Use Of Vessels Research Articles

Internal Mammary Artery and Vein as Recipient Vessels in Head and Neck Reconstruction<alt-title>Internal Mammary Vessels in Head and Neck Surgery</alt-title>

Free-tissue transfer for head and neck reconstruction has evolved since the mid-1950s. A variety of different recipient arteries and veins have been described for use in head and neck reconstruction. In our experience, the internal mammary artery (IMA) and internal mammary vein (IMV) have become increasingly important for achieving successful microvascular reconstruction. To illustrate the efficacy of the IMA and IMV recipient vessels in head and neck reconstruction, highlighting the different techniques used to harvest these vessels and outline decision making when approaching a neck where commonly used vessels are unavailable. Retrospective medical record review. Outpatient clinic setting. All free-tissue transfers performed between 2005 and 2011. All patients in whom the IMA or IMV recipient vessels were used were included. Twelve cases were performed with IMA and IMV harvest. Donor site, flap used, recipient artery and vein, success of transfer, flap survival, and presence of donor site complications. The IMA and IMV were harvested in 12 patients, with 11 successful free-tissue transfers. In 1 patient, the vessels were unusable, and a regional tissue transfer was performed. The IMA and IMV are excellent recipient vessels for use in head and neck reconstruction and should be considered for use in challenging reconstructive cases.

Abstract No. 379 - Comparison of patient radiation doses from digital subtraction and fluoro save acquisitions of femoral access sites prior to use of vascular closure devices

Purpose Prior to use of femoral closure devices, evaluation of the femoral artery access and the suitability of the vessel for use of a vascular closure device is routinely performed. Digital subtraction angiography (DSA) and digital flouroscopic loop (DFL) technology both provide a means to acquire and store angiographic images. We sought to evaluate the image quality and radiation dose associated with each of these modalities. Materials and Methods Using a phantom we simulated angiographic acquisitions of the femoral artery in the AP and 35 degree oblique projections and measured the dose during DSA and DFL acquisitions. We retrospectively selected 60 adult patients from the radiology database who had undergone elective outpatient cerebral angiography using the three different DFL acquisition protocols (15 fps, 7.5 fps and 4 fps). We selected 20 patients who had DSA documentation of the femoral access site and 60 who had DFL documentation of the femoral access site. We then reviewed the images for diagnostic quality to determine if a femoral closure device could be safely employed. We subsequently looked up the dose parameters recorded for the acquisitions and compared the dose for the acquisitions. Results For the phantom studies we found that the dose on the AP acquisitions was lower than the Oblique acquisitions. The DSA dose was higher than the DFL dose. The image quality was diagnostic for evaluation of the femoral artery with regards to access site suitability for use of the femoral closure device on all the clinical studies. The average dose to the patient was 57.9 mGy for DSA acquisitions versus 6.5 mGy, 2.8 mGy and 2.4 mGy for 15 fps, 7.5 fps and 4 fps respectively (p Conclusion Use of the Fluoro save feature on modern angiography equipment yields adequate images for the evaluation of femoral access sites for suitability of femoral closure devices and decreases both patient and operator radiation doses.

Mouse Model of Lymph Node Metastasis via Afferent Lymphatic Vessels for Development of Imaging Modalities

Animal studies of lymph node metastasis are constrained by limitations in the techniques available for noninvasive monitoring of the progression of lymph node metastasis, as well as difficulties in the establishment of appropriate animal models. To overcome these challenges, this study has developed a mouse model of inter-lymph-node metastasis via afferent lymphatic vessels for use in the development of imaging modalities. We used 14- to 18-week-old MRL/MpJ−/lpr/lpr (MRL/lpr) mice exhibiting remarkable systemic lymphadenopathy, with proper axillary lymph nodes (proper-ALNs) and subiliac lymph nodes (SiLNs) that are 6 to 12 mm in diameter (similar in size to human lymph nodes). When KM-Luc/GFP malignant fibrous histiocytoma-like cells stably expressing the firefly luciferase gene were injected into the SiLN, metastasis could be detected in the proper-ALN within 3 to 9 days, using in vivo bioluminescence imaging. The metastasis route was found to be via the efferent lymphatic vessels of the SiLN, and metastasis incidence depended on the number of cells injected, the injection duration and the SiLN volume. Three-dimensional contrast-enhanced high-frequency ultrasound imaging showed that the blood vessel volume and density in the metastasized proper-ALN significantly increased at 14 days after tumor cell inoculation into the SiLN. The present metastasis model, with lymph nodes similar in size to those of humans, has potential use in the development of ultrasound imaging with high-precision and high-sensitivity as well as other imaging modalities for the detection of blood vessels in lymph nodes during the progression of metastasis.

