Multiple variation of right renal and gonadal vascularization: report of two cases

We present two cases of multiple anatomical variations of the renal and gonadal vessels. The first case presented duplication of the renal vein and the presence of an accessory renal artery. However, the most interesting fact, in this case, was that the right gonadal vein emptied into the inferior right renal vein instead of ending in the inferior vena cava as would typically be the case. In the second case, we also found an accessory renal artery and the right gonadal vein emptied at the exact junction between the right renal vein and the inferior vena cava. Clinicians and surgeons should be familiar with anatomical variations to provide an accurate diagnosis during preoperative studies and to avoid surprises in abdominal surgical procedures.

A rare case of multiple visceral vascular variations around the kidneys: morphological and clinical aspects

Knowledge of the anatomical variations of the visceral branches of the abdominal aorta is important information for planning any surgeries in the region. We present here a rare constellation of variations of visceral vessels around the kidneys with a brief review of the recent literature. On the right side, an accessory renal artery was observed originating just distal to the main renal artery. The middle suprarenal artery was absent on the right side and there were two inferior suprarenal arteries originating from a branch of the main right renal artery. On the left side, the testicular artery had an arched course anterior to the left renal vein mimicking an unusual variety of nutcracker phenomenon. The right kidney was drained by two renal veins into the inferior vena cava. Knowledge of the coexistence of such complex anatomical variations might be helpful for clinicians during diagnostic and therapeutic procedures.

Experiences of robot assisted thrombectomy with 2-year follow-up

BACKGROUND

No consensus has been reached on operative procedures since a limited case series of robot-assisted inferior vena cava thrombectomy (RA-IVCT) and robot-assisted radical nephrectomy (RA-RN) have been described.

METHODS

The clinical data of 21 patients who underwent RA-IVCT and RA-RN were retrieved from the database. Preoperative preparation was used for assessment of the tumour. Surgical procedures were recorded, and operative skills were summarised.

RESULTS

The median IVC clamping time was 23 min, and IVC wall invasion was pathologically found in 2 cases. The mean postoperative hospital stay was 8.4 days and most patients recovered to full ambulation and oral feeding on the fourth day. None of the patients had liver or kidney dysfunction at the last follow-up (median, 24 months).

CONCLUSION

RA-IVCT presents technical challenges to surgeons. IVC control is an important part of the surgical process and different sides require different techniques.

Unusual Right Gonadal Vein Drainage: A Journey Into Rarity

The gonadal veins, responsible for draining from the paired gonads (testes in males and ovaries in females), exhibit variations in anatomy. Traditionally, the right gonadal vein directs its drainage into the inferior vena cava, while the left gonadal vein typically connects to the left renal vein. However, in the case of a 45-year-old woman diagnosed with a non-functional right kidney who underwent a right nephrectomy, an intraoperative observation revealed an unusual configuration: the right gonadal vein (ovarian) was found to drain directly into the right renal vein instead of its usual route into the inferior vena cava. This case report aims to elucidate this anomalous finding and provide a literature review on the prevalence of such anomalies in the existing research. This case report aims to raise awareness about the atypical drainage patterns of gonadal veins and underscore the importance of meticulous dissection of hilar renal vessels.

A case of novel combined variations of the renal and testicular vessels

Variations in the pattern of urogenital vessels can arise as a single occurrence or as a combination, which may increase the risk of unexpected injury during surgical procedures. Multiple variations in the renal and testicular vessels, in a novel combination, were observed during dissection of an 87-year-old Japanese male cadaver. In the present case, the patient had two renal arteries on each side. On the right side, the superior and inferior renal arteries emerged from the abdominal aorta at the L1 and L4 vertebrae levels, respectively. On the left side, the superior renal artery originated from the abdominal aorta at the level of the L1/L2 intervertebral disc, whereas the inferior renal artery arose at L4. The right testicular artery emerged from the abdominal aorta at the level of the L2 vertebra and crossed the inferior vena cava posteriorly. The venous system also exhibited some variations. The left renal vein passed posteriorly to the abdominal aorta and opened into the inferior vena cava at the level of the L2 vertebra. On the course to the inferior vena cava, the left renal vein was connected only to the first lumbar, azygos, and hemiazygos veins; blood was not collected from the left testicular and suprarenal veins, which usually open to the left renal vein. The patient had two right testicular veins. The lateral one opened into the angle between the right renal vein and the inferior vena cava at the level of the L2 vertebra, and the medial one drained into the inferior vena cava at a level slightly lower than the lateral one. Knowledge of the possible anatomical variations may be beneficial for performing safe retroperitoneal surgery and understanding the development of these vessels.

