Venous Sac Research Articles

Bilateral Congenital Pelvic Arteriovenous Malformation: A Case Report and Review of Literature.

Through a paradigmatic case and a systematic literature review, we present various endovascular strategies for treating pelvic paravesical arteriovenous vascular malformations (AVMs), with a focus on the efficacy of accessing the shunt point through direct puncture of the venous collector. A 42-year-old male with nonspecific pelvic pain underwent a computed tomography (CT) scan, which revealed bilateral pelvic AVMs characterized by a network of arteriolar afferents originating from the internal iliac arteries and the inferior mesenteric artery, draining into 2 interconnected giant venous sacs in the bilateral paravesical space. The malformation was classified as type II according to the Cho classification. Following an unsuccessful attempt at transarterial embolization, we devised a plan for bilateral transvenous embolization in 2 separate sessions. Venous access was achieved through percutaneous transperineal ultrasound-guided puncture of the dominant outflow venous sac. A microcatheter was then placed directly into the shunt point, where sclerosant and embolic agents were specifically delivered. Follow-up imaging showed complete obliteration of both pelvic AVMs. Effective hemostasis of pelvic paravesical AVMs can be achieved by targeting the shunt point from the aneurysmal dominant outflow vein, potentially through direct percutaneous puncture. This study aims to demonstrate the effectiveness of a transvenous approach in cases of embolization of pelvic paravesical arteriovenous vascular malformations (AVMs). The key to successful treatment lies in occluding the shunt point within the aneurysmal dominant outflow vein's wall, which can be reached transvenously and potentially through direct percutaneous puncture. Although arterial occlusion can be performed additionally, it should not be performed alone due to its higher risk of AVM persistence/recurrence.

Single-center 10-year retrospective analysis of Amplatzer Vascular Plug 4 embolization for pulmonary arteriovenous malformations with feeding arteries of

To evaluate the efficacy and safety of Amplatzer Vascular Plug 4 (AVP4) embolization in pulmonary arteriovenous malformations (PAVMs) with small- to medium-sized feeding arteries (<6 mm) and to identify factors affecting persistence and the main persistence patterns after embolization. Between June 2013 and February 2023, we retrospectively reviewed 100 patients with 217 treated PAVMs. We included PAVMs with feeding arteries <6 mm, treated with AVP4 embolization, and followed adequately with computed tomography (CT). Technical success was defined as flow cessation observed on angiography. Persistence was defined as less than a 70% reduction of the venous sac on CT. We evaluated adverse events for each embolization session. Patterns of persistence were assessed using follow-up angiography. Univariate and multivariate analyses were performed to evaluate factors affecting persistence based on the 70% CT criteria. Fifty-one patients (48 women, 3 men; mean age: 50.8 years; age range: 16-71 years) with 103 PAVMs met the inclusion criteria. The technical success rate was 100%. The persistence rate was 9.7% (10/103), and the overall adverse event rate was 2.9% (3/103) during a mean follow-up of 556 days (range: 181-3,542 days). In two cases, the persistence pattern confirmed by follow-up angiography involved reperfusion via adjacent pulmonary artery collaterals. The location of embolization relative to the last normal branch of the pulmonary artery was the only factor substantially affecting persistence. Embolization with AVP4 appears to be safe and effective for small- to medium-sized PAVMs. The location of the embolization relative to the last normal branch of the pulmonary artery was found to be the main determinant of persistence. Given the increasing demand for the treatment of small PAVMs, AVP4 embolization could be considered a viable and effective option for managing PAVMs with feeding arteries <6 mm.

Vein of Galen malformation with Obstructive Hydrocephalus- Endovascular Approach of Management : A Case Report

The vein of Galen malformation is a rare arteriovenous shunt that is estimated to represent 30% of all pediatric vascular malformations. Less than 1% of cerebral vascular malformations are aneurysmal abnormalities of the vein of Galen, making it a rare disorder. Despite being uncommon, VGM is of particular clinical importance since the large cerebral shunt volume causes a significant mortality rate when left untreated because to date, the treatment of patients with VGM remains challenging. Here we report a case of an 11-month-old baby who had VGM with obstructive hydrocephalus and was effectively treated by transarterial glue embolization of the fistula and the venous sac. Subsequently, the baby made a complete recovery. Bang. J Neurosurgery 2023; 13(1): 34-40

