Caveat Emptor: Lessons Learned from the Endovascular Treatment of Complex Aortic Pathologies
2015; Elsevier BV; Volume: 49; Issue: 4 Linguagem: Inglês
10.1016/j.ejvs.2014.12.001
ISSN1532-2165
AutoresEric L.G. Verhoeven, Αthanasios Katsargyris, Stéphan Haulon,
Tópico(s)Vascular Procedures and Complications
ResumoThe management of aortic aneurysm has evolved considerably over the last 20 years and few vascular surgeons in 1990 would have believed that within 25 years, aneurysm treatment would be close to becoming a day case intervention. Endovascular aortic aneurysm repair (EVAR) has largely replaced open repair of infrarenal abdominal aortic aneurysm (AAA) in anatomically suitable patients. This is despite the fact that while multicentre randomized trials revealed a clear survival advantage in the first 30 days (and again at 3 years), no late survival advantage favouring EVAR has been demonstrated.1Greenhalgh R.M. Brown L.C. Kwong G.P. Powell J.T. Thompson S.G. EVAR trial participantsComparison of endovascular aneurysm repair with open repair in patients with abdominal aortic aneurysm (EVAR trial 1), 30-day operative mortality results: randomised controlled trial.Lancet. 2004; 364: 843-848Abstract Full Text Full Text PDF PubMed Scopus (1637) Google Scholar, 2Prinssen M. Verhoeven E.L. Buth J. Cuypers P.W. van Sambeek M.R. Balm R. et al.A randomized trial comparing conventional and endovascular repair of abdominal aortic aneurysms.N Engl J Med. 2004; 351: 1607-1618Crossref PubMed Scopus (1670) Google Scholar Long-term surveillance after EVAR has revealed high rates of late complications, necessitating secondary and tertiary re-interventions. On reflection, many of these late technical failures probably represent situations where anatomical suitability criteria were not always respected or where the technique was poorly planned and/or executed from the outset.3Schanzer A. Greenberg R.K. Hevelone N. Robinson W.P. Eslami M.H. Goldberg R.J. et al.Predictors of abdominal aortic aneurysm sac enlargement after endovascular repair.Circulation. 2011; 123: 2848-2855Crossref PubMed Scopus (579) Google Scholar In addition, one should bear in mind that aneurysmal disease is a continuous pathological process. Early success does not always translate into long-term durability, particularly where the infrarenal aortic neck is subject to progressive dilatation.4Cao P. De Rango P. Parlani G. Verzini F. Fate of proximal aorta following open infrarenal aneurysm repair.Semin Vasc Surg. 2009; 22: 93-98Abstract Full Text Full Text PDF PubMed Scopus (9) Google Scholar, 5Rodway A.D. Powell J.T. Brown L.C. Greenhalgh R.M. Do abdominal aortic aneurysm necks increase in size faster after endovascular than open repair?.Eur J Vasc Endovasc Surg. 2008; 35: 685-693Abstract Full Text Full Text PDF PubMed Scopus (35) Google Scholar If vascular surgeons want to strive for optimal outcome, they have to respect anatomical restrictions for device usage, while also anticipating the consequences of disease progression (aortic neck dilatation, increasing iliac tortuosity). Following the success of EVAR in the treatment of infrarenal AAA, innovative surgeons and industry developed devices to achieve sealing in patients with more complex aneurysms (juxtarenal, thoracoabdominal). Fenestrated stent grafts expanded endovascular options for patients with juxtarenal AAA and excellent results from high volume centres have been published, but only after many years of experimentation and device innovation.6Greenberg R.K. Sternbergh 3rd, W.C. Makaroun M. Ohki T. Chuter T. Bharadwaj P. et al.Intermediate results of a United States multicenter trial of fenestrated endograft repair for juxtarenal abdominal aortic aneurysms.J Vasc Surg. 2009; 50: 730-737Abstract Full Text Full Text PDF PubMed Scopus (292) Google Scholar, 7Verhoeven E.L. Vourliotakis G. Bos W.T. Tielliu I.F. Zeebregts C.J. Prins T.R. et al.Fenestrated stent grafting for short-necked and juxtarenal abdominal aortic aneurysm: an 8-year single-centre experience.Eur J Vasc Endovasc Surg. 2010; 39: 529-536Abstract Full Text Full Text PDF PubMed Scopus (314) Google Scholar, 8Haulon S. Amiot S. Magnan P.E. Becquemin J.P. Lermusiaux P. Koussa M. et al.An analysis of the French multicentre experience of fenestrated aortic endografts: medium-term outcomes.Ann Surg. 