High acetylsalicylic acid dosing in infants after modified Blalock-Taussig shunt.

OBJECTIVE: Shunt-related adverse events are frequent in infants after modified Blalock-Taussig despite use of acetylsalicylic acid prophylaxis. A higher incidence of acetylsalicylic acid-resistance and sub-therapeutic acetylsalicylic acid levels has been reported in infants. We evaluated whether using high-dose acetylsalicylic acid can decrease shunt-related adverse events in infants after modified Blalock-Taussig. METHODS: In this single-centre retrospective cohort study, we included infants ⩽1-year-old who underwent modified Blalock-Taussig placement and received acetylsalicylic acid in the ICU. We defined acetylsalicylic acid treatment groups as standard dose (⩽7 mg/kg/day) and high dose (⩾8 mg/kg/day) based on the initiating dose. RESULTS: There were 34 infants in each group. Both groups were similar in age, gender, cardiac defect type, ICU length of stay, and time interval to second stage or definitive repair. Shunt interventions (18 versus 32%, p=0.16), shunt thrombosis (14 versus 17%, p=0.74), and mortality (9 versus 12%, p=0.65) were not significantly different between groups. On multiple logistic regression analysis, single-ventricle morphology (odds ratio 5.2, 95% confidence interval of 1.2-23, p=0.03) and post-operative red blood cells transfusion ⩾24 hours [odds ratio 15, confidence interval of (3-71), p<0.01] were associated with shunt-related adverse events. High-dose acetylsalicylic acid treatment [odds ratio 2.6, confidence interval of (0.7-10), p=0.16] was not associated with decrease in these events. CONCLUSIONS: High-dose acetylsalicylic acid may not be sufficient in reducing shunt-related adverse events in infants after modified Blalock-Taussig. Post-operative red blood cells transfusion may be a modifiable risk factor for these events. A randomised trial is needed to determine appropriate acetylsalicylic acid dosing in infants with modified Blalock-Taussig.

Recommendations for utilization of the paracorporeal lung assist device in neonates and young children with pulmonary hypertension.

The management of decompensating critically ill children with severe PH is extremely challenging and requires a multidisciplinary approach. Unfortunately, even with optimal care, these children might continue to deteriorate and develop inadequate systemic perfusion and at times cardiac arrest secondary to a pulmonary hypertensive crisis. Tools to support these children are limited, and at times, the team should proceed with offering extracorporeal support, especially in newly diagnosed patients who have not benefitted from medical therapy prior to their acute deterioration, in patients with severe pulmonary venous disease and in patients with alveolar capillary dysplasia. Currently, the only approved mode for extracorporeal support in pediatric patients with PH eligible for lung transplantation is ECMO. To decrease the risks associated with ECMO, and offer potential for increased duration of support, extubation, and rehabilitation, we transitioned four small children with refractory PH from ECMO to a device comprising an oxygenator interposed between the PA and LA. This work describes in great detail our experience with this mode of support with emphasis on exclusion criteria, the implantation procedure, and the post-implantation management.

Rescue Sternotomy in a 540†g Neonate for Right Atrial Perforation During Percutaneous Ductal Device Occlusion.

Percutaneous ductal device closure in neonates is gaining popularity. Cardiac perforation is a rare but catastrophic complication that can occur during this procedure. Surgical options to salvage this situation are limited in extremely low-weight babies. In this report, we describe one such case managed successfully and offer some suggestions to achieve a successful outcome.

Cardiopulmonary bypass in neonates and infants: advantages of high flow high hematocrit bypass strategy-clinical practice review.

Cardiopulmonary bypass is an integral and indispensable part of surgical repair of congenital heart defects. While the complications and morbidity secondary to the use of cardiopulmonary bypass has decreased considerably, there remains a significant incidence of clinically relevant renal and neurological injury. To provide more physiological delivery of oxygenated blood to the end-organs, our center has been successfully using a high-flow, high hematocrit cardiopulmonary bypass strategy since 2006. The essential components of this strategy include maintaining high flows (typically 200 mL/kg/min in neonates, 150-175 mL/kg/min in older infants weighing <10 kg, and 2.6 L/min/m2 in older children) throughout the duration of cardiopulmonary bypass irrespective of patient temperature, as well as maintaining a hematocrit of at least 32% on cardiopulmonary bypass. The incidence of post-operative acute kidney injury (around 3%) and clinical acute neurological events (<1%) with this strategy is considerably less when compared to other contemporary publications using the conventional cardiopulmonary bypass strategy. In this review, we discuss the rationale behind our approach and present evidence to support the high-flow, high-hematocrit strategy. We also discuss the practical aspects of our strategy and describe the adjuncts we use to derive additional benefits. These adjuncts include the use of a hybrid pH/alpha stat strategy during cooling/rewarming, aggressive use of conventional ultrafiltration during cardiopulmonary bypass, a terminal hematocrit of 40-45%, and avoidance of milrinone and albumin in the early peri-operative period. This results in a very low incidence of post-operative bleeding, facilitates chest closure in the operating room even in most neonates, helps in reducing the need for post-operative blood product transfusion and helps in achieving a favorable post-operative fluid balance early after surgery.

