Collagen-Sealed Polyester Vascular Prostheses Functionalized by Polycatecholamine Coatings.

Collagen-sealed polyester (PET) prostheses are commonly used in reconstructive vascular surgery due to their self-sealing properties. To prevent post-surgical infection, different modification methods have been tested but so far none have showed long-term satisfactory efficiency. For this reason, in the present study, a commercial collagen-sealed PET prosthesis was coated by a highly adhesive poly (L-DOPA) layer maintaining the sealing protein without losing the original properties and functionality. This modified (as proven by SEM, FTIR, XPS and contact angle) graft exhibited comparable wettability and elasticity as pristine commercial graft, as well as reduced hemolysis-inducing effect, lowered toxicity against human endothelial cells and reduced toxicity in Danio rerio model. Poly (L-DOPA)-coated grafts were shown to bind six times more aminoglycoside antibiotic (gentamicin) than pristine graft. Poly (L-DOPA)-coated antibiotic-bound prostheses exhibited an improved antibacterial activity (bacterial growth inhibition and anti-adhesive capacity) in comparison with pristine antibiotic-bound graft. Overall, poly (L-DOPA)-coatings deposited on PET vascular grafts can effectively functionalize collagen-sealed prostheses without the loss of protein sealing layer and allow for antibiotics incorporation to provide higher safety in biomedical applications.

Arterial reconstruction with human bioengineered acellular blood vessels in patients with peripheral arterial disease.

OBJECTIVE: Vascular conduit is essential for arterial reconstruction for a number of conditions, including trauma and atherosclerotic occlusive disease. We have developed a tissue-engineered human acellular vessel (HAV) that can be manufactured, stored on site at hospitals, and be immediately available for arterial vascular reconstruction. Although the HAV is acellular when implanted, extensive preclinical and clinical testing has demonstrated that the HAV subsequently repopulates with the recipient's own vascular cells. We report a first-in-man clinical experience using the HAV for arterial reconstruction in patients with symptomatic peripheral arterial disease. METHODS: HAVs were manufactured using human vascular smooth muscle cells grown on a biodegradable scaffold. After the establishment of adequate cell growth and extracellular matrix deposition, the vessels were decellularized to remove human cellular antigens. Manufactured vessels were implanted in 20 patients with symptomatic peripheral arterial disease as above-knee, femoral-to-popliteal arterial bypass conduits. After HAV implantation, all patients were assessed for safety, HAV durability, freedom from conduit infection, and bypass patency for 2 years. RESULTS: Twenty HAVs were placed in the arterial, above-knee, femoral-to-popliteal position in patients with rest pain (n = 3) or symptomatic claudication (n = 17). All HAVs functioned as intended and had no evidence of structural failure or rejection by the recipient. No acute HAV infections were reported, but three surgical site infections were documented during the study period. Three non-HAV-related deaths were reported. One vessel developed a pseudoaneurysm after suspected iatrogenic injury during a balloon thrombectomy. No amputations of the HAV implanted limb occurred over the 2-year period, and no HAV infections were reported in approximately 34 patient-years of continuous patient follow-up. CONCLUSIONS: Human tissue engineered blood vessels can be manufactured and readily available for peripheral arterial bypass surgery. Early clinical experience with these vessels, in the arterial position, suggest that they are safe, have acceptable patency, a low incidence of infection, and do not require the harvest of autologous vein or any cells from the recipient. Histologic examination of tissue biopsies revealed vascular remodeling and repopulation by host cells. This first-in-man arterial bypass study supports the continued development of human tissue engineered blood vessels for arterial reconstruction, and potential future expansion to clinical indications including vascular trauma and repair of other size-appropriate peripheral arteries.

Replacement of infected aortoiliac vascular grafts with bifurcated BioIntegral Surgical No-React® bovine pericardial xenografts.

