Development of PR & Restenosis after Percutaneous Balloon Pulmonary Valvuloplasty

Background: Pulmonary stenosis is not an uncommon congenital heart disease in our population. Various age groups present with severe pulmonary stenosis require intervention either surgical or percutaneous catheter-based. Often lifesaving surgical intervention is not feasible considering procedural risk, the patient’s physical condition, and young age. Percutaneous balloon pulmonary valvuloplasty is safe, effective, almost painless, economical, and less hospital stay in any age group with immediate and long-term success. This study aimed to analyze the rate of development of (Pulmonary Regurgitation) PR & restenosis after Percutaneous Balloon Pulmonary Valvuloplasty (PBPV). Material & Methods: This hospital-based prospective observational study was conducted in the Department of Paediatric Cardiology Combined Military Hospital (CMH), Dhaka from January to December 2021. 0-18 years aged 50 population with PS who were referred to the Paediatric Cardiology Department of CMH Dhaka during the study period were selected as study subjects as per inclusion criteria. The purposive Sampling technique was used in this study. Data were collected with a predesigned standard data collection sheet. Statistical significance was set as a 95% confidence level at a 5% acceptable error level. Categorical variables were expressed as frequency and percentages. Mean, standard deviation, and/or medians with interquartile ranges were used to express the continuous variables. Paired t-test was performed in categorical comparison. A p-value of <0.05 was considered statistically significant. Collected data were analyzed using SPSS Version 24. Written informed consent was taken from every parent. Ethical clearance was taken from the Ethics Review Committee of CMH Dhaka for conducting the study. Results: 50(6.39%) had isolated valvular PS. The international standard for the prevalence of isolated PS is 8-10% which is very close to this study’s result. In this study, male predominance was found with the male-female ratio of 3:2 though there was no gender dominance found in other studies. Out of 50 cases, 3(6%) are neonates,7(14%) are infants, 27 (54%) are 1-5 years aged, and 13(26%) are more than 5 years aged. A total of 13(26%) cases developed PR, and all 13 patients developed trivial PR on D1 echo, out of them 1 patient developed mild PR on D30 Echo but in D90 and D180 Echo patients persisted the same mild PR. Out of 50 cases, 46(92%) were successful and 4 cases were procedure failed. None of the successful cases developed restenosis. Out of 4 procedure failed cases 1 patient developed restenosis on D30 follow up and 2 patients develop restenosis on the D90 follow-up. At D180 follow up none of the patients developed restenosis. All the restenosis cases had dysplastic pulmonary valves. One patient’s PS gradient persisted at 30-50 mm of Hg throughout the follow-up period. Overall restenosis in 180-day follow-up is 3(6%) and the remaining 47(94%) cases lead a healthy life in 6 months follow-up. Reballooning was done immediately after diagnosis of restenosis in stenosed cases. Conclusion: Immediate and intermediate-term (6 months) follow-up with Doppler echocardiography showed excellent outcomes in all cases except 3 (6.0%) restenosis cases and 13 (26.0%) insignificant PR cases. The baby who all had restenosis, had the risk factor, like- dysplastic PV. It may be concluded that balloon valvuloplasty is the procedure of choice for moderate, severe, and critical pulmonary valve stenosis.

Medium-term follow-up of percutaneous pulmonary valve implantation using the Venus-P self-expanding valve / 中华实用儿科临床杂志

Objective:To evaluate the medium-term clinical and hemodynamic outcomes of percutaneous pulmonary valve implantation (PPVI) using a domestic Venus-P self-expanding valve in the treatment of severe pulmonary regurgitation after Tetralogy of Fallot (TOF).Methods:Retrospective study.From December 2017 to December 2020, 13 TOF patients with (17.8±4.7) years old and (50.2±12.3) kg underwent PPVI using the Venus-P self-expanding valve in the Department of Children′s Heart Center, Zhengzhou University People′s Hospital were recruited.The mean valve size was (31.9±3.1) mm.All patients received the transannular patch surgery and developed severe pulmonary regurgitation.After PPVI, 13 patients were followed up for at least 12 months.The operation-related complications, improvement of valve and heart function and the durability and reintervention of the Venus-P self-expanding valve were analyzed.The right ventricular end-diastolic volume index (RVEDVi) before and after operation was compared by the paired t-test, and the New York Heart Association (NYHA) class was compared by the paired Wilcoxon signed rank sum test. Results:PPVI was successfully performed in all 13 patients without death.At 6 months post-PPVI, cardiac magnetic resonance imaging findings showed that RVEDVi was significantly reduced[(145.7±9.6) mL/m 2vs.(100.2±12.2) mL/m 2, P<0.05], and the NYHA class was significantly improved ( P<0.05). One patient presented moderate pulmonary valve regurgitation at 12 months postoperatively.No vegetation was found on echocardiography, and blood culture was negative in this case.Six patients did not have postoperative pulmonary valve regurgitation, and the remaining presented mild or less pulmonary regurgitation.One patient had sudden ventricular tachycardia on the 6 th day postoperatively, which was converted to sinus rhythm after synchronous electrocardiography.Only one case underwent appendectomy 7 months after operation due to acute appendicitis, and the remaining did not require valve-related reintervention after implantation.During the follow-up for (22.8±8.0) months, no patients had perivalve leakage, stent migration and rupture.Complications like embolization and coronary artery compression were not reported. Conclusions:PPVI using the Venus-P self-expanding valve is safe and effective in patients with severe pulmonary valve regurgitation after TOF surgery, showing an acceptable medium-term follow-up outcome.Studies with a large sample size and long follow-up period are still needed to validate our findings.

