Number Of Feeding Arteries Research Articles

Postembolization Persistence of Pulmonary Arteriovenous Malformations: A Retrospective Comparison of Coils and Amplatzer and Micro Vascular Plugs Using Propensity Score Weighting.

BACKGROUND. Endovascular embolization of pulmonary arteriovenous malformations (PAVMs) was historically performed with embolic coils. The Amplatzer Vascular Plug device (AVP) was introduced for this purpose in 2007 and the Micro Vascular Plug device (MVP) in 2013. OBJECTIVE. The purpose of this study was to compare coils, AVPs, and MVPs in terms of risk of persistence after PAVM embolization by use of propensity score weighting to account for biases in device selection. METHODS. This retrospective study included 112 patients (78 women and girls, 34 men and boys; mean age, 45 years) who underwent embolization of 393 PAVMs with a single device type (coil, MVP, or AVP) from January 2003 to January 2020. Persistence was defined as less than 70% reduction in PAVM sac size or contrast enhancement of the sac on follow-up pulmonary CTA. A Cox proportional hazards regression model was used to assess associations between embolic device selection and PAVM persistence. Inverse propensity score weighting was used to account for differences in embolic device selection based on patient and PAVM characteristics. RESULTS. The median postembolization follow-up period was 1.5 years (IQR, 0.3-5.6 years). Persistence was found in 10% (41/393) of PAVMs, including 16% (34/207) of those treated with coils, 8% (7/88) of those treated with AVPs, and 0% (0/98) of those treated with MVPs. Variables associated with embolization device (p < .25) were age, sex, pediatric versus adult status, smoking status, PAVM complexity, PAVM laterality, number of feeding arteries, and feeding artery diameter. The Cox regression model incorporated inverse propensity score weighting to account for the differences between treatment groups in these variables and incorporated feeding artery diameter because of imbalance remaining after weighting. With coils as the referent, MVPs had a hazard ratio for persistence of less than 0.01 (95% CI, < 0.01 to < 0.01; p < .001), and AVPs had a hazard ratio of 0.37 (95% CI, 0.16-0.90; p = .03). CONCLUSION. The risk of persistence after PAVM embolization was significantly lower for MVPs alone than for coils or AVPs alone. In addition, the risk of persistence was lower for AVPs than for coils. CLINICAL IMPACT. The findings support the clinical use of MVPs as the preferred device for PAVM embolization over coils and polytetrafluoroethylene-covered plugs.

Four-dimensional digital subtraction angiography to assess cerebral arteriovenous malformations.

The performance of a novel prototype four-dimensional (4D) digital subtraction angiography (DSA) for cerebral arteriovenous malformation (AVM) diagnosis was evaluated and compared with that of two-dimensional (2D) and three-dimensional (3D) DSA. In this retrospective study, 37 consecutive cerebral AVM patients were included. The standard diagnostic results were concluded from the 2D and 3D DSA. Two 4D DSA volumes were reconstructed for each patient by a commercial and a prototype software, then evaluated by two independent experienced neurosurgeons, who were blinded to the diagnosis and treatment process. The evaluation results were compared with the diagnostic results on Spetzler-Martin (SM) Grading Scale, number of feeding arteries, number of draining veins, and intranidal aneurysms. Complete agreement was achieved between 4D DSA and 2D and 3D DSA in SM Grading Scale and intracranial aneurysm identification (agreement coefficient: 1) for both reviewers. The agreement coefficients were .888 and .917 for both reviewers in feeding artery number determination using 4D DSA product and 4D DSA prototype, respectively. The agreement coefficients in draining vein number determination were all larger than .94 for both reviewers using both 4D DSA volumes. The performance of this prototype 4D DSA in cerebral AVMs diagnosis was largely equivalent to that of 2D and 3D DSA combination. Four-dimensional DSA can be regarded as a very good complement for 2D DSA in cerebral AVM diagnosis.