2010; 251: 357-362Crossref PubMed Scopus (96) Google Scholar A recent overview comparing outcomes following open surgery for chimney EVAR and fenestrated EVAR (F-EVAR) in patients with complex AAA showed that F-EVAR was associated with a peri-operative mortality of 2.4%, with high rates of aneurysm exclusion and target vessel patency, while late complications secondary to endoleaks and disease progression were rare.9Katsargyris A. Oikonomou K. Klonaris C. Töpel I. Verhoeven E.L. et al.Comparison of outcomes with open, fenestrated, and chimney graft repair of juxtarenal aneurysms: are we ready for a paradigm shift?.J Endovasc Ther. 2013; 20: 159-169Crossref PubMed Scopus (200) Google Scholar, 10Mastracci T.M. Greenberg R.K. Eagleton M.J. Hernandez A.V. Durability of branches in branched and fenestrated endografts.J Vasc Surg. 2013; 57: 926-933Abstract Full Text Full Text PDF PubMed Scopus (238) Google Scholar F-EVAR is, however, a more complex endovascular technique and requires a much higher level of expertise. Careful patient selection and detailed pre-operative planning are mandatory as any technical failure can lead to serious complications, requiring extremely challenging “bail-out” options. The importance of having an integrated and fully functioning team cannot be underestimated. These types of procedures should not be planned and performed by solitary enthusiasts, no matter how motivated or skilled they might be. “The modern endovascular team” requires experienced nursing and operating personnel, with expertise in three dimensional imaging, anticipation of navigation difficulties, awareness of bail out manoeuvres, and a high level of knowledge regarding stent graft capabilities and limitations. Each of these parameters is crucial for delivering optimal patient outcomes. In addition, a hybrid endovascular suite providing perfect imaging quality and access to advanced imaging applications, and a large stock of back up materials and ancillary products is highly advisable. Despite the flourish of interest in F-EVAR and (more recently) branched EVAR (B-EVAR), a recently published paper clearly reiterates the need for strictly adhering to case selection, meticulous procedural planning, and technical execution. Raux et al.11Raux M. Patel V.I. Cochennec F. Mukhopadhyay S. Desgranges P. Cambria R.P. et al.A propensity-matched comparison of outcomes for fenestrated endovascular aneurysm repair and open surgical repair of complex abdominal aortic aneurysms.J Vasc Surg. 2014; 60: 858-863Abstract Full Text Full Text PDF PubMed Scopus (63) Google Scholar compared F-EVAR with open surgery in patients with complex AAA in two large volume centres. In this study, F-EVAR had higher 30 day mortality rates (9.5% vs. 2%), as well as higher procedural complications (24% vs. 7%) and graft related complications (30% vs. 2%) than open surgery. The high mortality rates after F-EVAR in this study are worrying and suggest that there may be concerns about generalizability within less experienced centres. F-EVAR procedures were performed in only one of the two centres, and only included 59 procedures that had been performed over a decade. The authors conceded that “the learning curve of the endovascular technique was likely to be responsible in part for the adverse outcomes observed in the F-EVAR cohort”. The authors reported no differences in cardiac, pulmonary, and renal events between F-EVAR and open surgery. This, therefore, raises the question whether the higher rate of observed complications after F-EVAR were the result of significant intra-operative technical difficulties leading to prolonged operative times, possibly because of poor anatomical patient selection. In short, if one reserves F-EVAR for only the most complex cases (where there will not be the commensurate level of technical expertise for dealing with complications) it should come as no surprise when good results do not follow. The evolution of F-EVAR and (more recently) B-EVAR has opened up the thoraco-abdominal aorta (TAAA) to endovascular repair. This clearly represents another level of technological complexity and, even in expert centres, mortality rates of 10% have been reported, along with not insignificant risks of paraplegia. Stent grafts for treating TAAA have to be individually customized to each patient's