Palliative pulmonary artery banding versus anatomic correction for congenitally corrected transposition of the great arteries with regressed morphologic left ventricle: Long-term results from a single center

Reverse double switch operation for the borderline left ventricle

OBJECTIVE(S)

This study investigates outcomes of the reverse double switch operation (R-DSO) and ventricular switch, novel approaches for patients with D-looped borderline left hearts that utilize the morphologic right ventricle as the systemic ventricle and the hypoplastic left ventricle as the subpulmonary ventricle.

METHODS

This retrospective review analyzed early outcomes of children who underwent R-DSO/ventricular switch at a single institution between 2015 and 2023. Our primary end points were right ventricular (RV) function and tricuspid regurgitation. Secondary outcomes included mortality, reoperation, and perioperative complications.

RESULTS

Twenty-eight patients underwent either R-DSO (n = 19) or ventricular switch (n = 9). In 19 patients, a decompressing bidirectional cavopulmonary shunt was utilized, creating a reverse 1.5 switch. Median age at R-DSO/ventricular switch was 3.1 years (range, 9 months-12 years). At a median follow-up of 1.0 year (range, 38 days-7.2 years), no mortalities or heart transplants had occurred. Mild-moderate or greater RV dysfunction was detected in 4 patients, and mild-moderate or worse tricuspid regurgitation was also detected in 4 patients. Three patients required reoperations. Preoperative RV ejection fraction <55% was associated with higher incidence of postoperative RV dysfunction.

CONCLUSIONS

The R-DSO/VS strategy is an alternative to single-ventricle palliation or anatomic biventricular repair in the borderline left heart. Concerns for RV dysfunction and tricuspid regurgitation mandate close monitoring. Patients with preoperative RV dysfunction may be at risk for postoperative RV dysfunction. Further studies with longer follow-up are needed to delineate outcomes in comparison to the Fontan pathway and identify optimal candidates for this novel strategy.

Echocardiographic Predictors of Readiness for Double Switch Operation and Postoperative Ejection Fraction in Patients With Congenitally Corrected Transposition of the Great Arteries Undergoing Left Ventricular Retraining

BACKGROUND

In patients with congenitally corrected transposition of the great arteries (ccTGA), assessment of readiness for the double switch operation (DSO) after pulmonary arterial band (PAB) placement involves cardiac magnetic resonance imaging (cMRI) to measure left ventricular ejection fraction (LVEF) and mass and cardiac catheterization (catheterization) to assess the ratio of left ventricular to right ventricular pressure (LV:RVp). The aims of this study were to describe the relationships between echocardiographic and catheterization and cMRI measures of readiness for DSO and to develop risk factors for left ventricular (LV) dysfunction after DSO on the basis of echocardiographic measures of ventricular-arterial coupling (VAC).

METHODS

Patients with ccTGA undergoing LV retraining at a DSO referral center were reviewed. LVEF measured by echocardiography was compared with that measured by cMRI, and LV:RVp measured by echocardiography was compared with that measured by catheterization using Bland-Altman analysis. The relationship between preoperative VAC markers and postoperative echocardiography was analyzed using ventricular end-systolic elastance (EES) and a novel marker consisting of the product of LVEF and LV:RVp (EFPR).

RESULTS

Thirty-one patients with 56 evaluations for DSO were included, 24 of whom underwent DSO. Echocardiographic LVEF correlated well with cMRI LVEF (r = 0.79), and Bland-Altman analysis slightly overestimated cMRI LVEF (mean difference, +3%). Echocardiographic LVEF had a moderate ability to identify normal cMRI LVEF (area under the curve, 0.80) and at an optimal cut point of echocardiographic LVEF threshold of 61%, there was 71% sensitivity and 76% specificity to detect cMRI LVEF ≥ 55%. Echocardiographic LV:RVp correlated well with LV/RVp by catheterization (r = 0.77) and slightly underestimated the catheterization value (mean difference, -0.11). Echocardiographic LV:RVp had a good ability to identify adequate LV:RVp by catheterization (area under the curve, 0.95) and at an optimal echocardiography cut point of 0.75 had 100% sensitivity and 85% specificity to detect a catheterization LV:RVp >0.9. Echocardiography-based criteria for DSO readiness (echocardiographic LVEF of 61% and LV:RVp of 0.75) demonstrated specificity of 97% and positive predictive value of 96% for published criteria of DSO readiness (cMRI LVEF of 55% and catheterization LV:RVp of 0.9). EES and EFPR correlated with post-DSO LVEF (ρ = 0.72 and ρ = 0.60, respectively). EFPR of 0.51 demonstrated 78% sensitivity and 100% specificity for post-DSO LV dysfunction (LVEF < 55%). Age at first PAB also strongly correlated with post-DSO LVEF (ρ = 0.75). No patient with first PAB at <1 year of age exhibited post-DSO LV dysfunction.

