Transcatheter Axial Pump Use in Pediatric Patients on Veno-Arterial Extracorporeal Membrane Oxygenation: An ACTION Collaborative Experience.

We report the largest pediatric multicenter experience with Impella pump use and peripheral veno-arterial extracorporeal membrane oxygenation (VA-ECMO) support. Utilizing the Advanced Cardiac Therapies Improving Outcomes Network (ACTION) collaborative database, we conducted a retrospective, multicenter study of all patients with cardiogenic shock requiring VA-ECMO support with subsequent Impella implant between October 2014 and December 2021. The primary outcome was defined as death while on Impella support. Secondary outcomes were recovery, transplantation, and transition to durable ventricular assist device (VAD) at the time of Impella explantation. Adverse events were defined according to the ACTION registry criteria. Twenty subjects were supported with Impella; Impella 2.5 (n = 3), CP (n = 12), 5.0/5.5 (n = 5). The median Interquartile range (IQR) age, weight, and body surface area at implantation were 15.6 years (IQR = 13.9-17.2), 65.7 kg (IQR = 53.1-80.7), and 1.74 m2 (IQR = 1.58-1.98). Primary cardiac diagnoses were dilated cardiomyopathy/myocarditis in nine (45%), congenital heart disease in four (20%), graft failure/rejection in four (20%), and three (15%) others. Most common adverse events included hemolysis (50%) and bleeding (20%). There were two deaths (10%) in the cohort. Nine patients (45%) were explanted for recovery, eight (40%) were transitioned to a durable VAD, and one (5%) underwent heart transplantation. Impella percutaneous pump support should be considered in the older pediatric population supported with peripheral VA-ECMO, as a means of left heart decompression, and a strategy to come off ECMO to achieve endpoints of myocardial recovery, transition to a durable VAD, or transplantation.

The Impact of Bicuspid Aortic Valve Leaflet Fusion Morphology on the Ascending Aorta and on Outcomes of Aortic Valve Replacement.

BACKGROUND: Patients with bicuspid aortic valves (BAVs) tend to develop dilation of the ascending aorta. The aim of this study was to analyze the impact of leaflet fusion pattern on aortic root diameter and outcomes in patients undergoing surgery for BAV vs tricuspid aortic valve (TAV) disease. METHODS: This is a retrospective review of 90 patients with aortic valve disease (mean [SD] age, 51.5 [8.2] years) who underwent aortic valve replacement for BAV (n = 60) and TAV (n = 30). Fusion of right-left (R/L) coronary cusps was identified in 45 patients, whereas the remaining 15 patients had right-noncoronary (R/N) cusp fusion. Aortic diameter was measured at 4 levels, and Z values were computed. RESULTS: There were no significant differences between the BAV and TAV groups for age, weight, aortic insufficiency grade, or size of implanted prostheses. However, a higher preoperative peak gradient at the aortic valve was significantly associated with R/L fusion (P = .02). Preoperative Z values of ascending aorta and sinotubular junction diameter were significantly higher in patients with R/N fusion than with the R/L (P < .001 and P = .04, respectively) and TAV (P < .001 and P < .05, respectively) subgroups. During the follow-up period (mean [SD], 2.7 [1.8] years), 3 patients underwent a redo procedure. At the last follow-up, the sizes of ascending aorta were similar among all 3 patient groups. CONCLUSION: This study suggests that preoperative dilation of the ascending aorta is more common in patients with R/N fusion than in patients with R/L and TAV but is not significantly different between all groups in the early follow-up period. R/L fusion was associated with an increased risk of preoperative presence of aortic stenosis.

Early Outcomes of Patients Undergoing Neoaortic Valve Repair Incorporating Geometric Ring Annuloplasty.

