Preservation of the pulmonary valve complex in tetralogy of fallot: how small is too small?

Early experience with surgical strategies aimed at preserving the pulmonary valve and annulus during repair of tetralogy of Fallot

Background :

During repair of tetralogy of fallot (TOF) we modified surgical strategies to preserve the valve and annulus if the pulmonary valve leaflets are pliable and not significantly dysplastic.

Methods :

Initially, the repair was done from the main pulmonary artery (Group-1, 215 patients) and later through an additional incision in the infundibulum of the right ventricle (Group-2, 73 patients). Recently, we changed the approach to commissurotomy of the fused leaflets by releasing the supra valvar tethering and delamination of the cuspal apparatus till the base to improve the mobility of the cusps and do a controlled commissurotomy (Group-3, 14 patients). With delamination, we could extend the limit of the repair to a z-score of –3.5.

Results :

There was no hospital mortality; two patients died at home after discharge. A mean follow-up of 42.01 months ± 19.25 is available for 198 patients (92%) for group 1, 16.03 ± 7.45 for group 2, and 4.07 ± 2.09 for group 3. The re-intervention-free survival is 94.4% in group 1. The z value improved from -3 (-3–-2) to -1.2 (-3 – 0), P = 0.001 in Group 1, from -2.8 (-3–-2.4) to -1 (-1.1–-0.7), P = 0.001 in Group 2 and from –3 (-4–-3) to -1, P = 0.001 in Group 3. In all the groups, there was trivial or mild pulmonary regurgitation.

Conclusions :

During repair of TOF, adequate valve/annulus sparing is possible if the repair is done from both the main pulmonary artery and infundibular incisions using the delamination technique.

Secondary repair of incompetent pulmonary valves after previous surgery or intervention: Patient selection and outcomes

OBJECTIVES

Pulmonary valve (PV) regurgitation (PR) is common after intervention for a hypoplastic right ventricular outflow tract. Secondary PV repair is an alternative to replacement (PVR), but selection criteria are not established. We sought to elucidate preoperative variables associated with successful PV repair and to compare outcomes between repair and PVR.

METHODS

Patients who underwent surgery for secondary PR from 2010 to 2017 by a single surgeon were studied. The PV annulus and leaflets were measured on the preoperative echocardiogram and magnetic resonance images, and the primary predictor variable was leaflet area indexed to ideal PV annulus area (iPLA) by magnetic resonance imaging. PV repair and PVR groups were compared using multivariable logistic regression, and with a conditional inference tree. Freedom from PV dysfunction and from reintervention were assessed with Kaplan-Meier survival analyses.

RESULTS

Of 85 patients, 31 (36%) underwent PV repair. By multivariable analysis, longer PV total leaflet length (cm/m²) (β = 3.00, standard error [SE] = 0.82, P < .001), larger PV z score (β = 1.34, SE = 0.39, P = .001), and larger iPLA (β = 8.13, SE = 2.62, P = .002) were associated with repair. iPLA of 0.90 or greater was 91% sensitive and 83% specific for achieving PV repair. At a median of 4.1 years follow-up, there was greater freedom from significant PR in the PV repair group (log rank P = .008).

CONCLUSIONS

Patients with an iPLA >0.9, and those with an iPLA between 0.7 and 0.9 with a PV annulus z score >0 should be considered for a native PV repair. At midterm follow-up, patients with a PV repair were not more likely to develop PR or to require reintervention when compared with patients undergoing PVR.

One-Year Follow-up After Tetralogy of Fallot Total Repair Preserving Pulmonary Valve and Avoiding Right Ventriculotomy

BACKGROUND

We reviewed our revised surgical strategy for tetralogy of Fallot (TOF) total correction to minimize early exposure to significant pulmonary regurgitation (PR) and to avoid right ventriculotomy (RV-tomy). Methods and Results: Since February 2016, we have tried to preserve, first, pulmonary valve (PV) function to minimize PR by extensive commissurotomy with annulus saving; and second, RV infundibular function by avoiding RV-tomy. With this strategy, we performed total correction for 50 consecutive patients with TOF until May 2018. We reviewed the early outcomes of 27 of 50 patients who received follow-up for ≥3 months. Mean patient age at operation was 10.2±5.0 months, and mean body weight was 8.8±1.2 kg. The preoperative pressure gradient at the RV outflow tract and the PV z-score were improved at most recent echocardiography from 82.0±7.1 to 26.8±6.4 mmHg, and from -2.35±0.49 to -0.55±0.54, respectively, during 11.1±1.6 months of follow-up after operation. One patient required re-intervention for residual pulmonary stenosis. Twenty-two patients had less than moderate PR (none, 1; trivial, 8; mild, 13), and 5 patients had moderate PR. There was no free or severe PR.

