Nghiên cứu ứng dụng kỹ thuật bảo tồn thiết bị dưới van hai lá trong phẫu thuật thay van hai lá - Luận án tiến sĩ y học

MINISTRY OF EDUCATION AND MINISTRY OF NATIONAL TRAINING DEFENCE VIETNAM MILITARY MEDICAL UNIVERSITY TRAN THANH BINH RESEARCH ON APPLICATION OF TECHNIQUES TO PRESERVE THE SUBVALVULAR APPARATUS IN MITRAL VALVE REPLACEMENT SURGERY MEDICAL DOCTORAL THESIS HANOI – 2022 MINISTRY OF EDUCATION AND MINISTRY OF NATIONAL TRAINING DEFENCE VIETNAM MILITARY MEDICAL UNIVERSITY TRAN THANH BINH RESEARCH ON APPLICATION OF TECHNIQUES TO PRESERVE THE SUBVALVULAR APPARATUS IN MITRAL VALVE REPLACEMENT SURGERY Speciality: Surgery Code: 9720104 MEDICAL DOCTORAL THESIS Supervisors : 1. Bui Duc Phu 2. Dang Ngoc Hung HANOI – 2022 DECLARATION I hereby declare that this is my own research work. The data and results stated in the thesis are honest and have never been published in any other works.month…2022 Thesis author TABLE OF CONTENTS Declaratio Table of contents List of Abbreviations List of Tables List of Charts List of Diagrams List of Figures INTRODUCTION.

MITRAL VALVE ANATOMY. Annulus firosus of mitral valve. Cusps of mitral valve. Subvalvular apparatus of mitral valve.

Arterial feeding mitral valve. Nerve distribution for mitral valve. MITRAL VALVE DISEASE. Mitral valve stenosis.

Mitral valve regurgitation. Mitral valve replacement surgery. History of mitral valve replacement surgery. Mechanical prosthetic mitral valve replacement surgery.

Mechanical mitral valve replacement surgery with preservation of the subvalvular apparatus. RESEARCH SUBJECTS AND METHODS. Study sample size. Steps to conduct research.

CLINICAL AND PARACLINICAL CHARACTERISTICS. General characteristics of the study group. Preoperative subclinical characteristics. Characteristics of intraoperatively cardiac injuries determination 80 3.

Characteristics of intraoperatively cardiac resuscitation. CHARACTERISTICS OF MONITORING AND TREATMENT IN THE POSTOPERATIVE PERIOD .4 RESULTS OF POSTOPERATIVE MONITORING AND INSPECTION. Characteristics of postoperative heart failure according to NYHA 95 3. Post-operative subclinical characteristics.

CLINICAL AND SUBCLINICAL CHARACTERISTICS. General characteristics of the study group. Preoperative clinical characteristics. Preoperative subclinical characteristics.

Characteristics of some lesions of the heart identified intraoperatively. Characteristics of intraoperatively cardiac resuscitation. Early results after mechanical mitral valve replacement surgery with preservation of subvalvular apparatus. POSTOPERATIVE MONITORING, INSPECTION, ASSESSING THE RESULTS.

Development of paraclinical characteristics in the postoperative period. Complications in the postoperative discharge period. 147 LIST OF WORKS TO DISCLOSURE RESEARCH RESULTS OF THESIS THEME. 148 REFERENCES APPENDIX LIST OF ABBREVIATIONS No.

Abbreviation Full English writing 1 ACC American College of Cardiology 2 AHA American Heart Association 3 ASA American society of Anesthesiologist 4 pt parterners 5 EACTS European Association for Cardio-Thoracic Surgery 6 EF Ejection Fraction 7 ESC European Society of Cardiology 8 Ao Aorta 9 PA Pulmonary artery 10 et al et alia 11 LVEDd Left Ventricular End Diastolic Dimension 12 LVEDs Left Ventricular End Systolic Dimension 13 EnT Endotracheal 14 RA Right atrium 15 LA Left atrium 16 NYHA New York Heart Association 17 PAPs Pulmonary Artery Pressure systolic 18 Pre - op Preoperative 19 Post - op Postoperative No. Abbreviation Full English writing 20 AF Atrial fibrillation 21 ECC Extracorporeal circulation 22 RV Right ventricle 23 TT Left ventricle 24 TV Tricuspid valve 25 MV Mitral valve 26 WHO World Health Organization LIST OF TABLES No. Name of tables Page 2. NYHA classification of heart failure.

