Prevalence and Predictors of Hereditary Hemorrhagic Telangiectasia and Capillary-Malformation Arteriovenous Malformation Syndrome Among Children with Neurovascular Malformations.

OBJECTIVE: To investigate the prevalence and predictors of hereditary hemorrhagic telangiectasia (HHT) and capillary-malformation arteriovenous malformation (CM-AVM) syndrome among children with no prior personal or family history of these diseases who presented with an arteriovenous shunt lesion. STUDY DESIGN: A retrospective chart review was completed on patients aged 0 through 21 years with arteriovenous shunt lesions evaluated at our Cerebrovascular Center. Diagnosis of definite or suspected HHT or CM-AVM was based on clinical features and genetic testing. Associations between final diagnosis and type and number of lesions, epistaxis, telangiectasias, CM, and pulmonary AVMs were assessed. RESULTS: Eighty-nine patients were included. Thirteen (14.6%) had definite HHT, 11 (12.4%) suspected HHT, and 4 (4.5%) definite CM-AVM. Having ≥2 episodes of epistaxis/year and ≥ 2 sites with telangiectasias were each associated with definite HHT (P < .001). Having ≥ 2 CM was associated with definite CM-AVM (P < .001). Pulmonary AVM was associated with increased odds of having definite HHT (OR = 6.3, 95% CI: 1.2-33.4). Multiple lesions (OR = 24.5, 95% CI: 4.5-134.8) and arteriovenous fistulas (OR = 6.2, 95% CI: 1.9-20.3) each increased the likelihood of having definite HHT or CM-AVM. Genetic testing was positive in 31% of patients tested. CONCLUSIONS: We recommend that children with neurovascular shunt lesions be offered genetic testing and undergo further evaluation for HHT and CM-AVM. Awareness and early diagnosis of these conditions is a critical step toward improving long-term outcomes and preventing disease-associated complications.

Fístula arteriovenosa para hemodiálisis en receptores de trasplante renal e Implicaciones en el síndrome cardiorenal tipo 4 / Arteriovenous fistula for hemodialysis in renal transplant recipients and implications in cardiorenal syndrome type 4

Introducción: La fístula arteriovenosa por vía quirúrgica para hemodiálisis constituye el acceso vascular de elección, para ese proceder depurador, no obstante, repercute negativamente sobre el aparato cardiovascular. Objetivo: Actualizar aspectos conceptuales y conductuales relativos a la permanencia de la fístula arteriovenosa para hemodiálisis posterior al trasplante renal. Métodos: Se revisó la literatura publicada en los últimos cinco años en las bases de datos; PubMed/Medline y Scopus y las fuentes de información; Cochrane Library y Ebsco. Resultados: La repercusión de la fístula arteriovenosa sobre el sistema cardiovascular tiene una marcada incidencia en diferentes alteraciones estructurales y funcionales del corazón que requieren de la adopción de una conducta destinada a evitar el riesgo. Se examinan puntos de vista convergentes y divergentes relacionados con la pertinencia de la fístula arteriovenosa como acceso vascular creado para hemodiálisis y la posibilidad de mantenerla luego del trasplante renal. Conclusiones: La fístula arteriovenosa supone el acceso vascular de apropiado para la supervivencia en hemodiálisis, sin embargo, las consecuencias de su permanencia sobre el aparato cardiovascular implican riesgo añadido de morbilidad y mortalidad(AU)

Introduction: Surgical arteriovenous fistula for hemodialysis is the vascular access of choice, this purifying procedure, however, has negative impact on the cardiovascular system. Objective: To bring up-to-date conceptual and behavioral aspects related to the permanence of the arteriovenous fistula for hemodialysis after renal transplantation. Methods: The literature published in the last five years was reviewed in PubMed/Medline and Scopus and information sources; Cochrane Library and Ebsco databases. Results: The repercussion of the arteriovenous fistula on the cardiovascular system has a marked incidence in different structural and functional alterations of the heart that require the adoption of a behavior to avoid risks. Convergent and divergent points of view related to the relevance of the arteriovenous fistula as a vascular access created for hemodialysis and the possibility of maintaining it after renal transplantation are examined. Conclusions: The arteriovenous fistula is the appropriate vascular access for survival in hemodialysis, however, the consequences of its permanence on the cardiovascular system imply an added risk of morbidity and mortality(AU)

Demography and Outcomes of Arteriovenous Fistula: Challenges and Future Directions.

