The use of infrared thermal imaging as a marker of tissue perfusion and predictor of arteriovenous fistula outcomes

The gold standard of vascular access is the arteriovenous fistula (AVF). Unfortunately it is associated with high rates of failing to mature. Therefore the ability to predict AVF outcomes would change clinical practice. Predictive markers of AVF outcomes were assessed in chapter 2. The literature and our study showed numerous contradictions. In chapter 3 we assessed a multifactorial approach with a systematic review on predictive models of maturation. The review found few models and the disparity between each one limits the development of a unified model. Recent development in infrared thermal imaging (IRTI) technology has made it portable and easy to use. In Chapter 4, we proved that IRTI is a valid and user-friendly method of measuring skin temperature and is comparable to traditional methods of thermometry. IRTI can be used to quantity reactive hyperaemia following a vascular occlusion test (chapter 5). In Chapter 6 we showed that IRTI is an accurate tool in predicting AVF outcome. It was shown to have superiority to intra-operative thrill and other independent patient factors. In conclusion IRTI has a definite role in patients with vascular access. There is also potential for its use in patients with other conditions such as peripheral vascular disease

Kliničke praktične smjernice za perioperacijsku i poslijeoperacijsku skrb o arterijsko-venskim fistulama i umetcima za hemodijalizu u odraslih

Krvožilni pristup omogućuje hemodijalizu koja spašava život. Stoga je nužna dobra funkcija krvožilnog pristupa koja omogućuje prikladan krvni protok radi uklanjanja tvari koje se u uremiji zadržavaju u krvi bolesnika, uz istodobno sniženje rizika od sustavne infekcije na najmanju moguću mjeru. Godine 2007. Europske smjernice najbolje prakse (engl. European Best Practice Guidelines – EBPG), prethodnice trenutačne Europske najbolje bubrežne prakse (engl. European Renal Best Practice – ERBP), donijele su nacrt skupine preporuka – vodiča pri donošenju odluka o upućivanju na pregled radi krvožilnog pristupa, o procjeni i nadzoru izbora pristupa te o postupcima kod komplikacija. (1) Otad su se znatno razvili ne samo dokazi na kojima se temelje ove preporuke nego i procesi nastajanja smjernica. (2) Kao odgovor na to, ERBP je ažurirao prethodno djelo u suradnji s raznim stručnjacima iz tog područja uključujući i predstavnike Društva za krvožilni pristup (engl. Vascular Access Society – VAS), kirurge za krvožilni pristup, radiologe, medicinske sestre za dijalizu, znanstvenike, bolesnike i one koji se za njih brinu. Nastojanje da se pridržavaju sve strože metodike izrade smjernica nalagalo je određena odricanja u pogledu područja obuhvata ovih smjernica. Posljedično, one ne „pokrivaju” baš sve iste teme kao njihova prethodna verzija. Neka su područja zajednička, a neka su arhivirana da bi ustupila mjesto novim pitanjima kojima su prednost dali i pružatelji zdravstvene skrbi i oni za koje se skrbi. Odvojeno su objavljene pojedinosti postupka izbora djelokruga problematike koju su smjernice obuhvatile. (3) Nastajanje ovih smjernica slijedilo je strog proces pregleda i procjene dokaza koji se temeljio na sustavnim pregledima rezultata kliničkih istraživanja te opservacijskih podataka gdje je to bilo potrebno. Strukturirani pristup slijedio je model sustava GRADE (hrv. stupanj), koji svakoj preporuci pripisuje stupanj s obzirom na sigurnost sveukupnih dokaza te snagu. (4) Gdje je to bilo primjereno skupina za izradu smjernica unijela je nestupnjevan savjet za kliničku praksu, a koji nije proistekao iz pregleda sustavnih dokaza. Kliničke praktične smjernice iz 2019. godine specifično pokrivaju peritransplantacijske i poslijetransplantacijske aspekte arterijsko-venskih (AV) fistula i umetaka (graftova). Drugi dio, koji je bio u nastajanju kada su ove smjernice išle u tisak, pokrit će aspekte izbora krvožilnog pristupa, prijeoperacijske procjene krvnih žila i središnje venske katetere. Unatoč nedostatku dokaza velike sigurnosti za većinu područja krvožilnih pristupa, ERBP se posvetio izradi smjernica velike kakvoće, dajući smjernicu gdje god je moguće, a popis preporuka za istraživanje ondje gdje se nije moglo uputiti smjernicom. Nadamo se da će ove smjernice i one planirane pomoći stručnoj zajednici pri donošenju odluka o postupcima, postupnicima i skrbi vezanima s krvožilnim pristupima, pomoći bolesnicima i onima koji se za njih brinu da steknu uvid u problematiku te olakšati zajedničko donošenje odluka u tom području

Early cannulation grafts for haemodialysis: An updated systematic review.

