Microvascular decompression of a vertebral artery loop causing cervical radiculopathy: illustrative case.

BACKGROUND: Vertebral artery loops are a rare cause of cervical radiculopathy. Surgical options for nerve root decompression include an anterior or posterior approach, with or without additional microvascular decompression. OBSERVATIONS: The authors describe a case of a 49-year-old man with a long-standing history of left-sided neck pain and migraines, who was found to have a vertebral artery loop in the left C3-4 neural foramen compressing the left C4 nerve root. The patient underwent a posterior cervical decompression with instrumented fusion and macrovascular decompression of the left C4 nerve root via Teflon felt insertion. In a literature review, we identified 20 similar cases that had also been managed surgically. LESSONS: Although the anterior approach is more frequently described in the literature, a posterior approach for nerve compression by a vertebral artery loop is also a safe and effective treatment. The authors report the third case of this surgical approach with a good outcome.

Transpeduncular Approach for Resection of Ruptured Fourth Ventricular Arteriovenous Malformation.

The lateral recess of the fourth ventricle can be challenging to access surgically. We present a case of a previously ruptured arteriovenous malformation (AVM) of the fourth ventricle that was surgically resected via a retrosigmoid craniotomy and transinferior cerebellar peduncular approach. The patient is a 54-year-old female who experienced an intraventricular hemorrhage several months before presentation to our institution. Imaging studies suggested the presence of an AVM located in the right lateral recess of the fourth ventricle. After discussion of all possible treatment options, the patient elected to proceed with surgical resection. To access the lesion, we performed a retrosigmoid craniotomy and entered into the fourth ventricle via s small incision in the inferior cerebellar peduncle. Postoperative imaging demonstrated complete removal of the AVM nidus. Video 1 demonstrates this approach and discusses the anatomic landmarks used to guide resection.

Common Carotid-Greater Saphenous-M2 Bypass for Myoepithelial Carcinoma Encasing the Carotid Artery.

Revascularization of the anterior circulation using a high-capacitance graft is sometimes necessary for treatment of cervical tumors encasing the internal carotid artery (ICA). In this surgical video, we aim to demonstrate the technical nuances of high-flow extra-to-intracranial bypass using a saphenous vein graft. The patient is a 23-year-old female who presented with a 4-month history of an enlarging left-sided neck mass, dysphagia, and 25-lb weight loss. Computed tomography and magnetic resonance imaging demonstrated an enhancing lesion encasing the cervical ICA. The patient underwent an open biopsy that established a diagnosis of a myoepithelial carcinoma. The patient was advised to undergo attempted gross total resection, which would require sacrifice of the cervical internal carotid artery. After the patient failed a balloon test occlusion of the left ICA, it was decided to perform a cervical ICA to middle cerebral artery M2 bypass using a saphenous vein graft, followed by tumor resection in staged fashion. Postoperative imaging demonstrated complete tumor removal and filling of the left anterior circulation via the saphenous vein graft. Video 1 discusses important preoperative and postoperative considerations, as well as highlights the technical nuances of this complex procedure. High-flow ICA to middle cerebral artery bypass using a saphenous vein graft can be employed to facilitate gross total resection of malignant tumors encasing the cervical internal carotid artery.

Intermediate-porosity stent for coil-reconstruction of mixed saccular-fusiform basilar trunk aneurysm.

Vertebrobasilar junction and basilar trunk aneurysms are extremely difficult to treat, with significant morbidity associated with bypass-trapping procedures. As a result, endovascular techniques including flow diversion and stent-assisted coil embolization have become the mainstay of treatment.1-3 Traditional flow diverters pose risk of occlusion of basilar perforator arteries while traditional stents used as adjuncts for coil-embolization often have high porosity and cannot function as flow diverters. On the other hand, the LVIS stent uniquely provides more porosity than other flow diverters,4,5 allowing patency of perforators while also being amenable to stent-assisted coiling. We present a case of a mixed saccular and fusiform basilar trunk aneurysm that underwent LVIS stent-assisted coil embolization. Using bifemoral access with triaxial systems, one microcatheter was placed in the aneurysm sac and another was used to deploy a stent from the basilar apex into the right vertebral artery. A durable angiographic outcome was observed at 9 months.

Staged stent-assisted, transcirculatory coiling of partially-thrombosed, mixed saccular and fusiform SCA aneurysm.

