Morphometry and skeletopy of kidneys and renal vessels in marmoset (Callithrix spp.).

BACKGROUND: Marmosets, Callithrix spp, are small New World monkeys that have gained importance as an experimental animal model for human. Despite its use, information on its renal morphometry, vascularization, and location are limited. Therefore, this study will supply basic anatomy for applied studies and for comparative anatomy. METHODS: Fifty cadavers of Callithrix spp were collected on highways from the Atlantic Forest biome, identified and injected with a 10% formaldehyde solution. Later, the specimens were dissected and the measurements and topography of the kidneys and renal vessels were recorded. Both left and right kidneys were significantly larger in females. RESULTS: In the specimens studied, the average body length was 20.00 ± 2.46 cm in males and 20.50 ± 1.98 cm in females (p = .43). The kidneys of the Callithrix spp. were symmetrical in shape and resembled a "bean." They were also pale brown with a smooth surface. In males, the most frequent location of the right kidney was at the L1-L2 level (92%), while the location of the left kidney was between L2 and L3 (76%). In females, the most frequent location of the right kidney was at the L1-L2 level (56%), while the location of the left kidney was between L2 and L3 (32%) (Table 1). However, in seven (28%) males and nine (36%) females, the kidneys were at the same level. CONCLUSIONS: In both sexes, there was a positive and significant linear correlation between body length and kidney length. Regardless of the variable location of the kidneys in both sides and in either sexe, the right kidney was always located more cranially than the left, similar to observations in other non-human primates.

Development of the renal vasculature.

The kidney vasculature has a unique and complex architecture that is central for the kidney to exert its multiple and essential physiological functions with the ultimate goal of maintaining homeostasis. An appropriate development and coordinated assembly of the different vascular cell types and their association with the corresponding nephrons is crucial for the generation of a functioning kidney. In this review we provide an overview of the renal vascular anatomy, histology, and current knowledge of the embryological origin and molecular pathways involved in its development. Understanding the cellular and molecular mechanisms involved in renal vascular development is the first step to advance the field of regenerative medicine.

The Cerebro-Renal System- Anatomical and Physiological Considerations.

The brain and kidney both uniquely are highly susceptible to vascular injury from shared vascular risk factors. However these are not sufficient to explain the complete extent of cerebrovascular disease especially small vessel disease in its myriad presentations that patients with chronic kidney disease manifest. They both require a large amount of blood supply to function optimally. Shared anatomical and physiological factors such as the presence of strain vessels, the local vascular autoregulation that control blood supply possible, results in the vulnerability of these organs to the vascular risk factors. Because it is a bidirectional system where each affects the other, it is best considered as a cerebro-renal unit.

Cadaveric study of arterial renal anatomy and its surgical implications in partial nephrectomy.

PURPOSE: Partial nephrectomy is gaining, nowadays, more interest in oncologic kidney surgery. This type of surgery requires the good knowledge of vascular renal anatomy to make it safe and to guarantee good functional and oncological outcomes. This paper exposes the clinical implication of the arterial renal anatomy in nephron-sparing surgery. METHODS: This is a cadaveric study of 71 human kidneys performed at Charles Nicolle mortuary. The right and left kidneys with surrounding tissues were removed en bloc with the adjacent part of the aorta and inferior vena cava, cleared and studied. Colored resin was injected in each artery, vein, and urinary ducts, with a specific color code for each structure. Corrosion technique was used to eliminate the surrounding tissue, leaving only the colored resin matrix. The Ternon anatomic classification of the inferior polar artery, based on its emergence point was used. RESULTS: Multiple renal arteries were noted in 9.85% of casts. Anterior and posterior division of main renal artery was found in 95.7% of cases. Posterior segmental artery crossed posteriorly the upper caliceal infundibulum and the renal pelvis in 93% of cases. The upper renal pole was vascularized by an apical segmental artery in 16.9% of cases and a superior polar artery in one case (1.4%). The mid pole of the kidney was supplied by a unique anterior branch and a single posterior branch in 40% of cases. Inferior polar artery was found in 52 casts (73.23%). Type I of Ternon was found in 6 casts (11.53%), Type II in 25 cases (48.07%), Type III in 19 cases (36.53%), Type IV in 2 cases (3.84%), and type V in 13 casts (25%). CONCLUSION: Renal vascular anatomy presents large variations. Good knowledge of the segmental arterial anatomy of the kidney is a primordial to a safe partial nephrectomy. Good preoperative vascular mapping can be of great help for the surgeon.

