Biventricular assist device implant using biatrial cannulation for restrictive cardiomyopathy.

Preoperative calculations showed that the 9-mm inlet, 6-mm outlet, 25-cc pump chambers and 65-73 bpm would be optimal for a 5-year-old patient suffering from restrictive cardiomyopathy, with a body surface area of 0.59 m2 (1.5 L/min flow for a cardiac index of 2.5). After re-sternotomy and standard bicaval cannulation for cardiopulmonary bypass, the procedure was performed under normothermic conditions and on the beating heart. Biventricular support was established with the Berlin Heart Excor using biatrial cannulation. For left atrial cannulation, induced ventricular fibrillation was used. The 9-mm inlet cannulas were inserted into the left and right atria, respectively. The 6-mm outlet cannulas were implanted using 8-mm interposition vascular grafts for the aorta and the main pulmonary artery, respectively. Cannulas were tunnelled through the epigastric space, with systems crossing outside of the body. The 25-cc chambers were used for both right ventricular assist device and left ventricular assist device support, which subsequently showed full emptying and filling.

Correction of absent pulmonary valve syndrome using hilum-to-hilum internal pulmonary artery plication plasty.

A 12-month-old girl (8.4 kg) with absent pulmonary valve syndrome and enlarged bilateral pulmonary arteries underwent trans-tricuspid ventricular septal defect closure, placement of a right ventricular-to-pulmonary artery conduit and hilum-to-hilum internal pulmonary artery plication plasty.

Impact of the operative technique on mid- and long-term results following paediatric heart transplantation.

AIMS: The aim of this study is to evaluate and compare the impact of the bicaval technique versus the biatrial technique (by Lower and Shumway) in paediatric heart transplant patients. Only a few studies investigate this matter regarding the long-term outcome after paediatric heart transplantation. We compared the two surgical methods regarding survival, the necessity of pacemaker implantation. METHODS AND RESULTS: All 134 patients (aged <18 years) - (group-1) biatrial (n = 84), versus (group-2) bicaval (n = 50), who underwent heart transplantation between October 1988 and December 2021, were analysed. Freedom from events were estimated using the Kaplan-Meier method. Potential differences were analysed using the log rank test and Cox proportional hazard models. Mean ± standard deviation: Bypass time (per minutes) was higher in the group 1 as compared with group 2 (P = 0.050). Survival was not significantly different (P = 0.604) in either groups. Eighteen patients required permanent pacemaker implantation in the group 1 and only one patient required it in the group 2 (P = 0.001). CONCLUSIONS: Paediatric heart transplantation using bicaval technique results similar long-term survival compared with the biatrial technique. The incidence of atrial rhythm disorders was significantly higher in the biatrial group, requiring a higher frequency of pacemaker implantation in this group. As a results, the bicaval technique has replaced the biatrial technique in our centre.

Valve-Sparing Aortic Root Replacement With Reimplantation vs Remodeling: A Meta-analysis.

BACKGROUND: Long-term outcomes of valve-sparing aortic root replacement (VSARR) with reimplantation vs remodeling in patients undergoing aortic root surgery remains a controversial subject. METHODS: This study was a pooled meta-analysis of Kaplan-Meier-derived data from comparative studies published by December 31, 2022. RESULTS: Fifteen studies met our eligibility criteria, comprising 3044 patients (1991 in the reimplantation group and 2018 in the remodeling group). Patients who underwent VSARR with remodeling had a higher risk of all-cause death (hazard ratio [HR], 1.54; 95% CI, 1.16-2.03; P = .002, log-rank test P < .001). Landmark analysis (with 4 years as the landmark time point) demonstrated that survival was lower in patients who underwent VSARR with remodeling (HR, 2.15; 95% CI, 1.43-3.24; P < .001) in the first 4 years. Beyond the 4-year time point, no difference in survival was observed (HR, 1.04; 95% CI, 0.72-1.50; P = .822). The risk for need of aortic valve and/or root reintervention was higher in patients undergoing VSARR with remodeling (HR, 1.49; 95% CI, 1.07-2.07; P = .019, log-rank test P < .001). We did not find statistically significant coefficients for the covariates of age, female sex, connective tissue disorders, bicuspid aortic valve, aortic dissection, coronary bypass surgery, total arch replacement, or annular stabilization, which means that these covariates did not modulate the effects observed in our pooled analyses. CONCLUSIONS: VSARR with reimplantation is associated with better overall survival and lower risk of need for reintervention over time compared with VSARR with remodeling. Regarding overall survival, we observed a time-varying effect that favored the reimplantation technique up to 4 years of follow-up, but not beyond this time point.

