Search Results (18)

Background: Mediastinal mass syndrome represents a major threat to respiratory and cardiovascular integrity, with difficult evidence-based risk stratification for interdisciplinary management. Methods: We conducted a narrative review concerning risk stratification and difficult airway management of patients presenting with a large mediastinal mass. This is supplemented by a case report illustrating our individual approach for a patient presenting with a subtotal tracheal stenosis due to a large cyst of the thyroid gland. Results: We identified numerous risk stratification grading systems and only a few case reports of regional anesthesia techniques for extracorporeal membrane oxygenation patients. Clinical Case: After consultation with his general physician because of exertional dyspnea and stridor, a 78-year-old patient with no history of heart failure was advised to present to a cardiology department under the suspicion of decompensated heart failure. Computed tomography imaging showed a large mediastinal mass that most likely originated from the left thyroid lobe, with subtotal obstruction of the trachea. Prior medical history included the implantation of a dual-chamber pacemaker because of a complete heart block in 2022, non-insulin-dependent diabetes mellitus type II, preterminal chronic renal failure with normal diuresis, arterial hypertension, and low-grade aortic insufficiency. After referral to our hospital, an interdisciplinary consultation including experienced cardiac anesthesiologists, thoracic surgeons, general surgeons, and cardiac surgeons decided on completing the resection via median sternotomy after awake cannulation for veno-venous extracorporeal membrane oxygenation via the right internal jugular and the femoral vein under regional anesthesia. An intermediate cervical plexus block and a suprainguinal fascia iliaca compartment block were performed, followed by anesthesia induction with bronchoscopy-guided placement of the endotracheal tube over the stenosed part of the trachea. The resection was performed with minimal blood loss. After the resection, an exit blockade of the dual chamber pacemaker prompted emergency surgical revision. The veno-venous extracorporeal membrane oxygenation was explanted after the operation in the operating room. The postoperative course was uneventful, and the patient was released home in stable condition. Conclusions: Awake veno-venous extracorporeal membrane oxygenation placed under local anesthetic infiltration with regional anesthesia techniques is a feasible individualized approach for patients with high risk of airway collapse, especially if the mediastinal mass critically alters tracheal anatomy. Compressible cysts may represent a subgroup with easy passage of an endotracheal tube. Interdisciplinary collaboration during the planning stage is essential for maximum patient safety. Prospective data regarding risk stratification for veno-venous extracorporeal membrane oxygenation cannulation and effectiveness of regional anesthesia is needed. Full article

African Swine Fever Virus (ASFV), resulting in strain-dependent vascular pathology, leading to hemorrhagic fever, is an important pathogen in swine. The pathogenesis of ASFV is determined by the array and spatial distribution of susceptible cells within the host. In this study, the replication characteristics of ASFV genotype I E70 (G1-E70) and ASFV genotype II Belgium 2018/1 (G2-B18) in the environment of small veins were investigated in an established vein explant model. Immunofluorescence staining analysis revealed that perivenous macrophages (CD163⁺ cells) were widely distributed in the explant, with most of them (approximately 2–10 cells/0.03 mm²) being present close to the vein (within a radius of 0–348 µm). Upon inoculation with G1-E70 and G2-B18, we observed an increase in the quantity of cells testing positive for viral antigens over time. G1-E70 replicated more efficiently than G2-B18 in the vein explants (7.6-fold for the ear explant at 72 hpi). The majority of ASFV⁺ cells were CD163⁺, indicating that macrophages are the primary target cells. Additional identification of cells infected with ASFV revealed the presence of vimentin⁺, CD14⁺, and VWF⁺ cells, demonstrating the cellular diversity and complexity associated with ASFV infection. By the use of this new vein explant model, the susceptibility of vascular and perivascular cells to an ASFV infection was identified. With this model, it will be possible now to conduct more functional analyses to get better insights into the pathogenesis of ASFV-induced hemorrhages. Full article

