Successful application of the Norwood procedure for infants without hypoplastic left heart syndrome

The Yasui operation: A single institutional experience over 30 years

Objective

The Yasui operation was introduced in 1987 for patients with 2 adequate ventricles, a ventricular septal defect, and aortic atresia or interrupted aortic arch. Despite promising early outcomes, left ventricular outflow tract obstruction (LVOTO) remains a long-term concern. The purpose of this study is to report our institutional experience with the Yasui operation.

Methods

We retrospectively reviewed all patients undergoing the Yasui operation between 1989 and 2021. Results are reported as median with interquartile range (IQR).

Results

Twenty-five patients underwent a Yasui operation (19 primary), at 11 days (IQR, 7-218 days) of life and weight of 3 kg (IQR, 2.8-4.1 days). Fundamental diagnosis was ventricular septal defect/interrupted aortic arch in 11 patients and ventricular septal defect/aortic atresia in 14. Follow-up was 96% (24 out of 25) at 5 years (IQR, 1.4-14.7) with 92% survival. Freedom from LVOTO reoperation was 91% at late follow-up with 2 patients requiring baffle revision at 6 and 9 years. Latest echocardiogram showed 100% of patients had normal biventricular function and 87% (20 out of 23) less than mild LVOTO at 5 years (IQR, 2.3-14.9). Diagnosis, aortic valve morphology, and material used were not predictors of LVOTO. Freedom from right ventricle-to-pulmonary artery conduit reoperation was 48% at a median of 5 years (IQR, 1.4-14.7). Conduit type was not a predictor of reintervention.

Conclusions

The Yasui operation can be performed with low morbidity and mortality in patients with 2 acceptable-size ventricles and aortic atresia or interrupted aortic arch with severe LVOTO. Despite some burden of reoperation, midterm reoperation for LVOTO is not common and ventricular function is preserved.

Surgical outcome of Yasui procedure for preserving biventricular function: single centre experience

BACKGROUND

Yasui procedure is surgical repair intended to preserve biventricular function for patients with left ventricle outflow tract obstruction associated with aortic arch lesions and ventricular septal defect.

METHODS

Retrospective chart review analysis of all patients who had Yasui procedure (2008-2020) comparing midterm outcome of one versus two stage repair.

RESULTS

Twenty patients (70% female) underwent Yasui procedure in our center. Eight patients (40%) had left ventricle outflow tract obstruction /interrupted aortic arch, 7 patients (35%) had left ventricle outflow tract obstruction /coarctation of aorta, 3 patients (15%) had double outlet ventricle and ventricular septal defect that were unattainable for tunneling to one of the semilunar valves without creating obstruction, and 2 patients (10%) had aortic atresia with hypoplastic aortic arch. All patients had associated ventricular septal defect. Fifteen patients (75%) had one-stage repair and 5 patients (25%) had two-stage repair. Means age and weight for one and two-stage repair were 1.3 ± 2 months, 13.4 ± 11.5 months and 3.3 ± 0.6 kg, 7.8 ± 3.4 kg, respectively. During follow up, 8 patients (40%) required re- intervention, mainly for right ventricle-pulmonary artery conduit either dilation or replacement. The average duration of follow up was 5 years with nil mortality.

CONCLUSION

Yasui procedure is effective approach for children who have left ventricle outflow tract obstruction associated with aortic arch anomalies and ventricular septal defect. Survival rate with single or staged repair is comparably good. During the first 5 year of follow up, nearly 40% of operated patients required re-intervention.

Long-term Results After Open Mitral Commissurotomy for a One-Month-Old Infant With Mitral Stenosis

The strategy for an infant with congenital mitral stenosis should be determined by three important factors: left ventricular volume, the degree of the systemic outflow tract obstruction, and the type of mitral valve dysfunction. A successful staged biventricular repair in early infancy for a patient who had congenital mitral stenosis with short chordae, hypoplastic left ventricle and coarctation of the aorta, and the long-term results are described. There were the following important hemodynamic factors that led to the successful biventricular repair in the patient. Total systemic output was barely supplied through the hypoplastic left ventricle after closure of the ductus arteriosus on admission. The neonate underwent repair of coarctation of the aorta alone as the initial stage at 9 days after birth. Also, spontaneous closure of the foramen ovale following repair of coarctation of the aorta accelerated the progressive left ventricular growth. Open mitral commissurotomy with an interatrial fenestration using the modified Brawley's approach was performed for a 40-day-old infant. Good left ventricular growth and good mitral valve function have been observed for 18 years after open mitral commissurotomy. Appropriate early augmentation of left ventricular inflow through the mitral valve might be effective for growth of a hypoplastic left ventricle. J. Med. Invest. 64: 187-191, February, 2017.