Model-driven survival prediction after congenital heart surgery.

OBJECTIVES: The objective of the study was to improve postoperative risk assessment in congenital heart surgery by developing a machine-learning model based on readily available peri- and postoperative parameters. METHODS: Our bicentric retrospective data analysis from January 2014 to December 2019 of established risk parameters for dismal outcome was used to train and test a model to predict postoperative survival within the first 30 days. The Freiburg training data consisted of 780 procedures; the Heidelberg test data comprised 985 procedures. STAT mortality score, age, aortic cross-clamp time and postoperative lactate values over 24 h were considered. RESULTS: Our model showed an area under the curve (AUC) of 94.86%, specificity of 89.48% and sensitivity of 85.00%, resulting in 3 false negatives and 99 false positives.The STAT mortality score and the aortic cross-clamp time each showed a statistically highly significant impact on postoperative mortality. Interestingly, a child's age was barely statistically significant. Postoperative lactate values indicated an increased mortality risk if they were either constantly at a high level or low during the first 8 h postoperatively with an increase afterwards.When considering parameters available before, at the end of and 24 h after surgery, the predictive power of the complete model achieved the highest AUC. This, compared to the already high predictive power alone (AUC 88.9%) of the STAT mortality score, translates to an error reduction of 53.5%. CONCLUSIONS: Our model predicts postoperative survival after congenital heart surgery with great accuracy. Compared with preoperative risk assessments, our postoperative risk assessment reduces prediction error by half. Heightened awareness of high-risk patients should improve preventive measures and thus patient safety.

Safety and efficacy of surgical correction of anomalous aortic origin of coronary arteries: experiences from 2 tertiary cardiac centres.

OBJECTIVES: This study aims to describe the outcomes of surgical correction for anomalous aortic origin of coronary artery (AAOCA) with regard to symptom relief. METHODS: We performed a retrospective multicentre study including surgical patients who underwent correction for AAOCA between 2009 and 2022. Patients who underwent concomitant cardiac procedures were also included. However, to analyse symptom relief, we only assessed the subgroup of symptomatic patients who underwent isolated correction for AAOCA. RESULTS: A total of 71 consecutive patients (median age 55, range 12-83) who underwent surgical correction for AAOCA were included in the study. Right-AAOCA was present in 56 patients (79%), left-AAOCA in 11 patients (15%) and single coronary ostium AAOCA in 4 patients (6%). Coronary unroofing was performed in 72% of the patients, coronary reimplantation in 28% and an additional neo-ostium patchplasty in 13% of the patients. In 39% of the patients, a concomitant cardiac procedure was performed. During follow-up, no cardiovascular-related death was observed. Three patients (4.2%) had a myocardial infarction and underwent postoperative coronary artery bypass grafting. Six patients (8.5%) needed postoperative temporary mechanical circulatory support. Among the 34 symptomatic patients who underwent isolated AAOCA correction, 70% were completely asymptomatic after surgery, 12% showed symptom improvement and no symptom improvement was observed in 18% of the patients (median follow-up 3.5 years, range 0.3-11.1). CONCLUSIONS: Correction for AAOCA can be safely performed with or without concomitant cardiac procedures. Performing AAOCA correction leads to a significant improvement in symptoms for most patients.

Benefit From a Humanitarian Pediatric Congenital Heart Surgery Program Over a 10-Year Period.

