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1 Coronary Artery Bypass Grafting
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The needle is now mounted backhand in the needle holder.
The correct mounting stance should be chosen with the
artery in mind, not the conduit. The assistant begins to follow
by maintaining tension on the suture. The surgeon then
grasps the vein by the adventitia near the ‘toe’ of the vein and
positions it 2–3mm above the ‘toe’ of the coronary artery,
with a little traction towards the toe. The next suture is
inserted into the vein outside-to-in. As soon as the needle is
through the vein, the assistant relaxes tension on the suture,
and the needle can be directly inserted into the artery at the
same mounting stance (provided the correct stance was
selected in the rst place). It is picked up outside the artery,
and the assistant resumes tension on the suture (Fig.1.4).
The same steps are repeated until the toe is reached and
passed. Each of these sutures can be done with a single backhand staged pass through both conduit and artery provided
the vein is positioned properly and the correct mounting
stance is chosen for the needle in the needle holder. If the
stance is wrong, there are techniques which allow stance
exchange in situ (without withdrawing the needle and needle
holder to remount). There should be ve toe sutures, gradually changing angle from 90° to the coronary artery to zero
and back to 90° on the opposite wall. For a right-handed surgeon, the switch from backhand to forehand should not take
place until the apex of the toe has been passed, that is, after
the fourth toe suture (Fig.1.5).
Fig. 1.4 The ‘far side’ of the distal anastomosis is being completed.
The assistant should follow by holding the suture tut when taking the
conduit and relaxing when taking the artery. Mount the needle ready for
the artery, not the conduit. As the latter is mobile, it can be picked up en
passant, allowing each stitch to be completed in a single, two-stage pass
5
Fig. 1.5 The toe of a distal anastomosis: note that there are ve toe
sutures, beginning at 90° to the artery on the far side and slowly rotating
through the ‘down-the-barrel’ suture to 90° on the near side
The needle is then mounted forehand. The tension on the
mosquito clip is released, and the clip positioned loose
towards the cranial end of the drape, which serves to keep the
artery open. The assistant holds the adventitia of the vein and
pulls it gently away from the surgeon, opening the space
between the vein and the artery. The anastomosis is then
completed with single-staged forehand suture passes. The
last suture is left loose, and cardioplegic solution is infused
down the vein to de-air the anastomosis before the suture is
tightened and then tied. Flow down the vein is checked by
the perfusionist by setting perfusion pressure of the cardioplegia solution at 100mmHg and reading the ow off the
pump.
The heart is then positioned for the OM graft. This
requires rotating the heart anticlockwise on the atria, which
should take the brunt of the twist instead of the ventricles. A
heavy suture is placed in the posterior pericardium, pulled
taut, and clipped between the teeth of the sternal retractor
rack. This tents the posterior pericardium into an elongated
peak on which the heart can be balanced. With the heart sufciently rotated (far enough so that the right graft is now on
the left-hand side of the ‘peak’), moist cold swabs are placed
to the right of the right atrium to x the heart on the right
side. Additional swabs are placed below the obtuse margin of
the heart superiorly. The left-sided pericardial stay is then
elevated and clipped to the drapes. With these manoeuvres,
the OM artery should be easily accessible with no further
retraction. Occasionally, if the OM is relatively posterior,
gentle nger pressure by the assistant through a swab placed
just to the right of the OM can improve the exposure. The
arteriotomy is made, and the anastomosis is then completed
in exactly the same way as the right-sided graft.
The LIMA anastomosis to the LAD is also done in exactly
the same way except for two steps. The rst is that the LIMA
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S. A. M. Nashef
is positioned at the top end of the wound on the surgeon’s side
with the pedicle secured with a clip the wound towel (holding
it by hand is not as helpful as it is in the case of a venous conduit). The second is that the LIMA arteriotomy is oversized by
at least 1cm. This is to allow accurate trimming of the LIMA
to size as the toe is approached, since the LIMA is far less
forgiving of size discrepancies than the saphenous vein. The
extra length of LIMA also provides a useful ‘handle’ of redundant LIMA which can be gripped with forceps with immunity
as it will form no part of the anastomosis when trimmed off.
The ideal time to trim the LIMA to size is one suture before
the toe. With the anastomosis completed, the bulldog on the
LIMA is removed and the suture tied after de-airing. Flow
down the LAD is now established. Within less than a minute,
the anterolateral surface of the left ventricle should contract
when touched. If it does not, there may be a technical problem
with ow down the anastomosis, which may need to be redone.
