Microsurgical Treatment of a Petrotentorial Dural Arteriovenous Fistula: The Vein, the Whole Vein, and Nothing but the Vein: 2-Dimensional Operative Video

Dural arteriovenous fistulas (dAVFs) consist of abnormal anastomoses between 1 or multiple meningeal arteries to meningeal veins, venous sinuses, or subarachnoid veins.1 dAVFs account for 10% to 15% of all intracranial arteriovenous lesions.2 dAVFs can be challenging to treat with various approaches that include microsurgical ligation, endovascular embolization (transarterial or transvenous), and stereotactic radiosurgery. All these treatments share the common goal of disconnecting the draining vein from the fistulous point. We present a case of a 43-yr-old male who presented with progressive headaches and was found to have an incidental Zipfel type 3A3 right petrotentorial dAVF on catheter angiography. The patient underwent a right retrosigmoid craniotomy and clipping of 2 separate venous outflows. The case illustrates the principle that multiple venous outflows can exist in dAVF and a thorough analysis of the venous phase of the angiogram as well as corresponding inspection of the fistula at the time of surgical exploration is a necessity to avoid partial obliteration. The patient remained neurologically intact postoperatively and had complete resolution of his fistula on postoperative angiography. We review the neuroimaging, operative video, and technical nuances and provide a short literature review on the topic.4 The patient gave informed consent for the procedure and verbal consent for this publication. The patient consented to the publication of their image.

Spontaneous resolution of a tentorial dural arteriovenous fistula fed by the artery of Wollschlaeger and Wollschlaeger after embolization of the main shunting point

Background: Tentorial dural arteriovenous fistula (TDAVF) is a rare intracranial vascular shunt. A TDAVF can be supplied by the Artery of Wollschlaeger and Wollschlaeger (AWW). However, a limited number of cases of TDAVF fed by the AWW have been reported to date. Case Description: A 70-year-old woman complaining of the right motor weakness underwent magnetic resonance imaging. A vascular lesion beneath the cerebellar tentorium was incidentally found with chronic infarction of the left corona radiata. Angiographically, the vascular lesion was a TDAVF supplied by the bilateral posterior meningeal arteries. No other apparent feeders were detected. The TDAVF had a shunting point on the inferior surface of the cerebellar tentorium with venous retrograde flow (Borden type III, Cognard type III). To prevent vascular events, endovascular embolization was performed using n-butyl-2-cyanoacrylate. Following embolization of the shunting point, a residual shunt fed by the AWW was identified. The shunt supplied by the AWW was not observed preoperatively. Follow-up angiography performed 1 week later revealed spontaneous disappearance of the residual shunt. The patient was followed-up in our outpatient clinic, and no recurrence of the TDAVF was confirmed postoperatively. Conclusion: Detection of mild feeding from the AWW to a TDAVF can be elusive preoperatively. Following embolization of the main shunting point, residual shunting from the AWW can resolve spontaneously.

Transverse dural arteriovenous fistula with bilateral sigmoid sinus stenosis treated with via transarterial embolization and venous stent placement: case report

BackgroundDural arteriovenous fistulas (DVAF) is a cerebrovascular disorder due to abnormal connections within meningeal arteries and cerebral veins. It is usually associated with sinus stenosis.Case PresentationWe describe a case of DAVF with bilateral sigmoid sinus stenosis successfully treated via transarterial embolization and unilateral stenting.ConclusionThe author reported a rare case of DAVF associated with with bilateral sigmoid sinus stenosis. Direct embolization with catheterization of contralateral MMA may by an alternative way to treat partial embolized DAVF, when main feeding arteries were occluded due to previous treatment. Unilateral sinus recanalization for bilateral sinus narrows could also obtain obvious benefit.

Dural venous system: angiographic technique and correlation with ex vivo investigations

BackgroundThe dural vasculature plays a key role in several important conditions, including dural fistulas and subdural collections. While in vivo investigations of intrinsic dural arterial angioarchitecture are rare, no angiographic studies of dural venous drainage exist to our knowledge.ObjectiveTo describe methods by which dural venous drainage might be visualized with current angiographic equipment and technique, and to correlate our results with existing ex vivo literature.MethodsDigital subtraction angiography and 3D angiography (rotational and Dyna CT) of dural neurovasculature were acquired in the context of subdural hematoma embolization and normal dura. Protocols for visualization of dural venous drainage were established, and findings correlated with ex vivo studies.ResultsMeningeal arteries supply both the skull and dura. Normal dural enhancement is accentuated by the presence of hypervascular membranes. Intrinsic meningeal veins/sinuses parallel outer layer arteries with well-known tram-tracking appearance. Dura adjacent to main arterial trunks drains via skull base foramina into the pterygopalatine venous plexus, or via emissary veins into the temporalis venous plexus. Dura near the sinuses drains into venous pouches adjacent to the sinus, before emptying into the sinus proper—possibly the same pouches implicated in the angioarchitecture of dural fistulas. Finally, posterior temporoparietal convexity dura, situated in a watershed-like region between middle and posterior meningeal territories, frequently empties into diploic and emissary veins of the skull. Wide variation in balance is expected between these three routes. Drainage patterns appear to correlate with venous embryologic investigations of Padget and ex vivo studies in adults.ConclusionsContinued attention to dural venous drainage may prove useful in the diagnosis and management of dural-based vascular diseases.