Low-dose CT angiography using ASiR-V for potential living renal donors: a prospective analysis of image quality and diagnostic accuracy.

PURPOSE: To assess image quality and diagnostic accuracy of low-dose computed tomography (CT) angiography using adaptive statistical iterative reconstruction V (ASiR-V) for evaluating the anatomy of renal vasculature in potential living renal donors. MATERIALS AND METHODS: Eighty of 100 potential living renal donors were prospectively enrolled and underwent multiphase CT angiography (e.g., unenhanced, arterial, and venous phases) to evaluate the kidney for donation. Either low-dose using ASiR-V or standard protocol was randomly applied. Image quality was analyzed qualitatively and quantitatively with contrast-to-noise ratio (CNR) and signal-to-noise ratio (SNR). Renal artery and vein number, early branching vessel from renal arteries, and drainage of left-sided ascending lumbar vein to left renal vein were assessed. Reference standard for renal vasculature was surgical confirmation. RESULTS: Size-specific dose estimate of low-dose CT angiography (9.5 ± 0.8 mGy) was significantly lower than standard CT angiography (22.7 ± 4.1 mGy) (p < 0.001). Thus, radiation dose was reduced by 58.2% with low-dose CT. Both CNR and SNR of low-dose CT were significantly higher than those of standard CT (p < 0.001). Between the two CT methods, image quality was similar qualitatively (p > 0.05). Of 80 participants, 44 (55.0%) underwent nephrectomy. Both CT methods accurately predicted the anatomy of renal vasculature (standard CT, 100% for all variables; low-dose CT, 96.6% for renal vessel number or early branching vessel and 85.7% for drainage of left-sided ascending lumbar vein to left renal vein; p > 0.05 for all comparisons). CONCLUSION: Low-dose CT angiography using ASiR-V is useful to evaluate renal vasculature for potential living renal donors. KEY POINTS: • In this prospective study, adaptive statistical iterative reconstruction V (ASiR-V) allowed 58.2% dose reduction while maintaining diagnostic image quality for renal vessels. • As compared with the standard protocol, the dose with ASiR-V was significantly lower (9.5 ± 0.8 mGy) than with standard computed tomography (CT) angiography (22.7 ± 4.1 mGy). • Low-dose CT using ASiR-V is useful for living donor evaluation before nephrectomy.

Safe exposure of the left renal vein during laparoscopic distal pancreatectomy for pancreatic ductal adenocarcinoma: anatomical variations and pitfalls.

PURPOSE: The left renal vein is technically difficult to expose during laparoscopic distal pancreatectomy for pancreatic ductal adenocarcinoma despite being an important landmark for posterior dissection. We hereby propose a novel technique to safely expose the left renal vein while avoiding the associated anatomical pitfalls. METHODS: The anatomy of the left renal artery and vein was analyzed using multidetector computed tomography. We initially exposed the left renal vein on the left posterior side of the superior mesenteric artery followed by exposure toward the left kidney. We retrospectively examined the perioperative results of this technique in 33 patients who underwent laparoscopic distal pancreatectomy. RESULTS: 15.7% of the patients had an accessory left renal artery coursing cranial to the vein. In 43.1%, the left renal arterial branch ventrally traversed the vein at the renal hilum, thereby posing a risk for arterial injury. The location of the left renal vein varies cranial (17.6%) or caudal (82.4%) to the pancreas. The left renal vein was exposed without any vascular injury using this technique. The median operative time was 259 min, blood loss was 18 mL, and R0 resection rate was 97.0%. CONCLUSIONS: The initial exposure of the left renal vein should, therefore, be on the left posterior side of the superior mesenteric artery.