Palliation Outcomes of Neonates Born With Single-Ventricle Anomalies Associated With Aortic Arch Obstruction

BACKGROUND

The two most common surgical strategies for the treatment of neonates born with single-ventricle anomalies associated with aortic arch obstruction are the Norwood operation and pulmonary artery banding plus coarctation repair (PAB+COA). We reviewed characteristics and outcomes of neonates who underwent those two surgical strategies at our institution.

METHODS

Between 2002 and 2012, 94 neonates with a single ventricle and aortic arch obstruction (excluding hypoplastic left heart syndrome) underwent Norwood (n = 65) or PAB+COA (n = 29). Outcomes were parametrically modeled, and risk factors associated with early and late death were analyzed.

RESULTS

Competing-risks analysis showed that, at 2 years after the operation, 24% of patients had died or received transplantation and 75% had undergone a Glenn shunt. At 5 years after the Glenn shunt, 10% of patients had died or received transplantation, 62% had undergone Fontan, and 28% were alive awaiting Fontan. Overall 8-year survival was 70%. Outcomes after Norwood included extracorporeal membrane oxygenation use in 9 (14%), unplanned reoperation in 13 (20%), hospital death in 10 (15%), and interstage death in 8 (12%), with 8-year survival of 66%. Outcomes after PAB+COA included extracorporeal membrane oxygenation use in 1 (3%), unplanned reoperation in 9 (30%), hospital death in 1 (3%), and interstage death in 3 (10%), with 8-year survival of 76%. There was an association trend between underlying anatomy and survival (hazard ratio [HR], 2.1; 95% confidence interval [CI], 0.9 to 4.7; p = 0.087). On multivariable analysis, factors associated with death were extracorporeal membrane oxygenation use (HR, 5.5; 95% CI, 1.9 to 15.9; p = 0.002), genetic syndromes/extracardiac anomalies (HR, 3.5; 95% CI, 1.5 to 8.2; p = 0.003), and weight of 2.5 kg or less (HR, 3.0; 95% CI, 1.3 to 7.2; p = 0.012).

CONCLUSIONS

Anatomic and patient characteristics influence palliation outcomes in neonates born with single-ventricle anomalies associated with aortic arch obstruction. Although the Norwood operation is applicable in most of these patients, the PAB+COA strategy is a valid alternative in well-selected patients.

Influence of Morphology and Initial Surgical Strategy on Survival of Infants With Tricuspid Atresia

BACKGROUND

Tricuspid atresia (TA) is a heterogeneous single-ventricle anomaly in which initial presentation and, consequently, timing and mode of palliation vary based on morphology and degree of pulmonary or systemic outflow obstruction. We report current era palliation outcomes and examine whether morphologic and, subsequently, surgical factors influence survival.

METHODS

From 2002 to 2012, 105 infants with TA underwent surgical palliation. Competing risks analyses modeled events after first-stage surgery (Glenn versus death) and after Glenn (Fontan versus death) and examined risk factors affecting outcomes.

RESULTS

Seventy-eight patients (74%) required neonatal first-stage palliation, including modified Blalock-Taussig shunt (n = 46, 44%), Norwood (n = 18, 17%), and pulmonary artery band (n = 14, 13%), whereas 27 (26%) received primary Glenn as their initial surgery. Hospital mortality was 5 patients (4.8%). Competing risks models showed that by 1 year after first-stage surgery, 15% of patients had died and 83% had undergone Glenn. By 5 years after Glenn, 2% of patients had died and 80% had undergone Fontan. Overall 8-year survival was 84%. On multivariable analysis, risk factors for mortality were genetic/extracardiac anomalies (hazard ratio 7.0, 95% confidence interval: 2.4 to 20.6, p < 0.001) and pulmonary atresia (hazard ratio 4.4, 95% confidence interval: 1.6 to 12.2, p = 0.004). Survival was not affected by initial palliation type (p = 0.36), ventriculoarterial discordance (p = 0.25), systemic outflow obstruction (p = 0.84), or arch obstruction (p = 0.62).

