Diffuse myocardial fibrosis following tetralogy of Fallot repair: a T1 mapping cardiac magnetic resonance study

Background

Adverse ventricular remodeling after tetralogy of Fallot (TOF) repair is associated with diffuse myocardial fibrosis.

Objective

The goal of this study was to measure post-contrast myocardial T1 in pediatric patients after TOF repair as surrogates of myocardial fibrosis.

Materials and methods

Children after TOF repair who underwent cardiac magnetic resonance imaging with T1 mapping using the modified look-locker inversion recovery (MOLLI) sequence were included. In addition to routine volumetric and flow data, we measured post-contrast T1 values of the basal interventricular septum, the left ventricular (LV) lateral wall, and the inferior and anterior walls of the right ventricle (RV). Results were compared to data from age-matched healthy controls.

Results

The scans of 18 children who had undergone TOF repair and 12 healthy children were included. Post-contrast T1 values of the left ventricular lateral wall (443?±?54 vs. 510?±?77 ms, P?=?0.0168) and of the right ventricular anterior wall (333?±?62 vs. 392?±?72 ms, P?=?0.0423) were significantly shorter in children with TOF repair than in controls, suggesting a higher degree of fibrosis. In children with TOF repair, but not in controls, post-contrast T1 values were shorter in the right ventricle than the left ventricle and shorter in the anterior wall of the right ventricle than in the inferior segments. In the TOF group, post-contrast T1 values of the RV anterior wall correlated with the RV end-systolic volume indexed to body surface area (r?=?0.54; r²?=?0.30; P?=?0.0238).

Conclusion

In children who underwent tetralogy of Fallot repair the myocardium of both ventricles appears to bear an abnormally high fibrosis burden.     

Course of Right and Left Ventricular Function in Patients with Pulmonary Insufficiency After Repair of Tetralogy of Fallot

Surgical repair of tetralogy of Fallot (TOF) frequently results in pulmonary valve insufficiency. Nevertheless, no serial information is available on the long-term impact of the valvular insufficiency on right and left ventricular function. Right and left ventricular ejection fraction was measured serially by radionuclide angiocardiography in 21 patients with at least moderate pulmonary insufficiency after repair of TOF. A baseline study was obtained an average of 1.2 years after repair, and a follow-up study was performed an average of 10.2 years after surgery. Changes in ventricular function over time and deviations from the normal range were analyzed. At baseline evaluation the mean right ventricular ejection fraction (RVEF; 0.52 ± 0.10) and left ventricular ejection fraction (LVEF; 0.68 ± 0.10) were normal. At the time of follow-up the mean RVEF had significantly decreased to 0.45 ± 0.09 (p < 0.01). The mean LVEF had decreased to 0.60 ± 0.11 (p < 0.02). This change was independent of the RVEF (r=−0.13). Eleven patients (52%) had an abnormal RVEF or LVEF at follow-up. Nineteen patients (90%) showed a decrease of 0.05 or more in RVEF, LVEF, or both between studies. These data suggest a negative impact of long-standing pulmonary insufficiency on right and left ventricular systolic function after repair of TOF. Therefore, continued surveillance of biventricular function in this patient population appears warranted.     

Surgical Strategy for Severe Aortic Hypoplasia and Aortic Stenosis With Ventricular Septal Defect and Normal Left Ventricle

At our institution, the strategy for patients with bicuspid aortic valve, aortic valve stenosis (<5 mm), and aortic hypoplasia [hypoplastic aortic arch, coarctation of the aorta (CoA), or interrupted aortic arch (IAA)] with ventricular septal defects (VSDs) as well as normal left ventricular (LV) volume and mitral valve size consists of two parts. The Norwood operation is applied as the first palliation for this group of patients. Second, the decision whether the patients are to undergo the Rastelli operation or a univentricular repair is made depending on the size of the right ventricle after the Norwood operation. This study aimed to examine whether the aforementioned surgical strategy for this group of patients is adequate or not. Seven patients undergoing the Norwood operation as the first palliation for bicuspid aortic valve, aortic valve stenosis (<5 mm), and aortic hypoplasia with VSDs as well as normal LV volume and mitral valve size between February 2005 and March 2010 at Kitasato University Hospital and the Gunma Children’s Medical Center were reviewed. Postoperative serum B-type natriuretic peptide (BNP) and central venous pressure (CVP) were measured in the patients undergoing the staged Norwood–Rastelli operation to assess whether the authors’ right ventricular end-diastolic volume index (RVEDVI) cutoff (80 % of normal) is adequate. At this writing, all seven patients are alive after a mean follow-up period of 58.8 ± 17.8 months. They all had aortic valve stenosis of <5 mm and a bicuspid aortic valve. Four patients had a diagnosis of CoA with VSD, and three patients had IAA with VSD. Six patients underwent biventricular repair, and one patient had univentricular repair due to the small RVEDVI (74 % of normal). The patients with 80–90 % of normal RVEDVI had higher BNP and higher CVP than those with more than 90 % of normal RVEDVI after the Rastelli operation, whereas the patient undergoing the Fontan operation had a low BNP level. In conclusion, the described strategy for patients with severe aortic hypoplasia and aortic stenosis with VSD as well as normal LV and mitral valve size is reasonable.     