CONCLUSIONS

At 1-year follow-up, the patients who underwent total TOF correction with our revised surgical strategy had acceptable results in terms of PV function. The preserved PV had a tendency to grow on short-term follow-up.

Echocardiographic Classification and Surgical Approaches to Double-Outlet Right Ventricle for Great Arteries Arising Almost Exclusively from the Right Ventricle

Selecting an appropriate surgical approach for double-outlet right ventricle (DORV), a complex congenital cardiac malformation with many anatomic variations, is difficult. Therefore, we determined the feasibility of using an echocardiographic classification system, which describes the anatomic variations in more precise terms than the current system does, to determine whether it could help direct surgical plans. Our system includes 8 DORV subtypes, categorized according to 3 factors: the relative positions of the great arteries (normal or abnormal), the relationship between the great arteries and the ventricular septal defect (committed or noncommitted), and the presence or absence of right ventricular outflow tract obstruction (RVOTO). Surgical approaches in 407 patients were based on their DORV subtype, as determined by echocardiography. We found that the optimal surgical management of patients classified as normal/committed/no RVOTO, normal/committed/RVOTO, and abnormal/committed/no RVOTO was, respectively, like that for patients with large ventricular septal defects, tetralogy of Fallot, and transposition of the great arteries without RVOTO. Patients with abnormal/committed/RVOTO anatomy and those with abnormal/noncommitted/RVOTO anatomy underwent intraventricular repair and double-root translocation. For patients with other types of DORV, choosing the appropriate surgical approach and biventricular repair techniques was more complex. We think that our classification system accurately groups DORV patients and enables surgeons to select the best approach for each patient's cardiac anatomy.

Assessment of Diffuse Ventricular Myocardial Fibrosis Using Native T1 in Children With Repaired Tetralogy of Fallot

BACKGROUND

Myocardial fibrosis is linked with adverse clinical outcomes in adults after tetralogy of Fallot repair (rTOF). Native T1 times (T1) by cardiac magnetic resonance have been shown to be a surrogate marker of diffuse myocardial fibrosis. The objective was to quantify native T1 in children post-rTOF and to evaluate their relationship with surgical, imaging, and clinical factors.

METHODS AND RESULTS

A retrospective cross-sectional study was performed. Midventricular native T1 were obtained in 100 children post-rTOF using a modified look-locker inversion recovery cardiac magnetic resonance sequence and compared with 35 pediatric controls. rTOF patients, aged 13.0±2.9 years, had higher indexed right ventricular (RV) end-diastolic (range 85-326 mL/m², mean 148 mL/m²) volumes, and lower RV and left ventricular (LV) ejection fractions compared with controls. RV, but not LV, T1 were higher in patients than in controls (1031±74 versus 954±32 ms, P<0.001) and female patients had higher RV T1 compared with males (1051±79 versus 1017±68 ms, P=0.02). LV T1 correlated with RV T1 (r=0.45, P<0.001), cardiopulmonary bypass (r=0.30, P=0.007), and aortic cross-clamp times (r=0.32, P=0.004). RV T1 correlated inversely with RV outflow tract gradient (r=-0.28, P=0.02). Longer aortic cross-clamp times were independently associated with LV and RV T1 on multivariable analysis. There was no association between exercise intolerance, arrhythmia, and native T1 or LV extracellular volume.

CONCLUSIONS

Children after rTOF do not have elevated LV native T1 or LV extracellular volume, but show evidence of increased RV native T1 suggestive of diffuse RV fibrosis, for which volume loading seems to be a risk factor. Surgical bypass and cross-clamp times are associated with fibrotic remodeling over a decade later.

