Arteriovenous Fistula Thrombosis Research Articles

Using Medicare Claims to Identify Acute Clinical Events Following Implantation of Leadless Pacemakers.

BackgroundThere is heightened interest in how real-world data (RWD) can be used to supplement or replace traditional mechanisms for collecting clinical information. A critical component in evaluating utility of RWD is assessing the validity and reliability of event measurement. Only two studies have validated Medicare claims with physician-adjudicated data collected in a clinical study and none in the pacemaker patient population. This study compares events identified in physician-adjudicated clinical registry data collected in the Micra Post-Approval Registry (PAR) with events identified via Medicare administrative claims in the Micra Coverage with Evidence (CED) Study.MethodsPatients who were dually enrolled in the Micra CED and the Micra PAR between March 9, 2017 and December 1, 2017 were included in the validation analysis. All patients intended to be implanted with a Micra device were eligible for participation in the Micra PAR. All Medicare fee-for-service beneficiaries implanted with a Micra device who met the 12-month continuous enrollment criteria were included in the Micra CED. We compared the count of acute (30-day) complications identified in the Medicare claims and the physician-adjudicated PAR data to assess agreement between data sources.ResultsThere were 230 patients dually enrolled in the Micra CED and Micra PAR studies during the study period. Overall, there were 17 acute events reported in either the Micra CED or the Micra PAR, with 95% agreement in the identification of events and absence of events between studies. Study disagreement between events reported in either study varied: arteriovenous fistula (50%), pulmonary embolism (67%), hemorrhage/hematoma (75%), and deep vein thrombosis (100%). Among physician-adjudicated events, there was no disagreement between the Micra CED and Micra PAR studies in any event type.ConclusionFindings from this study demonstrate high agreement in event identification between Medicare claims data and registries for patients implanted with Micra leadless pacemakers.

Outcomes from our model for a nurse-led vascular renal access surveillance clinic

Background: A patent arteriovenous fistula (AVF) with adequate flow is essential for performing successful hemodialysis. However, the literature currently reports 1-year patency rates of 69%–74%. Surveillance of AVFs has been proposed to prevent failure of fistulas with the associated morbidity and mortality. We implemented a renal access surveillance clinic with the aims of detecting stenoses and arranging treatment to avoid underdialysis and thrombosis of AVFs. Methods: The nurse-led vascular renal access surveillance clinic (VRAC) of the Royal Brisbane and Women's Hospital was created in 2015. The surveillance program is run by a full-time vascular clinical nurse with experience in renal access. Over the 3-year period of 2015–2017, 1006 patients were in the surveillance program. We compared the rates of intervention on fistulas and the incidence of thrombosed fistula in the 5 years preceding the initiation of our VRAC surveillance program, with the 3 years after it was commenced. Results: Our results show that our rates of intervention on threatened fistulas have increased since the program was established, and that the percentage of thrombosed fistulas has remained stable. Allowing this early triage has expedited management and freed more outpatient clinic time. Conclusion: We have compared outcomes before and after implementation of a nurse-led dialysis access surveillance program and have found that the percentage of thrombosed fistulas has remained stable as the rates of intervention have increased for threatened fistulas.

Management of the Bacterial Endocarditis of the Native Aortic Valve in a Patient with Chronic Hemodialysis

Infective endocarditis is one of the most important complications in hemodialysis patient due to vascular access, mainly in patients with central venous catheter (CVC) and arteriovenous (AV) graft. Infective endocarditis is associated with a high mortality for this category of patients. We present the case of a 56-year old male in hemodialysis treatment since 2015. He had a thrombosis of the native arteriovenous fistulas, which was corrected using an arteriovenous graft prosthesis. After a period of several months, the graft was thrombosed and a percutaneous thrombectomy of thrombosed hemodialysis graft was performed. Three months later the patient was identified with an infection of the graft, and also developed secondary bacteremic staphylococcal pneumonia and further aortic valve endocarditis. Infective endocarditis is a complex disease with a high mortality. A particular attention to this complication is required for hemodialysis patients who are using an AV graft because immediate diagnosis and treatment it is associated with a successful management of the infective endocarditis complication. Prevention strategies on following strict asepsis protocols, from placing the access to its manipulation during dialysis sessions, would lead to a significant reduction of this life-threatening complication in patients with hemodialysis.

