mohammed alsunaid, md section head, nephrology department of medicine king faisal specialist...

MOHAMMED ALSUNAID, MDMOHAMMED ALSUNAID, MD

Section Head, NephrologyDepartment of Medicine

King Faisal Specialist Hospital & Research Centre

Riyadh, Saudi Arabia

Clinical Scenario

• Mr Ahmed is 43 years old• CKD stage 4 due to FSGS• eGFR 18 mL/min• He was educated for preservation of

vascular access sites• Renal replacement therapy options

were discussed• He chose Hemodialysis (HD)

• Several years later, he came to the clinic with eGFR 9 mL/min

• Types of Chronic HD vascular access:A. Native arteriovenous fistulas (AVF), RC AVFB. Grafts (AVG)C. Double-lumen tunneled cuffed catheters

Clinical Scenario

AVF vs AVG46.4

20.6

0

10

20

30

40

50

AVFN=139

AVGN=78

P=0.001

Prospective study pre-operative vascular mapping

Allon, M, et al KI 2001; 60:2013-2020

Pri

mary

Failu

re R

ate

%

AVF vs AVG

0102030405060708090

AVFN=108

AVGN=52

58

7469

83

Prospective observational study RC AVF

Pri

mary

Pate

ncy

Rate

%

Silva, Jr, et al J Vasc Surg 1998;27:302-308

12 months

24 months

AVF vs AVGPri

mary

Su

rviv

al R

ate

%

at

2 y

ears

66

52

0

10

20

30

40

50

60

70

AVFN=139

AVGN=78

P=0.005

Prospective study pre-operative vascular mapping

Allon, M, et al KI 2001; 60:2013-2020

AVF vs AVG

P<0.001

0.57

1.67

0

0.5

1

1.5

2

AVFN=139

AVGN=78

Prospective study

Tota

l A

ccess

In

terv

en

tion

s/year

Pre-operative vascular mapping

Allon, M, et al KI 2001; 60:2013-2020

Access intervention: thrombectomy, angioplasty or surgical revision

AVF vs AVG

0

11.5

0

2

4

6

8

10

12

AVFN=108

AVGN=52

Infe

ctio

n R

ate

%

Prospective observational study Mean FU 15.2 months


Type of Vascular Access and Mortality

28

38 40

0

5

10

15

20

25

30

35

40

AVFN=1340

AVGN=3129

CVCN=875

2 Y

ears

Mort

alit

y %

Observational study USRDS DMMS Wave 1 Prevalent diabetic pts

Dhingra, RK, et al KI 2001; 60:1443-1451

Adjusted RR AVF vs AVG 1.41 (95%CI, 1.13 to 1.77) P<0.003Adjusted RR AVF vs CVC 1.54 (95%CI, 1.17 to 2.02) P<0.002

Type of Vascular Access and Mortality

An

nu

al M

ort

alit

y R

ate

%

11.7

14.216.1

02468

101214161820

AVFN=185

AVGN=296

CVCN=603

Adjusted RH AVF vs CVC 1.5 (95%CI, 1 to 2.2)Adjusted RH AVF vs AVG 1.2 (95%CI, 0.8 to 1.8)

Analysis from CHOICE Study Incident HD pts

Astro, BC, et al JASN 2005;16:1449-1455

AVF vs AVG

HigherLowerComplication Rate

LowerHigherPatency Rate

ShorterLongerTime to Use

LowerHigherPrimary Failure Rate

AVGAVF

Clinical Scenario

• He was referred to vascular surgeon

• Vascular surgeon referred him to radiologist for left upper extremity vascular mapping by duplex ultrasound

Is pre-operative vascular mapping by duplex US should be performed in all patients before

vascular access creation?

Yes N

o

53%

47%

1. Yes2. No

Pre-operative Vascular Mapping

14

62

24

63

30

7

0

10

20

30

40

50

60

70

Clinical ExaminationN=183

Doppler USN=172

AVF

AVG

CVC

AVF

AVG

CVC

Doppler US 9/1994-1/1997Clinical Exam 6/1992-8/1994

P<0.05C

reati

on

Rate

%



40

8.3

0

5

10

15

20

25

30

35

40


Doppler USN=108

Clinical Exam 6/1992 – 8/1994 Doppler US 9/1994 – 1/1997


AV

F Pri

mary

Failu

re R

ate

%

P<0.05


0102030405060708090


Doppler US (DU)N=160

48

63

8374

Clinical Exam 6/1992 – 8/1994 DU 9/1994-1/1997

Silva, Jr, et al J Vasc 1998; 27:302 - 308

Pri

mary

Pate

ncy

Rate

%

at

1 y

rAVF

AVGP<0.05


25

5.6

0

5

10

15

20

25

Physical ExaminationN=52

Doppler USN=72

P=0.002

Pri

mary

AV

F Fa

ilure

Rate

%

RCT CKD5

Mihmanli, I, et al J Ultras Med 2001; 20:217-222

The minimal advisable diameter of the anastomosed

vessels for the creation of successful AVF is:

