Interwoven Nitinol Stents to Treat Radiocephalic Anastomotic Arteriovenous Fistula Stenosis

Thomas, Shannon D.; Peden, Samantha; Crowe, Phillip; Varcoe, Ramon L.

doi:10.1177/1526602819842851

Cited by 19 publications

(14 citation statements)

References 27 publications

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“…All the AVFs that were stented because of dysfunction managed to provide adequate flow rates following the procedure 27 . Another case series published by Thomas et al, who used nitinol stents to treat JAS in 42 RC AVFs, reported a 1 year assisted primary patency rate of 92.9% 28 . Studies that directly compare PTA against stenting for JAS are not available at present.…”

Section: Juxta‐anastomotic Stenosismentioning

confidence: 99%

Swing segment stenosis: An unresolved challenge

Gunawardena

Ridgway

2022

Seminars in Dialysis

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The native arteriovenous fistula is considered the gold standard among all dialysis access options. Compared with alternatives such as grafts and central venous catheters, their use is associated with a lower risk of infective and thrombotic complications. This leads to better patient outcomes and reduced healthcare-associated costs.Recognizing these advantages, there is a global drive to increase the creation and use of such fistulas in hemodialysis patients. Swing segment stenosis is a common problem encountered with the creation and use of these fistulas that can hurt their maturation and longevity. A "swing segment" in an arteriovenous fistula is defined as a segment of vein that pursues a sharp, curved course. Due to poorly understood reasons, these swing segments tend to develop stenotic lesions that are extremely challenging to treat. This review aims to provide an overview of the pathophysiology, incidence, management, and prevention of these swing segment lesions. We believe that such knowledge will be useful for clinicians who deal with dialysis access creation and maintenance. | INTRODUCTIONThe native arteriovenous fistula (AVF) is considered the vascular access of choice for those who require long-term hemodialysis (HD). This is due to their superior long-term patency and lower complication rates compared with arteriovenous grafts (AVGs) and central venous catheters (CVCs). 1 Additionally, those who are dialyzed through AVFs enjoy better survival compared with those who use AVGs or CVCs. 2 Considering these advantages, the fistula first initiative was launched in 2003, to increase the use of AVFs for HD in 50% of new patients and 40% of current patients. Later, these goals were modified to achieve a 65% AVF use in current HD patients. 3 As the global emphasis on the creation and use of AVFs increased, issues with regard to their maturation and patency became more pertinent. Swing segment stenosis is one such common problem that can affect successful fistula maturation and longevity. 4 A mature AVF is characterized by a diameter of >5 mm and a flow rate of ≥500 ml/min. A successful native AVF is expected to reach these parameters after 4-8 weeks from its creation. 5 Up to 60% of AVFs may not achieve these targets, and swing segment stenosis has been identified as a leading cause for this problem. 6 According to some investigators, swing segment lesions were the commonest reason for AVF dysfunction. 7 A "swing segment" in an AVF is defined as a segment of the vein that follows a sharp, curved course. This segment can be located in the vein that comprises the fistula or in its natural drainage pathway. 5 Swing segments are created adjacent to the anastomosis in radiocephalic (RC), brachio-cephalic (BC), and brachio-basilic (BB) fistulas as a result of surgical mobilization of the vein. These juxta-anastomotic swing segments are termed "distal" swing segments (Figure 1A). A "proximal" swing segment is generated close to the axilla when the basilic vein is transposed in a BB AVF (Figure 1B). A "natural" sw...

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Section: Juxta‐anastomotic Stenosismentioning

confidence: 99%

Swing segment stenosis: An unresolved challenge

Gunawardena

Ridgway

2022

Seminars in Dialysis

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“…Do úvahy prichádza ako záchranná technika u rezistentnej lézie prípadne opakovanej intervencii za obdobie kratšie ako 3 mesiace a to u pacientov, u ktorých je z rôznych príčin vyčerpaná chirurgická intervencia. Nové práce s použitím pleteného stentu Supera naznačujú jeho výhody z hľadiska primárnej priechodnosti a nízkej miery opakovaných intervencií (18).…”