Biventricular Long Axis Function After Repair of Tetralogy of Fallot

Right ventricular restrictive physiology is common after repair of tetralogy of Fallot and relates to exercise performance and symptomatic arrhythmias. In this study, we examined biventricular long axis function in an attempt to clarify further the mechanical substrate of this phenomenon. We studied prospectively 95 patients with tetralogy of Fallot (age range 1–44.3 years) at a median of 4.3 years after repair with Doppler and M-mode echocardiography. Pulmonary arterial, tricuspid, and mitral Doppler spectrals and 2-D guided M-mode recordings of ventricular minor and long axes were obtained with simultaneous phonocardiogram and respirometer recordings. Right ventricular restriction was defined by the presence of antegrade pulmonary arterial flow during atrial systole throughout the respiratory cycle. Restrictive right ventricular physiology was demonstrated in 36 (39%) [group 1] of the 92 patients in whom the data were analyzed. Left ventricular function (FS, isovolumic relaxation time and transmitral E wave deceleration time) was not different in the two groups (p < 0.1, p < 0.6, and p < 0.8, respectively). The presence of antegrade diastolic flow shortened the pulmonary regurgitation in the restrictive group (PR duration/√RR 10.7 ± 2.1 vs 12.1 ± 2.1, p < 0.01). There was delayed onset of shortening (97.4 ± 24 vs 88.8 ± 24 ms, p= 0.01), and the amplitude of right atrioventricular ring excursion, corrected for body surface area, was significantly lower during atrial systole in the restrictive group (0.43 ± 0.15 vs 0.54 ± 0.2 cm/m², p < 0.01). There was also a tendency toward a smaller ratio of right to left total atrioventricular ring excursion in the same group (1.14 ± 0.19 vs 1.22 ± 0.23, p= 0.1). Impaired long axis function in patients with restrictive right ventricular physiology following repair of tetralogy of Fallot is associated with abnormal diastolic filling and may contribute to the long-term cardioprotective effect of restrictive physiology by limiting the degree of right ventricular dilatation.     

Low Incidence of Arrhythmias in the Right Ventricular Infundibulum Sparing Approach to Tetralogy of Fallot Repair

To improve outcomes, including arrhythmia incidence, for patients with tetralogy of Fallot (TOF), the authors’ institution adopted an approach that minimizes or avoids transmural incision of the right ventricular outflow tract. When pulmonary blood flow is insufficient during the neonatal period, placement of an aortopulmonary artery shunt is preferred, followed by complete repair later in infancy. This study reviewed the perioperative and mid-term arrhythmia outcomes at the authors’ institution using this approach. Patients who underwent TOF repair from 1995 to 2008 were included in the study. Patient demographics and surgical history were collected. The primary end points of the study included documented perioperative arrhythmias and arrhythmias at the 10-year follow-up assessment. Of the 298 patients who underwent TOF repair, 50 (17 %) had undergone prior placement of a systemic-to-pulmonary artery shunt. The median age at repair was 9.7 months (interquartile range, 6.3–16.2 months). Clinically significant perioperative arrhythmias were found in 12 patients (4 %) including 6 junctional tachycardias, 4 atrial tachycardias, and 1 temporary complete heart block. No patients were receiving antiarrhythmic medications more than 24 months after surgery. Of the 298 patients, 86 (29 %) had a follow-up period of 10 years or longer (median, 12.2 years). No patients experienced new arrhythmias, received antiarrhythmic therapy, experienced post-discharge ventricular tachycardia, had atrioventricular block, or required a pacemaker or defibrillator. The right ventricular infundibulum sparing approach is associated with an extremely low incidence of perioperative and midterm arrhythmias. The perioperative and mid-term outcomes compare favorably with existing data from programs favoring neonatal repair. Long-term follow-up evaluation is essential to determine whether this strategy can effectively alter late pathophysiology and minimize late-term arrhythmias and associated mortality.     