The incidence and prevalence rates of treated end-stage kidney disease (ESKD) patients are on the rise worldwide. Hemodialysis remains the main modality of providing renal replacement therapy for the ESKD patients, and the preferred vascular access is an arteriovenous fistula (AVF). The objective is to assess the patency rates and primary failures of the AVF. All patients who attended the Royal Hospital in Muscat, Oman, from January 2010 to December 2014 for AVF creation were included in this study. Data were extracted from the hospital's electronic medical record system where data are entered prospectively. During the period of study from 2010 to 2014, 465 primary fistulae were created in 427 patients. The mean age of the patient was 58 years. Only 6% needed general anesthesia, while the rest were done under regional or local anesthesia. Fifty-one percent of the patients were diabetic. Preemptive AVF was constructed in only 12% of patients. Most cases (47%) had left brachiocephalic (BC) fistulae. The left radiocephalic (RC) fistulae constituted 25.7% and the left brachiobasilic fistulae 9.9%. The remaining were constructed in the right upper limb. The total patency was achieved in 80% of fistulae and the failure rate was 20% at 6 months. Whereas, at 12 months, the total patency rate was 71% and the failure rate was 29%. Thus, we can conclude that more than 50% of patients, half of them being females, were diabetics. This resulted in more fistulae being constructed in the arm, namely left BC fistulae and left RC fistulae. Furthermore, it is important to note that only a very small percentage of patients had an established preemptive AVF. These factors may be responsible for a failure rate of 20% and 29% of the AVFs at 6 months and 12 months, respectively.

Factors influencing arteriovenous fistulas: A multicenter study.

In this cross-sectional, descriptive study, the arteriovenous fistulas (AVF) of HD patients were evaluated by physical examination and factors associated with AVF function and longevity were investigated. Data were collected using a patient information form and the Arteriovenous Fistula Assessment Scale (AVF-AS). The study population included 279 patients under chronic HD treatment. Their mean age was 61.14 ± 14.00 years and 58.6% were men. Age, AVF location, and number of AVFs created were identified as factors associated with AVF needle entry site and flow problems, stenosis, and risk of developing ischemic complications (p = 0.005, p = 0.000, p = 0.006, respectively). AVF dysfunction adversely affected HD pump speed (p = 0.000) and HD adequacy (p = 0.000). It was determined that gender, AVF location, last AVF duration, and total number of previous AVF were identified as the risk of AVF complications. The results of this study revealed that regular follow-up and evaluation are needed to minimize the risk of dysfunction and failure due to AVF complications.

Funcionabilidad y durabilidad de fístulas arterio-venosas para hemodiálisis en pacientes no diabéticos / Functionability and durability of arterio-venous fistulas for haemodialysis in non-diabetic patients

Introducción: Existe un incremento anual de pacientes con insuficiencia renal crónica tributarios a hemodiálisis. Para la realización de esta se requiere de la correcta inserción de accesos vasculares que sean duraderos y funcionales. Objetivo: Caracterizar la durabilidad y funcionabilidad de las fístulas arterio-venosas en pacientes no diabéticos con enfermedad renal crónica. Métodos: Se realizó un estudio ambispectivo en 60 pacientes no diabéticos, con enfermedad renal crónica, portadores de una fístula arterio-venosa interna autóloga. Se describieron las variables: edad, sexo, grado de la enfermedad, lugar de confección, durabilidad, funcionabilidad, intentos, superficialización, uso de prótesis de poli-tetra-fluoro-etileno y complicaciones. Resultados: La edad media de los pacientes fue de 55,7 ± 12,7 años y la mitad estuvo entre 40 y 59 años. Los del sexo masculino ocuparon el 71,7 por ciento. Las fístulas duraderas (66,7 por ciento) y las funcionales (71,7 por ciento) se mostraron como las de mayor aparición. Los pacientes con la enfermedad en grado 4 ocuparon el 51,7 por ciento. Las fístulas en zonas radio-cefálica (43,3 por ciento) y húmero-cefálica (45 por ciento) primaron. Solo el 71,7 por ciento tuvo un intento de cirugía. Únicamente en el 20 por ciento se realizó superficialización y cuatro pacientes (6,4 por ciento) recibieron prótesis de poli-tetra-fluoro-etileno. La trombosis representó la complicación más frecuente (25 por ciento). Conclusiones: La durabilidad y la funcionabilidad de las fístulas elaboradas se asociaron con factores como el grado de la enfermedad, el número de intentos, el uso de prótesis vasculares y las complicaciones(AU)

