Thesis (M.S.)--University of Wisconsin--Madison, 1976. / eContent provider-neutral record in process. Description based on print version record. Bibliography: leaves 126-135.

Thesis (doctoral)--Rijksuniversiteit te Groningen. / Bijlage: [2] folded leaves.

The impact of percutaneous renal artery angioplasty and stenting (PTRAS) for treatment of atherosclerotic renal artery stenosis (ARAS) is not fully understood, especially in patients with chronic kidney disease (CKD). We performed a retrospective cohort study of patients with significant ARAS and moderate to severe chronic kidney disease (estimated GFR 15-60 ml/min/1.73m2) who were treated medically or with PTRAS. The primary endpoint of this study was change in renal function over the first year after treatment. Secondary endpoints included hemodynamic outcomes, antihypertensive medication doses, end stage renal disease (ESRD), and death. We reviewed all patients with a diagnosis of significant ARAS and impaired GFR treated between 1997-2007 in the Veterans Affairs Connecticut Healthcare System (VACHS). A total of 118 patients met inclusion criteria (71 medical treatment, 47 PTRAS), with an average follow-up of 34 months. The students t-test was used to compare baseline characteristics, as well as renal and hemodynamic endpoints between the two treatment groups. The cohort had a mean age of 73 ± 9 years and average baseline GFR of 37.2 ± 14.9 ml/min/1.73m2. Demographic, clinical and laboratory characteristics at baseline were similar between the two groups, with the exception of higher diastolic blood pressure in the stent group at baseline (75 versus 70 mmHg, p=0.028). No statistically significant difference was found between the two treatment groups for any renal endpoints. After a steady decline in GFR in both the medical treatment and stent groups during the 12 months preceding diagnosis (-4.2 versus -4.0 ml/min/1.73m2, p=0.911), GFR stabilized in both groups over the year following diagnosis (decline in GFR of -1.6 versus -1.4 ml/min/1.73m2, p=0.938). Multivariate models did not reveal an association between treatment modality and percent change in GFR during follow-up. No difference was found in blood pressure outcomes at 12 months between the medical and stent groups. Antihypertensive therapy, measured in defined daily doses (DDDs), was significantly higher in the medical treatment group at 12 months (4.5 versus 3.5 DDDs, p=0.048), but lost significance thereafter. In addition, the number of deaths was significantly higher in the stented group on univariate analysis, although this did not remain significant on multivariable Cox analysis. No difference was found between treatment groups in the development of ESRD. These data suggest that, among patients with ARAS and CKD, medical therapy and renal artery stenting are comparable in stabilizing renal function.

Thesis (M.S.)--Medical College of Ohio, 2005. / "In partial fulfillment of the requirements for the degree of Master of Science in Biomedical Sciences." Major advisor: Christopher Cooper. Includes abstract. Document formatted into pages: iii, 150 p. Title from title page of PDF document. Title at ETD Web site : Acute renal injury after renal artery stenting. Bibliography: pages 136-147.

<p>Renal artery stenosis (RAS) is a potentially curable cause of hypertension and azotemia. Besides intra-arterial renal angiography there are several non-invasive techniques utilized to diagnose patients with suspicion of renal artery stenosis. Removing the stenosis by revascularization to restore unobstructed blood flow to the kidney is known to improve and even cure hypertension/azotemia, but is associated with a significant complication rate. </p><p>To visualize renal arteries with x-ray techniques a contrast medium must be used. In a randomized, prospective study the complications of two types of contrast media (CO₂ and ioxaglate) were compared. CO₂ was not associated with acute nephropathy, but induced nausea and had lower attenuation differences compared to Ioxaglate. Acute nephropathy was related to the ioxaglate dose and the risk was evident even at very low doses if the patients were azotemic with creatinine clearance <40 ml/min. </p><p>Evaluating patients for clinically relevant renal artery stenosis can be done utilizing several non-invasive techniques. MRA was retrospectively evaluated and shown to be accurate in detecting hemodynamically significant RAS. In a prospective study of 58 patients, evaluated with four methods for renal artery stenosis, it was shown that MRA and CTA were significantly better than ultrasonography and captopril renography in detecting hemodynamically significant RAS. The standard of reference was trans-stenotic pressure gradient measurement, defining a stenosis as significant at a gradient of ≥15 mmHg. The discrepancies were mainly found in the presence of borderline stenosis.</p><p>The outcome of percutaneous revascularization procedures showed a technical success rate of 95%, clinical benefit in 63% of treated patients, 30-day mortality 1.5% and major complication rate of 13%. The major complication rate for patients with baseline serum creatinine >300µmol/l was 32%. Our results compare favorably with published studies and guidelines.</p>

