Microvascular decompression for trigeminal neuralgia caused by vertebrobasilar compression

Novel classification and microsurgical anatomy of the basilar artery: a cadaveric study

PURPOSE

The trunk of the BA remains underrepresented in microsurgical studies. This study aims to address this gap by providing a detailed review of the BA's microsurgical anatomy, proposing a novel segmental classification of the artery and the significance of each segment in various surgical pathologies and approaches.

METHODS

A total of 20 cadaveric adult brain specimens were meticulously examined under high magnification, following Institutional Review Board approval. The dissection focused on the BA and its branches, with morphometric data collected, including dimensions and anatomical variations.

RESULTS

This study included 20 specimens. A novel classification was proposed base on the blood flow direction, including three segments. The inferior segment extended from the junction of the VA to the origin of the most rostral collateral artery, averaging 3.55 mm in diameter and lengths between 9.0 and 17.1 mm, with 3 to 4 caudal perforators. The middle segment, which ranged from the inferior border of the anterior inferior cerebellar artery (AICA) to the origin of the superior cerebellar artery, measured 3.44 mm in diameter and 15.2 mm in length, featuring 5-6 middle perforating branches. The superior segment ended at the bifurcation of the BA, with an average diameter of 4.2 mm and a length of 3.6 mm. The overall BA length averaged 30.7 mm, with a range of 23.5-38.2 mm.

CONCLUSION

A comprehensive understanding of the origin, course, branches and segments of the BA is crucial for mitigating vascular complications during both open and endovascular surgical procedures.

Interposition versus transposition technique in microvascular decompression for trigeminal neuralgia secondary to vertebrobasilar dolichoectasia: a systematic review and pooled meta-analysis

Introduction

Limited data are available comparing the interposition and transposition techniques for microvascular decompression (MVD) in patients with trigeminal neuralgia (TN) secondary to vertebrobasilar dolichoectasia (VBD); this study aims to review current findings on TN associated with VBD and compare the interposition and transposition techniques in terms of surgical morbidity and patient outcomes.

Methods

Following the PRISMA guidelines, PubMed/Medline, Web of Science, and SCOPUS databases were searched to identify studies reporting patients undergoing MVD for TN secondary to VBD. The studies were divided into two groups, interposition and transposition, based on the microvascular decompression technique used. Studies not reporting the diagnostic criteria, included less than five cases, or were not available in English were excluded.

Results

Fourteen eligible papers were retrieved, of which five studies reported cases undergoing the interposition technique, eight studies for the transposition technique, and one study reported cases from both groups. Data including preoperative and postoperative BNI class, comorbidities, and postoperative complications were retrieved to analyze and compare the two techniques in terms of efficacy and long-term outcomes in treating TN secondary to VBD.

Conclusion

Both interposition and transposition techniques for MVD yield high rates of pain relief in patients with TN secondary to VBD. While both approaches demonstrate similar efficacy, the interposition method is associated with a lower rate of long-term complications. Further research, preferably through randomized prospective studies, is needed to refine surgical strategies and improve patient outcomes.

Microvascular Decompression for Trigeminal Neuralgia Secondary to Vertebrobasilar Dolichoectasia: Review of the Literature and Illustrative Case

Classical trigeminal neuralgia (TN) is a chronic pain disorder characterized by severe, unilateral facial pain, often resulting from vasculonervous conflict. A less common cause of TN is vertebrobasilar dolichoectasia (VBD). Microvascular decompression (MVD) is the preferred surgical intervention for TN, but in case of VBD, the surgical procedure is more complex due to the aberrant vascular anatomy. This study aims to review the evidence on MVD for VBD-induced TN, and analyze operative challenges, efficacy, and postoperative outcomes. An illustrative case is also presented. We report on the case of a 62-year-old male with a 7-year history of right-sided TN affecting the maxillary (V2) and mandibular (V3) territories. The patient underwent MVD using the interposition technique, where Teflon sponges were placed between the basilar artery and the nerve. Postoperatively, the patient experienced complete pain relief without neurological deficits. At 12 months follow-up, the patient remained pain-free and off medications. We performed an extensive literature review using PubMed, Scopus, and Web of Sciences, highlighting the most relevant studies and findings on the topic. The literature review showed that, while MVD is effective in providing long-term pain relief in VBD-induced TN, the choice between interposition and transposition techniques remains debated. Interposition is easier to perform but may inadvertently increase nerve compression in some cases, whereas transposition offers more definitive decompression but carries higher technical risks. Our case and the available literature highlight the importance of individualized treatment planning in achieving optimal outcomes for patients with VBD-induced TN. Further research is needed to refine surgical techniques and minimize complications in this subset of TN patients.

Fully Endoscopic Microvascular Decompression for Trigeminal Neuralgia Caused by Vertebrobasilar Artery: A Case Series Review: 2-Dimensional Operative Video

BACKGROUND AND OBJECTIVE

Microvascular decompression (MVD) is the most definitive and preferred surgical treatment for trigeminal neuralgia (TN). Treatment of TN caused by the vertebrobasilar artery (VBA) has been reported to be challenging and less satisfactory in complications and recurrence. Endoscopy has been implemented to provide a comprehensive view of neurovascular conflicts and minimize brain tissue stretch injury while exploring the trigeminal nerve. However, there are few retrospective studies on the treatment of TN caused by VBA by fully endoscopic microvascular decompression (E-MVD). This article aimed to illustrate the safety and efficacy of E-MVD for TN caused by the VBA.

METHODS

Clinical data for 26 patients with TN caused by the VBA who underwent E-MVD from 2019 to 2022 were retrospectively analyzed. The characteristics of vertebrobasilar-associated TN were summarized. The safety and efficacy of E-MVD for vertebrobasilar-associated TN were estimated based on the analysis of intraoperative manipulation, postoperative symptom relief, and complications.

RESULTS

Intraoperatively, the vertebrobasilar artery was regarded as a direct offending vessel in all 26 patients with TN, the vertebral artery in 18 (69.23%) and the basilar artery in 10 (38.46%). In addition to the vertebrobasilar artery, other vessels involved included the superior cerebellar artery in 12 patients, anterior inferior cerebellar artery in 9, posterior inferior cerebellar artery in 1, and veins in 4. All patients underwent E-MVD, and TN was entirely resolved in 26 (100%) patients immediately postoperatively. During the follow-up period of 12-45 months, no recurrence or serious complications were found. There were no serious postoperative complications, such as cerebellar swelling, intracranial hemorrhage, or death.

CONCLUSION

E-MVD for vertebrobasilar-associated TN is effective and safe.

