Editor's Choice – Vascular Access: 2018 Clinical Practice Guidelines of the European Society for Vascular Surgery (ESVS)

Out-Patient versus In-Patient Arteriovenous Fistula Creation for Dialysis: Assessing Cost-Effectiveness Alongside Clinical Implications

(1) Background: The surgical procedure to create an arteriovenous fistula (AVF) can be performed in either an ambulatory or in-patient hospital setting, depending on the case's complexity, the anesthesia type used, and the patient's comorbidities. The main scope of this study is to assess the cost-effectiveness and clinical implications of surgically creating an AVF in both ambulatory and in-hospital settings. (2) Methods: We conducted a retrospective observational study, in which we initially enrolled all patients with end-stage kidney disease (ESKD) admitted to the Vascular Surgery Department, Emergency County Hospital of Targu Mures, Romania, to surgically create an AVF for dialysis, between January 2020 and December 2022. The primary endpoint of this study is to assess the cost-effectiveness of surgically creating an AVF in an ambulatory vs. in-hospital setting by comparing the costs required for the two types of admissions. Further, the 116 patients enrolled in this study were divided into two groups based on their preference for hospitalization: out-patients and in-patients. (3) Results: Regarding in-patient comorbidities, there was a higher prevalence of peripheral artery disease (PAD) (p = 0.006), malignancy (p = 0.020), and previous myocardial infarction (p = 0.012). In addition, active smoking (p = 0.006) and obesity (p = 0.018) were more frequent among these patients. Regarding the laboratory data, the in-patients had lower levels of white blood cells (WBC) (p = 0.004), neutrophils count (p = 0.025), lymphocytes (p = 0.034), and monocytes (p = 0.032), but there were no differences between the two groups regarding the systemic inflammatory biomarkers or the AVF type. Additionally, we did not register any difference regarding the outcomes: local complications (p = 0.588), maturation failure (p = 0.267), and primary patency (p = 0.834). In our subsequent analysis, we discovered no significant difference between the hospitalization type chosen by patients regarding AVF primary patency failure (p = 0.195). We found no significant association between the hospitalization type and the recorded outcomes (all ps > 0.05) in both multivariate linear regression and Cox proportional hazard analysis. (4) Conclusions: In conclusion, there are no significant differences in the clinical implications, short-term and long-term complications of AVF for out-patient and in-patient admissions. Additionally, we found no variation in the costs associated with laboratory tests and surgical supplies for an AVF creation. Therefore, it is safe to perform ambulatory AVFs, which can reduce the risk of hospital-acquired infections and provide greater comfort to the patient.

Evaluation of arteriovenous fistula maturation and early prediction of clinical eligibility, using ultrasound: The Fistula Maturation Evaluation (FAME) Study

INTRODUCTION

The study of time-related alterations of ultrasound-determined parameters during maturation, and the assessment of time to hemodynamic maturation, enabling early prediction of clinical eligibility, of hemodialysis autologous arteriovenous fistulae (AVF).

METHODS

This is an observational, prospective, study of only AVF-eligible patients referred for access creation, from 02/2019 to 02/2022 (ClinicalTrials.gov identifier: NCT0473687). Brachial artery diameter (dBA), access flow volume (FV), non-augmented efferent vein diameter (dEV), resistivity index (RI), and efferent vein total wall thickness (tEV), were assessed by ultrasound. Measurements were conducted daily in the first week and repeated on days 14, 21, 30, 60, and 90, postoperatively. The primary endpoint included the documentation of serial changes of flow and structural parameters related to AVF maturation in the first 90 days of the post-operative period and maturation early prediction. Secondary endpoints included the determination of factors affecting maturation.

RESULTS

One hundred one participants (mean age, 67 ± 6 years; 76 males) were enrolled. Average dBA and FV reached maximum on day 60 (5.64 ± 0.85 mm) and 90 (1.172 ± 617 mL/min), respectively. Day 7 values of dBA (5.48 ± 0.73 mm) and FV (1.039 ± 531 mL/min) did not alter significantly during the follow-up period. Parameters indicative of clinical functionality, dEV (5.82 ± 0.90 mm) and tEV (0.493 ± 0.10 mm), reached approximately 90% of maximum (6.66 ± 1.42 mm and 0.526 ± 0.11 mm), by day 14. RI reached minimum on day 30 (0.46 ± 0.09), without significant changes after day 2 (0.48 ± 0.09, p = 0.284). A significant correlation was identified, between day 7 FV and day 60 dEV (r = 0.40, p = 0.0002). A FV cut-off value ⩾657.51 mL/min, on day 7, predicted successful fistula maturation with 85% sensitivity and 100% specificity. Multivariate analysis identified female gender, age >75, diabetes, and wrist access as independent predictors of decreased values of maturation parameters.

CONCLUSION

Hemodynamic maturation is completed by the first postoperative week, while AVF is clinically functional, by the second. FV can be used for early prediction of maturation.

Application of a supporting catheter in surgery for forearm arteriovenous fistula construction

INTRODUCTION

This study explored the feasibility of a supporting catheter combined with modified end-to-side anastomosis in the operation of radio-cephalic arteriovenous fistula (RC-AVF) and evaluated the clinical application value of this technique.

METHODS

Sixty patients underwent RC-AVF operations in our hospital from January 2022 to June 2022. All the patients were treated with modified end-to-side AVF anastomosis and divided into the control group or the test group depending on whether a supporting catheter was applied. The clinical data of 60 cases were analysed retrospectively. Intraoperative related indices, the first time the fistula was used, the success rate of first puncture, the blood flow of first dialysis, the maturity condition of fistula, the size of anastomosis, the diameter of radial artery and drainage vein, the blood flow of brachial artery 8 weeks after operation and the incidence of complications within 6 months after operation were compared between the two groups.

RESULTS

Compared with that in the control group, the time spent on the vascular anastomosis in the test group was significantly shortened (p<0.05). The blood flow of the first dialysis, the size of the anastomosis, the diameter of the drainage vein, the blood flow of the brachial artery 8 weeks after the operation and the incidence of complications within 6 months after operation were significantly different between the two groups (p<0.05).

CONCLUSION

In the RC-AVF operation, using a supporting catheter can not only increase operation efficiency by reducing surgical injury and difficulty of vascular anastomosis, but also improve postoperative prognosis. RC-AVF is worth promoting in clinical practice.

Impact of stage-specific limb function exercises guided by a self-management education model on arteriovenous fistula maturation status

BACKGROUND

The exercise of limb function is the most economical and safe method to promote the maturation of arteriovenous fistula (AVF). However, due to the lack of a unified exercise standard in China, many patients have insufficient awareness of the importance of AVF, leading to poor effectiveness of limb function exercise. The self-management education model can effectively promote patients to take proactive health-related actions. This study focuses on the characteristics of patients during the peri-AVF period and conducts a phased limb function exercise under the guidance of the self-management education model to observe changes in factors such as the maturity of AVF.

AIM

To assess the impact of stage-specific limb function exercises, directed by a self-management education model, on the maturation status of AVFs.

METHODS

This study is a randomized controlled trial involving 74 patients with forearm AVFs from the Nephrology Department of a tertiary hospital in Sichuan Province, China. Patients were randomly divided into an observation group and a control group using a random number table method. The observation group underwent tailored stage-specific limb function exercises, informed by a self-management education model which took into account the unique features of AVF at various stages, in conjunction with routine care. Conversely, the control group was given standard limb function exercises along with routine care. The assessment involves the maturity of AVFs post-intervention, postoperative complications, and the self-management level of the fistula in both groups patients. Analyses were conducted using SPSS version 23.0. Count data were represented by frequency and percentage and subjected to chi-square test comparisons. Measurement data adhering to a normal distribution were presented as mean ± SD. The independent samples t-test was utilized for inter-group comparisons, while the paired t-test was used for intra-group comparisons. For measurement data not fitting a normal distribution, the median and interquartile range were presented and analyzed using the Wilcoxon rank sum test.

RESULTS

At the 8-wk postoperative mark, the observation group demonstrated significantly higher scores in AVF symptom recognition, symptom prevention, and self-management compared to the control group (P < 0.05). However, the variance in symptom management scores between the observation and control groups lacked statistical significance (P > 0.05). At 4 wk after the operation, the observation group displayed a superior vessel diameter and depth from the skin of the drainage vessels in comparison to the control group (P < 0.05). While the observation group did manifest elevated blood flow rates in the drainage vessels relative to the control group, this distinction was not statistically significant (P > 0.05). By the 8-wk postoperative interval, the observation group outperformed the control group with notable enhancements in blood flow rates, vessel diameter, and depth from the skin of drainage vessels (P < 0.01). Seven days following the procedure, the observation group manifested significantly diminished limb swelling and an overall reduced complication rate in contrast to the control group (P < 0.05). The evaluation of infection, thrombosis, embolism, arterial aneurysm stenosis, and incision bleeding showed no notable differences between the two groups (P > 0.05). By the 4-wk postoperative juncture, complications between the observation and control groups were statistically indistinguishable (P > 0.05).

CONCLUSION

Stage-specific limb function exercises, under the guidance of a self-management education model, amplify the capacity of AVF patients to discern and prevent symptoms. Additionally, they expedite AVF maturation and mitigate postoperative limb edema, underscoring their efficacy as a valuable method for the care and upkeep of AVF in hemodialysis patients.

The influence of near-infrared therapy on arteriovenous fistula patency in haemodialysis patients: A multicentre, randomised, controlled clinical trial

BACKGROUND

Arteriovenous fistula (AVF) is the preferred vascular access for patients undergoing haemodialysis (HD). AVF malfunction remains a major clinical problem and is a significant independent risk factor for death. Although far-infrared (FIR) therapy has been shown to reduce complications and improve the patency rate of AVFs in various studies, it has been cautiously recommended by the Kidney Disease Outcome Quality Initiative (KDOQI) guidelines for AVF care due to insufficient evidence. Therefore, it is necessary to identify more effective methods for preventing AVF dysfunction. Many in vitro studies and few clinical studies have examined the effects of near-infrared (NIR) therapy on the vasculature. This study will examine the effects of NIR therapy on AVF.

METHODS

A randomised, controlled, open-label, multicentre trial will compare the effect of NIR on AVF patency after 1 year of therapy with that of a control group of patients with existing AVF. One group of patients received NIR treatment above their AVFs, whereas the control group received regular care. The primary outcome is the primary fistula patency rate within 12 months. In addition, acute changes in inflammatory, vasodilatory and haemodynamic parameters after a single treatment in the first 40 participants will be examined. This study was registered in the Clinical Trials Registry (ChiCTR2300071305) at https://register.clinicaltrials.gov/.