OBJECTIVES: During congenital heart surgery, the pulmonary valve and root may be placed into the systemic position, yielding a "neoaortic" valve. With the stress of systemic pressure, the pulmonary roots can dilate, creating aneurysms and/or neoaortic insufficiency (neoAI). This report analyzes the early outcomes of patients undergoing neoaortic valve repair incorporating geometric ring annuloplasty. METHODS: Twenty-one patients underwent intended repair at six centers and formed the study cohort. Thirteen had previous Ross procedures, five had arterial switch operations, and three Fontan physiology. Average age was 21.7 ± 12.8 years (mean ± SD), 80% were male, and 11 (55%) had symptomatic heart failure. Preoperative neoAI Grade was 3.1 ± 1.1, and annular diameter was 30.7 ± 6.5 mm. RESULTS: Valve repair was accomplished in 20/21, using geometric annuloplasty rings and leaflet plication (n = 13) and/or nodular release (n = 7). Fourteen had neoaortic aneurysm replacement (13 with root remodeling). Two underwent bicuspid valve repair. Six had pulmonary conduit changes, one insertion of an artificial Nodulus Arantius, and one resection of a subaortic membrane. Ring size averaged 21.9 ± 2.3 mm, and aortic clamp time was 171 ± 54 minutes. No operative mortality or major morbidity occurred, and postoperative hospitalization was 4.3 ± 1.4 days. At discharge, neoAI grade was 0.2 ± 0.4 (P < .0001), and valve mean gradient was ≤20 mm Hg. At average 18.0 ± 9.1 months of follow-up, all patients were asymptomatic with stable valve function. CONCLUSIONS: Neoaortic aneurysms and neoAI are occasionally seen late following Ross, arterial switch, or Fontan procedures. Neoaortic valve repair using geometric ring annuloplasty, leaflet reconstruction, and root remodeling provides a patient-specific approach with favorable early outcomes.

Capturing Adult Congenital Heart Disease: Framework for Development of an Adult Congenital Heart Disease Mortality Risk Model.

BACKGROUND: As a formative step toward development of adult congenital heart disease (ACHD) risk-adjusted metrics, we describe The Society of Thoracic Surgeons (STS) ACHD population, procedural frequency, and early mortality. METHODS: Adults (≥18 years) with CHD (2014-2019) were identified in the STS Adult Cardiac Surgery (ASCD) and the Congenital Heart Surgery (CHSD) Databases. After deduplication, variable mapping, data concatenation, and harmonization of preprocedure factors, procedures were grouped, and unadjusted mortality was catalogued for the overall cohort and the cohort excluding patients with an isolated bicuspid aortic valve (BAV). RESULTS: Among 171 186 ACSD and 18 281 CHSD records, 152 731 unique records met inclusion criteria. Twenty-eight congenital diagnoses accounted for 86% of the overall cohort, and prevalence of ACHD increased over the study time frame. ACHD patients underwent operations to treat both acquired and CHD. Most common procedures overall and after excluding isolated BAV were aortic valve replacement (AVR), ascending aortic surgery, and coronary artery bypass grafting (CABG). After excluding isolated BAV, major procedure combinations occurred in 46% (31% had 2 major procedures and 3% had ≥4), and the most prevalent combinations included AVR + CABG (n = 2352), AVR + subaortic stenosis repair (n = 1481), and AVR + ascending aortic surgery (n = 1239). Unadjusted 30-day mortality was procedure dependent, 2.8% overall and 3.6% with isolated BAV excluded. CONCLUSIONS: The ACHD surgical population is heterogenous, and patients undergo surgery for CHD-related and adult/acquired procedure combinations. Early mortality is variable and influenced by surgical complexity. Excluding isolated BAV patients and developing procedure-based ACHD mortality risk models may be ideal but will require empirically derived grouping and collaboration.

Assessment of Current Society of Thoracic Surgeons Data Elements for Adults With Congenital Heart Disease.