Coronary arteries are small, and their walls may be transparent. They may have folds in the oor and, during the anastomosis, sections may place themselves in the line of the needle
pass, especially at bifurcations or when an artery dips into the
myocardium. Occasionally, the surgeon may inadvertently
pick up the opposite wall or the oor of the artery while completing the anastomosis. This is especially the case if access is
difcult or visibility is impaired by collateral ow of blood.
There is, however, a useful sign that warns the surgeon that the
needle has picked up something other than the intended edge:
the ‘no wall motion’ sign. When a needle touches the wall of
the coronary artery, we expect that wall to move slightly away
under the pressure of the advancing needle before penetration
happens. This very slight movement of the wall relative to the
rest of the artery is a reassuring sign that nothing else has been
picked up by the needle. If this wall motion relative to the rest
of the artery is not clearly seen, there is a good chance that the
back wall or some other part of the artery has been included in
the suture. The solution is to withdraw that suture, reinsert it,
and avoid a lot of potential grief later.
Once all the distal anastomoses have been completed, the
cross-clamp on the aorta is removed and the entire heart usually starts to contract in sinus rhythm provided the anastomoses were expeditiously performed and myocardial protection
was adequate.
Proximal Anastomoses
The most beautifully performed distal anastomoses are
utterly useless if the proximal anastomoses are not done with
care. In addition to a poorly performed suture, proximal
anastomoses may compromise the operation in four ways:
• Too long a conduit
• Too short a conduit
• A kink in the conduit
• A twist in the conduit
My system for preventing these problems relies on a number of technical steps. Other approaches exist, but this one is
easy and reliable.
To eliminate kinks, twists, and problems of length, each
vein graft is cannulated with a Codman needle on a bloodlled syringe. Blood is injected down the graft looking at its
entire length for twists or kinks (this may require lifting the
heart to see the entire length of the graft). During this inspection, blood is injected into the vein to ensure the measurement
of length is accurate for the graft as it will be while functioning
and to conrm free unimpeded ow. Then the graft is placed
in its anticipated nal position and, while still injecting blood
down it, the perfusionist lls the heart. When the heart is at
normal size, the assistant grasps the entire vein with a deBakey
forceps coming down vertically (not sideways or at an angle)
and the surgeon cuts the graft in line with the jaws of the forceps. This denes the toe and heel of the proximal anastomosis with no risk of rotation. The toe of the vein is then gripped
in a mosquito clamp and attached to a wound towel (if it
reaches without tension) or the body of the mosquito clip is
attached to the towel with a towel clip (if it doesn’t).
The positioning of vein grafts is usually straightforward:
diagonal and OM grafts leave the aorta towards the left, PD
and LVB graft s towards the right, and a graft to the RCA
straight down. An LVB graft and a graft to a terminal circumex are better placed towards the right and passing behind
the inferior vena cava.
Once the measurement and positioning of all vein grafts
are satisfactory, a partial occlusion clamp (or ‘sidebiter’) is
applied to the anterior surface of the aorta. Most surgeons use
a hole-punch to create the aortic incision for proximal anastomoses. I do not, and make simple straight incisions in the
aorta anteriorly, angled in the anticipated direction of the
graft to its target coronary vessel. If you do use a hole-punch,
remember to incise on the side of the aorta so that the vein
takes off towards the corresponding distal anastomosis. If you
are happy with simple straight incisions, these can made on
the most anterior part of the descending aorta and the graft
will leave the aorta like a plane taking off from a runway (in
a hole-punch anastomosis, the graft takes off from the aorta
like a rocket rather than a plane, hence the need for lateral
positioning of the punch holes to avoid the ‘rocket’ having to
bend back towards the heart with the risk of kinking).
The anastomosis is begun near the toe of the vein, outsideto- in. That suture is then placed into the aortic incision as
hard a forehand as you can manage, with your elbow right
across the patient if it’s an OM graft, for example (Fig.1.6).
