Radial-cephalic Fistula Research Articles

Radial Artery Deviation and Reimplantation (RADAR) to Accelerate the Maturation of Radial-Cephalic Fistulas for Hemodialysis in Patients with End-Stage Renal Disease.

The most common form of vascular access for hemodialysis is a native arteriovenous fistula, which connects the site of the artery to the end of the vein. The maturation process of the fistula plays a crucial role in the establishment of a functional vascular access. Radial artery stenosis is among the potential causes of maturation failure. In these cases, improving the fistula's blood flow may be difficult, as traditional surgical reanastomosis and endovascular intervention frequently fail. Radial artery deviation and reimplantation (RADAR) is a novel and effective technique for creating primary fistulas with a high patency rate. The main disadvantage of this procedure is the ligation of the radial artery and the subsequent known consequences. To accelerate maturation, we used RADAR as a secondary approach in three patients with radial artery stenosis and maturation failure. In all patients after surgery, we observed a significant increase in fistula blood flow. Two patients used fistulas for hemodialysis after surgery. We describe the image diagnosis, procedure, and benefits of this method. The RADAR technique may be successfully used as a secondary access in patients with maturation failure due to RA stenosis to accelerate fistula maturation.

#5737 THE ASSOCIATION OF SERUM IRISIN WITH EARLY PATENCY LOSS OF ARTERIOVENOUS FISTULA

Abstract Background and Aims In patients receiving hemodialysis (HD), arteriovenous fistula (AVF) is the preferred form of vascular access owing to its long-term patency and low risk of infection. Early patency loss of AVF (≤1 year) is associated with higher risk of mortality and morbidity. Irisin is thought to play a protective role in the regulation of endothelial function and vascular calcification. However, the relationship between serum irisin level and early patency loss of AVF is unclear. Method In 73 end-stage kidney disease (ESKD) patients, including pre-dialysis patients who receive AVF placement for the first time (n = 10), HD patients with early patency loss of AVF (n = 24), HD patients that lose AVF function more than 1 year (n = 39), fasting (>8 hours) serum irisin levels and other biochemical parameters (hemoglobin, serum albumin, calcium, phosphate, intact parathyroid hormone, triglyceride, total cholesterol, D-Dimer, fibrinogen, FGF23, C-reactive protein) were measured before receiving access placement or after AVF thrombosis. All patients had radial-cephalic fistula. Results Among 73 patients (median age 58 years, 60.3% male, 31.5% diabetes mellitus (DM)), patients with early patency loss of AVF had significantly higher serum irisin levels, and lower fibrinogen, compared with other two groups. Other characteristics had no significant difference among these three groups (shown in Table 1). Conclusion HD patients with early patency loss of AVF had higher serum irisin levels compared with pre-dialysis patients and HD patients whose AVF patency maintained more than 1 year. The increase of irisin may be related to its putative role in compensatory mechanisms against vascular injury, which is then lost with longer dialysis duration and aggravated vascular damage.

#3215 RHE EFFECT OF ANASTOMOTIC ANGLE ON MATURATION OF AUTOGENOUS ARTERIOVENOUS FISTULA AFTER END-TO-SIDE ANASTOMOSIS OF CEPHALIC VEIN AND RADIAL ARTERY

