RENOVASCULAR HYPERTENSION

1. Management of RVH
Dept of Urology
Govt Royapettah Hospital and Kilpauk Medical College
Chennai

2. Moderators:
Professors:
• Prof. Dr. G. Sivasankar, M.S., M.Ch.,
• Prof. Dr. A. Senthilvel, M.S., M.Ch.,
Asst Professors:
• Dr. J. Sivabalan, M.S., M.Ch.,
• Dr. R. Bhargavi, M.S., M.Ch.,
• Dr. S. Raju, M.S., M.Ch.,
• Dr. K. Muthurathinam, M.S., M.Ch.,
• Dr. D. Tamilselvan, M.S., M.Ch.,
• Dr. K. Senthilkumar, M.S., M.Ch.
Dept of Urology, GRH and KMC, Chennai. 2

3. 3
Dept of Urology, GRH and KMC, Chennai.

4. 4
Dept of Urology, GRH and KMC, Chennai.

5. Data from Animal Model of
Renal Artery Stenosis
Activation of
renin/Ang
system
CKD
Unilateral RAS
Ischemic
damage to
ipsilateral
kidney
Damage to
contralateral
kidney
Time

6. What Are the Goals of Treatment for
RAS?
❖Control hypertension
❖Aid in medical management
❖Prevent deterioration in renal function
– Forestall need for dialysis
– Defer death and disability
6
Dept of Urology, GRH and KMC, Chennai.

7. Chronic Renal Insufficiency and RAS
Who Benefits From Revascularization?
Trial of 51 patients with Creat>2.0 before
revascularization with >75% Bilateral
RAS:
• 67% had improvement in renal function
• 27% had stabilization in renal function
• Only 6% had worsening in renal function
• No demonstrated impact upon mortality
Novick et al. J Urol 1983; 129:907-12.
7
Dept of Urology, GRH and KMC, Chennai.

8. management
• Medial Fibroplasia – medical management
• Loss of renal function rare
• Only in pts with BP difficult to control with
multiple drugs
8
Dept of Urology, GRH and KMC, Chennai.

9. • Intimal or perimedial fibroplasia generally
progresses and often eventuates in ischemic
renal atrophy.
• in younger patients and to cause hypertension
that is extremely difficult to control.
• Early interventional therapy in these patients
is therefore indicated both to preserve renal
function and to minimize the need for long-
term antihypertensive medication.
9
Dept of Urology, GRH and KMC, Chennai.

10. Management protocols
• Unilateral or bilateral
• Type of disease
• Degree of ischemic nephropathy or azotemic
renovascular disease.
• Type of intervention
• Level of blood pressure
• Lipid profile
10
Dept of Urology, GRH and KMC, Chennai.

11. Optimal Medical Treatment
ARB + diuretic to get BP to
target
– <140/90 mm Hg
– <130/80 mm Hg with DM
LDL to goal
– Currently <100 (or 70) mg/dl
Diabetes Management
– HbA1c to target (<7%)
Smoking Cessation
Anti-platelet therapy (aspirin
+/- clopidogrel/prasugrel)

12. Threat to renal function
• This designation applies to patients with high-
grade (>75%) arterial stenosis affecting their
entire renal mass
1. stenosis is present bilaterally or
2. involves a solitary kidney
In these patients, the risk of complete renal arterial
occlusion is significant, and, if this occurs, the
clinical outcome is a critical decrease in functioning
renal mass with resulting renal failure.
Intervention to restore normal renal arterial blood
flow is indicated in such patients for the purpose of
preserving renal function.
12
Dept of Urology, GRH and KMC, Chennai.

13. Unilateral RAS
• The benefit of undertaking revascularization for
the preservation of renal function in patients
with unilateral ARAS and an unobstructed
contralateral renal artery is not established.
• If the opposite kidney is functioning but involved
with some type of parenchymal disorder,
revascularization of the ischemic kidney may
benefit some patients, but specific indications for
this approach are not well defined.
13
Dept of Urology, GRH and KMC, Chennai.

14. Type & timing of occlusion
• Complete occlusion - irreversible ischemic damage.
• gradual arterial occlusion - the viability of the kidney
maintained through the development of collateral
arterial supply
(1) angiographic demonstration of retrograde filling of the
distal renal arterial tree by collateral vessels on the side
of total arterial occlusion
(2) a renal biopsy showing well-preserved glomeruli,
(3) kidney size greater than 9 cm,
(4) function of the involved kidney on isotope renog-
raphy or intravenous pyelography.
When such criteria are present, restoration of normal
renal arterial flow can lead to recovery of renal function.
14
Dept of Urology, GRH and KMC, Chennai.

15. Renal function
• serum creatinine level >4 mg/dL
• the rate of decline in overall renal function is an
important determinant
• Severe nephrosclerosis is the most common form
of renal parenchymal disease in such patients;
• renal cholesterol embolization may be an
additional complicating feature
• Occasional patients with ESRD from IN have had
salvagable renal function on revascularization
15
Dept of Urology, GRH and KMC, Chennai.