Background: Endovascular treatment of popliteal aneurysms (PA) has increased in the last few years, quickly becoming the main treatment performed in many vascular centers, based on the acceptable and promising outcomes reported in the literature. However, endograft infections after endovascular popliteal aneurysm repair (EPAR) are the most dangerous complications to occur as they involve serious local compromise and usually require open surgical conversion and device explantation to preserve the affected extremity. Case report: We report two patients who were admitted to the emergency room of our hospital for pain and edema in the lower leg. Both patients had undergone exclusion of a ruptured PA a few years before by endovascular graft. CTA testing showed a significant volume of fluid-corpuscular collection related to perianeurysmal abscess collection in both cases. Blood cultures and drained material cultures were positive for Staphylococcus capitis in the first case and S. aureus in the second. Prophylactic antibiotics were administered for 10 days, then patients underwent an open surgical conversion with the complete explantation of endovascular material and a femoro-popliteal bypass using an autologous vein in the first case and a biological bovine pericardium prosthesis in the second case. The infective department of our hospital had defined a discharged specific antibiotic therapy for each patient, based on intraoperative microbiological samples. Furthermore, we have examined the literature and found six more cases described in case report articles that refer to popliteal graft infections by different microorganisms, mostly presenting acute limb ischemia as the first symptom and suggesting endograft explantation with open conversion and autologous vein bypass as the commonest therapeutic choice. Conclusions: The open surgical conversion of popliteal endograft infection is the best strategy to manage peripheral infection after an endovascular popliteal aneurysm repair procedure. Full article

Background: Autologous vein grafts are widely used for bypass procedures in cardiovascular surgery. However, these grafts are susceptible to failure due to vein graft disease. Our study aimed to evaluate the impact of the latest-generation FRAME external support on vein graft remodeling in a preclinical model. Methods: We performed autologous internal jugular vein interposition grafting in porcine carotid arteries for one month. Four grafts were supported with a FRAME mesh, while seven unsupported grafts served as controls. The conduits were examined through flowmetry, angiography, macroscopy, and microscopy. Results: The one-month patency rate of FRAME-supported grafts was 100% (4/4), whereas that of unsupported controls was 43% (3/7, Log-rank p = 0.071). On explant angiography, FRAME grafts exhibited significantly more areas with no or mild stenosis (9/12) compared to control grafts (3/21, p = 0.0009). Blood flow at explantation was higher in the FRAME grafts (145 ± 51 mL/min) than in the controls (46 ± 85 mL/min, p = 0.066). Area and thickness of neo-intimal hyperplasia (NIH) at proximal anastomoses were similar for the FRAME and the control groups: 5.79 ± 1.38 versus 6.94 ± 1.10 mm², respectively (p = 0.558) and 480 ± 95 vs. 587 ± 52 μm²/μm, respectively (p = 0.401). However, in the midgraft portions, the NIH area and thickness were significantly lower in the FRAME group than in the control group: 3.73 ± 0.64 vs. 6.27 ± 0.64 mm², respectively (p = 0.022) and 258 ± 49 vs. 518 ± 36 μm²/μm, respectively (p = 0.0002). Conclusions: In our porcine model, the external mesh FRAME improved the patency of vein-to-carotid artery grafts and protected them from stenosis, particularly in the mid regions. The midgraft neo-intimal hyperplasia was two-fold thinner in the meshed grafts than in the controls. Full article