Abstract Background and Aims Arteriovenous fistula (AVF) is the preferential choice of haemodialysis (HD) access, but failure of maturation of AVF is common. A previous French study had demonstrated reduced primary patency of radial-cephalic fistula with anastomotic angles < 30°. We have designed a study to determine if the angle of anastomosis affects the maturation of AVF in Chinese patients. Method We retrospectively studied our chronic patients who underwent the first cephalo-radial end-to-side anastomosis of AVF surgery at our Hospital from November 2019 to September 2022. All AVFs have been constructed by two of our dedicated nephrologists. The nephrologists performed the dissection and construction of the anastomosis according to the patient's anatomy. The angle of the anastomosis was not decided a priori and special care was given not to kink or twist the vein during the procedure. The AVF was defined as mature at 3 months if the blood flow was ≥ 500 ml/min and/or if the AVF was able to support adequate dialysis thrice a week. The patients were divided into two groups for evaluation using 45° of the AFV's anastomotic angles as cut-offs. The study has been approved by the local research and ethics committee. Statistics analysis: The IBM SPSS Statistics 26 software was used. The baseline characteristics of the two groups were analyzed using univariate analysis to find out if there was any statistical difference. The K-M curve was used to analyze if there was any statistical difference in AVF maturation between the two groups. Logistic regression was used to analyze the rate of maturation between the two groups, adjusted for confounding factors (including baseline characteristics and variables that have been shown as risk factors in previous studies, such as age, female gender, diabetes, preoperative vessel diameter, etc.), to determine whether the angle of anastomosis was an independent factor. Results A total of 159 Chinese patients were included in the study. The overall AVF maturation rate at 3 months was 93.08% (148/159 cases). Table 1 showed the patients’ baseline characteristics based on the AVF outcome. Table 2 showed the patients’ parameters in relation to different anastomotic angles (group 1: anastomotic angle ≤45°; group 2: >45°). The median time to AVF maturation of either group was 5 weeks (P = 0.9057, 95% CI 0.725-1.421) with no statistical difference. There was no statistical difference between the two groups in terms of age, gender, preoperative venous and arterial diameters, states of diabetes, coronary heart disease, peripheral vascular diseases, smoking, or biochemical parameters. Multivariate logistic regression analysis showed that there was no statistical difference between the two groups in AVF maturation rate at 3 months (OR = 0.976, 95% CI 0.273-3.489, P = 0.971). There was also no statistical difference after adjustment (OR = 0.863, 95% CI 0.231-3.233, P = 0.827). Conclusion This study has not established nor confirmed to any meaningful degree any relationship between the anastomotic angle using 45° as a cut-off and the maturation rate of AVF in Chinese patients at 3 months. Our overall AVF maturation rate was very high and none of the traditional risk factors for failed AVF nor the degree of anastomotic angle have any demonstrable effect on AVF maturation. The success might have been in part due to the skill and dedication of the nephrologists as operators. A prospective study involving a bigger patient group is necessary to further explore the effect of anastomotic angle on AVF maturation if any.

A clinical randomized controlled trial: moxibustion at Laogong interval with Panax notoginseng promoted the maturation of arteriovenous fistulae

BackgroundWe aim to study the clinical effect of moxibustion at Laogong interval with Panax notoginseng on the short-term maturation and long-term patency of arteriovenous fistula.MethodsSeventy-four pre-dialysis uremic patients who received distal forearm radial-cephalic fistula creations were enrolled in this study and randomly assigned to the control group and experimental group. After arteriovenous fistula creations, the control group underwent handgrip exercise, and the experimental group received moxibustion at Laogong acupoint interval with Panax notoginseng. Both groups received a 12-week treatment and were followed up for 24 weeks in all at the following time points: before creations and 2, 4, 8, 12, 24 weeks after creations. The diameter of anastomosis, the diameter and outflow of draining-veins 5 cm above anastomosis, the diameter and outflow of brachial arteries evaluated the maturation and patency of arteriovenous fistula. Enzyme linked immunosorbent assay determined serum levels of endothelin and nitric oxide.ResultsThe maturity rate in the experimental group was significantly higher than that in the control group at 4 weeks after arteriovenous fistula creations (P = 0.048). The diameter of anastomosis, the diameter of draining veins, and the blood flow of draining veins increased in both groups during the whole 24 weeks. The diameter and blood flow of brachial arteries ascended in both groups during the previous 12 weeks. Compared with the control group, moxibustion at Laogong interval with Panax notoginseng significantly improved the value of the diameter of draining-veins (P = 0.016), the blood flow of draining-veins (P = 0.015), the diameter of brachial arteries (P < 0.001), and the blood flow of brachial arteries (P = 0. 012) at 2 weeks, and enhanced the blood flow of draining-veins (P = 0.029) and brachial arteries (P < 0.001) at 12 weeks. Serum levels of endothelin were significantly lower (P = 0.047), and serum levels of nitric oxide were markedly higher (P < 0.001) in the experimental group than that in the control group at 2 weeks after creations.ConclusionsMoxibustion at Laogong interval with Panax notoginseng was non-invasive and promoted the maturation of arteriovenous fistula at 4 weeks after creations. However, its long-term beneficial effect on patency at 24 weeks after creations was not significant.Trial registration Chinese Clinical Trial Registry, No. ChiCTR1900024042. Registered, http://www.chictr.org.cn/index.aspx

Baseline characteristics of arm vessels by preoperative duplex ultrasonography in Korean patients for hemodialysis vascular access.

