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Monday, October 21, 2019

Chemoembolization Combined with Radiofrequency Ablation for Medium-Sized Hepatocellular Carcinoma: A Propensity-Score Analysis


Clinical question
Compare the effectiveness of combined chemoembolization and RF ablation, chemoembolization alone, and RF ablation alone in the treatment of patients with medium-sized HCC’s (3-5cm in size).

Take away point Large-bore aspiration mechanical thrombectomy is safe with a high technical (100%) and clinical success (88%) rates.

Reference
Chu, Hee Ho et al. Chemoembolization Combined with Radiofrequency ablation for Medium-Sized Hepatocellular Carcinoma: A Propensity-Score Analysis. Journal of Vascular and Interventional Radiology, Volume 30, Issue 10, 1533-43

Click here for abstract

Study design
Single-center, retrospective, cohort study of 538 patients treated between March 2000 – December 2016, with follow up until March 2018

Funding Source
None

Setting
Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.






Figure 2
Flow chart to determine treatment of a single medium-sized (3.1-5.0 cm) HCC. Patients included in this study were unsuitable for surgery or liver transplantation and had one the three treatments.

Summary

Definitive treatment of single medium-sized HCC, according to Barcelona Clinic Liver Cancer (BCLC), is surgical resection. However, this is not always feasible secondary to patient comorbidities and/or tumor location. Radiofrequency (RF) ablation is considered as curative in patients with small (<3cm) HCC’s. However, no such definitive literature exits for single lesions that fall in the medium-size range, between 3-5 cm. Multiple treatment modalities have been used to treat these medium sized lesions including a combination of TACE and RF ablation, TACE alone, and RF alone. The authors performed a retrospective analysis of these treatment types in patients with single medium sized HCC. Additionally they took their data and performed a propensity-score analysis with inverse probability weighting to reduce bias in treatment selection and other confounding variables.

All patients in this study has single medium sized HCC’s and were treated with one of the three therapies. The treatment pathways were chosen as the digression of the interventionist. TACE was performed with a combination of Lipiodol and Cisplatin (1:1 ratio) with a cisplatin dose of 2mg/kg body weight. Gel-foam slurry was infused after administration until arterial stasis was achieved. RF ablation was performed under ultrasound guidance within 2 weeks of chemoembolization (if performed). Of note there were statistically significant differences in the patient population with regards to Child-Pugh class, serum albumin level and tumor size. No major complications were reported as defined by SIR criteria.

The primary endpoint was overall survival (OS) from initial procedure to death. The secondary endpoint was recurrence free survival (RFS), which was determined from initial treatment to recurrence or death. Recurrence included local or distant recurrence and local was defined by a margin of 1 cm.

The mean follow up time for all patients was 59.6 months (SD – 46.9 mo; range: 2-208). Overall survival in combined, chemoembolization-only, and RF-only were 85 mo (95% CI: 51.2-118.8 mo), 56.5 mo (95% CI: 51.7-61.3 mo), and 52.1 mo (95% CI: 40.7-63.5 mo), respectively. Treatment was found to be a significant independent factor associated with OS (P=0.023). During follow up recurrent disease was found in 68.8% of combined group, 78% of the chemoembolization-only group, and 74.8% of the RF-only group. RFS in the combined, chemoembolization-only, and RF-only were 26.5 mo (95% CI: 22-31 mo), 14.1 mo (95% CI: 10.9-17.3 mo), and 14.1 mo (95% CI 9.7-18.5 mo), respectively.

Inverse probability weighting was performed to balance baseline characteristics. The differences in OS remained statistically significant with a P value of 0.022 (Fig 4a). Additionally the differences in RFS values were statistically significant with a P value of 0.002 (Fig 4b).

Commentary

The authors performed a similar study to multiple previous authors, with a much larger patient sample. The findings of this study fit and reinforce all of the current data in treating “unresectable” medium-sized HCC’s. However, the retrospective nature of the study and single center analysis limits its broad applications. Taking this into consideration we now have a larger pool of retrospective data to help reinforce the current trend in treating medium-sized HCC’s. This study provides evidence for future prospective studies to look at this question and help solidify an evolving treatment paradigm.

