Rat Model of Normothermic Ex-Situ Perfused Heterotopic Heart Transplantation.

Heart transplantation is the most effective therapy for end-stage heart failure. Despite the improvements in therapeutic approaches and interventions, the number of heart failure patients waiting for transplantation is still increasing. The normothermic ex situ preservation technique has been established as a comparable method to the conventional static cold storage technique. The main advantage of this technique is that donor hearts can be preserved for up to 12 h in a physiologic condition. Moreover, this technique allows resuscitation of the donor hearts after circulatory death and applies required pharmacologic interventions to improve donor function after implantation. Numerous animal models have been established to improve normothermic ex situ preservation techniques and eliminate preservation-related complications. Although large animal models are easy to handle compared to small animal models, it is costly and challenging. We present a rat model of normothermic ex situ donor heart preservation followed by heterotopic abdominal transplantation. This model is relatively cheap and can be accomplished by a single experimenter.

Rapid remodeling observed at mid-term in-vivo study of a smart reinforced acellular vascular graft implanted on a rat model.

BACKGROUND: The poor performance of conventional techniques used in cardiovascular disease patients requiring hemodialysis or arterial bypass grafting has prompted tissue engineers to search for clinically appropriate off-the-shelf vascular grafts. Most patients with cardiovascular disease lack suitable autologous tissue because of age or previous surgery. Commercially available vascular grafts with diameters of < 5 mm often fail because of thrombosis and intimal hyperplasia. RESULT: Here, we tested tubular biodegradable poly-e-caprolactone/polydioxanone (PCL/PDO) electrospun vascular grafts in a rat model of aortic interposition for up to 12 weeks. The grafts demonstrated excellent patency (100%) confirmed by Doppler Ultrasound, resisted aneurysmal dilation and intimal hyperplasia, and yielded neoarteries largely free of foreign materials. At 12 weeks, the grafts resembled native arteries with confluent endothelium, synchronous pulsation, a contractile smooth muscle layer, and co-expression of various extracellular matrix components (elastin, collagen, and glycosaminoglycan). CONCLUSIONS: The structural and functional properties comparable to native vessels observed in the neoartery indicate their potential application as an alternative for the replacement of damaged small-diameter grafts. This synthetic off-the-shelf device may be suitable for patients without autologous vessels. However, for clinical application of these grafts, long-term studies (> 1.5 years) in large animals with a vasculature similar to humans are needed.

The Outcome of Post-cardiotomy Extracorporeal Membrane Oxygenation in Neonates and Pediatric Patients: A Systematic Review and Meta-Analysis.

Objective: Post-cardiotomy extracorporeal membrane oxygenation (PC-ECMO) is a known rescue therapy for neonates and pediatric patients who failed to wean from cardiopulmonary bypass (CPB) or who deteriorate in intensive care unit (ICU) due to various reasons such as low cardiac output syndrome (LCOS), cardiac arrest and respiratory failure. We conducted a systematic review and meta-analysis to assess the survival in neonates and pediatric patients who require PC-ECMO and sought the difference in survivals by each indication for PC-ECMO. Design: Systematic review and meta-analysis. Setting: Multi-institutional analysis. Participants: Neonates and pediatric patients who requires PC- ECMO. Interventions: ECMO after open-heart surgery. Results: Twenty-six studies were included in the analysis with a total of 186,648 patients and the proportion of the population who underwent PC-ECMO was 2.5% (2,683 patients). The overall pooled proportion of survival in this population was 43.3% [95% Confidence interval (CI): 41.3-45.3%; I 2: 1%]. The survival by indications of PC-ECMO were 44.6% (95% CI: 42.6-46.6; I 2: 0%) for CPB weaning failure, 47.3% (95% CI: 39.9-54.7%; I 2: 5%) for LCOS, 37.6% (95% CI: 31.0-44.3%; I 2: 32%) for cardiac arrest and 47.7% (95% CI: 32.5-63.1%; I 2: 0%) for respiratory failure. Survival from PC-ECMO for single ventricle or biventricular physiology, was reported by 12 studies. The risk ratio (RR) was 0.74 for survival in patients with single ventricle physiology (95% CI: 0.63-0.86; I 2: 40%, P < 0.001). Eight studies reported on the survival after PC-ECMO for genetic conditions. The RR was 0.93 for survival in patients with genetic condition (95% CI: 0.52-1.65; I 2: 65%, P = 0.812). Conclusions: PC-ECMO is an effective modality to support neonates and pediatric patients in case of failed CPB weaning and deterioration in ICU. Even though ECMO seems to improve survival, mortality and morbidity remain high, especially in neonates and pediatric patients with single ventricle physiology. Most genetic conditions alone should not be considered a contraindication to ECMO support, further studies are needed to determine which genetic abnormalities are associated with favorable outcome.

