Spontaneous closure of an intracranial middle cerebral arteriovenous fistula

Spontaneous occlusion of a pial arteriovenous fistula after angiography: The role of iodinated contrast media

Intracranial non-galenic pial arteriovenous fistula (PAVF) is an extremely rare vascular malformation, where one or more pial arteries feeds directly into a cortical vein without any intervening nidus. Though occasionally they can be asymptomatic, neurological symptoms such as headache, seizure, or focal neurological deficit are more common presenting features. Life threatening or fatal hemorrhage is not uncommon, hence needed to be treated more often than not. Spontaneous occlusion of PAVF is reported only four times before. We report a 49-year-old gentleman, who was diagnosed to have a PAVF, possibly secondary to trauma. He presented 5 months and 22 days from initial digital subtraction angiography (DSA) for treatment, and follow-up angiogram showed complete obliteration. He denied any significant event, medication or alternate treatment during this period. His clinical symptoms were stable as well. We postulate iodinated contrast medium induced vasculopathy as a possible cause, which has been described for other vascular pathologies, but never for PAVF.

Endovascular Management of Hemorrhagic Stroke

Significant advances in endovascular neurosurgery tools, devices, and techniques are changing the approach to the management of acute hemorrhagic stroke. The endovascular treatment of intracranial aneurysms emerged in the early 1990s with Guglielmi detachable coils, and since then, it gained rapid popularity that surpassed open surgery. Stent-assisted coiling and balloon remodeling techniques have made the treatment of wide-necked aneurysms more durable. With the introduction of flow diverters and flow disrupters, many aneurysms with complex geometrics can now be reliably managed. Arteriovenous malformations and fistulae can also benefit from endovascular therapy by embolization using n-butyl cyanoacrylate (NBCA), Onyx, polyvinyl alcohol (PVA), and coils. In this article, we describe the role of endovascular treatment for the most common causes of intracerebral and subarachnoid hemorrhages, particularly ruptured aneurysms and vascular malformations.

Spontaneous closure of non-cavernous sinus dural arteriovenous fistulas: A case series and systematic review of the literature

BACKGROUND AND PURPOSE

To report 9 new cases of non-cavernous sinus dural arteriovenous fistulas (NCS-DAVFs) that closed spontaneously and systematically review reports of other cases in the literature.

MATERIAL AND METHODS

We performed a retrospective analysis of 9 cases from 2 institutions of NCS-DAVFs that closed spontaneously. Using PubMed and Scopus in accordance with the PRISMA guidelines, we systematically reviewed English language articles about NCS-DAVFs showing spontaneous closure.

RESULTS

Review of the cases from 2 institutions identified 9 cases of NCS-DAVFs showing spontaneous closure in follow-up magnetic resonance angiography (MRA), and the systematic review of the literature yielded an additional 38 cases, which had been diagnosed by repeated arteriography. Collectively, the patients included 23 men and 24 women with a mean age of 54 years. The shunts were located in the transverse-sigmoid sinus in 24 cases (51%), anterior condylar confluence in 11, and other locations in 12. Based on the venous drainage pattern on arteriography, 27 cases (57%) were classified as low-risk NCS-DAVF (without cortical venous reflux) and 17 were classified as high-risk NCS-DAVF (with cortical venous reflux). Shunt closure was observed within 3 months in 17 cases (36%). Extrinsic predisposing factors for shunt closure were detected in 14 cases (30%). These included angiography in 7 cases, sinus recanalization in 4, development of sinus occlusion in 2, and sinus compression by a newly developed hematoma in 1.

CONCLUSION

Spontaneous closures of NCS-DAVFs can occur for both high- and low-risk types. One-third of these closures occur within 3 months.

Congenital pial AVF along the falx cerebri with complete agenesis of the corpus callosum and bilateral parasagittal pachygyria-polymicrogyria secondary to chronic ischemia

OBJECTIVE

Pial arteriovenous fistula (AVF) is an extremely rare entity due to direct arterial connection with the venous plexus without an intervening capillary network. The objective of this article is to describe a unique case of congenital pial AVF along the interhemispheric falx with complete callosal agenesis and malformation of cortical development within the bilateral anterior cerebral artery territories. We also demonstrated the distinctive feature of temporal stability of the extensive intracranial abnormalities without active intervention. Less than 100 cases have been reported thus far, most of which involve the adult rather than pediatric age group. A comprehensive literature review of congenital pial AVF will also be included.

