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Nonsurgical treatment of scalp arteriovenous malformation using a combination of ultrasound-guided thrombin injection and transarterial coil embolization
Nonsurgical treatment of scalp arteriovenous malformation using a combination of ultrasound-guided thrombin injection and transarterial coil embolization Isao Nishijima, MD, Ryo Ikemura, MD, Masuichi Gushiken, MD, Kazufumi Miyagi, MD, and Kiyoshi Iha, MD, Okinawa, Japan Scalp arteriovenous malformations are treated by surgical excision in many patients. We report a patient with a scalp arteriovenous malformation who was successfully treated by a combination of ultrasound-guided thrombin injection (UGTI) and transarterial coil embolization. This patient was a 52-year-old man with a subcutaneous mass in the left retroauricular region. An angiogram showed that the mass was a nidus of arteriovenous malformation. We performed UGTI after transarterial coil embolization. No recurrence or complication was reported during 2 years of follow-up. This report describes the advantages of UGTI and the method for complete occlusion of the collateral artery. ( J Vasc Surg 2012;55:833-6.)
Soft tissue arteriovenous fistulas occur most commonly in the scalp. Although only 14% of the body surface area is in the head, 50% of integument arteriovenous fistulas occur in this region.1 Patients often complain of pain, tinnitus, an increase in the size of the arteriovenous malformation (AVM) mass, hemorrhage, and sometimes, necrosis of the scalp skin.2-4 Surgical excision is commonly performed for the treatment of scalp AVM.2,3,5 However, the excision is often associated with excessive blood loss, and sometimes, with the need for skin reconstruction. In many cases, recurrence is observed owing to recruitment of collateral supply.2 Preoperative embolization of a scalp AVM facilitates surgical excision by reducing blood loss.6,7 Barnwell et al8 reported patients with scalp AVM who received a combined treatment of injection of a sclerosing material and coil embolization. Here, we report a patient with a scalp AVM who was successfully treated by a combination of transarterial coil embolization and percutaneous thrombin injection for occlusion of the collateral artery. CASE REPORT A 52-year-old man with a 2-year history of a subcutaneous mass in the left postauricular region never visited a hospital because the only clinical symptom caused by the mass was tinnitus, which did not bother him. The patient accidently scratched the mass From the Department of Cardiovascular Surgery, Chubu Tokushukai Hospital. Competition of interest: none. Reprint requests: Isao Nishijima, MD, Department of Cardiovascular Surgery, Chubu Tokushukai Hospital, 3-20-1, Teruya, Okinawa City, Okinawa, Japan (e-mail: [email protected]). 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. 0741-5214/$36.00 Copyright © 2012 by the Society for Vascular Surgery. doi:10.1016/j.jvs.2011.08.013
while washing his head, and it immediately started to bleed. He was transported to our hospital by ambulance because the pulsating bleeding from the mass did not stop. His hemoglobin level on arrival was 15.0 g/dL, which dropped to 11.8 g/dL on the following day. We successfully stopped the bleeding by local compression with calcium alginate dressing and a bandage around the head. Multidetector-row computed tomography scan revealed a 3-cm mass composed of several inflow and outflow vessels at the postauricular region (Fig 1). A left external carotid angiogram revealed that the mass received blood from the occipital artery, posterior auricular artery, and superficial temporal artery. Hypertrophied venous drainage that was rapid filling and emptied only into the external carotid vein was via a collateral circulation. This was a fast-flow lesion composed of a nidus of feeding arteries and dilated veins. Therefore, the patient was diagnosed as having an AVM according to the International Society for the Study of Vascular Anomalies (ISSVA) classification. The subcutaneous mass, which caused the bleeding, was a nidus of the AVM. The internal carotid artery and vertebral artery were normal. First, we performed transarterial platinum coil embolization of the occipital, posterior auricular, and superficial temporal arteries in the catheterization laboratory. Then, we attempted to thrombose the nidus to block the blood supply from the collateral artery. Ultrasound-guided thrombin injection (UGTI) was performed (Fig 2). Thrombin (1000 U/mL) was slowly and continuously injected under the guidance of color and pulsed Doppler ultrasound imaging until the flow in the AVM disappeared completely (Fig 3). The procedure required 2500 units of thrombin. The patient was discharged on postoperative day 3. The AVM reduced and finally disappeared after the operation. No recurrence or complication was reported after 2 years of follow-up.