CONCLUSIONS

Despite morphologic and physiologic variations necessitating different palliative sequences, multistage palliation outcomes of various TA subtypes are comparable and generally good, with the exception of patients with associated genetic/extracardiac anomalies. The bulk of mortality is interstage, indicating continued opportunity for improvement in monitoring and managing patients during this critical period.

Current Outcomes of the Norwood Operation in Patients With Single-Ventricle Malformations Other Than Hypoplastic Left Heart Syndrome

Background:

Subsequent to increased experience with the Norwood operation in children with hypoplastic left heart syndrome (HLHS), its application has expanded to allow palliation of single-ventricle (SV) malformations other than HLHS. We describe current palliation outcomes in this group of SV patients.

Methods:

Between 2002 and 2012, 65 of the 303 Norwood operations were performed in non-HLHS SV patients. Competing risk analysis modeled events after Norwood and after subsequent Glenn and examined risk factors affecting outcomes.

Results:

Competing risk analysis showed that one year following Norwood, 24% of patients had died or received transplantation, 72% had undergone Glenn, and 4% were alive awaiting Glenn/Kawashima. Five years following Glenn, 9% of patients had died, 68% had undergone Fontan, and 23% were alive awaiting Fontan. Overall seven-year survival following Norwood was 68%. On multivariable analysis, mortality risk factors were unplanned cardiac reoperation (hazard ratio [HR]: 4.0 [1.5-10.6], P = .006), right dominant ventricle morphology (HR: 3.3 [1.3-8.3], P = .012), and postoperative extracorporeal membrane oxygenation (HR: 3.1 [1.1-9.0], P = .035).

Conclusions:

Operative death and interstage mortality continue to be problematic following Norwood palliation for non-HLHS SV variants. Outcomes seem comparable to those reported for HLHS, however they are influenced by underlying pathology; children with dominant left ventricle morphology (tricuspid atresia and double inlet left ventricle) have superior survival compared to those with dominant right ventricle morphology (mitral atresia, unbalanced atrioventricular septal defect, and most patients with atrial isomerism). Unplanned reoperations for technical imperfections diminish survival. Large multicenter studies might be warranted to better identify high-risk patients and provide guidance toward improving their survival.

Outcomes of the modified norwood procedure: hypoplastic left heart syndrome versus other single-ventricle malformations

Recent studies have suggested that survival after the modified Norwood procedure is influenced by anatomy and is worse for patients with hypoplastic left heart syndrome (HLHS) than for patients with other forms of functional single ventricle. This study aimed to compare the outcomes of the modified Norwood procedure for these two groups at a single center. A retrospective chart review compared modified Norwood procedure outcomes between children with HLHS (n = 40) and children with other single-ventricle malformations (n = 19) from January 2002 to August 2012. The HLHS patients had a lower mean age (10.0 ± 13.2 days) at the time of operation than the non-HLHS patients (16.5 ± 18.5 days). The difference was not significant. The number of patients with a Sano modification was significantly higher in the HLHS group (HLHS 85 % vs non-HLHS 32 %; p < 0.001). The follow-up data did not differ between the groups (HLHS 3.6 ± 3.2 years vs non-HLHS 4.8 ± 3.3 years, nonsignificant difference). The overall operative survival was 85 %: 83 % for the patients with HLHS and 89 % for the patients with non-HLHS (nonsignificant difference). The Kaplan-Meier transplant-free survival estimate at 10 years was 73 % and did not differ between the HLHS patients (67 %) and the non-HLHS patients (84 %, nonsignificant difference). The timing of stages 2 and 3 palliation (bidirectional Glenn and external conduit Fontan) did not differ significantly (HLHS, 7.0 ± 2.8 months and 3.0 ± 0.5 years vs non-HLHS 6.1 ± 1.7 months and 2.8 ± 0.8 years). The two groups were similar with respect to the need for post-Norwood extracorporeal membrane oxygenation support, aortic arch reinterventions, atrioventricular valve repair, pulmonary artery reconstruction, pacemaker implantation, and progression to bidirectional Glenn and Fontan completion. The modified Norwood reconstruction provides good palliation for HLHS as well as other forms of functional single-ventricle anatomy. Survival, postoperative morbidity, and progression to Glenn and Fontan are not significantly different.

Surgical strategy for severe aortic hypoplasia and aortic stenosis with ventricular septal defect and normal left ventricle

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

Accepting risk in clinical research: is the gene therapy field becoming too risk-averse?

