Decompression Surgery For Hemifacial Spasm Research Articles

Safety and efficacy of endoscope-assisted versus microscopic microvascular decompression surgery for hemifacial spasm: a prospective cohort study.

Microscopic microvascular decompression (M-MVD) is a classical treatment for relieving long-term hemifacial spasms (HFS). An endoscopy technique has recently been introduced to improve M-MVD; however, this application remains debatable. This study compared the safety and effectiveness of endoscope-assisted microvascular decompression (EA-MVD) and M-MVD for HFS. From February 2021 to September 2022, we enrolled 49 patients with HFS assigned to the EA-MVD (n = 26) and M-MVD (n = 23) groups. The patients were assessed with Park YS grades, operative time, hospital days, and complications. Evaluations were performed in the early postoperative period, at one month, 3months, 6months, and at least 12months. Twenty-three (23/26, 88.5%) patients in the EA-MVD group and 20 (20/23, 87.0%) patients in the M-MVD group achieved spasm-free relief, ranging over "excellent" and "good" Park YS grades. The operative time in the EA-MVD and M-MVD groups were 143 ± 28min and 145 ± 22min (p = 0.002). The duration of hospital stay was 6.8 ± 0.8days and 7.2 ± 1.3days in the EA-MVD and M-MVD groups (p = 0.002), respectively. All surgeries for HFS were successful, with no death, stroke, hearing loss, facial numbness, or other extreme complications. In conclusion, EA-MVD, compared with M-MVD, demonstrated equally effective outcomes with decreased operative time and hospital stays, providing bright intraoperative illumination and flexible surgical vision.

Optimal method for reliable lateral spread response monitoring during microvascular decompression surgery for hemifacial spasm

In this study, we propose an optimal method for monitoring the key electrophysiological sign, the Lateral Spread Response (LSR), during microvascular decompression (MVD) surgery for hemifacial spasm (HFS). Current monitoring methods and interpretations of LSR remain unclear, leading to potential misinterpretations and undesirable outcomes." We prospectively collected data from patients undergoing MVD for HFS, including basic demographics, clinical characteristics, and surgical outcomes. Stimulation intensity was escalated by 1 mA increments to identify the optimal range for effective LSR. We designated the threshold at which we can observe LSR as THR1 and THR2 for when LSR disappears, with high-intensity stimulation (30 mA) designated as THR30. Subsequently, we compared abnormal muscle responses (AMR) between the optimal range (between THR1 and THR2) and THR30. Additionally, we conducted an analysis to identify and assess factors associated with artifacts and their potential impact on clinical outcomes. As stimulation intensity increases, the onset latency to detect AMR was shortened. The first finding of the study was high intensity stimulation caused artifact that mimic the wave of LSR. Those artifacts were observed even after decompression thus interfere interpretation of disappearance of LSR. Analyzing the factors related to the artifact, we found the AMR detected at onset latency below 9.6 ms would be the lateral spreading artifact (LSA) rather than true LSR. To avoid false positive LSR from LSA, we should stepwise increase stimulation intensity and not to surpass the intensity that cause LSR onset latency below 10 ms.

Recent Advances in Intraoperative Brainstem Auditory Evoked Potential Monitoring during Microvascular Decompression Surgery for Hemifacial Spasm.

Brainstem auditory evoked potential (BAEP) testing during microvascular decompression (MVD) is very important in the treatment of hemifacial spasm (HFS). The reason for this is that the vestibulocochlear nerve is located immediately next to the facial nerve, so the vestibulocochlear nerve may be affected by manipulation during surgery. BAEP testing for detecting vestibulocochlear nerve damage has been further developed for use during surgery. In most HFS patients with normal vestibulocochlear nerves, the degree of vestibulocochlear nerve damage caused by surgery is well-reflected in the BAEP test waveforms. Therefore, real-time testing is the best way to minimize damage to the vestibulocochlear nerve. The purpose of this study was to review the most recently published BAEP test waveforms that were obtained during MVD surgery to determine the relationship between vestibulocochlear nerve damage and BAEP waveforms.