DISCUSSION Scalp AVM is generally treated by surgical excision.2,3,5 The risk of recurrence with preoperative embolization is 833
834 Nishijima et al
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Fig 1. A, Bleeding of the arteriovenous malformation was successfully stopped by local compression. B, The multidetector-row computed tomography volume-rendered image shows the nidus of the arteriovenous malformation located in the left retroauricular region.
Fig 2. Ultrasound-guided thrombin injection. A, Blood flow to the nidus was restricted. B, Thrombin was slowly and continuously injected under ultrasound guidance. C, Thrombus formation was observed in the nidus after thrombin injection.
high because of the recruitment of collateral supply.2 However, preoperative embolization of scalp AVM is useful to reduce blood loss during surgical excision.6,7 Surgical excision is often associated with large skin incisions, skin reconstruction is occasionally necessary, and it may cause facial nerve injury.2 Therefore, we chose nonsurgical treatment. Barnwell et al8 reported endovascular treatment of scalp AVM.8 This treatment involves coil embolization of the main vessel, followed by injection of embolic agents, including polyvinyl alcohol particles and liquid adhesives such as isobutyl-2-cyanoacrylate and N-butyl-2-cyanoacrylate (NBCA). Barnwell et al8 successfully treated seven patients with AVM by using liquid embolic agents to occlude the collateral supply.
We used UGTI in our patient to occlude the flow from the collateral artery. Cope first reported UGTI in 1986.9 He reported four instances of UGTI for pseudoaneurysms, including common iliac pseudoaneurysm, pseudoaneurysm rupture after femoropopliteal bypass grafting, posttraumatic fibular artery pseudoaneurysm, and hepatic pseudoaneurysm after percutaneous transhepatic cholangiodrainage. Taking into account the general status of all the patients in their report, surgical repair was considered highly invasive. After Liau et al10 reported UGTI for iatrogenic pseudoaneurysm of the femoral artery, many subsequent studies reported the same. According to Sheiman and Brophy,11 54 patients underwent UGTI for iatrogenic pseudoaneurysm of the femoral artery in 2001, with an initial success rate of 92.6% and a complication rate of 0%. Krueger et al12
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NBCA may cause neurologic deficits and bleeding complications in intracranial AVMs.18 Skin necrosis was reported in the craniofacial region after injection of NBCA.19 We consider that thrombin is safer than NBCA for inducing thrombosis because if leakage into the systemic circulation occurs, antithrombin III is a thrombinneutralizing factor that can abolish the clotting effect of thrombin.20 We prevented extension of the clot by stopping the thrombin injection when the ultrasound imaging showed the flow in the AVM disappeared. As with NBCA, using thrombin as an embolic agent may be followed by recurrence of the AVM. Some ablative agents are used for treatment of AVM. The most commonly used agents are hypertonic saline, sodium tetradecyl, and ethanol, which are used to ablate abnormal endothelial and smooth muscle cell. But these ablative agents, especially ethanol, carry complications of pain, skin necrosis, and nerve injury. CONCLUSIONS
Fig 3. Left external carotid angiogram shows that after the ultrasound-guided thrombin injection, blood flow in the arteriovenous malformation was completely occluded.
assessed the outcomes of 240 patients who underwent UGTI for iatrogenic pseudoaneurysm of the femoral and brachial arteries and showed that the initial success rate was 93.8%, the secondary success rate was 99.6%, and the complication rate was 0.8%. Complications in their report included one patient with reduced dorsalis pedis artery flow and one patient with allergic fever. Dorsalis pedis artery flow was restored the next day, and the allergic fever also disappeared promptly. No severe complications, such as arterial thrombosis, were noted. Saad et al13 overviewed treatment for pseudoaneurysms and recommended percutaneous coil embolization and injection of thrombin or glue when surgical intervention seems difficult for some reason.13 Many successful UGTI cases have been reported.14-17 Therefore, we thought thrombin might be used for embolic agents as well as NBCA or ethylene-vinyl alcohol copolymer (Onyx; ev3 Neurovascular, Irvine, Calif). Because thrombin requires few seconds to induce thrombosis, thrombin injection therapy is not efficient for occluding rapid blood flow in an aneurysm but can only restrict blood flow in a pseudoaneurysm. Thrombin alone is not sufficient to completely occlude a nidus of an AVM owing to the rapid blood flow in the nidus. In our patient, we first reduced the blood flow to the nidus by transarterial coil embolization of the main inflow vessels and then performed UGTI. Within the nidus, the thrombus induced by thrombin occluded the collateral artery. Therefore, the AVM disappeared completely. If the AVM is not easily accessible with percutaneous ultrasound guidance, transcatheter thrombin injection may be used.