Renal fibromuscular dysplasia and hypertension. / Renal fibromuskulær dysplasi og hypertensjon.

Fibromuscular dysplasia affects the muscles of small and medium-sized arteries. The aetiology of the condition is unknown; it is most frequently seen in middle-aged women, but can affect both sexes at any age. Hypertension is the most common clinical manifestation when the renal arteries are affected. The diagnosis is made based on clinical suspicion and specific angiographic findings. The treatment is aimed at normalisation of blood pressure with the aid of drugs or through revacularisation.

A Study on Variations of Branching Pattern of Renal Artery with its Clinical Significance.

Background The kidneys are supplied by a single renal artery originating from abdominal aorta. However, recent literature reports great variations in renal blood supply. Hence, it becomes mandatory for the clinicians to understand the abnormality and variations in the renal vasculature. Objective To evaluate the branching pattern of renal artery and its variations. Method The study consisted of Computed Topographic images of 206 kidneys. Numbers and branching pattern of renal artery were recorded. The data was analyzed for presence or absence, source of origin and type of accessory renal artery. Result The present study revealed that 73.79% of kidneys were supplied by a single renal artery, 25.72% by double renal artery and 0.49% by triple renal artery. The hillar branching pattern was recorded in 38.83% and early branching pattern was in 34.95%. The presence of accessory renal artery was recorded in 26.21%. They were originated from abdominal aorta in 22.81% and 3.40% from main renal artery. The prevalence of superior polar artery was found in 6.79%, hilar in 10.19% and inferior polar in 9.22%. Conclusion The knowledge of variations of renal artery becomes essential for the clinician to plan the adequate surgical procedures and to avoid any vascular complication.

The size of the renal artery orifice contributes to laterality of acute renal infarction.

BACKGROUND: Acute renal infarction (ARI) is a rare disease with atrial fibrillation being its main cause. The possible laterality of ARI is controversial. This study aimed to evaluate the association between anatomical features of the renal arteries and ARI. METHODS: This was a single-center cross-sectional study that evaluated the anatomical and clinical features of renal arteries. The anatomical features of the renal arteries were assessed using computed tomography. RESULTS: A total of 46 patients (mean age 71.3 ± 14.0 years; men, 59%) were enrolled. ARI involved the left kidney in 63%, right kidney in 28%, and both kidneys in 9% of patients. The right renal artery orifice was often higher than that of the left renal artery (71%). The angle of divergence from the abdominal aorta was similar on both sides. The left renal artery orifice was larger than that of the right (83 ± 24, 72 ± 24 mm2; p = 0.03, respectively). A larger left orifice was present in 72% of all cases. ARI involved the side with the larger orifice in 64% of patients. CONCLUSION: The size of the renal artery orifice may be a factor that contributes to the laterality of ARI. Assessment of anatomical features is important when considering the laterality of the disease.

Does the type of renal artery anatomic variant determine the diameter of the main vessel supplying a kidney? A study based on CT data with a particular focus on the presence of multiple renal arteries.

BACKGROUND: An in-depth knowledge of renal vascular anatomy is essential when planning many surgical procedures; however, a few data exists regarding renal artery diameter. The aim of this study was to assess this morphological feature and to investigate whether a correlation exists between renal artery diameter and the type of arterial supply, with a particular emphasis on variant anatomy and the presence of multiple renal arteries. MATERIALS AND METHODS: Computed tomography angiography (CTA) studies of 248 patients, i.e., a total of 496 kidneys, were evaluated. The mean age of the patients was 66.4 ± 15.01 years. Renal artery diameter was measured based on the type of arterial blood supply. RESULTS: The frequency of occurrence of three anatomic variants of renal arterial supply was established: single renal artery (RA) 43.35%, single artery with prehilar branching (pRA) 37.30%, and multiple renal artery (mRA) 19.35%. The diameter of single renal arteries, with either prehilar or hilar branching, was significantly larger than when multiple arteries were present. A detailed analysis of just the mRA variant demonstrated that the diameter of the renal arteries in men was larger (p = 0.012) than those in women and that there was no difference in diameter with regard to the side of the body (p = 0.219). CONCLUSIONS: The classification described in our study containing a detailed description of renal artery diameter. It may be helpful in clinical practice, especially for transplantologists, surgeons, and vascular surgeons.

