Mitochondrial DNA Depletion Syndrome—An Unusual Reason for Interstage Attrition after the Modified Stage 1 Norwood Operation

We describe a patient with a variant of the hypoplastic left heart syndrome who died 16 weeks after a modified stage 1 Norwood from a mitochondrial DNA depletion syndrome.     

Standardized Management Improves Outcomes after the Norwood Procedure

Background. In the past decade, many advances in the care of patients undergoing the Norwood procedure (NP) have been reported, but management remains nonstandardized at many institutions. We studied the impact of a standardized management protocol for neonates undergoing NP. Methods. Care of NP patients has been protocol‐driven at our institution since 2005, with routine use of regional low flow perfusion; near infrared spectroscopy; phenoxybenzamine with cardiopulmonary bypass; delayed sternal closure; peritoneal drainage; gastrostomy tubes; postoperative vocal cord assessment; and a home surveillance program of daily weight and oxygen saturation measurement. Patients undergoing NP from 2001 to 2004 (n = 40, group 1), in whom these interventions were only selectively employed, were retrospectively compared with those receiving standardized management from 2005 to 2007 (n = 40, group 2), with endpoints of survival in‐hospital and to stage 2 palliation (S2P). Effect of protocol elements on outcome was evaluated by univariate and multivariate analyses. Results. Hospital survival (95% vs. 70%, P= .003) and survival to S2P (85% vs. 58%, P= .006) was better in group 2. By univariate analysis, regional low flow perfusion, gastrostomy usage, and near infrared spectroscopy were associated with improved hospital and survival to S2P. In multivariable analysis, gastrostomy usage was associated with improved hospital survival (P= .027) and survival to S2P (P= .049), while our home surveillance program was a predictor of survival to S2P (P= .016). Conclusion. Protocol‐driven management of NP patients was associated with better hospital survival and survival to S2P. Among protocol elements, gastrostomy usage was linked to both improved hospital survival and survival to S2P. Home surveillance was associated with increased survival to S2P.     

Nutrition Algorithms for Infants with Hypoplastic Left Heart Syndrome; Birth through the First Interstage Period

Failure to thrive is common in infants with hypoplastic left heart syndrome and its variants and those with poor growth may be at risk for worse surgical and neurodevelopmental outcomes. The etiology of growth failure in this population is multifactorial and complex, but may be impacted by nutritional intervention. There are no consensus guidelines outlining best practices for nutritional monitoring and intervention in this group of infants. The Feeding Work Group of the National Pediatric Cardiology Quality Improvement Collaborative performed a literature review and assessment of best nutrition practices from centers participating in the collaborative in order to provide nutritional recommendations and levels of evidence for those caring for infants with single ventricle physiology.     

Variation in Interstage Outpatient Care after the Norwood Procedure: A Report from the Joint Council on Congenital Heart Disease National Quality Improvement Collaborative

Objective. The National Pediatric Cardiology Quality Improvement Collaborative (NPC‐QIC) is the first quality improvement collaborative in pediatric cardiology, and its registry captures information on interstage care and outcomes of infants after the Norwood procedure. The purpose of this study was to evaluate variation in interstage outpatient clinical care practices for infants discharged home after the Norwood procedure. Design. Data for the first 100 infants enrolled in the NPC‐QIC registry were evaluated. The care domains assessed for variation included: (1) discharge communication with outpatient cardiologist and primary care physician (PCP); (2) nutrition plan at hospital discharge; and (3) planned use of home surveillance strategies. Results. One hundred infants were discharged home between July 2008 and February 2010, from 21 participating US pediatric cardiac programs. Median age at discharge was 29 (11–188) days. Interstage outpatient care was provided at the Norwood center for 62 infants, at other centers for 25, and at a combination of centers for 13. Complete discharge communication (defined as written communication of medication list, nutrition plan, and red flag checklist) was relayed to only 45 outpatient cardiologists and to 26 PCPs. Nutrition route at discharge was exclusively oral in 49, combined oral and nasogastric (NG)/nasojejunal (NJ) in 38, exclusively NG/NJ in six, combined oral and gastrostomy tube (GT) in six, and exclusively GT in one infant. Home surveillance strategies were utilized for 81 infants (oximetry and weight monitoring in 77, oximetry alone in four), with no home surveillance in 19 infants. Conclusions. Considerable variation exists in interstage outpatient care after the Norwood procedure in the care domains of discharge communication, nutrition, and home surveillance. Standardizing care around evidence‐based practices may improve the outcomes for these very high‐risk children.     

