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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
Roughly a quarter of the cardiac output is supplied to the kidneys via the paired renal arteries. They branch from the aorta at the level of L2 just below the origins of the superior mesenteric (SMA) and adrenal arteries. The right artery passes behind the inferior vena cava (IVC) first, in contrast to the left, which passes almost directly to the kidney. Before entering the hilum, each artery initially gives off a single posterior segmental branch that passes behind the renal pelvis to supply the posterior aspect of the kidney. It can cause obstruction of the pelvi-ureteric junction if it passes in front of the ureter. After entering the hilum, the artery commonly divides into four anterior segmental branches (apical, upper, middle and lower). The divisions and blood supply of the anterior and posterior segmental arteries give rise to a longitudinal avascular plane, known as Brodel’s line, 1–2 cm posterior to convex border of the kidney. Segmental arteries give rise to lobar arteries within the renal sinus, which become interlobar arteries that lie in between the Columns of Bertin in the parenchyma. These give off arcuate branches, which become the interlobular arteries that eventually form the afferent arteries of the glomeruli. The renal vein lies in front of the artery in the renal hilum. The right vein is 2–4 cm in length in comparison to the left, which may be up to 10 cm. The left renal vein reaches the IVC by passing behind the SMA and in most cases in front of the aorta.
Urinary system
Published in A Stewart Whitley, Jan Dodgeon, Angela Meadows, Jane Cullingworth, Ken Holmes, Marcus Jackson, Graham Hoadley, Randeep Kumar Kulshrestha, Clark’s Procedures in Diagnostic Imaging: A System-Based Approach, 2020
A Stewart Whitley, Jan Dodgeon, Angela Meadows, Jane Cullingworth, Ken Holmes, Marcus Jackson, Graham Hoadley, Randeep Kumar Kulshrestha
The kidneys are supplied with blood by the right and left renal arteries, which arise from the lateral aspect of the aorta at around the level of the first lumbar vertebra, just below the origin of the superior mesenteric artery (Fig. 7.13b). Each kidney is usually supplied by a single main artery (Fig. 7.13c) but, not uncommonly, additional segmental arteries may arise directly from the aorta to supply parts of the kidney. The main renal artery divides into two or three lobar arteries, which further divide into segmental arteries, then interlobar arteries, with further divisions into the arcuate and interlobular arteries. The interlobular vessels feed into the afferent arterioles, which supply the glomeruli. After filtration, the blood leaves the glomeruli via efferent arterioles, which drain, in a similar distribution pattern to the afferent arterioles, into interlobular, arcuate and interlobar veins, through to the segmental and lobar veins, which finally drain into the main renal vein that carries blood to the inferior vena cava (IVC). The left renal vein normally passes over the anterior aspect of the aorta to enter the IVC. The left renal vein can sometimes pass behind the aorta to drain into 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.
Effect of inflammation on cytochrome P450-mediated arachidonic acid metabolism and the consequences on cardiac hypertrophy
Published in Drug Metabolism Reviews, 2023
Mohammed A. W. ElKhatib, Fadumo Ahmed Isse, Ayman O. S. El-Kadi
Regarding 18-HETE, it was found almost entirely in the neutral lipid part of the renal cortex (Carroll et al. 1997). It is intriguing to know that a direct association is established between increased 18-HETE levels and insulin resistance in the microvasculature. Also, it has been revealed that elevated levels of 18-HETE are correlated with aberrated vascular recruitment in the skeletal muscles. Subsequently, 18-HETE may be involved in insulin resistance (Chadderdon et al. 2016). In spontaneously hypertensive rats, enhanced phenylephrine vasoconstriction in the renal interlobar arteries has been ascribed to vasoregulatory response due to reduced vascular CYP2E1-generated 18(R)-HETE (Zhang F et al. 2005). This calls for further studies illuminating the roles of 17-HETE and 18-HETE in health and diseases, especially CVDs.
Basic hemodynamics and noninvasive cardiac output (Bioimpedance ICON Cardiometer): A diagnostic reliability during percutaneous nephrolithotomy bleeding under spinal anesthesia
Published in Egyptian Journal of Anaesthesia, 2021
Mohamed A. Ghanem, Ahmed S. El-Hefnawy
One of the most bothersome complications of PNL is haemorrhage. Direct access to the pelvicalyceal system and intrarenal manipulation during PNL procedures cause injury to the renal vasculature, particularly to the segmental and interlobar arteries. The renal-collecting system is rich in vascularization, covering 20% of the total cardiac output, and often results in haemorrhage during PCNL [26] many of the haemorrhage cases during PNL could be managed conservatively, however, 0.8% patients required a more invasive procedure to deal with the bleeding [27]. PNL operation caries risk of other haemodynamic instability saturations due to many factors such as; it necessitates high-level spinal anaesthesia, it is associated with progressive creeping silent unmeasurable arterial bleeding, it is done in prone position which augments haemodynamic instability in a difficult resuscitation position.
A 9.5-year-old boy with recurrent neurological manifestations and severe hypertension, treated initially for polyarteritis nodosa, was subsequently diagnosed with adenosine deaminase type 2 deficiency (DADA2) which responded to anti-TNF-α
Published in Paediatrics and International Child Health, 2020
Sezgin Sahin, Amra Adrovic, Kenan Barut, Selen Baran, Eda Tahir Turanli, Nur Canpolat, Osman Kizilkilic, Ozan Ozkaya, Ozgur Kasapcopur
Investigations. Haemoglobin was 9.8 g/dL, haematocrit 31.6%, MCV 59.6 fl, platelets 230 × 109/L, leucocytes 10.7 × 109/L [neutrophils 58%, polymorphonuclear leucocytes (PNL) lymphocytes, 31.0% and monocytes 10.0%]. Erythrocyte sedimentation rate (ESR) was 94 mm/h (<20) and C-reactive protein (CRP) 234 mg/L (<10). Owing to widespread myalgia, muscle enzymes were estimated but were within normal limits, as were analyses of electrolytes, liver and renal function and D-dimer levels. Screening tests for thrombophilia did not yield any tendency to thrombosis. Components of cell-mediated immunity and serum IgA (178 mg/dL), IgM (131 mg/dL) and IgE (20 mg/dL) were within normal limits. However, serum IgG was 1933 mg/dL (reference range for Turkish children aged 9 is 646–1620 [17]. Electromyography and nerve conduction studies of lower limbs demonstrated asymmetrical axonal polyneuropathy. There was no response to visual evoked potential and electroretinogram tests of the right eye. While brain MRI findings were compatible with hypertensive encephalopathy in the left prefrontal cortex, electroencephalography was normal. Conventional cranial and visceral angiography was performed to elucidate the malignant hypertension and neurological findings. Angiography of brain was normal. However, visceral angiography demonstrated irregularities and stenosis in some of the branches of the inferior mesenteric artery and renal interlobar arteries bilaterally (Figures 1 and 2).