Cardiac Surgery

Article Author:
Benjamin Senst
Article Editor:
Rene Diaz
Updated:
10/27/2018 12:31:27 PM
PubMed Link:
Cardiac Surgery

Introduction

Cardiac surgery is the specialty of medicine concerning the surgical treatment of pathologies related to the heart and thoracic aorta. The spectrum of modern cardiac surgery can be understood by its history beginning at the end of the 19th century.[1][2] Since then cardiac surgery developed through the work of numerous dedicated surgeons offering more and more treatments for diverse cardiac pathology. This development is still ongoing today.[3][4]

In 1882, Billroth performed the first pericardiectomy. The first successful treatment of cardiac trauma was done by Ludwig Rehn when he operated on a cardiac stab wound in 1896 against the wide held belief that the heart is not an organ on which surgeons should operate.[5] The development of cardiopulmonary bypass[6] was necessary to reach the structures of interest and was pushed by the high mortality of the early cardiac operations like embolectomy (first completed by Trendelenburg).

Surgical revascularization is one option to relieve ischemic heart disease with complicated atherosclerosis.[7] Vineberg implanted the left internal mammary artery (LIMA) into the anterior free wall forming no direct anastomoses to the coronary vessels.[8] He has observed, in earlier experiments, that collaterals develop when ischemia is present. During the 1960s several surgeons in different locations pioneered the first coronary artery bypass grafting (CABG) operations.[9] The era of reversing coronary artery disease started with the invention of cardiac catheterization by Forssman in 1929 and injection of contrast media to visualize coronary vessels and locate stenosis by Shirey in 1962. Bypass grafting and interventional revascularisation form the 2 main possibilities to treat ischemic heart disease besides drug treatment.

Surgical treatment of valvulopathies started closed mitral commissurotomy by passing a finger or instrument through the narrow orifice of the mitral stenosis to dilate or cut it as did Cutler in 1923 for the first time. The Hufnagel cage and ball valve was the first artificial valve introduced in 1952. It was placed in the descending thoracic aorta to prohibit blood flow reversal in aortic regurgitation. In 1967 a similarly structured valve, the Edwards cage and ball valve, had been implanted 1000 times for mitral valve disease.[10] Surgical techniques improved from early, single valve procedures to 4-valve replacement in 1992. Special techniques were introduced, for example, the Ross procedure replacing the aortic valve with pulmonic valve autograft. To treat proximal aortic dissection or aneurysm, Bentall implanted an artificial aortic valve combined with ascending aortic vessel prosthesis.

In 1944, cardiac surgeons Blalock, Taussig, and Thomas first forayed into the field of congenital heart lesions, when they operated on the tetralogy of Fallot, one of the cyanotic heart lesions.[11]There are also acyanotic heart lesions such as pulmonary stenosis.[12]

Regarding cardiac arrhythmias, the Cox-Maze procedure offers surgical treatment of atrial fibrillation. The evolution of cardiac pacemakers started by applying external electrodes to stimulate the heart. Lillehei placed electrodes directly to the heart during open heart surgery. The first implanted pacemaker lasted only 8 hours. Modern aggregates offer long-lasting solutions to diverse rhythm abnormalities.[13]

In 1967, several surgical teams around the world performed the first heart transplantations: Barnard in South Africa, Shumway in Stanford (offering increased post-transplant survival by adding immunosuppressive treatment), and Kantrowitz with pediatric transplantation in New York.[14]

Some devices can supply mechanical circulatory support. Since 1963, the intra-aortic balloon pump (IABP) enhanced left ventricular function through the mechanism of counterpulsation. Open heart surgery requires a cardiopulmonary bypass (CPB) to temporarily replace the human heart and lung by an external circuit consisting of pumps and an oxygenation membrane. Artificial hearts were first applied extracorporal in 1982. Later devices allowed for implantation.