The infection of a vascular prosthesis is potentially fatal, and its effective treatment still remains the greatest challenge for vascular surgeons. We present our initial experience using bovine pericardial vascular prostheses to replace infected aortoiliac vascular grafts. Six consecutive patients with infection of the graft were prospectively included in this study. Infection of the vascular graft was confirmed by clinical symptoms, laboratory tests and the results of computed tomography and positron emission tomography/computed tomography. In all cases, the infected aortoiliac graft was surgically removed and replaced by the bovine-pericardial BioIntegral aortic-bifemoral prosthesis. Technical success was achieved in every case with no in-hospital or 30 days mortality. One patient required revision of distal anastomosis due to recurrent bleeding at day four after surgery. One patient presented with upper gastrointestinal tract bleeding during the postoperative period, which was managed endoscopically. The mean hospital stay was 14 days (range 9-19). The control CT scan performed 2 months after surgery showed significant regression of abscesses and periprosthetic inflammation. Two patients died within 32 months of follow-up: one due to heart attack, the other due to generalized sepsis, which was correlated with the previous infection. Four patients are still in follow-up. The BioIntegral prosthesis is patent in all four cases, with no clinical or ultrasonographic signs of infection. Our brief investigation shows that a bovine pericardial prosthesis may be a valuable option in the treatment of vascular grafts infections.

Bioengineered human acellular vessels for dialysis access in patients with end-stage renal disease: two phase 2 single-arm trials.

BACKGROUND: For patients with end-stage renal disease who are not candidates for fistula, dialysis access grafts are the best option for chronic haemodialysis. However, polytetrafluoroethylene arteriovenous grafts are prone to thrombosis, infection, and intimal hyperplasia at the venous anastomosis. We developed and tested a bioengineered human acellular vessel as a potential solution to these limitations in dialysis access. METHODS: We did two single-arm phase 2 trials at six centres in the USA and Poland. We enrolled adults with end-stage renal disease. A novel bioengineered human acellular vessel was implanted into the arms of patients for haemodialysis access. Primary endpoints were safety (freedom from immune response or infection, aneurysm, or mechanical failure, and incidence of adverse events), and efficacy as assessed by primary, primary assisted, and secondary patencies at 6 months. All patients were followed up for at least 1 year, or had a censoring event. These trials are registered with ClinicalTrials.gov, NCT01744418 and NCT01840956. FINDINGS: Human acellular vessels were implanted into 60 patients. Mean follow-up was 16 months (SD 7·6). One vessel became infected during 82 patient-years of follow-up. The vessels had no dilatation and rarely had post-cannulation bleeding. At 6 months, 63% (95% CI 47-72) of patients had primary patency, 73% (57-81) had primary assisted patency, and 97% (85-98) had secondary patency, with most loss of primary patency because of thrombosis. At 12 months, 28% (17-40) had primary patency, 38% (26-51) had primary assisted patency, and 89% (74-93) had secondary patency. INTERPRETATION: Bioengineered human acellular vessels seem to provide safe and functional haemodialysis access, and warrant further study in randomised controlled trials. FUNDING: Humacyte and US National Institutes of Health.

Serum Neuron-Specific Enolase as a Marker of Brain Ischemia-Reperfusion Injury in Patients Undergoing Carotid Endarterectomy

In patients with atherosclerotic stenosis of the extracranial segment of internal carotid artery, surgical intervention is an effective method to prevent cerebral ischemic stroke. However, this surgical procedure may cause vascular brain damage. The aim of the study was to investigate consequential brain ischemia-reperfusion injury by measuring the cerebral specific marker, neuron-specific (NSE), in serum of patients having undergone internal carotid endarterectomy (CEA). The study involved 25 patients that underwent CEA due to internal carotid artery stenosis. Blood samples were obtained from each patient on three occasions: within 24 h prior to surgery, 12 h after surgery, and 48 h after surgery. Serum NSE levels were measured by a commercially available enzyme-linked immunosorbent assay. The study showed that serum NSE level was statistically significantly increased 48 h after CEA as compared with the level 12 h after surgery and the level before surgery (p<0.05). Difference in serum NSE between the level before surgery and 12 h after CEA was not statistically significant (p>0.05). Data from our study showed CEA to affect serum NSE in patients with significant internal carotid artery stenosis. Thus, serum NSE may be used as a biochemical marker of brain ischemia-reperfusion injury following CEA.

