DISASTER!!!!!

Functional AVF Attempted & Failed AVF

WHY AVF placements

Need for Grafts & catheters

AV access Functional

HOW

Duplex Ultrasound

• Linear Transducer

• 7.5 – 12 MHz

• Grey scale & Pulse Doppler

T

R

A

N

S

D

U

C

E

R

LOOK FOR WHAT

Arterial inflow

Venous outflow

WHAT………..ARTERY

Grey scale:

• Internal luminal diameter

• Calcification

• High bifurcation of brachial artery

WHAT………..ARTERY

Internal Luminal Diameter (>0.20 cm)

Qαr4

*Silva MB et al J Vasc Surg (1998), 27: 302-8.

*Lockhart Me et al J Ultrasound Med (2004), 23:161-8.

RADIAL ARTERY RADIAL ARTERY

WHAT………..ARTERY

Pulsed Color Doppler:

• Arterial spectral waveforms

• Modified Allen test

• Peak systolic/end-diastolic velocities

• Resistivity index

WHAT………..ARTERY

Arterial spectral waveforms

Triphasic Flow

WHAT………..ARTERY

Modified Allen test

Reversal of blood flow distal to the proximal occlusion

WHAT………..VEIN

Depth of vein- Fat, fifty, female

Internal luminal diameter

Compressibility, phlebosclerosis

Site & length of stenosis

Respiratory variation of flow

WHAT………..VEIN Internal luminal diameter (AVF > 2.5mm, AVG >4 mm)

* Silva MB et al J Vasc Surg (1998), 27: 302-8.

CEPHALIC VEIN CEPHALIC VEIN

WHAT………..VEIN

WHAT………..VEIN

Respiratory variation

Normal Respiratory Variation Slow Antegrade flow

without Respiratory

Variation