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Critical Care Nurse. 2002;22: 44-58
Copyright © 2002 by the American Association of Critical-Care Nurses.
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Clinical Article
CE Online

Beating-Heart Coronary Artery Bypass Graft Surgery: Indications, Advantages, and Limitations

Carol Chen-Scarabelli, MSN, ARNP-CS, CCRN

Carol Chen-Scarabelli is a nurse practitioner in the Division of Cardiothoracic Surgery, Jackson Memorial Hospital, University of Miami, Miami, Fla.

To purchase reprints, contact The InnoVision Group, 101 Columbia, Aliso Viejo, CA 92656. Phone, (800) 899-1712 or (949) 362-2050 (ext 532); fax, (949) 362-2049; e-mail, reprints{at}aacn.org.

To receive CE credit for this article, visit the American Association of Critical Care Nurses ’ (AACN) Web site at http://www.aacn.org, click on "Education" and select "Continuing Education," or call AACN’s Fax on Demand at (800) 222-6329 and request item No. 1158.

Cardiovascular disease is the leading killer in the United States among both men and women, affecting approximately 20% of the population before the age of 60 years.1 Each year, coronary artery disease is diagnosed in more than 1 million persons.2 Of this group, approximately 300 000 will undergo coronary artery bypass graft (CABG ) surgery.2 In the mid-1990s, the estimated annual cost of cardiac surgical procedures performed in the United States was $9 billion, and this estimate did not include an additional $1.2 billion incurred because of postoperative complications.3 In 2001, the estimated cost of cardiovascular disease and stroke in the United States was $298.2 billion.4 Of this amount, $100.8 billion was spent on coronary heart disease alone (exclusive of congestive heart failure), including $47.1 billion on hospital, nursing home, and physicians’ care.4 In this article, I examine beating-heart CABG surgery, its risks and benefits, and its potential economic impact on healthcare costs.


   HISTORICAL BACKGROUND
Top
 HISTORICAL BACKGROUND
TRADITIONAL CABG SURGERY
 MINIMALLY INVASIVE DIRECT CABG...
 OFF-PUMP CABG SURGERY VIA...
 NURSING CARE OF PATIENTS...
 SUMMARY AND FUTURE RESEARCH
 References
 
In 1952, Demikhov pioneered surgical myocardial revascularization with the internal mammary artery in canines.5 This accomplishment was soon duplicated by Murray (1952), Sabiston (1963), and Garrett (1964).5 However, the invention of beating-heart or off-pump CABG surgery is often attributed to Kolessov, who, in 1967, used a minithoracotomy incision, anastomosing the left internal mammary artery (LIMA) to the left anterior descending artery (LAD).6,7 Later pioneers of the off-pump technique include Favoloro, Garrett, and associates (in the United States); Trapp and Bisarya (in Canada); and Ankeney (in the United States)—all of whom performed off-pump CABG surgery from 1968 to 1975.6,7

However, the off-pump procedure was abandoned with the development of the cardiopulmonary bypass machine and cardioplegia and the routine use of these techniques, which afforded access to all areas of the heart.6,7 In the 1980s and 1990s, Benetti and colleagues in Argentina and Buffolo and his colleagues in Brazil reintroduced off-pump CABG surgery.8,9 This reinstitution in South America was partly due to economic reasons and limited healthcare resources.8,9

Yet, despite the existence of off-pump CABG surgery for almost half a century, the interest in performing CABG without cardiopulmonary bypass has only resurfaced during the past 10 years.10 This renewed interest has been attributed to several reasons: improvements in surgical and anesthetic techniques, economic advantages related to reduction in length of hospital stay and resource utilization, and minimization and/or elimination of risks associated with cardiopulmonary bypass. The safety and success of the off-pump CABG surgery, along with decreased costs and absence of adverse effects associated with cardiopulmonary bypass, have been major impetuses in the resurgence of this form of CABG surgery in the United States. Since then, off-pump CABG surgery has become increasingly commonplace as more cardiac surgeons overcome the learning curve involved with operating on a beating heart.11

Currently, off-pump CABG surgery accounts for about 20% of all CABG operations in the United States, and in many of these surgeries, a minimally invasive incision is used.5,12 According to the American Heart Association, approximately 110 000 patients have off-pump CABG surgeries each year.4

