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arteries. The interior of the left ventricle is then thoroughly irrigated with cold saline solution to wash away any
debris.
With sharp scissor dissection, a 3-mm thick layer of the endocardial fibrous lining of the left ventricular cavity is
stripped en masse for approximately 1 to 2 cm from the edge of the infarcted area. This theoretically removes
any abnormal foci of electrical activity.
Radical Endocardial Dissection
If a patient has a history of ventricular arrhythmia, it is advisable to carry out a radical endocardial resection while
performing the left ventricular remodeling. The procedure entails the dissection of a 2- to 3-mm thickness of the
endocardium of the left ventricle. The resection should be extensive, reaching to the base of the papillary muscle
and the aortic root, to ensure complete removal of any scattered arrhythmogenic foci. Cryoablation of the
transitional zone between the scar tissue and myocardium in patients with a ventricular aneurysm may be helpful.
Care must be taken not to damage the papillary muscle to avoid causing mitral insufficiency. Most of these
patients are candidates for implantation of an internal cardioverter-defibrillator device.
The liberal use of internal cardiac defibrillators and antiarrhythmic drugs has markedly decreased the
indication for endocardial resection.
Concomitant Mitral Valve Repair or Replacement
Some patients may have hemodynamically significant mitral regurgitation due to papillary muscle dysfunction
and/or mitral valve disease. Every attempt should be made to repair the valve either through the ventricle or
through a separate left atrial incision in the traditional way (see Chapter 6). If the valve is grossly diseased and
unsuitable for repair, it is replaced through the ventriculotomy. An attempt is made to preserve the subvalvular
apparatus. Excess leaflet tissue can be excised or incorporated in the sutures. Pledgeted sutures of 2-0 Ticron
are used to anchor the prosthesis in position (Fig. 10.9).
Choice of Prosthesis
Only a bileaflet mechanical or bioprosthesis should be used in the mitral position, especially if implanted through
the left ventriculotomy. Particular attention should be given to the orientation of the prosthesis, which is not as
familiar from the left ventricular aspect.
The direction of the sutures is from the left atrium toward the left ventricular cavity. The sutures are then passed
from the superior aspect of the prosthetic sewing ring to its inferior aspect so that when the sutures are tied, the
knots are on the left ventricular side (Fig. 10.9). Care
must be taken to ensure that the knots of the sutures do not interfere with the occlusive mechanism of the
prosthesis.
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FIG. 10.9 Technique for mitral valve replacement through a left ventriculotomy.
The ventricle should be closed in such a manner as to restore its normal geometry. This entails excluding the
akinetic and dyskinetic segment of the infarcted ventricular wall and thereby reducing the left ventricular volume.
A continuous 2-0 monofilament suture is placed deep into the scar along the edge of the normal left ventricular
wall and tied to create a purse-string effect (Fig. 10.10A).
The infarction frequently affects both the anterior wall of the left ventricle as well as a segment of the
septum. It is therefore important to include the edge of the scar on the septum in the purse-string suture. This
reduces the size of the defect in the left ventricular wall to a great extent and gives the left ventricular cavity a
relatively normal shape and geometry (Fig. 10.10B).
The “ideal” size of the left ventricular cavity can be approximated with commercially available sizers. The
recommended cavity size is 60 mL per square meter of body surface area of the patient. The appropriately sized
balloon is placed in the left ventricular cavity and a 2-0 Prolene suture is placed in the scar tissue along the
border of normal tissue. This is accomplished in a purse-string manner over the sizer, which is removed before
the suture is tied.
A Hemashield patch is cut into the appropriate size and shape of the defect and sewn into place with a
continuous suture of 3-0 Prolene, taking deep bites of the surrounding scar tissue. The suture line may have to
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be tightened with a nerve hook and reinforced with a few interrupted sutures buttressed with felt pledgets.
BioGlue can be applied to the suture line for added security. Only when the patient has been weaned off
cardiopulmonary bypass and there is no bleeding from the patch site should the excess left ventricular wall be
approximated over the patch to prevent the accumulation of blood and clot between the patch and ventricular
wall (Fig. 10.10C).
Tissue Covering the Left Ventricular Patch
Covering the left ventricular patch with infarcted wall minimizes the possibility of graft infection should
mediastinitis occur.
Coronary artery bypass grafting to diseased vessels is performed when possible to achieve maximal
revascularization of the heart. Special care is taken to deair the heart before removing the patient from
cardiopulmonary bypass (see Chapter 4).
A multicenter clinical trial did not demonstrate that addition of surgical ventricular restoration to coronary
bypass surgery in suitable patients with ischemic cardiomyopathy reduces mortality. However, this procedure
can restore ventricular geometry and volume in properly selected patients.
