Contemporary Cardiac Surgery

The field of cardiac surgery is still relatively new. With Stephen Paget stating in 1912 that "Surgery of the heart has probably reached the limit imposed by nature to all surgery; no new procedure and no discovery can solve the natural difficulties that attend a wound of the heart," surgeons were fascinated by surgery on the vital organ.

In the 1950s, Minnesota saw the first successful atrial septal defect closure, and John Gibbon's oxygenator made it possible to undertake more intricate open-heart procedures. Michael Debarked conducted the first successful coronary artery bypass graft in 1964, and Christian Barnard carried out the first heart transplant in South Africa in 1967.

Cardiac surgery has evolved greatly from these early, but relatively recent, days. The cardiopulmonary bypass has been improved, making it much safer than in the past, and valve prostheses are now more reliable and long-lasting than before. With outstanding results, cardiac surgeons are executing ever-more sophisticated operations on sick and more complicated patients. Transcatheter valve technology, minimally invasive surgery, and reliable ventricular assist devices are only a few of the technological advancements that have occurred in the most recent decades.

Cardiac surgery is evolving as a specialty; thus, it is up to surgeons to stay informed about the most recent advancements and what they can mean for their practice in the present and the future. The training of cardiothoracic surgeons and the distribution of resources within the healthcare system are both affected by these changes.

 

Cardiac Surgery Indications

• Heart valve disease. any condition that affects one or more of the heart's valves. A person may either inherit or acquire valvular heart disease.
• Amyloidosis. Amyloidosis is a condition marked by an abnormal protein buildup (known as amyloids) in several different body organs.
• Aortic disease. Aneurysms, tears in the inner lining, and penetrating ulcers are just a few of the conditions that can affect the aorta, the major artery carrying blood from the heart, and are exceedingly dangerous.
• Arrhythmia. Is a significant heart rhythm disorder that makes the heart beat too slowly or too quickly to effectively pump blood.
• Cardiomyopathy. Is the decline in heart muscle function, which frequently results in heart failure.
• Congenital heart disease. A congenital defect in the heart's and its supporting vessels' structure.
• Coronary artery disease. Causes angina, a heart attack, or congestive heart failure when arteries in the heart narrow or get obstructed.
• Heart failure. Likewise referred to as congestive heart failure (CHF). This happens when the heart muscle is unable to pump blood for a variety of reasons.
• Heart muscle enlargement. a hereditary disorder where the heart's muscle is unusually thick for no obvious reason. Blood flow to the rest of the body is impeded when the muscle of the left ventricle of the heart thickens more than usual.
• Pericarditis. the pericardium, the delicate sac (membrane) that encircles the heart, is inflamed.

 

Cardiac Surgery Contraindications

Risk factors and contraindications are assessed before an operation. Since severe cardiac disorders are the only ones that can be treated with surgery, the advantages of an operation as a last resort frequently exceed the dangers. The EuroScore risk stratification tool was created to evaluate operational risk. To determine whether patients are candidates for surgery, there are numerous alternative risk assessment measures available, such as the Parsonnet score or the Society of Thoracic Surgeons (STS) score.

The operation might need to be delayed because of the patient's instability. The time point of the operation may be challenging to choose for a patient with myocardial infarction who is scheduled for CABG. Endocarditis cases that require valve replacement may necessitate operating on a septic patient to limit the infectious source.

 

Cardiac Surgery Preparation

Your doctor and the rest of the medical staff will go over the potential risks and what to expect before, during, and after minimally invasive heart surgery with you.

You can talk to your doctor and the surgical team about any worries you have. Before your surgery, your doctor or another member of your care team may discuss advance directives or other matters with you.

In the areas of your body where the surgery will be performed, you might need to get your hair shaved. To lessen the chance of infection, your skin may be cleansed with a specific soap.

You should discuss your hospital stay with your family and any potential home assistance needs before being admitted to the hospital for surgery. You will receive instructions from your physician and the rest of the care staff to follow as you heal at home.