Transparency in a Pediatric Quality Improvement Collaborative: A Passionate Journey by NPC‐QIC Clinicians and Parents

Transparency—sharing data or information about outcomes, processes, protocols, and practices—may be the most powerful driver of health care improvement. In this special article, the development and growth of transparency within the National Pediatric Cardiology Quality Improvement Collaborative is described. The National Pediatric Cardiology Quality Improvement Collaborative transparency journey is guided by equal numbers of clinicians and parents of children with congenital heart disease working together in a Transparency Work Group. Activities are organized around four interrelated levels of transparency (individual, organizational, collaborative, and system), each with a specified purpose and aim. A number of Transparency Work Group recommendations have been operationalized. Aggregate collaborative performance is now reported on the public‐facing web site. Specific information that the Transparency Work Group recommends centers provide to parents has been developed and published. Almost half of National Pediatric Cardiology Quality Improvement Collaborative centers participated in a pilot of transparently sharing their outcomes achieved with one another. Individual centers have also begun successfully implementing recommended transparency activities. Despite progress, barriers to full transparency persist, including health care organization concerns about potential negative effects of disclosure on reputation and finances, and lack of reliable definitions, data, and reporting standards for fair comparisons of centers. The National Pediatric Cardiology Quality Improvement Collaborative's transparency efforts have been a journey that continues, not a single goal or destination. Balanced participation of clinicians and parents has been a critical element of the collaborative's success on this issue. Plans are in place to guide implementation of additional transparency recommendations across all four levels, including extension of the activities beyond the collaborative to support transparency efforts in national cardiology and cardiac surgery societies.     

Thromboses in the Native Aorta in Patients with Hypoplastic Left Heart Syndrome

We present four children with hypoplastic left heart syndrome (HLHS) and development of thrombus in the native aortic root. There are only two previously reported cases in the literature. In all four of our patients, thrombus was noted on transthoracic echocardiography. In one patient, surgical thrombectomy was performed, with subsequent deterioration and death. Thrombolysis was used in one patient, with suspected embolic events following his treatment. In the remaining two patients, medical management with chronic anticoagulation was successful in reducing the size of the thrombus.     

Freedom from Neoaortic Insufficiency: A Comparison of Classic Norwood and Norwood–Sano Procedures

Objectives. To investigate the incidence of neoaortic insufficiency in patients with hypoplastic left heart syndrome treated with the Norwood–Sano palliation and to compare it with that occurring after the classic Norwood procedure. Design, Setting, Patients, Interventions. This was a retrospective review of all echocardiograms of patients diagnosed with hypoplastic left heart syndrome (concomitant presence of left ventricular and aortic and mitral severe hypoplasia or atresia) who underwent staged palliation of the Norwood or Norwood–Sano type at a single academic institution between September 1999 and February 2005 and who survived a minimum of 3 months. Outcome Measures. Neoaortic insufficiency was categorized as absent or mild <1 mm jet width, moderate 1–3 mm jet width, or severe >3 mm jet width. The patients were grouped according to initial palliation, that is, classic Norwood and Norwood–Sano operation. Results. Fifty‐nine consecutive patients (median age of 20 months with a range from 3 to 66 months) satisfied inclusion criteria. Neoaortic insufficiency was absent or mild in 55 of 59 (93.22%) of the patients. There were 4 cases of significant neoaortic insufficiency at late follow‐up: 2 moderate following the classic Norwood and 1 moderate and 1 severe following the Norwood–Sano procedure, one of whom required valve replacement. Conclusions. In this series of patients with hypoplastic left heart syndrome, the Sano modification was not associated with an increased incidence of significant neoaortic insufficiency. When present, moderate/severe neoaortic insufficiency appeared late after initial palliation and was associated with recurrent ascending aortic or aortic arch pathology in every case.     

