Transannular Patch Repair Research Articles

Native Right Ventricular Outflow Tract Transcatheter Pulmonary Valve Replacement Without Pre-Stenting

A 31-year-old man with history of tetralogy of Fallot, status post-surgical repair with a transannular patch repair, and patch closure of the ventricular septal defect as a neonate, presented with symptomatic severe pulmonic regurgitation (PR). Additional pertinent medical history included history

Cardiac Magnetic Resonance in long term follow-up of Tetralogy of Fallot

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. To analyze CMR results in the follow-up of TOF patients. 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. 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). 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.

Predictors of ventricular tachyarrhythmia occurring late after intracardiac repair of tetralogy of Fallot: combination of QRS duration change rate and tricuspid regurgitation pressure gradient.

To determine potential predictors of ventricular tachyarrhythmia and sudden cardiac death (SCD) occurring late after repair of tetralogy of Fallot (TOF). Since 1964, 415 patients had undergone total repair for TOF at Niigata University Hospital. Of these, 89 patients who were followed for more than 10 years at our institute were retrospectively reviewed. The mean follow-up period was 24.3 years. During the study period, one patient died of cerebral bleeding, and two patients had SCD. The overall survival rates at 20, 30, and 40 years were 100%, 94.6%, and 94.6%, respectively. Eight (9.0%) patients required re-intervention during the late period associated with right ventricular outflow (n=4), tricuspid valve (n=3), aortic valve (n=2), and others (n=2). Ten (11.2%) patients had a history of ventricular tachycardia (VT) or ventricular fibrillation (VF), and six underwent implantation of an implantable cardiac defibrillator. Multivariate analysis selected the change rate of QRS duration [ms/year; odds ratio (OR), 2.44; 95% confidence interval (CI): 1.28-4.65; P=0.007] and the pressure gradient at tricuspid valve regurgitation on echocardiography (OR, 1.12; 95% CI: 1.02-1.22; P=0.017) as risk factors for VT/VF or SCD. Trans-annular patch (TAP) repair was not an independent risk factor for ventricular arrhythmia. The combination of rapid change rate of QRS duration and higher-pressure gradient at tricuspid regurgitation were risk factors for ventricular tachyarrhythmia late after TOF repair. Adequate surgical or catheter intervention for pressure and volume load in the right ventricle might decrease the prevalence of VT/VF and SCD.

Valve-sparing repair with intraoperative balloon dilation in tetralogy of Fallot: Midterm results and therapeutic implications

ObjectivesThe significant morbidity of long-term pulmonary regurgitation (PR) has driven the development of pulmonary valve (PV) sparing repair strategies in patients with tetralogy of Fallot (ToF). We assessed mid-term PV function in patients who underwent primary ToF repair with valve-sparing intraoperative balloon dilation (IBD) technique. MethodsWe evaluated 162 consecutive patients with ToF and pulmonary stenosis (ToF-PS) who underwent valve-sparing repair with IBD under 1 year of age. ResultsMedian age at surgery was 98 days (interquartile range [IQR], 72-126) and median follow-up was 2.5 years (IQR, 0.6-4.9). Median preoperative PV annulus z score was −2.2 (IQR, −2.5 to −1.8). Twenty-five patients (15.4%) required reintervention for residual valvular stenosis. Multivariable analysis demonstrated preoperative annulus z score less than −2.45 (P = .036) and younger age at surgery (P = .001) were independent risk factors for early reintervention for stenosis. Freedom from at least moderate PR was 77%, 61%, and 43% at 1, 3, and 5 years postrepair. Right ventricular dimensions were not significantly different compared with a matched cohort of patients undergoing transannular patch repair at midterm follow-up. ConclusionsPatients with ToF-PS who undergo valve-sparing repair with IBD develop progressive PR. Compared with transannular patch repair, the extent of RV dilation at midterm follow-up is not significantly different. Patients younger than 3 months of age and those with an annulus z score less than −2.45 experience higher rates of early reintervention for PV stenosis. In these patient subgroups, alternative strategies should be considered. This study suggests valve-sparing repair with IBD does not preserve long-term PV function in patients with ToF-PS.

Pulmonary valve restitution following transannular patch repair of tetralogy of Fallot.

