Chapter 174 - Acquired arteriovenous fistulas

Question 1

First description of acquired AVF

Answer 1

William Hunter 1761 attempted phlebotomy

Bruit and thrill descriptions

Question 2

Traumatic causes of AVF

Answer 2

1) stab wounds 63%
2) gun shot 26%
3) blunt 1%

Question 3

Iatrogenic AVF most common location

Answer 3

CFA 37%

Question 4

Rate of access complications using fluoroscopy or US

Answer 4

fluoroscopy 3.4%

US 1.4%

Question 5

Spontaneous AVF first described by and definition

Answer 5

Syme 1831

1) atherosclerotic
2) inflammatory
3) mycotic aneurysm
4) other infections and connective tissue diseases (rare)

Question 6

Rate of neck injuries resulting in carotid jugular AVF

Answer 6

4-27%

Question 7

Causes of vertebral artery AVF

Answer 7

1) iatrogenic 2/3

2) trauma 1/3

Question 8

AVF rate after subclavian vein catheterization

Answer 8

0.58%

Question 9

Iatrogenic AVF in radial and ulnar arteries rate

Answer 9

0.02-0.04%

Question 10

Incidence of CFA AVF iatrogenic

Answer 10

0.06-0.86%

Question 11

Factors predisposing iatrogenic femoral AVF

Answer 11

1) female
2) emergency procedure
3) anticoagulation
4) low distal puncture
5) HTN
6) prosthetic graft
7) age > 65
8) sheath > 8F
9) high BMI
10) femoral atherosclerosis
11) left-sided
12) multiple punctures
13) hostile groin

Question 12

Popliteal AVF as a % of all AVF

Answer 12

5-14%

Question 13

Cause of aorto-caval fistula

Answer 13

1) rupture or erosion of AAA (80-90%)

2) penetrating injury (10-20%)

Question 14

Lumbar disc procedures in causing AVF key points

Answer 14

1) rate 0.05%
2) risks with low aortic bifurcation at L4-L5
3) most common CIA injury right 43%, left 29%)

Question 15

risk of biopsy causing renal AVF

Answer 15

9-18%

1) large bore needle
2) lack of radiologic guidance
3) medullary penetration
4) atherosclerosis

Question 16

Causes of renal AVF

Answer 16

1) biopsy
2) nephrostomy tube
3) laser lithotripsy
4) mass ligation of renal pedicle

Question 17

Causes of splenic AVF

Answer 17

1) trauma/iatrogenic
2) mass ligation of splenic pedicle
3) erosion of pancreatic pseudocyst
4) rupture of noncalcified splenic artery aneurysm

Question 18

Causes of hepatic AVF

Answer 18

1) trauma/iatrogenic
2) transhepatic diagnostic catheterization
3) biliary drainage
4) TIPS
5) biopsy 5.4% risk
6) carcinoma
7) aneurysm

Question 19

Fistula size critical point for affecting normal arterial flow

Answer 19

Holman and Taylor

<1.5x diameter of inflow artery: normal arterial flow
>1.5x: 5x increase proximal artery flow
>3x diameter: diminished or reversed flow and 8x increase in proximal artery flow

> 350ml/min = cannot close spontaneously

Question 20

Chronic changes with AVF

Answer 20

2 months: structural changes become evident
15 months: established but may be reversible
2 years: irreversible changes

Question 21

Clinical presentation of AVF

Answer 21

75% small asymptomatic
Thrill/bruit 61-96%
Pulsatile mass 20-52%
Pain 70-80% (aorto/iliac avf)

Question 22

Nicoladoni-Branham sign

Answer 22

Temporary compression of artery proximal to fistula resulting in bradycardia and decrease pulse pressure

Question 23

signs of an aortocaval fistula

Answer 23

1) holosystolic murmur 75%
2) thrill 25%
3) CHF

Question 24

CTA diagnosis of AVF sen and spe

Answer 24

Sensitivity 90-95%

Specificity 99-100%

Question 25

Percentage of iatrogenic femoral AVFs that will close in 1 year

Answer 25

38-81%

Question 26

Renal AVFs that resolve within 4 years spontaneously

Answer 26

33-90%

Question 27

Compression therapy to treat AVF key points

Answer 27

1) low success rate 0-30% 2) long duration 15+days 3) skin ulcerations and DVTs

Question 28

Onyx is made of

Answer 28

Ethylene vinyl alcohol copolymer

Question 29

Success rate of embolization of small AVFs

Answer 29

89-92%

Question 30

Endovascular tools for treating AVF

Answer 30

1) embolization material 2) covered stents 3) amplatzer plugs

Question 31

Timing before normalization of cardiac, pulmonary and renal function of truncal AVF

Answer 31

Cardiac/pulmonary - immediate | Renal 48-72 hours

Question 32

Surgical repair of post-cath AVF success rate

Answer 32

89-96%

Question 33

Mortality and morbidity following spontaneous aorto-caval fistula

Answer 33

mortality 7-12% | Morbidity 36%: MI, PE, CVA, organ failure

Question 34

Success rate of stent + embolization in neck and arm AVF

Answer 34

83.9-100%

Question 35

Stent graft occlusion, restenosis (>50%), reintervention and mortality following neck and UE AVF embolization + stent

Answer 35

Occlusion: 5-10% Restenosis 4-20% Reintervention 6-12% Mortality 0-5.9%

Question 36

Aortocaval fistula endo success

Answer 36

84-94%

Question 37

Aortocaval fistula endo repair mortality and morbidity

Answer 37

Mortality 0-19% | Morbidity 12-46%

Question 38

% of renal AVF that require treatment

Answer 38

23-36%

Question 39

Embolization of renal AVF +/- stent graft success rate

Answer 39

90%

Question 40

Visceral artery aneurysm success rate of coil embolization

Answer 40

93.3-100%

Question 41

Mortality and morbidity of visceral artery aneurysm endo repair

Answer 41

Mortality 0-8.3% | Morbidity 10-12.5%

Question 42

Mortality and morbidity after splenic artery aneurysm reapir

Answer 42

Mortality 0% | Morbidity 40% splene infarction

Question 43

Mortality after hepatic aneurysm embolization

Answer 43

11%

Question 44

Decision to treat with open vs endo for AVF's

Answer 44

No real difference