Cohort Study Examining the Prevalence and Relationship with Outcome of Standard Modifiable Risk Factors in Patients with Peripheral Artery Occlusive and Aneurysmal Disease.

OBJECTIVE: The aim was to examine the presentation and outcome of patients with peripheral artery occlusive and aneurysmal disease (POAD) in relation to standard modifiable cardiovascular risk factors (SMuRFs; i.e., hypertension, diabetes, hypercholesterolaemia, and smoking). METHODS: A total of 2 129 participants with POAD were recruited from three vascular clinics in Queensland, Australia. SMuRFs were defined using established criteria. Participants were followed via outpatient appointments and linked data to record the primary outcome event of major adverse cardiovascular events (MACE). The association between SMuRFs and MACE was assessed using Cox proportional hazard analysis. Subanalyses examined the association of individual SMuRFs with MACE and assessed findings separately in participants with occlusive and aneurysmal disease. RESULTS: At recruitment 71 (3.3%), 551 (25.9%), 977 (45.9%), 471 (22.1%), and 59 (2.8%) participants had zero, one, two, three, and four SMuRFs. During a median follow up of 2.6 (interquartile range 0.4, 6.2) years, the risk of MACE was progressively higher with the increasing numbers of SMuRFs (adjusted hazard ratio [HR] 95% confidence interval [CI] 4.09, 1.29 - 12.91; 4.28, 1.37 - 13.41; 5.82, 1.84 - 18.39; and 9.42, 2.77 - 32.08; for one, two, three, or four SMuRFs, respectively) by comparison with those who were SMuRF-less at recruitment. Participants with occlusive disease were significantly more likely to have a greater number of SMuRFs than those with aneurysmal disease. In a subanalysis, there was a significantly higher risk of MACE with three or four SMuRFs in participants presenting with either occlusive or aneurysmal disease compared with those who were SMuRF-less. Hypertension, diabetes, and smoking but not hypercholesterolaemia were independently associated with increased risk of MACE. CONCLUSION: Very few patients presenting with POAD had no SMuRFs. There was a progressive increase in the risk of MACE in relation to the number of SMuRFs identified at entry.

The performance of heparin modified poly(ε-caprolactone) small diameter tissue engineering vascular graft in canine-A long-term pilot experiment in vivo.

Long-term in vivo observation in large animal model is critical for evaluating the potential of small diameter tissue engineering vascular graft (SDTEVG) in clinical application, but is rarely reported. In this study, a SDTEVG is fabricated by the electrospinning of poly(ε-caprolactone) and subsequent heparin modification. SDTEVG is implanted into canine's abdominal aorta for 511 days in order to investigate its clinical feasibility. An active and robust remodeling process was characterized by a confluent endothelium, macrophage infiltrate, extracellular matrix deposition and remodeling on the explanted graft. The immunohistochemical and immunofluorescence analysis further exhibit the regeneration of endothelium and smooth muscle layer on tunica intima and tunica media, respectively. Thus, long-term follow-up reveals viable neovessel formation beyond graft degradation. Furthermore, the von Kossa staining exhibits no occurrence of calcification. However, although no TEVG failure or rupture happens during the follow-up, the aneurysm is found by both Doppler ultrasonic and gross observation. Consequently, as-prepared TEVG shows promising potential in vascular tissue engineering if it can be appropriately strengthened to prevent the occurrence of aneurysm.

Trombosis antenatal de aneurisma espontáneo de conducto arterial / Antenatal thrombosis of arterial ductus spontaneous aneurysm

Los aneurismas espontáneos del conducto arterial se detectan inusualmente de forma prenatal. Su incidencia varía entre 1,5 por ciento y 8 por ciento de los embarazos. Usualmente se solucionan espontáneamente; sin embargo, pueden presentarse complicaciones letales como trombosis, embolia y ruptura. Los casos fatales descritos son escasos, la mayoría después del nacimiento. El objetivo es presentar el reporte de autopsia de un mortinato cuya causa de muerte fue la trombosis de aneurisma del conducto arterial. La madre fue una primigesta de 22 años de edad, con embarazo de 40 semanas sin antecedentes de importancia, atendida en un hospital de tercer nivel de Bucaramanga, Santander. Le realizamos una cesárea emergente por perfil biofísico fetal alterado y bradicardia fetal. Se obtuvo un mortinato masculino sin esfuerzo respiratorio, hipotónico, cianótico, que no respondió a maniobras de reanimación. Los hallazgos de autopsia relevantes fueron: dilatación auricular derecha y dilatación preductal con trombosis del conducto cuya luz estaba completamente ocluida por un coágulo. Los aneurismas ductales prenatales son una entidad que merece más estudio para determinar estrategias de diagnóstico precoz y seguimiento, y así disminuir el riesgo de desenlaces fatales(AU)

