Renovascular hypertension Dr Saad Al Shohaib KAUH.
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Transcript of Renovascular hypertension Dr Saad Al Shohaib KAUH.
Renovascular hypertension
Dr Saad Al Shohaib KAUH
Incidence Renovascular disease is an important
and treatable cause of hypertension and renal impairment
It accounts for less than 1% of mild and moderate hypertension but may be seen in 10 to 40% of hypertensive crises
Renal disease is the comments cause of secondary hypertension
Target population for screening Acute rise in serum creatinine shortly after ACE
inhibitor therapy or unexplained rapid deterioration in renal function with minimal proteinuria
Moderate to sever hypertension in a patient with diffuse atherosclerosis
Hypertension in a patient with a symmetric renal size or hypokalemia
Moderate to severe hypertension in patients with recurrent episodes of acute (flash) pulmonary edema or otherwise unexplained congestive heart failure
Screening tests Intravenous pyelogram – There
are two major findings on intravenous pyelography that suggest the presence of unilateral ischemia: a decrease in renal size; and delayed caliceal appearance time when compared to the contralateral kidney
Screening Plasma renin activity – The baseline
plasma renin activity is elevated in only 50 to 80 percent of patients with renovascular hypertension
. The predictive value can be increased by measuring the rise in the plasma renin activity one hour after the administration of 25 to 50 mg of captopril
screening Renogram following ACE
inhibitor the predictive value of radioisotope
scanning can be increased by enhancement with captopril.
Screening Duplex Doppler ultrasonography
has the advantage of providing both anatomic and functional assessment of the renal arteries
Time consuming Operator dependent and difficult It can be done after captopril
Recommendations In high risk patients may use subs
traction angiogram as an initial test MR angiography is a non invasive
alternative test particularly if combined with doppler
Postma CT Joosten FB etal AM J Hyper sept 1997
In one study 38 patients with hypertension were screened using MRA and subs traction angiogram
One patient was excluded 14 patients had renal artery steno sis
12 patients had more than 50% stenosis
All these stenos is were recognized by MRA
There were one false positive case by MRA
MRA has 100% sensitivity and 96% specifity
Postma CT; Joosten FB; Rosenbusch G; Thien TSO - Am J Hypertens 1997 Sep;10(9 Pt 1):957-63
Conclusion MRA has a great accuracy in
detecting clinically significant main renal artery stenos is
Significant stenosis Hem dynamically significant stenos only
should be corrected Good response to ACE inhibitors suggest the
presence of significant stenos increased Renal vein renin may suggest a
significant stenosis but this is not widely used Other tests used to screen for renovascular
hypertension would help to determine significance
CRF AND ISCHAEMIA Ischemia might be responsible for
decreased renal function in a significant number of patients with renal failure in older patients
Correction of ischemia would improve renal function
Renal insufficiency Unexplained progressive renal failure Benign urine sediment with sever renal
impairment Unilateral very small kidney with renal impairment Testing should be done with progressive renal
impairment uncontrolled pressure and recurrent pulmonary edema
Contrast may induce further renal damage
Ischemia and CRF Presence of diffuse atherosclerosis
make Reno vascular disease more likely
There is usually minimal proteinuria Uncontrolled hypertension Flash pulmonary edema Progressive renal failure with benign
urine sediment
Renovascular disease The earlier the intervention the
better the prognosis Contrast may cause further renal
damage Reversibility is more likely in
patients with rapid deterioration of renal function
Conclusion Renovascular hypertension should
be suspected in hypertensive crisis uncontrolled hypertension patients with hypokalemia and high BP
Presence of unequal kidney size or flash pulmonary edema make the diagnosis more likely
Conclusion The homodynamic effect of ِِACE
inhibitors help in the diagnosis reversibility of renal function as well as the significance of the stenosis
Uncontrolled hypertension in a patient with diffuse atherosclerosis particularly if associated with renal impairment is highly suggestive of renovascular hypertension
Conclusion MRA with Doppler ultrasound are good
screening tests Revascularization should be done in
hem dynamically significant stenosis Correction of significant bilateral
stenosis may improve renal failure and help to avoid dialysis in selected cases
Thank you