16. Absolute C/I
• patients with ESRD and ARAS without
complete occlusion are not appropriate
candidates for revascularization to restore
function.
• The two predominant morphologic lesions in
such patients are arteriolar nephrosclerosis
and atheroembolic renal disease, with the
former more often encountered.
16
Dept of Urology, GRH and KMC, Chennai.

17. Treatment
Interventions appropriate for patients with RAS/RVHT
may include
• Medical therapy
• Percutaneous transluminal angioplasty (PTA) with or
without vascular stent placement
• Surgical revascularization
• Intravascular ultrasonography-guided atherectomy
• Ablative surgery
17
Dept of Urology, GRH and KMC, Chennai.

18. Preop evaluation
• preoperative evaluation should include a
thorough search for coronary artery disease,
leading cause of operative death after surgical
revascularization.
• Cerebrovascular accident has also been a
significant cause of death
18
Dept of Urology, GRH and KMC, Chennai.

19. 19
Dept of Urology, GRH and KMC, Chennai.

20. Surgery
• Aortorenal bypass with a free graft of autogenous
hypogastric artery or saphenous vein remains a
popular method in patients with a healthy abdominal
aorta.
• Polytetrafluoroethylene aortorenal bypass grafts have
been successfully employed when an autogenous graft
is not available.
• Renal endarterectomy also continues to be used
occasionally to treat atherosclerotic renal artery
disease.
• Patients with complex branch renal artery lesions are
managed with extracorporeal microvascular
reconstruction and autotransplantation.
20
Dept of Urology, GRH and KMC, Chennai.

21. • Severe AS of aorta - - The most effective alternate
bypass techniques have been a splenorenal
bypass for left renal revascularization and a
hepatorenal bypass for right renal
revascularization.
• The absence of occlusive disease involving the
origin of the celiac artery is an important
prerequisite
• Use of the supraceliac or lower thoracic aorta for
renal revascularization is a more recent surgical
alternative in patients with significant
atherosclerosis of the abdominal aorta and its
major visceral branches. 21
Dept of Urology, GRH and KMC, Chennai.

22. Results
Cure -140/90 mm Hg, or less
Improvement: reduction in diastolic pressure of
10 to 15 mm Hg, or more, or become
normotensive on medication
22
Dept of Urology, GRH and KMC, Chennai.

23. Percutaneous Treatment of RAS
1978 - Gruentzig and colleagues report first balloon
angioplasty of renal artery stenosis
– Gruentzig A, Kuhlmann U, Vetter W. Treatment of
renovascular hypertension with percutaneous
transluminal dilatation of a renal artery stenosis. Lancet
1978; 1:801-802.
Fall 1978 - first renal artery angioplasty in US at
UVa. - Patient referred by Carlos Ayers to Charles
Tegtmeyer who obtained angioplasty balloon from
Gruentzig in exchange for fishing equipment.
– Tegtmeyer CJ, Dyer R, Teates CD, Ayers CR, Carey RM,
Wellons HA Jr, Stanton LW. Percutaneous transluminal
dilatation of the renal arteries: techniques and results.
Radiology 1980; 135(3);589-599

24. What role does revascularization
play?

25. PTA
• Dotter and Judkins in 1964
• intentional overdilatation of the renal artery by 1
mm.
• skilled vascular surgeon is immediately available
• Gruntzig coaxial technique uses an 8- or 9-Fr
renal guiding catheter through which a 4.3- or
4.5-Fr balloon catheter is passed over a guidewire
traversing the stenotic segment through a
femoral arterial puncture.
• fracture of the atherosclerotic plaque. Stretching
of the arterial wall with tearing of the media and
adventitia also occurs 25
Dept of Urology, GRH and KMC, Chennai.

26. Complications
• Transient deterioration of renal function is the
most frequently occurring complication and is
related to the contrast load delivered during
the procedure.
• Technical mishaps during PTA may lead to an
intimal dissection or even thrombosis of the
renal artery.
• FD - - PTA without Stent
26
Dept of Urology, GRH and KMC, Chennai.

27. PTA
• Technical success is achieved in more than 90% of patients,
and patency rates are 90-95% at 2 years for FMD and 80-85%
for atherosclerosis.
• Restenosis requiring repeat angioplasty has been reported in
fewer than 10% of patients with FMD and in 8-30% with
atherosclerotic stenosis.
• Improvement in blood pressure control with fewer
antihypertensive medications is achieved in 30-35% of
fibromuscular lesions and in 50-60% of atherosclerotic
lesions.
• A success rate of 83% has been reported with PTA in RAS
associated with renal transplantation.
27
Dept of Urology, GRH and KMC, Chennai.

28. 28
Dept of Urology, GRH and KMC, Chennai.

29. Left: A balloon angioplasty catheter is seen in situ across the left renal
artery stenosis.
Right: After angioplasty, an excellent anatomic (and functional) result was
achieved.
29
Dept of Urology, GRH and KMC, Chennai.

30. Left renal artery stenosis After PTA
30
Dept of Urology, GRH and KMC, Chennai.

31. 31
Dept of Urology, GRH and KMC, Chennai.

