To highlight veno-venous collaterals and portosystemic shunts as possible causes of cyanosis requiring evaluation or treatment below the diaphragm in patients with single-ventricle physiology during staged palliation.

Cyanosis can complicate staged single-ventricle palliation and is often evaluated with imaging isolated to the thorax. As a result, lesions below the diaphragm, such as veno-venous collaterals and portosystemic shunts, may be missed. Identification is important since these lesions can be treated via transcatheter techniques.

This study is a retrospective, single-centre case series of six patients.

Two patients following stage 2 palliation had multiple small veno-venous collaterals connecting to a reconstituted azygos with retrograde flow to below the diaphragm. Accessing veno-venous collaterals closer to their entry points below the diaphragm was more optimal for occlusion. Two patients following stage 3 palliation had veno-venous collaterals originating below the diaphragm and connecting to the pulmonary veins. Both patients required infrarenal inferior vena cava contrast injection to identify the veno-venous collateral. The final two patients had heterotaxy with either stage 2 or 3 palliation and were found to have bilateral pulmonary arteriovenous malformations secondary to a portosystemic shunt diverting hepatic factor away from the lungs. All patients had successful device closure of their veno-venous collaterals or portosystemic shunts.

The six patients discussed demonstrate the importance of evaluating below the diaphragm in single-ventricle physiology patients presenting with cyanosis.

While paediatric arteriovenous malformations (AVMs) often require aggressive therapeutic intervention due to their high bleeding incidence, choosing a course of treatment for deep and eloquent areas and asymptomatic cases is difficult. Sequelae are a concern in children, as they survive for longer after treatment. The authors have long recommended and implemented staged Gamma Knife radiosurgery (GKRS) in their treatment guidelines to maximise therapeutic effects.

Fifty-eight paediatric patients with AVM and ≤15 years old who underwent GKRS under general anesthesia from 2002 to 2020 were followed up for an average of 81·5 months. Obliteration dynamics and clinical outcomes were analysed.

The mean patient age was 10·5 years. The mean nidus volume was 6·6 cm3, the complete occlusion rate was 69%, the annual post-irradiation bleeding rate was 2·19% and nine (16%) cases had transient radiation-induced changes. One (1·7%) patient had sequela, and three (5·1%) developed encapsulated hematomas and cysts. Additionally, the 3- and 5-year cumulative occlusion rates were 39·0% and 53·3%, respectively. Multivariate analysis showed significantly higher occlusion rates in patients ≤12 years old and with a nidus volume of ≤4 cm3.

GKRS is a useful treatment for paediatric AVM; however, its use poses some challenges.

The management of extracranial arterio-venous malformations (AVMs) is complex and often requires a multidisciplinary approach. Currently, treatment includes surgical resection and embolotherapy.

We present the case of a foot AVM that was managed with adjuvant radiotherapy after previous surgery and embolotherapy had been attempted, and we discuss the role of radiotherapy in the management of extracranial AVMs.

The malformation was successfully eradicated with complete obliteration of the nidus and no recurrence.

The addition of radiotherapy in the management of extracranial arterio-venous malformations offers promising results using similar doses to those used in brain AVMs.

Hemodynamic factors have been implicated in hemorrhage from cerebral arteriovenous malformations (AVMs). The goal of this endovascular study is to analyze the hemodynamic variability in AVM feeders in a balanced group of ruptured and unruptured AVMs of various sizes and at both superficial and deep locations.

We monitored feeder artery pressure (FP) using microcatheters in 45 patients with AVMs (16 with hemorrhage, 29 without) during superselective angiography and AVM embolization.

Mean FP was 49 mm Hg. Significant determinants of FP were the systemic pressure (p < 0.001), AVM size (p = 0.03), and the distance of the microcatheter tip from the Circle of Willis (p = 0.06), but not the presence of hemorrhage, patient age, or feeder artery diameter. The FP in ruptured AVMs was 7 mm Hg higher than in unruptured ones (53.8 mm Hg vs. 47.1 mm Hg, p = 0.032). The presence or absence of venous outflow stenosis and the position of the AVM nidus (superficial or deep to the cortical surface) were important anatomical predictors of AVM presentation.

The pressure in the feeding artery supplying an AVM is the result of factors which include the systemic arterial pressure, the size of the AVM nidus, and the distance of the AVM from the Circle of Willis. The correlation between these variables makes it difficult to study the risk of hemorrhage as a function of a single factor, which may account for the variation in the conclusions of previous studies.

