Conclusions
The study shows impaired survival
and a notable lifetime risk of valve-related events after bioprosthetic
aortic root replacement. The risk of thromboembolism is prominent,
especially during earlier follow-up, suggesting higher risk of
thromboembolism early after operation.
Type of prosthesis, stented or stentless, is not associated with higher
valve-related events. Moreover, this study could be used as a benchmark
to compare outcome with other aortic root replacement procedures.
Background and aim of the
study
In young patients with aortic root disease, composite mechanical graft
replacement − Bentall-procedure− (1) is
widely used due to its long-term durability
(2). In elderly, biological aortic root
replacement is more common, because reoperations are less prominent due
to shorter life-expectancy and less structural valve degeneration (SVD)
(3, 4). This
age ‘turning-point’ however is arbitrary and biological valves are
increasingly implanted in middle-aged patients recently. Interestingly,
there are no large studies presenting outcome after bioprosthetic aortic
root replacement and our knowledge is mainly based on data reported on
aortic valve replacement. Additionally, most published studies have
limited follow-up duration, which is a limitation for the interpretation
of the results, particularly regarding SVD and reoperation hazard
(5).
Moreover, it is not known how a stentless biological valve prosthesis
compares to stented prosthesis with regard to durability and
valve-related outcome (6). Stentless
valves may have hemodynamic advantages, especially in smaller aortic
annulus, however, survival and long-term durability have not yet been
proved (7).
Conspicuously, transcatheter aortic valve implantation (TAVI) procedures
are gaining ground and with satisfying results, indicating that surgical
aortic valve replacement will probably become limited in the near future
(8). Nevertheless, when the aortic root is
affected and should be replaced, surgery is still the only
solution.
To provide comprehensive data on outcome
after bioprosthetic aortic root replacement and the possible effect of
the type of prosthesis, we conducted a systematic review of
observational reports on patient characteristics and valve-related
morbidity, mortality and reintervention with both stented and stentless
prostheses and explored potential determinants of outcome.