Coarctação de aorta abdominal justarrenal associada à hipertensão renovascular e claudicação incapacitante: tratamento utilizando ponte ilíaco-birrenal e técnica "paving and cracking" / Coarctation of the abdominal aorta associated with renovascular hypertension and incapacitating claudication: repair with iliac-birenal bypass and paving and cracking technique

Resumo Coarctação da aorta abdominal é uma causa rara de claudicação de membros inferiores e hipertensão refratária. O tratamento é complexo e exige conhecimento de diversas técnicas de reconstrução vascular. Apresentamos um caso de coarctação ao nível das artérias renais, seu tratamento e revisão da literatura. Paciente feminina, 65 anos, com hipertensão refratária desde os 35 anos, utilizando cinco medicações anti-hipertensivas em dose máxima. Pressão arterial média de 260/180mmHg e claudicação incapacitante (menos de 20 metros) bilateral. Angiotomografia computadorizada demonstrou coarctação de aorta justarrenal de 4 mm de maior diâmetro, calcificação circunferencial no local da estenose e tortuosidade da aorta infrarrenal. Foi submetida a tratamento híbrido, com ponte ilíaco-birrenal e implante de stent Advanta V12 no local da estenose. A paciente evoluiu satisfatoriamente e, 60 dias depois da cirurgia, apresentava-se com uma pressão arterial de 140/80mmHg, em uso de apenas duas medicações anti-hipertensivas e sem claudicação.

Abstract Coarctation of the abdominal aorta is a rare etiology of intermittent claudication and refractory hypertension. Treatment is complex and requires knowledge of several vascular reconstruction techniques. We report a case of aortic coarctation at the level of the renal arteries, describing its treatment and presenting a literature review. Female patient, 65 years old, with refractory hypertension since the age of 35, using five antihypertensive medications at maximum doses. Blood pressure was 260/180mmHg and she had disabling claudication (less than 20 meters). Computed tomography angiography showed a 4mm coarctation in the juxtarenal aorta, with circumferential calcification at the stenosis site, and tortuous infrarenal aorta. Hybrid repair was performed with an iliac-birenal bypass and implantation of an Advanta V12 stent at the stenosis site. The patient's postoperative course was satisfactory, she was free from claudication, and her blood pressure 60 days after surgery was 140/80mmHg, taking two antihypertensive medications.

Renovascular hypertension in pediatric patients: update on diagnosis and management.

Renovascular hypertension (RVH) is defined as an elevated blood pressure caused by kidney hypoperfusion, generally as a result of anatomic stenosis of the renal artery with consequent activation of the Renin Angiotensin-Aldosterone System. The main causes include genetic and inflammatory disorders, extrinsic compression, and idiopathic alterations. RVH is often asymptomatic and should be suspected in any child with refractory hypertension, especially if other suggestive findings are present, including those with severe hypertension, abdominal bruit, and abrupt fall of glomerular filtration rate after administration of angiotensin-converting enzyme inhibitors or angiotensin-receptor blockers. There is a consensus that digital subtraction angiography is the gold standard method for the diagnosis of RVH. Nevertheless, the role of non-invasive imaging studies such as Doppler ultrasound, magnetic resonance angiography, or computed tomographic angiography remains controversial, especially due to limited pediatric evidence. The therapeutic approach should be individualized, and management options include non-surgical pharmacological therapy and revascularization with percutaneous transluminal renal angioplasty (PTRA) or surgery. The prognosis is related to the procedure performed, and PTRA has a higher restenosis rate compared to surgery, although a decreased risk of complications. This review summarizes the causes, physiopathology, diagnosis, treatment, and prognosis of RVH in pediatric patients. Further studies are required to define the best approach for RVH in children.

Hipertensión Arterial Secundaria ¿por dónde empezar? / Secondary Arterial Hypertension, where to start?

30 to 40% of the adult population worldwide has been diagnosed with hypertension, among these patients 5 to 10% of them could have a possibly curable condition. In order to recognize this special population, the clinician must perform a complete work up and be aware of the main underlying causes of secondary hypertension. Often this could be a goal difficult to accomplish. The purpose of this article is to discuss the most frequent causes of secondary hypertension and offer a diagnostic approach for these patients. Clinicians should never forget that drug-related hypertension is a common cause that is discovered only with the help of a good medical history.

Importance of the commissural nucleus of the solitary tract in renovascular hypertension.