DISCUSSIONS

This study will explore the long-term and acute effects of NIR on AVFs. The study findings will provide information that can be used to develop new technical support for the prevention of AVF dysfunction in patients undergoing haemodialysis.

Assessment of volume flow rate in arteriovenous fistulas with a novel ultrasound Doppler device (earlybird): Trend analysis, comparison of methods, and inter- and intra-rater reliability

BACKGROUND

An accessible tool is required to analyze volume flow trends in arteriovenous fistulas for hemodialysis. Earlybird, an easy-to-place ultrasound Doppler device, has shown comparable accuracy to duplex ultrasound. In this study, we compared volume flow measurements obtained with duplex ultrasound and the dilution technique to an enhanced earlybird device, featuring a dual Doppler probe system, eliminating the requirement for a known insonation angle.

METHODS

Nine patients with a distal radiocephalic arteriovenous fistula were monitored for 12 months with regular volume flow measurements. Correlation and inter- and intra-class reliability analyses were conducted.

RESULTS

An overall moderate correlation was observed between earlybird and duplex ultrasound or dilution technique (intraclass correlation coefficient = 0.606 (95% confidence interval 0.064, 0.721) and 0.581 (0.039, 0.739), respectively). Duplex ultrasound compared to dilution measurements, demonstrated an overall moderate correlation (0.725 (0.219, 0.843)). Correlation between earlybird and duplex ultrasound was stronger for the arteriovenous fistula (0.778 (0.016, 0.901)) than the brachial artery (0.381 (-0.062, 0.461)). For earlybird, inter-rater reliability was excellent for the arteriovenous fistula (0.907 (0.423, 0.930)) and poor for the brachial artery (0.430 (0.241, 0.716)). Duplex ultrasound showed a good inter-rater reliability (arteriovenous fistula: 0.843 (0.610, 0.871), brachial artery: 0.819 (0.477, 0.864)). The overall intra-rater reliability was good for duplex ultrasound (rater A: 0.893 (0.727, 0.911); rater B: 0.853 (0.710, 0.891)), while excellent for earlybird (rater A: 0.905 (0.819, 0.928); rater B: 0.921 (0.632, 0.969)).

CONCLUSION

We observed a weaker correlation in the measurements of volume flow rates in arteriovenous fistulas when obtained using earlybird compared to dilution technique, unlike the comparison between duplex ultrasound and the dilution technique. However, inter-rater reliability for the arteriovenous fistula was excellent with earlybird and good with duplex ultrasound, indicating the potential of earlybird as a tool for frequent measurements, enabling trend surveillance and predicting adverse outcomes.

Preoperative mapping and multidisciplinary team are the key to success of arteriovenous access for hemodialysis

INTRODUCTION AND OBJECTIVES

Functional and durable vascular access is needed for adequate hemodialysis. Arteriovenous fistula is preferred over prosthetic grafts or central venous catheters, but it is associated with high rates of primary failure and maturation failure. Preoperative mapping of arm vessels with color Doppler ultrasound (CDU) has been shown to be helpful in achieving better short and long-term outcomes. Unfortunately, is more time-consuming than a physical examination and requires an experienced examiner and special equipment; some authors defend that CDU should not be part of the routine preoperative assessment. We reported our experience in preoperative vessel mapping using color Doppler ultrasound to purpose a vascular access to the surgical team, surveillance of vascular access, and evaluation of main outcomes (primary failure, maturation failure, and patency).

METHODS

This is a single-center retrospective study that includes patients who attended a specific appointment for vascular access planning consultation between January 2019 and December 2021. A nephrologist performed the physical exam and vascular mapping and proposed to the vascular surgeon team a specific type and location of vascular access. Patients were followed until one month after the first hemodialysis through functioning vascular access.

RESULTS

In this study, 167 patients were evaluated (114 incident patients - chronic kidney disease stage 4 or 5 - and 53 prevalent patients - under hemodialysis through central venous catheter). The vascular accesses proposed by nephrologist were radial-cephalic arteriovenous fistula in 70 patients (41.9%), brachio-cephalic arteriovenous fistula in 50 patients (29.9%), brachio-basilic arteriovenous fistula in 34 patients (20.4%), arteriovenous graft in 8 patients (4.8%) and central venous catheter in 2 patients (1.2%). Vascular access was constructed in 141 patients: distal arteriovenous fistula in 57 patients (40.4%), brachio-cephalic arteriovenous fistula in 54 patients (38.3%), brachio-basilic AVF in 27 patients (19.1%), and arteriovenous graft in 3 patients (2.1%). The created access corresponds to the proposed access in 129 patients (91.5%). Twenty-two (15.6%) primary failures were registered. Distal arteriovenous fistulas and diabetes mellitus were associated with a higher risk of primary failure (OR=3.929 (1.485-10.392), p=0.004; OR=3.867 (1.235-12.113), p=0.014, respectively). The incidence of maturation failure at eight weeks was 4.8%. The primary patency at 6, 12 and 24 months was 76.3%, 70.4% and 49.2%. Primary assisted patency was 84.8% at 6 and 12 months and 81.3% at 24 months.

CONCLUSIONS

This study demonstrates that the study of the entire vascular territory performed with color Doppler ultrasound, within a multidisciplinary team of nephrologists and vascular surgeons, is associated with high rates of autologous access and very low rates of primary failure and maturation failure (almost unprecedented in the literature).

Novel classification of proximal forearm perforator vein in the planning and creation of percutaneous and surgical Gracz-type arteriovenous fistulae

BACKGROUND

The perforator vein determines whether it is feasible to create a percutaneous (pAVF) or surgical "Gracz-type" arteriovenous fistula (sAVF). Creating a standard anatomic classification of the antecubital region is beneficial to both the selection of the appropriate device and/or procedure and technical outcomes. Accordingly, an analysis of a large cohort of patients undergoing pAVF/sAVF was performed, focusing on perforator vein anatomical suitability, and a novel anatomical classification of the antecubital region was developed and proposed.

METHODS

Between August 2018 and July 2022, chronic or end-stage kidney disease patients as well as patients anticipated an initiation of apheresis, who were referred for vascular access planning, underwent a standardized evaluation of upper extremities. A vessel mapping summary detailing the vasculature and the access creation plan was completed, indicating the anatomical suitability for sAVF and pAVF (Ellipsys and WavelinQ) techniques.

RESULTS

Of 524 patients, 36.5% were female (average age 65 years). 53.2% were on dialysis, 41.6% had diabetes, and 13.2% had a previously failed permanent dialysis access. The anatomy for successful pAVF creation was judged to be suitable in 54% of patients for an Ellipsys-pAVF, and 29.8% for WavelinQ-pAVF. Of the WavelinQ group, 54.4% had suitable anatomy for ulnar, 26.9% for radial, and 18.6% for both ulnar/radial anastomoses. Additionally, 60.7% had suitable anatomy for pAVF creation with at least one of the systems, while 22.5% were suited for both types of pAVF-systems. 80.3% were candidates for creation of a Gracz-AVF.

CONCLUSION

Overall, we found that about 60% of patients are likely candidates for a pAVF, with 80% being candidates for creation of a Gracz-AVF. Male patients have significantly higher suitability for most types of AVF creation, and younger patients are more suitable for Ellipsys-pAVF and RCAVFs. Most importantly, a universal classification of perforator vein was developed, which is indispensable in modern vascular access planning.

A rare hemodialysis vascular access complication-Internal jugular vein reflux

Hemodialysis (HD) arteriovenous fistulas commonly present with late vascular access complications, but are rarely in association with internal jugular vein (IJV) reflux. We reported two patients who had severe and mild IJV reflux, respectively. Case 1 was a 48-year-old male with end-stage renal disease (ESRD) who had been treated with HD for 5 years. He presented with persistent headaches, nausea, and vomiting. Combined with all the examinations, it was revealed severe IJV reflux, brachiocephalic vein stenosis, high-flow vascular access, and IJV valve dysfunction. Case 2 was a 59-year-old female with ESRD who had constructed an AVF for 4 months and had been on HD for only 1 day. She presented with dizziness and nausea after the first hemodialysis and duplex ultrasonography showed slightly continuous IJV reflux, high-flow vascular access, and IJV valve dysfunction. Furthermore, we reviewed 16 case reports to identify the characteristics of IJV reflux in HD patients. IJV reflux in HD patients may be caused by high-flow access, central venous stenosis or occlusion, and valve dysfunction. Severe IJV reflux can develop neurological symptoms secondary to intracranial venous reflux in this article. Etiological treatment is helpful for these patients, but there is a risk of recurrence.

Influence of renin-angiotensin system blockades on vascular access survival in patients on maintenance hemodialysis

INTRODUCTION

Results on the association between the use of renin-angiotensin system blockades (RASBs) and vascular access-related outcomes are inconsistent. We aimed to compare vascular access-related outcomes according to the use of RASBs in hemodialysis patients.

METHODS

This study used data from a national hemodialysis quality assessment program of the Republic of Korea (n = 54,903). Group 1 was not prescribed any blood pressure-lowering drugs (n = 28,521). Group 2 was prescribed other blood pressure-lowering agents except for RASBs (n = 9571). Group 3 was prescribed RASBs (n = 16,811). Vascular access-related outcomes were classified into intervention-free survival (IFS), thrombosis-free survival (TFS), and vascular access survival (VAS).

RESULTS

No significant difference in the three access survival rates was identified among the three groups. The multivariate Cox regression analyses indicated that Group 3 had better outcomes in IFS and TFS than Group 1. The numbers of angioplasties performed were significantly greater in Group 1 than in the other two groups. The numbers of thrombectomies performed were significantly the lowest in Group 3 among all the groups.

CONCLUSIONS

Our study revealed different results according to types of access survival in univariate or multivariate analyses. The association of RASBs with favorable outcomes in vascular access remains unclear.

Risk factors for in-stent restenosis in maintenance hemodialysis patients with central venous occlusive disease and biomechanical assessment of stents

OBJECTIVES

To investigate the risk factors and biomechanical mechanisms of in-stent restenosis (ISR) in central venous occlusive disease (CVOD).

PATIENTS AND METHODS

This retrospective study consecutively included 77 maintenance hemodialysis (MHD) patients with CVOD who received the first percutaneous transluminal angioplasty with stenting (PTS) due to symptomatic CVOD in a tertiary hospital. The mean age was 59.7 ± 14.0 years, and 51.9% of patients were male. The clinical characteristics, occurrence of ISR and patency rates were recorded. Finite element method was applied to assess the biomechanical properties of stents.

