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.

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.

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.

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.

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.

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.

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.

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' (BK_Ca). In cells from AF patients, Piezo1 activity and mRNA expression levels were higher than in cells from sinus rhythm patients, while BK_Ca activity (but not expression) was downregulated. Both Piezo1-knockdown and removal of extracellular calcium from the patch pipette resulted in a significant reduction of BK_Ca current during stretch. No co-immunoprecipitation of Piezo1 and BK_Ca was detected.

CONCLUSIONS

Human atrial fibroblasts contain at least two types of ion channels that are activated during stretch: Piezo1 and BK_Ca. While Piezo1 is directly stretch-activated, the increase in BK_Ca activity during mechanical stimulation appears to be mainly secondary to calcium influx via SAC such as Piezo1. During sustained AF, Piezo1 is increased, while BK_Ca activity is reduced, highlighting differential regulation of both channels. Our data support the presence and interplay of Piezo1 and BK_Ca 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.

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 replacement (AVR).

METHODS

Six centers established an intention-to-treat-design V-SARR-registry (German Aortic Root Repair Registry, GEARR, first-patient-in 10/2016) with main inclusion criterion "scheduled for V-SARR as Plan A". Clinical information, operative details, intraoperative valve/root measurements and clinical/TTE follow-up-data are documented.

RESULTS

Of a total of n=449, we report data on n=401 patients (81% male, mean age 51±14y). N=350 underwent V-SARR as scheduled (Group A, "David"-variants I 55%, III 2%, IV 13%, V 24%, V- Stanford 2%, Yacoub-Remodeling 2%), n=51 were converted to AVR (Group B). Median follow-up was 11 months (0-2.6y), cumulative follow-up 279 patient-years. In Group B there were less connective tissue disorders (6vs16%), fewer patients had LVEF>50% (60%vs90%), more had bicuspid aortic valves (BAV,45%vs28%), fewer patients had preoperative non/trace AR (2%vs20%). Fewer individuals in Group B had rare types of BAV (fused N/L, R/N, 10%vs30%) and more had unbalanced roots (56%vs40%). Immediate-postoperative AR was none/trace in 79%, and mild in 20%. At 30 days the dpmean was 7±5mmHg. None of the patients died in hospital, two strokes occurred. One patient needed early AVR as re-do surgery.

CONCLUSIONS

Main factors causing surgeons to convert a planned V-SARR to AVR include asymmetry of aortic valve/root, severity of AR, safety-reasons (LVEF), and BAV, but not rare types of BAV. GEARR will help us identify the impact on long-term outcomes of pre- and postoperative valvular anatomy and various V-SARR types.

Carbon monoxide improves haemodynamics during extracorporeal resuscitation in pigs

AIMS

Heart disease of different aetiology remains the leading cause of cardiac arrest (CA). Despite efforts to improve the quality of cardiopulmonary resuscitation (CPR), subsequent myocardial and systemic damage after CA still present a major long-term burden. Low-dose carbon monoxide (CO) is known to exert protective effects in cardiovascular pathophysiology but clinical applications are challenged by unfavourable delivery modes. We tested the hypothesis that extracorporeal resuscitation (E-CPR) in combination with controlled fast onset CO delivery results in improved cardiac physiology and haemodynamics. Damage-associated molecular pattern (DAMP) signalling may be part of the molecular mechanism.

METHODS AND RESULTS

In an established porcine model, E-CPR was performed. While E-CPR leads to similar results as compared to a conventional CPR strategy, CO delivery in combination with E-CPR demonstrated significant cardioprotection. Cardiac performance analysis using echocardiography and thermodilution techniques showed a CO-dependent improved cardiac function compared to severe myocardial dysfunction in CPR and E-CPR (left ventricular ejection fraction: Sham 49 ± 5; CPR 26 ± 2; E-CPR 25 ± 2; CO-E-CPR 31 ± 4; P < 0.05). While sublingual microcirculation was significantly compromised in CPR and E-CPR, CO delivery demonstrated a significant improvement in microvascular function (microvascular flow index: Sham 2.9 ± 0.1; CPR 2.2 ± 0.1; E-CPR 1.8 ± 0.1; CO-E-CPR 2.7 ± 0.1; P < 0.01). Histological and serological myocardial damage markers were significantly reduced (hsTroponin-T Sham 0.01 ± 0.001; CPR 1.9 ± 0.2; E-CPR 3.5 ± 1.2; CO-E-CPR 0.5 ± 0.2 ng/mL; P < 0.05). DAMP signalling was decreased ipse facto leading to influence of cardioprotective heat shock and cyclooxygenase response.