CASE DESCRIPTION

A 5-year-old child presented with headache and complex partial seizures. Imaging of the brain revealed the presence of polymicrogyria-pachygyria in the parasagittal frontoparietal lobes with associated underlying white matter hypodensities. Complete agenesis of the corpus callosum was also seen. In addition, enlarged and tortuous vessels were noted along the interhemispheric falx with no appreciable nidus. Bilateral dilated and tortuous ACAs were seen supplying the network of abnormal vessels along the falx. The radiological findings were stable on a follow-up MRI 12 years later.

CONCLUSION

Our reported case adds to current limited knowledge of this rare entity in the pediatric age group, which is traditionally treated aggressively and urgently. Our case demonstrated temporal stability of this lesion with no detrimental complications observed. This suggests that the outcome of pial AVFs with conservative treatment may not be as grim as previously thought.

Clipping of a Pediatric Pial Arteriovenous Fistula Located at Basilar Artery Tip Using a Hybrid Trapping-Evacuation Technique

BACKGROUND

Intracranial pial arteriovenous fistulas (PAVFs) are rare cerebrovascular lesions with high mortality rates. We report a rare case of pediatric PAVF at the basilar artery tip and its treatment with surgical clipping aided by a trapping-evacuation technique in a hybrid operating room.

CASE DESCRIPTION

An 18-month-old boy was admitted with hypoevolutism and 4-month history of weakness in the left extremities. Magnetic resonance imaging showed a giant aneurysm-like malformation in the area of midbrain and pons. Angiography showed a high-flow PAVF fed by the basilar artery and bilateral P1 segments of the posterior cerebral artery, with deep draining veins into the transverse sinus and straight sinus. Given the intrinsic characteristics of the lesion, such as deep location, giant fistula and varix, and multiple feeding arteries, clipping of PAVF was performed in a hybrid operating room aided by a trapping-evacuation technique to clearly identify and block the shunting point.

CONCLUSIONS

The successful obliteration of the lesion is reported. In addition, a brief review of literature comparing endovascular embolization, surgical disconnection, and hybrid technique for treatment of PAVF is included.

Endoscopic third ventriculostomy and choroid plexus cauterization with a rigid neuroendoscope in infants with hydrocephalus

OBJECT Combining endoscopic third ventriculostomy (ETV) with choroid plexus cauterization (CPC) has been shown to improve the success rate compared with ETV alone in infants (less than 24 months) with hydrocephalus who were treated in developing countries. The authors sought to evaluate the safety and efficacy of this procedure, using a rigid neuroendoscope, in a single North American center, and to assess whether the ETV success score (ETVSS), the CURE Children's Hospital of Uganda ETVSS (CCHU ETVSS), and other pre- and intraoperative variables could predict success. METHODS The authors performed a retrospective review of consecutive ETV/CPC procedures performed using a rigid neuroendoscope to treat infantile hydrocephalus. The infants underwent the procedure at Miami Children's Hospital between January 2007 and 2014, with at least one postoperative follow-up. Duration of follow-up or time to failure of ETV/CPC, the primary outcome measure, was documented. A repeat CSF diversion procedure or death was considered as a failure of ETV/CPC. The time to event was measured using a Kaplan-Meier analysis. The authors analyzed ETVSS, CCHU ETVSS, and pre- and intraoperative variables to determine their suitability to predict success. RESULTS Eighty-five patients (45 boys) with a mean age of 4.3 months (range 1 day to 20 months) underwent ETV/CPC. Etiology included intraventricular hemorrhage of prematurity in 44 patients (51.7%), myelomeningocele (MMC) in 7 (8.2%), congenital aqueductal stenosis in 12 (14.1%), congenital communicating hydrocephalus in 6 (7.1%), Dandy-Walker complex in 6 (7.1%), postinfectious hydrocephalus in 5 (5.8%), and other cause in 5 (5.8%). Six procedure-related complications occurred in 5 (5.8%) patients, including 2 hygromas, 1 CSF leak, and 3 infections. There were 3 mortalities in this cohort. ETV/CPC was successful in 42.1%, 37.7%, and 36.8% of patients at 6, 12, and 24 months follow-up, respectively. The median (95% CI) time to ETV/CPC failure was 4.0 months (0.9-7.1 months). In univariate analyses, both the ETVSS (hazard ratio [HR] 1.03; 95% CI 1.01-1.05; p = 0.004) and CCHU ETVSS (HR 1.48; 95% CI 1.04-2.09; p = .028) were predictive of outcome following ETV/CPC. In multivariate analysis, the presence of prepontine scarring was associated with ETV/CPC failure (HR 0.34; 95% CI 0.19-0.63; p < 0.001). Other variables, such as radiological criteria (prepontine interval, prepontine space, aqueductal stenosis, Third Ventricular Morphology Index) and intraoperative findings (ventriculostomy pulsations, extent of CPC), did not predict outcome. CONCLUSIONS ETV/CPC is a feasible alternative to ETV and ventriculoperitoneal shunt in infants with hydrocephalus. Both the ETVSS and CCHU ETVSS predicted success following ETV/CPC in this single-center North American cohort of patients.

