Involvement of the vertebral artery in hemifacial spasm: clinical features and surgical strategy

Bridge-layered decompression technique for vertebral artery-involved hemifacial spasm: technical note

BACKGROUND

Hemifacial spasm (HFS) is most effectively treated with microvascular decompression (MVD). However, there are certain challenges in performing MVD for HFS when the vertebral artery (VA) is involved in compressing the facial nerve (VA-involved). This study aimed to introduce a "bridge-layered" decompression technique for treating patients with VA-involved HFS and to evaluate its efficacy and safety to treat patients with HFS.

METHODS

A single-center retrospective analysis was conducted on the clinical data of 62 patients with VA-involved HFS. The tortuous trunk of VA was lifted by a multi-point "bridge" decompression technique to avoid excessive traction of the cerebellum and reduce the risk of damage to the facial-acoustic nerve complex. To fully decompress all the responsible vessels, the branch vessels of VA were then isolated using the "layered" decompression technique.

RESULTS

Among the 62 patients, 59 patients were cured immediately after the surgery, two patients were delayed cured after two months, and one had occasional facial muscle twitching after the surgery. Patients were followed up for an average of 19.5 months. The long-term follow-up results showed that all patients had no recurrence of HFS during the follow-up period, and no patients developed hearing loss, facial paralysis, or other permanent neurological damage complications. Only two patients developed tinnitus after the surgery.

CONCLUSION

The "bridge-layered" decompression technique could effectively treat VA-involved HFS with satisfactory safety and a low risk of hearing loss. The technique could be used as a reference for decompression surgery for VA-involved HFS.

A nomogram based on clinical multivariate factors predicts delayed cure after microvascular decompression for hemifacial spasm

BACKGROUND

The course of disease after microvascular decompression (MVD) in patients with hemifacial spasm (HFS) is variable. The purpose of this study was to develop and validate a nomogram to predict the probability of delayed cure after microvascular decompression in patients with hemifacial spasms based on clinical multivariate factors.

METHODS

A retrospective data collection was performed on 290 patients with HFS undergoing MVD at our center from January 2017 to January 2022. The patients were randomly assigned to the training cohort (n = 232) and validation cohort (n = 58) at a ratio of 8:2. Retrospective analysis was performed of information on clinical, radiological, and intraoperative findings and clinical outcomes. Univariate and multivariate analyses were performed in the training cohort, and a nomogram was constructed using a stepwise logistic regression approach. The receiver operating characteristic (ROC) was calculated to evaluate the reliability of the nomogram model. Decision curve analysis (DCA) was used to assess the clinical application value of the nomogram model.

RESULTS

In the training cohorts, 73 patients (73/232) had a delayed cure. In the validation cohorts, 18 patients (18/58) had a delayed cure. We developed a novel nomogram model to predict the risk of delayed cure after MVD in HFS patients based on the presence of vertebral artery compression, venous compression, absence of LSR, degree of facial nerve indentation, degree of neurovascular compression, and internal auditory canal vascular looThe area under the curve (AUC) of the nomogram model was 0.9483 in the training cohort and 0.9382 in the validation cohort. The calibration curve showed good correspondence between the predicted and actual probabilities in the training and validation groups. The decision curve showed that the nomogram model had good performance in clinical applications.

CONCLUSIONS

We developed and validated a preoperative and intraoperative multivariate factors nomogram to predict the possibility of delayed cure after MVD in HFS patients, which may help clinicians in the comprehensive management of HFS.

