renal artery stenosis: an important cause of hypertension dr claire hathorn spr, rhsc edinburgh 11...
TRANSCRIPT
Renal Artery Stenosis: An important cause of hypertension
Dr Claire HathornSpR, RHSC Edinburgh
11th May 2010
Presentation
• 3 year old girl
• Well• Minor intercurrent illness – A&E• BP 144/91
History & Examination
• Asymptomatic
• PMH – Eczema, viral induced wheeze• FH – nil of note
• Normal examination• Height and weight on 97th centile
Initial Investigations
• BP 120-140 / 90-100 mmHg
• Urinalysis negative• FBC, U&Es, LFTs, coagulation • 4 limb BP • ECG• Renal USS & dopplers
• ALL NORMAL
Further Investigations
• Renin 2.6• Aldosterone 136• Cortisol 192• PTH 34• ACTH 12• Complement 560• C3 1.01• C4 0.18• ANA neg
• Urine catecholamines N• Urine cortisol
11.9• Urine prot:creat ratio 39
(slightly raised)• Urine MC&S negative
Radiology
• Echo – normal
• DMSA – divided function 50%
• MR Angiogram – slight irregularity of superior surface of right renal artery, felt unlikely to represent stenosis. No evidence of duplex. Conclusion: normal.
DMSA
MR Angiogram
Specialist Opinions
• Cardiology:– No clinical evidence of coarctation– No LVH on Echo
• Ophthalmology – Examination normal– No hypertensive retinopathy
• No cause or complication of hypertension
Impression & Management
• Blood pressure not well-controlled on 3 drugs– Atenolol 20mg bd – Amlodipine 2.5mg od– Doxazosin 0.5mg od
• Renovascular disease most likely diagnosis
• Referred for formal angiography at Great Ormond Street Hospital
Angiography
• Critical stenosis of left upper pole branch of main renal artery
• Normal right renal arteries
• Angioplasty performed
• Atenolol & Doxazosin stopped• Aspirin started
Progress
• Remained hypertensive 1 month post-angioplasty: 120/61
• Amlodipine continued• Doxazosin restarted
• 3 months post-angioplasty, BP well-controlled: 50-75th centile
Discussion
Renovascular Hypertension
• Aetiology• Clinical Features• Investigations• Management
Renovascular Hypertension
• 5-10% of all childhood hypertension
• Amenable to potentially curative treatment
• Causes & management different to adults
Aetiology in Children
• Fibromuscular dysplasia – most common in UK
• Syndromes: Neurofibromatosis, Williams, Marfan• Vasculitides: Takayasu, Kawasaki• Extrinsic compression: Wilm’s, Neuroblastoma• Other: Renal transplant, trauma, radiation
Clinical Spectrum
• Bilateral disease in 53-78%• Intrarenal disease in 44%• Intrarenal & main artery stenosis in 31%
• Most children without co-morbidities have single focal branch artery stenosis
Tullus et al. Renovascular hypertension in children. Lancet. 2008;371:1453-1463
Anatomic distribution of renal artery stenosis in children: implications for imaging
• Cinncinnati Children’s Hospital, 1993-2005• 24 stenoses identified in 21 children, R=L• 12 male, mean age 9yrs 3mths (30 mths – 18 yrs)• No co-morbidities• 90% children had a single stenosis • 75% lesions located in branch / accessory arteries
Vo et al. Pediatric Radiology 2006;36:1032
Clinical Features
Schroff et al. Angioplasty for renovascular hypertension in children: 20 year experience. Pediatrics 2006;118:268-275
Presenting Feature No. n=33
Incidental finding 9
Cardiac (CCF, palpitations, murmur) 7
Headache +/- vomiting & lethargy 6
Acute hypertensive encephalopathy 3
Cerebrovascular accident 2
Facial palsy 2
Failure to thrive 2
Screening for NF1 2
Renovascular disease and more widespread arterial involvement
Schroff et al 2006 (%)
Stadermann et al 2010
(%)Bilateral RAS 48 51
Intrarenal disease 45 -
Cerebral 21 26
Aortic 24 40
Visceral - 23
Implications of widespread arterial disease
• Improved BP control– 11/13 (85%) isolated RAS– 6/20 (30%) associated intra or extra renal disease
• Recommend routine cerebrovascular imaging– MR / PET scanning
Schroff et al. Angioplasty for renovascular hypertension in children: 20 year experience. Pediatrics 2006;118:268-275
Investigation
• Doppler ultrasound• Measurement of plasma renin activity
– Captopril plasma renin test– Renal vein sampling
