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Renal Artery (renal + artery)

Distribution by Scientific Domains

Medical Sciences	76%
Life Sciences	23%

Distribution within Medical Sciences

Radiology & Imaging	35%
Cardiovascular Disease	9%
Pediatrics	3%
10 Other Subdomains	44%

Terms modified by Renal Artery

renal artery stenosis

renal artery stenting

Selected Abstracts

Laparoscopic Procurement of Kidneys with Multiple Renal Arteries is Associated with Increased Ureteral Complications in the Recipient

AMERICAN JOURNAL OF TRANSPLANTATION, Issue 6 2005
Jonathan T. Carter
This study investigates the effect of renal artery multiplicity on donor and recipient outcomes after laparoscopic donor nephrectomy. Three-hundred and sixty-one sequential procedures were performed over a 4-year period. Forty-nine involved accessory renal arteries; of these, 36 required revascularization and 13 were small polar vessels and ligated. The 312 remaining kidneys with single arteries served as controls. Study variables included operative times, blood loss, hospital stay, graft function and donor and recipient complications. Kidneys with multiple revascularized arteries had a longer mean warm ischemia time (35.3 vs. 29.2 min, p = 0.0003), and more ureteral complications (6/36 vs. 10/312, p = 0.0013) than single-artery controls. In contrast, ligation of a small superior accessory artery had no significant effect on donor operative time, blood loss, or complication rate while providing similar recipient graft function compared to single-artery controls. Renal artery number is important in selecting the appropriate kidney for laparoscopic procurement. Given the current excellent results with right-sided donor nephrectomy, kidneys with single arteries should be preferentially procured, irrespective of side. [source]

Vertebral artery fibromuscular dysplasia: an unusual cause of stroke in a 3-year-old child

DEVELOPMENTAL MEDICINE & CHILD NEUROLOGY, Issue 10 2003
Ana Camacho MD
Fibromuscular dysplasia (FMD) is a systemic arteriopathy which tends to affect renal arteries followed by cervicocranial vessels. It can lead to cerebral infarction if cephalic arteries are involved. FMD is an unusual cause of stroke in childhood that generally affects the carotid area. Only four cases of vertebral FMD and subsequent stroke have been reported previously and we present the youngest patient of all. A healthy 3-year-old female was admitted to Hospital Doce de Octubre in Madrid, Spain with cerebellar infarction. Angiography disclosed basilar artery thrombosis and typical signs of FMD in both vertebral arteries. No other angiographic alteration was noted in the other vessels studied. Her phenotype and other investigations were unremarkable. The patient was treated with anti-aggregation therapy (aspirin) and the outcome was excellent. Investigation of the occurrence in childhood of this kind of arteriopathy may lead to clarification of its natural history and speculation about its unclear pathogenesis. [source]

Methylenetetrahydrofolate reductase gene C677T mutation is related to the defects in the internal elastic lamina of the artery wall

EUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 12 2002
P. Hämelahti
Abstract Background The C677T mutation of the methylenetetrahydrofolate reductase (MTHFR) gene leads to C/C, C/T and T/T genotypes, which affect the plasma homocysteine concentration in humans. In mini-pigs, high serum homocysteine levels are associated with defects in the internal elastic lamina (IEL) of the artery wall, which are apparently related to the migration of smooth muscle cells into the intima during atherogenesis. We studied the association between the MTHFR genotypes and the number of gaps in the IEL in the wall of the five major abdominal arteries. Materials and methods The autopsy study included 123 subjects (90 males and 33 females) aged 18,93. For the light microscopy, a 0·5 cm circular segment of the coeliac, the superior mesenteric, the inferior mesenteric and the renal arteries were cut and embedded in paraffin blocks. The circumference of the IEL, the thickness of the intima and the number of the gaps per millimetre in the IEL were measured by MOP 3 image analysis. Results The T-allele carriers (C/T and T/T) of the MTHFR gene had significantly less gaps in the IEL than the subjects with the C/C genotype in the superior mesenteric and in the left renal arteries (2·02 ± 2·25 vs. 2·53 ± 1·89, P < 0·04 and 0·56 ± 1·09 vs. 1·82 ± 2·66, P < 0·02, respectively). The trend was similar for the coeliac and the right renal arteries. Conclusions Our result suggests that MTHFR polymorphism may be involved in the fragmentation of the IEL. [source]

Ischemic nephropathy in an elderly patient

GERIATRICS & GERONTOLOGY INTERNATIONAL, Issue 2 2008
Satoshi Hoshide
Congestive heart failure often occurs in patients with bilateral renal artery stenosis. Recently, Jacobson and Breyer, and Jacobson introduced the term "ischemic nephropathy", which implies critical bilateral involvement or global ischemia. Ischemic nephropathy is not only a cause of hypertension but also an important cause of end-stage renal disease. However, the aging kidney often show that the renal artery does not demonstrate stenosis of the main trunks, but stenosis of an atherosclerotic branch. We present a case of multiple atherosclerotic peripheral renal arteries, which might have caused ischemic nephropathy in an elderly hypertensive patient with advanced atherosclerosis. [source]