CONCLUSIONS

Echocardiographic measures of LVEF and LV:RVp are reliable indicators of reference standard modalities and can guide management during retraining. The preoperative VAC markers EES and EFPR may be useful markers of post-DSO LV dysfunction. Values of echocardiographic LV:RVp >0.75 are likely to meet pressure-generation criteria for DSO and should be considered for referral to catheterization and cMRI evaluation for DSO. PAB placement before 1 year of life may optimize LV outcomes in patients considered for DSO.

Congenitally corrected transposition: not correct at all

PURPOSE OF REVIEW

Congenitally corrected transposition of the great arteries is a rare congenital defect with several management options. Disagreement continues on strategies, such as anatomic repair, physiologic repair or observation-only. This review discusses recent data that provide further guidance for clinical decision-making.

RECENT FINDINGS

New data provide greater insights into practice patterns and outcomes. Recent data from high-volume centers show progressively high rates of systemic right ventricle dysfunction over time with lower rates of systemic left ventricle dysfunction following anatomic repair; there is a statistical trend towards better survival of anatomic repair patients. Data comparing anatomic repair to observation showed that anatomic repair patients had a lower hazard of reaching a composite adverse outcome. These complex operations are predominantly performed at a small subset of congenital heart surgery centers.

SUMMARY

Anatomic repair compared with physiologic repair may have better outcomes, although there are relatively high rates of morbidity for both approaches. In the patient without associated lesions, nonsurgical management can have excellent outcomes but is complicated by right ventricular failure over time. Multicenter research will help determine risk factors for bad outcomes; management at high volume, experienced centers will probably be beneficial for this complex patient population.

Management Options for Congenitally Corrected Transposition: Which, When, and for Whom?

Management strategies for congenitally corrected transposition of the great arteries (ccTGA) historically consisted of a physiologic repair, resulting in the morphologic right ventricle (mRV) supporting systemic circulation. This strategy persisted despite the development of heart failure by middle age because of the reasonable short-term outcomes, and the natural history of some patients with favorable anatomy (felt to demonstrate the mRV's ability to function in the long-term), and due to the less-than-optimal outcomes associated with anatomical repair. As outcomes with anatomical repair improved, and the long-term risk of systemic mRV dysfunction became apparent, more have begun to realize its advantages. In addition to the decision on whether or not to pursue anatomical repair, and the optimal timing, studies demonstrating the nuance to morphologic left ventricle retraining have demonstrated its feasibility. Further considerations in ccTGA have begun to be better understood, including: the management of a poorly functioning mRV, systemic tricuspid valve regurgitation, the utility of morphologic left ventricle outflow tract obstruction (native or surgically created) and pacing strategies. While some considerations are apparent: biventricular pacing is superior to univentricular, tricuspid regurgitation must be managed early with either progression towards anatomical repair (pulmonary artery banding if needed for retraining) or tricuspid replacement (not repair) based on the patient's age; others remain to be completely elucidated. Overall, the heterogeneity of ccTGA, as well as the unique presentation with each patient regarding ventricular and valvular function and center-to-center variability in management strategies has made the interpretation of published data difficult. That said, more recent long-term outcomes favor anatomical repair in most situations.

Impact of electrophysiological features acquired after anatomical repair of congenital corrected transposition of the great arteries on late mortality and ventricular dysfunction

OBJECTIVES

In patients with anatomically repaired congenitally corrected transposition of the great arteries, the impact of electrophysiological features on postoperative ventricular dysfunction remains less well known. Our goal was to investigate the role of fragmented QRS and QRS duration in mortality and systemic ventricular dysfunction after anatomical repair of corrected transposed great arteries.

METHODS

Consecutive patients who underwent anatomical repair in our institution from January 2005 to December 2017 were enrolled in this retrospective analysis. Fragmented QRS was defined as ≥1 discontinuous deflections in narrow QRS complexes, and ≥2 in wide QRS complexes, in 2 contiguous electrocardiogram leads. The primary end point was a composite of all-cause mortality and systemic ventricular dysfunction.