X-ray-computed tomography contrast agents.

X-ray-computed tomography contrast agents.

Interventional catheterisation of stenotic or occluded systemic veins in children with or without congenital heart diseases: early results and intermediate follow-up

Limited data exists on midterm results concerning paediatric interventions on stenotic or occluded systemic veins following indwelling lines, cardiac surgery, or catheterisations. The purpose of this study was to report our acute and intermediate results concerning patients with (Group A) and without (Group B) congenital heart diseases (CHD) over a 10-year period. From January 2000 to December 2010, 32 patients (23 in Group A and nine in Group B, respectively) underwent 39 interventional catheterisations aimed to dilate or recanalise occluded iliofemoral veins, inferior or superior venae cavae. Initial and follow-up catheterisation data were reviewed retrospectively. Midterm results were evaluated by means of echography, angiography, and CT scan in all 15 and 17 patients, respectively. Median age and weight of all patients at catheterisation were five years (range 0.1-18) and 15 kg (range 2-60), respectively. Fifty-two stents were implanted in 29 patients (32 vessels). In 25 patients 28 vessels were occluded and required recanalisation. There were no major complications. In all but three patients it was possible to treat the lesion. There were two procedural complications (5.1%): one acute stent occlusion and one local dissection. At a median follow-up of 2.5 years (range 1-10) we observed six complications of stenting (11.5%): two fractures, two occlusions and two restenoses. Interventional catheterisation of stenotic or occluded systemic veins grants good immediate results at a low rate of complication. Stent dilatation or recanalisation may open the vessel for use during future procedures. However, long-term results are yet to be established.

Doppler velocity measurements from large and small arteries of mice

With the growth of genetic engineering, mice have become increasingly common as models of human diseases, and this has stimulated the development of techniques to assess the murine cardiovascular system. Our group has developed nonimaging and dedicated Doppler techniques for measuring blood velocity in the large and small peripheral arteries of anesthetized mice. We translated technology originally designed for human vessels for use in smaller mouse vessels at higher heart rates by using higher ultrasonic frequencies, smaller transducers, and higher-speed signal processing. With these methods one can measure cardiac filling and ejection velocities, velocity pulse arrival times for determining pulse wave velocity, peripheral blood velocity and vessel wall motion waveforms, jet velocities for the calculation of the pressure drop across stenoses, and left main coronary velocity for the estimation of coronary flow reserve. These noninvasive methods are convenient and easy to apply, but care must be taken in interpreting measurements due to Doppler sample volume size and angle of incidence. Doppler methods have been used to characterize and evaluate numerous cardiovascular phenotypes in mice and have been particularly useful in evaluating the cardiac and vascular remodeling that occur following transverse aortic constriction. Although duplex ultrasonic echo-Doppler instruments are being applied to mice, dedicated Doppler systems are more suitable for some applications. The magnitudes and waveforms of blood velocities from both cardiac and peripheral sites are similar in mice and humans, such that much of what is learned using Doppler technology in mice may be translated back to humans.