Endovascular and percutaneous embolization of a giant post traumatic arteriovenous fistula of inferior epigastric vessels

BackgroundArteriovenous fistulas involving the anterior abdominal wall can result from trauma. Such fistulas may remain asymptomatic and undetected for a prolonged duration of time. They tend to recruit multiple arterial feeders with remodelling in the feeding arteries, making them challenging to treat.Case presentationWe discuss a rare case of a 60-year-old male who presented with complaints of a progressive painless swelling in right lower abdomen. There was a history of blunt injury to abdomen at the same site during alleged road traffic accident 3 years ago. On CT angiography, an arteriovenous fistula was localised to the anterior abdominal wall arising predominantly from the right inferior epigastric artery with a giant venous sac and terminating as a tortuous single venous channel into the right external iliac vein. Few other small feeders were also seen arising from branches of right superior epigastric artery along Winslow’s pathway. The main challenge in endovascular management of this patient was embolization of a high flow shunt with a large venous sac and multiple arterial feeders. The dominant arterial feeder was embolized using vascular plug. The superficial location of the lesion offered an additional percutaneous window besides endovascular approach. The venous sac was percutaneously accessed and embolized using n-butyl cyanoacrylate after balloon occlusion of outflow vein. On follow up ultrasonographic evaluation at 3 months, near complete thrombosis of the venous sac was achieved.ConclusionsTraumatic arteriovenous fistulas involving the inferior epigastric vessels are rare clinical entities. CT angiogram and digital subtraction angiography help in the optimal diagnosis and treatment planning. The use of mechanical embolization devices to cause flow arrest offers an opportunity to use liquid embolic agents which offer better percolation within the lesion. Interventional radiology offers an ideal management of these complex high flow fistulas with a good technical success and acceptable safety profile.

Neural Network Helps Determine the Hemorrhagic Risk of Cerebral Arteriovenous Malformation

We aimed to determine whether the hemorrhage risks of cerebral arteriovenous malformation (AVM), evaluated through digital subtraction angiography (DSA) using a neural network, were superior to those assessed through angioarchitecture. We conducted a retrospective review of patients with cerebral AVM who underwent DSA from 2011 to 2017. Angioarchitecture parameters, age, and sex were analyzed using univariate and multivariate logistic regression. Additionally, a neural network was trained using a combination of convolutional neural network (CNN) and recurrent neural network (RNN) architectures. The training dataset consisted of 118 samples, while 29 samples were reserved for testing. After adjusting for age at diagnosis and sex, single venous drainage (odds ratio [OR] = 2.48, p = 0.017), exclusive deep venous drainage (OR = 3.19, p = 0.005), and venous sac (OR = 0.43, p = 0.044) were identified as independent risk factors for hemorrhage. The angioarchitecture-based hemorrhagic prediction model achieved 69% accuracy with an AUC (area under the ROC curve) of 0.757, while the CNN–RNN-based model achieved 76% accuracy with an AUC of 0.748. We present a diagnostic performance for hemorrhagic risk assessment of AVMs that is comparable to the angioarchitectural analysis. By leveraging larger datasets, there is significant potential to enhance prediction accuracy further. The CNN–RNN algorithm not only can potentially streamline workflow within the angio-suite but also serves as a complementary approach to optimize diagnostic accuracy and treatment strategies.

Transhepatic ultrasound guided embolization as a successful novel technique in treatment of pediatric complex intrahepatic arterioportal fistula: a case report and review of the literature