BACKGROUND: To identify opportunities for enhanced data collection for adults with congenital heart disease (ACHD), a structured review of existing variables in The Society of Thoracic Surgeons (STS) Congenital Heart Surgery Database (CHSD) and the STS Adult Cardiac Surgery Database (ACSD) was conducted. METHODS: A working group was assembled representing multiple STS Workforces and Task Forces. The ACSD was reviewed systematically over eight 90-minute calls. ACSD version 4.20.2 and CHSD version 3.41 were used, and the ACSD was approached in sections. ACSD variables were classified as (1) represented in identical form in the CHSD (no further discussion), (2) represented in similar form in the CHSD (discussed for potential harmonization of definitions), or (3) not represented in the CHSD (discussed for potential inclusion). Variables felt to be relevant to ACHD were noted, and special consideration was given to STS required fields and variables used in existing STS adult risk models. Other factors that were examined were the frequency, use, and capture of existing ACSD variables. RESULTS: Over 22 weeks (8 calls), the existing 1069 variables in version 4.20.2 of the ACSD were discussed. Ultimately, 539 total variables were found to be both (1) relevant to ACHD and (2) not currently collected in the CHSD. These were recommended for inclusion in the next CHSD upgrade for patients aged ≥18 years. CONCLUSIONS: For adult patients having case records entered into the CHSD, the inclusion of a limited set of additional data fields from the ACSD should enhance capture of comorbidities and other clinical data relevant to the ACHD population.

Anomalous Aortic Origin of Right Coronary Artery: Outcomes of Surgical and Nonsurgical Treatment.

BACKGROUND: Anomalous aortic origin of right coronary artery (AAORCA) is a congenital heart lesion that may be associated with coronary ischemia and sudden death; however, the management of these patients remains controversial. The aim of this study was to analyze all patients with AAORCA managed at our center. METHODS: The medical records of patients with an isolated diagnosis of AAOCA were retrospectively reviewed, irrespective of symptoms, from 2007 to 2020. Follow-up was obtained by medical record review. AAORCA was diagnosed by echocardiogram and computed tomographic or magnetic resonance imaging studies in all patients. Treatment was based on anatomic, morphologic, and symptomatic features for patients older than 10 years with AAORCA. RESULTS: The review identified 86 patients with a median age of 16 years; of these, 26 (30%) were managed surgically and 60 (70%) are monitored nonsurgically. Surgical intervention included a "classic" unroofing in 10 (39%), neo-ostial creation in 7 (27%), modified unroofing with neo-ostial creation in 6 (23%), a "classic" unroofing with reimplantation in 2 (7%), and reimplantation only in 1 (4%). Surgical patients were significantly older (P = .01), described more chest pain symptoms (P = .004), had the presence of slitlike ostia (P = .03), and longer length of coronary artery narrowing (P = .0002). At follow-up (median, 3 years; range, 0-13 years), 100% of surgical patients underwent functional testing and had no evidence of ischemia. Postoperative evaluation included one or more of echocardiography, computed tomographic angiogram, magnetic resonance imaging, and exercise stress test. CONCLUSIONS: Our program uses a systematic approach for patients with AAORCA. With this paradigm, outcomes are excellent in the midterm, as validated with anatomic- and function-based testing.

De Novo Valve Tissue Morphology Following Bioscaffold Mitral Valve Replacement in a Juvenile Non-Human Primate Model.

The utility of implanting a bioscaffold mitral valve consisting of porcine small intestinal submucosa (PSIS) in a juvenile baboon model (12 to 14 months old at the time of implant; n = 3) to assess their in vivo tissue remodeling responses was investigated. Our findings demonstrated that the PSIS mitral valve exhibited the robust presence of de novo extracellular matrix (ECM) at all explantation time points (at 3-, 11-, and 20-months). Apart from a significantly lower level of proteoglycans in the implanted valve's annulus region (p < 0.05) at 3 months compared to the 11- and 20-month explants, there were no other significant differences (p > 0.05) found between any of the other principal valve ECM components (collagen and elastin) at the leaflet, annulus, or chordae tendinea locations, across these time points. In particular, neochordae tissue had formed, which seamlessly integrated with the native papillary muscles. However, additional processing will be required to trigger accelerated, uniform and complete valve ECM formation in the recipient. Regardless of the specific processing done to the bioscaffold valve, in this proof-of-concept study, we estimate that a 3-month window following bioscaffold valve replacement is the timeline in which complete regeneration of the valve and integration with the host needs to occur.

