An Arteriovenous Bioreactor Perfusion System for Physiological In Vitro Culture of Complex Vascularized Tissue Constructs.

Background: The generation and perfusion of complex vascularized tissues in vitro requires sophisticated perfusion techniques. For multiscale arteriovenous networks, not only the arterial, but also the venous, biomechanical and biochemical conditions that physiologically exist in the human body must be accurately emulated. For this, we here present a modular arteriovenous perfusion system for the in vitro culture of a multi-scale bioartificial vascular network.

Fabrication of heart tubes from iPSC derived cardiomyocytes and human fibrinogen by rotating mold technology.

Due to its structural and functional complexity the heart imposes immense physical, physiological and electromechanical challenges on the engineering of a biological replacement. Therefore, to come closer to clinical translation, the development of a simpler biological assist device is requested. Here, we demonstrate the fabrication of tubular cardiac constructs with substantial dimensions of 6 cm in length and 11 mm in diameter by combining human induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) and human foreskin fibroblast (hFFs) in human fibrin employing a rotating mold technology.

Fabrication and biomechanical characterization of a spider silk reinforced fibrin-based vascular prosthesis.

With fibrin-based vascular prostheses, vascular tissue engineering offers a promising approach for the fabrication of biologically active regenerative vascular grafts. As a potentially autologous biomaterial, fibrin exhibits excellent hemo- and biocompatibility. However, the major problem in the use of fibrin constructs in vascular tissue engineering, which has so far prevented their widespread clinical application, is the insufficient biomechanical stability of unprocessed fibrin matrices.

Development, comparative structural analysis, and first in vivo evaluation of acellular implanted highly compacted fibrin tubes for arterial bypass grafting.

The generation of small-caliber vascular grafts remains a significant challenge within the field of tissue engineering. In pursuit of this objective, fibrin has emerged as a promising scaffold material. However, its lack of biomechanical strength has limited its utility in the construction of tissue engineered vascular grafts.

A Hyperdynamic Arteriovenous Fistula Aneurysm After Long Time Renal Transplantation.

Closure of arteriovenous fistula should be considered in patients who underwent successful renal transplantation to avoid potential complications that may result from the presence of unused fistula especially, in patients who are predisposed to aneurysm formation in the future.

Mechanical Stimulation Induces Capillary Alignment in a Fibrin-Based .

Generation of bioartificial blood vessels with a physiological three-layered wall architecture is a long pursued goal in vascular tissue engineering. While considerable advances have been made to resemble the physiological and morphology and function in bioartificial vessels, only very few studies have targeted the generation of a , including its characteristic vascular network known as the which are essential for graft nutrition and integration. In healthy native blood vessels, capillary are aligned longitudinally to the vessel axis.

Preliminary application of native Nephila edulis spider silk and fibrin implant causes granulomatous foreign body reaction in vivo in rat's spinal cord.

After spinal cord injury, gliomesenchymal scaring inhibits axonal regeneration as a physical barrier. In peripheral nerve injuries, native spider silk was shown to be an effective scaffold to facilitate axonal re-growth and nerve regeneration. This study tested a two-composite scaffold made of longitudinally oriented native spider silk containing a Haemocomplettan fibrin sheath to bridge lesions in the spinal cord and enhance axonal sprouting.

Vascular procedures in patients with left ventricular assist devices: single-center experience.

Objective: A growing number of patients suffering from heart failure is living with a left ventricular assist device (LVAD) and is in the need for non-cardiac surgery. Vascular procedures due to ischemia, bleeding, or other device-related complications may be required and pose a challenge to the caregivers in terms of monitoring and management of these patients. Therefore, we reviewed our experience with LVAD patients undergoing vascular surgery.

A 3-Layered Bioartificial Blood Vessel with Physiological Wall Architecture Generated by Mechanical Stimulation.

The generation of cellularized bioartificial blood vessels resembling all three layers of the natural vessel wall with physiological morphology and cell alignment is a long pursued goal in vascular tissue engineering. Simultaneous culture of all three layers under physiological mechanical conditions requires highly sophisticated perfusion techniques and still today remains a key challenge. Here, three-layered bioartificial vessels based on fibrin matrices were generated using a stepwise molding technique.

Prospective evaluation of preoperative lung ultrasound for prediction of perioperative outcome and myocardial injury in adult patients undergoing vascular surgery (LUPPO study).

Background: Myocardial injury after non-cardiac surgery (MINS) is a frequent perioperative event in vascular surgery, associated both with worse outcome and subsequent cardiovascular events. Current guidelines advocate troponin (hs-cTnT) and NT-proBNP measurements in selected patients before surgery, but accurate preoperative identification of patients at risk for MINS is an unmet clinical need. Focused lung ultrasound (LUS) might help to select patients at increased risk for MINS, because it can visualize B-line artifacts correlating to cardiopulmonary disease.