Background: Tunneled central venous catheters are commonly used for dialysis in patients without a functional permanent vascular access. In an emergent setting, a non-tunneled, temporary central venous catheter is often placed for immediate dialysis. The most critical step in the catheter insertion is venipuncture, which is often a major cause for longer intervention times and procedure-related adverse events. To avoid this critical step when placing a more permanent tunneled catheter, an exchange over a previously placed temporary one can be considered. In this paper, we present a modified switching approach with a separate access site. Methods: In this retrospective analysis of a prospective database, we examined whether this modified technique is non-inferior to a de novo application. Therefore, we included all 396 patients who received their first tunneled dialysis catheter at our site from March 2018 to March 2023. Out of these, 143 patients received the modified approach and 253 the standard de novo ultrasound-guided puncture and insertion. Then, the outcomes of the two groups, including adverse events and infections, were compared by nonparametric tests and multivariable logistic regression. Results: In both groups, the implantations were 100% successful. Catheter explantation due to infection according to CDC criteria was necessary in 18 cases, with no difference between the groups (5.0% vs. 4.4% p = 0.80). The infection rate per 100 days was 0.113 vs. 0.106 in the control group, with a comparable spectrum of bacteria. A total of 12 catheters (3 vs. 9) had to be removed due to a periinterventional complication. An early-onset infection was the reason in two cases (1.3%) in the study group and five in the control group (1.9%). A total misplacement of the catheter occurred in two cases only in the control group. After adjustment for potential confounders via multivariable logistic regression there was not a significant difference in the complication rate (adjusted odds ratio, aOR = 0.53, 95% CI = 0.14–2.03, p = 0.351) but an estimated decreased risk overall based on the average treatment effect of −1.7% in favor of the study group. Conclusions: The present study shows that a catheter exchange leads to no more infections than a de novo placement; hence, it is a feasible method. Moreover, misplacements and control chest X-rays to exclude pneumothorax after venipuncture were completely avoided by exchanging. This approach yields a much lower infection rate than previous reports: 1.3% compared to 2.7% in all existing aggregated studies. The presented approach seems to be superior to existing switching methods. Overall, an exchange can also help to preserve veins for future access, since the same jugular vein is used. Full article

Pulmonary arteriovenous malformations (PAVMs) are vascular anomalies resulting in abnormal connections between pulmonary arteries and veins. In 80% of cases, PAVMs are present from birth, but clinical manifestations are rarely seen in childhood. These congenital malformations are typically associated with Hereditary Hemorrhagic Telangiectasia (HHT), a rare disease that affects 1 in 5000/8000 individuals. HHT disease is frequently caused by mutations in genes involved in the TGF-β pathway. However, approximately 15% of patients do not have a genetic diagnosis and, among the genetically diagnosed, more than 33% do not meet the Curaçao criteria. This makes clinical diagnosis even more challenging in the pediatric age group. Here, we introduce an 8-year-old patient bearing a severe phenotype of multiple diffuse PAVMs caused by an unknown mutation which ended in lung transplantation. Phenotypically, the case under study follows a molecular pattern which is HHT-like. Therefore, molecular- biological and cellular-functional analyses have been performed in primary endothelial cells (ECs) isolated from the explanted lung. The findings revealed a loss of functionality in lung endothelial tissue and a stimulation of endothelial-to-mesenchymal transition. Understanding the molecular basis of this transition could potentially offer new therapeutic strategies to delay lung transplantation in severe cases. Full article

The vascular network contributes to the development of follicles. However, the therapeutic mechanism between vascular remodeling and ovarian functions is still unclear. Therefore, we demonstrated whether increased HGF by placenta-derived mesenchymal stem cells (PD-MSCs) improves ovarian function in an ovariectomized rat model via vascular remodeling by Wnt signaling activation. We established a half-ovariectomized rat model in which damaged ovaries were induced by ovariectomy of half of each ovary, and PD-MSCs (5 × 10⁵ cells) were transplanted by intravenous injection. Three weeks after transplantation, rats in all groups were sacrificed. We examined the secretion of HGF by PD-MSCs through culture medium. The vascular structure in injured ovarian tissues was restored to a greater extent in the PD-MSC transplantation (Tx) group than in the nontransplantation (NTx) group (* p < 0.05). The expression of genes related to Wnt signaling (e.g., LRP6, GSK3β, β-catenin) was significantly increased in the Tx group compared to the NTx group (* p < 0.05). However, the expression of genes related to vascular permeability (e.g., Asef, ERG3) was significantly decreased in the Tx group compared to the NTx group (* p < 0.05). Follicular development was improved in the Tx group compared to the NTx group (* p < 0.05). Furthermore, to evaluate vascular function, we cocultivated PD-MSCs after human umbilical vein endothelial cells (HUVECs) with lipopolysaccharide (LPS), and we analyzed the vascular formation assay and dextran assay in HUVECs. Cocultivation of PD-MSCs with injured HUVECs enhanced vascular formation and decreased endothelial cell permeability (* p < 0.05). Also, cocultivation of PD-MSCs with explanted ovarian tissues improved follicular maturation compared to cocultivation of the Wnt inhibitor-treated PD-MSCs with explanted ovarian tissues. Therefore, HGF secreted by PD-MSCs improved ovarian function in rats with ovarian dysfunction by decreasing vascular permeability via Wnt signaling. Full article

