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Background: There is a continued interest in ex situ heart perfusion as an alternative strategy for donor heart preservation. We hypothesize that oxygenated machine perfusion of donor hearts at a temperature that avoids both normothermia and deep hypothermia offers adequate and safe preservation. Methods: Cardioplegia‐arrested porcine donor hearts were randomly assigned to six hours of preservation using cold storage (CS, n = 5) or machine perfusion using an oxygenated acellular perfusate at 21°C (MP, n = 5). Subsequently, all grafts were evaluated using the Langendorff method for 120 min. Metabolic parameters and histology were analyzed. Systolic function was assessed by contractility and elastance. Diastolic function was assessed by lusitropy and stiffness. Results: For both groups, in vivo baseline and post‐Langendorff biopsies were comparable, as were lactate difference and myocardial oxygen consumption. Injury markers gradually increased and were comparable. Significant weight gain was seen in MP (p = 0.008). Diastolic function was not impaired in MP, and lusitropy was superior from 30 min up to 90 min of reperfusion. Contractility was superior in MP during the first hour of evaluation. Conclusion: We conclude that the initial functional outcome of MP‐preserved hearts was transiently superior compared to CS, with no histological injury post‐Langendorff. Our machine perfusion strategy could offer feasible and safe storage of hearts prior to transplantation. Future studies are warranted for further optimization. [ABSTRACT FROM AUTHOR]

In the recent years, the use of extracorporeal membrane oxygenation (ECMO) has grown substantially, posing the need of having specialized medical and paramedical personnel dedicated to it. Optimization of the therapy, definition of new therapeutic strategies, and ECMO interaction with the cardiorespiratory system require numerous specific skills and preclinical models for patient successful management. The aim of the present work is to develop and validate a computational model of ECMO and connect it to an already existing lumped parameter model of the cardiorespiratory system. The ECMO model was connected between the right atrium and the aorta of the cardiorespiratory simulator. It includes a hydraulic module that is a representation of the tubing, oxygenator, and pump. The resulting pressures and flows within the ECMO circuit were compared to the measurements conducted in vitro on a real ECMO. Additionally, the hemodynamic effects the ECMO model elicited on the cardiorespiratory simulator were compared with experimental data taken from the literature. The comparison between the hydraulic module and the in vitro measurements evidenced a good agreement in terms of flow, pressure drops across the pump, across the oxygenator and the tubing (maximal percentage error recorded was 17.6%). The hemodynamic effects of the ECMO model on the cardiovascular system were in agreement with what observed experimentally in terms of cardiac output, systemic pressure, pulmonary arterial pressure, and left atrial pressure. The ECMO model we developed and embedded into the cardiorespiratory simulator, is a useful tool for the investigation of basic physiological mechanisms and principles of ECMO therapy. The model was sided by a user interface dedicated to training applications. As such, the resulting simulator can be used for the education of students, medical and paramedical personnel. [ABSTRACT FROM AUTHOR]

Purpose: Dumping is currently seen as a negative side effect of Roux-en-Y gastric bypass (RYGB). However, it may help patients to comply with their prescribed diet. In this study, we assess the role of dumping on weight loss in patients who have undergone conversion of failed restrictive surgery into RYGB.Methods: An analysis was performed of 100 consecutive patients who underwent revisional RYGB (rRYGB) between 2006 and 2011 due to inadequate weight loss or band intolerance after laparoscopic adjustable gastric banding (LAGB). The percentage of excess weight loss (%EWL) was used to evaluate weight reduction. The Sigstad clinical diagnostic index was used to detect dumping symptoms.Results: Fifty-five patients (59.1%) suffered from dumping. Overall, dumpers showed a greater %EWL than non-dumpers (83.8 ± 48.0 vs 66.9 ± 44.1%, respectively, p = 0.0725). When rRYGB was performed because of inadequate weight loss following LAGB, dumping played a crucial role in weight loss (88.0 ± 21.2 vs 68.9 ± 34.5%, p = 0.0137). This effect positively correlates to post-LAGB body mass index (BMI) with a statistically significant result at BMI > 35 kg/m2 (82.4 ± 15.7 vs 58.4 ± 32.4%, p = 0.00341). A regression analysis of the Sigstad dumping score and %EWL shows that dumping tends to increase the %EWL.Conclusions: This study provides new insights into the effect of dumping on weight loss in patients who underwent conversion of failed restrictive surgery into RYGB. Based on the findings in our patient group, we suggest that dumping helps patients achieve sustainable weight loss. Therefore, dumping can be regarded as a positive side effect rather than a complication. [ABSTRACT FROM AUTHOR]