CONCLUSIONS

CO treatment restores myocardial function and improves systemic macro- and microhaemodynamics in E-CPR through a reduction in DAMPs.

Staged Surgical Management of Anatomically Corrected Malposition of Great Arteries

A nine-month-old girl diagnosed with anatomically corrected malposition (atrioventricular discordance, ventriculoarterial concordance, and malposed great arteries) complicated by multiple ventricular septal defects (VSD) and multifactorial left ventricular outflow tract obstruction (LVOTO) presented for management after pulmonary artery banding. She underwent interim palliation in the form of bilateral cavopulmonary connections, a modified Damus-Kaye-Stansel-type anastomosis, and subsequent staged one-and-a-half ventricle repair (1.5 repair) at the age of three years in the form of VSD closure, hemi-Mustard, and LVOTO resection.

Carbon Monoxide Exerts Functional Neuroprotection After Cardiac Arrest Using Extracorporeal Resuscitation in Pigs

OBJECTIVES

Neurologic damage following cardiac arrest remains a major burden for modern resuscitation medicine. Cardiopulmonary resuscitation with extracorporeal circulatory support holds the potential to reduce morbidity and mortality. Furthermore, the endogenous gasotransmitter carbon monoxide attracts attention in reducing cerebral injury. We hypothesize that extracorporeal resuscitation with additional carbon monoxide application reduces neurologic damage.

DESIGN

Randomized, controlled animal study.

SETTING

University research laboratory.

SUBJECTS

Landrace-hybrid pigs.

INTERVENTIONS

In a porcine model, carbon monoxide was added using a novel extracorporeal releasing system after resuscitation from cardiac arrest.

MEASUREMENTS AND MAIN RESULTS

As markers of cerebral function, neuromonitoring modalities (somatosensory-evoked potentials, cerebral oximetry, and transcranial Doppler ultrasound) were used. Histopathologic damage and molecular markers (caspase-3 activity and heme oxygenase-1 expression) were analyzed. Cerebral oximetry showed fast rise in regional oxygen saturation after carbon monoxide treatment at 0.5 hours compared with extracorporeal resuscitation alone (regional cerebral oxygen saturation, 73% ± 3% vs 52% ± 8%; p < 0.05). Median nerve somatosensory-evoked potentials showed improved activity upon carbon monoxide treatment, whereas post-cardiac arrest cerebral perfusion differences were diminished. Histopathologic damage scores were reduced compared with customary resuscitation strategies (hippocampus: sham, 0.4 ± 0.2; cardiopulmonary resuscitation, 1.7 ± 0.4; extracorporeal cardiopulmonary resuscitation, 2.3 ± 0.2; extracorporeal cardiopulmonary resuscitation with carbon monoxide application [CO-E-CPR], 0.9 ± 0.3; p < 0.05). Furthermore, ionized calcium-binding adaptor molecule 1 staining revealed reduced damage patterns upon carbon monoxide treatment. Caspase-3 activity (cardiopulmonary resuscitation, 426 ± 169 pg/mL; extracorporeal cardiopulmonary resuscitation, 240 ± 61 pg/mL; CO-E-CPR, 89 ± 26 pg/mL; p < 0.05) and heme oxygenase-1 (sham, 1 ± 0.1; cardiopulmonary resuscitation, 2.5 ± 0.4; extracorporeal cardiopulmonary resuscitation, 2.4 ± 0.2; CO-E-CPR, 1.4 ± 0.2; p < 0.05) expression were reduced after carbon monoxide exposure.

CONCLUSIONS

Carbon monoxide application during extracorporeal resuscitation reduces injury patterns in neuromonitoring and decreases histopathologic cerebral damage by reducing apoptosis. This may lay the basis for further clinical translation of this highly salutary substance.

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.