Risk is an inescapable aspect of clinical research and is increasingly pertinent to the gene therapy field as the imperative for clinical trial activity grows. In recent years, the widely reported occurrence of serious adverse events (SAEs) in gene therapy studies, including trials for ornithine transcarbamylase (OTC) deficiency, X-linked severe combined immunodeficiency (SCID-X1), and rheumatoid arthritis, has heightened fear in public perceptions of gene therapy. Although it is essential to be cognizant of the risks involved in gene therapy research, there is a danger that gene therapy may become too risk-averse. If the field is to make progress, it is necessary to understand how risk is defined in gene therapy research, how understandings of risk differ, how risk is assessed, how decisions about risk are made, and how gene therapy risks are communicated to subjects and research participants during the informed consent process. In addition to minimizing the risks of clinical research through extensive preclinical safety studies, attention should be given to how decisions about risk and risk acceptability are made by researchers and subjects, and to the methods used to communicate risks to patients. Critical attention to risk will help ensure that the safety of subjects is protected, while also enabling research to develop better treatments for patients.

Stage I Palliation for Interrupted “Right” Aortic Arch Associated With Mitral Atresia

A 2.6 kg female with the diagnosis of type "B" interruption of the "right" aortic arch and mitral atresia underwent stage I palliation with translocation and anastomosis of the distal right carotid artery to the descending aorta. The distal main pulmonary artery was anastomosed to the under surface of the neoaortic arch. A modified Blalock-Taussig shunt was constructed between the left side innominate artery and the left pulmonary artery. The child awaits stage II palliation.

The nomenclature, definition and classification of hypoplastic left heart syndrome

The hypoplastic left heart syndrome encompasses a spectrum of cardiac malformations that are characterized by significant underdevelopment of the components of the left heart and the aorta, including the left ventricular cavity and mass. At the severe end of the spectrum is found the combination of aortic and mitral atresia, when the left ventricle can be close to non-existent. At the mild end are the patients with hypoplasia of the aortic and mitral valves, but without intrinsic valvar stenosis or atresia, and milder degrees of left ventricular hypoplasia. Although the majority of the patients are suitable only for functionally univentricular repair, a small minority may be candidates for biventricular repair. The nature of the syndrome was a topic for discussion at the second meeting of the International Working Group for Mapping and Coding of Nomenclatures for Paediatric and Congenital Heart Disease, the Nomenclature Working Group, held in Montreal, Canada, over the period January 17 through 19, 2003. Subsequent to these discussions, the Nomenclature Working Group was able to create a bidirectional crossmap between the nomenclature initially produced jointly on behalf of the European Association for Cardio-Thoracic Surgery and the Society of Thoracic Surgeons, and the alternative nomenclature developed on behalf of the Association for European Paediatric Cardiology. This process is a part of the overall efforts of the Nomenclature Working Group to create a comprehensive and all-inclusive international system of nomenclature for paediatric and congenital cardiac disease, the International Paediatric and Congenital Cardiac Code. In this review, we discuss the evolution of nomenclature and surgical treatment for the spectrum of lesions making up the hypoplastic left heart syndrome and its related malformations. We also present the crossmap of the associated terms for diagnoses and procedures, as recently completed by the Nomenclature Working Group.

The Southern Thoracic Surgical Association 50th anniversary celebration: the impact of STSA pediatric cardiothoracic surgery manuscripts on surgical practice

BACKGROUND

Members of the Southern Thoracic Surgical Association (STSA) have presented important pediatric cardiothoracic surgery papers at the annual meetings over the last 50 years. In order to determine the influence of these presentations on the practice of surgery, a review was undertaken. Early papers were characterized by emerging advances in open-heart surgery, anatomic congenital heart studies, and electrophysiologic discoveries that extended life with pacemakers. Later years were characterized by innovative myocardial preservation methods, improved cardiopulmonary bypass techniques, expanded homograft availability, emphasis on accurate repairs, intraoperative transesophageal echocardiography, and cardiopulmonary transplantation.

METHODS

All but one of the scientific programs of the annual meetings (that of 1964) were located. The programs were reviewed and 180 presentations were identified on topics in congenital heart disease, pediatric thoracic disease, and pediatric thoracic wall abnormalities. Of those 180 oral presentations, 155 manuscripts (86%) were eventually published or in press and available for critical review and analysis. Manuscripts were grouped by diagnosis or therapeutic intervention. We determined a "cumulative citation frequency" (CCF), which measures the number of times an article is cited in the bibliography of related papers in the universe of participating journals. The selected manuscripts were compared with the historic landmark contributions and the existing trends at the time, and the number of articles both by individual authors and from institutions were tallied.