Introduction: There is an annual increase of patients with chronic renal impairment who need haemodialysis. The correct insertion of vascular accesses that are durable and functional is required to perform haemodialysis. Objective: Characterize the durability and functionability of arterio-venous fistulas in non-diabetic patients with chronic kidney disease. Methods: An ambispective study was conducted in 60 non-diabetic patients, with chronic kidney disease carrying an autologous internal arterio-venous fistula. The described variables were: age, sex, stage of the disease, place of manufacture, durability, workability, attempts, superficialization, use of polytetrafluoroethylene prostheses, and complications. Results: The average age of patients was 55.7 ± 12.7 years and half were between 40 and 59 years old. Males were 71.7 percent. Durable (66.7 percent) and functional (71.7 percent) fistulas were shown as the most common ones. Patients with a grade 4 disease represented the 51.7 percent. Fistulas in radio-cephalic zones (43.3 percent) and humerus-cephalic zone (45 percent) prevailed. Only 71.7 percent had an attempt of surgery. Only 20 percent had superficialization and four patients (6.4 percent) received polytetrafluoroethylene prostheses. Thrombosis was the most common complication (25 percent). Conclusions: The durability and functionability of the prepared fistulas were associated with factors such as the stage of the disease, the number of attempts, the use of vascular prostheses, and the complications(AU)

Elective intervention for unruptured cranial arteriovenous malformations in relation to ARUBA trial: a National Inpatient Sample study.

BACKGROUND: In 2014, A Randomized Trial of Unruptured Brain Arteriovenous Malformations (ARUBA) concluded that medical management alone for cranial arteriovenous malformations (AVMs) had better clinical outcomes than interventional treatment. The impact of the ARUBA study on changes in the rates of intervention and outcomes is unknown. Thus, we investigated whether the conclusions from ARUBA may have influenced treatment modalities and outcomes of unruptured AVMs. METHODS: The National Inpatient Sample (NIS) was queried between 2006 and 2018, for adult patients with an AVM who were admitted on an elective basis. Interventions included open, endovascular, and stereotactic surgeries. Join-point regression was used to assess differences in slopes of treatment rate for each modality before and after the time-point. Logistic regression was used to assess the odds of non-routine discharge and hemorrhage between the two time-points for each treatment modality. Linear regression was used to assess the mean length of stay (LOS) for each treatment modality between the two time-points. RESULTS: A total of 40,285 elective admissions for AVMs were identified between 2006 and 2018. The rate of intervention was higher pre-ARUBA (n = 15,848; 63.8%) compared to post-ARUBA (n = 6985; 45.2%; difference in slope - 8.24%, p < 0.001). The rate of open surgery decreased, while endovascular and stereotactic surgeries remained the same, after the ARUBA trial time-point (difference in slopes - 8.24%, p < 0.001; - 1.74%, p = 0.055; 0.20%, p = 0.22, respectively). For admissions involving interventions, the odds of non-routine discharge were higher post-ARUBA (OR 1.24; p = 0.043); the odds of hemorrhage were lower post-ARUBA (OR 0.69; p = 0.025). There was no statistical difference in length of stay between the two time-points (p = 0.22). CONCLUSION: The rate of intervention decreased, the rate of non-routine discharge increased, and rate of hemorrhage decreased post-ARUBA, suggesting that it may have influenced treatment practices for unruptured AVMs.

Ischemic Stroke in Patients With Pulmonary Arteriovenous Fistulas.