Introduction: Spontaneous ductus arteriosus aneurysm is a condition rarely diagnosed on prenatal imaging. Literature reveals 1,5 to 8 percent incidence on pregnancies. Most cases have spontaneous resolution, nonetheless, life-threatening complications such thrombosis, embolism and rupture can occur. Fatal cases reports are scarce, most of them presenting on newborns, days to months after birth. Objective: To present the autopsy report of a stillbirth whose cause of death was thrombosis of the arterial duct aneurysm. Methods: A 22-year healthy prime mother with 40-week pregnancy was assisted at a tertiary hospital in Bucaramanga, Santander. She required emergency cesarean section due to low biophysical profile and fetal bradycardia. The newborn had no respiratory effort, was floppy, cyanotic and did not respond to resuscitation maneuvers. The relevant autopsy findings were right atrial dilatation and preductal dilation with thrombosis of the duct whose lumen was completely occluded by a clot. Conclusions: The prenatal ductal aneurysm is an entity that deserves more study to determine strategies for early diagnosis and follow-up thus decrease the risk of fatal outcomes(AU)

Association of statins with aortic, peripheral, and visceral artery aneurysm development.

Objectives Prior studies examining the effects of statins on arterial aneurysm development and progression yielded conflicting results due to their smaller size and presence of residual confounders. The objective of this study is to examine the association of statins with risk of being diagnosed with aortic, peripheral, and visceral artery aneurysm. Methods This was a retrospective cohort study of Tricare enrollees (from 1 October 2003 to 31 March 2012). Main outcomes were diagnosis of aortic, peripheral, or visceral artery aneurysm and undergoing aortic aneurysm repair procedure during follow-up period. Using 115 baseline characteristics, we generated a propensity score to match statin users and nonusers and examine the odds of outcomes (primary analysis). Secondary analysis examined outcomes at various subcohorts. Results Out of 10,910 statin users and 49,545 nonusers, we propensity score-matched 6728 pairs of statin users and nonusers. Statin users and nonusers had similar odds of being diagnosed with aortic, peripheral, and visceral artery aneurysms (odds ratio [OR]: 1.06, 95% confidence interval [95% CI]: 0.85-1.33) and of undergoing aortic aneurysm repair procedures (OR: 0.54, 95% CI: 0.22-1.35). Secondary analysis showed a tendency toward fewer aortic aneurysm procedures among statin users that did not reach statistical significance. However, high-intensity statin users in comparison to non-intensive statin users had higher adjusted odds of aortic, peripheral, and visceral artery aneurysms (OR: 1.76, 95% CI: 1.37-2.25, p < .0001). Conclusions This study does not support a clinically significant benefit or harm from statins regarding development of arterial aneurysm. However, secondary analyses may support the hypothesis proposed by previous research proposing a bidirectional role for statins.

Hyperglycemia Suppresses Calcium Phosphate-Induced Aneurysm Formation Through Inhibition of Macrophage Activation.

