Treatment of a pelvic arteriovenous malformation by stent graft placement combined with sclerotherapy
Article Outline
We present a 64-year-old woman with left leg swelling for 1 year. Computed tomography imaging showed a large pelvic arteriovenous malformation that consisted of multiple fine shunts between the left internal iliac artery and the long segment of the left external iliac vein. A stent graft was inserted within the left external iliac vein to occlude the arteriovenous shunts with consecutive transarterial sclerotherapy using absolute ethanol. This resulted in complete resolution of the pelvic arteriovenous malformation. To our knowledge, this is the first reported case of stent graft insertion within a large vein for treating arteriovenous malformation.
Embolization and sclerotherapy has been the primary mode of treatment for arteriovenous malformations (AVMs).1 Different approaches can be used for embolization and sclerotherapy, depending on the relation between the feeding artery, the complex network of arteriovenous shunts, and the draining vein. Traditionally, in cases of AVMs consisting of fine multiple shunts between arteries and a single draining vein, transvenous superselective catheterization and direct puncture of the nidus with a needle are recommended for embolization and sclerotherapy.1, 2, 3 We report the successful treatment of a pelvic AVM by stent graft placement within the single draining vein combined with transarterial sclerotherapy using absolute ethanol.
Case report
A 64-year-old woman presented with diffuse left leg swelling for 1 year and acute exacerbation for 1 week. She had no history of trauma or surgery. Her Eastern Cooperative Oncology Group Performance Status was grade 0.4 A duplex ultrasound scan to evaluate for venous thrombosis showed an abnormal arterial pulse at the left common iliac vein. This was suggestive of an arteriovenous fistula.
Computed tomography (CT) imaging showed left external iliac vein stenosis (Fig 1, A), multiple fine striations in the pelvic cavity with early enhancement of the left external iliac vein in the arterial phase (Fig 1, B), a compressed left common iliac vein by the left common iliac artery (Fig 1, C), and multifocal deep vein thrombosis along the left tibial and peroneal veins. Multiple collateral veins were noted along the lower anterior pelvic wall.
Fig 1.
Contrast-enhanced computed tomography scan showed (A) a compressed left external iliac vein (arrow), (B) multiple fine striations at the left pelvic cavity with abnormal arterial enhancement of the left external iliac vein (arrow) on arterial dominant phase, and (C) a compressed left common iliac vein (arrow) by the left common iliac artery. D, Aortography showed a vascular blush between the left internal iliac artery and left external iliac vein connected by fine multiple shunts. E, On late arterial phase, focal stenosis was noted at the proximal segment of left external iliac vein (arrow), with multiple pelvic collateral vessels. F, An oblique aortography showed a focal filling defect at the left common iliac vein (arrow), suggesting extrinsic compression by the left common iliac artery.
Aortography demonstrated vascular blush between the left internal iliac artery and the long segment of the left external iliac vein, connected with multiple fine shunts (Fig 1, D). Focal stenosis at the left external iliac vein (Fig 1, E) and compression of the left common iliac vein (Fig 1, F) were observed. This AVM, with focal stenosis of left external iliac vein, caused venous hypertension with resulting in left leg edema.
We inserted a 5F catheter through the right common femoral vein to avoid puncturing the hypertensive vein and performed left iliac venography (Fig 2, A). A 16- × 16- × 135-mm Excluder stent graft (W. L. Gore & Assoc, Flagstaff, Ariz) was deployed in the left external iliac vein and extending to the common iliac vein to occlude all of the fine shunts. An additional 14- × 60-mm (diameter × length) Smart Control stent (Cordis, Johnson & Johnson, Miami, Fla) was deployed at the left common iliac vein and extending to the proximal segment of left external iliac vein to treat the compression (Fig 2, B).
Fig 2.
A, B, A stent graft and stent were deployed within the left external iliac vein extended to the common iliac vein. C, Collapsed stent graft was noted after 1 week, and (D) an additional stent was deployed within the external iliac vein, overlapping the preexisting stent graft. E, An intra-arterial ethanol injection was performed using a microcatheter. A normal gluteal branch (arrow) was embolized using microcoils before the ethanol injection to avoid unwanted sclerotherapy.
Although the vascular blush was still present on follow-up angiography, the single drainage vein was no longer visualized. We therefore expected complete thrombosis of these multiple fine shunts within several days, with regression of left leg edema. At 1 week after the procedure, however, the patient's symptom was unchanged, and fluoroscopy confirmed a collapsed stent graft (Fig 2, C).
