Current status of heart transplantation

Cardiac transplantation has extended and improved the lives of patients suffering from severe heart failure over many decades. Despite advances in medical therapy, cardiac transplantation remains the definitive treatment for end-stage heart disease. Surgical techniques for organ procurement and implantation, development of appropriate methods for preserving the heart, and understanding the immunological challenges associated with transplantation were among the many areas which required focused investigation. In the current era, heart transplantation is associated with a low operative mortality and excellent long-term survival, however, the major obstacle of shortage of suitable donor organs remains. In the following chapter, recipient selection and management, donor organ procurement and preservation, and surgical techniques of heart transplantation are described in detail.

Surgical therapy for heart failure

Congestive heart failure affects 23 million people worldwide, and is the final pathway for many diseases that affect the myocardium. Successful intervention in acute coronary syndromes together with improved management of idiopathic dilated cardiomyopathy and dysrhythmia provide an ever-increasing number of advanced heart failure patients spread over a wide age range. In Western countries, coronary artery disease is responsible for about 70% of patients with idiopathic dilated cardiomyopathy and valvular heart disease accounting for 15%. Since 10% of patients older than 65 years suffer systolic left ventricular dysfunction, the numbers with heart failure will double within the next 25 years. For end-stage patients, cardiac transplantation provides the benchmark for increased longevity and symptomatic relief. However, the vast majority of patients are over 65 years of age or are referred with established comorbidity, which precludes transplantation.

Mitral valve repair: Conventional open techniques

Mitral valve repair is the preferred surgical option for nearly all patients with mitral regurgitation (MR) as its durability is widely recognized to be excellent. Advantages of mitral valve repair over mitral valve replacement include better preservation of left ventricular function, greater freedom from endocarditis and anticoagulant-related hemorrhage, and, in some cases, improved survival. Mitral valve repair has particular advantages in younger patients, who require lifelong anticoagulation if they receive mechanical prostheses. Mitral valve repair can be achieved in more than 90% of patients who have MR caused by prolapse. The forthcoming account includes an overview of the various techniques used in current practice.

Aortic valve: Conventional valve replacement and transcatheter valve implantation

The natural history of untreated severe aortic valve stenosis (AS), with an average survival of 3 years after the onset of angina or syncope and only 1½ years after onset of heart failure, strongly suggests early surgical therapy which represents the only curative option. Since the first pioneering work in the early 1960s, conventional aortic valve replacement (AVR) has become a routine procedure performed more than 200,000 times annually worldwide. The surgical technique of AVR has evolved to a highly standardized procedure resulting in excellent outcome and patient safety. Transcatheter techniques have emerged in the last decade allowing for valve implantation with avoidance of important complications of major surgery particularly in high-risk patients. However, potential drawbacks and procedure-related complications remain important. The techniques and technologies continue to emerge and improve. Conventional surgery, valve substitutes, and transcatheter technologies are discussed in this chapter.

Current status of lung transplantation

Lung transplantation is well established as a viable therapy for end-stage lung disease. Appropriate patient and donor selection, meticulous attention to technique, and continued improvement in the postoperative care of these patients will lead to optimal outcomes. Donor shortage and chronic allograft rejection continue to be the biggest hurdles preventing lung transplantation from reaching its full potential. Indications, recipient selection, donor procurement, surgical techniques, and postoperative outcomes are reviewed. The major identified causes of death in the first 30 days postoperatively are graft failure and non-cytomegalovirus (CMV) infections. After the first year, bronchiolitis obliterans syndrome and non-CMV infections were the predominant causes of death. Death caused by malignancies rises consistently until the 10-year mark, accounting for 12% of all deaths between 5 and 10 years after transplant.

Minimally invasive mitral valve repair

The practice of minimally invasive surgery is becoming increasingly widespread in the current era of cardiac surgery. Minimally invasive mitral valve surgery (MIMVS) describes many different surgical techniques used in the management of mitral valve (MV) disease. Variations in surgical techniques include a combination of the type of incision, direct visualization (videoscopic or robotic visualization), cardiopulmonary perfusion techniques, and aortic occlusion (external clamping, endo-clamping, or fibrillatory arrest). In this chapter, the history and current literature related to MIMVS are reviewed in detail. In addition, we discuss both important technical aspects associated with MIMVS, as well as our approach at the Saint Thomas Heart Institute.

Open and endovascular treatment options in thoracic aortic surgery

Open endovascular and hybrid repairs have recently emerged as a method for treating the different segments of the thoracic aorta. A full or upper-mini median sternotomy is the usual approach for proximal aortic disease and proximal and transverse arch repairs. Other approaches, such as minimally invasive right thoracotomy, have also emerged. Until recently, a left thoracotomy and thoracoabdominal approach has been the sole approach for treating lesions of the descending and thoracoabdominal thoracic aorta. In the 1980s, the first aortic repair with a self-fixing endoprosthesis was performed. In subsequent years, the technique of using a stent graft to treat an abdominal aortic aneurysm, and subsequently thoracic aortic aneurysm, was popularized, followed by extensive development of this technology. The different techniques and modalities for treatment are discussed in this chapter.

Aortic valve repair

Aortic valve replacement remains the gold standard for the treatment of severe aortic valve disease. Techniques for valve repair are emerging as a feasible alternative to valve replacement in selected patients. Advantages include potential reduction in the risks of prosthesis-related complications such as thromboembolism, endocarditis, anticoagulant-related hemorrhage, and reoperation due to structural valve deterioration. In this chapter, the key features of aortic valve and root anatomy, an approach to valve assessment and lesion classification, a demonstration of commonly used reparative techniques for aortic valve repair, and outcomes are reviewed. Furthermore, it also examines the outcomes of aortic valve repair in unselected cohorts, as well as distinct subsets of patients undergoing aortic valve preservation and repair.

Current status of minimally invasive, robotic and hybrid coronary artery bypass surgery

While coronary artery bypass graft (CABG) remains the gold standard in the treatment of multivessel coronary artery disease, it remains quite invasive. Techniques and evolving technologies of minimally invasive (including hybrid and robotic) approaches to coronary revascularization are reviewed in this chapter with a summary of the available supporting literature. Minimally invasive direct coronary bypass (MIDCAB) surgery uses an anterior, medially placed, mini-thoracotomy incision for both direct-vision left internal mammary (LIMA) harvest and creation of an anastomosis of the LIMA to a coronary artery in off-pump fashion. As in standard CABG, all patients should undergo a complete preoperative work-up, and body mass index and body habitus are to be noted. Obesity is considered a relative contraindication for MIDCAB as it may predispose to wound infection; this concern is primarily due to tissue necrosis caused by pressure on the wound edges by the retractor during LIMA harvest.

Off-pump versus on-pump coronary artery bypass grafting

Although an abundance of literature comparing on-pump (ONCAB) versus off-pump (OPCAB) coronary artery bypass grafting exists, the optimal surgical strategy remains controversial. While many centers have adopted off-pump techniques, OPCAB surgery remains in the minority of coronary artery bypass grafting procedures performed in the United States. Proponents of ONCAB cite the lack of convincing data in randomized trials demonstrating a benefit for OPCAB, while also citing large observational and registry data that suggest an associated reduction of in-hospital mortality and morbidity with OPCAB. Even more controversial are the reports of graft patency, completeness of revascularization, and the need for repeat revascularization. The advantages and limitations of off-pump surgery, along with its technical considerations, are discussed in detail in this chapter.