BACKGROUND AND PURPOSE: Pulmonary arteriovenous fistulas (PAVFs) are a treatable cause of acute ischemic stroke (AIS), not mentioned in current American Heart/Stroke Association guidelines. PAVFs are recognized as an important complication of hereditary hemorrhagic telangiectasia. METHODS: The prevalence of PAVF and hereditary hemorrhagic telangiectasia among patients admitted with AIS in the United States (2005-2014) was retrospectively studied, utilizing the Nationwide Inpatient Sample database. Clinical factors, morbidity, mortality, and management were compared in AIS patients with and without PAVF/hereditary hemorrhagic telangiectasia. RESULTS: Of 4 271 910 patients admitted with AIS, 822 (0.02%) were diagnosed with PAVF. Among them, 106 of 822 (12.9%) were diagnosed with hereditary hemorrhagic telangiectasia. The prevalence of PAVF per million AIS admissions rose from 197 in 2005 to 368 in 2014 (Ptrend, 0.026). Patients with PAVF were younger than AIS patients without PAVF (median age, 57.5 versus 72.5 years), had lower age-adjusted inpatient morbidity (defined as any discharge other than home; 39.6% versus 46.9%), and had lower in-hospital case fatality rates (1.8% versus 5.1%). Multivariate analyses identified the following as independent risk markers (odds ratio [95% CI]) for AIS in patients with PAVF: hypoxemia (8.4 [6.3-11.2]), pulmonary hemorrhage (7.9 [4.1-15.1]), pulmonary hypertension (4.3 [4.1-15.1]), patent foramen ovale (4.2 [3.5-5.1]), epistaxis (3.7 [2.1-6.8]), venous thrombosis (2.6 [1.9-3.6]), and iron deficiency anemia (2 [1.5-2.7]). Patients with and without PAVF received intravenous thrombolytics at a similar rate (5.9% versus 5.8%), but those with PAVF did not receive mechanical thrombectomy (0% versus 0.7%). CONCLUSIONS: Pulmonary arteriovenous fistula-related ischemic stroke represents an important younger demographic with a unique set of stroke risk markers, including treatable conditions such as causal PAVFs and iron deficiency anemia.

Hemobilia como causa infrecuente y grave de hemorragia digestiva alta / Hemobilia as a rare and serious cause of upper gastrointestinal bleeding

Introducción: La hemobilia es por definición una causa de hemorragia digestiva alta, donde existe una comunicación de la vía biliar en cualquiera de sus segmentos con vasos sanguíneos que desembocan a través de la ampolla de Vater. Su presentación es infrecuente y no sospechada en la práctica clínica diaria de gastroenterólogos, cirujanos, hepatólogos, clínicos e intensivistas, con un difícil manejo diagnóstico-terapéutico y una elevada morbi-mortalidad. Objetivo: Describir tres casos de pacientes con diagnóstico de hemobilia. Desarrollo: Se presentan tres casos con hemobilia que tuvieron una elevada mortalidad y con diferente etiología; en el primer caso por trombosis de la arteria hepática postrasplante hepático, el segundo secundario a un colangiocarcinoma de la unión hepatocística y el tercero con diagnóstico de un aneurisma de la arteria hepática derecha confirmado y parcialmente tratado por angiotomografía, posteriormente intervenido quirúrgicamente y único sobreviviente. Conclusiones: Resultaron tres casos con hemobilia de diferentes causas, con una elevada mortalidad por la intensidad de la hemorragia digestiva alta y las comorbilidades asociadas, además de señalar que ninguno de ellos presentó la tríada clásica reportada por Quincke(AU)

Introduction: Hemobilia is, by definition, a cause of upper gastrointestinal bleeding, where there is a communication of the bile duct in any of its segments with blood vessels that flow through the ampulla of Vater. It is rare and it is not suspected in the daily clinical practice of gastroenterologists, surgeons, hepatologists, clinicians and intensivists, hence the diagnostic-therapeutic management is difficult and it has high morbidity and mortality. Objective: To report three cases of patients with a diagnosis of hemobilia. Case report: We report three cases of hemobilia of high mortality and different etiology. The first case had post-liver transplantation hepatic artery thrombosis, the second had asecondary cholangiocarcinoma of the hepatocystic junction and the third had diagnosis of confirmed right hepatic artery aneurysm partially treated by CT angiography, subsequently operated on and the only survivor. Conclusions: These three hemobilia cases had different causes, and high mortality due to the intensity of the upper gastrointestinal bleeding and the associated comorbidities, in addition to noting that none of them exhibited the classic triad reported by Quincke(AU)

External Validation of the R2eD AVM Score to Predict the Likelihood of Rupture Presentation of Brain Arteriovenous Malformations.