The influence of hemorrhage presentation on clinical outcomes of curative embolisation in 125 cerebellar arteriovenous malformations

Background This study investigated the influence of periprocedural hemorrhage and clinical outcomes with an endovascular therapeutic strategy for cerebellar arteriovenous malformations (cAVMs). Methods From December 2006 to January 2018, 125 cAVMs were classified as types I–IV and received endovascular embolization via Onyx or Glubran 2. The risk factors of hemorrhage were analyzed using univariate and multivariate logistic analyses. A modified Rankin Scale (mRS) score was used to evaluate the neurological function before and 1 year after the operation. Results Of 125 patients, 63 had type I cAVMs, 2 type II cAVMs, 48 type III cAVMs, and 12 type IV cAVMs. A total of 88 (70.4%) patients had clinical manifestations of intracranial hemorrhage. Multivariate logistic regression analysis showed that age (OR, 2.276; 95% CI, 1.132 − 5.663), flow-related aneurysm (OR, 2.845; 95% CI, 1.265 − 6.248), lesion size (OR, 3.005; 95% CI, 1.119 − 5.936), and the number of feeding arteries (OR, 0.105; 95% CI, 0.081 − 0.312) were still the significant independent risk factors of intracranial hemorrhage. During a 1-year follow-up, 109 patients (87.2%) had good outcomes (mRS 0 − 2), 12 patients (9.6%) had poor outcomes (mRS 3 − 4), 4 patients (3.2%) died, and 3 patients had intracranial hemorrhage due to the incomplete embolization of cAVMs. Conclusions Endovascular embolization is a feasible treatment for cAVMs. Age, flow-related aneurysm, lesion size, and the number of feeding arteries are the significant risk factors of periprocedural hemorrhage. Moreover, the lesion characteristics must be given full consideration when using Onyx or Glubran 2 before cAVMs embolization.

Radiosurgery-Based AVM Scale Is Proposed for Combined Embolization and Gamma Knife Surgery for Brain Arteriovenous Malformations.

Background and purpose: To evaluate whether a radiosurgery-based arteriovenous malformation (AVM) scale (RBAS) could be used to predict obliteration of brain arteriovenous malformations (bAVMs) supposed for combined endovascular embolization (EMB) and gamma knife surgery (GKS) treatment.Methods: bAVM patients who underwent GKS with or without previous EMB from January 2011 to December 2016 at our institution were retrospectively reviewed. The patients were categorized into a combined treatment group and a GKS group. A 1:1 propensity score matching (PSM) was used to match the two groups. Pre-EMB and pre-GKS RBAS were assessed for every patient. Multivariate analysis was performed to find factors associated with complete obliteration in the combined treatment group. Survival analysis based on sub-groups according to RBAS was performed to compare obliteration rate and find cutoffs for appropriate treatment modalities.Results: A total of 96 patients were involved, and each group comprised 48 patients. There was no difference between the two groups in terms of obliteration rate (75.0 vs. 83.3%, p = 0.174). Pre-EMB RBAS (p = 0.010) and the number of feeding arteries (p = 0.014) were independent factors associated with obliteration rate in the combined treatment group. For the combined treatment patients, sub-group analysis according to pre-EMB RBAS (score <1.0, 1.0–1.5, and >1.5) showed statistical difference in obliteration rate (p = 0.002). Sub-group analysis according to RBAS between the two groups showed that the obliteration rate of the GKS group is significantly higher than the combined group when RBAS >1.5 (47.4 vs. 66.7%, p = 0.036).Conclusions: The RBAS is proposed to be efficient in predicting obliteration of bAVMs supposed to receive combined EMB and GKS treatment. Patients with RBAS >1.5 are inclined to be more suitable for GKS instead of the combined treatment.

A predictive model of incomplete response after transarterial chemoembolization for early or intermediate stage of hepatocellular carcinoma: consideration of hepatic angiographic and cross-sectional imaging.

