Typer A aortic dissection: Results of the Darts trial

Abstract

Acute DeBakey I aortic dissection is a highmorbidity and high-mortality condition. The objectives of the surgical treatment, as stated by Boszo SJ and associates from Canadian and German centers, are eliminating the primary intimal tear, sealing the false lumen to decompress it and maintaining pressurization of the true lumen. Although conventional repair is a life-saving procedure, the incapacity to seal the false lumen may lead to the creation of a new entry, distal to the anastomosis, acting in fact as a new entry with pulsed flow, pressurization of the false lumen, malperfusion, early mortality, reinterventions and shorter survival in the long term. The hybrid AMDS (Ascyrus Medical Dissection Stent) prosthesis has been designed to seal the false lumen and maintain pressurization of the true lumen. Initial positive results have been published, for which reason this paper presents immediate and medium-term results. This is a prospective, non- randomized study that enrolled 46 consecutive patients from several Canadian centers and one German center from March 2017 to January 2019. The mean follow-up was 631 days. Primary intimal tear was identified in all participants, with hemiarch repair in 45 cases and total aortic arch replacement in one patient. The authors report that this is the largest prospective study known in patients with this type of aortic dissection, with excellent results in this critical patient population and mortality rates of 13% at 30 days and 19.6% at one year in spite of the fact that 60% of the participants presented malperfusion. The 6.5% cerebrovascular accidents rate is low as compared to patients in a similar condition, in whom the literature reports rates of 11% to 46.7%. Postoperative medullary ischemia in this study was 0% and complete reversal of preoperative paralysis in all 3 patients with medullary malperfusion was evidenced. Remodelling of the proximal descending artery was proven in 77% of patients at one year, with 53% of cases presenting complete obliteration or thrombosis. The main limitation of the study according to the authors is its non-randomized, single-arm design. No comparisons were made with the results of the standard surgical repair in the same sites. The results of the study support the safety and efficacy of the AMDS hybrid prosthesis for the treatment of type I DeBakey aortic dissection.