Axial splitting of the medial antebrachial cutaneous nerve facilitates second-stage elevation of basilic or brachial vein in patients with arteriovenous fistula.

We describe a novel surgical technique to facilitate the second-stage elevation of the basilic or brachial vein in patients with first-stage brachial-basilic or autogenous brachial-brachial arteriovenous fistula by axial splitting of the medial antebrachial cutaneous nerve (MABCN). Filaments of the MABCN typically traverse the anterior aspect of the basilic and brachial veins. The second-stage elevation/shelf superficialization of the basilic or brachial vein, so as not to cause an injury to the MABCN, requires division of these veins with transposition over the nerve branches and subsequent reanastomosis. Our method of axial splitting of the MABCN enables elevation and shelf superficialization of the basilic or brachial vein without the division and reanastomosis of the vein. Twenty-eight patients underwent this simplified elevation. The nerve perineurium was incised longitudinally, nerve fibers were divided intrafascicularly, and cutaneous nerve branches were retracted aside. The vein was elevated between the divided nerves. On discharge and at 1-month follow-up, only one patient complained of localized patch hypoesthesia as reported in a simplified neurologic assessment questionnaire and neurologic examination.

Carotid surgery affects plasma kynurenic acid concentration: a pilot study.

BACKGROUND: An increase in plasma kynurenic acid (KYNA) concentration has been observed following surgery, inflammation, and cerebral pathologies. The aim of the present study was to analyze the changes in plasma KYNA concentration in patients undergoing carotid surgery (CS). MATERIAL AND METHODS: Adult patients undergoing elective carotid endarterectomy (CEA) or carotid angioplasty with stent placement (CAS) were studied. Plasma KYNA concentrations were analyzed before surgery and at 4 time points after CS. The amount of inflammation was measured as neutrophil-lymphocyte ratio (NLR). RESULTS: Forty patients (10 female and 30 male) aged 55-86 years of age were evaluated in this study. In patients with unstable carotid plaque, the plasma KYNA concentration was higher than in patients with stable carotid plaque. Moreover, the NLR was significantly higher in patients with unstable carotid plaque undergoing CEA than in patients undergoing CAS. Plasma KYNA concentration increased after surgery in patients undergoing CEA and CAS. There was a strong correlation between plasma KYNA concentration and NLR in patients with postoperative neurological disorders. CONCLUSIONS: CS increases plasma KYNA concentration, and changes in plasma KYNA concentration can indicate neurologic outcomes in patients undergoing CS.

Six-year outcomes of a phase II study of human-tissue engineered blood vessels for peripheral arterial bypass.

Objective: The human acellular vessel (HAV) was evaluated for surgical bypass in a phase II study. The primary results at 24 months after implantation have been reported, and the patients will be evaluated for ≤10 years. Methods: In the present report, we have described the 6-year results of a prospective, open-label, single-treatment arm, multicenter study. Patients with advanced peripheral artery disease (PAD) requiring above-the-knee femoropopliteal bypass surgery without available autologous graft options had undergone implantation with the HAV, a bioengineered human tissue replacement blood vessel. The patients who completed the 24-month primary portion of the study will be evaluated for ≤10 years after implantation. The present mid-term analysis was performed at the 6-year milestone (72 months) for patients followed up for 24 to 72 months. Results: HAVs were implanted in 20 patients at three sites in Poland. Seven patients had discontinued the study before completing the 2-year portion of the study: four after graft occlusion had occurred and three who had died of causes deemed unrelated to the conduit, with the HAV reported as functional at their last visit. The primary results at 24 months showed primary, primary assisted, and secondary patency rates of 58%, 58%, and 74%, respectively. One vessel had developed a pseudoaneurysm deemed possibly iatrogenic; no other signs of structural failure were reported. No rejections or infections of the HAV occurred, and no patient had required amputation of the implanted limb. Of the 20 patients, 13 had completed the primary portion of the study; however, 1 patient had died shortly after 24 months. Of the remaining 12 patients, 3 died of causes unrelated to the HAV. One patient had required thrombectomy twice, with secondary patency achieved. No other interventions were recorded between 24 and 72 months. At 72 months, five patients had a patent HAV, including four patients with primary patency. For the entire study population from day 1 to month 72, the overall primary, primary assisted, and secondary patency rate estimated using Kaplan-Meier analysis was 44%, 45%, and 60% respectively, with censoring for death. No patient had experienced rejection or infection of the HAV, and no patient had required amputation of the implanted limb. Conclusions: The infection-resistant, off-the-shelf HAV could provide a durable alternative conduit in the arterial circuit setting to restore the lower extremity blood supply in patients with PAD, with remodeling into the recipient's own vessel over time. The HAV is currently being evaluated in seven clinical trials to treat PAD, vascular trauma, and as a hemodialysis access conduit.