The purpose of the present study is to develop a predictive model for incomplete response (IR) after conventional transarterial chemoembolization (cTACE) for hepatocellular carcinoma (HCC) based on hepatic angiographic and cross-sectional imaging. Sixty patients with 139 target HCC lesions who underwent cTACE from February 2013 to March 2019 were included in this retrospective study. Hepatic angiographic features were identified: the number of feeding arteries, vascularity of the tumor, tumor staining on angiography, vascular lake phenomenon, and hepatic arterio-portal shunt. Cross-sectional imaging features were also identified: tumor extent, location, size, and enhancement pattern. Treatment response was assessed by the modified Response Evaluation Criteria in Solid Tumors (mRECIST) criteria. Logistic regression analysis was performed to determine the potential predictive factors for treatment response. To validate the predictive value of potential factors, the means of a decision tree were also calculated by Classification and Regression Tree (CART). P < 0.05 was considered statistically significant. The IR rate was 43.2% (60/139) in the entire study population. Logistic regression analysis showed that a tumor size > 50 mm (P = 0.005; odds ratio, 7.25; 95% CI 1.79-29.33), central location (P = 0.007; odds ratio, 0.14; 95% CI 0.03-0.59), and nondense tumor staining (P < 0.001; odds ratio, 0.08; 95% CI 0.02-0.28) were predictors of IR after cTACE. Decision tree analysis showed a good ability to classify treatment response with an accuracy of 78.4%. Tumor size > 50 mm, central tumor location, and nondense tumor staining were predictors of IR after cTACE. These factors should be taken into consideration when performing cTACE.

Feeding arteries and arteriovenous shunt for discrimination of soft tissue tumors.

Time resolved magnetic resonance angiography with interleaved stochastic trajectories (TWIST) allows for identification of tumor feeding arteries and arteriovenous shunt (AVS). We used TWIST to obtain number of feeding arteries (NFA) and detect AVS for 43 cases of pathology-confirmed soft tissue tumors. We compared normalized number of feeding arteries (nNFA) and AVS between malignant and benign tumors, and found nNFA was significantly greater in malignant tumors versus benign tumors (2.1 vs 1.3, P < .05). The incidence of AVS was significantly higher in malignant tumors versus benign tumors (87.5% vs 10.5%, P < .05). TWIST derived nNFA and AVS could be useful in the discrimination of benign and malignant soft tissue tumors.

Clinical outcomes and radiosurgical considerations for pediatric arteriovenous malformation: influence of clinical features on obliteration rate.

Gamma knife radiosurgery (GKRS) is an established treatment modality for brain arteriovenous malformation (AVM), but there have been few published studies examining the relationship between clinical features of AVM and successful obliteration with GKRS in pediatric patients. In the current study, we investigate the outcomes of GKRS for pediatric patients with brain AVM and analyze the variables that influence obliteration. We analyzed 68 pediatric patients (≤18years) with a mean follow-up period of 61.9months (range 6-215months). The following parameters were analyzed to determine their influence on obliteration of AVM treated by GKRS: age, sex, target volume, irradiation dose, prior treatment, location of AVM, nidus structure, velocity of AVM, location of venous drainage, number of feeding arteries, and initial presenting symptoms. Also, we estimated clinical factors which should be considered during the follow-up period. Of the 68 patients, complete obliteration was confirmed in 26 (38.2%) by cerebral angiography. The response rate of AVM for GKRS was 92.6%. No significant association was observed between any of the parameters investigated and the obliteration of AVM, with the exception of number of feeding arteries, which exhibited a statistically significant difference by univariate analysis (p=0.003). However, on multivariate analysis, nidus structure (p=0.007), velocity of the main arterial phase (p=0.013), velocity of the feeding artery phase (p=0.004), and the number of feeding arteries (p=0.018) showed statistical significance. GKRS yielded good long-term clinical outcomes in most pediatric patients. Multiple arterial feeding vessels, diffuse nidus structure, and fast flow of AVM were specific factors associated with a low rate of obliteration in pediatric AVMs.

Spinal arteriovenous malformations: Is surgery indicated?