Because it is not possible to completely avoid recurrence of AVM, no matter what method is chosen—including thrombin, ethanol, or surgical excision—what is the best way to treat AVM for patients? We conclude that a combination of UGTI and transarterial coil embolization is a minimally invasive treatment for scalp AVM that overcomes the need for surgical excision. REFERENCES 1. Watoson WL, McCarthy WD. Blood and lymph vessel tumors: a report of 1056 cases. Surg Gynecol Obstet 1940;71:569-98. 2. Malan E, Azzolini A. Congenital arteriovenous malformations of the face and scalp. J Cardiovasc Surg 1968;8:109-40. 3. Khodadad G. Arteriovenous malformations of the scalp. Ann Surg 1973;177:79-85. 4. Coleman CC, Hoopes JE. Congenital arteriovenous anomalies of the head and neck. Plast Reconstr Surg 1971;47:354-64. 5. Elkin DC, Harris MH. Arteriovenous aneurysm of the vertebral vessels: report of ten cases. Ann Surg 1946;124:934-51. 6. Balsys R, Cross R. Multiple aneurysm formation as a complication of interventive angiography. Radiology 1978;126:91-2. 7. Kasdon DL, Altemus LR, Stein BM. Embolization of a traumatic arteriovenous fistula of the scalp with radiopaque Gelfoam pledgets. Case report and technical note. J Neurosurg 1976;44:753-6. 8. Barnwell SL, Halbach VV, Dowd CF, Higashida RT, Hieshima GB. Endovascular treatment of scalp arteriovenous fistulas associated with a large varix. Radiology 1989;173:533-9. 9. Cope C, Zeit R. Coagulation of aneurysms by direct percutaneous thrombin injection. AJR Am J Roentgenol 1986;147:383-7. 10. Liau CS, Ho FM, Chen MF, Lee YT. Treatment of iatrogenic femoral artery pseudoaneurysm with percutaneous thrombin injection. J Vasc Surg 1997;26:18-23. 11. Sheiman RG, Brophy DP. Treatment of iatrogenic femoral pseudoaneurysms with percutaneous thrombin injection: experience in 54 patients. Radiology 2001;219:123-7. 12. Krueger K, Zaehringer M, Strohe D, Stuetzer H, Boecker J, Lackner K. Postcatheterization pseudoaneurysm: results of US-guided percutaneous thrombin injection in 240 patients. Radiology 2005;236:1104-10. 13. Saad NE, Saad WE, Davies MG, Waldman DL, Fultz PJ, Rubens DJ. Pseudoaneurysms and the role of minimally invasive techniques in their management. Radiographics 2005;25:S173-89. 14. Corso R, Carrafiello G, Intotero M, Solcia M. Large iatrogenic pseudoaneurysm of the posterior tibial artery treated with sonographically guided thrombin injection. AJR Am J Roentgenol 2003;180:1479-80.
836 Nishijima et al
15. Siu YP, Tong MKH, Leung KT, Kwan TH, Au TC, Cheung YK, et al. Renal artery pseudoaneurysm following renal transplantation and treatment by percutaneous thrombin injection. HK Med J 2006;12:80-1. 16. Elford J, Burrell C, Roobottom C. Ultrasound guided percutaneous thrombin injection for the treatment of iatrogenic pseudoaneurysms. Heart 1999;82:526-7. 17. Berg JC, Nolthenius RP, Casparie JW, Moll FL. CT-guided thrombin injection into aneurysm sac in a patient with endoleak after endovascular abdominal aortic aneurysm repair. AJR Am J Roentgenol 2000;175: 1649-51. 18. Lv X; Wu Z, Jiang C, Li Y, Yang X, Zhang Y, Zhang N. Complication risk of endovascular embolization for cerebral arteriovenous malforma-
JOURNAL OF VASCULAR SURGERY March 2012
tion. Eur J Radiol 2011 [Epub ahead of print] doi:10.1016/j. ejrad.2010.09.024. 19. Cil BE, Vargel I, Geyik S, Peynircioglu B, Cavusoglu T. Venous vascular malformations of the craniofacial region: pre-operative embolisation with direct percutaneous puncture and N-butyl cyanoacrylate. Br J Radiol 2008;81:935-9. 20. Krüger K, Zähringer M, Söhngen FD, Gossmann A, Schulte O, Feldmann C, et al. Femoral pseudoaneurysms: management with percutaneous thrombin injection–success rates and effects on systemic coagulation. Radiology 2003;226:452-8. Submitted Jul 4, 2011; accepted Aug 17, 2011.