Sphenoidal artery: review of the literature and analysis of a dissected arterially injected fetal orbit

Purpose The sphenoidal artery is considered a component of the complex and dangerous arterial anastomoses of the human orbitocranial region, particularly with the advent of interventional neuroimaging. The objective of this publication was to analyze the various descriptions of the sphenoidal artery in the literature as related to relevant photographs of a dissected arterially injected fetal middle cranial fossa and orbit. Methods Publications dealing with middle meningeal-ophthalmic arterial anastomoses, focusing on the sphenoidal artery, were reviewed. A relevant dissection of a fetal specimen was analyzed. Results The literature dealing with the sphenoidal artery is at times not in agreement. The nomenclature and anatomy of its passage through the superior orbital fissure or Hyrtl canal have variable descriptions. Photographs of the skull base of a dissected arterially injected fetal specimen show bilateral prominent orbital branches of the middle meningeal arteries. These branches entered both orbits in a course similar to the diagrammatic representations of the sphenoidal artery, and give rise to several major intraorbital arteries. This study provides the only photographic image in the literature of this variation in a human fetal anatomic dissection. Conclusions Review of the literature dealing with the sphenoidal artery shows inconsistent nomenclature and conflicting descriptions of its anastomotic connections, and varying evolutionary and embryologic theories. Analysis of the dissected fetal skull base indicates that the sphenoidal artery is not a distinct artery but just a middle meningeal orbital arterial branch, an important component of the complex and dangerous arterial anastomoses of the human orbitocranial region.

Traumatic acute epidural hematoma caused by injury of the diploic channels

Background: Traumatic acute epidural hematomas (EDHs) commonly develop by rupture of the meningeal arteries. EDH caused by an injury of the diploic channel (DC) has not been reported. Case Description: A 21-year-old man suffered a head injury while falling off the skateboard. At presentation, the patient was drowsy but did not exhibit any focal neurological deficits. Cranial computed tomography (CT) revealed a biconvex intracranial hematoma with 18-mm thickness in the high parietal region and a linear fracture that involved both the outer and inner tables and passed above the hematoma. A well-developed and large DC was observed near the hematoma. Patient’s consciousness level decreased at 12 h after admission with considerable growth of the hematoma. A frontoparietal craniotomy revealed an EDH. The dura mater and the meningeal arteries underneath the hematoma were intact. The medial bone cut caused brisk bleeds from the large DC. Postoperative CT revealed the cut of the DC and other finer DCs exhibiting air density and lying near the fracture. Based on these findings, we assumed that the EDH was developed by an injury of the DCs. Conclusion: Traumatic EDH can develop by an injury of the DCs. Careful observation of patient’s neurological status and precise interpretation of neuroimages is important to identify venous EDHs.

Characterisation of the calcitonin gene-related peptide receptor antagonists ubrogepant and atogepant in human isolated coronary, cerebral and middle meningeal arteries

Background Migraine has been associated with a dysfunctional activation of the trigeminovascular system. Calcitonin gene-related peptide, a neuropeptide released from the trigeminal nerve fibres, has an important role in the pathophysiology of migraine and is a current therapeutic target for migraine treatment. Methods We examined the effects of two novel calcitonin gene-related peptide receptor antagonists, ubrogepant and atogepant, on the relaxations induced by α calcitonin gene-related peptide in human isolated middle meningeal, cerebral and coronary arteries. Furthermore, the contractile responses to atogepant and ubrogepant per se were studied and compared to the responses elicited by zolmitriptan in proximal and distal human coronary arteries. Results In intracranial arteries, both blockers antagonized the calcitonin gene-related peptide-induced relaxations more potently when compared to the inhibition observed in distal human coronary arteries, with atogepant showing a higher potency. When analysing their antagonistic profile in HCA, ubrogepant showed a competitive antagonist profile, while atogepant showed a non-competitive one. Neither of the gepants had vasoconstrictor effect at any of the concentrations studied in human coronary arteries, whereas zolmitriptan elicited concentration-dependent contractions. Conclusion ubrogepant and atogepant differentially inhibit the calcitonin gene-related peptide-dependent vasodilatory responses in intracranial arteries when compared to distal human coronary arteries. Also, both gepants are devoid of vasoconstrictive properties in human coronary arteries.