Cardiac surgery represents high operative and perioperative risk requiring professional staff and advanced equipment. Besides the diseases that require cardiac surgery, the perioperative period shows a variety of characteristic pathologies: systemic inflammatory response following CBP, myocardial stunning and low cardiac output syndrome, arrhythmias, massive transfusion requirements and multiorgan involvement with kidney injury, stroke, and respiratory distress.

With the surge of interventional and minimally invasive methods to treat cardiac pathologies, the medical fields of cardiology and cardiac surgery recently need to adapt to these changes.[15] As Lytle and Mack described in their 2005 editorial, "The times they are changing" the field of cardiac surgery is undergoing a fundamental transformation. In his presidential address, Guyton said: "if we do not embrace innovation we will become its victims." Recent developments include the upcoming of cardiac arrest centers, broader and simpler application of extracorporeal membrane oxygenation (ECMO),[16] organizational changes such as fast-track hospital stay, and interprofessional decision making by heart teams, and challenges posed by an aging patient population.[17][18][19]

Anatomy

The rib cage surrounds the chest organs. This allows for additional protection against environmental influences but confers a higher difficulty for surgeons to reach the structures of interest. Surrounded by the ribs laterally, the sternum anteriorly, and the thoracic spine posteriorly, 2 compartments can be divided: the bilateral pleural and the mediastinal compartment. The pleural spaces contain both wings of the lung. The mediastinum encloses many structures such as the esophagus, the trachea, the vena cava superior and inferior, thoracic arteries, the vagus nerve, azygos vein, lymphatic vessels, thymic remnant and the pericardial sac containing the heart. The confined space of the pericardial sac poses the heart at risk for tamponade physiology. This occurs hematoma compresses the heart obstructing normal cardiac blood flow.[20]

As blood flows through the 4 chambers of the heart, it passes 4 valves. Reaching the right atrium via the superior and inferior vena cava, blood passes through the tricuspid entering the right ventricle and pulmonary valve to be released into pulmonary circulation. The right heart is a low-pressure system compared to the left heart, which supplies the systemic circulation that requires more myocardial tissue to produce higher pressure. Blood is collected from the 4 pulmonary veins to enter the left atrium, passes through the mitral valve, the left ventricle, and the aortic valve into the systemic circulation.[21] The aortic root comprises the sinuses of Valsalva, the interleaflet triangles, the sinotubular junction, and the aortic valve annulus with leaflet attachment; the 3 leaflets named according to the coronary arteries right, left, and noncoronary cusp (RCC, LCC, and NCC respectively). Since the parts of the valve apparatus are interdependent, surgeons might need to address connected structures to relieve pathology.

All cardiac valves are surrounded by an annulus that poses difficulties for creating artificial grafts without leakage. To illustrate the importance of anatomy and physiology, the example of mitral valve replacement and the negative consequence of left ventricular outflow tract obstruction can be named. While the aortic valve annulus is circular, the mitral valve annulus is more crescent-shaped requiring more sophisticated prosthesis and implantation technique. This is expressed by a plentitude of artificial valve models each having advantages and disadvantages regarding anatomic, physiologic, technical, and procedural characteristics. Having a closer look on the mitral valve the annulus and the anterior and posterior valve each consisting of 3 segments (A1 to A3 and P1 to P3) and are connected to the subvalvular apparatus which consists of chordae tendineae connecting the valve leaflet to the papillary muscles.

The heart has intrinsic rhythmic activity, that can be slowed or quickened through the influence of the autonomic nervous system with sympathetic reaction leading to accelerated heart rate and parasympathetic reaction leading to decelerated heart rate. The cardiac electrical conduction is structured hierarchically and runs from the sinus node through the right atrium to the atrioventricular node, the His bundle, and via the Purkinje fibers to the ventricles. The anatomic and physiologic role of the cardiac electrical activity is important to understand its clinical implications. Following cardiac surgery, atrial fibrillation is common. The Maze procedure applies anatomical knowledge to interrupt uncontrolled atrial activity for solving atrial fibrillation. The implantation of artificial heart valves can lead to atrioventricular blocking due to proximity to the valve area.

