MINISTRY OF EDUCATION AND TRAINING MINISTRY OF DEFENCE MILITARY MEDICAL UNIVERSITY LE THANH KHANH VAN EVALUATION OF THE TREATMENT IN RIGHT VENTRICULAR OUTFLOW TRACT OBSTRUCTION AT CHO RAY HOSPITAL Speciality: Surgery Code: 9720104 ABSTRACT OF MEDICAL DOCTORAL DEGREE HA NOI – YEAR 2019 THESIS COMPLETED AT MILITARY MEDICAL UNIVERSITY Tutor of thesis: Pham Tho Tuan Anh, Assoc.Prof.PhD Mai Van Vien, Assoc.Prof.PhD Reviewer 1: Nguyen Hoang Đinh, Assoc.Prof.PhD Reviewer 2: Hoang Đinh Anh, Assoc.Prof.PhD Reviewer 3: Nguyen Huu Uoc, Assoc.Prof.PhD The thesis was defended at assembly of the university on: o’clock date months year Can read for this thesis at: National library Military medical university’s library ………………………… ABSTRACT Introduction Congenital heart disease is one of the central topics that receives a lot of attention from cardiology, obstetrics and even in society Pulmonary stenosis is the narrowing of the exit from the right ventricle, reducing blood flow to the lungs Simple to complex lesions, appear in many pathologies: atrial septal defect, ventricular septal defect, tetralogy of Fallot, atrioventricular septal defect, right ventricle double outlet If we not fix and treat promptly and properly, it will lead to unpredictable consequences Children with mental and physical delays, always live in severe hypoxia Patients can die from complications: acute hypoxia, endocarditis, cerebrovascular thrombosis, brain abscess, heart failure, low quality of life and reduced life expectancy On the contrary, if the patient is treated, especially corrective surgery to thoroughly expand the right ventricular outlet, it will produce good results The right ventricular enlargement surgery in tetralogy of Fallot disease or non-tetralogy of Fallot should have the suitable considerations to preserve the morphology and function of the right ventricular outlet, not too broad or too narrow, which leads to heart failure later There are many characteristics and lesions affect to result to right ventricular enlargement surgery So we conducted a research on the topic "Evaluation of the treatment in right ventricular outflow tract obstruction at Cho Ray hospital" with two goals: Review some characteristics of pathology right ventricular outflow tract obstruction for surgical treatment at Cho Ray Hospital in the period of 2013-2017 Evaluate the results of surgical treatment of right ventricular outflow tract obstruction at Cho Ray Hospital Contributions of the thesis: Determine an overview of congenital heart disease with right ventricular out flowtract obstruction: physical geometry, anatomical lesions, treatment approaches Reflect in part the diversity of the disease with right ventricular out flowtract obstruction in tetralogy of Fallot, non-tetralogy of Fallot - Pulmonary artery annulus and main pulmonary artery dimension in TOF group is smaller in nonTOF group - Mortality and complication in TOF group is higher in nonTOF group Apply the Z scores to assess the size of pulmonary valve ring, pulmonary artery and its branches, then suggest surgery method suitable for different lesions of pulmonary stenosis Application of surgical methods - a transatrial, transpulmonary artery approach Positive results when thoroughly corrected surgical treatment, especially early repair surgery Structure of the thesis: The thesis consists of 126 pages (excluding references, appendices), including introduction, chapters (Overview, subjects and research methods, results, discussion) and conclusions The thesis includes 38 tables, 14 charts, 33 images List of references 122 documents (12 Vietnamese articles, 110 English articles) Chapter 1: OVERVIEW 1.1 A brief history of the studies of congenital heart disease with pulmonary stenosis 1.1.1 Over the world - Pulmonary valvular stenosis is one of the common congenital heart diseases, described by John Baptish Morgagni in 1761 - In 1888 Etienne Louis Arthur Fallot reported on tetralogy of Fallot with four characteristics regarding the pathophysiology, including pulmonary stenosis 1.1.2 In Vietnam In 1970, Dang Hanh De was the first Vietnamese who successfully performed surgery to totally repair tetralogy of Fallot At the same time, author Le Ngoc Thanh "research on surgical treatment of pulmonary valvular stenosis under temporary cessation of circulation at normal temperature", Nguyen Huu Uoc reports on "research on total surgical repair of tetralogy of Fallot in older children” is performed at Viet Duc Hospital, in 2008 Le Quang Thuu" research on total surgical repair of tetralogy of Fallot "at Hue Central Hospital 1.4 Pathophysiological of the right ventricular outflow tract 1.4.1 Abnormal development of pulmonary stenosis The strict development of the heart step by step over time This needs to happen in a proper sequence to avoid abnormalities in function and structure Most of the congenital defects in the heart begin with the combination of many genetic factors related to the family and the effects of the living environment 1.4.2 The position pulmonary stenosisi Right ventricular outflow tract obstruction can occur in a wellcoordinated position in many different locations including: at the pulmonary valve (valvular stenosis), below the pulmonary valve (Subvalvar pulmonary stenosis) or just above the pulmonary valve (Supravalvar pulmonary stenosis) A Valvular