Case Report of Cerebral Venous Sinus Thrombosis Complication after Microvascular Decompression Surgery in the Inactive Phase of Ulcerative Colitis

Background: The risk of thrombosis is high in patients with Ulcerative Colitis. The main location of thrombosis is in the extremity and pulmonary vein. Cerebral venous thrombosis is a rare location for thrombosis with high mortality. One of the risk factors for developing thrombosis is in association with surgery, especially during an active phase of Ulcerative Colitis (UC), and very few studies report cases occurring during the inactive phase. Hence, it is important for the surgeon to understand the risk of thrombosis, especially of cerebral sinus thrombosis in the Ulcerative Colitis patient. Case: We are presenting a fatal complication in a male patient of 62, who had sagittal sinus thrombosis and multiple intra-cranial hemorrhages in both frontal lobes 3 weeks after microvascular decompression surgery for hemifacial spasm. Conclusion: The risk of cerebral venous sinus thrombosis is higher in Ulcerative Colitis patients, especially in those who undergo surgery regardless of its type. Careful peri-operative assessment and treatment related to thromboembolism prevention are important to reduce complications in such cases.

Supratentorial Acute Subdural Hematoma During Fully Endoscopic Microvascular Decompression Surgery for Hemifacial Spasm

The endoscope has been widely used in microvascular decompression (MVD), which is the best curative treatment for hemifacial spasm. Supratentorial subdural hematoma (SDH) is rarely happened in MVD. The authors report 2 cases of SDH during full endoscopic MVD. The origin of bleeding is not confirmed during the operation. Rapid and excessive drainage of cerebrospinal fluid and the operation position may result the rupture of bridging veins, which result in the occurrence of SDH. However, there is no clear evidence to explain the clinical symptoms.

Association of intraocular pressure and postoperative nausea and vomiting after microvascular decompression - a prospective cohort study

BackgroundPostoperative nausea and vomiting is common in patients receiving microvascular decompression. In the current study, we examined whether postoperative nausea and vomiting is associated with reduced intraocular pressure (IOP) after microvascular decompression, a measure that reflects intracranial pressure.MethodsThis is a prospective cohort study. Adult patients scheduled for microvascular decompression surgery for hemifacial spasm between January 2020 and August 2020 were eligible. IOP was measured immediately before anesthesia induction and 30 min after patients regained complete consciousness using non-contact tonometry. IOP reduction was defined by at least 1 mmHg decrease vs. preoperative baseline. The primary outcome was vomiting on postoperative day 1.ResultsA total of 103 subjects were enrolled. IOP was reduced in 56 (54.4%) subjects. A significantly greater proportion of patients with IOP reduction had vomiting on postoperative day 1 (51.8% (29/56) vs. 23.4% (11/47) in those without IOP reduction; p = 0.003). In the multivariate regression analysis, vomiting on postoperative day 1 was associated with female sex [odds ratio = 7.87, 95% CI: 2.35–26.32, p = 0.001] and IOP reduction [odds ratio = 2.93, 95% CI: 1.13–7.58, p = 0.027].ConclusionsIn patients undergoing microvascular decompression surgery, postoperative IOP reduction is associated with postoperative vomiting.Trial registration:Chinese Clinical Trial Registry: ChiCTR2000029083. Registered 13 January 2020.

Advances in Intraoperative Neurophysiology During Microvascular Decompression Surgery for Hemifacial Spasm.

Microvascular decompression (MVD) is a widely used surgical intervention to relieve the abnormal compression of a facial nerve caused by an artery or vein that results in hemifacial spasm (HFS). Various intraoperative neurophysiologic monitoring (ION) and mapping methodologies have been used since the 1980s, including brainstem auditory evoked potentials, lateral-spread responses, Z-L responses, facial corticobulbar motor evoked potentials, and blink reflexes. These methods have been applied to detect neuronal damage, to optimize the successful decompression of a facial nerve, to predict clinical outcomes, and to identify changes in the excitability of a facial nerve and its nucleus during MVD. This has resulted in multiple studies continuously investigating the clinical application of ION during MVD in patients with HFS. In this study we aimed to review the specific advances in methodologies and clinical research related to ION techniques used in MVD surgery for HFS over the last decade. These advances have enabled clinicians to improve the efficacy and surgical outcomes of MVD, and they provide deeper insight into the pathophysiology of the disease.