Long-term clinical outcomes of coronary artery bypass grafting in young children with Kawasaki disease.

BACKGROUND: Although coronary artery bypass grafting is not frequently performed in children, Kawasaki disease is one of the most common indications for coronary artery bypass grafting in children. Here, we reviewed the long-term clinical outcomes including graft patency after coronary artery bypass grafting. METHODS: Between March 2004 and March 2013, six patients with Kawasaki disease underwent coronary artery bypass grafting. All patients were male. Their median age was 13.0 years (interquartile range, 7.8-17.8 years) at the timing of coronary artery bypass grafting, and the median age at the onset of Kawasaki disease was 3.3 years (interquartile range, 1.0-7.0 years). Four patients presented with multiple lesions including aneurysms. RESULTS: The median follow-up duration was 12.1 years (interquartile range, 9.5-13.1 years), and there were no operative complications or overall mortality. One patient had pre-operative symptoms such as exertional chest pain and dyspnoea on exertion, whereas one patient had ventricular tachyarrhythmia. There was an improvement in subjective symptoms after surgery in two patients. The left internal thoracic artery, right internal thoracic artery, and saphenous vein were used in five (83.3%), one (16.7%), and two (33.3%) cases, respectively. In all six patients, post-operative single-photon emission CT findings showed improved perfusion compared with pre-operative single-photon emission CT. All grafts were patent as confirmed by coronary angiography or CT angiography. CONCLUSIONS: Coronary artery bypass grafting could be a good surgical option in children with coronary lesions caused by Kawasaki disease in terms of graft patency and myocardial perfusion.

Tricuspid valve detachment for ventricular septal defect closure in infants <5 kg: should we be hesitant?

OBJECTIVES: We compared the clinical outcomes between tricuspid valve detachment (TVD) and non-TVD for ventricular septal defect (VSD) closure in infants <5 kg. METHODS: From January 2004 to April 2020, 462 infants <5 kg with VSD without more complex intracardiac lesions and who had undergone VSD closure through the trans-atrial approach were enrolled. Propensity score-matching analysis was performed. Clinical outcomes were compared between the paired TVD group (group D) and paired non-TVD group (group N). RESULTS: The median age and body weight at operation were 1.9 months [interquartile range(IQR), 1.4-2.5] and 4.2 kg (IQR, 3.7-4.6). The median follow-up duration was 83.4 months (IQR, 43.5-130.4). After matching, 44 pairs were extracted from each group. There were no significant differences in all-cause mortality (P = 0.176), reoperation (P = 0.172), postoperative morbidities, including residual VSD, aortic regurgitation, atrioventricular block and significant tricuspid regurgitation (TR) (P = 0.346) between group D and group N. However, group D showed significantly less TR progression during follow-up (P = 0.019). CONCLUSIONS: In infants <5 kg, TVD can be a reasonable and valid option for successful VSD closure without morbidities, including TR progression if the indication exists.

Three-Dimensional Printing of Congenital Heart Disease Models for Cardiac Surgery Simulation: Evaluation of Surgical Skill Improvement among Inexperienced Cardiothoracic Surgeons.

