A case of dural arteriovenous fistula draining to the diploic vein presenting with intracerebral hemorrhage

De Novo dural arteriovenous fistulas after endovascular treatment: Case illustration and literature review

Intracranial dural arteriovenous fistulas (dAVF) account for nearly 10-15% of all arteriovenous malformations. Although the majority of dAVF are effectively cured after endovascular intervention, there are cases of dAVFs that may recur after radiographic cure. We present the case of a 69-year-old female with de novo formation of three dAVFs in different anatomic locations after successive endovascular treatments. The patient's initial dAVF was identified in the right posterior frontal convexity region and obliterated with transarterial and transvenous embolization. The patient returned eight years later due to left-sided pulsatile tinnitus and a new dAVF in the left greater sphenoid wing region was seen on angiography. This was treated with transvenous embolization with complete resolution. One year later, she developed left sided pulsatile tinnitus again and was found to have a left carotid-cavernous dAVF. This is the first case report to our knowledge of the formation of three de novo dAVFs over multiple years in distinct anatomical locations. We also review the literature regarding de novo dAVFs after endovascular treatment which includes 16 cases. De novo dAVF formation is likely due to numerous factors including changes in venous flow and aberrant vascular development. It is important to further understand the relationship between endovascular treatment and recurrent dAVF formation to prevent subsequent malformations.

A Case of an Intraosseous Arteriovenous Fistula at the Squamous Part of the Occipital Bone with Spontaneous Occlusion of Diploic Venous Drainage

Objective

An intraosseous arteriovenous fistula (AVF) is a rare fistula with an intracranial shunted pouch. A case of an intraosseous AVF at the squamous part of the occipital bone with spontaneous occlusion of diploic venous drainage is described.

Case Presentation

The patient, a Japanese woman in her 80s, presented with headaches at the back of the head and a history of multiple unruptured cerebral aneurysms but no recent head trauma. MRA showed abnormal signals in the occipital diploic region, and DSA showed an intraosseous AVF with a shunted pouch in the squamous part of the occipital bone near the inion. This was not seen on MRA 6 months earlier. One month later, follow-up examinations showed spontaneous occlusion of the diploic venous drainage, leading to a change in retrograde drainage into the superior sagittal sinus. Transvenous coil embolization was performed, and the shunted pouch was completely occluded. Postoperatively, the patient's symptoms resolved, and subsequent follow-ups showed no recurrence of the AVF.

Conclusion

This case suggested that the vascular architecture of intraosseous AVFs might change over a short period. Transvenous embolization was effective in obliterating the intraosseous shunted pouch.

Endovascular treatment for sphenoidal region dural arteriovenous fistula

Sphenoidal region dural arteriovenous fistulas (DAVFs) are rare. Endovascular treatment (EVT) is an effective treatment approach. However, understanding and performing EVT for sphenoidal region DAVFs are difficult and challenging. Therefore, we performed a review to explore this issue further. In this review, we discuss the dural feeders and venous structures of the sphenoidal region, the angioarchitecture of sphenoidal region DAVFs, the role and principle of EVT, various EVT techniques, and the prognosis and complications associated with EVT. We found that various EVT techniques, including transarterial embolization (TAE), retrograde transvenous embolization (TVE), and direct puncture EVT, can be used to treat sphenoidal region DAVFs. TAE represents the most commonly utilized approach. TVE and direct puncture EVT should be limited to highly selective cases. EVT must penetrate the fistula and very proximal venous recipient pouch with a liquid embolic agent or coil the fistula point to have a complete curative effect. Successful EVT can lead to the obliteration of sphenoidal region DAVFs and a good clinical outcome. However, these complications cannot be neglected.

Complex torcular dural arteriovenous fistula leading to cortical venous reflux-induced severe varix and subsequent bilateral cerebral hemispheric hemorrhage: a case report

Background and importance

Dural arteriovenous fistulas (dAVFs) with cortical venous reflux (CVR) are associated with a higher incidence of intracranial hemorrhage (ICH). We report a rare case of a complex torcular dAVF with severe cortical veins (CV) varix leading to extensive bilateral cerebral hemorrhages. This discovery suggests a potential new subtype of dAVF. The case underscores the necessity of a comprehensive understanding of hemodynamic changes in dAVFs and the importance of considering venous compensatory capacity in treatment. This case challenges existing classifications and treatment strategies for dAVFs, highlighting the need for further research and discussion within the neurosurgical community.