The rodent renovascular hypertension model has been used to investigate the mechanisms promoting hypertension. The importance of the carotid body for renovascular hypertension has been demonstrated. As the commissural NTS (cNTS) is the first synaptic site in the central nervous system that receives information from carotid body chemoreceptors, we evaluated the contribution of cNTS to renovascular hypertension in the present study. Normotensive male Holtzman rats were implanted with a silver clip around the left renal artery to induce two-kidney, one-clip (2K1C) hypertension. Six weeks later, isoguvacine (a GABAA agonist) or losartan (an AT1 antagonist) was injected into the cNTS, and the effects were compared with carotid body removal. Immunohistochemistry for Iba-1 and GFAP to label microglia and astrocytes, respectively, and RT-PCR for components of the renin-angiotensin system and cytokines in the NTS were also performed 6 weeks after renal surgery. The inhibition of cNTS with isoguvacine or the blockade of AT1 receptors with losartan in the cNTS decreased the blood pressure and heart rate of 2K1C rats even more than carotid body removal did. The mRNA expression of NOX2, TNF-α and IL-6, microglia, and astrocytes also increased in the cNTS of 2K1C rats compared to that of normotensive rats. These results indicate that tonically active neurons within the cNTS are essential for the maintenance of hypertension in 2K1C rats. In addition to signals from the carotid body, the present results suggest that angiotensin II directly activates the cNTS and may also induce microgliosis and astrogliosis within the NTS, which, in turn, cause oxidative stress and neuroinflammation.

Hipertensión arterial secundaria a displasia fibromuscular de la arteria renal. A propósito de un caso / Hypertension secondary to fibromuscular dysplasia of the renal artery. Report of a case

Se presenta el caso clínico de una paciente que debutó con hipertensión arterial (HTA) grado II realizándose los estudios sistematizados correspondientes para descartar patologías secundarias. Dentro de los estudios de primera línea en la valoración merece destacarse la ecografía Doppler renal por la información que ella aporta, orientado al diagnóstico de estenosis de la arteria renal. La identificación de una HTA de origen renovascular supone el hallazgo de una de las causas reversibles de hipertensión. Dentro de esta etiología la más frecuente es la displasia fibromuscular (DFM) que mejora con la corrección de la estenosis mediante técnicas quirúrgicas o percutáneas con angioplastia con balón o stent. El objetivo es presentar un caso clínico para mostrar la complejidad del proceso diagnóstico y la importancia que tiene la sospecha clínica para la corrección oportuna de este tipo de HTA reversible...

Hipertensión arterial secundaria a displasia fibromuscular de la arteria renal. A propósito de un caso / Hypertension secondary to fibromuscular dysplasia of the renal artery. Report of a case

Se presenta el caso clínico de una paciente que debutó con hipertensión arterial (HTA) grado II realizándose los estudios sistematizados correspondientes para descartar patologías secundarias. Dentro de los estudios de primera línea en la valoración merece destacarse la ecografía Doppler renal por la información que ella aporta, orientado al diagnóstico de estenosis de la arteria renal. La identificación de una HTA de origen renovascular supone el hallazgo de una de las causas reversibles de hipertensión. Dentro de esta etiología la más frecuente es la displasia fibromuscular (DFM) que mejora con la corrección de la estenosis mediante técnicas quirúrgicas o percutáneas con angioplastia con balón o stent. El objetivo es presentar un caso clínico para mostrar la complejidad del proceso diagnóstico y la importancia que tiene la sospecha clínica para la corrección oportuna de este tipo de HTA reversible.

[Takayasu's arteritis in pregnancy: report seven cases]. / Arteritis de Takayasu en el embarazo: reporte de siete casos.

Takayasu's arteritis is a chronic and non-specific disease of young women in reproductive age that primarily affects the aorta, its branches and the pulmonary artery. Ramirez Cueto G. and Fernandez Del Castillo C. et al. published a case of pregnancy in Mexico and Takayasu's arteritis in 1968. There are no reports of this disease in pregnancy since. The purpose of this study is to describe the clinical course and perinatal outcome of seven pregnant patients with known diagnosis of Takayasu arteritis. The clinical course, laboratory findings, angiographic findings and perinatal outcomes were assessed in retrospect in seven pregnant patients with diagnosis of Takayasu's arteritis seen at the National Institute of Perinatology Isidro Espinosa Reyes (Mexico) during the period 2002-2010. The results of the conducted follow-up of 7 patients pregnant with Takayasu's arteritis were: 3 patients were complicated with pre-eclampsia and 2 newborn presented intrauterine growth restriction. Disease activity wasn't observed during pregnancy. No cases of congestive heart failure, brain ischemia or maternal deaths were presented. There were no fetal deaths. We didn't observed induced activity during pregnancy in the cases presented. The most common mother complication was type renovascular hypertension with added severe preeclampsia, which determined the presence of intrauterine growth restriction. There were no maternal or perinatal deaths.