Spinal ischaemia after thoracic endovascular aortic repair with left subclavian artery sacrifice: is there a critical stent graft length?

OBJECTIVES

Thoracic endovascular aortic repair (TEVAR) is used for treatment of thoracic aortic pathologies, but the covered stent graft can induce spinal ischaemia depending on the length used. The left subclavian artery contributes to spinal cord collateralization and is frequently occluded by the stent graft. Our objective was to investigate the impact of covered stent graft length on the risk of spinal ischaemia in the setting of left subclavian artery sacrifice.

METHODS

Twenty-six pigs (German country race, mean body weight 36 ± 4 kg) underwent simulated descending aortic TEVAR via left lateral thoracotomy, with left subclavian artery and thoracic segmental artery occlusion in normothermia. Animals were assigned to treatment groups according to simulated stent graft length: TEVAR to T8 (n = 4), TEVAR to T9 (n = 4), TEVAR to T10 (n = 4), TEVAR to T11 (n = 7) and TEVAR to T12 (n = 1) and a sham group (n = 6). End points included spinal cord perfusion pressure, cerebrospinal fluid pressure and spinal cord blood flow using fluorescent microspheres.

RESULTS

There were no group differences in spinal cord perfusion pressure drop or in spinal cord perfusion pressure regeneration potential at 3 h after the procedure: from a baseline average of 75 mmHg (95% confidence interval 71-83 mmHg) to 73 mmHg (67-75 mmHg) at 3 h in Group T10 versus from a baseline average of 67 mmHg (95% CI 50-81 mmHg) to 65 mmHg (95% confidence interval 48-81 mmHg) in Group T8. There were no differences in the spinal cord blood flow courses over time in the different groups nor was there any difference in cerebrospinal fluid pressure levels and cerebrospinal fluid pressure dynamics between groups. However, we did observe local blood flow distribution to the spinal cord that was inhomogeneous depending on the distance between the simulated stent graft end and the first thoracic anterior radiculomedullary artery.

CONCLUSIONS

The risk of spinal ischaemia after serial segmental artery occlusion does not depend on the distal extent of the aortic repair alone. Future attempts to allow patient risk stratification for spinal ischaemia need to focus on anterior radiculomedullary artery anatomy together with the extent of planned aortic repair.

Repair of Complex Transposition of Great Arteries: Up to 30 Years of Follow-up

BACKGROUND

To characterize treatment of transposition of great arteries with ventricular septal defect and left ventricular outflow tract obstruction (LVOTO) in Germany and to analyze late outcomes.

METHODS

German Registry for Congenital Heart Defects data were searched for transposition of great arteries with ventricular septal defect and LVOTO. One hundred thirty-nine patients were treated at 15 institutions between 1968 and 2016. Risk factor analyses were performed for the primary endpoints of death and reoperation/reintervention.

RESULTS

Follow-up was 88% complete, with a mean follow-up of 16 ± 7 years (median, 15 years [range, 1-48]) and a cumulative follow-up comprising 1739 patient-years. Atrial switches were performed in 15%, Rastelli procedure in 48%, Nikaidoh procedure in 9%, réparation a l'étage ventriculair (REV) in 8%, and arterial switch in 20%. Actuarial survival at 30 years was 86% (range, 83%-90%), with no difference between repairs. Freedom from primary reoperation was 17% (range, 12%-21%) at 30 years. Freedom from reoperation for LVOTO at 30 years was 74% (range, 70%-78%). Recurrent LVOTO was found in 9%, with risk factor diffuse subvalvular LVOTO (odds ratio, 9.8; P = .04). Late freedom from first reoperations other than right ventricle-to-pulmonary artery conduit was 60% (range, 59%-61%), with predictors multiple ventricular septal defect (hazard ratio, 6; P = .03) and Rastelli procedure (hazard ratio, 12; P = .03). Absolute reoperation rates were lowest for REV procedure (16% at a mean of 12 years).

CONCLUSIONS

Long-term survival is good without detectable differences between operations. Since the early 2000s increasing use of Nikaidoh and REV procedures was obvious, with REV performing particularly well. Surgery-specific and -unspecific reoperations are most common after the Rastelli technique.