Computed tomography angiogram: Accuracy in renal surgery

INTERNATIONAL JOURNAL OF UROLOGY, Issue 1 2009
Danny M Rabah
Objectives: To determine the sensitivity and specificity of computed tomography angiogram (CTA) in detecting number and location of renal arteries and veins as well as crossing vessels causing uretero-pelvic junction obstruction (UPJO), and to determine if this can be used in decision-making algorithms for treatment of UPJO. Methods: A prospective study was carried out in patients undergoing open, laparoscopic and robotic renal surgery from April 2005 until October 2006. All patients were imaged using CTA with 1.25 collimation of arterial and venous phases. Each multi-detector CTA was then read by one radiologist and his results were compared prospectively with the actual intra-operative findings. Results: Overall, 118 patients were included. CTA had 93% sensitivity, 77% specificity and 90% overall accuracy for detecting a single renal artery, and 76% sensitivity, 92% specificity and 90% overall accuracy for detecting two or more renal arteries (Pearson ,2 = 0.001). There was 95% sensitivity, 84% specificity and 85% overall accuracy for detecting the number of renal veins. CTA had 100% overall accuracy in detecting early dividing renal artery (defined as less than 1.5 cm branching from origin), and 83.3% sensitivity, specificity and overall accuracy in detecting crossing vessels at UPJ. The percentage of surgeons stating CTA to be helpful as pre-operative diagnostic tool was 85%. Conclusion: Computed tomography angiogram is simple, quick and can provide an accurate pre-operative renal vascular anatomy in terms of number and location of renal vessels, early dividing renal arteries and crossing vessels at UPJ. [source]

Complete robotic-assistance during laparoscopic living donor nephrectomies: An evaluation of 38 procedures at a single site

INTERNATIONAL JOURNAL OF UROLOGY, Issue 11 2007
Jacques Hubert
Objective: To evaluate our initial experience with entirely robot-assisted laparoscopic live donor (RALD) nephrectomies. Methods: From January 2002 to April 2006, we carried out 38 RALD nephrectomies at our institution, using four ports (three for the robotic arms and one for the assistant). The collateral veins were ligated, and the renal arteries and veins clipped, after completion of ureteral and renal dissection. The kidney was removed via a suprapubic Pfannenstiel incision. A complementary running suture was carried out on the arterial stump to secure the hemostasis. Results: Mean donor age was 43 years. All nephrectomies were carried out entirely laparoscopically, without complications and with minimal blood loss. Mean surgery time was 181 min. Average warm ischemia and cold ischemia times were 5.84 min and 180 min, respectively. Average donor hospital stay was 5.5 days. None of the transplant recipients had delayed graft function. Conclusions: Robot-assisted laparoscopic live donor nephrectomy can be safely carried out. Robotics enhances the laparoscopist's skills, enables the surgeon to dissect meticulously and to prevent problematic bleeding more easily. Donor morbidity and hospitalization are reduced by the laparoscopic approach and the use of robotics allows the surgeon to work under better ergonomic conditions. [source]

Early changes in renal hemodynamics in children with diabetes: Doppler sonographic findings

JOURNAL OF CLINICAL ULTRASOUND, Issue 6 2008
Piernicola Pelliccia MD
Abstract Purpose Although clinically evident diabetes-related microvascular complications are extremely rare in childhood, early functional and structural abnormalities may be present a few years after the onset of the disease. Renal Doppler resistance index (RI) is widely used for the evaluation of blood flow in renal parenchymal diseases. This study was designed to investigate the possible alteration of intrarenal Doppler RI in children with diabetes compared with healthy children. Methods The study was performed in 42 children with diabetes (age range, 6,18 years) and in 41 age-matched healthy controls, all having normal renal function. RI was measured with Doppler sonography in interlobular renal arteries. Results RI values were significantly greater in children with diabetes than in age-matched healthy controls (0.64 ± 0.03 versus 0.60 ± 0.04, P < 0.035). RI correlated positively with HbA1c (P < 0.001, r = 0.42) and diabetes duration (P < 0.05, r = 0.39). Conclusion Early changes in renal hemodynamics are detectable on Doppler sonography in children with diabetes without any evidence of renal dysfunction and may suggest a preclinical stage of diabetic nephropathy. © 2008 Wiley Periodicals, Inc. J Clin Ultrasound, 2008. [source]

Assessment of renal circulation in small for gestational age and appropriate for gestational age term newborns: A prospective study

