Renal arteries: anatomic study for surgical and radiological practice

Percutaneous antegrade management of large proximal ureteral stones using non-papillary puncture

Objective

To evaluate the feasibility and the safety of medial non-papillary percutaneous nephrolithotomy (npPCNL) for the management of large proximal ureteral stones.

Methods

We evaluated prospectively collected data of 37 patients with large proximal ureteral stones more than 1.5 cm in diameter treated by prone npPCNL. Depending on stone size, in-toto stone removal or lithotripsy using the Lithoclast® Trilogy (EMS Medical, Nyon, Switzerland) was performed. Perioperative parameters including operative time (from start of puncture to the skin suturing), stone extraction time (from the first insertion of the nephroscope to the extraction of all stone fragments), and the stone-free rate were evaluated.

Results

Twenty-one males and 16 females underwent npPCNL for the management of large upper ureteral calculi. The median age and stone size of treated patients were 58 (interquartile range [IQR]: 51-69) years and 19.3 (IQR: 18.0-22.0) mm, respectively. The median operative time and stone extraction time were 25 (IQR: 21-29) min and 8 (IQR: 7-10) min, respectively. One case (2.7%) of postoperative bleeding and two cases (5.4%) of prolonged fever were managed conservatively. The stone-free rate at a 1-month follow-up was 94.6%.

Conclusion

The npPCNL provides a straight route to the ureteropelvic junction and proximal ureter. Approaching from a dilated portion of the ureter under low irrigation pressure with larger diameter instruments results in effective and safe stone extraction within a few minutes.

Exploring Anatomical Variations of Abdominal Arteries Through Computed Tomography: Classification, Prevalence and Implications

BACKGROUND AND AIMS

Variations in the branches of the abdominal aorta are relatively prevalent and can impact certain surgeries. The accurate identification and differentiation of these variations pre- and intraoperatively are crucial to avoid negative clinical sequelae. This study aimed to investigate the prevalence of variations in some branches of the abdominal aorta and to identify the most frequent variants as well as any rare variants not previously classified in the existing classification systems. The study's findings may help improve the understanding and management of these variations.

MATERIALS AND METHODS

This retrospective study was conducted at the Department of Radiology at An-Najah National University Hospital (NNUH) and included 550 abdominal computed tomography (CT) angiographic scans for patients (51.5% males, 48.5% females) performed between January 2017 and January 2023.

RESULTS

Variations were most common in the hepatic arteries (34.7%), followed by the renal arteries (31.3%). Variations in the celiac trunk were the least frequent (9.8%). The gastro-splenic trunk (type V) was the most common celiac trunk variant. The most common hepatic artery variant was the replacement of the right hepatic artery (type III). Accessory renal arteries were more frequent on the left side and among males (P = 0.01). The celiac trunk variations had a significant association with the hepatic artery variations (P = 0.001) and the renal artery variations (P = 0.011), respectively.

CONCLUSION

There is a high prevalence of anatomical variations in the described vessels, and it matches the results in the reported literature. Our findings also suggest the possible coexistence of variants. We have also encountered rare variants, especially in the hepatic arterial system. Some of the hepatic arterial system variants are not included in the older classification systems, calling for an extension of the old systems (Michel's and Hiatt classification systems) or replacement with the newer (CRL or EX-CRL classification systems) to account for rare variants not previously classified. Radiologists and surgeons should be proficient in identifying and differentiating these variations to take precautions and actions for each variant individually.

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.

Preclinical optimization of a diode laser-based clamp-free partial nephrectomy in a large animal model

Kidney cancer is a common urologic malignancy with either laparoscopic (LPN) or robotic partial nephrectomy as therapeutic options of choice for localized tumors. However, renal resection and suturing are challenging steps of the procedure that can lead to complications such as prolonged warm ischemia, bleeding, and urinary fistulas. LPN with a diode laser is an efficient technique due to its cutting and/or coagulation attributes. Surprisingly, key laser features such as wavelength and power remain undefined. Using a large porcine model, we evaluated the laser range of wavelength and power in a clamp-free LPN and compared it to the established gold-standard LPN technique (i.e., cold-cutting and suturing). By analyzing surgery duration, bleeding, presence of urine leak, tissue damage related to the resected renal fragment and the remaining organ, hemoglobin levels, and renal function, we show that an optimized experimental diode laser clamp-free LPN (wavelength, 980 nm; power, 15 W) had shorter surgery time with less bleeding, and better postoperative renal function recovery when compared to the well-established technique. Together, our data indicate that partial nephrectomy with a diode laser clamp-free LPN technique is an improved alternative to the gold-standard technique. Therefore, translational clinical trials towards human patient applications are readily feasible.