Preoperative mapping with duplex ultrasonography is crucial for successful vascular access creation for hemodialysis. The aims of this study are to assess the baseline characteristics of arm vessels by preoperative duplex ultrasonography in Korean patients, to find out a preoperative duplex ultrasonography parameter precluding distal arteriovenous fistula creation, to assess the maturation failure rate of arteriovenous fistulas, and to identify associated risk factors. Preoperative duplex ultrasonography mapping for vascular access creation was done in all patients with end-stage renal diseases during the year 2015. The baseline data of duplex ultrasonography were retrospectively analyzed with follow-up clinical data. A total of 299 end-stage renal disease patients (mean age = 62 years, 62% male) were included. On preoperative duplex ultrasonography, mean diameters of radial artery and cephalic vein at wrist were 2.03 and 2.40 mm in the non-dominant arm and 2.10 and 2.26 mm in the dominant arm, respectively. The most common reason for precluding radial-cephalic arteriovenous fistula at wrist was small-sized cephalic vein. Multivariate logistic regression analysis revealed that the risk factors for inadequate vessels were warfarin treatment, old age (⩾75 years), and peripheral arterial occlusive disease. The rate of arteriovenous fistula maturation failure was 21% and vein diameter <2.5 mm was the only risk factor for arteriovenous fistula maturation failure by multivariate logistic regression analysis. Preoperative duplex ultrasonography evaluation is important to find out inadequate vessels for native arteriovenous fistula and to determine the location of vascular access.

Partial aneurysmectomy for treatment of autologous hemodialysis fistula aneurysm is safe and effective

ObjectiveThe purpose of this study was to evaluate the outcome and the factors associated with stenosis after treatment using partial aneurysmectomy for aneurysm in autologous arteriovenous fistulas. MethodsThis retrospective cohort study was conducted from July 2007 to June 2016 and included patients with complicated aneurysms in upper extremity autologous arteriovenous fistulas were treated by partial aneurysmectomy. Vascular ultrasound examination was performed every 6 months after the surgery. ResultsForty-one patients (median age, 37 years; 70.7% males) were included. Of the patients, 95.1% had a radial-cephalic fistula in the forearm and nearly 88% had 1 or 2 aneurysms in arteriovenous fistulas that had been created for 10 to 84 months. Technical success of partial aneurysmectomy was achieved in all patients. The access diameter (44.0 ± 5.1 mm vs 10.4 ± 1.8 mm; P < .01) and brachial artery blood flow (1618.2 ± 277.0 mL/min vs 772.1 ± 127.4 mL/min; P < .01) were significantly decreased after the surgery. The median follow-up time was 27 months (range, 12-43 months). The primary patency rates at 6 and 12 months were 100% and 95%, respectively. Loss of patency was due to stenosis of the remodeled fistulas, which occurred in seven patients (17%). Multivariate COX regression analysis revealed that diabetes (hazard ratio, 114.28; 95% confidence interval, 2.85-4583.94; P = .01) was a risk factor for the impaired primary patency rates. A larger postprocedure residual diameter trended to favor fistula patency (hazard ratio, 0.46; P = .07). Stenosis was successfully treated with percutaneous transluminal angioplasty. ConclusionsPartial aneurysmectomy is an effective and safe method for treating aneurysm of upper extremity autologous arteriovenous fistulas, leading to good 12-month primary patency and no aneurysm recurrence. Using a larger catheter to size the revised fistula during aneurysmectomy may increase access patency.

Improved outcomes with proximal radial-cephalic arteriovenous fistulas compared with brachial-cephalic arteriovenous fistulas

BackgroundBrachial-cephalic arteriovenous fistulas (BCFs) are associated with high-flow volumes, leading to potential risks such as arm swelling, steal syndrome, pseudoaneurysm (due to a pressurized access), and cephalic arch stenosis. We hypothesized that a proximal radial-cephalic fistula (prRCF) configuration mitigates these risks because a lower flow state is created. Furthermore, we also hypothesized that despite these lower flows, patencies (primary, primary assisted, secondary) are sustained. MethodsLeveraging a prospectively collected database supplemented with detailed medical record data, analyses of patients undergoing BCF and prRCF were completed (November 2008 through March 2016). Preoperative clinical and imaging characteristics, operative variables, and postoperative complications were reviewed. The primary end point was a composite of arm swelling, steal, and pseudoaneurysm at 2 years. Fistulograms and interventions (surgical revision, thrombectomy, endovascular treatment of cephalic arch stenosis) censored at 2 years were compared between configurations. Patencies were plotted using Kaplan-Meier techniques and compared using Cox proportional hazards. ResultsDuring the study period, 345 arteriovenous fistulas and 72 prosthetic grafts were primarily placed; 56 patients underwent BCF and 50 patients underwent prRCF with a mean follow-up of 1.8 ± 1.7 (standard deviation) years. Except for prRCF patients being older, there was no difference between the groups with regard to preoperative characteristics. The artery diameter used for anastomosis was significantly larger in the BCF group (4.0 ± 1.1 mm vs 2.6 ± 0.8 mm; P < .001), with higher flow volumes at 6-week ultrasound examination (1060 ± 587 mL/min vs 735 ± 344 mL/min; P < .001). Complications (arm swelling, steal, pseudoaneurysm) were significantly more common in the BCF group (P = .02). There was a trend, albeit statistically insignificant, for the BCF group to require more cephalic arch stenosis interventions. Of those patients needing dialysis within 1 year, both BCF and prRCF were successfully used in the majority of patients (n = 27 [66%] vs n = 25 [63%]; P = 1.0). Unadjusted and adjusted primary, primary assisted, and secondary patency rates were similar between the groups. ConclusionsprRCFs have fewer complications yet similar midterm durability compared with BCFs. When it is anatomically feasible, prRCFs should be constructed over BCFs because of their superior physiology and clinical outcomes.

