The routine resection of myxoma is SMR, with a long history, and many studies have proved that it is safe and feasible[5, 6, 9, 10]. However, SMR needs to split the sternum in the middle, which will destroy the normal bone structure of the sternum and increase the pain of the patient after the operation. With the use of wire and bone wax, the risk of foreign body rejection is higher in SMR, obese patients or patients with diabetes are more prone to incision fat liquefaction or infection, resulting in a prolonged unhealed incision, and large scars are left. Mini-MR adopts a small right chest incision operation method, the position of the surgical incision is hidden and the appearance is better. On the one hand, Mini-MR does not need to saw the sternum, thus maintaining the stability of the sternum, which is beneficial to reduce postoperative thoracic deformities and adverse reactions caused by wire fixation and other related complications. On the other hand, the respiratory function of patients who choose right chest small incision surgery is well protected because the normal structure of the sternum is maintained, and the postoperative pain of the patient is reduced, which is conducive to faster postoperative recovery and earlier discharge.
In this study, compared with the SMR group, the Mini-MR group had shorter operation time, longer aortic cross-clamp time, and longer CPB time, but the difference was no significant (P > 0.05). Minimally invasive surgery shortens the time of opening and closing the chest, but due to the small space and high difficulty, the time of heart operation is prolonged. The study by Dong et al.[11] showed that Mini-MR compared with SMR has a longer operation time, aortic cross-clamp time, and CPB time, but the difference is also no significant. Mini-MR relies on special minimally invasive surgical instruments and requires the assistance of thoracoscopy. The surgeon has a learning curve. At the same time, because the assistance of thoracoscopy is needed, the cooperation of assistants is also very important. With the improvement of surgical proficiency, the time of minimally invasive aortic cross-clamp and CPB time will gradually shorten to the same as that of median thoracotomy. Minimally invasive surgery will greatly shorten the overall operation time because it does not require complicated chest closure to stop bleeding.
Patients after cardiac surgery will be immediately transferred to the CSICU for monitoring and follow-up treatment, routinely given ventilator-assisted breathing and then transferred to the general ward for recovery after the condition is stable. Increased duration of ventilator-assisted has been shown to be related to pulmonary complications, length of stay in the hospital, and increased length of stay in CSICU[12, 13]. This study found that the ventilator assistance time of the Mini-MR group was significantly shorter than that of the SMR group, and the CSICU stay time and postoperative hospital stay were also greatly reduced. Early removal of the tracheal intubation can reduce pulmonary complications, and the short stay in the CSICU can enable the patient to be transferred to the general ward as soon as possible, which is conducive to postoperative recovery and shortens the hospital stay, thereby saving the patient's cost.
Massive postoperative drainage and blood transfusion will bring many complications. Massive postoperative drainage will lead to reoperation for hemostasis. Studies have shown that the amount of input red blood cells greater than 4 units is an independent risk factor for a lung infection[14]. Another study showed that blood transfusion plays an important role in the process of acute kidney injury after cardiac surgery[15]. This may be related to the decreased ability of red blood cells to deform during storage, impaired energy metabolism, and decreased oxygen-carrying capacity. The hemoglobin released by the red blood cells destroyed during the storage of red blood cells blocks the renal tubules, which may also be the cause of acute kidney injury after a large number of blood transfusions. Compared with SMR, Mini-MR can reduce postoperative drainage and postoperative blood transfusion rate.
The complications after cardiac surgery will increase the risk of death of the patient. In this study, there was no difference in the rate of stroke, the rate of pneumonia, the rate of pleural effusion, the rate of new-onset atrial fibrillation, the rate of renal insufficiency, the rate of poor incision healing, the rate of reoperation for hemostasis, and postoperative mortality between Mini-MR and SMR. This can also indicate that Mini-MR does not increase the risk of these postoperative complications compared with SMR. In addition, Mini-MR requires the establishment of peripheral cardiopulmonary bypass, so it needs to free the femoral artery, femoral vein. Free the femoral artery and vein may cause femoral artery dissection, thrombus, hemangioma, stenosis, etc[16]. This did not happen during our surgery. The maturity of surgical techniques can avoid such related complications.