Hand-sewn expanded polytetrafluoroethylene valved conduit for right ventricular outflow tract reconstruction / 中南大学学报(医学版)

OBJECTIVES@#Due to the lack of large-sized pulmonary valved conduit products in clinical practice, hand-sewn expanded polytetrafluoroethylene (ePTFE) valved conduit has been used for right ventricular outflow tract (RVOT) reconstruction in many heart centers around the world. This study aims to summarize the early results of the ePTFE valved conduit and the sewing technology of the conduit in combination with the latest progress, and to provide a reference for the application of ePTFE valved conduit.@*METHODS@#A total of 21 patients using ePTFE valved conduit for RVOT reconstruction in the Second Xiangya Hospital, Central South University from October 2018 to October 2020 were prospectively enrolled in this study. The age at the implantation of the conduit was 4.3 to 43.8 (median 15.1) years old, with weight of (38.9±4.1) kg. In this cohort, 14 patients underwent re-reconstruction of RVOT, including 12 patients with pulmonary regurgitation at 6.3 to 31.0 (median 13.8) years after tetralogy of Fallot (TOF) repair, and 2 patients with failed bovine jugular vein conduit (BJVC). Seven patients underwent Ross operations. Among them, 3 were for aortic valve stenosis, 2 were for aortic regurgitation, and 2 were for both stenosis and regurgitation. The ePTFE valved conduits were standard hand-sewn during the surgery. The 3 leaflets were equal in size with arc-shaped lower edge of the valve sinus. The free edge of the valve leaflets was straight with the length of about 1 mm longer than the diameter. The height of the valve sinus was 4/5 of the diameter. The junction of the valve leaflet was 3/4 of the height of the sinus. The designed leaflets were then continuous non-penetrating sutured into the inner surface of Gore-Tex vessel to make a valved conduit. Valved conduits with diameter of 18, 20, and 22 mm were used in 2, 9, and 10 cases, respectively. The surgical results, postoperative recovery time, and serious complications were summarized, and the changes of postoperative cardiac function status and hemodynamic status of the conduits were investigated.@*RESULTS@#During the implantation of ePTFE valved conduit for RVOT reconstruction, 2 patients underwent mechanical mitral valve replacement with Ross operation, 2 patients with pulmonary regurgitation with repaired TOF underwent left and right pulmonary artery angioplasty, and 1 patient with failed BJVC underwent tricuspid valvuloplasty. The cardiopulmonary bypassing time for patients underwent re-reconstruction of RVOT was (130.9±16.9) min, with aorta clamping for 1 patient to repair the residual defect of the ventricular septum. The cardiopulmonary bypassing and aorta clamping time for Ross operation were (242.7±20.6) min and (145.6±10.5) min, respectively. The duration of postoperative ventilator assistance, intensive care unit stay, and hospital stay were 3.5 h to 7.7 d (median 17.1 h),11.2 h to 29.5 d (median 1.9 d), and 6.0 to 56.0 (median 13.0) d, respectively. All patients survived after discharge from hospital. The follow-up rate after discharge was 100% with median time at 15.0 (13.0 to 39.0) months. No death happened during the follow-up. One patient underwent stent implantation due to right coronary stenosis 2 months after Ross operation. One patient underwent balloon dilation due to right pulmonary artery ostium stenosis 1 year after re-reconstruction of RVOT. The cardiac function of all patients recovered to NYHA class I 6 months after operation. The peak pressure gradient across the valve measured by transthoracic echocardiography before discharge was (9.4±2.6) mmHg (1 mmHg=0.133 kPa), and (18.3±6.1) mmHg at the last follow-up. There was no significant increase in the gradient during the follow-up (P=0.134). No patient suffered from mild or more pulmonary regurgitation.@*CONCLUSIONS@#Hand-sewn ePTFE valved conduit is feasible for RVOT reconstruction. It is a promising material for RVOT reconstruction which can effectively meet clinical need. In our experience, the ePTFE valved conduit is simple to manufacture with satisfactory early outcomes.In the application of ePTFE valved conduit, attention should be paid to implantation indications and postoperative anticoagulation management, especially to the preparation details of the valved conduit, to obtain better function and durability of the conduit after implantation.