Dilatable Pulmonary Artery Banding Palliation in Congenital Heart Disease.

BACKGROUND: Surgical pulmonary artery banding (PAB) has been limited in practice because of later requirement for surgical removal or adjustment. The aim of this study is to describe our experience creating a dilatable PAB via transcatheter balloon dilation (TCBD) in congenital heart disease (CHD) patients. METHODS: Retrospective chart review of adjustable PAB-outline anatomical variants palliated and patient outcomes. RESULTS: Sixteen patients underwent dilatable PAB-median age 52 days (range 4-215) and weight 3.12 kg (1.65-5.8). Seven (44%) of the patients were premature, 11 (69%) had ventricular septal defect(s) with pulmonary over-circulation, four (25%) atrioventricular septal defects, and four (25%) single ventricle physiology. Subsequent to the index procedure: five patients have undergone intracardiac complete repair, six patients remain well palliated with no additional intervention, and four single ventricles await their next palliation. One patient died from necrotizing enterocolitis (unrelated to PAB) and one patient required a pericardiocentesis postoperatively. Five patients underwent TCBD of the PAB without complication-Two had one TCBD, two had two TCBD, and another had three TCBD. The median change in saturation was 14% (complete range 6-22) and PAB diameter 1.7 mm (complete range 1.1-5.2). Median time from PAB to most recent outpatient follow-up was 868 days (interquartile range 190-1,079). CONCLUSIONS: Our institution has standardized a PAB technique that allows for transcatheter incremental increases in pulmonary blood flow over time. This methodology has proven safe and effective enough to supplant other institutional techniques of limiting pulmonary blood flow in most patients-allowing for interval growth or even serving as the definitive palliation.

Scavenging right atrial Bretschneider histidine-tryptophan-ketoglutarate cardioplegia: Impact on hyponatremia and seizures in pediatric cardiac surgery patients.

OBJECTIVE: Custodiol-HTK cardioplegia (Custodiol-HTK Koheler Chemie, GmbH, Bensheim, Germany) causes fluctuations in serum sodium levels, hyponatremia, and is associated with postoperative seizures. We investigated the influence of scavenging right atrial effluent during delivery on intraoperative serum sodium levels and postoperative seizure incidence in pediatric cardiac surgery patients. METHODS: A total of 204 patients younger than age 18 years undergoing congenital heart surgery between January 2016 and March 2018 were analyzed retrospectively. Serum sodium levels after administration of Custodiol-HTK cardioplegia were compared between the scavenge and nonscavenge groups and then in the propensity score-matched cohort (n = 96). Postoperative seizures were documented clinically and with electroencephalogram findings. Logistic regression models were used to identify the independent predictors of serum sodium level after aortic crossclamp. RESULTS: Of 204 patients, 156 (76.5%) were in the nonscavenge, and 48 (23.5%) in the scavenge groups. A serum sodium level <130 mEq/L after crossclamp and administration of Custodiol-HTK cardioplegia in the nonscavenge group were 70% versus 21% in the scavenge group (odds ratio, 8.8; 95% confidence interval, 4.1-18.3; P < .0001) in the entire cohort, and 77% versus 21% (odds ratio, 12.8; 95% confidence interval, 4.8-33.1; P < .0001) in the propensity score-matched cohort. Of 16 patients experiencing a postoperative seizure, 14 (87.5%) had a sodium level <130 mEq/L and 2 (12.5%) had a sodium level ≥130 mEq/L (odds ratio, 5.1; 95% confidence interval, 1.3-22.8; P = .021) after crossclamp. Postoperative seizures occurred in the nonscavenge group but not the scavenge group in the entire cohort (P = .02) and in the propensity score-matched patients (P = .041). Multivariable analysis of the entire cohort showed that scavenge intervention was an independent factor associated with significantly decreased risk of sodium level <130 mEq/L (odds ratio, 0.17; 95% confidence interval, 0.08-0.36; P = .000). CONCLUSIONS: Right atrial effluent scavenging was protective against fluctuations in serum sodium levels after crossclamp and Custodiol-HTK cardioplegia administration independently in both entire and matched cohort, and was also associated with decreased incidence of postoperative seizures.