Infrafloccular approach effectively prevents hearing complication in microvascular decompression surgery for hemifacial spasm

Objective The infrafloccular approach in microvascular decompression (MVD) surgery for hemifacial spasm (HFS) was investigated for the prevention of hearing complications. Methods Retrospective analysis of 136 patients who underwent MVD for HFS in 2019. The infrafloccular approach for MVD was adopted to resolve the symptom and protect hearing function. Postoperative hearing function was evaluated subjectively and objectively within 30 postoperative days, and later mainly subjectively. Postoperative condition of mastoid air cells based on the CT scan of the following day was also recorded. Results No final postoperative subjective hearing impairment was found in all patients. Mastoid air cells were opened in 105 patients, and subjective hearing impairment was recorded in 57 patients within 30 postoperative days, but all improved later. Increases in thresholds of greater than 10 dB in air conduction were observed in 28 patients, including 26 of transient conductive hearing loss (increases in the threshold of less than or equal to 10 dB). The other 2 patients with increases in the threshold of greater than 10 dB in both air and bone conduction had improvement confirmed by later audiometry. Conclusions Infrafloccular approach in MVD for HFS provides a good hearing outcome. Inclusion of postoperative hearing conditions in the later period is ideal for a precise hearing evaluation.

Improving recovery after microvascular decompression surgery for hemifacial spasm: experience from 530 cases with enhanced recovery after surgery (ERAS) protocol

Objective To assess the efficacy of microvascular decompression (MVD) for hemifacial spasm with an enhanced recovery after surgery (ERAS) protocol. Methods 984 hemifacial spasm patients who underwent MVD from Jan 2017 to Dec 2017 were analyzed. They were divided into the conventional treatment group (control; n = 453) and the later ERAS group (n = 531). The multimodal ERAS protocol consists of 23 perioperative elements. Time to feeding, mobilization, and urinary catheter removal, wound pain, postoperative nausea and vomiting (PONV), and total, preoperative, and perioperative hospital length of stay (LOS), along with outcomes and complications, were analyzed. Results The patients in both groups had similar clinical characteristics. Patients in the ERAS group had significantly higher rates of early feeding (469 [88.5%], ERAS, vs. 183 [40.6%], control; p < 0.05), early mobilization (497 [93.7%], ERAS, vs. 215 [47.7%], control; p < 0.05), and early removal of urinary catheter (458 [86.4%], ERAS, vs. 175 [38.8%], control; p < 0.05). The ERAS group also had a significantly lower incidence of wound pain (135 [25.5%], ERAS, vs. 348 [77.2%], control) and PONV (173 [32.6%], ERAS, vs. 251 (55.7%), control) (p < 0.05) and significantly shorter preoperative (0.9 ± 0.3 d, ERAS, vs. 2.3 ± 0.6 d, control), postoperative (4.1 ± 0.4 d, ERAS, vs. 5.8 ± 0.7 d, control), and total LOS (5.2 ± 0.3 d, ERAS, vs. 8.8 ± 0.6 d, control) (p < 0.05). There was no significant difference in outcomes or surgical complication rates between two groups. Conclusions Implementation of the ERAS protocol for patients undergoing MVD procedures for the treatment of HFS improved the quality of perioperative care without an increase in adverse events.

A prewarning sign for hearing loss by brainstem auditory evoked potentials during microvascular decompression surgery for hemifacial spasm

ObjectiveWe aimed to define the prewarning sign of brainstem auditory evoked potentials (BAEPs) associated with cerebellar retraction (CR) during microvascular decompression surgery for hemifacial spasm. MethodsA total of 241 patients with a latency prolongation of 1 ms or an amplitude decrement of 50% of wave V were analyzed. According to BAEPs before significant changes during CR, patients were classified into Groups A (latency prolongation of wave I [≥0.5 ms] without prolongation of the I–III interpeak interval [<0.5 ms]) and B (no latency prolongation of wave I [<0.5 ms] with prolongation of the I–III interpeak interval [≥0.5 ms]). BAEPs and postoperative hearing loss (HL) were compared between the two groups. ResultsGroup B comprised 160 (66.4%) patients. With maximal changes in wave V, latency prolongation (≥1 ms) with amplitude decrement (≥50%) was more common in Group B (p < 0.018). At the end of the operation, wave V loss was observed in 11 patients, including 10 patients from Group B. Five patients developed postoperative HL; all were from Group B. ConclusionsLatency prolongation of wave III during CR was associated with serious BAEPs changes and postoperative HL. SignificanceLatency prolongation of wave III is a significant prewarning sign.