Three-stage Palliation of Hypoplastic Left Heart Syndrome in the University HealthSystem Consortium

Objective. The objective of this study was to describe current management and short-term outcomes for patients with hypoplastic left heart syndrome representative of nationwide experience. Additionally, this study identifies risk factors associated with mortality in patients undergoing staged surgical palliation. Design. The University HealthSystem Consortium database was queried to identify all hospital admissions between 1998 and 2007 with a diagnosis of hypoplastic left heart syndrome. Procedure codes were used to determine surgical management, and outcomes were ascertained by discharge status (discharged, transferred, or expired). Results. Discharge data were present from 118 hospitals in the United States. First-stage surgical palliation was performed in 1949 neonates with 30% mortality. Mortality decreased from 43% in 1998 to 18% in 2007. Large institutional case volume and later era of surgery were associated with improved operative mortality in first-stage palliation. Primary cardiac transplantation was performed in 28 neonates, and rescue transplantation in 11, with 36% mortality. Second-stage palliation was performed in 1244 patients with 5.2% mortality, and third-stage palliation was performed in 1084 patients with 4.1% mortality. An additional 62 patients over 1 month of age at time of admission received cardiac transplantation with 15% mortality. Conclusions. First-stage palliative mortality for hypoplastic left heart syndrome fell dramatically over the past decade, while that for second- and third-stage procedures remained stable. The cumulative operative mortality for three-staged repair of hypoplastic left heart syndrome was 39% over the decade, but fell to 24% for procedures in 2007.     

Acute Interventions for Stenosed Right Ventricle‐Pulmonary Artery Conduit Following the Right‐Sided Modification of Norwood‐Sano Procedure

Introduction. The Norwood stage 1 procedure was modified by Sano with right ventricle‐pulmonary artery (RV–PA) conduit replacing BT shunt. In our institution, this has been further modified by placing the conduit from the RV outflow tract to the right side of the neo‐aorta. Patients and Methods. Between April 2002 and October 2008, 227 modified Norwood procedures were performed. Eighteen had the Sano modification with the conduit to the left of the neo‐aorta whereas 209 had the right‐sided modification, which is the study population. A total of 18 (8.6%) patients presented with cyanosis due to conduit stenosis with median age 4 months and median weight 6.3 kg. Results. Twelve patients underwent transcatheter stent placement in stenosed RV–PA conduit. A total of 16 coronary stents were implanted in 12 patients with 4 patients each receiving 2 stents. The mean saturations increased from 60% to 74%. There was one late mortality which was non‐procedure related. Five patients treated with surgical take down of the RV–PA conduit and creation of a cavo‐pulmonary shunt, whilst one patient had replacement of RV–PA conduit. There were no early postoperative deaths. The mean saturations improved from 54% to 75%. Conclusions. The RV–PA conduit stenosis is a life‐threatening complication after the modified Norwood Stage I procedure. This may require urgent surgery to replace the conduit or to perform a cavo‐pulmonary shunt but as an alternative, transcatheter stent placement can be used with equal effectiveness and with a low risk of complications. The catheter approach is less invasive and the results show that it is an excellent option to relieve the stenosis even in the right‐sided RV–PA conduit.     

Balloon Atrial Septostomy by a Right Internal Jugular Venous Approach in a Newborn with Hypoplastic Left Heart Syndrome with a Restrictive Atrial Septum

Hypoplastic left heart syndrome with an intact or highly restrictive atrial septum requires urgent decompression of the left atrium. Catheter‐based interventions from the femoral or umbilical veins represent the standard method of atrial decompression. Restrictive atrial septal defects located at the superior portion of the fossa ovalis can be difficult to cross from these access sites. Here, we describe a successful Rashkind balloon atrial septostomy performed from an internal jugular approach.     

