| BackgroundHypertrophic cardiomyopathy is a hereditary disease of left ventricular wall thickening that is not completely caused by abnormal cardiac load and is one of the most important causes of sudden death in adolescents.The incidence rate is about 0.2%.According to the 2014 European Society of Cardiology’s guidelines for the diagnosis and treatment of hypertrophic cardiomyopathy,whether left ventricular outflow tract obstruction can be judged based on whether the left ventricular outflow tract pressure difference at rest is≥30 mmHg,which divides hypertrophic cardiomyopathy into hypertrophic obstructive cardiomyopathy and hypertrophic non-obstructive cardiomyopathy.Surgical treatment is to remove the left ventricular outflow obstruction by surgery.The most common surgical procedure is to enlarge the ventricular septal resection.After the ventricular septal muscle resection by adequate resection of hypertrophy,the left ventricular outflow tract pressure difference can be significantly reduced,so the left ventricular outflow tract obstruction can be relieved and the left ventricular diastolic function can be improved.In recent years,with the continuous improvement of the auxiliary examination methods,more and more researchers have found that the left ventricular outflow tract obstruction is not only due to SAM phenomenon caused by abnormal hypertrophic myocardium and ventricular systolic phase inducing anterior mitral leaflet,abnormal mitral valve and subvalvular structures but also responsible for the left ventricular outflow tract obstruction.ObjectiveThis study was to retrospectively analyze the clinical data of patients with hypertrophic obstructive cardiomyopathy undergoing modified Morrow surgery n our hospital,to summarize the role of mitral value and subvalvular structures(mitral annulus,valve leaflet,chordae tendineae and papillary muscles)in aggravating left ventricular outflow tract obstruction in patients with hypertrophic obstructive cardiomyopathy,and the effect of handling abnormal mitral value apparatus on the surgical outcome,to provide clinical basis for surgical treatment of patients with hypertrophic obstructive cardiomyopathy.MethodThis study is a retrospective study of retrospective analysis of 27 patients with preoperative,postoperative,and postoperative June clinical data,from January 2015 to January 2018,who received modified Morrow surgery due to hypertrophic obstructive cardiomyopathy in the cardiovascular surgery of Southern Medical University Nanfang Hospital.Including basic information of patients,auxiliary examination results,specific procedures,complications,etc.According to the surgical procedure,the patients were divided into the simple ventricular septal myocardial resection group and the abnormal mitral and subvalvular structures.The survival of the patients and the results of the review were reviewed until June 30,2018.The left ventricular outflow tract obstruction and the occurrence of adverse events were evaluated.All data involved in the study were statistically analyzed using IBM SPSS Statistics 23.0 statistical software.Differences between groups of normal variable continuous variables were compared using Student,s t test or analysis of variance;Wileoxon rank sum test was used when the variance was not uniform.Comparisons between groups of categorical variable data were performed using Fisher’s exact test.All p values in this study were two-tailed,P<0.05 means the difference was statistically significant.ResultThis study found that echocardiography in all patients had mitral anterior leaflet SAM sign and varying degrees of mitral regurgitation.Intraoperative exploration of 77.8%(21)patients with anatomical abnormalities of the mitral valve or subvalvular structures,6 patients underwent modified Morrow surgery with simple ventricular septal myocardial resection.21 patients underwent anatomical abnormal mitral and subvalvular structures simultaneously after extensive resection of hypertrophic myocardium.9 patients underwent mitral valve replacement and underwent mitral valvuloplasty.The perioperative complications were mainly arrhythmia and ischemic stroke:1 case was paroxysmal atrial fibrillation,and the electrocardiogram was converted to sinus rhythm after 1 month;4 cases were complete atrioventricular block,implanted with permanent pacemaker.7 patients had atrioventricular block without further treatment and one of them had a left bundle branch block progressed to complete atrioventricular block and a permanent pacemaker was implanted in 3 month after operation.1 patient had massive cerebral infarction of the right hemisphere,leaving the sequelae of the left hemiplegia before discharge.1 patient died during perioperative period(3.7%),and the cause of death was low cardiac output syndrome and multiple organ failure.Compared with preoperative,the degree of mitral valve regurgitation was significantly reduced after surgery.The early mitral valve regurgitation score decreased from 2.32±0.80 to 0.24±0.44(p<0.001)after surgery,and the degree of mitral valve regurgitation and mitral valve regurgitation score 6 months after surgery were consistent with the early postoperative.The left ventricular outflow tract pressure difference after surgery decreased significantly.The early postoperative period had decreased from 94.56±25.75 mmHg before surgery to 17.08±9.06 mmHg(p<0.001),and 17.36±9.98 mmHg(p<0.001)at 6 months after surgery.The ventricular septum after surgery was significantly thinner,and the early postoperative period had decreased from 19.04±4.65 mm to 15.10±6.37 mm(p<0.001)before surgery,and 14.76±5.00 mm(p<0.001)at 6 months after surgery.The diameter of the left atrium after surgery was significantly smaller,and the early postoperative period was reduced from 48.64±5.72 mm before surgery to 45.19±5.01 mm(p<0.001),and 43.64±5.13mm(p<0.001)at 6 months after surgery.The pulmonary artery pressure decreased after surgery,and it decreased from 43.84±12.30 mmHg to 35.12±6.09mmHg(p=0.002)before surgery and 34.43±5.59 mmHg(p<0.001)at 6 months after surgery.The thickness of the posterior wall of the left ventricle was not significantly changed after surgery,but the 6-month postoperative examination showed that the thickness of the posterior wall of the left ventricle decreased from 11.63±2.08 mm before surgery to 10.64±1.96 mm(p=0.017).In addition to death and stroke patients,a total of 25 patients were involved in the evaluation of short-and medium-term surgery.Patients who underwent a simple ventricular septal myocardial resection group achieved good short-term surgery in 2 cases and 3 cases in less effective condition.Patients who underwent extended ventricular septal myocardial resection with abnormal mitral and subvalvular tissue groups achieved good short-term results in 20 patients,and no patients had poor short-term surgery effect.The difference between the two groups was statistically significant(p=0.004),which was better for short-term surgery in patients with mitral valve and subvalvular structures who underwent ventricular septal myocardial resection.Comparing the two groups of mid-term surgery results and the probability of adverse events,there was no significant difference between the groups.The follow-up period was 6 to 42 months,and there were no deaths during the follow-up period.The symptoms of all patients were significantly relieved compared with preoperative,and the quality of their life was significantly improved.There was no obvious SAM in the review echocardiography,and there was no moderate or above mitral valve regurgitation.ConclusionModified Morrow surgery can significantly reduce left ventricular outflow tract pressure difference and reduce mitral valve regurgitation,can better relieve left ventricular outflow tract obstruction,relieve chest tightness,dizziness and other symptoms,which improves the quality of life of patients with hypertrophic obstructive cardiomyopathy.The mitral valve and subvalvular structure are important factors influencing left ventricular outflow tract obstruction.In the process of modified Morrow surgery,it is necessary not only to fully enlarge the resection of hypertrophic ventricular septum,but also to actively treat abnormal mitral valve and subvalvular structures.Individualized modified Morrow surgery can better relieve left ventricular outflow obstruction for optimal surgical results. |
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