- Email: [email protected]
Endovascular Repair of Abdominal Aortic Aneurysms
570
Letters to the Editor
Mayo Clin Proc, April 2004, Vol 79
is the correct stance to take and because the FDA is compelled by its statute to do so.
2.
William K. Hubbard US Food and Drug Administration Rockville, Md
3.
Endovascular Repair of Abdominal Aortic Aneurysms To the Editor: In their recent article, Elkouri et al1 described their experience with endovascular repair of abdominal aortic aneurysm (EVAR) in 100 consecutive patients treated between June 26, 1996, and October 31, 2001. On the basis of their high frequency of secondary procedures (29%) and early surgical conversion rate of 3%, the authors concluded that because early complications and reinterventions are frequent, “current data are insufficient to support EVAR as the preferred treatment of AAAs [abdominal aortic aneurysms].” Although not stated in the article, of the 5 endovascular devices used, 2 devices never completed clinical trials (EVT and Vanguard). A third, the ANCURE device, is no longer approved for clinical use. Early endograft designs were associated with many complications in midterm follow-up, with secondary intervention rates between 26.6% and 29%.1,2 These discouraging numbers with early devices, when compared with the excellent clinical results and lower costs of conventional AAA repair, caused some authors (circa 2001) to infer that the new EVAR technique might be “a failed experiment.”3 Since 1999, we have performed 160 EVAR procedures using Food and Drug Administration–approved devices. At 13-month follow-up, 11% of patients have needed secondary procedures, but no patient has undergone early conversion to open repair. In addition, aneurysm diameter decreased or was unchanged in 98% of patients. We conclude that EVAR is a reasonable alternative to open AAA repair in selected patients. We believe the discrepancy between the high technical success and the frequent secondary procedures and early complications described by Elkouri et al1 is based on the types of devices used. Our current series includes 87 AneuRx devices (Medtronic AVE, Minneapolis, Minn), 41 Zenith devices (Cook Group Inc, Bloomington, Ind), 18 Talent devices (Medtronic), 12 ANCURE devices (Guidant Corp, St Paul, Minn), and 2 EXCLUDER devices (W. L. Gore & Associates, Inc, Flagstaff, Ariz). These secondand third-generation devices include structural and delivery system modifications that increase the deployment success and decrease the limb complication rate. Albert G. Hakaim, MD W. Andrew Oldenburg, MD Matthias O. Biebl, MD Mayo Clinic College of Medicine Jacksonville, Fla 1.
Elkouri S, Gloviczki P, McKusick MA, et al. Endovascular repair of abdominal aortic aneurysms: initial experience with 100 consecutive patients. Mayo Clin Proc. 2003;78:1234-1242.
Hölzenbein TJ, Kretschmer G, Thurnher S, et al. Midterm durability of abdominal aortic aneurysm endograft repair: a word of caution. J Vasc Surg. 2001;33(2, suppl):S46-S54. Collin J, Murie JA. Endovascular treatment of abdominal aortic aneurysm: a failed experiment. Br J Surg. 2001;88:1281-1282.
In reply: We thank Dr Hakaim and colleagues for their comments. The experience at the Mayo Clinic in Jacksonville, Fla, illustrates the fact that substantial progress has been made in this field and that second- and third-generation stent grafts and new designs entering the market have already decreased the risk of limb complications and the need for surgical conversions or frequent secondary interventions. Our article described a learning curve, during which 3 of 100 patients underwent early conversions from attempted EVT/ANCURE stent graft implantation to open repair; these stent grafts are no longer used in the United States. By the end of 2003, our experience with endograft placement for AAA had increased: In the subsequent 207 patients who underwent this procedure, we performed conversion to open repair in only 1 who had undergone endograft repair for a ruptured AAA. Currently, we offer all Food and Drug Administration (FDA)approved devices, including AneuRx, Zenith, and EXCLUDER stent grafts for endovascular repair. In 2003, 40% of AAA repairs (86 of 216) were performed using various endografts. The number of secondary interventions has decreased, but these procedures are still performed; the risk of late rupture of the AAA is small, but rupture may occur. Indications for treatment of type II endoleak were more liberal in the early years of our experience, and our article listed all reinterventions, including those not related to stent grafts (wound complications). Our reintervention rate for stent graft–related complications compares favorably with those published in other series but remains higher than reintervention rates after open repair.1,2 We do not disagree with the conclusion of Dr Hakaim and colleagues: This operation is a very good alternative for repairing AAA in selected patients. However, determination of “selected” is important. We remind Dr Hakaim and colleagues about the recent FDA Public Health Notification3 that was based on an analysis of aneurysm-related death rates in 942 patients treated with the AneuRx stent graft. The report came from the AneuRx investigational premarket study, which began in 1996. The FDA concluded that the risk of late mortality appears to be less for open surgery than for procedures using the AneuRx stent graft; the risk of AAA-related deaths after AneuRx stent graft repair was 0.4% per year compared with 0.18% per year after open AAA repair. On the basis of this information, the FDA concluded that the risk of late mortality associated with AAA repair may exceed that associated with open surgery in some institutions. Because of this, the overall AAA-associated mortality from the AneuRx stent graft is likely to exceed the AAA-associated mortality from open surgery at some point. Several factors need to be considered in determining the risk-benefit profile for patients with AAA, including the patient’s life expectancy, surgical risk, morphologic suitability for endovascular repair, experience of the surgeon and interventionist, the presence of rupture, and the patient’s willingness to
For personal use. Mass reproduce only with permission from Mayo Clinic Proceedings.