Intraoperative Neurophysiological Monitoring during Microvascular Decompression Surgery for Hemifacial Spasm

Hemifacial spasm (HFS) is due to the vascular compression of the facial nerve at its root exit zone (REZ). Microvascular decompression (MVD) of the facial nerve near the REZ is an effective and curative treatment for HFS. In MVD for HFS, intraoperative neurophysiological monitoring (IONM) has two purposes. The first purpose is to prevent injury to neural structures such as the vestibulocochlear nerve and facial nerve during MVD surgery, which is possible through IONM of brainstem auditory evoked potentials and facial nerve electromyography (EMG). The second purpose is the unique feature of MVD for HFS, which is to assess and optimize the effectiveness of the vascular decompression. The purpose is achieved mainly through monitoring of abnormal facial nerve EMG that is called as lateral spread response (LSR) and is also partially possible through Z-L response, facial F-wave, and facial motor evoked potentials. Through IONM mentioned above, MVD can be developed as a more safe and effective treatment for HFS. Keywords: Hemifacial spasm; Microvascular decompression surgery; Intraoperative neurophysiological monitoring

Significance of wave I loss of brainstem auditory evoked potentials during microvascular decompression surgery for hemifacial spasm

ObjectiveWe sought to define the significance of wave I loss of brainstem auditory evoked potentials (BAEPs) during microvascular decompression (MVD) surgery for hemifacial spasm. MethodsOut of 670 patients, 36 showed wave V loss during MVD surgery. These patients were classified into the following two groups based on wave I loss: Total wave loss, including wave I loss, and wave V loss with persistent wave I. We analyzed the differences in postoperative complications between the groups. We also investigated when wave I loss occurred during MVD surgery. ResultsOf the 36 patients, 24 (66.7%) exhibited wave I persistence and 12 (33.3%) exhibited total wave loss. The patients who showed total wave loss were significantly more likely to exhibit postoperative hearing loss (p = 0.009). In addition, these patients exhibited a significantly higher frequency of postoperative complications such as dizziness and tinnitus (p = 0.002 and p = 0.031, respectively). Total wave loss occurred more frequently after the decompressive procedure of MVD surgery. ConclusionsTotal wave loss, including wave I loss, was more closely associated with severe postoperative complications. Total wave loss occurred more frequently after the decompressive procedure of MVD surgery. SignificanceThese findings suggest the significance of wave I loss of BAEPs.

An Intraoperative Multibranch Abnormal Muscle Response Monitoring Method During Microvascular Decompression for Hemifacial Spasm

Intraoperative abnormal muscle response (AMR) is widely used as an indicator during microvascular decompression surgery for hemifacial spasm. Usually only 1 muscle is recorded, and not all patients show a response, leaving the surgery somewhat blinded. We propose an improved method to record from multiple muscles innervated by multiple branches of thefacial nerve to increase the positive AMR detection rate. Retrospective analysis was performed of 1604 patients with hemifacial spasm undergoing microvascular decompression at a single center. All patients were monitored for AMR by stimulating the zygomatic branch of the facial nerve. Only mentalis was recorded in 158 cases (single-branch AMR). Orbicularis oris, frontalis, and mentalis were simultaneously monitored in 148 cases (3-branch AMR), and platysma was further added in the remaining 1298 cases (4-branch AMR). Positive AMR detection rates were compared across the groups. Total positive AMR detection rates significantly increased as more muscles were included in monitoring and were 74.1% for single-branch AMR, 86.5% for 3-branch AMR, and 98.4% for 4-branch AMR. Detection rates from single muscles were not significantly different across the groups. For all available cases, rates were 73.5% from mentalis, 47.2% from frontalis, 64.1% from orbicularis oris, and 40.8% from platysma. This new multibranch AMR monitoring method can effectively increase the positive detection rate to as high as 98.4%. It is expected to better assist surgery.

Intraoperative Neurophysiological Monitoring during Microvascular Decompression Surgery for Hemifacial Spasm.