5%

10%

28%

14%

43%

a.1 mmb.1.5 mmc. 2 mmd.2.5 mme.3 mm

Pre-Operative Vascular Mapping100

19

0

20

40

60

80

100

< 1.6 mmN=7

> 1.6 mmN=47

Pri

mary

Failu

re R

ate

%

Prospective observational study RC AVF Vessel Diameter

Wong, V, et al Eur J Vasc Endovasc Surg 1996;12:207-213

Pre-operative Vascular MappingR

ate

%83

8.3

0

10

20

30

40

50

60

70

80

90

RC AVF N=108

1 yr Primary Patency

Primary Failure

Prospective observational study Vein diameter > 2.5 mm Artery diameter > 2 mm


• Left radiocephalic RC AVF was constructed

• Nephrologist decided to initiate HD

Clinical Scenario

The minimum maturation period of AVF

should be ideally:

0%

11%

0%

49%

40%a. < 2 weeksb. 2-4 weeksc. > 4 weeksd. > 6 weekse. > 8 weeks

Timing of First Cannulation%

of

faci

litie

s

2

34 3726

50

29

13 8

74

24

2

0102030405060708090

100

< 1 1-2 2-3 3-4

< 1 1-2 2-3 3-4

< 1 1-2 2-3

US

EURO

JAPAN

Observational study 309 HD facilities AVF 2154

MONTHS

Saran, R, et al (DOPPS) NDT 2004;19:2334-2340

Timing of First CannulationA

dju

sted

Rela

tive R

isk

of

Acc

ess

Failu

re

0.72

10.91 0.87

00.10.20.30.40.50.60.70.80.9

1

< 1 1-2 2-3 >3

P=NS

MONTHS

Observational study 309 HD Facilities AVF 2154

Ref

Saran, R, et al (DOPPS) NDT 2004;19:2334-2340

Time of First CannulationA

dj. H

aza

rd R

ati

o f

or

Pri

mary

AV

F Fa

ilure

1.94

1

0

0.5

1

1.5

2

<30 >30DAYS

Ref

(95% CI, 1.3 to 2.8) P<0.001

Prospective study, MC AVF 513

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

Time of First Cannulation

Rule of 6s:1) Access flow > 600 mL/min2) Vein diameter > 6 mm3) Vein depth < 6 mm

K/DOQI (CPG/CPR 2006) AJKD 2006; 48 (S1): 1

Clinical Scenario

• 6 weeks later, left RC AVF was cannulated smoothly

• Objective monitoring of access function at regular base was performed

The recommended objective monitoring of access function should

be performed at regular base by:

16%

2%

62%

2%

18%

a. Venous pressure measurement

b. Arterial pressure measurement

c. Dynamic venous pressure measurement

d. Static venous pressure measurement

e. Access flow measurement

Vascular Access Blood Flow Measurement

• Duplex US• US flow dilution (Transonic)• Crit-Line III• Crit-Line III TQA• Variable flow Doppler• In graft Velocitymetry• Blood velocity meter• Glucose pump test

Tordoir, J, et al NDT 2007; 22 (S2) : 88-117

Access Blood Flow Measurements Over Dialysis

TimeA

ccess

Blo

od

Flo

w m

L/m

in 1344

1308

1250

1150

1200

1250

1300

1350

1400

30 90 150MINUTES

P=0.03

Prospective study 32 HD Pts US dilution (transonic)

Rehman, SU, et al AJKD 1999; 34: 471-477

( 7%)

Access Blood Flow Measurement and BP

Changes

28

50

Decr

ease

in

Acc

ess

Blo

od

Fl

ow

% A

fter

90

min

s

Decrease MAP % 15 25

Prospective Study 32 HD Patients US Dilution (Transonic)

Rehman, SU, et al AJKD1999; 34: 471-477

Vascular Access Flow Measurement and Number of

Catheter InsertionsR

ela

tive R

isk f

or

the N

o.