Renal artery stenosis (RAS) is a potentially curable cause of hypertension and azotemia. Besides intra-arterial renal angiography there are several non-invasive techniques utilized to diagnose patients with suspicion of renal artery stenosis. Removing the stenosis by revascularization to restore unobstructed blood flow to the kidney is known to improve and even cure hypertension/azotemia, but is associated with a significant complication rate. To visualize renal arteries with x-ray techniques a contrast medium must be used. In a randomized, prospective study the complications of two types of contrast media (CO2 and ioxaglate) were compared. CO2 was not associated with acute nephropathy, but induced nausea and had lower attenuation differences compared to Ioxaglate. Acute nephropathy was related to the ioxaglate dose and the risk was evident even at very low doses if the patients were azotemic with creatinine clearance &lt;40 ml/min. Evaluating patients for clinically relevant renal artery stenosis can be done utilizing several non-invasive techniques. MRA was retrospectively evaluated and shown to be accurate in detecting hemodynamically significant RAS. In a prospective study of 58 patients, evaluated with four methods for renal artery stenosis, it was shown that MRA and CTA were significantly better than ultrasonography and captopril renography in detecting hemodynamically significant RAS. The standard of reference was trans-stenotic pressure gradient measurement, defining a stenosis as significant at a gradient of ≥15 mmHg. The discrepancies were mainly found in the presence of borderline stenosis. The outcome of percutaneous revascularization procedures showed a technical success rate of 95%, clinical benefit in 63% of treated patients, 30-day mortality 1.5% and major complication rate of 13%. The major complication rate for patients with baseline serum creatinine &gt;300µmol/l was 32%. Our results compare favorably with published studies and guidelines.

