Chapter 128 - renovascular disease aneurysm and arteriovenous fistulae Flashcards
Epidemiology of renal artery aneurysm
Autopsy incidence 0.01-0.09%
Angiogram incidence 0.73-0.97%
CTA incidence 0.7%
Renal artery aneurysms are bilateral in this percentage of patients
10%
Percentage of true aneurysm that are extraparenchymal
90%
Peak incidence in age of patients for renal artery aneurysm
40-60 years
Causes of true renal artery aneurysms
1) congenital medial degenerative process
2) atherosclerosis
3) FMD
Percentage of renal artery aneurysms that are saccular
75%
Most common place of renal saccular aneurysm and fusiform aneurysm
saccular - main renal artery bifurcation
fusiform - main trunk
Medial fibroplasia characteristic
1) multiple stenosis and poststenotic dilatation in distal 2/3 of renal artery
Rate of renal artery aneurysm in FMD patients
9.2%
Rare congenital cause of renal artery aneurysm
Ehlers-Danlos
Incidence of dissection in FMD
0.5-9%
Causes of intrarenal aneurysms
1) congenital
2) collagen vascular disease
3) posttraumatic
4) associated with AVF
Symptoms of renal artery aneurysm
1) rupture = pain, distension, hypotension
2) HTN due to distal embolization and segmental hypoperfusion
3) hematuria
Mortality rate after renal artery aneurysm rupture
10% in non-pregnant women and men
Size cutoff for repairing renal artery aneurysm
Traditionally 2cm but is being challenged
some say 3 some say 4
women of child bearing age, repair when 1.5x adjacent size
Pregnancy causes increased risk of rupture because
1) hyperdynamic state: increased blood volume and cardiac output
2) hormonal influences
3) increased intraabdominal pressure due to gravid uterus
Mortality rate of pregnant renal artery aneurysm rupture
Maternal 55%
Fetal 85%
Prevalence of HTN in patients with renal artery aneurysm
80%
Kocher maneuver
Reflect right colon and duodenum medially
Renal Aneurysm repair options
1) aneurysmorrhaphy
2) patch repair
3) reimplantation
4) bypass
5) extracorporial repair
6) nephrectomy (rupture)
7) endo embolization
8) endo stent
Mortality for renal artery aneurysm repair
1.7%
Patency after renal artery aneurysm repair
96% in 4 years
Mortality after ex vivo renal artery aneurysm repair
0-9.6%
Morbidity after renal artery aneurysm repair
10% open and endo
FMD aneurysm treatment
Balloon into the stenotic area
Surgery open
Intrarenal aneurysm treatment
Partial nephrectomy
Embolization
Intrarenal aneurysm often associated with this disorder
polyarteritis nodosa
Incidence of true congenital AVM of kidneys
0.04%
1 in 30,000 autopsies
Congenital AVM in kidney key points
1) 1/4 of all renal AVF
2) right kidney more often
3) cirsoid or varix-like
4) not neoplastic
5) irregular fibrosis or intimal hyperplasia and medial hypertrophy
Renal AVF key points
1) traumatic accounts for 70%
2) 1-2% from needle biopsy
3) 15-18% from arteriography
4) associated with FMD when dysplastic/aneurysmal artery erodes into neighbor veins
5) associated with renal cell carcinoma
Clinical presentation of renal AVF
1) hematuria 72% of congenital cases
2) HTN due to arterial steal and relative ischemia
3) CHF due to high output heart failure (tachy, LV hypertrophy, cardiomegaly, palpable thrill in flank)
4) continuous abdominal bruit
Endovascular treatment of renal AVF key points
1) coils and balloons used for larger vessel; liquid agents for smaller
2) loss of functional renal parenchyma 0-30%
3) recurrence 50% when Gelfoam used (reabsorbed)
4) covered stents or stent assisted coiling
5) RFA
Post-embolization symptoms
1) transient fever
2) leukocytosis
3) hypertension
Endovascular treatment of renal AVF success rate
80%