BACKGROUND: The aim of this study was to elucidate aspects of diabetes mellitus-induced suppression of aneurysm. We hypothesized that high glucose suppresses aneurysm by inhibiting macrophage activation via activation of Nr1h2 (also known as liver X receptor ß), recently characterized as a glucose-sensing nuclear receptor. METHODS AND RESULTS: Calcium phosphate (CaPO4)-induced aneurysm formation was significantly suppressed in the arterial wall in type 1 and 2 diabetic mice. A murine macrophage cell line, RAW264.7, was treated with tumor necrosis factor α (TNF-α) plus CaPO4 and showed a significant increase in matrix metalloproteinase 9 (Mmp9) mRNA and secreted protein expression compared with TNF-α alone. Elevated Mmp9 expression was significantly suppressed by hyperglycemic conditions (15.5 mmol/L glucose) compared with normoglycemic conditions (5.5 mmol/L glucose) or normoglycemic conditions with high osmotic pressure (5.5 mmol/L glucose +10.0 mmol/L mannitol). Nr1h2 mRNA and protein expression were suppressed by treatment with TNF-α plus CaPO4 but were restored by hyperglycemic conditions. Activation of Nr1h2 by the antagonist GW3965 during stimulation with TNF-α plus CaPO4 mimicked hyperglycemic conditions and inhibited Mmp9 upregulation, whereas the deactivation of Nr1h2 by small interfering RNA (siRNA) under hyperglycemic conditions canceled the suppressive effect and restored Mmp9 expression induced by TNF-α plus CaPO4. Moreover, Nr1h2 activation with GW3965 significantly suppressed CaPO4-induced aneurysm in mice compared with vehicle-injected control mice. CONCLUSIONS: Our results show that hyperglycemia suppresses macrophage activation and aneurysmal degeneration through the activation of Nr1h2. Although further validation of the underlying pathway is necessary, targeting Nr1h2 is a potential therapeutic approach to treating aneurysm.

Clinical Profile and Prognosis of Left Ventricular Apical Aneurysm in Hypertrophic Cardiomyopathy.

BACKGROUND: Hypertrophic cardiomyopathy with left ventricular apical aneurysm is a unique entity with diverse manifestations and varied prognoses among races. This study evaluated the prevalence, clinical characteristics and outcomes of apical aneurysm in Chinese patients with hypertrophic cardiomyopathy. METHODS: Consecutive patients with apical aneurysm were recruited from 1,844 patients with HCM treated at our hospital from 2002-2013. Basic clinical data and follow-up data were collected and analyzed. RESULTS: Apical aneurysm was identified in 24 patients (1.3%) (mean age: 52 ± 14 years). We identified an hourglass-shaped (71%) or distally hypertrophic (29%) left ventricle and found mural thrombi and nonsustained and sustained ventricular tachycardia in 11 (46%), 4 (17%) and 9 (38%) patients, respectively. During follow-up (5.0 ± 3.4 years [range: 1-14 years]), following were the clinical adverse events experienced by 14 patients (58%) (annual rate: 11.7%): sudden cardiac death (n = 4), appropriate discharge of an implantable cardioverter-defibrillator (n = 4), progressive heart failure (n = 4) or heart failure-related death (n = 1) and stroke (n = 4). The 4 patients who underwent aneurysmectomy had no adverse events. Patients with SCD had a lower ejection fraction (P = 0.004) and a larger left ventricular end-diastolic diameter (P < 0.001) than nonoperated survivors. CONCLUSIONS: Apical aneurysm is not rare in patients with HCM and it confers an extremely poor prognosis. Early aggressive therapies should be considered for this entity and prophylactic aneurysmectomy may be an option.

Pediatric Vasculitis.

Vasculitis is defined as inflammation of the blood vessels and can result in stenosis or aneurysm, which may in turn lead to occlusion or rupture of the vessel compromising tissue perfusion. The manifestations of these diseases depend on the size and site of the vessels effected. Vasculitis can be secondary to numerous inflammatory and infectious diseases but this review will concentrate on the systemic primary vasculitides and aims to discuss the presentations and approaches to management of a number of these conditions.

[INSULIN-LIKE GROWTH FACTOR 1 UNDER CONDITIONS OF THE BRAIN VASCULAR DISEASES.]

The system insulin-like growth factors (IGF) occupies an important place in the development and growth of the central nervous system (CNS). Gene expression of insulin-like growth factor I (IGF-1) and IGF-1 receptor are represented in all parts of the brain and are heavily concentrated in the cerebral vessels. IGF-1 is involved in neuro-, angiogenesis, in the stimulation of cell proliferation, and repair responses to damage for both the central and peripheral nervous system. IGF- 1 exerts antioxidant, anti-inflammatory and protective effects on the CNS. The review discusses the importance and the role of IGF-I in vascular diseases of the brain, in particular, aneurysms, the ischemic stroke, the aneurysmal subarachnoid hemorrhage, as well as neuroprotection.

Surgical strategy for Kommerell's diverticulum with aberrant subclavian artery.