RESULTS

Among 77 patients with a mean CVS score of 8.0 ± 2.8, 20.8%, 62.3%, and 16.9% of patients had the main vein of CVOD in the subclavian vein, brachiocephalic vein, and superior vena cava, respectively. A total of 72 (93.5%) patients received successful PTS treatment, for which the stents implanted were mainly Fluency covered stent (48.6%) and SMART bare stent (31.9%). During 15 (10-24)-months of follow-up, ISR occurred in 36.1% of the 72 patients. The primary and assisted primary patency rates at 6, 12, and 18 months were 78%, 56%, 42% and 95%, 90%, 87%, respectively. A prolonged dialysis vintage was an independent risk factor for ISR, yet the stent type or the main vein location was not correlated with ISR. Among three laser-engraving stents, the SMART stent was the best in terms of flexibility, stress, and strain on stents but worst in stress or strain on vessels. The Luminexx stent was the best in radial force and worst in stress or strain on stents. The Vici stent was the best in stress and strain on vessels and worst in radial force and flexibility.

CONCLUSIONS

An unsatisfactory comprehensive biomechanical performance from configurations rooted in existing stents may account for the high incidence of ISR in CVOD.

The difference in diameter between radial artery and cephalic vein correlates with primary patency of radio-cephalic arteriovenous fistula

INTRODUCTION

Autogenous radio-cephalic arteriovenous fistula (RCAVF) is preferred for chronic hemodialysis access. However, RCAVF still suffers from disappointing survival due to fistula dysfunction, with intimal hyperplasia (IH) as an underlying cause of this condition. The inconsistency of radial artery diameter (DRA) and cephalic vein diameter (DCV) is one of the factors affecting the shear disturbance, which is believed to trigger the onset of IH. However, there are no reports correlating the difference in DRA and DCV with RCAVF outcomes.

METHODS

This was a retrospective cohort study. Consecutive patients (n = 233) with a new RCAVF created were included if they underwent duplex ultrasound examination to evaluate preoperatively the radial artery diameter (DRA) and cephalic venous diameter (DCV). We then calculated radial artery-cephalic vein diameter difference (DCV minus DRA, termed DCV-DRA hereafter) and evaluated the association of the preoperative DCV-DRA with primary patency of RCAVF at 12 months. Subgroup analysis was also performed to explore effect modification by age, gender, radial artery diameter, and cephalic vein diameter with DCV-DRA.

RESULTS

After adjusting for age, gender, weight, and mean arterial pressure, the preoperative DCV-DRA was associated with primary patency of RCAVF at 12 months (adjusted Odds ratio [aOR], 1.524 per 1-mm increase; 95% confidence interval [95% CI], 1.048-2.218). The primary patency of RCAVF at 12 months was achieved in 69.4%, 71.8%,and 87.3% of patients with a preoperative DCV-DRA of ⩽-0.6 mm, (-0.5)-0.5 mm, and ⩾0.6 mm, respectively. P for trend was 0.029. Patients with DCV-DRA of ⩾0.6 mm had a much higher chance of 12-month patency than patients with DCV-DRA of ⩽-0.6 mm (aOR, 3.574; 95% CI, 1.276-10.010). Age, gender, radial artery diameter, and cephalic vein diameter did not modify the association of DCV-DRA with primary patency of RCAVF at 12 months.

CONCLUSIONS

Preoperative DCV-DRA may be an under-recognized predictor of RCAVF patency.

Y-shaped stenting of brachiocephalic vein in a symptomatic hemodialysis patient

Stenosis or obstruction of neck great veins represent a frequent and severe complication in hemodialysis patients. Endovascular treatment with percutaneous transluminal angioplasty and/or stenting of these veins is the gold standard to restore patency. However, the jugular vein is frequently overstented in these cases and this might lead to persistent symptomatology of those patients also losing an access for future catheter placement. Herein, we present the 6-months performance of a Y-shaped stenting of the brachiocephalic and internal jugular vein leading to complete resolution of the symptoms, and maintenance of the jugular vein access.

A meta-analysis of vascular access outcomes in hemodialysis patients aged 75 years or older

BACKGROUND

Several existing guidelines advocate the access creation without any specific recommendations for those patients over 75 years of age. The aim of this meta-analysis is to compare the outcomes of different vascular access procedures in the sub-group of elderly ESRD patients ⩾75 years of age.

METHODS

A literature search was performed using the MEDLINE and SCOPUS electronic databases. The analysis focused on studies with subgroups of elderly patients ⩾75 years of age with different vascular access procedures, and compared the failure rates of autologous versus prosthetic vascular access. Articles comparing patency rates of distal (forearm) versus proximal upper arm AVFs were also investigated.

RESULTS

Twelve relevant studies were identified and included in the meta-analysis. The pooled results revealed a statistically significant unassisted (primary) failure rate at 24 months in favor of autologous AVFs [odds ratio (OR): 0.56, 95% CI: 0.38-0.83, p = 0.003]. A secondary analysis revealed significantly higher 12 months unassisted (primary) and secondary failure rates of forearm AVFs compared with proximal upper arm AVFs (OR: 2.14, 95% CI: 1.53-2.97, p < 0.00001 and OR: 1.76, 95% CI: 1.12-2.78, p < 0.01 respectively).

CONCLUSION

An increased risk of failure of prosthetic vascular access procedures was found compared with autologous AVFs in patients ⩾75 years of age. Elderly patients ⩾75 years should not be excluded from creation of an autologous access, with proximal upper arm AVFs having better patency rates.

Comparing post-maturation outcomes of arteriovenous grafts and fistulae

BACKGROUND

Though arteriovenous grafts (AVG) mature more reliably than arteriovenous fistulae (AVF) and require fewer maturation procedures (MP) to obtain functional patency, AVG are thought to have worse function after maturation. We explored differences in post-maturation outcomes between the following groups: AVF patients who did (AS-AVF) and did not (unAS-AVF) require assisted maturation and AVG patients who did (AS-AVG) and did not (unAS-AVG) require assisted maturation.

METHODS

Using the US Renal Data System (2012-2017), we retrospectively identified patients who initiated dialysis with a central venous catheter, underwent AVF or AVG placement and achieved successful two-needle cannulation. Primary patency and access abandonment after maturation were compared across groups using competing risks regression methods, generating sub-hazards ratios (sHR).

RESULTS

We identified 42,664 AVF and 12,335 AVG that met inclusion criteria. A larger proportion of AVFs required interventions: 18,408 AVF (43.2%) versus 2594 AVG (21.0%; p < 0.01). Both AS-AVG and AS-AVF patients experienced patency loss at 1 year more frequently compared with unAS-AVG (67.5% & 57.5% vs 55.2% respectively). Patency loss was lowest in unAS-AVF (38.9%). These trends were robust on adjusted analysis (unAS-AVG reference, AS-AVG sHR = 1.44, p < 0.01; AS-AVF sHR = 1.08, p < 0.01, unAS-AVF sHR = 0.67, p < 0.01). AS-AVGs were more likely to be abandoned than unAS-AVGs (11.7% unAS-AVG vs 17.2% AS-AVG). Fistulae, assisted or not, had lower unadjusted rates of 1-year abandonment than grafts (8.9% AS-AVF vs 7.3% unAS-AVF). On adjusted analysis, AVF usage was protective against abandonment (unAS-AVG, reference; AS-AVF sHR = 0.67, p < 0.01; unAS-AVF sHR = 0.59, p < 0.01) while AS-AVG was not (AS-AVG sHR = 1.32, p < 0.01).

CONCLUSIONS

unAS-AVF have the best long-term outcomes. AS-AVF lose primary patency at a higher rate than unAS-AVG. AVGs may be a better choice than AVFs if veins are marginal and likely to require assisted maturation. Further research is needed to identify anatomic and physiologic factors that affect long-term performance and influence conduit choice.

The impact of stent-graft sizing on venous stenosis re-intervention and arteriovenous graft patency: Free-floating stent outflow is associated with improved outcomes

BACKGROUND

Early cannulation arteriovenous grafts (ecAVG) for dialysis access are limited by reintervention for venous stenosis (VS) despite their good initial patency. Whilst stent-grafts (SG) have shown promise, the optimal sizing is unclear. Therefore, this study aims to determine if outflow vein diameter, SG diameter or these relative to each other (V:Sr) alters outcomes, and if so, which is more important.

METHODS

Retrospective analysis was performed of Gore® Acuseal® ecAVGs with VS treated with Gore® Viabahn® SG over a 7-year period. Primary patency (PP), time to thrombosis and functional patency were analysed by SG length/diameter, vein diameter and V:Sr.

RESULTS

We identified 114 ecAVGs with median follow-up 492 days (IQR 189-770). SG length and diameter did not correlate with PP, however, there was a significant relationship between vein diameter and PP (RR = 0.901 (0.832-0.975), p = 0.01) and between V:Sr and PP (RR = 0.462 (0.255-0.838), x2 = 5.866, p = 0.0015). The optimal V:Sr was ⩾1.4 (i.e. vein diameter at least 40% greater than the stent-graft; or 'free-floating' stent outflow) (RR = 2.759 (1.670-4.558), p < 0.001), translating to a difference in median PP of 252 versus 496 days (IQR: 188-316; 322-670). On multivariate analysis, absolute vein diameter lost significance, whilst V:Sr remained an independently significant predictor of PP (RR = 3.247 (1.560-6.759), p = 0.02).

CONCLUSIONS

Placement of the SG outflow into a relatively larger segment of vein was associated with a significant increase in PP independent of the absolute vein diameter. This suggests that larger calibre SG which are apposed to the vein wall are not required for optimal primary patency, and indeed should be actively avoided. Instead, a 'free-floating' stent outflow which is undersized relative to the recipient vein (whilst maintaining a minimum anchoring calibre) is recommended where possible. This should be considered during intervention and may require selection of longer devices, where practical, to bring the stent outflow into a larger vein segment.

LEVEL OF EVIDENCE

Level 3a, Non-randomised controlled cohort/follow-up study.

Doppler ultrasound assessment of calcified radial arteries prior to radio-cephalic arterio-venous fistula placement: an observational study

BACKGROUND

In elderly and diabetic patients, arterial calcifications are prevalent and result in worse outcomes of arterio-venous fistulas (AVFs). Optimal ultrasound criteria for assessment of calcified arteries are unknown. We report our experience with ultrasound assessment of calcified arteries prior to placement of radio-cephalic (RC) AVFs.

