Evaluate the feasibility, short and medium-term results of transcatheter closure of perimembranous VSDs using the symmetrical double-disc device at Hanoi Heart Hospital. Find out some factors that affect the outcome of the technique.
MINISTRY OF EDUCATION MINISTRY OF HEALTH AND TRAINING HANOI MEDICAL UNIVERSITY NGUYEN CONG HA Research about short and mediumterm results of transcatheter closure of perimembranous VSD using the symmetrical doubledisc device Major : Internal Cardiology Code : 62720141 MEDICAL DOCTORATE THESIS HANOI 2020 THE THESIS WAS FULFILLED AT HANOI MEDICAL UNIVERSITY Scientific Supervisor: Professor Nguyen Lan Viet 1st Peerreviewer: Assoc. Prof. PhD. Pham Huu Hoa 2nd Peerreviewer: Assoc. Prof. PhD. Nguyen Ngoc Quang 3nd Peerreviewer: Assoc. Prof. PhD. Ta Manh Cuong Ph.D Thesis will be evaluated by the Hanoi medical University Thesis Board. At h / / /2020 The thesis can be found at: National Library Hanoi medical University Library BACKGROUND Ventricular septal defect (VSD) is when there is communication between the left ventricle chamber (LV) and the right ventricle (RV) with each other VSD is one of the most common congenital heart diseases (CHDs) accounting for 20 30% of CHDs In the treatment of VSD, the classic method is open surgery with the support of cardiopulmonary bypass (CPB) technique, which is considered as the gold standard method, but still, have some complications of CPB, anesthetic resuscitation, infection, and neurological complication … The first device designed to close of perimembranous VSDs (pVSD) is called Amplatzer muscular VSD occluder (AVSO) manufactured by AGA. In 2002, Hijazi et al reported that this device was used for 6 patients with the result that there were no cases of residual shunt and significant complications. After that, many studies applied Amplatzer instruments, but the rate of atrioventricular block (AVB) was still high, with a study of 5.7% which is much higher than that open surgery so now this AVSO device has stopped being applied due to this complication To increase efficiency and minimize complications, some new devices have recently been launched to overcome the disadvantages of Amplatzer. NitOcclud® Lê VSDCoils (Lê VSD Coils) have been applied and have been highly successful, despite the reduction of complications such as ABV, AVR but the rate of residual shunt and hemolysis is still high. Dr. Nguyen Lan Hieu and other authors also used devices that use for the closure of ductus arteriosus (DO) to close VSDs and had good short and mediumterm outcomes but there are still some complications The symmetrical doubledisc device was also created for the same purpose, this device has improved the design of Amplatzer with two symmetrical discs, the smaller left disc had larger thickness. This device has been studied and applied clinically for high success and low rate of complications in the longterm followup In Vietnam, Nguyen Lan Hieu and other colleagues have applied various types of devices to close perimembranous VSDs such as Le VSD Coils, PDA closure devices and have some reports for good outcomes in short and mediumterm. The symmetrical double disk devices have also been used and have good clinical results but there have been no specific studies on the safety and efficacy of this device. Therefore, we carried out the study: "Evaluate the Short and Mediumterm outcomes of Transcatheter Closure of Perimembranous VSDs using Symmetrical Doubledisc Devices" to: Evaluate the feasibility, short and mediumterm results of transcatheter closure of perimembranous VSDs using the symmetrical doubledisc device at Hanoi Heart Hospital 2. Find out some factors that affect the outcome of the technique NEW CONTRIBUTIONS OF THE THESIS The study had 84 patients with perimembranous VSDs who had transcatheter closure of perimembranous VSDs using the symmetrical doubledisc device from January 2012 December 2015. 