Iatrogenic pseudoaneurysm of the innominate artery in a neonate.

A 2.8-kg infant underwent urgent repair of a large iatrogenic pseudoaneurysm of the innominate artery, which was compressing the airway and superior vena cava, creating critical respiratory instability. The pseudoaneurysm was repaired with complete resolution of all respiratory symptoms.

Alternative cannulation strategy for pediatric ECMO.

Vascular access in children who require extracorporeal membrane oxygenation (ECMO) support can be a challenging endeavor particularly in those who have undergone prior median sternotomies or interventional procedures. We present an alternative cannulation strategy that can be utilized in pediatric patients requiring ECMO that involves utilization of the iliac vein via a retroperitoneal approach.

Current surgical techniques in the management of the symptomatic neonate with severe Ebstein anomaly: Too much, too little, or just enough?

The management of severely symptomatic neonates with Ebstein anomaly is challenging during the early neonatal period. Initial management goals should focus on mitigating a central shunt; providing respiratory mechanical support; providing an adequate but not excessive source of pulmonary blood flow; and minimizing pulmonary vascular resistance. For most patients thus stabilized, definitive repair should be prudently deferred until it is safe for a bailout bidirectional Glenn anastomosis to be added, usually at age 3 to 4 months. For those who remain critical, initial ligation of the large ductus and placing a more peripheral aortopulmonary shunt, or ligating the main pulmonary artery, should be weighed against a primary biventricular repair (Knott-Craig repair), or the Starnes' single-ventricle palliation. The Da Silva cone biventricular repair should generally be avoided during the early neonatal period. An initial Starnes' repair can be potentially converted to a biventricular repair in later infancy.

Impact of Different Cardiopulmonary Bypass Strategies on Renal Injury After Pediatric Heart Surgery.

BACKGROUND: The purpose of this study is to compare the incidence and severity of acute kidney injury (AKI) after open heart surgery in neonates and infants for two different cardiopulmonary bypass (CPB) strategies. METHODS: In all, 151 infants undergoing cardiac surgery were prospectively enrolled between June 2017 and June 2018 at two centers, one using conventional CPB (2.4 L · min-1 · m-2, 150 mL · kg-1 · min-1) with reduction of flow rates with moderate hypothermia and with a targeted hematocrit greater than 25% (center 1, n = 91), and the other using higher bypass flow rates (175 to 200 mL · kg-1 · min-1) and higher minimum hematocrit (greater than 32%) CPB (center 2, n = 60). The primary endpoint was the incidence of postoperative AKI as defined by Acute Kidney Injury Network criteria and risk factors associated with AKI. RESULTS: Preoperative characteristics and complexity of surgery were comparable between centers. The overall incidence of early postoperative AKI was 10.6% (16 of 151), with 15.4% (14 of 91) in center 1 and 3.3% (2 of 60) in center 2 (P = .02). Mean lowest flow rates on CPB were 78 mL · kg-1 · min-1 vs 118 mL · kg-1 · min-1 and mean highest hematocrit on separation from CPB were 33% vs 43% at center 1 and 2, respectively (P < .001). Center 1 used less packed red blood cells but more fresh frozen plasma than center 2 (P = .001). By multivariate analysis, only lower flows on CPB (78 vs 96 mL · kg-1 · min-1, P = .043) and lower hematocrit at the end of CPB (33% vs 37%, P = .007) were associated with AKI. CONCLUSIONS: In this contemporary comparative study, higher flow rates and higher hematocrit during cardiopulmonary bypass were associated with better preservation of renal function.

Surgical management of intrapericardial teratoma in the fetus.