Chronic pulmonary insufficiency following transannular patch repair of tetralogy of Fallot may mandate restoration of a competent pulmonary valve. Pulmonary valve leaflets that are preserved at initial surgery may grow and develop normal morphology and subsequent valve repair may be possible. We reviewed our experience with native pulmonary valve restitution following transannular patch repair (2001-15). The cohort included 9 patients with a median age of 18.7 (range 10.6-31.3) years. Operative technique involved reapproximation of the anterior commissure of the pulmonary valve. Median length of stay was 3 days, and there were no deaths. At median follow-up of 2.0 (0.4-13.5) years, pulmonary insufficiency was graded as ≤mild (n = 4), mild-moderate or moderate (n = 4) and moderate-severe (n = 1); pulmonary stenosis was ≤mild (n = 8) and moderate (n = 1), with median peak gradient of 21 (16-64) mmHg. No patient required reintervention. At reoperation to treat pulmonary insufficiency in repaired TOF, if residual leaflets are found with favourable anatomy, restitution of the native valve should be considered. This valve-preserving technique avoids the certain failure of a bioprosthesis and is associated with favourable early outcomes. The viability of this option may influence surgeons to leave the pulmonary leaflets in situ at the time of initial repair.

Earlier Pulmonary Valve Replacement in Down Syndrome Patients Following Tetralogy of Fallot Repair.

The association between Down syndrome and pulmonary hypertension could contribute to more severe pulmonary regurgitation after tetralogy of Fallot repair and possibly earlier pulmonary valve replacement. We compared cardiac magnetic resonance measures of pulmonary regurgitation and right ventricular dilation as well as timing of pulmonary valve replacement between those with and without Down syndrome after tetralogy of Fallot repair. Review of our surgical database from 2000 to 2015 identified patients with tetralogy of Fallot with pulmonary stenosis. Those with Down syndrome were compared to those without. The primary outcome of interest was time from repair to pulmonary valve replacement. Secondary outcomes included pulmonary regurgitation and indexed right ventricular volume on cardiac magnetic resonance imaging. The cohort of 284 patients included 35 (12%) with Down syndrome. Transannular patch repair was performed in 210 (74%). Down syndrome showed greater degree of pulmonary regurgitation (55±14 vs. 37±16%, p=0.01) without a significantly greater rate of right ventricular dilation (p=0.09). In multivariable analysis, Down syndrome (HR 2.3, 95% CI 1.2-4.5, p=0.02) and transannular patch repair (HR 5.5, 95% CI 1.7-17.6, p=0.004) were significant risk factors for valve replacement. Those with Down syndrome had significantly lower freedom from valve replacement (p=0.03). Down syndrome is associated with an increased degree of pulmonary regurgitation and earlier pulmonary valve replacement after tetralogy of Fallot repair. These patients require earlier assessment by cardiac magnetic resonance imaging to determine timing of pulmonary valve replacement and evaluation for and treatment of preventable causes of pulmonary hypertension.

An audit of surgical repair of Tetralogy of Fallot in an African tertiary care centre

Background: For patients undergoing Tetralogy of Fallot (TOF) repair at institutions in sub-Saharan Africa, data on type of surgical repair, operative mortality and important determinants of outcome such as age at operation and development of pulmonary regurgitation (PR) post-repair is scanty. Objective: To describe the outcomes of children diagnosed with TOF who underwent surgical repair at our center with emphasis on post-operative PR. Methods: This was a retrospective cohort study undertaken from 1 January 1994 to 31 December 2003 at Charlotte Maxeke Johannesburg Academic Hospital (CMJAH). The descriptive analysis of the clinical audit was done in 2010. Results: Fifty four (75%) patients were operated upon: 50 (92.5%) had complete repair and 4 (7.4%) had a palliative procedure in the form of a Blalock-Taussig (B-T) shunt. The median age for corrective surgery was 39.5 months. Twenty out of 50 (40%) patients had simple repair, 10 (20%) had repair which included pulmonary valvotomy, 15 (30%) had a transannular patch (TAP) repair with or without monocusp and 5 (10%) had conduit insertion. An evaluation of severe PR among all the repair groups in the immediate post-operative period ( 5 years), severe PR was documented in 3 (30%) patients with pulmonary valvotomy, 8 (53%) who had TAP repair, 2 (10%) patients with simple repair including 1 (20%) patient with a xenograft conduit. One out of 50 (2%) surgically corrected patients who had a complex anatomy died in the immediate post-operative period. Twenty eight out of 50 (56%) patients who had complete correction were lost to follow-up. Conclusion: Surgical correction occurs much later in infancy and childhood compared to developed countries. Severe PR is a serious complication strongly associated with all types of surgical repair of TOF and these patients require lifelong follow-up. Despite the small sample size, the operative mortality compares favourably to fi rst world centers.