81 patients successfully performed closure procedure ( 96.4%). The followup of patients after the procedure was the longest 61 months (≈ 5 years), the shortest was 20 months, during the followup time, none of the patients left the study The study showed that high efficacy, low complications, safety in patients with pVSDs selected with the size of defects ≤ 8mm, aortic edge ≥ 2,0 mm. After the procedure, we evaluated clinical symptoms such as delayed weight gain, recurrent pneumonia, heart failure and absent of typical systolic murmur of VSD. The parameters on cardioechography such as Left Ventricular End Diastolic Dimension (LVEDd), Pulmonary Arterial pressure (PAP) also decreased significantly after the procedure. Major complications were mild complications and recovered, had 1 patient (1.2%) had worsened TVR (3/4) after the followup time, especially no patients with grade III AVB which is one of the critical complications but we did not have any case in our study Factors affecting the outcome of the procedure are inappropriate anatomy size of defect such as large defects, lack of aortic edge are factors that directly affect failure cases of the procedure Other difficult obstacles such as difficulty in passing devices through the defects, retaking the snare, redo the procedure steps, exchanging larger devices due to the assessment of the defect on cardioechography and the incorrect image of the LV chamber; are limitations of the procedure The transthoracic Doppler cardioechography during the procedure also enhances the procedure LAYOUT OF THE THESIS The thesis consists of 153 pages consisting of 4 chapters; 45 pages of overview, 21 pages of subjects and research methods, 50 pages of results, 31 pages for discussion, 2 pages of conclusion, 1 page of recommendations. Tables; there are 57 tables; 14 charts; 24 figures; 180 references; 7 references in Vietnamese; 173 references in English CHAPTER 1: OVERVIEW 1.1 Prevalence and anatomy of VSDs VSD is the most common CHD, accounting for about 2030% of CHD, of which pVSD accounts for about 7080% of the total VSD types Hoffman's metaanalysis of 22 statistics found that the prevalence of VSD was 31% in CHDs An important anatomical feature is that the VSD is not aligned as a wall to separate the two ventricular chambers from which the VSD has a curved structure because of the round shape of the LV and the crescent shape of the RV hug the right front of the LV. It must also be remembered that VW's structure varies with the position of the wall pVSD is when the membrane part of the ventricular septum is not fully formed, the opening is near the anterior leaf edge and the leaf wall of TV. Not only is the defect in the membrane part but it seems to be surrounded by the fibrous tissue, membrane and tends to close. This fibrous tissue is also called the TI auxiliary organization, which can form a bulging sac structure. Van Praagh differentiated true pVSD, which is only a small hole in the membrane's septum. It is more accurate to call VSD with the perimeter around the membrane, because some VSDs have intact membrane but defects are around the membrane part, so the name pVSD is used more often. This VSD is closely related to the AV conduction path, which passes through the TI ring and follows the lower posterior edge of the defect then divides into the left and right branches. Therefore, when surgery to patch or close the defect with a device, there is a risk of damage to this transmission line Figure 1.1: Illustration of atrioventricular conduction pathway; and related to pVSD 1.2. Pathophysiology and clinical characteristics VSD which has no more cardiac defect causes left and right ventricular shunts that increase circulation to the lungs, increase left ventricular volume, and increase PA pressure. The degree of shunting depends on the diameter of the defect and the resistance of PA In newborns, the PA resistance is high and decreases gradually from the first days after birth and decreases rapidly in the first 46 weeks and returns to normal 23 months later. However, due to the high PA resistance, it is often not detected by clinical examination in the first months because the leftright shunts are not large enough to generate systolic murmur as well as other clinical symptoms. After 46 weeks of birth, the resistance to PA decreases, the shunt will grow then the murmur and symptoms of heart failure will be more significant 1.3. Diagnosis Patients with small defects are usually diagnosed when a systolic murmur is heard at the left sternum. When the resistance of the PA system increases, the murmur is weak and shorter The Doppler cardioechography is the best diagnostic tool for VSD. Cardioechography can detect very small defects, locate very precisely because it is possible to cut many different crosssections, this is an advantage over cardiography when limited to a few angles and using limited contrast agent 1.4. Treatment 1.4.1. Disease natural course and prognosis Most patients with small defects of VSD grow up normally. Some studies have found that VSD selfclosing rate is up to ¾ cases. The size of the defects tends to get smaller and the highest self closing ratio in the first years. In adults with small defects, Qp / Qs