Sintered Silicon Carbide: A New Ceramic Vessel Material for Microwave Chemistry in Single‐Mode Reactors

Silicon carbide (SiC) is a strongly microwave absorbing chemically inert ceramic material that can be utilized at extremely high temperatures due to its high melting point and very low thermal expansion coefficient. Microwave irradiation induces a flow of electrons in the semiconducting ceramic that heats the material very efficiently through resistance heating mechanisms. The use of SiC carbide reaction vessels in combination with a single-mode microwave reactor provides an almost complete shielding of the contents inside from the electromagnetic field. Therefore, such experiments do not involve electromagnetic field effects on the chemistry, since the semiconducting ceramic vial effectively prevents microwave irradiation from penetrating the reaction mixture. The involvement of electromagnetic field effects (specific/nonthermal microwave effects) on 21 selected chemical transformations was evaluated by comparing the results obtained in microwave-transparent Pyrex vials with experiments performed in SiC vials at the same reaction temperature. For most of the 21 reactions, the outcome in terms of conversion/purity/product yields using the two different vial types was virtually identical, indicating that the electromagnetic field had no direct influence on the reaction pathway. Due to the high chemical resistance of SiC, reactions involving corrosive reagents can be performed without degradation of the vessel material. Examples include high-temperature fluorine-chlorine exchange reactions using triethylamine trihydrofluoride, and the hydrolysis of nitriles with aqueous potassium hydroxide. The unique combination of high microwave absorptivity, thermal conductivity, and effusivity on the one hand, and excellent temperature, pressure and corrosion resistance on the other hand, makes this material ideal for the fabrication of reaction vessels for use in microwave reactors.

Multilayered polyelectrolyte films: a tool for arteries and vessel repair

Circulatory vascular diseases, especially those arising from atherosclerosis, are the predominant cause of mortality and morbidity in the developed world. Current therapies include the use of autologous vessels or synthetic materials as vessel replacements. The limited availability of healthy vessels for use as bypass grafts and the failure of purely synthetic materials in small-diameter sites necessitate the development of biological substitutes. Langer and Vacanti, proposed the concept of tissue engineering for the development of structures that can treat/replace damaged or diseased organs and tissues. The layer-by-layer (L-b-L) self-assembly technique has emerged as a simple and versatile method for coating biological and non-biological surfaces aimed for various biomedical applications. This review discusses the development of vascular therapies, focusing on the various possibilities of the L-b-L surface technology for the development of suitable grafts.

Stenting of stenotic or occluded iliofemoral veins, superior and inferior vena cavae in children with congenital heart disease: Acute results and intermediate follow up

To determine the short and intermediate term outcome following systemic venous stent placement in children with congenital heart disease. Patients with congenital heart disease are at risk of stenosis or occlusion of systemic veins following indwelling lines or catheterizations. Stent dilation may ameliorate symptoms and open the vessel for use during future procedures. We report our acute and intermediate results. All patients with systemic venous stent placement in the iliofemoral veins, inferior or superior vena cava at our institution between 1998 and 2006 were included. Initial and the follow-up catheterization data were reviewed retrospectively. 70 stents were placed in 33 patients (36 vessels). Median age was 2.6 years (0.2-14.2) and weight 11.5 kg (3.8-78.7). 17/36 vessels (47%) were occluded requiring recanalization. Following stent delivery, the mean minimum vessel diameter increased from 3.1 +/- 3.2 to 7.2 +/- 3.0 mm (P < 0.001). There were no major complications. Seventeen patients and vessels had a total of 62 follow-up catheterizations, with median length of follow-up 4.1 years (0.7-9.3). During intermediate follow up, 7/17 vessels (41%) required additional intervention. Six patients had additional balloon dilation of existing stents, and one additional stent was placed. Vessels were further dilated to 8.4 +/- 3.5 mm at the last catheterization. Systemic venous stents are safe and effective in recanalizing stenosed or occluded vessels. At follow-up, reocclusion can occur, however, previously placed stents can be safely recanalized if necessary. Future studies will determine if stenting is indicated in a broader population.

O DISCURSO DOS FRAGMENTOS: SÓCIO-COSMOLOGIA E ALTERIDADE NA CERÂMICA GUARANI PRÉ-COLONIAL

De acordo com as fontes etnohistóricas do século XVII, a decoração e a variabilidade formal da cerâmica Guarani estavam relacionadas aos diferentes tipos de uso dos vasilhames, sendo a cerâmica pintada usada principalmente em situações rituais. Com o objetivo de explorar a relação entre os grafismos e as categorias funcionais de vasilhas, bem como as variações estilísticas regionais e/ou cronológicas apresentadas pelas amostras, analisamos coleções de cerâmicas arqueológicas do litoral norte e da região noroeste do Rio Grande do Sul. No estudo de caso aqui apresentado, sugerimos que a cerâmica pintada apresenta alto potencial para análise de problemáticas relativas à alteridade e ao universo sócio-cosmológico Guarani pré-colonial.