IntroductionIntrahepatic vascular shunts “IHVS” are abnormal communications between intra-hepatic vasculature involving the arterial, portal, or hepatic venous system. Arterio-portal fistula “APF” is an intrahepatic communication between the hepatic arterial system and the portal venous system without any communication with the systemic venous circulation. APF is considered a rare cause of portal hypertension and gastrointestinal bleeding in infancy.Case presentationA 3-month-old Mediterranean female with known cardiac congenital anomalies presented to us with abdominal distension and diarrhea. Ultrasonography revealed massive ascites and computerized tomography (CT) abdomen with intravenous (IV) contrast revealed a left hepatic lesion. On further evaluation, an intrahepatic arterio-portal vascular malformation was detected. Attempted trans arterial embolization failed and radiology team successfully carried out direct trans hepatic ultrasound guided coiling of the aneurysmal venous sac followed by successful resection of segment 4 of the liver with the vascular malformation avoiding life threatening intra operative bleeding.ConclusionAny child with recurrent gastrointestinal bleeding, failure to thrive, vomiting, diarrhea, steatorrhea, splenomegaly, or ascites should be investigated for intrahepatic arterio-portal fistula “IAPF”. Our novel technique of direct trans hepatic ultrasound guided coiling is an alternative method if trans arterial embolization “TAE” failed.

Retrospective single-arm cohort study of video-assisted thoracic surgery for treatment of idiopathic peripherally located simple type pulmonary arteriovenous malformation in 23 consecutive patients

BackgroundAlthough case reports of video-assisted thoracic surgery (VATS) for pulmonary arteriovenous malformation (PAVM) have been published, studies analyzing more than 10 cases were limited. A retrospective single-arm cohort study was performed to investigate the efficacy of VATS in 23 consecutive patients with idiopathic peripherally located simple type PAVM.MethodsVATS was performed for wedge resection of 24 PAVMs in 23 patients, which included 4 males and 19 females with an age range of 25 to 80 years (mean: 59.6 ± 13.0). Two patients underwent simultaneous resection of lung carcinoma, one by wedge resection and another by lobectomy. Each medical record was analyzed according to the resected specimen, bleeding volume, postsurgical hospital stay length, duration of chest tube placement, and VATS time. The distance between pleural surface/fissure and PAVM was measured on CT, and the influence of this distance on identification of PAVM was investigated.ResultsIn all 23 patients, VATS was successfully performed, and the venous sac was included in each resected specimen. Bleeding volume was less than 10mL in all but one with 1900 mL bleeding volume due to simultaneous lobectomy for carcinoma, not wedge resection of PAVM. Postsurgical hospital stay length, duration of chest tube placement, and VATS time were 5.0 ± 1.4 days, 2.7 ± 0.7 days, and 49.3 ± 39.9 min, respectively. In 21 PAVMs with a distance of 1 mm or less, purple vessel or pleural bulge of PAVM was identified soon after insertion of a thoracoscope. In the remaining 3 PAVMs with a distance of 2.5 mm or more, additional efforts were needed for identification.ConclusionVATS was found to be a safe and effective to treatment for idiopathic peripherally located simple type PAVM. When the distance between pleural surface/fissure and PAVM was 2.5 mm or more, a plan and strategy for identification of PAVM should be prepared before VATS.

Endovascular embolization of idiopathic renal arteriovenous fistula – A case report and literature review

Idiopathic renal arteriovenous fistulas (RAVFs) are rare vascular anomalies with no identifiable etiology. We present a case of 65-year-female who was being evaluated for complaints of the right flank pain and dysuria with no past history of trauma or surgery. Computed tomography showed arteriovenous fistula in lower pole of the right kidney with dilated branch of the right renal artery and dilated venous sacs. The patient was planned for endovascular embolization. Right renal angiogram showed dilated lower polar artery with a single-hole arteriovenous fistula. Selective coil embolization of the arterial channel was done. Post-deployment angiogram showed complete occlusion of the fistula and normal opacification of remaining segmental branches. On follow-up 1-month later, the patient was in good general condition. With advancements in endovascular techniques, transcatheter embolization has become initial treatment of choice for managing RAVF due to its less incidence for complications and preservation of renal function.

Quantified flow and angioarchitecture show similar associations with hemorrhagic presentation of brain arteriovenous malformations