Transplant renal vein stent placement complicated by obstructive hematuria: A case report

BACKGROUND

Renal vein stenosis is uncommon following transplantation. We report acute renal vein stenosis post-transplant treated with an endovascular stent and complicated by urinary obstruction from clot formation.

METHODS

Retrospective case report.

RESULTS

A 16-year-old female 3 years post-transplant suffered anuria post-stenting with renal ultrasound demonstrating obstructive clot in the collecting system, a previously unreported complication. Subsequent nephroureteral JJ stent placement resulted in high-volume urine output.

CONCLUSION

This article underscores the high index of suspicion required for renal vein stenosis following transplantation and the need to monitor urine output closely following stent placement.

Vascular and Urinary Tract Anatomic Variants Relevant to Para-Aortic Lymphadenectomy in Women with Gynecological Cancers

BACKGROUND

Para-aortic lymphadenectomy is an essential part of gynecologic oncologic surgical treatment. The surgeon should be aware of the complex usual anatomy and its common variants.

METHODS

Between January 2021 and May 2023, 58 women underwent para-aortic lymphadenectomy for gynecologic malignancies.

RESULTS

Vascular and urinary tract anatomic variants were retrospectively reviewed from the prospective institutional database and results were compared with preoperative contrast-enhanced abdominal CT. Of these 58 women, 47 women had no vascular or urinary tract variants. One woman had a double inferior vena cava, two patients were found to have a retro-aortic left renal vein, four had accessory renal arteries, two had a double left ureter, one had a ptotic kidney in the iliac fossa, and one patient had bilateral kidney malrotation. Anatomic variants in the preoperative CT were described by a radiologist in only two patients, and additional vascular and urinary tract variants were found incidentally at the time of surgery.

CONCLUSIONS

Acknowledgment of vascular and urinary tract variants is helpful for the surgeon to establish an appropriate surgical plan and to avoid iatrogenic surgical trauma.

Anatomical study about the variations in renal vasculature

Renal vascularization is classically described as a renal artery and vein. However, this vascular pattern presents numerous anatomical variations in terms of their number, origin and course due to ontogenetic alterations. The aim was to carry out a descriptive study of the renal vascular pattern observed during the dissection of cadavers intended for teaching purposes. A descriptive and observational study of renal vascular anatomy was carried out by dissecting 16 renal blocks from 8 cadavers donated to science and used for teaching at the Faculty of Medicine of the University of Zaragoza. The prevalence of arterial variations was 75% (56.3% for polar renal arteries, 12.5% for pre-hilar branching and 6.25% for double communicating arterial arch) and venous was 62.5% (12.5% for polar renal veins, 25% for late venous confluence, 6.25% for triple renal vein and 18.75% for double circumaortic renal vein). We conclude that the renal vascular anomalies occur with high frequency; for this reason, knowledge of these anomalies is extremely important for the correct planning of numerous medical-surgical activities.

Trauma-associated left renal vein thrombosis with nutcracker syndrome

Background

Nutcracker syndrome is a compression of the left renal vein between the superior mesenteric artery and aorta, resulting in thrombogenesis. While renal vein thrombosis caused by renal disease is more common, solitary left renal vein thrombosis with nutcracker syndrome is rare.

Case Presentation

We present the case of a patient with trauma-associated left renal vein thrombosis with nutcracker syndrome. A 24-year-old woman with low body mass index taking oral contraceptives was admitted for trauma. She had multiple injuries, including thoracolumbar fractures, for which elective spinal fusion surgery was scheduled. As the D-dimer level elevated to 82.5 μg/dL preoperatively, enhanced computed tomography was performed, which revealed a solitary left renal vein thrombus.

Conclusion

This is the report of solitary left renal vein thrombosis in a patient with nutcracker syndrome after trauma. Patients with low body mass index and coagulopathy might have solitary left renal vein thrombosis associated with nutcracker syndrome.