anatomy and the required endovascular skills are much more complex, with access being required via both the upper and lower limbs. The logistical and organizational requirements also become much higher in terms of hardware (hybrid room mandatory) and software (back up materials of all kinds including a wide range of bridging stent grafts).12Hertault A. Maurel B. Sobocinski J. Martin Gonzalez T. Le Roux M. Azzaoui R. et al.Impact of hybrid rooms with image fusion on radiation exposure during endovascular aortic repair.Eur J Vasc Endovasc Surg. 2014; 48: 382-390Abstract Full Text Full Text PDF PubMed Scopus (132) Google Scholar Patient selection is critical. Although it is now possible to offer an endovascular solution to TAAA patients not suitable for open surgery, experience suggests that ASA Type IV patients do not do very well after TAAA branch grafting.13Verhoeven E.L. Katsargyris A. Bekkema F. Oikonomou K. Zeebregts C.J. Ritter W. et al.Ten-year experience with endovascular repair of thoracoabdominal aortic aneurysms: results from 166 consecutive patients.Eur J Vasc Endovasc Surg. 2015; (in press)Google Scholar Although the peri-procedural mortality rate in ASA IV patients was not significantly higher, cumulative survival was significantly lower, suggesting that relatively few will benefit from the procedure. Mortality rates in highly experienced centres are now below 10% (17/218 [7.7%] for Nürnberg and 14/204 [6.9%] for Lille), but some patients still died following intra-operative technical failures (rupture, limb ischaemia, mesenteric ischaemia, stroke).13Verhoeven E.L. Katsargyris A. Bekkema F. Oikonomou K. Zeebregts C.J. Ritter W. et al.Ten-year experience with endovascular repair of thoracoabdominal aortic aneurysms: results from 166 consecutive patients.Eur J Vasc Endovasc Surg. 2015; (in press)Google Scholar, 14Maurel B. Delclaux N. Sobocinski J. Hertault A. Martin-Gonzalez T. Moussa M. et al.Impact of early pelvic and lower limb reperfusion and attentive perioperative management on the incidence of spinal cord ischemia during thoracoabdominal aortic aneurysm endovascular repair.Eur J Vasc Endovasc Surg. 2015; (in press)Google Scholar Without the required organizational set up and experience, it is likely that other studies will report inferior results, which could jeopardize more widespread adoption of this technique. The WINDOWS multicentre French Registry reported outcomes in 268 patients who received F-EVAR or B-EVAR for juxtarenal AAA (group 1), suprarenal AAA and TAAA Type IV (group 2), and TAAA Type I, II, III (group 3).15Marzelle J. Presles E. Becquemin J.P. WINDOWS trial participants. Results and factors affecting early outcome of fenestrated and/or branched stent grafts for aortic aneurysms: a multicenter prospective study.Ann Surg. 2015; 261: 197-206Crossref PubMed Scopus (85) Google Scholar In hospital mortality was 6.5% for group 1 patients, 14.3% for group 2, and 21.4% for group 3. These increasing mortality rates probably reflect the effect of a learning curve in the treatment of increasingly complex aortic pathologies. Participating centres were considered to be “expert centres” if they had a previous experience of at least 15 F-EVAR/Β-EVAR procedures. Prior to enrolling patients, however, most centres only had experience with F-EVAR procedures in juxtarenal AAA patients and only started their experience with more complex cases during the trial. As mentioned earlier, lack of experience combined with the inclusion of high risk surgical patients with difficult anatomies, inevitably results in bad outcomes. The authors acknowledged that peri-operative mortality and morbidity rates were significantly influenced by intra-operative technical complications and increased procedural duration. This resulted in high rates of significant renal dysfunction and spinal cord ischaemia (SCI). SCI, for example, affected 16.6% of patients with a TAAA Type I, II, and III. The incidence of SCI after branched TAAA repair can be lower (than was observed in WINDOWS) through the use of a “strict” multidisciplinary protocol.16Guillou M. Bianchini A. Sobocinski J. Maurel B. D’elia P. Tyrrell M. et al.Endovascular treatment of thoracoabdominal aortic aneurysms.J Vasc Surg. 2012; 56: 65-73Abstract Full Text Full Text PDF PubMed Scopus (137) Google Scholar