

CONCLUSION

CKR resulted to be a cost-saving alternative compared with the surgical intervention.

Various surgical modalities for trigeminal neuralgia: literature study of respective long-term outcomes

BACKGROUND

The literature contains many varying, often conflicting surgical results. However, there is no study comparing long-term effectiveness of all surgical procedures for trigeminal neuralgia (TN). The aim of the present analysis is to report the long-term outcomes of surgical options of TN since the development of electronic databases, to evaluate them with the same clinical and statistical criteria and determine the most appropriate treatment.

METHOD

All studies that had a minimum 5 years or more (> or =5 years) mean duration of follow-up were included in the review. The identified studies were evaluated independently by two authors for quality using a modified inclusion criteria. The evaluated outcome measures of this study were, the initial acute pain relief (APR), follow-up pain free period and recurrence rates as well as complications. In comparisons of the data, the Student's t-test, Chi-square followed by Pearson's risk analysis tests were used. Kaplan-Meier actuarial analysis of pain free-survival curves were constructed for each surgical option that had enough data.

FINDINGS

Twenty-eight studies, mostly including microvascular decompression (MVD) and radiofrequency thermorhizotomy (RF-TR), that met the inclusion criteria were included in the review. The efficacy of MVD and percutaneous balloon microcompression (PBC) were similar (Odds ratio = 0.15, P > 0.05), and their effects were superior to those of the other modalities (P < 0.001). Although RF-TR provided a high initial pain relief, its average pain free rate was 50.4% for a mean follow-up of 5 years. The recurrence rate was high after RF-TR (46%), while the lowest recurrence rate (18.3%) was after MVD (P < 0.001). Within the long-term follow-up period recurrence of pain affects at least 19% of patients who undergo any surgical treatment for TN.

CONCLUSIONS

The study suggests that each surgical technique for treatment of trigeminal neuralgia has merits and limitations. However, MVD provides the highest rate of long-term patient' satisfaction with the lowest rate of pain recurrence.

Microvascular decompression for primary trigeminal neuralgia: long-term effectiveness and prognostic factors in a series of 362 consecutive patients with clear-cut neurovascular conflicts who underwent pure decompression

Object

The purpose of this study was to evaluate the long-term efficacy of microvascular decompression (MVD) and to identify the factors affecting outcome in patients treated for primary trigeminal neuralgia (TN). Only the cases with a clear-cut neurovascular conflict (vascular contact and/or compression of the root entry zone of the trigeminal nerve) found at surgery and treated with “pure” MVD (decompression of the root without any additional lesioning or cutting of the adjacent rootlets) were retained.

Methods

The study included 362 patients who were followed up over a period of 1 to 18 years (median follow-up 7.2 years). A Kaplan–Meier survival analysis was generated at 1 and 15 years of follow-up for all of the considered factors. According to Kaplan–Meier analysis, the success rate (defined as pain-free patients without any medication) was 91% at 1 year and estimated to be 73.38% after 15 years of follow-up.

Results

None of the following patient-related factors played any significant role in prognosis: sex, patient age at surgery, history of systemic hypertension, duration of neuralgia before surgery, or history of failed trigeminal surgery. Patients with atypical neuralgia (a baseline of permanent pain) had the same outcome as those with a typical (purely spasmodic) presentation. In addition, the side and topography of the trigeminal nerve did not play a role, whereas involvement of all three divisions of the nerve had a negative effect on outcome. Concerning anatomical factors, neither the type of the compressive vessel nor its location along or around the root was found to be significant. However, the severity of compression was important—the more severe the degree of compression, the better the outcome (p = 0.002). The authors also found that presence of focal arachnoiditis had a negative influence on outcome (p = 0.002).

Conclusions

Pure MVD can offer patients affected by a primary TN a 73.38% probability of long-term (15 years) cure of neuralgia. The presence of a clear-cut and marked vascular compression at surgery (and possibly—although not yet reliably—on preoperative magnetic resonance imaging) is the guarantee of a higher than 90% success rate.