Percutaneous angioplasty in the treatment of thrombosed hemodialysis fistulas: A single-center experience with 1 year of follow-up.

Thrombosis of a hemodialysis arteriovenous fistula (AVF) is a serious complication that needs urgent treatment. Most cases are treated surgically, but recently, endovascular strategies have become a viable alternative. This study is an evaluation of the success and patency rate of percutaneous balloon angioplasty of thrombosed hemodialysis fistulas using a drug-coated balloon (DCB) contrasted with a standard balloon (SB). The data of 33 patients with a thrombosed native hemodialysis AVF treated percutaneously in a tertiary care center were analyzed retrospectively. Success of the procedure was defined as restoration of flow with less than 30% residual stenosis and resumption of dialysis through the hemodialysis AVF. The success rate of the procedure and the patency rate at 1, 6, and 12 months were evaluated. The effect on patency of a DCB was compared to that of a SB. Twenty-five radiocephalic and 8 brachiocephalic thrombosed hemodialysis AVFs were treated during the study period. Flow was restored in 23 thrombosed fistulas, a success rate of 69.7%. The patency rate of successfully treated fistulas was 95.6% at 1 month, 76.1% at 6 months, and 57.9% at 12 months. Ten of the 23 re-established AVFs were treated with a DCB and the remainder were treated with a SB. The patency of the fistulas treated with a DCB was similar to that of a SB at 1 month (100% vs 92.3%, respectively; p=0.393). The patency rate of a DCB was greater than that of a SB at 6 months (88.9% vs 66.7%, respectively; p=0.258) and 12 months (75% vs 45.4%, respectively; p=0.219). Percutaneous intervention for thrombosed hemodialysis AVFs is a safe, minimally invasive, and effective procedure. There was a positive trend in the patency rate of patients treated with a DCB at 6 and 12 months compared with a SB.

Usefulness of mean platelet volume as a biomarker for diagnosing arterivenosus fistulas thrombosis in routine hemodialysis patients

Aim: Hemodialysis patients should have an access to a vessel. Thrombosis is responsible for 80-85% of fistula losses. Mean Platelet Volume (MPV) is routinely measured in complete blood count and shows the average volume of circulating platelets. In our study, we aimed to investigate whether MPV values may be used as a cheap and noninvasive marker in the early diagnosis and intervention of arteriovenous fistula (AVF) thrombosis.Material and Methods: This retrospective study included 48 patients having one or more episodes of late fistula thrombosis at the hemodialysis unit and 47 patients without history of AVF thrombosis.Results: Demographic and laboratory characteristics were used to compare between groups and no significant difference was found (p> 0.05). On the other hand, significant difference was reported (p=0.001) by the comparison of two groups. Logistic regression analysis, revealed that MPV was an independent risk predictor for the development of AVF thrombosis (p 0.05).Conclusion: AVF dysfunction leads to a significant cost and frequent hospitalization of the patient. Previously, MPV was stated to be a risk factor for arterial and venous thrombosis. This study showed that MPV values may be used in hemodialysis patients as a predictor of thrombosis. Further prospective and retrospective studies should be conducted in order to verify the finding of this study.