Endovascular embolization of pial arteriovenous fistula fed from P1 segment of posterior cerebral artery in 12 years old girl: case report and review of literature

OBJECTIVE

Intracranial pial arteriovenous fistulas (PAVFs) are rare vascular lesions with peculiar epidemiological, morphological, and pathophysiological characteristics. Since there is no nidus, PAVF treatment has been performed by direct disconnection of the arteriovenous communication via a surgical, endovascular, or a combined approach. We aim to outline the relevant variables to consider in planning an endovascular treatment strategy.

METHODS

We present a case of a 12 year old girl with a single feeder PAVF originating from the first segment (P1) of the left posterior cerebral artery with a varicose venous drainage into the right cavernous sinus.

RESULTS

We report the successful endovascular exclusion of the fistula with the release of a total of 27 detachable platinum coils with no complications at follow-up. Treatment strategy and nuances are discussed along with a review of the literature.

CONCLUSIONS

Morphology, age, embolization strategies, and materials are the different variables to be analyzed in the endovascular treatment of such lesions.

Effectiveness of intraoperative indocyanine green videoangiography in direct surgical treatment of pediatric intracranial pial arteriovenous fistula

Intracranial pial arteriovenous fistulas (AVFs) are rare cerebrovascular lesions. The authors report a rare case of pediatric pial AVF treated by direct disconnection with the aid of indocyanine green (ICG) videoangiography. A 3-year-old girl presented with developmental problems. Magnetic resonance imaging revealed brain atrophy and an anomalous left temporal vascular mass. Angiography showed a high-flow pial AVF in the early arterial phase fed by the M1 portion of the left middle cerebral artery and draining into the superficial sylvian vein and the vein of Trolard with a large varix. Given that her fistula was located in a superficial region that was easily accessible by craniotomy, the authors successfully disconnected her pial AVF by direct surgery aided by ICG videoangiography, which clearly confirmed the shunting point. In this report, the authors discuss the existing literature and compare the relative merits of endovascular versus surgical options for the treatment of pial AVF.

Pial arteriovenous fistula with giant varices: report of two cases with good surgical outcome

Pial arteriovenous fistulas (pAVF) are rare vascular lesions consisting of one or more arterial connections to a single venous channel without any intervening nidus of vessels or capillaries. Case 1: A 65-year-old woman with a complaint of headache and left hand paresthesia was referred to us. Magnetic resonance imaging showed a large saccular lesion with signal void in the posterior part of the right sylvian fissure and catheter angiography showed a giant venous aneurysm fed by one branch of the middle cerebral artery (MCA) and draining into the vein of Trolard. Case 2: A 12-year-old boy was transferred to our hospital with a history of sudden loss of consciousness and hemiplegia. Brain computed tomography revealed a massive hemorrhagic mass in the right hemisphere and cerebral angiography showed a pAVF with a large aneurysmal varix, which was fed by multiple branches of the right MCA and draining into the superior sagittal sinus. Both patients underwent craniotomy and after ligation of vascular connections, aneurysmal varices were removed completely. Surgical resection can be a safe method for treatment of pAVFs, particularly in those with large varices.

Endovascular treatment of cerebral dural and pial arteriovenous fistulas

Dural arteriovenous fistulas (DAVFs) are arteriovenous shunts from a dural arterial supply to a dural venous channel, typically supplied by pachymeningeal arteries and located near a major venous sinus. Pial arteriovenous fistulas (PAVFs) are composed of one or more arterial feeders draining into a single vein in the absence of an intervening nidus. Fistulas manifesting features of high risk for rupture should be treated aggressively, the spectrum of treatment varies from endovascular, surgical resection, and stereotactic radiosurgery. This article describes the natural history, clinical presentation, and treatment of dural and pial fistulas, with emphasis on endovascular treatment.