Radial artery deviation and reimplantation inhibits venous juxta-anastomotic stenosis and increases primary patency of radial-cephalic fistulas for hemodialysis

Although the end cephalic vein-to-side radial artery arteriovenous fistula is the "gold standard" procedure for primary hemodialysis access, it is associated with high rates of primary failure because of the development of neointimal hyperplasia and juxta-anastomotic stenosis. We report initial results of a new approach to perform radial-cephalic fistulas, radial artery deviation and reimplantation (RADAR), designed to avoid juxta-anastomotic stenosis. RADAR patients' data were prospectively maintained and retrospectively reviewed and compared with a historical control group of traditional radial-cephalic fistulas created in the same center. Duplex ultrasound was used to monitor maturation (flow ≥500mL/min and venous diameter ≥5mm) and to diagnose juxta-anastomotic stenosis. Study end points were rates of maturation, juxta-anastomotic stenosis, reintervention, and primary and secondary patency. There were 53 RADAR fistulas performed (follow-up, 10.5± 2.6months) and compared with 73 control fistulas (follow-up, 12.0± 6.6months). RADAR fistulas had increased rates of maturation compared with control fistulas (75% vs 45% at 6weeks, P= .001; 92% vs 71% at 3months, P= .003) and decreased incidence of juxta-anastomotic venous stenoses (2% vs 41%; P= .001). At 6months, RADAR fistulas had increased primary patency (93% vs 53%; P< .0001) and secondary patency (100% vs 89%; P= .0003) and decreased incidence of reinterventions (10% vs 74%; P= .001) compared with control fistulas. No RADAR fistulas caused ischemic symptoms. The RADAR technique is associated with less juxta-anastomotic stenosis, increased maturation and patency, and fewer secondary interventions. These improved outcomes suggest that RADAR may be the preferred surgical technique to perform radial-cephalic arteriovenous fistula.

Increased reintervention in radial-cephalic arteriovenous fistulas with anastomotic angles of less than 30 degrees

Although radial-cephalic (RC) and brachial-cephalic (BC) fistulas are the recommended primary accesses for hemodialysis, access failure is frequently due to juxta-anastomotic stenosis (JAS). Because increased turbulence at the anastomosis may lead to JAS, we hypothesized that an acute angle at the arteriovenous anastomosis is associated with JAS, reduced fistula patency, and increased reinterventions. Between February 2013 and September 2014, the anastomotic angle and vessel diameters were prospectively collected for all patients who underwent RC or BC fistula creation. The primary end point was reintervention on the juxta-anastomotic segment. Secondary end points were primary and secondary patency of the fistula. A total of 149 patients (median age, 72 years) received 73 RC and 76 BC fistulas; the median follow-up was 7 months (range, 1-22 months) for RC and 12 months (range, 2-24 months) for BC fistulas. The median anastomotic angle in RC fistulas, was 30°. Anastomotic angles of <30° were associated with reduced primary patency (38% vs 66%, P = .003) and secondary patency (84% vs 97%, P = .02) and increased numbers of reinterventions (67% vs 34%, P = .001). Cox analysis showed that an anastomotic angle of <30° was an independent factor predicting decreased primary patency (P = .009) and secondary patency (P = .03) as well as increased reinterventions (P = .004). In BC fistulas, the median anastomotic angle was 90°. Patients with anastomotic angles <90° and ≥90° had similar rates of primary patency (67% vs 67%, P = .39) and secondary patency (93% vs 94%, P = .89) at 6 months, with a similar reintervention rate at 12 months (31% vs 32%, P = .56). Vein diameter was the only factor that predicted reintervention (P < .0001). RC fistulas with anastomotic angles of <30° have reduced primary and secondary patency and increased numbers of reinterventions, suggesting that, if possible, surgeons should avoid an anastomotic angle of <30° when creating RC fistulas. Anastomotic angles of <90° or ≥90° may not play a role in outcome of BC fistulas.

