Re: Transcatheter N-butyl Cyanoacrylate Embolization of Pseudoaneurysms

Abstract

Our division read with great interest the article by Song et al (1Song H.H. Won Y.D. Kim Y.J. Transcatheter N-butyl cyanoacrylate embolization of pseudoaneurysms.J Vasc Interv Radiol. 2010; 21: 1508-1511Abstract Full Text Full Text PDF PubMed Scopus (32) Google Scholar) published in the October issue of JVIR, reporting the effectiveness of transcatheter embolization with n-butyl cyanoacrylate (NBCA) in selected patients with peripheral arterial pseudoaneurysms (PAs). We have several comments. First of all, we would like to congratulate the authors for their study, which represents the most important series to date reporting results on transarterial embolotherapy with NBCA glue as an embolic agent in such a setting. Recently, endovascular embolization has generated considerable interest as the first-line therapeutic method for PAs. The success rate is high, ranging from 62% to 100% in visceral PAs, and the morbidity and mortality rates are low (2Loffroy R. Guiu B. Cercueil J.P. et al.Transcatheter arterial embolization of splenic artery aneurysms and pseudoaneurysms: short- and long-term results.Ann Vasc Surg. 2008; 22: 618-626Abstract Full Text Full Text PDF PubMed Scopus (78) Google Scholar, 3Tokuda T. Tanigawa N. Shomura Y. et al.Transcatheter embolization for peripheral pseudoaneurysms with n-butyl cyanoacrylate.Minim Invasive Ther Allied Technol. 2009; 18: 361-365Crossref PubMed Scopus (21) Google Scholar). Most investigators agree that coils are the most appropriate embolic material (3Tokuda T. Tanigawa N. Shomura Y. et al.Transcatheter embolization for peripheral pseudoaneurysms with n-butyl cyanoacrylate.Minim Invasive Ther Allied Technol. 2009; 18: 361-365Crossref PubMed Scopus (21) Google Scholar). The study of Song et al (1Song H.H. Won Y.D. Kim Y.J. Transcatheter N-butyl cyanoacrylate embolization of pseudoaneurysms.J Vasc Interv Radiol. 2010; 21: 1508-1511Abstract Full Text Full Text PDF PubMed Scopus (32) Google Scholar) shows that embolization with NBCA as the sole embolic agent is a safe and effective technique for treatment of PAs at various locations. We absolutely agree with Song et al (1Song H.H. Won Y.D. Kim Y.J. Transcatheter N-butyl cyanoacrylate embolization of pseudoaneurysms.J Vasc Interv Radiol. 2010; 21: 1508-1511Abstract Full Text Full Text PDF PubMed Scopus (32) Google Scholar) about the efficacy and safety of glue embolization of the vessel supplying the PA. We find the use of NBCA particularly interesting, especially in patients in hemodynamically unstable condition with bleeding and in cases of underlying coagulopathy, because it provides faster and better hemostasis than other embolic agents. In our institution, selective embolization with NBCA as the only embolic agent has also become the salvage treatment of choice in many visceral and peripheral indications. However, we want to stress the fact that the use of NBCA requires training and considerable experience, given the risk of bowel infarction and glue reflux into other vessels. Reflux of NBCA may also result in its polymerization to the catheter tip. This bit of NBCA may then be stripped from the catheter during catheter retraction, resulting in nontarget embolization. The use of a proper technique, including prompt removal of the catheter after injection, as well as aspiration of the guide catheter after microcatheter removal, can significantly reduce this risk (2Loffroy R. Guiu B. Cercueil J.P. et al.Transcatheter arterial embolization of splenic artery aneurysms and pseudoaneurysms: short- and long-term results.Ann Vasc Surg. 2008; 22: 618-626Abstract Full Text Full Text PDF PubMed Scopus (78) Google Scholar). This technical note is very important and is not specified by Song et al (1Song H.H. Won Y.D. Kim Y.J. Transcatheter N-butyl cyanoacrylate embolization of pseudoaneurysms.J Vasc Interv Radiol. 2010; 21: 1508-1511Abstract Full Text Full Text PDF PubMed Scopus (32) Google Scholar). In addition, the major drawback of the use of NBCA is the compromised patency of the parent vessel. Consequently, NBCA cannot be used for proximal PAs arising from major peripheral or visceral arterial branches because of the risk of ischemic complications and end-organ damage. Moreover, this might explain the difficulties that the authors came across in one of their patients treated at the level of the main hepatic artery (1Song H.H. Won Y.D. Kim Y.J. Transcatheter N-butyl cyanoacrylate embolization of pseudoaneurysms.J Vasc Interv Radiol. 