The quality of vessel grafts is important for the outcome of CABG surgery. Surgeons can harvest a variety of vessels. Arteries are of superior, long-term durability compared to veins.[22] The quality of vessel grafts can be assessed preoperatively. Commonly used vessels include the left and right internal mammary arteries (RIMA), radial arteries and the saphenous veins (SVG). Due to vessel length, the RIMA is usually connected to the right coronary artery (RCA) and the LIMA to the left anterior descending artery (LAD). The posterior descending artery (PDA) and left circumflex artery (LCX) are commonly supplied with a venous bypass graft. Venous grafts can be used to create bypasses to smaller branches such as the diagonal branches of the LAD and marginal branches of the LCX.[23]

Indications

Indications for cardiac surgery are described in current guidelines.[24][25] Although there are differences between some recommendations general indications are same. Decision making is done in consensus with cardiologists meeting as a heart team. Prior imaging with echocardiography, computed tomography(CT) , or magnet resonance imaging (MRI) is routinely necessary.

In valvular heart disease, stenotic lesions and regurgitation can be differentiated. In general classification of valvulopathies is a 3-step approach, mild, moderate, and severe, in contrast to 4-step angiographic grading done in the catheterization laboratory. Severe valve regurgitation or stenosis requires intervention. Depending on the valve affected surgeons offer replacement or reconstruction.[26]

With the upcoming of transcatheter aortic valve replacement (TAVR) first introduced by Cribrier in 2002, the heart team decides on the surgical or interventional treatment of severe aortic stenosis.[27][28] When the opening area becomes less than 1 square centimeter, aortic stenosis is severe. The operative risk is an important consideration. People with high operative risk according to EUROScore or STS score should be treated with TAVR.[29] Lower risk scores allow for surgical aortic valve replacement (SAVR). High operative risk includes patients with porcelain aorta, liver cirrhosis child pugh B and C, previous CABG with lima, and frailty. Aortic valve endocarditis requires SAVR. The 2010 PARTNER Trial compared outcomes of TAVR and SAVR thus influencing patient selection.

Decision making in aortic regurgitation requires pathophysiologic consideration. Aortic regurgitation due to enlargement of ascending aorta requires operative treatment. Patient with symptoms due to severe aortic regurgitation also need surgery. Asymptomatic patients with decreased left ventricular ejection fraction (LVEF) or increased left ventricular residual volumes should also receive operation. (LVEF less than 50% or LVEDD greater than 70 mm or LVESD greater than 50 mm). Echocardiographic characteristics of severe aortic stenosis are vena contracta of more than 6 mm pressure half-time of less than 200 ms effective regurgitant office area of more than 30 and regurgitant volume of more than 60 ml.

Mitral stenosis is mainly caused by rheumatic heart disease which is rare in industrialized countries. Mitral regurgitation (MR) is treated depending on the etiology.[30] Primary MR describes the structural pathology of the mitral valve apparatus itself including leaflets, annulus, chords and papillary muscles. Primary MR is classified according to Carpentier. Secondary, which is functional MR, is caused by left ventricular dilatation, ischemia, and tethering. In contrast to aortic valve pathology lesion affecting the mitral valve are primarily treated with repairing techniques including Alfieri edge-to-edge, resection, annuloplasty, and neochordae. Severe MR is defined by echocardiographic criteria with vena contracta more than 7 mm, a regurgitant volume of more than 60 ml, and a regurgitant fraction of more than 50%.[31]

Multivalvular disease comprises an especially difficult decision making since studies are rare.[32] When an operation for left heart disease is considered, secondary tricuspid regurgitation can be corrected concomitantly. Criteria assess the right ventricle and the tricuspid valve to decide on the operation are not clear. Tricuspid area diameter of more than 40 mm is an indication for tricuspid valve repair when mitral valve surgery is planned.[33][34][35][36][37][38]

Cardiac surgery offers treatment for a plentitude of cardiac rhythm disturbances through the implantation of pacemakers such as dual chamber devices for atrioventricular blocks, defibrillators for ventricular arrhythmia, and cardiac synchronization therapy for advanced heart failure.

