Vein of Galen aneurysmal malformation: does size affect outcome?

PURPOSE: To validate a semiautomated method for segmenting vein of Galen aneurysmal malformations (VGAM) and to assess the relationship between VGAM volume and other angioarchitectural features, cardiological findings, and outcomes. METHODS: In this retrospective study, we selected all subjects with VGAM admitted to the Gaslini Children's Hospital between 2009 and 2022. Clinical data were retrieved from electronic charts. We compared 3D-Slicer segmented VGAM volumes obtained by two independent observers using phase-contrast MR venography to those obtained with manual measurements performed on T2-weighted images. The relationship between VGAM volumes and clinical and neuroimaging features was then explored. RESULTS: Forty-three subjects with VGAM (22 males, mean age 6.56 days) were included in the study. Manual and semiautomated VGAM volumes were well correlated for both readers (r = 0.86 and 0.82, respectively). Regarding reproducibility, the inter-rater interclass correlation coefficients were 0.885 for the manual method and 0.992 for the semiautomated method (p < 0.001). The standard error for repeated measures was lower for the semiautomated method (0.04 versus 0.40 of manual method). Higher VGAM volume was associated with superior sagittal sinus narrowing, jugular bulb stenosis, and aqueductal stenosis (p < 0.05). A weak correlation was found between VGAM volume and straight sinus dilatation (r = 0.331) and superior sagittal sinus index (r = - 0.325). No significant associations were found with cardiac findings, post-embolization complications, and outcome (p > 0.05). CONCLUSIONS: Semiautomated VGAM volumetry is feasible and reliable with improved reproducibility compared to the manual method. VGAM volume is not a prognostic factor for clinical outcome, but it is related to other venous findings with potential hemodynamic effects.

Neonatal intracranial haemorrhage secondary to vein of Galen aneurysmal dilatation.

Paediatric neurovascular anomalies associated with the vein of Galen (VG) comprise of a spectrum of rare, complex, and life-threatening conditions. In this group, the "vein of Galen aneurysmal dilatation" (VGAD) is a distinct entity that often presents with progressive neurological symptoms in older children. Acute haemorrhage in VGAD is uncommon. We present an unusual presentation of VGAD in a neonate and discuss the challenges faced in the management.

Use of greyscale and Doppler ultrasound in initial evaluation and follow-up of neurovascular malformations in children.

Pediatric intracranial arteriovenous shunts are rare vascular malformations that can be diagnosed prenatally or postnatally, as an incidental finding or due to complications. We propose a review of cerebral vascular malformations in newborns and infants with special emphasis on neurosonography and Doppler ultrasound as the first diagnostic method. Sonography can thus contribute in the planning of further studies that are always necessary, and in post-therapy follow-up.

Echocardiography evaluation of neonatal vein of Galen aneurysmal malformation.

BACKGROUND: In neonatal vein of Galen aneurysmal malformation, vein of Galen aneurysmal malformation echocardiography remains the mainstay for early detection and explains various haemodynamic changes occurring due to a large systemic arterio-venous shunt. However, there is limited evidence of echocardiography in risk stratifying neonatal vein of Galen aneurysmal malformation vein of Galen aneurysmal malformation. The objective of this study was to identify echocardiographic parameters that could be associated with major outcomes and guide timing of neuro-intervention. METHODS: In this retrospective chart review, infants < 28 days of age with the diagnosis of vein of Galen aneurysmal malformation vein of Galen aneurysmal malformation were included. Demographic, clinical, and echocardiographic parameters were compared in neonates who survived or died with neonatal presentation. A risk algorithm model based on key echocardiographic parameters was developed to determine those who are at risk of early death. RESULTS: Of the 19 neonates included, with median birth weight 3.1 kg (IQR 2.58-3.36), nine (47%) neonates died at median age of 5 days (IQR 4-17). All neonates showed retrograde diastolic flow at the level of descending aorta by colour Doppler on the first post-natal echocardiogram at median age of 2 days (IQR 1-5.5). An aortic antegrade-to-retrograde velocity time integral ratio of < 1.5 and supra-systemic pulmonary artery pressure had 100% positive predictive value of death (p = 0.029), whereas aortic antegrade-to-retrograde velocity time integral ratio of > 1.5 and sub-systemic pulmonary artery pressure had 100% positive predictive value of survival (p = 0.029). CONCLUSION: Combination of aorta antegrade-to-retrograde velocity time integral ratio and degree of pulmonary hypertension on the first post-natal echocardiogram may help stratify the severity of disease and guide optimal timing for neuro-intervention for neonatal vein of Galen aneurysmal malformation.

