Maintenance Of Arteriovenous Fistulas Research Articles

Osteopontin is a key regulator of vascular smooth muscle cell proliferation in the outflow vein of arteriovenous fistulas.

Despite advances in the maintenance of arteriovenous fistulas (AVFs), the patency rates remain suboptimal. Most AVFs fail due to outflow vein stenosis; however, the underlying mechanism of AVF stenosis remains unclear. The present study aimed to identify key factors associated with AVF outflow stenosis. We obtained gene expression profiling data for the outflow vein of AVF from three Gene Expression Omnibus database datasets (GSE39488, GSE97377, and GSE116268) and analyzed the common differentially expressed genes (DEGs). We evaluated a common DEG in an aortocaval mouse model and the stenotic outflow veins of AVFs collected from patients. Furthermore, we isolated vascular smooth muscle cells (VSMCs) from the inferior vena cava (IVC) of wild-type (WT) and osteopontin (Opn)-knockout (KO) mice and assessed the proliferation of VSMCs following stimulation with platelet-derived growth factors (PDGFs). OPN was the only common upregulated DEG among all datasets. OPN was expressed in the medial layer of the outflow vein of AVF in aortocaval mouse models and co-stained with the VSMC marker (α-smooth muscle actin). OPN expression was markedly increased in the VSMCs of stenotic outflow veins of AVF collected from patients undergoing hemodialysis compared to presurgical veins acquired during AVF formation surgery. PDGF-induced VSMC proliferation was significantly increased in the VSMCs isolated from the IVC of WT mice but not in those isolated from the IVC of Opn-KO mice. OPN may be a key gene involved in VSMC proliferation in the AVF outflow veins and a therapeutic target to improve the AVF patency rate.

Expert consensus on the establishment and maintenance of native arteriovenous fistula

Vascular access is the lifeline of hemodialysis patients. There are great differences in the establishment and use of vascular access in different countries and regions around the world. We believe that on the basis of good evaluation and planning, it is recommended that hemodialysis patients choose native arteriovenous fistula first. In view of the new progress of vascular access views domestic and international at home and abroad in recent years, we organized experts to recommend the establishment and maintenance of arteriovenous fistula (AVF) for the Chinese population, including preoperative evaluation and planning of the establishment of AVF, AVF surgery, perioperative drug intervention measures and postoperative maintenance, and put forward suggestions for future research directions. The recommendations in this consensus are general and clinicians need to make treatment decisions based on the actual situation.

How to carry out monthly blood flow surveillance of fistula in large-scale hemodialysis units: A cross-sectional study

The important effect of regular blood flow surveillance on arteriovenous fistula maintenance is emphasized. The ultrasonic dilution technique for blood flow surveillance can be performed during hemodialysis, but there are some limitations. Blood flow is traditionally measured by duplex Doppler ultrasound during the nondialysis period. However, the surveillance workload for arteriovenous fistula has increased with the rapid increase in the hemodialysis population size. Efficient methods for blood flow surveillance during hemodialysis are needed. Eighty-four hemodialysis patients with a forearm radiocephalic arteriovenous fistula were enrolled in this cross-sectional study. Each received blood flow measurements using ultrasonic dilution technique and duplex Doppler ultrasound during hemodialysis. Duplex Doppler ultrasound measurements included the blood flow of the brachial artery and radial artery. The correlations between these variables were analyzed. The correlation coefficients (r) between flow measured by ultrasonic dilution technique and brachial artery flow measured by duplex Doppler ultrasound, between flow measured by ultrasonic dilution technique and radial artery flow measured by duplex Doppler ultrasound, and between brachial artery flow and radial artery flow measured by duplex Doppler ultrasound were 0.724, 0.784, and 0.749, respectively (all p < 0.001). Blood flow measured by ultrasonic dilution technique was positively correlated with blood flow measured by duplex Doppler ultrasound during hemodialysis, suggesting that duplex Doppler ultrasound can be used to monitor the trends in the blood flow of the brachial artery and radial artery for timely intervention to improve patency during hemodialysis.