Evolution of right ventricular size over time after tetralogy of Fallot repair: a longitudinal cardiac magnetic resonance study

It is commonly believed that pulmonary regurgitation (PR) after surgical repair of tetralogy of Fallot (TOF) leads to progressive right ventricular (RV) enlargement. However, progressive RV dilatation has never clearly been documented in this patient population. Therefore, we studied the size of the RV over time in patients after surgical TOF repair. Fifty-one consecutive patients after surgical TOF repair underwent at least two cardiovascular magnetic resonance (CMR) exams using a single CMR scanner. Patients with RV outflow tract obstruction, interventions other than the initial repair and CMR exams with use of sedation were excluded. Three subgroups with different repair techniques were studied: transannular patch repair [n = 22, age 17 ± 10 years], subvalvular patch repair [n = 15, age 22 ± 8 years], or non-patch repair/infundibulectomy (n = 14, age 28 ± 11 years). Right ventricular end-diastolic volume index (RVEDVI) and PR fraction did not change during the 37 ± 21 months follow-up between first and last CMR in the whole group (RVEDVI: 118 ± 23 mL/m2 vs. 119 ± 23 mL/m2, P = 0.720; PR fraction: 33% (23-40%) vs. 32% (24-39%), P = 0.268). RVEDVI remained stable in all subgroups (transannular patch: 120 ± 21 mL/m2 vs. 122 ± 22 mL/m2, subvalvular patch: 112 ± 23 mL/m2 vs. 111 ± 23 mL/m2, non-patch: 123 ± 28 mL/m2 vs. 123 ± 23 mL/m2, P = 0.827). RVEDVI at last CMR did not differ between groups (P = 0.301). This study shows no progression of RV dilatation in patients after surgical repair of TOF with moderately dilated RVs and significant PR during a 3-year follow-up. RV dilatation in our patient group seems to be independent from surgical repair techniques.

A first population-based long-term outcome study in adults with repaired tetralogy of Fallot in Malta.

To determine overall and reintervention-free survival for repaired Maltese tetralogy of Fallot patients and to investigate the potential impact of gender, age at repair, genetic syndromes, previous palliation, and type of repair on these outcomes. All 130 tetralogy of Fallot patients born before the end of 1997 included in the local database were extracted. Surgical repair type, age at repair and operative survival were analyzed among the 103/130 repaired patients. Kaplan-Meier survival analyses were performed on the 75 repair survivors with complete follow-up data (mean follow-up 26.37 ± 9.27 (range 9.95-51.21) years). Patients born after 1985 were operated at a younger age (median 1.28 years) compared with patients born before 1985 (median 9.64 years) (P < .001). Transannular patch repair was the commonest operation among patients born after 1985 (43.90%), while repair without transannular patch use prevailed among those born before 1985 (66.13%). 90.24% of patients born after 1985 survived reparative surgery compared with 70.37% of those born before 1985. Of the 75 repair survivors, 7 (9.33%) died of cardiac causes and 22 (29.33%) needed reintervention during follow-up. Overall estimated mean survival was 45.56 years (95% CI 41.67-49.24) with estimated survival rate of 77.5% at 40 years from repair. Estimated mean reintervention-free survival was 37.71 years (95% CI 33.75-41.66) with estimated reintervention-free survival rate of 59.2% at 40 years. Patients with genetic syndromes had significantly lower overall survival after repair. Transannular patch repair was associated with significantly lower reintervention-free survival (median 32.37 years (95% CI 12.75-51.99)) compared with repair without transannular patch [median 44.21 years (95% CI 43.06-45.35); P = .03]. Although survival after tetralogy of Fallot repair in contemporary patients is very good, cardiac death can occur at any stage and structural reintervention is common. Regular follow-up with imaging and rhythm monitoring remains of utmost importance in all patients.

Implantation of the Medtronic Harmony Transcatheter Pulmonary Valve Improves Right Ventricular Size and Function in an Ovine Model of Postoperative Chronic Pulmonary Insufficiency.

