Balloon angioplasty in infants with aortic obstruction after the modified stage I Norwood procedure

Association of Interstage Monitoring Era and Likelihood of Hemodynamic Compromise at Intervention for Recoarctation Following the Norwood Operation

Background Intensive monitoring has been associated with a lower death rate between the Norwood operation and superior cavopulmonary connection, possibly due to early identification and effective treatment of residual anatomic lesions like recoarctation before lasting harm occurs. Methods and Results Neonates undergoing a Norwood operation and receiving interstage care at a single center between January 1, 2005, and September 18, 2020, were studied. In those with recoarctation, we evaluated association of era ([1] preinterstage monitoring, [2] a transitional phase, [3] current era) and likelihood of hemodynamic compromise (progression to moderate or greater ventricular dysfunction/atrioventricular valve regurgitation, initiation/escalation of vasoactive/respiratory support, cardiac arrest preceding catheterization, or interstage death with recoarctation on autopsy). We also analyzed whether era was associated with technical success of transcatheter recoarctation interventions, major adverse events, and transplant-free survival. A total of 483 subjects were studied, with 22% (n=106) treated for recoarctation during the interstage period. Number of catheterizations per Norwood increased (P=0.005) over the interstage eras, with no significant change in the proportion of subjects with recoarctation (P=0.36). In parallel, there was a lower likelihood of hemodynamic compromise in subjects with recoarctation that was not statistically significant (P=0.06), with a significant difference in the proportion with ventricular dysfunction at intervention (P=0.002). Rates of technical success, procedural major adverse events, and transplant-free survival did not differ (P>0.05). Conclusions Periods with interstage monitoring were associated with increased referral for catheterization but also reduced likelihood of ventricular dysfunction (and a suggestion of lower likelihood of hemodynamic compromise) in subjects with recoarctation. Further study is needed to guide optimal interstage care of this vulnerable population.

Indications for and outcomes of interstage catheter interventions following the Norwood procedure: A single-institution study

Aims

The aim of this study was to document the incidence, types, and outcome of interstage catheter interventions following the Norwood surgical palliation.

Patients and Methods

A retrospective single-center study of all patients surviving the Norwood operation was performed. All data concerning interstage catheter interventions up to the completion of the superior cavopulmonary shunt were collected.

Results

Catheter interventions were performed in 62 of 94 patients (66%; 38 males). These included interventions on the aortic arch (n = 44), the branch pulmonary arteries (PAs) (n = 17), and the Sano shunt (n = 14). Multiple interventions and repeat interventions were common. The minimum aortic arch diameter (pre- versus posttreatment) increased from median 3.1 (2.3-3.3) mm to 5.1 (4.2-6.2) mm (P < 0.001). The catheter pullback gradient decreased from 40 (36-46) mmHg to 9 (5-10) mmHg (P < 0.001), and the echocardiographic gradient from 54 (45-64) mmHg to 12 (10-16) mmHg (P < 0.001). The branch PA diameters increased from 2.4 (2.1-3.0) mmHg to 4.7 (4.2-5.1) mmHg (P < 0.001). The minimum Sano shunt diameters increased from 2.0 (1.5-2.1) mm to 5.9 (5.8-6.0) mm (P < 0.001); this was associated with an improvement in systemic saturation from 63% (60%-65%) to 80% (79-82%) (P < 0.001). Unexpected interstage death at home occurred in two patients who had received no interventions. The remainder received a superior cavopulmonary shunt palliation.

Conclusions

Catheter interventions were common. Systematic follow-up and a low threshold for reintervention are essential to the success of staged surgical palliation for this patient cohort.

Experience of stent implantation for recurrent aortic arch obstruction following Norwood or Damus-Kaye-Stansel operation over the last decade

BACKGROUND

Recurrent aortic arch obstruction following the Norwood procedure is recognised as an important complication. Balloon arch angioplasty is associated with a high recoarctation rate.

METHODS

We sought to evaluate the prevalence and outcome of stent implantation for recoarctation in children following Norwood or Damus-Kaye-Stansel procedure over the past decade at a single national cardiology centre.

RESULTS

Of 114 children who underwent Norwood procedure or Damus-Kaye-Stansel procedure between January 2003 and June 2013, 80 patients survived. Of these 15 children underwent stent implantation for recoarctation. Six of these patients had previous balloon angioplasty. The median age at stent implantation was 4.4 months (range 2-82 months). The median peak aortic arch gradient at catheterisation decreased from 26mmHg (range 10-70mmHg) to 2mmHg (range 0-20mmHg). The median luminal diameter increased from 4.7 mm (range 3.2-7.9 mm) to 8.6 mm (range 6.2-10.9 mm). The median coarctation index increased by 0.49 (range = 0.24-0.64). A Valeo stent was employed in 11 children, a Palmaz Genesis stent in 2 patients, a MultiLink stent in 1 child, and a Jomed covered stent in 1 child. Two factors were associated with the need for stent placement: previous arch angioplasty (p valve < 0.001, χ-square 11.5) and borderline left ventricle (p = 0.04, χ-square = 4.1). Stent migration occurred in one child. There were two deaths related to poor right ventricular systolic function and severe tricuspid regurgitation. Six patients underwent redilation of the stent with no complications.

CONCLUSIONS

The prevalence of recurrent aortic arch obstruction following Norwood/Damus-Kaye-Stansel procedure was 18%. Stent implantation is safe and reliably eliminates the aortic obstruction. Redilation can be successfully achieved to accommodate somatic growth or development of stent recoarctation.

Intervention for arch obstruction after the Norwood procedure: Prevalence, associated factors, and practice variability

OBJECTIVE

Arch obstruction after the Norwood procedure is common and contributes to mortality. We determined the prevalence, associated factors, and practice variability of arch reintervention and assessed whether arch reintervention is associated with mortality.