• Scintigraphy: DMSA or MAG3• CT & MR angiography
• Angiography: Gold Standard
DMSA scintigraphy before & after Captopril
Tullus et al. Renovascular hypertension in children. Lancet. 2008;371:1453-1463
CT Angiogram
Tullus et al. Renovascular hypertension in children. Lancet. 2008;371:1453-1463
MR Angiogram
Angiography
• With carefully selected patients, 40% RAS
• Important therapeutic opportunity
• Visualisation of abdominal vessels
Angiography: Indications
• Tulles et al. (2008)– BP >95th centile not well-controlled on 2 drugs– Other cause not identified
• Vo et al. (2006)– Unexplained persistent HT > 95th centile
• Shahdadpuri et al. (2000)– BP > 99th centile not controlled with 1 drug– Angiography abnormal in 43% patients
A 4-year-old hypertensive boy
Vo et al. Anatomic distribution of RAS in children. Pediatric Radiology 2006;36:1032
14 yr old hypertensive girl
Vo et al. Anatomic distribution of RAS in children. Pediatric Radiology 2006;36:1032
Medical Management
• Anti-hypertensives– Multiple often required– Adequate BP control often not possible– Adverse effects common– Avoid ACE inhibitors & angiotensin receptor blockers
• Concern re renal function if BP well-controlled due to under-perfusion of kidneys
Angioplasty• 1980 : 1st successful angioplasty in a child• Balloon diameter equal to proximal artery• Stent if residual diameter stenosis <50%
• Complications– Arterial spasm– Dissection– Arterial rupture
• Post-procedure: Aspirin 3-6 monthsTullus et al. Renovascular hypertension in children. Lancet. 2008;371:1453-1463
Angioplasty for renovascular hypertension in children: 20 year experience
• Retrospective review from GOS• All children undergoing PTA 1984-2003
– Only stenoses in main or large segmental arteries– Excluded transplants & inflammatory disorders
• 33 children, 1.9-17.9 yrs (median 10.3)– 10 with underlying syndromes– 16 bilateral RAS– 15 intrarenal disease
• 48 procedures, including 15 stentsSchroff et al. Pediatrics 2006;118:268-275
Angioplasty for renovascular hypertension in children: 20 year experience
• Final outcomes of PTA:– 18 (55%) improved BP control
• 11/13 (85%) if isolated main RAS
– 10 (30%) ongoing HT despite adequate dilation– 5 (15%) PTA unsuccessful – Restenosis in 2/27 native renal arteries after balloon
dilatation, 7/19 of stented arteries– 6 (18%) suffered complications, incl 1 death
Schroff et al. Pediatrics 2006;118:268-275
Left RAS before & after Angioplasty
Schroff et al. Angioplasty for renovascular hypertension in children: 20 year experience. Pediatrics 2006;118:268-275
Surgery
• For refractory HT when medical Rx & angioplasty have failed
• Nephrectomy
• Revascularisation procedures
• Aortic reconstruction
Results of surgical treatment for RVH in children: 30 yr single centre experience
• 37 children (65% male)• 1979 - 2008• Mean SBP 140 (105-300) mmHg • 53 surgical procedures
– Nephrectomy 18– Renovascular surgery 28– Aortic reconstruction 7
Stadermann et al. Nephrology Dialysis Transplantation. 2010;25(3):807-813
Results of surgical treatment for RVH in children: 30 yr single centre experience• 12 months post-op:
– 16 (43%) normal BP without treatment– 15 (41%) normal/improved BP on 1-4 drugs– 4 (11%) unchanged
• 90% overall improvement• Complications:
– Haemorrhage (5) – Septicaemia (5)– Chylous ascites (1)
Stadermann et al. Nephrology Dialysis Transplantation. 2010;25(3):807-813
Children not amenable to Angioplasty or Surgery
• Diffuse abnormalities of very small intrarenal arteries
• Antihypertensive medication– Uncontrolled on 6-7 drugs not uncommon
• Therapeutic trial with ACE inhibitor or angiotensin blocker warranted
Tullus et al. Renovascular hypertension in children. Lancet. 2008;371:1453-1463
Suggested Investigations(Tullus 2008)
Tullus et al. Renovascular hypertension in children. Lancet. 2008;371:1453-1463
Our Patient
• 3 months post-angioplasty• BP well-controlled on 2 drugs
• Close follow-up– BP– Renal function– DMSA
• ? Consider cerebrovascular imaging
Any Questions?