VESS15. Learning Curve for Fenestrated EVAR (FEVAR)

Objectives: Although radial-cephalic (RC)andbrachialcephalic (BC) fistulae are the recommended primary accesses for hemodialysis, access failure is frequently due to juxta-anastomotic stenosis. Experimental models show that the angle between the artery and the vein can induce disturbed flow that stimulates neointimal hyperplasia.We examinedwhether the anastomotic angle is associated with juxta-anastomotic stenosis and reintervention in RC and BC fistulae. Methods: Between February 2013 and September 2014, anastomotic angle and postoperative vessel diameters were prospectively collected for all patients after RC or BC fistula creation. The primary end point was reintervention on the juxta-anastomotic segment. Secondary end points were primary patency (PP) and secondary patency (SP) of the fistula. End points were calculated using Kaplan-Meier analysis, and multivariable analysis was performed using Cox regression. Results: A total of 149 patients (median age, 72 years) received 73 RC and 76 BC fistulae. Median follow-up was 7 months (range, 1-22 months) for RC and 12 months (range, 2-24 months) for BC fistulae. In RC fistulae, anastomotic angles$30 had fewer reinterventions (3months: 10% vs 36%; 6 months: 34% vs 67%; P 1⁄4 .001). Six-month PP and SP were also higher for angles $30 (PP: 66% vs 38%, P 1⁄4 .003; SP: 97% vs 84%, P 1⁄4 .02). Cox analysis showed that angle .2). Conclusions: Surgeons should ensure an anastomotic angle $30 when creating RC fistulae. Anastomotic angle may not play a role in outcome of BC fistulae.

VESS14. Increased Reintervention in Radial-Cephalic Arteriovenous Fistulae With Anastomotic Angles

Objectives: Although radial-cephalic (RC)andbrachialcephalic (BC) fistulae are the recommended primary accesses for hemodialysis, access failure is frequently due to juxta-anastomotic stenosis. Experimental models show that the angle between the artery and the vein can induce disturbed flow that stimulates neointimal hyperplasia.We examinedwhether the anastomotic angle is associated with juxta-anastomotic stenosis and reintervention in RC and BC fistulae. Methods: Between February 2013 and September 2014, anastomotic angle and postoperative vessel diameters were prospectively collected for all patients after RC or BC fistula creation. The primary end point was reintervention on the juxta-anastomotic segment. Secondary end points were primary patency (PP) and secondary patency (SP) of the fistula. End points were calculated using Kaplan-Meier analysis, and multivariable analysis was performed using Cox regression. Results: A total of 149 patients (median age, 72 years) received 73 RC and 76 BC fistulae. Median follow-up was 7 months (range, 1-22 months) for RC and 12 months (range, 2-24 months) for BC fistulae. In RC fistulae, anastomotic angles$30 had fewer reinterventions (3months: 10% vs 36%; 6 months: 34% vs 67%; P 1⁄4 .001). Six-month PP and SP were also higher for angles $30 (PP: 66% vs 38%, P 1⁄4 .003; SP: 97% vs 84%, P 1⁄4 .02). Cox analysis showed that angle .2). Conclusions: Surgeons should ensure an anastomotic angle $30 when creating RC fistulae. Anastomotic angle may not play a role in outcome of BC fistulae.

Use of the subcutaneous venous network of the forearm to create an arteriovenous fistula

The reconstruction of vascular access in patients with kidney allograft failure is a challenging problem. A case of a 62-year-old man with transplanted kidney insufficiency is described. The patient was initially dialyzed with a wrist radial-cephalic arteriovenous fistula. In the post-transplantation period, the enormously dilated venous part of the anastomosis was ligated and the part of the vein suspected of being the source of bacteremia was excised. The man was referred to our department due to kidney allograft failure for vascular access creation. During preoperative assessment, we unexpectedly found a soft thrill on the forearm. Doppler ultrasound confirmed fistula patency, although the blood supply was not sufficient to perform dialysis. Angiography showed the blood flow from the radial artery to the cephalic vein, through a complicated vessel system consisting of inter alia a dilated vein of the subcutaneous venous network. We successfully used this vein as the vascular access outflow for fistula recreation. In conclusion, making use of veins of the subcutaneous venous network of the forearm for creation of a native fistula should be considered in selected cases.