Although LIMA-to-LAD grafts have a 10-year or greater patency rate of 85% to 90%, percutaneous transluminal coronary angioplasty, for which the 6-month restenosis rate is 33% to 60%, was the most popular coronary revascularization procedure until a few years ago.13 The reason for the overwhelming popularity of angioplasty may be the morbidity associated with traditional CABG surgery. Nonetheless, the preference for angioplasty may wane with the advent of off-pump CABG surgery and the expected reduction in morbidity and mortality.13


   TRADITIONAL CABG SURGERY
Top
 HISTORICAL BACKGROUND
 TRADITIONAL CABG SURGERY
MINIMALLY INVASIVE DIRECT CABG...
 OFF-PUMP CABG SURGERY VIA...
 NURSING CARE OF PATIENTS...
 SUMMARY AND FUTURE RESEARCH
 References
 
CABG surgery is universally regarded as the gold standard for surgical revascularization of coronary arteries.2 In 1953, Gibbon successfully used the cardiopulmonary bypass apparatus in cardiac surgery to close an atrial septal defect.14 The systematic use of cardiopulmonary bypass was pioneered by John Kirklin in 1955.9 Conventional CABG surgery includes use of cardiopulmonary bypass, aortic cross clamping, hypothermia, and cardioplegia to stop the heart and divert blood flow from the heart to provide a motionless and bloodless field.2 Recovery may take as long as 4 to 6 weeks, with a mean hospitalization of 5 to 7 days, including 1 to 2 days in an intensive care unit.2 In 1996, CABG surgery was the most commonly performed major surgical procedure in the United States and accounted for use of more healthcare resources than did any other single therapeutic technique.12

Cardiopulmonary Bypass and Associated Risks
In cardiopulmonary bypass, blood is diverted from the heart and lungs to a machine in which oxygenation and circulation occurs. The 3 components of cardiopulmonary bypass are hemodilution, hypothermia, and anticoagulation.15,16 Hemodilution occurs as the patient’s blood becomes diluted with the isotonic crystalloid solution used to prime the bypass machine. Hypothermia (28°C–36°C) is used to reduce tissue oxygen requirements by approximately 50% to protect organs from ischemic injury.15,16 Finally, anticoagulation is necessary to prevent coagulation in the bypass machine once the patient’s blood comes into contact with the surfaces in the machine.15,16

These 3 components contribute to the clinical sequelae and complications associated with cardiopulmonary bypass, including coagulopathies. Excessive bleeding after cardiac surgery is related to alterations in the hemostatic system (related to hemodilution) and excessive activation of the hemostatic system.17 The risk of complications is high when the duration of cardiopulmonary bypass exceeds 2 hours and dramatically increases whenever bypass persists beyond 3 to 4 hours.15 This proportional increase in complications is attributed to the increase in blood trauma, altered capillary membrane permeability, and subsequent tissue anoxia.15

Clinical Sequelae
Common clinical adverse effects of cardiopulmonary bypass include lowered intravascular colloidal oncotic pressure, platelet damage, and the release of vasoactive substances into the plasma.15,18–20 Other common effects include alterations in fluid balance and urine output, hypertension, alterations in cardiovascular function, coagulopathies,17 electrolyte disturbances, cerebral dysfunction (eg, embolic or ischemic events),15,18–20 complement and neutrophil activation, increased risk of microembolism,21 altered renal perfusion, and disturbances in the pulmonary and gastrointestinal systems.15,21

Cardiopulmonary bypass causes systemic inflammation through the activation of serum proteins, leukocytes, and endothelial cells; interactions between leukocytes and endothelial cells; extravasation of leukocytes; secretion of cytokines; activation of platelets; activation of neutrophils, with degranulation; and endothelial dysfunction.18,19 In addition, during and after cardiopulmonary bypass, matrix metalloproteinases are released and synthesized. Matrix metalloproteinases are a family of enzymes that can degrade the extracellular matrix (which is essential for normal cellular architecture and function), leading to tissue damage.20 These cellular and molecular changes induced by cardiopulmonary bypass can lead to postoperative organ dysfunction and a resultant increase in postoperative morbidity and mortality18–20 (Table 1Go).


