Thread by @aishaikh

💥’Endovascular AVF for Dialysis’ -
Tweetorial

⚡️What is an Endovascular Arteriovenous Fistula?
⚡️How is an EndoAVF different from a surgically created AVF?
⚡️EndoAVF Outcomes?

@ASDINNews
#EndoAVF
#VascularAccessPearls
1/

💥First a poll:
In the next few years, Endovascular AVF will completely replace the Surgical AVF for hemodialysis

💥Let’s first briefly review the Surgical-AVFs

⚡️In 1966, Brescia & Cimino described the creation of the Radial-Cephalic AVF in the distal arm👇🏽

⚡️This proved to be revolutionary & AVF became the dialysis vascular access of choice

2/

💥AVF is the best vascular access for dialysis due to ⬇️ infection rate &
⬆️ patency compared to AVG or CVC

‼️But there is a caveat

⚡️AVF also have a high primary failure rate - meaning that a significant number of AVFs ~ 20% - 60% fail to mature

3/

💥There are many factors that contribute to high primary AVF failure rate
⚡️AVF maturation is dependent on vessel remodeling

⚡️Vessel trauma during surgical AVF creation likely contributes to neointimal hyperplasia which
➡️ stenosis ➡️ failure to mature

4/

💥 Additionally, AVFs that require more interventions (angioplasty) to achieve ‘maturation’ status tend to have:
⬇️ long-term patency👇🏽
⬇️ less cumulative survival👇🏽

⚡️As aptly pointed out in an editorial:
“Fistula Interventions: Less is More”

5/

💥Now let’s talk about the Endovascular AVF

⚡️EndoAVF is an AVF created using percutaneous catheter-guided technique

⚡️Currently 2 devices are approved for EndoAVF creation
📌Ellipsys
📌WavelinQ (old name EverlinQ)

6/

💥Both EndoAVF devices use forearm vessels for AV anastomosis creation

⚡️Both devices depend on the perforator vein to feed the superficial veins in the arm which are subsequently cannulated for dialysis
⚡️You may be wondering what a perforator vein is?

7/

💥What are Perforator Veins?
⚡️Veins that perforate muscular aponeuroses to connect the superficial veins to the deep veins👇🏽
⚡️Blood flows from superficial -> deep veins
⚡️Deep veins run parallel to the arteries (venae comitantes or accompanying veins)

8/

💥Is the concept of an anastomosis
b/w a forearm artery & a forearm perforator vein new?
⚡️Not at all

⚡️Kenneth Gracz described the Proximal Radial artery -> Perforator Vein AVF in 1977👇🏽
⚡️Gracz AVF is a ‘surgical AVF’ & has been used for many years
9/

💥How is EndoAVF different from Surgical AVF?

EndoAVF:
✅avoids vessel manipulation-likely
⬇️ neointimal hyperplasia
✅ preserves vasa vasora - likely
⬇️ fibrosis
✅ side to side AV anastomosis- likely
⬇️ vessel wall shear stress

10/

💥Ellipsys Device👇🏽

⚡️Creates the fistula (connection) b/w the forearm perforator vein & the proximal radial artery using thermal energy & pressure
⚡️It utilizes a single venous catheter system
⚡️Video Link👇🏽


11/

💥WavelinQ Device

⚡️Creates a fistula (connection) b/w the forearm artery (ulnar) & forearm deep vein (ulnar)
⚡️Dual magnet lined catheter system uses radiofrequency energy to create the anastomosis
⚡️Video Link👇🏽


12/

💥This table summarizes the differences between the Ellipsys and WavelinQ devices👇🏽

13/

💥EndoAVFs rely on perforator veins to direct the blood flow to the superficial veins

⚡️It is due to this fact that multiple veins can ‘mature’ & can be cannulated for dialysis
⚡️This is different from the surgical AVF where a single vein matures👇🏽

14/

💥Two Landmark Studies have evaluated the utility & safety of the EndoAVF creation devices👇🏽

⚡️NEAT Study (WavelinQ)
⚡️PIVOTAL Study (Ellipsys)

Both studies were single arm studies (meaning there was no comparator arm for Surgical-AVF)

15/

💥Both EndoAVF studies showed
⬆️ technical success, ⬆️ functional & cumulative patency, ⬇️ time to cannulation in comparison to what is reported in literature for Surgical AVFs👇🏽
‼️But there was no comparator arm for Surgical AVF in these studies

16/

💥A recent study reported an excellent 2-yr cumulative patency rate and low access failure rate for EndoAVF👇🏽
⚡️It also reported a high level of patient satisfaction with EndoAVF👇🏽

17/

💥It is important to recognize that success of EndoAVF is highly dependent on proper patient selection based on vascular parameters
⚡️Vascular Eligibility criteria for the EndoAVF devices is👇🏽
⚡️In NEAT & PIVOTAL Trials 72%-75% pts. met this criteria

18/

💥Early results of EndoAVF are good
⚡️Long term outcomes are unknown
⚡️It’s success will depend on education & training of patients, dialysis staff & nephrologists as EndoAVFs look & feel different from surgical AVFs (no scar) & multiple outflow veins

19/

💥EndoAVF offers an additional AV access option for pts. who are not candidates for a surgical distal radial-cephalic AVF or are not candidates for an open surgery
⚡️EndoAVF fits the KDOQI algorithm: Start distal & then move proximal for AVF creation

20/

💥Let’s retake the poll:
In the next few years, Endovascular AVF will completely replace the Surgical AVF for hemodialysis

💥Summary:

📍EndoAVF creation is minimally
invasive

📍EndoAVF has:
⬆️ technical success rate
⬆️ functional & cumulative patency
⬇️ time to cannulation
⬆️ patient satisfaction

‼️But proper patient selection is the
key

End/