A Heart Surgeon’s - Little Instruction Book
A hilarious article by Gianni Angelini (1) describes the return to Earth
of a couple of doctors, he a cardiac surgeon and she a cardiologist,
after a twenty-year stay on the planet Mars. They were understandably
concerned about reestablishing their clinical practice and while the
cardiologist discovered that a lot had changed and that she would have
to undergo new training, the cardiac surgeon was surprised by how
minimal changes had taken place in his daily practice and he was pleased
to see that he was able to start operating immediately because almost
nothing had changed in 20 years. There was still debate whether coronary
artery surgery (CABG) should be done on-pump or off-pump, whether using
single or multiple arterial grafts and whether the right internal
thoracic artery or the radial artery should be used. In other words, the
most commonly performed cardiac operation worldwide with almost 400,000
surgeries per year (2) hadn’t changed for more than two decades as if
cardiac surgeons had placed themselves out of history (3)
maintaining the status quo , refusing to accept the change and
motivating the refusal with the lack of indubitable scientific evidence
(4). In the meanwhile interventional cardiology had flourished for the
opposite reasons, making coronary angioplasty accepted and practiced
well beyond the real value attested by scientific evidence (5).
What the reasons of this behavior? Certainly not the lack of incentives
to change, just remember what Bruce Lytle wrote in 1999 in is historical
paper about the results of bilateral internal thoracic artery
harvesting: “It has been the position of some coronary artery surgeons
that the consideration of multiple arterial grafting could be ignored
because no clear evidence existed that outcomes were improved for any
patient subsets. That position is no longer tenable” (6). However after
more than twenty years the proportion of multiple arterial grafts
currently used in North America is less than 10% (7) and cardiac
surgeons are (instrumentally?) still looking for pristine scientific
evidence to justify the use of multiple arterial grafts (8). The same
fate has been struck to other innovations over the course of twenty
years, like off-pump CABG and composite Y-T grafts from LITA, to name a
couple. Proposed by a few enthusiastic innovators they have been
considered not effective (if not potentially dangerous) by the majority
of cardiac surgeons, some of whom have at times (artfully?) reported
adverse results hindering their spread (9).
There is more than the assumed lack of scientific evidence to explain
this reluctance to change, as the cost of change itself (10).
Regrettably the very good results achievable by the traditionalon-pump-LITA-LAD-plus-SV-grafts-from-ascending-aorta strategy
distracts attention from the benefits of more technically challenging
procedures. To put it another way: why change a simpler technique that
provides good results with a more complex one that could provide
better results?
The intrinsic nature of CABG surgery is therefore the main obstacle to
its improvement. Coronary surgery is micro-vascular surgery, for which
superlative technical skill is essential (11). Here, the better the
quality of suturing, the better the result of the operation, all other
boundary conditions being equal. At the same time CABG has been (and
currently is) the daily bread-and-butter of cardiac surgery, considered
by many surgeons a boring procedure to leave to residents at the
beginning of their career, preparatory to less frequent procedures
reputed of greater professional prestige. The net result of this mixture
is resistance to paradigm change (12), and the maintenance of the
”puzzle-solving” of the previous paradigm, in other words the status
quo.
The way to change paradigm goes through the restoration of CABG surgical
dignity, abandoning anachronistic legacies of the past and breaking free
from the one-size-fits-all practice, making patient specific
operations as much as possible. To achieve this goal the human factor is
extremely relevant. CABG requires advanced levels of expertise and
skills that cannot be provided by all the surgeons. CABG results can
still be greatly improved but this improvement goes hand in hand with a
parallel increase in technical complexity. Daily intentional
practice is hence mandatory to change the paradigm, to switch the
default setting from on-pump to off-pump, from aorto-coronary to Y-T
graft bypass, from saphenous vein to multiple arterial grafts, from
standard sternotomy to mini-thoracotomy. Constant dedication to CABG
improvement should make coronary surgery a subspecialty within the big
picture of cardiac surgery. As a consequence institutions dealing with
coronary artery disease patients should strive to have dedicated CABG
teams (13).
All these innovations are already among us but only a few see them. They
just need to be unveiled and practiced in the right way by properly
trained cardiac surgeons, wisely blended to make CABG patient specific.
We could change the paradigm overnight if we were ready to do it. But we
are not. And here we get to the heart of the problem: CABG training, or
what makes a cardiac surgeon an excellent CABG surgeon. Many qualities
are required, some essential, others merely desirable. Excellent
technical skill is key being CABG micro-vascular surgery. Someone is
gifted with steady hand and terrific precision of movements, someone
else is ham fisted and would do better to devote himself to other
sectors like valve surgery. Mentors should properly orient residents
helping them to express their personal talents. Then practice takes
over. As Aristotele said we are what we repeatedly do, so excellence is
not an act but a habit. Practice should comes first on low fidelity
simulators, as Paul Sergeant has elegantly demonstrated (14), and only
after in the clinical setting. Last but not least comes the cardiac
surgeon’s mindset. A good CABG surgeon should be obsessed for details,
starting with patient’s clinical history and phenotype evaluation,
passing through accurate coronary angiography analysis, planning the
surgical strategy and executing it
perfectly, up to postoperative management. As mentioned above within the
new paradigm innovations should be blended to provide a patient specific
operation, abandoning the one-size-fits-all modality. First-class
judgement is therefore important, oriented to the recognition of
individual patient characteristics and aimed at the specificity of the
operation.
The future of CABG for triple vessel disease can be bright if cardiac
surgeons will change the paradigm followed so far and will return inhistory , abandoning the current comfortable life and accepting
the burden represented by the cost of innovation, which has a path
already mapped out but not sufficiently trodden for guilty lack of
commitment. Off-pump, multiple arterial grafts and composite Y-T grafts
are a reality and are just waiting to be used more frequently in
clinical practice. Doing so would take a huge step forward in the
development of CABG.
Further innovations could probably come from robotics, artificial
intelligence and coronary suture devices but they will materialize only
if preceded by a complete mindset change on the part of cardiac surgeons
which can serve as a stimulus for research, change that is not going to
be minor and that should embrace also major changes in the cardiac
surgery training curriculum for the next generation of surgeons.