Analysis of surgical outcomes in 102 patients with renal cell carcinoma with venous tumor thrombus: A retrospective observational single-center study

The aim of the study was to assess short- and long-term results following radical nephrectomy with renal vein and inferior vena cava thrombectomy in patients with renal cell cancer with venous thrombus and to investigate impact of various demographical, clinical and histological factors on overall survival (OS). The medical records of 102 adult patients with renal cell cancer with venous thrombus admitted for surgery in Department of General, Vascular and Transplant Surgery from 2012 to 2019 were retrospectively analyzed. The tumor was more frequently located on the right side compared to the left one (55 vs. 47). According to Neves Zincke classification, the levels of venous thrombus were as follows: 1 to 48 (47%), 2 to 47 (46%), 3 to 6 (6%), and 4 to 1 (1%). Postoperative complications were noted in 16 (15.7%) patients. One (3%) patient (Neves Zincke 2) died of intraoperative pulmonary embolism during hospitalization. Clear cell carcinoma was the most common pathological type reported in 92 (90.2%) patients. Thirty nine (38.2%) patients were alive at the time of last follow-up. The median OS was 21.50 (0-101.17) months. The 1-year OS was 75.5%. Significantly better OS (median 38.03 months) was noted in patients with RCC Neves Zincke 1 compared to OS (median 14.79 months) in patients with Neves Zincke 2-4 VT (P = .008). Higher tumor staging (T3 vs. T4) (P = .038), nodal staging (N0 vs. N1) (P = .0008), Fuhrman histological grading (G1-2 vs. G3-4) (P = .033) were associated with a shorter OS. Patients with renal cell cancer with venous thrombus, with an acceptable perioperative risk, should be treated surgically, because radical nephrectomy with thrombectomy performed in a high volume surgical center is a safe procedure. Neves Zincke 2-4 venous thrombus, higher tumor and nodal staging, as well higher Fuhrman histological grading are associated with a shorter OS.

Venous supply of horseshoe kidneys and normal kidneys: an angio-MSCT-based study

BACKGROUND

Horseshoe kidney is a common developmental anomaly which can be associated with many atypical anatomical variants of blood supply. The aim of this study was to identify the anatomical variants of renal veins supplying horseshoe kidney, with particular emphasis on their relationship with the arterial system.

MATERIALS AND METHODS

The analysis included 94 patients with horseshoe kidney (HSK) and 248 persons with normal kidneys (NK). Based on CT-angiography, the number of renal arteries and veins was determined, along with the levels the arteries branched off the aorta and the veins communicated to their parental vessels.

RESULTS

423 renal arteries (4.5 per person) and 364 renal veins (3.78 per persons) were found in HSK group (p=0.004), as compared with 598 arteries (2.41 per person) and 567 veins (2.29 per person) in the NK group (p=0.025). Mean number of renal veins in women with HSK was higher than in men (4.11 vs. 3.72 per patient, p=0.03). In the HSK group, the number of renal arteries correlated significantly with the number of renal veins only among men (ks=0.35, p=0.009). In patients with Nk, significant correlations between the number of renal arteries and renal veins were found both in the whole group and among men and women.

CONCLUSIONS

HSK are drained by a higher number of renal veins than NK, especially in women; this also refers to accessory renal veins. The number of renal veins for HSK is less dependent on the number of corresponding arteries than these for NK.

A unique case of extrarenal calyces and associated vascular variations in an adult female cadaver

The following urogenital and vascular anomalies were observed in the left kidney of an 81-year-old female cadaver during routine dissection: three extrarenal calyces; an accessory renal artery originating directly from the abdominal aorta; and a circumaortic renal vein. The typical renal anatomical structures were identified, from anterior to posterior, as the renal vein, renal artery, and ureter appearing near the hilum of the left kidney. After closer examination, three extrarenal calyces were observed exiting from the hilum of the left kidney to form the pelvis, then narrowed and became the ureter which descended 21.5 cm to empty into the bladder. The accessory renal artery originated from the lateral aspect of the abdominal aorta 7.3 cm below the aortic origin of the left renal artery. A corresponding accessary renal vein, identified as a circumaortic vein, left the hilum 4.5 cm below the left renal vein and travelled posterior to the abdominal aorta to drain into the inferior vena cava. Extrarenal calyces are rare among urogenital tract variations. They can be associated with embryological abnormalities such as renal ectopia, horseshoe kidney or malrotation as well as clinical manifestations such as pelviureteric junction obstruction and hydronephrosis. Compression of the accessory renal artery can cause decreased blood flow to the inferior pole of the left kidney, thereby causing fibrosis, atrophy, or renal failure. The retro-aortic path of the circumaortic renal vein has been associated with posterior nutcracker phenomenon, haematuria, left renal vein thrombus formation, and renal vein hypertension. This unique combination of a collecting system anomaly and extrarenal vessel variations could have significant implications in abdominal surgery.