Biomimetic control of vascular smooth muscle cell morphology and phenotype for functional tissue‐engineered small‐diameter blood vessels

Small-diameter blood vessel substitutes are urgently needed for patients requiring replacements of their coronary and below-the-knee vessels and for better arteriovenous dialysis shunts. Circulatory diseases, especially those arising from atherosclerosis, are the predominant cause of mortality and morbidity in the developed world. Current therapies include the use of autologous vessels or synthetic materials as vessel replacements. The limited availability of healthy vessels for use as bypass grafts and the failure of purely synthetic materials in small-diameter sites necessitate the development of a biological substitute. Tissue engineering is such an approach and has achieved promising results, but reconstruction of a functional vascular tunica media, with circumferentially oriented contractile smooth muscle cells (SMCs) and extracellular matrix, appropriate mechanical properties, and vasoactivity has yet to be demonstrated. This review focuses on strategies to effect the switch of SMC phenotype from synthetic to contractile, which is regarded as crucial for the engineering of a functional vascular media. The synthetic SMC phenotype is desired initially for cell proliferation and tissue remodeling, but the contractile phenotype is then necessary for sufficient vasoactivity and inhibition of neointima formation. The factors governing the switch to a more contractile phenotype with in vitro culture are reviewed.

Development of a co-culture system for tissue engineered vascular grafts

Surgical replacement or bypass surgery is the most common treatment for coronary and peripheral atherosclerotic diseases, with just under 29,000 bypass cases performed in 2003 in the UK [1]. However, many patients do not have appropriate blood vessels for use as replacements and the development of tissue engineered vascular grafts (TEVG) offers a possible solution to this problem. Smooth muscle cells (SMC) and endothelial cells (EC) exist in close proximity to each other within the blood vessel interacting in a variety of ways which regulate the normal function of both cell types. Therefore establishing a stable co-culture system is vital for the development of a TEVG. For a TEVG to be fully functional it must be able to withstand the variety of mechanical stresses present in the dynamic vascular environment. These physical cues also provide signals regulating the development of the vessel. The mechanical stresses in vivo are extremely complex, but can be approximated by use of a physiological simulator. Previously developed models of co-culture under mechanical stress have examined the effect on cells under shear stress only [2–4,6]. The physiological simulator developed within our lab applies the three main forces of mechanical stress to the pseudovessel – strain, pressure and shear stress [5], allowing assessment of the cells and co-culture system under conditions close to those in vivo.

The X-Craft – a potential solution to littoral warfare requirements

The Office of Naval Research (ONR) in the United States commissioned the design and build of the X-Craft that will be used to demonstrate mission modularity and evaluate hydrodynamic performance and operational availability of the vessel for use in the littoral area. The vessel has been named ‘Sea Fighter’ and is classed as an FSF (Fast Sea Frame) which is a new class of vessels in the US Navy. X-Craft is required to carry up to 700 tonnes of deadweight and be capable of operating at a maximum speed of up to 60 knots and 45 knots in sea state 4. The X-Craft is also to be capable of self deployment over 4000nm at a speed of 20 knots. The X-Craft was built by Nichols Brothers Boat Builders in Washington State, USA and launched in February 2005. This paper describes in detail the design and development of the X-Craft hull form and in addition discusses the innovative technologies used onboard the X-Craft.

Analysis of the magnetic distribution within a high-temperature superconductor magnetic shielding cylinder by use of the finite element method

Abstract It is important to know the distribution of the magnetic field within a magnetic shielding vessel for use in the design of an effective magnetic shielding vessel. From experiments and theoretical analysis, the distribution of the magnetic fields, the magnetic flux densities Bz and Br along the respective axial and radial directions z and r, within a high-temperature superconductor cylinder were found. Theoretical values for Bz and Br were determined by the use of the finite element method. The experimental values were found to agree well with the theoretical values. These results were found to be important criteria in the design of an effective magnetic shielding vessel.