Soft tissue arteriovenous fistulas occur most commonly in the scalp. Although only 14% of the body surface area is in the head, 50% of integument arteriovenous fistulas occur in this region.1 Patients often complain of pain, tinnitus, an increase in the size of the arteriovenous malformation (AVM) mass, hemorrhage, and sometimes, necrosis of the scalp skin.2-4 Surgical excision is commonly performed for the treatment of scalp AVM.2,3,5 However, the excision is often associated with excessive blood loss, and sometimes, with the need for skin reconstruction. In many cases, recurrence is observed owing to recruitment of collateral supply.2 Preoperative embolization of a scalp AVM facilitates surgical excision by reducing blood loss.6,7 Barnwell et al8 reported patients with scalp AVM who received a combined treatment of injection of a sclerosing material and coil embolization. Here, we report a patient with a scalp AVM who was successfully treated by a combination of transarterial coil embolization and percutaneous thrombin injection for occlusion of the collateral artery. CASE REPORT A 52-year-old man with a 2-year history of a subcutaneous mass in the left postauricular region never visited a hospital because the only clinical symptom caused by the mass was tinnitus, which did not bother him. The patient accidently scratched the mass From the Department of Cardiovascular Surgery, Chubu Tokushukai Hospital. Competition of interest: none. Reprint requests: Isao Nishijima, MD, Department of Cardiovascular Surgery, Chubu Tokushukai Hospital, 3-20-1, Teruya, Okinawa City, Okinawa, Japan (e-mail: [email protected]). 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. 0741-5214/$36.00 Copyright © 2012 by the Society for Vascular Surgery. doi:10.1016/j.jvs.2011.08.013
while washing his head, and it immediately started to bleed. He was transported to our hospital by ambulance because the pulsating bleeding from the mass did not stop. His hemoglobin level on arrival was 15.0 g/dL, which dropped to 11.8 g/dL on the following day. We successfully stopped the bleeding by local compression with calcium alginate dressing and a bandage around the head. Multidetector-row computed tomography scan revealed a 3-cm mass composed of several inflow and outflow vessels at the postauricular region (Fig 1). A left external carotid angiogram revealed that the mass received blood from the occipital artery, posterior auricular artery, and superficial temporal artery. Hypertrophied venous drainage that was rapid filling and emptied only into the external carotid vein was via a collateral circulation. This was a fast-flow lesion composed of a nidus of feeding arteries and dilated veins. Therefore, the patient was diagnosed as having an AVM according to the International Society for the Study of Vascular Anomalies (ISSVA) classification. The subcutaneous mass, which caused the bleeding, was a nidus of the AVM. The internal carotid artery and vertebral artery were normal. First, we performed transarterial platinum coil embolization of the occipital, posterior auricular, and superficial temporal arteries in the catheterization laboratory. Then, we attempted to thrombose the nidus to block the blood supply from the collateral artery. Ultrasound-guided thrombin injection (UGTI) was performed (Fig 2). Thrombin (1000 U/mL) was slowly and continuously injected under the guidance of color and pulsed Doppler ultrasound imaging until the flow in the AVM disappeared completely (Fig 3). The procedure required 2500 units of thrombin. The patient was discharged on postoperative day 3. The AVM reduced and finally disappeared after the operation. No recurrence or complication was reported after 2 years of follow-up.
DISCUSSION Scalp AVM is generally treated by surgical excision.2,3,5 The risk of recurrence with preoperative embolization is 833
834 Nishijima et al
JOURNAL OF VASCULAR SURGERY March 2012
Fig 1. A, Bleeding of the arteriovenous malformation was successfully stopped by local compression. B, The multidetector-row computed tomography volume-rendered image shows the nidus of the arteriovenous malformation located in the left retroauricular region.
