Estudo do padrão arterial de 200 pedículos renais por meio de angiotomografias

Aspects of renal function and renal artery anatomy as indications for renal denervation

Renal denervation (RDN) is a minimally invasive, endovascular catheter-based procedure using radiofrequency, ultrasound, or alcohol-mediated ablation to treat resistant hypertension. As more attention is focused on the renal sympathetic nerve as a cause and treatment target of hypertension, understanding the anatomy of the renal artery may have important implications for determining endovascular treatment strategies as well as for future selection of devices and appropriate candidates for RDN treatment. However, the anatomical structure of the renal artery (RA) is complex, and standardized morphological evaluations of the RA structure are lacking. Computed tomography angiography or magnetic resonance angiography imaging is useful for assessing RA anatomy before conducting RDN. RA echocardiography is an established noninvasive screening method for significant stenosis. Major randomized controlled trials have limited enrollment to patients with preserved renal function, usually defined as an estimated glomerular filtration rate (eGFR) ≥ 45 mL/min/1.73 m2. Therefore, the level of renal function at which RDN is indicated has not yet been determined. This mini-review summarizes the characteristics of renal artery anatomy and renal function that constitute indications for renal denervation. (Role of Clinical Trials: K. Kario is an Executive Committee Principal Investigator for the Spyral OFF MED, the Spyral ON MED, the DUO and the REQUIRE; a Coordinating investigator for the TCD-16164 study; a Site Principal Investigator for the HTN-J, the Spyral OFF MED, the Spyral ON MED, the DUO, the REQUIRE and the TCD-16164 study). Evaluation of renal arteries for radiofrequency renal denervation. A Simultaneous quadrantal ablations at four sites in the main renal artery or the equivalent renal artery to the main renal artery. B If there is a renal artery branch with a diameter >3 mm in the middle of the main renal artery, this branch is the distal end of the main renal artery. In this case, four simultaneous and quadrantal ablations can be performed on the equivalent renal arteries. C Four simultaneous and quadrantal ablations can be performed in the branch renal artery. D Sonication should be spaced at least 5 mm (one transducer*) apart. Perform 2 to 3 mm proximal to the arterial bifurcation. Perform 2 to 3 mm distal to the abdominal aortic inlet.

Clinically important left superior polar artery giving rise to a left inferior suprarenal artery and an aberrant left inferior polar artery: a case report

The renal arteries arise from the lateral side of the abdominal aorta at the L2 vertebral level, just below the origin of the superior mesenteric artery. Multiple aberrant renal arteries can pose difficulties in renal transplantation, interventional radiological and urological procedures, renal artery embolization, angioplasty, or vascular reconstruction for congenital and acquired lesions. We present a case of a left kidney supplied by the left renal artery along with superior and inferior polar arteries, arising from the aorta and inferior mesenteric artery respectively. The inferior mesenteric artery was crossed by the left ureter and inferior mesenteric vein. The superior polar artery gave rise to an inferior suprarenal artery making the variation important for clinicians and surgeons.

Multidetector computed tomography angiography study of the renal arterial vasculature anatomy and its variations in a Bulgarian adult population

PURPOSE

Renal arterial anatomy has a great clinical importance during surgical and endovascular procedures. However, comprehensive data on renal arterial variations in the Bulgarian population has not yet been provided. The aim of this study was to conduct a detailed research about the normal anatomy and variations of the renal arteries in the Bulgarian population.

METHODS

Five hundred sixty-one patients underwent contrast-enhanced multidetector computed tomography scans for the period 2016-2021. The images were retrospectively reviewed. Number, branching pattern, origin level and course of the renal arteries were noted. Data were categorized on the basis of laterality, gender and symmetry.

RESULTS

Only 46.3% of the patients exhibited normal renal arterial anatomy. Variations were observed in 301 patients (53.7%). The most common variant was the presence of accessory renal arteries (ARA), discovered in 41.2% of the subjects. There was no significant difference based on gender and laterality (p > 0.05). Hilar ARA (72.6%) were significantly more common than polar ARA (p < 0.001). The most common origin location of the main renal arteries and ARA was the aorta, followed by the common iliac arteries. Early division was observed in 21.7% of the patients, significantly more common on the right. Precaval course was found in 0.5% of the right main renal arteries and in 30% of ARA and the difference was significant (p < 0.001).