The Use of Biological Heart Valves

BACKGROUND

Biological heart-valve prostheses have undergone continuous devel- opment up to the present, and technological advances have been made in catheter- assisted valve systems (transcatheter aortic valve implantation, TAVI) and minimally invasive routes of application. These parallel trends have led to major changes in therapeutic strategies, widening the spectrum of patients who are candidates for biological aortic valve implantation.

METHODS

This review is based on pertinent publications retrieved by a systematic search in PubMed employing the search terms "conventional biological aortic pros- thesis," "rapid deployment prosthesis," and "transcatheter aortic valve implantation/ replacement."

RESULTS

Among biological heart-valve prostheses, a distinction is drawn between stented (conventional, rapid-deployment, and catheter-assisted) and non-stented types. The long-term durability of conventional, surgically implantable biological valve protheses is by far the best documented: the reported 5-year reoperation rates range from 13.4% to 36.6%, and the pacemaker implantation rate is ca. 4%. Rapid-deployment prostheses combine the advantages of conventional and ca- theter-assisted techniques and facilitate minimally invasive approaches. The TAVI method is currently recommended for high- and intermediate-risk patients, while conventional valve replacement remains the method of choice for those at low risk. Rapid-deployment and TAVI prostheses is associated with a higher pacemaker im- plantation rate than conventional prostheses: these rates are 8.5-15.3% for TAVI and 6.0-8.8% for rapid-deployment valves. The intermediate-term durability of catheter-assisted and rapid-deployment prostheses appears promising, but their long-term durability is still unclear.

CONCLUSION

The further development of biological heart-valve prostheses in the form of improved conventional, transcatheter, and rapid-deployment prostheses now enables individualized treatment. Before any such procedure is performed, the car- diac team must assess the patient's risk profile and the advantages and disadvan- tages of each type of prosthesis to determine which is best.

Endovascular aortic arch repair using a double-branched approach

The last 15 years have overwhelmed the surgical community with a range of approaches in treating pathologies involving the aortic arch of which some are here to stay. The ones to stay are-in the authors' opinion-refined classical surgical approaches such as the frozen elephant trunk technique, near-orthotopic combined vascular and endovascular approaches such as subclavian to carotid transposition/bypass and double transposition, and finally, near-orthotopic advanced endovascular solutions such as the double-endovascular repair using fenestrated and/or branched solutions which will be the main focus of this article.

New insights into spinal cord ischaemia after thoracic aortic procedures: the importance of the number of anterior radiculomedullary arteries for surgical outcome

OBJECTIVES

Anterior radiculomedullary arteries (ARMAs) link dorsal segmental arteries and the intraspinal compartment of the spinal collateral network. The number of thoracic ARMA is highly variable from one person to another. The impact of the number of ARMAs on spinal cord perfusion during thoracic aortic procedures is unknown. We investigated the influence of the number of thoracic ARMAs on spinal cord perfusion in an aortic surgical large animal model.

METHODS

Twenty-six pigs were included (20 treatment animals, 6 sham animals, weight 34 ± 3 kg). The animals underwent ligation of the left subclavian artery and the thoracic segmental arteries via a left lateral thoracotomy with normothermia. After sacrifice, complete body perfusion with coloured cast resin was performed and the number of thoracic ARMAs was documented at autopsy. End points were spinal cord perfusion pressure, cerebrospinal fluid pressure, spinal cord blood flow (microspheres) and neurological outcome. Observation time was 3 h post-ligation.

RESULTS

The numbers of thoracic ARMAs ranged between 3 (n = 1) and 13 (n = 1). The mean number was 8. Animals were grouped according to number of thoracic ARMA: 6-7 (5 animals), 8-10 (8 animals) and 11-13 (5 animals). A large number of thoracic ARMAs was linked to (i) a lower drop in spinal cord blood flow from baseline to post-clamp, (ii) the presence and increased magnitude of hyperaemia evident 3 h post-clamp (P < 0.001) and (iii) the presence of early hyperaemia starting immediately post-clamp in animals with 11 or more ARMA (P < 0.001).

CONCLUSIONS

We showed that a large number of thoracic ARMA protects against spinal cord injury during descending aortic surgical procedures.1.