BACKGROUND: Kommerell's diverticulum is an extremely rare congenital aortic anomaly. Because of its rarity, the optimal surgical strategy for Kommerell's diverticulum has not been established. In this study, we reviewed our experience of surgical correction of this anomaly. METHODS: Between 2007 and 2013, we managed 9 surgical cases of Kommerell's diverticulum; 7 had a right aortic arch with an aberrant left subclavian artery, and 2 had a left aortic arch with an aberrant right subclavian artery. None of these patients had any symptom resulting from structural compression between the aneurysm and the aberrant subclavian artery. All patients underwent surgical treatment to prevent aneurysmal rupture. Six patients had replacement of the thoracic descending aorta and in-situ reconstruction of the aberrant subclavian artery through a right thoracotomy, and 3 underwent the same procedures through a left thoracotomy. Three different methods of extracorporeal circulation were applied, according to the anatomical features of each case. RESULTS: There was one hospital death. This patient developed severe cerebral infarction and died of multiple organ failure on the 65th postoperative day. There were no other major complications nor any need for rehospitalization. CONCLUSION: Kommerell's diverticulum should be treated using an optimal strategy based on each patient's anatomical features and other characteristics.

Early and late complications of endoscopic hemostatic techniques following different carotid artery injury characteristics.

BACKGROUND: The most dreaded hemorrhagic complication in endoscopic endonasal surgery is injury to the internal carotid artery (ICA). Although a number of treatment protocols are currently used, none have been formally investigated. This study aims to compare the efficacy of the muscle patch, bipolar diathermy, and aneurysm clip on hemostasis, pseudoaneurysm formation, and long-term vessel patency for different injury types in a sheep model of carotid bleeding. METHODS: Twenty-seven sheep underwent ICA dissection/isolation followed by the artery placement within a modified "sinus model otorhino neuro trainer" (SIMONT) model. Standardized linear, punch, and stellate injuries were made. Randomization of sheep to receive 1 of 3 hemostatic techniques was performed (muscle, bipolar, clip). Specific outcome measures included attainment of primary hemostasis, time to hemostasis, blood loss, pseudoaneurysm formation, and carotid patency on follow-up magnetic resonance imaging (MRI). RESULTS: Bipolar achieved primary hemostasis in 7 of 9 cases and 2 cases of secondary hemorrhage. It had no associated pseudoaneurysm formation. Carotid patency was variable on follow-up MRI. Muscle patch achieved 100% primary hemostasis with 2 cases of secondary hemorrhage. There were 2 cases of pseudoaneurysm and 100% patency rate on follow-up MRI. Aneurysm clip achieved 100% primary hemostasis with 1 case of secondary hemorrhage. No pseudoaneurysm formation and a 50% rate of carotid insufficiency on MRI. CONCLUSION: This study shows that the crushed muscle patch and aneurysm clip can be viable options in the management of ICA injury with short-term and long-term benefits. Complications associated with these techniques were comparable if not reduced when compared to the published literature.

Low-density lipoprotein receptor-related protein-1: role in the regulation of vascular integrity.

Low-density lipoprotein receptor-related protein-1 (LRP1) is a large endocytic and signaling receptor that is widely expressed. In the liver, LRP1 plays an important role in regulating the plasma levels of blood coagulation factor VIII (fVIII) by mediating its uptake and subsequent degradation. fVIII is a key plasma protein that is deficient in hemophilia A and circulates in complex with von Willebrand factor. Because von Willebrand factor blocks binding of fVIII to LRP1, questions remain on the molecular mechanisms by which LRP1 removes fVIII from the circulation. LRP1 also regulates cell surface levels of tissue factor, a component of the extrinsic blood coagulation pathway. This occurs when tissue factor pathway inhibitor bridges the fVII/tissue factor complex to LRP1, resulting in rapid LRP1-mediated internalization and downregulation of coagulant activity. In the vasculature LRP1 also plays protective role from the development of aneurysms. Mice in which the lrp1 gene is selectively deleted in vascular smooth muscle cells develop a phenotype similar to the progression of aneurysm formation in human patient, revealing that these mice are ideal for investigating molecular mechanisms associated with aneurysm formation. Studies suggest that LRP1 protects against elastin fiber fragmentation by reducing excess protease activity in the vessel wall. These proteases include high-temperature requirement factor A1, matrix metalloproteinase 2, matrix metalloproteinase-9, and membrane associated type 1-matrix metalloproteinase. In addition, LRP1 regulates matrix deposition, in part, by modulating levels of connective tissue growth factor. Defining pathways modulated by LRP1 that lead to aneurysm formation and defining its role in thrombosis may allow for more effective intervention in patients.