Pelvic Venous Congestion Secondary to a Circumaortic Renal Collar in an Adolescent Female: Report of a Case

We report a 13-year-old girl who presented with a recurrent abdominal pain that started after her menarche. The abdominal palpation revealed tenderness over the left ovarian point. The laboratory study, ultrasonography, and abdominal X-ray were normal. The computed tomography and magnetic resonance imaging showed a double left renal vein with a retroaortic component, an increased left parauterine circulation, and ipsilateral ovarian vein engorgement. A diagnostic and therapeutic phlebography allowed a selective catheterization of a group of pelvic varicose veins draining to the left ovarian and to the internal iliac veins. There were no complications during the procedure and the symptoms disappeared 2 days later. Circumaortic left renal vein may cause hematuria, proteinuria, pelvic congestion syndrome, and massive hemorrhage during surgery. A conservative treatment is recommended for patients without gynecourological/renal symptoms or with mild hematuria. The endovascular treatment by gonadal venous embolization is safe and effective.

A rare case report of renal vein pseudoaneurysm after blunt trauma

RATIONALE

Renal vein pseudoaneurysm after blunt trauma is an extremely rare clinical disease. Different interventions, such as conservative, surgical, and endovascular treatments, can be considered. However, previous studies have not described the optimal treatment strategies for this condition. Furthermore, there is a significant lack of prior case reports and of standardized treatment guidelines for trauma-induced renal vein pseudoaneurysm patients who previously maintained antithrombotic agent.

PATIENT CONCERNS

A 23-year-old female patient visited the emergency department after sustaining blunt injury caused by falling. The patient was diagnosed with multiple limb and rib fractures. A right renal vein pseudoaneurysm was found on abdominal computed tomography scan. Initially, there was no other organ damage, and the patient was hemodynamically stable. Thus, nonsurgical, conservative management was considered. However, the patient's hematocrit and hemoglobin levels decreased, and there was no hemodynamic improvement. The patient required lifelong treatment with aspirin because she previously underwent Fontan surgery, and orthopedic surgery for multiple fractures was planned. Thus, considering these factors, the treatment method was changed from conservative management to endovascular stent insertion.

DIAGNOSES

Abdominal computed tomography and renal venography revealed a right renal vein pseudoaneurysm.

INTERVENTIONS

On the basis of the abdominal computed tomography scan and renal venography findings, the endovascular stent graft was inserted across the pseudoaneurysm area.

OUTCOMES

Upon placement of the endovascular stent, hemoglobin and hematocrit levels gradually returned to normal. The patient's vital signs and general condition had improved. The patient recovered without any complications and was discharged 29 days after hospitalization.

LESSONS

Some patients with traumatic renal vein pseudoaneurysm do not experience hemodynamic improvement despite conservative treatment. Hence, endovascular procedure may be considered for these patients, particularly those who require antithrombotic treatment for a previous disease.

'Full prosthetic jacket': external stenting of the renal vein

Introduction: We present a case of positional compression of the left renal vein (LRV) after right nephrectomy and caval reconstruction, treated by external stenting using a reinforced vascular prosthesis.Case report: A 69-year-old female patient presented because of swelling of the left leg. A renal cell carcinoma (RCC) was visualized on computed tomography (CT) scan in the right kidney, with a thrombus occluding the inferior caval vein (ICV) and the right renal vein (RRV). A right nephrectomy was performed, with ligation of the already occluded ICV. Venotomy allowed thrombectomy of the ICV above the level of the renal veins. Venous return from the left kidney was secured by reconstruction of the confluence of the LRV and the ICV. Postoperatively, urinary output declined, leading to anuria and elevated levels of serum creatinine. With surgical exposition of the LRV, a flow of 387 mL/min was measured. After removal of exposition, flow in the LRV dropped to 51 mL/min. The positional compression was treated with a reinforced vascular PolyTetraFluoroEthylene (PTFE) prosthesis placed around the LRV.Discussion: Besides some reports on external stenting of the renal vein in the treatment of nutcracker syndrome (NS), this is the first report describing this technique outside this clinical entity.