POLYTETRAFLUOROETHYLENE-INDUCED GRANULOMA AND BRAINSTEM CYST AFTER MICROVASCULAR DECOMPRESSION FOR TRIGEMINAL NEURALGIA

OBJECTIVE

Microvascular decompression is commonly performed for medically refractory trigeminal neuralgia. A piece of polytetrafluoroethylene (PTFE) is usually placed between the trigeminal nerve and the blood vessel causing the compression. The procedure is effective and relatively safe, and PTFE is presumed to be inert. Reactions to PTFE are rare.

CLINICAL PRESENTATION

We report a patient who developed progressive neurological symptoms 5 years after microvascular decompression surgery. Imaging showed an enhancing cerebellopontine mass resembling a posterior fossa tumor with a large cyst compressing the brainstem.

INTERVENTION

Craniotomy was performed to decompress the cyst. Biopsy of the enhancing mass showed granulomatous inflammation. The patient underwent a second brainstem decompression surgery with placement of a catheter in the cyst connected to an Ommaya reservoir; she has moderate to severe residual neurological deficits.

CONCLUSION

This may be the first case of a severely disabling, space-occupying cyst resulting from a reaction to intracranial PTFE. Should this exceptionally rare complication be disclosed to patients or is it an idiosyncratic reaction unlikely to occur again?

Micro-vascular decompression for primary Trigeminal Neuralgia (typical or atypical). Long-term effectiveness on pain; prospective study with survival analysis in a consecutive series of 362 patients

BACKGROUND

Few publications on primary Trigeminal Neuralgia treated by Micro-Vascular Decompression (MVD) report large series, with long-term follow-up, using Kaplan-Meier (K-M) analysis. None was specifically directed to the comparative study of MVD effectiveness on Trigeminal Neuralgia with typical (i.e., with paroxysmal pain only) and atypical features (i.e., with association of a permanent background of pain).

METHOD

The authors report a series of 362 patients having clearcut vascular compression and treated with pure MVD - i.e., without any additional cut or coagulation of the adjacent root fibers. Follow-up was 1 to 18 y (8 y on average, with a median of 7.2 y). Results were considered overall, then separately for patients with typical (237 (65.5%)) and atypical (125 (34.5%)) clinical presentation.

FINDINGS

One year after operation, (294 (81.2%) of patients were totally-free - of paroxysmal pain, and also of permanent background pain - and not needing any medication) 13 (3.6%) still had a background of pain but without the need for medication which 55 patients (15.2%), treatment had failed. At latest review (8 y on average) the corresponding rates were 80, 4.9 and 15.1%, respectively. Kaplan-Meier analysis estimated the probability of total cure at 15 y to be 73.4%. There was no difference in the cure rate between patients with typical and atypical features at one year: 81 and 81.16%, respectively. The probability of cure at 15 y was identical for the two clinical presentations.

CONCLUSIONS

Pure MVD offers patients affected by Trigeminal Neuralgia due to vascular compression a long-lasting cure in three-fourths of the cases. Both typical and atypical presentations respond well to MVD, view in contrast to the classical view that an atypical presentation has an adverse effect on outcome after surgery.

Neuro-ophthalmic considerations in trigeminal neuralgia and its surgical treatment

PURPOSE OF REVIEW

In this review, we will briefly discuss the clinical manifestations and etiology of trigeminal neuralgia, outline the neuro-ophthalmic features of trigeminal neuralgia, and detail the neuro-ophthalmic side effects and complications of the surgical treatment of trigeminal neuralgia.

RECENT FINDINGS

There is a variety of surgical treatment modalities available for patients with trigeminal neuralgia intolerable or resistant to medical therapy. Significant ocular and visual morbidity can result from the surgical treatment of trigeminal neuralgia.

SUMMARY

Percutaneous or open surgical procedures for trigeminal neuralgia can result in corneal anesthesia, neurotrophic keratitis, exposure keratitis, herpetic keratitis, ocular motor cranial neuropathies, and optic neuropathy. Ophthalmologists should be aware of these potential problems because they may need to evaluate and provide care to patients with ocular or visual complaints following surgery for trigeminal neuralgia.

A Prospective Cost-Effectiveness Study of Trigeminal Neuralgia Surgery

OBJECTIVES

Approximately 8000 patients with trigeminal neuralgia undergo surgery each year in the United States at an estimated cost exceeding $100 million. We compared 3 commonly performed surgeries (microvascular decompression, glycerol rhizotomy, and stereotactic radiosurgery) to evaluate the relative cost-effectiveness of these operations for patients with idiopathic trigeminal neuralgia.