Valved conduits are often required to replace pulmonary arteries (PA). A widely used Contegra device is made of bovine jugular vein (BJV), preserved with glutaraldehyde (GA) and iso-propanol. However, it has several drawbacks that may be attributed to its chemical treatment. We hypothesized that the use of an alternative preservation compound may significantly improve BJV conduit performance. This study aimed to compare the macroscopic and microscopic properties of the BJV treated with diepoxide (DE) and GA in a porcine model. Twelve DE-BJVs and four Contegra conduits were used for PA replacement in minipigs. To assess the isolated influence of GA, we included an additional control group—BJV treated with 0.625% GA (n = 4). The animals were withdrawn after 6 months of follow-up and the conduits were examined. Explanted DE-BJV had a soft elastic wall with no signs of thrombosis or calcification and good conduit integration, including myofibroblast germination, an ingrowth of soft connective tissue formations and remarkable neoangiogenesis. The inner surface of DE-BJVs was covered by a thin neointimal layer with a solid endothelium. Contegra grafts had a stiffer wall with thrombosis on the leaflets. Calcified foci, chondroid metaplasia, and hyalinosis were observed within the wall. The distal anastomotic sites had hyperplastic neointima, partially covered with the endothelium. The wall of GA-BJV was stiff and rigid with degenerative changes, a substantial amount of calcium deposits and dense fibrotic formations in adventitia. An irregular neointimal layer was presented in the anastomotic sites without endothelial cover in the GA BJV wall. These results demonstrate that DE treatment improves conduit integration and the endothelialization of the inner surface while preventing the mineralization of the BJV, which may reduce the risk of early conduit dysfunction. Full article

Ischemia-reperfusion (I/R) events are involved in the development of various ocular pathologies, e.g., retinal artery or vein occlusion. We tested the hypothesis that resveratrol is protective against I/R injury in the murine retina. Intraocular pressure (IOP) was elevated in anaesthetized mice to 110 mm Hg for 45 min via a micropipette placed in the anterior chamber to induce ocular ischemia. In the fellow eye, which served as control, IOP was kept at a physiological level. One group received resveratrol (30 mg/kg/day p.o. once daily) starting one day before the I/R event, whereas the other group of mice received vehicle solution only. On day eight after the I/R event, mice were sacrificed and retinal wholemounts were prepared and immuno-stained using a Brn3a antibody to quantify retinal ganglion cells. Reactivity of retinal arterioles was measured in retinal vascular preparations using video microscopy. Reactive oxygen species (ROS) and nitrogen species (RNS) were quantified in ocular cryosections by dihydroethidium and anti-3-nitrotyrosine staining, respectively. Moreover, hypoxic, redox and nitric oxide synthase gene expression was quantified in retinal explants by PCR. I/R significantly diminished retinal ganglion cell number in vehicle-treated mice. Conversely, only a negligible reduction in retinal ganglion cell number was observed in resveratrol-treated mice following I/R. Endothelial function and autoregulation were markedly reduced, which was accompanied by increased ROS and RNS in retinal blood vessels of vehicle-exposed mice following I/R, whereas resveratrol preserved vascular endothelial function and autoregulation and blunted ROS and RNS formation. Moreover, resveratrol reduced I/R-induced mRNA expression for the prooxidant enzyme, nicotinamide adenine dinucleotide phosphate oxidase 2 (NOX2). Our data provide evidence that resveratrol protects from I/R-induced retinal ganglion cell loss and endothelial dysfunction in the murine retina by reducing nitro-oxidative stress possibly via suppression of NOX2 upregulation. Full article