Fig 2. Ultrasound-guided thrombin injection. A, Blood flow to the nidus was restricted. B, Thrombin was slowly and continuously injected under ultrasound guidance. C, Thrombus formation was observed in the nidus after thrombin injection.
high because of the recruitment of collateral supply.2 However, preoperative embolization of scalp AVM is useful to reduce blood loss during surgical excision.6,7 Surgical excision is often associated with large skin incisions, skin reconstruction is occasionally necessary, and it may cause facial nerve injury.2 Therefore, we chose nonsurgical treatment. Barnwell et al8 reported endovascular treatment of scalp AVM.8 This treatment involves coil embolization of the main vessel, followed by injection of embolic agents, including polyvinyl alcohol particles and liquid adhesives such as isobutyl-2-cyanoacrylate and N-butyl-2-cyanoacrylate (NBCA). Barnwell et al8 successfully treated seven patients with AVM by using liquid embolic agents to occlude the collateral supply.
We used UGTI in our patient to occlude the flow from the collateral artery. Cope first reported UGTI in 1986.9 He reported four instances of UGTI for pseudoaneurysms, including common iliac pseudoaneurysm, pseudoaneurysm rupture after femoropopliteal bypass grafting, posttraumatic fibular artery pseudoaneurysm, and hepatic pseudoaneurysm after percutaneous transhepatic cholangiodrainage. Taking into account the general status of all the patients in their report, surgical repair was considered highly invasive. After Liau et al10 reported UGTI for iatrogenic pseudoaneurysm of the femoral artery, many subsequent studies reported the same. According to Sheiman and Brophy,11 54 patients underwent UGTI for iatrogenic pseudoaneurysm of the femoral artery in 2001, with an initial success rate of 92.6% and a complication rate of 0%. Krueger et al12
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NBCA may cause neurologic deficits and bleeding complications in intracranial AVMs.18 Skin necrosis was reported in the craniofacial region after injection of NBCA.19 We consider that thrombin is safer than NBCA for inducing thrombosis because if leakage into the systemic circulation occurs, antithrombin III is a thrombinneutralizing factor that can abolish the clotting effect of thrombin.20 We prevented extension of the clot by stopping the thrombin injection when the ultrasound imaging showed the flow in the AVM disappeared. As with NBCA, using thrombin as an embolic agent may be followed by recurrence of the AVM. Some ablative agents are used for treatment of AVM. The most commonly used agents are hypertonic saline, sodium tetradecyl, and ethanol, which are used to ablate abnormal endothelial and smooth muscle cell. But these ablative agents, especially ethanol, carry complications of pain, skin necrosis, and nerve injury. CONCLUSIONS
Fig 3. Left external carotid angiogram shows that after the ultrasound-guided thrombin injection, blood flow in the arteriovenous malformation was completely occluded.
assessed the outcomes of 240 patients who underwent UGTI for iatrogenic pseudoaneurysm of the femoral and brachial arteries and showed that the initial success rate was 93.8%, the secondary success rate was 99.6%, and the complication rate was 0.8%. Complications in their report included one patient with reduced dorsalis pedis artery flow and one patient with allergic fever. Dorsalis pedis artery flow was restored the next day, and the allergic fever also disappeared promptly. No severe complications, such as arterial thrombosis, were noted. Saad et al13 overviewed treatment for pseudoaneurysms and recommended percutaneous coil embolization and injection of thrombin or glue when surgical intervention seems difficult for some reason.13 Many successful UGTI cases have been reported.14-17 Therefore, we thought thrombin might be used for embolic agents as well as NBCA or ethylene-vinyl alcohol copolymer (Onyx; ev3 Neurovascular, Irvine, Calif). Because thrombin requires few seconds to induce thrombosis, thrombin injection therapy is not efficient for occluding rapid blood flow in an aneurysm but can only restrict blood flow in a pseudoaneurysm. Thrombin alone is not sufficient to completely occlude a nidus of an AVM owing to the rapid blood flow in the nidus. In our patient, we first reduced the blood flow to the nidus by transarterial coil embolization of the main inflow vessels and then performed UGTI. Within the nidus, the thrombus induced by thrombin occluded the collateral artery. Therefore, the AVM disappeared completely. If the AVM is not easily accessible with percutaneous ultrasound guidance, transcatheter thrombin injection may be used.