Background: The charity organization Kinderherzen retten e.V. (KHR) enables humanitarian congenital heart surgery for pediatric patients from low- and middle-income countries at the University Heart Center Freiburg, Germany. The aim of this study was to assess periprocedural and mid-term outcomes of these patients for evaluation of KHR sustainability. Methods: Part one of the study comprised retrospective medical chart analyses of the periprocedural course of all KHR-treated children from 2008 to 2017, and part two a prospective evaluation of their mid-term outcome, assessed by questionnaires concerning survival, medical history, mental and physical development, and socioeconomic situation. Results: Of the 100 consecutively presented children from 20 countries (median age 3.25 years), 3 patients were not invasively treatable, 89 underwent cardiovascular surgery, and 8 received a catheter intervention only. There were no periprocedural deaths. Median postoperative duration of mechanical ventilation, intensive care stay, and total hospital stay was 7 (interquartile range [IQR] 4-21) hours, 2 (IQR 1-3) days, and 12 (IQR 10-16) days, respectively. Mid-term postoperative follow-up demonstrated a 5-year survival probability of 94.4%. The majority of patients received continued medical care in their home country (86.2% of patients), were in good mental and physical condition (96.5% and 94.7% of patients, respectively), and able to engage in age-appropriate education/employment (98.3% of patients). Conclusions: Cardiac, neurodevelopmental, and socioeconomic outcomes of patients treated via KHR was satisfactory. Thorough pre-visit evaluation and close contact with local physicians are crucial when providing this high-quality, sustainable, and viable therapeutic option for these patients.

The Yasui procedure with a modified right ventricle-to-pulmonary artery connection utilizing autologous left atrial appendage as a free graft.

A 9-month-old girl born with an interrupted aortic arch type B, an arteria lusoria (aberrant right subclavian artery) and a multilevel left ventricular outflow tract obstruction underwent a Yasui completion after an initial interim palliation. After the Damus-Kaye-Stansel procedure was carried out and the Sano shunt had been established as a source of pulmonary flow, the reported procedure comprised closure of the ventricular septal defect and the intraventricular baffling of left ventricular outflow through a malaligned ventricular septal defect, incision and partial resection of a conal septum and establishment of a right ventricle-to-pulmonary artery connection using an autologous left atrial appendage as a free graft. This technique consisted of dissecting and harvesting the left atrial appendage, which was then used as autologous material for an interposition plasty connecting the central pulmonary artery bifurcation segment with the upper rim of the infundibulotomy. Native, autologous tissue thus comprised the backwall of the newly created right ventricle-to-pulmonary artery continuity. Porcine pericardial patch plasty was then used to complete the remaining circumference of the right ventricle-to-pulmonary artery continuity.

Risk Assessment of Red Cell Transfusion in Congenital Heart Disease.

BACKGROUND: The storage time of packed red blood cells (pRBC) is an indicator of change in the product's pH, potassium, and lactate levels. Blood-gas analysis is a readily available bedside tool on every intensive care ward to measure these factors prior to application, thus facilitating a calculated decision on a transfusion's quantity and duration.Our first goal is to assess the impact of storage time on pH, potassium, and lactate levels in pRBC. The influence of those parameters in the transfused children will then be evaluated. METHODS: In this retrospective study, we conducted blood-gas analyses of pRBC units before they were administered over 4 hours to neonates, infants, and children in our pediatric cardiac intensive care ward. All patients underwent regular blood-gas analyses themselves, before and after transfusion. RESULTS: We observed a highly significant correlation between the storage time of pRBC units and a drop in pH, as well as an increase in potassium and lactate of stored red cells (p< 0.0001). Median age of recipients with a complete blood-gas dataset was 0.1 (interquartile range [IQR] = 0.0-0.7) years; median pRBC storage duration was 6 (IQR = 5-8) days. Further analyses showed no statistically significant effect on children's blood gases within 4 hours after transfusion, even after stratifying for pRBC storage time ≤7 days and >7 days. CONCLUSION: Stored red blood cells show a rapid decrease in pH and increase in potassium and lactate. Slow transfusion of these units had no adverse effects on the recipients' pH, potassium, and lactate levels.

Autologous free tissue transfer in paediatric patient with a univentricular heart.

We report on the case of a 30-month-old boy who developed severe deep cervical necrosis after bypass surgery for total cavopulmonary connection, followed by low-cardiac output and extracorporeal life support. As several bedside debridements failed to result in sufficient wound healing, a 2-stage necrectomy followed by autologous reconstruction with a free anterolateral thigh-flap was required. Due to impaired circulation, postoperative flap monitoring was extremely difficult. To ensure flap perfusion, mean arterial pressure had to be raised by catecholamines over 7 days.

German Aortic Root Repair Registry-Insights From the First 400 Consecutive Patients.