The next suture is then placed in the vein, and the corresponding suture on the aorta is the hardest backhand you can
manage. With these two in place, everything becomes progres-
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airing. If not, the last anastomosis is left loose while the perfusionist is asked to reduce the ow. The sidebiter is removed,
de-airing the aorta, and the suture is then quickly tied before
resuming full ow. Finally, a very easy way to check that the
proximal anastomoses are widely patent is to perform a ‘pop
test’ on each vein graft:
• The graft is occluded with forceps near its origin from the
aorta
• With thumb and forenger, the graft is gently milked at
towards the distal anastomosis for a few centimetres and
held closed
• The forceps is then taken away
Fig. 1.6 The proximal anastomosis starts at the toe of the conduit,
outside-to-in, with the aortic suture as hard a forehand as you can manage. The next suture will be the hardest backhand and, thereafter, the
suture stance becomes progressively easier until the heel
Fig. 1.7 The bayonet needle mount is particularly useful in the sutures
around the heel, between the backhand and forehand stances, but the
needle is unstable in the needle holder and will be dropped if it touches
anything before penetrating the target part of the aortic wall. Once the
heel is completed and the rst forehand pass is made, the conduit can be
parachuted down into the aorta and the remaining sutures are easily
done in single, two-stage passes
sively easier. A few more backhand sutures are then placed, and
the heel is reached. The heel is a sensitive point. It tends to be
that the needle stance switches from backhand to forehand at
the heel, and it is important to avoid excess travel on the aorta
at that point, since that can atten the vein into a ‘letterbox’ slit
and compromise ow into it. This problem can be averted by
the use of the ‘bayonet’ needle mounting stance, which allows
suturing at a stance between backhand and forehand (Fig.1.7).
The bayonet approach is easy, but the needle is highly
unstable in the holder, and care should be taken not to touch
the side of the aorta on insertion as that will almost certainly
drop the needle out of the jaws of the needle holder. The
instant the rst forehand suture is through, the vein can be
parachuted down and the remainder of the anastomosis completed very easily forehand.
When all proximal anastomoses are completed, the part
of the aorta within the sidebiter can be de-aired. If there is a
vein graft with no valves, unclamping it will achieve the de-
At that point, the attened length of vein should immediately
pop, visibly and palpably, within a fraction of a second, back to
its blood-lled status. If it doesn’t, remains at or lls slowly,
the anastomosis is obstructive and must be refashioned.
Technical Considerations forSpecial
Situations
Sequential Grafting
Sequential or ‘jump’ grafts can be very useful in many situations: shortage of conduit, a diseased aorta with limited
space for proximal anastomoses, or simply to reduce the
time needed for proximal anastomoses in multi-grafting,
such as quadruple CABG and above. The downside is the
risk of ‘too many eggs in one basket’ scenario and the fact
that, to ensure a successful sequential graft, the length and
the ‘lie’ of the conduit are critical to avoid kinking or undue
tension on the anastomoses causing distortion of the graft or
the target coronary. Some arteries are ideally situated for a
sequential graft: the PD and the left ventricular branch of the
RCA, the second diagonal and the LAD, and any of two or
more OM branches. Others can also be grafted sequentially,
but require additional care and extremely careful planning to
avoid the problems mentioned above.
For a good sequential graft, precise measurement of the
length of conduit between the two coronary arteriotomies is
crucial. First, make both arteriotomies, but keep the side-toside arteriotomy small (around 4mm). Position the conduit
over the heart with the distal end overlying the distal or endto- side arteriotomy. This determines where the conduit incision should be made for the side-to-side anastomosis. The
conduit is then lifted to expose its undersurface and lled
(with a saline syringe if it’s a vein or by moving the bulldog
clamp distally if it’s a mammary artery). The incision is then
made in the conduit. Sequential anastomoses are massively
easier to perform if the side-to-side one is done rst. The
suture technique is otherwise identical to that employed in a
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S. A. M. Nashef
non-sequential graft, but, if there is an angle in the path of
the conduit over either anastomosis, the start of the suture
on the conduit may have to be adjusted from the standard
1mm from the heel to 2 or 3mm in either direction. With
the side- to- side anastomosis completed, injecting saline or
blood cardioplegia down the graft should result in free ow
from the distal end of the conduit and from the end-to-side
arteriotomy if there is no complete occlusion between the
two arteries: this is a useful quality check. Then the end-toside anastomosis is done using the same technique, with a
similar adjustment if the conduit is approaching the coronary arteriotomy at an angle. In a well-performed sequential
graft, the only visible clue to the existence of the side-toside anastomosis should be the cut end of the suture, with no
discernible kinks, twists, or curves whatsoever in the
conduit.
Conduit Shortage
Sometimes there simply isn’t enough vein of good quality to
complete all of the grafts. Options to deal with such a situation include more usage of sequential grafting or attaching a
vein graft ‘piggy-backed’ to another if the former will simply not reach the ascending aorta without tension. For example, a diagonal graft can be very short and still reach the OM
graft. An OM1, OM2, or distal circumex graft that is too
short will often easily reach the aorta if it is passed between
the ascending aorta and the pulmonary artery.