In the sheep model with pathophysiologic changes similar to patients with repaired TOF, severe PR leads to fibrotic changes in the RV. Pulmonary valve replacement reverses these fibrotic changes. Early valve replacement led to a quick RV recovery, and in time there was no difference in outcome between early and late valve replacement. These data support the benefit of valve replacement for RV function and suggest that there is a margin in the timing of the surgery. The fibrotic changes correlated well with the circulating biomarker PICP, which can have an added value in the clinical follow-up of patients with repaired TOF., Competing Interests: This work was supported by the Foundation of Cardiac Surgery Research Belgium, an unrestricted grant from Medtronic, the Henri-Mertens Berx Foundation, and the National Fund for Scientific Research, Flanders. The authors have reported that they have no relationships relevant to the contents of this paper to disclose.PerspectivesCOMPETENCY IN MEDICAL KNOWLEDGE: The long-term risks in patients with rTOF partially depend on chronic RV volume overload. Creation of a large-animal model resembling the course of patients with TOF enables unraveling the pathophysiologic observations of remodeling and reverse remodeling of the RV. Severe PR with RV volume load showed fibrotic changes and hypertrophy with increased signaling. PVR alters the fibrotic and hypertrophic changes with decreased gene expression promoting collagen cross-linking and remodeling of the ECM. Although early PVR led to a quick RV recovery, eventually there was no difference in outcome between early and late valve replacement. TRANSLATIONAL OUTLOOK: In our sheep model, we could document, through tissue sampling, fibrosis related to PV regurgitation that correlated with PICP, which suggests further exploration of PICP in rTOF. The timing of valve implantation did not affect the eventual RV reverse remodeling process, calling for further clinical studies on optimal timing., (© 2023 The Authors.)

Purpose: Dumping is currently seen as a negative side effect of Roux-en-Y gastric bypass (RYGB). However, it may help patients to comply with their prescribed diet. In this study, we assess the role of dumping on weight loss in patients who have undergone conversion of failed restrictive surgery into RYGB., Methods: An analysis was performed of 100 consecutive patients who underwent revisional RYGB (rRYGB) between 2006 and 2011 due to inadequate weight loss or band intolerance after laparoscopic adjustable gastric banding (LAGB). The percentage of excess weight loss (%EWL) was used to evaluate weight reduction. The Sigstad clinical diagnostic index was used to detect dumping symptoms., Results: Fifty-five patients (59.1%) suffered from dumping. Overall, dumpers showed a greater %EWL than non-dumpers (83.8 ± 48.0 vs 66.9 ± 44.1%, respectively, p = 0.0725). When rRYGB was performed because of inadequate weight loss following LAGB, dumping played a crucial role in weight loss (88.0 ± 21.2 vs 68.9 ± 34.5%, p = 0.0137). This effect positively correlates to post-LAGB body mass index (BMI) with a statistically significant result at BMI > 35 kg/m 2 (82.4 ± 15.7 vs 58.4 ± 32.4%, p = 0.00341). A regression analysis of the Sigstad dumping score and %EWL shows that dumping tends to increase the %EWL., Conclusions: This study provides new insights into the effect of dumping on weight loss in patients who underwent conversion of failed restrictive surgery into RYGB. Based on the findings in our patient group, we suggest that dumping helps patients achieve sustainable weight loss. Therefore, dumping can be regarded as a positive side effect rather than a complication.