P1298 A conservative strategy for an uncommon complication of endocarditis

Abstract A 64-year-old man was admitted for aortic valve prosthesis endocarditis. He had relevant personal medical history of mechanical aortic valve implantation 6 years before, coronary arterial disease with bypass graft surgery, chronic kidney disease on haemodialysis (with a need to implantation of long-duration haemodialysis catheter due to arteriovenous fistula thrombosis), Diabetes mellitus type 2 for 20 years, peripheral artery disease and ischemic stroke 2 years before. He presented with a medical history of fever without evident clinical origin. From the diagnostic workup there were 4 blood cultures positive for methicillin-resistant Staphylococcus epidermidis. The bacteraemia was considered to be originated from the haemodialysis catheter and a new one was implanted. Transthoracic echocardiogram (TTE) at admission showed aortic anterior annulus dissection with an extensive dehiscence area (figure top-left). Subsequent evaluations showed fistulisation of the pseudoaneurysm to the right ventricle outflow tract (RVOT) (figure top-right and bottom-left) and the pulmonary trunk (PT) (figure bottom-right), as well as images compatible with vegetations at the septal cuspid of the pulmonary valve (figure yellow arrow). Furthermore, there was compromised right ventricle longitudinal systolic function and moderate tricuspid regurgitation with an estimated systolic pulmonary artery pressure of 80mmHg. Left ventricle systolic function was preserved and prothesis had no obstruction. Case was discussed with cardiothoracic surgery from 2 centres and both considered that the surgical risk was too high. Patient was treated in a conservative way with rifampicin and gentamicin for 15 days and also with vancomycin ad eternum (after haemodialysis sessions). Blood cultures at discharge were negative. He remained hemodynamically stable and with no evidence of heart failure during admission. Subsequent ambulatory clinical and echocardiographic monitoring was unremarkable in regarding to endocarditis, with no evidence of progression of endocarditis as well as no signs or symptoms of heart failure. Patient died 10 months later due to sepsis originated on a lower limb infection of irreversibly ischemic tissue (patient had refused amputation before). Discussion Infective endocarditis of mechanical prosthesis has different presentations depending on the involvement of prosthesis and periprosthetic structures, and it is associated with high morbidity and mortality. Pseudoaneurysm of the intervalvular fibrosa is an uncommon complication, furthermore when complicating with dissection to near structures such as RVOT and the PT in this case. Treatment is mainly surgical, however, in this case the surgical risk was too high due to comorbidities and a conservative strategy was adopted. It seems that it was a reasonable strategy as the patient evolution was unremarkable when regarding endocarditis. Unfortunately, he ended up dying from probably unrelated complications. Abstract P1298 Figure. Pseudoaneurysm with fistulization

Relationship of arteriovenous fistula stenosis and thrombosis with the platelet-lymphocyte ratio in hemodialysis patients.

The platelet-lymphocyte ratio, which was reported to have a strong relationship with chronic inflammation and thrombosis, is a useful biomarker. The purpose of this study was to evaluate the relationship between the platelet-lymphocyte ratio, arteriovenous stenosis, and thrombosis in patients with chronic renal failure. Patients who were referred to our interventional radiology department due to arteriovenous fistula dysfunction from dialysis units between August 2015 and December 2018 were retrospectively reviewed. In the study, 95 patients with arteriovenous fistula access problems were included. Patients were divided into two groups: stenosis (n = 52) and thrombosis (n = 43). Thirty-six subjects with a patent left radiocephalic arteriovenous fistula proven by both color Doppler ultrasonography and clinically were added to the control group. Blood samples were obtained on the same day before the fistulography. Platelet counts, lymphocyte counts, and platelet-lymphocyte ratio were found to be significantly different between the three groups. After the Bonferroni post hoc analysis, there was a significant difference between the stenosis and control group (p = 0.017), and the thrombosis and control group (p < 0.001) in terms of the platelet-lymphocyte ratio. No significant difference for any parameter was found between stenosis and thrombosis group. High levels of the platelet-lymphocyte ratio may be a supportive finding of arteriovenous fistula stenosis and thrombosis and can be taken into consideration during hemodialysis-dependent patients' follow-up.

Application of different doses of urokinase in the treatment of thrombosis of arteriovenous internal fistula

Objective To investigate the efficacy and safety of different doses of urokinase in the treatment of arteriovenous fistula thrombosis. Methods From January 2011 to September 2018, 118 patients underwent maintenance hemodialysis and autologous arteriovenous thrombosis in the department of nephrology of our hospital who were divided into three groups: group A (100 000 units of urokinase ), group B (500 000 units of urokinase ) and group C (1 million units of urokinase ) according to the dosage of urokinase thrombolysis. We compared the success rate of thrombolysis between the three groups and the incidence of thrombolysis complications between group B and group C. Results The success rate of thrombolysis in group C was significantly better than that in group A and B (P 0.05). Conclusions One million units of urokinase can significantly improve the success rate of thrombolysis of arteriovenous fistula, while the incidence of complications is not significantly different from 500 000 units, extending the service life of arteriovenous fistula in maintenance hemodialysis patients, without increasing the risk of bleeding complications, and effectively improving the quality of dialysis. Key words: Urokinase-Type Plasminogen Activator; Arteriovenous Anastomosis; Thrombosis

Haemostasis with suture-tourniquet technique following removal of large-bore venous sheaths for endovascular recanalization of acute thrombosis in native arteriovenous fistula

Haemostasis with suture-tourniquet technique following removal of large-bore venous sheaths for endovascular recanalization of acute thrombosis in native arteriovenous fistula

Dynamic Banding (DYBAND) Technique for Symptomatic High-Flow Fistulae.

