Pentalogy of Cantrell (PoC) is a congenital condition characterized by midline thoracoabdominal defects. We report a neonate presenting with mesocardia and a left ventricular diverticulum repaired in a 2-staged approach. Imaging confirmed cardiac and thoracoabdominal defects typical for pentalogy of Cantrell. The histopathology of the diverticulum demonstrated myocardial components with endothelial lining. This case highlights the diagnostic value of multimodal imaging, potential benefits of a staged repair approach, and provides insights into cardiac diverticula associated with pentalogy of Cantrell.

Right ventricular outflow tract (RVOT) obstruction is a hallmark of tetralogy of Fallot (ToF) and related anatomies. Surgical strategies include valve-sparing techniques or transannular patch (TAP) enlargements, optionally with monocusp patch plasty to restore valve competence. This study compares short- and medium-term outcomes of these strategies based on institutional data.A retrospective analysis was conducted on 83 ToF patients who underwent surgery between 2007 and 2021. Median age and weight at surgery were 164 days and 6.0 kg, respectively. Patients were grouped by surgical approach: valve-sparing (commissurotomy/delamination, n = 27; primary infundibulotomy, n = 7) and TAP (without monocusp, n = 38; with monocusp, n = 11). The primary endpoint was freedom from reintervention.Significant preoperative differences were found between groups, including valve morphology, pulmonary annulus z-values, oxygen saturation, and prior palliative interventions. Valve-sparing techniques were associated with less postoperative moderate/severe pulmonary regurgitation (17.6% versus 73.5%; p < 0.001) and a trend toward shorter ICU stays. TAP with monocusp resulted in significantly less pulmonary regurgitation than TAP alone (36.4% versus 84.2%; p = 0.002) and showed a trend toward fewer reinterventions after 5 years (0% versus 38.5%; p = 0.073), with a significant difference at 10 years (14.3% versus 71.4%; p = 0.024).Valve-sparing approaches yield better early outcomes and fewer long-term reinterventions when anatomically feasible. When TAP is necessary, adding a monocusp patch significantly reduces postoperative regurgitation and improves long-term durability.

OBJECTIVES:To investigate the long-term outcomes and risk factors for morbidity and mortality in patients with Ebstein's anomaly, including the effects of type and timing of valve surgery. METHODS:For this retrospective, record-based study, all patients with Ebstein's anomaly enrolled in the German National Register for Congenital Heart Defects up to June 2021 were eligible for inclusion. RESULTS:Non-surgical patients (n = 194/49% of 398 patients) had less tricuspid valve regurgitation (p < 0.001) and heart failure symptoms (p < 0.001) than surgical patients (n = 204/51%). Postoperative survival at 10, 20, and 30 years was 97%, 93%, and 80%. Eighty-one (40%) patients underwent multiple surgeries. Re-operation rates were lowest in patients with first valve surgery during adolescence (p = 0.0076). Postoperative NYHA class > I was more frequent with surgery delayed to older age (p < 0.001). Initial corrective surgery was complicated by complete atrioventricular block (CAVB) in 17 (9%) of patients. CAVB was more likely with older age (p = 0.001), and tricuspid valve replacement compared to reconstruction (p = 0.029). CAVB was associated with all-cause death (p < 0.001). Cone reconstruction reduced the risk of CAVB (p = 0.008) and tricuspid valve regurgitation (p < 0.001) compared to monocusp reconstruction. CONCLUSIONS:This registry-based study of Ebstein's anomaly corroborates good surgical long-term results, while re-operation rates remain high. Patients operated before adolescence were at the highest risk of re-operation, while older age at the time of the first surgery increased the risk of CAVB. The cone reconstruction was associated with improved tricuspid valve function and a lower risk of CAVB compared to monocusp reconstructions. Choosing an optimal time window for surgery and use of the cone reconstruction may therefore further improve outcomes.