Surgical Treatment of Native and Prosthetic Aortic Infection With Xenopericardial Tube Grafts

BACKGROUND

The study sought to report our results of surgical treatment of native and prosthetic aortic infection with xenopericardial tube grafts from the ascending aorta to beyond the bifurcation.

METHODS

Within a 28-month period, 20 patients were treated with a bovine self-made pericardial tube graft to replace infected vascular grafts (after conventional surgical aortic replacement or endovascular stent graft implantation) or to treat a contaminated surgical site. An integrated standardized therapeutic concept was applied in all patients, consisting of complete removal of the infected prosthetic material, extensive debridement, and orthotopic vascular reconstruction with self-made tube grafts constructed from a bovine pericardial patch.

RESULTS

Four patients died perioperatively (20%) due to sepsis, pulmonary failure, or sudden circulatory arrest. The mean follow-up was 18 months (first quartile 2, third quartile 17 months). Interval computed tomography scans revealed 100% freedom from proven aortic reinfection, but reinfection cannot be ruled out in 4 patients who died of unknown causes during follow-up or because of ongoing sepsis. Three patients required aortic reintervention for a suture-line aneurysm, for graft occlusion, and for the development of a neoaortointestinal fistulation, respectively.

CONCLUSIONS

Patients with infectious aortic disease present in a frail state and the initial and the late mortality is substantial. Yet, surgical treatment of native and prosthetic aortic infection with xenopericardial tube grafts shows promising short-term results with regard to durability and freedom from reinfection in any aortic segment. Further studies are needed to learn of the long-term behavior of these grafts.

Endovascular treatment of acute Type A aortic dissection-the Endo Bentall approach

Outcome after classical surgical repair of acute Type A aortic dissection has steadily improved over the years and several modifications in cannulation and perfusion added to this achievement. However, subgroups remain where results of classical surgical repair still have room for improvement, particularly patients with severe preoperative malperfusion as well as elderly patients with a limited physiological reserve. So far, only small case series or case reports have been published on the endovascular treatment of dissected ascending aortas. However, a tube alone is not sufficient to fix the entire complex underlying problem in the vast majority of patients with acute Type A aortic dissection. In addition, these published reports are either due to a favorable anatomy or due to very localized disease processes, which are the exception and not the rule. The concept of an endovascular valve-carrying conduit may significantly increase the number of patients suitable for endovascular therapy and it may soon be common practice.

Chronic type B "residual" after type A: what I would do?

"The major goal of surgery for acute type A aortic dissection is to have an alive patient." This motto still remains the most important directive. However, also depending onto the extent of the underlying pathology and consecutively depending onto the extent of primary surgery, there is and will be need for additional classical surgical or interventional treatment sooner or later during follow-up in a substantial number of patients having had surgery for acute type A aortic dissection. This article shall guide the interested reader through the underlying mechanisms as well as treatment options in patients with chronic type B "residual" after type A repair and shall finally suggest preventive strategies to reduce the occurrence of this pathology to a minimum.

Spinal Ischemia in Thoracic Aortic Procedures: Impact of Radiculomedullary Artery Distribution

BACKGROUND

The aim of this study was to assess the influence of thoracic anterior radiculomedullary artery (tARMA) distribution on spinal cord perfusion in a thoracic aortic surgical model.

METHODS

Twenty-six pigs (34 ± 3 kg; study group, n = 20; sham group, n = 6) underwent ligation of the left subclavian artery and thoracic segmental arteries. End points were spinal cord perfusion pressure (SCPP), regional spinal cord blood flow (SCBF), and neurologic outcome with an observation time of 3 hours. tARMA distribution patterns tested for an effect on end points included (1) maximum distance between any 2 tARMAs within the treated aortic segment (0 or 1 segment = small-distance group; >1 segment = large-distance group) and (2) distance between the end of the treated aortic segment and the first distal tARMA (at the level of the distal simulated stent-graft end = group 0; gap of 1 or more segments = group ≥1).

RESULTS

The number of tARMA ranged from 3 to 13 (mean, 8). In the large-distance group, SCBF dropped from 0.48 ± 0.16 mL/g/min to 0.3 ± 0.08 mL/g/min (p < 0.001). We observed no detectable SCBF drop in the small-distance group: 0.2 ± 0.05 mL/g/min at baseline to 0.23 ± 0.05 mL/g/min immediately after clamping (p = 0.147). SCBF increased from 0.201 ± 0.055 mL/g/min at baseline to 0.443 ± 0.051 mL/g/min at 3 hours postoperatively (p < 0.001) only in the small-distance group.

