Microvascular decompression for hemifacial spasm secondary to vertebrobasilar dolichoectasia: Surgical strategies, technical nuances and clinical outcomes

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.

Dolichoectasia of the ophthalmic artery: a case report on the treatment strategy in endovascular therapy and literature review

BACKGROUND

Dolichoectasia is a rare arterial condition characterized by the dilatation, tortuosity, and elongation of cerebral blood vessels. The vertebrobasilar artery and internal carotid artery are the common sites of dolichoectasia. However, dolichoectasia of the branch arteries, such as the ophthalmic artery (OA), is extremely rare. To the best of our knowledge, this is the first case of ophthalmic dolichoectasia that was successfully treated with endovascular internal coil trapping.

CASE PRESENTATION

A 54-year-old female patient presented with transient left ophthalmalgia and visual disturbance. Magnetic resonance imaging revealed a dilated and elongated left OA compressing the optic nerve at the entrance of the optic canal. However, a previous image that was taken 17 years back revealed that the OA was normal, which suggested the change in dolichoectasia was acquired. Cerebral angiography showed that the dilated and tortuous OA was running from the ophthalmic segment of the left internal carotid artery into the orbit. The symptoms could have been attributed to the direct compression of the dolichoectatic OA in the optic canal. A sufficient anastomosis between the central retinal artery and the middle meningeal artery was identified on external carotid angiography with balloon occlusion of the internal carotid artery. Endovascular treatment with internal trapping of the OA was performed due to ophthalmic symptom progression. Internal coil trapping of the OA was performed at the short segment between the OA bifurcation and the entrance of the optic canal. As expected, the central retinal artery was supplied via the middle meningeal artery after the treatment. The transient visual disturbance was immediately resolved. Ophthalmalgia worsened temporarily after the treatment. However, it completely resolved after several days of oral corticosteroid therapy. Postoperative angiography showed that the origin of the OA was occluded and that the OA in the optic canal was shrunk. The flow of the central retinal arteries via the middle meningeal artery was preserved.

CONCLUSIONS

OA dolichoectasia is rare, and its pathogenesis and long-term visual prognosis are still unknown. However, endovascular therapy can improve symptom by releasing the pressure site in the optic canal.

Endoscope-Assisted Microvascular Decompression in Hemifacial Spasm: 2-Dimensional Operative Video

INDICATIONS CORRIDOR AND LIMITS OF EXPOSURE

This video demonstrates our endoscope-assisted microvascular decompression (MVD) technique in hemifacial spasm. A 2-cm lower retrosigmoid approach is used to reach the facial nerve exit zone. The additional use of endoscopy serves to overcome the microscopes linear axis of view on the compression site.

ANATOMIC ESSENTIALS NEED FOR PREOPERATIVE PLANNING AND ASSESSMENT

A neurovascular conflict in the facial nerve exit zone is to be identified on CISS-MRI. A CT scan helps assessing the approach. Acoustic evoked potentials and facial nerve neuromonitoring including lateral spreads are required. 1.

ESSENTIAL STEPS OF THE PROCEDURE

The patient is positioned supine with 45° head rotation to the contralateral side. In addition, the operating table is tilted 30° to facilitate optimal cerebellar retraction by gravity avoiding the need for cerebellar spatula. The dura is incised parallel to the sigmoid sinus. With the operating microscope, the arachnoid is dissected exposing the vestibulocochlear nerve and the lower cranial nerves. The lower cranial nerve group is exposed up to the exit from the brain stem, enabling a subfloccular approach to the facial nerve exit zone. The endoscope is used to inspect the facial nerve and to identify the compressing vessel. Microscopically, the vessel is mobilized and the nerve decompressed by shredded Teflon. 2.

PITFALLS/AVOIDANCE OF COMPLICATIONS

Jugular vein compression by excessive head rotation must be avoided. Teflon placed directly onto the nerve can cause spasms itself. Opened mastoid cells are carefully sealed.