MATERIAL AND METHODS

We included 85 patients in whom a RC-AVF placement was planned. Patients were divided according to the presence of radial artery calcifications into a calcified group (moderate/severe calcifications, N = 18) and control group (no changes/mild atherosclerosis, N = 67). Doppler ultrasound parameters were analyzed in the calcified group with focus on assessment of the artery, including grading of calcifications and Doppler measurements at rest and during reactive hyperemia (RH).

RESULTS

In the calcified group mean patients' age was 72 ± 11 years, 72% were diabetics, mean resistance index (RI) during RH was 0.78 ± 0.09 (range 0.63-0.90). In 14 (78%) patients an AVF was successfully placed and in 12 it matured (67% maturation rate). A lower RI at rest was observed in the primary failure sub-group with high area under the ROC curve (0.89) and a cut-off value of 0.90 for RI. There was no difference in RI at RH between failed and matured AVFs. 1-year secondary patency was 66% and in eight patients with follow-up ultrasound available, blood flow was 350-1300 ml/min. For comparison, in the control group a radio-cephalic AVF was placed in all patients, primary failure rate was 6%, maturation rate 85% and 1-year secondary patency was 77%.

CONCLUSIONS

Our very limited experience suggests that successful RC-AVF placement and maturation with good 1-year patency rates is possible in patients with moderately/severely calcified arteries and RI during RH of up to 0.90.

A scoping review on surgical reduction of high flow arteriovenous haemodialysis access

Volume flow (Qa) > 1.5-2 l /minQa in arteriovenous accesses may be associated with high flow related systemic or locoregional complications. A variety of surgical techniques are advocated for Qa reduction. Aim of this scoping review is to provide an overview of available evidence regarding the efficacy of this broad spectrum of interventions for Qa reduction in patients with a high flow haemodialysis access. PubMed and Embase were searched according to PRISMA-guidelines. Studies on invasive management of HFA were selected. Inclusion required an English description of surgical techniques in human HFAs including pre- and postoperative access flow-values. Sixty-six studies on 940 patients (mean age 56 years (3-90 years), male 62%, diabetes mellitus 26%, brachial artery-based arteriovenous access 65%) fulfilled inclusion criteria. Performed techniques were banding (58%), revision using distal inflow (12%), plication/anastomoplasty (10%), graft interposition (5%), proximal radial artery ligation (3%), aneurysm repair (4%), or miscellaneous other techniques (8%). Definition of HFA, work-up, indication for surgery and intraoperative monitoring were diverse. All techniques reduced Qa on the short term (mean drop 0.9-1.7 l/min). Secondary access patency rates varied between 70% and 93% (mean follow-up 15 (0-189) months). Definitions of success and recurrence varied widely precluding a comparison of efficacy of techniques. Patient specific factors legitimizing invasive treatment for HFA are discussed. Recommendations on reporting standards when dealing with HFA surgery are provided. In conclusion, the present report on the current management of high flow access does not allow for drawing any definite conclusions due to a lack of standardization in definition, indications for surgical intervention and techniques. Randomized trials comparing different Qa reducing techniques in symptomatic patients are warranted, as are trials comparing a wait-and-see approach versus Qa reduction in asymptomatic patients. As an overview of the variety of techniques was lacking, this scoping review might serve as a map for future researchers.

Outcomes of stent grafts for treatment of central venous disease in hemodialysis patients

BACKGROUND

To evaluate the effectiveness of stent graft (SG) for the treatment of central venous disease (CVD) in hemodialysis patients.

METHODS

Between January 2014 and April 2022, 122 patients on hemodialysis with symptomatic CVD were treated with percutaneous transluminal angioplasty (PTA) and bare-metal stent (BMS) or SG placement. The mean follow-up was 14.5 months (IQR: 8.0, 24.2). Patency rates of the target sites were calculated using Kaplan-Meier and log-rank studies. Multivariate Cox proportional hazard models were used to evaluate the association between various characteristics and target site primary patency.

RESULTS

Technical success rate was 100%. At 3, 6, 12, and 24 months, the target sites primary patency rates were 86.4%, 74.2%, 45.1%, and 30.4% for PTA; 94.7%, 78.6%, 60.8%, and 45.6% for BMS; and 94.0%, 92.0%, 82.4%, and 66.8% for SG, respectively, and the assisted primary patency rates were 86.5%, 80.4%, 63.8%, and 46.0% for PTA; 94.7%, 89.5%, 77.5%, and 71.1% for BMS; 100%, 100%, 97.8%, and 83.4% for SG, respectively. The Kaplan-Meier analysis indicated that SGs achieved better primary and assisted primary patency than PTA or BMS (p<0.05). SG use and concomitant stenosis were the independent predictors of target site primary patency dysfunction in the multivariate analysis.

CONCLUSIONS

This study confirmed the better long-term patency of SG in comparison with PTA and BMS for the treatment of CVD in hemodialysis patients.

Dialysis for older adults: why should the targets be different?

The number of patients aged > 75-years treated by dialysis continues to increase, particularly in developed countries. Haemodialysis is a well-established treatment with national and international clinical guidelines designed to provide patients with optimal treatment. However, these were developed when the dialysis population was younger, and less co-morbid. This change in patient demographics questions whether these guideline targets still apply to older patients. More patients now start dialysis with residual kidney function and could benefit from a less frequent dialysis schedule. Older patients have a lower thirst drive, so lower interdialytic gains, reduced appetite, muscle mass and physical activity would potentially allow starting dialysis with less frequent sessions a practical option. Similarly, patients with residual kidney function and lower metabolic activity may not need to meet current dialyser Kt/Vurea clearance targets to remain healthy. Instead, some elderly patients may be at risk of malnutrition and might need liberalisation of the low salt, potassium and phosphate dietary restrictions, or even additional supplements to ensure adequate protein intake. Although a fistula is the preferred vascular access, a forearm fistula may not be an option due to vascular disease, while a brachial fistula can potentially compromise cardiovascular reserve, so a dialysis catheter becomes the de facto access, especially in patients with limited life expectancy. Thus, clinical guideline targets designed for a younger less co-morbid dialysis population may not be equally applicable to the older patient initiating dialysis, and so a more individualised approach to dialysis prescription and vascular access is required.

Axillary necklace graft salvage of a locally infected Haemodialysis with Reliable Outflow (HeRO®) graft

BACKGROUND

A 48-year-old patient presented 4 months after insertion of a right sided Haemodialysis with Reliable Outflow (HeRO®, Merit Medical) graft with a discharging abscess at the site of the brachial artery anastomosis. There was localised involvement of the arterial Gore® Acuseal inflow graft that necessitated its removal. The venous outflow component was thought salvageable as infection was well localised to the region of the antecubital fossa.

OBJECTIVES

Alternative access options were limited so we sought to preserve the venous outflow portion of the patient's original graft - minimising tissue damage and avoiding the need for a dialysis line.

METHODS

The infected arterial graft was excised, leaving behind the original SuperHero® connector and venous graft. A left sided tunnelled axillary necklace technique was utilised to restore arterial inflow.

RESULTS

After a four-day recovery, the patient went on to successfully resume their usual haemodialysis regimen without any complications. Convalescent imaging, repeat blood cultures, and monitoring of inflammatory markers showed no signs of residual infection at 6 weeks.

CONCLUSIONS

The originality of this case was the way in which an axillary necklace inflow graft was connected to the pre-existing venous outflow portion of the HeRO® haemodialysis graft system, allowing the excision of the infected inflow graft at the brachial anastomosis. This technique could be viewed as an effective salvage procedure as it allowed the venous outflow portion of the original graft to remain in situ, minimised tissue damage and enabled the patient to swiftly resume haemodialysis without the need for a line.

Zero upper arm hemodialysis fistulas: utopian or realistic goal?

BACKGROUND

Although distal native fistula is the best first-line vascular access (VA), upper arm fistula (UAF) prevalence is increasing worldwide, except in Japan. Our previous survey on 50% of hemodialysis patients (HP) revealed a prevalence of UAF of less than 5%, which is lower than the findings published by the DOPPS 5 study in our country. We analyzed the VA prevalence on 100% of HPs from our department.

METHODS

In December 2021, we investigated the prevalence of vascular access of 1295 hemodialysis patients from 17 dialysis factories. VAs were classified according to location into distal forearm fistula (DFF), middle-proximal forearm fistula (MPFF), and UAF. The department manages VA using a Hub and Spoke model. The hub performs simple and complex VA including Graft placement, the Percutaneous Transluminal Angioplasty (PTA) of fistulas and central stenosis, and the surgical and endovascular rescue of thrombosed or stenotic fistulas. The spokes perform mainly simple DFFs.

RESULTS

The mean age of 1295 HP (35% females and 21% diabetics) was 69 ± 12.4 years; 506 (39%) were over 75 years old. The prevalence of DFF, MPFF, UAF, GRAFT, and CVC was 63.5%, 10.1%, 3%, 0.7%, and 22.5%, respectively. Data comparison between our two surveys revealed a lower MPFF, UAF, and GRAFT prevalence and increased CVC prevalence. Patients aged 75 years or older, women, and diabetics showed a higher frequency of CVC and a lower prevalence of DFF.

CONCLUSIONS

The findings confirm the low prevalence of UAF found in our prior survey, demonstrating that UAFs can be reduced to 5% or less, as seen in Japanese experience.

Arteriovenous Fistula Closure Using a Simple Ligation Technique After Kidney Transplantation

BACKGROUNDS

There are advantages and disadvantages with closure of an arteriovenous fistula (AVF) after kidney transplantation, but some cases require closure. The general procedure for closure is angioplasty with exposure of the anastomotic site, but this is often time-consuming and complicated. We have developed a simpler, less invasive, and shorter procedure for AVF closure, in which the anastomotic site itself is not peeled off and the outflow vein close to this site is ligated using 1-0 silk. In this study, we examined the utility of this procedure.

METHODS

A retrospective case series study was conducted by review of electronic medical records of patients and surgeries. All patients (n = 52) who underwent AVF closure after kidney transplantation at our hospital between January 2008 and April 2021 were reviewed. Perioperative and long-term postoperative results were examined. This study was carried out following the ethical standards of the Declaration of Helsinki and Istanbul. Donors were not from prisoners, or from those individuals who are coerced of paid.

RESULTS

Simple ligation was performed for 46 patients (88.5%). The median time after renal transplantation was 40 (24.5-66.5) months. Median operative time and blood loss were 20 (12.2-30) minutes and 10 (5-15) mL, respectively. Two patients (4.3%) developed the aneurysm after the AVF closure using the simple ligation.