PSEUDOANEURYSM
Postinfarction false aneurysm is a rare phenomenon. It occurs when blood leaking from a myocardial rupture
slowly accumulates in the pericardial cavity. Reactionary adhesions limit the size of the pseudoaneurysm. Two-
dimensional echocardiography and ventricular angiography delineate the lesion quite vividly. Unlike left
ventricular aneurysms, eventual rupture of the pseudoaneurysm is virtually certain. Therefore, surgical
management must always be carried out on a semiurgent basis.
The surgical technique is similar to that described for true aneurysms. However, false aneurysms are often very
thin walled and may rupture easily during dissection and manipulation of the heart. Therefore, it is prudent to
initiate cardiopulmonary bypass by cannulating the femoral artery and vein (see Chapter 2). A median
sternotomy is then performed; the aorta is cross-clamped and cardioplegic arrest of the heart achieved before
addressing the pseudoaneurysm. If the pseudoaneurysm ruptures before aortic clamping, blood is removed from
the field and returned to
the pump by suckers. The aorta is quickly clamped, bleeding is brought under control, and cardioplegic arrest of
the heart is then accomplished.
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FIG. 10.10 A: Suture placed in the scar along the edge of the normal left ventricular wall. B: Purse-string suture
reducing the size of the defect. A small Hemashield patch is sutured in place to cover the defect. C: The defect
in the left ventricular wall is closed, and the scarred aneurysmal wall is approximated over the patch when
absolute hemostasis is achieved.
Pseudoaneurysms usually have small openings. The defect is closed with a patch of Hemashield using
interrupted 3-0 Ticron sutures buttressed with felt pledgets. The suture line is reinforced with a continuous
suture of 3-0 Prolene. Absolute hemostasis is obtained, and the heart is deaired (see Chapter 4).
ISCHEMIC MITRAL REGURGITATION
Besides complete or partial papillary muscle rupture, ischemic mitral valve prolapse may be caused by
elongation of a papillary muscle following infarction. Occasionally, necrosis of a separate commissural head of
papillary muscle gives rise to rupture of the commissural chord (Fig. 10.5B). However, ischemic mitral
regurgitation encountered following the acute postinfarction period is predominately functional. It is due to
annular dilation secondary to left ventricular enlargement and/or local left ventricular remodeling of the inferior
wall causing papillary muscle displacement with restricted motion of the mitral leaflets. The surgical approach to
chronic ischemic mitral regurgitation requires a precise understanding of the mechanisms involved (see Chapter
6).
INTRAAORTIC BALLOON PUMP
Occasionally, patients may require intraaortic balloon pump support after a cardiac surgical procedure.
Depressed left ventricular function, ongoing myocardial ischemia, and ventricular arrhythmias are all indications
for placement of an intraaortic balloon pump.
Technique for Placement of Intraaortic Balloon Pump
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If the patient has a palpable femoral pulse, the intraaortic balloon pump can be placed percutaneously using the
Seldinger technique. After the common femoral artery is entered, the guidewire is passed through the needle,
which is then removed. The dilator is introduced over the wire. The sheath is then passed over the wire into the
artery. The deflated prewrapped balloon catheter is then introduced through the sheath and positioned in the
descending thoracic aorta with the tip just distal to the takeoff of the left subclavian artery. Use of
transesophageal echocardiography aids in proper positioning of the intraaortic balloon.
Bleeding in Heparinized Patients
During or immediately after cardiopulmonary bypass, the patient is fully heparinized. Use of the percutaneous
technique may lead to hematoma formation, retroperitoneal hemorrhage, or bleeding around the balloon sheath.
This is especially likely to occur if it is difficult to palpate the femoral pulse, leading to inadvertent punctures of
the femoral vein or back wall of the femoral artery.
Improper Placement of the Balloon Catheter
The balloon catheter should be placed through the common femoral artery. If it is inserted through the superficial
femoral artery, lower extremity ischemia may result. The entry site of the balloon should be caudad to the
inguinal ligament. Placement above this level may lead to bleeding, which is difficult to control by external
pressure when the balloon catheter is removed.
Management of Lower Extremity Ischemia
If a patient develops evidence of leg ischemia after balloon pump placement, removing the sheath may allow
improved distal blood flow. Alternatively, smaller diameter balloon catheters are available and should be used in
patients with small femoral arteries.
In the operating room, when difficulties are encountered during weaning from cardiopulmonary bypass,
placement of an intraaortic balloon may be helpful. In these patients, often no femoral pulse can be palpated.