BACKGROUND: The objective was to provide initial data from our prospective valve-sparing aortic root replacement (V-SARR) registry and reasons for conversion to prosthetic aortic valve replacement. METHODS: Six centers established an intention-to-treat-design V-SARR-registry (the German Aortic Root Repair Registry; first patient in October 2016); the main inclusion criterion was being scheduled for V-SARR as plan A. Clinical information, operative details, intraoperative valve/root measurements, and clinical and transthoracic echocardiography follow-up-data are documented. RESULTS: Of a total of 449 patients, we report data for 401 (81% male; mean age 51 ± 14 years). Overall, 350 patients underwent V-SARR as scheduled, group A (David variants I 55%, III 2%, IV 13%, V 24%, V-Stanford 2%, and Yacoub remodeling 2%); and 51 were converted to aortic valve replacement (group B). Median follow-up was 11 months (range, 0 to 2.6 years), cumulative follow-up was 279 patient-years. In group B, there were fewer connective tissue disorders (6% vs 16%), fewer patients had left ventricular ejection fraction greater than 50% (60% vs 90%), more had bicuspid aortic valves (45% vs 28%), and fewer patients had preoperative none/trace aortic regurgitation (2% vs 20%). Fewer patients in group B had rare types of bicuspid aortic valve (fused N/L, R/N, 10% vs 30%) and more had unbalanced roots (56% vs 40%). Immediate postoperative aortic regurgitation was none/trace in 79% and mild in 20%. At 30 days, the mean transvalvular pressure gradient was 7 ± 5 mm Hg. None of the patients died in hospital; two strokes occurred. One patient needed early aortic valve replacement as redo surgery. CONCLUSIONS: The main factors causing surgeons to convert a planned V-SARR to aortic valve replacement include asymmetry of aortic valve/root, severity of aortic regurgitation, safety reasons (left ventricular ejection fraction), and bicuspid aortic valves (but not rare types). The German Aortic Root Repair Registry will help us identify the impact on long-term outcomes of preoperative and postoperative valvular anatomy and various V-SARR types.

Transposition of great arteries with left outflow tract obstruction and non-committed VSD: surgical management and late results.

OBJECTIVES: Transposition of the great arteries with ventricular septal defect (VSD) and left ventricular outflow tract obstruction (LVOTO) is a rare malformation. Our objective was to report on management and results of the cohort with non-committed VSD from a national registry for congenital heart disease. METHODS: Multicentre data were screened in the German National Registry for Congenital Heart Defects (Berlin, Germany) for repairs of transposition of the great arteries-VSD-LVOTO. A subgroup of patients with a remote/non-committed VSD was identified. End points included survival, reoperation and a composite of reoperations for LVOTO-/VSD- or baffle-related problem. RESULTS: N = 47 patients were identified treated in 14 different national centres between 1984 and 2020. The mean age was 14 (standard deviation 9) months, ranging from 7 days to 9.5 years. Nine patients (19%) were treated as neonates, 21 (45%) as infants and 17 children (36%) beyond the age of 1 year. Survival was >90% (80-100%) at 20 years. Freedom from any reoperation was 30% (10-50%) at 20 years. Freedom from the composite end point was 72% (50-90%) at 20 years. Patients after Rastelli underwent more reoperations compared to those without intraventricular baffle (freedom from reoperation 14% vs 50%, P = 0.1). The rates of the composite end point were similar when comparing Rastelli to other techniques (63% vs 83%, P = 0.32). CONCLUSIONS: The Rastelli operation yields robust results in the setting of non-committed VSD. Late results after neonatal arterial switch operation are outstanding. If LVOTO is not resectable and neonatal arterial switch operation suboptimal, interim palliation does not negatively impact outcome, patients can be safely delayed to beyond 1 year of age.

Heterogeneity and Remodeling of Ion Currents in Cultured Right Atrial Fibroblasts From Patients With Sinus Rhythm or Atrial Fibrillation.