IntroductionThe purpose of our study was to elucidate the impact of brain arteriovenous malformation (BAVM) flow and wall shear stress (WSS) on angioarchitecture and to evaluate their association with hemorrhagic presentations. Materials and methodsForty-one patients with BAVMs were evaluated by phase-contrast MR angiography. Volume flow rate and WSS were quantified. Angioarchitectural features such as location, angiogenesis, venous stenosis, venous ectasia, venous phlebitis, venous rerouting, exclusive deep vein and venous sac were evaluated by two neuroradiologists. The correlation between BAVM flow and size was evaluated with Spearman correlation coefficients. Differences of size, flow, and WSS between the hemorrhagic and non-hemorrhagic groups, the seizure and non-seizure groups, and between the different groups based on angioarchitecture were evaluated with Mann-Whitney U tests. Accuracy in predicting hemorrhage was evaluated with receiver operating characteristic curves. ResultBAVM flow was highly correlated with volume (ρ = 0.77). Higher flow was more commonly associated with angiogenesis, venous ectasia, venous rerouting, and venous phlebitis. Flow and angioarchitecture showed similar efficacy in differentiating hemorrhagic from non-hemorrhagic BAVMs. WSS did not demonstrate differences across any clinical groups. ConclusionFlow quantification and angioarchitecture analysis of BAVMs showed similar efficacy as evaluated by associations with hemorrhagic presentation. High flow affects both arterial and venous angioarchitecture, reflecting the nature of low vascular resistance in BAVMs.

Embolization Tactics of Spinal Epidural Arteriovenous Fistulas.

PurposeSpinal epidural arteriovenous fistulas (SEDAVFs) show an epidural venous sac often with venous congestive myelopathy (VCM) due to intradural reflux at a remote level to which a transarterial approach would be difficult. We present 12 cases of SEDAVF with VCM and describe 3 main tactics for effective transarterial embolization.Materials and MethodsAmong 152 patients with spinal vascular malformations diagnosed in our tertiary hospital between 1993 and 2019, 12 SEDAVF patients with VCM were included. Three different transarterial embolization tactics were applied according to the vascular configuration and microcatheter accessibility. We evaluated treatment results and clinical outcomes before and after treatment.ResultsTransarterial embolization with glue (20–30%) was performed in all patients. The embolization tactics applied in 12 patients were preferential flow (n=2), plug-and-push (n=6), and filling of the venous sac (n=4). Total occlusion of the SEDAVF, including intradural reflux, was achieved in 11 (91.7%) of 12 patients, and partial occlusion was achieved in 1 patient. No periprocedural complications were reported. Spinal cord edema was improved in all patients for an average of 18 months after treatment. Clinical functional outcome in terms of the pain, sensory, motor, and sphincter scale and modified Rankin scores improved during a mean 25-month follow-up (6.3 vs. 3.3, P=0.002; 3.6 vs. 2.3, P=0.002, respectively).ConclusionEndovascular treatment for 12 SEDAVF patients with VCM achieved a total occlusion rate of 91.7% without any periprocedural complication. The combined embolization tactics can block intradural reflux causing VCM, resulting in overall good clinical outcomes.

Pulmonary Arteriovenous Malformation Embolization: So Much Left to Learn

Embolization of pulmonary arteriovenous malformations (PAVMs) has been utilized effectively for more than 40 years. Initially performed using conventional coils and/or detachable balloons in the era of cut-film angiography, currently, there is an armamentarium of embolic devices and methods for effecting therapy. Two studies in this issue of the Journal of Vascular Interventional Radiology compare traditional feeding artery embolization with venous sac (“nidal”) embolization, and in both, sac embolization appeared to improve the occlusion rate of lesions (1,2).

Venous Sac and Feeding Artery Embolization versus Feeding Artery Embolization Alone for Treating Pulmonary Arteriovenous Malformations: Draining Vein Size Outcomes

PurposeTo investigate and compare venous sac and feeding artery embolization (VFE) with feeding artery embolization (FAE) alone for treatment of pulmonary arteriovenous malformations (PAVMs), based on difference in outcomes in decrease of the size of the draining vein. Materials and MethodsTwenty-six patients (7 male and 19 female; median age [interquartile range], 58 years [46–65 years]) with 42 simple PAVMs treated with coil embolization between August 2005 and December 2018 were retrospectively evaluated. Twenty PAVMs were treated with FAE early in the study period and compared with 22 PAVMs treated with VFE later in the study period. Follow-up computed tomography images obtained 8–20 months after embolotherapy were used for outcome analysis. Data related to patient demographics; follow-up period; baseline diameters of the feeding artery, venous sac, and draining vein; draining vein diameter after treatment; and decrease in the size of the draining vein, including the number reaching a threshold of 70% decrease, were compared between the 2 groups. ResultsThe draining vein decreased in size by a median of 46.4% in the FAE group and 66.3% in the VFE group, and the difference between the 2 groups was statistically significant (P = .009). There were no significant differences in the other parameters. ConclusionsVFE leads to a greater decrease in the size of the draining vein than FAE, suggesting that VFE results in more complete occlusion than FAE for treatment of PAVMs.