High flow rates may develop in arteriovenous fistula (AVF), resulting in clinical syndromes of steal, aneurysmal fistula, or high-output cardiac failure. Various techniques with varying success have been advocated to treat this difficult problem. We present a hemodynamically validated novel banding technique. We designed a computational fluid dynamic (CFD) model of the native high-flow AVF and tested various juxta-anastomotic venous diameters to determine the effect on AVF blood flow and pressure. We translated this principle in our banding technique, wherein adjustable banding was performed in conjunction with ultrasound-guided brachial artery flow measurement to determine the optimal band diameter. Polyurethane patch was used to fashion the adjustable band. Patient demographics, AVF flow parameters pre- and postintervention, operative intervention, and ultrasound follow-up data were collected prospectively. Our CFD testing demonstrated that the band diameter needed to achieve optimal distal blood pressure and preserve AVF flow depending on blood pressure, end capillary pressure, venous pressure, and vascular diameters. Five patients subsequently underwent dynamic banding of symptomatic high-flow AVF. Mean brachial artery blood flow rates pre- and postbanding were 2964 mL/min (confidence interval [CI]: 1487-4440 mL/min) and 1099 mL/min (CI: 571.7-1627 mL/min), respectively (P = .01). All patients had symptomatic improvement, and at a mean follow-up of 1 year, this benefit was sustained with no AVF thrombosis or loss. Adjustable dynamic band using ultrasound-guided brachial artery flow shows promising results in producing accurate AVF blood flow reduction with sustained efficacy in the short term for patients with symptomatic high-flow AVF.

Percutaneous transluminal angioplasty combined with thrombolysis for acute thrombosis in arterio-venous fistula and graft

To evaluate the efficacy of ultrasound or fluoroscopic-guided percutaneous transluminal angioplasty (PTA) combined with thrombolysis for the treatment of acutely thrombosed arteriovenous fistula (AVF) or grafts (AVG). One hundred and ninety-two hemodialysed patients, in whom the thrombosed arterio-venous AVF or AVG developed less than 72 h and there were no contraindications for thrombolysis and PTA, underwent PTA combined with thrombolysis therapy in Sir Run Run Shaw Hospital of Zhejiang University from October 2014 to October 2017. Under ultrasound and/or fluoroscopic guidance, balloon catheter was introduced to thrombosis sites along a guide wire. Then the balloon was inflated and normal saline mixed with urokinase and heparin was injected for thrombolysis. After blood flow was restored, angioplasty was performed on vascular stenosed sites. A total of 274 endovascular interventional operations were performed for 192 patients. The procedure success rate was 98.2%, clinical success rate was 93.8%and complication rate was 1.46%. The post-intervention primary patency rates for AVF group were 87.4%, 76.7%and 63.9%at 3, 6 and 12 months, respectively; while the post-intervention secondary patency rates were 93.7%, 91.6%and 83.0%, respectively. The post-intervention primary patency rates for AVG group were 60.7%, 51.5%and 43.1%at 3, 6 and 12 months, while the post-intervention secondary patency rates were 82.7%, 77.1%and 70.8%, respectively. PTA combined with thrombolysis is an effective and safe therapeutic option for AVF and AVG thrombosis, which would prolong hemodialysis access and save vascular resources for hemodialyzed patients.