Reconstruction of the Neopulmonary Root After Coronary Button Harvest for Arterial Switch Operation Using 2-ply Extracellular Matrix (Tyke): A Post-Implant Histology.

In children with Transposition of the Great Arteries (TGA), the pulmonary artery, and aorta are connected to the heart abnormally resulting in blue blood (deoxygenated) recirculating to the body and red blood (oxygenated) recirculating to the lungs. The arterial switch operation (ASO) is the standard of care for transposition of the great arteries (TGA), and given the low risk of early mortality and satisfactory long-term outcomes, focus is now on managing longer term complications such as neo-aortic root dilatation, and pulmonary artery stenosis. Since May 2016, we have used 2-ply extracellular matrix (ECM; Tyke) for reconstruction of the coronary button defects using a pantaloon patch. We present histology of implanted 2-ply ECM (Tyke) from a patient who went back to surgery for development of subaortic stenosis ~12 months after ASO.

The Destiny of Postoperative Residual Ventricular Septal Defects After Surgical Repair in Infants and Children.

PURPOSE: Residual ventricular septal defects (rVSDs) of small size are commonly seen on transesophageal echocardiography after surgical repair. This study aimed to determine the destiny of rVSD found on intraoperative echocardiogram. METHODS: Patients undergoing surgical repair of VSD as the primary procedure with available intraoperative and discharge echocardiograms between 2007 and 2017 were reviewed. Presence of an rVSD on intraoperative echo triggered review of discharge echo and of subsequent follow-up echocardiograms. RESULTS: One hundred four patients were analyzed. The mean age and weight for the entire cohort were 1.4 ± 2.9 years (median, 5.4 months; range, 29 days to 14 years) and 8.8 ± 9.9 kg (median, 5.1 kg; range, 2.7-58 kg), respectively. Sixty (57%) patients had rVSD at discharge, with mean size of residual VSD of 1.38 ± 0.92 mm (mode, 0.6; median, 2.2 mm; range, 0.5-3.9 mm). The mean follow-up time was 3.7 ± 3.1 years (range, 1 month to 9.3 years). Among those with rVSD at discharge, a residual shunt persisted in 73% at one-month follow-up. On follow-up at three years postdischarge, of the 60 patients with early rVSD, 6 had a persistent rVSD (10%) with a mean diameter of 3.0 ± 0.8 mm (range, 2.4-3.9 mm). CONCLUSIONS: Residual VSD after surgical repair is detected frequently on postoperative echocardiogram. The presence of rVSD was not associated with any preoperative, intraoperative, or postoperative factors. By three years of follow-up, only six patients continued to demonstrate rVSD with a mean diameter of 3 mm, suggesting that defects 3 mm or greater may be less likely to close spontaneously after three years.

Porcine Small Intestinal Submucosa Mitral Valve Material Responses Support Acute Somatic Growth.