JOURNAL OF CLINICAL ULTRASOUND, Issue 4 2008
Hana Kolarovszka
Abstract Purpose To compare selected parameters of renal circulation between small for gestational age (SGA) and appropriate for gestational age (AGA) newborns. Methods Fifty-two SGA and 100 AGA term newborns were examined. The size of the kidneys were measured, and renal blood flow in the central and intraparenchymal renal arteries were assessed via Doppler sonography. Peak systolic velocity (PSV), end diastolic velocity (EDV), mean blood flow velocity (V mean), resistance index (RI), and pulsatility index (PI) were determined and compared between the groups. Results No statistically significant differences in the velocity parameters were found between SGA and AGA infants in central renal arteries. Slightly higher RIs and PIs were seen in AGA newborns (RI, 0.76 ± 0.13 versus 0.78 ± 0.06 [p < 0.05]; PI, 1.65 ± 0.54 versus 1.84 ± 0.46 [p < 0.05]). There were statistically significant differences between the groups in all measured parameters in intraparenchymal arteries (RI, 0.57 ± 0.11 versus 0.63 ± 0.05 [p < 0.001]; PI, 0.89 ± 0.26 versus 1.09 ± 0.16 [p < 0.001]) except PSV (7.11 ± 1.55 versus 7.14 ± 0.81 cm/s [p > 0.05]). Conclusion Based on our findings, we suggest that renal circulation is not negatively influenced by intrauterine growth restriction in SGA neonates compared with AGA newborns. © 2007 Wiley Periodicals, Inc. J Clin Ultrasound, 2008 [source]

Reliability of intrarenal Doppler sonographic parameters of renal artery stenosis

JOURNAL OF CLINICAL ULTRASOUND, Issue 7 2003
Gülgün Demirpolat MD
Abstract Purpose The goal of this study was to retrospectively evaluate false-negative results of Doppler sonography in the diagnosis of renal artery stenosis (RAS) using intrarenal criteria. Methods We reviewed the clinical data and Doppler sonographic data for all patients in whom a diagnosis of RAS had been confirmed angiographically between November 1992 and January 2001. Mean intrarenal acceleration and acceleration time values,data obtained directly from color Doppler sonography,and findings of angiographic examination of the kidneys and stenotic renal arteries were evaluated. Results During the study period, 55 cases of RAS had been angiographically confirmed in 46 patients (25 male and 21 female; mean age, 50 ± 19 years [± standard deviation]). Intrarenal arterial acceleration, acceleration time values, or both were abnormal in 42 kidneys (76%) (group A) and normal in 13 kidneys (24%) (group B). The mean age ± standard deviation was significantly higher for patients in group B (60 ± 12 years) than for those in group A (47 ± 20 years) (p > 0.05). In group B, most of the stenotic lesions were atherosclerotic, and in all kidneys but 1, the lesions were located at the renal ostium or the proximal half of the artery. Conclusions Isolated use of intrarenal Doppler sonographic criteria for RAS may lead to an unacceptably high incidence of false-negative results in the diagnosis of this condition, especially in elderly patients. © 2003 Wiley Periodicals, Inc. J Clin Ultrasound 31:346,351, 2003 [source]

Duplex Doppler sonography of transplant renal artery stenosis

JOURNAL OF CLINICAL ULTRASOUND, Issue 3 2003
Ruth Helena de Morais MD
Abstract Purpose The aim of this study was to evaluate the accuracy of duplex Doppler sonography in diagnosing transplant renal artery stenosis (TRAS) and to determine which parameter is the most reliable for making that diagnosis. Methods Over a 3-year period, we sonographically evaluated patients who were referred for investigation of possible TRAS. We investigated the following parameters: peak systolic velocity (PSV) in the external iliac and renal arteries, acceleration time and acceleration in the intrarenal arteries, acceleration time in the renal artery, resistance index, and the ratio of the PSVs in the renal and external iliac arteries. We also used MR angiography and digital subtraction arteriography to verify the degree of stenosis. After the evaluations, the patients were classified into 2 groups, 1 with and the other without significant stenosis (> 50% narrowing of the lumen) on digital subtraction arteriography. We also included a control group of patients who had undergone renal transplantation at least 6 months before, had had a good course after transplantation, had a diastolic blood pressure of 90 mm Hg or less, and were taking a maximum of 1 antihypertensive drug. Results Our study population consisted of 22 patients suspected to have TRAS (10 without and 12 with confirmed significant stenosis) and 19 control patients. We found statistically significant differences between the mean values of these 3 groups except for the PSV in the iliac artery and the resistance index in the intrarenal arteries. The most accurate parameters to use in diagnosing TRAS were an acceleration time of 0.1 second or higher in the renal and intrarenal arteries, a PSV of greater than 200 cm/second in the renal artery, and a ratio of PSVs in the renal and external iliac arteries of greater than 1.8. Conclusions Duplex Doppler sonography is an excellent method for screening patients suspected to have TRAS and can help select which of those patients should undergo digital subtraction arteriography. © 2003 Wiley Periodicals, Inc. J Clin Ultrasound 31:135,141, 2003 [source]