The Diseased Ascending Aorta
This is often a problem in proximal anastomoses in our
increasingly aging and atherosclerotic patient population,
but, provided there is sufcient healthy aorta for safe cannulation and cross-clamping, problems with the proximal
anastomoses can be averted or side-stepped either by performing them on clamp to avoid the use of a sidebiter, or
performing just one proximal anastomosis and attaching all
other to that graft, or attaching one or more grafts elsewhere,
such as the innominate artery. If none of these are options,
replacing part of the ascending aorta may need to be done so
that the proximal anastomoses are made to the neo-aorta.
Woven Dacron aortic grafts are not easily amenable to partial
occlusion clamps, so the proximal anastomoses may need to
be done with the cross-clamp on.
Reference
1. Hosseinpour A-R, Hilton G, Nashef SAM. Techniques of nee-
dle stance exchange in situ. Interact Cardiovasc Thorac Surg.
2005;4:289–91.
Off Pump Coronary Artery Bypass
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Grafting
RizwanQ.Attia andRaviJ.de Silva
2
Off pump coronary revascularisation was performed rst in
St Petersburg in 1964 by Kolessov [1]. This technique was
soon overtaken by development of cardiopulmonary bypass
(CPB) and cardioplegia. The technique was revived again in
the 1980s, driven by the nancial benets of not needing the
bypass machine. Off pump has further developed with minimally invasive direct access coronary artery bypass
(MIDCAB), typically consisting of anastomosing the left
internal thoracic artery to the left anterior descending coronary artery through a small anterior left thoracotomy or
lower midline sternotomy. Access to the lateral myocardium
and right-sided vessels has been described [2]. The second
approach is multivessel grafting without CPB undertaken
through a median sternotomy allowing access to all coronary
target vessels. This allows standard techniques of internal
thoracic artery harvest. The introduction of stabilisation
devices, exposure techniques, and improved haemodynamic
management during the case has allowed increased graft
patency and widespread use of this technique for all coronary territories to construct as many anastomoses required to
treat the patient’s coronary artery disease [3–5].
Operating Room Setup andPreparation
Patient normothermia is preserved by keeping the operating
room warm, avoiding radiant heat loss and monitoring core
body temperature with a nasopharyngeal temperature probe.
A heating blanket is placed under the patient, and the patient
is kept warm at 37°C.We ensure that the heart-lung machine
and perfusionist are available with a primed cardiopulmo-
R. Q. Attia (*)
Department of Cardiothoracic Surgery and Transplantation,
Royal Papworth Hospital, Cambridge, UK
R. J. de Silva
Department of Surgery, Royal Papworth Hospital NHS Foundation
Trust, Cambridge, UK
e-mail: ravidesilva@nhs.net
nary bypass machine. Conrm availability of stabiliser
instruments, set of choice, a CO2 mister blower, and appropriately sized intracoronary shunts. Assure that the anaesthesiologist is comfortable with beating heart surgery as
collaboration is critical for success.
Anaesthetics
Involvement of the anaesthesia team is essential for successful off pump surgery. Maintenance of systolic pressure is
important for the heart to tolerate hemodynamically unfavourable positioning. Alpha agents, inotropic agents, optimal uid loading, and pacing are important to maintain
cardiac output during manipulations.
Surgical Technique
Standard median sternotomy is performed, and soft tissue
and bone haemostasis is achieved. In my practice, a long
pedicled left internal thoracic artery (ITA) is harvested using
diathermy in combination with small and medium ligation
clips. Length is important to ensure that there is no tension
on the anastomosis whilst the heart is being manipulated.
Simultaneous harvest of the long saphenous vein is undertaken using an endoscopic or open bridging technique. In
patients with severe proximal stenoses >90% or chronic total
occlusion who are young (below 65years of age), the radial
artery is an alternate conduit used for coronary artery grafting. In selected patients who are typically under 65years old,
not obese, non-smokers or those with extensive aortic calcication a second ITA is used as a conduit. Composite conduits (Y or T graft) with the left and right ITA and the radial
artery are carried out in cases where aortic clamping is not
possible to construct the proximal anastomoses.
Anticoagulation is achieved with 300 U/kg of. ACT is
measured every 30min to ensure optimal range.