Background: Conceptually, a tissue engineered heart valve would be especially appealing in the pediatric setting since small size and somatic growth constraints would be alleviated. In this study, we utilized porcine small intestinal submucosa (PSIS) for valve replacement. Of note, we evaluated the material responses of PSIS and subsequently its acute function and somatic growth potential in the mitral position. Methods and Results: Material and mechanical assessment demonstrated that both fatigued 2ply (∼65 µm) and 4ply (∼110 µm) PSIS specimens exhibited similar failure mechanisms, but at an accelerated rate in the former. Specifically, the fatigued 2ply PSIS samples underwent noticeable fiber pullout and recruitment on the bioscaffold surface, leading to higher yield strength (p < 0.05) and yield strain (p < 0.05) compared to its fatigued 4ply counterparts. Consequently, 2ply PSIS mitral valve constructs were subsequently implanted in juvenile baboons (n = 3). Valve function was longitudinally monitored for 90 days postvalve implantation and was found to be robust in all animals. Histology at 90 days in one of the animals revealed the presence of residual porcine cells, fibrin matrix, and host baboon immune cells but an absence of tissue regeneration. Conclusions: Our findings suggest that the altered structural responses of PSIS, postfatigue, rather than de novo tissue formation, are primarily responsible for the valve's ability to accommodate somatic growth during the acute phase (90 days) following mitral valve replacement. Impact Statement Tissue engineered heart valves (TEHVs) offer the potential of supporting somatic growth. In this study, we investigated a porcine small intestinal submucosa bioscaffold for pediatric mitral heart valve replacement. The novelty of the study lies in identifying material responses under mechanical loading conditions and its effectiveness in being able to function as a TEHV. In addition, the ability of the scaffold valve to support acute somatic growth was evaluated in the Baboon model. The current study contributes toward finding a solution for critical valve diseases in children, whose current prognosis for survival is poor.

Custodiol cardioplegia solution compared to cold blood cardioplegia in pediatric cardiac surgery: a single-institution experience.

OBJECTIVE: Custodiol is an intracellular, crystalloid cardioplegia solution that is a single-dose alternative to multi-dose cold blood cardioplegia; however, there is scarce data regarding its use in infants and children. The objective of this study was to compare its impact on myocardial function in infants. METHODS: Single-center retrospective review including 132 patients <12 months old undergoing biventricular repair. There were 106 patients who received single-dose Custodiol and 27 patients who received multi-dose blood cardioplegia. Demographic and echocardiographic data were compared between the two groups. RESULTS: Patients receiving Custodiol were slightly younger (100 ± 62 days) and lower weight (4.7 ± 1.3 kg) compared to 152 ± 86 days and 5.2 ± 1.3 kg for blood cardioplegia (p < 0.05). The Society of Thoracic Surgeons/European Association for Cardio-Thoracic Surgery Congenital Heart Surgery score was similar between both groups. Average cardiopulmonary bypass time was similar between both groups (Custodiol 93 ± 54 minutes vs. blood 81 ± 44 minutes, p = 0.46) as was aortic cross-clamp time (Custodiol 58 ± 33 minutes vs. cold blood 53 ± 33 minutes, p = 0.62). Pre-operative left ventricular ejection fraction was similar for blood 73 ± 8% versus Custodiol 70 ± 9%, p = 0.21. There was also no intergroup difference in left ventricular ejection fraction 24 hours post op (blood 64 ± 9% vs. Custodiol 65 ± 12%, p = 0.53) or at discharge (blood 66 ± 10% vs. Custodiol 66 ± 11%, p = 0.95). The pre-operative right ventricle function by fractional area change was also similar in blood cardioplegia (46 ± 13%) versus Custodiol (48 ± 9%, p = 0.38) and showed similar drops in parameters in the two groups 24 hours after surgery and at discharge. CONCLUSION: Single-dose Custodiol is as safe as blood cardioplegia for myocardial protection in congenital cardiac surgery for the cross-clamp times evaluated in this study. Evaluation at longer cross-clamp times would be helpful to determine if there is a greater benefit to single-dose Custodiol versus more repeated doses of blood cardioplegia for longer cross-clamp times.

Aquapheresis (AQ) in Tandem with Extracorporeal Membrane Oxygenation (ECMO) in Pediatric Patients.

