The aggressive approach and Freedom from re-operation?
The advocating of an aggressive intervention to replace the entire root
is yet to receive a wide consensus. 4,5,6,7 Surgically
replacing the entire root reduces the risk of subsequent dilation of the
aorta, future occurrences of aortic insufficiency, and the possibilities
of repeat dissections. These potential benefits would be expected to
increase the chances of freedom from re-operation, and improving
outcomes for long term survival.4
A retrospective study of 316 patients undergoing repair for ATAAD, had a
small sample size of 40 patients undergoing a complete root replacement.
With a mean average follow up of 26 months (94.6% complete), Nishida H
et al20 reported that these patients had a 100%
freedom from re-operation at 5 years. This was a significantly more
favorable outcome (p=0.029) than the patients not having their aortic
root replaced, who only had a 68.7% freedom from re-operation. The
aortic root events that led to the need for re-intervention, included 25
aortic dilations, 3 cases of aortic insufficiency, and 1
pseudoaneurysm20; These are long term physiological
complications which a root replacement can help
avoid.4
A much larger study by Di Eusanio et al.4 comprising
of 1,995 patients, reported that there was no statistically significant
difference (p=0.770) in the rates of freedom from re-operation at 3
years between the patients undergoing Bentall and VSRR methods of
repair, compared to those undergoing the conservative repair procedure.
However despite the large sample size, with a follow up that was only
54% complete, and results recorded at only 3 years, it is difficult to
be able to use these results alone to conclude that there would be no
significant differences in the long term for rates of
re-operation.4
Another study in the literature which although reported statistically
insignificant results, had in fact shown a clear trend of their crude
results towards more favourable outcomes for root replacement in regards
to freedom from re-operation.22 The 9 year freedom
from re-operation was reported by Ergin M and
colleagues22 as 87.5% for the root replacement group,
compared to 63.0% for the group without root being
replaced.9
Hysi I and colleagues reported outcomes for results up to 15 years
following the primary surgery and published their results with a much
longer average follow up period. The authors were able to show that
adding a root replacement in the treatment for ATAAD provides
significantly better (p=0.02) outcomes for freedom from
re-intervention.7 There were 93.4% of patients with
root replaced that were free from re-operation at 15 years, compared to
only 78% for those that underwent a supracomissural repair alone. This
was another study where the reasons for re-operations would have had a
far lower risk of occurrence had a root replacement been performed in
those patients. 4,7,20
Chiu P and colleagues6, had included 293 patients in
their retrospective study comparing root replacement(n=81) to limited
root repair(n=212), for treatment of TAAD. The article reported an
overall rate of re-operations to be 11.8% for the root repair group,
compared to 0% for the root replacement group (p=0.001). This is of
course again highly limited by the short median follow up time of 2.1
years, and the results being from a single tertiary center alone.
A short follow up period which is also not well completed, adds
significant limitations to the literature discussing the fate of the
aortic root.4-24 Given that much of the literature is
already weakened by their retrospective studies based on a single
center,4-26 such further limitations have strong
impacts on the already hindered reliability, bias, and reduced
statistical power from the small sample sizes.
The study published by Castrovinci S and colleagues27comparing 199 patients that underwent Bentall (n=108) or David (n=11)
procedures for root replacement, with those that had a conservative root
repair. The study reported results for freedom from re-operation until 7
years period with a 100% follow up rate, the results for root
replacement group was 96% freedom at 7 years, compared to only 80% for
the conservative repair (p=0.02). However following adjustments for
propensity score matching using a considerable number of covariates, the
rate of freedom from re-operation for root replacement group and without
root replacement at 7 years was; 98% and 86% respectively, however now
with a log-ranked p value of 0.06.27