OBJECTIVE: To evaluate the impact of surgical simulation training using a three-dimensional (3D)-printed model of tetralogy of Fallot (TOF) on surgical skill development. MATERIALS AND METHODS: A life-size congenital heart disease model was printed using a Stratasys Object500 Connex2 printer from preoperative electrocardiography-gated CT scans of a 6-month-old patient with TOF with complex pulmonary stenosis. Eleven cardiothoracic surgeons independently evaluated the suitability of four 3D-printed models using composite Tango 27, 40, 50, and 60 in terms of palpation, resistance, extensibility, gap, cut-through ability, and reusability of. Among these, Tango 27 was selected as the final model. Six attendees (two junior cardiothoracic surgery residents, two senior residents, and two clinical fellows) independently performed simulation surgeries three times each. Surgical proficiency was evaluated by an experienced cardiothoracic surgeon on a 1-10 scale for each of the 10 surgical procedures. The times required for each surgical procedure were also measured. RESULTS: In the simulation surgeries, six surgeons required a median of 34.4 (range 32.5-43.5) and 21.4 (17.9-192.7) minutes to apply the ventricular septal defect (VSD) and right ventricular outflow tract (RVOT) patches, respectively, on their first simulation surgery. These times had significantly reduced to 17.3 (16.2-29.5) and 13.6 (10.3-30.0) minutes, respectively, in the third simulation surgery (p = 0.03 and p = 0.01, respectively). The decreases in the median patch appliance time among the six surgeons were 16.2 (range 13.6-17.7) and 8.0 (1.8-170.3) minutes for the VSD and RVOT patches, respectively. Summing the scores for the 10 procedures showed that the attendees scored an average of 28.58 ± 7.89 points on the first simulation surgery and improved their average score to 67.33 ± 15.10 on the third simulation surgery (p = 0.008). CONCLUSION: Inexperienced cardiothoracic surgeons improved their performance in terms of surgical proficiency and operation time during the experience of three simulation surgeries using a 3D-printed TOF model using Tango 27 composite.

Long-Term Results of the Leaflet Extension Technique for Rheumatic Aortic Regurgitation: A 20-Year Follow-up.

BACKGROUND: Although aortic valve repair can reduce prosthesis-related complications, rheumatic aortic regurgitation (AR) caused by leaflet restriction is a significant risk factor for recurrent AR. In this study, we evaluated the long-term results of the leaflet extension technique for rheumatic AR. METHODS: Between 1995 and 2016, 33 patients underwent aortic valve repair using the leaflet extension technique with autologous pericardium for rheumatic pure AR. Twenty patients had severe AR and 9 had combined moderate or greater mitral regurgitation. Their mean age was 32.2±13.9 years. The mean follow-up duration was 18.3±5.8 years. RESULTS: There were no cases of operative mortality, but postoperative complications occurred in 5 patients. Overall survival at 10 and 20 years was 93.5% and 87.1%, respectively. There were no thromboembolic cerebrovascular events, but 4 late deaths occurred, as well as a bleeding event in 1 patient who was taking warfarin. Twelve patients underwent aortic valve reoperation. The mean interval to reoperation was 13.1±6.1 years. Freedom from reoperation at 10 and 20 years was 96.7% and 66.6%, respectively. CONCLUSION: The long-term results of the leaflet extension technique showed acceptable durability and a low incidence of thromboembolic events and bleeding. The leaflet extension technique may be a good option for young patients with rheumatic AR.

Differentiation between incomplete Kawasaki disease and secondary hemophagocytic lymphohistiocytosis following Kawasaki disease using N-terminal pro-brain natriuretic peptide.

PURPOSE: Hemophagocytic lymphohistiocytosis (HLH) is a hyperinflammatory syndrome with many causes, including Kawasaki disease (KD). The purpose of this study was to identify the laboratory tests needed to easily differentiate KD with HLH from incomplete KD alone. METHODS: We performed a retrospective study on patients diagnosed with incomplete KD and incomplete KD with HLH (HLH-KD) between January 2012 and March 2015. We compared 8 secondary HLH patients who were first diagnosed with incomplete KD with all 247 incomplete KD diagnosed patients during the study period. The complete blood count, erythrocyte sedimentation rate, platelet count, and serum total protein, albumin, triglyceride, C-reactive protein, N-terminal pro-brain natriuretic peptide (NT-proBNP), and ferritin levels were compared. Clinical characteristics and echocardiography findings were also compared between the 2 groups. RESULTS: The total duration of fever was longer in the HLH-KD group than in the KD group. White blood cell and platelet counts were higher in the KD group. Alanine aminotransferase, ferritin, and coronary artery diameter were increased in the HLH-KD group compared with those in the KD group. The median of NT-proBNP was significantly higher in the HLH-KD group than in the KD group at 889.0 (interquartile range [IQR], 384.5-1792.0) pg/mL vs. 233.0 (IQR, 107.0-544.0) pg/mL. CONCLUSION: The NT-proBNP level may be helpful in distinguishing incomplete KD from KD with HLH. The NT-proBNP level should be determined in KD patients with prolonged fever, in addition to the white blood cell count, platelet count, and ferritin level, to evaluate secondary HLH.