METHODS

Prospective nonrandomized trial at a tertiary referral center from July 1999 to December 2001. One hundred twenty-six consecutive patients underwent 153 operations (microvascular decompression, n=33; glycerol rhizotomy, n=51; stereotactic radiosurgery, n=69). Preoperative characteristics were similar between the groups with respect to sex, pain location, duration of pain, and atypical features. Facial pain outcomes were classified as excellent (no pain, no medications), good (no pain, reduced medications), fair (>50% pain reduction), and poor. The cost per quality adjusted pain-free year was compared between the groups. Mean follow-up was 20.6 months.

RESULTS

Patients having microvascular decompression more commonly achieved and maintained an excellent outcome (85% and 78% at 6 and 24 months) compared with glycerol rhizotomy (61% and 55%, P=0.01) and stereotactic radiosurgery (60% and 52%, P<0.01). No difference was detected between glycerol rhizotomy and stereotactic radiosurgery (P=0.61). The cost per quality adjusted pain-free year was $6,342, $8,174, and $8,269 for glycerol rhizotomy, microvascular decompression, and stereotactic radiosurgery, respectively. Reduction in the average cost of morbidity and additional surgeries to zero did not make either microvascular decompression or stereotactic radiosurgery more cost-effective than glycerol rhizotomy. Both microvascular decompression and stereotactic radiosurgery would be more cost-effective than glycerol rhizotomy if the cost of additional surgeries after glycerol rhizotomy increased 79% and 83%, respectively.

DISCUSSION

This analysis supports the practice of percutaneous surgeries for older patients with medically unresponsive trigeminal neuralgia. At longer follow-up intervals, microvascular decompression is predicted to be the most cost-effective surgery and should be considered the preferred operation for patients if their risk for general anesthesia is acceptable. More data are needed to assess the role that radiosurgery should play in the management of patients with trigeminal neuralgia.

Comparison of posterior fossa exploration and stereotactic radiosurgery in patients with previously nonsurgically treated idiopathic trigeminal neuralgia

Object

Stereotactic radiosurgery (SRS) is commonly performed in patients with trigeminal neuralgia, and numerous investigators have found that facial pain outcomes after this procedure are better for patients in whom prior surgery did not fail. Researchers in some centers claim that the results of SRS are equivalent to posterior fossa exploration (PFE). The goal in this study was to verify that claim.

Methods

Information was retrieved from a prospectively maintained database of patients less than 70 years old with idiopathic trigeminal neuralgia who underwent PFE (55 patients) or SRS (28 patients) as their initial surgery between 1999 and 2004. Of the two groups, patients who underwent radiosurgery were older (60.5 compared with 50.7 years, p < 0.001). Microvascular decompression was performed in 49 patients (89%) and partial nerve section was performed in six (11%) in the PFE group. The mean maximum dose for SRS was 89.1 Gy. At a mean follow-up duration of 25.5 months, patients who had undergone PFE were more commonly pain free without medications (75% at 1 year, 72% at 3 years) compared with the patients treated with SRS (59% at 1 and 3 years; p = 0.01). Additional surgery was performed in 10 patients (18%) after PFE, compared with eight patients (29%) after SRS (p = 0.4). Eight patients (15%) had either new facial numbness (six cases) or dysesthesias (two cases) after PFE, whereas 12 (43%) had either new facial numbness (eight cases) or dysesthesias (four cases) after SRS. No correlation was noted between the development of facial numbness and facial pain outcome after PFE (p = 0.37), whereas patients in whom trigeminal dysfunction developed after radiosurgery were more frequently free of pain (p = 0.02).

Conclusions

The results support PFE as a more effective primary surgery than SRS in patients with idiopathic trigeminal neuralgia. Moreover, injury to the trigeminal nerve during PFE is not required to achieve excellent facial pain outcomes.

Percutaneous retrogasserian glycerol rhizotomy for patients with idiopathic trigeminal neuralgia: a prospective analysis of factors related to pain relief

Object. The goal of this study was to analyze prospectively factors associated with facial pain outcomes after percutaneous retrogasserian glycerol rhizotomy (PRGR) for patients with medically unresponsive idiopathic trigeminal neuralgia.