Effect of Reconstructive Procedures of the Extracranial Segment of the Carotid Arteries on Damage to the Blood-Brain Barrier.

INTRODUCTION: Endarterectomy and angioplasty of the internal carotid artery are surgical measures for the prevention of ischemic stroke. Perioperative complications are caused by concomitant embolism and reperfusion syndrome leading to damage of the blood-brain barrier. METHODS: The study included 88 patients divided into two groups, depending on the surgical technique used: internal carotid artery endarterectomy (CEA), 66 patients, and percutaneous carotid angioplasty and stenting (CAS), 22 patients. Blood was drawn 24 h before surgery, as well as 8, 24, and 48 h post-surgery. The assessment of damage to the blood-brain barrier was based on the evaluation of the concentration of claudin-1 and occludin, aquaporin-4, the measurements of the activity of metalloproteinase-2 (MMP-2) and -9 (MMP-9), and the assessment of central nervous system damage, measured by changes in the blood S100ß protein concentration. RESULTS: A significant increase in the concentration of the blood-brain barrier damage markers and increased MMP-2 and MMP-9 activity were found in patient blood. The degree of damage to the blood-brain barrier was higher in the CEA group. CONCLUSIONS: The authors' own research has indicated that revascularization of the internal carotid artery may lead to damage to the central nervous system secondary to damage to the blood-brain barrier.

Five Year Outcomes in Patients with End Stage Renal Disease Who Received a Bioengineered Human Acellular Vessel for Dialysis Access.

OBJECTIVE: Patients with end stage renal failure who require haemodialysis suffer morbidity and mortality due to vascular access. Bioengineered human acellular vessels (HAVs) may provide a haemodialysis access option with fewer complications than other grafts. In a prospective phase II trial from 2012 to 2014 (NCT01744418), HAVs were implanted into 40 haemodialysis patients at three sites in Poland. The trial protocol for this "first in man" use of the HAV contemplated only two years of follow up, and the trial results were initially reported in 2016. In light of the retained HAV function seen in many of the patients at the two year time point, follow up for patients who were still alive was extended to a total of 10 years. This interim follow up report, at the long term time point of five years, assessed patient and conduit status in those who continued routine dialysis with the HAV. METHODS: HAVs are bioengineered by culturing human vascular smooth muscle cells on a biodegradable polymer matrix. In this study, patients with patent HAV implants at 24 months were followed every three months, starting at month 27 through to month 60, or at least five years post-implantation. This report contains the follow up functional and histological data on 29 of the original 40 patients who demonstrated HAV function at the 24 month time point. RESULTS: Eleven patients completed at month 60. One patient maintained primary patency, and 10 maintained secondary patency. Secondary patency was estimated at 58.2% (95% confidence interval 39.2-73.1) at five years, after censoring for deaths (n = 8) and withdrawals (n = 1). No HAV conduit infections were reported during the follow up period. CONCLUSION: This phase II long term follow up shows that the human acellular vessel (HAV) may provide durable and functional haemodialysis access for patients with end stage renal disease.

Polycatecholamine and gentamicin as modifiers for antibacterial and blood-biocompatible polyester vascular prostheses.