CONCLUSION

These results show novel insight into the prevalence of renal arterial variations in the Bulgarian population. Anatomic renal vasculature variants are common therefore awareness is crucial for the success of surgical and interventional procedures.

Long-term outcomes of left versus right laparoscopic living donor nephrectomy with multiple renal arteries

OBJECTIVES

The objective of this study is to compare the long-term graft outcomes of left versus right donor nephrectomy with multiple renal arteries, and therefore creating a reference for the expansion of the potential living kidney donor pool.

METHODS

Laparoscopic live donor nephrectomy cases between May 2010 and October 2020 were included in this retrospective cross-sectional study. The data relating to donor and recipient demographics, surgical and anatomical characteristics, recipient and graft status were retrieved and compared using nonparametric statistical methods and multivariate regression. Analyses were fit for survival factors.

RESULTS

A total of 1009 recipients were included in this retrospective cross-sectional study with their donors. 16.7% of the donors had been discovered to have more than one renal artery supplying the donated kidney. The acute rejection rate was 12.8%. Death-censored graft survival at post-operative year 5 for single renal artery transplants was 89.6%, 89.5% for left-sided multiple renal arteries, and 88.2% for right-sided ones.

CONCLUSIONS

Both right donor nephrectomy and left donor nephrectomy are safe procedures with no significant negatively impacted rates for neither survival nor complications of the recipients in the long-term, compared to single renal artery ones.

Correlation between Renal Artery Anatomy and Hypertension: A Retrospective Analysis of 3000 Patients

Objective

To assess the correlation between renal artery anatomy and blood pressure in Undiagnosed Hypertension and Diagnosed Hypertension.

Methods

The renal artery CT scanning imaging data and laboratory data of 3000 inpatients and outpatients were collected retrospectively in 4 centers of China. Morphometric parameters were assessed using the quantitative vascular analysis (unit: mM).

Results

687 cases (23.2%) had accessory renal arteries unilaterally, and 216 cases (7.3%) had bilateral accessory renal arteries, including left kidney 825 (27.9%) and right kidney 798 (27.0%). The presence of accessory renal arteries and renal artery branches was higher in the diagnosed hypertension group as compared with the undiagnosed hypertension group (MARB, pp < 0.001; ARA, p < 0.001; others, p < 0.001). Consequently, multivariate regression analysis showed that age (OR = 2.519 (95% CI: 0.990–6.411, p < 0.001)), dyslipidemia (OR = 1.187 (95% CI: 0.960–1.454, p = 0.007)), renal hilum Outside the main renal artery branch (MRAB) (OR = 2.069 (95% CI: 1.614–2.524, p = 0.002)), and accessory renal artery (ARA) (OR = 2.071 (95% CI: 1.614–2.634, p = 0.001)) were risk factors of hypertension. In addition, higher renin activity was associated with ARA patients (2.19 ± 2.91 vs. 1.75 ± 2.85, p < 0.001).

Conclusions

When comparing renal arteries side by side, the anatomical length of the renal arteries is significantly different. In addition, the prevalence of accessory renal arteries and renal artery branches is higher in the hypertension group. The auxiliary renal artery and the main renal artery branch outside the renal portal are independent factors of hypertension. Renal sympathetic nerve activity is affected by renin activity and is related to the accessory renal artery.

Prevalence and Relevance of Multiple Renal Arteries: A Radioanatomical Perspective

Background: A single renal artery supplies the kidney in 70% of the population but variation exists in the remaining 30%. Multiple renal arteries (MRA) in different permutations and combinations are one of the many forms of variants. Lack of awareness of multiplicity could have detrimental effects on the outcome of renal surgery. The present study aims at identifying the variants of renal artery based on its origin, multiplicity, and portal of entry in a cohort of people belonging to Southern India and its clinical implications thereof.

Methods: Multi-detector CT (MDCT) images of renal vasculature of 100 kidneys from 50 live kidney donors who attended the Department of Nephrology of our institution, from 2016 to 2018 were collected and studied for variations in renal arterial anatomy.

