Percutaneous Transanastomotic Stent Graft Deployment to Salvage Dysfunctional Native Forearm Radiocephalic Fistulae: Feasibility and Primary Patency at 12 Months.

PURPOSE: To evaluate feasibility and efficacy of transanastomotic self-expandable polytetrafluoroethylene stent graft placement for salvage of radiocephalic arteriovenous fistulae (RCAVFs). MATERIALS AND METHODS: From 2008 to 2016, 26 patients (21 male; age, 38-80 y) with dysfunctional RCAVFs for juxtaanastomotic lesions that were unresponsive to angioplasty underwent transanastomotic stent graft placement. Stenotic and thrombotic lesions were included. All were deemed unsuitable for surgical revision. Patency rates were calculated per Kaplan-Meier method. A Cox analysis was used to identify influencing factors. RESULTS: Thirty-two stent grafts (6 patients had 2 stents) were deployed. Anatomic and clinical success were achieved in all patients; no major complications occurred. Mechanical and/or pharmacologic thrombolysis was performed in 6 cases before stent graft deployment. During follow-up (median, 34.7 mo; range, 1.9-102.7 mo), 17 repeat interventions were required in 10 patients (43 procedures overall), for an endovascular intervention rate of 0.27 per year. At 3, 6, 12, and 24 months, primary patency (PP) rates were 96% ± 4 (95% CI, 75%-99%), 83% ± 7 (95% CI, 61%-93%), 78% ± 8 (95% CI, 55%-90%), and 69% ± 10 (95% CI, 46%-84%). The corresponding assisted PP rates were 96% ± 4 (95% CI, 76%-99%), 96% ± 4 (95% CI, 76%-99%), 92% ± 5 (95% CI, 71%-98%), and 82% ± 8 (95% CI, 60%-93%). Five AVFs were ultimately abandoned. Per Cox analysis, arterial diameter ≥ 4 mm was associated with better PP (P = .032). CONCLUSIONS: Transanastomotic stent graft placement for RCAVF salvage is feasible and safe, providing patency rates comparable with historical endovascular and surgical data. Its role should be evaluated in larger studies.

Vascular access for hemodialysis in Italy: What a national survey reveals.

BACKGROUND: Since in Italy there are no official data on vascular access (VA) for hemodialysis the Vascular Access Project Group (VAPG) of the Italian Society of Nephrology (SIN) designed a national survey. METHODS: A 35-question survey was designed and sent it to the Italian facilities through the SIN website. The basic questions were the prevalence, the location, and the surveillance of VA, the bedside use of ultrasound, the use of fluoroscopy for central venous catheter (CVC) placement, and of buttonhole technique, the role of nephrologist in the access creation. RESULT: The questionnaire was completed in June 2022 by 161 facilities. The survey registered 15,499 patients, approximately one-third of the Italian dialysis population. The prevalence of arteriovenous fistula (AVF), arteriovenous Graft (AVG), and CVC were 61.8%, 3.7%, and 34.5% respectively. The AVF location was 50% in distal forearm, 20% in meanproximal forearm, 30% in upper arm. For AVF creation, nephrologists were involved in 72% of facilities while for CVC placement in 62%. As regards VA monitoring, 21% of the facilities did not have a surveillance protocol; 60% did not register AVF thrombosis and 53% did not register CVC infections. Most of facilities use the fluoroscope during CVC placement, 37% when needed, and 22% never. Ultrasound-guided puncture of complex AVFs was used by 80% of facilities. Buttonhole puncture was used in 5% of patients. CONCLUSIONS: Some considerations emerge from the survey data: (1) The increasing CVC prevalence compared to DOPPS 5 study. (2) The low rate of AVG prevalence. (3) The nephrologist is the operator in many VA procedures. (4) The fluoroscopy for CVC placement and the US-guide puncture of the complex AVF are widely used in most facilities. (5) The practice of the buttonhole is not widespread. (6) When the operator is the nephrologist more distal fistulas are performed.

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

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

[Indications for vascular grafts as dialysis access; consensus from the Italian experience]. / Indicazioni all'uso delle protesi vascolari per l'accesso emodialitico: un'esperienza Italiana basata sul consenso.

