Virtual endoluminal aortic root views determined at coronary CT angiography - an important tool for improving anomalous coronary artery visualization and surgical planning.

Anomalous origin of the coronary arteries, though uncommon, is of great clinical concern. It can be the cause of sudden cardiac death and abnormal cardiac hemodynamics. Advances in electrocardiographically (ECG)-gated multi-detector CT have increased diagnostic accuracy in detecting anomalous origin of coronary arteries and their interarterial and intramural courses. Recent advances in multi-detector CT image processing software have allowed the creation of virtual endoluminal views of the aortic root and improved assessment of the intramural course (the length and relationship to the intercoronary commissure) of the coronary artery, which is of considerable surgical importance. We review our experience with virtual endoluminal imaging in our first 19 cases of interarterial coronary artery anomalies (17 cases of interarterial with intramural segment and 2 cases of purely interarterial course) diagnosed preoperatively and proven surgically.

Utility of the Medtronic microvascular plug™ as a transcatheter implantable and explantable pulmonary artery flow restrictor in a swine model.

BACKGROUND: A surgical pulmonary artery band (PAB) is used to control excessive pulmonary blood flow for certain congenital heart diseases. Previous attempts have been made to develop a transcatheter, implantable pulmonary flow restrictor (PFR) without great success. We modified a microvascular plug (MVP) to be used as a PFR. The objectives of this study were to demonstrate feasibility of transcatheter implantation and retrieval of the modified MVP as a PFR, and compare PA growth while using the PFR versus PAB. METHODS AND RESULTS: The PFR was implanted in eight newborn piglets in bilateral branch pulmonary arteries (PAs). Immediately post-PFR implantation, the right ventricular systolic pressure increased from a median of 20-51 mmHg. Transcatheter retrieval of PFR was 100% successful at 3, 6, and 9 weeks and 50% at 12-weeks post-implant. A left PAB was placed via thoracotomy in four other newborn piglets. Debanding was performed 6-weeks later via balloon angioplasty. On follow-up, the proximal left PA diameters in the PFR and the PAB groups were similar (median 8 vs. 7.1 mm; p = 0.11); albeit the surgical band sites required repeat balloon angioplasty secondary to recurrent stenosis. By histopathology, there was grade II vessel injury in two pigs immediately post-retrieval of PFR that healed by 12 weeks. CONCLUSIONS: Transcatheter implantation and retrieval of the MVP as a PFR is feasible. PA growth is comparable to surgical PAB, which is likely to require reinterventions. The use of the MVP as a PFR in humans has to be trialed before recommending its routine use.

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.

Femoral vein homograft as Sano shunt results in improved pulmonary artery growth after Norwood operation.

OBJECTIVE: To evaluate differences in interstage growth of pulmonary arteries between use of polytetrafluoroethylene and femoral vein homograft as Sano shunt during stage-I Norwood palliation. METHODS: A retrospective review of all patients who survived to the second stage following Norwood-Sano operation at two institutions was performed. Either polytetrafluoroethylene or the valved segment of femoral vein homograft was used for construction of the Sano shunt. The size of pulmonary arteries was compared at pre-Glenn catheterisation. RESULTS: A total of 48 neonates with the diagnosis of hypoplastic left heart syndrome or its variants comprised the study population. Femoral vein homograft of 5-6 mm diameter was used in 14 and polytetrafluoroethylene graft of 5 mm was used in 34 patients. The two groups were comparable in terms of preoperative demographics and age at time of pre-Glenn catheterisation (3.9±0.7 versus 3.4±0.8 months, p=0.06). Patients who received femoral vein homograft demonstrated a significantly higher pre-Glenn Nakata index [264 (130-460) versus 165 (108-234) mm2/m2, p=0.004]. The individual branch pulmonary arteries were significantly larger in the femoral vein group (right, 7.8±3.6 versus 5.0±1.2, p=0.014; left, 7.2±2.1 versus 5.6±1.9, p=0.02). There were no differences in cardiac index, Qp:Qs, ventricular end-diastolic pressure or systemic oxygen saturations. CONCLUSIONS: Utilisation of a valved segment of femoral vein homograft as right ventricle to pulmonary artery conduit during Norwood-Sano operation confers better interstage growth of the pulmonary arteries. Further studies are needed to evaluate the impact of femoral vein homograft on single ventricle function.

Left thoracic sympathectomy in a premature infant with long QT syndrome and heart failure.

Left thoracic sympathectomy has been shown to be an effective treatment for adults with long QT syndrome who are refractory to medical therapy. We report the successful use of left thoracic sympathectomy for the management of a 10-week-old premature baby with long QT syndrome and heart failure from a large ventricular septal defect and patent ductus arteriosus.

Right ventricular function after repair of tetralogy of Fallot: a comparison between bovine pericardium and porcine small intestinal extracellular matrix.