© The Author(s), under exclusive license to Springer Nature Switzerland AG 2023
F. C. Wells (ed.), Atlas of Cardiac Surgery, Springer Surgery Atlas Series, https://doi.org/10.1007/978-3-031-43195-1_2
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Sequence ofAnastomoses
This varies in accordance with the increasing order of cardiac displacement and manipulation required. As a guiding
principle, a greater degree of cardiac displacement can be
tolerated with increasingly complete revascularisation of the
myocardium. This means usually the rst graft is LITA to
LAD, the inferior wall grafts (RCA or PDA) and then the
lateral wall targets (OM). There is however variation depending on the patient anatomy and tolerability to displacement.
I construct the distal anastomosis followed by proximal
anastomosis rst to allow immediate myocardial perfusion
through the graft.
Set-up andPositioning
The pericardium is opened in the midline with thymic tissue
separated along the avascular midline plane. The pericardium is opened inferiorly as a T extending into the right pericardiophrenic angle whilst maintaining the right pleural
integrity. This extension of the pericardial incision is particularly important as it allows translocation of the heart into the
right pleural space when exposing the lateral wall coronary
targets (the pericardial stay is relaxed), as well as making the
inferior myocardial vessels more accessible (the pericardial
stay is under tension). Pericardial stay sutures are placed
three on each side with haemostats to create a pericardial
well. The surgeon needs to be able to manipulate the heart
markedly during the case with resulting inuences on the
haemodynamic response of the patient. Numerous techniques are used to achieve optimal heart positioning whilst
ensuring good haemodynamics. Blood pressure is continually optimised during the procedure, and the mean arterial
pressure maintained higher than 60mmHg by repositioning
the heart or patient, intravenous uids, selective use of vasoconstrictors, or temporary epicardial pacing. The most
important variable in off pump coronary artery surgery is a
clear and open dialogue between the surgeon and the anaesthetist to continuously optimise the haemodynamics which
facilitates exposure of the coronary arteries and the
operation.
Good exposure is obtained typically through a combination of heart rocking and using a stabiliser device. In addition, the pericardial stitches are used to enucleate the heart
especially for lateral wall target grafting.
Construction ofAnastomoses
totheAnteriorWall
The ITA is bought into the surgical eld between the rst and
second pericardial well sutures that are clipped to chest wall
through a slit in the left pericardium created to 2cm distance
from the left phrenic nerve. The artery is cut open with spring
scissors and ow assessed and distal end prepared. The heart
is lifted with the surgeon’s right hand, and one to two warm
moist gauze swabs are placed under the heart (Fig.2.1). This
is typically sufcient to bring the LAD into view. In patients
with large hearts which are displaced laterally, a deep pericardial retraction suture is required. A 1 Silk or Ethibond is
used 3–4cm below the left inferior pulmonary vein (Fig.2.2).
The suture must be placed rapidly and deliberately as lifting
the heart causes haemodynamic compromise with impaired
venous return as the inferior vena cava is kinked. The suture
is pulled taut and secured to the drape on the left side of the
patient. A small warm moist gauze swab is placed on the
suture, and the heart is placed on this to bring it into
midline.
The identied site along the vessel is stabilised using one
of the many stabilisers available on the market. The authors
use Octopus® (Medtronic Inc.) placed on the lower boarder
of the sternal retractor. The device works by using suction
cups lifting the area of the myocardium between two arms
and stabilising the coronary artery which is placed in the
middle. The stabiliser has to be used as such and not a retractor which would lead to damage to the myocardium. The
anterior heart
Conduit Harvest
This is carried out as already laid out in the chapter on ‘on
pump’ coronary artery bypass grafting.
Fig. 2.1 Positioning of the heart with the Octopus retractor so that the
anterior wall is stabilised for grafting the LAD
n
sutured to the skin
2 O Pump Coronary Artery Bypass Grafting
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First DPRS—at the
level of the LSPV
Second DPRS—twothirds of the distance
toward the diaphragm
Third DPRS—betwee
IVC and LSPV
Diaphragmatic
pericardial edge
Fig. 2.2 Positions for placement of deep pericardial sutures at various
levels to allow lateral wall exposure
proximal vessel occlusion is carried out using a small bulldog
clamp placed in the fat 1cm away from the vessel. Alternate
technique involves using silastic tape or 2/0 Prolene passed
widely around the proximal vessel. Usually, no distal occlusion is required. The use of intracoronary shunts is recommended in cases where there is evidence of myocardial
ischaemia on ECG or haemodynamic instability. The coronary artery is exposed using a 15 blade and opened with a
bever blade. The anastomosis is performed in the usual manner using 8/0 Prolene suture. A CO2 mister blower is used to
open the coronary artery and keep the operative eld clean.