Background/Objectives: Cardiovascular manifestations in pediatric Marfan syndrome (MFS) exhibit substantial heterogeneity. Early identification of patients at elevated risk of requiring cardiac surgery is essential to optimizing outcomes. This study aimed to determine phenotypic features associated with cardiovascular surgery in genetically confirmed pediatric MFS. Methods: Among the 1006 children evaluated, 214 with genetically verified MFS were included in the analysis. We categorized patients by the presence or absence of cardiac surgery during childhood. Systemic and cardiovascular features were assessed. We applied binary logistic regression to identify independent associated manifestations with surgical intervention. Results: 20/214 patients (9.3%, 11.5 ± 5.5 years) underwent cardiac surgery (50% aortic root replacement, 20% mitral valve surgery, 30% combined interventions). Extracardiac features—Marfan-type facial features, pectus carinatum, pes planus, hindfoot deformity, and myopia of ≥3 diopters—were significantly associated with an increased probability of surgery (OR 3.0–4.6). Tricuspid valve prolapse and pulmonary artery dilatation were more prevalent in surgical patients. Surgical patients exhibited higher systemic manifestation scores (9.2 vs. 5.2; p ≤ 0.05) per revised Ghent criteria (RGC). Conclusions: A higher systemic score (RGC) correlates with increased risk for surgery. Marfan-type facial features, pectus carinatum, pes planus, hindfoot deformity, and myopia ≥ 3 diopters were strongly associated with the need for early cardiac surgery. Comprehensive phenotypic assessment, including systemic manifestation scoring, enables risk stratification and supports timely surgical planning in pediatric MFS.

Functional univentricular heart disease is the most severe congenital condition, managed by Fontan surgery, which is life-sustaining by creating a non-contractile conduit yet limited by long-term complications. Decellularized ECM (dECM) scaffolds reseeded with contractile human cells offer a promising solution, but key factors for such a biological tube remain undefined. To evaluate the potential of cardiac dECM as a scaffold for recellularization in the development of a contractile Fontan conduit. A systematic review was performed of studies identified in PubMed, Embase, Web of Science, and the Cochrane Library on human or porcine cardiac tissue engineering. Decellularization outcome parameters included efficiency of DNA removal, ECM preservation, and cytocompatibility; recellularization parameters focused on cell viability, co-culture strategies, maturation, and contractility. Fifty-eight studies on decellularization of porcine or human cardiac tissue were included; 13 also investigated recellularization. Most studies reported more than 90

Background: Severe neonatal Ebstein’s anomaly (EA) is associated with a high risk of mortality. A new therapeutic approach aims to combine the advantages of Starnes’ procedure in stabilizing critically ill neonates with the long-term superiority of biventricular physiology after cone reconstruction. Case report: The echocardiography of a male preterm (36 weeks’ gestation; birth weight 2400 g) demonstrated EA Carpentier type C, membranous pulmonary atresia, and hypoplastic pulmonary arteries (PAs). After undergoing the Starnes procedure postnatally, multiple dilatations of the AP shunt and the Starnes fenestration followed. Cone reconstruction was performed at 15 months of age. Surgical revision addressed tricuspid and pulmonary valve insufficiency and PA bifurcation stenosis. Subsequently, PA branch stenosis with severe impairment of right ventricular function and dilatation required stent implantation. At the last follow-up, at 3 years of age, the patient was asymptomatic with sufficient exercise tolerance. Discussion: The American Association for Thoracic Surgery recently recommended evaluating all Starnes patients for potential conversion to cone. Consequently, the Starnes procedure should be modified to facilitate subsequent biventricular correction. Both the optimal timing of conversion and the appropriate assessment to reliably evaluate feasibility and the prospects for success require further investigation. Conclusions: Conversion from Starnes to cone is technically feasible, even in cases of severe EA, prematurity, low birth weight, and additional cardiac comorbidities, and provides promising initial results. Further research is needed to define candidacy and the optimal timing of conversion, and to assess long-term outcomes. The high therapeutic effort and complexity make this treatment approach suitable only for quaternary centers.