Variability of Pulmonary Regurgitation in Proportion to Pulmonary Vascular Resistance in a Porcine Model of Total Resection of the Pulmonary Valve: Implications for Early- and Long-Term Postoperative Management of Right Ventricular Outflow Tract Reconstruction With Resulting Pulmonary Valve Incompetence

INTRODUCTION

Pulmonary regurgitation (PR) is a major concern after right ventricular (RV) outflow tract surgery. We assessed the impact of physiological changes in pulmonary vasculature on hemodynamic severity of PR and RV function and their potential clinical implications for postoperative management using a porcine model with severe PR.

MATERIALS AND METHODS

Eight porcine models of acute PR were established by means of resection of pulmonary valve on cardiopulmonary bypass. After separation from bypass and stabilization, blood flow in the main pulmonary artery was measured by a pulsed Doppler flowmeter, and RV systolic function was assessed on the basis of RV segment shortening (RVSS), which was analyzed by sonomicrometry. In the acute PR model, we verified the impact of pulmonary vascular resistance (Rp) on pulmonary regurgitant fraction (PRF) and RV function. Pulmonary vascular resistance was changed by manipulating the level of PaCo 2 and by inhalation of nitric oxide (NO).

RESULTS

After bypass, the mean PRF was 40% ± 5%, and there was a deterioration of RV function. Under each ventilation condition (high CO2, low CO2, and NO 20 ppm), Rp was 836 ± 207 dyne × s × cm(-5), 499 ± 125 dyne × s × cm(-5), and 340 ± 102 dyne × s × cm(-5), respectively, and PRF was 60% ± 10%, 37% ± 5%, and 24% ± 4%, respectively, under each condition. They also showed a positive correlation in all animals. Cardiac output and RVSS were decreased by hypercapnia, while they were significantly improved after NO inhalation.

CONCLUSIONS

This study indicates that low Rp after right ventricular outflow tract reconstruction (RVOTR) resulting in acute PR is advantageous in reducing the severity of PR and RV volume load. These findings may have clinical implications for early and long-term postoperative management of patients subjected to RVOTR with resulting pulmonary valve incompetence.

Pulmonary annulus preservation lowers the risk of late postoperative pulmonary valve implantation after the repair of tetralogy of Fallot

The long-term benefits of pulmonary annulus preservation in tetralogy of Fallot (ToF) repair in patients with a marginally small pulmonary annulus are controversial. We sought to determine whether pulmonary annulus preservation (AP) is superior to transannular patching (TAP) in lowering the risk of pulmonary valve implantation (PVI) long after the repair of ToF. Of the 255 patients who underwent total correction of ToF during infancy between January 1989 and December 2005, 114 patients (AP group = 57, TAP group = 57) were selected by propensity score matching for various preoperative variables, such as age and body weight at operation, sex, pulmonary artery size, pre-repair palliation, anatomical types of ventricular septal defect, and Z-score of pulmonary valve annulus diameter (PVA-Z). The PVA-Z of the AP and TAP groups were -2.3 ± 1.3 and -2.1 ± 1.3, respectively (p = 0.547). The time to PVI was compared between the two groups. The median follow-up duration was 146 months (AP group: 141 months, TAP group: 147 months; p = 0.191). During the follow-up periods, there were 12 reoperations for the relief of right ventricular outflow tract obstruction (RVOTO), eight PVIs, and three late deaths. While freedom from reoperation for RVOTO was comparable between the two groups (p = 0.182), freedom from PVI at postoperative 15 years was significantly lower in the TAP group than in the AP group (74 and 100 %, p = 0.015). In repairing ToF with marginally small pulmonary valve annulus, AP is associated with a lower risk of late postoperative PVI.

Echocardiographic assessment after surgical repair of tetralogy of fallot

Surgical correction of tetralogy of Fallot is still one of the most frequently performed intervention in pediatric cardiac surgery, and in many cases, it is far from being a complete and definitive correction. It is rather an excellent palliation that solves the problem of cyanosis, but predisposes the patients to medical and surgical complications during follow-up. The decision-making process regarding the treatment of late sequel is among the most discussed topics in adult congenital cardiology. In post-operative Fallot patients, echocardiography is used as the first method of diagnostic imaging and currently allows both a qualitative observation of the anatomical alterations and a detailed quantification of right ventricular volumes and function, of the right ventricular outflow tract, and of the pulmonary valve and pulmonary arteries. The literature introduced many quantitative echocardiographic criteria useful for the understanding of the pathophysiological mechanisms involving the right ventricle and those have made much more objective any decision-making processes.

