Thread by @NMawlaMD

1/x EndoAVF vessel mapping and how I approach it. My first tweetorial.

Let’s review the anatomy specific to all endoAVF options.
Y’all see it all here, right? 🤠

#endoAVF #pAVF #NephTwitter #wavelinq #ellipsys @ASDINNews @KidneyAcademy @RenalFellowNtwk @SocietyAccess @VASAMD

2/x Vessels to study:
Upper arm cephalic (CV), basilic (BV) and median cubital vein (MCV).
Perforating vein (PV) - this is the key!
Deep veins: brachial (BrV), radial (RV) and ulnar (UV). lateral and medial
Arteries: proximal radial and ulnar

3/x Perforator: PV connects the superficial veins to the RV (usually lateral) and then the UV (also lateral). Start with the AVF outflow (CV, MCV or both) and which communicate to PV. And then follow PV down to deeper veins (RV, UV or both). it’s hard to get it all in one plane

4/x Median Cubital Vein: If the PV connects to MCV, study its course across the cubital fossa. If superficial and not tracking over the brachial artery, consider it for cannulation. Not all endo-basilics require a transposition.

5/x Let’s start. Left arm, right = lat, sweeping prox to distal. If you ever get lost, reorient based on brachial artery bifurcation or go into long view. Sometimes its easier to identify the vein by ID’ing the artery its traveling with. Now let’s break it down....

6/x Find and follow the PV down. Dual outflow (MCV and CV) here. Then it communicates through lateral RV to the lateral UV. Sometimes it terminates at the RV. Sometimes it bypasses RV and goes to UV. Sometimes it goes over the RA to UV.

7/x Ulnar WavelinQ: follow PV to UV and continue down. After interosseous vessels takeoff, the ulnars get smaller and start moving up the screen. Plan anast in common ulnar segment (before IO takeoff). Can also sometimes see bridges between medial and lateral UVs.

8/x If happy with common ulnars, next study your access sites and approach. Follow brachial vessels down to ulnars. Here lateral BrV goes nicely to LUV, same on medial side. Decide your anastomotic side, lat or med? Also scan ulnar veins at wrist for alternative access site.

9/x Radial WavlinQ: Again follow PV to LRV and then scan down arm over prox radial vessels. Here the RV seems to split into a larger medial RV and a smaller LRV. It’s not uncommon for MRV to wrap over the RA and join LRV like this (distal to PV).

10/x Next look at access site to get to the radial veins. Back to BrV to RV. A little trickier here from lateral BrV. But often wrist RV same size as proximal RV and thus easier wrist access. Can also consider superficial vein access for RV or UV.

11/x Ellipsys approach: PV down to RA. Access site CV or MCV? Look at needle entry angle from PV into RA from this view, ~45 degrees here. Easiest if straight vertical, most challenging is side entry. Be mindful of the recurrent RA takeoff, some can be large and look like RA.

12/x A tortuous PV might make needling for Ellipsys more challenging. A steep PV can as well. Pay attention to those factors too.

13/13 That’s it. Scan up and down and scan everyone you can to study. Go back and look at the unmarked one again and identify it all. And if you have your own tips, tricks, techniques, share with us please.