Pulmonary insufficiency is the nexus of late morbidity and mortality after transannular patch repair of tetralogy of Fallot. This study aimed to establish the feasibility of implantation of the novel Medtronic Harmony transcatheter pulmonary valve (hTPV) and to assess its effect on pulmonary insufficiency and ventricular function in an ovine model of chronic postoperative pulmonary insufficiency. Thirteen sheep underwent baseline cardiac magnetic resonance imaging, surgical pulmonary valvectomy, and transannular patch repair. One month after transannular patch repair, the hTPV was implanted, followed by serial magnetic resonance imaging and computed tomography imaging at 1, 5, and 8 month(s). hTPV implantation was successful in 11 animals (85%). There were 2 procedural deaths related to ventricular fibrillation. Seven animals survived the entire follow-up protocol, 5 with functioning hTPV devices. Two animals had occlusion of hTPV with aneurysm of main pulmonary artery. A strong decline in pulmonary regurgitant fraction was observed after hTPV implantation (40.5% versus 8.3%; P=0.011). Right ventricular end diastolic volume increased by 49.4% after transannular patch repair (62.3-93.1 mL/m2; P=0.028) but was reversed to baseline values after hTPV implantation (to 65.1 mL/m2 at 8 months, P=0.045). Both right ventricular ejection fraction and left ventricular ejection fraction were preserved after hTPV implantation. hTPV implantation is feasible, significantly reduces pulmonary regurgitant fraction, facilitates right ventricular volume improvements, and preserves biventricular function in an ovine model of chronic pulmonary insufficiency. This percutaneous strategy could potentially offer an alternative for standard surgical pulmonary valve replacement in dilated right ventricular outflow tracts, permitting lower risk, nonsurgical pulmonary valve replacement in previously prohibitive anatomies.

Pulmonary Valve Repair for Patients With Acquired Pulmonary Valve Insufficiency

Pulmonary valve (PV) insufficiency is often an acquired condition after treatment for pulmonary stenosis. It is recognized that PV insufficiency has serious deleterious effects. Although surgical replacement of the PV is efficacious, artificial valves inevitably fail and require re-intervention. The purpose of this study was to summarize our experience with PV repair in patients with acquired PV insufficiency. This was a retrospective review of 16 patients with marked PV insufficiency who underwent PV repair. Thirteen of these patients were born with tetralogy of Fallot (TOF) and had undergone a previous transannular patch repair. Three patients were born with critical pulmonary stenosis and had a surgical valvotomy or balloon valvuloplasty. The 13 patients with TOF had resection of their previously placed transannular patch with re-approximation of the anterior commissure. All 13 patients experienced a marked reduction in the degree of pulmonary insufficiency. None of these patients have experienced any increase in insufficiency during follow-up. The 3 patients with critical pulmonary stenosis had a variety of pathologic findings identified at the surgical procedure. One patient had a large gap between a commissure and underwent closure of that commissure. The second and third patients had torn leaflets repaired with pericardial and Gore-Tex patches (Gore, Inc, Flagstaff, AZ). The degree of PV insufficiency was decreased to mild in all 3 patients. However, 2 of these 3 patients have subsequently had an increase in the degree of pulmonary insufficiency. Patients with TOF who underwent a previous transannular patch may be candidates for bicuspidization of their native PV, and the results of this procedure have been quite stable at follow-up. PV repair for torn leaflets was effective in the short term but was less stable over time.

Aiming to Preserve Pulmonary Valve Function in Tetralogy of Fallot Repair: Comparing a New Approach to Traditional Management.

Pulmonary valve (PV) incompetence following transannular patch (TAP) repair of tetralogy of Fallot (TOF) results in long-term morbidity and mortality. Valve-sparing repairs have recently gained recognition; however, they may be associated with residual pulmonary stenosis (PS) in patients with small PV z scores. We sought to determine whether a repair that increases the PV annulus and augments the valve leaflet with a biomaterial would result in annular growth and in longer duration of valve competence compared with TAP. Eighty patients (median age 136days, range 4-350) who underwent surgical repair of TOF between 2010 and 2014 were included in the study. Patients were divided into three groups based on the PV intervention: balloon dilation/valvotomy (n=29), valve-sparing transannular repair (VSTAR) (n=19) and TAP (n=32). Intraoperative, early postoperative and midterm follow-up echocardiographic data (median 19months, range 1-59) were obtained. The primary outcomes were the presence and severity of pulmonary regurgitation and/or PS. Compared with TAP, VSTAR patients demonstrated significantly less severe PR with 100% freedom of severe PR immediately post-op (vs. 0% in TAP), 60% at 6months and 20% at 20months. There were no differences in PS between VSTAR and TAP at follow-up. A subgroup analysis of the VSTAR group was performed. PV z scores were calculated and fit to a random effects model. Patient data fit the model closely, predicting a reproducible increase in valve annulus size over time. With better short-term and comparable midterm results, VSTAR may be appropriate for TOF repair in patients with small PV that would conventionally require a TAP.