Polyester (PET) prostheses are commonly used in reconstructive vascular surgery. The most serious complication after implantation is early or late infection of the graft. Therefore, there is high demand to protect prosthesis against bacterial adhesion and biofilm development. For this reason, in this work PET prostheses were first coated by highly adhesive polycatecholamine layer. The grafts were then coupled with gentamicin and studied in relation to morphological and structural properties, biological safety (contact with blood, reaction of vascular endothelial cells (HUVEC), Danio rerio fish), drug release and antibacterial activity. Among two tested catecholamine monomers, L-DOPA was found to be more effective precursor in this process than dopamine. For L-DOPA, assistance of Cu2+, Mg2+ and Na+ ions seems to increase the amount of further immobilized drug. Coated prostheses exhibited greater human endothelial cell proliferation increase and lower cytotoxic effect than uncoated. The modification reduced the hemolysis observed for pristine commercial graft and limited the rate of abnormalities in D. rerio larvae, confirming the safety of the proposed modification. The coating allowed to double the amount of immobilized antibiotic in comparison with uncoated graft which resulted in increased antibacterial activity and reduced bacterial adhesion against 4 bacterial strains prevalent in biomaterials infections. Overall, poly(L-DOPA)-coatings deposited on PET vascular grafts can effectively functionalize these prostheses for higher safety in biomedical applications.

Klippel-Trenaunay Syndrome: Employment of a New Endovascular Treatment Technique-Mechanochemical Ablation Using the Flebogrif System.

BACKGROUND: Klippel-Trenaunay syndrome (KTS) is characterized by a triad of symptoms; varicose veins and venous malformations (VMs), capillary malformations (port-wine stain), and soft tissue and bone hypertrophy. Herein, we retrospectively studied six patients with KTS who underwent treatment with the Flebogrif system and evaluated their outcomes. METHODS: Six KTS patients aged 16-22 years who had undergone 18 non-thermal ablations using the Flebogrif system were enrolled. All patients underwent multistage foam sclerotherapy with 3% polidocanol at 3-4-week intervals. RESULTS: Venous clinical severity score (VCSS) analysis showed improvement in the patients' clinical condition. All patients reported a significant improvement in aesthetic outcomes. One patient presented with recanalization of ablated marginal veins during the 24-month follow-up period. Patients could return to full activity within 7-10 days after the procedure. None of the patients experienced serious systemic complications. CONCLUSION: The use of the Flebogrif system in treating various forms of chronic venous insufficiency, including in patients with KTS, provides a high success rate with a high closure rate.

[The role of matrix metalloproteinases and their tissue inhibitors in angiogenesis]. / Rola metaloproteaz macierzy i ich tkankowych inhibitorów w angiogenezie.

Cellular aspect of angiogenesis - the multilevel process involving the growth of new blood vessels from pre-existing vessels--includes migration and proliferation of the cells as well as remodelling of their environment--extracellular matrix (ECM). The key role in ECM remodelling is played by proteolytic enzymes classified as matrix metalloproteinases (MMPs). Recent research shows that performed by MMPs degradation of vascular ECM components is a significant event ocurring during angiogenesis. This process enables migration of endothelial cells that is crucial part in new vessel formation. MMPs also release sequestered angiogenic molecules, such as VEGF, bFGF and TGF-beta. Angiogenesis is a normal process in growth and development, as well as in wound healing, monthly reproductive cycle and during pregnancy. However, this is also a fundamental step in such conditions as malignancies, inflammation or ischaemia. The influence of MMPs on agiogenesis as terminal agents in many physio- and pathological events makes this group of enzymes very promissing aim of new therapeutic strategies based on modulation of angiogenesis.

Endovenous laser ablation is an effective treatment for great saphenous vein incompetence in teenagers.

OBJECTIVES: The current knowledge of chronic venous disease in teenagers and its treatment is very limited. The aim of the study is to present our experience and the available literature data on the treatment of varicose veins in teenagers with endovenous laser ablation of the great saphenous vein. METHODS: Five patients, aged 15-17 years, were qualified for surgery, based on typical signs and symptoms of chronic venous disease. Minimally invasive treatment with endovenous laser ablation of the great saphenous vein was applied. RESULTS: The technical success of surgery was achieved in all patients. Over a 2-year follow-up we did not observe any case of recanalisation of the great saphenous vein, recurrence of varicose veins, or serious complications, such as deep vein thrombosis or pulmonary embolism. One patient presented with resolving of post-operative bruising, and two cases of local numbness were transient. CONCLUSIONS: Endovenous laser ablation of the great saphenous vein in the treatment of chronic venous disease in teenagers is effective and safe. The method provides excellent cosmetic effects, very short recovery time and high levels of patient satisfaction.

