Lateral supracerebellar infratentorial approach for a ruptured cerebellomesencephalic fissure arteriovenous malformation resection

In this surgical video, the authors present a case of a 24-year-old male patient who presented with sudden-onset headache and imbalance. On examination, he had a right-sided dysmetria and was otherwise neurologically intact. MRI showed a right cerebellar hematoma associated with multiple flow voids in the cerebellomesencephalic fissure and an enlarged lateral mesencephalic vein. Preoperative angiogram confirmed an arteriovenous malformation supplied by branches of the superior cerebellar artery. The patient underwent a lateral supracerebellar infratentorial approach for resection of the arteriovenous malformation (AVM). He recovered well from surgery and was discharged home on postoperative day 6. Postoperative angiogram confirmed complete AVM resection.The video can be found here: https://youtu.be/tY4Go2n7V80

Anatomy of the deep venous system in vein of Galen malformation and its changes after endovascular treatment depicted by magnetic resonance venography

Background and purposeIt is classically thought that the internal cerebral veins (ICV) do not communicate with the venous pouch of vein of Galen malformations (VGM). We report on the anatomy of the deep venous system in VGM with special emphasis on the drainage of the ICV and possible changes after endovascular treatment.Materials and methodsWe retrospectively analyzed DSA and 2D time-of-flight MR venograms of 55 children with VGM. We evaluated all pre- and post-operative images for the presence of the ICVs and determined their route of venous drainage.ResultsOf 55 children, pre-operative 2D MRV detected the ICVs in 19 cases (35%) compared with one case (2%) for pre-embolization DSA (2%) (P<0.0001). Of the cases in which the ICVs were seen preoperatively, in 15 cases (78.9%) the ICV drained directly into the VGM while in the other four cases, the ICV used alternative venous drainage routes. On post-operative MRV, the ICVs were seen in 17 cases (31%) on MRV and 10 cases (18.2%) on DSA with drainage into an adult-like vein of Galen in 13 cases (76%), respectively (P=0.08). In four cases normal ICV drainage into the vein of Galen was seen even when the venous sac was closed. In two cases there was a change in ICV drainage from the vein of Galen to the lateral mesencephalic vein.ConclusionThe communication of the ICV with the VGM is a common phenomenon. Different changes of venous drainage routes do occur after treatment and are best seen on MRV.

Role of endovascular embolization for trigeminal neuralgia related to cerebral vascular malformation

Objective The objective of this article is to describe the trigeminal neuralgia related to cerebral vascular malformation that is rarely reported and the experience referring to endovascular treatment. Patients and methods A total of 10 patients who had cerebral vascular malformation (AVM and dAVF) in a single center presented with trigeminal neuralgia. Clinical and angiographic presentations as well as their clinical outcomes after embolization were reviewed. Results Of the 10 cases, seven dAVFs and three AVMs were detected. In contrast to the dilated feeding arteries, an ectasia of the draining vein that is adjacent to the root entry zone of the trigeminal nerve such as the petrosal vein and lateral mesencephalic vein has the major role in causing the trigeminal neuralgia. All of these patients had relief of facial pain after endovascular embolization during follow-up (mean 57.3 months, range 5 to 100 months). There were no permanent neurological deficits. Conclusions Endovascular embolization is an effective method in treating trigeminal neuralgia related to cerebral vascular malformation.

Microsurgical anatomy of the mesencephalic veins

Object The mesencephalic veins drain crucial brainstem areas. Due to the narrowness of the tentorial notch, these veins can become obstructed as a result of herniation or surgery, leading to hemorrhage and severe consequences for the patient. There is little in the literature about the mesencephalic veins. The aim of this study was to perform an exact analysis of their microanatomy. Methods Fifty-two cadaveric hemispheres were examined under an operating microscope, and measurements were made with a digital caliper. The authors focused on the basal vein (BV), pontomesencephalic vein (PMV), peduncular vein (PV), lateral mesencephalic vein (LMV), and other smaller veins. The PMV was identified in 84.6% of specimens (mean diameter 0.54 mm); the PV, in 86.5% (mean diameter 0.86 mm); and the LMV, in 100% (mean diameter 1.07 mm). Four types of LMV were identified on the basis of the vein's course. Other smaller veins were also differentiated according to whether they drained mainly the cerebral peduncle, the lemniscal trigone, or the tectum. These veins and their junctions with other veins were depicted. Conclusions A thorough understanding of the microanatomy of the mesencephalic veins is crucial in brainstem surgery in order to avoid brain damage due to venous infarction and subsequent edema. Because knowledge of the course, variations, and outflow system of these veins could improve surgical outcome, they warrant special attention during surgery.