RESULTS

Grouping by authors and institutions showed that 100 of 155 pediatric cardiothoracic manuscripts (65%) originated from 13 institutions. The CCF for the 20 leading articles ranged from 26 to 93.

CONCLUSIONS

This historical STSA 50-year record of pediatric cardiothoracic advances was accomplished in a milieu of collegial respect and camaraderie. Our annual meetings over the years have provided a venue for thoracic surgeons to share their ideas, innovations, and scientific inquiry. These contributions have significantly affected the practice of pediatric cardiothoracic surgery. The STSA has worked for 50 years and we trust that it will work for another 50 years and beyond.

Biventricular repair after Norwood palliation

BACKGROUND

In general, neonates with severe left ventricular outflow tract obstruction, aortic valvar stenosis or atresia, and arch hypoplasia with either interruption or coarctation, and a small left ventricle undergo Norwood palliation followed classically by a bidirectional cavopulmonary shunt and eventual modified Fontan. However, a subset of patients, usually neonates with a ventricular septal defect, may have adequate left ventricle and mitral valve sizes making them candidates for future biventricular repair (BVR). In view of the long-term advantage of BVR, the feasibility and outcome of this approach was studied. Additionally, echocardiographic data were reviewed in an attempt to develop objective prognostic criteria for selection of patients suitable for BVR.

METHODS

During a 4-year period, 8 of 58 infants undergoing Norwood palliation were identified as potential two-ventricle candidates. Their mean age was 6 days. Diagnoses included aortic atresia (n = 1), or aortic valve stenosis and subaortic stenosis (n = 7), with an interrupted aortic arch in 3 and coarctation in 4. All patients had a ventricular septal defect and a left ventricle that was considered to be apex forming. Mean mitral valve size was 11 mm (z-score = -1.7). Mean aortic valve size was 4.1 mm (mean z-score = -8.4).

RESULTS

All 8 patients survived Norwood palliation. Six subsequently underwent BVR with ventricular septal defect closure and a right ventricle to pulmonary artery conduit at a mean age of 7 months. One patient is awaiting repair, and 1 underwent a cavopulmonary shunt. At the time of BVR, mean mitral valve z-score was essentially unchanged at -1.4 (14 mm). No early deaths or late deaths occurred during a mean follow-up of 32 months.

CONCLUSIONS

A small subset of patients requiring Norwood palliation as newborns may be candidates for eventual BVR with low risk. In general, patients suitable for BVR have a mitral valve z-score of more than -3 and a normal-sized left ventricle. Recognition of neonatal BVR candidates enables consideration of complete neonatal repair. However, single-stage repair needs to be compared with the excellent results obtainable with the staged approach.

The infant with single ventricle and excessive pulmonary blood flow: results of a strategy of pulmonary artery division and shunt

BACKGROUND

The infant with a single ventricle and excessive pulmonary blood flow requires early protection of the pulmonary vascular bed to insure suitability for a subsequent Fontan procedure. The traditional approach, pulmonary artery banding, has had disappointing results. We have pursued an alternate strategy: division of the pulmonary artery, and placement of a systemic-to-pulmonary artery shunt. Potential sites of systemic outflow tract obstruction are simultaneously bypassed, by either a Damus-Kaye-Stansel, or modified Norwood procedure.

METHODS

From January 1996 to June 2001, 22 infants were treated by this strategy. Patients with hypoplastic left heart syndrome were excluded. Median age was 18 days (range 2 days to 6 months). In addition to pulmonary artery division and shunt, 3 of 22 patients underwent a Damus-Kaye-Stansel procedure, and 13 of 22 patients underwent a modified Norwood procedure.

RESULTS

There were no operative deaths, and one late death. Actuarial survival beyond 30 months was 90%. At follow-up catheterization in 22 patients, median transpulmonary gradient was 7 mmHg (range 4 to 18), and median pulmonary vascular resistance 1.9 Wood units (range 0.9 to 3.3). Twenty-one patients have undergone a subsequent bidirectional superior cavopulmonary connection, and 6 a Fontan procedure, with no deaths. No patient developed subaortic stenosis, or aortic arch obstruction. Neoaortic insufficiency was none or trivial in 12 patients, mild in 3, and moderate in 1.