Lack of aneurysm formation after carotid artery ligation in rabbits: a polymer MICROFIL® study.

INTRODUCTION: Previous studies have noted formation of saccular aneurysms along the distal basilar artery/P1 segments after carotid ligation in rabbits. In this prospective study we employed MICROFIL®, a polymer, which was used to fill the entire arterial tree, to examine the incidence of microaneurysm formation following right common carotid artery (RCCA) ligation in rabbits. METHODS: RCCA ligation was performed in 18 New Zealand White rabbits for 0 day (n = 2), 3 weeks (n = 6), or 16 weeks (n = 10). Three control rabbits without carotid surgery were sacrificed at 4 weeks. At the time of sacrifice, MICROFIL® MV-122 yellow was injected through left CCA to fill cerebral vasculature. After gross photographs were taken, specimens were embedded, sectioned, and stained for histopathological evaluation. Tissue and sections were carefully evaluated for microaneurysm formation, defined as a localized dilatation of the vessel wall, associated with fragmentation or complete loss of the internal elastic lamina (IEL), and/or medial degeneration. RESULTS: Gross examination with MICROFIL® opacification demonstrated no evidence of saccular aneurysm formation, but prominent perforating vessels were present in all 19 cases at, or adjacent to, the basilar terminus. Branches noted upon gross examination corresponded histologically to small, saccular contour defects, which demonstrated apparent loss of the IEL and apparent medial thinning. These observations, however, were a consequence of sectioning through the bases of perforating arteries, which simulated microaneurysm formation. CONCLUSIONS: Unilateral carotid ligation does not induce microaneurysm formation at the basilar terminus in rabbits. Prominent perforating arteries as well as tissue injury from the processing may simulate "aneurysms" histologically.

Dificultad diagnóstica en la enfermedad de Kawasaki incompleta / Diagnostic difficulty in incomplete Kawasaki disease

El manejo de los pacientes con sospecha de enfermedad de Kawasaki incompleta es difícil. La ausencia de marcadores específicos de la enfermedad y la similitud con otros procesos infecciosos mucho más frecuentes pueden conducir a un retraso en el diagnóstico. Es importante mantener un alto índice de sospecha para poder iniciar el tratamiento con inmunoglobulina precozmente y prevenir la afectación coronaria. Las recomendaciones de la Academia Americana de Pediatría y la Asociación Americana del Corazón son una guía útil para mejorar el rendimiento diagnóstico en estos casos. En el siguiente caso clínico exponemos una EK incompleta y se discuten las bases para el diagnóstico (AU)

The management of patients with suspicion of incomplete Kawasaki disease is difficult. The absence of specific markers of the disease and its similarity to other much more frequent infectious processes may lead to a delay in its diagnosis. It is important to maintain a high index of suspicion to be able to initiate immunoglobin treatment early and to prevent coronary involvement. The recommendations of the American Academy of Pediatrics and the American Heart Association are a useful guide to improve the diagnostic yield in these cases. We present an incomplete Kawasaki disease in the following clinical case and discuss the bases for its diagnosis (AU)

Circulating interferon-γ-inducible Cys-X-Cys chemokine receptor 3 ligands are elevated in humans with aortic aneurysms and Cys-X-Cys chemokine receptor 3 is necessary for aneurysm formation in mice.

OBJECTIVE: Inflammation is associated with the formation of aortic aneurysm. This study investigates the role of inducible Cys-X-Cys chemokine receptor 3 and its ligands in the pathogenesis of arterial aneurysms. METHODS: Plasma samples from patients with or without a diagnosis of thoracic aortic aneurysms were analyzed by enzyme-linked immunosorbent assay for the T-helper 1 cytokine interferon-γ and the interferon-γ-inducible chemokine receptor 3 ligands: interferon-inducible protein-10, interferon-inducible T-cell alpha chemoattractant, and monokine induced by interferon gamma. Patient charts were reviewed for demographics, initial aortic diameter, and growth rates. Aneurysm diameter and growth rates were correlated with plasma cytokine and chemokine levels using linear regression analysis. We used an animal model of aneurysm formation, where calcium chloride is applied topically to the carotid arteries of wild-type and Cys-X-Cys chemokine receptor 3(-/-) mice. After 10 weeks, the arteries were harvested and analyzed by histology and immunohistochemistry. RESULTS: Patients with thoracic aortic aneurysms had significant elevations in circulating interferon-γ, interferon-inducible protein-10, interferon-inducible T-cell alpha chemoattractant, and monokine induced by interferon gamma compared with referent patients (P < .001). Cytokine and chemokine plasma levels did not correlate with aneurysm size or growth rates. Cys-X-Cys chemokine receptor 3(-/-) mice were protected from aneurysm formation and showed decreased vascular infiltration by CD45(+) leukocytes. CONCLUSIONS: Elevated plasma levels of interferon-γ and Cys-X-Cys chemokine receptor 3-binding chemokines are present in patients with thoracic aortic aneurysms. The Cys-X-Cys chemokine receptor 3 receptor is necessary for vascular inflammation and the formation of arterial aneurysms in mice.

