Intraoperative indocyanine green angiography during microvascular decompression surgery: report of 30 cases

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.

Hearing Outcomes after Microvascular Decompression for Hemifacial Spasm: An Institutional Experience

Introduction

Hearing loss following microvascular decompression (MVD) for hemifacial spasm is one of the most dreaded complications. Several factors such as stretching of VIII cranial nerve, vasospasm of labyrinthine artery, and acoustic trauma due to drill noise may be considered in its causation. We evaluated the incidence and severity of hearing loss following MVD in hemifacial spasm and the factors which might be responsible for this complication.

Methods

A retrospective analysis of 30 patients operated for hemifacial spasm between January 1, 2014, and December 31, 2018, with at least 3 months of follow-up were included in the study. Retromastoid craniotomy was made, and Teflon was placed between involved vessel and VII nerve.

Results

Freedom from hemifacial spasm was noted in 27 of 30 patients. Moderate spasm persisted in one patient, which was controlled with medications. The recurrence was noted in 3 patients at 6 months follow-up. Postoperatively, hearing loss was found in one female patient. The offending vessel was both anterior inferior cerebellar artery (AICA) and posterior inferior cerebellar artery (PICA) loop, which was transpositioned during surgery, and the patient was spasm free postoperatively.

Conclusion

The incidence of hearing loss following MVD can be minimized using proper surgical techniques and various intraoperative adjuncts such as brainstem auditory evoked responses monitoring, use of endoscope, and indocyanine green or dual-image video angiography.

Direct visualization of improved optic nerve pial vascular supply following tuberculum meningioma resection: case report

Tuberculum sellae meningiomas frequently produce visual loss by direct compression from tumor, constriction of the optic nerve (ON) under the falciform ligament, and/or ON ischemia. The authors hypothesized that changes in visual function after tumor removal may be related to changes in blood supply to the ON that might be seen in the pial circulation at surgery. Indocyanine green (ICG) angiography was used to attempt to document these changes at surgery. The first patient in whom the technique was used had a left-sided, 1.4-cm, tuberculum meningioma. Time-lapse comparison of images was done postsurgery, and the comparison of video images revealed both faster initial filling and earlier complete filling of the ON pial circulation, suggesting improved pial blood flow after surgical decompression. In follow-up the patient had significant improvements in both visual acuity and visual fields function. Intraoperative ICG angiography of the ON can demonstrate measurable changes in pial vascular flow that may be predictive of postoperative visual outcome. The predictive value of this technique during neurosurgical procedures around the optic apparatus warrants further investigation in a larger cohort.

Application of indocyanine green video angiography in surgical treatment of intracranial aneurysms

Indocyanine green (ICG) video angiography has been used for several medical indications in the last decades. It allows a real time evaluation of vascular structures during the surgery. This study describes the surgical results of a senior vascular neurosurgeon. We retrospectively searched our database for all aneurysm cases treated with the aid of intraoperative ICG from 2009 to 2014. A total of 61 aneurysms in 56 patients were surgically clipped using intraoperative ICG. Clip reposition after ICG happened in 2 patients (3.2%). Generally, highly variable clip adjustment rates of 2%–38% following ICG have been reported since the introduction of this imaging technique. The application of ICG in vascular neurosurgery is still an emerging challenge. It is an adjunctive strategy which facilitates aneurismal evaluation and treatment in experienced hands. Nevertheless, a qualified vascular neurosurgeon is still the most important component of a high quality work.