Clinical Applications of Cardiac Magnetic Resonance Imaging After Repair of Tetralogy of Fallot

In the past 15 years, cardiovascular magnetic resonance (MR) has evolved into an imaging technique that provides adequate, and in part unique, information on residual problems in the follow-up of patients operated for tetralogy of Fallot. Spin-echo or gradient-echo cine magnetic resonance imaging allow detailed assessment of intracardiac and large vessel anatomy, which is particularly helpful in Fallot patients with residual abnormalities of right ventricular outflow and/or pulmonary artery. Multisection gradient-echo cine MRI can be used to obtain accurate measurements of biventricular size, ejection fraction, and wall mass. This allows serial follow-up of biventricular function. MR velocity mapping is the only imaging technique available that provides practical quantification of pulmonary regurgitation volume. MR velocity mapping can also be used to quantify right ventricular diastolic function in the presence of pulmonary regurgitation.     

Effect of Tadalafil on Myocardial and Endothelial Function and Exercise Performance After Modified Fontan Operation

Better postoperative management of patients who have undergone single ventricle (SV) Fontan procedure could potentially reduce long-term complications and improve the quality of life for patients. The present study determined the effect of tadalafil on myocardial and endothelial function and exercise performance after modified Fontan operation. Patients who had undergone SV modified Fontan operation were enrolled in this clinical trial. The demographic characteristics of the patients were recorded. Before administration of tadalafil and after the trial, ventricular function (MPI, EF, FS, E/A, VTI), exercise performance, and endothelial function were evaluated for sonographic and biochemical markers (FMD, IMT, ICAM, VCAM, NO) using echocardiography, exercise testing, vascular ultrasonography, and biochemical measurements, respectively. A single dose of tadalafil of 1 mg/kg was administered daily for 6 weeks, and the functional class of the patients before and after tadalafil was determined. A total of 15 patients completed this clinical trial. Tadalafil was shown to have a significant effect on myocardial function, exercise performance, and improvement in NYHA functional class (p < 0.05) of study population. It had no significant effect on the biochemical variables and endothelial function except for IMT (p > 0.05), which decreased significantly after tadalafil administration (p < 0.05). The findings indicate that tadalafil is a safe, well-tolerated agent for the use after modified Fontan operation to improve myocardial function and exercise performance and possibly reduce long-term morbidity and mortality of patients. More conclusive results could be obtained from further study with a larger sample size and long-term follow-up.     

Health-Related Quality of Life Compared With Cardiopulmonary Exercise Testing at the Midterm Follow-up Visit After Tetralogy of Fallot Repair: A Study of the German Competence Network for Congenital Heart Defects

This nationwide study aimed to evaluate health-related quality of life (QoL) experienced by children after tetralogy of Fallot repair and to compare self-reported physical ability with objective exercise performance. This prospective nonrandomized, government-funded multicenter study enrolled 168 patients (70 girls; ages 8–16 years) after tetralogy of Fallot repair at eight German heart centers. Health-related QoL was analyzed by the self-reported KINDL-R quality-of-life questionnaire. The patients’ actual exercise capacity was evaluated by a cardiopulmonary exercise test. Health-related QoL and cardiopulmonary exercise capacity were compared with those of an age-matched German standard population. Correlation of health-related QoL with self-estimated physical rating and cardiopulmonary exercise capacity were analyzed. Health-related QoL in children and adolescents after tetralogy of Fallot repair is without limitation. Compared with the standard population, all the items evaluated by the KINDL-R questionnaire showed better or similar values, whereas objective exercise capacity compared with that of the standard population was impaired. Peak oxygen uptake correlated significantly with the physical well-being (p = 0.002) and the total score (p = 0.01) of the KINDL-R questionnaire. Health-related QoL experienced by children and adolescents after tetralogy of Fallot repair is comparable with that of the healthy standard population. However, closer inspection shows that self-estimated physical functioning is significantly overestimated compared with actual exercise capacity. Quality-of-life instruments and exercise tests, therefore, should be used in a complementary manner with children to avoid eventually fatal misinterpretation of patient-estimated physical ability.     

