ACE inhibitor challenged renal scintigraphic studies offer noninvasive means of evaluating patients for renovascular hypertension, and provide help in selecting patients who will benefit most from interventional procedures designed for alleviation of renal artery stenosis. These studies provide functional assessment of each kidney which also helps the vascular surgeons to plan which renal artery to repair first, when bilateral renal arteries are stenotic, prior to an abdominal aortic aneurysm repair. Vasotec challenged Tc99mMAG3 renal scintigraphy is one of such tests with several advantages over other similar methods, and appears to have a great potential of being a preferred scintigraphic study for evaluation of renovascular hypertension.
Angiotensin-Converting Enzyme Inhibitors/diagnostic use ; Diagnosis, Differential ; Human ; Hypertension, Renovascular/physiopathology/*radionuclide imaging ; Radioisotope Renography ; Renal Artery Obstruction/radionuclide imaging

PURPOSE: We compared captopril renal scintigraphic criteria for the diagnosis of renovascular hypertension by unilateral renal artery stenosis. MATERIALS AND METHODS: The study group consisted of 24 patients (m/f =16/8, age: 39 +/- 18 years) with unilateral renal artery stenosis who underwent renal artery revascularization and captopril renal scintigraphy with 99mTc-diethylenetriaminepentaacetic acid between May 1995 and April 2004. The blood pressure response was classified as cure/improvement or failure. We evaluated captopril-induced changes in relative function (BCfun) and renogram grade (0 to 5: 0=normal, and 5=renal failure pattern without measurable uptake) (CBren) and the difference of renograms between the normal and stenotic kidney on captopril scan (CNren). RESULTS: Eight of 24 patients were cured and 11 improved and 5 patients were classified as failed revascularization. Significant predictors of a cure or improvement of blood pressure were younger age, stenosis by fibromuscular dysplasia or arteritis, BCfun, CBren and CNren. Areas under the receiver operating characteristic curve of age, BCfun, CBren and CNren were not significantly different. Positive and negative predictive values of predictors were 100% and 42% (age < or= 38) ; 92% and 50% (BCfun > or= 1%) ; 92% and 75% (CBren > or= 1), and 90% and 60% (CNren > or= 1), respectively. CONCLUSION: Captopril induced changes in renal function and renogram can reliably predict hypertension response to revascularization. Renogram pattern on captopril scan can diagnose renovascular hypertension without baseline data in patients with unilateral renal artery stenosis.
Arteritis ; Blood Pressure ; Captopril* ; Constriction, Pathologic ; Diagnosis* ; Fibromuscular Dysplasia ; Humans ; Hypertension ; Hypertension, Renovascular* ; Kidney ; Radionuclide Imaging ; Renal Artery Obstruction* ; Renal Artery* ; ROC Curve

BACKGROUND: Renovascular hypertension has variable etiologic diseases and therapeutic outcomes. We performed a retrospective analysis of the causes and treatment results of renovascular hypertension to elucidate long-term prognosis with respect to blood pressure and renal function. METHODS: We reviewed patients who were admitted to Seoul National University Hospital for evaluation of renovascular hypertension in period from January, 1983 to December, 2002. Diagnosis of renovascular hypertension was made by combination of positive functional studies such as captopril renal scintigraphy and/or captopril test and angiographic demonstration of significant stenoses in one or both of renal arteries. Patients who were followed up for more than six months were included and classified according to the etiologic disease and treatment modalities. Responses of blood pressure and renal function in each patient were periodically evaluated. RESULTS: Of 74 patients included, 37 were male and 37 were female. The median age of the patients was 40. Atherosclerotic renal artery stenosis was the most common diagnosis (31, 41.9%), followed by Takayasu's arteritis (21, 28.4%) and fibromuscular dysplasia (14, 18.9%). Control of blood pressure and preservation of renal function were significant in medical, radiological, and surgical therapy group. There was no significant difference in response of blood pressure and renal function to treatment among treatment groups. Poor response of blood pressure and deterioration of renal function were observed more frequently in patients with atherosclerotic renal artery stenosis than in those with Takayasu's arteritis or fibromuscular dysplasia. CONCLUSION: Atherosclerosis was the most common etiologic diagnosis of renovascular hypertension. Medical treatment showed satisfactory treatment results as compared to radiologic and surgical revascularization. Patients with atherosclerotic renal artery stenosis showed poorer control of blood pressure and preservation of renal function.
Atherosclerosis ; Blood Pressure ; Captopril ; Constriction, Pathologic ; Diagnosis ; Female ; Fibromuscular Dysplasia ; Humans ; Hypertension, Renovascular* ; Male ; Prognosis ; Radionuclide Imaging ; Renal Artery ; Renal Artery Obstruction ; Retrospective Studies ; Seoul ; Takayasu Arteritis