What is the possible cause of renovascular hypertension given the following:
- Sex: Female
- Age: 34
- Height: 5'2"
- Weight: 106 lbs
- Blood pressure: 140/100 (BP was around 90/60 during the prior 5 years)
- no tobacco use
- no alcohol use
- exercises 6 hours per week
- Epigastric bruit present
- Serum Creatinine: 1.1 mg/dl
- BUN: 18 mg/dl
- Serum Potassium: 51. mmol/l
- Nuclear renal scan with and without Capropril was positive and
showed a delayed excretory phase in the right kidney
- Renal MRA showed possible stenosis of the right renal artery
- Renal angiogram showed no evidence of stenosis or fibromuscular dysplasia

Hi inquiryminds,

Renovascular hypertension (RVHT), also called renal hypertension, is
caused by a narrowing of the arteries that carry blood to the kidneys.
Renal hypertension is known as a ?secondary? hypertension, meaning it
is caused by another condition in the body.  Fewer than 5% of all
people with hypertension develop renal hypertension, usually
developing it before the age of 30, or after the age of 50. Presence
of a bruit, a swooshing sound from the artery that indicates an
obstruction, can be heard with a stethoscope. The patient may develop
retinopathy.

There are two primary forms of renal hypertension:
1)Atherosclerotic renovascular hypertension -- This form is the most
prevalent, with up to 66% of renovasular hypertension cases being  the
atherosclerotic form. Plaque deposits adhere to the renal artery wall
and obstruct  the flow of blood, usually occurring in both kidneys.
(The same way that plaque obstructs arteries to the heart.)  Plaque is
composed of fat, cholesterol, degenerated cells, and calcium This form
is seen most commonly in men over the age of 45.


2)Renovascular hypertension due to  fibromuscular dysplasia --This
form occurs mainly in women under 45 years of age, and is caused by
the narrowing and a  thickening of the muscular wall of the arteries
going to the kidney.

Since your angiogram results have already ruled out the above causes,
we?ll focus on the unusual causes of renal hypertension.


1) Renal artery stenosis due to trauma such as a fall, or an injury.
?Trauma is generally caused by falls, road traffic accidents, blows,
sporting accidents, stab wounds and gunshot wounds?
http://www.medstudents.com.br/cirur/cirur4.htm

2)Takayasus arteritis : a granulomatous arteritis which affects the
aorta and its major branches, including the renal arteries. Most
commonly seen in Asian females under 35 years of age, and presents
with slight pulses in the arms and legs, chest pains, a difference in
blood pressur from right to left arm, hair loss, atrophy of skin and
muscle of the arms and legs.  In the US and Europe, the incidence of
this disease is 2.5 people, per million, per year. A complete medical
history, blood tests which include a CBC, and a sed rate (ESR), along
with other studies such as standard angiography, magnetic resonance
angiography (MRA), Doppler ultrasound, standard magnetic resonance
imaging (MRI) or computed tomography (CT) are used to diagnoses TA.
?Syncope and transient ischemic attacks in the carotid and
vertebrobasilar distributions may occur, along with claudication of
the jaws (with chewing or speaking) or arms. Muscle mass may be lost
from the face and arms. Visual disturbances are common. Occlusive
changes in the descending thoracic aorta sometimes produce a form of
acquired coarctation. Although the aortic arch vessels are most
frequently involved, the abdominal aorta (particularly the renal
arteries) may be affected, causing often serious renovascular
hypertension.? - TAKAYASU'S ARTERITIS   FOUNDATION INTERNATIONAL
The cause of TA is not clear, but viruses have been ruled out. The
tuberculosis mycobacterium may be a culprit: ?It is possible that TA
is linked to more than one infection. TB has been noted as a possible
cause. However, it is clear that not all persons with TA have TB.?

http://www.takayasus.com/virgin_int.html

http://www.takayasu.org/

http://www.takayasu.org/description.html

Penn State University
http://fred.hmc.psu.edu/ds/retrieve/fred/meshdescriptor/D013625
TA is more often seen in ?One-kidney? hypertension, which appears to
be  true in your case, as you state ?Renal MRA showed possible
stenosis of the right renal artery?
http://cnserver0.nkf.med.ualberta.ca/cn/Schrier/Volume3/chapte3/ADK3-03_7-9.QXD.pdf
http://www.takayasus.com/

3)Renal  transplant - Due to stenosis of the transplant renal artery.
(Stenosis means an abnormal narrowing of a bodily canal or passageway)
?Hypertension is seen in 50% of renal transplant cases, some of which
are due to stenosis of the transplant renal artery. Renal artery
aneurysm may cause hypertension because of mass effect upon the main
renal artery or an intrarenal branch?
http://www.amershamhealth.com/medcyclopaedia/Volume%20IV%202/HYPERTENSION%20RENAL.asp