Polytetrafluoroethylene patch versus autologous pericardial patch for right ventricular outflow tract reconstruction

Objective: Reconstruction of right ventricular outflow tract (RVOT) during repair of Tetralogy of Fallot (TOF) often requires placement of a transannular patch (TAP). The purpose of the present study was to compare the outcomes following reconstruction of RVOT using polytetrafluoroethylene (PTFE) patch versus autologous glutaraldehyde-fixed pericardial patch. Materials and Methods: Fifty-three consecutive patients undergoing TAP repair for TOF in a single institute were randomized into two groups: Group I (pericardial patch), Group II (PTFE patch) and their postoperative outcomes in terms of postoperative rhythm, duration of mechanical ventilation, mediastinal and pleural drainage, stay in the Intensive Care Unit (ICU) and hospital, were assessed. The preoperative and postoperative gradients across the RVOT, pulmonary insufficiency, systolic right ventricular function were assessed echocardiographically by an independent cardiology team. Results: There was one death; there were no differences between the two groups regarding the postoperative duration of mechanical ventilation, ICU, and hospital stay. The requirement of inotropes was less in the PTFE patch group compared to the pericardial patch group (12.80 ± 8.04 vs. 17.30 ± 7.21, median 10 vs. 20, P = 0.025). The re-exploration rate in the PTFE group was higher than the other group (6 vs. 1). There was no difference in the RV systolic function between the two groups as assessed by echocardiogram before discharge. Conclusion: RVOT reconstruction during TOF repair can safely be performed using a PTFE patch with results similar to an autologous patch of glutaraldehyde-treated pericardium. Its results in the mid and long term need further evaluation.

Development of a novel hybrid strategy for transcatheter pulmonary valve placement in patients following transannular patch repair of tetralogy of fallot

Transcatheter pulmonary valve replacement (tPVR) is an accepted therapy for treatment of dysfunctional right ventricular outflow tract (RVOT) conduits. At present, the majority of Fallot patients who undergo transannular patch (TAP) repair are not candidates for tPVR due to the large irregular nature of their RVOT. Herein, we describe a novel approach to assessing the RVOT in this group, which may then be used to design, test, and carry out hybrid RVOT modification and transcatheter valve implantation in this population. A retrospective analysis of TAP patients who underwent 3D modeling of the RVOT which was then used to develop individualized hybrid procedures designed to modify the RVOT, thereby rendering patients suitable for transcatheter valve implantation. Eight consecutive patients underwent 3D RVOT modeling followed by hybrid implantation of a transcatheter valve via a perventricular approach. A landing zone stent was placed in all and four required additional intravascular geometric remodeling of the RVOT prior to valve implant. Transcatheter valves were successfully implanted in all. There were no instances of valve malposition, embolization, or death. There was one minor procedural complication. No patient had more than trivial pulmonary regurgitation at follow-up. Using a hybrid approach to remodel the RVOT in TAP patients supported by preprocedural 3D-model planning allows for successful tPVR implantation in this population. A larger cohort and longer follow-up will be needed to determine the ultimate utility of this approach.

Percutaneous pulmonary valve implantation with the Venus P-valve: clinical experience and early results.

At present, the exclusion for percutaneous pulmonary valve implantation for free pulmonary regurgitation after tetralogy of Fallot repair includes an unfavourably large right ventricular outflow tract. To report feasibility and early experience with a recently developed transcatheter heart valve, Venus P-valveTM, implanted in six patients with severe pulmonary regurgitation with large right ventricular outflow tracts. Patients There were two female patients and four male patients. The median age of the patients was 18.5 years, and the mean body weight was 53.8 kg. All the patients were in NYHA class II and had severe pulmonary regurgitation after previous transannular patch repair of tetralogy of Fallot. The median time after the last surgical operation was 13.5 years. The Venus P-valveTM was successfully implanted in all the patients with implanted valve diameters ranging from 24 to 32 mm. The mean fluoroscopy time was 29.8 minutes. None of the patients had significant outflow tract gradient or pulmonary regurgitation immediately after valve implantation. Only one patient had unexpected mild proximal valve migration to the right ventricular body during withdrawal of the delivery system. It caused mild paravalvar leak and significant tricuspid regurgitation. At 6 months follow-up, the median of right ventricular end-diastolic volume indices decreased from 146 to 108 ml/m2 (p-value=0.046). The Doppler systolic peak gradient across the valve ranged from 4 to 40 mmHg, and there was no evidence of stent fracture on fluoroscopy or structural valve failure. The Venus P-valveTM can be implanted successfully and effectively in patients with severe pulmonary regurgitation and a large right ventricular outflow tract. The early results with this valve are encouraging.