Anatomical variability of kidney arterial vasculature based on zonal and segmental topography

Introduction

To date, there is no unified approach to the lobar, zonal, and segmental structure of the kidney vasculature. There is no recognizable approach to define basic characteristics in regard to the lobes and segments identifying of the kidney. The branching of the renal artery has often been the subject of scientific research. This study aimed to analyze the arterial anatomy on the basis of zonal and segmental topography.

Materials and methods

This study is a prospective cadaver study on autopsy material using corrosion casting and CT imaging techniques. The arterial vasculature was visualized using corrosive casting. In this study, 116 vascular casts were included. We identified the number of arteries in the kidney hilum, their topography, branching variations of the renal artery, and local blood supply zones of renal masses considering second- and third-order renal artery branches. We used a micro-CT BRUKER SkyScan 1178, digital camera, Mimics-8.1, and R.

Results

This study has shown that RA divides into two or three zonal arteries, forming a two- or three-zonal vascular supply system. In the case of the two-zonal system, 54.3% of cases accounted for RA branching into ventral and dorsal arteries, whereas 15.5% of cases referred to superior polar and inferior polar zonal arteries. The three-zonal system implies 4 types of RA branching: 1) superior polar, ventral, and dorsal zonal branches (12.9%); 2) ventral, dorsal, and inferior polar zonal branches (9.5%); 3) two ventral and one dorsal zonal branches (5.2%), and 4) superior polar, central, and inferior polar zonal branches (2.5%).

Conclusions

The results of this research make us reconsider Grave's classification theory.

Use of contrast-enhanced computed tomography to detect kidney infarction in dogs

Background

Kidney infarction is a renovascular disease diagnosed by contrast‐enhanced computed tomography (CECT) in humans.

Objectives

To describe the frequency of kidney infarction and to determine the detection of kidney infarction with CECT in dogs.

Animals

Eight hundred and twenty‐six abdominal CECT studies of 826 dogs.

Methods

A cross‐sectional retrospective study. Dogs with abdominal CT scans including CECT were retrospectively retrieved. Kidney infarction was classified into 3 grades based on the extent of infarction relative to total kidney area. The location and number of kidney infarctions in each kidney were expressed as number and percentage. The ability of visualization of kidney infarction in each multiplanar reconstruction (MPR) image plane was evaluated by agreement of 2 observers.

Results

The frequency of kidney infarction in dogs was 3.15% (26/826 dogs; 95% CI = 2.05‐4.61). Most kidney infarctions were classified as grade 1, or the lesions were less than 25% of the kidney (47/56, 83.93%) and most were detected at the caudal pole of the kidney (31/56, 55.35%) on the sagittal plane. On MPR image planes, the sagittal plane had the highest proportion (34/56, 60.71%) of excellent visual category to detect kidney infarction.

Conclusions and Clinical Importance

The CECT, especially the sagittal plane, is a useful diagnostic tool for the detection of kidney infarction in dogs.

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.

Anatomical variations of the renal artery: a computerized tomographic angiogram study in living kidney donors at a Nigerian Kidney Transplant Center

BACKGROUND

Understanding of the renal vascular anatomy is key to a safe and successful donor nephrectomy, which ultimately impacts on the renal graft function and survival in kidney transplant recipients.

OBJECTIVE

To report the various anatomical configurations of the renal artery identified in living kidney donors in a Nigerian kidney transplant institution.

MATERIALS AND METHODS

The computerized tomography angiograms of 100 consecutive living kidney donors were prospectively reviewed over an 18-month period. Anatomical variations of the renal arteries including accessory arteries and early divisions were noted. Duration of surgery and ischemic time were recorded intra-operatively. Data analysis was carried out using IBM SPSS version 20.

RESULTS

There were variations in renal artery configuration in 50 (50%) cases, 32% were accessory renal arteries while 18% were early branches of the renal artery. The classical bilateral solitary renal arteries were found in 50 (50%) of potential donors. There was statistically significant longer operating and ischemic time in donors with multiple renal arteries as compared with solitary arteries (p<0.05).

CONCLUSION

There are a wide variety of renal artery configurations seen in potential kidney donors. The classical solitary renal artery remains the commonest and most favourable configuration for donor nephrectomy and transplantation.

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.