MV-flow in the assessment of fetal vein of Galen aneurysmal malformation.

MV-Flow is a tool enables to acquire spatially and temporally coherent data on low-speed blood flow information. In our case, it allowed a better definition of vein of Galen aneurysmal malformation morphology, venous drainage and feeder vessels than standard ultrasound techniques.

Pulmonary Hypertension in Infants and Children with Vein of Galen Malformation and Association with Clinical Outcomes.

OBJECTIVE: To assess the extent and resolution of pulmonary hypertension (PH), cardiovascular factors, and echocardiographic findings associated with mortality in infants and children with vein of Galen malformation (VOGM). STUDY DESIGN: We performed a retrospective review of 49 consecutive children with VOGM admitted to Boston Children's Hospital from 2007 to 2020. Patient characteristics, echocardiographic data, and hospital course were analyzed for 2 cohorts based on age at presentation to Boston Children's Hospital: group 1 (age ≤60 days) or group 2 (age >60 days). RESULTS: Overall hospital survival was 35 of 49 (71.4%); 13 of 26 (50%) in group 1 and 22 of 23 (96%) in group 2 (P < .001). High-output PH (P = .01), cardiomegaly (P = .011), intubation (P = .019), and dopamine use (P = .01) were significantly more common in group 1 than group 2. Among patients in group 1, congestive heart failure (P = .015), intubation (P < .001), use of inhaled nitric oxide (P = .015) or prostaglandin E1 (P = .030), suprasystemic PH (P = .003), and right-sided dilation were significantly associated with mortality; in contrast, left ventricular volume and function, structural congenital heart disease, and supraventricular tachycardia were not associated. Inhaled nitric oxide achieved no clinical benefit in 9 of 11 treated patients. Resolution of PH was associated with overall survival (P < .001). CONCLUSIONS: VOGM remains associated with substantial mortality among infants presenting at ≤60 days of life owing to factors associated with high output PH. Resolution of PH is an indicator associated with survival and a surrogate end point for benchmarking outcomes.

ETV as treatment for obstructive hydrocephalus in an aneurysmal malformation of the vein of Galen in infants: case report and review of literature.

INTRODUCTION: A vein of Galen aneurysmal malformation (VGAM) is a high-flow arteriovenous malformation that typically presents in early childhood. Complications associated with this condition include heart failure and hydrodynamic disorders resulting from high blood flow. Hydrocephalus is one of the hydrodynamic disorders. It can present in a chronic form due to a defect in the absorption of cerebrospinal fluid (CSF) resulting from venous hypertension or in an acute/subacute form due to obstruction of normal circulation routes caused by the mass effect of the VGAM. Currently, endovascular closure of the lesion is considered the treatment of choice. However, in acute/subacute presentations of obstructive hydrocephalus, progression may occur despite endovascular treatment, necessitating a cerebrospinal fluid diversion procedure. Prior to the advent of endoscopic treatment, ventricular shunts were utilized, but outcomes were poor due to the pathological hydrodynamic parameters associated with the malformation. The role of endoscopic third ventriculostomy as a treatment option in these situations remains unclear, and there is limited literature available. Therefore, we present the case of a patient with a vein of Galen aneurysmal malformation and obstructive hydrocephalus, which was treated via ETV. Furthermore, a literature review was conducted. CASE DESCRIPTION: We present a 5-month-old infant who was diagnosed at birth with VGAM. At 2 months of age, a partial closure of the malformation was performed via endovascular. Subsequently, the patient presented at the emergency department with symptoms of irritability, lethargy, vomiting, feeding refusal, and "setting sun" sign of several days' duration due to obstructive hydrocephalus. The patient was successfully treated via ETV. Following this, a new arteriography was performed and revealed occlusion of the VGAM. The child clinically improved and currently exhibits mild psychomotor impairment after 1-year follow-up. CONCLUSION: In the literature, there are a limited number of reports on the treatment of obstructive hydrocephalus associated with VGAM via ETV. These reports have demonstrated good outcomes with minimal surgical complications. Our patient also exhibited good results. As such, ETV is a viable and safe option for the treatment of obstructive hydrocephalus associated with VGAM in pediatric patients. However, more research is needed to establish the effectiveness of ETV in comparison to other treatment options and to understand the long-term outcomes.

