JOURNAL OF VASCULAR SURGERY Volume 60, Number 4
criteria used for native arteries. The criteria used in COBEST have not been validated for diagnosis of restenosis after iliac artery stenting or stent grafting. No data are provided as to the distribution of the diagnostic modalities used to diagnose the stenoses in COBEST, nor do the authors provide data on how many patients had confirmation of the restenosis by angiography. Finally, COBEST did not stratify patients on the basis of the TransAtlantic Inter-Society Consensus (TASC) classification, and more than 60% of the patients had TASC B disease. Therefore, the study is underpowered to make any meaningful conclusion for the post hoc analysis of patients with TASC C and D disease where the authors indicated a difference in binary restenosis between the two stents. Our study and COBEST have clearly sparked interest. The DISCOVER6 trial will use some of the same end points as COBEST and will be underpowered for subgroup analyses. On the other hand, the planned assessment of quality of life and walking scores may help determine whether restenosis is an outcome that is important to patients. Misty D. Humphries, MD John Laird, MD Jessica Paz, BS William Pevec, MD Division of Vascular Surgery University of California Davis Medical Center Sacramento, Calif
Letters to the Editor 1121
of Norway and describes incidence, handling, and outcome for patients with rAAA in Norway, including those transferred to another hospital before operative repair. Interestingly, the proportions of patients transferred for treatment of rAAA, as well as the proportions of patients who underwent rAAA repair after transfer, are similar in both studies. The former is 19.1% in their study compared with 17.9% (87 of 487) in our study, the latter is 83.3% (706 of 847) in their study compared with 86.2% (75 of 87) in our study.1,2 Both studies indicate that most patients with rAAA can still be treated after transfer, which is good news, bearing in mind that centralization of vascular services leaves transfer and a subsequent operation as the only treatment option for a growing number of patients. Optimizing transfer time and communication between hospitals, including shared imaging, enabling preoperative preparation before the patient arrives, may improve results to a certain degree. Nevertheless, there can be no doubt that screening for AAA and elective operation will give much better results than even the most efficient transfer system for patients with rAAA and should be implemented as soon as possible.3-5 The screening algorithm, however, may have to be adapted due to changing epidemiology.6 Martin Altreuther, MD on behalf of the other authors2 Department of Vascular Surgery St. Olavs Hospital HF University Hospital of Trondheim Trondheim, Norway
Ehrin Armstrong, MD, MAS University of ColoradoeDenver Denver, Colo REFERENCES 1. Humphries MD, Armstrong E, Laird J, Paz J, Pevec W. Outcomes of covered versus bare-metal balloon-expandable stents for aortoiliac occlusive disease. J Vasc Surg 2014;60:337-44. 2. Mwipatayi BP, Thomas S, Wong J, Temple SEL, Vijayan V, Jackson M, et al. A comparison of covered vs bare expandable stents for the treatment of aortoiliac occlusive disease. J Vasc Surg 2011;54:1561-70. 3. Diehm N, Pattynama PM, Jaff MR, Cremonesi A, Becker GJ, Hopkins LN, et al. Clinical endpoints in peripheral endovascular revascularization trials: a case for standardized definitions. Eur J Vasc Endovasc Surg 2008;36:409-19. 4. Lal BK, Hobson RW II, Tofighi B, Kapadia I, Cuadra S, Jamil Z. Duplex ultrasound velocity criteria for the stented carotid artery. J Vasc Surg 2008;47:63-73. 5. AbuRahma AF, Mousa AY, Stone PA, Hass SM, Dean LS, Keiffer T. Duplex velocity criteria for native celiac/superior mesenteric artery stenosis vs in-stent stenosis. J Vasc Surg 2012;55:730-8. 6. Bekken JA, Vos JA, Aarts RA, de Vries JP, Fioole B. DISCOVER: Dutch Iliac Stent trial: COVERed balloon-expandable versus uncovered balloon-expandable stents in the common iliac artery: study protocol for a randomized controlled trial. Trials 2012;13:215. http://dx.doi.org/10.1016/j.jvs.2014.06.005
Regarding “Interfacility transfer and mortality for patients with ruptured abdominal aortic aneurysm” We were pleased to read the systematic analysis concerning interfacility transfer and mortality for patients with ruptured abdominal aortic aneurysm (rAAA) by Mell et al.1 We do disagree, however, with the first part of the discussion stating that their actual study was the first to describe population-level outcomes for patients with rAAAs, including patients transferred for care. Our analysis,2 published in 2012, is based on the entire population