Stereotactic Radiosurgery for Trigeminal Neuralgia Caused by Vertebrobasilar Compression: A Report of Four Cases

BACKGROUND

Microvascular decompression (MVD) of the trigeminal nerve is an effective procedure for treating patients with trigeminal neuralgia (TGN). However, vertebrobasilar decompression involves technical difficulties and demonstrates a higher risk of minor trigeminal hypesthesia/hypalgesia, transient diplopia, and hearing loss. Stereotactic radiosurgery (SRS) has been an effective alternative treatment for TGN. Few studies reported the treatment results of SRS for TGN caused by vertebrobasilar compression. This report presents the treatment results of SRS using gamma knife (GK) in four TGN cases.

MATERIALS AND METHODS

GK-SRS was performed for TGN due to vertebrobasilar compression in four patients, including two males and two females, aged 67-90 years. The maximum dose of 80 Gy was delivered at the retrogasserian portion (RGP) of the ipsilateral trigeminal nerve root.

RESULTS

All four cases with TGN achieved relief in four to 10 months after GK-SRS. However, TGN recurred 41 months after GK-SRS in one of the four cases. A second GK-SRS at the root entry zone (REZ) at a maximum dose of 70 Gy relieved pain again 10 days later. TGN in another case among the four partially recurred in three years but did not deteriorate until the patient died from old age 62 months after GK-SRS. The other three cases, including the one with repeat GK-SRS, were alive with complete TGN remission at the end of follow-up of 20-52 months. GK-SRS-related adverse effects were not observed in any case.

CONCLUSIONS

GK-SRS was a safe and effective treatment in all four TGN cases due to vertebral artery (VA)-basilar artery (BA) compression, although a second treatment session was added again for pain recurrence in one of the four cases.

The cerebellopontine angle cistern volumetric differences in trigeminal neuralgia patients with and without vertebrobasilar compression: a case-matched study

Previous studies have indicated that the small cerebellopontine angle (CPA) cistern plays a role in the pathogenesis of trigeminal neuralgia (TN), but they are likely not involved in TN associated with vertebrobasilar artery (VBA) compression because of its rarity. Forty-four patients with VBA-associated TN and 44 age-, sex-, and hypertension-matched TN patients without VBA compression (non-VBA-associated) were included. All patients underwent high-resolution MRI. The CPA cistern volumes were measured bilaterally. The presence of vertebrobasilar dolichoectasia (VBD) and laterality of the vertebrobasilar junction (VBJ) were observed. The CPA cistern volume on the affected side was smaller than the unaffected side (714.4 ± 372.8 vs 890.2 ± 462.2 mm3, p < 0.001) in non-VBA-associated TN patients, while VBA-associated TN patients show a larger CPA cistern on the affected side than the unffected side (1107.0 ± 500.5 vs 845.3 ± 314.8 mm3, p < 0.001). The prevalence of VBD was higher in patients with VBA-associated TN than in matched non-VBA-associated TN patients (90.9% vs 4.5%, p < 0.001). A positive correlation between the laterality of VBJ and the affected side was found in the VBA-associated TN group (p < 0.0001). Large CPA cistern may be a neuroradiological feature of VBA-associated TN, and most of the VBA-associated TN is accompanied by VBD. The presence of VBD and the lateral shift of VBJ may expand the CPA cistern by squeezing the surrounding tissue on the affected side and also increase the chance of VBA compression on the trigeminal nerve, resulting in the genesis of VBA-associated TN.

Computational Fluid Dynamics Analysis of Trigeminal Neuralgia Associated with the Vertebral Artery: A Report of Two Cases

Trigeminal neuralgia is a nerve disorder that causes unilateral severe facial pain. The clinical features of trigeminal neuralgia are agonizing, paroxysmal, anticipated in one or more divisions of the trigeminal nerve, with repetitive bursts of a few seconds, exacerbated by cutaneous stimuli. Microvascular decompression is proven effective, resulting in a positive outcome. Here, we report two cases of trigeminal neuralgia associated with the vertebral artery, who underwent endoscopic microvascular decompression. This case report aims to show the benefit of computational fluid dynamics evaluation of the neurovascular contact and its effect on change in wall shear stress magnitude of the offending vertebral artery after surgical management with microvascular decompression.

Efficacy and safety of computed tomography-guided percutaneous balloon compression for trigeminal neuralgia secondary to vertebrobasilar dolichoectasia

Percutaneous balloon compression (PBC) of Gasserian ganglion has been popularly used to treat trigeminal neuralgia (TN), one of the most painful syndromes in human experience. Vertebrobasilar dolichoectasia (VBD) is a rare cause of TN and remains challenging to treat. To our knowledge, no study has reported the therapeutic outcome of PBC for VBD-related TN (VBD-TN). In this retrospective study, we collected and analyzed the medical records of all patients undergoing PBC procedure for VBD-TN under the guidance of CT plus three-dimensional reconstruction at the Pain Management Center of Beijing Tiantan Hospital from January 2017 to December 2022. All 23 patients (15 men and 8 women) had a substantial pain relief as modified Barrow Neurological Institute (BNI) I-IIIb immediately after procedure. The follow-up duration ranged from 2 to 63 months, and at the last follow-up visit, only 3 patients (13%) relapsed (BNI IV-V). The cumulative recurrence-free survival was 95%, 87%, and 74% within 1, 3, and 5 years, respectively. Patients' reported satisfactory rate was 100% as Likert scale 4-5 throughout the whole follow-up period, with no severe complications occurring. Our data revealed promising efficacy and safety of PBC procedure for treatment of VBD-TN, thus suggesting a valuable option for pain control in these rare cases of TN. However, there has been no supporting evidence that PBC treatment is a preferred option to other treatments.

Postoperative hemorrhage after biomedical glue sling technique in microvascular decompression for vertebrobasilar artery-associated cranial nerve diseases: A retrospective study of 14 cases

Background

The biomedical glue sling technique is a convenient and effective method for vertebrobasilar artery-associated cranial nerve diseases but postoperative hemorrhage is poorly understood.

Methods

We retrospectively reviewed 14 of 1157 patients associated with cranial nerve diseases who were subjected to the biomedical glue sling technique in microvascular decompression at our hospital from January 2015 to January 2020.

Results

There were 14 patients with cranial nerve diseases included in this study. A clinical diagnosis of postoperative hemorrhage was made after an average of 41.75 h (ranging between 0.5 and 95 h). A cerebellopontine angle hemorrhage was presented in 5 patients, while basal ganglia hemorrhage was observed in 2 patients. Both a cerebellopontine angle and brainstem hemorrhage was seen in 1 patient. Distal supratentorial subdural hemorrhage was recorded in 6 patients. The correlation coefficient was -0.1601 (p = 0.7094) between the standard deviation of systolic blood pressure and the Hemphill Score, -0.2422 (p = 0.5633) between the coefficient of variation of systolic blood pressure and the Hemphill Score, and -0.0272 (p = 0.9489) between the range of systolic blood pressure and the Hemphill Score.