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  		Table 1 Clinical sequelae of cardiopulmonary bypass15–20,22–27

 
Adverse cerebral outcomes after traditional CABG surgery are relatively common and were associated with increases in mortality, length of hospitalization, and use of intermediate and long-term care facilities.22 In a study of 2108 patients involving 24 US institutions,28 129 patients (6.1%) had adverse cerebral outcomes. Patients were classified into 2 general categories of neurological outcome: type I (focal injury, stupor, or coma at discharge) and type II (deterioration in intellectual function, memory deficit, or seizures); 3.1% had type I outcomes and 3.0% had type II. Predictors of type I outcomes were proximal aortic atherosclerosis and history of neurological disease. Systolic hypertension at the time of admission, pulmonary disease, and excessive alcohol consumption were predictors of type II outcomes. Older age was a predictor for both types.

Although the occurrence of cognitive impairment after CABG surgery is unequivocal, the causes are debatable.22 In a study of cognitive function after open-heart surgery (valve surgery and CABG surgery), Benedict29 found that embolization was the primary cause of perioperative deficits. This finding was supported by the results of a prospective, randomized, controlled study23 of neurocognitive outcomes after off-pump or traditional CABG surgery. The results indicated that cognitive impairment was strongly associated with cardiopulmonary bypass and the occurrence of microemboli.23 No association was found between postoperative cognitive dysfunction after CABG surgery and the systemic inflammatory reaction after cardiopulmonary bypass.24 Because some of the patients in the study by Benedict29 had pre-operative neurocognitive deficits, the neuropsychological deficits might have been due to severe chronic cardiac disease as well as to open heart surgery.

However, the role of cardiopulmonary bypass in postoperative cognitive impairment is established. Using objective cognitive P300 auditory-evoked potential measurements, Kilo et al22 found that the use of cardiopulmonary bypass was the only predictor of short-term (7-day follow-up) and long-term (4-month follow-up) cognitive brain dysfunction after CABG surgery. The prevalence of cognitive impairment is high after CABG: up to 75% of patients at the time of discharge from the hospital and 30% of patients at 6 months after surgery.25 Early improvement in cognitive function seems to be followed by a later decline, and the presence of early post operative cognitive impairment is a predictor of later impairment.25

Morbidity and Mortality in CABG Patients
According to the national database of the Society of Thoracic Surgery, the overall mortality of patients who had CABG surgery from January 1995 through July 1996 (n = 230 730) was 3.1% (ranging from 1.9% mortality for first elective CABG surgery to 5.2% for repeat CABG surgery).8,30 In addition, complications occurred postoperatively, including neurological deficits, sternal wound infections, renal failure, pulmonary dysfunction, and atrial fibrillation. The prevalence of sternal infection (1.2% vs 1.3%) and atrial fibrillation (17.2% vs 16.8%) was similar for both first elective and repeat CABG surgeries.7 However, the prevalence of neurological deficits (4.2% vs 5.8%), renal failure (2.8% vs 5.1%), and pulmonary dysfunction (5.4% vs 10.5%) was significantly greater in patients who had repeat CABG surgery.8 A review of the 1997 data revealed little change from the 1996 data except for an increase in neurological deficits in patients who had repeat CABG surgery (Table 2Go).


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  		Table 2 Morbidity and mortality after conventional coronary artery bypass graft surgery with cardiopulmonary bypass*

 
The 3 major causes8,18–20,22,23,25,30 of complications in conventional CABG surgery are use of cardiopulmonary bypass; use of a median sternotomy incision; and manipulation of the aorta by either cross clamping or placement of proximal grafts, which may result in atherosclerotic cerebral emboli. Subsequently, avoidance of 1 or more of these factors (by using the beating-heart technique) may lead to a reduction in morbidity and mortality in CABG patients.


   MINIMALLY INVASIVE DIRECT CABG SURGERY
Top
 HISTORICAL BACKGROUND
 TRADITIONAL CABG SURGERY
 MINIMALLY INVASIVE DIRECT CABG...
OFF-PUMP CABG SURGERY VIA...
 NURSING CARE OF PATIENTS...
 SUMMARY AND FUTURE RESEARCH
 References
 
Minimally invasive direct CABG surgery (MIDCABG surgery) is defined as CABG surgery performed via the minithoracotomy approach (ie, left anterior thoracotomy) without cardiopulmonary bypass.14 Advantages of the MIDCABG procedure include elimination of cardiopulmonary bypass and its associated adverse effects; avoidance of the median sternotomy incision and aortic manipulation; shorter operating time; and shorter hospital length of stay, with resultant reduction in costs8 (Table 3Go).