The composition of landmark vein of Galen malformation research: the emergence of endovascular treatments.

BACKGROUND: Since the advent of endovascular treatment, the long-term prognosis of vein of Galen malformation (VOGM) has markedly improved; however, the nature of research leading to this point is unclear. The objective of this study was to define the composition of VOGM research to date, by means of a bibliometric analysis of the 100 most cited VOGM articles. METHODS: An electronic search of Elsevier's Scopus database was performed to identify the 100 most cited articles on VOGM screened against predetermined criteria. Data were then compared. RESULTS: The 100 most cited VOGM articles were published between 1974 and 2017 in 38 unique journals and originated from 16 unique countries. Mean citation count and rate were 59.4 citations and 2.9 citations/year, respectively. The USA (n = 42); Hôpital de Bicêtre, France (n = 15); and Dr. Pierre Lasjaunias (n = 16) were the largest individual country, institutional, and author contributors. Compared to the older articles (published < 2000), key differences for newer articles were statistically higher citation rates (P < 0.01), more authors (P < 0.01), higher proportion of endovascular treatment descriptions (P = 0.01), and more originating from Asia Pacific (P < 0.01). CONCLUSIONS: From the 100 most cited VOGM articles to date, there has been a noticeable shift from diagnosing VOGM based on the foundational work by Dr. Lasjaunias to understanding how we can model clinical outcomes now that endovascular treatment has become the standard of care. Significant shifts in prognosis are pending, and the current bibliometric data implicate we are on the precipice of more recent works making an impact in the near future.

Spontaneous thrombosis of vein of Galen malformation managed with surgical resection: a case­based review.

INTRODUCTION: Vein of Galen malformation (VOGM) is an exceptionally uncommon form of congenital intracranial vascular malformations. It is highly unusual for this lesion to spontaneously thrombose. The clinical presentation of a patient may range from being asymptomatic to critically ill. The underlying pathophysiological mechanisms that cause spontaneous thrombosis are still poorly understood. METHODS AND RESULTS: The literature on spontaneous thrombosis of VOGM was systematically reviewed, analyzed, and summarized with a focus on its pathophysiology, types, clinical presentations, diagnosis, management, and outcomes. It was also illustrated with a case presentation. The case presents an unusual presentation and location of a VOGM in a 2-year-old boy who was successfully treated with surgical resection. CONCLUSIONS: A handful of cases of thrombosed VOGM have been reported worldwide where surgery was used to treat the condition. Low-flow fistulas of the mural type are prone to spontaneous thrombosis, have delayed clinical presentations, and are typically diagnosed in young children. Among the many possible manifestations, hydrocephalus is by far the most common. In the absence of blood flow, MRI is the diagnostic test of choice. Depending on the patient's symptoms, surgery to either remove the aneurysm or divert the cerebrospinal fluid usually results in a good prognosis.

That which is unseen: 3D printing for pediatric cerebrovascular education.

INTRODUCTION: Pediatric cerebrovascular lesions are very rare and include aneurysms, arteriovenous malformations (AVM), and vein of Galen malformations (VOGM). OBJECTIVE: To describe and disseminate a validated, reproducible set of 3D models for optimization of neurosurgical training with respect to pediatric cerebrovascular diseases METHODS: All pediatric cerebrovascular lesions treated at our institution with adequate imaging studies during the study period 2015-2020 were reviewed by the study team. Three major diagnostic groups were identified: aneurysm, AVM, and VOGM. For each group, a case deemed highly illustrative of the core diagnostic and therapeutic principles was selected by the lead and senior investigators for printing (CSG/JM). Files for model reproduction and free distribution were prepared for inclusion as Supplemental Materials. RESULTS: Representative cases included a 7-month-old female with a giant left MCA aneurysm; a 3-day-old male with a large, complex, high-flow, choroidal-type VOGM, supplied from bilateral thalamic, choroidal, and pericallosal perforators, with drainage into a large prosencephalic vein; and a 7-year-old male with a left frontal AVM with one feeding arterial vessel from the anterior cerebral artery and one single draining vein into the superior sagittal sinus CONCLUSION: Pediatric cerebrovascular lesions are representative of rare but important neurosurgical diseases that require creative approaches for training optimization. As these lesions are quite rare, 3D-printed models and open source educational materials may provide a meaningful avenue for impactful clinical teaching with respect to a wide swath of uncommon or unusual neurosurgical diseases.