VARIANTS AND INDICATIONS FOR THEIR USE

Transposition is favored over interposition. Besides shredded Teflon, a Teflon-Bridge or Teflon-Sling can be placed. 3-5The patient consented to the procedure and to the publication of her image.

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.

Bridge technique for hemifacial spasm with vertebral artery involvement

BACKGROUND

To assess efficacy and safety of a newly developed decompression technique in microvascular decompression for hemifacial spasm (HFS) with vertebral artery (VA) involvement.

METHODS

A rigid Teflon (Bard^® PTFE Felt Pledget, USA) with the ends placed between the lower pons and the flocculus creates a free space over the root exit zone (REZ) of the facial nerve (bridge technique). The bridge technique and the conventional sling technique for VA-related neurovascular compression were compared retrospectively in 60 patients. Elapsed time for decompression, number of Teflon pieces used during the procedure, and incidences of intraoperative manipulation to the lower cranial nerves were investigated. Postoperative outcomes and complications were retrospectively compared in both techniques.

RESULTS

The time from recognition of the REZ to completion of the decompression maneuvers was significantly shorter, and fewer Teflon pieces were required in the bridge technique than in the sling technique. Lower cranial nerve manipulations were performed less in the bridge technique. Although statistical analyses revealed no significant differences in surgical outcomes except spasm-free at postoperative 1 month, the bridge technique is confirmed to provide spasm-free outcomes in the long-term without notable complications.

CONCLUSIONS

The bridge technique is a safe and effective decompression method for VA-involved HFS.

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

The vertebral artery (VA)-involved hemifacial spasm (HFS) has distinctive clinical features and performing microvascular decompression (MVD) is challenging. We described the clinical presentations of VA-involved HFS and the outcomes of MVD using the interposition method. Between January 2008 and March 2015, MVD was performed in 271 patients with VA-involved HFS. Demographic characteristics, preoperative severity, intraoperative findings, spasm-free outcome, and complications were retrospectively evaluated. A control group of 1500 consecutive patients with non-VA-involved HFS was enrolled. VA-involved HFS was associated with older age (p < 0.001), less female predominance (p < 0.001), more left-sided predominance (p < 0.001), and rapid symptom progression before MVD (p < 0.001). The Teflon Fulcrum method allowed intraoperative identification of the neurovascular compression site in 92.6% of the cases, and showed more severe indentation on the facial nerve (p < 0.001). Changes in the brainstem auditory evoked potentials during MVD (p < 0.001) and postoperative non-serviceable hearing loss (p < 0.001) were more frequent in patients with VA-involved than in non-VA-involved HFS. The spasm-free outcome and overall complication rates after MVD were not significantly different between the groups. VA-involved HFS has distinctive clinical features and poses a major surgical challenge for MVD success. The interposition method is a feasible surgical strategy in VA-involved HFS.

Efficacy and Complications of Microsurgical Neurovascular Decompression in 55 Patients With Hemifacial Spasm

OBJECTIVE

To analyze the efficacy and complications of microvascular decompression for hemifacial spasm.

STUDY DESIGN

Retrospective study.

SETTING

Regional hospital.

METHODS

Fifty-five patients with hemifacial spasm were treated by microvascular decompression. All patients with hemifacial spasm who underwent retrosigmoid microvascular decompression from May 2004 to January 2017 were included. Patients with no conflict on preoperative magnetic resonance imaging or with an alternate diagnosis were excluded.

RESULTS

The overall cure rate was 83.64%, with an average follow-up of 7.4 years. A left-sided hemifacial spasm was a healing-promoting factor (P = .01). The median healing was 0.03 months, and the mean was 6 months. The efficacy remained high in the medium term (88% at 3 years), long term (90.24% at 5 years), and very long term (90.48% at 8 years). The recurrence rate was 9.8%. Favorable criteria included a right-sided spasm (P = .01) and an average age of 62 years (P = .03). The specific complications were permanent facial palsy (3.63%), unilateral deafness (5.45%), and hearing loss (3.63%). No death was reported. Regarding the quality of life of the patients, 94.7% had a modified HFS-8 postoperative score of 0 (Hemifacial Spasm 8 Quality of Life Scale).