Intrapericardial teratomas often present as life-threatening problems when diagnosed during fetal life. They are large lesions that compress the heart and lungs and can result in tamponade if not treated expeditiously. We present a case of a large teratoma that was managed by prenatal pericardiocentesis followed by surgical resection.

Single Institution Experience With International Referrals for Pediatric Cardiac Surgery.

BACKGROUND: Pediatric cardiac surgery in developing countries poses many challenges. The practice of referring patients from abroad via nongovernmental organizations has occurred for many years. We describe our experience with international referrals for pediatric cardiac surgery via Gift of Life Mid-South to the Heart Institute, Le Bonheur Children's Hospital in Memphis, Tennessee. METHODS: We performed a retrospective descriptive review of data collected in our Society of Thoracic Surgeons Congenital Heart Surgery Database (STS CHSD) along with data from our electronic medical record from January 1, 2007, to December 31, 2017. Available data included patient demographics, diagnoses, surgical procedure, entire inpatient length of stay (LOS), complications, and operative mortality. Cardiac surgeries were grouped according to the Society of Thoracic Surgeons-European Association for Cardio-Thoracic Surgery Congenital Heart Surgery Mortality Categories (STAT Mortality Categories). Complications were defined according to the STS CHSD. RESULTS: In this retrospective descriptive study, case complexity level varied; however, 38% cardiac surgeries were in STAT Mortality Category 3 or 4. Honduras was the most common referral source with a total of 18 countries represented. Operative mortality remained very low (1 [1.4%] of 71 cardiac surgeries) despite patients being referred beyond infancy. There were an increasing number of complications and longer inpatient LOS (with greater variance) in STAT Mortality Category 4. CONCLUSIONS: International patients referred for congenital heart surgery can be successfully treated with an acceptable mortality rate despite late referrals. Inpatient LOS is related to surgical complexity. Follow-up studies are needed to determine the long-term outcomes of these patients.

Outcomes and Trends of Ventricular Assist Device Selection in Children with End-Stage Heart Failure.

We aimed to examine trends in ventricular assist device (VAD) selection, continuous flow devices (CFD) versus pulsatile flow devices (PFD), and their associated outcomes in children eligible for both device types. To accomplish this, the United Network for Organ Sharing database was reviewed for pediatric patients listed for heart transplant (HT) from January 2007 to June 2014. Patients were included if a durable VAD was present at wait listing or when removed from the waiting list and who met size eligibility for a CFD (BSA > 1.0 m). In total, 253 patients met inclusion criteria, 144 (57%) CFD and 109 (43%) PFD. Device type varied significantly based on year with CFD increasing from 11% in 2007 to 88% in 2014 (p < 0.01). PFD patients were younger, had a lower BSA, and an increased rate of extracorporeal membrane oxygenation and biventricular assist device support at listing. Survival to transplant or recovery was similar for CFDs and PFDs (96 vs. 94%; p = 0.57), as was the post-HT survival, 95% for both device types. Despite PFD patients having more risk factors for a poor outcome, survival was similar between device types. Even so, there is a dramatic trend toward CFD utilization in patients who are large enough to support one.

Improved survival after heart transplant for failed Fontan patients with preserved ventricular function.

BACKGROUND: Patients with a failing Fontan continue to have decreased survival after heart transplant (HT), particularly those with preserved ventricular function (PVF) compared with impaired ventricular function (IVF). In this study we evaluated the effect of institutional changes on post-HT outcomes. METHODS: Data were retrospectively collected for all Fontan patients who underwent HT. Mode of failure was defined by the last echocardiogram before HT, with mild or no dysfunction considered PVF and moderate or severe considered IVF. Outcomes were compared between early era (EE, 1995 to 2008) and current era (CE, 2009 to 2014). Management changes in the CE included volume load reduction with aortopulmonary collateral (APC) embolization, advanced cardiothoracic imaging, higher goal donor/recipient weight ratio and aggressive monitoring for post-HT vasoplegia. RESULTS: A total of 47 patients were included: 27 in the EE (13 PVF, 14 IVF) and 20 in the CE (12 PVF, 8 IVF). Groups were similar pre-HT, except for more PLE in PVF patients. More patients underwent APC embolization in the CE (80% vs 28%, p < 0.01). There was no difference in donor/recipient weight ratio between eras. There was a trend toward higher primary graft failure for PVF in the EE (77% vs 36%, p = 0.05) but not the CE (42% vs 75%, p = 0.20). Overall, 1-year survival improved in the CE (90%) from the EE (63%) (p = 0.05), mainly due to increased survival for PVF (82 vs 38%, p = 0.04). CONCLUSIONS: Post-HT survival for failing Fontan patients has improved, particularly for PVF. In the CE, our Fontan patients had a 1-year post-HT survival similar to other indications.

