Search Results (22)

Background: Heart failure in pediatric patients remains a major cause of morbidity and mortality, often associated with congenital heart defects and cardiomyopathies. Mechanical circulatory support (MCS) devices have emerged as critical therapeutic options, particularly as bridges to transplantation or recovery. The complexity of their use in children necessitates highly specialized solutions. This study aimed to evaluate the quality and performance of selected connection technologies between prosthetic vascular grafts and the outflow cannula of the Religa Heart PED^® pediatric pulsatile pump, with a focus on tightness, surface smoothness, and structural integrity. Methods: Mechanical testing was conducted on various connection types, including static tensile strength and long-term durability under pulsatile flow conditions with biological fluid analogs. Macro and microscopic evaluations assessed the surface quality and potential thrombogenic risks, biological testing encompassed permeability analysis in static and dynamic settings, and hemocompatibility was determined by acute thrombogenicity. Additionally, in vivo observations in a large animal model were used for final qualitative validation. Results: All connection types demonstrated sufficient mechanical strength, with no structural degradation or leakage observed in any samples following long-term testing. Thrombus formation was absent in adhesive connections with Dacron and polytetrafluoroethylene (PTFE) grafts but was observed in the mechanical connection with the PTFE prosthesis. In addition, in vivo studies confirmed the tightness, hemocompatibility, and mechanical stability of the adhesive connection with the Dacron prosthesis. Conclusions: The adhesive connection between the outflow cannula and a Dacron prosthesis demonstrated superior mechanical and biological performance, including resistance to thrombogenesis and hemolysis, as well as stable integration under in vivo conditions. This solution shows high potential for safe application in the Religa Heart PED^® system. Full article

Background/Objectives: Bovine pericardial valve conduits (PVCs) are commonly used for right ventricular outflow tract reconstruction in both pediatric and adult patients. Calcification, particularly prevalent in children and young adults, is a leading cause of conduit failure and is affected by the chemical composition of the treated biomaterials. In this study, we aimed to compare the structural changes in diepoxy-treated (DE-PVCs) and glutaraldehyde-treated PVCs (GA-PVCs) and to identify factors contributing to tissue mineralization in a large animal model. Methods: Pulmonary artery replacement was performed in minipigs (33–88 kg) using twelve DE-PVCs and four GA-PVCs. After six months, the animals were euthanized, and the explanted PVCs underwent macroscopic and microscopic examination. Results: Large calcium deposits formed along conduit joining suture (CJS) lines in all PVCs, regardless of the cross-linking agent. Mineral clusters surrounded the multifilament braided thread, and its fibers were encrusted with hydroxyapatite crystals. In DE-PVCs, no mineralization occurred outside the suture lines, and they showed successful integration and graft vitalization with a uniform neointima and well-developed endothelial monolayer. GA-PVCs developed a rigid external capsule, foci of collagen fiber calcification within the walls, and neointimal hyperplasia with limited endothelial coverage. Conclusions: In PVCs, calcification predominantly occurs along the CJS lines, where the multifilament suture acts as a nucleation site for hydroxyapatite crystals. DE treatment prevents collagen mineralization, unlike GA, and offers better integration, reduced neointimal hyperplasia, and a well-developed endothelial layer. These findings suggest that DE-PVCs may be a superior option for pediatric cardiac surgery by reducing calcification and improving conduit durability. Overall, the results will help optimize PVC manufacturing strategies to lower the risk of conduit failure. Full article