Clinic of vascular access: Results after implementing a multidisciplinary approach adding routine Doppler ultrasound

BackgroundA multidisciplinary approach and Doppler ultrasound (DU) assessment for the creation and maintenance of arteriovenous fistulas (AVF) for haemodialysis can improve prevalence and patency. The aim of this study was to analyze the impact of a new multidisciplinary vascular access (VA) clinic with routine DU. Material and methodsWe analyzed the VA clinic results from 2014 and 2015, before and after the implementation of a multidisciplinary team protocol (vascular surgeon/nephrologist) with routine DU in preoperative mapping and prevalent AVF. ResultsWe analyzed 345 and 364 patients from 2014 and 2015 respectively. The number of surgical interventions was similar in both periods (p=.289), with a trend toward an increase in preventive surgical repair of AVF in 2015 (17 vs. 29, p=.098). 155 vs. 169 new AVF were performed in 2014 and 2015, with a significantly lower primary failure rate in 2015 (26.4 vs. 15.3%, p=.015), and a non-significant increase in radiocephalic AVF, 25.8 vs. 33.2% (n=40 vs. 56), p=.159. The concordance between the indication at the clinic and the surgery performed also increased (81.3 vs. 93.5%, p=.001). Throughout 2015 fewer complementary imaging test were requested from the clinic (78 vs. 35, p<.001), with a corresponding reduction in costs (€ 87,716 vs. € 59,445). ConclusionsMultidisciplinary approach with routine DU can improve VA results, with a decrease in primary failure rate, higher likelihood of radiocephalic AVF, better management of dis-functioning AVF and lower radiological test costs.

Consulta de acceso vascular: resultados antes y después de la instauración de un programa multidisciplinar con realización de ecografía doppler de rutina

BackgroundA multidisciplinary approach and Doppler ultrasound (DU) assessment for the creation and maintenance of arteriovenous fistulas (AVF) for haemodialysis can improve prevalence and patency. The aim of this study was to analyse the impact of a new multidisciplinary vascular access (VA) clinic with routine DU. Material and methodsWe analysed the VA clinic results from 2014 and 2015, before and after the implementation of a multidisciplinary team protocol (vascular surgeon/nephrologist) with routine DU in preoperative mapping and prevalent AVF. ResultsWe analysed 345 and 364 patients from 2014 and 2015 respectively. The number of surgical interventions was similar in both periods (p=.289), with a trend towards an increase in preventive surgical repair of AVF in 2015 (17 vs. 29, p=.098). 155 vs. 169 new AVF were performed in 2014 and 2015, with a significantly lower primary failure rate in 2015 (26.4 vs. 15.3%, p=.015), and a non-significant increase in radiocephalic AVF, 25.8 vs. 33.2% (n=40 vs. 56), p=.159. The concordance between the indication at the clinic and the surgery performed also increased (81.3 vs. 93.5%, p=.001). Throughout 2015 fewer complementary imaging test were requested from the clinic (78 vs. 35, p <.001), with a corresponding reduction in costs (€87,716 vs. €59,445). ConclusionsMultidisciplinary approach with routine DU can improve VA results, with a decrease in primary failure rate, higher likelihood of radiocephalic AVF, better management of dis-functioning AVF and lower radiological test costs.

Sonography of Arteriovenous Fistulas and Grafts.

Arteriovenous fistulas (AVFs) and arteriovenous grafts (AVGs) are the vascular accesses of choice for long-term hemodialysis. Strategies to establish and maintain functioning AVFs and AVGs are essential. In addition to clinical evaluation, ultrasound plays a critical role in the evaluation and maintenance of AVFs and AVGs. AVFs have a high rate of failure to mature which can be reliably diagnosed with ultrasound. Treatable etiologies of the failure to mature can often be diagnosed with ultrasound. Causes of secondary AVG failure can also be diagnosed with ultrasound and treated. AVGs have a relatively short functional life expectancy due to a high rate of AVG thrombosis. Ultrasound is a safe, noninvasive way to diagnose vascular stenosis in both AVFs and AVGs prior to thrombosis, potentially saving the access. Routine surveillance ultrasound of asymptomatic AVFs and AVGs is controversial with conflicting studies on its benefit. Routine surveillance ultrasound of AVFs and AVGs is not common practice.