Variations of renal vascular anatomy in a nigerian population: A computerized tomography studys.

BACKGROUND: A broad spectrum of renal vascular variations has been reported by anatomists and radiologists. The prevalence of these variations is extremely divergent in different populations. Therefore, radiologists and surgeons in different climes must be knowledgeable about the type and prevalence of the variants in their area of practice to avoid diagnostic pitfalls and for optimization of surgical techniques. OBJECTIVE: The objective of this study is to describe the types and prevalence of renal vascular variations among patients undergoing contrast-enhanced computerized tomography (CECT) of the abdomen in a Nigerian population, as well as provide a concise review of literature on the embryological basis and clinical significance of the identified variations. MATERIALS AND METHODS: This study was a retrospective review of 200 CECT of the abdomen to identify variations of arterial (accessory, early branching, and precaval) and venous (multiple, retroaortic, and circumaortic) anatomy of the kidneys. RESULTS: We studied 200 patients, 102 (51%) females and 98 (49%) males. Age range is 18-90 years (mean = 53.08 ± 17.01). Prevalence of any renal vascular variations was 50%, arterial variations were 37%, and venous variations were 13%. Variations were significantly more common in males, P = 0.000075. The most common arterial variant was the accessory renal artery (23%) seen in 10% (right) and 13.0% (left); early branching was seen in 4.0% (right) and 0.5% (left) as well as precaval right renal artery seen in 4.5%. Venous variants were late confluence 3.0% (right) and 2.5% (left); multiple veins was seen in 2.5% (right) and 2.5% (left) as well as retroaortic left renal vein seen in 2.0%. The inferior polar accessory artery was the most prevalent accessory artery. Early arterial bifurcation was significantly more common on the right (P = 0.016) while other vascular variants showed no statistically significant association with laterality. CONCLUSION: Variation of renal vascular anatomy is a frequent finding among Nigerians. Radiologists and surgeons must be aware of these variants for optimization of surgical techniques.

Architecture of the rat nephron-arterial network: analysis with micro-computed tomography.

Among solid organs, the kidney's vascular network stands out, because each nephron has two distinct capillary structures in series and because tubuloglomerular feedback, one of the mechanisms responsible for blood flow autoregulation, is specific to renal tubules. Tubuloglomerular feedback and the myogenic mechanism, acting jointly, autoregulate single-nephron blood flow. Each generates a self-sustained periodic oscillation and an oscillating electrical signal that propagates upstream along arterioles. Similar electrical signals from other nephrons interact, allowing nephron synchronization. Experimental measurements show synchronization over fields of a few nephrons; simulations based on a simplified network structure that could obscure complex interactions predict more widespread synchronization. To permit more realistic simulations, we made a cast of blood vessels in a rat kidney, performed micro-computed tomography at 2.5-µm resolution, and recorded three-dimensional coordinates of arteries, afferent arterioles, and glomeruli. Nonterminal branches of arcuate arteries form treelike structures requiring two to six bifurcations to reach terminal branches at the tree tops. Terminal arterial structures were either paired branches at the tops of the arterial trees, from which 52.6% of all afferent arterioles originated, or unpaired arteries not at the tree tops, yielding the other 22.9%; the other 24.5% originated directly from nonterminal arteries. Afferent arterioles near the corticomedullary boundary were longer than those farther away, suggesting that juxtamedullary nephrons have longer afferent arterioles. The distance separating origins of pairs of afferent arterioles varied randomly. The results suggest an irregular-network tree structure with vascular nodes, where arteriolar activity and local blood pressure interact.

Anatomical study of renal arterial vasculature and its potential impact on partial nephrectomy.