Background: Living donor liver transplantation (LDLT) is the predominant transplantation technique in regions with low rates of deceased donation. Right-lobe grafting is adopted in most clinical and radiological donor/recipient scenarios. Due to the considerable variations in right-lobe hepatic venous anatomy, many techniques have been used over the years for the purpose of appropriate venous outflow reconstruction during the recipient procedure. In this paper, we present the technical details and consequences of a complex venous outflow reconstruction model (CORM) based on experience, and the long-term patency results obtained using the model. Methods: Data of patients with end-stage liver disease who underwent LDLT between 21 December 2017 and 29 November 2022 were prospectively collected and retrospectively reviewed. The nomenclature of CORM was assigned when three or more hepatic vein anastomoses were performed. Patients with CORM (CORM group; n = 69) were compared with non-CORM patients (non-CORM group; n = 130) in terms of demographic, pre- and postoperative clinical, and follow-up features. Results: Sixty-nine recipients had three or more separate outflow reconstructions (RHV, RIHV, and one or more anterior sectoral veins); these constituted the CORM group. The estimated graft volume of the CORM group was significantly lower than that of the non-CORM group (833 vs. 898; p = 0.022), and the mean GRWR was also significantly lower (1.1 vs. 1.2; p = 0.004). CORM cases showed longer anhepatic phases, as well as longer times for cold and warm ischemia, than non-CORM cases (63 vs. 51 min, 46 vs. 38 min, and 48 vs. 33 min, p < 0.001), though no difference was found with respect to total operative duration. There were no statistical differences between the two groups with respect to rates of in-hospital re-exploration, length of ICU stay, or length of total hospital stay. Graft survival rates at 1 year, 3 years, and 5 years were 88.1%, 83.3%, and 83.3%, respectively, in the CORM group, and 82.9%, 80.2%, and 70.6%, respectively, in the non-CORM group (p = 0.167). Conclusions: Performing three or more CORMs in right-lobe LDLT is not associated with inferior outcomes, either with regard to perioperative variables or to patient and graft outcomes. Right-lobe graft with complex venous anatomy from a living donor should not be a determinant factor for donor exclusion. Full article

Background: Hypothermic oxygenated machine perfusion (HOPE) has emerged as a critical innovation in liver transplantation (LTx), offering significant protection against ischemia-reperfusion injury (IRI). This study focuses on quantifying and characterizing immune cells flushed out during HOPE to explore its effects on graft function and post-transplant outcomes. Materials and Methods: Fifty liver grafts underwent end-ischemic HOPE. Perfusate samples were collected at three time points: at the start of perfusion, after 10 min, and at the end of perfusion. The samples were analyzed to quantify and characterize immune cells, assessing the effectiveness of HOPE in reducing cellular debris and its impact on graft quality. Results: The primary perfusate contained significant concentrations of immune cells, mainly segmented neutrophils, lymphocytes, and monocytes. After 10 min of perfusion, outflow cell concentration decreased by over 95%, and by the end of perfusion, a more than 99% reduction was observed. Conclusions: HOPE effectively reduces immune cell concentrations in liver grafts, suggesting a mechanism for improved graft function and reduced post-transplant complications. These findings support the continued use and optimization of HOPE in LTx. Full article

Background: The HeartMate 3 (HM3, Abbott) left ventricular assist device (LVAD) is the only commercially available option considered suitable for long-term circulatory support. External compression of the outflow graft causing obstruction (eOGO) is a serious adverse event affecting patients on long-term support. The obstruction occurs due to the accumulation of gelatinous substance between the bend relief and outflow graft. This systematic review evaluated all available studies with regard to the diagnosis and therapy of eOGOs. Methods: A systematic literature review and analysis of individual patient data was performed using MEDLINE/PubMed following PRISMA guidelines. Original works dating up to 31 October 2024 were considered. Results: Twenty-four publications that met the inclusion criteria were identified, providing individual data from 113 patients with a median support time to eOGO diagnosis of 809 days [588, 1095] and follow-up after treatment of 365 days [33, 605]. eOGO severity classification was performed on 108 patients according to our grading system. For treatment, most patients underwent surgery (n = 38) or stenting (n = 29). A hazard ratio of 0.75 [0.28, 2.03] was calculated for the surgical group versus the stenting group (p = 0.570). Conclusions: Concerning 30-day mortality, we did not find a significant difference between the eOGO severity of survivors and non-survivors. We found no significant differences in outcome between patients with differing eOGO severity and treatment strategy, namely stenting and surgery. Due to an increase in eOGO incidence after one year of support, we propose that clinicians monitor their patients for this complication when support time surpasses one year. Full article