A case of solitary kidney with duplex collecting systems and renal vascular variants in an adult male cadaver

We describe a unique solitary kidney with duplex collecting system and vascular variation observed in an 86-year-old white male formaldehyde- and phenol-fixed cadaver during routine academic dissection. The left renal fossa was empty with an intact adrenal gland, and the right renal fossa contained a fused renal mass with apparent polarity between the superior and inferior regions and two renal pelves converging into a single ureter. There were three right renal arteries supplying the renal mass; the superior and middle arteries were noted to be postcaval and the inferior artery was precaval. There were also two right renal veins draining into the inferior vena cava and following a regional distribution with the superior vein draining the inferior portion of the renal mass. Despite generally being asymptomatic, the detection of renal anatomical variants is clinically important for appropriate patient management and surgical interventions.

A simple, refined approach to diagnosing renovascular hypertension in children: A 10-year study

BACKGROUND

Despite advances in non-invasive vascular imaging, detection of renal artery stenosis via catheter angiography is the criterion standard for the diagnosis of renovascular hypertension (RVH). However, because of lack of evidence, the utility of various blood tests and imaging modalities remains unclear.

METHODS

We retrospectively analyzed the utility of blood tests (plasma renin activity [PRA], aldosterone, and renal vein renin [RVR] values) and imaging studies (computed tomography angiography [CTA], kidney ultrasonography [US]) by comparing them with catheter angiography. Ten pediatric patients with RVH at two institutions from January 2008 to December 2017 were recruited. The sensitivities for diagnosing RVH via imaging and blood tests (kidney [US], PRA, and aldosterone) were derived by examining patient records. Furthermore, the sensitivity and specificity of CT angiography were calculated by considering both the affected and non-affected renal arteries of the patients.

RESULTS

A high sensitivity for diagnosing RVH via kidney US (89%) and PRA (80%) was observed. The sensitivity and specificity of CTA were 100%, each. RVR sampling did not aid in the diagnosis of RVH; only two of six patients with unilateral RVH showed significant laterality of RVR boundary ratios. Renal scintigraphy facilitated detection of a non-functional kidney (split renal function <5%).

CONCLUSIONS

RVH in children could be diagnosed utilizing non-invasive blood and imaging tests, without catheter angiography. We recommend kidney length measurement along with measurement of PRA level, as a simple and highly useful screening test, followed by CTA as a diagnostic test.

Endovascular treatment of a teenager with nutcracker syndrome: a case report

The nutcracker syndrome is caused by compression of the left renal vein by the superior mesenteric artery and aorta and is associated with characteristic symptoms, such as lower abdominal pain, varicocele, and hematuria. Diagnosis is often difficult and, therefore, is often delayed. Invasive treatment is controversial, particularly in pediatric patients. However, it is indicated in cases of gross hematuria associated with anemia, renal function impairment, severe pelvic pain, or ineffective conservative treatment. We report the case of a 12-year-old boy presenting with severe hematuria for 12 hours, with no abnormal findings at a first evaluation, who progressed with severe anemia and urinary retention. Further investigation provided images suggestive of nutcracker syndrome, and endovascular stenting (smart control stent) followed by balloon dilatation was the treatment of choice. Hematuria ceased after the procedure, and the patient is still asymptomatic at 5-year follow-up.

Mesenchymal Stem Cell-Derived Extracellular Vesicles Induce Regulatory T Cells to Ameliorate Chronic Kidney Injury