CONCLUSION

Microvascular decompression for hemifacial spasm is an effective and lasting technique. Its low rate of complications and the considerable quality-of-life improvement should lead surgeons to propose it to patients as soon as botulinum toxin injections become ineffective or poorly tolerated.

Spasm Freedom Following Microvascular Decompression for Hemifacial Spasm: Systematic Review and Meta-Analysis

BACKGROUND

Hemifacial spasm (HFS) is a debilitating disorder characterized by intermittent involuntary movement of muscles innervated by the facial nerve. HFS is caused by neurovascular compression along the facial nerve root exit zone and can be treated by microvascular decompression (MVD). The goal was to determine rates and predictors of spasm freedom after MVD for HFS.

METHODS

A literature search using the key terms "microvascular decompression" and "hemifacial spasm" was performed. The primary outcome variable was spasm freedom at last follow-up. Analysis was completed to evaluate for variables associated with spasm-free outcome.

RESULTS

A total of 39 studies including 6249 patients were analyzed. Overall spasm freedom rate was 90.5% (5652/6249) at a follow-up of 1.25 ± 0.04 years. There was no significant relationship between spasm freedom versus persistent spasm and age at surgery, timing of follow-up, gender, disease duration, side of disease, or vessel type. Spasm freedom was more likely after an initial surgery versus a redo MVD (odds ratio 4.16, 95% confidence interval 1.99-8.68; P < 0.01).

CONCLUSIONS

MVD works well for HFS with cure rates >90% at 1-year follow-up in 6249 patients from 39 studies. A significant predictor of long-term spasm freedom at 1 year was an initial MVD as compared to repeat MVD. The majority of published manuscripts on MVD for HFS are heterogeneous single-institutional retrospective studies. As such, a large-scale meta-analysis reporting outcome rates and evaluating significant predictors of spasm freedom provides utility in the absence of randomized controlled studies.

Microvascular decompression for hemifacial spasm associated with distinct offending vessels: A retrospective clinical study

OBJECTIVE

To investigate the surgical effects and complications of microvascular decompression (MVD) for hemifacial spasm (HFS) based on different offending vessels, and report our surgical experience of HFS patients related to vertebral artery.

PATIENTS AND METHODS

MVDs performed in Nanjing Drum Tower Hospital between January 1, 2014 and December 31, 2017 were retrospectively studied, and 1152 patients with HFS were split into two groups in accordance with the offending vessels.

RESULTS

954 patients with HFS caused by small vascular compression were classified as Group A. 849 patients got cured immediately after MVD, while delayed resolution was identified in 101 patients. 4 patients were not relieved and 4 were relapsed during the follow-up period. We observed 76 cases of delayed facial paralysis, 7 cases of hearing loss, 2 hoarseness and 3 cases of CSF leakage after surgery. In Group B, 198 patients displayed HFS associated with the vertebral artery (VA). 144 cases were spasm free after surgery and 51 patients had a delayed resolution. 3 patients were not significantly ameliorated and 2 were relapsed during the follow-up period. The major postoperative complications included facial paralysis in 28 patients, hearing loss in 4 and hoarseness and dysphagia in 3. The two groups showed no operative death.

CONCLUSIONS

For the patients with HFS related to VA, the delayed cure rate and the incidence of postoperative cranial nerve complications were higher than HFS attributed to small vascular compression. And the two groups were not different in the long-term outcome and the incidence of permanent cranial nerve complications.