Systemic hypertension and transient ischemic attack in a 6-year-old girl with fibromuscular dysplasia treated with percutaneous angioplasty.

We describe a 6-year-old girl with arterial hypertension secondary to fibromuscular dysplasia with stenoses of both renal arteries and transient ischemic attack due to extracranial right internal carotid artery subtotal occlusion as well as left internal carotid artery stenosis. She was treated with percutaneous angioplasty of both renal and both carotid arteries.

Comparison of different pharmacodynamic models for PK-PD modeling of verapamil in renovascular hypertension.

INTRODUCTION: The aim of this work was to compare the suitability of different pharmacodynamic models for PK-PD modeling of verapamil cardiovascular effects in aortic coarctated rats (ACo), a model of renovascular hypertension. METHODS: A "shunt" microdialysis probe was inserted in a carotid artery of anaesthetized sham-operated (SO) and ACo rats for determination of verapamil plasma concentrations and their effects on blood pressure and heart rate after intravenous application (1 and 3 mg kg(-1)). Correlation between verapamil plasma levels and their cardiovascular effects was established by fitting data to a linear, and a conventional and modified E(max) model. RESULTS: No differences in verapamil volume of distribution were observed between experimental groups. Whilst clearance increased with dose in SO rats, no differences were found in verapamil clearance in ACo comparing both dose levels. A good correlation between verapamil plasma unbound concentrations and their hypotensive and chronotropic effects was found in both experimental groups using the tested PK-PD models. Although all pharmacodynamic models allowed a precise estimation of verapamil PK-PD parameters, linear and E(max) model did not permit an accurate PK-PD parameter estimation for the hypotensive and chronotropic effect, respectively. Conversely, the modified E(max) model allows both a precise and accurate estimation of PK-PD parameters for verapamil effects. Although, absolute verapamil blood pressure lowering effect was greater in ACo rats compared with SO rats, no differences were found in verapamil PK-PD parameters estimated for the hypotensive response. DISCUSSION: Side-by-side comparison of the tested pharmacodynamic models showed that accuracy of PK-PD parameters estimation by using the linear and classical E(max) model depends on the magnitude of concentration-effect curve covered in the study. Conversely, the modified E(max) model allowed both a precise and accurate estimation of PK-PD parameters, suggesting that the modified E(max) pharmacodynamic model is the most suitable for verapamil PK-PD modeling.

Evaluation of aortic remodeling in apolipoprotein E-deficient mice and renovascular hypertensive mice.

BACKGROUND: The apolipoprotein E-deficient mouse (ApoE) spontaneously develops hypercholesterolemia and atherosclerotic lesions in large arteries. It is also known that angiotensin II-induced hypertension accelerates the development of atherosclerosis in ApoE mice. The objective of this study was to evaluate the aortic remodeling process in ApoE mice during the early phase of atherosclerosis in two-kidney one-clip hypertensive (2K1C) mice and in mice with the coexistence of atherosclerosis and arterial hypertension. METHODS: Renovascular hypertension was induced in 8- to 9-week-old C57BL/6 (C57) and ApoE and compared to sham animals 28 days later. C57-2K1C and ApoE-2K1C mice showed hypertension, tachycardia, and cardiac hypertrophy of similar magnitude. RESULTS: ApoE and ApoE-2K1C mice showed high levels of plasma cholesterol (4.8- and 3.6-fold) and aorta lipid deposition (85- and 101-fold) compared to C57 mice. The aorta lumen area was increased in C57-2K1C and ApoE-2K1C mice (0.57 +/- 0.04 and 0.55 +/- 0.02 mm(2)) compared to C57 mice (0.50 +/- 0.02 mm(2), p <0.05). The aorta wall area was increased by 20% in C57-2K1C and by 12% in ApoE-2K1C mice compared to C57 and ApoE. CONCLUSIONS: The main finding of this study was the absence of aorta remodeling in ApoE mice at the early stage of atherosclerosis and an outward remodeling of similar magnitude in C57-2K1C and ApoE-2K1C mice.

Unexplained hematuria during pregnancy: right-sided nutcracker phenomenon.

We report a case of hematuria in a pregnant patient caused by right renal vein hypertension, as a result of compression of right renal, the inferior caval and the right gonadal veins because of posterior displacement of the pancreas caused by the presence of the gravid uterus. Hematuria resolved after a cesarean delivery. This condition has not been, to our knowledge, previously described.

