Discussion
Open aortic arch surgery is a complex surgical procedure requiring
meticulous planning and strict collaboration of surgical, anesthetic and
perfusionist teams. Specifically, in this type of surgery temporary
circulatory arrest is key to enable the replacement of the enlarged
aortic segment. Consequently, during open aortic arch surgery,
protection is required not only for myocardium (as during standard
classical cardiac surgery) but also for central nervous system and vital
organs. Our analysis shows that patients undergoing aortic arch surgery
are older (median 64 years (54-69)) with many co-existing conditions of
the heart and the aorta, often implicating the expansion of the scope of
planned surgery.
After having analyzed our 10-year outcomes of open aortic arch surgery,
we were struck by the high early mortality of 11.6%, significantly
higher than the mortality of 5.5% reported in the literature to date
[13]. Therefore, we decided to break up those 10 years into two
5-year periods.
The analysis of the first 5 years (group A) revealed that the early
learning curve period is associated with outcomes significantly worse
than those reported in literature. Particularly noticeable are early
mortality of 20% and stroke rate of 24%, whereas Thomas et al.
[13] report rates of 5.5% and 5% respectively after elective
surgery. These results can be regarded as even poorer, keeping in mind
that in most cases (68%) the surgery of aortic arch was limited to only
partial replacement (hemiarch). In this type of approach Lima et al.
[14] report early mortality of 2.9% and stroke rate of 4.1%. Worse
surgical outcomes in group A are reflected by longer ICU stay, longer
time of mechanical ventilation and more acute kidney failure and
pneumonia in comparison to group B. Another important factor affecting
the postoperative outcome was the central nervous system protection,
which in as many as 24% of patients was limited to deep hypothermic
circulatory arrest. This translated into high rate of stroke (24%).
With experience gained the number of operated patients increased from 25
patients (29%) in group A to 61 patients (71%) in group B, and the
scope of surgeries became more extended (from 32% total arch
replacements in group A to 66% in group B). Additionally, descending
aorta and aortic root became more frequently addressed. Frozen elephant
trunk with the use of the E-vita OPEN PLUS system (Jotec, Hechingen,
Germany) became the preferred technique for surgeries involving the
descending aorta.
In the second study group, complementary surgical procedures on aortic
root (valve sparing aortic root replacement (VSARR)) and aortic valve,
even though technically demanding and time consuming, were not avoided.
Of note is the rising ratio of repaired aortic valves from 50% in group
A to 79% in group B. The extending scope of surgery resulted in longer
CPB time in group B: 200 minutes vs 163 minutes (P =0.003) .
Despite the fact that patients in group B underwent more complex aortic
arch surgery, had more additional coronary and valvular procedures, and
more redo surgeries, the outcomes were significantly better than in
group A. The early mortality of 8.2% is similar to the data reported by
Patel et al [15] in his large series of 721 patients, and even
better than the early mortality of 15% reported from another polish
center by Hirnle et al [16].
Meticulous central nervous system protection contributed to the
reduction of stroke ratio to 1.6%, which is an excellent result, better
than the numbers reported by Patel et al. [15] (4.8%) and Hirnle et
al. [16] (9%). This low ratio of stroke is related to the
implementation of selective brain perfusion with cerebral oxygenation
monitoring in the majority of operated patients (96.7%), whereas DHCA
was used in only 2 patients (3.3%).
To summarize it seems that the key factor impacting the outcomes of open
aortic arch surgery is the experience of the team, which translates into
reproducible results on par with those reported by other surgical teams
specializing in the surgery of aortic arch. Estimated 5-year survival of
81% after open aortic arch surgery makes it a reliable and reproducible
cardiac surgical procedure, associated with good long-term outcomes.