The LITA pedicle is tacked down with a 6/0 Prolene suture
closet to the surgeon’s side.
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Fig. 2.3 Positioning for lateral wall target vessel revascularisation
cavity. Care must be taken during this step as the cardiac
output can drop signicantly if there is rotational torsion of
the vena cavae. This brings the obtuse marginal and posterolateral branches of the right coronary artery into view. An
Octopus® (Medtronic Inc.) stabiliser is used now xed to the
left boarder of the sternal retractor and onto the heart to stabilise the coronary artery. The technique for occlusion, opening, and anastomosis is as for anterior wall targets using 7/0
Prolene sutures.
Construction ofAnastomoses
totheLateralWall
A deep pericardial suture is used as described above this time
placed on the posterior pericardial surface on a line drawn
from the left inferior pulmonary vein to the inferior vena
cava, placed halfway between the two. The patient is placed
in steep Trendelenburg, and the table is raised and rotated
towards the surgeon. This in conjunction with the extended
‘T’ pericardial incision as previously described, allows heart
displacement to the right and apex to come anteriorly
(Fig. 2.3). The suspensory pericardial well sutures on the
right side are kept lose. In some cases with cardiomegaly, it
might be necessary as an additional manoeuvre to open the
right pleural space and dislocate the heart into the right chest
Construction ofInferior Wall Anastomoses
The right-sided pericardial stay sutures are pulled taut. The
table is in steep Trendelenburg position, and the heart is lifted
up with tension to the deep pericardial retraction suture to
expose the target vessel into the middle of the operative eld.
The Octopus® (Medtronic Inc.) stabiliser is used to immobilise the artery (Fig. 2.4). Temporary occlusion is carried out
with a bulldog clamp. Rarely, the ischaemia to the atrioventricular node can cause bradycardia. These cases might require
placement of temporary atrial pacing wires to increase the
heart rate. Right coronary artery exposure requires the table
made to be moved to a atter position, and retraction sutures
are relaxed with the heart falling to the left side of the chest
cavity. The technique for occlusion, opening and anastomosis
is as for anterior wall targets using 7/0 Prolene sutures.
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Inferior
wall
Fig. 2.4 Positioning for inferior wall target vessel revascularisation
Tips andTricks
• Anaesthesia support and active participation are essential
to maintain excellent haemodynamics throughout the
case and ensure there is no myocardial ischaemia during
construction of the anastomoses with judicious blood
pressure management to maintain coronary perfusion
pressures and collateral vascular beds.
• Surgeon must allow time for excellent presentation, stabilisation, and clean operative eld prior to opening, after
opening the vessel and construction of the anastomosis. If
the exposure is compromised, then the quality of the anastomosis will be compromised with risk to patient safety.
This would impact immediate and long-term outcomes
for the patient.
• The CO2 mister blower is an essential tool which must be
used judiciously at below 5L/min to allow visualisation
but prevent damage to the endothelial lining of the
vessels.
• Intracoronary shunts (Guidant Flocoil intracoronary
shunts from 1.5 to 2.5mm in 0.25mm increments) are not
R. Q. Attia and R. J. de Silva
routinely used by the author, however they are an important tool in minimising myocardial ischaemia and improving the safety of the operation.
Postoperative Management
Postoperative intensive care unit management was standardised for all patients. All patients received intravenous
nitroglycerin (0.1–8μg/kg/min) infusions for the rst 24h
unless hypotensive (systolic blood pressure< 90 mm Hg).
Choice of inotropic agents was dictated by the hemodynamic
data. Our institution favours dopamine as a rst-line inotropic agent. Patients are loaded with 300mg aspirin 6-h postoperatively if there is no bleeding. Other routine medications
included daily aspirin and resumption of cholesterollowering agents and beta blockers unless contraindicated.
Diuretics, angiotensin-converting enzyme inhibitors, other
anti-hypertensive agents, and oral anticoagulants were gradually introduced when indicated clinically. Dual antiplatelet
treatment for 6months postoperatively became the standard
of care in our institution for patients who presented as inhospital urgent cases.
References
1. Kolessov VI. Mammary artery-coronary artery anastomosis as
method of treatment for angina pectoris. J Thorac Cardiovasc Surg.
1967;54:535–44. https://doi.org/10.1016/s0022- 5223(19)43061- 4.