Congenital heart disease is divided into cyanotic and non-cyanotic lesions. Ventricular and atrial septal defects can be surgically closed. Special operation techniques have been developed for diseases such as Ebstein anomaly, tetralogy of Fallot, and transposition of the great vessels among others.

The most common benign tumor of the heart is an atrial myxoma. The most frequent malign cardiac tumor is a sarcoma. Secondary metastatic tumors to the heart are more frequent than primary cardiac tumors. Tumors may cause obstructive or embolic symptoms.

Pulmonary thrombendarterectomy may be necessary as a final treatment option for severe pulmonary embolism. With a certain extension of the thoracic aorta, operation of dissection and aneurysm and replacement with a vessel graft are indicated.

For the therapy of coronary artery disease (CAD), surgical revascularization can be a preferred option.[39] Decisions on management can be made by the heart team where cardiologists and cardiac surgeons meet. Decision aids are the syntax score describing the complexity of CAD to decide between treatment by CABG or percutaneous coronary intervention (PCI). Left main stem and triple vessel disease are common indications for CABG. High-risk PCI patients with increased operative risk may be treated percutaneously despite difficult stenotic lesions.

Terminal heart failure despite best medical therapy can be treated with cardiac resynchronization, implantation of assist devices or heart transplantation.[40] Resynchronization therapy is indicated in patients with a severe reduction in left ventricular function (LVEF less than 35%), symptoms described as NYHA III to IV and an electrocardiogram showing the QRS complex to be longer than 130 ms. In times of organ shortage, assist devices are becoming increasingly popular.[41][42] Studies showed comparable outcomes between these 2 treatment options.[43] The REMATCH trial showed 2-year survival advantage in patients with an assist device of 23% versus 8% with medical therapy. Slaughter and colleagues compared continuous flow assist devices to pulsatile flow LVADs. The median duration of support 1.7 years for continuous flow and 0.6 years for pulsatile flow with 88% and 79% of time spend outside hospital, respectively.[44] Timing and selection of patients for assist device implantation or heart transplantation is challenging. The INTERMACS classification and the Lietz-Mmiller destination risk score are useful tools in patient selection.

Contraindications

During operation preparation, risk factors and contraindications are evaluated. Since cardiac surgery is limited to advanced cardiac diseases benefits of operation as last treatment options often outweigh risks. To assess the operative risk the EuroScore risk stratification tool has been developed. There are many other risk tools such as the Parsonnet score or the Society of Thoracic Surgeons (STS) score to identify patients that are eligible for surgery.[45][46][47]

Instability of the patient may cause the operation to be postponed. In a patient with myocardial infarction planned for CABG, the time point of operation may be difficult to decide. Valve replacement in cases of endocarditis may require operating on a septic patient to control the infectious source.

Equipment

Cardiac surgery requires a lot of sophisticated equipment. For diagnostic purpose, pulmonary artery catheter, thermodilution techniques, pulse contour analysis, ultrasound, among others can be used to assess cardiac performance and disease. Critical issues related to cardiac output, volume responsiveness, and tissue oxygenation should be addressed.[48]

Equipment for treatment includes pacemakers, assist devices, extracorporeal membrane oxygenation (ECMO), and CPB. The application of CPB started in the 1930s when Gibbon used an external pump circuit to maintain life in Boston. The development was interrupted due to early drawbacks. Since then, modifications have been made. Dogliotti presented a partial heart and lung machine with 1 liter per minute flow in 1951. Hypothermic technique reducing metabolic demand and injury to the heart was first used by Lewis in 1952 when closing an atrial septal defect. Lillehei came up with the idea of cross circulation. He temporarily replaced one dog's circulation by sharing it with another dogs circulation. A broader application was possible with the mechanical heart-lung machine by Kirklin who made modifications to the IBM Gibbon machine, which increased the number of survivors. The use of CPB allows for venting the heart and clearing the operating area.[49]