Impact of Staged Palliation on Somatic Growth in Patients with Hypoplastic Left Heart Syndrome

Background. Somatic growth pattern in infants undergoing staged palliation for hypoplastic left heart syndrome (Norwood procedure [NP], stage 2 palliation [S2P], and Fontan procedure [FP]) during transition toward a more energy efficient series circulation is not well understood. Objectives. We sought to determine growth pattern in these infants and factors influencing it. Methods. Patients who underwent NP since 2001 and survived at least 1 year after S2P were followed until FP or death/heart transplantation (n = 46). Weight for age z-scores (WAZ) were measured prior to NP; at initial discharge; prior to S2P; at four time periods after S2P; and prior to FP. Impact of gender, race, era of NP, anatomic subtype, NP shunt type, gastrostomy, home-surveillance program (daily weights and pulse oximetry), and interstage oxygen saturation on WAZ was evaluated. Results. Repeated measures anova showed a significant change in WAZ across time periods (P < 0.0005), with a significant decline from Pre-NP to Pre-S2P (P < 0.0005) and steady increase from Pre-S2P to Pre-FP (P= 0.016). None of the factors evaluated had a significant effect on this growth pattern. Length of hospital stay after NP was negatively correlated with WAZ at discharge (P= 0.001), but not for other time periods. Intervals from discharge to S2P and NP to S2P interval did not correlate with WAZ. Conclusion. Somatic growth is significantly impaired after NP but recovers steadily following S2P, as the patient transitions toward separated series circulation. Earlier S2P may lead to earlier resumption of normal growth in this critical period of early infancy.     

Palliation via Hybrid Procedure of a 1.4‐kg Patient with a Hypoplastic Left Heart

Despite improvements in survival of patients with hypoplastic left heart syndrome (HLHS) with various palliative procedures, certain risk factors, such as weight less than 2.5 kg, continue to predict increased mortality. We report the palliation of a patient with HLHS weighing 1.4 kg via a hybrid procedure consisting of banding of the pulmonary arteries bilaterally, stenting the ductus arteriosus, and balloon atrial septostomy. We propose that this may be another alternative for palliation in this high‐risk patient group.     

Stent Dilatation of a Right Ventricle to Pulmonary Artery Conduit in a Postoperative Patient with Hypoplastic Left Heart Syndrome

A 10‐day‐old child with hypoplastic left heart syndrome (HLHS) underwent first‐stage palliation for HLHS, Norwood procedure with a Sano modification, i.e., placement of a right ventricular to pulmonary artery (RV‐PA) conduit. The patient developed progressively worsening systemic oxygen desaturation in the immediate postoperative period. Stenosis of the proximal RV‐PA conduit was diagnosed by echocardiography. In the catheterization laboratory stent placement in the conduit was performed. This resulted in increased systemic oxygen saturation. The patient was eventually discharged from the hospital with adequate oxygen saturations.     

A Review of Surgical Atrioventricular Block with Emphasis in Patients with Single Ventricle Physiology

We perceived an increased incidence of surgical atrioventricular (AV) block in patients with single ventricle physiology undergoing two ventricle rehabilitation for hypoplastic left heart syndrome compared to the overall incidence of surgical AV block for our institution. Retrospective investigation of our center's data revealed a statistically significant increase in the incidence of surgical AV block in the single ventricle population and two ventricle rehabilitation population compared to the two ventricle population. Here we review the literature with respect to historic definitions, incidence, risk factors, pre‐ and post‐op management, current indications for pacemaker placement and added cost and comorbidity associated with surgical AV block. We then offer possible strategies for decreasing the incidence of surgical AV block within both the single and two ventricle populations.