Results: Out of the 18% of kidneys observed with multiple renal arteries, 88.8% had double renal arteries (DRA) and 11.1% had triple renal arteries (TRA). Common types of the double renal arteries were - two hilar arteries (31.3%) and one hilar with one inferior polar artery (IPA, 31.3%). Triple renal arteries types - 50% with one hilar, one superior polar, and one inferior polar; 50% with two hilar and one inferior polar artery. No statistically significant association was noted between the incidence of multiple renal arteries and its laterality (p-value=0.193).

Conclusion: A thorough understanding of the renal artery variants is crucial for safe and efficacious uro-radiological interventional procedures.

Renal artery variations in patients with mild-to-moderate hypertension from the RADIANCE-HTN SOLO trial

PURPOSE

To assess the variability of renal artery (RA) anatomy and presence of RA-pathology in patients with mild-to-moderate hypertension enrolled in the RADIANCE-HTN SOLO trial.

BACKGROUND

RADIANCE-HTN SOLO was a multicenter, international, blinded, randomized, sham-controlled trial evaluating ultrasound-based endovascular renal denervation (RDN) in patients with mild-to-moderate hypertension while off antihypertensive medications.

METHODS

Eligible subjects had pre-randomization renal CT- or MR- angiography (CTA, MRA) to confirm anatomic suitability and to define RA ablation sites. All images were sent for independent review for evaluation of RA anatomy and other vascular pathology.

RESULTS

A total of 324 patients underwent RA imaging (282 CTA and 42 MRA). Of those, 178 had simple anatomy with a single left and single right RA with mean diameters of 5.4 ± 0.9 and 5.1 ± 0.8 mm and mean lengths of 40.0 ± 12.9 and 52.0 ± 13.1 mm, respectively. Twenty-seven patients (8.3%) had unilateral or bilateral dual RAs with mean diameters of 4.0 ± 0.9 mm on the left and 3.9 ± 0.9 mm on the right. Forty percent (129/324) of patients had at least 1 accessory RA, with mean accessory diameters of 2.4 ± 0.8 mm on the left and 2.3 ± 0.8 mm on the right. Twenty-eight patients (8.6%) had at least 1 short (<25 mm) main RA. Incidental findings included: 9 patients (2.8%) with atherosclerotic RA stenosis ≥30%, 9 patients (2.8%) with fibromuscular dysplasia of RA and 2 patients (0.6%) with kidney and adrenal gland tumors.

CONCLUSIONS

Pre-procedure CTA or MRA imaging is a valuable aid in assessing RA anatomy prior to RDN because of variable RA anatomy. CTA or MRA may detect RA lesions, and renal or adrenal tumors which may need additional workup prior to consideration of RDN.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov NCT02649426.

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.

Retrospective Analysis of the Comparison Between Single Renal Artery Versus Multiple Renal Arteries in Living Donor Kidney Transplant: Does It Affect the Outcome?

OBJECTIVES

There is an increased risk of vascular complications in kidney transplant for allografts with multiple renal arteries versus a single renal artery. We compared the clinical outcomes of living donor kidney transplant recipients who received allografts with a single renal artery versus multiple renal arteries.

MATERIALS AND METHODS

This retrospective analysis included all living-related donor kidney transplants that were performed by a single skilled urologist. All donor nephrectomies were performed by open method. The left kidney was preferred over the right for donor nephrectomy, except in cases of vascular problems or other contraindications, for which the right kidney was preferred. In most of the cases, kidneys were placed in the right iliac fossa for transplant by an extraperitoneal approach.

RESULTS

Of 97 living donor kidney transplants, 82 had a single renal artery (group 1) and 15 had multiple renal arteries (group 2). Patients ranged in age from 18 to 76 years old. Recipient ages (33.00 vs 29.46 years) and baseline serum creatinine values (8.61 vs 8.82 mg/dL) were comparable in groups 1 and 2 (P > .05). However, mean operative time and total ischemia time were significantly higher in the multiple renal artery group (221 and 53.45 minutes, respectively) compared with the single renal artery group (202 and 77.6 minutes, respectively). Graft survival at 1 year was 95.12% in the single renal artery group and 93.33% in the multiple renal artery group. Patient survival at 1 year was 96.34% in the single renal artery group and 93.33% in the multiple renal artery group.