Normal reference values for magnetic resonance imaging measurements of the fetal internal jugular veins in middle and late pregnancy.

BACKGROUND: At present, there is a lack of normal magnetic resonance imaging (MRI) morphometric reference values for fetal internal jugular veins during middle and late pregnancy. OBJECTIVE: We used MRI to assess the morphology and cross-sectional area of the internal jugular veins of fetuses during middle and late pregnancy and to explore the clinical value of these parameters. MATERIALS AND METHODS: The MRI images of 126 fetuses in middle and late pregnancy were retrospectively analysed to determine the optimal sequence for imaging the internal jugular veins. Morphological observation of the fetal internal jugular veins in each gestational week was carried out, lumen cross-sectional area was measured and the relationship between these data and gestational age was analysed. RESULTS: The balanced steady-state free precession sequence was superior to other MRI sequences used for fetal imaging. The cross section of fetal internal jugular veins was predominantly circular in both the middle and late stages of pregnancy, however the prevalence of an oval cross section was significantly higher in the late gestational age group. The cross-sectional area of the lumen of the fetal internal jugular veins increased with increasing gestational age. Fetal jugular vein asymmetry was common, with the right jugular vein being dominant in the high gestational age group. CONCLUSION: We provide normal reference values for fetal internal jugular veins measured by MRI. These values may form the basis for clinical assessment of abnormal dilation or stenosis.

Vein of Galen Aneurysmal Malformation with Anomalous Right Superior Vena Cava to the Left Atrium Leading to Atypical Clinical and Echocardiographic Findings.

Vein of Galen aneurysmal malformation (VGAM) is a rare intracranial vascular malformation which typically presents in a critically ill newborn with intractable heart failure, severe pulmonary hypertension, and right heart dilation. We report two unusual cases of neonates with VGAM and anomalous connection of right superior vena cava to the left atrium. Both neonates were diagnosed with VGAM in utero and were clinically stable after birth with dilation of the left atrium and left ventricle and no evidence of pulmonary hypertension. One case with hydrocephalus underwent transcatheter embolization at 1 week of age. The other case without hydrocephalus underwent elective transcatheter embolization at 4 months. We postulate that the presence of a right superior vena cava to the left atrium provides a physiological advantage and counters the left-to-right shunt from the arteriovenous malformation. This provides insight to a potential treatment strategy to improve outcomes in patients with severe heart failure and pulmonary hypertension secondary to VGAM.

Pial arteriovenous fistula resembling the vein of Galen aneurysmal malformation, treated with staged endovascular embolization: a case report.

A 41-month-old boy was presented to our hospital because of an intracranial mass suspected of cerebrovascular malformation. He was admitted and received cerebral angiography. The angiography result confirmed the intracranial mass was the dilated vein of Galen resulting from a pial arteriovenous fistula, which quite resembling the vein of Galen aneurysmal malformation. Considering one-time embolization of the fistula may greatly change the distribution of intracranial blood flow, we decided to perform staged embolization. In the first stage, we partially embolized the fistula, resulting in a sharp decrease in blood flow to the lesion. The second intervention was performed one month later, and completely embolized the fistula. The boy recoverd well and returned to normal childhood without any neurological deficits. Follow-up MR images obtained at 10 months after the last procedure showing total obliteration of the pAVF, gradually shrinking of the varix, and remodeling of the vein of Galen.

Vein of Galen aneurysm, dilated cardiomyopathy, and slender habitus in a patient with a recurrent pathogenic variant in PACS2.

The PACS2 gene encodes a multifunctional sorting protein involved in nuclear gene expression and pathway traffic regulation that has been shown to be highly expressed during human prenatal brain development. Pathogenic variants in PACS2 have been recently shown to be implicated in a phenotype with global developmental delay/intellectual disability, seizures, autistic traits, facial dysmorphic features, and cerebellar dysgenesis. Here, we report a 25-year-old male with intellectual disability, epileptic encephalopathy, cerebellar dysgenesis, facial dysmorphism, and a previously reported pathogenic variant in PACS2. To our knowledge, this is the oldest patient reported who, in addition to the known phenotype described in PACS2 patients, presented with a vein of Galen malformation and dilated cardiomyopathy as previously unreported findings.