Calcifications associated with pediatric intracranial arterial aneurysms: incidence and correlation with pathogenetic subtypes

BACKGROUND AND PURPOSE

Little is known about calcifications associated with pediatric intracranial arterial aneurysms (IAA). We sought to characterize calcifications associated with pediatric IAA according to aneurysm pathogenetic subtype.

MATERIALS AND METHODS

Patients with IAA less than 20 years of age were retrospectively identified. Three fellowship-trained neuroradiologists independently reviewed each patient's CT studies for calcifications of the parent artery or aneurysm. Aneurysmal calcification (ANC) was correlated with characteristics of the patient (age, sex) and aneurysm pathogenetic subtype, size, morphology, rupture status, and location.

RESULTS

Thirty-three patients (mean age 10 years) with 43 IAA were analyzed. There were no parent artery calcifications. Nine IAA were calcified. IAA in children with non-hemodynamic risk factors (arteriopathy, trauma, infection, tumor) were more commonly calcified than idiopathic IAA (p = 0.029). More than one third of the pediatric IAAs in this group (arteriopathy, infection trauma, tumor) were calcified. IAA ≥ 10 mm were more likely to be calcified (p = 0.03). IAA that were ruptured at presentation were less likely to be calcified (p = 0.03). ANC was not significantly associated with patient age (≤10 years vs. >10 years), sex, morphology (fusiform vs. saccular) or location (anterior vs. posterior circulation).

CONCLUSION

Aneurysmal but not parent artery calcifications are associated with a significant minority of pediatric IAA. Pediatric ANCs are associated with underlying non-hemodynamic vascular risk factors (arteriopathy, infection, trauma, and tumor), size ≥10 mm and non-hemorrhagic presentation.

Intracerebral pial arteriovenous fistula with large venous varix: A rare case report

BACKGROUND

Intracerebral pial arteriovenous fistulas (AVFs) are rare vascular lesions of the brain. These lesions are composed of one or more direct arterial connection to a single venous channel without true intervening nidus and usually have associated venous varix or giant venous aneurysms. Intracerebral varices are occasionally associated with high-flow AVF, and usually treated by interrupting the feeding arteries leaving the varices intact.

CASE DESCRIPTION

We report a rare case of a 24-year-old male with a single-channel pial AVF of the left cerebral hemisphere, which was fed by the left anterior cerebral artery (ACA) and was associated with large venous varix and continuous varicose venous dilatation. This superficially located varix was over 6 cm in diameter posing significant mass effect and had calcified walls. Direct surgical flow disconnection followed by removal of large varix resulted in complete disappearance of pial AVF without complication.

CONCLUSION

Though endovascular occlusion of feeding arteries offers a simple and safe option, direct surgical removal should be considered in rare cases of intracerebral superficially located large AVF with calcified wall and mass effect.

Rapid and progressive venous thrombosis after occlusion of high-flow arteriovenous fistula

BACKGROUND

Cerebral venous thrombosis developing after surgical or endovascular obliteration of arteriovenous fistula (AVF) is a rare but devastating complication that has not been adequately reported.

CASE DESCRIPTION

Two patients presenting with AVF (1 pial, 1 dural) and large venous pouches were successfully treated by surgical and endovascular means and were neurologically intact postoperatively. Rapid neurologic deterioration was seen on postoperative day 5 in the first patient and postoperative day 2 in the second patient. Both patients had massive cerebral venous thromboses on brain imaging and surgical exploration. One patient died and the other was severely disabled.

CONCLUSION

Rapid occlusion of a high-flow AVF resulting in significant venous stasis can precipitate thrombosis of the venous system distal to the fistulous point. In the presence of large venous pouches and significant venous stasis, strict therapeutic anticoagulation may be required to prevent cerebral venous thrombosis. Therapeutic anticoagulation, though feasible following endovascular treatment, may prove particularly challenging after open surgical interventions given the risk of hemorrhagic complications.