METHODS

From 2005 to 2017, 593 neonates in the Congenital Heart Surgeons' Society Critical Left Heart Obstruction cohort underwent a Norwood procedure. Median follow-up was 3.7 years. Multivariable parametric models, including a modulated renewal analysis, were performed.

RESULTS

Of the 593 neonates, 146 (25%) underwent 218 reinterventions for arch obstruction after the Norwood procedure: catheter-based (n = 168) or surgical (n = 50) at a median age of 4.3 months (quartile 1-quartile 3, 2.6-5.7). Interdigitation of the distal aortic anastomosis was protective against arch reintervention. Development of ≥ moderate tricuspid valve regurgitation and right ventricular dysfunction at any point was associated with arch reintervention. Nonsignificant variables for arch reintervention included shunt type and preoperative aortic measurements. Surgical arch reintervention was protective against arch reintervention, but transcatheter reintervention was associated with increased reintervention. Arch reintervention was not associated with increased mortality. There was wide institutional variation in incidence of arch reintervention (range, 0-40 reinterventions per 100 years patient follow-up) and in preintervention gradient (range, 0-64 mm Hg).

CONCLUSIONS

Interdigitation of the distal aortic anastomosis during the Norwood procedure decreased the risk of arch reintervention. Surgical arch reintervention is more definitive than transcatheter. Arch reintervention after the Norwood procedure is not associated with increased mortality. Serial surveillance for arch obstruction, integrated with changes in right ventricular function and tricuspid valve regurgitation, is recommended after the Norwood procedure to improve outcomes.

Evaluation of Residual Coarctation in Infants with a Single Right Ventricle after Stage I Palliation

In infants with a single right ventricle (RV), stage I palliation involves aortic reconstruction, systemic-to-pulmonary shunt placement, and atrial septectomy. Many require re-intervention for residual coarctation of the aorta (CoA). Doppler echocardiography can detect residual CoA in most infants, but its ability to predict severity has not been studied. This study compares gradients from Doppler interrogation to those from cardiac catheterization in infants with residual CoA. We performed a retrospective study of infants after stage I palliation from 2000 to 2014. Infants with an echocardiogram and catheterization before the second-stage palliative surgery were included. Infants with an echocardiogram >30 days before catheterization were excluded. Doppler-derived gradients were compared to catheterization-derived gradients. Echocardiographic assessment of tricuspid valve (TV) and RV function were recorded. The cohort included 95 infants, and thirty-three (35%) had CoA. Doppler-derived and catheterization-derived gradients correlated weakly in infants with CoA (r = 0.37, p = 0.036) and without CoA (r = 0.35, p = 0.005). Among infants with CoA, 17/33 had none or trivial tricuspid regurgitation (TR) and normal RV function, and Doppler-derived gradients correlated with catheterization gradients in this group (r = 0.71, p = 0.001). In 16/33 infants with ≥moderate TR or RV dysfunction, gradients did not correlate (r = -0.003, p = 0.992). After a stage I palliation in infants with single RV and CoA, Doppler-derived gradients poorly predicted the severity of CoA. Infants with normal TV or RV function had Doppler-derived gradients more predictive of catheterization-derived gradients. Doppler-derived gradients have limited utility in determining the severity of CoA after a stage I palliation.

Hypoplastic left heart syndrome - a review of supportive percutaneous treatment

Due to the complex anatomical and haemodynamic consequences of hypoplastic left heart syndrome (HLHS), patients with the condition require multistage surgical and supportive interventional treatment. Percutaneous interventions may be required between each stage of surgical palliation, sometimes simultaneously with surgery as hybrid interventions, or after completion of multistage treatment. Recent advances in the field of interventional cardiology, including new devices and techniques, have significantly contributed to improving results of multistage HLHS palliation. Knowledge of the potential interventional options as well as the limitation of percutaneous interventions will enable the creation of safe and effective treatment protocols in this highly challenging group of patients. In this comprehensive review we discuss the types, goals, and potential complications of transcatheter interventions in patients with HLHS.

Right-ventricular global longitudinal strain may predict neo-aortic arch obstruction after Norwood/Sano procedure in children with hypoplastic left heart syndrome

Neo-aortic arch obstruction (NAAO) is a common complication following the Norwood/Sano procedure (NP) for hypoplastic left heart syndrome (HLHS) and is associated with increased morbidity and mortality. However, there is currently no objective method for predicting which patients will develop NAAO. This study was designed to test the hypothesis that hemodynamic changes from development of NAAO after NP in patients with HLHS will lead to changes in myocardial dynamics that could be detected before clinical symptoms develop with strain analysis using velocity vector imaging. Patients with HLHS who had at least one cardiac catheterization after NP were identified retrospectively. Strain analysis was performed on all echocardiograms preceding the first catheterization and any subsequent catheterization performed for intervention on NAAO. Twelve patients developed NAAO and 30 patients never developed NAAO. Right ventricular strain was worse in the group that developed NAAO (-6.2 vs. -8.6 %, p = 0.040) at a median of 59 days prior to diagnosis of NAAO. Those patients that developed NAAO following NP were significantly younger at the time of first catheterization than those that did not develop NAAO (92 ± 50 vs. 140 ± 36 days, p = 0.001). This study demonstrates that right ventricular GLS is abnormal in HLHS patients following NP and worsening right ventricular strain may be predictive of the future development of NAAO.