Clinical evaluation, medical management and outcome of atrioventricular canal defects

The relative effects of interatrial shunting, interventricular shunting and atrioventricular valve function will determine the general course of patients with atrioventricular canal defects. This report reviews the natural history, medical management and current outcome of this group of patients. The overall long-term survival of patients with primum atrial septal defect following repair was found to match that of the general population. Results following complete AV canal repair have similarly improved significantly in the last decade. However, residual mitral valve dysfunction remains an important post-operative issue. Straddling, stenosis or atresia of part of the AV valve, often results in significant hypoplasia of a ventricular chamber. In extreme cases, the management will generally follow that of other single ventricle variants, eventually resulting in Fontan palliation. The clinical course and outcome of these and other complex variants such as atrioventricular canal defect with tetralogy of Fallot is discussed.     

Value of the new Doppler-derived myocardial performance index for the evaluation of right and left ventricular function following repair of tetralogy of fallot

The systolic and diastolic function in both ventricles may be altered even after successful corrective surgery of tetralogy of Fallot. The aim of this study was to assess the combined diastolic and systolic function of both ventricles using the Doppler-derived myocardial performance index (MPI) in patients with operated tetralogy of Fallot (TOF). We performed a prospective analysis of 51 patients following corrective surgery of TOF: 21 had a subannular patch, 20 had a homograft implantation at initial operation, and 10 were reoperated with secondary homograft implantation. Patients were examined with Doppler echocardiography, and the MPI, which incorporates ejection and isovolumetric relaxation and contraction times and is an index of global ventricular function, was calculated 10.2 +/- 8.0 (0.89-36) years after surgery. In 86.4% of the examined patients the right ventricular isovolumetric relaxation time was shortened compared to the normal published range or even did not exist (negative value) (p <0.01). The right ventricular MPI was paradoxically below the normal published range in 76.5% of the examined patients. The left ventricle global function was impaired in 23.5% of the examined patients, mainly due to altered systolic function with a prolonged left ventricular isovolumetric contraction time. The z score of the comparison between patients' left ventricular isovolumetric contraction time and the normal published values was 3.03. Patients with severe pulmonary regurgitation also had a prolongation of the isovolumetric relaxation time compared to patients with mild to moderate pulmonary regurgitation. The noncompliant right ventricle may shorten the right ventricular isovolumetric relaxation time, resulting in a paradoxically low right MPI. This may reduce the sensitivity of the index in recognizing patients with right ventricular dysfunction following corrective surgery of TOF. Additional diastolic impairment occurs in patients with right ventricular volume overload.     

Two Cases of Warfarin-Induced Tracheobronchial Calcification After Fontan Surgery

This study identified tracheobronchial cartilage calcification in children with congenital heart disease. Calcification of the tracheobronchial airways has been found previously in adults receiving warfarin and in children receiving warfarin after mitral valve replacement. A 9-year-old girl who had received a Fontan repair 6 years previously underwent a cardiac computed tomography (CT) scan to evaluate pulmonary artery size. The result was an incidental finding of extensive tracheobronchial cartilage calcification. A retrospective review of all pediatric Fontan patients who had undergone cardiac CT was conducted to search for calcification of the tracheobronchial cartilage. The study investigated ten pediatric Fontan patients who had undergone cardiac CT scanning. Two patients with extensive calcification of the tracheobronchial airways were identified. The index case had hypoplastic left heart syndrome, and the patient had undergone a staged repair with the Fontan at the age of 3 years. A 16-year-old boy with tricuspid atresia had undergone staged repair and Fontan at the age of 3.5 years. These two patients had received continuous warfarin therapy for 6 and 13 years, respectively. Other common causes of airway calcification were excluded from the study. This report describes warfarin-induced tracheobronchial calcification in patients after the Fontan procedure. This finding has possible implications for airway growth and vascular calcification.     

Exercise Performance Following Repair of Hypoplastic Left Heart Syndrome: A Comparison with Other Types of Fontan Patients

Reports of exercise performance after Fontan surgery for hypoplastic left heart syndrome (HLHS) are lacking. We compared the exercise performance of total cavopulmonary connection type (TCPC) of Fontan subjects with HLHS (group 1, n= 7) to those not requiring a Norwood procedure having a systemic right ventricle (group 2, n= 6) or a systemic left ventricle (group 3, n= 8). The subjects underwent assessment of resting pulmonary mechanics followed by maximal exercise testing with a bicycle or treadmill protocol. ECG, oxygen consumption, and carbon dioxide production were measured continuously. There was not a significant difference seen between HLHS and the comparison groups for the following parameters: maximum heart rate, maximum oxygen consumption, respiratory exchange ratio, breathing reserve, and arterial oxygen saturation at rest or exercise. Exercise performance in the TCPC type of Fontan patients was comparable regardless of ventricular morphology or surgical approach.     