Hemifacial spasm (HFS) is due to the vascular compression of the facial nerve at its root exit zone (REZ). Microvascular decompression (MVD) of the facial nerve near the REZ is an effective treatment for HFS. In MVD for HFS, intraoperative neurophysiological monitoring (INM) has two purposes. The first purpose is to prevent injury to neural structures such as the vestibulocochlear nerve and facial nerve during MVD surgery, which is possible through INM of brainstem auditory evoked potential and facial nerve electromyography (EMG). The second purpose is the unique feature of MVD for HFS, which is to assess and optimize the effectiveness of the vascular decompression. The purpose is achieved mainly through monitoring of abnormal facial nerve EMG that is called as lateral spread response (LSR) and is also partially possible through Z-L response, facial F-wave, and facial motor evoked potentials. Based on the information regarding INM mentioned above, MVD for HFS can be considered as a more safe and effective treatment.

Missed Culprits in Failed Microvascular Decompression Surgery for Hemifacial Spasm and Clinical Outcomes of Redo Surgery

To identify causes of recurrent hemifacial spasm (HFS) after initial microvascular decompression (MVD) and to assess the feasibility of redo MVD. The study included 21 patients who underwent redo MVD over the last 2 decades. Their medical charts were retrospectively reviewed for preoperative medical history, previous and redo MVD intraoperative findings, and previous and redo MVD postoperative outcomes. Redo MVDs were the second operation in 20 patients and the third operation in 1 patient. The median interval between previous and redo MVD was 46.3 months (range, 14.4-188.2 months). Compression of offending vessels such as a vein or perforating artery located medial to or at the cisternal segment of the facial nerve was found to be a possible cause of previous MVD failure. MVD failure resulted from neglect of offending vessels in 10 patients, insufficient decompression in 7 patients, and untouched neurovascular compression sites in 4 patients. Spasm-free rates after redo MVD were 80.5% at 1 year and 90.5% in the last year of follow-up (median, 15.8 months; range, 3.6-152.0 months). Permanent hearing loss and facial palsy were each observed in 2 patients (9.5%). In addition, 1 patient each experienced cerebellar infarction and vocal cord palsy. Redo MVD remains a feasible treatment option for patients with HFS who failed to benefit from previous MVD, but it is associated with an increased risk of cranial nerve and vascular injuries.

Transposition of the Culprit Artery Passing Between the Facial Nerve and Auditory Nerve in Microvascular Decompression Surgery for Hemifacial Spasm

Decompression of the culprit artery causing hemifacial spasm (HFS), which passes between the facial nerve (cranial nerve [CN] VII) and the auditory nerve (CN VIII), can be difficult, especially if the artery compresses CN VII right after passing between the 2 nerves. Perforators or small arteries branching from near the compression site to adjacent structures can hinder the decompression process because such vessels can anchor the passing condition. The effect of such perforators or small arteries on the decompression process in such cases was investigated. The culprit artery passed between any part of CN VII and VIII in 59 of 396 consecutive patients with HFS who underwent microvascular decompression. The culprit artery compressed CN VII right after passing between the 2 nerves in 22 of the 59 cases. Direction of the perforators or small arteries from near the compression site and direction of decompression of the culprit artery were analyzed in these 22 cases. Perforators or small arteries were observed in 20 cases, predominantly in the medial direction. The culprit artery was mobilized toward the petrous bone direction in most cases. No clear relationship was found between the 2 factors. Variation of curvature or tortuosity of the culprit artery and length of perforators or small branches may also have affected the decompression process and the directions. Adequate dissection near the compression site to obtain maximum mobilization of the culprit artery is necessary to achieve successful decompression in such cases.

Mobilization of the Anterior/Posterior Inferior Cerebellar Artery on the Cerebellar Surface in Microvascular Decompression Surgery for Hemifacial Spasm: Potential Effect on Hearing Preservation.