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12817078&dopt=Abstract

4) Even rarer causes of renal arterial stenosis or obstruction include
emboli, renal artery aneurysm,  inadvertent ligation during surgery,
and extrinsic compression of the renal pedicle by tumors, and Page
Kidney(chronic subcapsular hematoma.)
From eMedicine (You may need a free subscription to this site to read
the entire article.)
http://www.emedicine.com/med/topic2862.htm
Mayo Clinic
http://www.mayo.edu/proceedings/2002/nov/7711rc.pdf
Amersham Health
http://www.amershamhealth.com/medcyclopaedia/Volume%20IV%202/PAGE%20KIDNEY.asp
Journal of Nephrology
http://www.sin-italia.org/jnonline/Vol16n3/329.html
Johns Hopkins University
http://www.hopkinsmedicine.org/surgery/vascular/diseases/renala.html

http://www.accessatlanta.com/health/healthfd/shared/health/adam/ency/article/001272.html;COXnetJSessionID=AZ6ewG57IpLW8rtCRxFRrHCUp9VKJzxedoid0UJYqTmJFQ3L0sKn!-1507703438?urac=n&urvf=10754279342720.910031103978511

See pictures of  renal angiography here:
http://www.rad.uab.edu/Visions/Fall99/Fall99.htm


Additional Information on RVHT:
West Suburban Cardiologists:
http://www.westsubcardiology.com/pages/htn/fibromusculardysplasia.htm
Health A to Z
http://www.healthatoz.com/healthatoz/Atoz/ency/renovascular_hypertension.html
http://www.healthatoz.com/healthatoz/Atoz/ency/renal_artery_stenosis.html
eMedicine
http://www.emedicine.com/med/topic2006.htm
Life Stages:
http://www.lifestages.com/health/renal.html
American Heart Association
http://hyper.ahajournals.org/cgi/content/full/40/1/34
Medline Plus
http://www.nlm.nih.gov/medlineplus/ency/article/000204.htm#Causes,%20incidence,%20and%20risk%20factors


To sum it up, inquiryminds, the cause of RVHT in this case *could* be
Takayasus arteritis or a kidney injury or trauma. The fact that the
renal scan, and the MRA showed possible stenosis in just one kidney
suggests it *could* be Takayasus arteritis or injury or trauma.  I am
not including renal transplant as a possibility, as you did not list
that in your question; but if there has been a kidney transplant, it
likely could be the cause of renal hypertension. Your results indicate
a serum creatinine and BUN within normal limits, although the
creatinine is at the upper limit of normal, and a potassium that is at
the upper end of normal. (I am assuming you meant a potassium value of
5.1 and not 51.0, which is not compatible with life!) You do not state
plasma rennin levels, which, can be normal in renal hypertension, but
elevated after Captopril dosing. The blood pressure is elevated, which
is consistent with renal hypertension, as is the bruit, the Captopril
scan, and the MRA. Keep in mind that this answer is not a diagnosis,
but merely information to help you become informed of possible causes.

I hope you find this information helpful. If any part of my answer is
unclear, please request an Answer Clarification, before rating. This
will allow me to assist you further, if possible.

Regards,
crabcakes-ga

Search Terms
Renal hypertension
RVHT
Takayasus arteritis
Renal stenosis

---

Request for Answer Clarification by inquiryminds-ga on 30 Jan 2004 13:50 PST

Thank you for your very concise response.  I do have a follow up
question.  Some of the possibilities you pointed out involve lesions
in the artery.  Wouldn't the angiogram rule those causes out too?

---

Clarification of Answer by crabcakes-ga on 30 Jan 2004 23:05 PST

Hi inquiryminds,
I wanted to let you know that I will follow up with this clarification shortly!
Regards,crabcakes

---

Clarification of Answer by crabcakes-ga on 31 Jan 2004 13:07 PST

Yes, inquiryminds, an arteriogram would show lesions in the renal artery.
A lesion can be an abnormal body structure change, and not just a
surface lesion similar to what we usally refer to as "skin lesions" or
cuts, wound, etc.

See Number 2 on this page.Scrool down to see diagnostic tests, which
include angiography.
 All of the following are considered "renal lesions"
a. Renal artery atherosclerosis
b. Renal artery fibromuscular dysplasia
c. Renal artery aneurysm
d. Renal arteriovenous malformation
e. Takayasu's arteritis
f. Middle aortic syndrome/congenital hypoplasia
g. Atheroembolic disease
h. Renal artery trauma
i. Embolic occlusion
j. Renal artery dissection
http://apdvs.vascularweb.org/APDVS_Contribution_Pages/Curriculum/450.html


Hope this helps clear things up!
Sincerely, crabcakes

Thank you for the rating!

Looking for information about rare conditions is not always the
easiest thing to do.  The researcher did a great job with that and
also did a great job explaining the conditions.

Renovascular hypertension is "secondary' because it's due to a
decrease of blood pressure coming into a kidney. The kidney senses
this and attempts to raise the blood pressure by keeping water and
constricting blood vessels. As the causes of renovascular hypertension
seem to have been "ruled out" by the tests you have had done, I would
go back and relook at the original diagnosis. Medical diagnosis is
based on eveluating the problem [high blood pressure] and making a
value judgement as to [1.]the more likely of the causes and pursuing
them with confirmatory tests  and [2.] making sure serious but
unlikely causes are determined NOT to be there. The bruit kicked in
the search for RV hypertension because "when you  hear hoofbeats, look
for horses, not zebras".

The captopril challenge test looks at how the flow through the kidney
responds to increased renin, the messenger that raises BP, that
happens after captopril lowers BP in the kidney. There are other
causes of increased renin than restricted flow into the kidney.

It may be that the thinking [diagnostic] process of your physician was
"ruling out" renovascular hypertension.

ALSO.... double check that the angiogram results evaluated were really
yours and there wasn't a mixup.