CONCLUSIONS

In patients with a functional single ventricle and excessive pulmonary flow, a strategy of pulmonary artery division and shunt, along with prophylactic bypass of systemic outflow obstruction, carries low operative and midterm mortality. It provides consistent protection of the pulmonary vascular bed, avoids subaortic stenosis and aortic arch obstruction, minimizes neoaortic insufficiency, and ensures suitability for progression along a Fontan pathway. These results provide a comparison for alternate strategies, including pulmonary artery banding.

Hemodynamic effects of inspired carbon dioxide after the Norwood procedure

BACKGROUND

Mortality in the early postoperative period after the Norwood procedure remains substantial. Inspired carbon dioxide (CO2) has been suggested to improve hemodynamic status in this setting. Inspired CO2 can be delivered by one of two strategies, ie, with or without an accompanying increase in minute ventilation. The hemodynamic effects of these two strategies have not previously been studied in a controlled fashion.

METHODS

Seventeen infants (median age, 9 days; range, 4 to 49 days) undergoing Norwood procedures were prospectively enrolled in this crossover study. Patients were studied while sedated, paralyzed, and mechanically ventilated 1 day to 6 days after operation. The inspired oxygen fraction was kept constant (mean value, 0.24 +/- 0.01). Measurements were made at five time points: 1 = baseline; 2 = inspired CO2 with increased ventilation; 3 = baseline; 4 = inspired CO2 alone; and 5 = baseline. Mixed venous oxygen saturation was monitored using indwelling lines in the superior vena cava.

RESULTS

Inspired CO2 with increased ventilation produced a rise in mean airway pressure with no change in arterial CO2 tension or pH. This strategy had no effect on hemodynamic status or oxygen delivery. Inspired CO2 alone produced a rise in arterial CO2 tension and a fall in arterial pH (respiratory acidosis). This strategy resulted in significant improvement in both variables of systemic oxygen delivery: mixed venous oxygen saturation increased from 48% +/- 2% to 56% +/- 2% (p < 0.05), and arteriovenous oxygen saturation difference decreased from 3% +/- 2% to 26% +/- 2% (p < 0.05).

CONCLUSIONS

Inspired CO2 after the Norwood procedure can improve oxygen delivery. This improvement occurs only if minute ventilation is kept constant. There is no improvement if minute ventilation is increased. Clinical use of inspired CO2 may be limited by the accompanying fall in pH. Differentiation of cerebral from total-body effects of inspired CO2 will require further study.

Successful biventricular repair after initial Norwood operation for interrupted aortic arch with severe left ventricular outflow tract obstruction

BACKGROUND

Management of newborns with interrupted aortic arch (IAA) remains challenging. Associated severe left ventricular outflow tract obstruction (LVOTO) have often led to increased mortality with neonatal biventricular repair. We review our experience with an alternative approach for this complex surgical problem.

METHODS

From May 1991 to June 1999, 28 neonates were treated for IAA. Thirteen of 28 neonates (46%) had type B IAA, ventricular septal defect (VSD) and severe LVOTO (Z value -2 to -7; mean -5 +/- 1.7). Mean age was 8 days (3 to 23 days old) with average weight of 3.3 kg (2.4 to 4.2 kg). Eight of 13 (62%) had anomalous right subclavian artery. Ten of 13 (77%) had thymic aplasia and chromosome 22 region qll deletion. All 13 patients were treated initially with a modified Norwood procedure.

RESULTS

There were no perioperative deaths. Complications included 2 patients with recurrent arch stenosis treated with balloon dilatation. Two patients had systemic arterial shunt revision. Follow-up ranged from 2 to 99 months old (mean 39 months). There were 2 late deaths unrelated to any operation. Nine of 12 patients had a second stage palliation consisting of a bidirectional Glenn shunt. Six patients went on to have biventricular repairs (3 Ross-Konno, 2 Rastelli, 1 VSD closure with LVOT resection). One patient had a modified Fontan operation and 5 patients are awaiting potential biventricular repair.

CONCLUSIONS

Children with IAA and severe LVOTO may be managed by initial Norwood palliation with an excellent outcome likely. This initial "univentricular" approach has enabled eventual successful biventricular repair despite severe LVOTO.

Single ventricle with systemic obstruction in early life: comparison of initial pulmonary artery banding versus the Norwood operation

OBJECTIVES

The outcomes of initial pulmonary artery banding (PAB)+/-coarctation repair are compared with the Norwood operation in newborns with single ventricle (SV) and systemic obstruction (SO).