Arteriovenous fistulae for chronic intermittent haemodialysis: A modified surgical technique

Abstract A side-to-end technique for arteriovenous fistulae of the wrist vessels for use in chronic intermittent haemodialysis with venepuncture is proposed. A series of 14 patients in whom this technique has been used is presented. A survey of the different shunting techniques described in the literature is given and their advantages and disadvantages are discussed. The problem of turbulence due to a sharp angulation of the flow through the anastomosis and the possibility of its causing aneurysmata and thrombosis of the fistulae are considered. This problem and its sequelae, together with the problem of the use of the sole remaining artery of the hand when the other has been either occluded or ligated in previous operations, and the possibility of creating an arteriovenous fistula with a vein distant from the artery, are all overcome by this technique.

Tissue Engineering of Recellularized Small-Diameter Vascular Grafts

A tissue-engineered small-diameter arterial graft would be of benefit to patients requiring vascular reconstructive procedures. Our objective was to produce a tissue-engineered vascular graft with a high patency rate that could withstand arterial pressures. Rat arteries were acellularized with a series of detergent solutions, recellularized by incubation with a primary culture of endothelial cells, and implanted as interposition grafts in the common femoral artery. Acellular grafts that had not been recellularized were implanted in a separate group of control animals. No systemic anticoagulants were administered. Grafts were explanted at 4 weeks for definitive patency evaluation and histologic examination; 89% of the recellularized grafts and 29% of the control grafts remained patent. Elastin staining demonstrated the preservation of elastic fibers within the media of the acellular grafts before implantation. Immunohistochemical staining of explanted grafts demonstrated a complete layer of endothelial cells on the lumenal surface in grafts that remained patent. Smooth muscle cells were observed to have repopulated the vessel walls. The mechanical properties of the matrix were comparable to native vessels. Such a strategy may present an alternative to autologous harvest of small vessels for use in vascular bypass procedures.

Catheter Position for Adequate Intra-arterial Chemotherapy for Advanced Pancreatic Cancer: Evaluation with CT during Arterial Injection of Contrast Material

To identify the drug infusion vessel for use in obtaining the best drug distribution in arterial infusion chemotherapy for advanced pancreatic cancer. In 16 cases of advanced pancreatic cancer (pancreatic head, n = 12; pancreatic body and/or tail, n = 4), computed tomography during arterial injection of contrast material was performed at the time of angiography. The sites of catheter placement were celiac artery, superior mesenteric artery, and their branches, such as gastroduodenal artery, inferior pancreatico-duodenal artery, or dorsal pancreatic artery. In the cases of pancreatic head cancer, all except one with hepatomesenteric vascular variation were supplied by the celiac artery and superior mesenteric artery (dual supply). In the cases of pancreatic body and/or tail cancer, two were supplied by celiac artery alone and two showed dual supply. In the cases of pancreatic head cancer, when the areas supplied by the main trunk were compared with those supplied by its branches, three of nine cases on the celiac artery side and four cases on the superior mesenteric artery side showed that the areas were not consistent, with a partial defect observed in the areas supplied by branches of the superior mesenteric artery. In the cases of pancreatic body and/or tail cancer, on both sides, one of two cases was not consistent. To achieve optimal drug distribution in arterial infusion chemotherapy for advanced pancreatic cancer, drug infusion via both the celiac artery and superior mesenteric artery is required in the majority of cases. In many cases, optimal drug distribution is not attainable with drug infusion via a branch; therefore, drug infusion should be administered via the main trunk.