Upper limb vascular calcification score as a predictor of mortality in diabetic hemodialysis patients

This study evaluated the correlation between an upper limb vascular calcification (Vc) score (VcS) and late all-cause mortality in diabetic hemodialysis patients with distal upper limb arteries medial wall sclerosis (Mönckeberg disease). We retrospectively reviewed Vc in bilateral upper limb plain radiographs and in duplex ultrasound images performed before radial-cephalic fistula (RCF) creation in diabetic hemodialysis patients. Only medial linear calcifications outlining the vessel wall were considered positive on X-ray images, whereas for ultrasound reviews, only continuous highly echogenic plaques producing bright white echos with shadowing were considered to be medial calcification. A VcS was then applied in each patient. Every half of each of the three main arterial conduits (brachial, radial, and ulnar arteries) in each arm was counted as 1 if it contained ≥ 6 cm of linear calcification, whereas absence of calcification or minimum calcification (length <6 cm) was counted as 0. Long-term all-cause mortality was compared between patients with a low or moderate VcS <8 (group I), patients with a high VcS ≥ 8 (group II), and patients with VcS = 0 (control group). Kaplan-Meier statistics were used for comparisons among the groups. Nineteen patients had a VcS <8, 21 had VcS ≥ 8, and 43 patients had VcS = 0. The study patients had a mean age of 68 ± 10 years (range, 42-83 years; P = .23). Before early conversion to a RCF, dialysis therapy in 59 (71.1%) had already been initiated through central venous catheters (CVCs). The mean follow-up for groups I, II, and controls was 41.4 ± 41.2 months (range, 4-144 months), 34.15 ± 31.3 months (range, 1-108 months), and 66.7 ± 32.5 months (range, 12-126 months), respectively (P = .0009). Forty-seven patients died during the follow-up period (12 in group II and 24 in the controls; P = .88). Survival rates at 12, 24, 36, and 48 months were 78.3%, 65.7%, 54.8%, and 48.1% for group I; 75.2%, 58.8%, 49.3%, and 42% for group II; and 97.7%, 93.1%, 76.8%, and 71.8% for the control group, respectively (P = .013 for all groups; P = .044 for group II vs controls). Patients with (subgroups) or without CVCs at baseline had similar late mortality rates. Patients with CVCs/Vc had lower survival rates than those with CVCs/no Vc at 1 year (73.3% vs 96.5%) and at 3 years (47.7% vs 75.8%; P = .038). CVCs were related to increased risk of death only in subgroup II patients compared with the subcontrol group patients (75.4% vs 37.9% at 5 years, respectively; P = .034). Diabetic hemodialysis patients exposed to high levels of upper extremity arterial medial VcSs upon receiving RCFs have an increased long-term mortality risk compared with diabetic hemodialysis patients with no Vc and receiving the same access. Patients with CVCs/Vc had the lowest survival rates.

Tips and tricks in creation of forearm arteriovenous fistulae.

Forearm arteriovenous fistula (AVF) is a direct anastomosis between the radial artery and the cephalic vein or the ulnar artery and the basilic vein, which are small-caliber vessels. The surgical technique must be precise to avoid postoperative stenosis of the anastomosis which may result in early thrombosis or nonmaturation. In our experience, microsurgery and preventive hemostasis are two major contributions to creation of forearm AVF. Using these techniques, construction of a radial-cephalic fistula was possible in 78% of children in our hospital, with 60% secondary patency rates at 4 years. In a personal unpublished series, 69% of the first arteriovenous angioaccess of adult patients were forearm fistulae, with 63% and 91% primary and secondary 1-year patency rates, respectively. Finally, 68% primary patency and 96% secondary patency rates at 1 year were reported by Pirozzi et al. in adults with an internal diameter of <1.6 mm in the radial artery.