The efficacy of temporary clamping of V3 with a suboccipital far-lateral approach in microvascular decompression for Hemifacial spasm associated with the vertebral artery

Hemifacial spasm (HFS) is often caused by compression of the vertebral artery (VA) directly or indirectly as a result of other intervening vessels, so VA-associated HFS is difficult to treat. Recently, we have achieved good surgical outcomes using a far lateral approach and temporary clamping of V3 for VA-associated HFS. Herein, we present our method with an accompanying surgical video. From April 2018 to March 2019, 5 patients with VA-associated HFS underwent surgery, and pre-and postoperative symptoms and postoperative complications were evaluated. In the procedure, the suboccipital muscles were dissected and reflected layer by layer, and the extracranial VA (V3) was secured within the suboccipital triangle. A lateral suboccipital craniotomy followed by far lateral drilling was made to widen the surgical field from the caudolateral side. After reducing the VA flow pressure by temporary clamping of V3, the VA was transposed using a Teflon sling via two triangular space above and below the lower cranial nerves (LCNs). Causative vessels included direct VA compression in two cases and intervening vessels in three cases. The symptoms disappeared in four cases and improved satisfactorily in one case. One patient had mild hearing loss (approximately 10 dB) and hoarseness, but both improved 9 months after surgery. There was no postoperative cerebrospinal fluid leakage in any cases. A wide surgical field via the far lateral approach and the temporary clamping of V3 contributed to thorough observation of the REZ and safe and complete VA transposition.

Wedge-technique for transposition of the vertebral artery in microvascular decompression for hemifacial spasm: technical nuances and surgical outcomes

BACKGROUND

Transposition of the vertebral artery (VA) for microvascular decompression for hemifacial spasm (HFS) is often challenging. Various procedures have been proposed to transpose the immobile tortuous VA that cannot be decompressed satisfactorily in the usual manner.

METHODS

A Teflon piece that is cut into a wedge shape was used for transposition of the VA as an offending artery in HFS. One or more wedge-shaped Teflon pieces were simply inserted into a small space between the VA and the brainstem or cerebellar hemisphere without any contact with the entry into the root exit zone (REZ) of the facial nerve. A minimal space can be created by slight mobilization of the VA through rostral or caudal, or in between to the lower cranial nerves (LCNs). In cases of a hypertrophic VA that is hard to mobilize, two or more rigid wedge-shaped Teflon pieces that are coated by fibrin glue can be applied to obtain adequate mobilization of the VA. Moreover, a much harder Teflon bar, which is bent into a V shape, can be used in cases of an immobile VA. Once the VA is transposed to an appropriate position, the Teflon, VA, and contacted surface of the brainstem are fixed together by drops of fibrin glue.

RESULTS

The offending arteries were VA-posterior inferior cerebellar artery (PICA) in eight cases, VA in four cases, PICA in four cases, VA-anterior inferior cerebellar artery (AICA) in one case, and AICA in one case. Eighteen cases of HFS were successfully treated using the "Wedge technique." Symptoms disappeared within 2 weeks in all patients. Transient facial nerve palsy developed in one case, and transient hoarseness developed in one case.

CONCLUSIONS

The wedge technique is a simple straight-line maneuver that facilitates sufficient transposition of the VA without any related complications. This technique is also useful for other large offending vessels, such as the anterior or posterior inferior cerebellar arteries, which are hard to mobilize due to the torque of the vessels.

Anatomic Variation and Hemodynamic Evolution of Vertebrobasilar Arterial System May Contribute to the Development of Vascular Compression in Hemifacial Spasm

BACKGROUND

Hemifacial spasm (HFS) is caused by vascular compression of the facial nerve. The definitive mechanism of offending vessel formation remains unclear. The aim of this study was to explore whether the anatomic and hemodynamic characteristics of the vertebrobasilar artery play a role in problematic vessel formation in HFS.

METHODS

Imaging data of 341 patients with HFS who underwent microvascular decompression were reviewed retrospectively and compared with 360 control subjects. Hemodynamics of typical anatomic variations of the vertebral artery (VA) were analyzed using computational fluid dynamics software.