CONCLUSIONS

The safety of kidney transplants of allografts with multiple renal arteries is equal to the safety of transplants of allografts with a single renal artery in terms of vascular complications and acute tubular necrosis, as well as patient and graft survival.

QUANTITATIVE MORPHO-FUNCTIONAL ANALYSIS OF SIMMETRY-ASIMMETRY CONDITION OF HUMAN NORMAL KIDNEY

The aim of the present research was to perform quantitative morpho-functional analysis of the symmetry-asymmetry condition of human normal autopsy and “live” kidneys using the complex of morphological and ultra-sonographic methods. METHODS: Morphometric study of 10 autopsy kidneys of healthy men 36 - 60 years of age was conducted; retrospective analysis of data obtained by vital ultra-sonographic study of 65 kidneys of men without renal diseases at the same age period was performed as well. All kidneys were with a single renal artery. RESULTS: The kidney length and width are statistically significantly greater on right, than on left, but there were no statistically significant differences between right and left kidneys in thickness of the kidney and size of its parenchyma. Results of morphometric study of autopsy renal glomeruli, as well as multislice computed tomographic angiography and doppler investigation of renal artery in color duplex scan mode did not show any statistically significant differences on right and on left. CONCLUSIONS: For determining of the standard quantitative indicators of kidney it is necessary to take into account the age and gender of the studied people, as well as the effect of side.

Computed tomography evaluation of renal artery morphometry in adults. The impact of age and gender

OBJECTIVES

To determine the effect of age and gender on diameters and lengths of the renal arteries. Methods: This is a retrospective study. A total of 50 asymptomatic volunteers were selected randomly and scanned by multi-detector CT to assess the diameters and lengths of the renal arteries. The study conducted at King Abdulaziz Specialized Hospital (KAASH) and King Faisal Hospitals, Taif, Saudi Arabia between October 2017 and March 2018.  The lengths and diameters of the main arteries were measured and compared to age and gender of the participants. Results: The mean length of right renal artery was significantly longer than the left one (4.47±.70 versus 3.714±.68 cm, p less than 0.001). Length of right and left renal arteries were significantly higher in males than females (p=0.02 and p=0.03). Diameters of both left and right renal arteries were higher in males than females (5.482±1.37 versus 5.288±1.09 cm, and 5.544±1.14 versus 5.188±1.05 cm). The diameters of renal arteries varied significantly with age, specifically in elders (p=0.001).

CONCLUSION

The mean length and mean diameter were significantly different between females and males, and between left and right main renal arteries. Age and gender have a significant impact on the length and diameters of main renal arteries.

The Anatomy of Renal Arteries in Adults

Detailed extraparenhymal renal hilar dissection was performed on 110 fixed cadaveric kidneys (60 from male cadavers and 50 from female cadavers). We analyzed the number of renal arteries, angles between renal arteries and abdominal aorta, length and diameter of the renal arteries. Multiple renal arteries were present in 20.9% of cases, with a slightly higher incidence on the right side (21.8%: 20.0%). The angle between the aorta and the RRA varied from 30° to 100° with a mean of 64.1°, while the angle between the abdominal aorta and the LRA was 40° to 115°, with a mean of 67.3°. The external caliber of the RRA at the point of origin from the abdominal aorta was 5 mm to 9.1 mm, with a mean of 6.8 mm. The same caliber of the LRA was 3.7 to 9.6 mm with a mean of 7.0 mm. The average length of the renal artery from the point of origin from the abdominal aorta to the branching point was 36.2 mm for the right renal artery and 30.7 mm for the left renal artery. The average length of the renal artery from the point of origin from the abdominal aorta to the renal hilum was 65.1 mm for the right one and 54.7 mm for the left one. Knowledge of the number of renal arteries, their mode of entry into the kidney, the angles they build with the abdominal aorta, their diameter and length has practical applications in interventional radiology and surgery of the kidney and its environment.