Mid-term follow-up of pulmonary regurgitation in repaired asymptomatic TOF patients by transannular patch: A prospective cardiac MRI study

ObjectiveThe long-term outcome of Tetralogy of Fallot (TOF) surgical repair in developing countries is still unknown. Therefore the aim of the study was the quantification of pulmonary regurgitation (PR) and right ventricular functions using cardiac magnetic resonance (CMR) in order to follow up midterm post transannular patch repair of asymptomatic TOF patients. MethodsWe prospectively studied 37 asymptomatic corrected TOF patients (aged 18years or less), aged at surgery was of median, min/max of (19, 8/48months). Cardiac functions were assessed using routine steady state free precession techniques. PR quantification was performed using the routine velocity encoding phase contrast in the main pulmonary artery. ResultsFour patients had mild PR, 26 had moderate PR and seven had severe PR, with a median value of PR% in CMR amounting to 29% (max: 75% and min: 13%). Indexed right ventricle end-diastolic volume amounted to (mean±SD) 130±38ml, and indexed right ventricle end-systolic volume amounted to 63±26ml. ConclusionAccurate quantitative assessment of PR in the mid and long-term course of TOF patients is paramount. CMR has to be introduced as a new modality in Egypt in the follow up course of asymptomatic TOF patients.

Assessment of Right Ventricular Function in Post Operative Patients of Tetralogy of Fallots and Its Predictive Factors

Introduction: Right ventricular (RV) dysfunction can occur early and late in patients after intracardiac repair (ICR) for Tetralogy of Fallots (TOF). This study focuses on early RV dysfunction as there is limited data on it. Aims & Objective: RV function was studied with respect to its incidence, course over 3 months, co-relation with peri operative factors and serum iron levels. Material & Method: All patients of TOF undergoing ICR during July 2007-October 2008, done by single surgeon at a single centre, were prospectively studied. Patients were divided into group A (with RV dysfunction) and group B (without RV dysfunction). All patients underwent pre operative & post operative clinical assessment, biochemical evaluation (serum iron profile & CK MB) and 2D echocardiography (pulse Doppler & tissue Doppler). Echocardiography was done at 24 hours, 4 weeks & 12 weeks of ICR. Patients were also assessed for intra operative parameters including cross clamp time, by pass time, acidosis, RV and PA pressures. Results: 24 patients underwent ICR (transannular patch repair) with mean age of 7.31 ± 4.74 years. RV dysfunction was present in 13 patients (54.2%) but was persistent only in 15.3% (2/13) at 12 weeks. Presence of cyanotic spell (p = 0.006), recurrent chest infection (p = 0.002), raised heamatocrit (p = 0.02), and rise in serum iron level (p = 0.002) were significantly associated with post operative RV dysfunction. It resulted in prolong ICU stay and slower recovery. Pre operative RV dysfunction was associated with difficult weaning from bypass and poor post operative outcome (p < 0.001). Conclusion: RV dysfunction is commonly present even after satisfactory ICR. Its aetiology remains unclear in such setting. In our study, pre operative clinical profile and serum iron fluctuations were important determinants of post operative outcome.