Syndecan-4 Is an Independent Predictor of All-Cause as Well as Cardiovascular Mortality in Hemodialysis Patients.

BACKGROUND: Left ventricular hypertrophy is associated withincreased mortality in hemodialysis (HD) patients.Syndecan-4 plays a role in many processes that are involved in the heart fibrosis and hypertrophy.We designed this study to prospectively determine whether syndecan-4 was predictive of mortality in a group of HD patients. METHODS: In total, 191 HD patients were included. Clinical, biochemical and echocardiographic parameters were recorded. HD patients were followed-up for 23.18 ± 4.02 months. RESULTS: Syndecan-4 levels correlated strongly with geometrical echocardiographic parameters and ejection fraction. Relations with pressure-related parameters were weak and only marginally significant. Using the receiver operating characteristics the optimal cut-off points in predicting all-cause as well as cardiovascular (CV) mortality were evaluated and patients were divided into low and high syndecan-4 groups. A Kaplan-Meier analysis showed that the cumulative incidences of all-cause as well as CV mortality were higher in high serum syndecan-4 group compared with those with low serum syndecan-4 (p<0.001 in both cases).A multivariate Cox proportional hazards regression analysis revealed syndecan-4 concentration to be an independent and significant predictor of all-cause (hazard ratio, 2.99; confidence interval, 2.34 to 3.113; p<0.001)as well as CV mortality (hazard ratio, 2.81;confidence interval, 2.28to3.02; p<0.001). CONCLUSIONS: Serum syndecan-4 concentration reflects predominantly geometrical echocardiographic parameters. In HD patients serum syndecan-4 concentration is independently associated with all-cause as well as CV mortality.

[The role of matrix metalloproteinases in venous leg ulcers development]. / Rola metaloproteaz macierzy w powstawaniu owrzodzen zylnych goleni.

Venous leg ulcers are one of the most serious therapeutic and economic problems of current medicine. In spite of the rapid progress in the diagnostics of venous disorders, the pathogenesis of venous leg ulcers remains unclear. Current medicine describes many theories that try to explain the patophysiology of venous ulceration. Recent studies have revealed the role of extracellular matrix degradation processes in venous leg ulcers. The family of enzymes classified as matrix metalloproteinases (MMPs) play the leading role in these processes. The extensive knowledge of MMPs and the role played by them in venous leg ulcers and wound healing may result in development of the new methods of management with many vascular disorders.

Superficialization of segmentally matured brachial vein complex as the last possible native, upper arm vascular access for hemodialysis.

PURPOSE: We present a case report on superficialization of the segmentally matured brachial vein complex as the last possible native vascular access for hemodialysis in the upper arm. METHODS: A 57-year-old, female patient was hemodialysed for 14 years. Due to multiple failures of her previous forearm and upper arm vascular access for hemodialysis, the last attempt at the creation of upper arm native vascular access was planned in terms of the formation of a two-stage autogenous brachial-brachial arterio-venous fistula (ABBA). The second stage exposure of the brachial vein - 4 weeks after anastomosis with the brachial artery showed an unusual intraoperative situation. Segmental maturation of both brachial veins, connected by a bridging vein was encountered. Both the mature segments of the brachial veins, connected by the bridging vein were elevated/superficialized into a subcutaneous bed. Immature parts of brachial veins were left near their anatomical position. RESULTS: Superficialized venous conduit was easily accessible and provided adequate parameters of uncomplicated hemodialysis for 6 months. In month 7, thrombosis of the fistula caused by an embolus due to an atrial fibrillation episode required thrombo-embolectomy. The fistula is still in use 13 months after its creation. CONCLUSIONS: Our technique is feasible in cases of unusual, segmental maturation of both brachial veins during two-stage ABBA formation. Selective superficialization of matured segments only may provide suitable access for hemodialysis. Vascular access surgeons should be aware of possible anatomical variations and be prepared to perform unusual access configurations as dictated by the local anatomy.