Children with cardiopulmonary failure requiring extracorporeal membrane oxygenation (ECMO) are at risk for fluid overload (FO) despite the normal estimated glomerular filtration rate (eGFR). It has been shown that survival in the intensive care unit (ICU) is inversely proportional to FO. Therefore, fluid removal, or prevention of FO, in these critical cases has the potential to improve survival. Aquapheresis (AQ), a procedure used for fluid removal, with success in patients with heart failure has also been used in children with acute oliguric kidney injury (AKI), to prevent and treat FO. The purpose of this article was to describe the use of Aquadex FlexFlow® for AQ in pediatric patients on ECMO, as a means to provide a simplified and safe form of fluid removal with minimal impact on ECMO therapy. The principal variables collected include patients' demographics, urine output, serum creatinine, withdrawal and infusion pressures, ultrafiltration (UF) rates, and ECMO flow ranges, along with length of stay in pediatric ICU and survival. Patient survival was 100% with preserved eGFR. The ECMO flows were not affected by AQ. Urine output decreased somewhat during therapy, with little AQ machine pressure variations. Range of UF tolerated without hemodynamic abnormalities was 1.24-6.2 mL/kg/h, allowing the patients to maintain their pre-AQ body weight, while receiving intravenous (IV) nutrition and medications. This article describes the use of AQ in tandem with ECMO in a user-friendly and safe way to provide UF in children requiring cardiopulmonary support, with minimal flow and hemodynamic disturbance.

Sacubitril/Valsartan: potential treatment for paediatric heart failure.

The Prospective comparison of angiotensin receptor antagonist Valsartan and neprilysin inhibitor Sacubitril with angiotensin-converting enzyme inhibitor (enalapril) to determine impact on Global Mortality and Morbidity in Heart Failure trial has demonstrated that Sacubitril/Valsartan is superior to Enalapril in reducing the risks of both sudden cardiac death and death from worsening heart failure. This novel combination, Sacubitril/Valsartan, is also shown to reduce the risk of hospitalisation and progression of heart failure in adults. However, the benefit of Sacubitril/Valsartan in paediatric heart failure patients is unknown. In this review, we discuss the similarities and differences in pathophysiology of heart failure in children versus adults, and the potential role of Sacubitril/Valsartan in paediatric heart failure patients.

Mitral valve replacement using a handmade construct in an infant.

We recently reported the feasibility of a handmade left atrioventricular valve using decellularized extracellular matrix for 3 months in a failed repair of AV canal defect. We present the use of an extracellular matrix mitral valve for 9 months in an infant with an un-repairable congenitally malformed valve. The valve functioned perfectly without anticoagulation until the patient expired from non-cardiac complications of their fibrillin gene defect. This report adds further experience using valves made from extracellular matrix in the systemic ventricle both in terms of application and in terms of short-term durability of the construct.

Hydrodynamic Assessment of Aortic Valves Prepared from Porcine Small Intestinal Submucosa.

Infants and children born with severe cardiac valve lesions have no effective long term treatment options since currently available tissue or mechanical prosthetic valves have sizing limitations and no avenue to accommodate the growth of the pediatric patient. Tissue engineered heart valves (TEHVs) which could provide for growth, self-repair, infection resistance, and long-term replacement could be an ideal solution. Porcine small intestinal submucosa (PSIS) has recently emerged as a potentially attractive bioscaffold for TEHVs. PSIS may possess the ability to recruit endogenous cardiovascular cells, leading to phenotypically-matched replacement tissue when the scaffold has completely degraded. Our group has successfully implanted custom-made PSIS valves in 4 infants with critical valve defects in whom standard bioprosthetic or mechanical valves were not an option. Short term clinical follow-up has been promising. However, no hydrodynamic data has been reported to date on these valves. The purpose of this study was to assess the functional effectiveness of tri-leaflet PSIS bioscaffolds in the aortic position compared to standard tri-leaflet porcine bioprosthetic valves. Hydrodynamic evaluation of acute PSIS function was conducted using a left heart simulator in our laboratory. Our results demonstrated similar flow and pressure profiles (p > 0.05) between the PSIS valves and the control valves. However, forward flow energy losses were found to be significantly greater (p < 0.05) in the PSIS valves compared to the controls possibly as a result of stiffer material properties of PSIS relative to glutaraldehyde-fixed porcine valve tissue. Our findings suggest that optimization of valve dimensions and shape may be important in accelerating de novo valve tissue growth and avoidance of long-term complications associated with higher energy losses (e.g. left ventricular hypertrophy). Furthermore, long term animal and clinical studies will be needed in order to conclusively address somatic growth potential of PSIS valves.