Lateral Suboccipital Infrafloccular Approach with Extensive Arachnoid Dissection for Vertebral Artery-Associated Hemifacial Spasm: Two-Dimensional Operative Video

Hemifacial spasm (HFS) is generally caused by compression of the root exit zone (REZ) of the facial nerve by the anterior and posterior inferior cerebellar arteries and occasionally the vertebral artery (VA). Owing to its large caliber and high stiffness, microvascular decompression (MVD) for VA-associated HFS is considered more difficult, and the result is worse than for HFS not associated with the VA.^1,2 Therefore, a safer, more reliable MVD is required for VA-associated HFS. In Video 1, we demonstrate our MVD technique in a 57-year-old woman who presented with left HFS owing to facial nerve compression by a dolichoectatic VA. A lateral suboccipital infrafloccular approach with extensive arachnoid dissection was performed. Arachnoid dissection was started from the cisterna magna and continued from the caudal to the rostral direction. This extensive arachnoid dissection provided access to the facial nerve REZ through the infrafloccular route with gentle retraction of the flocculus in the caudorostral direction, while avoiding strong retraction of cranial nerve VIII and the cerebellum. In addition, we were able avoid damaging the neurovascular structures in the operative field. This is mandatory to make the operative field bloodless and facilitate identifying the relationship between the facial nerve REZ and the offending vessels. MVD of the facial nerve REZ was achieved. The patient's postoperative course was uneventful, and her HFS resolved postoperatively. Patient consent was obtained to perform the surgery and to publish the surgical video.

Endoscopic assisted microvascular decompression for vertebral artery - Associated hemifacial spasm – A case report

Introduction

and importance: Vertebral-artery associated hemifacial spasm is rare. Microvascular decompression (MVD) of hemifacial spasm (HFS) associated with the vertebral artery (VA) shows high rates of incomplete cure and complications compared to non-VA-related HFS.

Case presentation

A 39-year-old male who presented with a 2-year history of progressive left-sided typical HFS. Endoscopic assisted MVD for VA-associated HFS via a retro-sigmoid keyhole was performed. Neurovascular conflicts by both the VA and the AICA around the root exit zone of the facial nerve in sandwich type were successfully decompressed.

Clinical discussion

Vertebral-artery associated hemifacial spasm is challenging. With the assistance of endoscopy, multiple neurovascular conflicts were clearly demonstrated without significant cerebellar retraction. The VA and AICA were safely interposed with preservation of perforators under excellent view.

Conclusion

Endoscopic assisted MVD offers reliable decompression with minimum invasiveness in case of VA-associated HFS with multiple compressions.

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Vertebral artery- associated hemifacial spasm is rare and challenging.

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Endoscope assisted MVD was an effective treatment of VA- associated HFS.

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Utilization of endoscope provides a broader view without brain retraction and ability to identify multiple compressions.

The outcome of microvascular decompression for hemifacial spasm: a systematic review and meta-analysis

Microvascular decompression (MVD) is the first choice of surgery for hemifacial spasm (HFS). MVD surgery for vertebral artery (VA)-associated HFS is more difficult than for non-VA-associated HFS. There is controversy about the cure rate and complication of MVD for HFS in previous studies. We searched PubMed, Web of Science, and Embase for relevant publications. Based on the search results, we compared the outcomes of MVD for VA-associated HFS and non-VA-associated HFS. At the same time, we analyzed spasm-free rates and the complications and assessed the relationship between VA-associated HFS and gender, left side, and age. For analysis, six studies that included 2952 patients in the VA-associated group and 604 in the non-VA-associated group were selected. The effective rate of MVD was not significantly different between both groups (OR = 1.16, 95% CI 0.81-1.67, P = 0.42). Compared to non-VA-associated group, the transient complications (OR = 0.64, 95% CI 0.46-0.89, P = 0.008) and permanent complications (OR = 0.28, 95% CI 0.15-0.54, P = 0.0001) occurred more frequently in VA-associated group. The rate of hearing loss was significantly higher in VA-associated HFS than non-VA-associated HFS (OR = 0.35, 95% CI 0.19-0.64, P = 0.0007); the facial paralysis after operation was not significantly different between both groups (OR = 1.25, 95% CI 0.91-1.72, P = 0.17). There were older patients (WMD = 3.67, 95% CI 3.29-4.05, P < 0.00001) and more left-sided HFS (OR = 0.23, 95% CI 0.19 - 0.29, P < 0.0002) in the VA-associated HFS group than non-VA-associated HFS group, while the non-VA-associated HFS group was female-dominated (OR = 1.58, 95% CI 1.32 - 1.89, P < 0.00001). Both groups achieved good results in MVD cure rates. In VA-associated HFS, the complication rate of decompression and the rate of hearing loss after operation were higher than in non-VA-associated HFS, but the facial paralysis after operation was similar in both groups, and most complications were transient and disappeared during follow-up. VA-associated HFS is more prevalent in older adults, less prevalent in women, and more predominantly left-sided. More clinical studies are needed to better compare the efficacy and complication of MVD between both groups.