RESULTS

A total of 74 patients were included. Among them, 30, 15 and 29 underwent the Senning arterial switch, the Senning Rastelli and the hemi-Mustard/bidirectional Glenn/Rastelli procedures, respectively. The primary end point occurred in 9 (12.2%) patients and included 7 late deaths and 2 cases of late-onset systemic ventricular dysfunction. Fragmented QRS and QRS prolongation were noted in 19 (25.7%) and 21 (28.4%) patients, respectively. In patients with the primary end point, QRS fragmentation (6/9 vs 10/65; P < 0.001) and QRS prolongation (6/9 vs 15/65; P = 0.013) were noted more frequently than in patients without the primary end point. No statistical differences in these electrocardiogram findings were found among patients treated with 3 surgical strategies.

CONCLUSIONS

Appearance of QRS fragmentation or QRS prolongation is associated with death or ventricular dysfunction in anatomically repaired corrected transposition of the great arteries. Although there is a trend that QRS fragmentation and QRS prolongation appear more frequently in patients who had the Senning-arterial switch operation, there is no statistically significant difference associated with these electrocardiogram features among varied procedures.

Pulmonary Hypoplasia Resulting from Pulmonary Artery Banding in Infancy: A Neonatal Rat Model Study

The aim of this study was to establish a neonatal rat model of decreased pulmonary blood flow (PBF) for studying pulmonary pathophysiological changes in newborn lung development with reduced PBF. Horizontal thoracotomy surgery with banding of the main pulmonary artery (PA) was performed on 30 rats in the PA banding (PAB) group and without banding on another 30 rats in the sham group within 6 h after birth. The body growth and mortality were recorded. Constriction of PA was checked by echocardiography on postnatal day 7 (P7). Lung morphology was assessed with computed tomography scanning and three-dimensional reconstruction. Histological differences of two groups were evaluated using hematoxylin and eosin (H&E) staining, Masson's trichrome staining, TdT-mediated dUTP nick-end labeling assay, and CD31 labeling with microscopic examination. PA ultrasound confirmed the establishment of constriction on P7. Relative to the sham group, the neonates' physical growth, survival fraction, and lung geometry volume were decreased in the PAB group over time (p < 0.05). Histologic appearance with reduced PBF characterized a markedly simplified alveolarization with noted lower radial alveolar count and alveolar septal thickness in the PAB group (p < 0.0001), pulmonary arteries with thinner/uneven membranous layers and smaller lumina. The deficient alveolar capillary bed, enhanced pulmonary collagen deposition, and increased apoptotic alveolar epithelium were significant in the PAB group compared to the sham group (p < 0.0001). A neonatal rat PAB model demonstrated that PBF reduction during early infancy impairs alveolarization and pulmonary microvasculature.

Surgical Outcomes of Anatomical Repair for Congenitally Corrected Transposed Great Arteries

BACKGROUND

The outcomes of anatomical repair for patients with congenitally corrected transposed great arteries remain unclear and the indications for different procedures are poorly understood.

METHODS

From January 2005 to February 2016, consecutive corrected transposition patients who underwent anatomical repair at the current institution were enrolled in this retrospective study. Varied types of anatomical repair were individually customised.

RESULTS

A total of 85 patients were included. Fifty-one (51) and 35 patients presented with left ventricular outflow tract obstruction and cardiac malposition, respectively. Thirty-nine (39) patients presented with moderate-to-severe tricuspid regurgitation. Thirty-four (34), 19, and 32 patients underwent Senning arterial switch operations, Senning-Rastelli, and hemi-Mustard-Rastelli-bidirectional Glenn, respectively. Early after repair, there were five in-hospital deaths and nine re-operations. During 4.6 years (range, 0.5-10.3) of follow-up, seven late deaths were documented. Estimated overall survival rate after anatomical repair was 89.3%, 85.0%, and 85.0% at 1 year, 3 years, and 5 years, respectively. Instead of Senning-Rastelli, most (75.0%) early left ventricular dysfunctions were noted in patients who underwent Senning arterial switch procedures. However, all the late left ventricular dysfunctions were found in patients who underwent previous left ventricular retraining. In patients with left ventricular outflow tract obstruction, the hemi-Mustard-Rastelli-bidirectional Glenn shunt provided a lower early mortality (0% vs 15.8%, p = 0.047).

CONCLUSIONS

Favourable outcomes can be achieved for anatomical repair of corrected transposition. Left ventricular dysfunction was a significant postoperative issue. Hemi-Mustard-bidirectional Glenn-Rastelli procedure may provide benefits for patients with associated left ventricular outflow tract obstruction and cardiac malposition. Each procedure has its own advantages in varied anatomy.