Central venous stenosis and methods of its treatment in hemodialysis patients

There is no doubt that the optimal vascular access is arteriovenous fistula (AVF). However, the proportion of patients receiving hemodialysis using central venous catheters is very high. Largely due to this, the incidence of central venous stenosis (CVS) in this category of patients is one of the highest: the prevalence ranges from 2 to 40%. Against the background of functioning AVF from the ipsilateral side, CVS proceeds with much more pronounced symptoms than in the general population of patients with this pathology. There is no doubt that stenosis of the central veins is a precursor of AVF thrombosis, recurrent infections, reduction of blood flow in the limb in general and AVF in particular, and consequently - increase in recirculation and decrease in the effectiveness of HD. Endovascular surgery is the «gold standard» treatment for CVS. Technical success is at least 80-90% of the cases. As a rule, endovascular operations not only lead to the immediate reduction of symptoms of venous hypertension, but also allow the use of fistulas for hemodialysis in the near future after the intervention. At the same time, clinical success is achieved much less frequently. Primary patency in six months is about 50%, secondary patency in two years - 60-80%. The use of cutting balloon catheters may be associated with greater secondary patency than using standard balloon catheters, but slightly increases the risk of complications. An effective way to improve the results of CVS plastic is the use of stents, which allow to increase the patency after surgery. Indications for the primary use of stents is a debatable issue. However, stenting is undoubtedly effective in the case of rapid occurrence of recurrent stenosis or rigid stenosis and recoil immediately after surgery. In addition, one of the problems associated with the use of stents is the risk of their migration. This risk increases in patients with functioning AVF. Skepticism about the use of stents in patients on hemodialysis is also added by the fact that in randomized controlled studies, when comparing isolated balloon angioplasty and angioplasty using uncovered stents, there was no significant difference in the recurrence of stenosis. At the same time, the use of covered stents provides a significant increase in access survival. In addition, the use of drug-coated balloon catheters may provide some advantage over standard uncoated balloon catheters. Open surgical interventions have slightly better results in the treatment of CVS (annual primary patency of 80-90%) compared to endovascular methods. Nevertheless, open reconstructions are associated with a much greater risk of intra- and postoperative complications, in most cases require clavicle section or sternotomy, general anesthesia, and are associated with greater postoperative mortality. In this regard, percutaneous transluminal angioplasty is deservedly considered to be a common method of treatment of CVS. Open surgery can be used in case of unsuccessful attempts to resolve stenosis endovascular while maintaining a pronounced clinical symptoms. On the face of the fact that the available methods of treatment of this pathology in patients on hemodialysis with functioning vascular access do not fully meet the clinical needs. Currently, there is no consensus on many aspects of the use of endovascular interventions for the correction of vascular access dysfunction, which requires additional research.

Haemostasis with suture-tourniquet technique following removal of large-bore venous sheaths for endovascular recanalization of acute thrombosis in native arteriovenous fistula

Haemostasis with suture-tourniquet technique following removal of large-bore venous sheaths for endovascular recanalization of acute thrombosis in native arteriovenous fistula

Are the platelet indices useful biomarkers of arteriovenous fistula thrombosis in hemodialysis patients?

Are the platelet indices useful biomarkers of arteriovenous fistula thrombosis in hemodialysis patients?

Arteriovenous fistula thrombosis is associated with increased all-cause and cardiovascular mortality in haemodialysis patients from the AURORA trial.

BackgroundThe impact of arteriovenous fistula (AVF) or graft (AVG) thrombosis on mortality has been sparsely studied. This study investigated the association between AVF/AVG thrombosis and all-cause and cardiovascular mortality.MethodsThe data from 2439 patients with AVF or AVG undergoing maintenance haemodialysis (HD) included in the A Study to Evaluate the Use of Rosuvastatin in Subjects on Regular Hemodialysis: An Assessment of Survival and Cardiovascular Events trial (AURORA) were analysed using a time-dependent Cox model. The incidence of vascular access (VA) thrombosis was a pre-specified secondary outcome.ResultsDuring follow-up, 278 AVF and 94 AVG thromboses were documented. VA was restored at 22 ± 64 days after thrombosis (27 patients had no restoration with subsequent permanent central catheter). In multivariable survival analysis adjusted for potential confounders, the occurrence of AVF/AVG thrombosis was associated with increased early and late all-cause mortality, with a more pronounced association with early all-cause mortality {hazard ratio [HR] < 90 days 2.70 [95% confidence interval (CI) 1.83–3.97], P < 0.001; HR > 90 days 1.47 [1.20–1.80], P < 0.001}. In addition, the occurrence of AVF thrombosis was significantly associated with higher all-cause mortality, whether VA was restored within 7 days [HR 1.34 (95% CI 1.02–1.75), P = 0.036] or later than 7 days [HR 1.81 (95% CI 1.29–2.53), P = 0.001].ConclusionsAVF/AVG thrombosis should be considered as a major clinical event since it is strongly associated with increased mortality in patients on maintenance HD, especially in the first 90 days after the event and when access restoration occurs >7 days after thrombosis. Clinicians should pay particular attention to the timing of VA restoration and the management of these patients during this high-risk period. The potential benefit of targeting overall patient risk with more aggressive treatment after AVF/AVG restoration should be further explored.