 

Coronary Artery Bypass Grafting

The primary cause of mortality is still cardiovascular diseases, there is still a demand for coronary surgery. Reoperative coronary artery surgery is becoming more common in addition to original revascularization treatments. For cardiac surgeons, coronary artery bypass grafting still makes up the majority of their workload. According to data from the Society of Thoracic Surgeons (STS) database, the number of revascularization procedures carried out in the US has gradually decreased since 2010.

A sizable trial, the randomized multi-center SYNTAX trial, published 5-year follow-up results in 2013. The SYNTAX trial, which paved the way for the significance of a cardiac team, is a pivotal study in the management and treatment of coronary disease. Furthermore, according to the SYNTAX trial, coronary artery bypass grafting (CABG) is superior in patients with complicated lesions (as determined by the SYNTAX score) and diabetes. Similar findings were made in the FREEDOM study, which randomly assigned patients to get CABG or multi-vessel stenting.

Guidelines for the use of arterial grafts in CABG patients were released by the STS in 2016. To maximize patient benefit, the recommendations strongly support the use of a second arterial graft in addition to the left internal mammary artery. The surgeon must make a complex decision here, taking into consideration factors including the structure of the native coronary vessels, the availability of conduits, and potential risks from the sternal wound, for instance. To ensure the best practice is implemented, the use of a second artery conduit should be audited for both use and outcome. This could allow CABG to give increasingly good outcomes for the proper patients.

Off-pump coronary artery bypass (OPCAB) grafting's function has been investigated recently, however, a lot of studies have been very critical of the procedure, particularly about graft patency and under-revascularization. Small amounts of OPCAB expertise were needed for the randomized on- or off-bypass study, which could be expected to influence the results. Additional research has revealed some potential advantages for OPCAB, particularly in reducing the risk of stroke and the need for transfusions. Off-pump skills are still a crucial component of a modern surgeon's toolkit. Not every surgeon or patient will likely benefit from OPCAB as a routine surgery.

To get the greatest results for patients with increasingly complex coronary disease, cardiac surgeons must put their best foot forward as the number of angioplasty treatments has increased.

 

Aortic Valve Disease

Alain Cribier performed the first transcatheter aortic valve implantation (TAVI) in 2001, and it has since developed to represent at least half of all aortic valve replacements in major aortic stenosis centers. As the number of referrals and patients evaluated rises, the implementation of a TAVI program may also increase the number of surgical aortic valve replacements conducted. The frequency of stroke, bleeding, and serious vascular injury has reduced as valve and deployment system advancements have been implemented. As a result, there are now more patients who qualify for the transfemoral approach, whereas trans-aortic and trans-apical access are declining. Additionally, TAVI's technical proficiency has made it possible to perform increasingly complex cases, such as valve-in-valve procedures for bioprostheses that have degenerated or concomitant left main coronary stenting.

The planned PARTNER 3 trial will examine TAVI in lower-risk patients with an STS score of less than 4%. Currently, it is the therapy of choice for patients who pose an excessively high risk. TAVI may eventually replace other treatments for aortic stenosis as it advances toward treating people at lower risk. In cardiac surgery, transcatheter technology will grow in importance.

Cardiac surgeons must acquire the abilities that will enable them to actively take part in the actual valve placement in a heart team model. Surgery and cardiology should both be able to perform the fundamental procedure as part of a multidisciplinary team, and each should be able to offer its unique expertise. For instance, a cardiologist can do angioplasty procedures when necessary and a surgeon can conduct surgery if necessary. Additionally, as implants are placed, there will be a rise in the number of patients who require additional surgery, even for serious issues like endocarditis. A surgeon will be able to perform the required surgery on these patients if they are familiar with the process. In a setting where the surgeon and the cardiologist are on an equal footing in the heart team, procedures should be divided between the two operators.

The development and use of TAVI have highlighted the significance of a heart team for the evaluation of patients for TAVI, much like coronary artery disease. The CT scan and 3D TOE technologies that are utilized to plan TAVI are advancing to provide better size and foresee implantation difficulties. The process of selecting patients is also getting better, and preoperative evaluation now gives frailty a lot of weight because of its relation to increased 1-year mortality. These teams for selection and work-up must still include surgeons.