Role of myocardial hypertrophy on acute and chronic right ventricular performance in relation to chronic volume overload in a porcine model: Relevance for the surgical management of tetralogy of Fallot

The age for correction of tetralogy of Fallot has progressively declined to the postnatal period, often despite an increased rate of transannular patch repair. However, the long-term effect of premature exposure to chronic pulmonary insufficiency on the right ventricle remains unknown. On the basis of the relationship between the duration of pressure overload and age, the role of previous pressure load-related hypertrophy on right ventricular (RV) performance after chronic volume overload was investigated in a porcine model. RV hypertrophy (RVH), induced by pulmonary artery banding, was studied in pigs with (RVH plus pulmonary insufficiency [PI]) and without (RVH) subsequent PI. The effect of volume overload was compared between these 2 groups and pigs without RVH but with PI and controls (sham). Both acute and chronic effects on RV function were studied using conductance technology and validated using echocardiography. After chronic volume overload, the end-systolic and end-diastolic volumes were smaller in the RVH+PI group than in the PI group, including a lower pulmonary regurgitation fraction (25% ± 5% vs 35% ± 5%; P = .002). RVH resulted in better preserved systolic function, confirmed by an increased preload recruitable stroke work slope (14.7 ± 1.8 vs 9.3 ± 1.3 Mw.s/mL; P = .025) and higher RV ejection fraction (51% ± 3% vs 45% ± 4%; P = .05). Myocardial stiffness was impaired in the RVH+PI group versus the PI group (β, 0.19 ± 0.03 vs 0.12 ± 0.02 mL(-1); P = .001), presenting restrictive physiology only in the condition associating RVH and PI. The results of the present study have demonstrated that RVH attenuates the RV remodeling process related to chronic PI. It enables better preservation of contractility but at the cost of sustained diastolic impairment. These findings might help to determine the timing and strategy for repair of tetralogy of Fallot when RV outflow tract morphology indicates a definite need for transannular reconstruction.

Cardiovascular MR Imaging after Surgical Correction of Tetralogy of Fallot: Approach Based on Understanding of Surgical Procedures

Tetralogy of Fallot (TOF) is one of the most common congenital heart diseases for which patients are referred for postoperative magnetic resonance (MR) imaging evaluation. The most common surgical procedures for TOF repair include infundibulectomy, transannular pulmonary artery patch repair, and right ventricle-pulmonary artery conduit placement. In the past few decades, surgery has proved successful, but most patients require repeat imaging throughout their lives. MR imaging is now frequently used for morphologic and functional evaluation after TOF repair. The most common late postoperative sequelae and residual lesions include right ventricular outflow tract aneurysm and dyskinesis, conduit failure, pulmonary regurgitation, tricuspid regurgitation, right ventricular failure, residual main and branch pulmonary artery stenosis, branch pulmonary artery aneurysm, left pulmonary artery kinking, and residual or recurrent ventricular septal defect. The imaging approach for the evaluation of patients with repaired TOF should be guided by the surgical procedure used and the complications that are expected. Knowledge of the most common postoperative problems and their cardiovascular MR imaging appearances is essential for good radiology practice in this clinical setting.

Restrictive versus Nonrestrictive Physiology Following Repair of Tetralogy of Fallot: Is There a Difference?

Long-term outcome in repaired tetralogy of Fallot (TOF) is related to chronic pulmonary insufficiency (PI), right ventricular (RV) dilation, and deterioration of RV function. The aim of this study was to characterize clinical differences between restrictive and nonrestrictive RV physiology in young patients with repaired TOF. Patients were prospectively enrolled from February 2008 to August 2009. Each had a clinic visit, brain natriuretic peptide assessment, exercise test, cardiac magnetic resonance study, and echocardiographic examination with assessment of regional myocardial mechanics. Consistent antegrade diastolic pulmonary arterial flow with atrial contraction identified restrictive RV physiology. Twenty-nine patients (median age, 12 years; range, 8-33 years; nine male patients) were studied. Twelve had restrictive RV physiology. The median time since initial TOF repair was 12 years (range, 5-27 years). Restrictive physiology appeared more prevalent after transannular patch repair and was not influenced by other demographic features. The restrictive group had more PI (46% vs 28%, P = .002), larger RV end-diastolic volumes (128 vs 98 mL/m(2), P = .046), but similar ejection fractions, brain natriuretic peptide levels, New York Heart Association classes, and exercise capacity. RV basal and mid free wall peak diastolic strain rate differed between groups, negatively correlating with exercise time and positively correlating with PI in patients with restrictive physiology. Restrictive RV physiology correlates with a larger right ventricle and increased PI after TOF repair but does not negatively affect other markers of myocardial health. Diastolic regional RV myocardial mechanics, particularly diastolic velocity and peak diastolic strain rate, differ for postoperative TOF patients with restrictive and nonrestrictive RV physiology; longitudinal study is necessary to understand the relationship of regional myocardial mechanics and patients' clinical status.