Cardiac fibroblasts express multiple voltage-dependent ion channels. Even though fibroblasts do not generate action potentials, they may influence cardiac electrophysiology by electrical coupling via gap junctions with cardiomyocytes, and through fibrosis. Here, we investigate the electrophysiological phenotype of cultured fibroblasts from right atrial appendage tissue of patients with sinus rhythm (SR) or atrial fibrillation (AF). Using the patch-clamp technique in whole-cell mode, we observed steady-state outward currents exhibiting either no rectification or inward and/or outward rectification. The distributions of current patterns between fibroblasts from SR and AF patients were not significantly different. In response to depolarizing voltage pulses, we measured transient outward currents with fast and slow activation kinetics, an outward background current, and an inward current with a potential-dependence resembling that of L-type Ca2+ channels. In cell-attached patch-clamp mode, large amplitude, paxilline-sensitive single channel openings were found in ≈65% of SR and ∼38% of AF fibroblasts, suggesting the presence of "big conductance Ca2+-activated K+ (BK Ca )" channels. The open probability of BK Ca was significantly lower in AF than in SR fibroblasts. When cultured in the presence of paxilline, the shape of fibroblasts became wider and less spindle-like. Our data confirm previous findings on cardiac fibroblast electrophysiology and extend them by illustrating differential channel expression in human atrial fibroblasts from SR and AF tissue.

Piezo1 and BKCa channels in human atrial fibroblasts: Interplay and remodelling in atrial fibrillation.

AIMS: Atrial Fibrillation (AF) is an arrhythmia of increasing prevalence in the aging populations of developed countries. One of the important indicators of AF is sustained atrial dilatation, highlighting the importance of mechanical overload in the pathophysiology of AF. The mechanisms by which atrial cells, including fibroblasts, sense and react to changing mechanical forces, are not fully elucidated. Here, we characterise stretch-activated ion channels (SAC) in human atrial fibroblasts and changes in SAC- presence and activity associated with AF. METHODS AND RESULTS: Using primary cultures of human atrial fibroblasts, isolated from patients in sinus rhythm or sustained AF, we combine electrophysiological, molecular and pharmacological tools to identify SAC. Two electrophysiological SAC- signatures were detected, indicative of cation-nonselective and potassium-selective channels. Using siRNA-mediated knockdown, we identified the cation-nonselective SAC as Piezo1. Biophysical properties of the potassium-selective channel, its sensitivity to calcium, paxilline or iberiotoxin (blockers), and NS11021 (activator), indicated presence of calcium-dependent 'big potassium channels' (BKCa). In cells from AF patients, Piezo1 activity and mRNA expression levels were higher than in cells from sinus rhythm patients, while BKCa activity (but not expression) was downregulated. Both Piezo1-knockdown and removal of extracellular calcium from the patch pipette resulted in a significant reduction of BKCa current during stretch. No co-immunoprecipitation of Piezo1 and BKCa was detected. CONCLUSIONS: Human atrial fibroblasts contain at least two types of ion channels that are activated during stretch: Piezo1 and BKCa. While Piezo1 is directly stretch-activated, the increase in BKCa activity during mechanical stimulation appears to be mainly secondary to calcium influx via SAC such as Piezo1. During sustained AF, Piezo1 is increased, while BKCa activity is reduced, highlighting differential regulation of both channels. Our data support the presence and interplay of Piezo1 and BKCa in human atrial fibroblasts in the absence of physical links between the two channel proteins.

Small Conductance Ca2 +-Activated K+ (SK) Channel mRNA Expression in Human Atrial and Ventricular Tissue: Comparison Between Donor, Atrial Fibrillation and Heart Failure Tissue.

In search of more efficacious and safe pharmacological treatments for atrial fibrillation (AF), atria-selective antiarrhythmic agents have been promoted that target ion channels principally expressed in the atria. This concept allows one to engage antiarrhythmic effects in atria, but spares the ventricles from potentially proarrhythmic side effects. It has been suggested that cardiac small conductance Ca2+-activated K+ (SK) channels may represent an atria-selective target in mammals including humans. However, there are conflicting data concerning the expression of SK channels in different stages of AF, and recent findings suggest that SK channels are upregulated in ventricular myocardium when patients develop heart failure. To address this issue, RNA-sequencing was performed to compare expression levels of three SK channels (KCNN1, KCNN2, and KCNN3) in human atrial and ventricular tissue samples from transplant donor hearts (no cardiac disease), and patients with cardiac disease in sinus rhythm or with AF. In addition, for control purposes expression levels of several genes known to be either chamber-selective or differentially expressed in AF and heart failure were determined. In atria, as compared to ventricle from transplant donor hearts, we confirmed higher expression of KCNN1 and KCNA5, and lower expression of KCNJ2, whereas KCNN2 and KCNN3 were statistically not differentially expressed. Overall expression of KCNN1 was low compared to KCNN2 and KCNN3. Comparing atrial tissue from patients with AF to sinus rhythm samples we saw downregulation of KCNN2 in AF, as previously reported. When comparing ventricular tissue from heart failure patients to non-diseased samples, we found significantly increased ventricular expression of KCNN3 in heart failure, as previously published. The other channels showed no significant difference in expression in either disease. Our results add weight to the view that SK channels are not likely to be an atria-selective target, especially in failing human hearts, and modulators of these channels may prove to have less utility in treating AF than hoped. Whether targeting SK1 holds potential remains to be elucidated.