CONCLUSION

The simple ligation technique had a relatively shorter operative time and only 2 cases had aneurysm formation. These results suggest that this technique is an option for closure of an AVF after kidney transplantation.

Improving accuracy of vascular access quality classification in hemodialysis patients using deep learning with K highest score feature selection

OBJECTIVE

To develop and evaluate a novel feature selection technique, using photoplethysmography (PPG) sensors, for enhancing the performance of deep learning models in classifying vascular access quality in hemodialysis patients.

METHODS

This cross-sectional study involved creating a novel feature selection method based on SelectKBest principles, specifically designed to optimize deep learning models for PPG sensor data, in hemodialysis patients. The method effectiveness was assessed by comparing the performance of multiple deep learning models using the feature selection approach versus complete feature set. The model with the highest accuracy was then trained and tested using a 70:30 approach, respectively, with the full dataset and the SelectKBest dataset. Performance results were compared using Student's paired t-test.

RESULTS

Data from 398 hemodialysis patients were included. The 1-dimensional convolutional neural network (CNN1D) displayed the highest accuracy among different models. Implementation of the SelectKBest-based feature selection technique resulted in a statistically significant improvement in the CNN1D model's performance, achieving an accuracy of 92.05% (with feature selection) versus 90.79% (with full feature set).

CONCLUSION

These findings suggest that the newly developed feature selection approach might aid in accurately predicting vascular access quality in hemodialysis patients. This advancement may contribute to the development of reliable diagnostic tools for identifying vascular complications, such as stenosis, potentially improving patient outcomes and their quality of life.

Elevated Leukocyte Glucose Index Is Associated with Long-Term Arteriovenous Fistula Failure in Dialysis Patients

(1) Background: Arteriovenous fistula (AVF) is the preferred type of vascular access for dialysis in patients with end-stage kidney disease (ESKD). However, the primary patency of AVF at one year is under 70% due to several risk factors and comorbidities. Leukocyte glucose index (LGI), a new biomarker based on blood leukocytes and glucose values, has been found to be associated with poor outcomes in cardiovascular disease. The aim of this study is to analyze the impact of LGI on the long-term primary patency of AVF following dialysis initiation. (2) Methods: We conducted a retrospective observational study in which we initially enrolled 158 patients with ESKD admitted to the Vascular Surgery Department of the Emergency County Hospital of Targu Mures, Romania, to surgically create an AVF for dialysis between January 2020 and July 2023. The primary endpoint was AVF failure, defined as the impossibility of performing a chronic dialysis session due to severe restenosis or AVF thrombosis. After follow-up, we categorized patients into two groups based on their AVF status: "functional AVF" for those with a permeable AVF and "AVF failure" for those with vascular access dysfunction. (3) Results: Patients with AVF failure had a higher prevalence of atrial fibrillation (p = 0.013) and diabetes (p = 0.028), as well as a higher LGI value (1.12 vs. 0.79, p < 0.001). At ROC analysis, LGI had the strongest association with the outcome, with an AUC of 0.729, and an optimal cut-off value of 0.95 (72.4% sensitivity and 68% specificity). In Kaplan-Meier survival analyses, patients in the highest tertile (T3) of LGI had a significantly higher incidence of AVF failure compared to those in tertile 1 (p = 0.019). Moreover, we found that patients with higher baseline LGI values had a significantly higher risk of AVF failure during follow-up (HR: 1.48, p = 0.003). The association is independent of age and sex (HR: 1.65, p = 0.001), cardiovascular risk factors (HR: 1.63, p = 0.012), and pre-operative vascular mapping determinations (HR: 3.49, p = 0.037). (4) Conclusions: In conclusion, high preoperative values of LGI are positively associated with long-term AVF failure. The prognostic role of the biomarker was independent of age, sex, cardiovascular risk factors, and pre-operative vascular mapping determinations.

Lipectomy as an alternative for superficialization of autologous AVF in obese patients: experience of a referral center in Amazon

Background

The preferred vascular access for hemodialysis is a native arteriovenous fistula (AVF) because it offers the best results in the short and long terms, lower morbidity and mortality, and has additional advantages in relation to central venous catheters or arteriovenous grafts. However, obesity can present an additional challenge because of the barrier of subcutaneous cellular tissue covering the surface of the vein to be punctured.

Objectives

The authors review their experience with excision of subcutaneous tissue (lipectomy) overlying upper arm cephalic vein arteriovenous fistulas in obese patients.

Methods

Consecutive vascular access patients undergoing lipectomy for cannulation with difficult access because of vein depth were reviewed. Cephalic vein depth was measured by ultrasound in all cases.

Results

Twenty-two patients were reviewed (15 men and 7 women), with a mean body mass index of 34.0 kg/m2 (range: 28-40 kg/m2). Mean age was 58.4 years. The mean preoperative vein depth of 7.9 mm (range: 7.0-10.0 mm) was reduced to 4.7 mm (range: 3.0-6.0 mm) (P 0.01). The mean follow-up period for patients was 13.2 months. Four patients were lost to follow-up and four died during the period due to causes unrelated to vascular access.

Conclusions

Obesity should not be a limiting factor to creation of a native AVF, since lipectomy is a relatively simple option for superficialization, enabling functioning native and deep arteriovenous fistulas in obese patients.

The Tunnelled Atrial Catheter: A Promising Solution for Vascular Capital Depletion in Dialysis despite Associated Thrombi

Introduction

Longer survival in dialysis led to a higher incidence of vascular access complications and failure. With the limited access to kidney transplantation programs and peritoneal dialysis, exhaustion of vascular access for hemodialysis is an increasingly common situation. Among the available options, atrial tunneled dialysis catheter (ATDC) has been reported as an effective vascular access in this population. Methodology. We report the experiences of two nephrology centers in Tunis with ATDC as an ultimate vascular access for dialysis. Case Reports. Two patients with exhausted vasculature underwent ATDC insertion in 2020 and 2022, respectively, as a vascular access of last resort. Both patients underwent CRBI, which resolved with favorable outcomes. One case was complicated by post-operative thrombosis and was successfully treated with thrombolysis. Both patients are currently on dialysis via their ATDC with a catheter patency of 29 months.

Conclusion

ATDC is a life-saving and safe vascular access in cases of depleted vasculature. Little more than 50 cases have been reported in the literature during the last 30 years. As the frequency of vasculature exhaustion is expected to increase, preservation of veinous access in patients at risk of chronic kidney disease have never been more crucial.

A practical review of barriers and challenges to a definitive randomised trial of grafts versus fistula

A definitive randomised controlled trial of arteriovenous fistula (AVF) versus arteriovenous grafts (AVG) has been advocated for more than a decade, but as yet, none has been completed. The aim of this article is to summarise the theoretical barriers, review the difficulties in trial design and practicalities that have thus far prevented this from occurring.

Does central venous stenosis affects the brachial artery flow volume and peripheral vascular resistive index in patients on maintenance hemodialysis? A retrospective study

BACKGROUND

A well-functioning vascular access (VA) is crucial for the patients on maintenance hemodialysis (HD). Central venous stenosis (CVS) is a common, yet, overlooked complication of VA as its diagnosis is challenging. Moreover, its effect on the flow volume (FV) and the peripheral resistive index (RI) was not well discussed before. Despite the availability of doppler ultrasound (DUS) in most centers, direct visualization of central veins using DUS is quite difficult.

METHODS

This is a retrospective single-center self-controlled cohort study that was conducted in a specialized vascular access management tertiary center in Japan and included all patients with CVS who underwent percutaneous transluminal angiography (PTA) with or without vascular stenting in the period from January 2014 to September 2022. The patients were divided according to their VA type into arteriovenous fistula (AVF), and arteriovenous graft (AVG) groups, then subdivided, according to the type of stenosis, into two subgroups: CVS, and mixed central and peripheral venous stenosis (MVS) groups. The FV and RI of the feeding artery were compared in the same procedure before and after PTA to assess the impact of the procedure itself.

RESULTS

Data of 485 percutaneous transluminal angiography procedures (PTA), performed in 95 patients during the period from January 2014 to September 2022, were collected. FV and RI were significantly affected in the patients with MVS than patients with CVS. After PTA, both FV and RI were significantly improved. The improvement rate of FV and RI after PTA were significantly higher in patients with MVS than patients with CVS. However, it was difficult to determine the cut-off value to diagnose or to assess the improvement of CVS.

CONCLUSION

Our findings suggest that FV and RI measurement by DUS are good tools, along with the clinical findings for assessment of CVS in certain situations.

The ımpact of radiofrequency ablation on quality of life/symptoms (VEINES-QOL/Sym questionnaire score) in patients with chronic venous ınsufficiency

Purpose

Chronic venous insufficiency is defined as a progressive disease that impairs the quality of life. Symptomatic patients can be treated with a 97% success rate through endovenous radiofrequency ablation (RFA) procedures. The aim of this study is to evaluate the effect and impact of RFA therapy on both the Venous Insufficiency Epidemiological and Economic Study Quality of Life/Symptom Questionnaire (VEINES-QOL/Sym) scale and the VEINES-QOL/Sym severity score in patients with isolated vena saphena magna insufficiency.

Methods

Between March and June 2018, a retrospective analysis was conducted on 45 patients with a healthy vena saphena parva. They were divided into two groups based on the diameter of the great saphenous vein (GSV). Patients with GSV < 6 mm were assigned to group I (n = 22, 15 males, 7 females, mean age 52.45 ± 13.98 years), while patients with GSV ≥ 6 mm were assigned to group II (n = 23, 14 males, 9 females, mean age 55.04 ± 10.18 years). The pre-procedural Clinical-Etiology-Anatomy-Pathophysiology (CEAP) classification and post-procedural quality of life and symptom assessment at 12-24 months were evaluated using the VEINES-QOL/Sym questionnaire scale.

Results

When all patients were assessed in terms of the VEINES-QOL/Sym questionnaire scale, compared to the previous year, it was found that 57.8% of patients (n = 26) still experienced complaints, and 24.4% of patients (n = 14) reported slightly worse symptoms than the previous year. In group II, 56.5% of patients (n = 13) reported experiencing similar complaints as the previous year, while 30.4% (n = 7) noted slightly worse symptoms.

Conclusions

Our study findings revealed that the increase in vessel diameter does not significantly impact the severity of symptoms and quality of life outcomes after RFA therapy; however, it does have a notable impact on the improvement of symptom characteristics. As a result, early intervention for symptomatic patients is crucial in order to address their symptoms and improve their quality of life.