Congenitally Corrected Transposition Presenting in the First Year of Life: Survival and Fate of the Systemic Right Ventricle

Introduction:

Knowledge gaps exist in the life expectancy and functional outcome of patients with congenitally corrected transposition (ccTGA) presenting early in life, which is relevant in the evaluation of early anatomic repair.

Methods:

In a single-center analysis, 91 patients with ccTGA were identified over 25 years, of which 31 presented with biventricular anatomy in the first year of life and formed the study cohort. End points for analysis included survival, moderate or worse tricuspid valve regurgitation, and systemic right ventricle (RV) dysfunction. Median follow-up was 4.9 years (range: 7 days to 20 years).

Results:

Among 31 patients presenting in the first year of life, 9 (29%) never received cardiac surgery, while 22 (71%) underwent 36 cardiac operations. Overall freedom from moderate or severe systemic RV dysfunction was 75% at 10 years. Overall survival was 82% at 10 years. Surgical mortality was 5.6% (2/36). Among survivors with a systemic RV, 23 (100%) of 23 were Ross or NYHA class I or II at last follow-up.

Conclusions:

Congenitally corrected transposition presenting in the first year of life and maintaining a systemic RV can expect (1) long-term survival of more than 80% at 10 years, (2) low expected surgical mortality (overall 6%), and (3) 75% late freedom from major RV dysfunction at 10 years. Pending multi-institutional analyses, this experience with a systemic RV in ccTGA provides an initial benchmark for comparison when considering early elective anatomic correction.

Congenitally Corrected Transposition of the Great Arteries: Anatomic, Physiologic Repair, and Palliation

Congenitally corrected transposition of the great arteries (ccTGA) is a lesion that rarely occurs in isolation. The presenting physiology of ccTGA is predominantly secondary to the concurrent cardiac lesions; however, as the child ages, unrepaired ccTGA results in progressive failure of the morphologic right ventricle under the strain of maintaining a systemic pressure. Repair of ccTGA was initially focused on rectification of the underlying physiologic aberrations, but in recent years, the focus of repair has shifted toward anatomic correction to avoid failure of the morphologic right ventricle. This anatomic repair is commonly associated with improved long-term mortality at the cost of increased short-term mortality. Key preoperative considerations such as morphologic left ventricular pressure, tricuspid valve competency, and out flow tract obstructions can assist in determining the optimal repair for individual patients. An alternative, single ventricle, pathway has been proposed for any patient without optimal preoperative anatomy to improve long-term survival. Adjunctive repair options including pulmonary artery banding and one-and-a-half ventricle repairs have also been proposed to augment the survival curves.

The Impact of the Left Ventricle on Right Ventricular Function and Clinical Outcomes in Infants with Single-Right Ventricle Anomalies up to 14 Months of Age

BACKGROUND

Children with single-right ventricle anomalies such as hypoplastic left heart syndrome (HLHS) have left ventricles of variable size and function. The impact of the left ventricle on the performance of the right ventricle and on survival remains unclear. The aim of this study was to identify whether left ventricular (LV) size and function influence right ventricular (RV) function and clinical outcome after staged palliation for single-right ventricle anomalies.

METHODS

In the Single Ventricle Reconstruction trial, echocardiography-derived measures of LV size and function were compared with measures of RV systolic and diastolic function, tricuspid regurgitation, and outcomes (death and/or heart transplantation) at baseline (preoperatively), early after Norwood palliation, before stage 2 palliation, and at 14 months of age.

RESULTS

Of the 522 subjects who met the study inclusion criteria, 381 (73%) had measurable left ventricles. The HLHS subtype of aortic atresia/mitral atresia was significantly less likely to have a measurable left ventricle (41%) compared with the other HLHS subtypes: aortic stenosis/mitral stenosis (100%), aortic atresia/mitral stenosis (96%), and those without HLHS (83%). RV end-diastolic and end-systolic volumes were significantly larger, while diastolic indices suggested better diastolic properties in those subjects with no left ventricles compared with those with measurable left ventricles. However, RV ejection fraction was not different on the basis of LV size and function after staged palliation. Moreover, there was no difference in transplantation-free survival to Norwood discharge, through the interstage period, or at 14 months of age between those subjects who had measurable left ventricles compared with those who did not.

CONCLUSIONS

LV size varies by anatomic subtype in infants with single-right ventricle anomalies. Although indices of RV size and diastolic function were influenced by the presence of a left ventricle, there was no difference in RV systolic function or transplantation-free survival on the basis of LV measures.