Avanços na avaliação e no tratamento da hipertensão renovascular / Advances on evaluation and treatment of renovascular hypertension

A hipertensão renovascular é secundária à isquemia renal. É causada principalmente por doença aterosclerótica da artéria renal e displasia fibromuscular. A ativação do eixo renina-angiotensina-aldosterona e suas conseqüências hemodinâmicas é o principal fator fisiopatológico. A investigação diagnóstica está indicada em pacientes com características clínicas sugestivas da doença. A avaliação é feita através de métodos não-invasivos, como a ultra-sonografia com Doppler, a ressonância nuclear magnética, a tomografia computadorizada espiral e a cintilografia renal com captopril. A avaliação invasiva com a arteriografia permanece o padrão-ouro no diagnóstico da hipertensão renovascular. Há duas escolhas possíveis de tratamento: o medicamentoso e a revascularização cirúrgica ou percutânea. As indicações mais claras de angioplastia em estenoses hemodinamicamente significativas são a displasia fibromuscular e, no caso de doença aterosclerótica, hipertensão não-controlada, perda de função renal progressiva e edema pulmonar recorrente sem causa cardíaca identificada.

Diagnostic role of new Doppler index in assessment of renal artery stenosis.

BACKGROUND: Renal artery stenosis (RAS) is one of the main causes of secondary systemic arterial hypertension. Several non-invasive diagnostic methods for RAS have been used in hypertensive patients, such as color Doppler ultrasound (US). The aim of this study was to assess the sensitivity and specificity of a new renal Doppler US direct-method parameter: the renal-renal ratio (RRR), and compare with the sensitivity and specificity of direct-method conventional parameters: renal peak systolic velocity (RPSV) and renal aortic ratio (RAR), for the diagnosis of severe RAS. METHODS: Our study group included 34 patients with severe arterial hypertension (21 males and 13 females), mean age 54 (+/- 8.92) years old consecutively evaluated by renal color Doppler ultrasound (US) for significant RAS diagnosis. All of them underwent digital subtraction arteriography (DSA). RAS was significant if a diameter reduction > 50% was found. The parameters measured were: RPSV, RAR and RRR. The RRR was defined as the ratio between RPSV at the proximal or mid segment of the renal artery and RPSV measured at the distal segment of the renal artery. The sensitivity and specificity cutoff for the new RRR was calculated and compared with the sensitivity and specificity of RPSV and RAR. RESULTS: The accuracy of the direct method parameters for significant RAS were: RPSV >200 cm/s with 97% sensitivity, 72% specificity, 81% positive predictive value and 95% negative predictive value; RAR >3 with 77% sensitivity, 90% specificity, 90% positive predictive value and 76% negative predictive value. The optimal sensitivity and specificity cutoff for the new RRR was >2.7 with 97% sensitivity (p < 0.004) and 96% specificity (p < 0.02), with 97% positive predictive value and 97% negative predictive value. CONCLUSION: The new RRR has improved specificity compared with the direct method conventional parameters (RPSV >200cm/s and RAR >3). Both RRR and RPSV show better sensitivity than RAR for the RAS diagnosis.

Hypertension induced by aortic coarctation above the renal arteries is associated with immune cell infiltration of the kidneys.

BACKGROUND: Renal tubulointerstitial infiltration of activated T cells and macrophages is invariably present and plays a role in elevation of arterial pressure in nearly all animal models of hypertension (HTN). The role, if any, of elevated renal arterial pressure in the pathogenesis of this inflammatory process is uncertain. Also unclear is whether the cellular infiltration is caused by the local activation of immune cells in the kidney or a consequence of leukocyte activation in the systemic circulation. METHODS: We studied activation of peripheral blood leukocytes and cellular infiltration in the kidneys of Sprague-Dawley rats with abdominal aorta coarctation (banding) above renal arteries, which causes severe HTN proximal but not distal to coarctation. RESULTS: Compared with the sham operated controls, the aorta-banded group exhibited tubulointerstitial accumulation of activated T cells, macrophages, angiotensin-II positive cells, leukocyte function-associated antigen-1 integrin expressing cells, increased nitrotyrosine abundance (a measure of oxidative stress), and increased macrophage chemoattractant protein-1 in the kidneys which are not exposed to HTN in this model. These findings were associated with the activation of the circulating leukocytes in the aorta-banded animals. CONCLUSIONS: Increased baromechanical stress is not a requisite for accumulation of T cells and macrophages in the kidney in the coarctation-induced HTN and possibly in other hypertensive disorders. On the contrary, renal hypoperfusion and the consequent activation of renin-angiotensin system may mediate this process by promoting local induction of chemoattractant and inflammatory cytokines. The observed tubulointerstitial inflammation in this model is associated with leukocyte activation in the systemic circulation.