Usefulness of transthoracic echocardiography to accurately diagnose recoarctation of the aorta after the Norwood procedure

Recoarctation of the aorta (RCoA) is a major cause of morbidity and mortality after the Norwood procedure. We sought to identify transthoracic echocardiographic (TTE) indexes associated with RCoA and to develop a highly sensitive and specific diagnostic score for accurate diagnosis. All subjects who underwent a Norwood procedure from December 2005 to December 2009 were identified. Subjects were excluded if they did not undergo a TTE within 1 month of an outcome-defining event (cardiac catheterization, autopsy, or surgery). RCoA was defined as arch intervention at catheterization or surgery or findings of RCoA at autopsy. Of 113 subjects included for analysis, RCoA occurred in 19 (17%). All TTE indexes were significantly associated with RCoA in univariate testing. In the final multivariate model, peak isthmus velocity >2.5 m/s (p <0.001), coarctation index, defined as the ratio of the narrowest region of the descending thoracic aorta to the distal descending thoracic aorta diameter <0.7 (p <0.01), and decrease in ventricular systolic performance (p = 0.03) were all significantly associated with RCoA. A composite score was developed using a peak velocity of >2.5 m/s (2 points), coarctation index <0.7 (1 point), and a decrease in ventricular systolic performance (1 point). A score of ≥2 diagnosed RCoA with 100% sensitivity and 85% specificity. The score performed equally well regardless of shunt type. In conclusion, a composite score of TTE indexes accurately discriminates RCoA in patients who have undergone the Norwood procedure.

Catheter interventions in the staged management of hypoplastic left heart syndrome

AIM

To analyse the current practice and contribution of catheter interventions in the staged management of patients with hypoplastic left heart syndrome.

METHODS

This study is a retrospective case note review of 527 patients undergoing staged Norwood/Fontan palliation at a single centre between 1993 and 2010. Indications and type of catheter interventions were reviewed over a median follow-up period of 7.5 years.

RESULTS

A staged Norwood/Fontan palliation for hypoplastic left heart syndrome was performed in 527 patients. The 30-day survival rate after individual stages was 76.5% at Stage I, 96.3% at Stage II, and 99.4% at Stage III. A total of 348 interventions were performed in 189 out of 527 patients. Freedom from catheter intervention in survivors was 58.2% before Stage II and 46.7% before Stage III. Kaplan-Meier freedom from intervention post Fontan completion was 55% at 10.8 years of follow-up. Post-stage I interventions were mostly directed to relieve aortic arch obstruction--84 balloon angioplasties--and augment pulmonary blood flow--15 right ventricle-to-pulmonary conduit interventions; post-Stage II interventions centred on augmenting size of the left pulmonary artery--73 procedures and abolishing systemic venous collaterals--32 procedures. After Stage III, the focus was on manipulating the size of the fenestration--42 interventions--and the left pulmonary artery -31 procedures.

CONCLUSION

Interventional cardiac catheterisation constitutes an integral part in the staged palliative management of patients with hypoplastic left heart syndrome. Over one-third (37%) of patients undergoing staged palliation required catheter intervention over the follow-up period.

A 10-year single-centre experience in percutaneous interventions for multi-stage treatment of hypoplastic left heart syndrome

OBJECTIVES

The purpose of this paper is to report our 10 years of experience of interventional treatment of patients with hypoplastic left heart syndrome and to focus on the frequency, type, and results of percutaneous interventions during all the stages of palliation, considering the different techniques, devices, and complications.

BACKGROUND

Constant progress in surgical treatment of congenital heart defects in the last decade has significantly improved the prognosis for children with hypoplastic left heart syndrome. However, morbidity and mortality remain relatively high. Modern interventional procedures complement or occasionally replace surgical treatment.

METHODS

Between January, 2001 and December, 2010, 161 percutaneous interventions were performed in 88 patients with hypoplastic left heart syndrome. Patients were divided into four groups: (a) before the first surgical treatment including hybrid approach, (b) after first-stage Norwood operation, (c) after second-stage bidirectional Glenn operation, and (d) after third-stage Fontan operation.

RESULTS

Percutaneous interventions resulted in statistically significant changes in pulmonary artery pressures, vessel diameters, and O2 saturation. Complications occurred in 4.3% of interventions and were related mainly to stent implantation in stenosed pulmonary arteries.

CONCLUSIONS

Percutaneous interventions may result in haemodynamic stability and reduction in the number of operations. They may result in significant changes in pulmonary artery pressures, vessel diameters, O2 saturation, with a low rate of complications, which are mainly related to stent implantation in the pulmonary arteries.

Intervention for recoarctation in the single ventricle reconstruction trial: incidence, risk, and outcomes

BACKGROUND

Recoarctation after the Norwood procedure increases risk for mortality. The Single Ventricle Reconstruction (SVR) trial randomized subjects with a single right ventricle undergoing a Norwood procedure to a modified Blalock-Taussig shunt or a right ventricle-pulmonary artery shunt. We sought to determine the incidence of recoarctation, risk factors, and outcomes in the SVR trial.

METHODS AND RESULTS

Recoarctation was defined by intervention, either catheter based or surgical. Univariate analysis and multivariable Cox proportional hazard models were performed with adjustment for center. Of the 549 SVR subjects, 97 (18%) underwent 131 interventions (92 balloon aortoplasty, 39 surgical) for recoarctation at a median age of 4.9 months (range, 1.1-10.5 months). Intervention typically occurred at pre-stage II catheterization (n=71, 54%) or at stage II surgery (n=38, 29%). In multivariable analysis, recoarctation was associated with the shunt type in place at the end of the Norwood procedure (hazard ratio, 2.0 for right ventricle-pulmonary artery shunt versus modified Blalock-Taussig shunt; P=0.02), and Norwood discharge peak echo-Doppler arch gradient (hazard ratio, 1.07 per 1 mm Hg; P<0.01). Subjects with recoarctation demonstrated comorbidities at pre-stage II evaluation, including higher pulmonary arterial pressures (15.4±3.0 versus 14.5±3.5 mm Hg; P=0.05), higher pulmonary vascular resistance (2.6±1.6 versus 2.0±1.0 Wood units·m(2); P=0.04), and increased echocardiographic volumes (end-diastolic volume, 126±39 versus 112±33 mL/BSA(1.3), where BSA is body surface area; P=0.02). There was no difference in 12-month postrandomization transplantation-free survival between those with and without recoarctation (P=0.14).