Double switch operations: Should we perform physiologic or anatomic repair in congenitally corrected transposition of the great arteries

The seeking for the optimal surgical treatment of congenitally corrected transposition of the great arteries (cTGA) is ongoing. Physiologic (conventional) repair approaches, leaving the morphologic right ventricle (MRV) on the systemic circulation side, cause systemic ventricle and tricuspid valve failure, particularly in the long-term. Double Switch operations (anatomic repair) were aimed to convert the morphologic left ventricle to systemic ventricle and MRV to pulmonic ventricle. Gradual improvement in the early and midterm results of double switch operations in the last 20 years rendered anatomic repair to become a preferred procedure. Thanks to the preservation of ventricular functions through anatomic repair, patients with congenitally cTGA may survive longer with normal/near normal functional capacity. However, studies with larger sample size and longer follow-up duration are required to establish a more definite judgement.

The hemi-Mustard, bidirectional Glenn and Rastelli procedures for anatomical repair of congenitally corrected transposition of the great arteries/left ventricular outflow tract obstruction with positional heart anomalies†

OBJECTIVES

The hemi-Mustard and bidirectional Glenn (BDG) procedures combined with the Rastelli procedure have been applied to selected cases of congenitally corrected transposition of the great arteries (ccTGA) for potential benefit over the classic atrial switch procedure. The aim of this study was to analyse our experience with the hemi-Mustard, BDG and Rastelli procedures as an anatomical correction for patients with ccTGA/left ventricular outflow tract obstruction (LVOTO) with positional heart anomalies.

METHODS

In this retrospective study, 31 consecutive patients with corrected transposition underwent the hemi-Mustard/BDG procedures with the Rastelli operation between 2011 and 2015. The median age was 5.4 (range: 0.75-12) years. Positional anomalies were present in all patients. Eleven patients underwent BDG initially; they then had the second-stage hemi-Mustard and Rastelli procedures; 'one-stage repair' (hemi-Mustard/BDG and the Rastelli procedures) was performed in 20 cases.

RESULTS

There were no in-hospital deaths, and 3 patients received a pacemaker. One patient had an atrial baffle obstruction that was observed in the early postoperative period; 7 patients had prolonged pleural effusions that developed more frequently in the one-stage repair group (7/20 vs 0/11, P =  0.033). During the mean follow-up of 3.3 years, 1 late death was noted, and no conduit replacements were required. Twenty-five (83.3%) patients are in New York Heart Association classes I and II at the latest follow-up.

CONCLUSIONS

Hemi-Mustard, BDG and the Rastelli procedures are technically feasible for correction of ccTGA/left ventricular outflow tract obstruction (LVOTO) and cardiac malposition. Nevertheless, postoperative pleural effusion is the most prevalent complication in the one-stage repair. Two-stage repair may reduce the risk of pleural effusion-related complications.

Anatomic Repair of Congenitally Corrected Transposition of the Great Arteries: Single-Center Intermediate-Term Experience

We present our experience for patients who have undergone an anatomic repair (AR) for congenitally corrected transposition of the great arteries (CCTGA) at the Children's Hospital of Wisconsin. A retrospective chart review of patients who underwent AR for CCTGA from 2001 to 2015 was performed. The cohort consisted of 15 patients (74% male). Median age of anatomic repair was 15 months (range 4.5-45.6 months). Four patients had a bidirectional Glenn (BDG) prior to AR. At the time of AR,-9 (60%) underwent Senning/Rastelli procedure, 4 (26.6%) had double switch operation, and 2 (13.3%) underwent only Senning with VSD closure. Median duration of follow-up was 5.5 years (0.05-14 years). Reoperations prior to discharge included BDG, revision of pulmonary venous baffle, closure of residual VSD, and pacemaker placement. Late reoperations included left ventricular outflow tract obstruction repair, conduit replacement, melody valve placement, and pacemaker implantation. At their most recent follow-up, no patient had heart failure symptoms and only 1 had severely diminished function that improved with cardiac resynchronization therapy. Moderate mitral regurgitation was noted in 15% (2/13), and severe in 7% (1/13). Moderate tricuspid regurgitation was noted in 15% (2/13). One patient, 7% (1/13), developed moderate aortic insufficiency. There was a 100% survival at the time of the most recent follow-up. Patients with CCTGA who have undergone AR have excellent functional status and mid-term survival but reinterventions are common. Longer term studies are needed to determine both the extent and spectrum of reinterventions as well as long term survival.