INTRODUÇÃO: A hipertensão renovascular (HRV) decorrente da estenose de artéria renal (EAR) é uma patologia potencialmente curável, mas os benefícios da revascularização não são alcançados por todos porque selecionar pacientes com base nos critérios clínicos ou angiográficos pode não ser suficiente para se obter o sucesso clínico. Existe um grande interesse em se desenvolver exames para detectar a presença de EAR e avaliar seu significado funcional. OBJETIVOS: avaliar se a redução da Taxa de Filtração Glomerular (TFG) medida com EDTA-51Cr após o uso de captopril consegue diferenciar pacientes hipertensos com EAR daqueles sem estenose da artéria e avaliar se existe correlação entre as variações da TFG e a evolução de pacientes submetidos a diferentes tratamentos. MÉTODOS: Foram estudados 41 pacientes com hipertensão arterial de difícil controle que foram divididos em dois grupos: GP: 21 pacientes com EAR e GH: 20 pacientes sem EAR. Os pacientes foram submetidos à medida de TFG com EDTA-51Cr pré e após a administração do captopril. Os pacientes do GP realizaram simultaneamente cintilografia com DMSA-99mTc para avaliação da função renal diferencial. Os pacientes com estenose de artéria renal foram subdivididos de acordo com o tratamento recebido: clínico (GP-CL) ou por intervenção (GP-I). As medidas das TFGs antes e após o captopril foram comparadas entre os grupos. Foi também, investigado se a relação pré/pós captopril tinha correlação com a resposta clínica dos pacientes. RESULTADOS: a média da TFG (ml/min./1,73m2) no total de pacientes estudados, foi de 56,7±26,5 na fase pré-captopril e 47,0±24,4 após o captopril. A modificação da TFG determinada pelo captopril,foi avaliada pela relação da filtração glomerular pré/pós-captopril. A média da relação TFG pré/pós-captopril foi 1,36 ±0,54 no grupo total de pacientes e quando foi feita a comparação entre a TFG pré e pós-captopril, houve uma redução significativa (p= 0,016). O GH mostrou relação média da TFG pré/pós-captopril de 1,13, valor significativamente menor que o GP que teve a relação média de 1,57 (p= 0,007). Quando foi avaliada a variação da TFG após o captopril nos dois grupos não foi observada diferença estatisticamente significativa no GH (p=0,68), mas observou-se diferença significativa no GP (p<0,001). No total, 15 pacientes apresentaram melhora dos seus níveis pressóricos, sendo oito do grupo de intervenção e sete do grupo clinico, não havendo diferença estatisticamente significativa em relação à melhora clínica entre os dois grupos (p=0,36). Quando comparamos os pacientes com e sem melhora clínica não se observou diferença significativa na TFG basal (p=0,09) ou na relação TFG pré/pós-captopril (p=0,74). A função renal diferencial obtida pelo DMSA-99mTc pré e pós captopril não mostrou diferença estatisticamente significativa nos rins com e sem estenose, (p=0.09). CONCLUSÃO: O captopril acarreta uma redução significativa da TFG e esta redução é mais acentuada em pacientes com EAR, mas não houve correlação entre as mediadas da TFG e a evolução clínica dos pacientes / INTRODUCTION: Renovascular hypertension (RVH) resulting from renal artery stenosis (RAS) is a potential curable pathology, but the revascularization benefits are not reached among all patients because selecting patients on the basis of clinical and angiographic criteria may not be sufficient to achieve clinical success. There has been increasing interest in developing screening tests capable of accurately detecting the presence of RAS and also of evaluating its functional consequences PURPOSE: the purpose of this study was to evaluate if captopril induced changes in 51Cr-EDTA clearance could be used to differentiate between hypertensive patients with and without renal artery stenosis and to investigate if there was a correlation between these changes and patients clinical response to therapy. METHODS: 41 patients with poor-controlled severe hypertension were studied. Patients were divided into two groups: GP=patients with renal artery stenosis (n=21), and GH=patients without renal artery stenosis (n=20). They were submitted to a Glomerular Filtration Rate (GFR) measurement with EDTA-51Cr pre and post captopril administration. The GP patients were submitted simultaneously to 99mTc-DMSA scintigraphies to estimate individual renal function. GP patients were further subdivided according to the treatment strategy: optimization of clinical treatment (GP-Cl) and interventional procedures (GP-I). The GFRs before and after captopril administration were compared between the groups. It was also investigated if baseline to post-captopril GFR ratio had a correlation to clinical response of patients. RESULTS: The GFR average (ml/min./1,73m2) on the total patients, was 56,7±26,5 on pre-captopril phase and 47,0±24,4 post captopril. The GFR alteration determinated by captopril was evaluated by Baseline/post-captopril GFR ratio. Baseline/post-captopril GFR mean ratio was 1,36 in total patients and the GFR had a significant decrease after captopril administration (p value 0.016). Baseline/post-captopril GFR mean ratio in GH was 1.13, value significantly lower than the GP which had the average relation of 1,57 (p= 0,007). When GFR pre and post-captopril was compared among the two groups separately, there was no significantly difference on the GH (p=0,68), but a expressive difference was observed on GP (p<0,001). 15 patients had a clinical response to the treatment. Clinical response was observed in 8/10 patients from GP-I and 7/11 from GP-Cl and there was not observed a significantly difference between the two groups (p=0,36). Comparing the groups with or without clinical improvement there was not a significantly difference on the GRF baseline (p=0,09) or on or baseline/post-captopril ratio (p=0,74). When evaluating the differential renal function obtained by pre and post-captopril DMSA-99mTc, significantly difference was not observed (p=0.09) for the kidneys with or without stenosis. CONCLUSION: captopril induced a decrease in GFR of hypertensive patients and it is more pronounced in patients with renal artery stenosis, but no correlation was observed between captopril induced decrease in GFR and clinical response of patients submitted to interventional or clinical treatment

