Discussion
Patients with BAV present with multiple configurations of the cusps,
commissures, sinuses with/without additional aortopathy [13]. The
mechanism of AR in BAV can be diverse. Cusp prolapse, fenestration or a
restrictive cusp can cause AR. In addition, annulus dilatation or root
enlargement can be existent. Therefore, during BAV repair, the surgeon
has to consider all aspects of pathological changes in cusp and aortic
root in order to restore the valve geometry [7]. Aortic valve repair
is a feasible alternative to valve replacement that is referred to as
Class IC indication in the 2017 European Association for Cardio-Thoracic
Surgeons/European Society of Cardiology Guidelines for management of
valvular heart disease [14]. Reconstruction of BAV has been already
described in the 1990´s by Cosgrove and colleagues with triangular
resection and plication of the prolapsing cusp [15]. We used that
technique and modified it in our series to create a larger coaptation
surface. The pericardial patch augmentation was evolved in addition to
the mid-leaflet plication technique [5]. In patients with BAV and
additional root dilatation we combined BAV repair with aortic valve
reimplantation procedure (David procedure) to create a competent valve
and restore the root geometry. We performed a subgroup analysis and
compared the results of isolated BAV repair (group 1) with the David
procedure in patients with BAV. In our series the in-hospital mortality
was 1% (n=1) in group 1, and 2% (n=1) in group 2 (p=0.6). We did not
observe any neurological events (stroke) perioperatively. The BAV repair
data of our study demonstrate that it is a safe procedure and comparable
to published in-hospital mortality rates between 0 and 1% [7,16].
CPB duration was significantly longer in group 2 (132±41 minutes in
group 1 vs 191±52 minutes in group 2, p<0.01). Similar results
were observed for cross-clamp time. This might be related to additional
root reimplantation technique in Group 2 that is a complex procedure.
The fact that significantly more patients of Group 1 received
pericardial patch augmentation (89%) in comparison of Group 2 patients
(71%, p<0.01) did not have an impact on the reoperation rate
when comparing the two groups. The 5- and 10-year freedom from
reoperation were similar in both groups, (p=0.83). Reported 10-year
freedom from reoperation ranges between 78% and 81% in large series
with BAV repair which is comparable to our results [16,17]. In our
series, we observed a high number of endocarditis (n=7) at the late
follow-up which was the cause of reoperation in 44% of patients. It is
hard to explain why the observed endocarditis rate is so high. The
aortic valve mean gradient was significantly higher in group 1 (17±12
mmHg) in comparison to group 2 (9±5 mmHg, p<0.01; Table 4).
This could be related to a slightly higher aortic valve mean gradient of
group 1 patients preoperatively that increased in course of time.
Pericardial patch augmentation seems to have a negative impact on AV
repair durability as 92% of patients of Group 1 who had to be
reoperated on the AV or had AR≥2° in the follow-up period received
pericardial patch augmentation at time of primary operation. Similar
results were observed in Group 2 (67%).
Our 5- and 10-year survival were good in both groups and did not differ
significantly (p=0.31; Figure 2). Other published data with reported
10-year survival between 92% and 100% are comparable to our results
[7,16,17]. The inferior 10-year survival in Group 1 in comparison to
Group 2 might be related to a longer follow-up period of Group 1 and
could also be influenced by more concomitant procedures at time of
operation that have been performed in Group 1 (mitral and tricuspid
valve procedures; Table 2). The cumulative linearized incidence of all
valve-related complications (bleeding, stroke, endocarditis,
reoperation) was 2.9% /patient-year in group 1, respectively
4%/patient-year in group 2, (p=0.6) which is lower to the reported
incidence of prosthetic valve complications of 5% per patient per year
[18]. Our results demonstrate that BAV repair techniques are safe
and feasible. The mid-term durability of BAV repair is encouraging.