Pre-operative ultrasound mapping before arteriovenous fistula formation: an updated systematic review and meta-analysis

BACKGROUND

Arteriovenous fistula represents the preferred vascular access for patients with kidney failure requiring hemodialysis. Surgeons have traditionally used physical examination to identify the most suitable vessels. This meta-analysis aims to evaluate whether ultrasound mapping should be routinely performed before arteriovenous fistula creation.

METHODS

Medline, Scopus, Web of Science and CENTRAL were systematically searched from inception to November 1, 2022. Randomized controlled trials and cohort studies comparing routine ultrasound mapping to physical examination in terms of arteriovenous fistula patency were included. Meta-analysis was performed by fitting random-effects models. The study protocol has been prospectively registered in PROSPERO (CRD42023402390).

RESULTS

Overall, 18 studies were included, comprising 3655 participants. Routine pre-operative ultrasound mapping was associated with significantly lower rates of primary arteriovenous fistula failure (Risk Ratio-RR: 0.56, 95% confidence intervals-CI: 0.37-0.84, low certainty). A significant outcome was observed by separately pooling randomized controlled trials (RR: 0.37, 95% CI: 0.25-0.54). Routine ultrasound mapping was also associated with significantly higher rates of 1-year primary arteriovenous fistula patency (RR: 1.33, 95% CI: 1.19-1.47, moderate certainty). This effect remained significant in the analysis of randomized controlled trials (RR: 1.26, 95% CI: 1.02-1.56).

CONCLUSIONS

Implementing routine pre-operative ultrasound mapping of vessels is associated with significantly better outcomes in terms of early arteriovenous fistula failure and primary patency rates at 12 months. Further research should confirm the long-term benefits of routine ultrasound examination and evaluate its cost-effectiveness in different populations.

Assessment of the performance of vascular access for hemodialysis

BACKGROUND

Life and quality of life on hemodialysis depends on adequate vascular access. An autogenous arteriovenous fistula (AVF) has the best performance, while the use of a central venous catheter (CVC) may have a negative impact on fistula performance and may be associated with increased systemic inflammation. Our objective is to evaluate the performance of vascular accesses in patients undergoing a chronic hemodialysis program.

METHODS

This is an observational, cross-sectional, and descriptive study that included patients on chronic hemodialysis for more than 90 days. Patients with an acute systemic inflammatory disease and those with acute cardiovascular illness were excluded. Clinical data, dialysis session parameters, and serum levels of inflammatory markers were evaluated.

RESULTS

A total of 91 patients were evaluated, 59 (65%) had an AVF and 32 patients (35%) had a CVC. The adequacy rate was 67%; being 67.8% with AVF and 65.6% with CVC. Among the causes of AVF inadequacy, the ones that presented the highest prevalence ratio (PR) were non-mature AVF (PR: 4.055; 95% CI: 2.017-8.151), pseudoaneurysm (PR: 6.580; 95% CI: 3.723-11.629) and presence of hematoma (PR: 4.360; 95% CI: 2.125-8.946), p < 0.001. Among the catheter group, the causes of inadequacy with the highest PR were the presence of access thrombosis, indicating the use of thrombolytics (PR: 11.103; 95% CI: 4.746-25.977; p < 0.001) and infection (PR: 2.984; 95% CI: 1.293-6.889; p = 0.010). Median primary AVF patency was 72 months compared to 7 months of catheters (p < 0.001). There was no significant difference in serum inflammatory markers between the two groups.

CONCLUSIONS

Adequacy rates of vascular accesses did not differ between the groups, but the primary and functional patency of AVF is 10 times higher than that of catheters. Infection in dialysis catheters is associated with worse access performance. There was no association between systemic inflammation and vascular access.

Use of a Paclitaxel Drug-Eluting Stent for the Treatment of Hemodialysis Access Outflow Stenosis

PURPOSE

To evaluate the outcomes and durability of drug-eluting stents (DESs) for the treatment of hemodialysis access outflow stenosis.

MATERIAL AND METHODS

A single-center retrospective analysis was conducted of all patients with hemodialysis vascular access outflow stenosis treated with a paclitaxel-coated DES (Eluvia; Boston Scientific, Marlborough, Massachusetts) between January 2020 and July 2022. A total of 34 DESs were implanted to treat outflow stenosis in 32 patients. Primary target lesion patency after stent deployment was the main outcome. Comparison between the time interval free from target lesion reintervention (TLR) after previous plain balloon angioplasty (PBA) and that after stent deployment for the same target lesion was considered a secondary outcome.

RESULTS

The primary patency at 6, 12, and 18 months was 63.1%, 47.6%, and 41.7%, respectively. The secondary patency rate was 100% at 18 months. The median time interval free from TLR increased from 4.1 to 11.9 months (P < .001). No adverse events were observed during the median follow-up period of 387 days.

CONCLUSIONS

The patency rates after use of DES for hemodialysis access outflow stenosis were comparable with results for drug-coated balloons and stent grafts, addressing recoil and minimizing the risk of jailing by a covered stent.

Midterm outcomes of arteriovenous fistula aneurysm repair with simultaneous inflow revision or outflow tract revascularization

OBJECTIVE

The aim of this study was to investigate the 2-year outcomes of extensive revisions aimed at simultaneously addressing arteriovenous fistula (AVF) aneurysms, outflow stenosis, and/or high flow volumes.

METHODS

This was a retrospective cohort study in a tertiary referral center. The study population comprised hemodialysis patients with aneurysmal AVFs requiring revision. Subjects were eligible if they were ≥18 years of age and had aneurysm repair associated with inflow revision or treatment of outflow lesions. Patients were followed-up for a minimum of 2 years, and the primary outcome measure was cumulative patency.

RESULTS

Our cohort comprised 93 patients with a mean age of 56 ± 12 years. The most frequent access type was brachiocephalic fistula (61%), and the median access age at the time of revision was 66 months (interquartile range, 46-93 months). The median access flow volume was 2300 ml/min (interquartile range, 1281-2900), and 31 subjects (33%) presented aneurysms associated with both high flow and venous obstruction. Aneurysm repair consisted of aneurysmorraphy in the overwhelming majority (95%). Inflow revision was performed in a total of 49 cases (53%), and outflow tract obstruction was treated in 71 patients (72%), with 27 patients (29%) receiving a simultaneous 3-component revision. At 2 years, the primary, primary assisted, and cumulative patencies were 60% ± 1%, 91% ± 3%, and 94% ± 3%, respectively. The most frequent indication for first-time reinterventions was outflow tract stenosis (24%). Aneurysm recurrence was observed in 13 subjects (14%) during the entire follow-up and was responsible for reinterventions in seven of them (8%), with a 2-year freedom from aneurysm-related reintervention rate of 95% ± 3%.

CONCLUSIONS

Extensive AVF revision with simultaneous aneurysm repair, inflow revision, and outflow tract revascularization is feasible, safe, and associated with favorable 2-year patency rates.

Endovascular tools for vascular access stenosis: Flow-chart proposal

Stenosis represents the most relevant arteriovenous fistula (AVF) pathology and can affects the entire conduit forming the fistula, from afferent artery to central venous vessels. Correction of vascular access stenosis significantly affects the survival and quality of life for end stage renal disease patients (ESRD) dependent on hemodialysis. Guidelines consider the procedure of percutaneous transluminal angioplasty (PTA) relevant for the primary treatment of these lesions with excellent results in restoring AVF immediately at the end of the procedure. From first AVF angioplasty in 1981 to now, wide scientific innovation has led to development of new devices, composed by different materials and technologies, specific for the site and the type of stenosis to be treated, able to manage resistant stenotic lesion and to reduce stenosis recurrences. International guidelines do not clearly specify all treatment possibilities in the individual case. In this review the authors want to provide specific information on most used devices for stenosis treatment based on literature evidence, showing when and where to use the various tools available with flow-chart treatment proposal.

Realtime monitoring of thrombus formation in vivo using a self-reporting vascular access graft

BACKGROUND

Chronic kidney disease (CKD) affects 10% of the global population costing over a hundred billion dollars per annum and leading to increased risk of cardiovascular disease. Many patients with CKD require regular haemodialyses. Synthetic arteriovenous grafts (AVG) are increasingly used to provide rapid vascular connection for dialysis. Initially, they have excellent patency rates but are critically limited by neointimal hyperplasia at the venous anastomosis, which drives subsequent thrombosis, graft failure and death.

METHODS

Here, we describe a system in which electrical impedance spectroscopy sensors are incorporated circumferentially into the wall of a synthetic arteriovenous graft. This is combined with an implantable radiotelemetry system for data transmission outside the patient. The system was tested using monolayers of endothelial and smooth muscle cells as well as swine blood and clots with explanted human carotid artery plaques. Sensor testing was then performed in vitro and the device was implanted in vivo in female swine.

RESULTS

The device can wirelessly report the accumulation of biological material, both cells and blood. Differences are also detected when comparing controls with pathological atheroma. In swine differences between blockage formation in a graft were remotely obtained and wireless reported.

CONCLUSIONS

Combining electrical impedance spectroscopy and an implantable radiotelemetry system enables graft surveillance. This has the potential to be used for early detection of venous stenosis and blood clot formation in real-time in vivo. In principle, the concept could apply to other cardiovascular diseases and vascular implantable devices.

Therapeutic strategies based on non-ionizing radiation to prevent venous neointimal hyperplasia: the relevance for stenosed arteriovenous fistula, and the role of vascular compliance

We have reviewed the development and current status of therapies based on exposure to non-ionizing radiation (with a photon energy less than 10 eV) aimed at suppressing the venous neointimal hyperplasia, and consequentially at avoiding stenosis in arteriovenous grafts. Due to the drawbacks associated with the medical use of ionizing radiation, prominently the radiation-induced cardiovascular disease, the availability of procedures using non-ionizing radiation is becoming a noteworthy objective for the current research. Further, the focus of the review was the use of such procedures for improving the vascular access function and assuring the clinical success of arteriovenous fistulae in hemodialysis patients. Following a brief discussion of the physical principles underlying radiotherapy, the current methods based on non-ionizing radiation, either in use or under development, were described in detail. There are currently five such techniques, including photodynamic therapy (PDT), far-infrared therapy, photochemical tissue passivation (PTP), Alucent vascular scaffolding, and adventitial photocrosslinking. The last three are contingent on the mechanical stiffening achievable by the exogenous photochemical crosslinking of tissular collagen, a process that leads to the decrease of venous compliance. As there are conflicting opinions on the role of compliance mismatch between arterial and venous conduits in a graft, this aspect was also considered in our review.