Four-dimensional flow MRI quantification of pulmonary regurgitation in patients with repaired tetralogy of Fallot: a study on reproducibility and consistency / 中华放射学杂志

Objective@#To investigate the feasibility and consistency of four-dimensional flow (4D flow) quantification of pulmonary regurgitation in patients with repaired Tetralogy of Fallot (ToF) by comparing with conventional two-dimensional flow (2D flow) and echocardiography.@*Methods@#Both the 4D flow and 2D flow imaging were acquired with repaired ToF (a total of 21 patients) consecutively on 3.0 T MR scanner from May 2018 to August 2018. Pulmonary flow and regurgitant fraction were measured by a commercial post processing software Circle CVI42. All patients underwent echocardiography within one week after or before MR examination. The inter/intra-observer variability by 2D/4D f1ow and agreement between the two methods were investigated by interclass correlation coefficients (ICC) and Bland-Altman analyses. The agreement between MR and echocardiography were analyzed by weighted Kappa coefficient. The correlation between pulmonary regurgitation and cardiac function was also investigated by Pearson analysis.@*Results@#All patients were included and completed the examinations successfully. Both inter-observer and intra-observer agreement by 4D flow for total forward volume (ICC=0.993, 0.996, respectively, P<0.001), total backward volume (ICC=0.994, 0.997, respectively, P<0.001) and regurgitant fraction (ICC=0.968, 0.985, respectively, P<0.001) were good. The total forward volume, total backward volume and regurgitant fraction measured by 2D flow and 4D flow reached a good agreement (ICC=0.954, 0.913,0.721,respectively,P<0.001). The consistency was good for severity of regurgitation measured by 2D flow (weighted Kappa=0.897, P<0.001) and 4D flow (weighted Kappa=0.710, P=0.001) compared with echocardiography. Significant correlation was found among right ventricular cardiac index(r=0.600, P<0.05), right ventricular end-diastolic volume index(r=0.788, P<0.05), right ventricular end-systolic volume index(r=0.683, P<0.05) and left ventricular end-diastolic volume index(r=0.578, P<0.05), left ventricular end-systolic volume index(r=0.687, P<0.05) with regurgitant fraction measured by 2D flow. Regurgitant fraction measured by 4D flow had a significant correlation with right ventricular cardiac index(r=0.606, P<0.05), right ventricular end-diastolic volume index(r=0.685,P<0.05), right ventricular end-systolic volume index(r=0.534, P<0.05) and left ventricular end-diastolic volume index(r=0.459, P<0.05), left ventricular mass index(r=0.633, P<0.05).@*Conclusion@#4D flow MRI provides highly reproducible measurements of pulmonary flow on morphology and haemodynamics in patients with repaired ToF compared with 2D flow MRI and echocardiography.

Four?dimensional flow MRI quantification of pulmonary regurgitation in patients with repaired tetralogy of Fallot: a study on reproducibility and consistency / 中华放射学杂志