Analysis of spinal cord blood supply combining vascular corrosion casting and fluorescence microsphere technique: A feasibility study in an aortic surgical large animal model.

INTRODUCTION: Spinal cord ischemia after cardiovascular interventions continues to be a devastating problem in modern surgery. The role of intraspinal vascular networks and anterior radiculomedullary arteries (ARMA) in preventing spinal cord ischemia is poorly understood. MATERIALS AND METHODS: Landrace pigs (n = 30, 35.1 ± 3.9 kg) underwent a lateral thoracotomy. Fluorescent microspheres were injected into the left atrium and a reference sample was aspirated from the descending aorta. Repeated measurements of spinal cord and renal cortical blood flow from the left and right kidneys with three different microsphere colors in five pigs were taken to validate reproducibility. Spinal cord blood flow to the upper thoracic (T1-T4), mid-thoracic (T5-T8), lower thoracic (T9-T13), and lumbar (L1-L3) levels were determined. After euthanasia, we carried out selective vascular corrosion cast and counted the left and right ARMAs from levels T1-T13. RESULTS: Blood flow analysis of the left and right kidneys revealed a strong correlation (r = .94, p < .001). We detected more left than right ARMAs, with the highest prevalence at T4 (p < .05). The mean number of ARMAs was 8 ± 2. Their number in the upper thoracic region ranged from 2 to 7 (mean of 5 ± 1), while in the lower thoracic region they ranged from 0 to 5 (mean of 3 ± 1 [p < .001]). CONCLUSIONS: This study shows that combining fluorescence microsphere technique and vascular corrosion cast is well suited for assessing the blood flow and visualizing the arteries at the same time.

The intraspinal arterial collateral network: a new anatomical basis for understanding and preventing paraplegia during aortic repair.

OBJECTIVES: The anatomical distribution pattern of epidural intraspinal arteries is not entirely understood but is likely to substantially impact maintaining perfusion during segmental artery sacrifice when treating acute and chronic thoraco-abdominal aortic diseases. We investigated the anatomical distribution pattern of intraspinal arteries. METHODS: Twenty fresh, non-embalmed cadaveric human bodies were studied. Anatomical dissection and investigation of the epidural arterial network were performed according to a standardized protocol. We used a generalized mixed linear model to test whether the presence probability for certain vessels differed between vertebrae/segments. RESULTS: There was craniocaudal continuity of all ipsilateral longitudinal connections from T1 to L5 by the anterior radicular artery. The mean [±standard deviation (SD)] number of transverse anastomoses was 9.7 ± 2.1. The presence probability of transverse anastomoses along the spine was different between vertebrae (P < 0.0001). There were 2 distribution peaks along the spine: 1 peak around T4-T6 and 1 around T11. The mean (±SD) number of thoracic and lumbar anterior radiculomedullary arteries (ARMAs) was 3.0 ± 1.1. The probability of the presence of ARMAs along the spine was different for each vertebral segment (P < 0.0001). Between ARMAs there were gaps of up to a maximum of 9 vertebrae. All Adamkiewicz arteries were located caudally to T7. The median segment of the Adamkiewicz presence was T10/11. CONCLUSIONS: The epidural collateral network shows craniocaudal continuity. The number of transverse anastomoses is high. The number of ARMAs is low, and there is considerable variation in their distribution and offspring, which is highly likely to impact perfusion during segmental artery sacrifice when treating thoraco-abdominal aortic disease.