Background/Objectives: In recent years, manufacturers have developed new low-profile stent grafts to allow endovascular treatment of abdominal aortic aneurysms (AAA) in patients with small access vessels. We evaluated the early and mid-term outcomes of the Incraft (Cordis Corp, Bridgewater, NJ, USA) ultra-low profile endograft implantation in a high-volume single center. Methods: Between 2014 and 2023, 133 consecutive endovascular aneurysm repair (EVAR) procedures performed using the Incraft endograft were recorded in a prospective database. Indications included infrarenal aortic aneurysms, common iliac aneurysms, and infrarenal penetrating aortic ulcers. Mid-term results were analyzed using the Kaplan–Meier method. Results: During the study period, 133 patients were treated with the Cordis Incraft endograft, in both elective and urgent settings. The Incraft graft was the first choice for patients with hostile iliac accesses, a feature characterizing at least one side in 90.2% of the patients in the study cohort. The immediate technical success rate was 78.2%. The intraoperative endoleak rate was 51.9% (20.3% type 1 A, 0.8% type 1 B, and 30.8% type 2 endoleak). Within 30 days, technical and clinical success rates were both 99.3%; all type 1A and 1B endoleaks were resolved at the 30-day follow-up CT-angiogram. After a mean follow-up of 35.4 months, the actuarial freedom from the re-intervention rate was 96.0%, 91.1%, and 84.0% at 1, 3, and 5 years, respectively. The iliac leg patency rate was 97.1%, 94.1%, and 93.1% at 1, 3, and 5 years, respectively. No statistically significant differences were observed between hostile and non-hostile access groups, nor between the groups with grade 1, grade 2, and grade 3 access hostility. Conclusions: The ultra-low profile Cordis Incraft endograft represents a valid option for the endovascular treatment of AAA in patients with hostile iliac accesses. The procedure can be performed with high rates of technical and clinical success at 30 days and the rates of iliac branch occlusion observed during the follow-up period appear acceptable in patients with poor aorto-iliac outflow. Full article

A new accessory was developed to allow implantation of left ventricular assist devices (LVADs) without requiring an anastomosis to the ascending aorta. The accessory combines the LVAD inflow and outflow into a dual-lumen device. Initial prototypes encountered reduced pump performance in vitro, but a second-generation prototype successfully addressed this issue. This feasibility study aimed to demonstrate the anatomic fit, safe implantation, and hemodynamic effectiveness of the LVAD with the accessory. The accessory was implanted in ten female pigs (104 ± 13 kg). Following sternotomy and apical coring under cardiopulmonary bypass, a balloon catheter was retrogradely inserted and exteriorized through the coring site, where it was inflated within the distal third of the outflow graft. It was utilized to pull the accessory’s outflow across the aortic valve. After LVAD attachment, the catheter was removed. Echocardiography revealed no relevant valve regurgitation post-implantation. During ramp testing, pump flow increased from 3.7 ± 1.2 to 5.4 ± 1.2 L/min. Necropsy confirmed correct accessory placement in nine animals. No valve lesions or device thrombosis were observed. The accessory enabled LVAD implantation without compromising pump performance. Future work includes design refinements for implantation without cardiopulmonary bypass and long-term testing in a chronic heart failure model. Full article

Transcatheter pulmonary valve replacement is a minimally-invasive alternative treatment for right ventricular outflow tract dysfunction and has been rapidly evolving over the past years. Heart valve prostheses currently available still have major limitations. Therefore, one of the significant challenges for the future is the roll out of transcatheter tissue engineered pulmonary valve replacement to more patients. In the present study, biodegradable poly-ε-caprolactone (PCL) nanofiber scaffolds in the form of a 3D leaflet matrix were successfully seeded with human endothelial colony-forming cells (ECFCs), human induced pluripotent stem cell-derived MSCs (hMSCs), and porcine MSCs (pMSCs) for three weeks for the generation of 3D tissue-engineered tri-leaflet valved stent grafts. The cell adhesion, proliferation, and distribution of these 3D heart leaflets was analyzed using fluorescence microscopy and scanning electron microscopy (SEM). All cell lineages were able to increase the overgrown leaflet area within the three-week timeframe. While hMSCs showed a consistent growth rate over the course of three weeks, ECFSs showed almost no increase between days 7 and 14 until a growth spurt appeared between days 14 and 21. More than 90% of heart valve leaflets were covered with cells after the full three-week culturing cycle in nearly all leaflet areas, regardless of which cell type was used. This study shows that seeded biodegradable PCL nanofiber scaffolds incorporated in nitinol or biodegradable stents will offer a new therapeutic option in the future. Full article