However, CPB comes with side effects. Exposure to the circuit elicits a systemic inflammatory response.[50] Changes to the operation technique, such as decreasing time and size of CPB, and changing the surface of the tubes have an effect. The inflammatory response to CPB appears similar to infection triggered an inflammatory reaction with increased inflammatory markers and signs of shock, but the time course is different, peaking on the first postoperative day and decreasing after that.[51] Cuthbertson described SIRS due to CPB as ebb and flow process with initial reduced metabolic activity lasting 2 to 3 days, followed by hypermetabolic phase lasting for over a week. Several solutions have been proposed such as aprotinin, heparin-coated CPB circuits, hemofiltration, leukofiltration, and off-pump coronary artery bypass (OPCAB).[52][53]

Use of CPB and assist devices requires frequent coagulation tests. Together with cases of postoperative hemorrhage, usual coagulation diagnostic such as international normalized ratio (INR) and partial thromboplastin time (PTT) and more detailed laboratory assessment, for example, rotational thrombelastography, activated clotting time (ACT) or certain coagulation factors (antithrombin III, fibrinogen, factor VII) may be necessary.[54]

Veno-venous ECMO includes an oxygenator and thus supports the respiratory system in adding oxygen and removing carbon dioxide. Veno-arterial ECMO not only allows for oxygenation and decarboxylation but also replaces cardiac output partially. Cannulation for VA-ECMO is either placed centrally in the ascending aorta at sternotomy producing antegrade flow or peripherally with cannulas placed in the external iliac artery and vein. ECMO can be used as a bridge to recovery, bridge to bridge and bridge to transplant modality.

The use of intra-aortic balloon pump has decreased since studies could not show any benefit in mortality. Initial physiologic consideration was improved diastolic coronary perfusion of the coronaries and pull effect during systole via counterpulsation of a balloon placed in the descending thoracic aorta.

In valve replacement, decision making on which prosthetic heart valve to use is necessary. Mechanical heart valves offer higher resistance to structural valve degeneration (SVD) but require lifelong anticoagulation. Mechanical heart valves are recommended for younger patients. Bioprosthetic heart valves either from porcine or pericardial tissue do not require anticoagulation but may suffer from earlier SVD and reoperation.[55] Bioprosthetic heart valves are indicated in women that wish to have children and older patients. An additional option for aortic valve replacement is Ross procedure which is a pulmonic autograft placed in aortic position.[56]

Personnel

After finishing medical school, graduates can apply for training in cardiac surgery. The length and content of the postgraduate curriculum differ. With prior general surgical experience, cardiac surgery training can be completed with an additional 2 years specialization. On the other hand, 6-year training programs including subspecialty training in minimally invasive surgery, adult cardiac surgery, pediatric and congenital cardiac surgery, vascular surgery, endovascular interventions, general thoracic surgery, or heart failure surgery.

Training is highly competitive and demanding due to the changing nature of the specialty with increasingly elderly and multimorbid population, working hour restrictions, and new interventional methods. Recent evaluations have predicted shortages for professionals in different countries during the next decades.

Apart from cardiac surgeons, additional disciplines come together to form the cardiac perioperative team. These include extracorporeal technologist, cardiac anesthesia, cardiac intensive care, surgical nurses, cardiologists, and radiologists. Each of them have special training.

Preparation

When sending a patient for cardiac surgery, the following preparations should be taken: 

  • Blood tests to assess a broad range of body systems function (kidney and liver function tests, coagulation, complete blood count [CBC], electrolytes)
  • ECG to check for normal cardiac rhythmic activity
  • Echocardiography and cardiac catheterization to detect coronary artery disease and valvulopathies
  • Chest x-ray or chest computed tomography to visualize thoracic comorbidities and plan operative technique
  • Ultrasound of the neck vessels to evaluate stroke risk
  • Ultrasound of lower extremity veins as possible grafts

Carotid doppler ultrasound examination should be done in patients with left main disease, peripheral vascular disease, carotid bruits, history of CVA, history of heavy tobacco use, and age older than 65 years. When significant stenosis is detected, further tests might be necessary and endarterectomy performed.