Severity grade of mitral stenosis. Severity grading of mitral regurgitation. Severity grading of tricuspid regurgitation. Pressure gradient across the prosthetic mitral valve.

Degree of para-prosthetic valve regurgitation. Age and gender. Characteristics of some anthropometric indicators. Relationship between gender and severity of heart failure according to NYHA.

Characteristics of some Pre - op general clinical symptom. Characteristics of electrocardiogram and chest X-ray. Characteristics of the image of the mitral valve apparatus on Pre - op echocardiography. Heart morphological and functional characteristics on Pre - op echocardiography related to mitral valve disease types.

Characteristics of some combined lesions on Pre - op echocardiography. Thrombosis in the LA appendage was determined intraoperatively. Characteristics of MV injury determined intraoperatively. Techniques to cut, repair and preserve the leaflets of the mitral valve in mitral valve replacement surgery.

Components of the mitral valve and subvalvular apparatus are preserved. Name of tables Page 3. Type and size of mechanical valve used in mitral valve replacement surgery. Other techniques used during mechanical mitral valve replacement surgery with posterior leaflet preservation.

Ao clamping time, ECC time (minutes). Heart rate characteristics after Ao clamp release. Post - op time characteristics. The relationship between the time of Post - op ventilator with the level of NYHA and the status of Pre - op AF.

Correlation between Post - op ventilator time with some factors. The relationship between the time of Post - op intensive care with the level of NYHA and the status of Pre - op AF. Correlation between Post - op intensive care time with some factors. Characteristics of vasopressor drug use in the Post - op period.

Echocardiography to check and evaluate early Post - op results. Early Post - op complications. Characteristics of changes in Post - op NYHA level. Change of AF status on Post - op electrocardiogram.

The change of the degree of pressure gradient across the mechanical valve on the ultrasonic. The change of the maximum pressure gradient (mmHg) across the mechanical valve on Post - op echocardiography. Change of LA diameter (mm) on ultrasound. Change of LVEDd (mm) after surgery.

Change of LVEDs (mm) on ultrasound. Change of EF (%) after surgery. Name of tables Page 3. Change of Post - op PAPs (mmHg).

Changes of TV regurgitation on ultrasound. LV diameter in the authors' study. 136 LIST OF CHARTS No. Name of charts Page 3.

The degree of Pre - op heart failure according to NYHA. Groups of mitral valve disease. Evolution of NYHA level after surgery. Change of Post - op AF status.

Change of Post - op LA diameter (mm). Change of Post - op LV diameter. Change of Post - op EF. Change of Post - op PAPs (mmHg).

Progression of Post - op TV regurgitation. 108 LISTS OF DIAGRAMS No. Name of diagram Page 2. Diagram of research steps.

73 LIST OF FIGURES No. Name of figures Page 1. MV image (viewed from the atria) in systole and diastole. Picture of mitral fibrous annulus.

Saddle-shape diagram of the mitral annulus. Rough and smooth part of the leaflets. Left ventricular division during diastole. Areas of the mitral margin and the edges of the MV.

Morphology of the subvalve apparatus: chordae tendinae and papillary muscles. The types of chordae tendineae of the mitral valve are classified according to the position of attachment on the leaflets. The types of chordae tendineae arise from the posterior medial papillary muscle group. Pictures of the position, orientation and grouping of the LV papillary muscles.

Types of LV papillary muscle morphologies. Arteries feeding papillary muscles. Schematic diagram of the nerve distribution of the valve leaflets of MV. Image of mitral stenosis.

The leaflets are thickened, calcified, adherent to the two edges of the valve; chordae tendineaes ares thickened, shortened. Description of the classic technique of replacing the prosthetic mitral valve. Illustration of Miki .'s technique of preserving both leaflets. Illustration of David's technique of preserving both leaflets.