32. Effect of RA Revascularization on
HTN
Study Device N Cure Improved
Klinge stent 134 10% 68%
Lossino stent 153 12% 51%
DRASTIC balloon 106 7% 68%
Rocha stent 150 6% 50%
Dorros stent 145 1% 52%

33. Angioplasty and STent for
Renal Artery Lesions
NEJM 2009;361:1953-
1962

34. ASTRAL Trial
Substantial atherosclerotic RAS
Suitable for endovascular revascularization
Patient's doctor was uncertain that the patient
would benefit from revascularization
No revascularisation
(n = 403)
Medical treatment according to
local protocol
Revascularisation
(n = 403)
with angioplasty and/or stent
(and medical treatment)

35. PATIENT CHARACTERISTICS
Revasc. Medical P-value
Mean age (range) 70 (42 – 86) 71 (43 – 88) 0.7
Male 63% 63% 0.9
Current smoker 20% 22% 0.5
Diabetes 31% 29% 0.5
CHD 49% 48% 0.2
PVD 41% 40% 0.7
GFR (ml/min) 40.3
(5.4 – 124.5)
39.8
(7.1 – 121.7)
0.7

36. Blood Pressure, Cholesterol,
Stenosis

37. Procedural Complications
38 periprocedural complications in 31 of the 359
patients (9%) who underwent revascularization
(including 1 of the 24 patients in the medical-
therapy group who crossed over to
revascularization)
Nineteen of these events (in 17 patients) were
considered to be serious complications
– Pulmonary edema (1) and Myocardial infarction (1)
– Renal embolizations (5), Renal arterial occlusions (4) and
Renal-artery perforations (4)
– Femoral-artery aneurysm (1)
– Cholesterol embolism leading to peripheral gangrene and
amputation of toes or limbs (3)

38. Survival

39. • “An important limitation of our trial concerns the population
that we studied. As noted, patients were enrolled in the trial
only if their own physician was uncertain as to whether
revascularization would provide a worthwhile clinical
benefit.”
• Patient selection (single center)
– 508 patients with atherosclerotic renovascular disease
– Of these, 283 patients had renal-artery stenosis of more than 60%
– 71 underwent randomization
– 24 underwent revascularization outside the trial
• poorly controlled hypertension
• rapidly declining renal function,
– 188 received medical treatment only.

40. Circulation 2007;115;271-276
Circulation 2007;115;263-270

41. • NIH Funded Trial
• Prospective, multi-center, two armed, randomized,
unblinded survival (time to event) clinical trial
• To test the hypothesis that optimal medical
therapy + stenting reduces the incidence of
cardiovascular and renal events compared to
optimal medical therapy alone in patients with
systolic hypertension
• >100 centers participating

42. n Documented history of
systolic hypertension
(>155 mm Hg) on 2 or
more antihypertensive
medications
n One or more renal
artery stenosis (> 60%
stenosis)
n All patients receive
OMT - Randomization
to stent vs no stent
Large and with long term
follow-up
Clinically important outcomes
– Cardiovascular or Renal
Death
– Stroke
– Myocardial Infarction
– Hospitalization from CHF
– Progressive Renal
Insufficiency
– Renal Replacement

43. When revascularisation?
In the absence of trials showing benefit from
revascularisation over conventional therapy and the
significant risk of complications it seems reasonable
to restrict procedures to patients who fail medical
therapy with:
– resistant or poorly-controlled hypertension
– recurrent flash pulmonary edema
– dialysis-dependent kidney failure resulting from renal
artery stenosis
– chronic renal insufficiency and bilateral renal artery
stenosis
– renal artery stenosis to a solitary functioning kidney.
Agency for Healthcare Research and Quality
(AHRQ)
Available at www.guideline.gov

44. Vascular stent placement
• Vascular stenting is considered complementary to PTA.
• Many vascular stents are now available, which can be either
self-expanding or balloon expandable. Drug-eluting stents are
also available.
• Intravascular stents placed during angioplasty may be helpful
in the prevention of restenosis.
• Early results suggest that stenting may prove useful in patients
with ostial disease, in those in whom restenosis occurs after
PTA, or in those with complications (e.g. renal artery
dissection) resulting from PTA.
• Primary renal artery stenting in patients with atherosclerotic
RAS has a high technical success rate and a low complication
rate.
44
Dept of Urology, GRH and KMC, Chennai.

45. Intravascular ultrasonography-guided
atherectomy
• In a single reported case, hypertension
secondary to AD was successfully diagnosed
with intravascular sonography, and
intravascular sonography-guided renal
atherectomy was curative.
45
Dept of Urology, GRH and KMC, Chennai.

46. Summary
RAS is an unusual cause of hypertension but a
common finding in patients with vascular disease
RAS identifies patients with very poor prognosis
and a high risk of cardiovascular events
Revascularization will benefit select patients with
RAS but convincing evidence of improved
cardiovascular outcomes in most patients is lacking
A better understanding of the pathophysiology of
RAS is needed in order to design more effective
therapies