REFERENCES 1. Mell MW, Wang NE, Morrison DE, Hernandez-Boussard T. Interfacility transfer and mortality for patients with ruptured abdominal aortic aneurysm. J Vasc Surg 2014;60:553-7. 2. Brattheim BJ, Eikemo TA, Altreuther M, Landmark AD, Faxvaag A. Regional disparities in incidence, handling and outcomes of patients with symptomatic and ruptured abdominal aortic aneurysms in Norway. Eur J Vasc Endovasc Surg 2012;44:267-72. 3. Scott RA, Wilson NM, Ashton HA, Kay DN. Influence of screening on the incidence of ruptured abdominal aortic aneurysm: 5-year results of a randomized controlled study. Br J Surg 1995;82:1066-70. 4. Lindholt JS, Juul S, Fasting H, Henneberg EW. Screening for abdominal aortic aneurysms: single centre randomized controlled trial. BMJ 2005;330:750-2. 5. Ashton HA, Buxton MJ, Day NE, Kim LG, Marteau TM, Scott RA, et al. Multicentre Aneurysm Screening Study Group. The Multicentre Aneurysm Screening Study (MASS) into the effect of abdominal aortic aneurysm screening on mortality in men: a randomized controlled trial. Lancet 2002;360:1531-9. 6. Svensjø S, Bjørck M, Gürtelschmid M, Gidlund KD, Hellberg A, Wanhainen A. Low prevalence of abdominal aortic aneurysm among 65year-old Swedish men indicates a change in the epidemiology of the disease. Circulation 2011;124:1118-23. http://dx.doi.org/10.1016/j.jvs.2014.05.103
Reply Our study is the first to describe population level outcomes in the United States, and we appreciate the references provided by Dr Altreuther describing a European experience. It is noteworthy that the findings of both studies are quite similar, despite differences in health care delivery systems, geography, and distances. We also agree that the best treatment for ruptured abdominal aortic aneurysm (rAAA) is prevention, with early detection and effective surveillance.1,2 For those who present with rAAA and cannot receive treatment at the initial presenting facility, we found that the benefits of transfer for repair appear to be eclipsed by those who die en route or after arrival to the receiving hospital without receiving
criteria used for native arteries. The criteria used in COBEST have not been validated for diagnosis of restenosis after iliac artery stenting or stent grafting. No data are provided as to the distribution of the diagnostic modalities used to diagnose the stenoses in COBEST, nor do the authors provide data on how many patients had confirmation of the restenosis by angiography. Finally, COBEST did not stratify patients on the basis of the TransAtlantic Inter-Society Consensus (TASC) classification, and more than 60% of the patients had TASC B disease. Therefore, the study is underpowered to make any meaningful conclusion for the post hoc analysis of patients with TASC C and D disease where the authors indicated a difference in binary restenosis between the two stents. Our study and COBEST have clearly sparked interest. The DISCOVER6 trial will use some of the same end points as COBEST and will be underpowered for subgroup analyses. On the other hand, the planned assessment of quality of life and walking scores may help determine whether restenosis is an outcome that is important to patients. Misty D. Humphries, MD John Laird, MD Jessica Paz, BS William Pevec, MD Division of Vascular Surgery University of California Davis Medical Center Sacramento, Calif
Letters to the Editor 1121
of Norway and describes incidence, handling, and outcome for patients with rAAA in Norway, including those transferred to another hospital before operative repair. Interestingly, the proportions of patients transferred for treatment of rAAA, as well as the proportions of patients who underwent rAAA repair after transfer, are similar in both studies. The former is 19.1% in their study compared with 17.9% (87 of 487) in our study, the latter is 83.3% (706 of 847) in their study compared with 86.2% (75 of 87) in our study.1,2 Both studies indicate that most patients with rAAA can still be treated after transfer, which is good news, bearing in mind that centralization of vascular services leaves transfer and a subsequent operation as the only treatment option for a growing number of patients. Optimizing transfer time and communication between hospitals, including shared imaging, enabling preoperative preparation before the patient arrives, may improve results to a certain degree. Nevertheless, there can be no doubt that screening for AAA and elective operation will give much better results than even the most efficient transfer system for patients with rAAA and should be implemented as soon as possible.3-5 The screening algorithm, however, may have to be adapted due to changing epidemiology.6 Martin Altreuther, MD on behalf of the other authors2 Department of Vascular Surgery St. Olavs Hospital HF University Hospital of Trondheim Trondheim, Norway
