- After an acute aortic dissection, the need for subsequent aortic arch intervention was similar in Loeys-Dietz syndrome (LDS) patients and Marfan syndrome (MFS) patients
- Among patients with root aneurysms without acute aortic dissection, 12% of LDS patients but only 1.3% of MFS patients needed subsequent aortic arch surgery
- In the LDS group, survival was worse in patients who needed additional aortic arch interventions than in those who did not (6% vs. 33%, P = .007)
- Because patients with LDS who undergo elective root repair are at greater risk for subsequent arch interventions, consideration should be given to complete removal of the distal ascending aorta during initial surgery
Like Marfan syndrome (MFS), Loeys–Dietz syndrome (LDS) is a genetic connective tissue disorder that predisposes patients to aortic aneurysms, putting them at risk of aortic dissection. In both syndromes, early elective repair of the aortic root is typically performed to protect against dissection.
Experts disagree about whether the aortic arch should be repaired at the time of aortic root intervention. Patients with MFS who undergo elective root surgery are at low-risk of needing reintervention on the aortic arch unless they develop Stanford type B dissection. However, LDS has a more aggressive clinical course.
In research conducted at Johns Hopkins Medical Center led by Massachusetts General Hospital cardiac surgeon Duke E. Cameron, MD, it was found that patients with LDS who undergo elective root repair are at higher risk than patients with MFS of needing subsequent arch interventions. In The Journal of Thoracic and Cardiovascular Surgery, the team reports how that finding has changed its approach to management.
The researchers retrospectively analyzed 335 patients with LDS or MFS who underwent elective or emergent aortic surgery between 1995 and 2015. The article discusses the thresholds for surgery and surgical techniques.
The researchers conducted telephone interviews with the patient, a family member or the primary care physician and performed a detailed chart review in all patients. The average length of follow-up was 6.2 years for LDS patients and 6.7 years for MFS patients.
Aortic Arch Intervention
The researchers divided the patients into four groups for analysis of aortic arch intervention. Primary arch interventions were those performed at the time of aortic root and/or ascending aortic surgery. Secondary interventions were any aortic arch surgery after aortic root and/or ascending aorta replacement. There four groups were:
- Group 1: 12 patients with LDS who had acute aortic dissection (AAD) at initial presentation or during follow-up — seven patients had some form of aortic arch intervention: one had primary hemiarch replacement (HAR) and six had a secondary total arch replacement (TAR)
- Group 2: 67 patients with LDS who never had AAD — three patients underwent primary HAR or TAR, and eight patients had to undergo secondary HAR or TAR
- Group 3: 26 patients with MFS who had AAD at initial presentation or during follow-up — 10 patients required primary HAR or TAR, and 13 underwent secondary TAR
- Group 4: 230 patients with MFS who never had AAD — one patient needed primary HAR, and three had secondary TAR
The risk of secondary arch intervention among patients who had AAD was similar in the LDS and MFS groups (46% vs. 50%, P = NS). Conversely, among patients who never had AAD, the need for arch repair at initial root surgery was significantly greater with LDS than MFS (5% vs. 0.4%, P = .04), as was the need for secondary aortic surgery (12% vs. 1.3%, P = .0004).
All told, LDS was associated with a threefold higher risk of secondary intervention compared with MDS.
LDS Group Survival
Three of the 79 patients in the LDS group died in-hospital and there were seven late deaths. Six of those 10 deaths occurred in patients who had TAR at some point. Patients with LDS who needed any type of secondary aortic arch intervention had worse survival than those who did not (6% vs. 33%, P = .007).
The Case for Aggressive Initial Intervention in LDS
The researchers also report that the average time interval between initial aortic root repair and secondary arch repair was similar in the LDS and MFS groups. However, the mode of failure was different:
- In MFS, there was dilation of the dissected arch after repair for type A dissection or more rapid progression after type B dissection with a retrograde component
- In LDS, the continuous growth of the non-resected distal ascending aorta and the proximal arch was prevalent. There were also several cases of aortic pseudoaneurysm and dehiscence at the distal suture line
This difference led the researchers to believe that more complete arch intervention might prevent subsequent interventions in patients with LDS. For adults, they now suggest liberal use of a short hypothermic circulatory arrest time or selective antegrade cerebral perfusion to enable complete removal of the ascending aorta, even in elective cases.
The surgeons are more reluctant to follow this strategy in children who have a normal size aortic arch. The commercially available multibranched prostheses have fixed size arm branches and distances between them that would present challenges in growing children.
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