CONCLUSIONS

Recoarctation is common after Norwood and contributes to pre-stage II comorbidities. Although with intervention there is no associated increase in 1-year transplantation/mortality, further evaluation is warranted to evaluate the effects of associated morbidities.

Risk factors for a positive neoaortic arch gradient after stage I palliation for hypoplastic left heart syndrome

BACKGROUND

Providing unobstructed systemic blood flow is one goal of stage I palliation for hypoplastic left heart syndrome. Although clinically significant obstruction is defined when the arch gradient exceeds 15 mm Hg, any positive gradient constitutes obstruction, which may impair ventricular function. We sought to identify risk factors before stage I palliation that result in a positive neoaortic arch gradient before bidirectional Glenn.

METHODS

Reviewed were 51 neonates who underwent stage I palliation and subsequent bidirectional cavopulmonary anastomosis procedures for hypoplastic left heart syndrome. Echocardiograms before stage I palliation were reviewed for aortic dimensions. Cardiac catheterization before bidirectional cavopulmonary anastomosis determined the aortic arch gradient and degree of right ventricular dysfunction.

RESULTS

Of the 51 patients, 24 (47%) had a negative or absent arch gradient. Patients with a positive gradient had a median gradient of 5 mm Hg (range, 1 to 60 mm Hg). The diameter of the ascending aorta and proximal transverse arch indexed to the descending thoracic aorta (0.5 ± 0.2 vs 0.7 ± 0.4 and 0.4 ± 0.2 vs 0.6 ± 0.2 mm, p = 0.02 and p = 0.01) and lower birth weight (3.1 ± 0.5 vs 3.4 ± 0.4 kg, p = 0.03) were risk factors of a positive neoaortic arch gradient. Further, the degree of arch obstruction was inversely related to the degree of right ventricular function (odds ratio, 1.08; p < 0.01).

CONCLUSIONS

Lower birth weight and a smaller aortic diameter confer a higher risk of developing a positive neoaortic arch gradient, resulting in reduced right ventricular function.

Recoarctation after the norwood I procedure for hypoplastic left heart syndrome: incidence, risk factors, and treatment options

BACKGROUND

Early survival after the Norwood I procedure has improved over the years, but subsequent morbidity is not yet well assessed. The aim of this study was to review the incidence of recoarctation, evaluate risk factors, and analyze treatment options.

METHODS

We reviewed the medical records of 124 consecutive patients with hypoplastic left heart syndrome (HLHS) who underwent the Norwood I procedure. Reconstruction of the aortic arch was performed in a standardized manner, removing all visible ductal tissue and enlarging the distal anastomosis with a Y incision into the descending aorta. Angiographic assessment with measurement of the peak gradient across the aortic arch was performed before the second stage was performed.

RESULTS

Recoarctation of the aorta was documented in 13 patients (13.4%) at a mean time of 6.4 ± 5 months after the Norwood procedure. One patient died before the recoarctation could be treated. Right ventricular function was good in all except 1 patient at the time of diagnosis. Ten patients underwent 16 percutaneous balloon angioplasties, and 2 patients underwent operative enlargement of the neoaorta. The pretreatment peak gradient of 24.1 ± 16 mm Hg (10-64 mm Hg) across the aortic arch was significantly reduced to 6.3 ± 4 mm Hg (0-14 mm Hg) after angioplasty or operation (p = 0.003). There were no procedure-related deaths. No risk factor for recoarctation could be identified.

CONCLUSIONS

A standardized surgical technique for reconstruction of the aorta leads to a low recoarctation rate. Balloon angioplasty can be performed in the majority of patients before the second-stage procedure.

Superior cavopulmonary anastomosis timing and outcomes in infants with single ventricle

OBJECTIVES

We sought to identify factors associated with the timing and surgical outcomes of the superior cavopulmonary anastomosis.

METHODS

The Pediatric Heart Network's Infant Single Ventricle trial database identified participants who underwent superior cavopulmonary anastomosis. Factors potentially associated with age at superior cavopulmonary anastomosis, length of stay and death by 14 months of age were evaluated. Factors included subject demographics, cardiac anatomy, measures from neonatal hospitalization and pre-superior cavopulmonary anastomosis visit, adverse events, echocardiographic variables, intraoperative variables, superior cavopulmonary anastomosis type, and number of concurrent cardiac surgical procedures. Age at superior cavopulmonary anastomosis was analyzed using Cox proportional hazards regression. Natural log length of stay was analyzed by multiple linear regression.

RESULTS

Superior cavopulmonary anastomosis was performed in 193 subjects at 5.2 months of age (interquartile range, 4.2, 6.2) and weight of 5.9 kg (interquartile range, 5.3, 6.6). The median length of stay was 7 days (interquartile range, 6, 10). There were 3 deaths and 1 transplant during the superior cavopulmonary anastomosis hospitalization, and 3 deaths and 3 transplants between discharge and 14 months of age. Age at superior cavopulmonary anastomosis was associated with center and interstage adverse events. A longer length of stay was associated with younger age and greater case complexity. Superior cavopulmonary anastomosis type, valve regurgitation, ventricular ejection fraction, and ventricular end-diastolic pressure were not independently associated with age at superior cavopulmonary anastomosis or the length of stay.

CONCLUSIONS

Greater case complexity and more frequent interstage adverse events are associated with an earlier age at superior cavopulmonary anastomosis. Significant variation in age at superior cavopulmonary anastomosis among centers, independent of subject factors, highlights a lack of consensus regarding the optimal timing. Factors associated with length of stay could offer insights for improving presuperior cavopulmonary anastomosis care and surgical outcome.