Metabolic syndrome (MetS) profoundly changes the contents of mesenchymal stem cells and mesenchymal stem cells-derived extracellular vesicles (EVs). The anti-inflammatory TGF-β (transforming growth factor-β) is selectively enriched in EVs from Lean but not from MetS pigs, but the functional impact of this endowment remains unknown. We hypothesized that Lean-EVs more effectively induce regulatory T cells in injured kidneys. Five groups of pigs (n=7 each) were studied after 16 weeks of diet-induced MetS and unilateral renal artery stenosis (RAS; MetS+RAS). Two groups of MetS+RAS were treated 4 weeks earlier with an intrarenal injection of either Lean-EVs or MetS-EVs. MetS+RAS had lower renal volume, renal blood flow, and glomerular filtration rate than MetS pigs. Compared with Lean-EVs, MetS-EVs were less effective in improving renal function and decreasing tubular injury and fibrosis in MetS+RAS. Lean-EVs upregulated TGF-β expression in stenotic kidney and increased regulatory T cells numbers more prominently. Furthermore, markedly upregulated anti-inflammatory M2 macrophages reduced proinflammatory M1 macrophages, and CD8⁺ T cells were detected in stenotic kidneys treated with Lean-EVs compared with MetS-EVs, and renal vein levels of interleukin-1β were reduced. In vitro, coculture of Lean-EVs with activated T cells led to greater TGF-β-dependent regulatory T cells induction than did MetS-EVs. Therefore, the beneficial effects of mesenchymal stem cells-derived EVs on injured kidneys might be partly mediated by their content of TGF-β signaling components, which permitting increased Treg preponderance. Modulating EV cargo and transforming their functionality might be useful for renal repair.

Endovascular Treatment of an Extensive Iliocaval and Renal Vein Thrombosis Secondary to Inferior Vena Cava Stenosis and May-Thurner Type Iliac Vein Compression: A Case Report

A 23-year-old presenting with an acute history of back pain, leg swelling, and claudication was diagnosed with an extensive iliocaval thrombosis, extending from the popliteal veins into the inferior vena cava (IVC) and left renal vein. He was treated with a combination of endovascular techniques, including EKOS and AngioJet. An underlying congenital IVC stenosis and May-Thurner type iliac vein compression were subsequently treated with venoplasty and stenting. To our knowledge, this is the first report of the use of EKOS for renal vein thrombosis and we highlight the complementary nature of different endovascular techniques for managing complex venous thrombotic disease.

Evaluation of the frequency of left renal vein variations in computed tomography and its relationship with cancer development

BACKGROUND

Left renal vein (LRV) variations occur in 0.8-10.2% of the population. The most common LRV variations are retroaortic left renal vein (RLRV) and circumaortic left renal vein (CLRV). The purpose of this study is to determine the frequency of LRV variations in a large series on computed tomography (CT) and to investigate the association between LRV and malignancy development.

MATERIALS AND METHODS

Between January 2015 and January 2017, an abdominal CT examination of 12,341 (5505 female, 6836 male) patients was evaluated retrospectively in this study. Patients' clinical and demographic data were recorded using the Hospital Information System.

RESULTS

Left renal vein variations were detected in 314 (2.54%) of the 12,341 patients within the study. Of the 314 cases found to have LRV variations, 227 (1.84%) had RLRV, and 87 (0.70%) had CLRV. There was no statistical difference in total LRV variations (p = 0.083) and CLRV variation (p = 0.96) groups in terms of gender. However, the RLRV variation was found to be 1.32 times higher in males than in females (p = 0.039). Of the 314 patients with LRV variations, 73 (23.2%) had any sort of concomitant malignancy.

CONCLUSIONS

A high incidence of malignancy was detected in patients with LRV variations. Of the LRV variations, RLRV variation is more common than CLRV variation. The presence of total LRV variations and CLRV variations is not associated with gender; whereas the presence of RLRV variation is more common in males.

Duplicated inferior vena cava with coexisting multiple vascular anomalies and their clinical implications: a case report

The paper presents the case of a 23-year-old man with multiple venous anomalies. The abnormalities were asymptomatic, and they were detected accidentally on routine abdominal ultrasound examination. The anomalies were found in the inferior vena cava, right testicular vein, left renal vein, and hepatic veins. Familiarity with different developmental variants within the inferior vena cava and other venous vessels plays a crucial role in ultrasound imaging. Vascular anomalies, although rare, should be taken into account in the differential diagnosis of focal lesions within the abdominal cavity. Also, variation in vascular anatomy may be a precipitating factor for blood flow disorders, and hence predispose patients to deep vein thrombosis and other pathological conditions. The reported case serves as a valuable addition to the knowledge of the vascular system that radiologists use in their everyday practice when performing diagnostic ultrasound examinations.