Methods. Between July 1999 and December 2003, 98 patients underwent PRGR in the manner described by Håkanson. The mean patient age was 72.1 years and the average pain duration prior to PRGR was 8.6 years. Fifty patients (51%) had previously undergone surgery. In six patients (6%), the trigeminal cistern could not be defined and the procedure was aborted; six patients were lost to follow-up review. An excellent facial pain outcome was defined as the absence of facial pain without medications.

Thirty-two (35%) of 92 patients either received no benefit (17 patients) or experienced recurrent pain (15 patients) and required additional surgery at a mean of 7.5 months after PRGR; the mean duration of follow-up review in the other 60 patients was 28.7 months (range 3–52 months). Including patients who did not receive a glycerol injection, the 1- and 3-year chances of an excellent facial pain outcome were 61 and 50%, respectively. A multivariate analysis of clinical and surgical factors showed that the facial pain exhibited on glycerol injection correlated with excellent facial pain outcomes (relative risk [RR] = 1.02; 95% confidence interval [CI] 0.26–1.77; p < 0.01), whereas patients who experienced any constant pain less frequently had excellent outcomes (RR = 1.13; 95% CI 0.06–2.20; p = 0.04). Forty-six patients (53%) experienced either mild numbness/parathesias (39 patients) or dysesthesias (seven patients). New trigeminal deficits after PRGR were associated with excellent facial pain outcomes (RR = 1.25; 95% CI 0.56–1.93; p < 0.001).

Conclusions. Percutaneous retrogasserian glycerol rhizotomy remains a good operation for patients with medically unresponsive trigeminal neuralgia who are considered poor candidates for posterior fossa exploration. Predictive factors for success include patients without any constant facial pain, patients with immediate facial pain during glycerol injection, and patients with new trigeminal deficits after PRGR.

Percutaneous controlled radiofrequency trigeminal rhizotomy for the treatment of idiopathic trigeminal neuralgia: 25-year experience with 1,600 patients

OBJECTIVE

The objective of this study was to evaluate the effectiveness of percutaneous, controlled radiofrequency trigeminal rhizotomy (RF-TR). The outcome of 1,600 patients with idiopathic trigeminal neuralgia after RF-TR was analyzed after a follow-up period of 1 to 25 years.

METHODS

A total of 1,600 patients with idiopathic trigeminal neuralgia underwent 2,138 percutaneous radiofrequency rhizotomy procedures between 1974 and 1999. Sixty-seven patients had bilateral idiopathic trigeminal neuralgia, and 36 of them were treated with bilateral RF-TR; 1,216 patients (76%) were successfully managed with a single procedure, and the remainder were treated with multiple procedures. Benzodiazepines and narcotic analgesics were used for anesthesia because patient cooperation during the procedures was essential so that the physician could create selective, controlled lesions.

RESULTS

The average follow-up time was 68.1 +/- 66.4 months (range, 12-300 mo). Acute pain relief was accomplished in 97.6% of patients. Complete pain relief was achieved at 5 years in 57.7% of the patients who underwent a single procedure. Pain relief was reported in 92% of patients with a single procedure or with multiple procedures 5 years after the first rhizotomy was performed. At 10-year follow-up, 52.3% of the patients who underwent a single procedure and 94.2% of the patients who underwent multiple procedures had experienced pain relief; at 20-year follow-up, 41 and 100% of these patients, respectively, had experienced pain relief. No mortalities occurred. After the first procedure was performed, early pain recurrence (<6 mo) was observed in 123 patients (7.7%) and late pain recurrence was observed in 278 patients (17.4%). Complications included diminished corneal reflex in 91 patients (5.7%), masseter weakness and paralysis in 66 (4.1%), dysesthesia in 16 (1 %), anesthesia dolorosa in 12 (0.8%), keratitis in 10 (0.6%), and transient paralysis of Cranial Nerves III and VI in 12 (0.8%). Permanent Cranial Nerve VI palsy was observed in two patients, cerebrospinal fluid leakage in two, carotid-cavernous fistula in one, and aseptic meningitis in one.

CONCLUSION

Percutaneous, controlled RF-TR represents a minimally invasive, low-risk technique with a high rate of efficacy. The procedure may safely be repeated if pain recurs.