Conclusions

The incidence of postoperative hemorrhage after MVD with the biomedical glue sling technique is higher than with traditional MVD and most cases have a favorable prognosis. Postoperative symptoms are the main area of concern and changes in symptoms usually suggest the occurrence of hemorrhage. Several factors, including surgical procedures, the release of CSF, and blood pressure might be associated with hemorrhaging. We still believe such a technique is an efficient approach to treating complicated cranial nerve diseases.

Anterior transpetrosal approach for microvascular decompression associated with the dolichoectatic vertebrobasilar artery in two patients with refractory trigeminal neuralgia: Technical note

Background

Trigeminal neuralgia (TN) due to compression from the dolichoectatic vertebrobasilar artery (DVBA) is extremely rare and difficult to treat due to its morphological characteristics. We report two cases of good transposition of DVBA and postoperative course obtained using the anterior petrosal approach and a new vasoculopexy method.

Methods

We describe two cases of microvascular decompression (MVD) for refractory TN associated with DVBA. In both cases, MVD was performed through the anterior petrosal approach. The DVBA was decompressed using a GORE-TEX sling and WECK clip in an inferomedial direction.

Results

Complete pain relief without new neurological deterioration was achieved immediately in both patients.

Conclusion

We experienced a rare condition of TN due to exclusion by the DVBA. The anterior transpetrosal approach was extremely effective in this case. This approach secured the surgical field, allowed transposition of the DVBA, and caused no perioperative complications.

Microvascular decompression by interposition method for treatment of trigeminal neuralgia due to vertebrobasilar dolichoectasia: a retrospective single-center study

Trigeminal neuralgia (TN) due to vertebrobasilar dolichoectasia (VBD) is a rare disease that can be challenging to treat. The objectives of this study are to investigate the characteristics of patients with TN due to VBD and to analyze the efficacy of microvascular decompression (MVD) by the interposition method for treatment of the condition. From 2010 until 2020, the data of 30 patients with TN due to VBD who were treated with MVD by the interposition method were analyzed retrospectively. The characteristics of the patients were compared with those of patients with non-VBD TN (n = 815). Kaplan-Meier survival analysis was performed to determine pain-free survival. The 30 patients (21 males, 9 females; mean age, 63.03 years) accounted for 3.55% of all patients with TN during the study period. In 30 patients, the offending vessel was the basilar artery (BA) in 1 patient, the vertebral artery (VA) in 6 patients, the VA plus the superior cerebellar artery (SCA) in 6 patients, the VA plus the anterior inferior cerebellar artery (AICA) in 12 patients, and the VA + SCA + AICA in 5 patients. Compared to non-VBD TN patients, those with TN due to VBD were significantly more likely to be male, to have TN of the left side, and to have hypertension (all P < 0.001). Mean age at surgery (P = 0.057) and symptom duration (P = 0.308) were comparable between the two groups. All 30 patients had immediate relief of facial pain after MVD and could stop medication. There were no postoperative complications. Over mean follow-up of 76.67 months, 3 patients had recurrence. The mean duration of pain-free survival was 70.77 months. In conclusions, TN due to VBD appears to be more likely in males, in those with hypertension, and to involve the left side. The interposition method performed by experienced and skilled neurosurgeons is a safe and effective treatment for TN due to VBD. Further studies are needed to analyze the associated long-term results and the pain recurrence rate among this special population.

Comparison of Microvascular Decompression and Two Isocenters Gamma Knife for the Treatment of Trigeminal Neuralgia Caused by Vertebrobasilar Dolichoectasia

Background: Vertebrobasilar dolichoectasia (VBD) is one of the rare causes of trigeminal neuralgia (TN). The common surgical treatments for patients with TN caused by VBD (VBD-TN) are microvascular decompression (MVD) and Gamma Knife radiosurgery (GKRS). However, the therapeutic effects of the two methods have not been clinically compared, so this study was performed to evaluate the treatment outcomes of MVD and GKRS for patients with VBD-TN.

Methods: The retrospective study was performed from March 2011 to March 2019 in Wuhan Union Hospital. A total of 80 patients diagnosed with VBD-TN were included in this study, and they were divided into the MVD group (n = 46) and GKRS group (n = 34) according to the surgical methods. The imaging data, intraoperative findings, treatment outcomes, and complications of the two groups were analyzed and compared. Meanwhile, the influencing factors of the treatment effect are also explored on the two groups.

Results: Patients who underwent MVD were younger than patients who underwent GKRS (median ages were 61.1 and 65.4 years old, respectively, p = 0.03). The median follow-up was 61.1 months for the MVD group and 56.8 months for the GKRS group. The favorable outcomes [Barrow Neurological Institute (BNI) pain score, BNI scores I–II] occurred in 97.8% of patients treated with MVD and in 78.9% of patients treated with GKRS (p = 0.009). The favorable outcomes in the percentage of patients after MVD 1, 3, 5, and 7 years were 95.7, 85.1, 74.2, and 74.2%, respectively, whereas the corresponding percentages after GKRS were 76.5, 66.2, 56.6, and 47.2%, respectively (p = 0.031). The postoperative complications (except facial numbness) in the MVD group were higher than those in the GKRS group (p = 0.036), but the incidence of new and worsening facial numbness was lower in the GKRS group (p < 0.001).

Conclusions: MVD is superior to GKRS in obtaining and maintaining favorable outcomes for patients with VBD-TN, but it also comes with more complications other than facial numbness. Thus, the treatment program can be tailored to a patient's unique condition and wishes.

Microvascular decompression for trigeminal neuralgia due to vertebrobasilar artery compression: a systematic review and meta-analysis

Trigeminal neuralgia (TN) caused by vertebrobasilar artery (VBA) compression is a rare event, reported between 2 and 6% (Linskey et al. J Neurosurg 81:1-9,1992, Vanaclocha et al.World Neurosurg 96:516-529,2016) of the time. Microvascular decompression (MVD) is advised for drug-resistant pain and, although technically challenging, is associated with an excellent outcome in current literature (Apra et al.Neurosurg Rev 40:577-582,2017, Cruccuet al. EurJ Neurol 15:1013-1028,2008, Linskey et al. J Neurosurg 81:1-9,1992). The authors performed a systematic review and meta-analysis of the literature examining the rate of MVD for trigeminal neuralgia caused by VBA compression and the post-operative outcome. The systematic search of three databases was performed for studies published between January 1990 and October 2020. Random-effects meta-analysis was used to pool the analyzed outcomes, and random-effects meta-regression was used to examine the association between the effect size and potential confounders. Funnel plot followed by Egger's linear regression was used to test publication bias. We included 9 studies, and the overall rate of TN due to VBA compression was 3.4% (95% CI 2.5-4.3%, p < 0.01, I² = 67.9%) among all MVD for TN. Immediately after surgery, 96% (p < 0.01, I² = 0%) of patients were pain-free, and at last follow-up, approximately 93% (p < 0.01, I² = 0%) of patients were classified as BNI I-II. Hearing impairment and facial numbness were the most common long-term complications ensuing MVD for VBA compression (5% and 13%, respectively). In conclusion, the surgical management of trigeminal neuralgia caused by VBA compression is associated with good outcome and low rate of post-operative complications. Further studies are needed to analyze the long-term results and the rate of pain recurrence among this population.