Clinical presentation

A 56-year-old male was admitted to the hospital presenting with dizziness, fatigue, and numbness. Brain CT scans revealed extensive bilateral cerebral hemorrhages. Digital subtraction angiography (DSA) identified a complex torcular dAVF. No cerebral sinus venous thrombosis was detected, but a venous variation in the left transverse sinus was observed. Preoperative DSA demonstrated the patient's well-developed venous compensatory ability. Subsequently, the patient underwent transarterial embolization. The patient made a good recovery. Follow-up DSA and MR angiography at 3 months and 1 year post-treatment showed no recurrence.

Conclusion

DAVFs are rare lesions, prone to ICH, particularly when CVR is involved. We report a rare case of CVR with severe varix leading to hemorrhagic lesions in both cerebral hemispheres. Our aim is to alert neurosurgical colleagues worldwide to this potential new subtype and to evaluate treatment options, in order to assist those who may encounter such cases in the future.

Diploic arteriovenous fistulas with marked cortical venous reflux

Diploic arteriovenous fistulas are rare arteriovenous shunts involving the skull, which often drain antegradely into the internal or external jugular veins. Diploic arteriovenous fistulas with marked cortical venous reflux are extremely rare. Here, we present the case of a patient with diploic arteriovenous fistulas with marked cortical venous reflux and a literature review. A 73-year-old woman presented with headache. Magnetic resonance angiography revealed abnormal signal intensity in the diploic layer of the left frontal bone. Digital subtraction angiography demonstrated a diploic arteriovenous fistulas located in the left frontal bone. The arteriovenous fistulas were fed by multiple branches of the left external carotid artery, mainly from the middle meningeal artery, branches of the ophthalmic artery, and the inferolateral trunk. The fistulas drained into the cerebral cortical veins surrounding the frontal lobe via an emissary vein of the frontal bone. With the femoral arterial approach, transarterial catheterization into the shunted diploic vein was performed with a small tapered microcatheter, and the arteriovenous fistulas were completely embolized with N-butyl-2-cyanoacrylate. The patient was discharged without complications. No recurrent arteriovenous fistulas were observed during the 12-month follow-up period. Endovascular treatment is an effective technique for the curative treatment of diploic arteriovenous fistulas.

A rare case of diploic venous anomaly: asymptomatic venous sac expanding in the diploe

BACKGROUND

Vascular anomalies accompanied with the diploic veins are rare. Among them, sinus pericranii, which is characterized by abnormal connections between intra- and extracranial venous systems, is relatively common. Besides sinus pericranii, a few cases of subepicranial varix with connections to diploic veins have been reported, but these varices had no connections to intracranial venous sinuses. Herein, we present a rare case of an expanding venous sac in the diploe which communicated with the intracranial sinus but not with the extracranial venous systems.

CASE PRESENTATION

An adult woman presented to us with a minor transient headache. Although no abnormal appearances were found on her scalp, imaging studies showed a club-shaped venous sac in the left parietal diploe that communicated with the superior sagittal sinus and diploic veins on the medial and lateral sides, respectively. It was revealed that the lesion had expanded as compared with a previous computed tomography image. Surgery was performed to intercept venous supply from the diploic veins, and the lesion was filled with thrombi. In a follow-up of 15 months, there was no recurrence of abnormal venous flow. Histological examination showed the endothelial lining in the membranous wall of the sac, which is typically observed in sinus pericranii. However, no communication with the pericranial veins of the scalp was identified on the imaging studies and intraoperative observation. Accordingly, it was diagnosed as another entity "intradiploic varix".

CONCLUSIONS

The abnormal connection between the intracranial and the diploic venous systems via the large venous sac was surgically treated. It was pathologically similar to sinus pericranii, but anatomically considered to be another form of venous anomaly. In cases of expanding lesions, surgical treatment is recommended.