of

Cath

ete

r In

sert

ion

s

0.2

0.59

0

0.1

0.2

0.3

0.4

0.5

0.6

AVF N=60 AVG N=101

P < 0.05(95% CI, 0.04 to 0.88)

P < 0.05(95% CI, 0.37 to

0.93)

Meta-analysis AVF=1 RCT AVG=1 RCT Tonelli, M, et al AJKD 2008; 51: 630-640

Vascular Access Flow Measurement and Access

ThrombosisR

ela

tive R

isk f

or

Th

rom

bosi

s

0.47

0.94

0

0.2

0.4

0.6

0.8

1

AVF N=360 AVG N=446

P < 0.05(95% CI, 0.28 to 0.77)

(95% CI, 0.77 to 1.16)

Meta-analysis AVF 4RCT AVG 6RCT

Tonelli, M, et al AJKD 2008; 51: 630-640

Access Flow Measurement and Access Loss

0.65

1.08

0

0.2

0.4

0.6

0.8

1

1.2

AVF N=141 AVG N=381

Meta-analysis AVF 2 RCT AVG 4 RCT

Tonelli, M, et al AJKD 2008; 51: 630-640

Rela

tive R

isk f

or

Acc

ess

Loss (95% CI, 0.83 to 1.40)

(95% CI, 0.28 to 1.51)

Clinical Scenario

US dilution technique was used at monthly bases for access flow measurement

700 (22%)840 (7%)

900Access flow measurement mL/min

7/20086/20082/2007-3/2008

Date

What Should Be Done Next?

16%21%

0%

61%

2%

a. Repeat access flow measurement

b. Perform duplex USc. Perform MRAd. Perform fistulogram

+ percutaneous transluminal angioplasty (PTA)

e. Perform surgical revision

Degree of Stenosis and PTA

72

23

65

17

0

10

20

30

40

50

60

70

80

Baseline Post-PTA Baseline Post-PTAAVF=33 AVG=65

P<0.005

Prospective Observational study, MC US dilution

Van der Linden, J, et al JASN 2002; 13:715 - 720

Deg

ree o

f S

ten

osi

s %

Access Flow Measurement and PTA

304

638

371

674

0

100

200

300

400

500

600

700

Baseline Post-PTA Baseline Post-PTA

AVF=33 AVG=65

P<0.0001

Prospective observational study, MC US dilution


Acc

ess

Flo

w

mL/

min

Primary Patency Post-PTA50

25

0

10

20

30

40

50

AVF AVG

P=0.03

Pri

mary

Pate

ncy

Rate

Post

-PTA

at

6/1

2 %



Repeat PTA Procedures

24 (169 days)

43 (109 days)

0

5

10

15

20

25

30

35

40

45

AVF=25 AVG=35


Rep

eat

PTA

Rate

%


Clinical Scenario

• PTA was done for 70% stenosis at venous outflow site with good result

• Access flow measurement improved from 700 to 860 mL/min (within 1 week)

• Few months later, he underwent kidney transplantation from deceased donor.

The indication for pre-emptive percutaneous transluminal angioplasty

(PTA) is:

7%

40% 42%

5%5%

a. Decrease of access flow > 10%

b. Decrease of access flow > 20%

c. AVG flow < 800 mL/min

d. AVF flow < 800 mL/min

e. AVF flow < 600 mL/min

Pre-emptive Intervention

Variable EBPG 2007

CSN/CPG2006

Reduction of access flow %

> 20 > 20

AVF flow (forearm) mL/min

< 300 < 500

AVG flow mL/min < 600 < 650

1. Tordoir, J, et al NDT 2007; 22 (S2) : 88-1172. Jindal, K, et al JASN 2006; 17 (S1): 1-27

Conclusion1. Upper extremities vein preservation for every

patient with CKD (dorsum of the hand)2. AVF is the preferred type of VA and should be

placed as distal as possible3. Physical examination and vascular mapping

with Doppler US of upper extremity should be performed before VA creation

4. Minimal diameter of vessels is 2 mm for AVF creation

5. Minimal period for AVF maturation is one month

Conclusion

6. Measuring access blood flow at regular base should be performed (US dilution)

7. Early detection of VA dysfunction (thrombosis)

8. Pre-emptive corrective intervention (PTA)9. Decrease patient morbidity, hospital

admissions and healthcare costs10. Access monitoring programs should be

included as part of routine dialysis care

mohammed alsunaid, md section head, nephrology department of medicine king faisal specialist...

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