An update of the effect of far infrared therapy on arteriovenous access in end-stage renal disease patients.

The life qualities of end-stage renal disease (ESRD) patients rely largely on adequate dialysis, and a well-functioning vascular access is indispensable for high quality hemodialysis. Despite the advancement of surgical skills and the optimal maintenance of arteriovenous fistula (AVF), malfunction of AVF is still frequently encountered and has great impact on the life of ESRD patients. Several medical, mechanical and genetic prognostic factors are documented to affect the patency of AVF and arteriovenous graft (AVG). Heme oxygenase-1 (HO-1) is one of the genetic factors reported to play a role in cardiovascular disease and the patency of vascular access. Far infrared (FIR), a novel therapeutic modality, can not only conduct heat energy to AVF but also stimulate the non-thermal reactions mediated by HO-1. The use of FIR therapy significantly enhances the primary patency rate and maturation of AVF with fewer unfavorable adverse effects, and also achieves higher post-angioplasty patency rate for AVG. The only limitation in proving the effectiveness of FIR therapy in enhancing patency of AVF is that all the studies were conducted in Chinese people in Taiwan and thus, there is a lack of evidence and experience in people of other ethnicities.

Patient oriented management for the creation of arteriovenous fistula for hemodialysis.

Hemodialysis access is of paramount importance for end-stage renal failure (ESRF) patients. Creation and maintenance of arteriovenous fistula (AVF) by a dedicated team increases the success and duration of the hemodialysis. The aim of this study is to report a patient oriented standardized surgical technique performed by a single surgeon on the success of AVF creation. A single surgeon performed all AVF operations. The records of all patients who were operated for AVF creation without using synthetic grafts through a 3 year period (2009-2011) were included. The patients were examined and operated on by a previously defined standard protocol. A total of 221 procedures were done for 209 patients. The mean age was 65±11,4 years. Immediate function rate was 95.9% (n=212). Follow-up was possible for 182 patients (82.3%). For an average follow-up time of 11,3 months, the death rate was 20.8% (n=38) and the rate of AVF patency was 73.7% (n=134). Sustaining patency of AVF is difficult in these systemically deranged patients. A focused approach by a dedicated team will increase the success rate.

Strategies for the Creation and Maintenance of Reconstructed Arteriovenous Fistulas Using the Forearm Basilic Vein

Reconstruction of an arteriovenous fistula (AVF) after an initial failure to provide long-term patency has been desired in the era when hemodialysis patients' prognosis is improving. The forearm basilic vein AVF should be considered, before an artificial graft shunt or an AVF in the cubital region. The present study was designed to establish a strategy for the creation and maintenance of AVFs using the forearm basilic vein. This study reviewed 76 cases of reconstructed AVF including 18 cases using the basilic vein (23.7% of total cases). The following four points were considered: arm positioning of the cubital flexion position combined with the forearm supinated position; several small skin incisions with a subcutaneous tunnel; sufficient venous dilatation using Fogarty balloon catheter; and early percutaneous angioplasty introduction for immature AVF. The primary and secondary patency rates were examined. A radiobasilic AVF was created through a subcutaneous tunnel in two cases. The primary and secondary patency rates of AVF with the basilic vein were 54.7% and 76.7% respectively, whereas those of AVF with the cephalic vein were 49.3% and 71.3%. The basilic was not inferior to the cephalic vein (P-value of the log-rank test for primary and secondary patency rates were 0.927 and 0.811, respectively). Early stage percutaneous angioplasty was effective in five cases with immature AVF. The forearm basilic vein was useful in AVF reconstruction and equivalent to radiocephalic reconstruction. Careful observation and percutaneous angioplasty during the early period after the surgery were essential for long-term patency.

Fistula Salvage by Endovascular Therapy

Fistulas are considered superior to synthetic grafts as a hemodialysis vascular access; however, fistulas are not without problems. To maximize the number of fistulas being used in prevalent patients, it is important to have a program designed to salvage early failures or fistulas that fail to mature and those that become dysfunctional during the course of usage. Endovascular techniques have proven to be very effective in the management of both of these problems. These fistulas should be aggressively evaluated and treated because treatment carries with it a high expectation of successful salvage of what would have otherwise been an abandoned access.