METHODS

Between January 1987 and July 2000, 22 patients (median age, 12 days) with SV and aortic arch obstruction (AAO), subaortic stenosis (SAS), or both underwent surgery. Two initial surgical approaches were used: PAB+/-coarctation repair (group I, seven patients); Norwood type operation (group II, 15 patients).

RESULTS

The overall mortality was 32% (seven of 22 patients). There was no late mortality. The mortality in group I was 43% versus 27% in group II. Recently, there has been no mortality following the Norwood operation in the last eight patients operated since 1995. Of the survivors, nine patients have undergone the Fontan operation and four patients have had the bidirectional Glenn (BDG) with no deaths. There was one repair of supravalvar aortic stenosis at the time of BDG in group II as opposed to eight reinterventions for SAS and/or AAO in four patients in group I (P=0.01).

CONCLUSIONS

PAB+/-coarctation repair for SV and SO is associated with a high mortality and a high reoperation rate for SAS or recurrent AAO. Although the Norwood operation was also associated with a high mortality early on, it can now be performed with excellent outcome. This improvement, combined with a low reintervention rate for SAS or AAO, suggests that the Norwood operation is likely to emerge as the procedure of choice for SV and SO.

Considerations in biventricular repair after the Norwood procedure

OBJECTIVE

The Norwood procedure can be applicable as a first stage palliation in children who can eventually undergo a biventricular repair. Although usual management of these patients is a primary neonatal repair, in selected patients staged approach with a Norwood procedure in the neonatal period followed by a Rastelli procedure in the infancy for conversion to two-ventricle physiology has been used alternatively.

METHODS

We report our experiences on two infants who underwent a previous palliation with the Norwood procedure for lesions other than hypoplastic left heart syndrome and converted to two-ventricle physiology by the use of a Rastelli-type procedure. This report examines considerations in biventricular repair after the Norwood procedure especially need for ventricular septal defect enlargement and approach to placement of the right ventricle to pulmonary artery conduit.

RESULTS

Both of the infants who underwent staged approach with an initial Norwood procedure for lesions other than hypoplastic left heart syndrome survived the operations and were clinically well at mid-term follow-up.

CONCLUSION

In selected patients, the staged approach is an alternative in management of malformations other than hypoplastic left heart syndrome which share the important physiologic features of aortic outlet obstruction and ductal dependency of systemic circulation. We recommend routine enlargement of ventricular septal defect and proper positioning of the conduit at the time of subsequent biventricular repair.

Congenital Heart Surgery Nomenclature and Database Project: hypoplastic left heart syndrome

Hypoplastic left heart syndrome (HLHS) encompasses a spectrum of structural cardiac malformations that are characterized by severe underdevelopment of the structures in the left heart-aorta complex, including the left ventricular cavity and mass. The severe end of the spectrum consists of aortic atresia and mitral atresia with a nonexistent left ventricle, whereas at the mild end patients have aortic valve and mitral valve hypoplasia without intrinsic valve stenosis, and milder degrees of left ventricular hypoplasia, recently described as hypoplastic left heart complex (HLHC). Although the overwhelming majority of the patients can only have a univentricular repair, a small minority of patients with HLHS, particularly those that are described as having HLHC, may be candidates for biventricular repair. In this paper, the extant nomenclature for HLHS is reviewed for the purpose of establishing a unified reporting system. The subject was debated and reviewed by members of the STS-Congenital Heart Surgery Nomenclature and Database Committee and representatives from the European Association for Cardiothoracic Surgery. Efforts were made to include all relevant nomenclature categories using synonyms where appropriate. A comprehensive database set is presented, which is based on a hierarchical scheme. Data are entered at various levels of complexity and detail that can be determined by the clinician. These data can lay the foundation for comprehensive risk stratification analyses. A minimum database set is also presented which will allow for data sharing, and would lend itself to basic interpretation of trends. Outcome tables relating diagnoses, procedures, and various risk factors are presented.

Results of Norwood stage I operation: comparison of hypoplastic left heart syndrome with other malformations

OBJECTIVE

We compared the Norwood stage I operation for hypoplastic left heart syndrome and other complex malformations with ductus-dependent systemic circulation.

