Neurotologic Complications Following Microvascular Decompression: A Retrospective Study

Transcutaneous electrical acupoint stimulation to prevent dizziness after microvascular decompression for hemifacial spasm: A randomized controlled trial

BACKGROUND

Dizziness often occurs after microvascular decompression (MVD), and therapeutic options are limited. The aim of this trial was to determine the potential efficacy of transcutaneous electrical acupoint stimulation (TEAS), against dizziness and its safety in patients undergoing MVD.

METHODS

Adult patients scheduled to undergo MVD for hemifacial spasm under total intravenous anesthesia were randomized at a 1:1 ratio to receive, after extubation, 30-min TEAS in the mastoid region as well as Fengchi acupoints (GB20) and Neiguan acupoints (PC6) or 30-min sham stimulation. The primary outcome was the incidence of dizziness at 2 h after surgery. Secondary outcomes included dizziness, postoperative nausea and vomiting (PONV) or headache severity, rescue medication, changes in intraocular pressure before and after surgery, length of stay, dizziness symptoms 4 weeks after discharge, and surgical complications.

RESULTS

A total of 86 patients (51.9 ± 9.4 years of age; 67 women) were enrolled. One patient (in the TEAS arm) was excluded from analysis due to conversion to sevoflurane anesthesia. The rate of dizziness at 2 h after surgery was 31.0 % (13/42) in the TEAS arm vs. 53.5 % (23/43) in the sham control arm (P = 0.036). TEAS was also associated with significantly lower severity of dizziness, based on a 10-point scale, during the first 24 h after surgery. None of the other secondary efficacy outcomes differed significantly between the two arms. All postoperative complications were Clavien-Dindo grade I or II. The rate of postoperative complications was 21.4 % (9/42) in the TEAS arm vs. 16.3 % (7/43) in the sham control arm (P = 0.544).

CONCLUSIONS

Compared with sham control, TEAS was associated with a lower incidence of dizziness within 2 h and lower severity of dizziness within 24 h post-operatively, but no improvement in other outcomes, in adult patients undergoing MVD for hemifacial spasm.

Evaluating Changes in Pulsatile Flow With Endovascular Stents in an In Vitro Blood Vessel Model: Potential Implications for the Future Management of Neurovascular Compression Syndromes

BACKGROUND

Neurovascular compression syndromes (NVCS), encompassing conditions such as trigeminal neuralgia, hemifacial spasm, and glossopharyngeal neuralgia, significantly impair patient quality of life through abnormal vascular compression and micro-pulsation of vasculature on cranial nerves at the Obersteiner-Redlich zone. The modulation of pulsatile flow dynamics via endovascular stents presents a novel research frontier for alleviating these syndromes.

AIM

The primary aim of this investigation was to delineate the impact of various endovascular stents on pulsatile flow within an in vitro model of a blood vessel, thereby elucidating their potential applicability in the therapeutic management of NVCS.

MATERIALS AND METHODS

A simple in vitro analog of a posterior circulation artery was developed, employing an intravenous pump to replicate cardiac-induced blood flow. Within this model, alterations in pulsatile flow were quantitatively assessed following the introduction of three categorically distinct endovascular stents, varying in size. This assessment was facilitated through the employment of both micro-Doppler and Doppler ultrasound methodologies.

RESULTS

The Pipeline 5x35 mm stent (Medtronic, Minneapolis, MN) demonstrated the most significant reductions in peak systolic velocity (Vmax) and pulsatility index (PI), PI especially over the stent, suggesting its potential for drastically altering blood flow dynamics. Similarly, Neuroform Atlas 4.5x30 mm and Neuroform Atlas 4x24 mm stents (Stryker, Kalamazoo, MI) also showed notable decreases in hemodynamic parameters, albeit to different extents. Statistical analysis confirmed that these changes were significantly different from the control (P < 0.0001 for PI and Vmax; P < 0.05 for inter-stent comparisons), except for proximal PI means, which did not significantly differ from the control (P = 0.2777).