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  		Table 3 Advantages and disadvantages of off-pump and minimally invasive direct coronary artery bypass graft surgery

 
Avoidance of the median sternotomy incision eliminates the risk of sternal wound infections, which may occur after partial or temporary sternal devascularization.37 Mortality rates up to 40% have been reported for patients who have sternal wound infections, with a notably increased risk in patients with diabetes mellitus, chronic obstructive pulmonary disease, morbid obesity, or advanced age.37

Limitations of MIDCABG surgery include limitation of access and exposure; technical difficulty in operating on a beating heart with blood in the field, and the associated learning curve; and limited data on long-term patency when the MIDCABG technique is used.8,21,38 MIDCABG surgery is limited to vessels on the anterior surface of the heart and to those accessible via the right internal mammary artery or the LIMA.21 In addition, patients with lesions on the posterior aspect of the heart that cannot be bypassed with the right gastroepiploic artery are not candidates for MIDCABG surgery.21 Two critical elements in MIDCABG surgery are (1) harvesting an adequate length of the internal mammary artery of excellent quality to allow a tension-free anastomosis and (2) achieving a technically perfect anastomosis.39


   OFF-PUMP CABG SURGERY VIA A MEDIAN STERNOTOMY APPROACH
Top
 HISTORICAL BACKGROUND
 TRADITIONAL CABG SURGERY
 MINIMALLY INVASIVE DIRECT CABG...
 OFF-PUMP CABG SURGERY VIA...
NURSING CARE OF PATIENTS...
 SUMMARY AND FUTURE RESEARCH
 References
 
Off-pump CABG and MID-CABG surgery have similar advantages, except that the former requires a median sternotomy incision. The consensus from the Oxford Conference in 1996 on minimally invasive CABG surgery was that the median sternotomy approach (whether full or partial lower incision) was associated with little morbidity, allowed excellent access for LAD and right coronary artery (RCA) anastomoses, and offered access to marginal branches of the circumflex artery.9

In a July 1996 survey11 of 162 cardiothoracic surgeons, 81% of the respondents thought that the avoidance of cardiopulmonary bypass was preferable to the avoidance of the median sternotomy incision. The consensus of the Oxford meeting was that minimal access methods (eg, the minithoracotomy incision) were more time-consuming and apparently less reliable than the sternotomy access in ensuring accuracy of coronary artery anastomosis on a beating heart.9

Advantages of off-pump CABG surgery via the sternotomy approach include the ability to do limited multivessel revascularization and less pain for patients than with minithoracotomy incisions8 (Table 3Go).

Indications
Indications for off-pump CABG surgery include (1) multivessel disease requiring revascularization; (2) contraindications or increased risk for cardiopulmonary bypass, such as severe myocardial dysfunction; immunosuppression; history of transient ischemic attacks or cerebrovascular accidents; heavily calcified aortas; aortic disease with increased risk of dissection, rupture, or embolization; impaired renal function or need for dialysis; and history of previous cardiac surgery; (3) patients who are Jehovah’s Witnesses who refuse transfusions of blood and blood products40; and (4) other high-risk patients such as those with advanced age, respiratory problems, or other systemic disease40,41 (Table 4Go). Despite the cardioprotective effects of cardioplegia, the risk of mortality remains high for patients with severe myocardial depression (ejection fraction <0.35) who have surgical cardiac revascularization with the use of cardiopulmonary bypass.46 In contrast, use of the off-pump technique reduces the mortality risk in patients with myocardial dysfunction,47 including those with hibernating myocardium.48


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  		Table 4 Indications and contraindications for off-pump and minimally invasive coronary artery bypass graft surgery*

 
Myocardial hibernation is a downregulation of myocardial contractile function as an adaptive response to ischemia (either chronic ischemia or repetitive episodes of ischemia and reperfusion) that maintains myocardial integrity and viability.49–51 This reduction of myocardial function in low-flow or low-metabolism areas of the heart protects against myocardial necrosis.50 Established features of myocardial hibernation include lack of necrosis and recovery of function upon reper-fusion.49,50 Up to 50% of patients with coronary artery disease and impaired left ventricular function may have areas of viable myocardium that can regain function upon reperfusion.51,52