Radiosurgery for Trigeminal Neuralgia Secondary to Dolichoectatic Vessels: Case Series and Review of Literature

Even for seasoned neurosurgeons who have mastered the microvascular decompression (MVD) techniques, trigeminal neuralgia (TGN) secondary to vertebrobasilar dolichoectatic vessels remains a challenge. Often, patient is either medically infirm or unwilling for invasive surgical interventions. Alternative treatment options including Gamma Knife radiosurgery (GKRS) are considered in such a situation with variable success. This study aimed to evaluate the role of GKRS in patients with trigeminal neuralgia with dolichoectatic vessels and severe cross compression. We prospectively managed three male patients of intractable TGN secondary to dolichoectatic vascular compression with single-session GKRS. The cisternal component of the trigeminal nerve was targeted with 90 Gy radiation at 100% isodose with a single 4-mm collimator. The patients were regularly evaluated on clinical parameters for pain relief (Barrow Neurological Institute (BNI) score), sensory complaints, and outcome. All patients had satisfactory pain control (BNI I–IIIa) at 3 months of interval only to get recurrent pain (BNI IV–V) after 6 months. The treatment was eventually considered a failure after 6-month duration and one patient needed MVD for pain control. Post-GKRS pain control remains inferior in patients with dolichoectasia compared with typical TGN. GKRS should be offered only as a salvage or rescue procedure and should not be used as an alternative treatment of MVD in patient population with dolichoectatic vessels.

Microvascular decompression for trigeminal neuralgia attributable to the vertebrobasilar artery: decompression technique and significance of separation from the nerve root

BACKGROUND

Separation of the vertebrobasilar artery (VBA) from the trigeminal nerve root in microvascular decompression (MVD) is technically challenging. This study aimed to review the clinical features of VBA involvement in trigeminal neuralgia and evaluate surgical decompression techniques in the long term.

METHODS

We retrospectively reviewed the surgical outcomes of 26 patients (4.4%) with VBA involvement in 585 consecutive MVDs for TGN using a Teflon roll for repositioning the VBA. The final operative status of the nerve decompression was categorized into two groups: the separation group and the contact group. Separation of the VBA from the nerve root was completed in 13 patients in the separation group, and slight vascular contact remained in the remaining 13 patients of the contact group. The clinical features of VBA-related TGN were investigated and the operative results were analyzed.

RESULTS

Multiple arteries are involved in neurovascular compression (NVC) in most cases. The anterior inferior cerebellar artery was the most common concomitant artery (69%). The site of the NVC varies from the root entry zone to the distal portion of the root. All patients were pain-free immediately after surgery and maintained medication-free status during the follow-up period, except for one patient (3.8%) who had recurrent facial pain 8 years after surgery. Postoperative facial numbness was observed in six patients (23%). Of these, one patient showed improvement within 3 months and the other five patients had persistent facial numbness (19.2%). Other neurological deficits include one dry eye, one diplopia due to trochlear nerve palsy, two decreased hearing (< 50 db), two facial weaknesses, and two cerebellar ataxia. Although most of them were transient, one dry eye, two hearing impairments, and one cerebellar ataxia became persistent deficits. Statistical analyses revealed no difference in surgical efficacy or complications in the long term between the two groups.

CONCLUSIONS

Slightly remaining vascular contact does not affect pain relief in the long term. Our study indicated that once the tense trigeminal nerve is loosened, further attempts to mobilize the VBA are not necessary.

Location of the abducens nerve stretched by a tortuous vertebrobasilar artery in trigeminal neuralgia

BACKGROUND

Trigeminal neuralgia (TGN) caused by the vertebrobasilar artery (VBA) is uncommon. The abducens nerve root is frequently dislocated by a tortuous VBA near the trigeminal nerve root. This unusual location of the root is not well known. This study aimed to investigate the location of the stretched abducens nerve root.

METHODS

The objective is 26 patients with VBA-related TGN who underwent microvascular decompression (MVD). We retrospectively investigated the course of the abducens nerve root with magnetic resonance imaging (MRI) with three-dimensional (3D) imaging and surgical findings. The displacement of the abducens nerve root on the affected side was compared to the contralateral side.

RESULTS

The abducens nerve root was distorted by a tortuous VBA (46.2%) or the anterior inferior cerebellar artery (53.8%). The average length of the cisternal segment was stretched to 23.4 mm versus 12.4 mm on the contralateral side. The peak point of the elevated abducens nerve root was mostly located rostro-medial (65.4%) or caudo-medial (34.6%) to the neurovascular compression site of the trigeminal nerve with a mean distance of 9.1 mm. Contact with the trigeminal nerve root was observed in 7 patients (26.9%). Three-dimensional imaging was consistent with the surgical findings and useful in predicting the location of the abducens nerve root. No abducens nerve palsy was noted in our series.

CONCLUSIONS

The abducens nerve root is located near the trigeminal nerve root in VBA-related TGN. Preoperative understanding of the unusual course of the abducens nerve root contributes to avoiding accidental nerve injury during MVD.

Microvascular decompression for trigeminal neuralgia caused by vertebrobasilar dolichoectasia: interposition technique versus transposition technique

BACKGROUND

Various techniques of microvascular decompression have been proposed for trigeminal neuralgia (TN) caused by vertebrobasilar dolichoectasia (VBD) with two main modalities: interposition and transposition. This retrospective study compares the outcomes of two techniques belonging to different modalities for VBD-associated TN.

METHODS

From January 2011 to April 2017, 39 patients underwent MVD for VBD-associated TN. The transposition method chosen was the biomedical glue sling technique. Patients were divided into the interposition group (n = 16) and the transposition group (n = 23). The radiologic data, intraoperative findings, complications, and outcomes were analyzed.

RESULTS

The 1-, 3-, and 5-year pain-free (BNI class I) maintenance rates were 100.0, 91.1, and 91.1%, respectively, in the transposition group and 87.5, 74.5, and 58.7% in the interposition group (p = 0.032). Postoperative complications were similar in both groups, but there was a trend for higher incidence of postoperative facial hypoesthesia using the interposition technique (p = 0.06).

CONCLUSION

In cases of VBD-associated TN, the transposition technique using biomedical glue was superior to the traditional interposition technique in maintaining a pain-free status, with no increase in the incidence of complication.

[Microvascular decompression in trigeminal neuralgia following vertebrobasilar dolichoectasia]

OBJECTIVE

To analyze our own results with literature data and substantiate microvascular decompression in patients with trigeminal neuralgia (TN) following vertebrobasilar dolichoectasia (VBD).

