The Outcome of Sling Retraction Technique in Microvascular Decompression for Hemifacial Spasm:

The value of intraoperative indocyanine green angiography in microvascular decompression for hemifacial spasm to avoid brainstem ischemia

PURPOSE

Despite being rarely reported, ischemic insults resulting from compromising small brainstem perforators following microvascular decompression (MVD) remain a potential devastating complication. To avoid this complication, we have been using indocyanine green (ICG) angiography intraoperatively to check the flow within the small brainstem perforators. We aim to evaluate the safety and usefulness of ICG videoangiography in MVD.

METHODS

We extracted retrospective data of patients who received ICG videoangiography from our prospectively maintained database for microvascular decompression. We noted relevant data including demographics, offending vessels, operative technique, outcome, and complications.

RESULTS

Out of the 438 patients, 15 patients with a mean age (SD) of 53 ± 10.5 years underwent intraoperative ICG angiography. Male:female was 1:1.14. The mean disease duration prior to surgery was 7.7 ± 5.3 years. The mean follow-up (SD) was 50.7 ± 42.0 months. In 14 patients, the offending vessel was an artery, and in one patient, a vein. Intraoperative readjustment of the Teflon pledget or sling was required in 20% (3/15) of the cases. No patient had any sort of brainstem ischemia. Eighty percent of the patients (12/15) experienced complete resolution of the spasms. 86.7% (13/15) of the patients reported a satisfactory outcome with marked improvement of the spasms. Three patients experienced slight hearing affection after surgery, which improved in two patients later. There was no facial or lower cranial nerve affection.

CONCLUSION

Intraoperative ICG is a safe tool for evaluating the flow within the brain stem perforators and avoiding brainstem ischemia in MVD for hemifacial spasm.

Macrovascular Decompression for Hemifacial Spasm Using Sling Technique

Hemifacial spasm (HFS) is a painless, involuntary twitching of the facial muscles that usually involves the orbicularis oculi muscle.^1,2 It is commonly caused by the anterior inferior cerebellar artery or posterior inferior cerebellar artery.^1,2 However, a dolichoectatic vertebrobasilar artery (VBA) can impinge the facial nerve.¹ Macrovascular decompression with sling transposition is a common management paradigm.^1-9 We present a case of a 56-year-old male who presented with left-sided HFS, pulsatile tinnitus, and hearing loss for the past 2 years. The patient underwent a retrosigmoid craniotomy and Gore-Tex sling transposition of a dolichoectatic VBA (Video 1). Complete improvement of symptoms was noted postoperatively with no associated complications. We review the preoperative workup, operative technique, relevant anatomy, and literature and provide technical pearls for this procedure.

Reoperation for residual or recurrent hemifacial spasm after microvascular decompression

PURPOSE

Microvascular decompression (MVD) surgery is the only potential curative method for hemifacial spasm (HFS). Little attention is paid to those recurrent/residual HFS cases. We want to study the potential etiology of those recurrent/residual HFS cases and evaluate the value of reoperation.

METHODS

We retrospectively reviewed reoperation hemifacial spasm patients in our hospital. Intraoperative videos or images were carefully reviewed, and the etiology of recurrent/residual HFS is roughly divided into three categories. Intraoperative findings, surgical outcomes, and complications were carefully studied to assess the value of reoperation for recurrent/residual HFS patients.

RESULTS

A total of 28 cases were included in our case series. Twenty-three of them are recurrent HFS cases, and 5 of them are residual HFS cases. The mean follow-up duration is 24.96 months. There are seventeen patients with missed culprit vessels or insufficient decompression of root exit zone (REZ), eight patients with Teflon adhesion, and three patients with improper application of decompression materials in our case series. The final reoperation outcome with 17 excellent, seven good, and four fair, respectively. Eight (28.57%) of them experienced long-term complications after reoperation.

CONCLUSION

Re-operation for recurrent/residual HFS is an effective therapy and can achieve a higher cure rate. However, the complication rate is higher compared to the first MVD surgery. Accurately identifying REZ and proper decompression strategies to deal with the culprit vessels are very important for surgical success.

TRIAL REGISTRATION NUMBER

UIN: researchregistry7603. Date of registration: Jan. 31st, 2022 "retrospectively registered".

Transposition of Vessels for Microvascular Decompression of Posterior Fossa Cranial Nerves: Review of Literature and Intraoperative Decision-Making Scheme

INTRODUCTION

Microvascular decompression with transposition of the involved vessels provides good surgical outcomes in cases of complex and recurrent neurovascular compression syndromes. We conducted a literature review to illustrate the variations in the surgical techniques used for transposition and to provide a practical decision-making scheme for transposition of the involved vessel.

METHODS

A PubMed Medline database record search was conducted using the following algorithm ("Microvascular Decompression Surgery"[Mesh]) OR (((Microvascular) OR (Macrovascular)) AND decompression AND surgery) AND (transposition). Only articles that detailed the intraoperative techniques were included.

RESULTS

A total of 48 articles were included. The adjacent anatomical walls to which the compressing vessel can be anchored were divided into 4 groups; A: roof (tentorium cerebelli), B: anterior wall (posterior surface of petrous bone and clivus), C: posterior wall (petrosal surface of the cerebellum), and D: "no wall" required. A new decision-making scheme based on the following 2 questions was designed: 1) is the conflicting vessel amenable to transposition to a nearby wall in the cerebello-brainstem space? 2) what is the closest wall to secure the transposed vessel?

CONCLUSIONS

Transposition of the involved vessel is a valuable procedure for microvascular decompression of the posterior fossa cranial nerves. Anchoring the vessel to the adjacent anatomical wall ensures secure transposition. The proposed algorithm provides a systemic scheme to identify the optimal anatomical wall, and to determine the technique and material that can be used to anchor involved vessel. This scheme is an efficient method to inform the intraoperative decision-making process.

Treatment of Venous Hemorrhage Between Vestibulocochlear Nerve and Hypertrophic Flocculus During Microvascular Decompression Procedure for Hemifacial Spasm

Hemifacial spasm is a kind of painless, intermittent, involuntary, and irregular unilateral facial muscles convulsion. Microvascular decompression has become the standard surgical procedure for hemifacial spasm after years of popularization and development. In the article, the authors described in detail a therapeutic strategy for rapid intracranial venous bleeding between vestibulocochlear nerve and hypertrophic flocculus. When simple compression hemostasis failed, the authors applied fibrin glue and gelatin sponges for hemostasis and finally successfully controlled venous bleeding. The patient's symptoms were completely relieved after operation. Routine postoperative examination of head computed tomography revealed no intracranial hemorrhage. The combination of fibrin glue and gelatin sponges may be a possible solution for complicated and intractable venous hemorrhage during microvascular decompression procedure in some patients with hemifacial spasm.