Post author
Hasnain Hasham, MD
Interventional Radiology Fellow
Dotter Interventional Institute
Oregon Health and Science University, Portland, OR
@irhasham

Friday, October 18, 2019

Midterm outcomes of endovascular repair for Stanford type B aortic dissection with aberrant right subclavian artery


Clinical question

Is complete endovascular repair durable for Type B aortic dissections with aberrant right subclavian artery?

Take away point
Complete endovascular therapy for Type B aortic dissection with aberrant right subclavian artery is a feasible, durable option with positive early- and mid-term outcomes.

Reference
Midterm outcomes of endovascular repair for Stanford type B aortic dissection with aberrant right subclavian artery. Zhang et al. JVIR. 2019;30:1378-1385.

Click here for abstract

Study design
Single institution, single arm retrospective cohort study of 15 patients. 

Funding source
China Medical Board Distinguished Professorship Award and the National Natural Science Foundations of China

Setting
Second Xiangya Hospital, Central South University, Hunan, People’s Republic of China 


Summary 


A treatment algorithm for patients with Stanford Type B aortic dissection with the aberrant right subclavian artery (ARSA) was created based on the distance between the entry tear to the ARSA. If the distance was >15 mm (Type 1), TEVAR would be performed without any technical modifications owing to a favorable proximal landing zone. If the distance was <15 mm but >15 mm existed between the tear and the left subclavian artery (Type 2), the artery supplying the dominant vertebral artery was preserved while the contralateral artery was sacrificed. If <15 mm existed between the tear and left subclavian artery (Type 3), the artery supplying the dominant vertebral artery was preserved while the contralateral artery was sacrificed. In patients with codominant vertebral arteries, the ARSA was preserved in Type 2 patients while both subclavian arteries were preserved in Type 3 patients.

Technical modifications to TEVAR included fenestration for patients with an entry tear on the inner curve of the aorta, chimney (stent-graft preservation dependent on antegrade flow) for preservation of the left subclavian artery from left brachial approach, and periscope/snorkel (stent-graft preservation dependent on retrograde flow) for preservation of the ARSA from femoral approach.

Stent-grafts were oversized to account for concomitant diverticulum of Kommerell to cover the diverticulum without additional embolization of the diverticulum.

Follow-up included clinic visit and CTA at 2 weeks, 3 months, 6 months, and 12 months post-procedure. Mean follow-up was 33 +/- 20 months. There was 100% technical success. No mortalities were noted. No neurologic sequelae were noted. All stent-grafts remained patent with shrinking of the false lumen at 2 weeks.


Commentary


Although this paper is a small series from a single institution, the authors included a relatively high number of patients considering the rarity of this anatomy, which had previously only been described in case reports. Notably, the outcome for this cohort was remarkable with no delayed endoleaks and no clinically significant adverse events. Even with 13 patients undergoing chimney modification for preservation of the left subclavian artery, no delayed Type 1A endoleaks were identified. Whether this can be attributed to the wide variation in the duration of follow-up should be further investigated, since three patients with dominant left vertebral artery had less than 8 months of follow-up.

In the short- and mid-term outcomes of completely endovascular repair appear superior compared to outcomes of hybrid approach, with rates of brachial plexus injury of 12.5% and Type 1A endoleak of 18.8%. This study shows promise for completely endovascular repair although longer-term follow up is needed.

This paper also expands on previously published treatment algorithms for endovascular repair of aortic anatomy in a technically challenging population.


Post Authors 
Eric King, MD
Vascular & Interventional Radiology Fellow
Rush University Medical Center
Chicago, Illinois
@ercking

Sreekumar Madassery, MD
Assistant Professor, Vascular & Interventional Radiology
Director, Advanced Vascular & Interventional Radiology Fellowship
Rush University Medical Center
Rush Oak Park Hospital
Chicago, Illinois
@kmadass, vir_rush

Friday, October 11, 2019

Distal Radial Artery Access for Noncoronary Endovascular Treatment Is a Safe and Feasible Technique


Clinical question
Is distal radial artery (DRA) access for noncoronary interventional radiology procedures feasible and safe?

Take away point
DRA access is a feasible and safe technique for abdominal interventional radiology embolization procedures. No radial artery occlusion or other major complications were observed in patients who underwent follow-up ultrasound.

Reference
van Dam, Lievay et al. Distal Radial Artery Access for Noncoronary Endovascular Treatment Is a Safe and Feasible Technique. Journal of Vascular and Interventional Radiology, Volume 30, Issue 8, 1281 - 1285

Click here for abstract

Study design
Retrospective review of 82 punctures in 56 patients.

