Acute type A aortic dissection (AAAD) is an emergency associated with high morbidity and mortality, requiring immediate surgical intervention in most cases. Over the years, advancements in diagnosis and surgical treatment have reduced early mortality rates to approximately 10%–15%. Traditionally, surgical management has been limited to exclusive replacement of the ascending aorta, even in cases involving the aortic root. In such cases, the root is preserved, usually reinforcing it and resuspending the aortic valve. Alternatively, aortic root replacement can be performed, either with valve preservation or replacement with a valved conduit. Late reinterventions following aortic dissection are common in both proximal (aortic root) and distal (aortic arch) parts of the aorta. Conservative management of AAAD repair is associated with progressive root dilation, repeated dissections, or involvement of the aortic valve, leading to a higher reintervention rate. This rate is reduced with a comprehensive treatment of the root; however, the net effect of an aggressive approach to the aortic root in AAAD and its outcomes remains insufficiently explored.

The aim of this study is to compare early and late mortality and reoperation rates between aggressive and conservative treatment of the aortic root in AAAD. To achieve this, an analysis was conducted on patients operated on between 1992 and 2020 at Leiden University Medical Center (n = 322). Comparisons were made between patients who received treatment limited solely to the ascending aorta, those with ascending aortic treatment including interventions on the root (reinforcement, valve resuspension), and those with aortic root replacement, with or without valve replacement. Additionally, a subgroup analysis was conducted for patients operated on in three different periods: 1992–1999, 2000–2012, and post-2012. The median follow-up duration was 5.1 (0–21) years and 7.1 (0–25) years for the root replacement and conservative surgery groups, respectively. Outcomes in each group were analyzed with respect to early mortality, overall survival, and the need for reintervention due to complications in the root or aortic valve. The frequency of comprehensive aortic root approaches increased over the years, from 19% in earlier periods to 78% more recently. Early mortality decreased over the years, despite the adoption of a more aggressive approach, and remained lower in the subgroup of patients who underwent aortic root replacement. The conservative approach was associated with a higher risk of late mortality and reintervention, with aortic valve insufficiency being the most common cause.

Based on these results, the authors conclude that aortic root replacement is a safe approach and can be applied in AAAD with good long-term clinical outcomes without an increase in in-hospital mortality.

COMMENTARY:

The treatment of AAAD is one of the most complex and unpredictable surgeries we can face. Improvements in diagnosis, perioperative management, and surgical techniques play a crucial role in reducing mortality in recent years. This, along with the development of new prostheses, has encouraged many surgeons to opt for a more aggressive approach, even in emergency surgery. Aiming to minimize the amount of residual dissected aorta both distally and proximally. This is reflected in the group of Arabkhani et al., who significantly increased the rate of aortic root replacement in aortic dissections over the past two decades. Although aortic root surgery inevitably entails a longer surgical time and greater procedural complexity, no detrimental effect on postoperative complication rates was observed; indeed, better outcomes were achieved in terms of mortality and reintervention rates. This could be explained by advances over time in perioperative management, including earlier diagnosis and better monitoring; additionally, they noted a shift in cannulation techniques over the decades, moving from femoral to axillary access. The early mortality observed was comparable to data from the International Registry of Acute Aortic Dissection, ranging from 16% to 27%.

However, the study is not without limitations. This research pertains to a single center with a heterogeneous patient population, spanning a very long timeframe and involving various degrees of aortic dissection that were not taken into account. Furthermore, they acknowledge data loss, especially in the group of patients operated on during the initial period (1990s). Most importantly, no reference is made to the criteria guiding the choice of surgical strategy. Surgery must be tailored to the patient’s profile; an elderly patient with comorbidities might not withstand extensive surgery. Whereas a conservative approach in a younger patient may not provide long-term resolution, necessitating a second intervention with the added risk that entails. This could lead to interpretations that are not necessarily applicable to other populations or to daily clinical practice.

Aortic root replacement is a procedure that adds complexity to a surgery that is already challenging in emergency situations. In expert hands, it may yield even better outcomes compared to more traditional approaches, but we must remember to select the best option based on each patient’s comorbidities and characteristics. Therefore, further studies are needed to explore strategies tailored to individual cases.

REFERENCE:

Arabkhani B, Verhoef J, Tomšič A, van Brakel TJ, Hjortnaes J, Klautz RJM. The Aortic Root in Acute Type A Dissection: Repair or Replace? Ann Thorac Surg. 2023 Jun;115(6):1396-1402. doi: 10.1016/j.athoracsur.2022.06.041.