Technical performance score as predictor for post-discharge reintervention in valve-sparing tetralogy of Fallot repair

Recognition of late problems following repair of tetralogy of Fallot (TOF) with a transannular patch has stimulated modifications to preserve pulmonary valve (PV) function. This study assesses the ability of technical performance score (TPS) to determine the need for post-discharge reinterventions (RIs) in valve-sparing TOF repair. We retrospectively reviewed 157 patients following valve-sparing repair of TOF from 2007-2012. We assigned TPS as Class 1 (optimal), Class 2 (adequate), or Class 3 (inadequate) based on discharge echo and clinical criteria. Preoperative, discharge, and follow-up PV Z scores and post-discharge RIs were documented. Reasons for Class 2 or 3 designation were right ventricular outflow tract (RVOT) gradient in 52, pulmonary regurgitation in 13, residual ventricular septal defects in 7, both RVOT gradient and ventricular septal defects in 13, and both RVOT gradient and pulmonary regurgitation in 37 patients. Median follow-up was 19.6 (range: 0.1-86.1) months. Class 3 patients had a significantly longer median intensive care unit and hospital stay compared with Class 1 (3 vs 2 days [P = 0.015] and 7 vs 5 days [P < 0.001], respectively). Post-discharge RIs were significantly lower in Class 1 vs Class 2 and Class 3 (P = 0.003). Class 1 patients had significantly larger PV Z scores compared with Class 2 or Class 3 patients (P < 0.001). TPS is associated with post-discharge RI rate after valve-sparing TOF repair. Preoperative PV Z score is highly correlated with Class I TPS. Patient selection based on preoperative PV Z scores may help determine if valve-sparing approach is appropriate, thus minimizing the need for RIs.

Pulmonary valve preservation and restoration strategies for repair of tetralogy of Fallot

Despite tremendous advances in surgical treatment of tetralogy of Fallot, augmenting the small right ventricular outflow tract remains a challenge. Transannular patch augmentation revolutionised surgical management, but did so at the expense of rendering patients with pulmonary insufficiency and the resulting problems associated therewith. Recent surgical efforts have focused on pulmonary valve preservation at initial correction and pulmonary valve restoration after transannular patching, with favourable results. In this manuscript, we review methods of pulmonary valve preservation and restoration.

Chronic pulmonary valve insufficiency after repaired Tetralogy of Fallot: diagnostics, reoperations and reconstruction possibilities

Complete correction of Tetralogy of Fallot, the most common cyanotic congenital heart defect, has now become routine. However, late residual lesions, primarily chronic pulmonary valve insufficiency, may have a negative impact on right-ventricular function, leading to the need for reoperation to insert a competent valve at the right-ventricular outflow. The diagnostic modalities pertaining to the failing right ventricle, the timing for eventual reintervention and the various surgical reconstruction possibilities of the right-ventricular outflow tract are still controversial and evolving, and are reviewed with a brief overview on current trends and future outlooks.

Physiological and Phenotypic Characteristics of Late Survivors of Tetralogy of Fallot Repair Who Are Free From Pulmonary Valve Replacement

Background—

Pulmonary valve replacement (PVR) after repair of tetralogy of Fallot is commonly required and is burdensome. Detailed anatomic and physiologic characteristics of survivors free from late PVR and with good exercise capacity are not well described in a literature focusing on the indications for PVR.