A case of pial arteriovenous fistula with giant venous aneurysm and multiple varices treated with coil embolization

Intracranial pial arteriovenous fistulas (AVFs) are rare vascular lesions of the brain. These lesions consist of one or more arterial connection to a single venous channel without true intervening nidus. A 24-year-old woman visited to our hospital because of headache, vomiting, dizziness and memory disturbance that persisted for three days. She complained several times of drop attack because of sudden weakness on both leg. Cerebral angiograms demonstrated a giant venous aneurysm on right frontal lobe beyond the genu of corpus callosum, multiple varices on both frontal lobes fed by azygos anterior cerebral artery, and markedly dilated draining vein into superior sagittal sinus, suggesting single channel pial AVF with multiple varices. Transarterial coil embolization of giant aneurysm and fistulous portion resulted in complete disappearance of pial AVF without complication.

Single hole cerebral arteriovenous fistula between the anterior choroidal artery and the basal vein of Rosenthal in a child

PURPOSE

The purpose of this study was to show the first reported case of a cerebral arteriovenous fistula (CAVF) from the anterior choroidal artery (AChoA) to the basal vein of Rosenthal in a Child.

CASE REPORT

A 4-month-old male infant with no previous history presented a left thalamic intraparenchymal hemorrhage with secondary intraventricular spread and hydrocephalus. An external ventricular drainage was placed, and a digital subtracted angiography showed a left single hole CAVF. The left AChoA was the single arterial feeder directly connected to the ipsilateral basal vein of Rosenthal. After stabilization and good recovery, he was transferred to our institution for endovascular treatment. He was embolized using the arterial feeder with four Guglielmi detachable coils that produced complete exclusion of the fistula. The patient was discharged 10 days after the procedure without new neurological deficit.

CONCLUSIONS

CAVFs are exceptional, with an incidence between 4.7% and 17% of all brain AVMs in large reported series. They can arise from any artery of the brain with a great dominance at the supratentorial location. This is the first reported case of a CAVF from the AChoA draining to the basal vein of Rosenthal.

Coil-based endovascular treatment of single-hole cerebral arteriovenous fistulae: experiences in 11 patients

BACKGROUND

An SHF is rare pial arteriovenous shunt with no nidal component, of which the feeder drains directly into a single venous channel. Casting with NBCA was described previously, but its control demands operator to accumulate a considerable learning curve. We are to present our experiences of coil-based endovascular treatment of SHF.

METHODS

Eleven patients harbored 12 SHFs (5 men, 6 women; mean age, 28.4 years; age range, 4-73 years), and they presented with hemorrhage, seizure, collapse, orbital mass, and as an incidental lesion. The location was frontal for 3, temporal for 5, parietal in 2, and occipital in 2 patients. The angioarchitectures, the methods of endovascular treatment, and outcomes were analyzed.

RESULTS

Fifteen feeders arose from 4 anterior, 8 middle, and 3 posterior cerebral arteries. The coil framework was constructed at the fistula before the penetration of a low concentrated NBCA. Nine fistulae were occluded completely, and 3 fistulae were occluded to near-completion with micro-AVM. There was no recanalization of SHF, either growth of a micro-AVM during follow-up period (mean, 48.3 months; range, 6-120 months). One patient with postprocedure hemorrhage developed hemiplegia, but 1 patient with seizure and the other 9 asymptomatic patients were uneventful.

CONCLUSIONS

The coil-based endovascular treatment can achieve safe and stable occlusion of SHF, and the preventions against venous thrombosis and perfusion breakthrough should be essential.

Endovascular treatment of brain arteriovenous fistulas

BACKGROUND AND PURPOSE

Brain arteriovenous fistulas (BAVFs) are dangerous lesions with significant risks for hemorrhage and re-hemorrhage; thus, the management of BAVFs is an important subject. Flow disconnection can be accomplished by surgical or endovascular techniques. We reviewed the experience in our endovascular treatment of patients with BAVFs.

MATERIALS AND METHODS

From March 2006 to March 2008, a total of 9 consecutive patients with nontraumatic BAVFs were treated at Beijing Tiantan Hospital. Dural arteriovenous fistulas and Galen aneurysmal malformations were excluded from this study. We retrospectively reviewed the medical records, cerebral angiograms, and endovascular reports for each patient. Radiographic outcome was assessed by posttreatment angiography. Clinical outcome was assessed for every patient.

RESULTS

There were 9 patients with a total of 11 BAVFs. The mean age at presentation was 17.8 years. The clinical presentations were intracranial hemorrhage in 4 patients, headaches in 2 patients, and seizure in 1 patient, with 2 patients diagnosed incidentally. All lesions were supratentorial, and a venous varix was found on angiographic examination. Seven patients were treated with coils, 1 with Onyx-34, and 1 with a combination of coils and glue. All 9 lesions were completely obliterated as demonstrated on follow-up angiographic examination. With a mean follow-up of 5.7 months (range, 3-12 months), all patients were neurologically excellent with no symptoms (modified Rankin Scale, 0).