A cardiopulmonary bypass strategy to support a patient with vein of Galen malformation.

We present a dissection of the patent ductus arteriosus and pulmonary artery for surgical repair utilising cardiopulmonary bypass in the setting of vein of Galen malformation. Several strategies were employed to attenuate the cerebral shunt including pH-stat, high cardiac index, restrictive venous drainage, continuous ventilation and deep hypothermic circulatory arrest. The patient recovered from surgery with no apparent neurological sequelae.

CT angiographic study of the cerebral deep veins around the vein of Galen.

Research on the anatomy of cerebral deep veins (CDVs) around the vein of Galen (VG) is very important and has fundamental clinical significance. Large-scale anatomical studies of CDVs using computed tomography angiography (CTA) are rarely reported. A retrospective study of the CDVs around the VG was conducted in Chinese patients of Han nationality. One hundred cases were included in the final analysis. The patients were aged from 17 to 78 years (mean: 42.3 years). Also, 46% of the patients were female. The diameter of the internal cerebral vein (ICV) at its beginning and termination points ranged from 0.4 to 2.8 mm (1.49 ± 0.39 mm) and 0.4 to 3.5 mm (2.05 ± 0.47 mm), respectively. There was statistical significance regarding the diameter of the ICV at its beginning and termination points (P <0.01). The ICV length ranged from 28.5 to 47.9 mm (36.86 ± 3.74 mm). The length of the straight sinus (SS) ranged from 30.2 to 57.8 mm (43.6 ± 6.37 mm). The length of the VG ranged from 1.5 to 41.8 mm (9.30 ± 4.76 mm). The angle at the VG and SS transition area ranged from 25.4 to 110.6° (77.2 ± 18.0°). This study was a meaningful attempt to conduct anatomical research of CDVs using CTA. Preoperative familiarity with the normal venous structure and its variation around the VG would be helpful for endovascular treatment.

Spontaneous thrombosis of a vein of Galen malformation associated with acute sinusitis: a case report.

The vein of Galen malformation is caused by an abnormal shunting between choroidal arteries and the median prosencephalic vein during embryological development, leading to increased blood flow to the deep cerebral veins, intracranial damage, and systemic repercussions. Idiopathic spontaneous thrombosis of a vein of Galen malformation is rare, and its association with acute sinusitis has not been reported in the literature. We present the case of a girl with a postnatal diagnosis of a vein of Galen malformation at the age of 16 months, with secondary pulmonary hypertension that was adequately controlled with spironolactone. At 3 years old, while expecting elective endovascular treatment, the patient developed spontaneous thrombosis of the vein of Galen malformation, concomitant to an acute sinusitis episode, with complete resolution of the vascular malformation and secondary pulmonary hypertension. The patient continued with normal neurological development over a 5-year follow-up. We discuss the main pathophysiologic mechanisms that can explain spontaneous thrombosis of VOGMs and the patient's outcome. Awareness of different mechanisms that can lead to spontaneous thrombosis can help in the decision-making process and prompt targeted approaches to individual patients with a vein of Galen malformation.

High Output Cardiovascular Physiology and Outcomes in Fetal Diagnosis of Vein of Galen Malformation.

Vein of Galen aneurysmal malformation (VGAM) is a rare anomaly associated with poor outcomes from high output cardiac failure and neurologic complications. Studies addressing fetal cardiovascular status and outcomes in this population are limited. A single-center retrospective review was conducted on patients with a prenatal diagnosis of VGAM who underwent a fetal echocardiogram between January 2015 and July 2019. Fetal echocardiographic data, brain magnetic resonance imaging (MRI) findings and outcomes were collected. Nine fetuses [median gestational age at echocardiogram 34 (1.1) weeks] were included. All patients had superior vena cava dilation and reversal of diastolic flow in the transverse aortic arch. Median cardiothoracic (CT) ratio was 0.39 (0.09). Right ventricular (RV) and left ventricular (LV) dysfunction was present in 66% and 11% fetuses, respectively. Four out of five patients that underwent postnatal endovascular neurosurgical interventions at our center were alive at follow-up (mean 2.7 years). Of the non-survivors (n = 5), 3 received comfort care because of severe brain damage and died in the neonatal period. Non-survivors more commonly had > mild tricuspid regurgitation (TR) (40% vs. 25%) and > mild RV dilation (60% vs. 25%). Combined cardiac index (CCI) was higher in non-survivors when compared to survivors (672.7 vs. 530.2 ml/kg/min, p = 0.016). Fetuses with significant parenchymal damage on brain MRI tended to have a higher CCI than those without (979.8 vs. 605.0 ml/kg/min, p = 0.047). RV dysfunction, TR and elevated CCI are more commonly seen in non-survivors with VGAM. A higher CCI is seen in those deemed untreatable due to significant parenchymal volume loss. Future multicenter studies are needed to assess for prenatal prediction of outcomes in this high-risk population.