Name of figures Page 1. Illustrateion of technique for complete preservation of posterior leaves. Illustration of technique for complete preservation of posterior leaves. Image of opening LA.

Picture of mitral regurgitation due to degeneration. Stenosis and mitral regurgitation images. Image of anterior valve leaf suspension stitch, evaluation of the subvalvular apparatus. Anterior leaflet resection image.

Anterior and anterolateral ligament and muscle column resection images. After the anterior leaflet ligament remove and attached to the anterolateral muscle column. Image of removing calcifications in the annulus and posterior leaflets. The image of calcification removal, thinning of the thickened fibrous annulus.

Image of stitching cushioned U- shape roll joints. Image of stitching loose threads to fix mechanical valves. Image of placing a mechanical mitral valve into the heart chamber. Image of a mechanical mitral valve fixed in right place.

Image of checking the opening and closing of mechanical leaflet valves. Electrocardiogram with 6 arms (Nihon Kohden). Philips HD 11 XE ultrasound machine. Name of figures Page 2.

Extracorporeal Circulator Sarn™ 8000. St Jude valve. 69 1 INTRODUCTION Common diseases of the mitral valve are stenosis, regurgitation, stenosis combined with regurgitation. The most common cause is rheumatic heart disease, in addition, it can be caused by infection, degeneration, systemic disease.

physical changes of the leaflets and subvalvular apparatus (the corresponding papillary muscle and chordae tendinaes) such as thickening, calcification, contracture, hypertrophy, etc. Medical treatment is the first stage of treatment, very important to reduce symptoms and disease progression. But to completely solve the physical damage in the mitral valve, it is necessary to use surgical interventions such as valve repair or replacement. Valve repair is the technique of first choice, but when the physical damage to the valve is too severe to be repaired, it is indicated to replace the MV with a mechanical or biological prosthetic valve [2].

Mechanical valves have high durability, but there is always a potential risk of blood clot formation, so after surgery, anticoagulants must be used for life; and biological valves rarely cause blood clots, but there is always a potential risk of organ degeneration, so after a period (8-15 years) the patient must be re-operated to replace a new valve. Therefore, mechanical valves are the first choice for young patients (under 60 - 65 years old) and have no contraindications to anticoagulation [3], [4]. The world's first successful mechanical MV replacement surgery was performed by Nina S. on March 11th, 1960, with the classic technique of resection of both leaflets and subvalvular chordae tendinaes [5].

However, later studies have shown that preserving the leaflets and subvalvular apparatus will help better improve left ventricular function after surgery [6], [7], [8], [9]… Depending on the specific lesion and experience, the surgeon can apply either 2 the technique of preserving both leaflets or the technique of preserving the posterior leaflet. In the technique of preserving both leaflets, the preservation of the anterior leaflet can affect the action of the mechanical valve and obstruct the left ventricular outflow after surgery. The technique of preserving posterior leaves can limit these disadvantages, especially in cases where the anterior leaf and its subvalvular apparatus suffer from severe fibrous lesions, calcification, shrinkage, hypertrophy, etc. In Vietnam, MV replacement surgery has been performed since 1971, in which the technique of MV replacement with preservation of the subvalvular apparatus has also been applied in some cardiac surgery centers, but it is still highly dependent on experience of each surgeon [10].

At Hue Central Hospital, for many years, mechanical MV replacement surgery has been used to preserve the subvalvular apparatus with the posterior leaflet preservation technique [11]. The use of this technique is based on the following assessment: Most patients with indications for MV replacement surgery are due to post-rheumatic MV disease with prolonged disease duration, valve lesions are usually thickened fibrous, retractile, calcified. Therefore, it often causes MV narrowing, accompanied by small LV size. If the technique is used to preserve both leaflets and chordae tendineaes, after surgery, the preserved part of the anterior leaflet has the risk of affecting the operation of the mechanical valve and especially causing the LV outflow tract stenosis syndrome, which can lead to complications named "left ventricular lethargy", even left ventricular rupture due to left ventricular overload right after surgery.