Funding Source
No reported funding

Setting
Department of Radiology, Erasmus Medical Center, Rotterdam, The Netherlands






Figure 1. 
Optimal location of distal radial artery access at the deep palmar arch superficial to the scaphoid and trapezium.


Summary
Distal radial artery access has shown to be a safe technique for interventional radiology embolization procedures. The authors performed a retrospective review of 82 DRA procedures in 56 patients. Procedural details and complications were reviewed during the admission and at follow up.

The Barbeau test was used to evaluate radioulnar collateral circulation before the procedure. The preferred puncture site was at the DRA at the anatomical snuffbox (radial fossa). A mixture of 300 μg nitroglycerin and lidocaine 2% was given for analgesia and vasodilation, access was gained with ultrasound guidance using a 21-gauge needle and radial artery sheath, and an anti-spasmolytic mixture of 200 μg nitroglycerin, 2.5 mg verapamil, and 5000 IE heparin was administered. Patent hemostasis was achieved using a Safeguard Radial Compression Device.

Procedures included transarterial chemoembolization, Y-90 pretreatment work up, Y-90 treatment, and hepatic, renal, and splenic artery embolization. The mean number of DRA accesses per patient was 1.46. There was a 97.6% technical success rate. There were 8 minor complications, including 3 hematomas and 1 case of pain without hematoma. All minor complications resolved without treatment. Follow up ultrasound was available after 54 procedures at a mean time of 55 days. Only 1 complication at the DRA was seen on ultrasound. There was 1 case of a non-flow limiting focal dissection, which had resolved on follow up procedure 38 days later.

Commentary
The authors retrospectively reviewed 82 distal radial artery procedures. The results were promising and showed a 97.6% technical success rate without any major complications or cases of radial artery occlusion. Follow up ultrasound imaging provides further reassurance of the safety of DRA access. Access at the distal radial artery, distal to the superficial palmar arch shows theoretical benefit without increased complication. While the data is encouraging, larger patient populations and long term follow up would be helpful to further understand the safety and benefits.

Post Author
Maxwell R. Cretcher, DO
Resident Physician, Integrated Interventional Radiology
Dotter Department of Interventional Radiology
Oregon Health & Science University

Monday, October 7, 2019

Identification of Parameters Influencing the Vascular Structure Displacement in Fusion Imaging during Endovascular Aneurysm Repair


Clinical question
Can we safely perform a zero-contrast procedure relying solely on fusion imaging? What contributes to renal ostia displacement by the insertion of a stiff system during endovascular aneurysm repair (EVAR) of abdominal aortic aneurysm (AAA)?

Take away point
Sharper angulation between aneurysm neck and sac results in decreased fusion imaging accuracy and precludes EVAR deployment without contrast validation.

Reference
Identification of Parameters Influencing the Vascular Structure Displacement in Fusion Imaging during Endovascular Aneurysm Repair. Lalys F. et al. Journal of Vascular and Interventional Radiology (JVIR), Volume 30, Issue 9, 1386-1392.

Click here for abstract

Study design
Single arm, prospective, cohort study of 50 patients undergoing EVAR.

Funding Source
No reported funding

Setting
Academic hospital, University Rennes, France.





Figure 1
EndoNaut station main screen visualization during an EVAR procedure, with the fusion overlaid on the fluoroscopic image on the left and the corresponding 3D visualization on the right.

Summary

Fusion imaging technology has been shown to decrease contrast usage and radiation dose in both standard and complex endovascular aneurysm repair (EVAR) of abdominal aorta aneurysm (AAA). However, its relevance is limited by deformation of vascular structures after insertion of stiff devices during the procedure. The authors performed a prospective study of 50 patients undergoing EVAR to quantify the displacement of the lowest renal artery ostium and to identify the contributing anatomical parameters.

Patients included in this study were adults undergoing EVAR, who were not open-repair candidates, had AAA diameter greater than 50 mm, or had AAA growth rate greater than 10 mm per year. Patients were excluded if a fenestrated or branched endograft was used, or if the repair was performed for ruptured AAA.

EndoNaut station was used for fusion workflow. Digital subtraction angiogram performed intra-procedurally after insertion of stiff devices but prior to EVAR deployment was compared with the fusion roadmap generated pre-operatively using CT angiography. A large number of anatomical parameters were measured, including tortuosity index, length, diameter, angulation, calcification, thrombus, and distance to spine of the relevant vascular segments. Sharpest angulation, as defined by Van Keulen et al, was also calculated.