Due to the increasing focus on neurodevelopment in children with congenital heart disease (CHD), early predictive markers are crucial for implementing interventions and improving neurodevelopmental outcomes. As postoperative delirium (PD) is known to have a long-term impact on neurocognitive function in adults, studies on the prevalence of and modifiable risk factors for PD offer new perspectives. We conducted a retrospective, single-centre study screening for PD using the Cornell Assessment of Pediatric Delirium (CAPD). We distinguished PD from iatrogenic withdrawal syndrome (IWS) by using the Withdrawal Assessment Tool 1 (WAT-1). A confirmatory, multivariate regression analysis was performed and included various pre-, intra-, and postoperative variables. The screening compliance rate was 95% among the 311 patients. The prevalence of PD was 40.2%, and 46.4% of the patients developed IWS. Infants were at the highest risk for PD (OR 2.9, p = 0.05). Prolonged mechanical ventilation > 100 h (OR 7.4, p = 0.003), infusion therapy with ketamine (OR 3.3, p = 0.009), IWS (mild: OR 7.7, p = < 0.001, severe: OR 17.0, p = < 0.001) and low cardiac output syndrome (LCOS) (OR 3.9, p = 0.02) were significant predictive risk factors for PD. Overall, PD and IWS are highly prevalent in paediatric cardiac intensive care units (pCICUs), especially in infants and children with prolonged ventilation durations who require multiple sedatives. This is one of the most extensive single-centre studies in the pCICU population, and the results revealed that IWS and lactatemia in the context of LCOS are novel predictors of PD.

OBJECTIVESA second paediatric report has been generated from the European Registry for Patients with Mechanical Circulatory Support (EUROMACS). The purpose of EUROMACS, which is operated by the European Association for Cardio-Thoracic Surgery, is to gather data related to durable mechanical circulatory support for scientific purposes and to publish reports with respect to the course of mechanical circulatory support therapy. Since the first report issued, efforts to increase compliance and participation have been extended. Additionally, the data provided the opportunity to analyse patients of younger age and lower weight.METHODSParticipating hospitals contributed pre-, peri- and long-term postoperative data on mechanical circulatory support implants to the registry. Data for all implants in paediatric patients (≤19 years of age) performed from 1 January 2000 to 1 July 2019 were analysed. This report includes updates of patient characteristics, implant frequency, outcome (including mortality rates, transplants and recovery rates) as well as adverse events including neurological dysfunction, device malfunction, major infection and bleeding.RESULTSTwenty-nine hospitals contributed 398 registered implants in 353 patients (150 female, 203 male) to the registry. The most frequent aetiology of heart failure was any form of cardiomyopathy (61%), followed by congenital heart disease and myocarditis (16.4% and 16.1%, respectively). Competing outcomes analysis revealed that a total of 80% survived to transplant or recovery or are ongoing; at the 2-year follow-up examination, 20% died while on support. At 12 months, 46.7% received transplants, 8.7% were weaned from their device and 18.5% died. The 3-month adverse events rate was 1.69 per patient-year for device malfunction including pump exchange, 0.48 for major bleeding, 0.64 for major infection and 0.78 for neurological events.CONCLUSIONSThe overall survival rate was 81.5% at 12 months following ventricular assist device implant. The comparison of survival rates of the early and later eras shows no significant difference. A focus on specific subgroups showed that survival was less in patients of younger age (<1 year of age) (P = 0.01) and lower weight (<20 kg) (P = 0.015). Transplant rates at 6 months continue to be low (33.2%) The fact that the EUROMACS registry is embedded within the European Association for Cardio-Thoracic Surgery Quality Improvement Programme offers opportunities to focus on improving outcomes.

IntroductionVentricular unloading during prolonged bed rest, mechanical circulatory support or microgravity has repeatedly been linked to potentially life-threatening arrhythmias. It is unresolved, whether this arrhythmic phenotype is caused by the reduction in cardiac workload or rather by underlying diseases or external stimuli. We hypothesized that the reduction in cardiac workload alone is sufficient to impair ventricular repolarization and to induce arrhythmias in hearts.MethodsRat hearts were unloaded using the heterotopic heart transplantation. The ECG of unloaded and of control hearts were telemetrically recorded over 56 days resulting in >5 × 106 cardiac cycles in each heart. Long-term electrical remodeling was analyzed using a novel semi-automatic arrhythmia detection algorithm.Results56 days of unloading reduced left ventricular weight by approximately 50%. While unloading did not affect average HRs, it markedly prolonged the QT interval by approximately 66% and induced a median tenfold increase in the incidence of ventricular arrhythmias in comparison to control hearts.ConclusionThe current study provides direct evidence that the previously reported hypertrophic phenotype of repolarization during cardiac unloading translates into an impaired ventricular repolarization and ventricular arrhythmias in vivo. This supports the concept that the reduction in cardiac workload is a causal driver of the development of arrhythmias during ventricular unloading.