Limited exposure of the common femoral artery is achieved through a small longitudinal incision with minimal
dissection. A purse-string suture of 4-0 Prolene incorporating only adventitial tissue is placed on the anterior
surface of the common femoral artery. The needle, wire, dilator, and balloon catheter are sequentially passed
through this purse-string site. The suture is left long with the ends secured together by a metal clip and buried in
the wound. The incision is closed in layers around the balloon catheter. Subsequently, the balloon may be
removed under local anesthesia at the patient's bedside. The femoral arteriotomy is closed by simply tying the
previously placed Prolene suture (Fig. 10.11).
FIG. 10.11 Technique for placement of intraaortic balloon catheter.
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11
Heart Transplantation
Heart transplantation has emerged as an effective therapy for patients with end-stage heart diseases. In 2005, a
total of 2,125 heart transplants were performed in the United States. The major obstacle to more widespread
application of heart transplantation is donor shortage.
DONOR SELECTION
Matching of a donor heart to a specific recipient requires consideration of many donor and recipient factors,
several of which have changed over time. Although there is no absolute maximum age for cardiac donors, many
centers use an upper age limit of 55 to 65 years.
A history of diabetes mellitus in the donor with microvascular disease, long-standing donor hypertension with left
ventricular hypertrophy (by electrocardiogram or echocardiogram), or prolonged high-dose donor heart inotropic
requirement may be associated with an increased risk of early graft failure. Segmental or global wall motion
abnormality of the donor heart can be associated with brain death and should not be considered a
contraindication to transplantation. Resuscitation with thyroid hormone or the addition of inotropes and/or
vasoconstrictors may lead to improvement in left ventricular function. The donor can then be reassessed with a
repeat echocardiogram or a pulmonary artery catheter.
It is generally recommended that male donors older than 40 years and female donors older than 45 years
undergo a coronary angiogram if available. Presence of significant coronary artery disease (>50% lesions) in two
or more major coronary arteries is usually a contraindication to utilization of a donor heart. However, for critically
ill recipients, donor hearts with discrete coronary stenoses can undergo bypass grafting using recipient conduits
ex vivo, and be transplanted with acceptable short-term outcomes.
Aside from the considerations mentioned earlier, other contraindications to the use of a donor heart include
positive human immunodeficiency virus (HIV) serology, positive hepatitis C serology, donor malignancies other
than primary brain tumor, and systemic bacterial infection (especially with gram-negative organisms).
It is important to match the donor heart to the clinical situation of the recipient. For a critically ill recipient, the
donor criteria may be relaxed, as the alternatives of either continued waiting on the list or a ventricular assist
device may carry a higher mortality risk.
Size matching of the donor and recipient is important. Severe undersizing can lead to the inability of the donor
heart to support the recipient's circulation, especially if there is evidence of primary graft dysfunction. Most
programs require a donor-to-recipient weight ratio of at least 0.7. Oversizing can lead to restrictive physiology
due to limited recipient mediastinal space. This issue is especially relevant in patients whose native heart
disease is not dilated. Donor-recipient size matching has to be considered in association with other donor and
recipient variables (i.e., an undersized female donor heart may not be suitable for a male recipient with
pulmonary hypertension, especially in a setting of mild donor left ventricular hypertrophy and/or long ischemic
time). Caution needs to be exercised when using a donor with multiple risk factors: older age, left ventricular
hypertrophy, long ischemia time, and others.
PRESERVATION SOLUTION
The ideal preservation solution will ensure microvascular, cellular, and functional integrity of the donor heart
during the ischemic phase. Experience with the currently used preservations solutions (University of Wisconsin
and Celsior solution) have shown excellent myocardial functional recovery, especially when the ischemic time is
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less than 6 hours.
University of Wisconsin solution is an “intracellular” based solution (low sodium, high potassium) and contains
several classes of impermeable molecules to minimize cellular swelling. Because of the concern about the
deleterious effects of high potassium concentrations on microvasculature, Celsior solution, which is an
“extracellular” solution, was developed. In addition to many impermeable molecules, Celsior also has glutamate
that serves as a substrate for energy production. Several studies have shown that both solutions afford similar
protection
to the donor heart during preservation. We currently use University of Wisconsin solution as our preservation
solution of choice.
DONOR OPERATION
Upon arrival at the donor hospital, the procurement surgeon will review the donor's medical records to ensure the
accuracy and completeness of all data. The donor is placed in supine position with arms extended by the side.
