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General
- Screen hypertensive patients who have unusual presentations or are refractory to medical regimens in order to identify those with surgically correctable causes.
Specific Tests
- Laboratory tests
- Serum blood urea nitrogen (BUN), creatinine, sodium, potassium, bicarbonate, chloride
- Urinalysis with electrolytes
- Peripheral plasma renin activity
- Radiologic evaluation
- Rapid sequence intravenous pyelography (IVP)
- Approximately 70 percent of patients with documented RVH will have a positive intravenous pyelogram by the following criteria.
- A difference in length between kidneys of more than 1 cm
- Delayed pyelocalycele appearance time
- Decreased concentration or prolongation in the early nephrogram (10 to 30 sec) on the involved side
- Underfilling of the collecting systems
- Segmental renal atrophy
- Notching of the upper ureter or renal pelvis by enlarged collateral vessels
- Radionuclide scanning
- Radiologic Evaluation
- Rapid sequence intravenous pyelography (IVP) this is as stated
- Radionuclide scanning-this is stated
- Duplex ultrasonography
- Captopril renal scintigraphy
- Magnetic resonance angiography (MRA)
- Computed tomography angiograpy (CTA)
- Arteriography
- Renovascular lesions are defined by arteriography
- Intravenous digital subtraction angiography
- Intra-arterial digital subtraction arteriography
- Evaluate the anatomy of the renal artery
- Multiple arteries to both kidneys are frequent
- Atherosclerotic stenosis differentiated from fibrodysplastic lesions
Functional Renal Studies
General
- Permits the diagnosis of renal artery disease in the presence of hypertension
- Does not confirm the diagnosis of RVH
- Two tests are currently available
Differential Renal Function Studies
- May be of value in evaluating the viability of severely ischemic kidneys and the likelihood of salvage
- Test requires catheterization of both ureters, prolonged collection of urine volumes, and multiple sample analysis of specimens for volume, sodium concentration, osmolality, and reabsorption of filtered sodium and water
- Reserved for special situations due to the test's low sensitivity and the relatively high rate of urologic complications (3-5 percent)
Renal Vein Renin Assays
- Renin samples are collected from the inferior vena cava and both renal veins by a catheter placed percutaneously in a retrograde fashion via a femoral vein
- The renal venous renin ratio is calculated by dividing the renin level of the ischemic kidney by the renin level of the contralateral kidney
- A ratio of 1.5 to 1 is considered abnormal
- The renal vein renin ratio cannot be used as the sole criterion of selection for intervention due to the considerable number of false-negative results and the large number of these patients that benefit from interventions
- Confounding factors that may interfere with validity of assay include:
- Interference of antihypertensive medication with renin release
- Suppression of renin release by volume expansion and salt loading
- Variability of renin release from the kidney
- Catheter placement error (lumbar vein, left renal vein proximal to gonadal or lumbar vein)
- Renal: systemic renin index has been shown to reliably predict those patients who will be cured of RVH with intervention compared with those whose condition would only be improved
Etiology
- Atherosclerotic renovascular disease
- The most common etiology of renovascular disease
- Men are affected twice as often as women, reflecting the prevalence of arteriosclerosis in the male population
- The sex difference is less apparent in the elderly
- Frequency of renovascular arteriosclerosis is more common in elderly patients than atherosclerosis in general.
- Fibrodysplastic lesions
- Affect less than 0.5 percent of the general population.
- Although uncommon, it is second only to atherosclerosis as the most frequent cause of RVH.
- Intintal dysplasia
- Medial fibroplasias
- Perimedial dysplasia
- Developmental renal artery stenoses
- Account for approximately 40 percent of childhood RVH
- Renal artery aneurysm
- Hypertension (most common), associated arterial stenosis, dissection of the artery, arteriovenous fistula formation, thromboembolism, or compression of arterial branches by the aneurysm.
- Renal artery dissection
- Renal artery embolism
History and Clinical Presentation
- There are no distinctive clinical features that enable the clinician to make the diagnosis of RVH
- Suggestive findings in both the history and physical examination might lead one to suspect RVH
- Hypertension in young women and children. Sudden onset of hypertension.
- Severe hypertension after age 55
- Sudden difficulty controlling previously well-controlled hypertension
- Development of renal failure while on angiotensin converting enzyme inhibitors
- An abdominal bruit (audible in 40 to 50 percent of all patients with RVH)
References
Calligaro P, Modern Management of Renovascular Hypertension and Renal Salvage, Williams & Wilkins, 1996.
Dean RH, Krueger TC, Whiteneck JM, et al: Operative management of renovascular hypertension: Results after a follow-up of fifteen to twenty-three years. J Vasc Surg 1:234-422, 1984.
Galanski M, Prokop M, Chavan A, et al: Renal artery stenosis: Sprial CT angiography. Radiology 189:185-192, 1993.
Martin LG, Price RB, Casarella WJ, et al: Percutaneous angioplasty in the clinical management of renovascular hypertension: Initial and long term results. Radiology 155:629, 1985.
Meier GH, Sumpio B, Black HR, Gusberg RJ; Captopril renal scintography. An advance in the detection and treatment of renovascular hypertension. J Vasc Surg 11:770-777, 1990.
Prince MR, Narasimham DL, Stanley JC, et al: Breath-hold gadolinium-enhanced MR angiography of the abdominal aorta and its major branches. Radiology 197:785, 1995.
Raynaud AC, Beyssen BM, Turmel-Rodrigues LE, et al. Renal artery stent placement: Immediate and midterm technical and clinical results. JVIR 5:849, 1994.
Strandnesss DE. Duplex scanning in diagnosis of renovascular hypertension. Surg Clin North Am 70:109-117, 1990. Please log-in or register in order to submit comments. Powered by AkoComment! |