Aortography was repeated, and the vascular blush with the single draining vein (ie, pelvic AVM) was still opacified with the collapsed stent graft. An additional 14- × 80-mm (diameter × length) Luminexx stent (Bard, Tempe, Ariz) was deployed within the left external iliac vein, overlapping the collapsed stent-graft (Fig 2, D). Multiple fine shunts were superselected using a 2.4F Renegade microcatheter (Boston Scientific, Watertown, Mass). On left internal iliac angiography, coil embolization was performed at the proximal segment of the normal gluteal artery to avoid unwanted sclerotherapy through this branch (Fig 2, E).
We performed sclerotherapy of the shunts using 2.5 mL of 99% ethanol. We chose ethanol because of its effectiveness as a sclerosant and the unavailability of another sclerosant. Several test injections with contrast were performed under fluoroscopy, and the amount and injection rate of ethanol were based on the amount and injection rate of contrast required to fill the fine shunts of the AVM without opacifying normal vessels.3 Postprocedural aortography showed absence of AVM opacification. Left leg edema disappeared after 3 days, and the patient was discharged without complications.
Follow-up CT after 6 months showed the completely thrombosed AVM and no recurrence (Fig 3, A and B). Beginning 2 days before the initial procedure, systemic anticoagulation had been instituted with heparin and was switched to warfarin to treat the preexisting deep vein thrombosis and to maintain patency through the stent graft and stent within the left common and external iliac vein. Deep vein thrombosis along the left tibial and peroneal veins resolved on follow-up CTs.
Fig 3.
A follow-up computed tomography scan at 6 month showed no opacification of the pelvic arteriovenous malformation and a patent stent graft.
Discussion
Pelvic AVMs are rare vascular lesions and are notoriously difficult to diagnosis and treat, as well as being potentially life threatening because of the potential for spontaneous hemorrhage and congestive heart failure. Embolectomy and sclerotherapy is the primary mode of treatment for pelvic AVMs.1, 3, 5, 6
We performed stent graft insertion in the left external iliac vein to treat the AVM and stent insertion in the left common iliac vein to treat the compression. This patient had a very rare type of pelvic AVM, because there were multiple fistulas between the internal iliac artery and the long segment of the iliac vein. Direct puncture of the nidus was impossible, and intra-arterial sclerotherapy raised concern about unwanted thrombosis of the draining vein.
Total occlusion of the dominant outflow vein (left external iliac vein) of the AVM with coils can occlude the pelvic AVM, but it is not a good option for the treatment of the associated left leg swelling. We therefore selected a stent graft to occlude the multiple fine shunts between the feeding arteries and the single draining vein and to maintain good outflow of left leg. However, the stent graft did not have enough expansile force to occlude the AVM and prevent it from collapsing by the arterial flow from the multiple shunting. Additional stenting and intra-arterial sclerotherapy were required to relieve the collapsed stent graft and induce complete thrombosis of the pelvic AVM.
There could be some argument about the width discrepancy between the stent graft and the stents. In first procedure, we chose the nitinol stent to treat the compressed left common iliac vein for considering venous tortuosity. Unfortunately, the largest diameter of the nitinol stent was 14 mm. In the second procedure, we chose the nitinol stent rather than another stent with strong radial force, such as the Wallstent (Boston Scientific), for the collapsed stent graft. Although the nitinol stent has a weaker radial force than the Wallstent, the Wallstent has a weaker characteristic, unexpected shortening. We chose the Luminexx because it has the strongest radial force among the nitinol stents. Also, 14 mm is a largest diameter in the nitinol stents. We were aware of the size discrepancy between the stents and the stent graft, but we expected that the 2-mm discrepancy would not cause critical instability between the stent and stent graft. Moreover, for the favorable patency of the stents and stent graft, anticoagulation was applied beginning 2 days before the procedure.
We know of no previous reports in the literature on the patency of a stent graft within the vein. Consequently, concerning stent graft patency and the fixation problem between the vessel wall and the stent graft,7, 8 we selected a nitinol stent bonded to expanded polytetrafluoroethylene as the material for the external iliac vein stent graft.
Conclusion
We successfully performed embolization and sclerotherapy for a pelvic AVM using stent graft placement within a single draining vein and ethanol sclerotherapy through the fine arterial feeders. This technique may be effective to treat an AVM consisting of multiple fine shunting between arteries and long segment of a single draining vein. Long-term follow-up is required to assess recurrence of the AVM and evaluate the long-term patency of the stent graft within the large vein.
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Competition of interest: none.
The editors and reviewers of this article have no relevant financial relationships to disclose per the JVS policy that requires reviewers to decline review of any manuscript for which they may have a competition of interest.
PII: S0741-5214(09)02309-X
doi:10.1016/j.jvs.2009.11.036
© 2010 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.