The infrafloccular approach in microvascular decompression (MVD) for hemifacial spasm (HFS) reduces the risk of postoperative hearing impairment. However, location of the anterior/posterior inferior cerebellar artery (AICA/PICA) on the cerebellar surface in the surgical route requires mobilization to maintain the approach direction for the protection of hearing function. To evaluate the effectiveness of mobilization of the AICA/PICA on the cerebellar surface in the surgical route. Retrospective review of 101 patients dividing their cases into 2 groups, the mobilized group and nonmobilized group. Surgical results, brainstem auditory evoked potentials (BAEPs), age, and duration of microsurgery were compared. In the mobilized group, whether the artery was responsible for the HFS or not, and whether the artery branched perforators to the cerebellar surface or choroid plexus or not, were analyzed. No permanent hearing impairment occurred in any patient. The AICA/PICA was mobilized in 26 patients. No significant difference was found in surgical results, BAEP findings, and duration of microsurgery between the 2 groups, but age was younger in the mobilized group (P<.01). The mobilized artery was responsible in 14 cases and branched perforators in 7 cases in the mobilized group. The perforators did not obstruct mobilization. Mobilization of the AICA/PICA from the cerebellar surface is a useful technique to maintain the infrafloccular approach in MVD for HFS. This technique reduces the risk of postoperative hearing impairment.

Transposition of posterior inferior cerebellar artery could have caused ischemic complication in microvascular decompression for hemifacial spasm

Abstract Ischemic complications are generally rare complications in microvascular decompression surgery for hemifacial spasm. We report a case of posterior inferior cerebellar artery (PICA) infarction post-microvascular decompression. A 68-year old woman with a 2-year history of right hemifacial spasm underwent microvascular decompression surgery. Preoperative magnetic resonance image (MRI) showed that her PICA ran through closely to the root exit zone of her facial nerve. We treated the PICA with a string of polytetra fluoroethylene. After surgery, the patient complained about vertigo, and her MRI revealed ischemic changes in the medulla. She was eventually discharged without any neurological deficit. We reviewed our intraoperative video and found that certain steps in the detachment of the vessel, and minor changes in vessel position could have induced vascular obstruction and ischemia. Herein, we also discuss the choice of decompression methods and emphasize that the transposition of vessels was too invasive in this case. An appropriate method of decompression should carefully be performed in such cases, and review of surgical videos is beneficial.

Failed microvascular decompression surgery for hemifacial spasm: a retrospective clinical study of reoperations.

To investigate the repeat microvascular decompression on hemifacial spasm patients who failed the first MVD. Twenty-six patients underwent late redo MVD in our institution from January 1, 2011 to December 31, 2015. The clinical features, surgical findings, outcomes, and complications of the repeat MVD were analyzed retrospectively. Twenty-four (92.3%) patients were cured immediately after the redo MVD. Delayed relief was found in two (7.7%) patients; it took 6days and 2weeks for them to obtain complete relief. No recurrence was found during follow-up. Surgical complications including three (11.5%) facial paralysis and one (3.8%) hearing loss. We suggested that repeat MVD can be performed 2years after the first MVD if the spasm was not resolved. Repeat MVD for HFS is effective.

Failed microvascular decompression surgery for hemifacial spasm due to persistent neurovascular compression: an analysis of reoperations.

OBJECT Microvascular decompression (MVD) surgery for hemifacial spasm (HFS) is potentially curative. The findings at repeat MVD in patients with persistent or recurrent HFS were analyzed with the aim to identify factors that may improve surgical outcomes. METHODS Intraoperative findings were determined from review of dictated operative reports and operative diagrams for patients who underwent repeat MVD after prior surgery elsewhere. Clinical follow-up was obtained from the hospital and clinic records, as well as telephone questionnaires. RESULTS Among 845 patients who underwent MVD performed by the senior author, 12 had been referred after prior MVD for HFS performed elsewhere. Following repeat MVD, all patients improved and complete spasm resolution was described by 11 of 12 patients after a mean follow-up of 91 ± 55 months (range 28-193). Complications were limited to 1 patient with aggravation of preexisting hearing loss and mild facial weakness and 1 patient with aseptic meningitis without sequelae. Significant factors that may have contributed to the failure of the first surgery included retromastoid craniectomies that did not extend laterally to the sigmoid sinus or inferiorly to the posterior fossa floor in 11 of 12 patients and a prior surgical approach that focused on the cisternal portion of the facial nerve in 9 of 12 patients. In all cases, significant persistent neurovascular compression (NVC) was evident and alleviated more proximally on the facial root exit zone (fREZ). CONCLUSIONS Most HFS patients will achieve spasm relief with thorough alleviation of NVC of the fREZ, which extends from the pontomedullary sulcus root exit point to the Obersteiner-Redlich transition zone.