Interventional Radiology in Renal Trauma

Traumatic injuries to the kidney and collecting system can range widely from small lacerations to significant bleeding and its sequelae. Urinary obstruction can occur in the renal pelvis, ureters, or urethra. Interventional radiology plays a significant role in treatment and management, in many cases requiring emergent action. Endovascular embolization is frequently the first-line approach to treating hemorrhage. Percutaneous interventions for urinary obstruction include nephrostomy and suprapubic catheter placement. In this article, we outline the clinical approach and interventional methods used in the evaluation and treatment of renal trauma. Several case presentations demonstrate the role of interventional radiology in renal trauma.

Technical aspects to maximize the hyperaccuracy three-dimensional (HA3D™) computed tomography reconstruction for kidney stones surgery: a pilot study

The aim of the current prospective pilot study was to describe a hyperaccuracy three-dimensional (HA3D^™) model reconstruction technique, specifically developed to maximize the visualization of the renal collecting system's anatomy, and its relationship with the stones, vessels and renal parenchyma, and to compare the HA3D^™ virtual models with the intraoperative findings. The image acquisition was performed using a CT scanner (Toshiba, Aquilion Prime) and included the unenhanced, arterial, venous and excretory phases. The DICOM format CT images were processed by MEDICS Srl ( www.medics3d.com , Turin, Italy). In total, study included three patients with renal stone scheduled for non-papillary prone percutaneous nephrolithotomy (PCNL). The median age and BMI were 51 (range 49-54) and 25.5 (range 25.0-32.7), respectively. The median stone size was 1170 mm² (range 830-1520) and median stone density was 1130 HU (range 600-1340). In all cases, the quality of the CT images acquired with our protocol was adequate to perform the HA3D^™ reconstruction. Median operative and puncture time were 39.4 (range 35.2-44.0) and 1.9 (range 1.8-2.1) mins, respectively. The success rate for the first attempt of the percutaneous puncture was 100%, and only one PCNL tract was sufficient to complete the surgery. All three patients were stone-free on the third postoperative day. A dedicated imaging acquisition protocol and a tailored 3D model reconstruction process specifically developed for kidney stones treatment allow obtaining HA3D^™ highly relevant models to greatly match intraoperative findings during PCNL with the potential of minimizing bleeding and organ injury complications.

The prevalence of anatomical variants of the coeliac trunk and renal arteries on contrast-enhanced abdominal computed tomography scans at Dr George Mukhari Academic Hospital

Background

Anatomical variations of the coeliac trunk and renal arteries should be radiologically reported as they affect the surgical approach and subsequent outcome in patients.

Objectives

The aim of this study was to determine the prevalence of anatomical variations of the coeliac trunk and renal arteries and whether there is a relationship between the occurrence of these variations at Dr George Mukhari Academic Hospital.

Method

Arterial phase abdominal computed tomography (CT) or CT abdominal angiograms performed during January and December 2017 were analysed. The variations of the coeliac trunk and renal arteries were classified according to accepted classification systems and expressed as a percentage of the study population.

Results

A normal classical coeliac trunk was present in 82.2% and a non-classical pattern was present in 9.7%. The most common variation of the coeliac trunk other than the non-classical pattern was a hepatosplenic trunk, which was present in 3% of the study population. A normal right and left renal artery was present in 88.2% and 83.7%, respectively. The most common variations of the renal arteries were bilateral hilar arteries seen in 3.4% on the right and 9.1% on the left. Renal artery variations were more prevalent on the left than on the right. Concurrent variations of both the right and the left renal arteries were present in 2.4% and variations of both the coeliac trunk and renal arteries were present in 5% of the study population.

Conclusion

The most common variation of the coeliac trunk in this study is comparable to other studies in non-African populations. Concurrent vascular variations between the renal arteries and between the coeliac trunk and renal arteries may co-exist.

A Unique Case of Incomplete Bifid Ureter and Associated Arterial Variations

Introduction. Urogenital and vascular anomalies, including a left duplex kidney and a left aberrant renal artery that gave rise to the left ovarian artery, were observed in a 77-year-old female cadaver during a routine dissection. Description. A left aberrant renal artery, which gave rise to the left ovarian artery, was observed originating from the aorta 4 cm below the left renal artery. Two independent contributions to a bifid ureter were found originating from the hilum of the left kidney. These two contributions descended 12.4 cm and 10.6 cm, respectively, posterior to the left aberrant renal artery and lateral to the left ovarian artery before uniting anterior to the psoas major muscle to descend 12.7 cm to the bladder. Significance. While the duplex kidney is a relatively common congenital anomaly that can be asymptomatic, it can also potentially be associated with compression of renal vasculature or the ureter. Ureteral compression can then result in several pathologies including reflux, urinary tract infection (UTI), ureteropelvic junction obstruction, or hydronephrosis. Compression of renal and ovarian vasculature can result in altered blood flow to the kidney and ovary, potentially causing fibrosis, atrophy, or organ failure. Current imaging techniques alone are insufficient for correct diagnostics of such complications, and they must be supplemented with a thorough understanding of the respective anatomical variations.