Anticoagulation in the perioperative period needs special consideration. Platelet inhibiting drugs should be stopped before operation depending on the kind of medication. For example, clopidogrel should be stopped 5 days before surgery, ASA and heparin can be continued until the operation. The benefit of revascularization should be balanced with bleeding risk. Strategies to reduce bleeding complication in patients requiring urgent surgery under the impact of anticoagulation include OPCAB, coagulation diagnostic and adapted management giving coagulation factors and platelet transfusion, and antifibrinolytic agents.[57][58][59][58][60][61]

Technique

Open heart surgery is the traditional approach to reach the heart via opening the thorax by sternotomy or upper hemisternotomy. CABG is one of the most frequent operations in the world. Once the pericardial sac is opened (with inverted T incision sparing both side phrenic nerves), cannulation, CPB, and cardioplegia being applied the heart can be moved to identify the arteries of interest. Epiaortic ultrasound is used to assess atherosclerosis of the ascending aorta. When grafts have been harvested, they can be connected in direct, y or t manner to the coronaries and the aorta. Following anastomis, the success is proven by checking flow rates through the grafts. After finishing CPB, the thorax is closed in a stepwise approach and finally securing the sternum with wires. Pleural and mediastinal suction drains are left in place for the following postoperative days. Intraoperatively placed epicardial electrodes connected to an external pacemaker help to treat rhythmic complications but are removed before hospital discharge.

OPCAB is especially useful in patients with high operative risk[62] and significant atherosclerosis of the ascending aorta because clamping during CPB may release thrombogenic material and cause a stroke. The no-touch technique avoids manipulation of the potentially thromboembolic endothelial surface of the ascending aorta by using the internal mammary arteries or innominate artery. It requires stabilizers and positioners for accurate anastomosis to the coronary vessels and is especially useful in patients with high operative risk. For these patients, surgical LIMA to LAD anastomosis combined with later PCI to other affected arteries as hybrid coronary staged revascularization may be advantageous compared to usual CABG.[63][64] The inflammatory response is the same with on-pump versus off-pump surgery, but other positive effects have been found. The transfusion requirements, for example, are reduced. The off-pump bypass may be feasible in up to 95% of CABG patients, but recently only 20% of surgical revascularization is done through this technique.

Minimally invasive surgery (MIDCAB) and endoscopic coronary artery bypass grafting (TECAB) are done through smaller incisions, video-guided, and with the help of special instruments. It requires additional training, hence, it is offered only in some centers. Patients may profit from less surgical trauma and faster postoperative convalescence. Many procedures can be done through a minimally invasive technique. Since the invention of the robotic surgery, these systems have also found their ways into the cardiac operating room.

The myocardium can be protected by using cardioplegia and hypothermia.[65] Different cardioplegic solutions are available. Cardioplegia can be applied anterograde aortic root or retrograde through the coronary sinus.[66][67][68] Brain protection during cardiac surgery can be achieved via improving perfusion of the brain, decreasing thrombogenicity through changes to blood constituents and anticoagulation.[69][70][69][71]

There are certain valve-repairing techniques such as bicuspidization, DeVega, and clover technique for the tricuspid valve and Alfieri edge-to-edge, foldoplasty, neochordae, and sliding plasty for the mitral valve. Aneurysms and dissections of the ascending aorta may be operated using David, Yacoub, or Bentall techniques depending on the requirement to replace or spare the aortic valve.[72][73]

Complications

The overall mortality in cardiac surgery is between 2% and 3%. Major complications include postoperative bleeding, stroke[74][75], renal failure,[76] mesenteric ischemia, atrial fibrillation,[77] cardiogenic shock,[78] and respiratory distress. Postoperative bleeding, hemorrhagic shock coagulation disorders such as heparin-induced thrombocytopenia are reasons why 10% to 20% of national blood products are consumed in cardiac surgery. Acute kidney injury occurs in up to 18% of patients undergoing cardiac surgery. Two percent of all require renal replacement therapy. The number of complications may serve as a quality indicator and may influence reimbursement and patients choice.

