Chapter 130 - Renovascular and aortic developmental disorders Flashcards
Mid aortic syndrome first used by
1963 Sen
Classification of mid aortic syndrome and its relative prevalence
Suprarenal 69%
Intrarenal 23%
Infrarenal 8%
Diffuse hypoplasia of abdominal aorta - also along spectrum of disease
Embryology in mid aortic syndrome
evidence in this theory
Two dorsal aorta over-fuse
1) single lumbar instead of paired
2) multiple renal accessory arteries (2x likelihood)
Genetic syndromes associated with mid aortic syndrome
1) Neurofibromatosis NF-1 (13-25%)
2) William syndrome
3) Alagille syndrome
4) Tuberous sclerosis
Inflammatory/infectious etiology of mid aortic syndrome
1) maternal rubella in 1st trimester
2) takayasu aortoarteritis
3) umbilical artery catheterization (also associated with aortic thrombosis and mycotic aneurysms)
Aortic coarctation association with splanchnic and renal artery stenosis
Splanchnic 87%
Renal 62%
Etiology of pediatric renal artery stenosis in NA and Asia/Africa/SA
NA: developmental (NF-1)
Asia/Africa/SA: inflammatory, Takayasu
Embryologic origin of CA and SMA
Vitelline arteries
Rate of renovascular HTN as a cause of 2ndary HTN in kids
8-10%
Intetinal ischemia due to mid aortic syndrome
6% of mid-aortic syndrome patients only
Symptoms of pediatric renovascular HTN
1) HTN
2) headache, seizure, visual disturbance
3) epistaxis
4) renal insufficiency
5) Bell’s palsy
6) hemorrhagic stroke
7) hypertensive encephalopathy
8) flash pulmonary edema
Renal US to detect aortorenal stenosis sen and spe
90% sen
68% spe
Rate of cerebral vascular abnormalities in mid aortic syndrome
3-13%
occlusive and aneurysmal
Goal of HTN therapy in children
Reduce to 95percentile
If LVH or target organ identified then reduce to 90th percentile
Classes of antihypertensives
1) ACEi
2) ARBs
3) combined alpha beta blocker
4) beta blocker
5) diuretic
6) central alpha agonist
7) calcium channel blocker
8) peripheral alpha antagonist
9) vasodilators
Principle of antihypertensive meds
Use one until max dose or side effect
Diuretic use in controlling pediatric blood pressure
Used in combination with something else or else increase renin release will exacerbate HTN
Surgical treatment of mid aortic syndrome
1) Patch angioplasty
2) thoracoabdominal bypass
3) retroperitoneal tissue expander
Conduit for thoracoabdominal bypass in mid aortic syndrome
ePTFE > dacron because less likely to have postimplantation dilatation
When does patch not work in mid aortic syndrome
Aorta too small such that the suture lines overlap
Diameter of grafts to use in thoracoabdominal bypass for mid aortic syndrome
Young children: 8-12 mm
Early adolescent 12-16 mm
Late adolescent/adults 14-20 mm
When is it ok to not leave graft redundancy in thoracoabdominal bypass of youth
after age 9 because axial growth is limited
Rate of reoperation in mid aortic syndrome
10% in 5-12 years
At what age is renal revasc more durable
after 3 years of age
defer repair whenever possible until age 3
Conduit in pediatric renal reconstruction
Internal iliac artery
GSV not good - aneurysmal degeneration in 50%
Why are splenorenal reconstructions not idea
Chance of developing celiac stenosis in this patient population
Indication for nephrectomy in pediatric
1) Non-reconstructable disease (multiple intrarenal stenosis)
2) diminutive non-functioning kidney 2-3cm in size
3) contralateral kidney assumed to be adequate
Large series of pediatric renovascular HTN
1) University of Michigan
2) Hospital Beaujon (France)
3) Cleveland clinic
4) Vanderbilt University (philadelphia)
Cure rates of HTN with renovascular revasc in children
66-70% cure
23-27% improvement
3-11% fail
Rate of complication following endovascular treatment of mid aortic syndrome
30%
Endovascular treatment success for mid aortic syndrome
Freedom from reintervention at 1 and 5 years
1 year 55%
5 year 33%
Remedial open revasc of renal artery in pediatric after failed endo vs primary open revasc
cure rate and improvement rate of HTN
Remedial 25% cure, 54% improve
primary 70% cure, 27% improve
Principle of endovascular treatment of congenital reno stenosis
1) no stent - intimal hyperplasia
2) only at high centers
3) high risk of rupture, pseudoaneurysm, recurrence