Objective To investigate the feasibility and consistency of four-dimensional flow (4D flow) quantification of pulmonary regurgitation in patients with repaired Tetralogy of Fallot (ToF) by comparing with conventional two-dimensional flow (2D flow) and echocardiography. Methods Both the 4D flow and 2D flow imaging were acquired with repaired ToF(a total of 21 patients) consecutively on 3.0 T MR scanner from May 2018 to August 2018. Pulmonary flow and regurgitant fraction were measured by a commercial post processing software Circle CVI42. All patients underwent echocardiography within one week after or before MR examination. The inter/intra-observer variability by 2D/4D f1ow and agreement between the two methods were investigated by interclass correlation coefficients (ICC) and Bland-Altman analyses. The agreement between MR and echocardiography were analyzed by weighted Kappa coefficient. The correlation between pulmonary regurgitation and cardiac function was also investigated by Pearson analysis. Results All patients were included and completed the examinations successfully. Both inter-observer and intra-observer agreement by 4D flow for total forward volume (ICC=0.993, 0.996, respectively, P<0.001), total backward volume (ICC=0.994, 0.997, respectively, P<0.001)and regurgitant fraction(ICC=0.968, 0.985, respectively, P<0.001) were good. The total forward volume, total backward volume and regurgitant fraction measured by 2D flow and 4D flow reached a good agreement (ICC=0.954, 0.913,0.721,respectively,P<0.001). The consistency was good for severity of regurgitation measured by 2D flow (weighted Kappa=0.897, P<0.001) and 4D flow (weighted Kappa=0.710, P=0.001) compared with echocardiography. Significant correlation was found among right ventricular cardiac index(r=0.600, P<0.05), right ventricular end-diastolic volume index(r=0.788, P<0.05), right ventricular end-systolic volume index(r=0.683, P<0.05) and left ventricular end-diastolic volume index(r=0.578, P<0.05), left ventricular end-systolic volume index(r=0.687, P<0.05) with regurgitant fraction measured by 2D flow. Regurgitant fraction measured by 4D flow had a significant correlation with right ventricular cardiac index(r=0.606, P<0.05), right ventricular end-diastolic volume index(r=0.685, P<0.05), right ventricular end-systolic volume index(r=0.534, P<0.05) and left ventricular end-diastolic volume index(r=0.459, P<0.05), left ventricular mass index(r=0.633, P<0.05). Conclusion 4D flow MRI provides highly reproducible measurements of pulmonary flow on morphology and haemodynamics in patients with repaired ToF compared with 2D flow MRI and echocardiography.

Resonancia magnética cardíaca en el seguimiento alejado de pacientes con tetralogía de Fallot / Cardiac Magnetic Resonance in long term follow-up of Tetralogy of Fallot

INTRODUCCIÓN: La tetralogía de Fallot (TF) es la cardiopatía congénita cianótica más frecuente. La insuficiencia pulmonar (IP) y dilatación del ventrículo derecho (VD) son las complicaciones más frecuentes a largo plazo. La resonancia magnética cardiaca (RMC) es el "gold standard" para la evaluación del VD. OBJETIVO: Analizar la información obtenida de las RMC en el seguimiento de pacientes con TF. PACIENTES Y MÉTODO: Se incluyeron RMC realizadas entre 2007 y 2012 a pacientes con TF, reparados con parche transanular (PTA) o ampliación infundibular (AInf) y sin recambio valvular pulmonar (RVP). La fracción de regurgitación pulmonar (FRP), el volumen y función ventricular fueron evaluados. RESULTADOS: Se realizaron 122 RMC a 114 pacientes. Edad promedio al examen 15,4 ± 7,4 años. 53,3% presentó IP severa (> 40%). La media del volumen de fin de diástole del VD (VFDVD) fue 157,3 ± 38,6 ml/m2, fin de sístole (VFSVD) de 85,3 ± 27 ml/m2 y fracción de eyección (FEVD) 46,4 ± 7,1%. 48,4% presentaba un VFDVD mayor de 150 ml/m2 y el 32,8% mayor a 170 ml/ m2. El PTA se relacionó con mayores volúmenes de VD que la AInf. VFDVD mayor a 170 ml/m2 mostraron peor FEVD (FEVD 47,9 ± 7% vs 43,2 ± 6,4%, p < 0,01). DISCUSIÓN: Casi la mitad mostró una significativa dilatación del VD demostrando que la indicación de RMC es tardía en el seguimiento. El PTA se asoció con mayores VFDVD y VFSVD pero no a peor FEVD.