Methods and Results—

Survival and freedom from PVR were tracked in 1085 consecutive patients receiving standard tetralogy of Fallot repair in a single institution from 1964 to 2009. Of 152 total deaths, 100 occurred within the first postoperative year. Surviving patients between 10 and 50 years of age had an annual risk of death of 4 (confidence limit, 2.8–5.4) times that of normal contemporaries. To date, 189 patients have undergone secondary PVR at mean age of 20±13 years (36% of those alive at 40 years of age). A random sample of 50 survivors (age, 4–57 years) free from PVR underwent cardiovascular magnetic resonance, echocardiography, and exercise testing. These patients had mildly dilated right ventricles (right ventricular end-diastolic volume=101±26 mL/m 2 ) with good systolic function (right ventricular ejection fraction=59±7%). Most had exercise capacity within normal range ( z peak o 2 =−0.91±1.3; z e / co 2 =0.20±1.5). In patients >35 years of age with normal exercise capacity, there was mild residual right ventricular outflow tract obstruction (mean gradient, 24±13 mm Hg), pulmonary annulus diameters <0.5 z , and unobstructed branch pulmonary arteries.

Conclusions—

An important proportion of patients require PVR late after tetralogy of Fallot repair. Patients surviving to 35 years of age without PVR and with a normal exercise capacity may have had a definitive primary repair; their right ventricular outflow tracts are characterized by mild residual obstruction and pulmonary annulus diameter <0.5 z .

Native Pulmonary Valve Restoration After Remote Tetralogy of Fallot Repair

Methods to repair tetralogy of Fallot have evolved from large ventriculotomy, large transannular patch placement techniques to smaller, transatrial approaches with valve-sparing strategies in select patients. Despite these advances, there continue to be patients in whom transannular patch is inevitable, and the management of the resulting pulmonary insufficiency that develops from this has been the source of considerable discussion. Techniques aimed at restoring pulmonary valve competence utilizing the remaining valve leaflets after transannular patch placement have recently been proposed for very select patient populations. We review the technical aspects of the operation including removal of the transannular patch and bicuspidization of a formerly tricuspid pulmonary valve, which results in a competent, nonstenotic valve. This report confirms the feasibility of these operative details and highlights the importance of planning before initial repair of tetralogy of Fallot as a way to prepare for a future valve restoration procedure and therefore avoid prosthetic valve placement.

Subpulmonary stenosis assessed in midtrimester fetuses with tetralogy of Fallot: a novel method for predicting postnatal clinical outcome

This study aimed to determine whether quantification of subpulmonary stenosis (SPS) in tetralogy of Fallot (TOF) in the second-trimester fetus can predict postnatal clinical outcome measured by pulmonary valve size and/or timing or type of intervention. The study retrospectively identified fetuses with TOF from 1998 to 2010 diagnosed at 26 weeks gestation or earlier. The data evaluated included pre- and postnatal pulmonary valve z-scores (PVZ). To quantify fetal SPS, the authors created a novel index, the SPS/DAO ratio, a ratio of the minimum infundibular diameter to the descending aorta diameter (DAO). Multiple linear regression was used to predict postnatal PVZ from prenatally determined parameters, including SPS/DAO. Fetal parameters were analyzed by logistic regression for association with postnatal outcomes, namely, timing of surgery (<1 month), used as a surrogate for severity, and type of surgery [transannular patch (TAP) vs valve sparing surgery]. A total of 23 fetuses met the inclusion criteria. The mean gestational age was 21.8 ± 1.9 weeks (range, 16.6-25.4 weeks). There was excellent correlation between predicted and measured PVZ (r = 0.82; p < 0.0001) using the following derived equation: -3.68 + (0.91 × prenatal PVZ) - (4.44 × SPS/DAO) - 3.19 (prenatal PVZ × SPS/DAO). An SPS/DAO value lower than 0.5 had 100 % sensitivity and 56 % specificity for repair before the age of 1 month, and a value lower than 0.47 had 100 % sensitivity and 75 % specificity for TAP repair. Prenatal PVZ and the SPS/DAO ratio at 26 weeks gestation or earlier can reliably predict postnatal PVZ in fetuses with TOF. Quantification of SPS with the SPS/DAO ratio identifies patients who may require early intervention secondary to disease severity and may predict the type of repair, thereby influencing prenatal counseling.