Accessory renal arteries involved in atherosclerotic occlusive disease at the aortic bifurcation

Accessory renal arteries (ARAs) are embryonic remnants found in more than one-third of patients and occurring bilaterally in 10% of the population. Very few reports have documented such vessels arising near or at the level of the aortic bifurcation. Furthermore, the presence of ARAs has yet to be described in the context of atherosclerotic disease. Here, we present a unique case of large bilateral ARAs originating above the aortic bifurcation concurrent with symptomatic aortoiliac atherosclerotic disease. We highlight the embryologic and clinical significance of these vessels as well as discuss their potential role in accelerating atherosclerotic disease processes.

The bovine kidney as an experimental model: Simulated partial nephrectomy of the cranial pole and proportional analysis of the arterial segments

Previous studies have shown that the pig kidney is not a good model for some procedures. This study aimed to describe the relationship between the collecting system and the intrarenal arteries, the arterial segments, and to evaluate the bovine kidney as an experimental model for partial nephrectomy of the cranial pole. Polyester resin endocasts of the kidney collecting system together with the intrarenal arteries were prepared. Thirty-two kidneys were used to evaluate the relationship between the collecting system and the intrarenal arteries, while 25 kidneys were transversally sectioned at different points to simulate partial nephrectomy of the cranial pole. Polyester resin of different colors was injected into each segmental artery of the 24 kidneys to evaluate the arterial segments proportionally. The renal artery was divided into cranial and caudal primary branches in 75% of the cases. The cranioventral branch curved on the cranial pole and ran toward the ventral mid-zone in 56.3% of the cases, resembling the retropelvic artery of the human kidney. The kidney was divided into two (25%) or three (75%) arterial segments. The caudal arterial segment had the highest proportional volume (62%). The cranioventral branch was damaged in 28.6% of the kidneys sectioned 1 cm inside the hilum. The arterial branching pattern, the arterial segmentation, and the impairment of the arterial supply after the simulated partial nephrectomy of the cranial pole are quite different from those found in humans. Thus, all differences should be taken into account when using the bovine kidney as a model.

Anatomical background of ovine kidney for use as animal model: analysis of arterial segmentation, proportional volume of each segment and arterial injury after cranial pole partial nephrectomy

OBJECTIVE

To study the arterial segments of ovine kidney, present a proportional volume analysis of each kidney arterial segment, and analyze arterial injuries caused by simulated partial nephrectomy of cranial pole.

MATERIALS AND METHODS

Forty-eight ovine kidneys injected with polyester resin into the renal arteries and collecting system were used in this study. Eighteen kidneys were used to study the arterial segments and the proportional volume of each renal segment. Other 30 kidneys were submitted to superior pole resection at a distance of 1.0cm, 0.5cm, or exactly at the cranial hilar edge, just before the resin hardening. These endocasts were used to evaluate the arterial injuries caused by these different resection planes.

RESULTS

Ovine renal artery divided into two (ventral and dorsal) or three segmental arteries. Dorsal segment presented higher proportional volume than ventral segment. For kidneys with three segments, the third segment was on the caudal region (caudo-ventral or caudo-dorsal segment) and presented the lowest proportional volume. None of the resected kidneys (at 1.0, 0.5 or at the cranial hilar edge) presented injury of arterial branches that irrigate non-resected region.

CONCLUSION

The segmental distribution of renal artery, the proportional volume of each segment and arterial injuries after cranial pole resection in ovine kidneys are different from what is observed in human kidneys. Meanwhile, ovine kidneys show a primary segmental division on anterior and posterior, as in humans, but different from swine. These anatomical characteristics should be considered when using ovine as animal models for renal experimental and/or training procedures.

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.

A Case Study of Malrotated Kidneys with Asymmetric Multiple Renal Arteries, Variant Venous Drainage, and Unilateral Ureteral Duplication

Variations in the arterial, venous, and ureteral patterning of the right (r) and left (l) kidneys are common; however, concomitant involvement with all three systems is rare. Specimens that demonstrate anatomic variation across multiple systems provide an opportunity to illustrate links between anatomic concepts, embryologic development, clinical practice, and education. During anatomic study of the abdominal cavity, a total of five major arteries (3l and 2r) emerged from the aortic and common iliac axes in a cadaveric donor. Through continued study, multiple contributing veins, of different caliber, coalesced into four major renal veins (2l and 2r) that returned blood from the kidneys to the inferior vena cava (IVC) at different locations. In addition, unilateral duplication of the kidney with concomitant ureters was evident on the right side. Both ureters continued inferiorly and independently entered the bladder, each with an observable orifice adjacent to the bladder trigone. Most evident in the specimen was the anteriorly directed hilum for both kidneys. Reported measures for each of the observed anatomic variations suggest that the current specimen has an estimated incidence of less than 0.3%. This comparatively rare specimen provides an example of important anatomic concepts that are relevant to educational and clinical practices.