Myocardial infarction following cardiac surgery is classified as type 5 myocardial infarction according to the universal classification of myocardial infarction. The incidence is between 5% to 10%. Diagnosing postoperative myocardial infarction is challenging since cardiac enzymes are routinely elevated due to manipulation during operation and symptoms are influenced by postoperative status. Therefore, other diagnostic modalities should be emphasized, for example, electrocardiogram (ECG) echocardiography, and coronary angiography to assess bypass patency. Echocardiography may show septal wall motion abnormalities not related to myocardial ischemia. Signs of refractory schock, arrhythmias are highly suggestive of myocardial infarction. Myocardial infarction following CABG can be divided into graft related and non graft related. Early graft dysfunction is observed in up to 3%. Non graft related causes include insufficient myocardial protection and embolization. Treatment strategy for type 5 myocardial infarction include conservative medical treatment, pci, and redo cabg.[79][80][81]

Following mitral valve replacement (MVR), obstruction of the left ventricular outflow tract (LVOT) can occur. This is described as systolic anterior motion (SAM) of the anterior mitral leaflet. Treatment is proposed in a step-wise manner. Starting with beta-blockers, increasing afterload with fluids, and allowing hypertension, and finally reoperation with different surgical techniques: edge-to-edge, posterior leaflet (PL) shortening, short neochord, sliding plasty, and ellipsoid excision of anterior leaflet (AL).[82] Preoperative risk factors include thick basal interventricular septum (IVS), small LV, a short distance between the interventricular septum and the mitral leaflet coaptation point, tall posterior leaflet, and an aorto-mitral angle of less than 120 degrees.[83][84][83]

Fever, edema, and increased inlammatory markers can be routinely observed in patients in the postoperative ward. Thus, it might be challenging to differentiate patients with true infection and evolving sepsis.[85] The time course can give additional information. Signs and symptoms of infection after the second to the third day of operation should prompt investigation for infection.[86]

Perioperative antibiotic prophylaxis is used to reduce postoperative infections. Guidelines recommend cephalosporine prophylaxis during the 24 to 48 hour perioperative period. Deep sternal wound infection (DSWI) is a unique postoperative complication of cardiac surgery occuring with a frequency of 0.4% to 4%. It may progress to mediastinitis resulting in great mortality. Treatment of DSWI consists of pathogen-specific antibiotics (frequently cultured strains include Staphylococcus aureus or Staphylococcus epidermidis treated with clindamycin or according to resistance pattern), surgical exploration, and application of negative-pressure wound therapy (NPWT).

Healthcare professionals caring for patients with assist devices should be aware of unique device complications. Due to the necessity of anticoagulation, regular testing of coagulation should be performed. If coagulation is not within target levels either thrombosis or bleeding can occur. High power output with increased LDH indicates pump thrombosis. Hemolysis and deranged coagulation will lead to mucosal bleeding as hematuria, melena, and hemoptysis. [87] Studies have shown near equal outcomes comparing terminal heart failure patients treated with assist device to heart transplantation. Nevertheless, 1-year survival without any adverse event might only be 30%.

Clinical Significance

Cardiac surgery plays an important role in cardiovascular health. The prevalence of cardiovascular diseases is increasing continuously due to the epidemiologic transition implicating atherosclerosis, hypertension, and associated lifestyle risk factors. Regarding costs, cardiac surgery represents 1% to 2% of the healthcare budget in the United States, with an average inpatient cost of $40,000 summing up to $20 billion in total. There will be an increased demand for healthcare professionals specializing in cardiology and cardiac surgery.[88]

Enhancing Healthcare Team Outcomes

The heart team illustrates an excellent example of patient-centered care. Professionals in different fields of medicine, cardiologists, interventionalists, cardiac surgeons, radiologists, and other health care providers come together to find the best solution for the individual patient.[89]