Because most donors are multiorgan donors, the donor is prepped from neck to midthigh. Midline sternotomy
incision is performed as previously described. In smaller community hospitals, a sternal saw may not be available
and a Lebsche knife may be used. The pericardium is opened and pericardial sutures are placed. The right
pleural space is opened widely. The heart is systematically examined for size, evidence of right ventricular
dysfunction, contusion, aneurysm, segmental wall motion abnormality, or a thrill suggestive of valvular heart
disease. The course of the coronary arteries is palpated for evidence of calcification or plaques. If the quality of
the donor heart is acceptable, this information is communicated to the recipient hospital.
The dissection of the donor heart is started by freeing the superior vena cava from pericardial reflection to the
innominate vein. The azygous vein is usually tied and divided to ensure sufficient length of the superior vena
cava.
For recipients with congenital heart disease who have previously undergone a classic or bidirectional Glenn
procedure, a longer segment of innominate vein may be required.
The aorta is dissected distally beyond the innominate artery take-off. The needle for administration of
preservation solution is inserted into the ascending aorta and secured (Fig. 11.1). When the other procurement
teams have completed their respective organ dissections, heparin at a dose of 300 units per kilogram of body
weight is administered.
The most important step in heart procurement is to ensure that the donor heart is emptied. The pericardium on
the right side is incised at the level of the hemidiaphragm down to the inferior vena cava. The superior vena cava
is clamped and the inferior vena cava is transected so that the blood from the heart empties into the right chest
cavity.
If the lungs are being harvested, exsanguination has to be done into the abdomen by the abdominal team.
When the heart is empty (usually after 5 to 10 beats), the aortic cross-clamp is applied and the preservation
solution is administered into the aortic root. We measure pressure in the ascending aorta and maintain it
between 50 and 70 mm Hg. The apex of the heart is elevated toward the right side, and the left inferior
pulmonary vein is incised where it joins the left atrium (Fig. 11.2). The pericardium is filled with ice slush to
ensure topical cooling. A total
of 10 mL per kg of donor body weight of University of Wisconsin solution is administered, which may take several
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minutes. During this time, the procurement surgeon must ensure that the heart is not distended by frequent
palpation of the left ventricle. The donor heart usually stops beating after 30 seconds of perfusion with the
preservation solution.
FIG. 11.1 The donor heart is prepared. Antegrade cardioplegia needle has been placed, and the aortic cross-
clamp is applied.
FIG. 11.2 After dividing the inferior vena cava, the left inferior pulmonary vein is transected at its point of entry
into the left atrium (when lungs are not being harvested).
When the lungs are also being harvested, the incision is made halfway between the left inferior pulmonary
vein entry into the left atrium and the atrioventricular groove. This maintains adequate cuffs of pulmonary veins
for lung harvest.
When the infusion of the preservation solution is complete, the heart is excised. This is accomplished by dividing
the superior vena cava or innominate vein proximal to the clamp. The remaining pulmonary veins are transected
as they enter the left atrium. Alternatively, if the lungs are being harvested, the incision on the left atrium is
continued circumferentially just anterior to the pulmonary vein orifices. The aortic arch is transected just distal to
the innominate artery and the main pulmonary artery is divided. If the lungs are not being harvested, the proximal
right and left pulmonary arteries can be divided to provide extra pulmonary artery length (Fig. 11.3).
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FIG. 11.3 Excised donor heart. The sinoatrial node is marked with an X.
The heart is removed from the donor and taken to the back table. It is inspected for the presence of a patent
foramen ovale or valvular abnormalities. If a patent foramen ovale is found, it is closed with a figure-of-eight or
continuous Prolene suture through the inferior vena caval opening, using forceps to expose the interatrial
septum. The valves are visualized to rule out vegetations, small perforations, or clots that may have been missed
by the preoperative echocardiogram. A piece of donor pericardium is also harvested and packed with the donor
heart.
Strips or pledgets of donor pericardium are very useful in reinforcing aortic and pulmonary artery suture
lines.
The donor heart is packed in a minimum of three sterile plastic bags and then placed in a plastic container full of
ice for transport. Several donor lymph nodes are also taken for prospective cross-matches.
RECIPIENT SURGERY
A pulmonary artery catheter and an arterial line are placed in the recipient. The recipient does not undergo
general anesthesia until the donor heart has been examined and found to be satisfactory. We usually allow 1
hour from skin incision to the arrival of the donor heart for recipients who have not undergone a previous
sternotomy. In patients with a prior sternotomy, this period is extended to 2 hours to allow adequate time to
complete the dissection of the native heart.
Right Ventricular Wall Injury
In patients with a prior sternotomy and biventricular failure with a distended right ventricle, the surgeon may
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