BACKGROUND: The porcine small intestinal extracellular matrix reportedly has the potential to differentiate into viable myocardial cells. When used in tetralogy of Fallot repair, it may improve right ventricular function. We evaluated right ventricular function after repair of tetralogy of Fallot with extracellular matrix versus bovine pericardium. METHOD: Subjects with non-transannular repair of tetralogy of Fallot with at least 1 year of follow-up were selected. The extracellular matrix and bovine pericardium groups were compared. We used three-dimensional right ventricular ejection fraction, right ventricle global longitudinal strain, and tricuspid annular plane systolic excursion to assess right ventricular function. RESULTS: The extracellular matrix group had 11 patients, whereas the bovine pericardium group had 10 patients. No differences between the groups were found regarding sex ratio, age at surgery, and cardiopulmonary bypass time. The follow-up period was 28±12.6 months in the extracellular matrix group and 50.05±17.6 months in the bovine pericardium group (p=0.001). The mean three-dimensional right ventricular ejection fraction (55.7±5.0% versus 55.3±5.2%, p=0.73), right ventricular global longitudinal strain (-18.5±3.0% versus -18.0±2.2%, p=0.44), and tricuspid annular plane systolic excursions (1.59±0.16 versus 1.59±0.2, p=0.93) were similar in the extracellular matrix group and in the bovine pericardium group, respectively. Right ventricular global longitudinal strain in healthy children is reported at -29±3% in literature. CONCLUSION: In a small cohort of the patients undergoing non-transannular repair of tetralogy of Fallot, there was no significant difference in right ventricular function between groups having extracellular matrix versus bovine pericardium patches followed-up for more than 1 year. Lower right ventricular longitudinal strain noted in both the groups compared to healthy children.

Influence of weight at the time of first palliation on survival in patients with a single ventricle.

BACKGROUND: Numerous advances in surgical techniques and understanding of single-ventricle physiology have resulted in improved survival. We sought to determine the influence of various demographic, perioperative, and patient-specific factors on the survival of single-ventricle patients following stage 1 palliation at our institution. METHODS: We conducted a retrospective study of all single-ventricle patients who had undergone staged palliation at our institution over an 8-year period. Data were collected from the Society of Thoracic Surgeons Congenital Heart Surgery database and from patient charts. Information on age, weight at stage 1 palliation, prematurity, genetic abnormalities, non-cardiac anomalies, ventricular dominance, and type of palliation was collected. Information on mortality and unplanned reinterventions was also collected. RESULTS: A total of 72 patients underwent stage 1 palliation over an 8-year period. There were 12 deaths before and one death after stage 2 palliation. There was no hospital mortality following Glenn or Fontan procedures. On univariate analysis, low weight at the time of stage 1 palliation and prematurity were found to be risk factors for mortality following stage 1 palliation. However, multivariable Cox regression analysis revealed weight at stage 1 palliation to be a strong predictor of mortality. The type of stage 1 palliation did not have any influence on the outcome. No difference in survival was noted following the Glenn procedure. CONCLUSION: Low weight has a deleterious impact on survival following stage 1 palliation. This is mitigated by stage 2 palliation. The type of stage 1 palliation itself has no bearing on the outcome.

Common pulmonary vein atresia: report of three cases and review of the literature.

Common pulmonary vein atresia is a rare and usually fatal congenital anomaly, in which the pulmonary veins come together to form a confluence that does not connect to the left atrium. We report our experience with three cases of common pulmonary vein atresia and review the literature on this anomaly. The diagnosis of common pulmonary vein atresia must be entertained in any newborn that presents with cyanosis, refractory acidosis, and decreased systemic perfusion within the first 48 hours of life. Echocardiography is a useful screening tool, but cardiac catheterisation is the preferred diagnostic tool. Common pulmonary vein atresia can be fatal without surgical intervention, but survival after surgery continues to be poor.

Lessons learned with the use of CentriMag as short-term ventricular assist device in a child.

The CentriMag ventricular assist device is an extracorporeal, third-generation, continuous flow device. The rapidity and simplicity of operation along with low priming volume make it attractive for use in children with refractory heart failure. We report the successful use of CentriMag as a bridge to recovery in a child and discuss issues that are unique to its use in children.

Surgical management of symptomatic neonates with Ebstein's anomaly: choice of operation.