2. Watanabe G, Misaki T, Kotoh K, Furuta H, Ueyama K. [Minimally
invasive direct coronary artery bypass grafting (MIDCAB) for right
and circumex coronary artery systems]. Kyobu Geka Jpn J Thorac
Surg. 1998;51:300–4.
3. Raja SG, Benedetto U, Chudasama D, Daley S, Husain M, Amrani
M. Long-term follow-up of off-pump and on-pump coronary
artery bypass grafting. Innovations. 2014;9:122–9. https://doi.
org/10.1097/imi.0000000000000042.
4. Raja SG, Benedetto U. Off-pump coronary artery
bypass grafting. Mo Med. 2020;109:157–65. https://doi.
org/10.1007/978- 3- 030- 24174- 2_16.
5. Raja SG. Total arterial off-pump coronary revascularization:
the holy grail? Curr Opin Cardiol. 2019;34:552–6. https://doi.
org/10.1097/hco.0000000000000645.
Surgical Treatment ofComplications
https://t.me/medicina_free
ofAcute Myocardial Infarction:
Postinfarction Ventricular Septal Defect
andFree Wall Rupture
ChooNg
3
Rupture of the ventricular chamber (septum or free wall) following myocardial infarction is a relatively infrequent condition with high mortality. The condition has become
increasingly uncommon because of early intervention on
coronary occlusion with acute percutaneous intervention.
This condition, resulting from transmural infarction can lead
to breakdown of the muscle (usually within 2–4days) and
the creation of a communication between the right and left
ventricles, a ventricular septal defect (VSD) or a ventricular
free wall rupture.
In septal rupture, there is a variable amount of left-toright shunting, and it often leads to symptoms of heart failure. The clinical presentation ranges from an asymptomatic
murmur to cardiogenic shock. In ventricular free wall rupture, this can result in tamponade and sudden cardiovascular
collapse. Ventricular free wall rupture is only survivable if
the infarcted area has formed adhesions to the parietal pericardium, thereby walling off the rupture. In this situation,
some patients can present late with this provided the recovery from the initial infarct is uncomplicated.
Ventricular Septal Defect
The ventricular septum has a dual blood supply from the left
and right coronary arteries. The exact distribution is variable.
In a right coronary dominant system or a balanced supply
with a large circumex vessel, transmural infarction caused
by occlusion of these vessels will usually cause an inferolateral infarct with an inferior or basal VSD.In a dominant
left coronary system, the infarction will be more towards the
apex or antero-apical. The more proximal the occlusion of
the coronary artery (especially in a dominant artery: right
C. Ng (*)
Department of Cardiothoracic Surgery, Royal Papworth Hospital
NHS Foundation Trust, Cambridge, UK
e-mail: c.ng@nhs.net
versus left circumex) leads to more myocardium being
affected and therefore the outcome is likely to be worse.
Therefore, an apical VSD is the easiest to repair and carries the best outcome. An infero-basal infarct and inferior
VSD will almost always present with severe right ventricular
dysfunction and this tend to be associated with the worse
outcome. The clinical presentation of patients with post
myocardial infarction VSD depends largely on the size of the
infarction and the size and therefore the degree of left-toright shunting. In the case of a right coronary artery occlusion, this has a greater impact as the right ventricle does not
respond well to volume loading from a left-to-right shunt per
se without the added insult of a myocardial infarction of the
territory supplied by the right coronary artery.
The initial management in any case would be acute percutaneous intervention to open any viable coronary arteries to
improve the blood supply immediately. If this is not possible,
then medical support for cardiogenic shock which usually
will include intra-aortic balloon pump support is necessary.
Conservative management has a very high mortality in the
rst 30days.
The timing of surgical treatment can be determined by
consideration of three clinical aspects; the time from acute
myocardial infarction, the degree of cardiogenic shock (combination of infarcted myocardium and degree of left-to-right
shunt), and the degree of end-organ malperfusion causing
irreversible damage.
Scenario 1
The current indication for surgical revascularisation in acute
myocardial infarction is largely centred around the presence
of cardiogenic shock and the size of ‘at risk’ myocardium.