SCA aneurysms are rare, making data on their management sparse compared to other posterior circulation aneurysms. While saccular aneurysms at the SCA origin can be treated with primary coiling or surgical clipping, fusiform and distal SCA aneurysms often require endovascular techniques such as stent-assisted coil embolization or parent vessel occlusion. We present a case of a mixed saccular/fusiform SCA aneurysm that underwent staged stent-assisted coil embolization. A right SCA stent was placed in the first stage. Given the acute angle between the BA and the SCA, microcatheter access and stent placement proved challenging. The decision was made to allow the stent to endothelialize and return in a staged fashion to perform a trans-radial, transcirculatory (trans-left PCoA, trans-left PCA) coil embolization. This provided a straight course between the left P1 segment and the right SCA origin, allowing easy microcatheter navigation through the stent and into the aneurysm for coil embolization.

Far-Lateral Transcondylar Approach to a Right Cervicomedullary Dural Arteriovenous Fistula of the Posterior Fossa.

Objectives Dural arteriovenous fistulas (DAVFs) at the cervicomedullary junction are uncommon and often accompanied by subarachnoid hemorrhage (SAH). We aim to illustrate in detail the microsurgical procedure for treating a DAVF located at the cervicomedullary junction. Design We present a two-dimensional operative video that includes clinical history, preoperative imaging, surgical strategy, still images with labels, clinical course, and postoperative imaging. Setting The microsurgery was performed at an academic medical center. Participant The patient is a 55-year-old female who presented with SAH, acute onset headache, nausea, and vomiting. Angiography demonstrated right vertebral artery vasospasm and a persistent arteriovenous shunt at the cervicomedullary junction supplied by small perforating arteries of the right vertebrobasilar junction ( Fig. 1 ). Main Outcome Measures The patient was placed in the park-bench position with the head turned to the contralateral side. A hockey stick incision was made, followed by a right-side far-lateral transcondylar approach. Indocynanine green videoangiography was performed to help identify the areas of arteriovenous shunting. Multiple clips were placed to interrupt vessels that corresponded to arterial feeders at the level of the C1 and C2 nerve root sleeves ( Fig. 2 ). The dura was closed in a water tight fashion and the posterior fossa was reconstructed with a titanium mesh. Results Postoperative imaging showed no evidence of continued arteriovenous shunting. The patient was discharged in good clinical condition with an uneventful postoperative course. Conclusion A deep understanding of the microsurgical vascular anatomy is necessary for successful occlusion of a cervicomedullary DAVF. The link to the video can be found at: https://youtu.be/-LfOcNB05BY .

Suboccipital craniectomy with bilateral cerebellomedullary fissure dissection for resection of a ruptured tonsillar/vermian AVM occupying the roof of the fourth ventricle in a pregnant patient.

Posterior fossa arteriovenous malformations (AVMs) in pregnant patients can present unique considerations for surgical treatment, including positioning to minimize pressure on the fetus, minimization of radiation exposure, and ethical considerations regarding emergency surgery. This video outlines surgical treatment of a ruptured tonsillar/vermian AVM performed in a staged fashion after emergent suboccipital craniotomy with posterior fossa decompression in the setting of a life-threatening infratentorial hemorrhage. Later, bilateral cerebellomedullary fissure dissection, exposure and dissection of the tela choroidea and inferior medullary velum, and disconnection of arterial feeders from the posterior inferior cerebellar artery (PICA) allowed resection of this AVM occupying the roof of the fourth ventricle. This study was approved by the UCSF Human Research Protection Program IRB no. 18-26938. The video can be found here: https://youtu.be/rTYUGanopUE.

Supracerebellar Approach for Resection of a Falcotentorial Dural Arteriovenous Fistula with Pial Tectal Arteriovenous Malformation Component Associated with a Left Parafalcine Meningioma.

