The concept of minimally invasive cardiac surgery is the surgical correction of the pathological and anatomical state of the heart and the restoration of its physiological function. Cardiac surgery is a product of modern medicine, and the safety and effectiveness of cardiac surgery is due to extracorporeal circulation and myocardial protection. For decades, median incision, extracorporeal circulation, and cardiac arrest have been the standard operation in cardiac surgery. The standard median incision in cardiac surgery allows for adequate exposure of all anatomical structures of the heart and is the incision of choice in almost all cardiac surgical procedures.
The main sources of trauma in cardiac surgery at this stage are: surgical access, extracorporeal circulation, cardiac arrest, and myocardial ischemia. There are several core issues corresponding to the current development of minimally invasive cardiac surgery: avoidance of extracorporeal circulation and thus reduction of extracorporeal circulation injuries, reduction of surgical incisions and bleeding and transfusion, delicate operations, interventional and hybridization techniques.
Minimally invasive techniques currently used in cardiac surgery
1.Non-extracorporeal circulation surgery of the heart
In the field of cardiac surgery, coronary artery bypass grafting and partial atrial fibrillation surgery are the few procedures that can be done without extracorporeal circulation. The coronary artery travels on the surface of the heart and does not require intracardiac manipulation, which in itself should be a non-extracorporeal procedure. However, since the beginning of this procedure, the debate about extracorporeal versus non-extracorporeal coronary artery bypass grafting has not stopped.
This is because the fundamental problem of coronary artery disease is myocardial ischemia, and adequate revascularization is the goal of coronary artery bypass grafting. The controversial points focus on the safety of the procedure, the degree of recanalization, the immediate results and the long term patency of the vascular bridge.
Undoubtedly, exposing different parts of the coronary target vessels without affecting systemic hemodynamics and performing delicate microsurgical operations in the presence of a beating heart is significantly more difficult than surgery in the quiet state of the heart under extracorporeal circulation and requires a longer learning time and learning curve. Since the development of special stabilizers for bypass, automatic anastomoses, and a variety of specialized equipment, it has gradually shown its advantages in the competition with conventional coronary artery bypass graft surgery. For experienced operators, non-extracorporeal coronary artery bypass grafting can achieve exactly the same results as extracorporeal circulation surgery.
The development of transcatheter radiofrequency ablation technology has contributed to the understanding of the mechanisms of atrial fibrillation, especially regarding the triggering mechanism of atrial fibrillation, which has led to a breakthrough in the treatment of atrial fibrillation. The invention of bipolar radiofrequency ablation forceps has made it possible to ablate atrial fibrillation under surgical thoracoscopy. Surgery has a unique advantage in the treatment of atrial fibrillation, and he can complete the continuous transmural ablation route, which can remove the left heart ear and eliminate the site of left atrial thrombosis, thus achieving the effect that is difficult to be achieved by transcatheter technology.
2.Small incision and thoracoscopy
Surgery traditional cardiac surgery usually in the median incision, trauma, blood loss, minimally invasive cardiac surgery is the earliest idea is to reduce the surgical incision, avoid splitting the sternum, reduce perioperative blood loss, or change the access route to make the incision more concealed and beautiful.
After more than 10 years of clinical practice, there are several mature surgical access options in clinical practice.
(1) Small upper sternal incision. It is suitable for pediatric aortic valve and pulmonary valve surgery.
(2) Small lower sternal incision. One can complete most of the direct intracardiac surgery (incision below the sternal angle or in this plane).
(3) Small right anterolateral thoracic incision. It is suitable for most direct intracardiac procedures and is particularly suitable for female patients.
(4) Small right parasternal incision – suitable for intracardiac surgery with direct visualization through the right heart, but nowadays this incision is used less frequently.
(5) Small right subaxillary incision. It is possible to perform a direct right heart surgery. However, the reduction of the incision does not necessarily mean the reduction of surgical trauma. On the contrary, the small incision often increases the difficulty of surgery due to insufficient exposure and may increase intraoperative accidents and perioperative complications. This is contrary to the original purpose of minimally invasive surgery: to reduce or mitigate the physical and mental trauma of surgery through small incisions while ensuring the surgical safety of the patient.
The development of thoracoscopic techniques has broadened the perspective of cardiac surgeons, the application of special fine instruments has lengthened the arms of cardiac surgeons, and the extracorporeal circulation technology via femoral arterial diversion has made minimally invasive cardiac surgery possible. It is worth mentioning that because thoracoscopic cardiac surgery does not significantly increase the cost of surgery and is more suitable for the current national conditions, it can be assumed that in the next decade, thoracoscopic cardiac surgery technology will be the mainstream of minimally invasive cardiac surgery technology in China. At present, in the field of thoracoscopic cardiac surgery, coronary artery bypass grafting, correction of simple precordial disease, mitral valve repair and replacement surgery and resection of cardiac mucinous tumor can be done under full thoracoscopy or with the assistance of thoracoscopy. Of course, to do this technique well, in addition to the need to go through a certain learning curve, it also requires the use of sophisticated instruments to achieve the desired results.
3.Robotic cardiac surgery
At present, the main surgical robots are “da Vinci” and “Zeus” two surgical systems, both of which have been certified by the FDA and the European CE field. These two robotic systems can obtain three-dimensional images. During surgery, the surgeon transmits instructions to the robot’s two robotic arms through a converter to manipulate surgical instruments to perform surgical operations such as cutting, separation, hemostasis, ligation, and suturing according to the surgeon’s remote instructions. Since the joints of the robotic arms can be extended into the patient’s body cavity, they can imitate the movement of human wrist joints.
Thus, the surgical action is closer to the fine movements of human hands, and the operation is more precise and smooth due to the magnification of the image and the stability of the robotic arm. At present, robotic surgery has been able to perform coronary artery bypass grafting, atrial septal defect repair, mitral valvuloplasty, and resection of cardiac cavity masses. However, the price factor, the complexity of cardiac surgery and the degree of fine operation have limited the application and scale of robotic cardiac surgery in China, and it is only carried out in a limited number of cardiac centers at present.
4.Interventional technology
The application of interventional therapy in cardiology is a newcomer in the invasive treatment of heart disease. Interventional achieves the purpose of previous surgical open-heart surgery through limited trauma. Currently, coronary interventional techniques are becoming more and more mature and have shown strong competitive ability. Currently, most patients with paroxysmal atrial fibrillation and isolated atrial fibrillation receive transcatheter radiofrequency ablation techniques, and interventional occlusion of unclosed arterial ducts is a routine treatment for arterial ducts. Currently, transcatheter valve implantation is also enthusiastically pursued. Percutaneous aortic valve implantation has been attempted in China.
It is the eternal law of medicine to obtain the maximum therapeutic effect with the least trauma at any given time. The scalpel, lumpectomy, catheter, and drugs are only tools in the hands of the physician, but the patient is always the core of medical care. Clinicians provide the best treatment to patients. With the development of medicine, the boundaries of medical and surgical procedures are blurring. At this stage, surgeons should be brave enough to face new things, accept new technologies, learn new technologies and promote new technologies. In the face of change, they should be the promoters and beneficiaries of change, and should not be the bearers and losers of change.