Hereditary hemorrhagic telangiectasia (HHT) is a disease of abnormal vasculature where patients are predisposed to strokes of multiple etiologies. We assessed yearly stroke incidence among Albertans with HHT and compared with the general population. Given the tendency for stroke in HHT patients, we expected HHT patients to have higher stroke incidence, in particular at younger ages.

Population-based administrative health data on inpatient and ambulatory admissions were extracted over a 16-year period using International Classification of Diseases (ICD)-9 and ICD-10, Canada codes. We analyzed overall occurrence of strokes in Alberta by age, gender, stroke subtype, and diagnosis of HHT.

The age-standardized incidence rate of stroke in HHT was 450 per 100,000 compared with 260 per 100,000 in the general population with a rate ratio of 1.73 (95% confidence interval (CI) [1.046-2.842]). This study found a higher HHT prevalence in Alberta (1 in 3800) compared to the world average of 1 in 5000. Women were also more likely to be diagnosed with HHT, with a 3.25:1 female gender preponderance in the yearly incidence.

This study not only shows that HHT patients are at higher risk of having a stroke but also quantifies that risk using an age-adjusted metric in Alberta. This province has a higher than expected disease burden of HHT, with the majority of cases affecting women. Our study found that acute ischemic strokes and transient ischemic attacks are far more common than hemorrhage in HHT. As HHT is a rare, multi-system, chronic disease, these patients should be referred to an HHT Centre of Excellence.

To determine whether patients with hereditary haemorrhagic telangiectasia were being screened according to international guidelines, and to review recent evidence in order to provide up-to-date guidelines for the initial systemic management of hereditary haemorrhagic telangiectasia.

A retrospective case note analysis was conducted, assessing patients in terms of screening for: genetics, cerebral arteriovenous malformations, pulmonary and hepatic arteriovenous malformations, and gastrointestinal telangiectasia. Databases searched included Medline, the Cumulative Index to Nursing and Allied Health Literature, and Embase.

Screening investigations were most frequently performed for hepatic arteriovenous malformations and least frequently for genetics. Recent data suggest avoiding routine genetic and cerebral arteriovenous malformation screening because of treatment morbidities; performing high-resolution chest computed tomography for pulmonary arteriovenous malformation screening; using capsule endoscopy (if possible) to reduce complications from upper gastrointestinal endoscopy; and omitting routine liver enzyme testing in favour of Doppler ultrasound.

Opportunities for systemic arteriovenous malformation screening are frequently overlooked. This review highlights the need for screening and considers the form in which it should be undertaken.

To observe spike activity in electroencephalograms (EEGs), patients with symptomatic partial epilepsy are rarely monitored during the hyperventilation stages.

A 38-year-old woman suffered from a ruptured arteriovenous malformation in the left temporal lobe. One and a half years later, the patient experienced her first generalized convulsion. EEG showed small spikes in the posterior of the left temporal lobe, which was observed during the hyperventilation and posthyperventilation stages. Because the location of the spikes correlated with the site of the lesion as observed from radiographic findings, she was diagnosed with lateral temporal lobe epilepsy. Drug treatment resulted in no further convulsive episodes and the patient has since returned to work.

EEG recordings during hyperventilation should be regarded as an effective technique in analyzing epilepsy because of its ease and cost-effectiveness compared with other methods such as single-photon emission computed tomography.

To report the case of a spontaneous arteriovenous malformation involving the auricula, external auditory meatus, middle ear and part of the petrous apex, and also to provide updated information about its management.

A 33-year-old woman presented complaining of accelerated growth of a retro-auricular swelling during her latest pregnancy, together with pain, pulsatile tinnitus and ear discharge. An arteriovenous malformation occupying the right auricula, external auditory canal, mastoid proccess of the temporal bone and the lateral half of the petrous segment was diagnosed, using temporal computerised tomography and magnetic resonance imaging. The lesion was embolised with polyvinyl alcohol particles at angiography. Excision of the arteriovenous malformation nidus was performed. Three years post-operatively, magnetic resonance imaging showed no residual lesion or recurrence at the temporal bone and petrous apex, although a few scanty, serpiginous, vascular remnants had persisted.

In the head and neck, arteriovenous malformations usually occur intracranially; they are rare outside the cranium. To our knowledge, there have been no previously published cases of such an extensive arteriovenous malformation involving the temporal region. Apropos of our case, the definition, clinical findings, diagnostic approaches and therapeutic management of arteriovenous malformations are discussed.