INTRODUCCIÓN: Tetralogy of Fallot (TOF) is the most frequent cyanotic congenital heart disease. Pulmonary regurgitation (PR) and right ventricle (RV) enlargement and dysfunction are the most common long-term complications. Cardiac magnetic resonance (CMR) is the gold standard for RV evaluation. OBJECTIVE: To analyze CMR results in the follow-up of TOF patients. PATIENTS AND METHOD: All CMR performed between 2007 and 2012 in TOF patients with transannular patch (TAP) repair or infundibular widening, and without pulmonary valve replacement (PVR) were included. Pulmonary regurgitant fraction (PRF), ventricular end-diastolic (EDV) and end-systolic volume (ESV), and ejection fraction (EF) were examined. RESULTS: 122 CMR were performed in 114 patients. Average age at CMR was 15.4±7.4 years. 53.3% of them presented severe PR (> 40%). RVEDV was 157.3 ± 38.6 ml/m2, RVESV was 85.3 ± 27 ml/m2 and RVEF was 46.4 ± 7.1%. RVEDV was > 150 ml/ m2 in 48.4% and > 170 ml/m2 in 32.8% of patients. Patients with TAP showed larger RV volumes compared with those with infundibular widening. RVEDV > 170 ml/m2 showed worse RVEF that those with lower RVEDV (47.9 ± 7% vs 43.2 ± 6.4%, p < 0.01). CONCLUSION: Almost half of the pa tients showed significant RV enlargement, demonstrating that the indication of CMR is late in their follow-up. TAP was associated with higher RVEDV and RVESV, but no worse RVEF.

Assessment after radical correction of Fallot’s tetralogy / Монголын Анагаах Ухаан

Background @#The frequency of tetralogy of Fallot among newborns and infants is 5.6-14.0% of all congenital heart defects [5, 14, 17] The most frequent complication of the early postoperative period is right ventricular failure, which is formed when the anatomy of the right ventricle and the progressive pulmonary regurgitation are disturbed [1, 3, 12]. With the development of new minimally invasive methods of examination and their introduction into clinical practice, the understanding of hemodynamic parameters after surgical correction, pathophysiological mechanisms of development of right ventricular dysfunction has improved. </br> One of these methods is transpulmonary thermodilution and pulse waveform analysis, which allows in the early hours after operation to determine preload, heart function and postload parameters [9, 20]. </br> In the long-term period, many patients after radical correction have right ventricular dysfunction due to many years of massive pulmonary regurgitation. With the introduction of MRI improved understanding of the pathophysiological mechanisms of development of right ventricular dysfunction.. Recent reports indicate that the global functional assessment of the right ventricle after surgical correction does not reflect its present function [7, 10].@*Aim@#The aim of the study was to estimate the early postoperative indices of hemodynamics in different types of the right ventricular output plastics after radical correction of Fallot’s tetralogy and to access the functional state of the right ventricle in the long- term postoperative period.@*Materials and Methods@#On the basis of cardiovascular surgery department of the Shastin P.N. hospital, a prospective cohort study of 52 patients (28 boys, 24 girls), underwent radical correction of Fallot’s tetralogy, was conducted. </br> Patients were divided into 2 groups by the type of reconstruction of the right ventricular outlow tructs: group I included patients with transannular plasty of the output part (group I, 26 patients), group II-patients with preserved fibrous ring of the pulmonary artery (group II, 26 patients). The postoperative hemodynamic status was assessed with transpulmonary thermodilution. The right ventricular function in the long-term period was estimated by means of US and MRI.@*Results@#During the first postoperative hours, hemodynamic indices according transpulmonary thermodilution technique were significantly lower in group I and reliable differed from group II. However, later (12.24,48 hour after), restoration of hemodynamic indices in group I, which did not significantly differ from group II, was observed. In the long-term period, ejection of the right ventricle was reliable higher in group II, while terminal diastolic volume of the right ventricle was significantly higher in group I. Pulmonary regurgitation was also significantly higher in group I-36.7 (32,44) versus 13,2 (3;14) (p<0,01).@*Conclusions@#Preservation of pulmonary artery fibrous ring provides better parameters of hemodynamics in the early postoperative period including systolic and diastolic functions. In the long-term period, this group of patients is less subjected to the right ventricular function.

Long-term follow-up of percutaneous self-expanding pulmonary valve implantation / 复旦学报（医学版）