In Italy, the use of arteriovenous grafts (AVGs) is limited (1-4%) due to different approaches to vascular access management compared to other countries, where guidelines that may not apply to the Italian setting have been produced. Therefore, the Vascular Access Study Group of the Italian Society of Nephrology produced this position paper, providing a list of 8 recommendations built upon current guidelines. The most controversial and innovative issues of the existing guidelines have been summed up in 12 different topics. We selected 60 Italian dialysis graft experts, nephrologists and vascular surgeons (PP1SIN Study Investigators). They were asked to express their approval or disapproval on each issue, thus creating a new method to share and exchange information. Almost all agreed on specific criteria for the choice of AVG over native arteriovenous fistulas (AVF) and tunneled venous catheters (tVC) and on the necessary conditions to implant them. They did not fully agree on the use of AVG in obese patients and patients at risk of developing ischemia, as an alternative to brachiobasilic fistula with vein transposition, and in case of a poorly organized setting. When AVF is feasible, it should be preferred. AVGs are indicated when superficial veins are unavailable or to repair an AVF (bridge graft). An AVG is an alternative to tVC if the expected patient survival is long enough to allow clinical benefits. The ultimate choice of the graft type is made by the physician in charge of the surgical intervention. Antithrombotic prophylaxis may be justified in some cases.

[Vascular access for hemodialysis: recommendations of the Vascular Access Study Group of the Italian Society of Nephrology]. / Gli accessi vascolari per emodialisi: le raccomandazioni del Gruppo di Studio della Società Italiana di Nefrologia.

The Vascular Access Study Group of the Italian Society of Nephrology has scheduled four national studies regarding the choice, implantation and use of vascular access. Study topics will include 1) utilization of vascular grafts for hemodialysis; 2) indications and use of venous catheters; 3) tunneled central venous catheter infection; 4) organization of the implantation and repair of vascular access. After examining the difficulties in implementing international guidelines on vascular access in Italy and the differences in practice patterns between our and other countries (where the most important studies were published), the Study Group set out to prepare four position papers based on discussion of controversial aspects of the international guidelines by nephrologists and surgeons experienced in the Italian practice. An innovative operative method for verifying the consensus on vascular access practice patterns was used. The final aim was to write a document addressed to vascular access operators (surgeons and nephrologists) based on the consensus of experts on controversial vascular-access- related issues. The project will include yearly updates of the documents.

High success rate in salvage of catheter-related bloodstream infections due to Staphylococcus aureus, on behalf of project group of Italian society of nephrology.

BACKGROUND: Catheter-related bloodstream infections caused by Staphylococcus aureus represent one of the most fearful infections in chronic haemodialysis patients with tunnelled central venous catheters. Current guidelines suggest prompt catheter removal in patients with positive blood cultures for S. aureus. This manoeuvre requires inserting a new catheter into the same vein or another one and is not without its risks. METHODS: A protocol based on early, prompt diagnosis and treatment has been utilized in our renal unit since 2012 in an attempt to salvage infected tunnelled central venous catheters. We prospectively observed 247 tunnelled central venous catheters in 173 haemodialysis patients involving 167,511 catheter days. RESULTS: We identified 113 catheter-related bloodstream infections (0.67 episodes per 1000 days/tunnelled central venous catheter). Forty were caused by S. aureus, including 19 by methicillin-resistant S. aureus (79% saved) and 21 by methicillin-sensitive S. aureus (90% saved), of which 34 (85%) were treated successfully. Eight recurrences occurred and six (75%) were successfully treated. A greater than 12 h time to blood culture positivity for S. aureus was a good prognostic index for successful therapy and tunnelled central venous catheter rescue. CONCLUSION: Our data lead us to believe that it is possible to successfully treat catheter-related bloodstream infection caused by S. aureus and to avoid removing the tunnelled central venous catheter in many more cases than what has been reported in the literature. On the third day, it is mandatory to decide whether to replace the tunnelled central venous catheter or to carry on with antibiotic therapy. Apyrexia and amelioration of laboratory parameters suggest continuing systemic and antibiotic lock therapy for no less than 4 weeks, otherwise, tunnelled central venous catheter removal is recommended.

[Cost analysis of haemodialysis catheter related bloodstream infection through the DRG system, "on behalf of Project Group of Vascular Access of Italian Society of Nephrology"].

Catheter related bloodstream infections (CRBSI) represent a complication that often requires hospitalization and the use of economic resources. In Italy, there is no literature that considers the costs of CRBSI for tunneled catheters (CVCt). The aim of this work is to evaluate the relative costs of CRBSI through the DRG system. From 2012 to 2017 we examined 2.257 hospital discharge forms, 358 of which relating to haemodialysis patients. Patients with CVCt (167), compared to FAVs (157), on average stay in hospital longer (10 vs. 8 days), entail higher costs (+8.5%) and higher admissions rate for infections (+114%). The incidence of CRBSI was 0.67 episodes per 1000 CVCt/days. CRBSI accounts for 23% of the cases of hospitalization of patients with CVCt and 5.2% of total hospitalization costs. Complicated CRBSI involve a 9% increase in average costs compared to simple ones, with patients staying in hospital three times longer. The cost of a CRBSI varies from €4,080 up to €14,800, with an average cost of €5,575. The costs calculated here are less than a third of that reported in American literature but this can be explained by the different reimbursement rates systems. The methodology of CRBSI costs through DRGs appears simple, and its main limit is the correct compilation of the discharge form. This is a reminder that discharge forms are an integral part of the medical record and can become important in recognizing the cost of the medical services provided.