BACKGROUND: The R2eD AVM scoring system has been recently proposed to predict the risk of hemorrhagic presentation of brain arteriovenous malformations (AVMs). OBJECTIVE: To perform the first external validation of this R2eD AVM score. METHODS: Over a retrospective 10-yr period from 2009 to 2019, 122 patients with brain AVMs fit the inclusion criteria. All components required to calculate the R2eD AVM score had to be available. Patient demographics and score calculations were recorded, as well as the circumstances of their presentation. Multivariable analysis was performed to assess predictors of rupture in the study cohort. Next, area under the receiver operating characteristics and linear-by-linear association were employed to assess the effectiveness of the models. RESULTS: The mean age of the entire cohort was 45.2 yr, and 8% of patients were nonwhite. A total of 48 (39.3%) patients presented with AVM rupture. In univariable analysis, all 5 categories demonstrated P < .15 association with rupture risk. In multivariable analysis, race (nonwhite), size <3 cm, and exclusive deep venous drainage remained in the model with an area under the curve (AUC) of 0.677. The utilization of the R2eD AVM score yielded an AUC of 0.711. CONCLUSION: Even though mitigated by sample size, this study demonstrated acceptable external validity of the R2eD AVM score.

Trends in Incidence of Intracranial and Spinal Arteriovenous Shunts: Hospital-Based Surveillance in Okayama, Japan.

BACKGROUND AND PURPOSE: To date, the incidence of intracranial and spinal arteriovenous shunts has not been thoroughly investigated. We aimed to clarify recent trends in the rates of intracranial and spinal arteriovenous shunts in Japan. METHODS: We conducted multicenter hospital-based surveillance at 8 core hospitals in Okayama Prefecture between April 1, 2009 and March 31, 2019. Patients who lived in Okayama and were diagnosed with cerebral arteriovenous malformations, dural arteriovenous fistulas (DAVFs), or spinal arteriovenous shunts (SAVSs) were enrolled. The incidence and temporal trends of each disease were calculated. RESULTS: Among a total of 393 cranial and spinal arteriovenous shunts, 201 (51.1%) cases of DAVF, 155 (39.4%) cases of cerebral arteriovenous malformation, and 34 (8.7%) cases of SAVS were identified. The crude incidence rates between 2009 and 2019 were 2.040 per 100 000 person-years for all arteriovenous shunts, 0.805 for cerebral arteriovenous malformation, 1.044 for DAVF, and 0.177 for SAVS. The incidence of all types tended to increase over the decade, with a notable increase in incidence starting in 2012. Even after adjusting for population aging, the incidence of nonaggressive DAVF increased 6.0-fold while that of SAVS increased 4.4-fold from 2010 to 2018. CONCLUSIONS: In contrast to previous studies, we found that the incidence of DAVF is higher than that of cerebral arteriovenous malformation. Even after adjusting for population aging, all of the disease types tended to increase in incidence over the last decade, with an especially prominent increase in SAVSs and nonaggressive DAVFs. Various factors including population aging may affect an increase in DAVF and SAVS.

Spinal Neurovascular Malformations in Klippel-Trenaunay Syndrome: A Single Center Study.