OBJECTIVE: Symptomatic neonates with Ebstein's anomaly pose significant challenge. Within this cohort, neonates with associated anatomical pulmonary atresia have higher mortality. We review our experience with this difficult subset. METHODS: A total of 32 consecutive symptomatic neonates with Ebstein's anomaly underwent surgical intervention between 1994 and 2013. Of them, 20 neonates (62%, 20/32) had associated pulmonary atresia. Patients' weights ranged from 1.9 to 3.4 kg. All patients without pulmonary atresia had two-ventricle repair. Of the 20 neonates, 16 (80%, 16/20) with Ebstein's anomaly and pulmonary atresia had two-ventricle repair and 4 had single-ventricle palliation, of which 2 underwent Starnes' palliation and 2 Blalock-Taussig shunts. Six recent patients with Ebstein's anomaly and pulmonary atresia had right ventricle to pulmonary artery valved conduit as part of their two-ventricle repair. RESULTS: Overall early mortality was 28% (9/32). For those without pulmonary atresia, mortality was 8.3% (1/12). For the entire cohort of neonates with Ebstein's anomaly and pulmonary atresia, mortality was 40% (8/20; p=0.05). Mortality for neonates with Ebstein's anomaly and pulmonary atresia having two-ventricle repair was 44% (7/16). Mortality for neonates with Ebstein's anomaly and pulmonary atresia having two-ventricle repair utilising right ventricle to pulmonary artery conduit was 16% (1/6). For those having one-ventricle repair, the mortality was 25% (1/4). CONCLUSIONS: Surgical management of neonates with Ebstein's anomaly remains challenging. For neonates with Ebstein's anomaly and anatomical pulmonary atresia, single-ventricle palliation is associated with lower early mortality compared with two-ventricle repair. This outcome advantage is negated by inclusion of right ventricle to pulmonary artery conduit as part of the two-ventricle repair.

A Simplified Staged Left Ventricular Recruitment Strategy to Achieve Biventricular Repair in a Neonate With Hypoplastic Left Heart Variant.

Hypoplastic left heart complex presents a diverse spectrum of variants. Traditional management has been dichotomous, involving either single ventricle palliation or high-risk biventricular repair. Surgical approaches to achieve biventricular repair in children with borderline left ventricle are continually evolving. One such method is the staged left ventricular recruitment (SLVR) strategy. Here, we illustrate a unique surgical approach to SLVR, achieving biventricular repair over 22 months in a neonate with hypoplastic left heart variant.

Bloodless surgery in a pediatric Jehovah's Witness.

Pediatric cardiac surgery in Jehovah's Witness patients who refuse the use of blood products remains a challenge because of the extreme hemodilution caused by priming the circuit and subsequent cardiopulmonary bypass. We report our successful strategy for reducing the prime volume for a 2-year-old Jehovah's Witness patient who required open heart surgery. We modified our conventional bypass circuit requirements for this size child by incorporating a lower prime oxygenator and reducing the size of the venous line and circuit, which decreased the circuit prime volume. We managed to reduce our initial sanguineous prime volume from 315 to 210 mL. The prime was further reduced to 160 mL by minimizing circuit length at the field and with venous prime sequestration prebypass. The postbypass hematocrit was 31%. Bloodless pediatric cardiac surgery in Jehovah's Witness patients can be performed safely. Incorporating a lower prime oxygenator into a revised circuit alleviated the need for blood transfusion and allowed us to achieve our calculated flow rate of 2.6 L/min/m2 while maintaining a hematocrit of 31%.

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.

Incidence of Acute Neurological Events in Neonates and Infants Undergoing Cardiac Surgery Using a High-Hematocrit/ High-Flow Bypass Strategy.

Background: The incidence of new acute neurological injury occurring in neonates and infants during cardiac surgery utilizing cardiopulmonary bypass is reportedly 3% to 5%. In 2013, we adopted a high flow rate, and high hematocrit bypass strategy, and sought to assess the incidence of early neurological injuries associated with this strategy. Methods: Neonates and infants undergoing cardiopulmonary bypass between January 2013 and December 2019 (n = 714) comprise the study. Adverse neurological events (ANEs) were defined as any abnormality of pupils, delayed awakening, seizures, focal neurological deficits, concerns prompting neurological consultation, or any abnormality on neurological imaging in the postoperative period. Our bypass strategy included a high flow rate (150-200 mL/kg/min), without reduction of flow rates during cooling and maintaining a target hematocrit on bypass > 32% with a terminal hematocrit of > 42%. Results: Median weight at the time of the procedure was 4.6 kg (IQR 3.6-6.1 kg) with the smallest patient weighing 1.36 kg. There were 46 premature patients (6.4%). There were 149 patients (20.9%) patients who underwent deep hypothermic circulatory arrest with a median time of 26 min (IQR 21-41 min). Hospital mortality was 3.5% (24/714, 95% CI: 2.28-5.13). The incidence of neurological events as defined above was 0.84% (6/714, 95% CI: 0.31-1.82). Neurological imaging identified ischemic injury in 4 patients and intraventricular hemorrhage in 2. Conclusions: High flow/high hematocrit bypass strategy was associated with a low incidence of ANE in this vulnerable population.

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.

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.

Ross-Konno Operation in an Infant With a Quadricuspid Pulmonary Valve and Anomalous Aortic Origin of the Right Coronary Artery.

Anomalous aortic origin of the right coronary artery from the left aortic sinus is a rare congenital anomaly that is generally repaired during adolescence when the condition is associated with symptoms. It is rarely diagnosed in infancy. Similarly, a quadricuspid pulmonary valve is also a rare finding, and there are scant data to evaluate whether this malformation of the pulmonary valve is suitable to be used for a Ross operation. This report describes a case in which both these anomalies coexisted in an infant who underwent a successful Ross-Konno operation.