Objective To evaluate the long-term efficacy of percutaneous pulmonary valve implantation (PPVI) and the durability of the home-made self-expanding pulmonary valve (Venus-P).Methods From May,2013 to Nov.,2015,14 patients who underwent percutaneous pulmonary valve implantation at Zhongshan Hospital,Fudan University and received at least 1 year follow-up were enrolled,including 3 males and 11 females,with an average age of (35.8 ± 7.8) years.All patients with tetralogy of Fallot received radical resection and developed severe pulmonary regurgitation.The longterm mortality,the operation related complications,the short term and long-term effect of PPVI,as well as the durability and effect of the self-expanding pulmonary valve were evaluated in the 14 patients.Results Over an average follow-up period of (2.3 ± 0.8) years (1.0-3.5 years),only 1 patient died (6.7 ％).During the follow-up,no deterioration,infective endocarditis,malignant arrhythmia and other serious complications was observed,and nobody needed reoperation.There was no valve displacement,valve stent fracture,obvious circumferential leakage and pulmonary regurgitation.After PPVI,an acute improvement in pulmonary artery diastolic pressure was observed [(4.93 ± 3.37) mmHg vs.(11.47 ± 4.61) mmHg,P＜0.05].Six month postoperatively,right ventricular end diastolic volume measured by cardiac nuclear magnetic resonance was significantly reduced [(139.29± 18.21)mL/m2 vs.(83.03 ± 20.0) mL/m2,P＜0.05].At 1 year follow up,the across valve pressure difference were (20.85 ± 4.45) mmHg calculated by the echocardiography,and the NYHA cardiac function (Ⅰ-Ⅲ:4 cases;Ⅰ-Ⅱ:10 cases) was improved 1-2 degree and the distance of 6-minute walk test were significantly increased [(475.00 ± 55.06) m vs.(594.23 ± 194.51) m,P＜0.05].Meanwhile,the QRS duration decreased was also observed.The changes of the QRS duration have statistical significance after 1 and 3 months of the PPVI when compared with the baseline [(169.93 ± 21.34) ms vs.(159.87 ± 24.4) ms or (160.00 ± 27.0 ms,P＜0.05].Conclusions PPVI using home-made self-expanding pulmonary valve (Venus-P) for chronic pulmonary regurgitation has good long-term efficacy and low complication rate,and the valve is durable.

Pulmonary stenosis and pulmonary regurgitation: both ends of the spectrum in residual hemodynamic impairment after tetralogy of Fallot repair / 소아과

Repair of tetralogy of Fallot (TOF) has shown excellent outcomes. However it leaves varying degrees of residual hemodynamic impairment, with severe pulmonary stenosis (PS) and free pulmonary regurgitation (PR) at both ends of the spectrum. Since the 1980s, studies evaluating late outcomes after TOF repair revealed the adverse impacts of residual chronic PR on RV volume and function; thus, a turnaround of operational strategies has occurred from aggressive RV outflow tract (RVOT) reconstruction for complete relief of RVOT obstruction to conservative RVOT reconstruction for limiting PR. This transformation has raised the question of how much residual PS after conservative RVOT reconstruction is acceptable. Besides, as pulmonary valve replacement (PVR) increases in patients with RV deterioration from residual PR, there is concern regarding when it should be performed. Regarding residual PS, several studies revealed that PS in addition to PR was associated with less PR and a small RV volume. This suggests that PS combined with PR makes RV diastolic property to protect against dilatation through RV hypertrophy and supports conservative RVOT enlargement despite residual PS. Also, several studies have revealed the pre-PVR threshold of RV parameters for the normalization of RV volume and function after PVR, and based on these results, the indications for PVR have been revised. Although there is no established strategy, better understanding of RV mechanics, development of new surgical and interventional techniques, and evidence for the effect of PVR on RV reverse remodeling and its late outcome will aid us to optimize the management of TOF.

Surgical Management of Chronic Pulmonary Regurgitation After Relief of Right Ventricular Outflow Tract Obstruction

Relief of right ventricular (RV) outflow tract obstruction in tetralogy of Fallot or similar physiology often results in pulmonary regurgitation (PR). The resultant chronic volume overload can lead to RV dilatation, biventricular dysfunction, heart failure symptoms, arrhythmias and sudden death. Although pulmonary valve replacement (PVR) can lead to improvement in the functional class and a substantial decrease or normalization of RV volumes, the optimal timing of PVR is not well defined. Benefits of PVR have to be weighed against the risks of this procedure including subsequent reoperation. This article reviews the pathophysiology of chronic PR, evidence-based benefits and risks of PVR, options for valve substitute, and optimal timing of PVR in patients with chronic PR after relief of RV outflow tract obstruction.