The level of origin of renal arteries in horseshoe kidney vs. in separated kidneys: CT-based study

Purpose

Horseshoe kidney is a rare congenital anomaly with potential clinical implications. The aim of this study was to determine the number of renal arteries and veins and the level at which the arteries branched off their parental vessels in individuals with horseshoe kidney (HSK) and in persons with separated kidneys (SK).

Materials and methods

The analysis included computed tomography angiography studies of 331 patients (83 HSK and 248 SK). The number of renal vessels and diameters of renal arteries were determined, along with the level at which they branched in relation to other ramifications (four groups of origin were proposed) and their entrance of the vessels to the kidney.

Results

Number of renal arteries in HSK group was 4.57 ± 1.39 per patient and 2.4 ± 0.43 in SK group (p < 0.0001). The distribution of branching level of renal arteries in HSK group was: I group ~ 57%, II group ~ 27%, III group ~ 15% and IV group < 1%, whereas in SK group the distribution was respectively: I group ~ 99%, II group < 1%, III and IV group − 0% (p = 0.0001). In HSK group, diameter of renal arteries branching above the IMA was 4.61 ± 1.58 mm, as compared with 3.96 ± 1.34 mm for the arteries branching below (p = 0.0004). Number of veins was 566 in SK group (87.70% of kidneys were supplied by single vein) and 323 in HSK group (9.64% kidneys were supplied by two veins) (p < 0.0001).

Conclusion

In HSK group, renal arteries significantly more often branch off their parental vessels below the origin of IMA and such vessels are usually smaller.

Positional relationships of abdominal aortic branches for contrast radiography of the inferior mesenteric artery using the coeliac trunk and superior mesenteric artery as landmarks

PURPOSE

To establish a method by which angiography of the inferior mesenteric artery (IMA) can be performed smoothly, we investigated the relative locations of the coeliac trunk (CT), superior mesenteric artery (SMA), IMA, and left renal artery (LtRA).

METHODS

From a total of 60 cadavers, 32 cadavers with few arteriosclerotic lesions and little vascular tortuosity were selected for the study. The abdominal aorta (Ao) were removed and incised on both lateral side, along the vertical axis and transected into the ventral and dorsal sides. The intravascular lumen on the ventral side of the Ao was photographed using a digital camera, and the horizontal and vertical diameters of the sites of confluence of the CT, SMA, and IMA, were measured on the computer screen. We also calculated the distances between the branches, including the CT, SMA, IMA, LtRA, and the common iliac artery (CoI).

RESULTS

Although the SMA-IMA distance did not correlate with the CT-SMA distance, the ratio of the SMA-IMA to CT-CoI distance was four times greater than the ratio of the CT-SMA to CT-CoI distance.

CONCLUSIONS

The site of branching of the IMA can be inferred to some extent from the CT and SMA distance.

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.

Percutaneous Nephrolithotomy Puncture and Tract Dilation: Evidence on the Safety of Approaches to the Infundibulum of the Middle Renal Calyx

OBJECTIVE

To investigate the anatomical relations of the papillary, infundibular, and pelvic approach to percutaneous nephrolithotomy and evaluate the amount of vascularization at the respective sites.

MATERIALS AND METHODS

^99mTc-dimercaptosuccinic acid single-photon emission computed tomography/computed tomography (SPECT/CT) renal scintigraphies or computed tomography perfusion (CTP) was performed in 40 patients (prone n = 20 or supine position n = 20). The angle of approach (AoA) for access tracts and the respective regions of interest to the mid-calyceal papilla and infundibulum as well as renal pelvis were designed and compared.

RESULTS

The design of access tracts aiming to the renal pelvis, papilla, and infundibulum of the renal calyx was impossible for the nondilated collecting systems as all these tracts were in close vicinity. In both SPECT/CT and CTP, there was no statistical difference between the AoA for infundibular or pelvic access in comparison with the papillary puncture in either prone or supine position regardless of the degree of dilation of the system. The comparison of the measurements in the regions of interest showed that there was no difference in blood supply between the infundibular and pelvic access in comparison with the papillary approach in both positions regardless of the degree of collecting system dilation.