Resistance index in fetal interlobar renal artery with renal pelvic dilatation up to 10 mm

JOURNAL OF CLINICAL ULTRASOUND, Issue 2 2003
Simay Altan Kara MD
Abstract Purpose The purpose of this study was to compare the resistance indices (RIs) in the fetal interlobar renal arteries (IRAs) of third-trimester fetuses with or without pelvicaliceal dilatation of up to 10 mm and to compare them with those of the full-term healthy infants. Methods Women with uncomplicated, low-risk, singleton third-trimester pregnancies were examined sonographically. The RIs in the IRAs were measured in the fetuses, who were stratified into 3 groups according to the anteroposterior diameter of the renal pelvic dilatation: group I, no dilatation; group II, 1,5-mm dilatation, and group III, 6,10-mm dilatation. Results In total, 178 women were examined. We could study both kidneys in 139 of the fetuses; in the other 39, only 1 kidney could be imaged perfectly. This yielded a total of 317 kidneys. Group I fetuses included 172 (54%); group II, 98 (31%); and group III, 47 (15%) of the kidneys. The mean (± standard deviation) RIs in the IRAs were 0.81 ± 0.09, 0.80 ± 0.07, and 0.80 ± 0.06 in the 3 groups, respectively, with no statistically significant difference between the groups (p = 0.72). There was also no statistically significant difference between the RIs recorded in the right and left kidneys. The mean RI in the IRAs of the 34 infants who were available for follow-up 6,12 weeks after delivery was 0.73 ± 0.07, which was significantly less than that recorded in the third-trimester fetuses (p = 0.005). Conclusions The RI in the fetal IRA does not differ in fetuses with and without renal pelvic dilatation of up to 10 mm. Thus, an increase in the RI or an RI that significantly differs between the right and left kidneys should be investigated further for possible renal pathology. © 2003 Wiley Periodicals, Inc. J Clin Ultrasound 31:75,79, 2003 [source]

Changes in renal artery resistance after meal-induced splanchnic vasodilatation in cirrhotic patients

JOURNAL OF CLINICAL ULTRASOUND, Issue 9 2001
Pascal Perney MD
Abstract Purpose A relationship between vasomotor tone changes in mesenteric and renal vessels in cirrhotic patients has been suspected but remains controversial. The aim of this study was to assess by duplex Doppler sonography the changes in the circulatory resistance of the renal arteries and superior mesenteric artery (SMA) following meal-induced splanchnic vasodilatation. Methods Twenty-seven cirrhotic patients and 15 healthy volunteers with no hepatic or renal dysfunction were prospectively included in the study. The resistance index (RI) of the SMA and of the right and left renal arteries was measured by duplex Doppler sonography before and 30 minutes after ingestion of a standard 400-kcal balanced liquid meal. Values in controls and patients and values before and after the meal were compared, and correlations between RIs, Child-Pugh class (liver function), and creatinine clearance were assessed in cirrhotic patients. Results The fasting renal artery RI was greater in cirrhotic patients than in controls (p < 0.0001), but there was no difference in fasting SMA RIs. After the meal, there was a significant decrease in the SMA RI in controls (0.85 ± 0.04 before versus 0.74 ± 0.03 after meal, p = 0.0001) and in cirrhotic patients (0.85 ± 0.04 before versus 0.77 ± 0.04 after, p = 0.0001) and a significant increase in the renal artery RI (0.57 ± 0.06 before versus 0.62 ± 0.05 after in controls, p = 0.001; 0.68 ± 0.07 before versus 0.70 ± 0.07 after in cirrhotic patients, p = 0.001). No correlation was found in cirrhotic patients between the changes in renal artery RI and the postprandial SMA RI decrease, the Child-Pugh class, or the creatinine clearance. Conclusions Meal-induced SMA vasodilatation (RI decrease) is associated with a marked increase in the renal artery RI, worsening the renal vasoconstriction in cirrhotic patients. © 2001 John Wiley & Sons, Inc. J Clin Ultrasound 29:506,512, 2001. [source]

An Enhanced Device for Transluminal Retrieval of Vascular Stents Without Surgical Procedures: Experimental Studies

JOURNAL OF INTERVENTIONAL CARDIOLOGY, Issue 3 2010
MASAYUKI TSUCHIDA M.D.
Background: Although efforts have been focused on developing endovascular procedures by which intravascular devices such as stents could be effectively deployed, few data exist regarding devices for the nonsurgical retrieval of deployed stents. Therefore, we designed to enable retrieval of deployed stents without a surgical procedure. Methods: The device consisted of four components: ultra-low profile forceps with 2.0 mm in diameter, conducting shaft with 1.8 mm in diameter, control handle by which the forceps is opened or closed, and a covering sheath. This device was designed to advance into the vessel lumen along a 0.014-inch guidewire by over the wire fashion. Results: The forceps could firmly catch nonexpanded as well as expanded tubular-type stents with open cells in an in vitro model that was 4.0 mm in diameter. Then, we used this device in porcine renal arteries with 2.5,5.0 mm in diameter. At first, a fragmented 0.014-inch guidewire could be safely removed without vessel damage that was confirmed by intravascular ultrasound. This device could successfully remove four of five inappropriately and 11 of 14 appropriately deployed stents. Under these conditions, intravascular ultrasound demonstrated minor vessel wall dissection in two-third of cases. Conclusions: These results demonstrate that the present device can be used for transluminal removal of foreign bodies such as nonexpanded as well as expanded stents in acute phase. Further miniaturization may enable using this type of device in the renal as well as coronary arteries. (J Interven Cardiol 2010;23:264,270) [source]