We investigated the role of a sirolimus-embedded silk microneedle (MN) wrap as an external vascular device for drug delivery efficacy, inhibition of neointimal hyperplasia, and vascular remodeling. Using dogs, a vein graft model was developed to interpose the carotid or femoral artery with the jugular or femoral vein. The control group contained four dogs with only interposed grafts; the intervention group contained four dogs with vein grafts in which sirolimus-embedded silk-MN wraps were applied. After 12-weeks post-implantation, 15 vein grafts in each group were explanted and analyzed. Vein grafts applied with the rhodamine B–embedded silk-MN wrap showed far higher fluorescent signals than those without the wrap. The diameter of vein grafts in the intervention group decreased or remained stable without dilatation; however, it increased in the control group. The intervention group had femoral vein grafts with a significantly lower mean neointima-to-media ratio, and had vein grafts with an intima layer showing a significantly lower collagen density ratio than the control group. In conclusion, sirolimus-embedded silk-MN wrap in a vein graft model successfully delivered the drug to the intimal layer of the vein grafts. It prevented vein graft dilatation, avoiding shear stress and decreasing wall tension, and it inhibited neointimal hyperplasia. Full article

Though permanent pacemaker implantation is the only effective therapy for certain bradyarrhythmias in dogs, it is not without risks. Bacterial infection of the device is one of the most common complications. Human guidelines recommend besides systemic antibiotics, surgical explantation of the pacing lead and pulse generator in case of device-infection. This report describes a 13.5-year-old dog that received a transvenous endocardial permanent pacemaker because of syncopal episodes resulting from paroxysmal third-degree atrio-ventricular block. Five days after an uneventful surgery, a painful swelling appeared around the subcutaneous part of the lead where this was inserted into the jugular vein. A 4-week course of amoxicillin and clavulanic acid combined with enrofloxacin failed to clear the infection on long-term. Ultrasound-guided puncture of the abscess was performed to gain a sample for bacterial culture and antibiogram. Oral clindamycin of 4 weeks’ duration successfully resolved the infection with Staphylococcus aureus without having to explant the device. Repeated ultrasonographic examinations and fine-needle aspiration biopsies were used to evaluate for persistent local inflammation, guiding the length of the antibiotic therapy. Though the described approach has traditionally been ill-advised because of the risk of introducing bacteria and damaging the pacemaker lead, it was successful in our case. Full article

This study is preliminary to an experiment to be performed onboard the International Space Station (ISS) and on Earth to investigate how low gravity influences the healing of sutured human skin and vein wounds. Its objective was to ascertain whether these tissue explants could be maintained to be viable ex vivo for long periods of time, mimicking the experimental conditions onboard the ISS. We developed an automated tissue culture chamber, reproducing and monitoring the physiological tensile forces over time, and a culture medium enriched with serelaxin (60 ng/mL) and (Zn(PipNONO)Cl) (28 ng/mL), known to extend viability of explanted organs for transplantation. The results show that the human skin and vein specimens remained viable for more than 4 weeks, with no substantial signs of damage in their tissues and cells. As a further clue about cell viability, some typical events associated with wound repair were observed in the tissue areas close to the wound, namely remodeling of collagen fibers in the papillary dermis and of elastic fibers in the vein wall, proliferation of keratinocyte stem cells, and expression of the endothelial functional markers eNOS and FGF-2. These findings validate the suitability of this new ex vivo organ culture system for wound healing studies, not only for the scheduled space experiment but also for applications on Earth, such as drug discovery purposes. Full article