Pulmonary Valve Replacement With Small Intestine Submucosa-Extracellular Matrix in a Porcine Model.

BACKGROUND: Prosthetic materials available for pediatric pulmonary valve replacement (PVR) lack growth potential, inevitably leading to a size mismatch. Small intestine submucosa-derived extracellular matrix (SIS-ECM) has been suggested to possess regenerative properties. We aimed to investigate its function and potential to increase in size as a PVR in a piglet. METHODS: An SIS-ECM trileaflet valved conduit was designed. Hanford minipigs, n = 6 (10-34 kg), underwent PVR with an intended survival of six months, with monthly echocardiograms evaluating valve size and function. The conduit was excised for histologic analysis. RESULTS: Of the six, one was sacrificed at three months for midterm analysis, and one at month 3 due to endocarditis. The remaining four constituted the study cohort. The piglet weight increased by 186% (19.56 ± 10.22 kg to 56.00 ± 7.87 kg). Conduit size increased by 30% (1.42 ± 0.14 cm to 1.84 ± 0.14 cm; P < .01). The native right ventricular outflow tract increased by 43% and the native pulmonary artery by 84%, resulting in a peak gradient increase from 10.08 ± 2.47 mm Hg to 36.25 ± 18.80 mm Hg (P = .03). Additionally, all valves developed at least moderate regurgitation. Conduit histology showed advanced remodeling with myofibroblast infiltration, neovascularization, and endothelialization. The leaflets remodeled beginning at the base with the leaflet edge being less cellular. In addition to the known endocarditis, bacterial colonies were discovered within a leaflet in another. CONCLUSIONS: The SIS-ECM valved conduit implanted into a piglet demonstrated cellular infiltration with vascular remodeling and an increase in diameter. Conduit stenosis was a result of slower rates of size increase than native tissue. Suboptimal leaflet performance requires design modifications.

Successful bridge through transplantation with berlin heart ventricular assist device in a child with failing fontan.

In patients with failed Fontan circulation, end-stage heart failure can develop or Fontan physiology failure requiring transplantation. Experience with ventricular assist device support for these patients as a bridge to heart transplantation has been limited and often not resulted in successful hospital discharge. We report the successful use of the Berlin Heart EXCOR (Berlin Heart, The Woodlands, TX) ventricular assist device in bridging a child with Fontan circulation and systolic dysfunction to heart transplantation and discharge home.

Continuous Flow Device Support in Children Using the HeartWare HVAD: 1,000 Days of Lessons Learned From a Single Center Experience.

The purpose of this study is to provide a single center experience with a continuous flow device in adolescents with end-stage heart failure. A retrospective single center analysis of patients aged 18 years or younger implanted with HVAD (HeartWare Inc, Framingham, MA) between October 2012 and March 2014 was performed. Demographics, preimplant and postimplant clinical data, survival, and adverse events (AEs) were recorded. A matched group of adults based on diagnosis, body surface area (BSA), and time period were used for outcome comparisons. Six adolescents with dilated cardiomyopathy were implanted with the HVAD. Median age and BSA were 13.4 years and 1.45 m2, respectively. All were Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) profile-1 or profile-2. Median days on device were 108 with total patient-days on device of 1,017. Four adolescents were discharged home on device all in New York Heart Association 1. Five underwent transplantation with 100% survival. There were 18 AEs with one AE per 170 days on device. Compared with the adult cohort (n = 5), there was no difference in 1 year survival (p = 0.32). HVAD support in adolescents is highly successful as a bridge to transplantation. It provides early rehabilitation and improvement in quality of life. Morbidity is not negligible but appears comparable with that seen in adults.

Pediatric Quality of Life while Supported with a Ventricular Assist Device.