Mean displacement of the lowest renal artery ostium was 4.1 ± 2.4 mm (range, 0–11.7 mm), with a left/right displacement of 1.6 ± 1.7 mm (range, 0–6.9 mm) and a craniocaudal displacement of 3.5 ± 2.4 mm (range, 0–11.3 mm). Sharpest angulation between the aneurysmal neck and sac contributed significantly to the accuracy of fusion imaging (p = 0.00001).


Commentary

The authors in this study quantified the degree of renal artery ostia displacement after insertion of stiff devices during EVAR. They further identified the sharpest angulation between the aneurysmal neck and sac as a significant contributor in fusion imaging accuracy. The findings support the need for better fusion imaging technology with semi-automatic intra-procedural adjustments, especially in EVAR cases with significant angulation between the aneurysmal neck and sac. The paper also underlines the importance of small-amount contrast injection prior to EVAR deployment for confirmation of major vascular ostia. Future fusion imaging technology with more adaptive intra-procedural capability, potentially with the assistance of artificial intelligence, should be validated in a similar manner with prospective design and anatomical analysis before we proceed to attempt a zero-contrast EVAR deployment.

Post Author
Ningcheng (Peter) Li, MD, MS
Integrated Interventional Radiology Resident, PGY-3
Department of Interventional Radiology
Oregon Health and Science University, Dotter Interventional Institute
@NingchengLi

Friday, October 4, 2019

Safety and Efficacy of Acute Pulmonary Embolism Treated via Large-Bore Aspiration Mechanical Thrombectomy Using the Inari FlowTriever Device



Clinical question
Is it safe and effective to use the Inari FlowTriever Device in treating acute pulmonary embolism?

Take away point
Large-bore aspiration mechanical thrombectomy is safe with a high technical (100%) and clinical success (88%) rates.

Reference
Wible, Grant C. et al. Safety and Efficacy of Acute Pulmonary Embolism Treated via Large-Bore Aspiration Mechanical Thrombectomy Using the Inari FlowTriever Device. Journal of Vascular and Interventional Radiology, Volume 30, Issue 9, 1370-75

Click here for abstract

Study design
Single center, retrospective, cohort study of 46 patients between March 2018 – March 2019

Funding
One of the authors is a paid consultant for Inari and another receives research support from Inari.

Setting
St. Luke’s Hospital and University of Missouri – Kanas City school of medicine, Kansas City, MO, USA.







Figure 2
CT angiogram of a 68-year-old female with saddle pulmonary embolism (a). Right and left pulmonary angiogram demonstrating large filling defects corresponding to patients know PE (b,c). Post aspiration mechanical thrombectomy angiogram demonstrating significant improvement in pulmonary artery flow (d,e). Back table photographs of aspirated clot using the large-bore Inari device (f).


Summary


The authors performed a retrospective analysis of the Inari FlowTriever device at their institution when treating massive and intermediate-high risk sub-massive pulmonary embolism. They evaluated the technical success and clinical success of the device in the first year of use at their institution. Technical success involved appropriate device positioning and clinical success was defined by angiographic removal of central clot and change in pulmonary artery pressures before and after clot retrieval. Adverse outcomes were defined by the SIR guidelines of endovascular treatment of PE.

Patients included in this study were referred to IR for massive or intermediate-high risk sub-massive PE. No patients were excluded in the timeframe observed and 2 procedure-related adverse outcomes were reported.

All patients had aspiration mechanical thrombectomy with the Inari FlowTriever device with a 100% technical success rate. Pre and post-aspiration mechanical thrombectomy pressures were obtained, except in 4 cases, where the authors experienced failure of the pressure transducer. A 22F sheath was advanced into the suprarenal IVC via the common femoral vein and the 20F Inari aspiration guide catheter (AGC) was advanced over an 0.035 Amplatz wire into the main or lobar pulmonary artery. Aspiration thrombectomy was performed with the assistance of the self-expanding Nitinol discs to facilitate mechanical clot engagement prior to aspiration. This process was repeated several times in multiple pulmonary arteries until angiographic resolution of central clot was achieved.