Mid-Term Results of Reconstruction of the Right Ventricular Outflow Tract Using Cryopreserved Homografts

PURPOSE: Homograft benefits include excellent hemodynamics, resistance to infection, decreased thromboembolic events, ease of handling, and lack of need for anticoagulation. We examined the short and mid-term results of right ventricular outflow tract (RVOT) reconstruction using cryopreserved homografts. PATIENTS AND METHODS: From May 1998 to May 2005, 20 patients (male:female=10:10) underwent RVOT reconstruction using cryopreserved homografts. The median age was 23.8 years (range, 0.9 to 43.3 years) and the median body weight was 57kg (range, 7.3 to 80kg). Eighteen patients underwent re-operation after shunt or corrective operations. Homograft failure was defined as either re-operation for homograft replacement or patient death. Homograft dysfunction was defined as grade 3 or more than 3 of graft regurgitation and more than 40mmHg of transvalvular pressure gradient under echocardiographic examination. RESULTS: No operative mortality occurred and there were three major complications. Graft failure was observed in one male patient with tetralogy of Fallot. The 8-year freedom from graft failure was 87.5+/-11.7% and the 7-year freedom from graft dysfunction was 62.3+/-17.9%. Multivariable analysis revealed that the independent factor for graft dysfunction was age less than 10 years. In the analysis according to age group, the 7-year freedom from graft dysfunction in the group of patients older than 10 years was 100% and 25.0+/-21.7% in patients age 10 or younger (p= 0.03). CONCLUSION: Right ventricular outflow reconstruction using cryopreserved homografts provided excellent short and mid-term results in most patients in this study. However, in patients younger than 10 years old, homografts for RVOT reconstruction showed a high dysfunction rate at mid-term.

Early and mid-term results of pulmonary valve reconstruction in surgical repair of tetralogy of Fallot; comparison with other techniques of right ventricular outflow reconstruction / 소아과

PURPOSE: The purpose of this study is to determine whether the new pulmonary valve reconstruction technique prevents short-term postoperative pulmonary regurgitation and improves early and mid-term clinical outcome. METHODS: We reviewed postoperative echocardiographic variables and chest X-ray films from 31 patients who had undergone valve reconstruction(pulmonary valve reconstruction group:PVR) for the repair of TOF between April 2000 and August 2004. We compared the clinical data of these patients with those from 47 patients who had right ventricular outflow tract reconstruction with a monocusp valve(monocusp ventricular outflow patch group:MVOP) and 22 patients who had a transannular patch repair without a monocusp valve(transannular patch group:TAP). RESULTS: In the PVR group, 25 patients(81 percent) had trivial or mild pulmonary regurgitation in their early post operative echocardiogram. Only 12 patients(26 percent) in the MVOP group had mild pulmonary regurgitation; and no patient in the TAP group had it. Pulmonary valve function was good in 96 percent of the PVR group, 36 percent of the MVOP group, and none in the TAP group in early post-operative echocardiogram. Follow-up echocardiogram(1, 2, 3, 4 years later) of the MVOP and TAP groups showed moderate pulmonary regurgitation and severely decreased valve function in almost all cases. However, in the PVR group 54 percent(16/28), 50 percent(14/28), 37 percent(9/24), and 31 percent(5/16) of the patients had trivial or mild pulmonary regurgitation 1, 2, 3 and 4 years after operation, respectively. The valve function remained good in 80 percent(24/30), 64 percent(18/28), 57 percent(12/21), and 31 percent(5/16) of the patients 1, 2, 3 and 4 years after operation respectively. CONCLUSION: Pulmonary valve reconstruction is effective in reducing pulmonary regurgitation and right ventricular dilatation in the repair of TOF, even though regurgitation increases with time. Further study is needed to determine long-term results.

The Relationship of Pulmonary Regurgitation and Exercise Performance after Repair of Tetralogy of Fallot

PURPOSE: We investigated the relationship between severity of pulmonary regurgitation (PR), exercise capacity, right ventricular (RV) volume overload and RV function in the patients with long-term follow-up after repair of tetralogy of Fallot (TOF). METHODS: To evaluate exercise capacity, cardiopulmonary exercise test (CPX) was performed in 26 patients and 18 normal controls on a treadmill, and maximal oxygen consumption (VO(2max)) and anaerobic threshold (AT) were compared among the two groups. To assess severity of PR, RV volume and function, magnetic resonance imaging (MRI) study was performed in the patient group and the PR fraction (%), RV end-diastolic volume (EDV), end-systolic volume (ESV) and ejection fraction(EF) were measured. Patient group was divided into two subgroups by age and influences of PR on RV volume and function were compared among these subgroups. RESULTS: VO(2max) and AT were significantly decreased in the patients in comparison to the control subjects (28.9+/-10.4 vs 38.1+/-9.9 ml/kg/min, P=0.01; 0.98+/-0.53 vs 1.44+/-0.59 l/min, P=0.03). PR fraction inversely correlated with the VO(2max) (r=-0.58, P<0.01) and had a tendency toward inverse correlation with AT (r=-0.35, P=0.15). In young age group less than 15 years, no significant correlation between RVEDV, RVESV, corrected QRS duration (cQRS) and PR fraction (r=0.48, P=0.19; r=0.45, P=0.22; r=0.12, P=0.76) was observed, but in old age group, RV volume (RVEDV: r=0.73, P=0.01; RVESV: r=0.61, P=0.04) and the cQRS (r=0.66, P=0.03) were increased according to the severity of PR. RVEDV and RVESV showed inverse correlations with RVEF (r-0.59, P=0.003; r= -0.78, P<0.001), and RVEF showed positive correlation with VO(2max) (r=0.62, P=0.04). CONCLUSION: Patients in long-term follow-up after repair of TOF showed impaired exercise capacity than normal subjects. PR has a negative influence on the exercise tolerance in this group of patients, and the deleterious effects of PR on RV volume and QRS prolongation may related with the age and/or duration of PR. RV volume overload may deteriorate RV function and cause resultant exercise impairment.