Spinal Epidural Fistulas–A Separate Entity to Dural Fistulas with Different Angioarchitecture and Treatment Approach

Spinal epidural arteriovenous fistulas (SEAVFs) are the rarest variety of spinal vascular malformation and are often misdiagnosed as type 1 spinal dural fistula. This retrospective study highlights the salient anatomic differentiating points of these entities and also highlights the importance of a planned endovascular treatment approach using different routes of access. Efficacy of the endovascular treatment at 3 months follow-up was also studied. We retrospectively reviewed 11 treated patients with SEAVF. Existence of epidural arteriovenous fistula in all these patients was confirmed by spinal angiography. The Aminoff-Logue Scale score was assigned both before and after the procedure. The statistical results were expressed as percentages, and the preprocedure scale was compared with the postprocedure scale at 3 months by using a nonparametric Wilcoxon signed-rank test. The patients ranged in age from 7 to 53 years, with male predominance. Paraparesis was the commonest symptom, and 1 patient had congestive cardiac failure caused by a large fistula. Location was mostly dorsolumbar with intradural venous reflux into the perimedullary venous system (Castilla type A) noted in 3/11(27%) patients, and the remaining 73% patients had Castilla type B1 with an enlarged epidural venous sac. Therapeutic embolization was performed from arterial, venous, or combined routes. The 3-month postprocedure clinical assessment showed statistically significant (P < 0.004) improvement in the Aminoff-Logue Scale score. The differentiating points between SEAVF compared with type 1 spinal dural fistula are emphasized. The study also highlights the importance of a good angiographic assessment to best access the fistula by arterial, venous, percutaneous, or combined routes. Endovascular treatment resulted in statistically significant clinical improvement at 3 months follow-up.

Pulmonary arteriovenous malformation (PAVM) embolization: prediction of angiographically-confirmed recanalization according to PAVM Diameter changes on CT

BackgroundTo assess pulmonary arteriovenous malformation (PAVM) recanalization after embolization based on PAVM diameter changes on computed tomography (CT), with pulmonary angiography used as a gold standard.MethodsA retrospective review was done of patients from 2008 to 2019 with a PAVM treated with endovascular embolization. The treatment outcome was determined by conventional angiography. Follow-up pulmonary angiography was performed when recanalization was suspected on CT, or embolization of all lesions in multiple PAVM patients could not be completed in a single session. Patients who had no preprocedural or follow-up CT were excluded. Draining vein, feeding artery, and venous sac diameter were measured on CT, and diameter reduction rates were compared with the widely-used, binary 70 % criteria.ResultsForty-one patients with 114 PAVMs were treated during the study period. Eight patients with 50 PAVMs met the inclusion criteria. Mean vein, artery, and venous sac diameter reduction rates were as follows: 59.2 ± 9.3 %, 47.5 ± 10.6 %, and 62.6 ± 13.2 %, respectively, in the occluded group and 5.4 ± 19.5 %, 11.3 ± 17.7 %, and 26.8 ± 14.2 %, respectively, in the recanalized group. The area under the receiver operating characteristic curves for PAVM recanalization for the draining vein was 1.00, showing a better result than the artery (0.97) and sac (0.99). Patients showed > 42 % draining vein diameter reduction in the occluded group and < 32 % in the recanalized group. The widely-used 70 % criteria showed low specificity for predicting recanalization (draining vein, 7.3 %; venous sac, 41.7 %) but 100 % sensitivity for both the draining vein and venous sac.ConclusionsThe widely-used 70 % binary criteria showed limited performance in predicting outcomes in this angiographically-confirmed case series. Further investigations are warranted to establish a strategy for detecting recanalization after PAVM embolization.