Minimally invasive surgical closure of atrial septal defects is gaining widespread acceptance and can be performed via a right midaxillary thoracotomy. In addition, the procedure can be performed in ischaemic cardiac arrest or fibrillation with a core body temperature between 34°C and 36°C. OBJECTIVES:We present our single-centre results of paediatric patients who underwent surgical atrial septal defect II closure via lateral thoracotomy. METHODS:Retrospective analysis. Patients were divided into a cardiac arrest group and a cardiac fibrillation group. All procedures were performed via right midaxillary thoracotomy through a single incision without side ports. RESULTS:All 37 consecutive patients between March 2019 and August 2022 (median age 3 years; percentile 25th: 2; 75th: 5 years) in both groups were free of mortality and postoperative morbidity such as haemodynamically relevant residual shunt or malignant arrhythmias. Cardiopulmonary bypass time was significantly shorter in the fibrillation group (mean: 34.7 min vs 52.6 min, P = 0.01), and all patients were weaned off the ventilator immediately postoperatively. Length of the intensive care unit stay was not different between the 2 groups. Postoperative hospital stay was significantly longer in patients with cardiac arrest (mean: 5.6 days vs 4.9 days, P = 0.04). Postoperative laboratory parameters did not differ between the 2 groups. All patients were discharged with normal left ventricular function and normalized cardiac enzymes. CONCLUSIONS:Minimally invasive closure of an atrial septal defect during atrial fibrillation is a safe procedure with results comparable to those of an induced cardiac arrest procedure.

Congenital heart disease (CHD) is the most common birth defect, and up to 50% of infants with CHD require cardiovascular surgery early in life. Current clinical practice often involves thymus resection during cardiac surgery, detrimentally affecting T-cell immunity. However, epidemiological data indicate that CHD patients face an elevated risk for infections and immune-mediated diseases, independent of thymectomy. Hence, we examined whether the cardiac defect impacts thymus function in individuals with CHD. We investigated thymocyte development in 58 infants categorized by CHD complexity. To assess the relationship between CHD complexity and thymic function, we analyzed T-cell development, thymic output, and biomarkers linked to cardiac defects, stress, or inflammation. Patients with highly complex CHD exhibit thymic atrophy, resulting in low frequencies of recent thymic emigrants in peripheral blood, even prior to thymectomy. Elevated plasma cortisol levels were detected in all CHD patients, while high NT-proBNP and IL-6 levels were associated with thymic atrophy. Our findings reveal an association between complex CHD and thymic atrophy, resulting in reduced thymic output. Consequently, thymus preservation during cardiovascular surgery could significantly enhance immune function and the long-term health of CHD patients.

Background In patients with tetralogy of Fallot (ToF) or ToF-like anatomy, factors possibly impacting the longevity of biological valves in the pulmonary position were investigated. Method Between 1997 and 2017, 79 consecutive hospital survivors with a median age of 8.7 years (range: 0.2-56.1 years; interquartile range [IQR]: 14.8 years) with ToF or ToF-like anatomy underwent surgical implantation of Contegra (n = 34), Hancock (n = 23), Perimount (n = 9), pulmonary homograft (n = 9), and miscellaneous (n = 4) conduits. The median internal graft diameter was 19 mm (range: 11-29 mm; IQR: 8 mm) which refers to a median z-score of 0.6 standard deviation (SD) (range: -1.8 to 4.0 SD; IQR: 2.1 SD). Results The median time of follow-up was 9.4 years (range: 1.1-18.8 years; IQR: 6.0 years). Thirty-nine patients (49%) underwent surgical (n = 32) or interventional (n = 7) pulmonary valve re-replacement. Univariate Cox regression revealed patient age (p = 0.018), body surface area (p = 0.004), internal valve diameter (p = 0.005), and prosthesis z-score (p = 0.018) to impact valve longevity. Multivariate Cox regression analysis, however, did not show any significant effect (likely related to multicollinearity). Subgroup analysis showed that valve-revised patients have a higher average z-score (p = 0.003) and younger average age (p = 0.007). Conclusion A decreased longevity of biological valves in the pulmonary position is related to younger age, lower valve diameter, and higher z-score. Because valve size (diameter and z-score) can be predicted by age, patient age is the crucial parameter influencing graft longevity.