Renal-aortic ratio as an objective measure of renal artery diameter a computed tomography angiography study

Background

Considering vital role of renal arteries in many surgical procedures, diameter of renal arteries seems to be an important measure of kidney perfusion. In this study, we analyzed a new parameter, renal-aortic ratio (R-Ar) as an objective measure of the renal artery diameter.

Method

The study included CT angiographic images from 254 patients (129 women and 125 men). R-Ar was calculated by dividing the diameter of the main renal artery for each kidney by the aortic diameter.

Results

R-Ar values for the whole study group ranged between 0.0863 and 0.5083; the ranges of R-Ar values for women and men patients were 0.1150–0.5083 and 0.0863–0.4449, respectively. In 412 cases (81.10%), the kidney was supplied by a single renal artery (RA variant) and in 96 (18.90%) by more than one artery (sRA variant). A significant difference was found in R-Ar values for RA and sRA variants (p = 0.0008). When the anatomical variant of renal perfusion was not considered on statistical analysis, a significant difference was found between the R-Ar values for women and men (p = 0.0259). No statistically significant difference was observed in R-Ar values for the right and left kidneys (p = 0.3123). Spearman’s coefficient of rank correlation between patient age and renal-aortic ratio values for the whole study group equaled − 0.36.

Conclusion

The analysis of the renal-aortic ratio values demonstrated that the diameter of renal arteries depended primarily on their number, and the relative diameter of renal arteries in women was larger than in men.

Renal artery anatomy assessed by quantitative analysis of selective renal angiography in 1,000 patients with hypertension

AIMS

With increasing attention to renovascular causes and targets for hypertension there arises a critical need for more detailed knowledge of renal arterial anatomy. However, a standardised nomenclature is lacking. The present study sought to develop a standardised nomenclature for renal anatomy considering the complexity and variation of the renal arterial tree and to assess the applicability of the nomenclature.

METHODS AND RESULTS

One thousand hypertensive patients underwent invasive selective renal artery angiography in nine centres. Further, renovasography was performed in 249 healthy swine as a surrogate for normotensive anatomy. Anatomical parameters were assessed by quantitative vascular analysis. Patients' mean blood pressure was 168/90±26/17 mmHg. The right main renal artery was longer than the left (41±15 mm vs. 35±13 mm, p<0.001), but the left had a greater diameter (5.4±1.2 vs. 5.2±1.2 mm, p<0.001). Accessory renal arteries and renal artery disease were documented in 22% and 9% of the patients, respectively. Other than exhibiting a longer left main renal artery in uncontrolled hypertensives (+2.7 mm, p=0.034) there was no anatomical difference between patients with controlled and uncontrolled hypertension. Main renal artery mean diameter was smaller in patients with impaired kidney function (GFR <90 ml/min, left -0.5 mm, right -0.4 mm, both p<0.001).

CONCLUSIONS

Renal arterial anatomy differs between sides but shows no difference between patients with and without blood pressure control. Impaired GFR was associated with small main renal artery diameter.

Geographic Distribution of Multiple Arteries and Veins of 878 Kidney Donors From a Transplant Center in Turkey

AIM

The diagnosis and management of multiple renal arteries and veins have gained importance with the increasing number of kidney transplantations and improved techniques in interventional radiology and vascular reconstructions. The aim of this study is to define and to detect the rate of multiple renal arteries and veins in our living kidney transplant donors coming from all parts of our country.

METHODS

Abdominal computed tomography angiogram findings of 878 kidney transplant donors were analyzed. The presence and the distribution of multiple renal arteries and veins in donors coming from 7 geographic regions in Turkey were noted.

RESULTS

The presence of multiple renal arteries was observed in 34% (48/141) of patients in the Marmara Region, 36.7% (79/215) of patients in the Black Sea Region, 37.2% (64/172) of patients in the Central Anatolia Region and 36.1% (30/83) of patients in the Southeastern Anatolia Region. The highest incidences of multiple renal arteries were observed in the Mediterranean and Aegean regions, affecting 40% (32/80) and 41.9% (26/62) of patients, respectively, while East Anatolia was found to have the lowest incidence, affecting 28% (35/125) of patients. The incidence of multiple renal veins also varied across regions. The highest incidence was observed in the Central Anatolia Region, where 23.3% (40/172) of patients were affected; the lowest was seen in the Aegean Region, where 11.3% (7/62) of patients were affected. In Turkey as a whole, 35.8% (314/878) of patients presented with multiple renal arteries, while the rate of multiple renal veins was found to be 19% (167/878) among our donors.