OBJECTIVES: To validate Graves' classification of the intrarenal arteries and to verify the absence of collateral arterial blood supply between different renal segments, in order to maximize peri-operative and functional outcomes of partial nephrectomy. MATERIALS AND METHODS: The study was performed on 15 normal kidneys sampled from eight unembalmed cadavers. Kidneys with the surrounding perirenal fat tissue were removed en bloc with the abdominal segment of the aorta. The renal artery was injected with acrylic and radiopaque resins, with the specimen suspended in water. CT examination of the injected kidneys was performed to analyse the branches located deeply. After imaging acquisition, the specimens were treated with sodium hydroxide for removal of the parenchyma to obtain vascular casts. RESULTS: Ten casts (66.6%) showed the classic subdivision of the main artery into single posterior and anterior branches. With regard to the distribution of the segmental or second-order arteries, only two casts (13%) showed a pattern similar to that described by Graves, characterized by four segmental (second-order) branches coming from the anterior renal artery (apical, superior, middle and inferior). In the remaining 13 kidneys (87%) a different arterial vascular network was detected. In 10 casts (80%) a single renal segment was vascularized by two or more different branches coming from an artery leading to another segment (multiple vascularization). Multiple vascularization was observed in three (20%) apical segments, five (33%) superior segments, six (40%) middle segments, seven (47%) inferior segments and two (13%) posterior segments. CONCLUSIONS: This study shows that in the human kidneys the arterial vasculature is frequently different from that described by Graves. Moreover, in a significant percentage of cases, a single renal segment receives two or more branches that originate from an artery leading to another segment.

Modeling of Kidney Hemodynamics: Probability-Based Topology of an Arterial Network.

Through regulation of the extracellular fluid volume, the kidneys provide important long-term regulation of blood pressure. At the level of the individual functional unit (the nephron), pressure and flow control involves two different mechanisms that both produce oscillations. The nephrons are arranged in a complex branching structure that delivers blood to each nephron and, at the same time, provides a basis for an interaction between adjacent nephrons. The functional consequences of this interaction are not understood, and at present it is not possible to address this question experimentally. We provide experimental data and a new modeling approach to clarify this problem. To resolve details of microvascular structure, we collected 3D data from more than 150 afferent arterioles in an optically cleared rat kidney. Using these results together with published micro-computed tomography (µCT) data we develop an algorithm for generating the renal arterial network. We then introduce a mathematical model describing blood flow dynamics and nephron to nephron interaction in the network. The model includes an implementation of electrical signal propagation along a vascular wall. Simulation results show that the renal arterial architecture plays an important role in maintaining adequate pressure levels and the self-sustained dynamics of nephrons.

Changes in Renal Anatomy After Fenestrated Endovascular Aneurysm Repair.

OBJECTIVE: To assess short- and long-term movement of renal arteries after fenestrated endovascular aortic repair (FEVAR). METHODS: Consecutive patients who underwent FEVAR at one institution with a custom-made device designed with fenestrations for the superior mesenteric (SMA) and renal arteries, a millimetric computed tomography angiography (CTA), and a minimum of 2 years' follow-up were included. Angulation between renal artery trunk and aorta, clock position of the origin of the renal arteries, distance between renal arteries and SMA, and target vessel occlusion were retrospectively collected and compared between the pre-operative, post-operative (<6 months), and last (>12 months) CTA. RESULTS: From October 2004 to January 2014, 100 patients met the inclusion criteria and 86% of imaging was available for accurate analysis. Median follow-up was 27.3 months (22.7-50.1). There were no renal occlusions. A significant change was found in the value of renal trunk angulation of both renal arteries on post-operative compared with pre-operative CTA (17° difference upward [7.5-29], p < .001), but no significant change thereafter (p = .5). Regarding renal clock positions (7.5° of change equivalent to 15 min of renal ostial movement): significant anterior change was found between post-operative and pre-operative CTA (15 min [0-30], p = .03 on the left and 15 min [15-30], p < .001 on the right), without significant change thereafter (15 min [0-30], p = .18 on the left and 15 min [0-15] on the right, p = .28). No changes were noted on the distance between renal and SMA ostia (difference of 1.65 mm [1-2.5], p = .63). CONCLUSION: The renal arteries demonstrate tolerance to permanent changes in angulation after FEVAR of approximately 17° upward trunk movement and of 15-30 min ostial movement without adverse consequences on patency after a median of more than 2 years' follow-up. The distance between the target vessels remained stable over time. These results may suggest accommodation to sizing errors and thus a compliance with off the shelf devices in favourable anatomies.