The Efficacy and Safety of <2 cm Micro-Keyhole Microvascular Decompression for Hemifacial Spasm

Objective: Microvascular decompression (MVD) surgery has been accepted as a minimally invasive surgical modality for the treatment of hemifacial spasm (HFS). However, the size of the bone window does not match the concept of minimally invasive. This study is aimed at evaluating the efficacy and safety of <2 cm micro-keyhole MVD.

Methods: A total of 148 patients with HFS diagnosed in the First Affiliated Hospital of Chongqing Medical University from January 1, 2019, to July 1, 2020, who underwent MVD in the neurosurgery department of the hospital were collected. Surgery was performed by a retrosigmoid keyhole approach with the bone hole diameter <2 cm, which was named micro-keyhole MVD. The efficacy and safety of the micro-keyhole MVD were evaluated by statistical analysis of the efficacy of the micro-keyhole MVD and the incidence of postoperative complications.

Results: The effect of micro-keyhole MVD was satisfying (cure or partial remission) in 97.2% (n = 144). The failure and recurrence rates were 2.7% (n = 4) and 0.6% (n = 1), respectively. Among them, immediate facial palsy, delayed facial palsy, hearing loss, and cerebrospinal fluid (CSF) leakage were found in 0.6% (n = 1), 8.1% (n = 12), 4.7% (n = 7), and 1.3% (n = 2). Only one patient developed cerebellar infarction, which was complicated by “moyamoya disease.” The micro-keyhole MVD in the treatment of HFS can achieve a high remission rate and reduce the incidence of surgical complications.

Conclusion: Micro-keyhole MVD is a safe and effective minimally invasive treatment for HFS. This technique does not increase the incidence of cranial nerve injury. Meanwhile, it reduces the incidence of CSF leakage and hearing loss (HL).

Challenging Microvascular Decompression Surgery for Hemifacial Spasm

OBJECTIVE

Microvascular decompression (MVD) is the most effective treatment for hemifacial spasm (HFS). However, surgical difficulties due to complex anatomy or revision surgery can endanger the functional integrity of the brainstem. We describe surgically challenging cases and provide operative guidance that may be helpful for neurosurgeons who perform MVDs.

METHODS

Of 3028 patients with HFS who underwent MVDs consecutively by a single neurosurgeon, complex or unusual cases associated with surgical difficulty were selected. Medical charts and images were reviewed, with the primary focus being intraoperative findings, operative techniques, and clinical outcomes. All MVDs were performed using the interposition method.

RESULTS

Surgically difficult cases were categorized into six types: tandem, perforator, atypical location, encircling, revision, and penetrating types. During the follow-up period (11.5-42.7 months; median 24.9 months), the spasm-free rate was 88.4%. Intraoperative changes in brainstem auditory evoked potentials were observed in 31.5% of patients. Immediate postoperative facial palsy and deafness were observed in 6.0% and 1.5% of patients, respectively. Revision surgery showed the highest surgical morbidity among the unusual HFS types. Detailed illustrations and descriptions of MVD in patients with surgically challenging HFS are provided.

CONCLUSIONS

Complex or unusual HFS types carry higher surgical risks in MVD. Neurosurgeons performing MVDs need to be prepared to manage complex HFS cases in order to achieve favorable clinical outcomes.