CONCLUSIONS

As 80% of the kidney transplantations performed in Turkey involve living donors, we think it will be useful to have knowledge of not only the presence of multiple renal arteries and veins, but also the distribution of this feature throughout the different regions of the country.

Morphological and clinical aspects of the occurrence of accessory (multiple) renal arteries

Renal vascularization variants vastly differ between individuals due to the very complex embryogenesis of the kidneys. Moreover, each variant may have implications for clinical and surgical interventions. The number of operating procedures continues to grow, and includes renal transplants, aneurysmorrhaphy and other vascular reconstructions. In any surgical technique, unawareness of the presence of multiple renal arteries may result in a fatal outcome, especially if laparoscopic methods are used. The aim of this review is to comprehensively identify the variation within multiple renal arteries and to highlight the connections between the presence of accessory renal arteries and the coexistence of other variants of vascularization. Another aim is to determine the potential clinical implications of the presence of accessory renal arteries. This study is of particular importance for surgeons, intervention radiologists, nephrologists and vascular surgeons.

Analysis of renal artery morphometery in adults: A study conducted by using Multidetector computed Tomography Angiography

Objective:

To determine a reference range of renal artery measurements by using Multidetector Computed Tomography (MDCT) angiography and to find association of renal artery measurements with side of artery, gender and age.

Method:

Two hundred and fifty study participants without renal artery disease who werepresented to Radiology Department, Ziauddin Hospital, Karachi, from November, 2016 to April, 2017 were included in this study. Main renal artery measurements were taken on Multidetector computed angiography and variation with side, gender and age were analyzed. Statistical analysis was done on Statistical Package for Social Sciences (SPSS) version 20. Independent sample T test, one way ANOVA and Pearson’s correlation analysis were applied. P-value of < 0.05 was considered significant.

Results:

A significance difference (p=0.001) was seen between mean right renal artery (diameter 6.66 ± 0.39 mm; length 44.69 ± 2.48 mm) and left renal artery (diameter 6.79 ± 0.36; length 35.10 ± 2.86 mm). Females found to have smaller mean diameter and length of renal arteries than males. However, a weak negative correlation was seen between mean renal artery diameter and age (right r= -0.158, p=0.0121; left r= -0.017, p= 0.708).

Conclusion:

The mean diameter and mean length were found to be significantly different between right and left main renal artery and between males and females. A significant weak negative correlation was observed between renal artery diameter and age.

Anatomical variations of the renal arterial vasculature: An Australian perspective

INTRODUCTION

Variations of the renal arteries have been studied and published across various population groups, but similar information for the ethnically diverse nation of Australia is lacking. This study describes the pattern of renal artery anomalies in a section of the Australian population based on computed tomography (CT) angiograms of the abdomen and cadaveric dissection.

METHODS

The renal arterial vasculature of 594 kidneys from 300 subjects (28 cadavers, 272 CT) was studied. The number and pattern of renal arteries were categorised on the basis of laterality, point of origin and termination in the kidney (superior pole, hilum and inferior pole), symmetry and sex.

RESULTS

Multiple renal arteries were discovered in 22% of subjects and 12.12% of kidneys. The most common pattern observed was the presence of one variant renal artery (93.1%), compared to the finding of two (5.6%) and three (1.4%) multiple arteries. The aorta was the most frequent site of origin for anomalous vessels, while the hilum was the predominant point of entry. No significant difference was established between left- and right-sided kidneys (13.8% vs. 12.5%; P = 0.627); however, unilateral distribution was more common than bilateral additional renal arteries (16.7% vs. 3.4%; P < 0.01), and variations among males were more than females (27.2% vs. 15.2%; P < 0.05). A higher rate of multiple renal arteries was noted in cadaveric dissections compared to CT images (46.4% vs. 19.5%; P < 0.01).