Factors influencing the operating time for single-port laparoscopic radical nephrectomy: focus on the anatomy and distribution of the renal artery and vein.

OBJECTIVE: It is considered that laparoscopic single-site surgery should be performed by specially trained surgeons because of the technical difficulty in using special instruments through limited access. We investigated suitable patients for single-port laparoscopic radical nephrectomy, focusing on the anatomy and distribution of the renal artery and vein. METHODS: This retrospective study was conducted in 52 consecutive patients who underwent single-port radical nephrectomy by the transperitoneal approach. In patients undergoing right nephrectomy, a 2-mm port was added for liver retraction. We retrospectively re-evaluated all of the recorded surgical videos and preoperative computed tomography images. The pneumoperitoneum time (PT) was used as an objective index of surgical difficulty. RESULTS: The PT was significantly shorter for right nephrectomy than left nephrectomy (94 vs. 123 min, P = 0.004). With left nephrectomy, dissection of the spleno-renal ligament to mobilize the spleen medially required additional time. Also, the left renal vein could only be divided after securing the adrenal, gonadal and lumbar veins. In patients whose renal artery was located cranial to the renal vein, PT tended to be longer than in the other patients (131 vs. 108 min, P = 0.070). In patients with a superior renal artery, the inferior renal vein invariably covered the artery and made it difficult to ligate the renal artery via the umbilical approach at the first procedure. CONCLUSIONS: These findings indicate that patients undergoing right nephrectomy in whom the renal artery is not located cranial to the renal vein are suitable for single-port laparoscopic radical nephrectomy.

Computer-assisted study of the axial orientation and distances between renovisceral arteries ostia.

PURPOSE: Endovascular navigation in aortic, renal and visceral procedures are based on precise knowledge of arterial anatomy. Our aim was to define the anatomical localization of the ostia of renovisceral arteries and their distribution to establish anatomical landmarks for endovascular catheterization. METHODS: Computer-assisted measurements performed on 55 CT scans and patients features (age, sex, aortic diameter) were analyzed. p values <0.05 were considered statistically significant. RESULTS: The mean axial angulation of CeT and the SMA origin was 21.8° ± 10.1° and 9.9° ± 10.5°, respectively. The ostia were located on the left anterior edge of the aorta in 96 % of cases for the CeT and 73 % for the SMA. CeT and SMA angles followed Gaussian distribution. Left renal artery (LRA) rose at 96° ± 15° and in 67 % of cases on the left posterior edge. The right renal artery (RRA) rose at -62° ± 16.5° and in 98 % of cases on the right anterior edge of the aorta. RRA angle measurements and cranio-caudal RRA-LRA distance measurements did not follow Gaussian distribution. The mean distances between the CeT and the SMA, LRA, and RRA were 16.7 ± 5.0, 30.7 ± 7.9 and 30.5 ± 7.7 mm, respectively. CeT-SMA distance showed correlation with age and aortic diameter (p = 0.03). CeT-LRA distance showed correlation with age (p = 0.04). The mean distance between the renal ostia was 3.75 ± 0.21 mm. The RRA ostium was higher than the LRA ostium in 52 % of cases. RRA and LRA origins were located at the same level in 7 % of cases. CONCLUSION: Our results illustrate aortic elongation with ageing and high anatomical variability of renal arteries. Our findings are complementary to anatomical features previously published and might contribute to enhance endovascular procedures safety and efficacy for vascular surgeons and interventional radiologists.

Radiofrequency Ablation, MR Thermometry, and High-Spatial-Resolution MR Parametric Imaging with a Single, Minimally Invasive Device.