BACKGROUND: A number of studies have demonstrated spinal anomalies associated with Klippel-Trenaunay syndrome (KTS). To date, there are no large consecutive series examining the prevalence and subtype distribution of spinal neurovascular malformations in patients with KTS. OBJECTIVE: To report the spectrum and incidence of spinal neurovascular manifestations in the KTS population. METHODS: This was a cross-sectional study. Consecutive patients with definite KTS as defined by International Society for the Study of Vascular Anomalies criteria who underwent spinal neuroimaging at our institution were included. All studies were evaluated by a staff neuroradiologist and a senior radiology resident for the presence of developmental venous anomalies, cavernous malformations (CMs), and arteriovenous shunts (AVS). RESULTS: A total of 116 patients with definite KTS who underwent spinal neuroimaging were included. A total of 23 neurovascular anomalies were found in 19 patients (16.4%), including 4 patients with multiple anomalies. These included 5 patients with spinal cord CMs (4.3%), 14 patients with a paraspinal or epidural venous malformation (12.1%), and 4 patients with an AVS (3.4%). Of the AVS, 3 were epidural arteriovenous fistulas, 1 of which likely formed de novo in an epidural venous malformation. One was a conus medullaris arteriovenous malformation. CONCLUSION: Our study cohort of 116 KTS patients demonstrated a wide spectrum of spinal neurovascular anomalies with a relatively high prevalence. Potential phenotypic descriptions of KTS should include the possibility for spinal neurovascular anomalies.

Exome sequencing of 112 trios identifies recessive genetic variants in brain arteriovenous malformations.

BACKGROUND: Brain arteriovenous malformation (BAVM) is a main cause of cerebral hemorrhage and hemorrhagic stroke in adolescents. Morphologically, a BAVM is an abnormal connection between cerebrovascular arteries and veins. The genetic etiology of BAVMs has not been fully elucidated. In this study, we aim to investigate potential recessive genetic variants in BAVMs by interrogation of rare compound heterozygous variants. METHODS: We performed whole exome sequencing (WES) on 112 BAVM trios and analyzed the data for rare and deleterious compound heterozygous mutations associated with the disease. RESULTS: We identified 16 genes with compound heterozygous variants that were recurrent in more than one trio. Two genes (LRP2, MUC5B) were recurrently mutated in three trios. LRP2 has been previously associated with BAVM pathogenesis. Fourteen genes (MYLK, HSPG2, PEAK1, PIEZO1, PRUNE2, DNAH14, DNAH5, FCGBP, HERC2, HMCN1, MYH1, NHSL1, PLEC, RP1L1) were recurrently mutated in two trios, and five of these genes (MYLK, HSPG2, PEAK1, PIEZO1, PRUNE2) have been reported to play a role in angiogenesis or vascular diseases. Additionally, abnormal expression of the MYLK protein is related to spinal arteriovenous malformations. CONCLUSION: Our study indicates that rare recessive compound heterozygous variants may underlie cases of BAVM. These findings improve our understanding of BAVM pathology and indicate genes for functional validation.

Cerebral arteriovenous fistulae.

Dural arteriovenous fistulae (dAVFs) are diverse, complex lesions that share the common feature of arteriovenous shunting without an intervening nidus. In this chapter, the ensuing discussion is organized by dAVF location, followed by further consideration of less common, distinct types of dAVFs-carotid cavernous fistulae, pial arteriovenous fistulae, and vein of Galen malformations. For each lesion type, epidemiology, clinical presentation, imaging findings, classification considerations, and treatment options are discussed.

Dural Arteriovenous Fistulae After Cerebral Venous Thrombosis.

BACKGROUND AND PURPOSE: This analysis examined the frequency of dural arteriovenous fistulae (dAVF) after cerebral venous thrombosis (CVT) in patients included in a randomized controlled trial comparing dabigatran etexilate with dose-adjusted warfarin (RE-SPECT CVT [A Clinical Trial Comparing Efficacy and Safety of Dabigatran Etexilate With Warfarin in Patients With Cerebral Venous and Dural Sinus Thrombosis]), who had systematic follow-up magnetic resonance (MR) imaging. METHODS: RE-SPECT CVT was a Phase 3, prospective, randomized, parallel-group, open-label, multicenter, exploratory trial with blinded end point adjudication. We allocated patients with acute CVT to dabigatran 150 mg twice daily or dose-adjusted warfarin, for 24 weeks and obtained a standardized MR protocol including time-of-flight MR angiography, 3-dimensional phase-contrast venography, and 3-dimensional contrast-enhanced MR venography at the end of the treatment period. A blinded adjudication committee assessed the presence of dAVF in a predefined substudy of the trial. RESULTS: We analyzed development of dAVF in 112 of 120 randomized patients; 57 allocated to dabigatran and 55 to warfarin. For 3 (2.7%) of these 112 patients, quality of follow-up imaging was insufficient to evaluate dAVF. A dAVF (Borden I) was found in 1 patient (0.9%) allocated to warfarin; however, this dAVF was already present at baseline. The patient did not present with hemorrhage at baseline or during the trial and was asymptomatic at follow-up. CONCLUSIONS: Despite systematic imaging, we found no new dAVF 6 months after CVT. Routine follow-up cerebral MR angiography aiming to detect new dAVF 6 months after CVT has a very low yield. Registration: URL: https://www.clinicaltrials.gov. Unique identifier: NCT02913326.