There were 2 major procedure-related complications. One with intra-procedural hemoptysis requiring in intubation and another with a hematocrit drop of 15%. Both patients recovered and were discharged from the hospital. 2 patients died in the 30 day post-operative period, which the authors attributed to events prior to the procedure – metastatic pancreatic cancer and severe anoxic brain injury.

There was 100% technical success as defined by the authors. Aspiration related intra-procedure blood loss averaged 280ml with a maximum of 520ml resulting in an average hematocrit drop of 4.6% +/- 2.8% per case. Intra-procedural PA pressure decrease was achieved in 37 patients (88%). Average mean PA pressure improved from 33.9 +/- 8.9 mm Hg before to 27.0 +/- 9 mm Hg after, with a decrease of 6.9 mm Hg (P < 0.0001 and CI 5.0-8.8). All patients survived to hospital discharge.

Commentary


The authors evaluated the safety and efficacy of the Inari FlowTriever device at their institution over a one-year period. The findings of this study demonstrate the Inari device can be a treatment alternative in patients who are unable to receive systemic or local TPA in the setting of trauma, recent major surgery or other contraindication. This study only looked at a single centers experience with the device, which is useful in evaluating its success in the other interventional radiology departments. Establishing safety is a promising first step in assessing a new treatment paradigm, though comparison with systemic and local lytic and aspiration treatments is still needed.

Post Author
Hasnain Hasham, MD
Interventional Radiology Fellow
Dotter Interventional Institute
Oregon Health and Science University, Portland, OR
@irhashamz

Monday, September 30, 2019

Comparison of Imaging Changes and Pain Responses in Patients with Intra- or Extraosseous Bone Metastases Treated Palliatively with Magnetic Resonance- Guided High-Intensity–Focused Ultrasound


Clinical question
Does pain response differ in patients with intraosseous versus extraosseous bone metastases after ablation with MR guided High-Intensity-Focused Ultrasound (HIFU)? Can follow up MR predict treatment response?

Take away point
Patients with intraosseous tumors had significant improvement in pain from baseline after ablation with MR guided HIFU while to those with extraosseous tumors did not. Follow up with MR after ablation with HIFU does not predict efficacy of treatment.

Reference
Giles SL, Brown MRD, Rivens I, et al. Comparison of Imaging Changes and Pain Responses in Patients with Intra- or Extraosseous Bone Metastases Treated Palliatively with Magnetic Resonance-Guided High-Intensity-Focused Ultrasound. J Vasc Interv Radiol JVIR. 2019;30(9):1351-1360.e1. doi:10.1016/j.jvir.2019.02.019

Click here for abstract

Study design
Single arm, prospective study of 21 patients with dominant, painful bone metastasis (9 with intraosseous disease and 12 with extraosseous cortical breach) treated with MR guided HIFU.

Funding Source
Sponsor: Institute of Cancer Research, United Kingdom
Collaborators: Phillips Medical Systems, Cancer Research UK

Setting
Multicenter Study







Figure 4
Several scoring systems were utilized by the authors to evaluate post-procedure pain reduction. In this figure, the results of case report forms (CRFs) are shown for treated tumor for (a) 9 patients in the intraosseous group and (b) 12 patients in the extraosseous group. At days 30, 60, and 90 after treatment, scores were significantly lower than those in pretreatment (Pre Tx) for the intraosseous group but not for the extraosseous group.

Summary

High intensity focused ultrasound (HIFU) has shown promising results for palliative treatment of pain from bone metastases potentially related to thermal denervation of periosteum. The authors performed a prospective study of 21 patients with either interosseous or extraosseous painful bone metastasis who were then treated with MR guided HIFU. Gadolinium enhanced T1W images were obtained at the completion of treatment and at 30, 60 and 90 day follow up. Patient pain was assessed using various scoring systems at the time of the procedure and at follow up in addition to recorded analgesic use, which was compared before and after ablation. Patients were categorized as responders and non-responders in regard to post procedure alleviation of pain.

A difference from baseline pain was only statistically significant for patients with interosseous tumor on follow up. While 67% of patients with interosseous tumors were classified as responders at 30 days, only 33% of patients in the extraosseous group responded.

While imaging results of the ablated tumor showed nonenhancement in the majority of interosseous tumors, post procedure enhancement patterns of ablated extraosseous tumors varied. There was no difference in follow up imaging enhancement characteristics for patients who were classified as responders or non-responders.