Exercise Studies in Patients with Transposition of the Great Arteries After Atrial Repair Operations (Mustard/Senning): A Review

Exercise evaluation studies of patients after atrial repair surgery for transposition of the great arteries, as in tetralogy of Fallot, represent only a small fraction of the 3970 Medline references (1966 to mid-1997) concerning this congenital heart lesion. We have abstracted data from 27 studies from 20 institutions reporting on measurements during exercise on work capacity, heart rate response, respiratory gas exchange, or radionuclide/radiographic systemic ventricular ejection fraction measurements in addition to resting pulmonary function measurements. These studies provide almost uniform general conclusions that even after 20 or more years of follow-up (1) most patients ``report' that they are asymptomatic in performing usual levels of physical activities; (2) significant abnormalities are present, often in more than half of the patients studied, in one or more of the exercise measurements when compared to control subjects; and (3) the diminished exercise performance is related to a diminished cardiac output, results from diminished stroke volume but is also related to a blunted heart rate response.     

Continuous Cerebral and Myocardial Perfusion During One-Stage Repair for Aortic Coarctation With Ventricular Septal Defect

Controversy still exists concerning the use of deep hypothermic circulatory arrest (DHCA) and selective antegrade cerebral perfusion (SACP) for repair of aortic coarctation (CoA) with ventricular septal defect (VSD). This report therefore describes outcomes of patients undergoing continuous cerebral and myocardial perfusion (CCMP) under mild hypothermia compared with DHCA and SACP. Retrospective analysis was performed for 110 consecutive patients undergoing anatomic reconstruction of CoA with VSD closure between 1999 and 2011. Patients repaired under CCMP with mild hypothermia (32 °C) (group A, n = 60) were compared with those repaired under DHCA (18 °C) and SACP (group B, n = 50). In group A, the single arterial cannula perfusion technique was used for 15 patients (25 %), and the dual arterial cannula perfusion technique was used for 45 patients (75 %). The preoperative data were similar in the two groups. Group A had no hospital mortalities, compared with two mortalities (4 %) in group B. Group A had shorter myocardial ischemic and cardiopulmonary times, fewer delayed sternal closures, a shorter time to extubation, lower postoperative lactate levels, and fewer patients with low cardiac output requiring extracorporeal membrane oxygenation or with multiorgan failure than group B. During the postoperative course, no clinical or electrical neurologic events occurred in either group. The mean follow-up period was 5.2 ± 3.2 years for group A and 7.5 ± 3.1 years for group B (P = 0.048). One late death occurred in group B and no late deaths in group A. The actuarial survival for the two groups was similar (100 % for group A vs 96 % for group B; P = 0.264). The freedom from all types of cardiac reintervention was 96.7 % in group A and 89.6 % in group B (P = 0.688). All the patients were free of neurologic symptoms. The authors’ perfusion strategy using CCMP with mild hypothermia for repair of CoA with VSD is feasible, safe, and associated with improved postoperative recovery and should be the method of choice.     

Clinical Significance of Thrombosis in an Intracardiac Blind Pouch After a Fontan Operation

The univentricular heart after the Fontan operation may have a blind pouch formed by the pulmonary stump or rudimentary ventricle according to the anatomy before surgery. Thrombosis in an intracardiac blind pouch of patients with a univentricular heart is a hazardous complication. Because only a few reports have described this complication, the authors evaluated the clinical significance of thrombosis in an intracardiac blind pouch of a univentricular heart. They performed a retrospective review of medical records from August 1986 to December 2007. Four patients were confirmed as having thrombosis in a pulmonary artery stump and one patient as having thrombosis in a rudimentary ventricle shown by cardiac computed tomography (CT). This represents 1.85% (5/271) of patients with ongoing regular follow-up evaluation after the Fontan operation. The median age at diagnosis was 14.2 years. Two of the five patients were taking aspirin and one patient was taking warfarin when they were identified for the development of thrombosis. None of the patients demonstrated thrombosis in the Fontan tract or venous side of the circulation. Brain magnetic resonance imaging (MRI) showed that three patients had cerebral infarction and one patient had suggestive old ischemia. Three patients with thrombus in the pulmonary stump underwent pulmonary artery stump thrombectomy and pulmonary valve obliteration. One patient with thrombus in the rudimentary ventricle underwent ventricular septal defect (VSD) closure with thrombectomy. Thrombus in a blind pouch could cause systemic thromboembolism despite little blood communication. Therefore, surgical modification of the pulmonary stump and VSD closure of the rudimentary ventricle are required to reduce the risk of later thrombus formation. Clinicians should not overlook the possibility of thrombus in a ligated pulmonary artery stump or a rudimentary ventricle after the Fontan operation, which may increase the risk of embolic stroke for patients with single-ventricle physiology.     