MATERIAL AND METHODS

A total of 504 patients with TN underwent surgery in 1998-2018. Patients with TN following VBD were included into a retrospective study. There were 4 men and 10 women aged 66 years (range 51-80). Outcomes were evaluated using BNI (Barrow Neurological Institute) scale. PubMed database was used for literature review.

RESULTS

TN caused by VBD was diagnosed in 2.8% of patients. Left-sided trigeminal pain was observed in 10 patients, right-sided - in 4 cases. One patient had concomitant hemifacial spasm. MVD followed by shielding of trigeminal nerve root with shredded Teflon was performed in all patients. We did not perform fixation of vertebrobasilar vessels. In one case, open partial trigeminal nerve root rhizotomy was done in addition to MVD. All patients had pain-free early postoperative period. There were no deaths or major complications. There was transient cranial nerve dysfunction lasting no more than three months (facial numbness - 1, IV nerve dysfunction - 1, VI nerve dysfunction - 1, transient partial facial palsy (House-Brackmann II) - 2, hipoacusia - 2 patients). There was no facial pain recurrence in our group. Mean follow-up period was 5.5 years (range 6 months - 16 years).

CONCLUSION

MVD is an effective option in the treatment of TN following VBD. In these cases, operation is technically more difficult compared to MVD with intact vessels. However, surgery is much more effective than all the available alternatives. The possibilities of vessel transposition in VBD with or without fixation are limited and ineffective. Teflon wool interposition at the points of conflict is an effective and sufficient technique.

The long-term clinical outcomes of microvascular decompression for treatment of trigeminal neuralgia compressed by the vertebra-basilar artery: a case series review

Background

Microvascular decompression (MVD) is a type of neurosurgery used to treat trigeminal neuralgia (TN) caused by the vertebrobasilar contact/compression. The surgery is not risk-free, however; it may cause recurrent facial pain or other side-effects. The objective of this study was to assess the long-term pain relief and the complications of MVD surgery for the vertebrobasilar compression treatment.

Methods

Twenty-three patients with TN compressed by the vertebra-basilar artery (VBA) were treated with MVD. Teflon felt was placed between the brain stem and the offending artery to mobilize the artery towards the skull base and the clivus. The Barrow Neurological Institute (BNI) Pain Intensity Scale score was used to assess pre- and post-surgical pains.

Results

Of 23 patients with pre-operative BNI IV to V, 19 patients (83%) were pain-free after surgery. Four patients experienced transient partial pain relief with BNI II–III, and 3 of them (13%) were completely pain-free within 3 months. The success rate was 96%. Three patients (13%) had pain recurrences, and one received a second MVD surgery for pain relief during the period of follow-up. Four patients suffered from TN hypesthesia, and only 2 patients (8.6%) had permanent facial hypesthesia, while one patient (4.3%) developed a gradual hearing loss after surgery.

Conclusions

While our success rate of immediate pain relief after surgery was comparable with some reports, the percentage of patients who had pain recurrences was lower, and cases who had permanent facial hypesthesia or developed a gradual hearing loss were fewer after MVD surgery. Our rate of transient complications was higher, and the postoperative pain relief seemed unusually delayed. Our study indicates that MVD is an effective, reliable, and safe neurosurgery for treatment of TN compressed by the VBA albeit our small sample size. Failure of treatment and recurrence of the disease as well as complications could be minimized by preventing displacement of the Teflon implant and extraneous Teflon touching the trigeminal nerves.

Adverse Events After Microvascular Decompression: A National Surgical Quality Improvement Program Analysis

BACKGROUND

Although microvascular decompression (MVD) is a durable treatment for medically refractory trigeminal neuralgia, hemifacial spasm, or glossopharyngeal neuralgia attributable to neurovascular conflict, few national studies have analyzed predictors of postoperative complications.

OBJECTIVE

To determine the incidence and risk factors for adverse events after MVD.

METHODS

Patients who underwent MVD were extracted from the prospectively collected National Surgical Quality Improvement Program registry (2006-2017). Multivariable logistic regression identified predictors of 30-day adverse events and unplanned readmission; multivariable linear regression analyzed predictors of a longer hospital stay.

RESULTS

Among the 1005 patients evaluated, the mortality was 0.3%, major neurologic complication rate 0.4%, and 2.8% had a nonroutine hospital discharge. Patient age was not a predictor of any adverse events. Statistically significant independent predictors both of any adverse event (9.2%) and of a longer hospitalization were American Society of Anesthesiologists (ASA) classification III-IV designation and longer operative duration (P ≤ 0.03) The 30-day readmission rate was 6.8%, and the most common reasons were surgical site infections (22.4%) and cerebrospinal fluid leakage (14.3%). Higher ASA classification, diabetes mellitus, and operative time were predictors of readmission (P < 0.04).

CONCLUSIONS

In this National Surgical Quality Improvement Program analysis, postoperative morbidity and mortality after MVD was low. Patient age was not a predictor of postoperative complications, whereas higher ASA classification, diabetes mellitus, and longer operative duration were predictive of any adverse event and readmission. ASA classification provided superior risk stratification compared with the total number of patient comorbidities or laboratory values. These data can assist with preoperative patient counseling and risk stratification.

Kawase Approach for Dolichoectactic Basilar Artery Macrovascular Decompression in a Patient With Trigeminal Neuralgia: Case Report

BACKGROUND AND IMPORTANCE

Trigeminal neuralgia (TN) secondary to a dolichoectatic basilar artery (DBA) is an extremely rare phenomenon. The Kawase approach for macrovascular decompression of this rare pathology been used rarely.

CLINICAL PRESENTATION

This report describes macrovascular decompression and basilar artery transposition in a 69-yr-old male presenting with progressively worsening left-sided typical TN secondary to a DBA compression. The DBA was successfully decompressed off of the trigeminal nerve via a pterional craniotomy and anterior petrosectomy. The patient had immediate improvement in TN symptoms postoperatively. The patient remained symptom free with nonbothersome facial numbness in the V3 segment at 8-mo postoperative follow-up in clinic. The patient suffered a sixth nerve palsy following surgery, which was later corrected by strabismus surgery. The natural history and epidemiology of TN, results of macrovascular decompression secondary to DBA compression via a traditional suboccipital retrosigmoid approach, and potential advantages of the Kawase approach are also discussed.

CONCLUSION

The macrovascular decompression strategy succeeded because the compressive force was applied by the DBA to the nerve in a superolateral direction, and the decompressive sling pulled the DBA away from the nerve in an inferomedial direction. The working space and access to the clival dura through the Kawase approach allowed proper corrective pull with a sling.