PURPOSE Early cannulation grafts are specifically designed for dialysis, whereas standard expanded polytetrafluoroethylene grafts were not. There is developing collective experience and literature available to allow the assessment of outcomes of these early cannulation grafts. The aim of this review was to review the evidence for both short- and long-term outcomes of early cannulation grafts. METHODS Using standardized searches of electronic databases in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses, the primary outcomes for this study were primary and secondary patency rates for early cannulation grafts for dialysis at 12 months and beyond. Secondary outcomes were timing of first cannulation, rates of access thrombosis, steal syndrome, pseudo-aneurysm and infection. RESULTS A total of 19 studies were identified and included. These were divided into different graft types. Flixene™, Avflo™, Acuseal™ and Vectra™ grafts all showed that early cannulation within 72 h is possible. Twelve-month pooled primary and secondary patency rates were 43.3% (95% confidence interval: 31.6-55.4) and 73.4% (95% confidence interval: 63-82.7) for the Flixene graft, 58.2% (95% confidence interval: 48-68.1) and 79.2% (95% confidence interval: 68-88.7) for the Avflo graft, 43.6% (95% confidence interval: 30.7-56.9) and 70.5% (95% confidence interval: 49.7-87.8) for the Acuseal graft and 63.7% (95% confidence interval: 53.4-73.4) and 85.8% (95% confidence interval: 82.9-88.4) for the Vectra graft. Data for outcome beyond 12 months were limited to the more recent studies. CONCLUSION This review confirms that early cannulation is not detrimental on the early outcome of early cannulation graft patencies. It has also shown that both Vectra and Avflo grafts have adequate long-term patencies. The data do not allow specific graft recommendations, as comparative trials would be required

Early cannulation grafts for haemodialysis:a systematic review

Purpose Arteriovenous grafts have advantages compared with central venous catheters for dialysis access and guidelines suggest their use as second choice after arteriovenous fistulas. Standard practice with expanded polytetrafluoroethylene (ePTFE) grafts has been to avoid cannulation for 2 weeks following placement, but new generation grafts have been marketed for their early cannulation properties allowing use as an alternative to central venous catheters for prompt access. The aim of this review is to search the current literature for evidence of early cannulation of new generation grafts and to assess their patency and complication rates. Methods Electronic databases were searched for studies assessing the use of early cannulation grafts for dialysis in accordance with PRISMA. The primary outcomes for this study were primary patency rate, primary-assisted patency rate and secondary patency rate. Secondary outcomes were timing of first cannulation, rates of access thrombosis, steal syndrome, pseudo-aneurysm and infection. Results Following strict inclusion/exclusion criteria by two reviewers, 15 studies were included in our review and divided into the different types of graft. Flixene, Avflo, Rapidax and Acuseal grafts showed that early cannulation within 72 h was possible; there was no evidence of the use of Vectra within 2 weeks of placement. All grafts showed similar patency and complication rates as previously published data on standard ePTFE grafts. Conclusion Our review showed that early cannulation is possible without detriment, but data did not allow specific graft recommendations. Therefore, we feel that a multicentre, randomised controlled trial is necessary to compare early cannulation grafts. </jats:sec

End-stage vascular access failure: can we define and can we classify?

Background: Renal replacement therapy using dialysis has evolved dramatically over recent years with an improvement in patient survival. With this increased longevity, a cohort of patients are in the precarious position of having exhausted the standard routes of vascular access. The extent of this problem of failed access or ‘desperate measures ’ access is difficult to determine, as there are no uniform definitions or classification allowing standardization and few studies have been performed. The aim of this study is to propose a classification of end-stage vascular access (VA) failure and subsequently test its applicability in a dialysis population. Methods: Using anatomical stratification, a simple hierarchical classification is proposed. This has been applied to a large dialysis population and in particular to patients referred to the complex access clinic dedicated to patients identified as having exhausted standard VA options and also those dialysing on permanent central venous catheters (CVC). Results: A simple classification is proposed based on a progressive anatomical grading of (I) standard upper arm options exhausted, (II) femoral options exhausted and (III) other options exhausted. These are further subdivided anatomically to allow ease of classification. When applied to a complex group of patients (n = 145) referred to a dedicated complex access clinic, 21 patients were Class I, 26 Class II and 2 Class III. Ninety-six patients did not fall into the classification despite being referred as permanent CVC