Transcatheter Thrombolysis with Percutaneous Transluminal Angioplasty Using a Trans-Brachial Approach to Treat Thrombosed Arteriovenous Fistulas.

BackgroundArteriovenous fistulas (AVFs) are used to provide vascular access for hemodialysis in patients with end-stage renal failure. However, stenosis and thrombosis can compromise long-term AVF patency. The objective of this study was to evaluate catheter thrombolysis with percutaneous transluminal angioplasty (PTA), using a trans-brachial approach, for acutely thrombosed AVFs.Material/MethodsThis retrospective study examined 30 cases of AVF thrombosis treated between January 1, 2015 and January 1, 2017. All patients received transcatheter thrombolysis with PTA using a trans-brachial approach. AVF patency was assessed after 6 months.ResultsThrombolysis with PTA was performed at 2 to 72 h after diagnosis of AVF occlusion due to acute thrombosis, and AVF patency was restored in all patients. After 6 months, the primary and secondary patency rates were 76.7% and 93.3%, respectively. For type I stenosis, primary patency was achieved in 10 of 16 patients (62.5%) and secondary patency was achieved in 14 of 16 patients (87.5%). For type II stenosis, primary patency was achieved in 13 of 14 patients (92.9%) and secondary patency was achieved in 14 of 14 patients (100%). Comparing type I and II stenosis, a significant difference was detected in the rates of primary patency (odds ratio=0.909, 95% confidence interval 0.754–1.096, P=0.049), but not secondary patency (P=0.178), after 6 months.ConclusionsOur study provides preliminary evidence that catheter-directed thrombolysis with PTA using a trans-brachial approach can achieve high patency rates when used to treat acutely thrombosed AVFs.

Comparative efficacy and safety of local and peripheral venous thrombolytic therapy with urokinase for thrombosed hemodialysis arteriovenous fistulas.

Arteriovenous fistula (AVF) thrombosis is a common complication in patients undergoing hemodialysis, and early intervention is required. Urokinase has been used as a thrombolytic agent for declotting the thrombosed access. However, the optimal route for infusing urokinase remains to be determined. In the present retrospective observational study, 49 patients who underwent local venous infusion and 57 patients with peripheral venous infusion of urokinase were included. A urokinase dosage of 300,000 U was administered until successful thrombolysis, which was a maximum of three times. Age, sex, period of dialysis, time of AVF placement, systolic and diastolic blood pressure and thrombus age were similar between the two groups. The efficacy of urokinase infusion via the two routes in resolving thrombosed AVFs, defined as successful fibrinolysis, and the safety, defined as the number of bleeding events, was compared. The cumulative thrombolysis success rate following three sessions of thrombolytic therapy in the local venous thrombolysis group was higher compared with that in the peripheral venous thrombolysis group (85.7 vs. 68.4%; P=0.04). The local thrombolysis group exhibited less ecchymosis (4.1 vs. 14.0%; P=0.07), epistaxis (2.0 vs. 10.5%; P=0.08) and gingival bleeding (4.1 vs. 19.3%; P=0.02) events compared with the peripheral thrombolysis group. Further analyses demonstrated that systolic [odds ratio (OR)=1.10; 95% confidence interval (CI), 1.03-1.17; P<0.01] and diastolic (OR=1.08; 95% CI, 1.02-1.14; P<0.05) blood pressure were protective factors, whereas thrombus age (OR=0.91; 95% CI, 0.84-0.99; P<0.05) was a risk factor for thrombolysis success among patients who underwent local thrombolytic therapy. Overall, the results suggest that local venous infusion of urokinase is superior to peripheral venous infusion for the treatment of patients with thrombosed fistulas.