METHODS

A retrospective study of 194 patients who underwent a Norwood stage I palliation between 1990 and 1998 was conducted. Malformations in 131 patients were classified as hypoplastic left heart syndrome, defined as aortic and mitral atresia or severe stenosis, normal segmental anatomy, intact ventricular septum, and hypoplasia of the left ventricle. Sixty three patients had other lesions: hypoplastic left ventricle with ventricular septal defect (n = 18), unbalanced complete atrioventricular canal (n = 9), complex double-outlet right ventricle (n = 14), double-inlet left ventricle (n = 11), tricuspid atresia with transposition of the great arteries (n = 6), and others (n = 5), including heterotaxia.

RESULTS

Operative (>30 days) and 1-year survivals were lower for patients with hypoplastic left heart syndrome than for those with other lesions (63.4% vs 81%, P =.008, and 51.2% vs 71.4%, P =.02, respectively). The presence of a nonhypoplastic left ventricle (n = 27) was associated with higher operative and 1-year survivals (96.3% vs 64.7%, P =.002; 88.9% vs 52. 7%, P <.001). A restrictive atrial septal defect and prematurity tended to increase mortality across both groups. Cox proportional hazards regression indicated that a single right ventricle was the most important independent predictor of death (P <.001). Operative mortality for all patients undergoing the stage I procedure decreased from 38.5% (1990-1994) to 21.4% after 1994 (P =.02).

CONCLUSIONS

The survival of patients with malformations other than hypoplastic left heart syndrome after the Norwood procedure is greater than for those with hypoplastic left heart syndrome. Staged palliation is valid surgical therapy in these patients, with good results in intermediate follow-up.

Aortic atresia with a ventricular septal defect: modified single-stage neonatal biventricular repair

BACKGROUND

The spectrum of hypoplastic left heart disease is diverse but the surgical repair is strictly dichotomous, culminating in either a univentricular or a biventricular surgical repair. Although aortic atresia with a ventricular septal defect historically has been managed by conversion to a univentricular physiology, a biventricular repair occasionally has been attempted in stages or in conjunction with the implantation of multiple allografts or prosthetic conduits. Our repair strategy recently has evolved to the use of a modified single-stage biventricular repair using only autologous tissues without conduits.

METHODS

Retrospective analysis (1989 to 1997) of neonates with aortic atresia with a ventricular septal defect.

RESULTS

Five neonates underwent repair of aortic atresia with a ventricular septal defect. One died in the hospital. The mean age and weight of the neonates who underwent repair were 7.8 days (range, 2 to 17 days) and 3.2 kg (range, 3 to 3.6 kg), respectively. Three neonates had a univentricular repair and 2 had a modified biventricular repair. The latter two procedures were successful and the patients were discharged from the hospital.

CONCLUSIONS

Long-term results are lacking to attest to this surgical modification's superiority over either the standard multistage univentricular operation or the single-stage biventricular repair using multiple conduits. However, we are optimistic that routine use of this modification will enable a greater percentage of neonates to undergo a biventricular repair without the need for serial conduit revisions or future aortoplasty.

Results of Norwood's operation for lesions other than hypoplastic left heart syndrome

Norwood's operation provides satisfactory palliation for neonates with hypoplastic left heart syndrome. The dominant physiologic features of hypoplastic left heart syndrome, ductal dependency of the systemic circulation and parallel pulmonary and systemic circulations, are shared by a multitude of other less common congenital heart malformations. Theoretically, these should be equally amenable to palliation by Norwood's operation. Between January 1990 and June 1994, 60 neonates with malformations other than hypoplastic left heart syndrome underwent initial surgical palliation by Norwood's procedure. Diagnoses included single left ventricle with levo-transposition of the great arteries (12); critical aortic stenosis (8); complex double-outlet right ventricle (8); interrupted aortic arch with ventricular septal defect and subaortic stenosis (7); ventricular septal defect, subaortic stenosis, and coarctation of the aorta (7); aortic atresia with large ventricular septal defect (6); tricuspid atresia with transposition of the great arteries (6); heterotaxy syndrome with subaortic obstruction (3); and other (3). There were 10 hospital deaths and 50 survivors (83% survival). After the introduction of inspired carbon dioxide therapy into the postoperative management protocol (1991), 42 of 47 patients survived (89% survival). Mortality was independent of diagnosis and essentially the same as that for hypoplastic left heart syndrome. With minor technical modifications, Norwood's operation provides satisfactory initial palliation for a wide variety of malformations characterized by ductal dependency of the systemic circulation in anticipation of either a Fontan procedure or a biventricular repair.