Clipping of Basilar Perforator Pure Arterial Malformation Aneurysm: 2-Dimensional Operative Video

Pure arterial malformations are rarely-encountered intracranial lesions, often mistaken for arteriovenous malformations. A minority of these lesions may harbor associated aneurysms. In a recent series of 12 patients with pure arterial malformations, 3 patients had associated aneurysms.1 As the authors describe, the presentation and natural history of pure arterial malformations generally are considered benign. In over 85% of cases reported in the literature, they are discovered incidentally and in cases with documented follow-up the angio-architecture tends to remain stable.1 However, here we present the case of an aneurysm associated with a pure arterial malformation managed with microsurgical clipping. The patient presented to us with the development of hemorrhage within and/or around the lesion and the development of a partial CN III palsy. Using a cranio-orbital approach, we successfully performed clipping of the offending vessel in the region of the basilar apex. Critical to the successful treatment of this lesion were: the correct identification of the offending vessel, recognition of the presence of perforating arteries, and clipping of the offending artery distal to the origin of the perforating arteries. This case represents a rare instance of a symptomatic pure arterial malformation with associated aneurysm. Verbal consent was provided by the patient for reproduction and publication of her case.

“Macrovascular” Decompression of Dolichoectatic Vertebral Artery Causing Hemifacial Spasm Using Goretex Sling: 2-Dimensional Operative Video

Hemifacial spasm is characterized by painless and involuntary spasms of the muscles supplied by the facial nerve, most commonly involving the orbicularis oculi. The most common cause of hemifacial spasm is compression of the facial nerve's root by the anterior inferior, or posterior inferior, cerebellar arteries (AICA or PICA). However, in <1% of cases, the compression can be due to a dolichoectatic vertebral artery. Microvascular decompression using Teflon patties may be sufficient when the offending artery is small (eg, AICA or PICA). However, the size and tortuosity of the vertebral artery (especially one that is dolichoectatic) may require a more robust means of decompression (ie, “macrovascular decompression”). In this operative video we demonstrate our technique for managing a patient with hemifacial spasm due to a dolicoectatic vertebral artery. We use a Goretex® (W.L. Gore & Associates Inc, Newark, Delaware) sling secured to the dura of the posterior petrous ridge to suspend the vertebral and posterior inferior cerebellar arteries, thereby decompressing the root entry zone of the facial nerve. Teflon felt pieces are added as a second layer of security. Key steps to this technique include: (1) visualization of the root entry zone, (2) extensive arachnoid dissection to allow adequate mobilization of the vertebral artery, 12 and (3) securing the sling in a trajectory that prevents kinking of the vertebral artery and its branches.

“Birdlime” technique using TachoSil tissue sealing sheet soaked with fibrin glue for sutureless vessel transposition in microvascular decompression: operative technique and nuances

OBJECTIVEMicrovascular decompression (MVD) is effective for the treatment of trigeminal neuralgia (TN), hemifacial spasm (HFS), and glossopharyngeal neuralgia. The transposition technique is the standard procedure to avoid adhesions and granuloma around the decompression site but is more complex and difficult to perform than the interposition technique. The authors describe a simple and safe MVD transposition procedure they call the “birdlime” technique, which uses a tissue glue–coated collagen sponge soaked with fibrin glue, and the results of this technique.METHODSThe authors retrospectively reviewed the medical charts and radiographic findings of 27 consecutive patients with TN (8 patients) and HFS (19 patients) who, between January 2012 and December 2015, had undergone an MVD transposition procedure utilizing a tissue glue–coated collagen sponge (TachoSil tissue sealing sheet) soaked with fibrin glue (Tisseel 2-component fibrin sealant, vapor heated). Offending arteries among the patients with TN were the superior cerebellar artery (SCA) in 5 patients, the SCA and anterior inferior cerebellar artery (AICA) in 2, and the AICA in 1. Those among the patients with HFS were the vertebral artery (VA) in 3 patients, the VA and AICA in 4, the VA and posterior inferior cerebellar artery (PICA) in 3, the PICA in 4, the AICA in 1, the AICA-PICA in 3, and the PICA and AICA in 1. Operations were performed according to the Jannetta procedure. The offending artery was transposed and fixed to the dura mater of the petrous bone using TachoSil pieces soaked with fibrin glue. Postoperative constructive interference in steady-state MRI was performed to evaluate the change in the position of the offending artery.RESULTSTransposition of the offending artery was easily and safely performed in all patients. All patients had total remission of symptoms directly after the procedure. No severe complications occurred. The postoperative course was uneventful. No recurrences, adhesions, or dysfunction of the cranial nerves was observed in any of the patients. Postoperative MRI showed that the offending vessels were displaced and fixed in the appropriate position.CONCLUSIONSThe described transposition technique provides an easy and adjustable way to perform MVD safely and effectively. In addition, this transposition and fixation technique is simple and avoids the risk of needle injury close to the cranial nerves and vessels. This simple sutureless technique is recommended for MVD to reduce the risk of intraoperative neurovascular injury.

