Welz, Matthew E.

Abstract Cognard type V dural fistulas represent a rare and unique entity, and present clinically with myelopathy. They are frequently located around the foramen magnum and are most commonly fed by dural branches of the vertebral and external carotid artery. Detection requires meticulous angiography to define the angioarchitecture of the fistula, which in turn defines the treatment modality. We present the case of a 63 yr old woman, after informed consent was obtained, with prolonged, severe and progressive lower extremity myelopathy for 6 yr, with T2-weighted signal changes in the thoracic spinal cord on magnetic resonance imaging (MRI). Cervical MRI was unremarkable. Following computed tomography (CT), angiography of the spinal canal that revealed tortuous and dilated veins on the thoracic spinal cord surface, catheter angiography was performed. This demonstrated a fistula in relation to a dural branch of left vertebral artery with a characteristic single draining vein coursing caudally to the thoracic level, with delayed outflow suggestive of venous hypertension. Given the fact that the dural feeder was tortuous and relatively small, thus, precluding distal microcatheter access, and with presence of a single accessible draining vein, microsurgical treatment was preferred. Following a midline suboccipital craniotomy in prone position, a limited vertical dural opening was performed. Careful microsurgical arachnoid dissection revealed the arterialized draining vein with the aid of Indocyanine Green angiography. The draining vein was clipped, coagulated, and disconnected. Postoperative recovery was uneventful and the patient is undergoing rehabilitation therapy. Follow-up angiography showed complete elimination of the fistula. Salient teaching points are narrated at conclusion.

Background Of the minimally invasive “keyhole” alternatives to the pterional region, the supraorbital eyebrow approach is the most widely adopted. Yet it can prove disadvantageous when a more direct lateral microsurgical trajectory of attack to the Sylvian fissure and anterior middle fossa are needed. Objective The extended lateral orbital (XLO) approach was designed to be direct and minimally invasive, with the sphenoid ridge at the center of exposure. Methods Five injected cadaver heads were used for anatomic study of the XLO approach. The anatomic course of the frontalis branch of facial nerve was studied in relation to the XLO incision. Following XLO incision, the bone exposure was measured. The intracranial microsurgical exposure was assessed subjectively. Application of the technique in representative clinical operative cases is provided. Results The frontalis nerve was protected in the subgaleal fat pad, with an average minimum distance of 2.3 cm from the XLO incision. The mean calvarial area exposure was 4.95 cm2 and consistently centered on the sphenoid ridge. Excellent access to ipsilateral Sylvian's fissure, perisylvian regions, and supra-/parasellar structures was possible. The main limitations related to exposure of the posterior Sylvian fissure and the expected limitations of microsurgical instrument manipulation from a smaller craniotomy. Conclusions The XLO approach is a minimally invasive keyhole approach to the pterional region that affords a unique lateral trajectory via a craniotomy centered on the sphenoid ridge. Excellent exposure to properly selected lesions is possible. The incision is at a safe distance from the frontalis branch and shows excellent cosmetic healing.

Abstract We present the case of a 56-yr-old right-handed male, after informed consent was obtained, who presented with acute confusion and agitation, on the background of a remote history of an uncomplicated resection of a left parietal grade 2 glioma. Imaging revealed a large, acute right temporal intracerebral hemorrhage (ICH). Standard vascular workup for the cause of the ICH included catheter angiography. No direct cause of the hemorrhage was revealed; however, a high grade parasagittal dural arteriovenous fistula (DAVF) with cortical venous reflux was noted close to the prior craniotomy site. The venous reflux was towards the left hemisphere, but it was hypothesized that similar reflux on the right side may have been present and was not presently evident due to thrombosis. The DAVF was embolized by endovascular means, followed by evacuation of the hematoma. Follow-up angiogram 7 mo later revealed a high-flow, right superior temporal cortical arteriovenous malformation (AVM). The DAVF unfortunately had also progressed. Endovascular occlusion of both lesions was attempted but was not successful. Subsequently, microsurgical resection for both the vascular malformations was performed with careful pre- and intraoperative planning to obtain a successful clinical and angiographic result. In this video, we summarize diagnostic and therapeutic nuances that have broad implications for the workup of ICH and the strategic management of a unique scenario involving a brain AVM and high-grade cranial dural fistula in the same patient. Prior to each procedure, informed consent was obtained from the patient, which includes consent for publication.

Abstract BACKGROUND AND IMPORTANCE Aneurysms of the ophthalmic artery (OA) within the orbit and optic canal are extremely rare. Given the peripheral location of these aneurysms and the fact that most are fusiform, parent artery occlusion is preferred for symptomatic aneurysms. However, the impact of OA occlusion on vision is not always innocuous. Balloon occlusion testing (BOT) of the OA has the potential to gauge the possibility of visual compromise, in addition to assessing collaterals. While BOT has been assessed for carotid artery occlusion, its role in OA occlusion has not been well defined. CLINICAL PRESENTATION We describe a patient with a 6-mm intracanalicular OA aneurysm who was treated with endovascular coil embolization of the aneurysm and occlusion of the parent artery. We performed a 30-min balloon occlusion test, in which we verified intact visual and neurological function. Collateral vascularity was confirmed. Complete occlusion was achieved and the patient recovered with intact visual and neurological function. We provide a review of literature pertaining to parent artery occlusion of OA aneurysms that occur within optic canal and orbit. A brief note on anatomy of OA and collaterals is provided. CONCLUSION Endovascular parent artery occlusion is an effective treatment for OA aneurysms that occur in optic canal and orbit. Assessment of effect of occlusion on vision is important. BOT can assess this and provide valuable information. Recovery or preservation of visual function is highly dependent on preoperative visual status.