Biologically effective dose and prediction of obliteration of unruptured arteriovenous malformations treated by upfront Gamma Knife radiosurgery: a series of 149 consecutive cases.

OBJECTIVE: Arteriovenous malformations (AVMs) present no pathologic tissue, and radiation dose is confined in a clear targeted volume. The authors retrospectively evaluated the role of the biologically effective dose (BED) after Gamma Knife radiosurgery (GKRS) for brain AVMs. METHODS: A total of 149 consecutive cases of unruptured AVMs treated by upfront GKRS in Lille University Hospital, France, were included. The mean length of follow-up was 52.9 months (median 48, range 12-154 months). The primary outcome was obliteration, and the secondary outcome was complication appearance. The marginal dose was 24 Gy in a vast majority of cases (n = 115, 77.2%; range 18-25 Gy). The mean BED was 220.1 Gy2.47 (median 229.9, range 106.7-246.8 Gy2.47). The mean beam-on time was 32.3 minutes (median 30.8, range 9-138.7 minutes). In the present series, the mean radiation dose rate was 2.259 Gy/min (median 2.176, range 1.313-3.665 Gy/min). The Virginia score was 0 in 29 (19.5%), 1 in 61 (40.9%), 2 in 41 (27.5%), 3 in 18 (12.1%), and 4 in 0 (0%) patients, respectively. The mean Pollock-Flickinger score was 1.11 (median 1.52, range 0.4-2.9). Univariate (for obliteration and complication appearance) and multivariate (for obliteration only) analyses were performed. RESULTS: A total of 104 AVMs (69.8%) were obliterated at the last follow-up. The strongest predictor for obliteration was BED (p = 0.03). A radiosurgical obliteration score is proposed, derived from a fitted multivariable model: (0.018 × BED) + (1.58 × V12) + (-0.013689 × beam-on time) + (0.021 × age) - 4.38. The area under the receiver operating characteristic curve was 0.7438; after internal validation using bootstrap methods, it was 0.7088. No statistically significant relationship between radiation dose rate and obliteration was found (p = 0.29). Twenty-eight (18.8%) patients developed complications after GKRS; 20 (13.4%) of these patients had transient adverse radiological effects (perilesional edema developed). Predictors for complication appearance were higher prescription isodose volume (p = 0.005) and 12-Gy isodose line volume (V12; p = 0.001), higher Pollock-Flickinger (p = 0.02) and Virginia scores (p = 0.003), and lower beam-on time (p = 0.03). CONCLUSIONS: The BED was the strongest predictor of obliteration of unruptured AVMs after upfront GKRS. A radiosurgical score comprising the BED is proposed. The V12 appears as a predictor for both efficacy and toxicity. Beam-on time was illustrated as statistically significant for both obliteration and complication appearance. The radiation dose rate did not influence obliteration in the current analysis. The exact BED threshold remains to be established by further studies.

Cerebrovascular Malformations in a Pediatric Hereditary Hemorrhagic Telangiectasia Cohort.