   NURSING CARE OF PATIENTS WHO HAVE MIDCABG OR OFF-PUMP CABG SURGERY
Top
 HISTORICAL BACKGROUND
 TRADITIONAL CABG SURGERY
 MINIMALLY INVASIVE DIRECT CABG...
 OFF-PUMP CABG SURGERY VIA...
 NURSING CARE OF PATIENTS...
SUMMARY AND FUTURE RESEARCH
 References
 
Preoperative Phase
Educating patients and their families about what to expect before, during, and after MID-CABG or off-pump CABG surgery should be started in the preoperative phase and continued through discharge from the hospital.42 Patients who have off-pump CABG surgery may be safely discharged from the hospital as early as the second day after the surgery. Thus, the nursing care plan must incorporate preoperative education about the expected postoperative events and early discharge planning. Patients with a median sternotomy incision are prohibited from driving and heavy lifting (nothing greater than 4.5 kg) for 4 to 6 weeks to avoid sternal dehiscence.

Aggressive pulmonary toilet and progression of activities are the cornerstones of any fast-tracking program. Preoperative education must incorporate information on early extubation, coughing, deep breathing, use of the incentive spirometer, rapid progression of activities, adequate pain control, and expectations about length of stay.42 Risk factors for coronary artery disease and lifestyle modification should also be discussed.42

A detailed history and physical examination must be conducted, along with preoperative testing, explanation of the procedure, discussion of the possibility of conversion to conventional CABG surgery if necessary, and surgical risks.36 The 2 main indications and risk factors for conversion of off-pump to conventional CABG surgery are hemodynamic instability or compromise during off-pump CABG surgery and inability to access the areas that require revascularization. Careful preoperative evaluation of candidates for off-pump CABG surgery and a thorough assessment of patients’ needs, discharge planning, and patients’ education are essential to a successful and rapid recovery and early discharge from the hospital.

Intraoperative Phase
Intraoperative monitoring of patient undergoing off-pump CABG surgery typically includes a combination of the following: arterial pressure monitoring, 12-lead electrocardiographic (ECG) monitoring, transesophageal echocardiography to detect wall motion abnormalities and optimize preload, and assessment of flow velocity and graft patency.42 Anesthesia management includes use of short-acting agents, aggressive pain control, and single-lung ventilation (of the right lung) to improve access and reduce cardiac movement caused by inflation and deflation of the left lung.42

Conventional immobilization techniques include use of pharmacological agents, such as ß-blockers and calcium channel blockers (to induce bradycardia) and/or adenosine (to produce temporary cardiac standstill), to help to reduce the technical difficulty of performing surgery on a beating heart.35,42,43

Exposure, stabilization, and immobilization techniques have improved to allow exposure of the lateral, posterior, and inferior walls of the heart in an attempt to achieve complete revascularization. Exposure techniques include (1) use of deep pericardial retraction sutures or use of a similar pericardially based retraction system (to rotate and vertically displace the apex of the heart), (2) use of the Trendelenburg position, and (3) rotation of the operating table.43,44

Stabilization techniques are used to immobilize the target area for anastomosis on a beating heart. The 2 stabilization techniques involve use of either a suction or a compression device.47 Suction stabilizers (eg, the Octopus 2 Tissue Stabilization System, Medtronic, Inc, Minneapolis, Minn) lift the epicardium and pull the tissue taut to immobilize the target area. Compression stabilizers push downward to compress the myocardium and restrict its motion.53 In one study,43 routine use of a mechanical stabilizer device at the anastomotic site was associated with an increase in the patency rate of the LIMA-to-LAD anastomosis (97% vs 89% with the conventional immobilization technique of pharmacologically induced bradycardia, P = .06).

Furthermore, nonstabilized anastomosis and snare injury associated with sutures encircling the LAD may result in technical failure at the anastomotic site.54 All anastomotic stenoses are thought to occur during the revascularization procedure as a consequence of technical mistakes or, more rarely, thrombotic complications.55

Before anastomosis, the target coronary artery is temporarily occluded proximally and distally. Because of the risk of ischemia during the occlusion, patients’ hemodynamic status, wall motion, and ECG changes must be monitored.42 ST-segment elevation varies according to the vessel occluded and the duration of occlusion.45 Thus, despite a shorter occlusion time when the LAD was used (vs the diagonal branch of the LAD and the RCA), ST-segment elevation was higher when the LAD was occluded (range, 0–11 mm) than when the diagonal branch and RCA were occluded (range, 0–1 mm).45 ST-segment elevations are more pronounced with LAD occlusion because the LAD perfuses a larger myocardial area than the circumflex artery and RCA do.45