First-in-human feasibility study of the aXess graft (aXess-FIH): 6-Month results

OBJECTIVE

The creation of an arteriovenous fistula (AVF) is considered the most effective hemodialysis (HD) vascular access. For patients who are not suitable for AVF, arteriovenous grafts (AVGs) are the best access option for chronic HD. However, conventional AVGs are prone to intimal hyperplasia, stenosis, thrombosis, and infection. Xeltis has developed an AVG as a potential alternative to currently available AVGs based on the concept of endogenous tissue restoration. The results of the first 6-month follow-up are presented here.

METHODS

The aXess first-in-human (FIH) study [NCT04898153] is a prospective, single-arm, multicenter feasibility study that evaluates the early safety and performance of the aXess Hemodialysis Graft. A total of 20 patients with end-stage renal disease were enrolled across six European investigational sites.

RESULTS

At 6-months follow-up, all grafts were patent with primary and secondary patency rates were 80% and 100%, respectively. Three patients required a re-intervention to maintain graft patency, while one re-intervention was required to restore patency. One graft thrombosis and zero infections were reported.

CONCLUSION

The expected advantages of the novel aXess Hemodialysis Graft over conventional AVGs would be evaluated by the analysis on long-term safety and effectiveness during the 5-year follow-up of the currently ongoing trial.

Vascular access challenges in hemodialysis patients with superior vena cava syndrome

BACKGROUND

Superior vena cava syndrome in hemodialysis patients resulting from previous or current use of a tunneled central vein catheter is a rare but potentially severe condition. Two aspects have to be addressed during management and treatment: the restoration of central venous flow and the creation of an alternative vascular access to guarantee hemodialysis.

RESEARCH DESIGN

Conforming to the current guidelines and literature, we present a stepwise approach and discuss therapeutic options. The removal of the tunneled central vein catheter should be attempted and a native vascular access created whenever feasible.

RESULTS

First, an upper extremity AVF should be preserved or, as in our case, made functional. Endovascular treatment of CVSO should primarily consist of balloon dilatation. Placement of a stent or stent graft should be considered as a secondary option. HeRO graft placement may be considered in recurrent CVSO and recanalization with a Surfacer. LL-AVF or AVG need to be discussed and may be an alternative for certain HD patients when the risk of lower limb ischemia and infection is considered.

CONCLUSION

Several therapeutic options are available and the basic principles are well established in the literature, although the level of evidence is not high. Therefore, we propose a stepwise and interdisciplinary approach to guide the challenging decision-making process in SVC.

Point-of-Care Arterio-Venous Fistula Ultrasound in the Outpatient Hemodialysis Unit-A Survey on the Nurses' Perspective

The preservation of complication-free arterio-venous fistulas (AVF) for long-term hemodialysis (HD) use is associated with better overall patient outcomes, which is why this is a current goal in any HD center. Point-of-care ultrasound (POCUS) for in-center AVF assessment has proven its benefits in the identification of vascular access (VA) complications and as an additional tool to avoid blind cannulation. The current study aims to assess the change in the HD nurses' perceptions regarding AVF POCUS use in the HD center. The nursing staff anonymously answered a Likert scale questionnaire with five questions related to various aspects of AVF POCUS utility shortly after the technique had been implemented and at a 5-year follow-up. The results showed an overall positive attitude toward this method, both at implementation and at follow-up, with no statistically significant score changes for four out of the five items assessed. However, we found a statistically significant reduction in the nurses' cannulation confidence scores at the 5-year follow-up (p < 0.01). Overall, AVF POCUS implementation is regarded as a useful tool, with major benefits both for the patient and for the medical team. The current study results aim to support the introduction of AVF POCUS assessment as a standard practice from the nursing staff's viewpoint. This study was not registered.

Use of Covered Stents in Cannulation Sites as a Last Option to Salvage Failing Vascular Access

PURPOSE

Controversy exists regarding the treatment of recurrent stenosis in vascular access at cannulation sites with a covered stent as repeated cannulation may damage the stent. The purpose of this study was to review covered stent placement at cannulation sites to salvage failing vascular access.

MATERIALS AND METHODS

A total of 11 patients were included for the purpose of this study. Eight patients (72.7%) received a covered stent due to recurrent stenosis, 2 (18.2%) due to an acute occlusion, and in 1 case (9.1%), the covered stent was used to repair a damaged polytetrafluoroethylene arteriovenous graft (PTFE AVG).

RESULTS

Primary patency after stent placement was 40.9% at 6 months, primary-assisted patency was 79.5% at 12 months, and secondary patency was 80% at 24 months. No significant problems were observed during the dialysis sessions after stent placement. The intervention rate per patient-year was not significantly different before or after covered stent placement, at 3.8 (IQR=9.5) interventions per year versus 2.5 (IQR=3.0) interventions per year (p=0.280).

CONCLUSION

In conclusion, treating failing vascular access with problems at cannulation sites with covered stents can be considered.

CLINICAL IMPACT

Treating vascular access stenosis at cannulation sites with covered stents can successfully prolong vascular access life.

Transjugular approach: comparison with conventional endovascular treatment of native arteriovenous fistulas

OBJECTIVES

The aim of this study was to compare the outcomes of the transjugular approach with those of the conventional approach for endovascular treatment of arteriovenous fistulas (AVFs).

METHODS

Between May 2015 and July 2019, 112 patients with endovascular treatment of dysfunctional or immature AVFs were included and divided into the transjugular (n = 46) and conventional (n = 66) groups. Electronic medical records and angiography of the patients were retrospectively reviewed to assess technical and clinical success rates, time to first fistulography, total procedure time, primary and secondary patency, and complications in both groups.

RESULTS

There were no significant differences in technical success rate (87.0% vs 97.0%; P = .062), clinical success rate (80.4% vs 90.9%; P = .109), or total procedure time (60.2 vs 57.9 min; P = .670) between the groups. Cox proportional hazards models showed that the cumulative primary patency was significantly higher in the transjugular group than in the conventional group (P = .041; 6-month patency rates, 93.8% vs 91.5%). Also, a statistically significant difference was found between the cumulative secondary patency of the groups (P = .014; 6-month patency rates, 91.4% vs 86.5%). No major complications were observed.

CONCLUSIONS

Transjugular endovascular treatment of AVFs was successful and effective. Longer patency periods were observed when treated via transjugular access.

ADVANCES IN KNOWLEDGE

This article compared the outcomes of transjugular approaches with those of conventional approaches in the endovascular treatment of native AVFs and showed higher patency periods/rates in the transjugular group than in the conventional group.

International survey of radiocephalic arteriovenous fistula: ISRAF survey

AIMS

The objective of this survey was to encompass the full scope of international practice, entailing all technical, non-technical, preoperative stratification and functional maturation (FM) of RCAVF.

METHODS

The survey contained n = 19 questionnaires with n = 46 variables completed by n = 85 providers from n = 21 nations across n = 5 continents. The numerical values were subjected to mean with standard error whereas the nominal data to a non-parametric (Kruskal-Wallis & Spearman correlation test) and analysis of variance (ANOVA). The test of homogeneity, & probability was reported 95% confidence intervals (CI) alongside error plots. Furthermore, a decision and higher attribute tree model was constructed based on current survey for higher FM in RCAVF.

RESULTS

FM is independently associated with volume of surgeon per year (procedures performed) (p < 0.01) [High Volume: 73% (95% CI, 68-77%) versus Average volume: 63% (95% CI, 59-66%) vs Low volume: 56% (95% CI, 51-61%)]. FM increased by 8% with every 20 more procedures per group of surgeons on end point of FM. Amongst continents: Australia, America, Asia and South America demonstrated higher FM to Africa & Europe (p < 0.05). UK possessed a lower FM 58% (95% CI, 48-68%) in comparison to the world & Europe respectively [65% (95% CI, 61-70%) vs 61% (95% CI, 58--65%)]. There was a positive causal link between angle of anastomosis at 30-76° (p < 0.01), longitudinal & S-shaped incision & arteriotomy length of 3 & 4 mm to higher FM (p < 0.05).

CONCLUSION

FM in RCAVF is independently & incrementally associated with the volume of surgeon per year. There is a diverse inclusion, exclusion and technical approach in RCAVF creation. This survey advocates the importance of international collaboration and/or registry in assimilation, consolidate and development of consensus.

Efficacy and safety of implantable vascular support in the treatment of arteriovenous fistula: A single-arm meta-analyses

BACKGROUND AND OBJECTIVES

VasQ (Laminate Medical Technologies, Israel) is an external support device for autologous arteriovenous fistula (AVF) designed to improve anastomotic blood flow and reduce neointimal hyperplasia. However, different studies have shown that the efficacy of the VasQ device in improving AVF is inconsistent. The purpose of this study was to conduct a meta-analysis to further evaluate the efficacy and safety of the VasQ device.

DESIGN, SETTING, PARTICIPANTS, AND MEASUREMENTS

Two reviewers independently searched studies published in PubMed, EMBASE, Cochrane, Web of Science, CNKI, and Wan Fang databases from inception to 2023. The Cochrane Systematic Evaluation Bias Risk Tool Version 1 was used to assess the risk of RCTS bias. The ROBINS-I tool was used to assess the risk of bias in non-randomized studies. A Single-arm meta-analysis was performed, and a random effects model was used for all analyses.

RESULTS

We identified six trials involving 146 patients and conducted a meta-analysis. The results showed that after 6 months of VasQ device treatment, the primary patency rate of AVF was [76.4% (95%CI: 0.608-0.920), p < 0.01] while the secondary patency rate was [76.5% (95%CI: 0.572-0.958), p < 0.01]. The maturity rate of AVF 1 month after surgery was [88.5% (95%CI: 0.818-0.952), p = 0.46]. The incidence of anastomotic stenosis was [8.9% (95%CI: 0.015-0.163), p = 0.23], and the incidence of anastomotic venous thrombosis was [10% (95%CI: 0.035-0.179), p = 0.38].

CONCLUSIONS

Meta-analysis data of this study show that the VasQ device has a good effect in improving the patency rate of AVF and does not increase the occurrence of adverse events. However, due to the limitation of the number and quality of included studies, more high-quality studies are needed to confirm this in the future.

FLOW: Flow dysfunction of hemodialysis vascular access: A randomized controlled trial on the effectiveness of surveillance of arteriovenous fistulas and grafts

INTRODUCTION

It is assumed that identification and correction of asymptomatic stenoses in the vascular access circuit will prevent thrombosis that would require urgent intervention to continue hemodialysis treatment. However, the evidence base for this assumption is limited. Recent international clinical practice guidelines reach different conclusions on the use of surveillance for vascular access flow dysfunction and recommend further research to inform clinical practice.

