Long-term chronic rheumatic heart disease often leads to multivalvular lesions. These patients are characterized by a longer disease duration, more severe myocardial damage, and often secondary dysfunction of important organs and systemic immune deficiency, which increases the difficulty of surgical treatment.
Clinical data
There were 356 cases in this group, 136 males and 220 females, aged 13 to 76 years, with an average of 42.8±7.8 years. The disease duration was 5~40 years, with an average of 22.6±6.2 years. The preoperative cardiac function was graded by NYHA, with 23 cases of class II, 128 cases of class III, and 205 cases of class IV. The cardiothoracic ratio on X-ray chest radiographs ranged from 0.62 to 0.98. 208 cases had moderate or higher pulmonary hypertension. The electrocardiogram showed 320 cases of atrial fibrillation, 86 cases of left ventricular hypertrophy and/or strain, 78 cases of biventricular hypertrophy, and 145 cases of right ventricular hypertrophy. The types of multivalvular lesions are shown in the table.
Table Types of valvular lesions
Type of lesion Number of cases (%)
Mitral valve lesion + functional tricuspid insufficiency 127 35.7
Mitral lesion + organic tricuspid insufficiency 14 3.9
Combined mitral + aortic valve lesion (combined lesion) 136 38.2
Combined lesion + functional tricuspid insufficiency 67 18.8
Combined lesion + organic tricuspid valve lesion 12 3.4
Total 356 100
Surgical method
Surgery was performed under general anesthesia and moderate hypothermic extracorporeal circulation. Myocardial protection method was used in most of the early cases (84 cases) with cold crystalloid fluid for cascade perfusion, and in the later cases with cold blood high potassium fluid. 116 cases were perfused cascade, 134 cases were perfused retrograde, 22 cases were perfused cascade + retrograde, and in 136 cases a small amount of warm blood low potassium fluid was applied for reperfusion before opening the ascending aorta. Aortic valve + mitral valve replacement (DVR) was performed in 136 cases, mitral valve replacement (MVR) + tricuspid pulmonary plication (TVP) in 127 cases, DVR + TVP in 67 cases, DVR + tricuspid valve replacement (TVR) in 12 cases, and MVR + TVR in 14 cases. There were 597 prosthetic valves implanted, including 388 St. jude bileaflet valves (including 36 H-P aortic valves), 166 Sorin bileaflet valves (including 5 supra-annular aortic valves), 26 Beijing G-K valves, 6 Lanzhou C-L valves, 5 St. jude bioprosthetic valves, and 6 Edwards Lifescience bioprosthetic valves. The prosthetic flaps were fixed with interrupted mattress sutures with spacers. of 194 TVPs, 156 were modified DeVega method, 15 were modified Devega method + Key method, 10 were Key method, 11 were shaped ring method, and 2 were junctional dissection and shaping + modified Devega method. The aortic block time ranged from 24 to 222 minutes (mean 95.0±36.9 minutes), and the extracorporeal circulation ranged from 69 to 277 minutes (mean 150.6±54.2 minutes).
Results
There were 6 early postoperative deaths with a mortality rate of 1.7%, which were 2 cases of postoperative ventricular arrhythmia, 2 cases of posterior left ventricular wall rupture, 1 case of low cardiac output, and 1 case of hemoptysis. There were 10 cases of early postoperative hypovolemia, 2 of which were taken off after 24 hours of left heart assist with centrifugal pump; 8 cases of MOF. There were 2 cases of late death, both of them were end-stage patients before surgery, and they died 5 and 8 months after surgery due to MOF. Among the 348 cases discharged from the hospital, one case died of other diseases 4 years after surgery; the remaining patients were followed up for 2-124 months without major complications such as bleeding and thrombosis, and cardiac function recovered to class I-II in 339 cases and class III in 8 cases.
Discussion
1, Enhancement of preoperative preparation.
Patients with multivalvular lesions often have a long course, complex disease, poor cardiac function, and some patients also have combined multivisceral functional impairment, so preoperative preparation must be emphasized to improve the safety of surgery. We consider improving the patient’s general condition, adjusting cardiopulmonary function, improving coagulation mechanisms, and correcting water-electrolyte imbalance as the four important aspects of preoperative preparation. For elderly patients, it is also necessary to pay attention to the possibility of combined coronary heart disease, and coronary angiography is routinely performed before surgery.
2.Strengthen myocardial protection.
For patients with multivalvular lesions, good intraoperative myocardial protection is not only the basis of surgery, but also an important issue that directly affects early and long-term surgical outcomes. In recent years, we have used blood-containing high-potassium fluid perfusion, and in the case of combined aortic valve lesions, retrograde interstitial or continuous perfusion via coronary venous sinus cannula is applied, and in some cases, cascade perfusion is added, so that the myocardium has a more adequate blood supply during arrest, which avoids or reduces ischemic and hypoxic damage to the myocardium. In 136 cases, warm hypokalemic fluid reperfusion was applied before opening the ascending aorta, which had a good effect on cardiac rewarming and reducing myocardial ischemia-reperfusion injury. We also routinely perform modified ultrafiltration after stopping extracorporeal circulation intraoperatively, which can rapidly reduce systemic and myocardial edema, thus improving myocardial function and reducing pulmonary vascular resistance.
3, Selection of the appropriate surgical approach.
(1) the choice of valve type: in order to facilitate surgical exposure, DVR is generally done first for MVR, so it is advisable to measure the size of the aortic valve annulus previously in order to make a suitable size selection. For patients with small aortic or aortic annulus, in recent years we have used the non-reversal suture method of the spacer under the annulus, which we believe has the advantages of easy surgical operation (within a certain range to avoid annular enlargement), increased effective orifice area, and firm valve suture; at the same time, we try to use special prosthetic valves, such as the St. Jude H-valve. Such as St. Jude H-P valve, Sorin supra-annular aortic valve, generally can meet the requirements of resting and active cardiac output.
(2) Pay attention to the management of tricuspid valve lesions: the management of functional tricuspid valve insufficiency is still controversial, but most tend to take active surgical management to avoid difficulties in resuscitation, while facilitating the recovery and improvement of early and late postoperative cardiac function. In our group, we mostly use the modified DeVega method of valvuloplasty, which differs from the usual double-headed needle for side-by-side continuous suturing. We change the lateral approach to the annulus to a continuous suture from the atrial surface, obliquely toward the tricuspid annulus, which is stronger than the usual side-by-side suture and less likely to lead to proximal and distal valvuloplasty failure caused by cutting and tearing. For patients with severe tricuspid valve lesions or failed shaping attempts, TVR is performed. because of the risk of failure of the biologic valve, we mostly use mechanical valves and only use biologic valves for older patients.
4. Enhanced postoperative management.
In this group, there were 333 cases (93.5%) of preoperative cardiac function class III-IV, and there were many cases of combined pulmonary hypertension. 208 cases (58.4%) of preoperative moderate pulmonary hypertension in this group, coupled with the long operation time, were prone to postoperative hypocapnia syndrome and respiratory failure, so the postoperative cardiopulmonary function of patients must be closely monitored and coordinated. For individual patients with severe low cardiac output, resuscitation treatment can be performed as early as possible with auxiliary devices such as centrifugal pumps. 2 cases in this group were taken off the machine after 24 hours of application of left heart assist by centrifugal pumps with good results.