Percutaneous Transluminal Angioplasty for Radial-Cephalic Fistulae With Stenosis at the Arteriovenous Junction

IntroductionThe aim of this study was to analyze the predictive factors for initial success and long-term patency of percutaneous transluminal angioplasty for radial-cephalic (RC) fistulae with stenosis at the arteriovenous junction (AVJ). Stenosis at the AVJ of RC fistulae involves both the feeding artery and drainage vein and is similar to a bifurcation lesion, which carries a worse outcome. The optimal intervention method for this type of lesion is currently unknown. MethodsNinety-one percutaneous transluminal angioplasty procedures for stenosis at the AVJ of RC fistulae were reviewed retrospectively. Parameters including age, sex, location of the RC fistula (right or left arm), approach site (radial artery or cephalic vein) and involvement of proximal radial artery (PRA) dilatation were analyzed for initial procedure success and long-term patency rates. ResultsThe total initial success rate was 94.5%. The existence of total occlusion was recognized as the only factor significantly associated with a high procedural failure rate (39% versus 0%, P < 0.001). For long-term patency rate, the only significant factor was the involvement of PRA dilatation (P = 0.026 by Cox-Mantel and 0.03 by generalized Wilcoxon methods). The 6-month, 1-year and 18-month patency rates were 64%, 45.3% and 20.9%, respectively, for all procedures, and 70.7% versus 57.8%, 56.1% versus 35.6% and 36.6% versus 6.7% for procedures with and without PRA dilatation, respectively. ConclusionsIn treating stenosis at the AVJ of RC fistulae, while initial procedural failure occurred mainly in occluded lesions, involvement of PRA dilatation was the only significant predictive factor associated with long-term patency.

An Ode to Cimino

The aim of the study was to ascertain whether a Cimino First policy can be implemented successfully in tertiary practice using a standardized technique. This is a retrospective study. All first radial-cephalic (Cimino) fistulas placed by a single surgeon in incident patients were studied. A standardized surgical technique was used paying attention to the dorsal cephalic branch. No balloon maturation or early surveillance was performed. Kaplan-Meier survival analysis using survfit function in R (Vienna) was applied. Fifty-seven (69%) of 83 new accesses were radial cephalic fistulas. Of these, 44 (77.2%) were men. The patients were aged 17 to 83 (mean 54.1; SD 14.6) years. Whites comprised of 21 (36.8%), maori 18 (31.6%), and pacific islanders 16 (28.1%). Comorbidities included diabetes in 32 (56.1%), hypertension in 47 (82.5%), and hyperlipidemia in 25 (46.3%; n=54). Twenty-six (45.6%) were pre-dialysis. Mean body mass index was 30.74 (SD 6.9) Kg/m² (n=56). Mean vein diameter was 3.3 mm (range 2.1-6.2 mm; n=36). Twenty-six (45.6%) had had previous central lines. Forty-four (77.2%) fistulas matured. Mean maturation time was 14.0 weeks. Thirty-six (63.2%) were used for dialysis while eight patients remained pre-dialysis with patent fistulas. Primary patency at one year and 18 months was 69.2% and 57.4% respectively. The figures for assisted primary patency were 85.6% and 72.3% respectively. Secondary patency was 87.6% and 83.9% at one and two years. Cimino fistulas can be performed in a majority of patients with good results using a standardized surgical technique. The importance of the dorsal cephalic branch needs to be studied.

Drug-Eluting Stent for the Treatment of Early Fistula Failure

Introduction: Morbidity and mortality in chronic haemodialysis patients is related to dialysis efficiency. Several complications may occur with vascular access, usually associated with a stenosis. This is known to occur frequently in the venous outflow. Stenosis of the arterial side is not as frequently discussed, but it is also likely to compromise fistula function. Traditionally, surgical and percutaneous interventions have been used to treat failing fistulas, but the employment of drug-eluting stents for the treatment of failing fistulas due to the arterial stenosis has been described rarely. Methods: A 65-year-old male patient referred to our ambulatory because of hand ischemia during haemodialysis treatments only few days after radial-cephalic fistula creation. After physical and echo-color-doppler examination, angiography was performed and percutaneous intervention was proposed. After the positioning of a guiding catheter, the lesion was crossed with a 0.014” guide wire followed by direct drug-eluting stent implantation. Results: Final angiogram showed a good result and a preserved flow through the fistula. Six months later the patient was asymptomatic and the fistula was still working. Conclusion: Although further prospective studies are necessary, percutaneous transluminal angioplasty (PTA) with drug-eluting stents implantation could be considered a safe and effective technique for the treatment of arteriovenous fistulas stenosis.