2010; 21: 1508-1511Abstract Full Text Full Text PDF PubMed Scopus (32) Google Scholar). Indeed, even though PAs in their study were mainly located at a distal level, visceral PAs can often be located proximally, especially PAs that are caused by pancreatitis or surgery, and we would like to highlight the fact that glue embolization should not be attempted in these cases. Then, covered stent placement can be performed but is often impossible or technically difficult because of the tortuosities of the visceral parent arteries. The only means to preserve the patency of the parent artery in these cases is to perform superselective arterial embolization by three-dimensional coil packing of the PA sac with use of controlled detachable microcoils placed in a concentric fashion, possibly in combination with an injection of Onyx embolic agent. We recently reported excellent results with this technique regardless of the clinical presentation, cause, or location of the lesion at the level of major peripheral or visceral arterial branches (4Loffroy R. Rao P. Ota S. et al.Packing technique for endovascular coil embolisation of peripheral arterial pseudo-aneurysms with preservation of the parent artery: safety, efficacy and outcomes.Eur J Vasc Endovasc Surg. 2010; 40: 209-215Abstract Full Text Full Text PDF PubMed Scopus (32) Google Scholar). We suggest that this conservative therapeutic option may deserve to be used whenever possible, as it preserves the patency of the parent artery. In conclusion, our experience suggests that transcatheter embolization with NBCA in well trained hands is effective and safe in patients with distal PAs, and does not cause more ischemic complications than other embolic agents if used cautiously. Conversely, glue embolization should absolutely not be attempted for PAs located at the level of major peripheral or visceral arteries. Our division read with great interest the article by Song et al (1Song H.H. Won Y.D. Kim Y.J. Transcatheter N-butyl cyanoacrylate embolization of pseudoaneurysms.J Vasc Interv Radiol. 2010; 21: 1508-1511Abstract Full Text Full Text PDF PubMed Scopus (32) Google Scholar) published in the October issue of JVIR, reporting the effectiveness of transcatheter embolization with n-butyl cyanoacrylate (NBCA) in selected patients with peripheral arterial pseudoaneurysms (PAs). We have several comments. First of all, we would like to congratulate the authors for their study, which represents the most important series to date reporting results on transarterial embolotherapy with NBCA glue as an embolic agent in such a setting. Recently, endovascular embolization has generated considerable interest as the first-line therapeutic method for PAs. The success rate is high, ranging from 62% to 100% in visceral PAs, and the morbidity and mortality rates are low (2Loffroy R. Guiu B. Cercueil J.P. et al.Transcatheter arterial embolization of splenic artery aneurysms and pseudoaneurysms: short- and long-term results.Ann Vasc Surg. 2008; 22: 618-626Abstract Full Text Full Text PDF PubMed Scopus (78) Google Scholar, 3Tokuda T. Tanigawa N. Shomura Y. et al.Transcatheter embolization for peripheral pseudoaneurysms with n-butyl cyanoacrylate.Minim Invasive Ther Allied Technol. 2009; 18: 361-365Crossref PubMed Scopus (21) Google Scholar). Most investigators agree that coils are the most appropriate embolic material (3Tokuda T. Tanigawa N. Shomura Y. et al.Transcatheter embolization for peripheral pseudoaneurysms with n-butyl cyanoacrylate.Minim Invasive Ther Allied Technol. 2009; 18: 361-365Crossref PubMed Scopus (21) Google Scholar). The study of Song et al (1Song H.H. Won Y.D. Kim Y.J. Transcatheter N-butyl cyanoacrylate embolization of pseudoaneurysms.J Vasc Interv Radiol. 2010; 21: 1508-1511Abstract Full Text Full Text PDF PubMed Scopus (32) Google Scholar) shows that embolization with NBCA as the sole embolic agent is a safe and effective technique for treatment of PAs at various locations. We absolutely agree with Song et al (1Song H.H. Won Y.D. Kim Y.J. Transcatheter N-butyl cyanoacrylate embolization of pseudoaneurysms.J Vasc Interv Radiol. 