BACKGROUND: We determined the frequency of cerebrovascular malformations in a pediatric cohort with hereditary hemorrhagic telangiectasia. METHODS: Retrospective cohort study of 54 children diagnosed with hereditary hemorrhagic telangiectasia at a tertiary care center. All neuroimaging was reviewed to assess for number and types of cerebrovascular malformations and for intracerebral hemorrhage and arterial ischemic stroke. Clinical charts were reviewed for clinical manifestations, genetic mutation, and clinically evident intracerebral hemorrhages and arterial ischemic strokes. RESULTS: Among 54 children with hereditary hemorrhagic telangiectasia with a median age of 3.5 years (interquartile range 0.4 to 7.9 years) at diagnosis, neuroimaging was performed in 52 (96.3%) at a median age of 5.2 years (interquartile range 1.8 to 9 years). Fourteen of 52 imaged children (26.9%) had cerebrovascular malformations. Cerebrovascular malformations included arteriovenous malformations, arteriovenous fistulas, vein of Galen malformations, and developmental venous anomalies. Six of the 14 children with cerebrovascular malformations (42.9%) had multiple malformations. Three children developed new cerebral arteriovenous malformations over time. Six children (11.1%) had clinically evident intracerebral hemorrhage, arterial ischemic stroke, or transient ischemic attack. The three children with intracerebral hemorrhage presented at young ages (4.3 to 7.7 years). CONCLUSIONS: More than a quarter of children with hereditary hemorrhagic telangiectasia who were imaged had cerebrovascular malformations, and overt stroke occurred in more than 10%. Intracerebral hemorrhages can occur in pediatric hereditary hemorrhagic telangiectasia patients at young ages, and new cerebral arteriovenous malformations may develop over time. Early screening with neuroimaging including neurovascular imaging as well as repeat neuroimaging may be warranted in children with hereditary hemorrhagic telangiectasia.

Study of Arteriovenous Fistula Cases in a Tertiary Care Hospital: A Descriptive Cross-sectional Study.

INTRODUCTION: Arteriovenous fistulas are a preferred choice for hemodialysis access in chronic kidney disease patients. There is increased adoption of arteriovenous fistula creation in Nepal. Our objective is to study various arteriovenous fistulas that have been created in our center. METHODS: This is a descriptive cross-sectional study conducted in a tertiary care hospital including all cases of arteriovenous fistula creation from January 2018 to December 2019. We obtained the ethical clearance from the institutional review committee of Kathmandu University School of Medical sciences. Convenient sampling method was used. Detailed vascular mapping and color doppler ultrasonography was done in the bilateral upper limb as preoperative preparation and to choose a site for arteriovenous fistula creation. Data were entered into the Statistical Package for the Social Sciences version 20 for analysis. RESULTS: Among 50 patients, the most common location was brachiobasilic 20 (40%) patients followed by brachiocephalic 18 (36%), radiocephalic 11 (22%), and arteriovenous graft between the brachial artery and axillary vein 1 (2%). The mean duration of hospital stay was 1.44 days. Three (6%) patients required re-intervention, all within 24 hours. Two (4%) patients had a failure of arteriovenous fistula requiring the creation of a new arteriovenous fistula. CONCLUSIONS: Brachiobasilic was the most common location for arteriovenous fistula creation. Reintervention was not common.

Changes in Clinical Presentation and Treatment Over Time in Patients with Unruptured Intracranial Arteriovenous Malformations.

OBJECTIVE: Treatment of unruptured intracranial arteriovenous malformations (AVMs) has become controversial since the ARUBA (A Randomized Trial of Unruptured Brain Arteriovenous Malformations) study was published in 2014. We sought to analyze changes in the demographics, clinical presentation, and treatment strategies in 2 patient cohorts from the same institution separated by 40 years. METHODS: We retrospectively reviewed the electronic medical records for a consecutive series of patients with unruptured intracranial AVMs seen at the Mayo Clinic between 2003 and 2017 and compared them with a previously published historical cohort from the same institution seen between 1974 and 1985. RESULTS: There were 273 patients in the contemporary cohort, of which discovery of the AVM was incidental in 123 (45.1%), a 3.5-fold increase compared with the 13.1% out of 168 patients in the historical cohort (P < 0.0001). Consequently, the percentage of patients with seizures as the presenting symptom leading to the diagnosis of AVM decreased from 57.7% in the historical cohort to 28.9% in the contemporary cohort (P < 0.0001). Interventional treatment was utilized in 220 (81.5%) contemporary patients compared with 49 (29.2%) historical patients (P < 0.0001). CONCLUSIONS: Compared to 40 years ago, more patients are presenting with incidentally discovered intracranial AVMs and are undergoing interventional treatment. Better understanding of the natural history, developments in endovascular therapy, and stereotactic radiosurgery, as well as improvements in microsurgical techniques have led to a substantial increase in patients undergoing invasive treatment.