INTRODUÇÃO: A hipertensão renovascular (HRV) decorrente da estenose de artéria renal (EAR) é uma patologia potencialmente curável, mas os benefícios da revascularização não são alcançados por todos porque selecionar pacientes com base nos critérios clínicos ou angiográficos pode não ser suficiente para se obter o sucesso clínico. Existe um grande interesse em se desenvolver exames para detectar a presença de EAR e avaliar seu significado funcional. OBJETIVOS: avaliar se a redução da Taxa de Filtração Glomerular (TFG) medida com EDTA-51Cr após o uso de captopril consegue diferenciar pacientes hipertensos com EAR daqueles sem estenose da artéria e avaliar se existe correlação entre as variações da TFG e a evolução de pacientes submetidos a diferentes tratamentos. MÉTODOS: Foram estudados 41 pacientes com hipertensão arterial de difícil controle que foram divididos em dois grupos: GP: 21 pacientes com EAR e GH: 20 pacientes sem EAR. Os pacientes foram submetidos à medida de TFG com EDTA-51Cr pré e após a administração do captopril. Os pacientes do GP realizaram simultaneamente cintilografia com DMSA-99mTc para avaliação da função renal diferencial. Os pacientes com estenose de artéria renal foram subdivididos de acordo com o tratamento recebido: clínico (GP-CL) ou por intervenção (GP-I). As medidas das TFGs antes e após o captopril foram comparadas entre os grupos. Foi também, investigado se a relação pré/pós captopril tinha correlação com a resposta clínica dos pacientes. RESULTADOS: a média da TFG (ml/min./1,73m2) no total de pacientes estudados, foi de 56,7±26,5 na fase pré-captopril e 47,0±24,4 após o captopril. A modificação da TFG determinada pelo captopril,foi avaliada pela relação da filtração glomerular pré/pós-captopril. A média da relação TFG pré/pós-captopril foi 1,36 ±0,54 no grupo total de pacientes e quando foi feita a comparação entre a TFG pré e pós-captopril, houve uma redução significativa (p= 0,016). O GH mostrou relação média da TFG pré/pós-captopril de 1,13, valor significativamente menor que o GP que teve a relação média de 1,57 (p= 0,007). Quando foi avaliada a variação da TFG após o captopril nos dois grupos não foi observada diferença estatisticamente significativa no GH (p=0,68), mas observou-se diferença significativa no GP (p<0,001). No total, 15 pacientes apresentaram melhora dos seus níveis pressóricos, sendo oito do grupo de intervenção e sete do grupo clinico, não havendo diferença estatisticamente significativa em relação à melhora clínica entre os dois grupos (p=0,36). Quando comparamos os pacientes com e sem melhora clínica não se observou diferença significativa na TFG basal (p=0,09) ou na relação TFG pré/pós-captopril (p=0,74). A função renal diferencial obtida pelo DMSA-99mTc pré e pós captopril não mostrou diferença estatisticamente significativa nos rins com e sem estenose, (p=0.09). CONCLUSÃO: O captopril acarreta uma redução significativa da TFG e esta redução é mais acentuada em pacientes com EAR, mas não houve correlação entre as mediadas da TFG e a evolução clínica dos pacientes / INTRODUCTION: Renovascular hypertension (RVH) resulting from renal artery stenosis (RAS) is a potential curable pathology, but the revascularization benefits are not reached among all patients because selecting patients on the basis of clinical and angiographic criteria may not be sufficient to achieve clinical success. There has been increasing interest in developing screening tests capable of accurately detecting the presence of RAS and also of evaluating its functional consequences PURPOSE: the purpose of this study was to evaluate if captopril induced changes in 51Cr-EDTA clearance could be used to differentiate between hypertensive patients with and without renal artery stenosis and to investigate if there was a correlation between these changes and patients clinical response to therapy. METHODS: 41 patients with poor-controlled severe hypertension were studied. Patients were divided into two groups: GP=patients with renal artery stenosis (n=21), and GH=patients without renal artery stenosis (n=20). They were submitted to a Glomerular Filtration Rate (GFR) measurement with EDTA-51Cr pre and post captopril administration. The GP patients were submitted simultaneously to 99mTc-DMSA scintigraphies to estimate individual renal function. GP patients were further subdivided according to the treatment strategy: optimization of clinical treatment (GP-Cl) and interventional procedures (GP-I). The GFRs before and after captopril administration were compared between the groups. It was also investigated if baseline to post-captopril GFR ratio had a correlation to clinical response of patients. RESULTS: The GFR average (ml/min./1,73m2) on the total patients, was 56,7±26,5 on pre-captopril phase and 47,0±24,4 post captopril. The GFR alteration determinated by captopril was evaluated by Baseline/post-captopril GFR ratio. Baseline/post-captopril GFR mean ratio was 1,36 in total patients and the GFR had a significant decrease after captopril administration (p value 0.016). Baseline/post-captopril GFR mean ratio in GH was 1.13, value significantly lower than the GP which had the average relation of 1,57 (p= 0,007). When GFR pre and post-captopril was compared among the two groups separately, there was no significantly difference on the GH (p=0,68), but a expressive difference was observed on GP (p<0,001). 15 patients had a clinical response to the treatment. Clinical response was observed in 8/10 patients from GP-I and 7/11 from GP-Cl and there was not observed a significantly difference between the two groups (p=0,36). Comparing the groups with or without clinical improvement there was not a significantly difference on the GRF baseline (p=0,09) or on or baseline/post-captopril ratio (p=0,74). When evaluating the differential renal function obtained by pre and post-captopril DMSA-99mTc, significantly difference was not observed (p=0.09) for the kidneys with or without stenosis. CONCLUSION: captopril induced a decrease in GFR of hypertensive patients and it is more pronounced in patients with renal artery stenosis, but no correlation was observed between captopril induced decrease in GFR and clinical response of patients submitted to interventional or clinical treatment