Microvascular decompression for hemifacial spasm associated with the vertebral artery

The aim of this study was to discuss the baseline characteristics of hemifacial spasm (HFS) associated with the vertebral artery (VA) and evaluate microvascular decompression (MVD) as a surgical treatment of the associated HFS. From February 2010 to February 2015, 118 consecutive patients with HFS underwent MVD. Of these, 29 cases of HFS were associated with VA, this series was compared with the remaining non-VA-associated HFS. Of the 29 cases of VA-associated HFS, the VA was directly compressing the root exit zone (REZ) in eight cases. In the other 21 cases, the VA contacted REZ indirectly via its branches. The symptoms were completely relieved in 26 cases (89.7%) and partially relieved in another two cases (6.9%). Between the VA-associated group and non-VA-associated group, no statistically significant difference existed in the surgical results. VA-associated HFS is not a rare condition. For all cases of VA-associated HFS, indirect compression due to VA was more common. MVD for VA-associated HFS still can achieve good results.

Macrovascular Decompression of the Brainstem and Cranial Nerves: Evolution of an Anteromedial Vertebrobasilar Artery Transposition Technique

BACKGROUND: Tortuous and dolichoectatic vertebrobasilar arteries can impinge on the brainstem and cranial nerves to cause compression syndromes. Transposition techniques are often required to decompress the brainstem with dolichoectatic pathology. We describe our evolution of an anteromedial transposition technique and its efficacy in decompressing the brainstem and relieving symptoms.

OBJECTIVE: To present the anteromedial vertebrobasilar artery transposition technique for macrovascular decompression of the brainstem and cranial nerves.

METHODS: All patients who underwent vertebrobasilar artery transposition were identified from the prospectively maintained database of the Vascular Neurosurgery service, and their medical records were reviewed retrospectively. The extent of arterial displacement was measured pre- and postoperatively on imaging.

RESULTS: Vertebrobasilar arterial transposition and macrovascular decompression was performed in 12 patients. Evolution in technique was characterized by gradual preference for the far-lateral approach, use of a sling technique with muslin wrap, and an anteromedial direction of pull on the vertebrobasilar artery with clip-assisted tethering to the clival dura. With this technique, mean lateral displacement decreased from 6.6 mm in the first half of the series to 3.8 mm in the last half of the series, and mean anterior displacement increased from 0.8 to 2.5 mm, with corresponding increases in satisfaction and relief of symptoms.

CONCLUSION: Compressive dolichoectatic pathology directed laterally into cranial nerves and posteriorly into the brainstem can be corrected with anteromedial transposition towards the clivus. Our technique accomplishes this anteromedial transposition from an inferolateral surgical approach through the vagoaccessory triangle, with sling fixation to clival dura using aneurysm clips.

Clinical analysis and surgical treatment of trigeminal neuralgia caused by vertebrobasilar dolichoectasia: A retrospective study

BACKGROUND

Trigeminal neuralgia (TN) caused by vertebrobasilar dolichoectasia (VBD) is rare and needs further exploration. The purpose of this study is to investigate the clinical features and surgical treatment of TN caused by VBD.

METHODS

15 patients with TN caused by VBD were included in our study. The patient data regarding clinical characteristics, neuroimaging presentations, intraoperative findings and treatment outcomes were analyzed retrospectively. Moreover, the previous relevant literature was reviewed simultaneously. Simple MVD was performed in 13 cases and MVD plus trigeminal nerve selective partial posterior rhizotomy (SPPR) was conducted in 2 patients.

RESULTS

Of all patients, 7 cases were female and 8 were male. The average age at operation was 60.8 years old (range, 35yrs-75yrs). 13 patients suffered from hypertension and 7 had a history of stoke. The extended and ectatic vetebrobasilar artery (VBA) was preliminarily identified in preoperative imaging presentations and finally confirmed during surgical procedure. The facial neuralgia disappeared immediately after surgery in all patients. All patients were relieved of pain (BNI score I) with an average of 29.8 months follow-up.

CONCLUSIONS

Our results suggest that simple MVD is effective for TN caused by VBD. MVD plus SPPR can be cautiously performed if patient has advanced age and is susceptible to numbness.

Microvascular decompression for trigeminal neuralgia secondary to vertebrobasilar dolichoectasia. Case report, literature review, and pooled case analysis

INTRODUCTION

Vertebrobasilar dolichoectasia is a condition in which there is elongation and dilatation of the vertebral and basilar arteries. Few studies have been reported that focus on cases of trigeminal neuralgia (TN) secondary to vertebrobasilar dolichoectasia (VD) and treated by microvascular decompression (MD).

PATIENTS AND METHODS

A case is presented of trigeminal neuralgia caused by vertebral artery compression. An analysis of the microsurgical technique, as well as a systematic review of the literature about this uncommon nerve compression is performed, in order to investigate, by pooled case analysis, if MD is a good option for this type of patient.

RESULTS

A total of 7 studies were included for analysis, to which the present case was added, making a total of 56 patents. There were excellent results in 53 cases, and partial recovery in 3, with a mean follow up of 54 months. No major complications were found.

DISCUSSION

The good clinical results and absence of postoperative mortality or severe morbidity in our pooled case series lead us to recommend MD as the preferred treatment for TN caused by VD in patients in whom major surgery is not contraindicated.

Efficacy of stereotactic gamma knife surgery and microvascular decompression in the treatment of primary trigeminal neuralgia: a retrospective study of 220 cases from a single center

OBJECTIVES

A retrospective study was undertaken to compare the efficacy of stereotactic gamma knife surgery (GKS) and microvascular decompression (MVD) in the treatment of primary trigeminal neuralgia (TN) at a single center. The study included the evaluation of clinical outcomes of pain relief and pain recurrence and complications associated with GKS and MVD.

METHODS

The study included 202 patients with primary TN and was conducted between January 2013 and December 2014; about 115 patients were treated with GKS and 87 patients were treated with MVD. TN pain was evaluated using the Barrow Neurological Institute and the visual analog scale scoring systems. Preoperative magnetic resonance tomographic angiography was performed for all patients. Microscope-assisted MVD used the suboccipital retrosigmoid sinus approach. GKS targeted the trigeminal nerve root entry zone with a margin radiation dose of 59.5 Gy, and brainstem dose <12 Gy. Posttreatment follow-up was for 2 years.

RESULTS

Postoperative Barrow Neurological Institute scores for patients treated with GKS and MVD were significantly improved compared with preoperative scores (P<0.01). Reduction in postoperative pain following MVD (95.4% patients) was significantly greater than that following GKS (88.7% patients) (P<0.01). Postoperative visual analog scale scores of the MVD group were significantly reduced compared with those of patients treated with GKS at the same postoperative time points (P<0.01). Patients treated with GKS had a significantly increased rate of loss of corneal reflex compared with patients treated with MVD (P=0.002).

CONCLUSION

Both GKS and MVD are safe and effective first-line and adjunctive treatment options for patients with TN. The clinical outcomes of pain relief and reduction of pain recurrence were better with MVD. For GKS, this study showed that the optimal radiation therapeutic dose range was 70-90 Gy, but brainstem radiation protection is recommended.