Hypoplastic left heart syndrome: current considerations and expectations

In the recent era, no congenital heart defect has undergone a more dramatic change in diagnostic approach, management, and outcomes than hypoplastic left heart syndrome (HLHS). During this time, survival to the age of 5 years (including Fontan) has ranged from 50% to 69%, but current expectations are that 70% of newborns born today with HLHS may reach adulthood. Although the 3-stage treatment approach to HLHS is now well founded, there is significant variation among centers. In this white paper, we present the current state of the art in our understanding and treatment of HLHS during the stages of care: 1) pre-Stage I: fetal and neonatal assessment and management; 2) Stage I: perioperative care, interstage monitoring, and management strategies; 3) Stage II: surgeries; 4) Stage III: Fontan surgery; and 5) long-term follow-up. Issues surrounding the genetics of HLHS, developmental outcomes, and quality of life are addressed in addition to the many other considerations for caring for this group of complex patients.

Late catheter interventions in hypoplastic left heart syndrome

Interventional cardiology plays a key role in the diagnosis and management of patients with functionally univentricular physiology after the various stages of surgical palliation. The interventions performed are widely variable in type, including angioplasty of stenotic vessels and implantation of stents in stenotic vessels; closure of defects such as collaterals, leaks in baffles, and fenestrations; creation of fenestration; and more. In the setting of venous hypertension associated with stenosis at the Fontan baffle, conduit, or pulmonary arteries, stent implantation is often preferred, as the aim is to eliminate completely the narrowing, given that relatively mild stenosis can have a significant detrimental hemodynamic effect in patients with functionally univentricular circulation. The procedure is highly successful. In patients who fail after Fontan procedure, creation of a fenestration is often performed, with variable technique depending on the underlying anatomic substrate. To increase chances of patency of the fenestration, implantation of a stent is often required, particularly in the setting of an extracardiac conduit. For those patients with cyanosis and favorable Fontan hemodynamics, closure of the fenestration is performed using atrial septal occluder devices with high success rate. Coils compatible with magnetic resonance imaging are used widely to treat collateral vessels, although on occasion other specific embolization tools are required, such as particles or vascular plugs. Postoperative arch obstruction is successfully managed with angioplasty at a younger age, while implantation of a stent in the aorta is reserved for older patients. Specifics of these interventional procedures as applied to the population of patients with functionally univentricular hearts are described in this manuscript.

Lessons from inter-stage cardiac magnetic resonance imaging in predicting survival for patients with hypoplastic left heart syndrome

This study describes single-unit experience and explores risk stratification, with protocolised inter-stage cardiac magnetic resonance imaging for infants with hypoplastic left heart syndrome. Survival was retrospectively analysed among the cohort of locally followed survivors of Norwood Stage I procedure, who underwent magnetic resonance imaging under general anaesthesia from 2003 to 2008. This included 32 patients: 17 with Sano conduit and 15 with arterio-pulmonary shunt. The median (inter-quartile range) age and weight at scan were 3.1 (2.6-4.6) months and 5.0 (4.5-5.3) kilograms, respectively. Using morphologic definitions, the median coarctation index was 0.71 (0.57-0.83). The degree of proximal right and left pulmonary artery narrowing was 25% (14-44%) and 25% (11-50%), respectively. The median right ventricular ejection fraction was 54% (48-59%). The ejection fraction was not related to the coarctation index or to pulmonary artery narrowing. Patients were followed up for a median of 19.2 (10.8-46.0) months, during which 13 (41%) had an intervention in addition to routine Norwood Stage II surgery and seven died. Risk of death was related to reduced right ventricular ejection fraction, with a hazard ratio of 0.91 (95% confidence interval 0.85-0.98, p = 0.02), and the cumulative number of focal stenoses of neo-aortic arch and pulmonary arteries (hazard ratio 2.71, 95% confidence interval 1.14-6.44, p = 0.02).

CONCLUSIONS

In addition to comprehensive three-dimensional morphologic imaging, inter-stage cardiac magnetic resonance imaging provides a ventricular functional index that may predict outcome in patients with hypoplastic left heart syndrome. Measures to preserve right ventricular systolic function and relieve stenoses are paramount within the complex management strategies for these patients.

Coarctectomy combined with an interdigitating arch reconstruction results in a lower incidence of recurrent arch obstruction after the Norwood procedure than coarctectomy alone

OBJECTIVE

Recurrent aortic arch obstruction after the Norwood procedure continues to be a source of morbidity. We sought to determine if a modified interdigitating technique for aortic arch reconstruction during the Norwood procedure decreased recurrent arch obstruction.

METHODS

A total of 142 consecutive infants undergoing the Norwood procedure were divided into groups according to surgical technique: Group 1 (n = 79, January 1999 to May 2003) underwent arch reconstruction with complete coarctectomy followed by anastomosis of the descending aorta to the transverse arch. Group 2 (n = 63, June 2003 to September 2006) underwent complete coarctectomy plus a modified interdigitating technique. Catheterization before stage 2 palliation was reviewed for hemodynamics and angiographic arch dimensions, and a coarctation index was calculated.

RESULTS

Reintervention for recurrent coarctation occurred in 28% (22/79) of group 1 patients compared with 2% (1/63) of group 2 patients (P = .001). Aortic pressures, gradients, dimensions, and coarctation index were consistently more favorable for group 2.

CONCLUSIONS

Coarctectomy plus an interdigitating arch anastomosis was superior to coarctectomy alone and resulted in a dramatically decreased incidence of recurrent arch obstruction.

Factors associated with subsequent arch reintervention after initial balloon aortoplasty in patients with Norwood procedure and arch obstruction

OBJECTIVES

The aim of this study was to determine whether there are identifiable factors associated with increased risk for aortic arch reintervention in patients who have undergone balloon aortoplasty (BD) for aortic arch obstruction (COA) after the Norwood procedure (NP).