Drowning is one of the leading causes of accidental deaths in children worldwide. However, the use of long-term extracorporeal life support (ECLS) in this setting is not widely established, and rewarming is often achieved by short-term cardiopulmonary bypass (CPB) treatment. Thus, we sought to add our experience with this means of support as a bridge-to-recovery or to-decision. This retrospective single-center study analyzes the outcome of 11 children (median 23 months, minimum-maximum 3 months-6.5 years) who experienced drowning and subsequent cardiopulmonary resuscitation (CPR) between 2005 and 2016 and who were supported by veno-arterial extracorporeal membrane oxygenation (ECMO), CPB, or first CPB then ECMO. All but one incident took place in sweet water. Submersion time ranged between 10 and 50 minutes (median 23 minutes), water temperature between 2 degrees C and 28 degrees C (median 14 degrees C), and body core temperature upon arrival in the emergency department between 20 degrees C and 34 degrees C (median 25 degrees C). Nine patients underwent ongoing CPR from the scene until ECMO or CPB initiation in the operating room. The duration of ECMO or CPB before successful weaning/therapy withdrawal ranged between 2 and 322 hours (median 19 hours). A total of four patients (36%) survived neurologically mildly or not affected after 4 years of follow-up. The data indicate that survival is likely related to a shorter submersion time and lower water temperature. Resuscitation of pediatric patients after drowning has a poor outcome. However, ECMO or CPB might promote recovery in selected cases or serve as a bridge-to-decision tool.

Primary cardiac tumors in children are very rare and may be associated with severe arrhythmias and sudden infant death syndrome. These cardiac arrhythmias vary depending on the location and size of the tumor. Sixty-four percent of children with cardiac fibroma, the second most common benign cardiac tumor in children, have ventricular arrhythmias, affecting therapeutic management and risk profile of these children. We report on two siblings with cardiac fibromas whose clinical presentations differed depending on their locations and size of the tumors. The first child, a three-year-old girl, was diagnosed with a cardiac fibroma in the left ventricle at the age of 8 months after surviving resuscitation due to ventricular fibrillation. Secondary prophylactic implantation of an ICD was performed. On propranolol, no further malignant arrhythmias have occurred to date. The seven-month-old brother was diagnosed postnatally with a cardiac tumor adjacent to the right ventricle. A few weeks after birth, the boy had refractory supraventricular tachycardia and ventricular arrhythmia that only resolved with amiodarone. In genetic testing, Gorlin–Goltz syndrome was diagnosed in both children. Conservative pharmacological therapy is a therapeutic strategy for asymptomatic patients with cardiac fibromas. The anti-arrhythmic medication depends on the location of the tumor. Implantation of an ICD should be performed in cases of malignant arrhythmias. In rare cases, there is an association between cardiac tumors and genetic syndromes, such as Gorlin–Goltz syndrome. These should always be considered when such a tumor is diagnosed.

ObjectivesDelayed sternal closure is a routine procedure to reduce hemodynamic and respiratory instability in pediatric patients following cardiac surgery, particularly in neonates and infants. In this setting, the possible links between sternal wound infection and delayed sternal closure are still a matter of debate. As a part of our routine, there was a low threshold for delayed sternal closure, so we reviewed our experience with sternal wound infections with a focus on potentially related perioperative risk factors, particularly delayed sternal closure.MethodsWe retrospectively identified 358 operated neonates (37%) and infants (mean age 3.6 months) in our local congenital heart disease database between January 2013 and June 2017. Potential risk factors for sternal wound infections, such as age, gender, complexity (based on Aristotle- and STS-EACTS mortality category), reoperation, use of cardiopulmonary bypass, extracorporeal membrane oxygenation, mortality and delayed sternal closure (163/358, 46%), were subjected to uni- and multivariate analysis.ResultsA total of 26/358 patients (7.3%) developed a superficial sternal wound infection. There were no deep sternal wound infections, no mediastinitis or sepsis. Applying univariate analysis, the prevalence of sternal wound infections was related to younger age, more complex surgery and delayed sternal closure. However, in multivariate analysis, sternal wound infection was only associated with delayed sternal closure (p = 0.013, odds ratio 8.6). Logistic regression revealed the prevalence of delayed sternal closure to be related to younger age, complexity, and the use of extracorporeal membrane oxygenation.ConclusionIn patients younger than one year, sternal wound infections are clearly related to delayed sternal closure. However, in our cohort, all sternal wound infections were superficial and acceptable, considering the improved postoperative hemodynamic stability.