CONCLUSION

These findings provide application of an evidence-based teaching tool that facilitates education regarding renal arterial variations in Australia.

Multidetector computed tomography angiography of the renal arteries: normal anatomy and its variations

Conventional angiography is still considered the gold standard for the study of the anatomy and of vascular diseases of the abdomen. However, the advent of multidetector computed tomography and techniques of digital image reconstruction has provided an alternative means of performing angiography, without the risks inherent to invasive angiographic examinations. Therefore, within the field of radiology, there is an ever-increasing demand for deeper knowledge of the anatomy of the regional vasculature and its variations. Variations in the renal vascular system are relatively prevalent in the venous and arterial vessels. For various conditions in which surgical planning is crucial to the success of the procedure, knowledge of this topic is important. The aim of this study was to familiarize the general radiologist with variations in the renal vascular system. To that end, we prepared a pictorial essay comprising multidetector computed tomography images obtained in a series of cases. We show patterns representative of the most common anatomical variations in the arterial blood supply to the kidneys, calling attention to the nomenclature, as well as to the clinical and surgical implications of such variations.

Accessory (multiple) renal arteries - Differences in frequency according to population, visualizing techniques and stage of morphological development

The aim of this paper is to comprehensively analyze the literature focused on frequency of the presence of the accessory renal arteries in the human body. A systematic analysis of papers has been made. With regard to ethnicity, the incidence of accessory renal arteries fluctuates from 4% in a Malaysian population to 61.5% in a Brazilian population. The frequency is lowest in eastern and southern Asia (from 4% to 18.4%). In some, not ethnically homogenous populations, wide span of occurrence of accessory renal arteries is described (e.g. American - averaging from 18% to 28.8%). A higher frequency of accessory renal arteries was observed in fetuses compared to adults. Moreover, differences in the presence and number of accessory renal arteries reported in different papers are a consequence of type of visualizing technique used in research - especially when computed tomography and anatomical dissection were compared. The increasing number of surgical interventions, especially where laparoscopic methods are concerned, underlines the importance of such knowledge especially to surgeons, interventional radiologists, nephrologists, and vascular surgeons.

Retrospective morphometric study of the suitability of renal arteries for renal denervation according to the Symplicity HTN2 trial criteria

OBJECTIVE

The aim of this study was to describe the renal arteries of humans in vivo, as precisely as possible, and to formulate an expected value for the exclusion of renal denervation due to the anatomical situation based on the criteria of the Symplicity HTN trials.

DESIGN AND SETTING

In a retrospective cohort study, the renal arteries of 126 patients (57 women, 69 men, mean age 60 ± 17.2 years (CI 57.7 to 63.6)) were segmented semiautomatically from high-contrast CT angiographies.

RESULTS

Among the 300 renal arteries, there were three arteries with fibromuscular dysplasia and one with ostial renal artery stenosis. The first left renal artery was shorter than the right (34 ± 11.4 mm (CI 32 to 36) vs 45.9 ± 15 mm (CI 43.2 to 48.6); p<0.0001), but had a slightly larger diameter (5.2 ± 1.4 mm (CI 4.9 to 5.4) vs 4.9 ± 1.2 mm (CI 4.6 to 5.1); p>0.05). The first left renal arteries were 1.1 ± 0.4 mm (CI 0.9 to 1.3), and the first right renal arteries were 0.3 ± 0.6 mm (CI 0.1 to 0.5) thinner in women than in men (p<0.05). Ostial funnels were up to 14 mm long. The cross-sections were elliptical, more pronounced on the right side (p<0.05). In 23 cases (18.3%), the main artery was shorter than 2 cm; in 43 cases (34.1%), the diameter was not >4 mm. Some 46% of the patients, or 58.7% when variants and diseases were taken into consideration, were theoretically not suitable for denervation.

CONCLUSIONS

Based on these precise measurements, the anatomical situation as a reason for ruling out denervation appears to be significantly more common than previously suspected. Since this can be the cause of the failure of treatment in some cases, further development of catheters or direct percutaneous approaches may improve success rates.