Morphologic Changes of the Pulmonary Arteries after Stent Implantation on Branch Pulmonary Artery Stenosis: Impact of Pulmonary Insufficiency

PURPOSE: Intravascular stent implantation for the treatment of postoperative branch pulmonary artery(PA) stenosis has been used successfully. However, the cross sectional area of contralateral branch PA does not regress in spite of the successful dilation of the stenotic branch PA after stent implantation. We analyzed the morphologic and hemodynamic factors on the size of branch PA after successful stent implantation. METHODS: The subjects in our study were 23 children who had undergone stent implantaion from Jan. 1995 to Jul. 2002 in the Division of Yonsei Pediatric Cardiology. We evaluated the cross sectional area index(CSAI) of branch PA before and after stent implantation at follow-up catheterization. We also investigated factors such as residual pulmonary stenosis, pulmonary regurgitation(PR), systolic pressure of right ventricle, and lung perfusion scan. RESULTS: The CSAI of the RPA without stenosis changed from mean 238+/-17 mm2/BSA to mean 249+/-20 mm2/BSA(P=0.47), but didn't regress. The CSAI of the LPA with stenosis was increased effectively by stent implantation from the mean 102+/-12 mm2/BSA to mean 125+/-11 mm2/BSA(P< 0.05). At follow up after stent implantation, the CSAI of PA is correlated with the residual PR fraction after stent implantation. CONCLUSION: In a group with increased residual PR, CSAI of RPA was found to be significantly increased between the pre- and post-stages of stent implantation. So, we suspect that the pulmonary regurgitation remaining after right ventricle outlet tract(RVOT) dilatation surgery is correlated with the increase in CSAI of RPA.

Volumetric Quantitation of Pulmonary Regurgitation and Right Ventricular Function in Postoperative Tetralogy of Fallot by Echocardiography and Magnetic Resonance Imaging

PURPOSE: Despite improved surgical techniques, pulmonary regurgitation is a common postoperative sequelae in patients with tetralogy of Fallot. Pulmonary regurgitation may induce deterioration of right ventricular performance, right ventricular dilatation and ventricular arrhythmia. The evaluation of the clinical significance of pulmonary regurgitation in postoperative tetralogy of Fallot has been troublesome since there was no technique that could accurately quantitate volume of pulmonary flow. Magnetic resonance imaging (MRI) with velocity mapping provided data on the volumetric quantitation of pulmonary regurgitation. The purpose of this present study was to assess right ventricular function and the severity of pulmonary regurgitation after surgical correction of tetralogy of Fallot by echocardiography and MRI. METHODS: Echocardiography and MRI were performed on nine patients with total surgical correction of tetralogy of Fallot. Quantitative volumetric assessment of pulmonary reguritation and right ventricular function was done. RESULTS: The pulmonary regurgitant volume was similar between echocardiography and MRI, and the pulmonary velocity was significantly larger by MRI in comparison with echocardiography. Right ventricular end-diastolic volume and stroke volume were similar in both two methods, but end-systolic volume was significantly larger by MRI in comparison to echocardiography. Pulmonary regurgitant volume was positively correlated with right ventricular end-systolic volume, end-diastolic volume and stroke volume. Each parameter (pulmonic velocity, pulmonary regurgitant volume, right ventricular end-diastolic volume, end-systolic volume, stroke volume) was significantly correlated linearly between echocardiography and MRI. CONCLUSION: Cine MRI with velocity mapping is an accurate method for the noninvasive, volumetric quantitation of pulmonary regurgitation after surgical correction of tetralogy of Fallot.