Renovascular imaging in the NSF Era

JOURNAL OF MAGNETIC RESONANCE IMAGING, Issue 6 2009
Giles Roditi MD
Abstract The detection of the association between nephrogenic systemic fibrosis (NSF), a rare but potentially life-threatening disease only encountered in patients with severely impaired renal function, and the previous administration of some Gd-chelates has cast a shadow on the administration of Gd-chelates in patients with chronic renal failure. So far, contrast-enhanced MR-angiography (MRA) was considered the best diagnostic modality in patients with suspected renal disease. This review explores the most appropriate use of renal MRA with a focus on newly developed nonenhanced MRA techniques. Nonenhanced MRA techniques mainly based on SSFP with ECG-gating allow for acceptable spatial resolution to visualize at least the proximal parts of the renal arteries. In addition functional renal imaging techniques and their current clinical role are critically appreciated. J. Magn. Reson. Imaging 2009;30:1323,1334. © 2009 Wiley-Liss, Inc. [source]

Aneurysms of the renal arteries associated with segmental arterial mediolysis in a case of polyarteritis nodosa

PATHOLOGY INTERNATIONAL, Issue 3 2009
Yoshiko Soga
This is the first report of segmental arterial mediolysis (SAM) accompanied with polyarteritis nodosa (PN), and manifesting aneurysms of the renal arteries. A 73-year-old woman was admitted to hospital because of a high fever. Laboratory tests showed leukocytosis with increased CRP level in the serum. Myeloperoxidase-anti-neutrophil cytoplasmic antibody (MPO-ANCA) and proteinase 3 (PR3)-ANCA were negative. There were no signs indicating infection or malignancy. After admission renal function rapidly deteriorated. Treatment was then started with daily oral prednisolone and hemodialysis. On the 40th day of hospitalization the patient suddenly became comatose. Cranial CT showed a subarachnoid hemorrhage. The patient died and an autopsy was performed. The pathological findings showed necrotizing vasculitis of the small arteries in various organs, but not associated with that of arterioles or renal glomerular lesions, indicating PN. Unexpectedly, the segmental arteries of the bilateral kidneys showed vascular lesions of dissecting aneurysms, indicating SAM. This case indicates that SAM is one of the causes of aneurysms in PN and is clinically important when the clinical course of PN patients rapidly advances. [source]

Laparoscopic Procurement of Kidneys with Multiple Renal Arteries is Associated with Increased Ureteral Complications in the Recipient

Macroscopic Features of the Arterial Supply to the Reproductive System of the Male Ostrich (Struthio camelus)

ANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 4 2007
M. Z. J. Elias
Summary The macroscopic features of the arterial supply to the reproductive system of the male ostrich was studied in 16 pre-pubertal and eight sexually mature and active birds. The left and right cranial renal arteries arise from the aorta, between the cranial divisions of the kidneys. These vessels supply the cranial divisions of the kidneys, the testes, the epididymides and the cranial segments of the ducti deferentia. Accessory testicular arteries which arise directly from the aorta are present in 45.8% of the specimens. They supply the testes and cranial parts of the ducti deferentia. They are variable in number and origin, and four variants are identified. A cranial ureterodeferential branch originates from the cranial renal artery, supplies the cranial portion of the ductus deferens and ureter, and runs caudally to anastomose with the middle renal artery. The sciatic artery arises laterally from the aorta, just caudal to the acetabulum, and gives rise, ventrally, to a common trunk, the common renal artery, which divides into the middle and caudal renal arteries. The middle renal artery gives rise to the middle ureterodeferential branch which supplies the middle part of the ductus deferens and ureter. A few centimetres caudal to the kidney, the aorta terminates in three branches, namely, the left and right internal iliac arteries and the median caudal artery. The internal iliac artery divides into the lateral caudal artery and the pudendal artery; the latter gives off caudal ureterodeferential branches that supply the caudal segments of the ductus deferens and ureter. In addition, the pudendal artery gives off vessels that supply the cloaca, some of which continue to the base of the phallus, where they form an arterial network. In conclusion, the pattern of the blood supply to the reproductive organs of the male ostrich is, in general, similar to that of the domestic fowl and pigeon, although there are a few highlighted distinctive features. [source]