Present status of surgery in congenital heart disease

A brief historical review of surgery for congenital heart disease is presented. Palliative procedures designed to improve a given physiologic abnormality, such as systemic artery (or venous) to pulmonary artery shunts of various types to increase the pulmonary blood flow, banding of the pulmonary artery to decrease the pulmonary blood flow and surgical or balloon atrial septostomy to augment intracardiac mixing have been performed with success. Most of the congenital heart defects can be corrected by open heart surgical techniques; those requiring prior pallition and those that can be operated without prior palliative surgery are listed. The mortality rates for several common congenital heart defects are tabulated. Recent surgical advances include early total surgical correction for tetralogy of Fallot, Mustard and Jatene operations for transposition of the great arteries, Fontan operation and its newer modifications for tricuspid atresia, intraventricular septation or modified Fontan for single ventricle, new operations for hypoplastic left heart syndrome and newer prosthetic valves, particularly left ventricular apex to descending aorta conduit. Prostaglandin E₁ for ductal dilation in patients with severe righ ventricular outflow tract obstruction, balloon and knife enlargement of atrial defects to enhance interatrial mixing and catheter closure techniques for nonsurgical repair of atrial septal defect and patent ductsus arteriosus are also reviewed briefly.     

Left ventricle volume measured by cardiac CT in an infant with a small left ventricle: a new and accurate method in determining uni- or biventricular repair

Left ventricle volume is a factor in determining the type of surgical treatment in patients with a hypoplastic left ventricle. The volume of the hypoplastic left ventricle can be measured by echocardiography and cardiac MRI. In an infant with congenital heart disease and a small left ventricle, cardiac CT was used for this measurement and biventricular repair was performed. The left ventricular end-diastolic volume index showed a gradual increase from 23.2 to 47.9 ml/m² 4 months after the biventricular repair, and the postoperative outcome was excellent. Cardiac CT provided an accurate volume of the hypoplastic left ventricle in this infant with congenital heart disease; that volume was used to determine the type of surgical repair.     

低龄儿童法乐四联症根治术中右室流出道疏通的策略

目的 探讨低龄儿童法乐四联症根治术中右室流出道的疏通策略.方法 回顾性分析2005年12月至2009年10月经本院手术治疗的172例年龄4岁以下的法乐四联症患儿临床资料,将全部病例按肺动脉加宽方式不同分为3组,Ⅰ组未跨肺动脉瓣环补片;Ⅱ组跨肺动脉瓣环补片,且-2＜Z - scores＜0;Ⅲ组跨肺动脉瓣环补片,且0...     

Valve-Sparing Tetralogy of Fallot Repair With Intraoperative Dilation of the Pulmonary Valve

Deleterious long-term effects of pulmonary regurgitation after tetralogy of Fallot (TOF) repair have become evident during the last two decades. Subsequently, different groups have developed strategies aimed at preserving the pulmonary valve function. However, the results of these approaches are not well known. From July 2009 through March 2012, 38 patients underwent primary repair of TOF at the authors’ institution. Of these, 12 children (7 boys) underwent attempted pulmonary valve-sparing surgery with intraoperative dilation of the pulmonary valve. The technical details as well as the echocardiographic preoperative and follow-up data for this repair were recorded, with a special focus on the feasibility of the technique and the effects on pulmonary valve function. No patient in the series died. At repair, the median age was 6 months (range 3.4–126 months), and the median weight was 7.6 kg (range 4.7–47 kg). Intraoperative dilation of the pulmonary valve was technically feasible for all the patients. Two patients had unsuccessful dilation and underwent a transannular patch procedure. During a median follow-up period of 22 months (range 6–30 months), the pulmonary valve diameter and z-score improved significantly. Moreover, the annular size normalized, whereas the mean right ventricular outflow tract (RVOT) gradient remained at the mild level (median, 24 mmHg; range 12–36 mmHg). At the most recent follow-up evaluation, three patients showed moderate pulmonary regurgitation. Intraoperative dilation of the pulmonary valve in patients undergoing TOF repair is feasible and provides good relief of obstruction. Moreover, the pulmonary valve annulus grows through the follow-up period. Longer follow-up studies are needed to evaluate the exact role of this strategy in this population.