Complete Myogenic Differentiation of Adipogenic Stem Cells Requires Both Biochemical and Mechanical Stimulation.

Vascular tissue engineering of the middle layer of natural arteries requires contractile smooth muscle cells (SMC) which can be differentiated from adipose-derived mesenchymal stem cells (ASC) by treatment with transforming growth factor-β, sphingosylphosphorylcholine and bone morphogenetic protein-4 (TSB). Since mechanical stimulation may support or replace TSB-driven differentiation, we investigated its effect plus TSB-treatment on SMC orientation and contractile protein expression. Tubular fibrin scaffolds with incorporated ASC or pre-differentiated SMC were exposed to pulsatile perfusion for 10 days with or without TSB.

Dehydration improves biomechanical strength of bioartificial vascular graft material and allows its long-term storage.

Introduction: We have recently reported about a novel technique for the generation of bioartificial vascular grafts based on the use of a compacted fibrin matrix. In this study, we evaluated the effects of a dehydration process on the biomechanical properties of compacted fibrin tubes and whether it allows for their long-term storage.

Materials And Methods: Fibrin was precipitated from fresh frozen plasma by means of cryoprecipitation and simultaneously with a thrombin solution applied in a high-speed rotating casting mold.

Outgrowing endothelial and smooth muscle cells for tissue engineering approaches.

In recent years, circulating progenitors of endothelial cells and smooth muscle cells were identified in the peripheral blood. In our study, we evaluated the utilization of both cell types isolated and differentiated from peripheral porcine blood in terms for their use for tissue engineering purposes. By means of density gradient centrifugation, the monocyte fraction from porcine blood was separated, split, and cultivated with specific culture media with either endothelial cell growth medium-2 or smooth muscle cell growth medium-2 for the differentiation of endothelial cells or smooth muscle cells.

Adrenomedullin Is Associated With Surgical Trauma and Impaired Renal Function in Vascular Surgery Patients.

Background:: Patients undergoing vascular surgery are prone to perioperative organ injury because of both higher prevalence of cardiovascular risk factors and the extent of surgery. Early detection of organ failure is essential to facilitate appropriate medical care. Midregional pro-adrenomedullin (MR-proADM) has been investigated in acute medical care settings to guide clinical decision-making regarding patient pathways and to identify patients prone to imminent cardiovascular or inflammatory complications.

[Pseudoaneuryma after transradial puncture in systemic lysis of basilar artery thrombosis].

History: Because of neurological symptoms as a result of thrombotic occlusion of the basilar artery, a successful revascularization after systemic Actilyse application was performed in a 78 year old patient. Later, it came to the formation of a pseudoaneurysm at the radial artery, punctured for invasive blood pressure measurement.

Treatment And Course: After oscillographic respectively ultrasound detection of a 2 cm wide pseudoaneurysm from the radial artery, the surgical resection of the aneurysm sac was performed.

Novel method for the generation of tissue-engineered vascular grafts based on a highly compacted fibrin matrix.

Unlabelled: The generation of tissue-engineered blood vessel substitutes remains an ongoing challenge for cardiovascular tissue engineering. Full biocompatibility and immediate availability have emerged as central issues for clinical use. To address these issues, we developed a technique that allows the generation of highly stable tubular fibrin segments.

Renal function interferes with copeptin in prediction of major adverse cardiac events in patients undergoing vascular surgery.

Objective: Precise perioperative risk stratification is important in vascular surgery patients who are at high risk for major adverse cardiovascular events (MACE) peri- and postoperatively. In clinical practice, the patient's perioperative risk is predicted by various indicators, e.g.

Unusual Case of an Arterial Thoracic Outlet Syndrome due to Srb Anomaly.

A thoracic outlet syndrome (TOS) is caused by arterial or nervous obstruction because of skeletal or muscular anomalies and hypertrophies. Congenital rib anomalies occur with low incidences (0.15-0.

Perioperative levels and changes of high-sensitivity troponin T are associated with cardiovascular events in vascular surgery patients.

Objectives: Myocardial infarction after major surgery is frequent, drives outcome, and consumes health resources. Specific prediction and detection of perioperative myocardial infarction is an unmet clinical need. With the widespread use of high-sensitive cardiac troponin T assays, positive tests become frequent, but their diagnostic or prognostic impact is arguable.

Eight-year experience with cryopreserved arterial homografts for the in situ reconstruction of abdominal aortic infections.

Objective: This study investigated short-term and long-term outcomes in patients with abdominal aortic infection (mycotic aneurysm, prosthetic graft infection, aortoenteric fistula) managed by total excision of the aneurysm or the infected vascular graft and in situ aortic reconstruction with a cryopreserved arterial homograft (CAH).

Methods: From January 2000 to December 2008, 110 consecutive patients underwent CAH implantation for treatment of vascular infections. In 57 (52%), in situ revascularization of the abdominal aorta with Y-prosthesis constructed from CAHs was performed.