Regression of dural arteriovenous fistulae after venous flow reconstructive surgery in a case with hemangiopericytoma at the confluence of sinuses

Complete Resection of a Torcular Herophili Hemangiopericytoma without Sinus Reconstruction: A Case Report and Review of the Literature

A 78-year-old woman presented to the emergency department with mild headaches and a sudden onset of blurred vision. Computerized tomography scan and magnetic resonance imaging showed what was described at first as a meningioma invading and occluding the torcular Herophili, the posterior third of the superior sagittal sinus and the proximal part of the right transverse sinus. Gross total resection of the tumor was performed without reconstructing dural sinuses. The patient was discharged home without new neurological deficit. Histopathology was in favor of a hemangiopericytoma Grade II World Health Organization (WHO). Total body positron emission tomography [18F]fluorodeoxyglucose found no secondary location. Radiotherapy was planned post-operatively.

Superior sagittal sinus dural arteriovenous fistula with changes in angiographic findings associated with contiguous parasagittal meningioma: A case report

Background:

Meningioma and dural arteriovenous fistula (dAVF) located at the same site are rare. The present case demonstrated the transformation of tumor feeding vessels into the pial feeder of the dAVF over time, which may help to elucidate the pathogenesis of tumor-associated dAVF.

Case Description:

A 71-year-old man presented with convulsion. Magnetic resonance (MR) imaging showed a right parasagittal sinus meningioma invading the superior sagittal sinus (SSS). Bilateral external carotid angiography showed dAVF at the SSS, near the site of tumor invasion. The right internal carotid angiography showed tumor staining from the anterior cerebral artery with intra-tumor arteriovenous shunting, with stagnation of tumor blood flow, suggesting impairment of perfusion to the SSS. Four years after the initial diagnosis, the patient was admitted to hospital with status epilepticus, and MR imaging showed an enlarged tumor. Carotid angiography revealed transformation of the tumor feeders to the pial feeder of the dAVF. The findings of shunting to the SSS had intensified, and stenosis had occurred in the posterior third of the SSS. The venous return showed retrograde flow anteriorly to the SSS. The patient underwent endovascular embolization and tumor resection. The shunt had disappeared.

Conclusion:

This report supports the proposal that impaired venous return is an important factor in the shunt occurrence of dAVF. Neurosurgeons should consider that cases of meningioma invading the venous sinuses may be complicated by dAVF and changes may occur over time.

Dural arteriovenous fistula associated with intratumor hemorrhage

Dural arteriovenous fistula (dAVF) associated with an intracranial tumor is a relatively rare condition. Furthermore, to our knowledge, this is the first case report of dAVF associated with intratumor hemorrhage. We experienced this very rare case and report it here, along with a literature review. A 59-year-old woman presented with transient aphasia and dysgraphia. Computed tomography, magnetic resonance imaging, and angiography showed left anterior cranial fossa dAVF and a tumor with an intratumor hemorrhage. Cerebral angiography demonstrated AV shunts from the left ethmoidal artery via cortical vein flow into the superior sagittal sinus. She underwent shunt-point extirpation for the dAVF and removal of the tumor. The histological finding indicated transitional meningioma. The patient was discharged without any neurological deficit. A dAVF with intratumor hemorrhage is very rare and may be due to the venous congestion of the tumor draining vein by venous hypertension caused by the dAVF.

The role of angiogenesis in dural arteriovenous fistulae: the story so far

Intracranial dural arteriovenous fistulae are a commonly encountered pathology that can present with a variety of different clinical symptoms. Although there is a significant body of work relating to the natural history and treatment of dural arteriovenous fistulae the exact underlying pathogenesis remains elusive. Various different pathogenetic models have been put forward but there is now a growing body of evidence implicating angiogenesis and the involvement of angiogenetic factors. In this review we attempt to show how the various animal and human studies performed over the past two decades have contributed to the proposed hypothesis on the development of dural arteriovenous fistulae.

Preoperative embolization of intracranial hemangiopericytomas: case series and introduction of the transtumoral embolization technique

Background and purpose

Hemangiopericytomas (HPCs) are rare dural-based neoplasms. Preoperative embolization of these notoriously hypervascular tumors can be challenging as they often receive their dominant blood supply from pial feeders arising from the internal carotid artery (ICA) or vertebrobasilar (VB) circulation. This study reviews our historical experience with HPC embolization and introduces the transtumoral technique for backfilling pial tumor vasculature by delivering Onyx-18 through diminutive external carotid artery (ECA) feeders.

Methods

A retrospective review of all preoperative HPC embolizations performed at Anonymous University #1 (September 2002–November 2014) and Anonymous University #2 (January 2014–November 2014) is presented.

Results

Fifteen patients with pathologically confirmed HPC underwent 17 embolizations. More extensive devascularization percentages were achieved for HPCs with primarily ECA blood supply (76.4±10.7%; n=6) than with HPCs supplied via the ICA/VB circulation (57.9±26.9%; n=8; p=0.046). There was a trend towards greater devascularization of ICA/VB-dominant HPCs embolized with Onyx (70.0±34.6%; n=4) versus polyvinyl alcohol particles (33.3±15.3%; n=3). The extent of angiographic devascularization negatively correlated with intraoperative blood loss (rho=−0.71; p=0.005). There were no embolization-related complications.

Conclusions

The extent of preoperative embolization of HPCs correlates with decreased intraoperative blood loss. However, HPCs with an ICA/VB-dominant blood supply remain challenging embolization targets, demonstrating reduced devascularization percentages compared with ECA-dominant counterparts. The authors favor the use of Onyx for ICA/VB-dominant HPCs, noting a trend towards an improved devascularization rate.