New therapeutic options provided by off-label deployment of stent graft for tailored arteriovenous access salvage: Two cases.

A tailored therapy to patient requirements by combining endovascular and surgical steps can be necessary to prolong the life of a vascular access. Stent grafts play a growing role for the therapy of dialytic access complications. Randomized multi-center trials, however, support the on-label use of stent grafts in the treatment of graft venous outflow and in-stent restenosis. The main contraindication to their use is an ongoing infection. We report two cases of new off-label application of Viabahn (Gore, flagstaff, USA) stent graft. In the first case, the failure of a radiocephalic early cannulation graft was treated by stent graft placement on the arterial inflow anastomosis, when emergent angiographic examination revealed the previously unknown high takeoff of the radial artery from the axillary artery. At 13-month follow-up, the target lesion remained untreated. In the second case, elbow stent graft occlusion with extended thrombosis occurred in a right radiocephalic fistula after 3 years of unassisted patency. Being the last option for vascular access, successful endovascular recanalization was carried out. After 3 months, however, the clinical setting relapsed. A two-stage hybrid strategy with vascular surgeon was arranged due to ongoing signs of local infection. Flow was restored by emergent thromboaspiration associated with a new stent graft placement as a endovascular bridge to subsequent surgical treatment. After 2 days, the overlapped stent grafts were excised as planned. Surgical rerouting was completed by polytetrafluoroethylene prosthetic bridge implantation across the elbow. At 4 months, the follow-up remained uneventful. In selected instances, the off-label use of stent grafts may expand the therapeutic options of the vascular access team.

The vascular access in the elderly: a position statement of the Vascular Access Working Group of the Italian Society of Nephrology.

The incident hemodialysis (HD) population is aging, and the elderly group is the one with the most rapid increase. In this context it is important to define the factors associated with outcomes in elderly patients. The high prevalence of comorbidities, particularly diabetes mellitus, peripheral vascular disease and congestive heart failure, usually make vascular access (VA) creation more difficult. Furthermore, many of these patients may have an insufficient vasculature for fistula maturation. Finally, many fistulas may never be used due to the competing risk of death before dialysis initiation. In these cases, an arteriovenous graft and in some cases a central venous catheter become a valid alternative form of VA. Nephrologists need to know what is the most appropriate VA option in these patients. Age should not be a limiting factor when determining candidacy for arteriovenous fistula creation. The aim of this position statement, prepared by experts of the Vascular Access Working Group of the Italian Society of Nephrology, is to critically review the current evidence on VA in elderly HD patients. To this end, relevant clinical studies and recent guidelines on VA are reviewed and commented. The main advantages and potential drawbacks of the different VA modalities in the elderly patients are discussed.

Stent Grafts Provided Superior Primary Patency for Central Venous Stenosis Treatment in Comparison with Angioplasty and Bare Metal Stent: A Retrospective Single Center Study on 70 Hemodialysis Patients.

PURPOSE: To compare patency in dialysis patients following different endovascular treatment of symptomatic central venous stenosis. MATERIALS AND METHODS: A 10-year retrospective evaluation in 70 patients (32 men) dialyzing through vascular access (33, 47%) and tunneled catheters (37, 53%) was made. Three cohorts were compared: angioplasty alone (22), bare metal stent (28), and stent graft (20). Patencies were described with Kaplan-Meier method, and Cox uni- and multivariate models were analyzed to find factors associated. RESULTS: All patients had a favorable anatomical and clinical outcome. Restenosis occurred in 22 (31%) of 70 patients requiring 41 additional interventions; 34 of 70 patients died (median follow-up 19.4 months). Primary patency at 3, 6, 12, and 24 months was 100%, 100%, 100%, and 84% for stent graft versus 90%, 79%, 58%, and 43% for angioplasty (P = .014) versus 84%, 80%, 75%, and 46% for bare-metal stent (P = .062). The overall comparison was more favorable for stent graft (P = .020) when the sites of lesions were matched. Patencies for angioplasty and bare-metal stents were equivalent (P = .141). A lower risk of restenosis (hazard rate [HR] 0.20, confidence interval [CI] 0.06-0.7) and fewer reinterventions (P < .01) were associated with stent graft, whereas age (HR 1.04, CI 1.001-1.08) and cardiovascular disease (HR 2.26, CI 1.06-4.84) influenced the overall survival. No difference in assisted primary patency was found. CONCLUSION: Stent graft seems to improve primary patency for central venous stenosis and requires fewer reinterventions in a dialysis population with a high prevalence of long-term catheters.

Dialysis catheter-related superior vena cava syndrome with patent vena cava: long term efficacy of unilateral Viatorr stent-graft avoiding catheter manipulation.