Long-term Behaviour of Cryopreserved Arterial Grafts Versus Prosthetic Micrografts

Introduction. When a patient has no suitable vessels for use as grafts in bypass or reconstruction procedures, two of the options available are the use of a cryopreserved vessel or an expanded polytetrafluoroethylene (ePTFE) prosthesis. This study was designed to compare the long-term behaviour of these vascular substitutes.Material and methods. We established three study groups by grafting the following vessel substitutes to the iliac artery in Spraque–Dawley rats: arterial autografts (GI, n=12), cryopreserved syngenic arterial grafts (cryoisografts) (GII, n=12), and ePTFE micrografts (GIII, n=12). The animals were sacrificed 180 days after surgery, at which time the graft specimens were morphologically evaluated by light and electron microscopy, immunolabelling (ED1/α-actin) and morphometric analysis of the neointima.Results. At the time of sacrifice, graft patency was 100% for the autografts and cryoisografts, while 10% of the ePTFE micrografts showed fully-occlusive thrombosis. Intimal hyperplasia was observed in grafts in GI and GII; the neointima being thinner in the cryoisografts (54.36±2.26 μm) than the autografts (161.30±3.91 μm). The endothelium formed over the prosthetic micrografts was unstable, with areas of subendothelial thickening (9.37±3.18 μm). Cell loss and medial layer degeneration were observed in both GI and GII specimens, while the GIII grafts were colonised by cells on their luminal surface.Conclusions. All three grafts show good long-term tolerance when used in an arterial setting. Following long-term implant, autografts and cryoisografts show similar alterations that give rise to the complete loss of the muscle component of the tunica media along with the formation of a stable neointima. This new layer takes on the role of the tunica media.

Sample Selection for Ceramic Use-alteration Analysis: the Effects of Abrasion on Soot

Ceramic use-alteration analysis is a useful approach to determine vessel function. However, some forms of post-use alteration hinder analysts from recognizing use alteration and/or selecting appropriate samples for analysis. This paper illustrates how, through replication and experimental work, researchers can determine which pieces are relatively unaffected by post-use processes and should have preserved use alteration.The case study here considers the effects of one post-use process (abrasion) on one kind of use alteration (sooting) on one type of material (low-fired, fibre-tempered ceramic vessels broken into sherds). Fragmentation and nonuse alteration of vessel and sherd surfaces are problems particularly for Late Archaic (5000–3000bp) fibre-tempered ceramic assemblages from the Southeast and Midwest United States.First, the identification of soot on fibre-tempered sherds from three Archaic sites in Georgia is described. Manufacturing method and firing temperatures for Archaic vessels were then determined, and this information was used to produce test tiles and vessels for use in abrasion experiments. Test tiles and sooted sherds were abraded with water and gravel for different periods of time to observe soot removal. Guidelines for sample selection of fibre-tempered sherds for use-alteration analysis are based on these experimental observations.

Magnetic resonance angiography of peripheral runoff vessels

Recent improvements in magnetic resonance imaging techniques have made magnetic resonance angiography (MRA) a very useful adjunct to invasive angiography. Fifty-five limbs in 51 patients with occlusive peripheral vascular disease were studied with both MRA and contrast arteriography. The magnetic resonance and contrast arteriograms were read by radiologists and surgeons and separate interventional plans were based on each study. The MRA findings differed significantly from those of conventional arteriography in 26 limbs (48%). In every case MRA visualized all of the same vessels and hemodynamic stenoses seen on the contrast arteriogram. In 48% of the cases, however, MRA revealed additional findings. Thus the discrepancies in the two studies were always the result of the failure of the arteriogram to reveal all of the patent vessels seen on MRA. The additional information provided by MRA resulted in alteration of the interventional plan in 11 cases (22%). In nine cases (18%) target vessels suitable for use in a limb-salvage procedure were identified by MRA, although they had been missed by conventional arteriography. In all of these cases, intraoperative arteriograms confirmed the suitability of these vessels for use in technically successful bypass procedures. In two cases (4%) additional information provided by MRA identified a target runoff vessel for bypass grafting that proved to be a better alternative than the one that would have been chosen on the basis of contrast arteriography. It is concluded that MRA has greater sensitivity than contrast arteriography in the identification of distal runoff vessels and it is suggested that use of this noninvasive technique as an adjunct or possibly eventually as an alternative to contrast arteriography may result in increased limb salvage and decreased morbidity in the management of patients with peripheral vascular disease.