Chapter 142 - Fibromuscular dysplasia

Question 1

Fibromuscular dysplasia definition

Answer 1

1) Nonatheromatous noninflammatory proliferative process

2) medium sized conduit (long) arteries most common (renal, ICA)

Question 2

First description of FMD

Answer 2

1938 String of beads appearance

Question 3

Epidemiology of FMD

Answer 3

1) women > 90%
2) age 20-60
3) 10% familial
4) caucasians 95%

Question 4

FMD and renal stenosis key points

Answer 4

1) 2nd most common renal stenosis

2) most common renal HTN in children

Question 5

FMD associations with other factors and conditions

Answer 5

1) smoking
2) estrogen
3) ACE polymorphism
4) phenochromocytoma
5) Marfan
6) Alport syndrome
7) Takayasu

Question 6

Pathogenesis of FMD

Answer 6

1) Vasovasorum damage from motion
2) long arteries with less vasovasorum more likely
3) Right renal > left renal to be affected and have ptosis

Question 7

Differential diagnosis of FMD

Answer 7

1) Neurofibromatosis 1
2) EDS4
3) Williams syndrome
4) vasculitis

Question 8

Differentiating NF1 and FMD

Answer 8

NF1 has characteristic skin lesions

Question 9

Differentiating EDS4 from FMD

Answer 9

1) acrogeric dysmorphism
2) skin elasticity
3) distal joint laxity

in EDS4

Question 10

Differentiating williams syndrome from FMD

Answer 10

1) facial dysmorphism
2) supra-aortic stenosis
3) behaviour changes

in Williams

Question 11

Angiographic classification of FMD

Answer 11

1) Multifocal string of beads

2) focal with single area of stenosis

Question 12

Histopathologic scheme of FMD

Answer 12

1) Intima fibroplasia (5-10%)
2) medial fibroplasia (80-85%)
3) periarterial/adventitial fibroplasia (<1%)

Question 13

Secondary events from dysplastic lesions in FMD

Answer 13

Aneurysm 17% (1/3 in renal)

Dissection 20% (1/5 in renal)

Question 14

Medial fibroplasia of FMD subdivided classes

Answer 14

1) Medial fibroplasia
2) perimedial fibroplasia
3) medial hyperplasia

Question 15

Intimal fibroplasia key points

Answer 15

1) young no gender difference
2) collagen deposition in intima
3) disrupted internal elastic lamina
4) focal ring-like stenosis

Question 16

Medial fibroplasia key points

Answer 16

1) Age 20-70
2) female:male 5-9:1
3) thinned media alrternating with thickened fibromuscular ride with collagen
4) can have secondary intimal hyperplasia
5) string of beads with beads larger than native vessel
6) distal 2/3 of main renal and branches 25%

Question 17

Perimedial fibroplasia key points

Answer 17

1) young female < 50
2) patchy collagen deposition
3) intact external elastic lamina
4) string of bead but diameter less than native

Question 18

Adventitial fibroplasia

Answer 18

1) no gender difference
2) collage replace normal adventitia
3) unifocal to long stenosis

Question 19

Multiple vascular bed rate in FMD

Answer 19

2 vascular bed: 35%

3 vascular bed: 22%

Question 20

difference in FMD and atherosclerotic lesions affecting renal function

Answer 20

FMD is mainly RAAS driven

Atherosclerosis can also be inflammatory driven

Question 21

FMD natural history from asymptomatic in 4 years

Answer 21

1) 25% get HTN

2) 40% get FMD progression angiographically (overestimate)

Question 22

Percentage of secondary hypertension in all HTN

Answer 22

5%

Question 23

Indications for the evaluation of secondary HTN

Answer 23

1) require 3+ drugs
2) sudden elevation Cr and worsening HTN
3) <50 years old
4) spontaneous hypokalemia
5) bruit
6) flash pulmonary edema

Question 24

Limitations of MRA and CTA in size of vessels

Answer 24

2mm

Question 25

Gold standard for FMD diagnosis

Answer 25

Catheter DSA

Question 26

Indication for treating FMD

Answer 26

1) refractory HTN 2) intolerance/noncompliance to meds 3) impaired renal function 4) renal size decreased > 1cm