Letters to the Editor
Mayo Clin Proc, April 2004, Vol 79
is the correct stance to take and because the FDA is compelled by its statute to do so.
2.
William K. Hubbard US Food and Drug Administration Rockville, Md
3.
Endovascular Repair of Abdominal Aortic Aneurysms To the Editor: In their recent article, Elkouri et al1 described their experience with endovascular repair of abdominal aortic aneurysm (EVAR) in 100 consecutive patients treated between June 26, 1996, and October 31, 2001. On the basis of their high frequency of secondary procedures (29%) and early surgical conversion rate of 3%, the authors concluded that because early complications and reinterventions are frequent, “current data are insufficient to support EVAR as the preferred treatment of AAAs [abdominal aortic aneurysms].” Although not stated in the article, of the 5 endovascular devices used, 2 devices never completed clinical trials (EVT and Vanguard). A third, the ANCURE device, is no longer approved for clinical use. Early endograft designs were associated with many complications in midterm follow-up, with secondary intervention rates between 26.6% and 29%.1,2 These discouraging numbers with early devices, when compared with the excellent clinical results and lower costs of conventional AAA repair, caused some authors (circa 2001) to infer that the new EVAR technique might be “a failed experiment.”3 Since 1999, we have performed 160 EVAR procedures using Food and Drug Administration–approved devices. At 13-month follow-up, 11% of patients have needed secondary procedures, but no patient has undergone early conversion to open repair. In addition, aneurysm diameter decreased or was unchanged in 98% of patients. We conclude that EVAR is a reasonable alternative to open AAA repair in selected patients. We believe the discrepancy between the high technical success and the frequent secondary procedures and early complications described by Elkouri et al1 is based on the types of devices used. Our current series includes 87 AneuRx devices (Medtronic AVE, Minneapolis, Minn), 41 Zenith devices (Cook Group Inc, Bloomington, Ind), 18 Talent devices (Medtronic), 12 ANCURE devices (Guidant Corp, St Paul, Minn), and 2 EXCLUDER devices (W. L. Gore & Associates, Inc, Flagstaff, Ariz). These secondand third-generation devices include structural and delivery system modifications that increase the deployment success and decrease the limb complication rate. Albert G. Hakaim, MD W. Andrew Oldenburg, MD Matthias O. Biebl, MD Mayo Clinic College of Medicine Jacksonville, Fla 1.
Elkouri S, Gloviczki P, McKusick MA, et al. Endovascular repair of abdominal aortic aneurysms: initial experience with 100 consecutive patients. Mayo Clin Proc. 2003;78:1234-1242.
Hölzenbein TJ, Kretschmer G, Thurnher S, et al. Midterm durability of abdominal aortic aneurysm endograft repair: a word of caution. J Vasc Surg. 2001;33(2, suppl):S46-S54. Collin J, Murie JA. Endovascular treatment of abdominal aortic aneurysm: a failed experiment. Br J Surg. 2001;88:1281-1282.
In reply: We thank Dr Hakaim and colleagues for their comments. The experience at the Mayo Clinic in Jacksonville, Fla, illustrates the fact that substantial progress has been made in this field and that second- and third-generation stent grafts and new designs entering the market have already decreased the risk of limb complications and the need for surgical conversions or frequent secondary interventions. Our article described a learning curve, during which 3 of 100 patients underwent early conversions from attempted EVT/ANCURE stent graft implantation to open repair; these stent grafts are no longer used in the United States. By the end of 2003, our experience with endograft placement for AAA had increased: In the subsequent 207 patients who underwent this procedure, we performed conversion to open repair in only 1 who had undergone endograft repair for a ruptured AAA. Currently, we offer all Food and Drug Administration (FDA)approved devices, including AneuRx, Zenith, and EXCLUDER stent grafts for endovascular repair. In 2003, 40% of AAA repairs (86 of 216) were performed using various endografts. The number of secondary interventions has decreased, but these procedures are still performed; the risk of late rupture of the AAA is small, but rupture may occur. Indications for treatment of type II endoleak were more liberal in the early years of our experience, and our article listed all reinterventions, including those not related to stent grafts (wound complications). Our reintervention rate for stent graft–related complications compares favorably with those published in other series but remains higher than reintervention rates after open repair.1,2 We do not disagree with the conclusion of Dr Hakaim and colleagues: This operation is a very good alternative for repairing AAA in selected patients. However, determination of “selected” is important. We remind Dr Hakaim and colleagues about the recent FDA Public Health Notification3 that was based on an analysis of aneurysm-related death rates in 942 patients treated with the AneuRx stent graft. The report came from the AneuRx investigational premarket study, which began in 1996. The FDA concluded that the risk of late mortality appears to be less for open surgery than for procedures using the AneuRx stent graft; the risk of AAA-related deaths after AneuRx stent graft repair was 0.4% per year compared with 0.18% per year after open AAA repair. On the basis of this information, the FDA concluded that the risk of late mortality associated with AAA repair may exceed that associated with open surgery in some institutions. Because of this, the overall AAA-associated mortality from the AneuRx stent graft is likely to exceed the AAA-associated mortality from open surgery at some point. Several factors need to be considered in determining the risk-benefit profile for patients with AAA, including the patient’s life expectancy, surgical risk, morphologic suitability for endovascular repair, experience of the surgeon and interventionist, the presence of rupture, and the patient’s willingness to
For personal use. Mass reproduce only with permission from Mayo Clinic Proceedings.