Treatment of instent restenosis following stent-supported renal artery angioplasty

CATHETERIZATION AND CARDIOVASCULAR INTERVENTIONS, Issue 3 2007
Thomas Zeller MD
Abstract Objectives: We prospectively studied the long-term outcome of endovascular treatment of instent renal artery stenosis (IRAS). Background: Restenosis is a considerable drawback of stent-supported angioplasty of renal artery stenosis especially in small vessel diameters. The appropriate treatment strategy is not yet defined. Patients and Methods: During a 10-year period 56 consecutive patients (65 lesions) with their first IRAS were included in a prospective follow-up program (mean follow-up 53 ± 25 months, range 6,102). Primary endpoint of the study was the reoccurrence of IRAS (, 70%) after primarily successful treatment of the first IRAS determined by duplex ultrasound. Results: Primary success rate was 100%, no major complication occurred. Nineteen lesions were treated with plain balloon angioplasty (group 1, 30%), 42 lesions with stent-in-stent placement (group 2, 65%) using various bare metal balloon expandable stents, and 4 lesions with drug-eluting stent angioplasty (group 3, 6%). During follow-up, overall 21 lesions (32%) developed reoccurrence of IRAS: n = 7/19 in group 1 (37%), n = 14/42 in group 2 (33%), and n = 0/4 in group 3 (0%; P = 0.573). Reoccurrence of IRAS was more likely to occur in smaller vessel diameters than in larger ones [3,4mm: 4/7 (57%); 5 mm: 11/26 (42%); 6 mm: 5/25 (20%); 7 mm: 1/7 (14%), P = 0.088]. Multivariable analysis found bilateral IRAS and IRAS of both renal arteries of the same side in case of multiple ipsilateral renal arteries as independent predictors for reoccurrence of IRAS. Conclusion: Treatment of IRAS is feasible and safe. The data demonstrate a nonsignificant trend towards lower restenosis with restenting of IRAS versus balloon angioplasty of IRAS. Individual factors influence the likelihood of reoccurrence of IRAS. © 2007 Wiley-Liss, Inc. [source]

Usefulness of translesional pressure gradient and pharmacological provocation for the assessment of intermediate renal artery disease

CATHETERIZATION AND CARDIOVASCULAR INTERVENTIONS, Issue 3 2006
Noah J. Jones MD
Abstract Objective: We sought to determine the hemodynamic significance of intermediate RAS by measuring translesional systolic pressure gradients (TSPG), using a pressure-sensing guidewire at baseline and after acetylcholine (ACh) induced hyperemia, following selective renal artery angiography. Background: Renal artery stenosis (RAS) is a cause of reversible hypertension and nephropathy. Stenting effectively relieves RAS, however improvement in blood pressure control or renal function is variable and unpredictable. Hemodynamic significance is usually present with RAS when diameter stenosis is >75%, but is less predictable in intermediate (30%,75%) RAS. Methods: Twenty-two patients (26 renal arteries) with uncontrolled hypertension underwent invasive hemodynamic assessment because of intermediate RAS, defined as radiocontrast angiographic diameter stenosis (DS) between 30% and 75% (quantitative DS was measured prospectively). Translesional pressure gradients were measured using a 0.014" pressure-sensing wire. Hyperemia was induced by administration of intrarenal ACh. Results: Visual and measured angiographic lesion severity did not correlate with TSPG either at baseline (visual DS, R2 = 0.091, P = 0.13; measured DS, R2 = 0.124, P = 0.07) or with hyperemia (visual DS, R2 = 0.057, P = 0.24; measured DS, R2 = 0.101, P = 0.12). Baseline and maximal hyperemic gradient did correlate (R2 = 0.567; P < 0.05). Pharmacological provocation produced a significant increase in TSPG (mean; baseline, 18 ± 21 vs. hyperemia, 34 ± 41 mm Hg; P < 0.05). A hemodynamically significant lesion (TSPG > 20 mm Hg) was found in 14/26 (54%) arteries (13 patients); 13 (60%) patients subsequently underwent renal artery stenting for hemodynamically significant RAS. At follow-up (at least 30 days), there was a significant decrease in systolic blood pressure (mean; 167 ± 24 vs. 134 ± 19 mm Hg; P < 0.001). Conclusions: Intrarenal administration of ACh induces hyperemia and can be used to unmask resistive renal artery lesions. Gradient measurement and induced hyperemia may be warranted in the invasive assessment of intermediate renal artery stenoses, rather than relying on stenosis severity alone. Further study is needed to determine whether translesional pressure gradients and pharmacological provocation predict clinical benefit after renal artery stenting. © 2006 Wiley-Liss, Inc. [source]

Role of protein kinases in mediating diabetes-induced augmented vasoconstriction to endothelin-1 in the renal arteries of STZ-diabetic rats