Ehrin Armstrong, MD, MAS University of ColoradoeDenver Denver, Colo REFERENCES 1. Humphries MD, Armstrong E, Laird J, Paz J, Pevec W. Outcomes of covered versus bare-metal balloon-expandable stents for aortoiliac occlusive disease. J Vasc Surg 2014;60:337-44. 2. Mwipatayi BP, Thomas S, Wong J, Temple SEL, Vijayan V, Jackson M, et al. A comparison of covered vs bare expandable stents for the treatment of aortoiliac occlusive disease. J Vasc Surg 2011;54:1561-70. 3. Diehm N, Pattynama PM, Jaff MR, Cremonesi A, Becker GJ, Hopkins LN, et al. Clinical endpoints in peripheral endovascular revascularization trials: a case for standardized definitions. Eur J Vasc Endovasc Surg 2008;36:409-19. 4. Lal BK, Hobson RW II, Tofighi B, Kapadia I, Cuadra S, Jamil Z. Duplex ultrasound velocity criteria for the stented carotid artery. J Vasc Surg 2008;47:63-73. 5. AbuRahma AF, Mousa AY, Stone PA, Hass SM, Dean LS, Keiffer T. Duplex velocity criteria for native celiac/superior mesenteric artery stenosis vs in-stent stenosis. J Vasc Surg 2012;55:730-8. 6. Bekken JA, Vos JA, Aarts RA, de Vries JP, Fioole B. DISCOVER: Dutch Iliac Stent trial: COVERed balloon-expandable versus uncovered balloon-expandable stents in the common iliac artery: study protocol for a randomized controlled trial. Trials 2012;13:215. http://dx.doi.org/10.1016/j.jvs.2014.06.005
Regarding “Interfacility transfer and mortality for patients with ruptured abdominal aortic aneurysm” We were pleased to read the systematic analysis concerning interfacility transfer and mortality for patients with ruptured abdominal aortic aneurysm (rAAA) by Mell et al.1 We do disagree, however, with the first part of the discussion stating that their actual study was the first to describe population-level outcomes for patients with rAAAs, including patients transferred for care. Our analysis,2 published in 2012, is based on the entire population
REFERENCES 1. Mell MW, Wang NE, Morrison DE, Hernandez-Boussard T. Interfacility transfer and mortality for patients with ruptured abdominal aortic aneurysm. J Vasc Surg 2014;60:553-7. 2. Brattheim BJ, Eikemo TA, Altreuther M, Landmark AD, Faxvaag A. Regional disparities in incidence, handling and outcomes of patients with symptomatic and ruptured abdominal aortic aneurysms in Norway. Eur J Vasc Endovasc Surg 2012;44:267-72. 3. Scott RA, Wilson NM, Ashton HA, Kay DN. Influence of screening on the incidence of ruptured abdominal aortic aneurysm: 5-year results of a randomized controlled study. Br J Surg 1995;82:1066-70. 4. Lindholt JS, Juul S, Fasting H, Henneberg EW. Screening for abdominal aortic aneurysms: single centre randomized controlled trial. BMJ 2005;330:750-2. 5. Ashton HA, Buxton MJ, Day NE, Kim LG, Marteau TM, Scott RA, et al. Multicentre Aneurysm Screening Study Group. The Multicentre Aneurysm Screening Study (MASS) into the effect of abdominal aortic aneurysm screening on mortality in men: a randomized controlled trial. Lancet 2002;360:1531-9. 6. Svensjø S, Bjørck M, Gürtelschmid M, Gidlund KD, Hellberg A, Wanhainen A. Low prevalence of abdominal aortic aneurysm among 65year-old Swedish men indicates a change in the epidemiology of the disease. Circulation 2011;124:1118-23. http://dx.doi.org/10.1016/j.jvs.2014.05.103
Reply Our study is the first to describe population level outcomes in the United States, and we appreciate the references provided by Dr Altreuther describing a European experience. It is noteworthy that the findings of both studies are quite similar, despite differences in health care delivery systems, geography, and distances. We also agree that the best treatment for ruptured abdominal aortic aneurysm (rAAA) is prevention, with early detection and effective surveillance.1,2 For those who present with rAAA and cannot receive treatment at the initial presenting facility, we found that the benefits of transfer for repair appear to be eclipsed by those who die en route or after arrival to the receiving hospital without receiving