CONCLUSIONS

BAVFs are more frequent in younger patients and frequently lead to intracranial hemorrhage. Staged endovascular coil embolization of BAVFs may be a good appropriate treatment technique.

Intracranial pial arteriovenous fistula

A 33-year-old woman presented with a rare intracranial pial arteriovenous fistula manifesting as monoparesis and hypesthesia of the right lower extremity. Computed tomography demonstrated an approximately 10-mm diameter subcortical hematoma in the left postcentral gyrus. Two months after suffering the ictus, angiography demonstrated a pial arteriovenous fistula in the late arterial phase fed by the left paracentral artery and drained into the left precentral vein. No nidus or dural arteriovenous fistula was detected. Left parietal craniotomy was performed and the pial arteriovenous fistula was extirpated by electrocoagulation. Intraoperative angiography demonstrated disappearance of the fistula. She experienced no postoperative neurological deterioration, but hypesthesia of the right leg persisted. Obliteration of the pial arteriovenous fistula was reconfirmed by postoperative angiography. She suffered no rebleeding episodes during the 36-month follow-up period. Pial arteriovenous fistula causing mild symptoms should be treated by flow disconnection because the direct arteriovenous shunt and attendant high blood flow usually results in huge venous varices. To determine whether direct surgery or endovascular treatment is appropriate, the position and shape of the lesion must be known.

Nongalenic arteriovenous fistulas: history of treatment and technology

✓ Nongalenic cerebral arteriovenous fistulas (AVFs) are uncommon, high-flow vascular lesions first treated by Walter Dandy and his colleagues by using open surgery with ligation of the feeding artery. Due to advances in endovascular technology over the past four decades that make possible the control of high flow in AVFs, treatment has evolved from the sole option of surgery to include the alternative or adjunct option of endovascular embolization. The authors of this review discuss the history of nongalenic AVF treatment, including techniques of both surgery and interventional neuroradiology and the technological developments underlying them.

Surgical treatment of pial cerebellar arteriovenous fistulas with aneurysm of the main feeding artery

BACKGROUND

Intracranial pial arteriovenous fistulas (pAVFs) are rare vascular lesions only recently considered distinct from arteriovenous malformations. Conservative management was associated with a high mortality rate. The abnormality of the lesion arises from its high-flow nature. The authors present a case of a cerebellar pAVF associated with aneurysms of the main feeding artery that was surgically treated.

CASE DESCRIPTION

A 54-year-old woman was referred to us after an attack of severe headache and vomiting. Computerized tomography scan visualized a hematoma of the fourth ventricle. Digital subtraction angiography (DSA) revealed a cerebellar pAVF mainly fed by the right posteroinferior cerebellar artery (PICA) and with drainage into one of the superior cerebellar veins. The PICA presented a saccular aneurysm on its fourth segment and a fusiform dilatation on its third segment. The patient underwent surgical operation via a midline suboccipital craniotomy. The fusiform dilatation was wrapped and the saccular aneurysm was clipped. The most fistulous connections were closed. The draining vein at the level of torcular herophili was closed by application of a clip. Control DSA demonstrated exclusion of both the aneurysms and the fistula from the circulation. At 1-year follow-up, the patient was neurologically intact.

CONCLUSIONS

The association of a cerebellar pAVF and an aneurysm is rare. Surgical treatment of multiple-channel arteriovenous fistulas by closure of venous varix should guarantee the exclusion from the circulation and avoid recruitment of new arterial connections and recurrence. Attention must be paid to normal venous channels draining into the varix.

Successful endovascular treatment of cerebral arteriovenous fistula

Childhood intracranial varix is rare and has been associated mostly with vein of Galen fistula or arteriovenous malformation. We present one patient with intracranial arteriovenous fistula with concomitant giant varix in a child. We treated the patient with endovascular embolization and obtained complete closure of fistula without morbility and mortality. The main radiologic and pathophysiologic features of this unusual entity, as well as the available therapeutic options, are discussed.