Conventional wisdom dictates that surgical revascularisation
should be delayed for up to 48–72 h from the time of the
acute infarction if possible as the hospital mortality is much
more favourable. Therefore, if a patient now has an added
mechanical complication such as a VSD with ‘spiralling’
© The Author(s), under exclusive license to Springer Nature Switzerland AG 2023
F. C. Wells (ed.), Atlas of Cardiac Surgery, Springer Surgery Atlas Series, https://doi.org/10.1007/978-3-031-43195-1_3
13
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C. Ng
cardiogenic shock despite maximum conventional ionotropic
support including an intra-aortic balloon pump (IABP)
catheter augmentation but is still within 48 h of an acute
event, that patient represents the highest risk group of
patients dying within hours. If appropriate age and morbidity
permitting, these patients should be offered salvage surgery.
Modern day cardiac surgery now has extracorporeal circulatory and ventilatory support at its disposal and it is now considered ‘not prohibitive’ to support such patients in the
postoperative period as a bridge until the myocardium has
recovered. The other small advantage of extracorporeal circulatory and ventilatory support as it gives the surgical repair
and ventriculotomy, the best chance of success in a left ventricle that is not pressure or volume loaded.
Scenario 2
This is probably the most common group of patients where
the initial cardiogenic shock is rescued by medical support
including IABP augmentation. The timing of surgery is now
determined by the surgeon who has time to consider when it
is ‘favourable’ to proceed. A word of caution. These patients
may appear stable but can exhibit ‘soft’ signs of end-organ
malperfusion and can deteriorate insidiously. Obviously
delaying surgery for weeks gives the best chance of surgical
repair but clearly also ‘super selects’ the patients that are
going to do well. These patients should be offered surgery as
soon as the ‘throes’ of acute myocardial event has subsided,
and the patients are metabolically corrected.
Scenario 3
These patients are stable with little or no medical support
and are usually those who did not require initial support with
IABP.The VSD is technically chronic within 4–6weeks, and
indication for surgical repair is primarily to prevent deterioration of right ventricular function. These patients can even
be considered for percutaneous closure depending on the
location of the defect.
Free Wall Rupture
Post-mortem studies reveal that ventricular free wall rupture
occurs about ten times more frequently than postinfarction
ventricular septal rupture, occurring in about 11% of patients
following anterior myocardial infarction. The incidence has
been found to be as high as 31%. Ventricular rupture and
cardiogenic shock are now the leading causes of death following anterior myocardial infarction and together account
for over two-thirds of early deaths in patients suffering their
rst acute infarction. In the pre-thrombolytic era, 90% of
ruptures occurred within 2weeks after infarction, with the
peak incidence at 5days. In contrast, the time to cardiac rupture (not frequency of rupture) seems to be accelerated by
thrombolysis and coronary reperfusion, sometimes occurring within hours (especially in a hypertensive patient) from
the onset of symptoms.
Acute free wall rupture is usually not amenable to treatment as those patients who exhibit sudden cardiovascular
collapse rarely survive. A subacute rupture is characterised
by a smaller tear, which may be temporarily sealed by clot or
brinous pericardial adhesions. Those who survived to the
initial subacute rupture are still very much at risk of dying
from cardiac tamponade from pericardial collection. In general, surgery should be undertaken immediately.
Simple drainage of pericardial collection either via percutaneous approach or surgical drainage is not recommended
as the risk of re-collection or secondary rupture is very high
in a portion of left ventricular wall that is signicantly weakened and not supported.
Rarely these patients present in heart failure from a rupture that was clinically missed (chronic) that is now con-
tained and forms a large false aneurysm. Surgical repair is
almost always recommended, age and comorbidities
permitting.
Surgical Approach andTechnique
Both conditions are managed by conventional open-heart
surgery with median sternotomy and cardiopulmonary
bypass with bicaval cannulation with snaring of both inferior
and superior vena cava and ascending aorta arterial return.
Moderate hypothermia is used especially in acute situation to
protect the end organs.
Snaring of both cava obviously prevents entrainment of
air across the VSD but is optional in a free wall rupture.
Venting of the left heart is usually not necessary when the
left ventricle is going to be laid open but a vent in the pulmonary artery does help minimise blood return from the pulmonary vasculature. Often, placing a vent in the left ventricle
via the right superior pulmonary vein after the ventriculotomy is closed helps with de-airing of heart chambers.
Judicious myocardial protection with cold blood cardioplegia (antegrade alone or in combination with retrograde) is
crucial.
Concurrent coronary artery bypass graft surgery can be
considered if there are signicant by-stander coronary artery
disease. Pragmatic view should be taken when coronary
artery bypass graft surgery for moderate coronary artery disease will add signicant amount of ischaemic time in a salvage situation. There is controversy regarding performing
bypass graft surgery to the area of infarcted myocardium
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