Primary MR is mainly caused by severe infective endocarditis, rheumatic heart disease, connective tissue disease, ischemic disease, and other diseases [9]. Regardless of the cause, MR can cause abnormal anatomical structure or function of the annulus valve, leaf valve, chordae tendineae, papillary muscle, and atrioventricular wall, which can aggravate regurgitation [10, 11]. The most important treatments for MR are MVP and MVR. Almost all patients with MVR need to take anticoagulant drugs throughout their lives, and these patients have a relatively poor quality of life and a high possibility of other complications arising [12].
Thoracoscopic valvuloplasty requires only three holes to be made in the intercostal space of the right thoracic cavity; each hole is approximately 2–3 cm in diameter, and no median thoracotomy is required. The trauma to the patient is significantly reduced, allowing for quick patient recovery and short hospital stays. The patient with the shortest time in the ICU was 7 hours. Currently, MVP is the preferred treatment for MR, except in patients with ischemic lesions. MVP better preserves the left ventricular structure and functional status, reduces the occurrence of complications such as endocarditis, thromboembolism, and anticoagulation-related bleeding, and improves the long-term survival rate of patients. MVP involves a minimally invasive small incision, limited intraoperative field of vision, and limited operating space; therefore, the accurate preoperative diagnosis and accurate intraoperative positioning of the oesophageal ultrasound are essential.
The measured value of TTE can be used as an objective indicator of the patient's surgical efficacy.
In this study, transthoracic echocardiography was performed before the operation, 1 week after the operation, and 3 months after the operation. The relevant indexes of the cardiac structure measurements were then analysed. There were statistically significant differences in LAD, LVD, and EF, while there were no statistically significant differences in MV and MVG. After MVP, mitral valve regurgitation and volume load decreased significantly, the heart structure returned to normal, and LAD and LVD decreased. EF swiftly decreased in one week due to heart surgery trauma before returning back to normal. In a small number of patients, the mitral valve orifice flow rate increased, which may be due to the relative reduction of the valve orifice area by the sutures. In these patients, the valve orifice flow rate and pressure difference increased, but there was no statistical significance. Moreover, in the preoperative evaluation, the valve regurgitation area of 3D-TEE was more comprehensive than that of TTE. 3D-TEE was closer to the degree of intraoperative valvular insufficiency and could be evaluated objectively and accurately.
The location of the valvular disease and the choice of the forming ring are critical to the success of the surgery.
Previously, the size of the ring was selected by using a petal meter. After forming the valve, a water injection test was performed in the left ventricle to observe whether lobular prolapse and regurgitation was still present. However, these operations were all observed in the empty state of the heart under cardiopulmonary bypass, which is very different from the physiological state of the normal filling and pulsation of the heart. Therefore, the positioning of the leaflet lesions and the selection of the valve annulus by these previous methods are of low reliability. Choosing an appropriately sized ring can minimize the mitral valve annulus, increase the effective area of the anterior and posterior valves, correct the mitral incomplete state, and reduce MR. 3D TEE can help surgeons accurately select the appropriate forming ring before surgery (Fig. 5).
In this study, it was found that the most frequently selected ring was #30, followed by #28. If the selected valve ring is too large, it cannot effectively fill the role of a contracture valve ring. If the selected base is too small, the base of the ventricular septum will be too thick, which may cause secondary left ventricular outflow tract stenosis. Therefore, it is vital during MVP to accurately locate the lobe lesion and select the appropriate size of the valve annulus. The relevant data showed that there were more prolapses in areas A2 and P2, and the correlation between the 3D-TEE diagnosis and intraoperative diagnosis of mitral valve prolapse was 0.958, which indicated a good correlation. 3D-TEE, with its unique real-time three-dimensional reconstruction capability and high resolution, was helpful for comprehensively analysing the condition of the MR valves, conducting accurate assessments, and providing reliable imaging for the selection of effective rings. In conclusion, 3D-TEE can be used to determine the aetiology and diagnosis of MV, and it can be used to help reconstruct 3D images of the lobe lesions.
The advantages of thoracoscopic surgery and the important role of "one-stop" echocardiography.
The median sternotomy is a classical approach in cardiac surgery and allows enough exposure of the surgical field. However, the chest wall and sternum are severely injured by this operation; the patient endures a great deal of pain and wounds heal slowly and are prone to infection. In addition, this operation leaves a visible scar up to about 25 cm in the middle of the chest [13]. It had been reported that the minimally invasive MV surgery is popular due to its advantage over the robotic and standard approach [14].
When compared to traditional thoracotomy, the main advantages of minimally invasive thoracoscopic heart surgery are as follows: it avoids a large chest incision and sternotomy wound, significantly reduces tissue damage, and maintains the overall structure of the thorax [13]. Moreover, there is less bleeding in the operation field during and after the operation, and the pain is light, which can reduce the incidence of blood transfusion [15]. Patients can get out of bed in the early postoperative period, which is conducive to the postoperative recovery of elderly patients. Studies have shown that thoracoscopic MV surgery results in relatively less inflammation and injury reaction than median sternotomy [16]. This surgical method shortens the patient’s stay in the intensive care unit and the number of days of hospitalization, reduces medical expenses, and relieves the psychological stress of patients in hospital.
Since the skin incision is small and located on the side chest wall, the postoperative scar is relatively small and hidden, which better meets the patient's aesthetic needs.
Overall, TTE can provide an objective impression from the heart structure and function. Moreover, TTE is easy to operate, has good repeatability, and high acceptance among patients. It is the first choice for postoperative follow-up and condition monitoring.
3D-TEE can guide thoracoscopic extracorporeal circulation venous intubation, accurately locate valve leaflets, and reconstruct three-dimensional images of valve leaflets. It provides realistic imaging during examination that can assist cardiologists in formulating surgical plans, guide clinicians to quickly and accurately position the lesion site, evaluate immediate postoperative efficacy, and shorten the operation time. These advantages make it helpful in guiding the patient’s postoperative recovery, providing the appropriate medication and nursing, and improving the patient’s perioperative survival rate and long-term prognosis.