A Perforating Artery Compressing the Nerve Rootlet and Causing Glossopharyngeal Neuralgia

BACKGROUND A surgical procedure for glossopharyngeal neuralgia (GPN) was selected from microvascular decompression, glossopharyngeal and upper vagal rhizotomy, or a combination of these procedures based on the presence of arteries compressing the glossopharyngeal and vagal rootlets. The offending artery is usually a main trunk or branch of the cerebellar arteries. A perforating artery is a known but uncommon variation of the offending artery that causes GPN. The appropriate procedure for such cases is unknown. OBJECTIVE To analyze the clinical significance of the perforating artery in GPN, we describe 2 patients with a perforating artery compressing the rootlet, and its mobilization relieved neuralgia. We examined the validity of decompressing a perforating artery as an alternative to rhizotomy in such cases. METHODS We independently reviewed 12 GPN patients treated with microvascular decompression. The patients' pain severity, medication doses, preoperative imaging studies, intraoperative findings, and outcomes were examined. RESULTS Eleven patients had neurovascular compression of the glossopharyngeal nerve. In 2 of the patients, a perforating artery compressed the rootlet, thereby generating an indentation and creating a discoloration of the rootlet. Mobilizing the perforating artery with no additional rhizotomy provided complete pain relief with no significant complications and allowed the discontinuation of medications. CONCLUSION Even a small perforating artery can cause GPN when it compresses the rootlet. In such cases, mobilization of the perforating artery with no additional rhizotomy is an effective surgical option.

Trigeminal neuralgia caused by a trigeminocerebellar artery

This 31-year-old woman presented with typical right trigeminal neuralgia caused by a trigeminocerebellar artery, manifesting as pain uncontrollable with medical treatment. Preoperative neuroimaging studies demonstrated that the offending artery had almost encircled the right trigeminal nerve. This finding was confirmed intraoperatively, and decompression was completed. The neuralgia resolved after the surgery; the patient had slight transient hypesthesia, which fully resolved within the 1st month after surgery. The neuroimaging and intraoperative findings showed that the offending artery directly branched from the upper part of the basilar artery and, after encircling and supplying tiny branches to the nerve root, maintained its diameter and coursed toward the rostral direction of the cerebellum, which indicated that the artery supplied both the trigeminal nerve and the cerebellum. The offending artery was identified as the trigeminocerebellar artery. This case of trigeminal neuralgia caused by a trigeminocerebellar artery indicates that this variant is important for a better understanding of the vasculature of the trigeminal nerve root.

Microvascular Decompressions in Patients With Coexistent Hemifacial Spasm and Trigeminal Neuralgia

BACKGROUND: Although microvascular decompression (MVD) is widely accepted as the effective therapy for hemifacial spasm (HFS) or trigeminal neuralgia (TN), the surgical treatment of coexistent HFS and TN in an individual is seldom addressed. OBJECTIVE: To discuss the operative strategy of MVD for both the hemifacial and trigeminal nerves. METHODS: Nine consecutive cases of coexistent HFS and TN caused by neurovascular confliction in the same side were studied. Except for one, the patients suffered from HFS followed by ipsilateral TN. All patients underwent MVD and were followed up for 3 to 30 months. Each surgery was analyzed retrospectively. RESULTS: Intraoperatively, a looped vertebral artery (VA) shifted to the suffered side was found in 8 patients. The VA was regarded as the direct or indirect offending artery. After MVDs, the spasm ceased immediately in 6 patients; the other 3 patients had delayed relief within 3 months. The pain disappeared immediately in 7 of 9 patients. One patient felt relief after a week, and 1 had pain but improved slightly. No recurrence or complication was found. CONCLUSION: A shifted VA loop may account for this tic convulsif syndrome. MVD is a reasonable and effective therapy with a high cure rate for the disease. The key to the surgery is to move the VA proximally. The dissection should be performed rostrally starting from the caudal cranial nerves.