OBJECTIVE: Ventricular assist devices (VADs) have emerged as an important treatment option for bridging pediatric patients with heart failure to transplant. VADs have shown improved survival; however, the pediatric quality of life (QoL) while on VAD support is unknown. We aimed to evaluate the QoL of our pediatric patients while supported with a VAD. DESIGN: In this prospective study, pediatric patients who underwent VAD placement, and their parents, were administered a generic Pediatric Quality of Life Inventory (PedsQL) 4.0 pre-VAD implant, when feasible, after the acute postoperative period, and then periodically until heart transplant or death. Their final scores while on support were compared with three previously reported groups: healthy controls, outpatients with severe heart disease, and children after heart transplant. RESULTS: From January 2008 to July 2014, 13 pediatric patients required VAD support greater than 2 weeks and completed a PedsQL. The mean age at implant was 10.0 ± 4.2 years and median duration of support was 1.6 (0.5-19.7) months. Eleven (85%) patients survived to transplant with one (8%) patient remaining alive on support. The median duration of support prior to their final PedsQL was 1.4 (0.5-11.4) months. Patients self-reported significantly (P < .05) lower total and physical QoL scores when compared with all three comparison groups. Self-reported psychosocial QoL scores were significantly lower than healthy controls only. Parent proxy-reported scores were significantly lower than all three comparison groups for all three categories (P < .05). CONCLUSIONS: A large deficit exists in the total QoL of pediatric patients supported by a VAD compared with outpatient management of severe heart disease or postheart transplant patients; however, VAD patients do represent a group with more severe heart failure. Improvements in QoL must be made, as time spent with a VAD will likely continue to increase.

Early Biventricular Assist Device Use in Children: A Single-Center Review of 31 Patients.

Biventricular assist device (BiVAD) support is considered a risk factor for worse outcomes compared with left ventricular assist device (LVAD) alone for children with end-stage heart failure. It remains unclear whether this is because of the morbidity associated with a second device or the underlying disease severity. We aimed to show that early BiVAD support can result in good survival by analyzing our prospectively collected database for all pediatric patients who underwent BiVAD implantation. From 2005 to 2009, BiVADs were used exclusively. From 2010 to 2014, LVAD alone was considered, maintaining a low threshold for BiVAD support. All BiVADs were pulsatile devices. Thirty-one patients with median age of 3.5 years received BiVAD support. Diagnoses included dilated cardiomyopathy in 17 (55%), myocarditis in 6 (19%), and congenital heart disease in 3 (10%). Survival to transplant was achieved in 27 (87%) with a median duration of 41 days (interquartile range, 15-69). Adverse event rates (per 100 days of support) were bleeding at 0.52, infection at 1.17, and central nervous system dysfunction at 0.78. Of those who survived to transplant, 26 (96%) remain alive with a median follow-up of 55 months. These results show that BiVAD support can bridge patients to transplant with excellent long-term survival.

Incidence of Platelet Dysfunction by Thromboelastography-Platelet Mapping in Children Supported with ECMO: A Pilot Retrospective Study.

BACKGROUND: Bleeding complications are common and decrease the odds of survival in children supported with extracorporeal membrane oxygenation (ECMO). The role of platelet dysfunction on ECMO-induced coagulopathy and resultant bleeding complications is not well understood. The primary objective of this pilot study was to determine the incidence and magnitude of platelet dysfunction according to thromboelastography (TEG(®))-platelet mapping (PM) testing. METHODS: Retrospective chart review of children <18 years old who required ECMO at a tertiary level hospital. We collected TEG(®)-PM and conventional coagulation tests data. We also collected demographic, medications, blood products administered, and clinical outcome data. We defined severe platelet dysfunction as <50% aggregation in response to an agonist. RESULTS: We identified 24 out of 46 children on ECMO, who had TEG(®)-PM performed during the study period. We found the incidence of severe bleeding was 42% and mortality was 54% in our study cohort. In all samples measured, severe qualitative platelet dysfunction was more common for adenosine diphosphate (ADP)-mediated aggregation (92%) compared to arachidonic acid (AA)-mediated aggregation (75%) (p = 0.001). Also, ADP-mediated percent of platelet aggregation was significant lower than AA-mediated platelet aggregation [15% (interquartile range, IQR 2.8-48) vs. 49% (IQR 22-82.5), p < 0.001]. There was no difference in kaolin-activated heparinase TEG(®) parameters between the bleeding group and the non-bleeding group. Only absolute platelet count and TEG(®)-PM had increased predictive value on receiver operating characteristics analyses for severe bleeding and mortality compared to activated clotting time. CONCLUSION: We found frequent and severe qualitative platelet dysfunction on TEG(®)-PM testing in children on ECMO. Larger studies are needed to determine if the assessment of qualitative platelet function by TEG(®)-PM can improve prediction of bleeding complications for children on ECMO.