A 66-year-old woman presented with a 4.5- × 4-cm left posterior parafalcine meningioma and visual loss in her left eye (Video 1). Prior to meningioma embolization, angiography confirmed an incidental high-risk falcotentorial dural arteriovenous fistula (DAVF) with pial tectal arteriovenous malformation (AVM) and flow-related aneurysms of the superior cerebellar artery (SCA) and posterior cerebral artery (PCA). Arterial supply to the AVM/DAVF consisted of branches of the middle meningeal artery, tentorial branches of the internal carotid arteries, and the PCA and SCA. Drainage into the vein of Galen (VG) and venous reflux into the precentral cerebellar vein (PCCV) were identified. The patient underwent transarterial embolization of the DAVF via the left middle meningeal artery using Onyx with a significant decrease of arterial venous shunting. A semi-sitting supracerebellar approach was performed. The subarachnoid space of the tentorium, cerebellar hemispheres, vermis, quadrigeminal, and ambient cisterns was dissected to reveal the boundaries of the lesion. Indocyanine green video angiography was done before and after in situ occlusion to identify the arterial supply and early venous drainage. The vascular lesion was disconnected circumferentially around the edges of the pial portion of the AVM, and the feeders were carefully cauterized and cut. The vessels on the surface of the brainstem were occluded in situ to prevent any parenchymal transgression. Finally, the drainage into the VG and the venous reflux to the PCCV were ligated. Postoperative angiography showed no residual DAVF or AVM and regression of aneurysms. The patient was discharged with no added deficits, and the meningioma was totally resected several months later.

Combined Pterional Transsylvian and Bifrontal Interhemispheric Approach to Ruptured Subcallosal and Pericallosal Brain Arteriovenous Malformation with Skeletonization of the Entire A2 ACA Segment.

A 39-year-old man presented with a large left paramedian frontal lobe intracerebral hemorrhage. Computed tomography angiography and magnetic resonance imaging revealed a tangle of vessels arising from the anterior cerebral arteries (ACAs) and dilated draining veins entering the superior sagittal sinus. Angiography confirmed a Spetzler-Martin grade 3, supplemented 2 arteriovenous malformation (AVM) with predominant supply from branches of the left ACA with superficial and deep drainage (Video 1). The case illustrates an unusual cerebrovascular pathology involving the entire A2 ACA segment. The AVM extended from the A1/2 junction along the entire A2 segment past the genu of the corpus callosum (A3 segment). A combined pterional transsylvian and bifrontal interhemispheric approach was performed. The proximal sylvian fissure and opticocarotid cistern were opened to expose the A1/2 junction. Once proximal control was obtained, the hematoma was evacuated to define the lateral border of the AVM. The interhemispheric fissure was then opened to identify the draining vein and the distal pericallosal arteries. The interhemispheric approach also defined the medial border of the AVM. The A2 ACAs were then skeletonized from the AVM from the A1/2 junction to the pericallosal arteries. Aneurysm clips were used to interrupt large AVM feeders from the A2 arteries, which avoids cautery and heat transmission to the parent vessel. Once the AVM was disconnected and skeletonized from the A2s, the draining vein was clipped and the nidus was removed. Indocyanine green angiography confirmed patency of the A2s and pericallosal arteries. Postoperative angiography demonstrated no residual shunting, and the patient was discharged in good condition.

Supracerebellar Approach to Radiation-Induced Giant Capillary Telangiectasia Within Juvenile Pilocytic Astrocytoma of Upper Brainstem.

Radiation-induced telangiectasia of the central nervous system has been described predominantly in children, with up to 20% of patients affected after 3-41 years of radiotherapy.1,2 We present the case of a 45-year-old male with a pontine pilocytic astrocytoma treated with standard-dose radiation for 6 weeks in 1993. He developed a 3-cm multicystic, hemorrhagic brainstem lesion but was asymptomatic. The lesion caused severe brainstem mass effect, compatible with cavernous malformation or capillary telangiectasia.3 It has been reported that cavernomas and capillary telangiectasias share a similar pathologic process.4,5 The patient was surgically treated with a supracerebellar infratentorial approach to diagnose the hemorrhagic component of the lesion and ensure there was no transformation of the pilocytic astrocytoma (Video 1). He was placed in a gravity-dependent supine position with the head flexed and turned to allow for natural relaxation of the cerebellum via gravity-a technique we previously described.6 Surgical treatment proceeded with a left suboccipital craniotomy to decompress the cyst and facilitate removal of the intraaxial lesion. We took care to avoid injuring the fourth and fifth cranial nerves and branches of the superior cerebellar artery. No further lesional tissue was seen in the resection cavity. Interestingly, the final pathologic diagnosis indicated a mix of both pilocytic astrocytoma and radiation-induced capillary telangiectasia. From the surgeon's perspective, capillary telangiectasias appear similar to cavernous malformations on gross inspection, so pathologic confirmation is essential. Postoperative imaging demonstrated total resection of the lesion. The patient was discharged on postoperative day 3 with no neurologic deficit.