BACKGROUND

BD has been shown to be an effective acute therapy for COA after the NP. However, recurrent obstruction requiring repeat intervention is not uncommon.

METHODS

All patients who underwent BD as the initial intervention for COA after the NP from to January 1993 to May 2009 were retrospectively analyzed (n = 116).

RESULTS

The median age at initial BD was 4.5 months. The median follow-up period was 3.4 years. Procedures were considered acutely successful in 92% of patients, with a median gradient reduction overall from 24 to 3 mm Hg (p < 0.0001) and a COA diameter increase of 52% (p < 0.0001). By Kaplan-Meier analysis, freedom from reintervention was 69% at 1 year and 58% at 5 years, and freedom from reoperation was 82% at 1 year and 79% at 5 years. By Cox regression analysis, proximal arch obstruction, age <3 months at BD, moderate or greater ventricular dysfunction, moderate or greater atrioventricular valve regurgitation on pre-catheterization echocardiography, and higher post-BD coarctation gradient were associated with shorter freedom from reoperation.

CONCLUSIONS

Despite a high acute success rate, a significant proportion of patients treated with BD for post-NP COA underwent reintervention during follow-up. The risk for arch reintervention is highest in patients with proximal arch obstruction, those age <3 months at the time of BD, and those with less successful acute results.

Fontan "Ten Commandments" revisited and revised

Choussat's "Ten Commandments," which describes the components of an ideal Fontan candidate, was first published in 1977. Despite the wisdom in these commandments, it is clear from a historic perspective that total compliance with all criteria does not necessarily portend excellent long-term survival. I believe the end point of the original commandments should be modified to include improvement in long-term survival. I suggest the following single commandment: "Thou Shalt Be Perfect."

What is the clinical utility of routine cardiac catheterization before a Fontan operation?

Patients with single-ventricle circulation presenting for Fontan completion routinely undergo cardiac catheterization despite ongoing debate concerning its additive value. Increasing interest in noninvasive preoperative evaluation alone led the authors to analyze the utility of routine pre-Fontan catheterization and to determine whether a subset of patients could avoid this invasive procedure. Patients younger than 5 years referred for pre-Fontan evaluation were retrospectively reviewed. Medical records and catheter angiograms were examined, and catheterizations were categorized as "additive" based on predetermined criteria. Associations between precatheterization variables, catheterization findings, and short-term postoperative outcomes were evaluated. Cardiac catheterization was clinically nonadditive for 89 of 175 patients undergoing pre-Fontan evaluation (51%). There were no robust precatheterization predictors of a nonadditive catheterization. Echocardiography did not fully demonstrate the relevant anatomy of 115 patients (66%), most frequently due to inadequate visualization of the pulmonary arteries, and 22 patients had additive catheterizations due to new diagnostic findings alone. Interventions at catheterization were frequent and deemed "important" for 64 patients (37%). Catheterization hemodynamic data were not associated with early postoperative outcomes. Minor catheterization complications occurred for 51 patients (29%) and major complications for 4 patients (2%). Although at least 50% of the patients presenting for Fontan completion may be able to avoid routine catheterization safely, an echocardiography-based imaging strategy alone is insufficient to allow proper identification of those who could be evaluated noninvasively. A more comprehensive imaging strategy not based solely on echocardiography should be considered.

Interventions complementing surgery as part of multistage treatment for hypoplastic left heart syndrome: one center's experience

BACKGROUND

Interventional procedures often are used as part of multistage treatment for hypoplastic left heart syndrome (HLHS). This study aimed to evaluate the efficacy of interventions in multistage treatment of HLHS.

METHODS AND RESULTS

Between 1999 and 2007, 78 interventions were performed for 58 children with HLHS at different stages of surgical treatment. Group 1, involving 30 interventions for 22 patients with postoperative pulmonary arterial stenosis, showed reduced pulmonary artery pressure and increased vessel diameter. Group 2, involving 15 interventions after the Norwood operation for 12 patients with aortic arch obstruction, showed success for 11 patients. Group 3, involving eight balloon angioplasties of narrowed Glenn anastomosis for seven patients, showed abolition of the pressure gradient between the superior vena cava and the right pulmonary artery. Group 4, involving eight interventional closures of a fenestration for eight patients after a Fontan operation, showed increased oxygen saturation for all eight patients. Group 5, involving seven interventions for six patients in whom venovenous collaterals were closed percutaneously, showed improved oxygen saturation. For Group 6, uncommon miscellaneous interventions were used to stabilize the patients' condition before the next surgical treatment.

CONCLUSIONS

Interventional procedures play an important role during multistage treatment of HLHS. They allow for a reduction in the number of operations or stabilization of the patients' condition before the next surgical treatment.

Ventricular function deteriorates with recurrent coarctation in hypoplastic left heart syndrome

BACKGROUND

Recurrent coarctation (re-CoA) after stage I palliation in hypoplastic left heart syndrome (HLHS) is deleterious. We studied whether re-CoA had an effect on ventricular systolic function.

METHODS

Retrospectively reviewed were HLHS patients surviving stage I Norwood palliation (stage I) and cavopulmonary shunt (CPS) between January 2004 and February 2007. Echocardiographic right ventricular fractional area change (RV-FAC) was used to evaluate ventricular systolic function after stage I, before CPS, and before Fontan procedures. Cardiac catheterization and magnetic resonance imaging data before CPS were reviewed to assess re-CoA, using a coarctation index (CI = isthmus diameter/descending aortic diameter).