CELL BIOCHEMISTRY AND FUNCTION, Issue 5 2006
Mariam H. M. Yousif
Abstract Diabetes is associated with increased reactivity of the renal vascular bed to endothelin-1 (ET-1). It has been observed that diabetes is associated with over-expression of ETA - and ETB -receptors in the rat renal cortex. However it is not known if these receptors are over-expressed in the renal artery. The objectives of this study were to determine changes in ET-1 receptors and signalling pathways in diabetic renal arteries, to determine the relative roles of protein kinase C and tyrosine kinase activation in mediating these responses and to investigate the role of Rho-kinase activity in mediating the vasoconstrictor responses to ET-1. This study was performed on isolated renal artery segments obtained from STZ-diabetic rats. Results from this study showed that the vasoconstrictor response to ET-1 was potentiated in the diabetic renal artery segments compared to the control animals. Using selective ET-1 receptor antagonists, BQ123 and BQ788, the enhanced ET-1-induced vasoconstriction was shown in this study not to be related to changes in receptor affiinity or receptor subtype distribution. However, the augmented vasoconstrictor response to ET-1 in the diabetic renal artery preparations may be related to increased influx of Ca2+ through L-type channels and also to increased tyrosine kinase activity. Copyright © 2005 John Wiley & Sons, Ltd. [source]

Three-dimensional visualization of renal artery stenosis by 64-channel multiple detector-row computed tomographical angiography: review of two paediatric cases

ACTA PAEDIATRICA, Issue 3 2010
N Ueda
Abstract Three-dimensional visualization of renal arteries has recently been established by helical contrast-enhanced multiple detector-row computed tomographical angiography (MDCTA) in adults. So far, no information is available on its use in children. We reported two children with renal artery stenosis detected by 64-channel MDCTA. The first patient probably had fibromuscular dysplasia and the other neurofibromatosis type1. The technique showed a left renal artery stenosis with a small left kidney in the first patient and a right renal artery stenosis in the second. Conclusion:, MDCTA is an accurate and noninvasive imaging technique, easily performed in children, and can be used as an alternative diagnostic modality in children with suspected renovascular hypertension. [source]

Organ-specific ligation-induced changes in harmonic components of the pulse spectrum and regional vasoconstrictor selectivity in Wistar rats

EXPERIMENTAL PHYSIOLOGY, Issue 1 2006
Tse Lin Hsu
It has been shown previously that the amplitudes of the harmonic components of the pulse spectrum vary in specific patterns when the arteries leading to different organs are ligated, with the variations in the harmonics being linearly additive. Since ligation can be regarded as a vast increase in organ resistance, the present study examined the potential of using these ligation-induced variations in the pulse spectrum as reference parameters for an increase in vascular resistance and for regional vasoconstrictor selectivity. A vasoconstrictor, either arginine vasopressin (AVP) or angiotensin II (Ang II), was infused into anaesthetized Wistar rats via the femoral vein for 1 h. The distinct harmonic-specific drug effects on the pulse spectrum were simulated by combining renal artery and superior mesenteric artery ligations in different ratios, the ratio with the lowest mean square difference determining the regional drug selectivity. The ratios indicated that the effect of AVP on the pulse spectrum was attributable to the combined effect of ligating the renal and superior mesenteric arteries, while the effect of Ang II was attributable to ligation of the renal artery. The results are comparable with those of investigations of regional vascular resistance performed using traditional methods. Our findings indicate that the ligation-induced variations in the pulse spectrum can be used to determine regional increases in vascular resistance. This implies that blood pressure can be used as the sole parameter to determine which arterial bed has been affected by the vasoconstrictor, and how seriously. [source]

Ischemic nephropathy in an elderly patient

Computed tomography angiogram: Accuracy in renal surgery

The para-aortic ridge plays a key role in the formation of the renal, adrenal and gonadal vascular systems

JOURNAL OF ANATOMY, Issue 6 2010
Sumio Isogai
Abstract Renal, adrenal, gonadal, ureteral and inferior phrenic arteries vary in their level of origin and in their calibre, number and precise anatomical relationship to other structures. Studies of the origin and early development of these arteries have evoked sharp disputes. The ladder theory of Felix, which states that ,All the mesonephric arteries may persist; from them are formed the phrenic, suprarenal, renal and internal spermatic arteries' has been generally quoted in the anatomical textbooks without rigorous verification for 100 years. In this study, we re-examined this theory by performing micro-injection of dye and resin into rat (Rattus norvegicus) embryos. Our results revealed that most of the mesonephric arteries had degenerated before the metanephros started its ascent. The definitive renal, adrenal, gonadal, ureteral and inferior phrenic arteries appeared as new branches from the gonadal artery and/or directly from the abdominal aorta to the para-aortic ridge. Coincidental to this, the anatomical architecture of the inter-renal vascular cage, which consists of the interlobar and arcuate arteries and their collateral veins, was completed within the developing metanephros. We demonstrated that the delicate renal vascular cage switched from the primary renal artery to the definitive renal artery and that the route of venous drainage changed from the posterior cardinal vein to the inferior (caudal) vena cava. [source]