Tetralogy of Fallot with atrioventricular septal defect: surgical strategies for repair and midterm outcome of pulmonary valve-sparing approach

Repair for tetralogy of Fallot (TOF) with complete atrioventricular septal defect (CAVSD) has been reported with good early and intermediate outcomes. Morbidity, however, remains significantly high. To date, repair of CAVSD/TOF using a pulmonary valve-sparing technique (PVS) and freedom from valve reoperation are not well defined. A study was undertaken to investigate outcomes. This study was conducted in as a retrospective investigation. Between January 1988 and December 2008, 13 consecutive patients with CAVSD/TOF were identified, and their records were reviewed retrospectively. Of these 13 patients, 9 had Rastelli type C CAVSD. Trisomy 21 was present in 9 cases (69 %; 7 with type C). Five patients had received a systemic-to-pulmonary shunt (SPS) before complete repair at a mean age 1.7 ± 0.6 months. All the patients survived until complete repair. At complete CAVSD/TOF repair, AVSD was corrected with a two-patch technique in all patients. For eight patients (61.5 %), PVS was used. The remaining five patients had transannular patch (TAP) repair. The mean age at complete repair was 6.3 ± 2.4 months. At complete repair, the mean cardiopulmonary bypass time was 173.5 ± 30.6 min, and the cross-clamp time was 134.7 ± 28.8 min. There was one hospitalization and no late deaths. The median follow-up period was 9.2 years [interquartile range (IQR), 4.7-13.3 years]. The actuarial survival was 90.0 ± 9.5 % at 1 year, 90 ± 9.5 % at 5 years, and 90 ± 9.5 % at 8 years. Of the 12 survivors, 6 had some reintervention during the follow-up period. Within the first 11 years after complete repair, two patients underwent left atrioventricular (AV) valve repair, and one patient had right AV valve repair. Two patients had residual VSD closure. Four patients underwent the first right ventricular outflow tract (RVOT) reintervention for critical insufficiency or stenosis at a mean interval of 6 ± 21) months. One patient had a second RVOT reoperation. Findings showed that CAVSD/TOF with PVS was related to significantly higher freedom from RVOT reintervention (100 % at 1, 5, and 8 years compared with 80 ± 17.9 % at 1 year, 60 ± 21.9 % at 5 years, and 40 ± 21.9 % at 8 years for CAVSD/TOF using TAP; P < 0.05). No patient who underwent PVS had left ventricular outflow tract obstruction requiring reoperation. Overall freedom from any reintervention was 90.9 ± 8.6 % at 1 year, 71.6 ± 14.0 % at 5 years, and 53.7 ± 8.7 % at 8 years in this group of patients. Correction of TOF with CAVSD can be performed at low risk with favorable intermediate-term survival and satisfactory freedom from reoperation. Use of TAP can be avoided in almost two thirds of patients and may influence freedom from early RVOT reintervention.

Technical modification enabling pulmonary valve-sparing repair of a severely hypoplastic pulmonary annulus in patients with tetralogy of Fallot

OBJECTIVES

Although pulmonary valve-sparing repair is preferable for patients with tetralogy of Fallot, the repair of very small pulmonary valves is challenging. The present study evaluates our modification for preserving severely hypoplastic pulmonary valves in patients with tetralogy of Fallot.

METHODS

Sixty-eight consecutive patients who underwent complete repair of a tetralogy of Fallot between 2005 and 2011 were retrospectively reviewed. Patients with pulmonary atresia, absence of a pulmonary valve, atrioventricular septal defect and/or subarterial ventricular septal defect were excluded. There were 19 (28%) patients with a severely hypoplastic pulmonary annulus determined by preoperative echocardiography (z-score <-4). For these patients, we collected echocardiographic data and information about their postoperative course.

RESULTS

Valve preserving was successful in 11 of 19 (58%) of the z < -4 group, compared with 48 of 49 (98%) of the z > -4 group. In the z < -4 valve-sparing subgroup (n = 11), the preoperative pulmonary valve diameter z-score was -4.9 (range -6.3 to -4.3), and an approach involving ventriculotomy with no transannular patch was employed at a mean age of 6.9 (range 2.2-16.1) months. In this subgroup, residual right ventricular outflow tract velocity was 2.4 ± 0.6 m/s at discharge from the hospital. During a mean follow-up of 2.6 ± 2.4 years, no reintervention was necessary. Late right ventricular outflow tract velocity was 2.2 ± 0.6 m/s, and there was no severe pulmonary regurgitation. The pulmonary valve annulus grew in relation to the patient's body surface area (z = -0.51, range -4.2-0.24) without any aneurysmal changes in the right ventricular outflow tract.