Concomitant multiple anomalies of renal vessels and collecting system

Although anomalies of renal vessels and collecting system are relatively frequent, their concomitant occurrence is a rare event. During dissection of a 75-year-old male formalin-embalmed cadaver, we found multiple variations in the renal vessels and renal collecting system. Both kidneys were normal in size and anteriorly malrotated, with duplex collecting system and duplex ureter. One ureter drained the upper part of the kidney and the second ureter drained the lower part of the kidney. Superior and inferior collecting systems were separated by renal parenchyma. The right kidney had two renal arteries, the first renal artery (main renal artery) originating from the abdominal aorta, passing behind the inferior vena cava (IVC) and entering the kidney through the superior and inferior renal hilum. The second artery was the inferior polar artery. In addition, the right kidney had two renal veins as well. Three renal tributaries emerged from the upper and lower portion of the right renal hilum, and they joined to form the main renal vein which drained into the IVC. The lower renal vein was the inferior polar vein. The left kidney had four renal arteries (two hilar arteries and two polar arteries). The main left renal vein emerged from both superior and inferior left renal hilum, passed in front of the abdominal aorta and drained into the IVC. The left kidney also had the inferior polar vein which was divided behind the aorta (retro aortic vein) into two venous trunks. These venous trunks drained separately into posteromedial aspect of the IVC. Finally, the right testicular vein was formed by two tributaries and drained into the IVC, whereas the two left testicular veins drained separately into the left main renal vein.

Warfarin-induced spontaneous retroperitoneal hemorrhage from the renal vein: A rare case with an uncommon etiology

The overall rate of major bleeding in patients with atrial fibrillation receiving warfarin therapy is approximately 4%. Among these 4% patients, spontaneous retroperitoneal hemorrhage (SRH) is a rare but potentially lethal complication with a nonspecific presentation that can lead to missed or delayed diagnosis. The current literature provides little direction for diagnosis and management of such cases. Anticoagulation-related SRH is associated with a high mortality rate (approximately 20%). Despite the vague presentation, prompt diagnosis is crucial to reverse the anticoagulation and prevent further bleeding. Contrast-enhanced computed tomography (CT) of the abdomen is the imaging modality of choice in suspected cases. Patients with SRH require aggressive treatment with blood transfusions, interventional radiological procedures, percutaneous drainage or surgical evacuation of the hematoma. We report a case of warfarin-induced SRH from the renal vein in a patient who presented to our emergency department with acute, nonspecific abdominal pain and shock. We diagnosed the patient with warfarin-induced SRH on the basis of clinical suspicion and characteristic CT findings. We initially treated the patient conservatively, followed by embolization of the right renal artery during the late course of hospital stay, and he was discharged with good recovery. SRH should be considered in the differential diagnosis of abdominal pain, hypotension, and/or decreased hemoglobin levels in patients receiving anticoagulation therapy, especially in those with preexisting end-stage renal disease.

A Case of Renal Oncocytoma with Renal Venous Tumor Thrombus

Renal oncocytoma is generally regarded as a benign renal tumor. We herein report a case of large renal oncocytoma with renal venous tumor thrombus. The patient may need to be carefully followed up because hematogenous metastasis may occur.

A deadly trap for para-aortic lymph node dissection in patients with horseshoe kidney as a complication: a case report

Horseshoe kidney is a rare congenital renal dysplasia. It is often associated with various anatomical abnormalities, including renal vessel and ureter variability, which increase unpredictable surgical risks. This current report describes the case of a 42-year-old woman diagnosed as having cervical squamous cell carcinoma complicated by horseshoe kidney. She underwent laparoscopic radical hysterectomy, bilateral oophorectomy and lymph node dissection, including dissection of the pelvic, presacral and para-aortic lymph nodes. The surgery was challenging, but no serious complications occurred. Postoperative multi-slice computed tomography angiography confirmed the anatomical variation of the renal location, ureter and renal vessels. To our knowledge, this is the first reported case of cervical carcinoma complicated with horseshoe kidney.

Evaluation of Vascular Structures of Living Donor Kidneys by Multislice Computed Tomography Angiography before Transplant Surgery: Is Arterial Phase Sufficient for Determination of Both Arteries and Veins?

Objectives

The aim of our study was to determine the efficacy of preoperative early arterial Computed tomography angiography (CTA) in donor nephrectomy, to assess the renal arterial and venous structures of donor kidneys.

Materials and Methods

Seventy living donor candidates were included to this study, who had CTA for the assessment of their renal vessels in our hospital between January 2011 and January 2015. Only early arterial phase images were obtained to avoid exposing the patients from high dose of radiation. Scans were reported by two radiologists independently. The number of renal arteries, veins and their tributaries were documented. The donor kidneys were removed by two consultant surgeons, and after back-table perfusion the same details were recorded and taken as the reference findings for the operation side.