Central venous catheters are the most frequent causes of benign central vein stenosis. We report the case of a 79-year-old woman on hemodialysis through a twin catheter in the right internal jugular vein, presenting with superior vena cava (SVC) syndrome with patent SVC. The clinically driven endovascular therapy was conducted to treat the venous syndrome with a unilateral left brachiocephalic stent-graft without manipulation of the well-functioning catheter. The follow-up was uneventful until death 94 months later.

A refinement of Hong's technique for the removal of stuck dialysis catheters: an easy solution to a complex problem.

AIM: A long-term tunneled hemodialysis catheter can be difficult or impossible to pull out if a fibrin sleeve has attached it to the venous wall. We report the outcome of a refinement of Hong's technique for removing incarcerated catheters aimed at improving its feasibility and safety. METHODS: We applied a modification of Hong's technique in four patients (two males, age ranging from 51 to 68 years) with jugular twin hemodialysis catheters (five of eight lines incarcerated). Hong pioneered the technique of endoballooning to expand a stuck central venous catheter, thus freeing it from adhesions. In our technical refinement, we cut the catheter close to its venous entry point in order to facilitate pullout and inserted a valved introducer as access for guide wires as well as for inflations of the catheter balloon. A stiff guide wire was placed in the inferior vena cava to avoid potential damage to heart cavities. Dilation was monitored under fluoroscopy with constrictions showing points where the catheter was incarcerated. If adhesions persisted through the same introducer, endoluminal dilations were repeated with a larger diameter balloon until the catheter was released. New catheters can be positioned using the stiff guide wire already in place. All removals were carried out under local anesthesia in an angiographic room by interventional radiologists. RESULTS: All catheters were successfully removed without complications. Average fluoroscopy time for removal was 12 minutes. In the case of a Tesio catheter removed after 12 years because of infection, a computed tomography scan 2 months later revealed persistence of a calcified fibrin sleeve in the vessel. CONCLUSIONS: Hong's technique was confirmed to be a simple, safe and highly effective way to remove incarcerated long-term central venous catheters. The refinements we adopted made the procedure more flexible and possibly less prone to complications. By properly using ordinary tools available anywhere, Hong's technique could be considered Columbus' egg in this previously risky field.

Indications for vascular grafts as hemodialysis access: consensus from experience in Italy.

INTRODUCTION: In Italy, the use of arteriovenous grafts (AVG) is limited (1-5 %) due to different approaches to vascular access (VA) management as compared to other countries, where guidelines (which may not apply to the Italian setting) have been produced. Therefore, the Study Group (GdS) on VA of the Italian Society of Nephrology produced this position paper, providing a list of 8 recommendations built upon current guidelines. METHODS: The most controversial and innovative issues of existing guidelines have been summed up in 12 different statements. We selected 60 Italian dialysis graft experts, nephrologists and vascular surgeons (PP1SIN Study Investigators). They were asked to express their agreement/disagreement on each issue, thus creating a new method to share and exchange information. RESULTS: Most of them agreed (consensus > 90%) on specific criteria set to choose AVG over native AVF (nAVF) and tunnelled venous catheter (tVC) and on the necessary conditions to implant them. They did not fully agree on the use of AVG in obese patients, in patients at risk of developing ischemia, on the priority of AVG as an alternative to brachial-basilic fistula with vein transposition, and in case of a poorly organized setting regarding graft maintenance. Keeping in mind that the nAVF should be preferred whenever is feasible, AVGs are indicated when superficial veins are unavailable or to repair a nAVF (bridge graft). An AVG is an alternative to tVC if the expected patient survival is long enough to guarantee its clinical benefits.

Developing recommendations for vascular access for hemodialysis: Vascular Access Working Group of the Italian Society of Nephrology.

This paper presents an overview of the project carried out by the Vascular Access (VA) Working Group of the Italian Society of Nephrology with the aim of developing 4 position papers at the national level on how to choose, use, and implant the different, possible types of vascular access. The topics of the project are: 1) recommendations on the use of prosthetic arteriovenous fistulas for vascular access in hemodialysis, 2) recommendations on the use of venous catheters for hemodialysis, 3) infections induced by a venous catheter for hemodialysis, and 4) how to create and maintain a vascular access for hemodialysis. This paper also gives an explanation of the difficulties existing in Italy in the implementation of international guidelines, mostly due to significant differences in the procedures for the creation of VA, compared with the countries where most of the literature on the subject has been published. Individual position papers were drafted for each of the different topics. A list of recommendations was produced based on existing guidelines. Then these recommendations were critically reviewed by experts working in Italy, who expressed their opinion on their inclusion in position papers. The working method used to gather the opinions of the various experts is described. The final target is to provide clinicians interested in VA with updated documents on selected topics. Such documents will be updated periodically, and they will present a thorough overview of expert opinions.