Microsurgical treatment of trigeminal neuralgia in patients older than 70 years: An efficacy and safety study

INTRODUCTION

The increasing incidence of trigeminal neuralgia (TN) with age together with population ageing call for reexamination of surgical treatment options for refractory TN in elderly patients.

METHODS

Retrospective review of a consecutive series of patients older than 70 who underwent microvascular decompression (MVD) for refractory TN between 1997 and 2015. Outcomes based on the Barrow Neurological Institute pain intensity score (BNI score) and surgical complications were compared to those of patients younger than 70 undergoing MVD in the same period.

RESULTS

Forty patients older than 70 (mean = 74.8 years) underwent interventions. At a mean follow-up time of 34 months, 73% of the patients presented complete absence of pain without medication (BNI I) and 85% had good pain control with or without medication (BNI I-III). A comparison of these patients with the 85 patients younger than 70 treated surgically during the same period did not find a significant association between age and achievement of pain control (BNI I-II). However, there was a significant association between age older than 70 and complete pain relief (BNI I; P=.03). The mean hospital stay in patients over 70 was also significantly longer (P=.04), although the postsurgical complication rate was similar to that in younger patients.

CONCLUSIONS

Elderly patients with refractory TN may benefit from treatment with MVD and the probability of success and surgical risk are comparable to those in younger patients.

Trigeminal neuralgia and hemifacial spasm associated with vertebrobasilar artery tortuosity

BACKGROUND

The tortuous vertebrobasilar artery (TVBA) often causes neurovascular conflicts in patients with trigeminal neuralgia (TN) and hemifacial spasm (HFS). Implementation of microvascular decompression (MVD) in these circumstances is hindered due to stiffness of the enlarged and dilated arteries and is often accompanied by poor outcomes. The surgical strategy in cases of trigeminal neuralgia and hemifacial spasm associated with the TVBA should be clarified in order to achieve good outcomes.

MATERIAL AND METHODS

MVD was performed in 268 TN patients and 71 HFS patients. The TVBA as a compressing vessel was identified in 30 cases (11 cases of TN, 18 cases of HFS, and 1 patient with painful tic convulsif). All patients underwent MVD and a retrospective analysis of clinical outcomes.

RESULTS

Compression caused by the vertebral artery was found in all HFS patients and 4 TN patients, and compression caused by the basilar artery was observed in 7 TN cases. Additional compression of the cranial nerve root entry/exit zone by cerebellar vessels was observed in 21 cases. The TVBA was mobilized by dissection of arachnoid adhesions between the vessel and the brainstem and retracted laterally. Then, the TVBA was retracted from the brainstem to the caudorostral direction. These manipulations resulted is "spontaneous" decompression of the cranial nerves without placing prostheses between the artery and the nerve root entry/exit zone. In all cases (except two), the displaced TVBA was fixed between the enlarged artery and brainstem using pieces of the patient's muscle and adipose tissues, followed by application of fibrin glue. A cylindrical silicone prosthesis was used in 1 case. In another case, the TVBA was retracted using a fascial loop fixed to the dura mater of the petrous pyramid by means of a suture. After application of MVD, TN and HFS symptoms completely regressed. There were several transient complications and 2 cases of permanent hearing loss. No clinical symptom recurrence was observed.

CONCLUSION

MVD is the most effective surgical treatment of TN and HFS caused by the TVBA. The TVBA should be retracted from the brainstem without placing prostheses in the nerve root entry/exit zone.

Gamma knife radiosurgery to the trigeminal ganglion for treatment of trigeminal neuralgia secondary to vertebrobasilar ectasia

Background:

We report the result obtained using Gamma knife stereotactic radiosurgery on the trigeminal ganglion (TG) in a patient with trigeminal neuralgia (TN) secondary to vertebrobasilar ectasia (VBE).

Case Description:

Retrospective review of medical records corresponding to one patient with VBE-related trigeminal pain treated with radiosurgery. Because of the impossibility of visualization of the entry zone or the path of trigeminal nerve through the pontine cistern, we proceeded with stereotactic radiosurgery directed to the TG. The maximum radiation dose was 86 Gy with a 8-mm and a 4-mm collimator. The follow-up period was 24 months. The pain disappeared in 15 days, passing from Barrow Neurological Institute (BNI) grade V to BNI grade IIIa in 4 months and then to grade I. The patient did not experience noticeable subjective facial numbness.

Conclusions:

This experience showed that Gamma knife radiosurgery was effective in the management of VBE-related trigeminal pain, using the TG as radiosurgical target.

Trigeminal neuralgia caused by a trigeminocerebellar artery

This 31-year-old woman presented with typical right trigeminal neuralgia caused by a trigeminocerebellar artery, manifesting as pain uncontrollable with medical treatment. Preoperative neuroimaging studies demonstrated that the offending artery had almost encircled the right trigeminal nerve. This finding was confirmed intraoperatively, and decompression was completed. The neuralgia resolved after the surgery; the patient had slight transient hypesthesia, which fully resolved within the 1st month after surgery. The neuroimaging and intraoperative findings showed that the offending artery directly branched from the upper part of the basilar artery and, after encircling and supplying tiny branches to the nerve root, maintained its diameter and coursed toward the rostral direction of the cerebellum, which indicated that the artery supplied both the trigeminal nerve and the cerebellum. The offending artery was identified as the trigeminocerebellar artery. This case of trigeminal neuralgia caused by a trigeminocerebellar artery indicates that this variant is important for a better understanding of the vasculature of the trigeminal nerve root.

Long-term effectiveness of an ad hoc tailored titanium implant as a spacer for microvascular decompression in the treatment of trigeminal neuralgia caused by megadolichoectatic basilar artery anomaly: 9-year follow-up

An enlarged, elongated, ectatic, and sclerotic aberration of the vertebrobasilar system is known as a megadolichoectatic basilar artery (BA) anomaly. The anomaly is often involved in the pathological process of trigeminal neuralgia by compressing and distorting the trigeminal nerve. First-line medical treatment includes drug therapy, but a second-line surgical procedure could be effective in medication-resistant cases. The authors report the case of a 65-year-old man with a 12-year history of progressing trigeminal neuralgia who underwent microvascular decompression after the first-line drug treatment had failed. This case is unique because an in situ tailored titanium microplate was used as a spacer to alleviate compression by the BA on the trigeminal nerve. The titanium implant provided durable and sufficient retraction for the sclerotic arterial complex when the trigeminal nerve was placed in the tunnel of the implant. The 9-year follow-up examination proves the safety and long-term efficacy of titanium implants in the treatment of trigeminal neuralgia caused by a megadolichoectatic BA anomaly. The method applied in this case was not intended to be and certainly is not an alternative to routine microvascular decompression-this surgical solution may be reserved for some extreme cases.