CONCLUSION

These findings affirm the potential of endovascular stents to substantially modulate arterial pulsatility. The observed decrease in pulsatile flow resultant from endovascular stent application has the potential to attenuate ectopic nerve excitation, a hallmark of NVCS. Consequently, this research highlights the prospective utility of endovascular stents in developing minimally invasive therapeutic approaches for NVCS.

Comparison of the efficacy in improving trigeminal neuralgia in petroclival meningioma between microsurgery and radiosurgery: a meta-analysis

The purpose of this study was to systematically review studies in the literature to assess the superiority between microsurgery and radiosurgery regarding the efficacy in improving petroclival meningioma (PCM)-related trigeminal neuralgia (TN). PubMed, Embase, Web of Science, and Cochrane clinical trial databases were systematically searched from the inception until December 08, 2022. The overall proportion of patients with improved TN after treatment in all six included studies was 56% (95% confidence interval [CI], 35-76.9%). Higgins I2 statistics showed significant heterogeneity (I2 = 90%). Subgroup analysis showed that the proportion of improved TN was higher in the microsurgery group than that in the radiosurgery group (89%; 95% CI, 81-96.5% vs. 37%, 95% CI, 22-52.7%, respectively, p < 0.01). Subgroup analysis (for studies that documented the number of posttreatment Barrow Neurological Institute scores 1 and 2) revealed that the proportion of pain-free without medication after treatment was higher in the microsurgery group than that in the radiosurgery group (90.7%; 95% CI, 81-99.7% vs. 34.5%, 95% CI, 21.3-47.7.7%, respectively, p < 0.01). Based on the results of this meta-analysis, we concluded that microsurgery is superior to radiosurgery in controlling PCM-related TN.

Microvascular decompression for hemifacial spasm: Complications after 292 procedures without neurophysiological monitoring

Background

Hemifacial spasm (HFS) is characterized by involuntary, progressive, and intermittent spasms in the upper and lower facial muscles. Due to the high success rate, microvascular decompression (MVD) is the treatment of choice, and intraoperative neuromonitoring (INM) is considered useful for achieving safe surgery. Still, most centers do not have this technology.

Methods

We analyzed 294 patients with HFS treated with MVD without INM. We only included patients with a neurovascular etiology while excluding other causes, such as tumors. As part of the postoperative evaluation, we assessed preoperative magnetic resonance imaging and pure-tone audiometry.

Results

The main complication was peripheral facial paralysis in 50 patients, followed by hypoacusis in 22 patients and deafness in 17 patients, associated with a failed surgical outcome (P = 0.0002). The anterior inferior cerebellar artery (AICA) was an offending vessel, and the involvement of more than one vessel was significantly associated with the development of facial nerve palsy (P = 0.01). AICA was also associated with hearing impairment (P = 0.04). Over 90% of immediate complications improve in the follow-up (6 months), and one patient did not show a cure for initial HFS.

Conclusion

MVD is the method with the highest long-term cure rates for treating HFS; however, we must inquire into the multiple factors of the patient and the surgeon to predict surgical outcomes. INM is not a must during MVD for HFS. We recommend its use depending on the availability and mainly on the surgeon's skills, for surgeons.

Surgical treatment for Trigeminal neuralgia

Various treatments for trigeminal neuralgia (TN) are known to yield initial satisfactory results; however, the surgical treatment has excellent long-term outcomes and a low recurrence rate. Surgical treatment addresses the challenge of vascular compression, which accounts for 85% of the causes of TN. As for surgical treatment for TN, microvascular decompression (MVD) has become the surgical treatment of choice after Peter J. Jannetta reported the results of MVD surgery in 1996. Since then, many studies have reported a success rate of over 90% for the initial surgical treatment. Most MVDs aim to separate (decompress) the culprit vessel from the trigeminal nerve. To increase the success rate of surgery, accurate indications for MVD and management of the offender vessels without complications are critical. In addition, if there is no vascular compression, partial sensory rhizotomy or internal neurolysis can be performed to improve surgical outcomes.