RESULTS

Fifty-one patients were included, and 21 had a CI of less than 0.75 (mean, 0.82 +/- 0.19; 21). Twelve patients required arch balloon dilation between CPS and Fontan. The change of RV-FAC for all patients between stage I and CPS was -2.2% +/- 9.6%. Pearson correlation coefficient demonstrated a significant correlation between lower CI values and lower RV-FAC at the pre-CPS echocardiogram (r = .35, p = 0.03); and lower CI values and greater decrease in RV-FAC between stage I and pre-CPS evaluation (r = 0.40, p = 0.018). At follow-up pre-Fontan, RV-FAC for patients who underwent balloon dilation for re-CoA recovered to a level that was inferior but not significantly different from that of patients who did not need balloon dilation.

CONCLUSIONS

Recurrent aortic arch obstruction after stage I for HLHS is associated with worse RV systolic function at the time of stage II operation. Timely intervention on the re-CoA results in recovery of RV function.

Factors affecting long-term risk of aortic arch recoarctation after the Norwood procedure

BACKGROUND

The purpose of this study was to identify factors predicting risk of aortic arch recoarctation after the Norwood procedure.

METHODS

Patient records were reviewed retrospectively for consecutive patients who underwent the Norwood procedure from 1996 to 2005. Preoperative and intraoperative parameters were identified for analysis. Aortic arch recoarctation was defined by the need for catheter or surgical reintervention. Data were analyzed using survival analysis, with freedom from intervention as the outcome. Factors predicting need for reintervention were analyzed using Cox proportional hazards regression.

RESULTS

Thirty-five recoarctations were observed in 117 patients (30%). Freedom from aortic arch reintervention at six months, one, three, and five years were 72%, 63%, 56%, and 52%, respectively. The majority of arch reinterventions occurred in the first six months (63%), involving either surgical (43%) or catheter (57%) techniques. The use of bovine pericardium showed the greatest risk for potential recoarctation (hazard ratio = 1.81 [0.90-3.64], p = 0.09). Age, gender, weight, ascending aortic diameter, ventricular morphology, primary anatomic diagnosis, and coarctation shelf resection were not found to be predictors of recoarctation.

CONCLUSIONS

Most interventions for aortic arch recoarctation after the Norwood procedure occur within the first six months of life. The type of patch material used for arch reconstruction appears to influence, most strongly, the long-term risk of aortic arch recoarctation.

Anterograde stent implantation for treatment of recurrent coarctation after Norwood operation

Although balloon angioplasty (BA) has become the standard therapy for recurrent aortic arch obstruction, pressure gradient relief is often not complete, with a high incidence of restenosis after BA. We report our experience with anterograde stent implantation for treatment of recurrent arch obstruction in patients with hypoplastic left heart syndrome after Norwood operation. Between March 2003 and January 2006, seven patients with the Norwood procedure required BA. The average weight was 6.3 kg (range, 4.4-9.8 kg). Four patients had undergone prior BA. For the purpose of relieving aortic arch obstruction, we used five Palmaz Genesis (PG) XD stents, and for palliative purposes we used one PG 124P stent and one Jostent, 6-12 mm. The average time after Norwood stage I was 177 days (range, 56-365 days). In six of seven patients the procedure was performed antegradely from the femoral vein. In all patients the procedure was effective. The peak systolic gradient fell from 29 mm Hg (range, 5-70 mm Hg) to 3 mm Hg (range, 0-10 mm Hg). There were no complications. No aneurysm, stent dislocation, or severe bleeding was observed. In two of seven patients three growth-related redilatations were performed. We conclude that implantation of stents at the site of recurrent coarctation after Norwood operation shows excellent gradient relief. To reduce the risk of vascular complications due to arterial access in this small group of patients, the procedure can be done safely anterogradely.

Routine continuous perfusion for aortic arch reconstruction in the neonate

Continuous perfusion has evolved over the past 15 years as a viable cerebral protection strategy for neonatal aortic arch reconstruction. It presents an attractive alternative to deep hypothermic circulatory arrest. However, because of its relatively recent development, a standardized technique for its application is lacking. Here we describe our approach for continuous perfusion for repairs of the aortic arch based on experience with over 700 cases.

Cardiac magnetic resonance imaging after stage I Norwood operation for hypoplastic left heart syndrome

BACKGROUND

After the Norwood operation, a patient's suitability for proceeding to a bidirectional cavopulmonary connection (BCPC) is assessed by a combination of echocardiography and diagnostic cardiac catheterization. In this study, we describe the results of 37 patients who underwent cardiovascular magnetic resonance (MR) assessment before BCPC.

METHODS AND RESULTS

Cardiovascular MR and echocardiography were performed in 37 infants with hypoplastic left heart syndrome before BCPC, and the findings were compared with surgical findings. MR assessment of ventricular function and valvar regurgitation were compared with echocardiography. MR exhibited high sensitivity and specificity for identification of neoaortic (sensitivity 86%, specificity 97%) and left pulmonary artery (sensitivity 100%, specificity 94%) obstruction. Echocardiography exhibited poor sensitivity for identification of vascular stenosis. The mean right ventricular ejection fraction calculated from the MR data was 50+/-10%. There was general agreement between MR and echocardiographic measures of ventricular function, although patients with good function on echocardiography demonstrated a wide range of ejection fractions. There was good agreement between MR and echocardiography for identification of valvar regurgitation.

CONCLUSIONS

Cardiovascular MR can be used to define ventricular and valvar function and vascular anatomy in infants with hypoplastic left heart syndrome after the Norwood operation. We have shown how this information can be used to plan the BCPC and identify any revisions or additional valvar surgery.

Impact of re-coarctation following the Norwood operation on survival in the balloon angioplasty era

OBJECTIVES

The objective of this study was to determine the efficacy of balloon angioplasty (BA) by comparing the immediate and long-term outcomes of patients with and without re-coarctation after a Norwood procedure.

BACKGROUND

Although BA has become the standard means for treating recurrent coarctation following a Norwood operation, it has been suggested that re-coarctation remains a significant cause of morbidity and mortality.