Engineered heart muscle (EHM) can be implanted epicardially to remuscularize the failing heart. In case of a severely scarred ventricle, excision of scar followed by transmural heart wall replacement may be a more desirable application. Accordingly, we tested the hypothesis that allograft (rat) and xenograft (human) EHM can also be administered as transmural heart wall replacement in a heterotopic, volume-loaded heart transplantation model. We first established a novel rat model model to test surgical transmural left heart wall repair. Subsequently and in continuation of our previous allograft studies, we tested outcome after implantation of contractile engineered heart muscle (EHM) and non-contractile engineered connective tissue (ECT) as well as engineered mesenchymal tissue (EMT) allografts as transmural heart wall replacement. Finally, proof-of-concept for the application of human EHM was obtained in an athymic nude rat model. Only in case of EHM implantation, remuscularization of the surgically created transmural defect was observed with palpable graft vascularization. Taken together, feasibility of transmural heart repair using bioengineered myocardial grafts could be demonstrated in a novel rat model of heterotopic heart transplantation.

Vascular rings are congenital aortic arch malformations in which the arch and its branching vessels encircle the oesophagus and trachea. The extent of symptoms and the age at initial presentation depend upon the exact arch configuration. Patients with anatomically complete vascular rings generally present earlier in life than their counterparts with incomplete ones. The latter may not necessarily lead to signs of disease and often remain undiagnosed for a long time. In contrast, the complete rings produce compression symptoms in almost all affected patients [1, 2]. Two main variants of true vascular rings can be distinguished: double aortic arch (DAA) and right aortic arch with left ligamentum (RAA-LD). According to large surgical series, they combined represent the majority of all symptomatic vascular rings [3–5]. Since the first surgical division of a vascular ring by Robert E. Gross at Boston Children’s Hospital in 1945, care for children with these types of vascular abnormalities has evolved dramatically. Nowadays, CT or MRI complements echocardiography in the preoperative work-up, and for surgical planning, the barium oesophagram is needed only in exceptional cases. In addition, the surgeon can accurately assess the success of the measures utilizing pre- and perioperative flexible bronchoscopy. Operative mortality does rarely occur in contemporary series. Furthermore, the operative morbidity following the surgical management of DAA or RAA-LD is comparatively low, and complications like chylothorax, pneumothorax, pleural effusion and bleeding rarely have a lasting negative effect on the course of the patient [4]. Nevertheless, a subset of patients suffers from residual symptoms and signs of tracheo-oesophageal compression, and some even need reintervention or reoperation. Prenatal, early detection of vascular rings could play an essential role in detecting the symptoms of tracheo-oesophageal compression promptly after birth and immediately initiating imaging and treatment.

Abstract OBJECTIVES Univentricular malformations are severe cardiac lesions with limited therapeutic options and a poor long-term outcome. The staged surgical palliation (Fontan principle) results in a circulation in which venous return is conducted to the pulmonary arteries via passive laminar flow. We aimed to generate a contractile subpulmonary neo-ventricle from engineered heart tissue (EHT) to drive pulmonary flow actively. METHODS A three-dimensional tubular EHT (1.8-cm length, 6-mm inner diameter, ca. 1-mm wall thickness) was created by casting human-induced pluripotent stem cell-derived cardiomyocytes (0.9 ml, 18 mio/ml) embedded in a fibrin-based hydrogel around a silicone tube. EHTs were cultured under continuous, pulsatile flow through the silicone tube for 23 days. RESULTS The constructs started to beat macroscopically at days 8–14 and remained stable in size and shape over the whole culture period. Tubular EHTs showed a coherent beating pattern after 23 days in culture, and isovolumetric pressure measurements demonstrated a coherent pulsatile wave formation with an average frequency of 77 ± 5 beats/min and an average pressure of 0.2 mmHg. Histological analysis revealed cardiomyocytes mainly localized along the inner and outer curvature of the tubular wall with mainly longitudinal alignment. Cell density in the center of the tubular wall was lower. CONCLUSIONS A simple tube-shaped contractile EHT was generated from human-induced pluripotent stem cells and developed a synchronous beating pattern. Further steps need to focus on optimizing support materials, flow rates and geometry to obtain a construct that creates sufficient pressures to support a directed and pulsatile blood flow.