Question 27

BP target in fmd

Answer 27

BP < 140/80 in DM < 130/80

Question 28

First line antiHTN drugs 5 classes

Answer 28

1) ACEi 2) ARB 3) beta blocker 4) CCB 5) diureticsd

Question 29

Renal angioplasty in FMD key points

Answer 29

1) 0.15 mg nitroglycerin helps with vasospasm 2) cutting balloons not used unless IVUS shows adequate thickness of wall and not hypoplastic 3) stent usually not needed

Question 30

Complications following endo treatment of FMD

Answer 30

1) access 3-26% 2) dissection 1.4-6.7% 3) rupture 2-6% 4) branch occlusion 1-5%

Question 31

Factors that increase need for reintervention endo in FMD

Answer 31

1) branch vessel involvement | 2) complex lesions

Question 32

Indications for treating FMD with open surgery

Answer 32

1) complication following endo | 2) concurrent aneurysm disease

Question 33

Role of mannitol in renal protection

Answer 33

1) diuresis | 2) hydroxyl free radical scavenger

Question 34

Dose of mannitol for renal protection

Answer 34

12.5-20g

Question 35

Open renal artery repair in FMD key points

Answer 35

1) cannot reimplant because too short 2) conduit GSV, IIA, prosthetic 3) renal protection

Question 36

Autotransplantation of kidney key points

Answer 36

1) cold perfusion with Saline, Ringers or Wisconsin (4C, 500 ml) 2) Take patch off IVC to ease in anastamosis

Question 37

Complication of open surgery in FMD

Answer 37

1) morbidity 19-28% 2) post-op occlusion 3.8-13% 3) restenosis 0-16% 4) vein graft dilatation late 20-44%

Question 38

Pediatric causes of renal artery stenosis

Answer 38

1) FMD 2) developmental RAS 3) NF1 4) Moyamoya 5) Takayasu 6) Alagille syndrome 7) Williams syndrome

Question 39

Percent of pediatric HTN due to RAS

Answer 39

8-10%

Question 40

Rate of bilateral carotid FMD

Answer 40

35-85%

Question 41

Epidemiology of carotid FMD

Answer 41

Female 40-60 make up 60-90% of all cases

Question 42

Rate of carotid FMD causing emboli, thrombosis, dissection leading to aneurysm

Answer 42

< 10%

Question 43

Location of lesion of carotid FMD compared to atherosclerotic

Answer 43

more distal in FMD

Question 44

Rate of kinking in carotid FMD

Answer 44

5%

Question 45

Rate of concurrent atherosclerotic disease in carotid FMD

Answer 45

20%

Question 46

Rate of carotid aneurysms in carotid FMD

Answer 46

21.1%

Question 47

Rate of carotid dissection in carotid FMD

Answer 47

5.6 - 75%

Question 48

rate of Concurrent vertebral FMD in carotid FMD

Answer 48

7-38%

Question 49

rate of Intracranial aneurysm and occlusive disease in carotid FMD

Answer 49

51% 80% solitary lesion, 20% multiple usually same side as carotid lesion

Question 50

Rate of coexisting renal FMD in carotid FMD

Answer 50

8-40%

Question 51

Neurological symptoms on presentation in carotid FMD

Answer 51

1) stroke 12-27% 2) hemispheric TIA 31-42% 3) amaurosis fugax 22-28% 4) Horner 12.4% 5) cranial nerve abn 9.4% 6) focal neuro deficit 13.6%

Question 52

Sensitivity and specificity of carotid bruit for carotid FMD

Answer 52

Sen 45.4% | Spe 93.7%

Question 53

1st line treatment of asymptomatic carotid FMD

Answer 53

1) antiplatelet | 2) monitor

Question 54

Special considerations for carotid FMD different from atherosclerotic

Answer 54

1) multiple lesions which one to treat 2) concurrent aneurysm intracranial 3) concurrent HTN 4) contralateral asymptomatic lesion what to do 5) cannot use existing evidence on degree of stenosis

Question 55

Surgical technique in carotid FMD

Answer 55

1) percutaneous angioplasty 2) Open dilation technique 3) open angioplasty 4) interpositional bypass data limited for all

Question 56

Open dilation of carotid FMD stroke rate

Answer 56

1.4-2.6% TIA 1.4-7.7% Cranial nerve injury 5.1-16.7%