Obstruction of the LVAD flow path can occur when blood clots or tissue overgrowth form within the inflow cannula, pump body, or outflow graft, and it can lead to thrombus, embolism, and stroke. The goal of this study was to measure the impact of progressive pump inflow obstruction on the pressure and flow dynamics of the LVAD-supported heart using a mock circulatory loop. Pump obstruction (PO) was produced by progressively blocking a fraction of the LVAD inlet area. Pressures, flows, and the midplane velocity field of the LV were measured for three LVAD speeds and six PO levels. Pressure and flow decreased with PO, shifting more of the flow through the aortic valve such that the total flow decreased by 6–11% and decreased the efficiency of the work of the native heart up to 60%. PO restricts diastolic flow through the LVAD, which reduces mitral inflow and decreases the strength and energy of the intraventricular vortices. The changes in flow architecture produced by PO include flow stasis and increased shear, which predispose the system to thromboembolic risk. Analysis of the contributions to external work may enable early detection, which allows time for therapeutic intervention, reducing the likelihood of pump replacement and the risk of complications. Full article

Recipients of uterus transplantation have unique factors that may increase their risk of cervical insufficiency. This report describes a uterus transplant recipient with cervical insufficiency resulting in two second-trimester miscarriages. After McDonald cerclages (one that failed), she underwent an interval transabdominal cerclage and delivered a healthy term child in her third pregnancy. The longitudinal information of this case provides observations from which we can propose testable hypotheses that address venous outflow and inflammation. This case also suggests that there could be a role for prophylactic cerclage placement at the time of transplantation. Full article

Heart failure is a global health concern with significant implications for healthcare systems. Left ventricular assist devices (LVADs) provide mechanical support for patients with severe heart failure. However, the placement of the LVAD outflow graft within the aorta has substantial implications for hemodynamics and can lead to aortic insufficiency during long-term support. This study employs computational fluid dynamics (CFD) simulations to investigate the impact of different LVAD outflow graft locations on aortic hemodynamics. The introduction of valve morphology within the aorta geometry allows for a more detailed analysis of hemodynamics at the aortic root. The results demonstrate that the formation of vortex rings and subsequent vortices during the high-velocity jet flow from the graft interacted with the aortic wall. Time-averaged wall shear stress (TAWSS) and oscillatory shear index (OSI) indicate that modification of the outflow graft location changes mechanical states within the aortic wall and aortic valve. Among the studied geometric factors, both the height and inclination angle of the LVAD outflow graft are important in controlling retrograde flow to the aortic root, while the azimuthal angle primarily determines the rotational direction of blood flow in the aortic arch. Thus, precise positioning of the LVAD outflow graft emerges as a critical factor in optimizing patient outcomes by improving the hemodynamic environment. Full article

Background: Autologous vein bypass provides excellent long-term results in critical limb-threatening ischemia (CLTI), but a substantial portion of patients have insufficient vein length. In limbs with two distal outflow vessels and limited vein length, a vascular prosthesis may be combined with autologous vein for a sequential composite bridge bypass (SCBB). Results regarding graft function, limb salvage and reinterventions are presented. Methods: Between January 2010 and December 2019, 47 consecutive SCBB operations with a heparin-bonded PTFE-prosthesis and autologous vein were performed. Grafts were followed with a duplex scan with prospective documentation in a computerized vascular database. Retrospective analysis of graft patency, limb salvage and patient survival was performed. Results: Mean follow-up was 34 months (range 1–127 months). 30-day mortality was 10.6% and 5-year patient survival 32%. Postoperative bypass occlusion occurred in 6.4% and late occlusions or graft stenoses in 30%. Two prostheses developed late infection and seven legs were amputated. Primary, primary assisted, secondary patency and limb salvage rate were 54%, 63%, 66% and 85% after 5 years, respectively. Conclusions: SCBB patency and limb salvage were good despite a high early postoperative mortality. Combination of a heparin-bonded PTFE-prosthesis and autologous vein appears to be a valuable tool in CLTI in case of insufficient vein. Full article

