INVITED COMMENTARY
Endovascular Aneurysm Repair of Ruptured Abdominal Aortic Aneurysms J.S. Lindholt
a,*
, J. Laustsen
b
a
Elitary Research Centre of Individualized Medicine in Arterial Disease (CIMA), Department of Cardiothoracic and Vascular Surgery, Odense University Hospital, Odense, Denmark b Department of Cardiothoracic and Vascular Surgery, Skejby University Hospital, Aarhus, Denmark
In this edition of the European Journal of Vascular and Endovascular Surgery, Balm et al. have performed an excellent state-of-the-art review of the endovascular treatment of ruptured abdominal aortic aneurysms (rAAA) e so called REVAR.1 This review is based on separate analyses of randomized controlled trials (RCTs), observational studies and administrative registries of rAAA repair, and shows a non-significant relative risk reduction of about 10% in 30 day- and/or in-hospital postoperative mortality in favour of REVAR. This is in contrast to the observational studies and administrative registries which demonstrate a significant relative risk reduction of about 50% - even after adjustment for hemodynamic instability in a subgroup analysis. The authors interpret the differing results as being caused by selection bias and residual confounding, which may at least be a part of the explanation, but selection bias could also point towards the null hypothesis of the RCTs. Such selection bias could be a result of relatively more stable conditions than in real life, giving time to gain informed consent, and for trial preparation, etc. Such patients may easily have a much better prognosis, and from a logical point of view the worse the clinical status of the patient, the better a minimally invasive treatment should be compared with major surgery. So existing RCTs may not have evaluated cases in which REVAR might be potentially superior in unstable patients who could benefit from an occlusive aortic balloon and REVAR instead of major surgery with fast aortic clamping through a large laparotomy incision. Observational studies and registries without doubt include such cases, as REVAR is increasingly employed. Consequently, in addition to evaluating the efficacy of REVAR in selective RCTs, a necessary and more relevant way from a patient- and society perspective, is to evaluate the population-based effectiveness of having two methods instead of one, for treating ruptured AAA. This requires evaluation of the overall mortality of ruptured AAA at population level and at hospital level with and without REVAR. However, this metaanalysis cannot answer this, nor can it answer whether the
DOI of original article: http://dx.doi.org/10.1016/j.ejvs.2014.03.003 * Corresponding author. J.S. Lindholt, Elitary Research Centre of Individualized Medicine in Arterial Disease (CIMA), Department of Cardiovascular Surgery, Odense University Hospital, Sdr. Boulevard 29, Odense, Denmark. E-mail address: [email protected] (J.S. Lindholt). 1078-5884/$ e see front matter Ó 2014 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.ejvs.2014.03.007
REVAR option increases the proportion receiving repair. It is not just postoperative survival that may be improved, but the option of treatment by REVAR may also increase the proportion being offered repair leading to increased rupture survival. Nevertheless, based on the RCTs, the authors of the current review and meta-analysis conclude correctly that REVAR is not inferior to open repair for short-term survival, but in terms of the comparison, cost is of major importance, and there have been reports indicating that length of stay in intensive care, use of blood products, and total length of stay, are significantly reduced by REVAR.2 From the cost perspective, this could make REVAR more attractive than open repair. However, these reports are based on observational studies and may thus be subject to selection bias. Hopefully, the investigators behind the existing RCTs will be able to address this question. Nevertheless, the health resource consequences of introducing REVAR must also be evaluated both at population and hospital level before a full view can be taken. However, it must be assumed that in a situation of equal cost effectiveness, the minimally invasive procedure will probably be preferred by the patients, their relatives, professionals, and health administrators. This creates a novel and challenging situation, as a 24-hour quality service for both REVAR and open repair performed by experienced surgeons and interventionists, who need to perform a minimal volume of procedures to maintain acceptable experience, will be difficult to achieve in all vascular departments because of cost and the number of available specialists.3,4 REFERENCES 1 van Beek SC, Conijn AP, Koelemay MJ, Balm R. Endovascular aneurysm repair versus open repair for patients with a ruptured abdominal aortic aneurysm; a systematic review and metaanalysis of short-term survival. Eur J Vasc Endovasc Surg; 2014 [in press]. 2 Visser JJ, van Sambeek MR, Hunink MG, Redekop WK, van Dijk LC, Hendriks JM, et al. Acute abdominal aortic aneurysms: cost analysis of endovascular repair and open surgery in hemodynamically stable patients with 1-year follow-up. Radiology 2006;240:681e9. 3 Landon BE, O’Malley AJ, Giles K, Cotterill P, Schermerhorn ML. Volume-outcome relationships and abdominal aortic aneurysm repair. Circulation 2010;122:1290e7. 4 Holt PJ, Poloniecki JD, Khalid U, Hinchliffe RJ, Loftus IM, Thompson MM. Effect of endovascular aneurysm repair on the volume-outcome relationship in aneurysm repair. Circ Cardiovasc Qual Outcomes 2009;2:624e32.