Surgical and endovascular flow disconnection of intracranial pial single-channel arteriovenous fistulae

INTRODUCTION

Intracranial pial single-channel arteriovenous (AV) fistulae are rare vascular lesions of the brain. They differ from AV malformations in that they lack a true "nidus" and are composed of one or more direct arterial connections to a single venous channel. They often are associated with a venous varix because of their high-flow nature. The pathological aspects of pial AV fistulae arise from their high-flow dynamics; therefore, we think that disconnection of the AV shunt is enough to obliterate the lesion, and that lesion resection is unnecessary. Flow disconnection can be accomplished via surgical or endovascular means. Certain lesions have angiogeometric configurations, however, that are unfavorable for endovascular treatment. We reviewed the experience in our combined neurosurgical and neuroendovascular unit in the treatment of patients with pial single-channel AV fistulae.

METHODS

From 1991 to 1999, the combined neurovascular unit at the Massachusetts General Hospital treated nine consecutive patients with nontraumatic intracranial pial single-channel AV fistulae. Carotid-cavernous fistulae and vein of Galen malformations were excluded from this analysis. The combined neurovascular team planned the treatment strategy for each patient on the basis of the anatomic location and the angiogeometry of each lesion. We retrospectively reviewed the medical records, office charts, operative reports, endovascular reports, and x-rays for each patient. Radiographic outcome was assessed by use of posttreatment angiography. Clinical outcome was assessed by an independent nurse practitioner.

RESULTS

A treatment strategy of flow disconnection was used in all nine patients and was accomplished surgically in six patients, endovascularly in two patients, and by combined techniques in one patient. All nine lesions were completely obliterated as demonstrated radiographically, including obliteration of the venous varices associated with three of the lesions. With a mean long-term clinical follow-up of 3.2 years (range, 0.3-8.4 yr), four patients were neurologically excellent with no deficits, two patients had pretreatment neurological deficits that did not worsen after treatment, one patient had transient dysphonia and dysphagia postoperatively that resolved, one patient had mild weakness after treatment, and one patient had moderate homonymous hemianopia after treatment.

CONCLUSION

Single-channel pial AV fistulae can be treated by a strategy of flow disconnection. Resection of the lesion is not necessary. Flow disconnection can be accomplished either surgically or endovascularly; however, certain angiogeometric configurations are more favorable for surgical treatment. An experienced combined neurosurgical and neuroendovascular team can carefully determine the most appropriate treatment modality on the basis of patient-specific and angiospecific factors.

Arteriovenous fistula with associated aneurysms coexisting with dural arteriovenous malformation of the anterior inferior falx. Case report and review of the literature

This 24-year-old man presented with an unusual case of a high-flow arteriovenous fistula (AVF). This lesion was similar to giant AVFs in children that have been previously described in the literature. In patients in whom abnormalities of the vein of Galen have been excluded and in whom presentation occurs after 20 years of age, a diagnosis of congenital AVF is quite unusual. The fistula in this case originated in an enlarged callosomarginal artery and drained into the superior sagittal sinus via a saccular vascular abnormality. Two giant aneurysmal dilations of the fistula were present. In an associated finding, a small falcine dural arteriovenous malformation (AVM) was also present. Arterial supply to the AVM arose from both external carotid arteries and the left vertebral artery, with drainage through an aberrant vein in the region of the inferior sagittal sinus into the vein of Galen. Craniotomy with exposure and trapping of the AVF was performed, with subsequent radiosurgical (linear accelerator) treatment of the dural AVM. Through this combination of microsurgical trapping of the AVF and radiotherapy of the dural AVM, an excellent clinical outcome was achieved.

Interdisciplinary evaluation of cerebral hemodynamics in the treatment of arteriovenous fistulae associated with giant varices

The techniques for the treatment of intracranial arteriovenous fistulae include angiographic balloon occlusion of the fistula as well as direct surgical attack. Regardless of the method, the occurrence of severe hyperemia caused by a lack of autoregulation after obliteration of the fistula remains a significant concern. We report the use of single photon emission computed tomography and transcranial Doppler studies to assess the occurrence of hyperemia during trial balloon occlusion of such fistulae in two patients. Single photon emission computed tomography and transcranial Doppler studies confirmed the lack of hyperemia during the test occlusion, allowing consideration of treatment plans involving acute fistula occlusion without the difficulty imposed by gradual occlusion and permitting a more accurate evaluation of risk. The purpose of this report is to illustrate how clinical evaluation of intracranial hemodynamics can contribute significantly to treatment decisions.