Factors Contributing to Major Neurological Complications From Vein of Galen Malformation Embolization

Major neurological complications from the embolization of vein of Galen malformations (VOGMs) are poorly understood. We provide a detailed analysis of contributors to periprocedural neurological complications and lessons learned. To assess the rate of major periprocedural neurological complications following VOGM embolization with major procedural and strategic contributors. This retrospective cohort study was conducted at a quarternary referral pediatric hospital (Hospital for Sick Children; Toronto, Ontario, Canada) from January 1999 to December 2018 with a mean clinical follow-up of 44.7 months; all children with VOGM diagnosed and/or treated were eligible (n = 48). Thirty-three patients who underwent endovascular treatment were included. Endovascular staged transarterial embolization performed in 33 patients over 91 sessions. The primary outcome was the rate of periprocedural neurological complications (occurring within 1 week of embolization). The secondary outcomes were mortality, long-term neurological outcomes, and contributing anatomical and management factors to neurological complications. Of 33 patients who underwent embolization (31 boys [64.6%]; 17 girls [35.4%]; median age at first embolization, 4 months [range, 0-29 months]), 10 patients (30.3%) developed major periprocedural neurological complications. Five of these patients died. Univariate logistic regression analyses identified internal cerebral vein drainage to the main venous sac of the VOGM and use of a microcatheter with a distal outer diameter of more than 2.0F as significant predictors of poor neurological outcomes. Lessons learned from our experience include the need to assess the internal cerebral vein drainage pattern on preprocedural magnetic resonance venography, avoidance of excessive embolization into the venous sac, treatment of more distal fistulae before proximal fistulae to avoid a sump effect, and preferably use of smaller (<2.0F outer diameter) microcatheters in neonatal embolization procedures. In this cohort, 10 patients with VOGM treated with embolization (30.3%) experienced major periprocedural neurological complications, half of whom died. While these outcomes are superior to historic conservative and surgical treatment results, ongoing improvements in treatment and pretreatment diagnostic approaches are needed. Awareness of the lessons learned from our experience can help to avoid similar complications in the future for this vulnerable population.

Abstract No. 663 Greater shrinkage of the draining vein of pulmonary arteriovenous malformations after venous sac and feeding artery embolization than after feeding artery embolization alone

Abstract No. 663 Greater shrinkage of the draining vein of pulmonary arteriovenous malformations after venous sac and feeding artery embolization than after feeding artery embolization alone

Complex Arteriovenous Malformation in a Kidney with Multiple Renal Arteries: A Case Report

The abnormal communications between arteries and veins outside the capillary level are called Arteriovenous Malformation (AVM). A 25-year-old known hypertensive on irregular medications, presented with acute stroke (Computed Tomography (CT) brain revealed left putamen haemorrhage). On evaluation, all routine investigations were normal except for microscopic haematuria. Ultrasound (USG) KUB showed right AVM and on further evaluation with 320 slice Contrast Enhanced Computed Tomography (CECT) abdomen with angiogram and 3D reconstruction revealed right kidney supplied by three renal arteries. The second renal artery was dilated (1.1 cm diameter) and communicates directly with aneurysmally dilated right renal vein (2.9 cm diameter). Digital Subtraction Angiography (DSA) with angioembolisation was done four days’ postadmission. Large second renal artery with a direct Arteriovenous Fistula (AVF) draining into the renal vein with aneurysmal venous sacs was occluded with 16 mm, 12 mm and 10 mm coils. Complete obliteration of fistula was confirmed. Then the inferior most third renal artery was accessed and angiogram revealed RAVM with multiple feeders shunting into the venous sacs and it was occluded with 40% glue. Postoperative day one USG showed thrombosed venous aneurysmal sacs and occlusion of the arterial fistulae. He was discharged at four weeks with antihypertensive and antiseizure medications. During the follow-up there was no loss in the function of the kidney and micro or macroscopic haematuria was not detected.