Pre-operative graft planning should aim to preserve flow in the left subclavian artery and both internal iliac arteries as a priority, together with pre-operative spinal catheter placement for cerebral spinal fluid (CSF) drainage. Intra- and post-operatively, the anaesthetic team should aggressively correct any hypotensive episodes, as well as monitor CSF drainage. Another important factor is the need to restore pelvic and lower limb perfusion as soon as possible. Use of an open approach to femoral access vessels and encirclement of puncture sites with purse string sutures is routine. This facilitates early removal of introduction systems/sheaths, in order to rapidly restore blood flow to the pelvis and lower limbs. Apart from reducing lower limb ischaemia time and reperfusion injury, early blood flow restoration to the lower limbs may also have a positive impact on the prevention of SCI by increasing collateral flow and by reducing reperfusion oedema around the spinal cord.17Etz C.D. Kari F.A. Mueller C.S. Silovitz D. Brenner R.M. Lin H.M. et al.The collateral network concept: a reassessment of the anatomy of spinal cord perfusion.J Thorac Cardiovasc Surg. 2011; 141: 1020-1028Abstract Full Text Full Text PDF PubMed Scopus (212) Google Scholar, 18Zhu P. Li J.X. Fujino M. Zhuang J. Li X.K. et al.Development and treatments of inflammatory cells and cytokines in spinal cord ischemia-reperfusion injury.Mediators Inflamm. 2013; 2013: 701970PubMed Google Scholar Finally, a “staged approach” (implantation of a thoracic endograft 4–6 weeks prior to the F-EVAR/B-EVAR repair) also has the potential to reduce the risk of paraplegia through arteriogenic preconditioning. The “collateral network concept”, described by Etz et al.,17Etz C.D. Kari F.A. Mueller C.S. Silovitz D. Brenner R.M. Lin H.M. et al.The collateral network concept: a reassessment of the anatomy of spinal cord perfusion.J Thorac Cardiovasc Surg. 2011; 141: 1020-1028Abstract Full Text Full Text PDF PubMed Scopus (212) Google Scholar is based upon the principle of a remodelling process driven by pressure gradients across paraspinal collaterals. Evidence suggests that staged repair significantly reduces paraplegia rates after extensive thoracoabdominal aortic aneurysm repair.19Etz C.D. Zoli S. Mueller C.S. Bodian C.A. Di Luozzo G. Lazala R. et al.Staged repair significantly reduces paraplegia rate after extensive thoracoabdominal aortic aneurysm repair.J Thorac Cardiovasc Surg. 2010; 139: 1464-1472Abstract Full Text Full Text PDF PubMed Scopus (149) Google Scholar An “off the shelf” four branch graft is now available for use in acute TAAA cases. However, there is a potential downside in that some surgeons/interventionists may be tempted to implant these devices in less than optimal anatomical situations in order to avoid the 6 week delay, which is otherwise necessary to manufacture custom made devices. While compromise is understandable in life threatening situations (e.g., rupture), advocating the use of off the shelf devices in elective patients with inappropriate anatomy will almost certainly jeopardize mid- and long-term outcomes. Our initial experience with this new four branch device is positive, but the need for additional materials and ancillary products does increase, and it can be quite challenging to catheterize some of the target vessels because anatomical vessel alignments are less than perfect. In conclusion, the available evidence suggests that more complex aortic endovascular procedures (especially branched repair of TAAAs) should be focused within higher volume institutions that can provide all treatment options, have experience in dealing with technically challenging intra-operative problems and where multidisciplinary cooperation is such that the choice of treatment is not influenced by specialty, political, or financial aspects.20Holt P. Thompson M.M. Centralisation: putting patients first.Eur J Vasc Endovasc Surg. 2010; 40: 580-581Abstract Full Text Full Text PDF PubMed Scopus (9) Google Scholar, 21Haulon S. Barillà D. Tyrrell M. Part one: for the motion. Fenestrated endografts should be restricted to a small number of specialized centers.Eur J Vasc Endovasc Surg. 2013; 45: 200-203Abstract Full Text Full Text PDF PubMed Scopus (8) Google Scholar
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