Purpose To develop and demonstrate in vitro and in vivo a single interventional magnetic resonance (MR)-active device that integrates the functions of precise identification of a tissue site with the delivery of radiofrequency (RF) energy for ablation, high-spatial-resolution thermal mapping to monitor thermal dose, and quantitative MR imaging relaxometry to document ablation-induced tissue changes for characterizing ablated tissue. Materials and Methods All animal studies were approved by the institutional animal care and use committee. A loopless MR imaging antenna composed of a tuned microcable either 0.8 or 2.2 mm in diameter with an extended central conductor was switched between a 3-T MR imaging unit and an RF power source to monitor and perform RF ablation in bovine muscle and human artery samples in vitro and in rabbits in vivo. High-spatial-resolution (250-300-µm) proton resonance frequency shift MR thermometry was interleaved with ablations. Quantitative spin-lattice (T1) and spin-spin (T2) relaxation time MR imaging mapping was performed before and after ablation. These maps were compared with findings from gross tissue examination of the region of ablated tissue after MR imaging. Results High-spatial-resolution MR imaging afforded temperature mapping in less than 8 seconds for monitoring ablation temperatures in excess of 85°C delivered by the same device. This produced irreversible thermal injury and necrosis. Quantitative MR imaging relaxation time maps demonstrated up to a twofold variation in mean regional T1 and T2 after ablation versus before ablation. Conclusion A simple, integrated, minimally invasive interventional probe that provides image-guided therapy delivery, thermal mapping of dose, and detection of ablation-associated MR imaging parametric changes was developed and demonstrated. With this single-device approach, coupling-related safety concerns associated with multiple conductor approaches were avoided. © RSNA, 2016 Online supplemental material is available for this article.

The gross anatomy of the renal sympathetic nerves revisited.

Catheter-based renal denervation techniques focus on reducing blood pressure in resistant hypertension. This procedure requires exact knowledge of the anatomical interrelation between the renal arteries and the targeted renal nervous plexus. The aim of this work was to build on classical anatomical studies and describe the gross anatomy and anatomical relationships of the renal arteries and nerve supply to the kidneys in a sample of human cadavers. Twelve human cadavers (six males and six females), age range 73 to 94 years, were dissected. The nervous fibers and renal arteries were dissected using a surgical microscope. The renal plexus along the hilar renal artery comprised a fiber-ganglionic ring surrounding the proximal third of the renal artery, a neural network along the middle and distal thirds, and smaller accessory ganglia along the course of the nerve fibers. The fibers of the neural network were mainly located on the superior (95.83%) and inferior (91.66%) surfaces of the renal artery and they were sparsely interconnected by diagonal fibers. Polar arteries were present in 33.33% of cases and the renal nerve pattern for these was similar to that of the hilar arteries. Effective renal denervation needs to target the superior and inferior surfaces of the hilar and polar arteries, where the fibers of the neural network are present. Clin. Anat. 29:660-664, 2016. © 2016 Wiley Periodicals, Inc.

Multiple variations of the renal and testicular vessels: possible embryological basis and clinical importance.

During routine dissection of the abdominal cavity of a 55-year-old African male cadaver, multiple anomalies including renal and testicular vessels were encountered. The right kidney was supplied by three right hilar renal arteries arising from the abdominal aorta at different vertebral levels whereas only one left renal artery supplied the left kidney. On the right three renal veins drained the kidney into the inferior vena cava. In contrast, the left kidney was drained by a single renal vein which received a large primary posterior tributary. The primary posterior tributary had three tributaries from the posterior lumbar region. The right testis had two sources of arterial supply; one from the subcostal artery and another from the abdominal aorta. The left testis was supplied normally by a single testicular artery. The right testis was drained by four testicular veins as follows: one drained into the subcostal vein, the other two drained separately for a longer course and joined shortly before draining into the right main renal vein, the fourth one drained into the anterior aspect of the inferior vena cava at the level of the second lumbar vertebra. On the left, the testicle was drained by two testicular veins which travelled separately from the deep inguinal ring and joined shortly before they drain into the left renal vein. This variation may represent an immature form of complicated development of kidneys and testes. Additionally, emphasis must be put on preoperative vascular examination to avoid surgical complications from variant vessels in this region.