When to first cannulate Vascular Access for Hemodialysis

Müjdat YENİCESU, M. D.

October 23, 2014

• Vascular Access (VA) is still the Achilles’ heel of long term hemodialysis (HD) therapy.

• NKF DOQI guidelines recommend AVF as the first choice of primary VA for HD therapy.

• VA cannulation involves inserting two, occasionaly one, large bore needles into the fistula veins.

• The native vein has a rather thin wall and is relatively fragile.• Once a fistula created, it must develop to the point that it is usable. The AVF must

be adequately mature to allow repeat cannulation.• Optimal waiting time before first use of VA is not known.• Early cannulation has been shown to be associated with shorter survival.

Introduction

AJKD, 1995, 26:341-346

AJKD, 1995, 26:341-346

AJKD, 2002, 40: 1264-1276

Creation, cannulation and survival of AVF:data from the DOPPS. KI, 2003, 63(1):323

Creation, cannulation and survival of AVF:data from the DOPPS. KI, 2003, 63(1):323

Creation, cannulation and survival of AVF:data from the DOPPS. KI, 2003, 63(1):323

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Creation, cannulation and survival of AVF:data from the DOPPS. KI, 2003, 63(1):323

• This group reported (2002) that the presence of temporary catheters at the hdx initiation was associated with earlier cannulation and shorter survival of the first AVF created for incident patients.

• They explained this relationship with insufficient maturation period because of catheter complications.

Figure 1. Kaplan-Meier curves of time to failure (primary patency from first cannulation) by use of catheters (CVC) at dialysis start (A) and by maturation category in days (B).

Ravani P et al. JASN 2004;15:204-209

©2004 by American Society of Nephrology

AVF maturity;How do we know AVF is mature enough for cannulation?

• The high pressure and flow artificially introduced when a fistula is created causes the involved vein to undergo a series of changes characterized by dilation and thickening of the wall.

• This process, reffered to as maturation, eventually renders the fistula usable as a vascular access.

• Data suggest that adequte fistula size and blood flow helps predict fistula maturation.

• An experienced dialysis nurse were also 80 % accurate in predicting the ultimate utility of a fistula for dialysis.

Radiology, 2002;225(1):59/Hdx arteriovenous fistula maturity: US evaluation

NKF-KDOQIVascular Access 2006Work Group Membership

• Another rule; • Arterialized vein intima-media (IMT) thickness of >0.13 mms was associated with

successful cannulation in a study of new AVFs using high frequency ultrasound.

Seminars in Dialysis, 2013, 26(3):315-322. What Nephrologists Need to Know about Vascular Access Cannulation Radioloy, 2011, 261(2): 616-624. Arteriovenous fistulas for hemodialysis: application of high-frequency US to assess vein wall morphology for cannulation readiness

•Cannulation before two weeks of age should be avoided.•Cannulation between two to four weeks may be attempted but only if the fistula is considered mature.•Cannulation after four weeks of maturation may be safe, if the fistula is mature.

Conclusions relating to timing of cannulation of AV fistulas

NDT 2005, 20(4): 688.