Because it is not possible to completely avoid recurrence of AVM, no matter what method is chosen—including thrombin, ethanol, or surgical excision—what is the best way to treat AVM for patients? We conclude that a combination of UGTI and transarterial coil embolization is a minimally invasive treatment for scalp AVM that overcomes the need for surgical excision. REFERENCES 1. Watoson WL, McCarthy WD. Blood and lymph vessel tumors: a report of 1056 cases. Surg Gynecol Obstet 1940;71:569-98. 2. Malan E, Azzolini A. Congenital arteriovenous malformations of the face and scalp. J Cardiovasc Surg 1968;8:109-40. 3. Khodadad G. Arteriovenous malformations of the scalp. Ann Surg 1973;177:79-85. 4. Coleman CC, Hoopes JE. Congenital arteriovenous anomalies of the head and neck. Plast Reconstr Surg 1971;47:354-64. 5. Elkin DC, Harris MH. Arteriovenous aneurysm of the vertebral vessels: report of ten cases. Ann Surg 1946;124:934-51. 6. Balsys R, Cross R. Multiple aneurysm formation as a complication of interventive angiography. Radiology 1978;126:91-2. 7. Kasdon DL, Altemus LR, Stein BM. Embolization of a traumatic arteriovenous fistula of the scalp with radiopaque Gelfoam pledgets. Case report and technical note. J Neurosurg 1976;44:753-6. 8. Barnwell SL, Halbach VV, Dowd CF, Higashida RT, Hieshima GB. Endovascular treatment of scalp arteriovenous fistulas associated with a large varix. Radiology 1989;173:533-9. 9. Cope C, Zeit R. Coagulation of aneurysms by direct percutaneous thrombin injection. AJR Am J Roentgenol 1986;147:383-7. 10. Liau CS, Ho FM, Chen MF, Lee YT. Treatment of iatrogenic femoral artery pseudoaneurysm with percutaneous thrombin injection. J Vasc Surg 1997;26:18-23. 11. Sheiman RG, Brophy DP. Treatment of iatrogenic femoral pseudoaneurysms with percutaneous thrombin injection: experience in 54 patients. Radiology 2001;219:123-7. 12. Krueger K, Zaehringer M, Strohe D, Stuetzer H, Boecker J, Lackner K. Postcatheterization pseudoaneurysm: results of US-guided percutaneous thrombin injection in 240 patients. Radiology 2005;236:1104-10. 13. Saad NE, Saad WE, Davies MG, Waldman DL, Fultz PJ, Rubens DJ. Pseudoaneurysms and the role of minimally invasive techniques in their management. Radiographics 2005;25:S173-89. 14. Corso R, Carrafiello G, Intotero M, Solcia M. Large iatrogenic pseudoaneurysm of the posterior tibial artery treated with sonographically guided thrombin injection. AJR Am J Roentgenol 2003;180:1479-80.
836 Nishijima et al
15. Siu YP, Tong MKH, Leung KT, Kwan TH, Au TC, Cheung YK, et al. Renal artery pseudoaneurysm following renal transplantation and treatment by percutaneous thrombin injection. HK Med J 2006;12:80-1. 16. Elford J, Burrell C, Roobottom C. Ultrasound guided percutaneous thrombin injection for the treatment of iatrogenic pseudoaneurysms. Heart 1999;82:526-7. 17. Berg JC, Nolthenius RP, Casparie JW, Moll FL. CT-guided thrombin injection into aneurysm sac in a patient with endoleak after endovascular abdominal aortic aneurysm repair. AJR Am J Roentgenol 2000;175: 1649-51. 18. Lv X; Wu Z, Jiang C, Li Y, Yang X, Zhang Y, Zhang N. Complication risk of endovascular embolization for cerebral arteriovenous malforma-
JOURNAL OF VASCULAR SURGERY March 2012
tion. Eur J Radiol 2011 [Epub ahead of print] doi:10.1016/j. ejrad.2010.09.024. 19. Cil BE, Vargel I, Geyik S, Peynircioglu B, Cavusoglu T. Venous vascular malformations of the craniofacial region: pre-operative embolisation with direct percutaneous puncture and N-butyl cyanoacrylate. Br J Radiol 2008;81:935-9. 20. Krüger K, Zähringer M, Söhngen FD, Gossmann A, Schulte O, Feldmann C, et al. Femoral pseudoaneurysms: management with percutaneous thrombin injection–success rates and effects on systemic coagulation. Radiology 2003;226:452-8. Submitted Jul 4, 2011; accepted Aug 17, 2011.