CONCLUSIONS

Although our modification of valve-sparing repair for severely hypoplastic pulmonary valves in patients with tetralogy of Fallot could not be applied in all patients, this strategy enabled acceptable growth of the valve annulus, with only mild stenosis during the early to mid-term follow-up. This modification seems to be an option, even for a very small pulmonary valve.

Balloon pulmonary valvotomy as interim palliation for symptomatic young infants with tetralogy of Fallot

Objectives:

To describe the case selection, technique and immediate and short-term results of balloon pulmonary valvotomy (BPV) in young infants with tetralogy of Fallot (TOF).

Background:

Symptomatic young infants with TOF can either undergo corrective surgery or Blalock-Taussig (BT) shunt. Corrective surgery in early infancy is associated with significant morbidity and is not a realistic option in many centers. BT shunt carries the risk of branch pulmonary artery distortion and shunt occlusion.

Methods:

Infants less than three months with a significant valvar pulmonary stenosis (with or without associated infundibular and annular component) and oxygen saturation ≤80% were offered BPV. The right ventricular outflow tract (RVOT) was crossed with 4F Judkin's right coronary catheter and the valve was crossed with 0.014” coronary guide wire. Serial balloon dilatations were done with over the wire coronary balloons (3-4 mm) and Mini Tyshak balloons up to a balloon annulus ratio of 2:1, depending upon the improvement in saturation and formation of annular waist.

Results:

Seventeen infants less than three months of age with tetralogy of Fallot (median age: 33 days, range: 10-90 days, weight: 3.47 ± 0.87 kg, pulmonary annulus Z score: -5.59 ± 1.04) including eight neonates underwent palliative BPV between May 2004 and March 2007. The mean balloon annulus ratio was 1.4 ± 0.28 and fluoroscopy time was 26.18 ± 20.2 minutes. The mean oxygen saturation increased significantly from 73 ± 7% to 90 ± 3.68% following BPV (p = 0.0001). The only major complication was RVOT perforation and pericardial tamponade in one infant. The mean follow-up period was 23 ± 12 months. Two babies developed significant desaturation requiring surgery in the six months following BPV. There was a significant increase in pulmonary annulus. The z score for the pulmonary annulus improved from -5.59 ±1.04 before BPV to - 4.31 ± 1.9 at the time of last follow-up (p = 0.018). The mean Z score of hilar right pulmonary artery (RPA) increased significantly from -1.19 ± 1.78 before BPV to 0.7 ± 0.91 after BPV (p = 0.001). The mean Z score of hilar left pulmonary artery (LPA) increased significantly from -1.28 ± 1.41 to 0.03 ± 1.29 after BPV (p = 0.005). Eight patients underwent corrective surgery.

Conclusions:

Balloon pulmonary valvotomy is safe and effective. It significantly improves the growth of pulmonary annulus and branch pulmonary arteries. Thus it can be considered as an interim palliative procedure for symptomatic young infants with TOF and predominant valvar pulmonary stenosis.

Pericardial Monocusp for Pulmonary Valve Reconstruction: A New Technique

Enhancing the pulmonary annulus renders the pulmonary valve incompetent in cases of tetralogy of Fallot. A pressure-loaded right ventricle may change to a volume-loaded ventricle, which may dilate and eventually dysfunction. This study evaluated a new technique of fashioning a monocusp valve from untreated autologous pericardium suspended on a transannular patch. It was assessed in 40 children undergoing complete repair of tetralogy of Fallot between January 2005 and December 2007. 24 patients had a transannular patch alone (group A) and 16 received a transannular patch with the autologous pericardial monocusp valve (group B). All patients were followed up for 1 year with transthoracic echocardiography to determine pulmonary insufficiency. There was no significant difference in cardiopulmonary bypass or aortic crossclamp times, postoperative chest tube drainage, duration of inotropic usage, intensive care unit or hospital stay between groups. Univariate analysis showed significantly lower grades of pulmonary insufficiency in group B. This technique for creating an autologous pericardial monocusp valve is an inexpensive, simple, and reliable procedure that effectively reduces pulmonary insufficiency at the 1-year follow-up.