Mechanically processed stromal vascular fraction (mSVF) is a promising source for regenerative purposes. To study the in vivo fate of the mSVF, we herein used a vascularized tissue engineering chamber that insulates the target mSVF from the surrounding environment. In contrast to previous models, we propose an arteriovenous (AV) shunt between saphenous vessels in rats without a venous graft. Mechanical SVF was processed from the fat pads of male Sprague Dawley rats, mixed with a fibrin hydrogel and implanted into an inguinal tissue engineering chamber. An arteriovenous shunt was established between saphenous artery and vein. On the contralateral side, an mSVF-fibrin hydrogel mix without vascular axis served as a non-vascularized control. After two and six weeks, rats were sacrificed for further analysis. Mechanical SVF showed significant numbers of mesenchymal stromal cells. Vascularized mSVF explants gained weight over time. Perilipin and CD31 expression were significantly higher in the mSVF explants after six weeks while no difference in DAPI positive cells, collagen deposition and FABP4 expression was observed. Morphologically, no differentiated adipocytes but a dense cell-rich tissue with perilipin-positive cells was found after six weeks. The phosphorylation of ERK1/2 was significantly enhanced after six weeks while Akt activation remained unaltered. Finally, mSVF explants stably expressed and released VEGF, bFGF and TGFb. Vascularized mSVF is able to proliferate and express adipocyte-specific markers. The AV shunt model is a valuable refinement of currently existing AV loop models in the rat which contributes to the fundamental 3R principles of animal research. Full article

Long-term graft patency determines the prognosis of revascularization after coronary artery bypass grafting (CABG). Ischemia-reperfusion (I/R) injury of the graft suffered during harvesting and after implantation might influence graft patency. Aspirin, a nonsteroidal anti-inflammatory drug improves the long-term patency of vein grafts. Whether aspirin has the same effect on arterial grafts is questionable. We aimed to characterize the beneficial effects of aspirin on arterial bypass grafts in a rodent revascularization model. We gave Lewis rats oral pretreatment of either aspirin (n = 8) or saline (n = 8) for 5 days, then aortic arches were explanted and stored in cold preservation solution. The third group (n = 8) was a non-ischemia-reperfusion control. Afterwards the aortic arches were implanted into the abdominal aorta of recipient rats followed by 2 h of reperfusion. Endothelium-dependent vasorelaxation was examined with organ bath experiments. Immunohistochemical staining were carried out. Endothelium-dependent maximal vasorelaxation improved, nitro-oxidative stress and cell apoptosis decreased, and significant endothelial protection was shown in the aspirin preconditioned group, compared to the transplanted control group. Significantly improved endothelial function and reduced I/R injury induced structural damage were observed in free arterial grafts after oral administration of aspirin. Aspirin preconditioning before elective CABG might be beneficial on free arterial graft patency. Full article

Background: In the case of complicated kidney transplantation, when the accessory artery is severed, the main task is to decide whether to restore renal blood flow and which method should be used. In this report, we present a case of kidney transplantation with vascular reconstruction using an ovarian vein as an interposition graft between a larger branch of the main renal artery and the lower polar artery which was severed during kidney explantation. Case summary: Kidney transplantation using an ovarian vein was performed for a 34-year-old woman with end-stage renal disease on 1 April 2020 in the Hospital of Lithuanian university of health sciences (LUHS) Kaunas Clinics. A lower accessory renal artery was severed during kidney explantation. As the ovarian vein of the donor remained and matched the diameter of the severed vessel, it was decided to use it as an insertion between the main renal artery and the accessory renal artery of the inferior pole. The cold ischemic time was 770 min and the warm ischemic time was 37 min. A month after transplantation, the patient’s condition and daily urine output were normal and the serum creatinine level decreased rapidly. Fifteen months after the surgery, the function and structure of the transplant remained normal and there was no evidence of serious vascular complications on CT scans. This is the first case where graft function was verified after transplantation using three-dimensional CT angiography. Conclusions: If an inferior polar artery is severed, vascular reconstruction must be performed to preserve the function of the graft. Usually, the gonadal vein is available during donor nephrectomy; therefore, it can be explanted without additional difficulties or incisions. Although we have not reported any complications, further studies are recommended on the long-term outcomes of this alternative approach for the reconstruction of short renal arteries. Full article