CONCLUSION

The use of SPECT/CT and CTP showed that the punctures to the mid-calyceal renal papilla-fornix and infundibulum as well as the renal pelvis at the same level have similar AoA. The sites of the parenchyma involved in the tract dilation of the respective approaches are not related to significant differences in terms of vascularization.

Anatomical variations of the renal arteries: Cadaveric and radiologic study, review of the literature, and proposal of a new classification of clinical interest

PURPOSE

To analyse the variations of the renal arteries in two samples, cadaveric and computerized tomographic (CT) images, as well as to propose a simple classification of such variations based on the obtained results and an extensive review of the literature on the topic.

MATERIAL AND METHODS

Sixty human dissected kidneys and their vessels, and 583 abdominal CT were studied.

RESULTS

A total of 86 arteries were described in the cadaveric sample, whereas 1223 were analysed in the radiological one. Five types (a-e) and patterns (I-V) have been stablished in the classification. Type a, aortic hilar artery, incidences were 79% in cadavers and 95% in CT; Type b, hilar upper polar artery, incidences were 10% in cadavers and 2% in CT; Type c, aortic upper polar artery, incidences were 5% in cadavers and 2% in CT; Type d, aortic lower polar artery, incidences were 3% in cadavers and 1% in CT; Type e, hilar lower polar artery, incidences were 2% in cadaver and less than 0.1% in CT. The pattern represents the number of arteries reaching one kidney. Patterns I-IV were found in cadavers (I: 78%; II: 19%; III and IV: 2%); in CT sample only patterns I (88%) and II (12%). Pattern V was added because it has been described in the reviewed literature.

CONCLUSIONS

Type a and pattern I are the most prevalent, both in the cadaveric and the CT samples. Also in the consulted literature. There are no differences in the types and pattern incidences by side or sex. A simple, comprehensive and useful classification is proposed.

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.

Multiple anatomical variations of the renal vessels associated with malrotated and unrotated kidneys: a case report

Variations in the number of renal vessels represent the most common anatomical variations in renal vasculature. Here, a rare case of multiple anatomical variations of renal vessels was found in a 70-year-old female cadaveric dissection. Three renal arteries and two renal veins were observed to supply the right kidney, which was malrotated and ectopic; on the left side, the kidney was unrotated and presented two renal arteries and normal renal vein. In particular, we paid attention to the pattern of the three renal arteries that originated from the lateral side of the aorta and passed anteriorly to the inferior vena cava. A rare case of ovarian vein that drained into the right renal vein was also reported. The descriptions of these multiple anatomical variations should be considered by clinicians for performing correct surgical and radiological procedures.

Usage of invisible near infrared light (NIR) fluorescence with indocyanine green (ICG) and methylene blue (MB) in urological oncology. Part 1

INTRODUCTION

Near infrared (NIR) technology has recently garnered much interest as a tool for intraoperative image-guided surgery in various surgical sub-disciplines. In urology, although nascent, NIR technology is also fostering much enthusiasm. This review discusses the two major fluorophores, indocyanine green (ICG) and methlyene blue (MB), with NIR guidance in experimental and clinical urology. The authors aim to illustrate and analyze the currently available initial studies to better understand the potential and practicability of NIR-guided imaging in the diagnosis and surgical outcome improvement. In the first part of the study we analyzed problems associated with sentinel lymph node biopsy, NIR-guided detection and imaging of tumors.

MATERIAL AND METHODS

PubMed and Medline databases were searched for ICG and MB use in urological settings, along with data published in abstracts of urological conferences.

RESULTS

Although NIR-guided ICG and MB are still in their initial phases, there have been significant developments in major domains of urology, including uro-oncological surgery: 1) sentinel lymph node biopsy, 2) detection and imaging of tumors.

CONCLUSIONS

Much like in other fields of surgical medicine, the application of NIR technology in urology is at its early stages. Therefore, more studies are needed to assess the true potential and limitations of the technology. However, initial developments hint towards a pioneering tool that may influence various aspects of urology.

Morphological characteristics of renal artery and kidney in rats

The gross anatomy and morphometry of the kidney and renal arteries were studied in the strains of laboratory rat: Sprague-Dawley (Sp) and Wistar (W) rats. Total of 106 three-dimensional endocasts of the intrarenal arteries of kidney that were prepared using standard injection-corrosion techniques were examined. A single renal artery was observed in 100% of the cases. The renal arteries were divided into a dorsal and a ventral branch. The dorsal and ventral branches were divided into two branches, the cranial and caudal branch. Renal arteries were classified into types I and II, depending on the cranial and caudal branches and their made of branching. The present study also showed that the right kidney was slightly heavier than the left one and that the kidney of the male was generally larger than that of the female. The mean live weights of the Sprague-Dawley and Wistar rats were found to be 258.26 ± 5.9 and 182.4 ± 19.05 g, respectively. The kidney weights were significantly correlated (P < 0.01) with body weights. The kidney weights were not found significantly correlated (P > 0.01) with the length of renal arteries.