The current strategy of repair of tetralogy of Fallot in children and adults

OBJECTIVES

The strategies of repair of tetralogy of Fallot change with the age of patients. In children older than 4 years and adults, the optimal strategy may be to use different method of reconstruction of the right ventricular outflow tract from those followed in younger children, so as to avoid, or reduce, the pulmonary insufficiency that is increasingly known to compromise right ventricular function.

METHODS

From April, 2001, through May, 2008, we undertook complete repair in 312 patients, 180 male and 132 female, with a mean age of 11.3 years +/-0.4 years, and a range from 4 to 48 years, with typical clinical and morphological features of tetralogy of Fallot, including 42 patients with the ventriculo-arterial connection of double outlet right ventricle. The operation was performed under moderate hypothermia using blood cardioplegia. The ventricular septal defect was closed with a Dacron patch. When it was considered necessary to resect the musculature within the right ventricular outflow tract, or perform pulmonary valvotomy, we sought to preserve the function of the pulmonary valve by protecting as far as possible the native leaflets, or creating a folded monocusp of autologous pericardium.

RESULTS

The repair was achieved completely through right atrium in 192, through the right ventricular outflow tract in 83, and through the right atrium, the outflow tract, and the pulmonary trunk in 36 patients. A transjunctional patch was inserted in 169 patients, non-valved in all but 9. There were no differences regarding the periods of aortic cross-clamping or cardiopulmonary bypass. Of the patients, 5 died (1.6%), with no influence noted for the transjunctional patch. Of those having a non-valved patch inserted, three-tenths had pulmonary regurgitation of various degree, while those having a valved patch had minimal pulmonary insufficiency and good right ventricular function postoperatively, this being maintained after follow-up of 8 to 24-months.

CONCLUSIONS

Based on our experience, we suggest that the current strategy of repair of tetralogy of Fallot in older children and adults should be based on minimizing the insertion of transjunctional patches, this being indicated only in those with very small ventriculo-pulmonary junctions. If such a patch is necessary, then steps should be taken to preserve the function of the pulmonary valve.

State of the art of cardiac surgery in patients with congenital heart disease

During the last 20 years, pediatric cardiac surgery has been characterized by important changes, with reductions in surgical mortality and the achievement of complete repair at an earlier age, thus avoiding multiple procedures and strongly ameliorating the global outcome of these patients. In this review, we describe the actual trends in the surgical treatment of cardiac malformations. We analyze two groups of patients: in the first group (septal defects, tetralogy of Fallot, transposition of the great arteries, aortic stenosis and coarctation) the indications are well established and the goal is represented by a lessening of the surgical trauma and post-operative morbidity, with stable results in the follow-up. In the second group (univentricular heart, pulmonary atresia and intact ventricular septum, double discordance, conduit, hypoplastic left heart syndrome), the lesions are still considered complex and submitted to ongoing experimental and clinical research, in order to improve the post-surgical history of these diseases.

Advances in pediatric cardiovascular surgery: anatomic reconstruction of the left ventricular outflow tract in transposition of the great arteries with pulmonic valve abnormalities

In the past years, advances in pediatric cardiovascular surgery have occurred in many areas with some of the greatest strides being made in complex repairs in younger age groups. Aggressive early corrections while higher risk, may in the long run provide a child with a normal anatomic heart, and corresponding myocardial growth and physiology.

Surgery for congenital heart disease

General agreement has been reached on the indications for treating most congenital cardiac malformations. Strong disagreement exists, however, about timing and methods of treatment, either for congenital heart defects, for which the approach should be standardized after years of use, and even more when a new technique or a new approach is introduced to replace the existing ones. The ideal solution should be to perform prospective, randomized studies, with long-term follow-up, possibly with preliminary experimental studies to support the hypothesis. Unfortunately this is rarely possible, either because of the nonreproducibility of the malformation in an experimental environment, or because prospective, randomized studies with adequate follow-up are rarely feasible, due to the relatively small number of children with the same congenital heart defect. An updated review of the current trends in congenital heart surgery, based on the papers published in the past year, is presented here.