New method of forced implantation of permanent catheters for hemodialysis into critically stenosed or occluded central veins.

UNLABELLED: The aim of the study was to report a novel technique of forced implantation of catheters for hemodialysis into critically stenosed or occluded central veins, without preceding angioplasty or stenting. MATERIAL AND METHODS: Sixteen patients with central venous occlusive disease, requiring urgent hemodialysis underwent this procedure. Catheterization of stenosis - occlusion was initially performed with soft guidewire, subsequently exchanged to stiff guidewire. Forced insertion of dilators, peel-off sheath throughout the stenosis or occlusion and finally implantation of the catheter completed the procedure. Our technique does not require pre-procedural angioplasty or stent deployment. RESULTS: In all patients postoperative hemodialysis was managed with satisfactory adequacy. No early or late complications related to the procedure occurred. We did not observe any clinically significant aggravation of symptoms of central vein stenosis or occlusion. Complications, not-related to the procedure included one, late skin entry site infection and one, late catheter thrombosis. These were managed without the necessity of catheter exchange. CONCLUSIONS: Our technique of forced implantation of catheters for hemodialysis into critically stenosed or occluded central veins without previous balloon predilatation or stenting is simple and diminishes the total cost of the procedure. Provides quick vascular access for hemodialysis in life threatening situations.

Efficacy evaluation of bio trombina ® 400 in mini mall y invasive treatment of complications (pseudoaneurysms), after venipuncture for diagnostic purposes. Authors' own experience - case study of 38 patients.

UNLABELLED: Common use of venipuncture on upper and lower limbs for diagnostic purposes (such as coronarography or arteriography), and also during the course of treatment (angioplasty), very often bares a complication in the form of pseudoaneurysms. According to various reports, the incidence of pseudoaneurysms ranges from 0.005% to 0.5% of all vascular procedures requiring arterial cannulation (Common Femoral Artery, Brachial Artery, Radial Artery). The use of Bio Trombina® 400 in the embolization of pseudoaneurysms allows minimally invasive and effective treatment. The aim of the study was to evaluate the efficacy of pseudoaneurysm embolization with the use of Trombina 400, authors' own experience. MATERIAL AND METHODS: In the years 2011 - 2013, the authors of this study performed 38 vascular interventional procedures involving pseudoaneurysms as complications of venipuncture in upper and lower limbs for diagnostic and treatment purposes. All procedures involved the direct injection of thrombin into the chamber of the pseudoaneurysm under the guidance of USG Doppler (6.2 MHz linear head). 34 cases presented single chamber pseudoaneurysms while 4 cases involved multi- chamber pseudoaneurysms, which required several thrombin reinjections (Bio Trombina® 400) into each of the chambers. Pseudoaneurysm maximum size of 4 cm was set as an inclusion criterion for the embolization procedure. Furthermore, all pseudoaneurysms with a significantly wide tract in transverse dimensions were treated as an exclusion criterion because of high risk of the peripheral arteries embolization. RESULTS: Initial success was observed in 36 patients (94.73%) in the first day after the procedure, 1 patient (2.63%) underwent thrombin reinjection procedure in the second day after the first embolization. Another patient (2.63%) underwent an open procedure in which the Common Femoral Artery was accessed, the clot evacuated, and CFA was sutured with continuous suture Prolene 6-0. CONCLUSIONS: 1. Embolization of pseudoaneurysms with USG Doppler-guided thrombin injection is an effective course of treatment for complications of cannulation. 2. The safety of pseudoaneurysm embolization depends on a surgeon's experience. It is also crucial to keep in mind the inclusion and exclusion criteria for this type of procedure (the size of a pseudoaneurysm, the width of its base). 3. Furthermore, its cost effectiveness and short hospitalization period make pseudoaneurysm embolization an effective and valuable alternative to the classic approach.