Auto localization and segmentation of occluded vessels in robot-assisted partial nephrectomy

Hilar dissection is an important and delicate stage in partial nephrectomy during which surgeons remove connective tissue surrounding renal vasculature. Potentially serious complications arise when vessels occluded by fat are missed in the endoscopic view and are not appropriately clamped. To aid in vessel discovery, we propose an automatic method to localize and label occluded vasculature. Our segmentation technique is adapted from phase-based video magnification, in which we measure subtle motion from periodic changes in local phase information albeit for labeling rather than magnification. We measure local phase through spatial decomposition of each frame of the endoscopic video using complex wavelet pairs. We then assign segmentation labels based on identifying responses of regions exhibiting temporal local phase changes matching the heart rate frequency. Our method is evaluated with a retrospective study of eight real robot-assisted partial nephrectomies demonstrating utility for surgical guidance that could potentially reduce operation times and complication rates.

Accessory renal arteries in a Caribbean population: a computed tomography based study

INTRODUCTION

The commonest variation to the classic anatomic description of renal arterial supply is the presence of accessory renal arteries. The incidence varies widely according to ethnicity. There is no data on the prevalence of these anomalies in persons of Caribbean ethnicity.

METHODS

All CT scans done over two years from July 1, 2010 to June 30, 2012 were retrospectively evaluated. The anatomy of the renal arterial supply was reported from these studies and the anatomy of accessory renal arteries was documented.

RESULTS

There were 302 CT scans evaluated and accessory renal arteries were present in 109/302 (36.1%) CT scans, 95% confidence interval 30.6%, 41.4%. There were 71/309 (23.5%) patients with accessory arteries on the left and 54/309 (17.9%) had them on the right (p 0.087). Of these, 16 (14.7%) patients had bilateral accessory renal arteries present. The most common origin for the accessory arteries was the abdominal aorta in 108 (99.1%) cases and in 1 case the accessory artery arose from the coeliac trunk. There were 80 left sided accessory renal arteries: 17 (21.3%) upper polar and 27 (33.8%) lower polar arteries. Of 62 right sided accessory arteries, 14 (22.6%) were upper polar and 26 (42%) were lower polar arteries.

CONCLUSION

This is the first population-based report of anatomic anomalies in renal arterial supply in a Caribbean population. These are important findings that may affect vascular and urologic procedures on persons of Caribbean ethnicity.

Experimental model of lower pole nephrectomy using human 3-dimensional endocasts: analysis of vascular injuries

OBJECTIVE

To establish an experimental model for lower pole nephrectomy using 3-dimensional endocasts of human kidneys.

METHODS

We studied 38 adult kidneys. The ureters, veins, and arteries were dissected and injected with yellow, blue, and red polyester resin, respectively. While the resins were still in a gel state, we performed lower pole guillotine sections at various distances from the hilar zone. The sample was divided into 4 groups: A, At hilar zone (11 kidneys); B, 0.5 cm from the hilar zone (12 kidneys); C, 1.0 cm from the hilar zone (8 kidneys); and D, 1.5 cm from the hilar zone (7 kidneys).

RESULTS A

At hilar zone-arteries: in 4 cases (36.36%), the lower segmental artery (LSA) was injured; veins: in 5 cases (45.45%), the lower venous trunk was injured (LVT). B: 0.5 cm from the hilar zone-arteries: the LSA was injured in 1 case (8.3%); veins: in 4 cases (33.3%), a lesion occurred to the LVT. C: 1.0 cm from the hilar zone-arteries: there were no lesions to LSA, but the infundibular arteries were damaged in all cases; veins: the interlobular veins were damaged in 3 of 11 cases (27.27%). D: 1.5 from the hilar zone-arteries: we observed lesions to the infundibular arteries in all cases; veins: arcuate veins were damaged in 4 of 7 cases (57.14%).

CONCLUSION

Lower pole nephrectomies performed at less than 1.0 cm from the hilar zone presented a significantly high incidence of injuries to large arteries and veins.

Multiple renal arteries with renal cell carcinoma: Preoperative evaluation using computed tomography angiography prior to laparoscopic nephrectomy

Objective

To investigate anatomical variations in the renal arteries of patients with renal cell carcinoma (RCC) using computed tomography angiography (CTA).