Section: Endovaskulárna Liečba Dysfunkčnej Dialyzačnej Fistulyunclassified

Hemodialysis vascular access dysfunction and its endovascular treatment

Vorčák¹,

Zeleňák²,

Sýkora³

et al. 2020

Vnitř Lék

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Hemodialyzovaní pacienti so zlyhanými obličkami sú odkázaní na fungujúci cievny prístup -najčastejšie arterio-venóznu fistulu (AVF). Jej životnosť je ohrozená vznikom stenóz, ktoré je potrebné riešiť pred vznikom trombózy. Primárnou liečbou väčšiny stenóz je angioplastika, ktorá predlžuje jej životnosť. Vysoký technický úspech je dosiahnutý pomocou vysokotlakých balónikov a balónikov s čepieľkami. Z hľadiska dlhodobej priechodnosti je potrebné angioplastiku často opakovať. Primárnu priechodnosť zvyšujú balóniky uvoľňujúce cytostatikum. Stenty a stentgrafty sa v oblasti AVF používajú zriedka u inoperabilných pacientov a vo vybraných lokalitách. Rozvoj techník umožnil endovaskulárnu liečbu trombózy fistuly, po ktorej zároveň nasleduje angioplastika príčinnej stenotickej lézie. Endovaskulárne oklúzne techniky AVF sú alternatívou chirurgie u inoperabilných pacientov. U pacientov so zachovanou funkciou obličiek alebo s alergiou je možné intervenciu navigovať bez použitia jódovej kontrastnej látky, a to pod ultrazvukovou kontrolou prípadne použitím oxidu uhličitého.Kľúčové slová: angioplastika, centrálna venózna stenóza, dialýza, endovaskulárna liečba, stenóza arterio-venóznej fistuly. Hemodialysis vascular access dysfunction and its endovascular treatmentHemodialysed patients with end stage renal disease are reliant to proper function of vascular access -mostly arterio-venous fistula (AVF). AVF patency is jeopardized by stenosis formation, which needs to be treated before thrombosis. Angioplasty is primarily indicated and prolongs vascular access patency. High pressure balloons and cutting balloons aid to high technical success rate. Angioplasty needs to be repeated in order to maintain long term patency. Drug-eluting balloons prolong long term patency. Stents and stentgrafts are seldom used in inoperable patients and in selected locations. Technical advances allowed endovascular treatment in AVF thrombosis followed by angioplasty of culprit lesion. Vascular access endovascular occlusion is alternative for surgery in inoperable patients. In patients with residual renal function or iodine allergy, intervention could be ultrasound guided or carbon dioxide could be used without the need of iodine contrast.

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“…A diseased AVF is addressed by either surgical revision where the vessel is restructured or endovascular treatment where angioplasty and stent implantation is used. Endovascular treatment, and more specifically, flexible stent implantation has been shown to sustain AVF patency with periodic reintervention without abandonment of the AVF [15]. Many computational fluid dynamic (CFD) studies [7] on AVF geometries have been conducted to understand the influence of the hemodynamics on the disease onset.…”

Section: Introductionmentioning

confidence: 99%

A numerical investigation of a stented arteriovenous fistula

Gunasekera¹,

Ng²,

Thomas³

et al. 2020

Australasian Fluid Mechanics Conference (AFMC)

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An arteriovenous fistula (AVF) is a surgically created vasculature for end stage renal disease patients who require haemodialysis. The AVF is susceptible to high failure rates mainly due to the onset of intimal hyperplasia which is known to be linked to disturbed hemodynamics. One method adopted to treat this condition is to implant a flexible stent in the diseased region. In the present study, a silicone model of a patient-specific AVF was implanted with the Supera stent and subsequently scanned using a micro-CT. Using the segmentation of the high resolution scan, the AVF geometry with the stent detail was recreated and Reynolds averaged Navier Stokes simulations were conducted with pulsatile inlet flows of Reynolds numbers ranging from 345 to 730. Subsequently, two low velocity zones which translated to low wall shear stress zones were identified in the AVF.Other flow behaviour such as twisting flow from the high flow zones to low flow zones were also apparent. This study forms the basis to extend into large eddy simulations to detail the flow disturbances in the AVF to better understand the impact of the stent on the AVF health.

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Interwoven Nitinol Stents to Treat Radiocephalic Anastomotic Arteriovenous Fistula Stenosis

Cited by 19 publications

References 27 publications

Swing segment stenosis: An unresolved challenge

Swing segment stenosis: An unresolved challenge

Hemodialysis vascular access dysfunction and its endovascular treatment

A numerical investigation of a stented arteriovenous fistula

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