Is aortic valve-sparing root reimplantation sustainable in Loeys–Dietz patients?

Patients with connective tissue disease, including Marfan syndrome (MFS) and Loeys–Dietz syndrome (LDS), represent a challenge for both conservative medical management and surgical therapy. This is especially true when it comes to the timing and extent of aortic operations, as well as their sustainability. In the current issue of the EJCTS, Seike et al. [1] present the results of their retrospective study comparing the early and late outcomes of patients with MFS and LDS who underwent elective aortic valve-sparing root reimplantation (AVSRR). The early results were excellent with no perioperative permanent neurologic events or deaths. Despite these remarkable early results, the real points of interest of this study are related to (i) the long-term performance of the reimplanted aortic valve and (ii) the incidence of aortic events and reintervention. With regard to the first point, AVSRR is nowadays regarded as an accepted and durable treatment option for patients with aortic root aneurysms. The durability of AVSRR in MFS patients has been shown previously by many groups [2–4]. However, it could be possible that some of these studies, especially older ones, also include some LDS patients who were mis-diagnosed as MFS at that time. In contrast to MFS, less is known about the performance of AVSRR in patients with LDS due to its lower prevalence. The Johns-Hopkins group, who described LDS in 2005 [5], has probably the most experience with AVSRR in LDS patients [6]. In the present study, the cumulative incidence of relevant aortic regurgitation in the long term was comparable in both groups, suggesting a durable function of the reimplanted valve in both MFS and LDS patients. However, 5 MFS patients required reoperation of the aortic valve during follow-up, while no LDS patient required reoperation. This could be due to the small sample size, which also represents one of the major limitations of the present study. For sure, LDS is a very rare disease, but n = 10 is clearly prone to bias. Regarding the second point, it has been reported previously that LDS seems to have a more aggressive course necessitating more frequent aorta-related interventions. The authors of the present study investigated the long-term prospects of the aorta in patients with connective tissue disease a couple of years ago and confirmed a higher rate of aortic arch operation in LDS patients when compared to MFS patients [7]. One criticism of the previous study was that Seike et al. also included patients who had a previous aortic dissection, which may have led to a misleadingly high rate of aortic growth [8]. The authors fixed this issue in the present study, but this also led to a smaller sample size (see above). Nonetheless, Seike et al. confirm a higher rate of aortic events/operations in LDS patients. What might we learn from the present study? First, this study confirms previous reports and underlines that AVSRR is applicable to both MFS and LDS patients. The perioperative risk is low, and the long-term durability of the aortic valve seems not to be inferior to non-syndromic patients. Second, patients should reliably receive genetic testing when connective tissue disorder is suspected. Unfortunately, an MFS or LDS diagnosis is far too often overlooked. Third and as a direct consequence, close monitoring of MFS and especially LDS patients is essential. It still happens that patients undergo surgery but are poorly monitored and ‘get lost’ during follow-up and then present years later with the dramatic progression of aortic pathologies. Ideally, patients with connective tissue disorders are seen in specialized clinics or centres with sufficient expertise. Still, there remains an unanswered question. Although Seike et al. demonstrate a higher incidence of aortic events after root surgery in LDS patients, it remains unknown how aggressively the aortic arch of those patients should be treated when they present for aortic root surgery. Prophylactic hemiarch replacement has been proposed as a reasonable intervention. However, this approach does not address the entire arch and still leaves room for arch dilation, eventually necessitating a redo sternotomy for total aortic arch replacement. On the contrary, the risk posed by prophylactic total arch replacement at the time of root surgery is hard to justify. In the end, the present study cannot give a satisfactory answer to this difficult question, and we must wait for future studies to address and hopefully answer this question.