Predictive Parameters Functioning Arteriovenous Fistula for Hemodialysis in the Elderly

Abstract Elderly patients with end stage kidney disease represent a challenge for surgeons to create a vascular access. Determine predictive parameters functionality of the arteriovenous fistulas for hemodialysis in the elderly. The study was organized as a retrospective study at the Center for Dialysis, Clinic for Urology and Nephrology, Clinical Center Kragujevac. The study included patients older than 65 years with arteriovenous fistula thrombosis, in the period of four years, in which there is information on the length of the functioning fistula. The study included 48 patients, mean age 71.3±5.2 years, 29 (60%) men and 19 (40%) women. The data were analyzed according to gender and demographic structure, type of anastomosis, positioning, length of functioning fistulas, and the lumen diameter of the arteries and veins that are used to create a fistula. The median length of functioning arteriovenous fistula, based on Kaplan-Meier model, is 16 months (95% CI 6.9-25.1). Median functioning for proximaly located fistulas was 24 months (range, 1-259), while median functioning in patient with distally located fistulas was 8 months (range, 1-96). The difference in relation to the positioning of the fistula was statistically significant (p=0.006). In univariate Cox regression model, a statistically significant predictor of the functioning of arteriovenous fistulae is fistula positioning (B=0.700; p=0.022). The predictive parameter of survival of arteriovenous fistulas in elderly is proximally located fistula.

Using CorMatrix for partial and complete (re)construction of arteriovenous fistulas in haemodialysis patients: (Re)construction of arteriovenous fistulas with CorMatrix.

CorMatrix is an acellular extracellular matrix that acts as a biological scaffold and remodels into site-specific tissue. We used it for the (re)construction of arteriovenous fistulas. In this prospective pilot case study, we used CorMatrix in six patients. We included patients who required vascular access reconstruction due to thrombosis of unsalvageable arteriovenous fistulas, patients with high-flow arteriovenous fistulas and patients with microvasculature in which autologous arteriovenous fistulas did not mature, requiring reconstruction with a graft. We sutured the CorMatrix plate into a tubular shape and then constructed arterial and venous anastomoses. There were no periprocedural complications, CorMatrix-related infections, bleeding or limb swelling after the procedures. CorMatrix was first punctured after 8-10 weeks. In five patients, a percutaneous angioplasty due to CorMatrix stenosis was performed; in one patient, a stent was placed due to refractory stenosis. We observed eight thromboses during the observation period (four in one patient). Perianastomotic stenosis of CorMatrix and interdialytic hypotension were the causes of the thrombosis in five patients, cephalic arch stenosis in two patients and thromboembolism to the brachial artery and arteriovenous fistula in one patient. Thrombendarteriectomy was successful in 87.5% of patients, and one patient required arteriovenous fistula reconstruction. After a median observation period of 12.5 (range 4-23) months, all arteriovenous fistulas were patent, with a median brachial artery flow of 1450 (range 700-1700) mL/min. Arteriovenous fistula (re)construction with CorMatrix seems to be feasible and safe, with a relatively high incidence of neointimal hyperplasia, predominantly at venous anastomoses, but additional clinical studies are needed.

Non-venous causes of leg and arm swelling

Extremity swelling, pain, edema and erythema are non-specific signs and symptoms for an upper or lower extremity deep venous thrombosis (DVT). There is a poor clinical accuracy to diagnose DVT. The clinical signs and symptoms of DCVT are often mimicked by other pathologies (musculoskeletal, other vascular and infectious disorders). In this presentation we will discuss the differential diagnoses and conditions, which may mimic the clinical signs and symptoms of a DVT such as musculoskeletal causes (lymphadenopathy, hematoma and abscesses, muscle tears, soft tissue masses, popliteal cysts and joint effusions), fluid collections/edema (groin, popliteal fossa and calf) and arterial causes (pseudoaneurysm, arteriovenous fistula and arterial thrombosis).