Purpose:To identify clinico-radiological distinguishing features in various types of spinal arteriovenous malformations (AVM) with an aim to define the role of surgical intervention.Materials and Methods:Hero's modified Di Chiro classification differentiated four types of spinal AVMs on digital subtraction angiogram (DSA) in 74 patients: I. Dural arteriovenous fistulae (n = 35, 47.3%); II. Glomus/intramedullary (n = 13, 17.6%); III. Juvenile/metameric (n = 4, 5.4%); and, IV. Ventral perimedullary fistula (n = 21, 28.4%). A patient with extradural AVM remained unclassified. Demographic profiles, DSA features and reason for surgical referral were recorded. Statistical comparison of discrete variables like gender, spinal cord level, presentation and outcome was made using Chi-square test; and, continuous variables like age, feeder number, duration of symptoms and number of staged embolizations by one way analysis of variance with Boneferoni post hoc comparison. Embolization alone (n = 39, 52.7%), surgery alone (n = 16, 21.6%), and combined approach (n = 4, 5.4%) were the treatments offered (15 were treated elsewhere).Results:Type I-AVM occurred in significantly older population than other types (P = 0.01). Mean duration of symptoms was 13.18 ± 12.8 months. Thoracic cord involvement predominated in type-I and III AVMs (P = 0.01). Number of feeding arteries were 1 in 59.7%; 2 in 29.0%; and, multiple in 11.3% patients, respectively. Staged embolization procedures in type-III AVM were significant (P < 0.01). Surgical referral was required due to: Vessel tortuosity/insufficient parent vessel caliber (n = 7); residual AVM (n = 4); low flow AVM (n = 3); and, multiple feeders (n = 2). Check DSA (n = 34) revealed complete AVM obliteration in 26 and minor residual lesion in eight patients. Neurological status improved in 26 and stabilized in 25 patients.Conclusions:Differentiating between Type I-IV AVMs has a significant bearing on their management. Surgical intervention should be considered as an important adjunct/alternative to therapeutic embolization.

Local Recurrence After Chemoembolization of Hepatocellular Carcinoma: Uptake of Gadoxetic Acid as a New Prognostic Factor

The purpose of this article is to investigate whether there is a difference in susceptibility to transcatheter arterial chemoembolization between hepatocellular carcinomas (HCCs) showing high uptake and those showing low uptake of gadoxetic acid in the hepatobiliary phase of MRI. One hundred HCCs that achieved optimal chemoembolization, as assessed by immediate CT in 60 patients, were classified as having high (n = 19) or low (n = 81) uptake of gadoxetic acid on MRI performed before chemoembolization. The local recurrence rates were estimated using the Kaplan-Meier method, and differences between the groups were compared using the log-rank test. The following factors were also correlated with the local recurrence rate using the Cox proportional hazards model for a univariate analysis: high uptake of gadoxetic acid, number of feeding arteries, extrahepatic arterial supply, Child-Pugh class, clinical tumor stage, size, location, and iodized oil accumulation in the noncancerous tissue surrounding the lesion. Parameters that were significant at p < 0.05 were entered into a multivariate model. The 1- and 3-year local recurrence-free rates were 95% in high-uptake HCCs and 66% and 54%, respectively, in low-uptake HCCs (log-rank test, p < 0.01). The low uptake of gadoxetic acid was the only significant predictor of early local recurrence (hazard ratio = 9.24; p = 0.03) by multivariate analysis. HCCs showing high uptake of gadoxetic acid appear to be susceptible to chemoembolization.

Surgical resection of scalp arteriovenous malformation: Case illustration

Arteriovenous malformation (AVM) of the scalp is a rare lesion whose natural history remains to be elucidated. The report describes a case of a patient with a history of minor head trauma who presented with spontaneous bleeding from the scalp due to a relatively small scalp AVM. Several imaging modalities were used to establish the diagnosis, map the vascular malformation, and plan management. The optimal treatment strategy for this type of lesion remains controversial. Based on the size of AVM and the number of feeding arteries, this patient was treated with complete surgical excision alone. The clinical course was good, without postoperative complication or recurrence. Three-dimensional computed tomography angiography (3D-CTA) was useful for diagnosis, management and follow-up of this small extracranial scalp AVM.