The effect of the buttonhole method vs. the traditional method of AV fistula cannulation on hemostasis, needle stick pain, pre-needle stick anxiety, and presence of aneurysms in ambulatory patients on hemodialysis.

The purpose of this study was to compare the effect of the buttonhole method to the traditional method of cannulation on time to hemostasis, needle stick pain, pre-needle stick anxiety, and aneurysm size. Forty-five participants from two naturally occurring groups were accessed at four monthly intervals from a chronic dialysis unit yielding 170 units of data. Results supported the buttonhole method of cannulation as advantageous as opposed to the traditional method of AV fistula cannulation.

Tratamento endovascular de aneurismas cirsoideos do couro cabeludo / Endovascular treatment of scalp cirsoid aneurysms

OBJETIVO: Relatar os resultados da aplicação de técnicas endovasculares no tratamento de aneurismas cirsoideos do couro cabeludo. MATERIAIS E MÉTODOS: Quatro pacientes com diagnóstico de aneurismas cirsoideos foram submetidos ao tratamento por via endovascular. Todos os quatro pacientes incluídos nesta série tinham malformações arteriovenosas e foram tratados apenas com embolização. RESULTADOS: Três pacientes foram submetidos a tratamento endovascular mediante embolização transarterial e um foi tratado por punção direta da porção venosa. Os resultados clínicos e cosméticos foram satisfatórios em todos os pacientes. Não houve recidiva clínica durante o período de acompanhamento. CONCLUSÃO: A via endovascular é uma alternativa segura e eficaz no tratamento dos aneurismas cirsoideos. Embora possa ser efetivamente utilizado como uma alternativa adjuvante ou complementar à cirurgia, especialmente quando é necessário lidar com aferências profundas, a maioria dos casos pode ser totalmente curada apenas com a terapêutica endovascular. A escolha do método de tratamento deve ser baseada em uma variedade de características próprias da lesão, incluindo sua angioarquitetura, tamanho e apresentação clínica.

OBJECTIVE: To report results of the application of endovascular techniques in the management of scalp cirsoid aneurysms. MATERIALS AND METHODS: Four patients diagnosed with cirsoid aneurysms were submitted to treatment by endovascular approach. All the four patients included in the present series had arteriovenous malformations and were treated solely by embolization. RESULTS: Three of the patients underwent endovascular treatment by transarterial embolization and one was treated by direct puncture of the venous segment. Both clinical and cosmetic outcomes were satisfactory in all of the patients. Clinical relapse was not observed along the follow-up period. CONCLUSION: The endovascular approach is safe and effective in the management of crisoid aneurysms. Although this technique can be used as an adjuvant or complement to surgery, particularly in cases where deep afferents are involved, complete resolution can be achieved only with endovascular treatment. The choice of treatment method should be based on a range of typical characteristics of the lesion, including angioarchitecture, size and clinical presentation.

[The peculiarities of formation repetitive AV-fistula].

The issues concerning the formation of an arteriovenous fistula (AV-fistula) remain to be one of the most important in modern vascular surgery and nephrology. 193 surgically treated patients in the terminal stage of chronic renal insufficiency have been analyzed and examined. 136 operations and 57 repeated procedures of surgical correction of vascular access or formation of new access were performed. The conical vascular prosthesis (diameter 4-6 mm and 5-7 mm; length - 40 cm and 60) for appropriate hemodialysis is recommended. In case of failure of vascular access for hemodialysis PTFE vascular access grafts as the most suitable are recommended.