Postoperative Phase
Because patients undergoing off-pump CABG surgery do not have cardiopulmonary bypass, the adverse effects associated with bypass are avoided. In a prospective study comparing postoperative complications in patients who had off-pump and conventional CABG surgery,41 the prevalence of arrhythmias and pulmonary and neurological sequelae was significantly lower in the patients who had the off-pump procedure. The 2 groups did not differ significantly in the prevalence of infections, perioperative myocardial infarctions, or hemorrhage. In addition, the patients who had the off-pump procedure experienced faster recovery periods and earlier discharge from the hospital. In a recent randomized multicenter prospective study,56 at 1-month follow-up, completeness of revascularization, operative mortality, recurrent angina, and prevalence of postoperative atrial fibrillation were similar for patients who had off-pump CABG surgery and patients who had conventional CABG surgery.

Despite the esthetic appeal of the minithoracotomy incisions, the median sternotomy incision is considered less painful.9 Pain due to thoracotomy incision is caused by intercostal nerve injury associated with traction on the edges of the wound.9,42 In addition, the pain may persist for years if the intercostal nerves are damaged or severed during the thoracotomy approach.37 Regardless of the type of incision used, adequate pain control is essential to reduce myocardial oxygen consumption and facilitate rapid progression of activities and aggressive pulmonary toilet.8,36

As previously noted, cardiopulmonary bypass is associated with numerous deleterious effects, including catecholamine release with significant elevations in epinephrine and norepinephrine levels at 2 to 4 hours after bypass.16,26 These changes may result in elevations in systemic vascular resistance and hypertension, thereby necessitating infusion of sodium nitroprusside, enoldopam, or other vasodilatory agents to control systemic blood pressure and reduce systemic vascular resistance to protect suture lines and prevent bleeding. The need for such agents is less in patients who have off-pump CABG surgery because catecholamine release in these patients is markedly less than that in patients who have conventional CABG surgery.

Excess sodium and water retention associated with potassium excretion may occur in patients who have cardiopulmonary bypass because of elevations in renin, angiotensin, and aldosterone levels and increases in the plasma concentration of antidiuretic hormone.16,26 Subsequently, diuresis, potassium replacement, and judicious fluid administration are commonly needed. In contrast, patients who have off-pump CABG surgery do not usually require diuresis and fluid restriction. Additionally, blood glucose levels and depressed insulin response may occur in patients who have cardiopulmonary by-pass.16,26 Theoretically, patients who have off-pump CABG surgery should have fewer abnormalities in blood glucose levels and insulin sensitivity, but few studies seem to indicate this association. Finally, patients who have off-pump CABG surgery can be extubated as soon as they awaken and meet respiratory weaning parameters.

ECG monitoring is essential to detect myocardial ischemia and injury. A preoperative baseline ECG should be obtained for comparison with postoperative ECGs. In order to detect ischemia associated with acute graft closure, the ST segment should be monitored. Lead selection may be based on the location of the coronary artery anastomosis. The anastomosis of the right internal mammary artery to the RCA is monitored with the inferior leads (II, III, and aVF), whereas the pre-cordial leads (V1 through V4) are used for the LIMA-to-LAD anastomosis.36 The lateral leads (I, aVL, V5, V6) are used to monitor anastomoses involving the circumflex artery or the obtuse marginal branches of the circumflex artery. There are no leads to monitor the posterior wall of the heart directly; therefore, reciprocal changes are monitored (eg, ST-segment depression; T-wave inversion; and tall R waves in anterior leads, especially V1).57

Because a mechanical stabilizer and traction sutures are used, postpericardiotomy syndrome is common in patients who have off-pump CABG surgery. This autoimmune syndrome is characterized by the presence of a pericardial friction rub, postoperative fever, pleuritic chest pain, pleural effusions, and eosinophilia.58–61 The overall prevalence of the syndrome is 17.8%, but prevalence is increased in younger patients and in patients who have a history of prednisone use, pericarditis, or aortic valve replacement or who received enflurane or halothane anesthesia.58–61 Postpericardiotomy syndrome is an important cause of morbidity after cardiac surgery and may cause acute vein graft closure and potentially lethal cardiac tamponade.58–61 This syndrome is often diagnosed on the basis of the characteristic signs and symptoms, but tests such as echocardiograms, ECGs, and laboratory analysis may aid in the diagnosis.59–63 If not otherwise contraindicated, as in patients with chronic renal failure or aspirin allergy, a nonsteroidal anti-inflammatory agent (eg, indomethacin) may be used to treat postpericardiotomy syndrome.63,64