Trigeminal neuralgia related to megadolichobasilar artery compression: a prospective series of twenty-nine patients treated with gamma knife surgery, with more than one year of follow-up

BACKGROUND

Trigeminal neuralgia (TN) secondary to megadolichobasilar artery (MBA) compression is considerably difficult to manage surgically.

OBJECTIVE

This study aims to evaluate the safety/efficacy of Gamma Knife surgery (GKS) in this special group of patients.

METHODS

Between July 1992 and November 2010, 29 patients with >1 year of follow-up presenting with MBA compression were treated with GKS at Timone University Hospital. Radiosurgery was performed using a Gamma Knife (model B, C or Perfexion). A single 4-mm isocenter was positioned in the cisternal portion of the trigeminal nerve at a median distance of 9.1 mm (range: 6-18.2 mm) from the emergence.

RESULTS

The median follow-up period was 46.1 months (range: 12.9-157.9 months). Initially, all patients (100%) were pain free; the average time to complete pain relief was 13.5 days (range: 0-240 days). Their actuarial probability of remaining pain free without medication at 0.5, 1 and 2 years was 93.1, 79.3 and 75.7%, respectively, and remained stable until 13 years after treatment. The actuarial probability of hypoesthesia onset at 6 months was 4.3%; at 1 year it reached 13% and remained stable until 13 years after treatment.

CONCLUSIONS

GKS proved to be reasonably safe and effective on a long-term basis as a first- and/or second-line surgical treatment for TN due to MBA compression.

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

BACKGROUND

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

Trigeminal neuralgia in a patient with Marfan syndrome: case report

Marfan syndrome can demonstrate tortuous and elongated intracranial arteries. However, these arteries rarely cause neurovascular compression resulting in hemifacial spasm or trigeminal neuralgia. The authors report a 33-year-old woman who was diagnosed as Marfan syndrome, suffered from trigeminal neuralgia. Magnetic resonance (MR) angiography showed tortuous and elongated left vertebral artery (VA). The coronal section of three dimensional (3D) MR cisternography with contrast enhancement showed that the left trigeminal nerve was compressed from underneath by the tortuous and elongated left VA. After successful surgery of microvascular decompression, the patient’s symptom resolved and no recurrence was encountered. Neurosurgeons should not only be aware of hemifacial spasm but also of trigeminal neuralgia caused by elongated vessels in a patient with Marfan syndrome, although it is an extremely rare condition. In addition, offending vessel is not atherosclerotic in younger patients unlike usual cases of trigeminal neuralgia. Thus, microvascular decompression can be easier than usual cases. Care should be taken to prevent arterial dissection during transposition by using some technical tips.

Microvascular decompression on patients with trigeminal neuralgia caused by ectatic vertebrobasilar artery complex: technique notes

BACKGROUND

Due to its anatomical features, the vertebrobasilar artery complex (VBA) seldom contributes to the neurovascular conflict in patient with trigeminal neuralgia (TN). However, once it offends the trigeminal root, this large artery is really difficult to manipulate during microvascular decompression (MVD) surgery. Therefore, the surgical strategy for such cases needs to be detailed in order to obtain a satisfactory outcome.

METHODS

From 2009 through 2011, 475 consecutive TN patients underwent MVDs in our department. Among them, ten were found in which an ipsilateral deviating ectatic vertebrobasilar artery complex (VBA) offended the trigeminal nerve. Those cases were focused on in this study and each operation was analyzed retrospectively.

RESULTS

During the operation, the vertebral artery was regarded as the direct culprit in six (60 %) patients, while the basilar artery in four (40 %). As companions, some smaller vessels were also observed to be close to the nerve, including the superior cerebellar artery (SCA) in five, veins in two and anterior inferior cerebellar artery (AICA) in two. The neurovascular conflict was discovered in the cisternal segment of the trigeminal root in eight, while in the root entry zone (REZ) in two. In six out of the ten cases, the affected nerves were demonstrated to be squeezed towards the tentorium by the ectatic VBA. Postoperatively, the symptom of pain totally disappeared immediately in eight (80 %) patients, while it was relieved apparently in two (20 %). During the follow-up period of 3-30 months, no recurrence or complication was found, except for one patient who had numbness of the face.

CONCLUSION

With a proper strategy, MVD is probably the most effective therapy for the TN cases caused by ectatic vertebrobasilar artery complex. The substance of the surgery is to withdraw the proximal vertebral artery caudally via a lateroinferior cerebellar approach.

Outcomes of Gamma Knife surgery for trigeminal neuralgia secondary to vertebrobasilar ectasia

OBJECT

Vertebrobasilar ectasia (VBE) is an unusual cause of trigeminal neuralgia (TN). The surgical options for patients with medically refractory pain include percutaneous or microsurgical rhizotomy and microvascular decompression (MVD). All such procedures can be technically challenging. This report evaluates the response to a minimally invasive procedure, Gamma Knife surgery (GKS), in patients with TN associated with severe vascular compression caused by VBE.

METHODS

Twenty patients underwent GKS for medically refractory TN associated with VBE. The median patient age was 74 years (range 48-95 years). Prior surgical procedures had failed in 11 patients (55%). In 9 patients (45%), GKS was the first procedure they had undergone. The median target dose for GKS was 80 Gy (range 75-85 Gy). The median follow-up was 29 months (range 8-123 months) after GKS. The treatment outcomes were compared with 80 case-matched controls who underwent GKS for TN not associated with VBE.

RESULTS

Intraoperative MR imaging or CT scanning revealed VBE that deformed the brainstem in 50% of patients. The trigeminal nerve was displaced in cephalad or lateral planes in 60%. In 4 patients (20%), the authors could identify only the distal cisternal component of the trigeminal nerve as it entered into the Meckel cave. After GKS, 15 patients (75%) achieved initial pain relief that was adequate or better, with or without medication (Barrow Neurological Institute [BNI] pain scale, Grades I-IIIb). The median time until pain relief was 5 weeks (range 1 day-6 months). Twelve patients (60%) with initial pain relief reported recurrent pain between 3 and 43 months after GKS (median 12 months). Pain relief was maintained in 53% at 1 year, 38% at 2 years, and 10% at 5 years. Some degree of facial sensory dysfunction occurred in 10% of patients. Eventually, 14 (70%) of the 20 patients underwent an additional surgical procedure including repeat GKS, percutaneous procedure, or MVD at a median of 14 months (range 5-50 months) after the initial GKS. At the last follow-up, 15 patients (75%) had satisfactory pain control (BNI Grades I-IIIb), but 5 patients (25%) continued to have unsatisfactory pain control (BNI Grade IV or V). Compared with patients without VBE, patients with VBE were much less likely to have initial (p = 0.025) or lasting (p = 0.006) pain relief.

CONCLUSIONS

Pain control rates of GKS in patients with TN associated with VBE were inferior to those of patients without VBE. Multimodality surgical or medical management strategies were required in most patients with VBE.