Uterus-related infertility affects 3–5% of all young women, including Mayer-Rokitansky-Küster-Hauser (MRKH) syndrome, hysterectomy, or severe Asherman syndrome. For these women with uterus-related infertility, uterus transplantation is now a viable option. We performed the first surgically successful uterus transplant in September 2011. The Donor was a 22-year-old nulliparous woman. After five failed pregnancy attempts (pregnancy losses), ET attempts were discontinued in the first case, and a search for underlying etiology was performed, including static and dynamic imaging studies. Perfusion computed tomography revealed an obstructed blood outflow, particularly in the left anterolateral part of the uterus. In order to correct blood flow obstruction, a revision surgery was planned. By laparotomy, a saphenous vein graft was anastomosed between the left utero-ovarian and left ovarian vein. Perfusion computed tomography performed after the revision surgery confirmed the resolution of venous congestion and a decrease in uterine volume as well. Following surgical intervention, the patient was able to conceive after the first embryo transfer attempt. The baby was delivered with cesarean section at 28 weeks’ gestation due to intrauterine growth restriction and abnormal Doppler ultrasonography findings. Following this case, our team performed the second uterus transplantation in July 2021. The recipient was a 32-year-old female with MRKH syndrome, and the donor was a 37-year-old multiparous braindead woman due to intracranial bleeding. After the transplant surgery, the second patient experienced menstrual bleeding six weeks after the operation. Seven months after the transplant, in the first ET attempt, pregnancy was achieved, and she delivered a healthy baby at 29 weeks of pregnancy. Uterus transplantation from a deceased donor is a feasible option for treating uterus-related infertility. When confronted with recurrent pregnancy losses, vascular revision surgery via arterial or venous supercharging could be an option in order to deal with focal underperfused areas defined by imaging studies. Full article

Purpose: We report on the clinical course and management of patients supported with durable implantable LVADs who developed outflow graft obstructions at a large academic center. Methods: We performed a retrospective review of patients receiving LVAD support from 2012 through 2020. Patients who developed an outflow graft obstruction diagnosed by computed tomography angiography (CTA) or angiogram were identified, and patient characteristics and outcomes were reported. Results: Of the 324 patients supported by LVAD at our institution, 11 patients (3.4%) were diagnosed with outflow graft obstructions. The most common presentation was low flow alarms, which was present in 10/11 patients, and the remaining patient presented with lightheadedness. Patients had minimal LDH elevation with 8/11 presenting with less than 2-fold the upper limit of normal. Transthoracic echocardiograms were not diagnostic, but CTA enabled non-invasive diagnoses in 8/11 of the patients. Three patients with extrinsic compression of the outflow graft successfully underwent endovascular stent placement, and three patients with outflow cannula kinks received supportive care. Of the five patients diagnosed with intraluminal thromboses, one received a heart transplant, one underwent an outflow graft revision, and three received supportive care due to comorbidities. Conclusion: Outflow graft obstructions remain a rare, but serious complication. The true prevalence of this entity is likely underestimated due to the non-specific clinical presentation. CTA is a pivotal non-invasive diagnostic step. Patients with external compression were successfully treated with endovascular stenting. Full article

Background: Homocysteine (Hcy) is involved in various methylation processes, and its plasma level is increased in cardiac ischemia. Thus, we hypothesized that levels of homocysteine correlate with the morphological and functional remodeling of ischemic hearts. Thus, we aimed to measure the Hcy levels in the plasma and pericardial fluid (PF) and correlate them with morphological and functional changes in the ischemic hearts of humans. Methods: Concentration of total homocysteine (tHcy) and cardiac troponin-I (cTn-I) of plasma and PF were measured in patients undergoing coronary artery bypass graft (CABG) surgery (n = 14). Left-ventricular (LV) end-diastolic diameter (LVED), LV end-systolic diameter (LVES), right atrial, left atrial (LA) area, thickness of interventricular septum (IVS) and posterior wall, LV ejection fraction (LVEF), and right ventricular outflow tract end-diastolic area (RVOT EDA) of CABG and non-cardiac patients (NCP; n = 10) were determined by echocardiography, and LV mass was calculated (cLVM). Results: Positive correlations were found between Hcy levels of plasma and PF, tHcy levels and LVED, LVES and LA, and an inverse correlation was found between tHcy levels and LVEF. cLVM, IVS, and RVOT EDA were higher in CABG with elevated tHcy (>12 µM/L) compared to NCP. In addition, we found a higher cTn-I level in the PF compared to the plasma of CABG patients (0.08 ± 0.02 vs. 0.01 ± 0.003 ng/mL, p < 0.001), which was ~10 fold higher than the normal level. Conclusions: We propose that homocysteine is an important cardiac biomarker and may have an important role in the development of cardiac remodeling and dysfunction in chronic myocardial ischemia in humans. Full article