Transvenous Pressure Monitoring Guides Endovascular Treatment of Vein of Galen Malformation: A Technical Note.

INTRODUCTION: Vein of Galen malformations (VGMs) are complex congenital arteriovenous malformations that generally require serial endovascular treatment sessions to slowly correct the high-flow fistulous connections that cause increased venous pressures and ultimately lead to the classic presentations of heart failure, hydrocephalus, and intracranial hemorrhages. Despite the advances in endovascular technology and embolic materials, the resolution of embolization is often limited to the subjective view of diminished flow on angiograms. CASE REPORT: An 8-month-old patient with a VGM developed clinical signs of heart failure and growing head circumference with ventriculomegaly. The patient was treated endovascularly with a transvenous approach for coil embolization while undergoing continuous monitoring of the post-malformation venous pressures. The arterial and venous systolic blood pressures (SBP) were collected at serial time points and used to measure estimated 95% confidence interval bounds for arteriovenous SBP gradients and determine when sufficient coil embolization and flow reduction was thought to be achieved. CONCLUSION: The transvenous pressure monitoring demonstrated progressively increasing pressure gradients between the arterial and venous systems that correlated with the degree of flow reduction on angiographic runs. The patient underwent successful coil embolization of the VGM and had improvement of heart failure and ventricular size in follow-up at 8-month post-op. This provides a novel technique to introduce an objective measurement that can guide the embolization of a VGM.

Hirayama Disease in a Patient with a History of Late-Onset Symptomatic Vein of Galen Aneurysmal Malformation.

INTRODUCTION: The purpose of this report is to present a rare case of Hirayama disease (HD) in a patient with a history of late-onset symptomatic vein of Galen aneurysmal malformation (VGAM). This report may provide new insights into the pathophysiology of HD, a rare disorder consisting of insidious onset of unilateral weakness and atrophy of the forearm and intrinsic hand muscles. These symptoms are believed to result from cervical myelopathy affecting the anterior horn cells due to abnormal compressive forces on the spinal cord from adjacent anatomical structures (i.e., dura and/or epidural veins), but this has not been proven. VGAM is a rare congenital cerebral vascular malformation, consisting of high-flow arteriovenous shunting between a persistent median prosencephalic vein and arterial feeders, which most frequently presents in the early neonatal period with congestive heart failure. CASE PRESENTATION: We report the case of an otherwise healthy boy who presented with heart failure due to VGAM at 7 years and subsequently presented at 14 years with left-sided HD. His cervical MRI with neck flexion revealed enlarged epidural veins at the C5-C6 spinal level with anterior, leftward displacement of the posterior dura and spinal cord as well as left hemicord flattening and/or atrophy at this level. He underwent successful surgical treatment by C5-C6-C7 osteoplastic laminotomies and tenting and expansile autologous duraplasty, during which enlarged, engorged epidural veins were confirmed and coagulated. This halted the progression of his left hand weakness and atrophy and allowed significant functional improvement. Postoperative catheter angiogram showed no anatomical connection between the persistent VGAM and the engorged epidural veins, and genetic testing revealed no genetic predisposition of vascular malformations. DISCUSSION/CONCLUSION: In this patient, a combined surgical technique was performed that included epidural venous plexus coagulation with posterior autologous duraplasty and dural fixation using tenting sutures. This combined approach led to a favorable clinical and radiographic outcome with no complications or limitations and has not been previously proposed in the literature, to our knowledge. Although not completely ruled out, we found no angiographic connection or genetic predisposition to suggest there is a pathophysiological link between HD and VGAM.