Please cite this article in press as: Lindholt JS, Laustsen J, Endovascular Aneurysm Repair of Ruptured Abdominal Aortic Aneurysms, European Journal of Vascular and Endovascular Surgery (2014), http://dx.doi.org/10.1016/j.ejvs.2014.03.007
Endovascular Aneurysm Repair of Ruptured Abdominal Aortic Aneurysms J.S. Lindholt
a,*
, J. Laustsen
b
a
Elitary Research Centre of Individualized Medicine in Arterial Disease (CIMA), Department of Cardiothoracic and Vascular Surgery, Odense University Hospital, Odense, Denmark b Department of Cardiothoracic and Vascular Surgery, Skejby University Hospital, Aarhus, Denmark
In this edition of the European Journal of Vascular and Endovascular Surgery, Balm et al. have performed an excellent state-of-the-art review of the endovascular treatment of ruptured abdominal aortic aneurysms (rAAA) e so called REVAR.1 This review is based on separate analyses of randomized controlled trials (RCTs), observational studies and administrative registries of rAAA repair, and shows a non-significant relative risk reduction of about 10% in 30 day- and/or in-hospital postoperative mortality in favour of REVAR. This is in contrast to the observational studies and administrative registries which demonstrate a significant relative risk reduction of about 50% - even after adjustment for hemodynamic instability in a subgroup analysis. The authors interpret the differing results as being caused by selection bias and residual confounding, which may at least be a part of the explanation, but selection bias could also point towards the null hypothesis of the RCTs. Such selection bias could be a result of relatively more stable conditions than in real life, giving time to gain informed consent, and for trial preparation, etc. Such patients may easily have a much better prognosis, and from a logical point of view the worse the clinical status of the patient, the better a minimally invasive treatment should be compared with major surgery. So existing RCTs may not have evaluated cases in which REVAR might be potentially superior in unstable patients who could benefit from an occlusive aortic balloon and REVAR instead of major surgery with fast aortic clamping through a large laparotomy incision. Observational studies and registries without doubt include such cases, as REVAR is increasingly employed. Consequently, in addition to evaluating the efficacy of REVAR in selective RCTs, a necessary and more relevant way from a patient- and society perspective, is to evaluate the population-based effectiveness of having two methods instead of one, for treating ruptured AAA. This requires evaluation of the overall mortality of ruptured AAA at population level and at hospital level with and without REVAR. However, this metaanalysis cannot answer this, nor can it answer whether the
DOI of original article: http://dx.doi.org/10.1016/j.ejvs.2014.03.003 * Corresponding author. J.S. Lindholt, Elitary Research Centre of Individualized Medicine in Arterial Disease (CIMA), Department of Cardiovascular Surgery, Odense University Hospital, Sdr. Boulevard 29, Odense, Denmark. E-mail address: [email protected] (J.S. Lindholt). 1078-5884/$ e see front matter Ó 2014 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.ejvs.2014.03.007
REVAR option increases the proportion receiving repair. It is not just postoperative survival that may be improved, but the option of treatment by REVAR may also increase the proportion being offered repair leading to increased rupture survival. Nevertheless, based on the RCTs, the authors of the current review and meta-analysis conclude correctly that REVAR is not inferior to open repair for short-term survival, but in terms of the comparison, cost is of major importance, and there have been reports indicating that length of stay in intensive care, use of blood products, and total length of stay, are significantly reduced by REVAR.2 From the cost perspective, this could make REVAR more attractive than open repair. However, these reports are based on observational studies and may thus be subject to selection bias. Hopefully, the investigators behind the existing RCTs will be able to address this question. Nevertheless, the health resource consequences of introducing REVAR must also be evaluated both at population and hospital level before a full view can be taken. However, it must be assumed that in a situation of equal cost effectiveness, the minimally invasive procedure will probably be preferred by the patients, their relatives, professionals, and health administrators. This creates a novel and challenging situation, as a 24-hour quality service for both REVAR and open repair performed by experienced surgeons and interventionists, who need to perform a minimal volume of procedures to maintain acceptable experience, will be difficult to achieve in all vascular departments because of cost and the number of available specialists.3,4 REFERENCES 1 van Beek SC, Conijn AP, Koelemay MJ, Balm R. Endovascular aneurysm repair versus open repair for patients with a ruptured abdominal aortic aneurysm; a systematic review and metaanalysis of short-term survival. Eur J Vasc Endovasc Surg; 2014 [in press]. 2 Visser JJ, van Sambeek MR, Hunink MG, Redekop WK, van Dijk LC, Hendriks JM, et al. Acute abdominal aortic aneurysms: cost analysis of endovascular repair and open surgery in hemodynamically stable patients with 1-year follow-up. Radiology 2006;240:681e9. 3 Landon BE, O’Malley AJ, Giles K, Cotterill P, Schermerhorn ML. Volume-outcome relationships and abdominal aortic aneurysm repair. Circulation 2010;122:1290e7. 4 Holt PJ, Poloniecki JD, Khalid U, Hinchliffe RJ, Loftus IM, Thompson MM. Effect of endovascular aneurysm repair on the volume-outcome relationship in aneurysm repair. Circ Cardiovasc Qual Outcomes 2009;2:624e32.
Please cite this article in press as: Lindholt JS, Laustsen J, Endovascular Aneurysm Repair of Ruptured Abdominal Aortic Aneurysms, European Journal of Vascular and Endovascular Surgery (2014), http://dx.doi.org/10.1016/j.ejvs.2014.03.007