METHODS

The FLOW trial is a double-blind, multicenter, randomized controlled trial with a 1:1 individual participant treatment allocation ratio over two study arms. In the intervention group, only symptomatic vascular access stenoses detected by clinical monitoring are treated, whereas in the comparison group asymptomatic stenoses detected by surveillance using monthly dilution flow measurements are treated as well. Hemodialysis patients with a functional arteriovenous vascular access are enrolled. The primary outcome is the access-related intervention rate that will be analyzed using a general linear model with Poisson distribution. Secondary outcomes include patient satisfaction, access-related serious adverse events, and quality of the surveillance process. A cost effectiveness analysis and budget impact analysis will also be conducted. The study requires 828 patient-years of follow-up in 417 participants to detect a difference of 0.25 access-related interventions per year between study groups.

DISCUSSION

As one of the largest randomized controlled trials assessing the clinical impact of vascular access surveillance using a strong double-blinded study design, we believe the FLOW trial will provide much-needed evidence to improve vascular access care for hemodialysis patients.

Comparison of Lower and Upper Extremity Arteriovenous Graft: A Retrospective Clinical Analysis with 5-Year Follow-Up

BACKGROUND

For patients in whom an upper extremity (UE) vascular access cannot be established, the lower extremity (LE) arteriovenous graft (AVG) could be selected. However, the application of LE AVG is limited owing to its high infection rate, uncertain patency time, and technical difficulties. This study aimed to compare the long-term patency rates and the incidence of vascular access complications of AVG in the LE and UE to provide a reference for the applications of AVG, especially in the LEs.

METHODS

This was a retrospective analysis of patients who successfully underwent LE or UE AVG placement from March 2016 to October 2021. Patient characteristics were collected and compared using parameter or nonparameter tests according to data type. Postoperative patency was evaluated using Kaplan-Meier test. Postoperative complication incidence density and intergroup comparison were estimated using the Poisson distribution.

RESULTS

Twenty-two patients with LE AVG and 120 patients with UE AVG were included. The 1-year primary patency rate was 67.4% (±11.0% standard error [SE]) in the LE group and 30.1% (±4.5% SE) in the UE group (P = 0.031). The assisted primary patency rate at postoperative months 12, 24, and 36 was respectively 78.6% (±9.6% SE), 65.5% (±14.4% SE), and 49.1% (±17.8% SE) in the LE group and 63.3% (±4.6% SE), 47.5% (±5.4% SE), and 30.4% (±6.1% SE) in the UE group (P = 0.137). The secondary patency rate at postoperative months 12, 24, and 36 remains 95.5% (±4.4% SE) in the LE group and 89.3% (±2.9% SE), 83.7% (±3.9% SE), and 73.0% (±6.2% SE), respectively, in the UE group (P = 0.200). Postoperative complications included stenosis, occlusion/thrombosis, infection, steal syndrome, pseudoaneurysm, severe postoperative serum swelling, and AVG exposure. The total incidence rates of postoperative complications were 0.87 (95% confidence interval [CI] 0.59-1.23) versus 1.61 (95% CI 1.45-1.79) (P = 0.001) cases/person-year, the incidence rates of stenosis were 0.45 (95% CI 0.26-0.73) versus 0.92 (95% CI 0.80-1.06) (P = 0.005) cases/person-year and the incidence rates of occlusion/thrombosis were 0.34 (95% CI 0.17-0.59) versus 0.62 (95% CI 0.52-0.74) cases/person-year in the LE group compared to those in the UE group (P = 0.041).

CONCLUSIONS

LE AVG had higher primary patency rate and lower postoperative complication incidence than UE AVG. With the development of interventional technology, both LE AVG and UE AVG exhibited high secondary patency rates. LE AVG can be a reliable and long-term alternative for appropriately selected patients with unusable UE vessels.

Central Venous Access Devices for the Delivery of Systemic Anticancer Therapy: An Economic Evaluation

OBJECTIVES

Patients undergoing long-term anticancer therapy typically require one of 3 venous access devices: Hickman-type device (HICK), peripherally inserted central catheter (PICC), or implantable chest wall port (PORT). Recent evidence has shown PORT is safer and improves patient satisfaction. However, PORT did not show improvement in quality-adjusted life-years and was more expensive. Decisions regarding cost-effectiveness in the United Kingdom are typically informed by a cost-per-quality-adjusted life-year metric. However, this approach is limited in its ability to capture the full range of relevant outcomes, especially in the context of medical devices. This study assessed the potential cost-effectiveness of HICK, PICC, and PORT in routine clinical practice.

METHODS

This is a cost-consequence analysis to determine the trade-offs between the following outcomes: complication, infection, noninfection, chemotherapy interruption, unplanned device removals, health utilities, device insertion cost, follow-up cost, and total cost, using data from the Cancer and Venous Access clinical trial. We conducted value of implementation analysis of a PORT service.

RESULTS

PORT was superior in terms of overall complication rate compared with both HICK (incidence rate ratio 0.422; 95% CI 0.286-0.622) and PICC (incidence rate ratio 0.295; 95% CI 0.189-0.458) and less likely to lead to an unplanned device removal. There was no difference in chemotherapy interruption or health utilities. Total cost with device in situ was lower on PORT than HICK (-£98.86; 95% CI -189.20 to -8.53) and comparable with PICC -£48.57 (95% CI -164.99 to 67.86). Value of implementation analysis found that PORT was likely to be considered cost-effective within the National Health Service.

CONCLUSION

Decision makers should consider including PORT within the suite of venous access devices available within in the National Health Service.

Transhepatic double lumen hemodialysis catheter in exhausted vascular access: Feasibility, functionality, and outcome among hemodialysis patients

INTRODUCTION

Permanent arteriovenous fistula and graft are considered the best options for hemodialysis in end-stage renal disease patients. Temporary access using the internal jugular or femoral veins is the feasible option in acute cases of dialysis and if permanent access is unavailable. Occasionally, however, these access sites are unusable after consecutive blockage of the upper and lower extremities veins. A transhepatic or translumbar approach might be the only unconventional way to ensure a sufficient blood flow for adequate dialysis.

METHOD

Retrospective data on all transhepatic catheters (THCs) in patients at the King Faisal Specialist Hospital and Research Center in Jeddah, Saudi Arabia were collected. The catheters were inserted over a 10-year period (2009-2019). A minimum of 1 year of follow-up from the last catheter insertion was considered for analysis.

RESULTS

A total of 12 patients had THCs with a mean age of 42.5 ± 12.2 and pre-insertion mean dialysis duration of 130.0 ± 72.9 months. All catheters were functional from the start with no immediate complications. A total of 35 catheter replacements over guidewires were made with a median of 2.0 catheters (range of 0-10). The mean blood flow was 300 ± 30 ml/minute with a mean Kt/v of 1.4 ± 0.4. The median initial (primary) device service interval was 68 (range 6-1531 days) and the median total access site service interval was 392 (range 76-2698 days). Catheter complications included catheter migration, thrombosis, and bloodstream infection occurring at a rate of 0.12, 0.18, and 0.046 per 100 catheter days respectively.

CONCLUSIONS

Transhepatic catheters provide safe, feasible access in patients with exhausted vascular access. Patients who undergo THC insertion should be worked up for innovative permanent vascular access or urgent transplantation utilizing unconventional vascular techniques to avoid death due to lack of access.

A systematic review of right atrial bypass grafting in the management of central venous occlusive disease in patients undergoing hemodialysis

INTRODUCTION

Central venous occlusive disease (CVOD) is a complication that can occur in patients with end-stage renal disease who are receiving hemodialysis. When CVOD develops, patients often require multiple re-interventions to maintain their dialysis access. CVOD can be treated by various strategies such as balloon angioplasty, stenting, lower limb or extra-anatomical grafts, hybrid grafts or surgical bypasses such as right atrial (RA). In this systematic review, we aim to evaluate the indications, technical aspects, and outcomes after RA bypass grafting for the treatment of CVOD in hemodialysis patients.

METHODS

A systematic and comprehensive literature search was conducted using various electronic databases. We included articles that reported described and reported outcomes of RA bypass grafting for the treatment of CVOD in hemodialysis patients. A narrative review of the indications and technical aspects of RA bypass grafting was performed. We also pooled and reported the primary patency, secondary patency, postoperative complications, and 30-day mortality of RA bypass grafting.

RESULTS

A total of 21 studies with 55 patients who underwent RA bypass grafting were included in our systematic review. Follow-up period ranged from 0.5 to 84 months. The mean pooled primary patency and secondary patency of RA bypass grafting were 8.1 ± 4.9 and 21.7 ± 20.1 months, respectively. The incidence of early postoperative complications such as surgical site infection, bleeding, and access thrombosis was 0%, 4%, and 4%, respectively. The overall 30-day mortality was 4%.

CONCLUSIONS

This systematic review summarizes the patient characteristics, technical features and outcomes of RA bypass grafting in the treatment of hemodialysis-related CVOD. RA bypass grafting may be a viable last-resort option when less invasive or conventional treatment options have been exhausted.

Hemodialysis Access: US for Preprocedural Mapping and Evaluation of Maturity and Access Dysfunction

Patients with kidney failure require kidney replacement therapy. While renal transplantation remains the treatment of choice for kidney failure, renal replacement therapy with hemodialysis may be required owing to the limited availability and length of time patients may wait for allografts or for patients ineligible for transplant owing to advanced age or comorbidities. The ideal hemodialysis access should provide complication-free dialysis by creating a direct connection between an artery and vein with adequate blood flow that can be reliably and easily accessed percutaneously several times a week. Surgical arteriovenous fistulas and grafts are commonly created for hemodialysis access, with newer techniques that involve the use of minimally invasive endovascular approaches. The emphasis on proactive planning for the placement, protection, and preservation of the next vascular access before the current one fails has increased the use of US for preoperative mapping and monitoring of complications for potential interventions. Preoperative US of the extremity vasculature helps assess anatomic suitability before vascular access creation, increasing the rates of successful maturation. A US mapping protocol ensures reliable measurements and clear communication of anatomic variants that may alter surgical planning. Postoperative imaging helps assess fistula maturation before cannulation for dialysis and evaluates for early and late complications associated with arteriovenous access. Clinical and US findings can suggest developing stenosis that may progress to thrombosis and loss of access function, which can be treated with percutaneous vascular interventions to preserve access patency. Vascular access steal, aneurysms and pseudoaneurysms, and fluid collections are other complications amenable to US evaluation. ©RSNA, 2023 Supplemental material is available for this article. Test Your Knowledge questions for this article are available through the Online Learning Center.