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Anatomy & Embryology
Published in Manit Arya, Taimur T. Shah, Jas S. Kalsi, Herman S. Fernando, Iqbal S. Shergill, Asif Muneer, Hashim U. Ahmed, MCQs for the FRCS(Urol) and Postgraduate Urology Examinations, 2020
Anatomy of the renal vasculature. Which one is TRUE?The posterior segmental artery is formed after entering the renal hilum.Arcuate arteries give rise to interlobar arteries.There are four anterior segmental arteries.PUJ obstruction may be caused by an anterior segmental artery.The left renal vein passes in front of the superior mesenteric artery to reach the IVC.
Urinary Tract
Published in George W. Casarett, Radiation Histopathology: Volume II, 2019
The blood vasculature of the kidney is abundant, and about one-fifth of the body’s blood passes through the kidneys per min. Interlobar arteries arise as branches of the renal artery, pass between the pyramids of the kidney, and become arcuate arteries at the cortical-medullary junction. The interlobular arteries are branches of arcuate arteries and follow a radial course through the cortex. The interlobular arteries give off branches to the glomeruli (afferent arterioles) which, after breaking up into the glomerular capillary loops, reform as efferent arterioles which supply capillaries surrounding cortical tubules (Figures 1B and 1C). The interlobular arteries also give off some terminal branches to the renal capsule and subjacent cortex, and the efferent glomerular arterioles, in addition to supplying the blood vessels of the nearby cortical tubules, also give off branches (arteriolae rectae) to the medulla from efferent arterioles near the medulla. The tubules of both the cortex and the medulla are surrounded by capillary plexuses arising from the efferent arterioles of the glomeruli. It is probable that the convoluted tubules of each nephron are usually supplied with the blood that has just passed through the glomerulus of that nephron. Renal arterioles tend to be end arterioles, the only supply to the regions served.
Histopathologic Patterns in Hypertensive Nephrosclerosis in African Americans
Published in Meguid El Nahas, Kidney Diseases in the Developing World and Ethnic Minorities, 2005
The so-called “benign hypertensive nephrosclerosis” vascular lesions vary depending on the size of the vessels involved. Arcuate and larger arteries show intimal fibrosis and sometimes splitting of the internal elastic lamina. Interlobular arteries show fibroelastic intimal expansion with reduplication of the internal elastic lamina. Small arteries and arterioles show medial thickening with multilayered smooth muscle cells and intimal proliferation. Arteriolar hyalinosis of afferent arterioles, typically eccentric, is common. In contrast, accelerated hypertensive nephrosclerosis shows lesions in interlobular arteries with marked intimal edema, proliferation of myointimal cells with mucoid matrix, which later organizes to a characteristic concentric “onionskin” pattern of intimal fibrosis. These alterations may also affect the arcuate arteries and extend into arterioles. Sometimes blood constituents in the vascular wall in the subendothelial space, such as red blood cell fragments and intraluminal fibrin thrombi, may be seen. Malignant hypertensive nephrosclerosis is diagnosed morphologically when fibrinoid necrosis of the vessel wall is present. Malignant hypertension as a presenting finding is now rare in the United States. However, in a large series reported in Brazil of 81 biopsied patients who presented with primary hypertensive nephrosclcrosis underlying their moderate renal insufficiency, 43% showed lesions indicative of malignant nephrosclerosis (20).
Vascular effect of levonorgestrel intrauterine system on heavy menstrual bleeding: is it associated with hemodynamic changes in uterine, radial, and spiral arteries?
Published in Journal of Obstetrics and Gynaecology, 2021
Hanifi Şahin, Arif Güngören, Burak Sezgin, Burak Ün, Eda Adeviye Şahin, Kenan Dolapçioğlu, Rahime Nida Bayik
The arcuate arteries of the uterine were visualised in the sagittal plane (anterior or posterior) to obtain radial artery Doppler findings and the intramyometrial flow velocity waveforms were detected through the radial artery exit. Three consecutive waveforms were visualised, and the PI and RI were calculated. Using Doppler examination of the spiral artery, the subendometrial region is consisted of a 5-mm hyperechoic halo, surrounding the hyperechogenic margin (basal endometrium). Colour Doppler ultrasound was used to evaluate the blood flow of the subendometrial region with a pulse repetition frequency of 3 cm/s and a colour gain of 80 ± 2 to obtain the blood flow of the small vessels. The spectral (radiating) fluctuations were obtained from the high colour-density vessels. The continuity of these fluctuations was confirmed. Three similar consecutive waveforms were obtained to calculate the PI and RI of the spiral artery and the mean values were recorded.
Intrarenal resistive index conundrum: systemic atherosclerosis versus renal arteriolosclerosis
Published in Renal Failure, 2019
Gabriel Ștefan, Cosmin Florescu, Alexandru-Anton Sabo, Simona Stancu, Gabriel Mircescu
For Doppler ultrasonography examination a real-time ultrasound device with color Doppler capacity (Samsung HM70A) and a 3.5 MHz convex-type transducer (CA1-7AD) were used. The examination was performed early in the morning, after 8-h overnight fast, with the patient in supine position and after at least 15 min rest. The signals were obtained from interlobar and arcuate arteries in the upper, middle, and lower parts of the kidney. The RRI was calculated as [(peak- systolic velocity – end-diastolic velocity)/peak systolic velocity]. The RRI value for each kidney was the mean of all 6 measurements. A mean RRI value was obtained for each patient by averaging the two kidneys’ mean RRIs (Spearman correlation coefficient between the two kidneys RRI measurements was 0,95, p < 0.001). The use of antihypertensive medication was not suspended before RRI measurement. Ultrasonographic examination that included RRI assessment was performed the day before the renal biopsy. In order to avoid inter-observer variability, all Doppler examinations were performed by the same examiner who was unaware of the study or the clinical details of the patients.
Arcuate artery calcification on transvaginal sonography may predict coronary artery heart disease
Published in Journal of Obstetrics and Gynaecology, 2019
Mustafa Sengul, Emre Ekmekci, Emine Demirel, Raziye Torun, Nihan Kahya Eren, Sefa Kelekci
Uterine artery calcification was first described by Camiel et al. (1967) during the withdrawal of pelvic radiographs and they reported uterine artery calcifications to be a marker of atherosclerotic disease. The main branches given off by uterine arteries divide into anterior and posterior arcuate arteries, which traverse the uterine myometrium to anastomose with arcuate branches from the contralateral side. Along with their course, the arcuate arteries give off radial branches that penetrate the uterine wall and terminate as basal arteries to provide blood supply to the endometrium (Occhipinti et al. 1991). Arcuate arterial calcification manifests as symmetric, hyperechoic foci with acoustic shadowing at the periphery of the uterine myometrium.