Methods

Patients diagnosed with RCC were evaluated using CTA prior to undergoing laparoscopic nephrectomy. Any anatomical variations of the renal arteries on the side affected by the RCC were recorded. The CTA results were compared with the observations made during surgery and those produced by conventional digital subtraction angiography.

Results

A total of 107 patients with RCC were enrolled in the study. Multiple renal arteries were found in 11 patients (10.3%). Accessory renal inferior polar arteries were the most common type of multiple renal arteries. Multiple renal arteries acting as the feeding arteries to the RCC were found in five patients (4.7%).

Conclusion

CTA can be used as part of the preoperative evaluation prior to laparoscopic nephrectomy to provide anatomical information about the presence of multiple renal arteries in the affected kidney of patients with RCC. This could help with planning the surgery and reducing surgical complications.

Supernumerary renal arteries and their embryological and clinical correlation: a cadaveric study from north India

Background. Classically, each kidney is supplied by a single renal artery originating from abdominal aorta. The present study aimed at its variations and their embryological and clinical correlation. Material and Methods. The formalin-fixed thirty-seven cadavers from north India constituted the material for the study. During routine abdominal dissection conducted for medical undergraduates at the department of anatomy, the kidneys along with their arteries were explored and the morphological variations of renal arteries were noted. Results. We observed supernumerary renal arteries in 23/37 (62.2%) cases (48.6% of aortic origin and 13.5% of renal origin) on the right side and 21/37 (56.8%) cases (45.9% of aortic origin and 10.8% of renal origin) on the left side. Supernumerary renal arteries entered the kidney through hilum, superior pole, and inferior pole. Conclusion. Awareness of variations of renal artery is necessary for surgical management during renal transplantation, repair of abdominal aorta aneurysm, and urological procedures and for angiographic interventions.

Near infrared fluorescence imaging after intravenous indocyanine green: initial clinical experience with open partial nephrectomy for renal cortical tumors

OBJECTIVE

To evaluate the safety of near infrared fluorescence (NIRF) of intravenously injected indocyanine green (ICG) during open partial nephrectomy, and to demonstrate the feasibility of this technology to identify the renal vasculature and distinguish renal cortical tumors from normal parenchyma.

METHODS

Patients undergoing open partial nephrectomy provided written informed consent for inclusion in this institutional review board-approved study. Perirenal fat was removed to allow visualization of the renal parenchyma and lesions to be excised. The patients received intravenous injections of ICG, and NIRF imaging was performed using the SPY system. Intraoperative NIRF video images were evaluated for differentiation of tumor from normal parenchyma and for renal vasculature identification.

RESULTS

A total of 15 patients underwent 16 open partial nephrectomies. The mean cold ischemia time was 26.6 minutes (range 20-33). All 14 malignant lesions were afluorescent or hypofluorescent compared with the surrounding normal renal parenchyma. NIRF imaging of intravenously injected ICG clearly identified the renal hilar vessels and guided selective arterial clamping in 3 patients. No adverse reactions to ICG were noted, and all surgical margins were negative on final pathologic examination.

CONCLUSION

The intravenous use of ICG combined with NIRF is safe during open renal surgery. This technology allows the surgeon to distinguish renal cortical tumors from normal tissue and highlights the renal vasculature, with the potential to maximize oncologic control and nephron sparing during open partial nephrectomy. Additional study is needed to determine whether this imaging technique will help improve the outcomes during open partial nephrectomy.

Variations of renal artery in 820 patients using 64-detector CT-angiography

PURPOSE

Renal artery variations are important for clinical reasons. The aim of this study is to determine the originating level and variations of renal arteries with 64-channel multidetector computed tomography (MDCT).

MATERIALS AND METHODS

In a university hospital, 820 patients who underwent MDCT angiography of the abdominal aorta were retrospectively evaluated. The number, early division (ED), and originating level of renal artery were evaluated retrospectively. Variations of the renal artery on both sides, the difference between the genders with variations of the renal artery, were compared with chi-square test.

RESULTS

Renal artery originating from the level of L1-L2 intervertebral disc was found in 37.0% and 38.9% of patients on the right and left sides, respectively. Renal artery variations, including extrarenal artery (ERA), were found in 27% and ED in 26.7% of the patients. Significant differences were found in ED and ERA prevalence for genders (p = 0.006 and p = 0.043, respectively). The prevalence of both variations is higher in males.

CONCLUSIONS

An awareness of renal vascular variations is very important for both surgeons and radiologists. In this series, renal arterial variations were found in approximately one-fourth of the study population.