Duplex Doppler sonography of transplant renal artery stenosis

Resistance index in fetal interlobar renal artery with renal pelvic dilatation up to 10 mm

Doppler velocimetry of maternal renal circulation in pregnancy-induced hypertension

JOURNAL OF CLINICAL ULTRASOUND, Issue 8 2001
Hidehiko Miyake MD
Abstract Purpose The purpose of this study was to evaluate whether the Doppler waveforms of the maternal main renal, segmental, and interlobar arteries are altered in women with pregnancy-induced hypertension (PIH) compared with healthy pregnant women. Methods Flow waveforms of the maternal main renal, segmental, and interlobar arteries were obtained from 42 healthy pregnant women between 24 and 41 weeks of gestation and 21 women with PIH between 28 and 40 weeks of gestation using pulsed Doppler sonography. We used spectral analysis to measure the peak systolic and end-diastolic velocities and the acceleration time. The presence or absence of the normal early systolic compliance peak-reflective-wave complex (ESP) was assessed in only the main renal artery. Results The acceleration times of the segmental and interlobar arteries were significantly prolonged in the PIH group compared with those in the healthy pregnant women. Of the 21 women with PIH, 3 showed loss of the ESP in the renal artery, but these changes were not significant. Conclusions Decreased systolic acceleration and the absence of ESP, the hemodynamic indicators for significant proximal stenosis, suggest that severe stenosis or continuous vasospasm in the proximal arteries, such as the main renal or segmental artery, may be implicated in the pathogenesis of PIH. © 2001 John Wiley & Sons, Inc. J Clin Ultrasound 29:449,455, 2001. [source]

High-resolution renal MRA: Comparison of image quality and vessel depiction with different parallel imaging acceleration factors

JOURNAL OF MAGNETIC RESONANCE IMAGING, Issue 1 2006
Henrik J. Michaely MD
Abstract Purpose To investigate the image quality and vessel depiction of renal MRA with integrated parallel imaging techniques (iPAT) using acceleration factors of 2 and 3. Materials and Methods In this prospective study renal MRA was performed on 14 and 12 patients with acceleration factors of 3 and 2, respectively. For the MRA a 3D-GRE sequence with an acquired spatial resolution of 0.9 × 0.8 × 1.0 mm3 was applied (TR/TE = 3.79 msec/1.39 msec, FOV = 400 mm × 320 mm, acquired matrix = 512 × 384, flip angle = 25°) on a 32-channel 1.5T MR scanner. The acquisition time was 26 seconds with iPAT 2, and 19 seconds with iPAT3. All parameters other than acquisition time and acceleration factor were kept constant. To assess the signal-to-noise ratio (SNR) we performed repetitive phantom measurements using iPAT 2 and 3. The images were rated by two radiologists in terms of noise, artifacts, and the quality of vessel depiction for the proximal, segmental, and subsegmental renal artery. A Mann-Whitney U-test and kappa-test were used for statistical analysis. Results SNR decreased significantly with iPAT 3 in the phantom measurements. The two readers found no difference in noise, but significantly fewer artifacts with iPAT 3. The depiction of segmental vessels was significantly better for both readers with iPAT 3, and the subsegmental vessels were rated significantly better by one reader. iPAT 3 also resulted in a better interreader agreement. Conclusion The use of iPAT 3 for renal MRA enables a better depiction of the distal parts of the renal artery. The decrease in SNR is not diagnostically impairing. J. Magn. Reson. Imaging 2006. © 2006 Wiley-Liss, Inc. [source]

Spatial refractive index measurement of porcine artery using differential phase optical coherence microscopy

LASERS IN SURGERY AND MEDICINE, Issue 10 2006
Jeehyun Kim PhD
Abstract Background and Objectives We describe a methodology to record spatial variation of refractive index of porcine renal artery using differential phase optical coherence microscopy (DP-OCM). Study Design/Materials and Methods The DP-OCM provides quantitative measurement of thin specimen phase retardation and refractive index by measuring optical path-length changes on the order of a few nanometers and with a lateral resolution of 3 µm. The DP-OCM instrumentation is an all-fiber, dual-channel Michelson interferometer constructed using a polarization maintaining (PM) fiber. Results Two-dimensional en face dual-channel phase images are taken over a 150,×,200 µm region on a microscopic slide, and the images are reconstructed by plotting a two-dimensional refractive index map as the OCM beam is moved across the sample. Conclusions Because the DP-OCM can record transient changes in the optical path-length, the system may be used to record quantitative optical path-length alterations of tissue in response to various stimuli. A fiber-based DP-OCM may have the potential to substantially improve in vivo imaging of individual cells for a variety of clinical diagnostics, and monitoring applications. Lasers Surg. Med. © 2006 Wiley-Liss, Inc. [source]