Routine Preoperative Venous and Arterial Mapping Increases Both, Construction and Maturation Rate of Upper Arm Autogenous Arteriovenous Fistulae

To test the hypothesis that routine preoperative mapping and transposed brachial-basilic vein fistula (TBBVF) increases arteriovenous fistulae (AVFs) construction rates, without altering maturation rate. Over a 4-year period, 709 vascular accesses were performed, including 467 AVFs (radial-cephalic fistula [RCF], n = 217, brachial-cephalic fistula [BCF], n = 139, TBBVF, n = 111) and 251 prosthetic grafts. During the last 2 years, preoperative mapping was performed routinely by means of ultrasound, and TBBVFs were preferentially used over arteriovenous grafts (AVGs). Over the study, construction rate of upper arm AVF increased significantly from 12% to 53% and use of prosthetic grafts decreased from 55% to 19% (P < .001). Maturation rate of RCFs, BCFs, and TBBVFs during the first part of the study was 75%, 50%, and 30% (P = .003), compared to 79%, 82%, and 86% (P = .43), respectively, during the second part. Routine preoperative upper extremity mapping with ultrasound increases not only AVF construction rate, but also their maturation likelihood.

Management of perianastomotic stenosis of direct wrist autogenous radial-cephalic arteriovenous accesses for dialysis

Radial-cephalic fistulas (RCFs) perianastomotic stenoses (PASs) are on and around the fistula anastomosis. This group of lesions encompasses juxta-anastomotic stenosis (stenosis located on the venous side within 3 cm away from the anastomosis), anastomotic, and arterial stenosis. The purpose of our study was to assess the postintervention primary patency and assisted postintervention primary patency (APP) rates for surgery and angioplasty when treating these stenoses. The secondary endpoint was to identify factors that might influence the procedure's patency rates. This retrospective study included 73 consecutive patients treated for lack of maturation PASs between January 1999 and December 2005 in two interventional centers. Patients' mean age was 65 years old. Stenoses were treated by surgery (n = 21) or percutaneous transluminal angioplasty (PTA; n = 52). Surgery meant creation of a new anastomosis excluding the area of stenosis. Preoperative characteristics including the patient's age, gender, comorbidities, stenosis location, and length were not statistically different between the two groups. The mean follow-up was 39 months for PTA and 49 months for surgery. Anatomical and clinical success rates were 86% and 90% for surgery, and 75% and 92% for PTA. At 1 year, the primary patency rates were 71 ± 10% for surgery and 41 ± 6% for PTA, respectively (P < .02). There was no significant difference between the two groups with respect to assisted primary patency (95% vs 92%). In the PTA group, stenosis location at the anastomosis itself was a risk factor of early recurrence (P = .047). The complication rate was similar between surgery and PTA. Our results suggest that the treatment of anastomotic stenoses should be surgical rather than endovascular. Angioplasty and surgery have shown similar results when used to treat other perianastomotic stenoses, but repeat procedures were more frequent with angioplasty.

The middle-arm fistula as a valuable surgical approach in patients with end-stage renal disease

American and European guidelines recommend the distal radial-cephalic fistula (dRCF) as the first and best hemodialysis access in patients with end-stage renal disease (ESRD). However, this kind of arteriovenous fistula (AVF) shows a limited primary unassisted patency and frequently needs surgical revisions or angiographic procedures, or both. When dRCF is not feasible, guidelines suggest a proximal brachiocephalic AVF. The middle-arm fistula (MAF), or autogenous forearm radial-median direct access, has been suggested as a possible alternative approach. This study evaluated MAF primary unassisted patency, the most frequent causes of MAF failure, and the possible related factors. Data on patients with a MAF placed from January 1991 until June 2008 were retrospectively collected. The probability of MAF failure overall and by the main subgroups was estimated according to Kaplan-Meier with Greenwood standard error (SE). Comparison of failure among different subgroups was performed using the log rank test in univariate analyses. The Cox regression model was used to investigate factors that independently affected the overall hazard of failure and cause-specific hazard of thrombosis. At the end of follow-up, 14.0% of MAF failed (11.6% thrombosis, 1.7% stenosis, 0.7% failed maturation), and 44.2% of MAF were still working. Cumulative probability of MAF unassisted primary patency after 4 years from the creation was 79%. Univariate analyses highlighted that women (P = .019), underweight patients (P = .010), and MAF implantation after starting hemodialysis (P < .001) had a higher risk of MAF failure for any cause than men, normal and overweight patients, and MAF implanted before starting hemodialysis. Results of the Cox multivariate analysis for overall MAF failure confirmed that only MAF implantation before starting hemodialysis is a protective factor against any failure (P = .003), whereas female gender (P = .016) was associated with an increase of the thrombosis hazard ratio to 2.04 (95% confidence interval, 1.14-3.63). Our data demonstrate that MAF has a good unassisted primary patency and suggest that this kind of AVF could be a valuable alternative surgical approach when dRCF is not feasible in ESRD patients.