CONCLUSIONS

We demonstrate experimental data showing that distribution patterns of tARMAs correlate with the degree of SCBF drop and insufficient reactive parenchymal hyperemia in aortic procedures. Individual ARMA distribution patterns along the treated aortic segment could help us predict the individual risk of spinal ischemia.

Progression of Aortic Regurgitation After Different Repair Techniques for Congenital Aortic Valve Stenosis

We sought to characterize the incidence of AR progression and determine risk factors for AR progression in a consecutive series of infants and children after surgical correction of congenital aortic valvular and supravalvular stenosis. N = 30 patients underwent repair of the aortic valve for isolated congenital aortic valve stenosis (n = 14, 47 %) or combined with aortic regurgitation (AR, n = 16, 53%). N = 27 (90%) had a valvular and n = 3 patients (10%) presented with supravalvular pathology of their aortic valve. In n = 16 patients (53%) a bicuspid and in n = 2 (6%) patients, a unicuspid valve was present. Comparative survival was analyzed using the Cox model and log-rank calculations. Log-rank calculations were performed for variables reaching statistical significance in order to identify differences in survival between groups. Commissurotomy was performed in n = 20 patients, patch implantation in n = 4, cusp shaving in n = 8, cusp prolapse correction in n = 3, and cusp augmentation in n = 4 patients. In patients with combined dysfunction and preoperative AR, AR was successfully reduced by the initial procedure, and postoperatively the overall median AR grade was 1+ (range 0-2.5+, p = 0.001, for AR reduction among patients with any grade of preoperative AR). By the time of follow-up echocardiography, the median AR grade had significantly progressed toward 1.5+ (p = 0.004). At the time of mid-term follow-up at 3.2 years, none of the patients had moderate or severe AR grades >2.5+. Patients with a monocuspid aortic valve and patients who had some kind of patch implantation into their cusps or commissures or shaving of thickened cusps were more likely to present with progression of aortic regurgitation. Monocuspid aortic valve and patch implantation, as well as cusp shaving, are probably linked to AR progression. The standard procedure of commissurotomy results in an absolute rate of AR progression of 40 % over a medium-term follow-up period.

Residual and Progressive Aortic Regurgitation After Valve-Sparing Root Replacement: A Propensity-Matched Multi-Institutional Analysis in 764 Patients

BACKGROUND

Residual/progressive aortic regurgitation (rAR, pAR) after valve-sparing aortic root replacement (V-SARR) can lead to reoperations. We sought to characterize risk factors of mild rAR and pAR after V-SARR in a multicenter cohort. The effect of additional cusp repair on valve function was analyzed using propensity matching.

METHODS

A total of 1,015 patients after V-SARR were identified with (n = 288, 28%) or without additional cusp/commissure repair (n = 727, 72%) at four cardiac units in Germany. A total of 764 patients fulfilling transthoracic echocardiography follow-up-criteria comprised the study cohort. Logistic regression was used for risk factor analysis with endpoints rAR, new onset AR, and pAR. t tests and analyses of variance were used for between-group differences. The effects of additional cusp repair on valve function were studied comparing propensity-matched quintiles.

RESULTS

The incidence of rAR was 29%, with influencing factors aneurysm size (p = 0.07) and preoperative aortic valve function (p = 0.08). It was found more often among nonsyndromic patients (34% vs. 14%; OR, 0.4; p < 0.001). Progression of rAR was detectable in 30% after a mean of 4.3 years. The progression rate of rAR ∼ 0.3 grades per patient-year within the first 5 years. When quintiles identified by propensity score were compared, additional cusp repair was linked to new onset AR (p = 0.016) while it was not linked to rAR (p = 0.14) or pAR (p = 0.5).

CONCLUSIONS

The incidences of rAR and pAR are considerable after V-SARR. Patients should be operated on before large aneurysms are present. New onset AR after an initially good functional result is more likely after an additional cusp repair, while rAR and pAR are not influenced by cusp repair.