METHODS

Patients who survived a Norwood operation from December 1986 through June 2001 were studied. Differences between groups were evaluated by t test and logistic regression. Survival differences were tested by log-rank tests using Kaplan-Meier survival curves.

RESULTS

Fifty-eight of 633 patients underwent treatment for re-coarctation (9.2%). Thirty-five patients underwent BA (before 1988, 23 had surgery). Median age at catheterization was 6.6 months (1.9 to 35.6 months). Balloon angioplasty was successful (gradient <10 mm Hg) in 32 of 35 patients (92%). There were no BA-related deaths or neurologic complications. Recurrent obstruction after BA occurred in seven patients (20%); five underwent re-dilation. Kaplan-Meier estimates of freedom from recurrent obstruction after initial BA were 97% at one month, 79% at one year, and 79% at five years. There were no differences in survival between patients with re-coarctation treated by BA and patients who did not undergo treatment for re-coarctation.

CONCLUSIONS

We found that 9.2% of patients underwent treatment for re-coarctation following a Norwood operation. Balloon angioplasty is effective, with low morbidity, no early mortality, and no difference in long-term survival when compared with patients who did not have re-coarctation. Recurrent coarctation following BA occurred in 17% of patients, usually within the first year after BA.

Staged surgical management of hypoplastic left heart syndrome: a single institution 12 year experience

OBJECTIVE

To describe a 12 year experience with staged surgical management of the hypoplastic left heart syndrome (HLHS) and to identify the factors that influenced outcome.

METHODS

Between December 1992 and June 2004, 333 patients with HLHS underwent a Norwood procedure (median age 4 days, range 0-217 days). Subsequently 203 patients underwent a bidirectional Glenn procedure (stage II) and 81 patients underwent a modified Fontan procedure (stage III). Follow up was complete (median interval 3.7 years, range 32 days to 11.3 years).

RESULTS

Early mortality after the Norwood procedure was 29% (n = 95); this decreased from 46% (first year) to 16% (last year; p < 0.05). Between stages, 49 patients died, 27 before stage II and 22 between stages II and III. There were one early and three late deaths after stage III. Actuarial survival (SEM) was 58% (3%) at one year and 50% (3%) at five and 10 years. On multivariable analysis, five factors influenced early mortality after the Norwood procedure (p < 0.05). Pulmonary blood flow supplied by a right ventricle to pulmonary artery (RV-PA) conduit, arch reconstruction with pulmonary homograft patch, and increased operative weight improved early mortality. Increased periods of cardiopulmonary bypass and deep hypothermic circulatory arrest increased early mortality. Similar factors also influenced actuarial survival after the Norwood procedure.

CONCLUSION

This study identified an improvement in outcome after staged surgical management of HLHS, which was primarily attributable to changes in surgical technique. The RV-PA conduit, in particular, was associated with a notable and independent improvement in early and actuarial survival.

Late outcomes in patients with surgically treated congenital heart disease

Optimizing late outcomes should be the end result of improvements in medical and surgical care for congenital heart disease (CHD). In addition to mortality, significant morbidities after surgery for CHD need to be considered. These include the need for reintervention, cardiovascular complications, exercise limitations, neurocognitive morbidities, effects on pregnancy, difficulty obtaining insurance, need for chronic medications, and impaired functional status and quality of life. Long-term outcome studies are difficult to perform, and their interpretation is complicated by intervening changes in management. Specific discussion of long-term follow-up of tetralogy of Fallot, D-transposition of the great arteries, and hypoplastic left heart syndrome illustrates the myriad management changes over the last three decades, the challenges in predicting outcomes for recent patients, and the need for ongoing initiation of long-term follow-up studies.

Mid-Term results for double inlet left ventricle and similar morphologies: timing of Damus-Kaye-Stansel

BACKGROUND

Patients with double inlet left ventricle/l-transposition and similar morphologies have their systemic outflow traverse a bulboventricular foramen (BVF), which has a propensity to narrow over time. A Norwood procedure may be performed as the initial palliation. We prefer aortic arch repair and pulmonary artery banding, delaying Damus-Kaye-Stansel (DKS) or BVF resection until the second palliation. The aims of this study were to compare our results with those reported for Norwood strategy and examine the development of systemic outflow obstruction.

METHODS

Retrospective study of patients with double inlet left ventricle, L-TGA or similar morphology presenting between 1990 and 2000. Follow-up with clinical assessment, echocardiography and catheter studies.

RESULTS

Twenty-five patients had initial palliation with pulmonary artery banding with repair of any associated arch obstruction. Twelve patients had DKS performed as part of their second stage procedure, and 3 had DKS performed later for recurrent stenosis after prior enlargement of BVF. Six patients had BVF resection without later restenosis and 4 patients did not develop BVF stenosis. There was one early death (4%) and two late (8%). Fontan completion was achieved in 20 of the 22 survivors. There were no cases of DKS obstruction, no pulmonary valve had more than mild regurgitation.

CONCLUSIONS

Our approach achieves low operative mortality and morbidity and compares favorably with reported results for Norwood palliation. The significant rate of systemic outflow obstruction in those who did not undergo DKS at the second stage confirms the utility of early DKS in children with this morphology.

Management of paediatric patients undergoing diagnostic and invasive cardiology procedures

Since diagnostic cardiac catheterization in children with congenital heart disease was first reported in 1947, echocardiography has been used as a non-invasive diagnostic tool in congenital heart disease, resulting in a decrease in diagnostic cardiac catheterizations. However, the total number of cardiac catheterizations remained at a steady level until the mid-1980s and has since increased progressively. This is a result of the introduction of interventional transcatheter techniques to improve or correct congenital heart malformations. Since the first description of balloon atrial septostomy, the range of indications for such techniques has steadily increased, particularly in the past 15 years. 'Deep' sedation or general anaesthesia is essential for the conduct of cardiac catheterization in children, particularly in the younger age group.