RESULTS

Asymmetry of the left and right VAs was prevalent, and the left VA was the most dominant VA. A dominant VA was more prevalent in the HFS group than in the control group (P = 0.026). Left HFS had a significantly higher proportion of a left dominant VA, and right HFS had a significantly higher proportion of a right dominant VA (P < 0.001). Computational fluid dynamics models showed that angulation and tortuosity of vessels caused remarkable pressure difference between vascular walls of opposite sides. Dynamic clinical observations showed the mode of vessel transposition coincided with biomechanical characteristics.

CONCLUSIONS

Anatomic variations and hemodynamics of the vertebrobasilar arterial system are likely to contribute to vascular compression formation in HFS.

Methicillin-resistant Staphylococcus aureus Meningitis as a Complication of Facial Nerve Decompression for Vertebrobasilar Dolichoectasia

We present a case of a 55-year-old lady with intermittent twitching of the left side of her face, involving her left eyelid and the angle of the mouth, ongoing for two years. She failed multiple trials of botulinum toxin injections as well as oral anti-spasmodic medications. The patient was diagnosed with an ectatic left vertebral artery, causing a compression of cranial nerve VII on the same side on magnetic resonance imaging (MRI) of the brain. She underwent neurosurgery with a microvascular decompression of the ectatic artery with a resolution of hemifacial spasms. However, her postoperative course was complicated by headaches and low-grade fevers. She also had leukocytosis on a laboratory evaluation. The postoperative computed tomography (CT) scan of her head was normal. The patient had a lumbar puncture done, which showed an elevated white cell count in cerebrospinal fluid (CSF) analysis and the CSF culture was positive for methicillin-resistant Staphylococcus aureus (MRSA) bacteria. She was diagnosed with MRSA meningitis as a postoperative complication following microvascular decompression. The patient had a revision surgery of the decompression site, including wound debridement and did well postoperatively.

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.

Brainstem and Autonomic Nervous System Dysfunction: A Neurosurgical Point of View

Central autonomic control nuclei and pathways are mainly integrated within the brainstem, especially in the medulla oblongata. Lesions within these structures can lead to central dysautonomia.Central autonomic control structures can be damaged by tumors, during surgery, or by other neurosurgical pathologies. These may elicit clinical or subclinical autonomic complications that can constitute a serious clinical problem.The authors present a broad review of the central autonomic nervous system, its possible dysfunctions, and the relation between neurosurgery and this "not-well-known system". Preliminary results of an autonomic study of brainstem lesions that is currently being carried out by the authors are also shown.

Bioglue-Coated Teflon Sling Technique in Microvascular Decompression for Hemifacial Spasm Involving the Vertebral Artery

Objective

Microvascular decompression (MVD) for hemifacial spasm (HFS) involving the vertebral artery (VA) can be technically challenging. We investigated the therapeutic effects of a bioglue-coated Teflon sling technique on the VA during MVD in 42 cases.

Methods

A bioglue-coated Teflon sling was crafted by the surgeon and applied to patients in whom neurovascular compression was caused by the VA. The radiologic data, intra-operative findings with detailed introduction of the procedure, and the clinical outcomes of each patient were reviewed and analyzed.

Results

The 42 patients included in the analysis consisted of 22 females and 20 males, with an average follow-up duration of 76 months (range 24–132 months). Intraoperative investigation revealed that an artery other than the VA was responsible for the neurovascular compression in all cases : posterior inferior cerebellar artery (PICA) in 23 patients (54.7%) and anterior inferior cerebellar artery (AICA) in 11 patients (26.2%). All patients became symptom-free after MVD. Neither recurrence nor postoperative neurological deficit was noted during the 2-year follow-up, except in one patient who developed permanent deafness. Cerebrospinal fluid (CSF) leak occurred in three patients, and one required dural repair.

Conclusion

Transposition of the VA using a bioglue-coated Teflon sling is a safe and effective surgical technique for HFS involving the VA. A future prospective study to compare clinical outcomes between groups with and without use of this novel technique is required.