Assessment of 3D-TOF-MRA at 3.0 tesla in the characterization of the angioarchitecture of cerebral arteriovenous malformations: a preliminary study

The characterization of brain arteriovenous malformation (AVM) angioarchitecture remains rewarding in planning and predicting therapy. The increased signal-to-noise ratio at higher field strength has been found advantageous in vascular brain pathologies. To evaluate whether 3.0T time-of-flight (TOF) magnetic resonance angiography (MRA) is superior to 1.5T TOF-MRA for the characterization of cerebral AVMs. Fifteen patients with AVM underwent TOF-MRA at 3.0T and 1.5T and catheter angiography (DSA), which was used as the gold standard. Blinded readers scored image quality on a four-point scale, nidus size, and number of feeding arteries and draining veins. Image quality of TOF-MRA at 3.0T was superior to 1.5T but still inferior to DSA. Evaluation of nidus size was equally good at 3.0T and 1.5T for all AVMs. In small AVMs, however, there was a tendency of size overestimation at 3.0T. MRA at 3.0T had increased detection rates for feeding arteries (+21%) and superficial (+13%) and deep draining veins (+33%) over 1.5T MRA. 3.0T TOF-MRA offers superior characterization of AVM angioarchitecture compared with 1.5T TOF-MRA. The image quality of MRA at both 3.0 and 1.5T is still far from equal to DSA, which remains the gold standard for characterization of AVM.

Endovascular Embolization of Large Hepatic Arteriovenous Fistulas

Treatment of hepatic artery to portal vein fistulas (HAPFs) has shifted in the past two decades from surgical resection of the involved liver to embolization. A uniform technique for percutaneous intervention has not been established because the approach is influenced by the size, location, and number of feeding arteries. We report two cases of HAPFs treated with embolization at our institution. Different outcomes in these two patients illustrate several fundamental principles in the treatment of HAPFs.

Diagnosis: Pulmonary arteriovenous malformation (PAVM)

Diagnosis: Pulmonary arteriovenous malformation (PAVM)

Embolisation of Small (&lt; 3 cm) Brain Arteriovenous Malformations

The role of embolisation in the treatment of small < 3cm) brain arteriovenous malformations (AVMs) has not been elucidated. We reviewed our experience using embolisation in the treatment of small AVMs and correlated a proposed grading system based on the angioarchitecture to the percentage obliteration achieved by embolisation. Eighty-one small AVMs in 80 patients were embolised from 1984 to 1999. The age range was from 3 to 72 years. The AVMs were given a score from 0 to 6 based on the angioarchitecture. The assigned scores were as follows: nidus (fistula = 0, < 1 cm = 1, 1-3 cm = 2), type offeeding arteries (cortical = 0, perforator or choroidal = 1), number of feeding arteries (single = 0, multiple = 2) and number of draining veins (single = 0, multiple = 1). Angiographic results based on percentage obliteration were grouped into three categories: complete, 66-99%, and 0-65%. The goal of embolisation was cure in 27 AVMs, pre-surgical in 23, pre-radiosurgery in 26, and elimination of an aneurysm in five. Embolisation achieved complete obliteration in 22 (27%) of the 81 AVMs. In the AVMs where the goal was cure, 19 (70%) of 27 were completely obliterated. In the AVMs with angioarchitecture scores of 0-2, 12 (86%) of 14 were cured, with scores of 3-4, 8 (34%) of 24 were cured and with scores of 5-6, 2 (4%) of 44 were cured. Embolisation resulted in transient morbidity of 5.0%, permanent morbidity of 2.5%, and mortality of 1.2%. There were no complications in AVMs with scores of 0-2. Embolisation is an effective treatment of small AVMs when the angioarchitecture is favourable (scores 0-2). This includes pure fistulas and AVMs with a single, pial, feeding artery.

Surgical treatment of cerebral arteriovenous malformations. Follow-up study of 43 cases.

In 43 patients with arterio-venous malformations and one patient with a cavernous haemangioma, whose angiomas were completely removed by the same Surgeon, pre- and postoperative angiograms were reviewed and the clinical results documented in a follow-up study. Mortality rate (7%) and severe disability (7%) are significantly lower than in untreated patients. A poor outcome strongly depends on the number of feeding arteries, on localization (midline) and size.