The sutureless or rapid deployment aortic valve is TAVI's chief competition. The Sorin Perceval S valve and the Edwards Lifesciences Intuity valve are two promising prostheses. The use of a sutureless valve reduces cardiopulmonary bypass time and cross-clamp time to lessen the adverse effects of extracorporeal perfusion, which is of particular importance to the high-risk group. Sutureless valves present an effective alternative to TAVI in the appropriate patient population, whether carried out by a standard sternotomy or a minimally invasive surgery (hemisternotomy or right anterior thoracotomy). The possibility of a shorter hospital stay, less bleeding, and more patient satisfaction, when used via a minimally invasive procedure, is very attractive. The modern cardiac surgeon must develop minimally invasive techniques and wiring skills to take full advantage of these technologies.

 

Mitral Valve Disease

According to current valvular heart disease guidelines, mitral valve repair should be done for degenerative mitral disease in hospitals with a 95% success rate and a mortality rate of less than 1%. Since a few years ago, minimally invasive mitral valve surgery has become more and more common. To achieve high levels of success, the implementation of a minimally invasive mitral repair (MIMR) program necessitates a strong commitment from a skilled mitral valve surgeon as well as the operating room team of anesthesiologists, echocardiographers, perfusionists, and nursing personnel.

A learning curve is involved in training or setting up a minimally invasive mitral program. The Leipzig group released the learning curves for beginning mitral surgeons, recommending that before proficiency is reached, at least 75 cases must be completed. It is anticipated that a suitable repair can be made with a low mortality rate because mitral valves are often referred for repair in younger individuals at earlier stages of illness. The patient shouldn't have to spend to become proficient, so it's crucial to set up a reliable mentoring program.

The mitral valve is the subject of two interventional technology devices: the MitraClip and the transcatheter mitral valve replacement (TMVR). Patients with poor left ventricular function and extensive mitral regurgitation can have the catheter equivalent of an edge-to-edge repair using the MitraClip. Published results don't compare well to surgical data, and MitraClip's function isn't yet fully understood. For patients with severe MR who are inoperable or at high risk, the TMVR will initially be more appealing than its aortic counterpart. Implants of a valve inside another valve or a valve inside a ring are used to repair or replace bioprostheses that have failed. The TMVR falls entirely under the domain of the surgeon; it necessitates trans-apical access, and surgeons should be in charge of any procedure involving direct heart entrance.

 

Aortic Disease and the Endovascular Approach

A significant portion of the cardiac surgeon's duty is aortic dissection. Even with an increase in the number of old and ill patients, the outcomes for surgical repair of aortic dissection have gotten better over time. Improvements in acute care management, anesthesia, and surgical technique have increased survival. Endovascular surgery is being investigated as a potential alternative for very high-risk patients in cases where a long open operation may not be beneficial. Descending aortic pathology is frequently addressed by a vascular surgeon. Vascular surgery is increasingly being used to treat difficult arch pathology and even ascending aortic pathology endovascularly.

The development of hybrid technologies, such as the Thoraflex graft or the E-Vita graft, has made it possible to quickly deploy a frozen elephant trunk transplant for difficult aortic arch surgery, even in an emergency. The femoral artery is used for the retrograde placement of the transplant. The stent deployment is followed by the conclusion of the open proximal operation. It is advantageous to be able to use novel grafts that enable quicker and more precise surgery as patients' aortic diseases become more complex.

 

Cardiac Surgery Risks

The risk of complications is reduced with minimally invasive heart surgery than with open-heart surgery. Still, there is a possibility for:

• Bleeding.
• Infection.
• Abnormal heartbeats (arrhythmias).
• Stroke.

If your surgeon decides that the minimally invasive technique is no longer safe, they may occasionally change to open procedures in mid-surgery. Although it's uncommon, it's still vital to be aware that it could happen.

 

Conclusion

Cardiovascular health is greatly affected by cardiac surgery. The epidemiologic transition linking atherosclerosis, hypertension, and related risk factors from lifestyle choices is contributing to the ongoing rise in the prevalence of cardiovascular illnesses. Cost-wise, heart surgery accounts for 1% to 2% of the US healthcare budget, with an average inpatient expense of $40,000 totaling $20 billion. The need for healthcare workers with expertise in cardiology and cardiac surgery will rise.