Commentary: Contraventional wisdom: Primary management of lower-extremity malperfusion syndrome prior to ascending aortic repair in acute type A aortic dissection

Central MessageAscending aortic repair remains the standard for type A aortic dissection. Upfront endovascular revascularization for lower-extremity malperfusion syndrome may be an option for a subset of patients.See Article page 101. In this issue of JTCVS Open, Norton and colleagues1Norton E.L. Orelaru F. Naeem A. Wu X. Kim K.M. Williams D.M. et al.Treating lower, extremity malperfusion syndrome in acute type A aortic dissection with 2 endovascular, revascularization followed by delayed aortic repair.J Thorac Cardiovasc Surg Open. 2022; 10: 101-110Scopus (3) Google Scholar present their experience managing patients with acute type A aortic dissection (ATAAD) presenting with concomitant lower-extremity malperfusion syndrome (LE-MPS). ATAAD with malperfusion has high in-hospital morbidity and mortality.2Berretta P. Patel H.J. Gleason T.G. Sundt T.M. Myrmel T. Desai N. et al.IRAD experience on surgical type A acute dissection patients: results and predictors of mortality.Ann Cardiothorac Surg. 2016; 5: 346-351https://doi.org/10.21037/acs.2016.05.10Crossref PubMed Scopus (104) Google Scholar Norton and colleagues1Norton E.L. Orelaru F. Naeem A. Wu X. Kim K.M. Williams D.M. et al.Treating lower, extremity malperfusion syndrome in acute type A aortic dissection with 2 endovascular, revascularization followed by delayed aortic repair.J Thorac Cardiovasc Surg Open. 2022; 10: 101-110Scopus (3) Google Scholar suggest treating patients with ATAAD and associated LE-MPS with endovascular fenestration/stenting first, followed by delayed open aortic repair is a reasonable approach. We commend the authors for thinking outside the box, as the in-hospital mortality for ATAAD with malperfusion remains high. It is important to note this study focuses on malperfusion syndrome of the lower extremities, defined as evidence of tissue necrosis with sensory and motor dysfunction, and not the more commonly encountered lower-extremity malperfusion without tissue necrosis, and correctly does not try to also include coronary, cerebral, or visceral ischemia. Not all malperfusion syndromes are the same in terms of physiologic impact, and therefore inclusion of all types would not make for an appropriate comparison. Taking this one step further, it is important to note that not all malperfusion syndromes for the legs are the same, varying by amount of necrosis. If the limb is clearly not salvageable, primary major amputation should be performed rather than revascularization. In addition, patients with sensory only deficits have less of an acute ischemic insult than those with motor dysfunction. Laboratory markers are also variable, for example, creatinine kinase is dependent on muscularity of the patient in addition to degree of ischemia. The authors used appropriate measures to identify LE-MPS given these constraints. This study's utility is limited, however, by small sample size and lack of a better control group. In the International Registry of Acute Aortic Dissection, 9.7% of patients presented with concurrent lower-extremity malperfusion, although unclear how many had malperfusion syndrome, and overall in-hospital mortality for ATAAD ranged from 22% to 31% over a 20-year period.3Evangelista A. Isselbacher E.M. Bossone E. Gleason T.G. Eusanio M.D. Sechtem U. et al.Insights from the international registry of acute aortic dissection: a 20-year experience of collaborative clinical research.Circulation. 2018; 137: 1846-1860https://doi.org/10.1161/CIRCULATIONAHA.117.031264Crossref PubMed Scopus (463) Google Scholar Beck and colleagues4Beck C.J. Germano E. Artis A.S. Kirksey L. Smolock C.J. Lyden S.P. et al.Outcomes and role of peripheral revascularization in type A aortic dissection presenting with acute lower extremity ischemia.J Vasc Surg. 2022; 75: 495-503.e5https://doi.org/10.1016/j.jvs.2021.08.050Abstract Full Text Full Text PDF PubMed Scopus (4) Google Scholar studied 81 patients with ATAAD and LE-MPS, and they demonstrated in-hospital mortality of 21% with only 30% of these patients requiring revascularization after central repair. In comparison, this cohort reports 6 of 25 patients died before undergoing open repair, raising concerns for this treatment strategy; however, overall in-hospital mortality was 31%, which is comparable with other reports. Descriptive nomenclature, in particular of distal extent, also matters for appropriate comparisons. The Society for Vascular Surgery has come out with a new naming system for aortic dissections that better describes the extent of the dissection and will be helpful moving forward for comparative analysis of multi-institutional registry data.5Lombardi J.V. Hughes G.C. Appoo J.J. Bavaria J.E. Beck A.W. Cambria R.P. et al.Society for Vascular Surgery (SVS) and Society of Thoracic Surgeons (STS) reporting standards for type B aortic dissections.J Vasc Surg. 2020; 71: 723-747https://doi.org/10.1016/j.jvs.2019.11.013Abstract Full Text Full Text PDF PubMed Scopus (165) Google Scholar Endovascular options continue to rapidly develop for aortic dissection, but an innovation gap remains for fenestration. The use of intravascular ultrasound is critical for identifying the true lumen as well as entry/exit tears and branching vessels. Balloon angioplasty (fenestration) works by equalizing the pressure between the true and false lumen therefore allowing re-expansion of the true. Acute success of this technique depends on number of entry/exit tears present. In summary, the treatment strategy described by Norton and colleagues has merit but needs further investigation. Next steps should include a direct comparison between patients presenting with ATAAD and LE-MPS who undergo open aortic repair first compared with those who undergo endovascular intervention up front with delayed open aortic repair. Treating lower extremity malperfusion syndrome in acute type A aortic dissection with endovascular revascularization followed by delayed aortic repairJTCVS OpenVol. 10PreviewTo assess the outcomes of emergency revascularization with endovascular fenestration/stenting followed by delayed open aortic repair in patients with acute type A aortic dissection with lower extremity (LE) malperfusion syndrome (MPS); that is, necrosis and dysfunction of the lower extremity.