Commentary

The authors in this study evaluated 21 patients with painful bone metastasis after treatment with MR guided High Intensity Focused Ultrasound. While the findings are encouraging for patients with intraosseous disease where the bone cortex remains undisrupted with significant improvement in pain for 67% of their patients at 30 days, results for extraosseous extension of disease were less promising. The authors alluded to the fact that patients with extraosseous disease may have more advanced disease at the time of treatment and more studies evaluating ablative thermal dose per tumor volume in these patients are required. While follow up MR may be beneficial for monitoring disease progression, preliminary results from this study showed that MR could not predict efficacy of treatment. As noted by the authors, in the future, this finding may point to fewer burdensome MRs obtained after ablation.

Post Author
Teodora Bochnakova MD
Assistant Professor
Department of Interventional Radiology
Oregon Health and Science University, Portland, OR
@T_bochnakova

Friday, September 27, 2019


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


Clinical question
How safe and efficacious is ethanol and coil embolization of type II arteriovenous malformations (AVM) using a new subtype classification?

Take-away point
Embolization of type II AVMs using ethanol and coils within the framework of the new subtype classification described is safe and efficacious. Additionally, there is a higher cure rate for type IIa AVMs compared to type IIc AVMs.

Reference
Ko, Seong Eun et al. Subclassification and Treatment Results of Ethanol Embolotherapy of Type II Arteriovenous Malformations of the Extremity and Body. Journal of Vascular and Interventional Radiology, Volume 30, Issue 9, 1443 - 1451

Click here for abstract

Study design
Retrospective review

Funding source
Self-funded or unfunded

Setting

Single institution 
 




 

Summary 

Recognizing that the treatment strategy of type II AVMs differs according to variations in the draining veins, the authors of this retrospective review propose a new subtype classification of type II AVMs according to the morphology of the draining vein.    

A total of 316 patients with congenital body and extremity AVMs were included in the study. After performing arteriography to define morphology and flow dynamics, AVMs were treated with a combination of coils and ethanol. Coils were utilized to reduce the flow velocity within the venous segment, followed by ethanol to obliterate the residual fistulae. For type IIa AVMs (shunts between multiple arterioles and a focal segment of the draining vein) the venous segment was accessed via direct puncture or transvenous cannulation followed by embolization with coils. Once slow flow was seen within the AVM post coil embolization, high-concentration ethanol was injected through a transarterial microcatheter or through the percutaneous needle or transvenous catheter to complete embolization. For type IIb AVMs (multiple shunts between multiple arterioles and a venous sac), the venous sac was punctured, embolized with coils, and ethanol then injected through the needle or transarterial microcatheter. For type IIc AVMs (shunts between multiple arterioles and a long segment of draining vein), direct puncture or transvenous cannulation was performed for coil embolization with ethanol injection performed between deployment of multiple coils. The median clinical follow-up period was 12 months among 75 patients. 

The overall treatment outcomes of ethanol embolotherapy with or without coils were cure in 70 lesions (83%), marked improvement in 6 lesions (7%), improvement in 5 lesions (6%), no change in 1 lesion, and treatment failure or aggravation in 2 lesions (2%). Among AVM subtypes, the cure rate was highest in type IIa AVMs (37 of 39; 95%), followed by types IIb (19 of 25; 76%) and IIc (13 of 20; 65%). There were 19 (10%) minor and 6 (3%) major complications (total of 189 treatment sessions). The complication rate was not significantly different among the subtypes of type II AVMs (P >.05). Major complications included compartment syndrome, acute pancreatitis, arm amputation due to infection, massive hematuria, and lymphedema. There was no mortality related to embolotherapy.


Commentary
Various sclerotic agents and methods for embolization of type II body and limb AVMs have been described in the literature. The authors have demonstrated that ethanol, which may be the preferred embolic agent for such AVMs due its strong devascularization effect, can be used with similar efficacy and less risk of complication compared to methods already described by reducing shunt volume by means of coil embolization of the draining vein and allowing for use of a smaller volume of ethanol. Therefore, understanding the drainage pattern of these AVMs is important and the alternative subtype classification described here for body and limb AVMs will provide an additional framework for how we think about-and approach-these complex vascular lesions.

Post Author
Zagum Bhatti, MD
Assistant Professor
Department of Radiology, Interventional Radiology Division
University of Texas Health Science Center at Houston, Houston, TX
@ZagumBhatti