Embolization using hydrogel-coated coils for pulmonary arteriovenous malformations

PurposeTo prospectively evaluate the efficacy and safety of embolization using hydrogel-coated coils for the treatment of pulmonary arteriovenous malformations (PAVMs). Materials and methodsThe outcomes of 21 PAVMs in 19 patients (3 men and 16 women; mean age, 58.8±15.2 [SD] years; age range 14–78 years) treated by venous sac embolization (VSE) with additional feeding artery embolization were prospectively evaluated. For VSE, using one or more 0.018-inch hydrogel-coated coils was mandatory. Recanalization and/or reperfusion were evaluated by pulmonary arteriography 1 year after embolization. ResultsThe mean feeding artery and venous sac sizes were 4.0mm and 8.5mm, respectively. Embolization was successfully completed in 20/21 PAVMs, yielding a technical success rate of 95%. The feeding artery was also embolized in 17/20 successful PAVMs (85%). A technical failure occurred in one PAVM, where embolization was abandoned because of migration of one bare coil to the left ventricle. The mean numbers of hydrogel-coated coils and bare platinum detachable coils used for VSE were 3.3±2.1 (SD) (range, 1–8) and 4.4±3.9 (SD) (range, 1–17), respectively. The mean percentages of hydrogel-coated coils in number, length, and estimated volume were 42.9%, 33.3%, and 72.7% respectively. One patient with one PAVM was lost to follow-up after 3 months. Neither recanalization nor reperfusion was noted in the remaining 19 PAVMs (success rate, 19/19 [100%]). One grade 4 (coil migration) adverse event occurred, and it was treated without any sequelae. ConclusionVSE using hydrogel-coated coils with additional feeding artery embolization is a safe and effective treatment for PAVM.

Subclassification and Treatment Results of Ethanol Embolotherapy of Type II Arteriovenous Malformations of the Extremity and Body

To evaluate the safety and efficacy of ethanol and coil embolization of type II arteriovenous malformation (AVM) according to a new subtype classification. Eighty-four type II AVMs in the body or extremity of 79 patients who underwent AVM treatment from 1996 to 2017 were retrospectively subclassified according to the angiographic morphology of the draining vein as type IIa (arterioles shunt to focal segment of single draining vein), type IIb (arterioles shunt to venous sac with multiple draining veins), and type IIc (arterioles shunt along long segment of draining vein). Coil and ethanol embolization of the focal or long segment of the draining vein or the venous sac was performed with direct puncture or transvenous approach according to subtype. Treatment outcomes, number of treatment sessions, and complications were analyzed. AVM cure (ie, complete embolization) rates were 95%, 76%, and 65% in types IIa, IIb, and IIc AVMs, respectively. The cure rate of type IIa AVMs was significantly better than that of type IIc AVMs (P= .015). Median numbers of treatment sessions were 1 in types IIa and IIb AVMs and 2.5 in type IIc AVMs, with a significant difference between type IIc and the other 2 types (P < .05). Minor complications occurred in 20% of patents and major complications occurred in 7%. The cure rate of type IIa AVMs was significantly better than that of type IIc AVMs, which also required significantly more treatment sessions than the other 2 types.

Efficacy and Safety of Transvenous Embolization of Type II Renal Arteriovenous Malformations with Coils

PurposeTo evaluate the efficacy and safety of transvenous coil embolization of the venous sac for type II renal arteriovenous malformation (AVM). Materials and MethodsA retrospective review was conducted of 8 patients (5 women and 3 men; mean age, 57 years; age range, 41–69 years) who underwent transvenous coil embolization for type II congenital renal AVM at 5 different hospitals between 2012 and 2018. Additional intra-arterial ethanol injection was performed if shunt flow persisted after venous sac coiling. Technical success was defined as complete occlusion of shunt flow with coil embolization. Clinical success was defined as no symptom recurrence during the follow-up period. The renal parenchymal infarction rate was measured on computed tomography (CT), and procedure-related complications were reviewed. ResultsNine sessions of embolization were performed for 8 patients. The mean venous sac size was 24 mm (range, 10–39 mm), and a mean of 14 micro and/or micro-detachable coils (range, 3–50) were used. The technical success rate was 88% (7 of 8) using coil embolization. One patient (12%) required additional ethanol injection to complete occlusion of the shunt flow and had a less than 10% parenchymal infarction on follow-up CT. No procedure-related complications or recurrences occurred during a mean clinical follow-up period of 20.8 months (range, 4.7–76.6 months). ConclusionsTransvenous coil embolization of type II renal AVM showed an 88% technical success rate. One patient (12%) showed less than 10% renal parenchymal infarction after additional ethanol injection. No additional complications or recurrences occurred during the follow-up period.