To alleviate anxiety about early discharge, patients and their families need 24-hour telephone access to a designated contact person who can address any concerns or problems after discharge. This access is especially important in the first 2 weeks after hospital discharge because the majority of patients call about concerns and problems during this period.42 The designated person (whether a clinical coordinator, clinical nurse specialist, nurse practitioner, or physician’s assistant) should have clinical expertise in the care of cardiothoracic surgical patients in order to identify problems early and consequently intervene in a timely manner to ensure the best possible outcomes.

Implications for Fast Tracking
The off-pump approach can facilitate fast tracking by incorporating several important components: early extubation, shorter stays in the intensive care unit and the hospital, early preoperative education, accelerated activity progression and aggressive pulmonary toilet, and subsequent early discharge (Table 5Go). However, education of and acceptance by patients and hospital staff (including nursing and other healthcare disciplines) are essential to the success of such a program. Revision of staffing and bed allocation, as well as cross training of nursing personnel, may be necessary.


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  		Table 5 Clinical pathway for patients having off-pump or minimally invasive direct coronary artery bypass surgery

 

   SUMMARY AND FUTURE RESEARCH
Top
 HISTORICAL BACKGROUND
 TRADITIONAL CABG SURGERY
 MINIMALLY INVASIVE DIRECT CABG...
 OFF-PUMP CABG SURGERY VIA...
 NURSING CARE OF PATIENTS...
 SUMMARY AND FUTURE RESEARCH
References
 
CABG surgery is the most commonly performed major operation in the United States3; an estimated 553 000 CABG procedures were performed on 336 000 patients in 1998.4 Off-pump CABG surgery provides an option for patients who would not otherwise be able to undergo medically necessary CABG surgery because of the risks associated with use of cardiopulmonary bypass.

Adoption of off-pump CABG surgery is growing because of the economical benefits. The avoidance of extracorporeal circulation and the attendant morbidity are associated with a reduced utilization of resources, which, in the current cost-cutting era, is an important factor for hospital administrators.

As the role of the off-pump CABG approach in surgical myocardial revascularization evolves, scrutiny of the procedure should continue because many areas still need to be investigated.65 The increased prevalence of superficial sternal wound infections that occur in patients with diabetes mellitus who have off-pump CABG surgery needs to be studied further.40 Another area that requires further investigation is the long-term patency of the anastomotic grafts used in patients who have MIDCABG and off-pump CABG surgery. Other areas requiring more research include myocardial injury and postoperative arrhythmias, systemic inflammatory response to organ damage, graft function, length of stay and hospital costs, early and late mortality, type and adequacy of revascularization, and indications for the use of off-pump CABG surgery.65

In conclusion, off-pump CABG surgery, although more technically demanding with an attendant learning curve, is a safe and cost-effective approach to coronary revascularization. Currently, it is mainly used in high-risk patients. Determining new subgroups of patients who can benefit from off-pump surgery might reduce both mortality and the prevalence of major and minor postoperative complications, resulting in a lower consumption of economical resources.


   Acknowledgments
 
I thank my husband, Tiziano Scarabelli, MD, for his support and valuable assistance in preparing this manuscript. This article is dedicated to my husband, family, and cardiothoracic surgical nursing colleagues at Jackson Memorial Hospital in gratitude for their encouragement.


   References
Top
 HISTORICAL BACKGROUND
 TRADITIONAL CABG SURGERY
 MINIMALLY INVASIVE DIRECT CABG...
 OFF-PUMP CABG SURGERY VIA...
 NURSING CARE OF PATIENTS...
 SUMMARY AND FUTURE RESEARCH
 References
 

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  8. Mack MJ. Perspectives on minimally invasive coronary artery surgery: current assessment and future directions. Int J Cardiol. 1997;62(suppl 1):S73–S79.
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  10. Zenati M, Domit TM, Saul M, et al. Resource utilization for minimally invasive direct and standard coronary artery bypass grafting. Ann Thorac Surg. 1997;63 (6 suppl):S84–S87.
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