Transcript When to first cannulate Vascular Access for

When to first cannulate Vascular Access for Hemodialysis
Müjdat YENİCESU, M. D.
October 23, 2014
Introduction
• 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.
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
14
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
• 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-KDOQI
Vascular Access 2006
Work 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
Conclusions relating to timing of cannulation of AV fistulas
• 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.
NDT 2005, 20(4): 688.