stenosis: congenital valvular stenosis accounts for - 10% of congenital heart disease Damage to the valve often involves trileaflet, markedly thickened and myxomatous cusps, leading to a narrow center B Subvalvar pulmonary stenosis: Subvalvar pulmonary stenosis is often seen in association with ventricular septal defect and rarely isolated subvalvar pulmonary stenosis The location of the obstruction may be a discrete fibromuscular ridge/ring or hypertrophied muscle bundles Alternatively, hypertrophied supporting bands of the right ventricle may occur, resulting in dividing the right ventricle into two chambers C Supravalvar pulmonary stenosis: Supravalvar pulmonary stenosis can be isolation, pulmonary trunk stenosis or pulmonary artery branches stenosis It accounts for 2-3% of congenital heart disease, is often complicated, on both sides, and spreads into the mediastinum or lung hilum, which is common in tetralogy of Fallot 1.5 Congenital heart diseases with right ventricular outflow tract obstruction Right ventricular outflow tract obstruction may occur in many congenital heart diseases, divided into two groups: right ventricular outflow tract obstruction in tetralogy of Fallot (TOF) and right ventricular outflow tract obstruction in non-tetralogy of Fallot (non-TOF) 1.5.1 Right ventricular outflow tract obstruction in tetralogy of Fallot: Tetralogy of Fallot includes right ventricular outflow tract obstruction, a large ventricular septal defect, right ventricular hypertrophy and an overriding aorta 1.5.1.1 Anatomic defects a Infundibulum The shift to the left, up and front of the infundibulum or infundibular septum causes right ventricular out flow tract obstruction, leading to obstruction under pulmonary artery The subpulmonary infundibulum is too small, it cannot fill the space above the ventricular septum and septal band, resulting in a ventricular septal defect Failure of normal morphogenetic movement of the infundibular septum to occur results in aortic overriding The stretching of the right ventricular free wall or the ventricular septum contributes to the pulmonary stenosis Therefore, author Van Praagh suggested the tetralogy of Fallot basically is a “monology”, just anomaly, namely, underdevelopment of the subpulmonary infundibulum and its sequelae b Pulmonary valve in tetralogy of Fallot: According to Kirklin narrowing Pulmonary valve occurs about 75% of tetralogy of Fallot cases, 50% - 75% are bicuspid valves, 5% not have pulmonary valve Narrow valves are often caused by dysplasia and no separation of bicuspid valve, ligature on the valve or a combination of the above factors c Pulmonary trunk and its branches in tetralogy of Fallot: Pulmonary trunk is usually smaller and shorter than usual The narrowest part pulmonary trunk is usually at the junction of the sinus tube The arterioles in the lobules of the lungs may be smaller than normal with the thin middle layer, due to low vascular pressure or lack of blood to the lungs 1.5.2 Right ventricular outflow tract obstruction in non-tetralogy of Fallot Right ventricular out flow tract obstruction with atrial septal defect or ventricular septal defect, or isolated right ventricular outflow tract obstruction 1.5.3 Right ventricular outflow tract obstruction with complex congenital heart diseases - Complete atrial-ventricular canal - Double outlet right ventricle 1.6 Diagnose 1.6.1 Clinical a Tetralogy of Fallot: Patients may manifest: cyanosis, heart murmur, finger clubbing, easy tiring, shortness of breath, and physical and mental developmental delay Cardiovascular: normal T1, decreased or inaudible T2, arrhythmia A harsh grade 2/6 to 5/6 systolic ejection murmur rib cage II - III near the left side of the sternum spreading behind the back b Right ventricular out flowtract obstruction in non-tetralogy of Fallot disease: Severe stenosis, early clinical symptoms, severity depends on degree of stenosis However, in mild patients there is no clear symptom, accidentally discovered during physical examination periodic health Sometimes it is found in other congenital syndromes 1.6.2 Diagnostic Tests a Cardiopulmonary X-ray: The majority of patients have normal heart size, small pulmonary trunk: an ax-shaped sign The abnormal "coeur-en-sabot" (boot-like) appearance of a heart due to the right ventricular hypertrophy Lung circulation is reduced: the two pulmonary hilum are less dark than usual b Electrocardiogram: there is increased right axis deviation from right ventricular hypertrophy with associated high amplitude Rs waves in V1, then accidentally rS from V2 to V6 Branches are blocked incompletely c Echocardiography: A definitive diagnosis and diagnosis of accompanied lesions 1.7 Treatment of right ventricular outflow tract obstruction 1.7.1 Medical treatment Mainly temporary treatment and prevention of complications 1.7.2 The index for evaluating the severity of right ventricular outflow tract obstruction a Differential pressure through valve pulmonary artery In clinical, based on the pressure difference through pulmonary valve (pressure difference between right ventricle - pulmonary artery) levels of severity and based on which to give indications for treatment, or follow the progress of the disease, or the post-surgical results + Normal or negligible: pressure difference between right ventricle pulmonary artery