2010; 21: 1508-1511Abstract Full Text Full Text PDF PubMed Scopus (32) Google Scholar) about the efficacy and safety of glue embolization of the vessel supplying the PA. We find the use of NBCA particularly interesting, especially in patients in hemodynamically unstable condition with bleeding and in cases of underlying coagulopathy, because it provides faster and better hemostasis than other embolic agents. In our institution, selective embolization with NBCA as the only embolic agent has also become the salvage treatment of choice in many visceral and peripheral indications. However, we want to stress the fact that the use of NBCA requires training and considerable experience, given the risk of bowel infarction and glue reflux into other vessels. Reflux of NBCA may also result in its polymerization to the catheter tip. This bit of NBCA may then be stripped from the catheter during catheter retraction, resulting in nontarget embolization. The use of a proper technique, including prompt removal of the catheter after injection, as well as aspiration of the guide catheter after microcatheter removal, can significantly reduce this risk (2Loffroy R. Guiu B. Cercueil J.P. et al.Transcatheter arterial embolization of splenic artery aneurysms and pseudoaneurysms: short- and long-term results.Ann Vasc Surg. 2008; 22: 618-626Abstract Full Text Full Text PDF PubMed Scopus (78) Google Scholar). This technical note is very important and is not specified by Song et al (1Song H.H. Won Y.D. Kim Y.J. Transcatheter N-butyl cyanoacrylate embolization of pseudoaneurysms.J Vasc Interv Radiol. 2010; 21: 1508-1511Abstract Full Text Full Text PDF PubMed Scopus (32) Google Scholar). In addition, the major drawback of the use of NBCA is the compromised patency of the parent vessel. Consequently, NBCA cannot be used for proximal PAs arising from major peripheral or visceral arterial branches because of the risk of ischemic complications and end-organ damage. Moreover, this might explain the difficulties that the authors came across in one of their patients treated at the level of the main hepatic artery (1Song H.H. Won Y.D. Kim Y.J. Transcatheter N-butyl cyanoacrylate embolization of pseudoaneurysms.J Vasc Interv Radiol. 2010; 21: 1508-1511Abstract Full Text Full Text PDF PubMed Scopus (32) Google Scholar). Indeed, even though PAs in their study were mainly located at a distal level, visceral PAs can often be located proximally, especially PAs that are caused by pancreatitis or surgery, and we would like to highlight the fact that glue embolization should not be attempted in these cases. Then, covered stent placement can be performed but is often impossible or technically difficult because of the tortuosities of the visceral parent arteries. The only means to preserve the patency of the parent artery in these cases is to perform superselective arterial embolization by three-dimensional coil packing of the PA sac with use of controlled detachable microcoils placed in a concentric fashion, possibly in combination with an injection of Onyx embolic agent. We recently reported excellent results with this technique regardless of the clinical presentation, cause, or location of the lesion at the level of major peripheral or visceral arterial branches (4Loffroy R. Rao P. Ota S. et al.Packing technique for endovascular coil embolisation of peripheral arterial pseudo-aneurysms with preservation of the parent artery: safety, efficacy and outcomes.Eur J Vasc Endovasc Surg. 2010; 40: 209-215Abstract Full Text Full Text PDF PubMed Scopus (32) Google Scholar). We suggest that this conservative therapeutic option may deserve to be used whenever possible, as it preserves the patency of the parent artery. In conclusion, our experience suggests that transcatheter embolization with NBCA in well trained hands is effective and safe in patients with distal PAs, and does not cause more ischemic complications than other embolic agents if used cautiously. Conversely, glue embolization should absolutely not be attempted for PAs located at the level of major peripheral or visceral arteries. Transcatheter N-butyl Cyanoacrylate Embolization of PseudoaneurysmsJournal of Vascular and Interventional RadiologyVol. 21Issue 10PreviewTo report clinical experience with N-butyl cyanoacrylate (NBCA) for embolization of pseudoaneurysms at various locations. Full-Text PDF