Results

A total of 70 potential live kidney donors underwent renal CTA, among them fifty five patients had donor nephrectomy. A total of 140 kidneys were evaluated by CTA and the vessels of 55 harvested kidneys were compared with CTA findings. There were 40 kidneys that had at least one accessory or polar artery. There were 5 early branching renal arteries, two retroaortic and two circumaortic renal veins. Three kidneys had multiple renal veins. Operation findings were totally consistent with CTA findings in patients who underwent donor nephrectomy.

Conclusion

Arterial phase CTA is sufficient for evaluation of both arterial and venous vessels of kidneys, and precontrast, venous or late phase imaging should be preserved only for chosen circumstances to avoid high radiation exposure.

Anesthetic management of radical nephrectomy in patients with renal cell carcinoma involving renal vein or inferior vena cava

OBJECTIVE

To investigate the perioperative anesthetic management of patients diagnosed with renal cell carcinoma (RCC) metastasized into the renal vein or inferior vena cava (IVC) after undergoing radical nephrectomy to provide clinical evidence for rational anesthetic interventions.

METHODS

A total of 81 patients with RCC extending into the renal vein or IVC, aged 17-73 years, undergoing radical nephrectomy were recruited. Preoperative status, intraoperative management, average operation time, average estimated blood loss, postanesthesia outcomes, and postoperative complications were retrospectively analyzed.

RESULTS

The mean operation time was 288 minutes (range 146-825 minutes). The mean estimated blood loss was recorded as 1905 mL (range 200-7000 mL). Among 81 cases, 9 patients (11.1%, 1 level II, 3 level III, and 5 level IV) were switched to undergo cardiopulmonary bypass. Significant hemodynamic fluctuations were observed in 39 patients who presented with level II-IV of tumor thrombus. One patient had pulmonary embolism and died of active cardiopulmonary resuscitation. The mean postoperative hospital stay was 12.8 days. Twenty-five cases with level III-IV tumor thrombus were transferred to the intensive care unit with endotracheal intubation due to massive intraoperative blood loss. The remaining 55 cases were transferred to the postanesthesia care unit 2 hours before being transferred to the ward. One patient had postoperative acute coronary syndrome and was discharged after effective interventions.

CONCLUSION

Anesthetic management and intensive postoperative care play a pivotal role in the success of complete resection of RCC that metastasize into the IVC.

[LEIOMYOSARCOMA ARISING FROM THE RENAL VEIN]

A 47-year-old female presented to a clinic complaining of right back pain. A CT scan revealed a right retroperitoneal mass and she was referred to our department for further evaluation. Contrast-enhanced CT and MRI revealed a right retroperitoneal mass (6 cm) in the hilum of the right kidney that invaded the right renal vein and inferior vena cava (IVC). Suspecting a tumor arising from retroperitoneal tissues involving the right renal vein and IVC, the decision was made to excise the tumor with the right kidney, renal vein, and a portion of the IVC. The histologic findings indicated that the tumor was a leiomyosarcoma originating from the renal vein wall. The tumor cells were spindle-shaped and stained positive for desmin, caldesmon and HHF35. The post-operative course was uneventful and she was recurrence-free 20 months after surgery. In addition to presenting a case of a leiomyosarcoma of the renal vein, a short review of the literature is provided.

Right circumcaval ureter and double right renal vein in the Brazilian shorthair cat (Felis catus): two case reports

Variations of the renal veins are well described in the literature, although variations concerning the ureter are considered a rare finding in cats. The circumcaval ureter is one of the rarest variations of the ureter and is characterised by a loop of the ureter posterior to the caudal vena cava. This variant is also known as preureteral vena cava and retrocaval ureter. It is thought to be caused by a deviation during embryonic development of the aforementioned vein. Due to its rarity, there are scarce reports of the circumcaval ureter in cats, and its association with two renal veins makes it less common as well. These variations should be preoperatively identified in order to avoid complications in kidney transplants, ureteral surgeries and cystoscopies, for instance. The present work aims to report two cases of a circumcaval ureter with two renal veins in two different Brazilian shorthair cats (Felis catus).

Malignant Solitary Fibrous Tumor of the Renal Vein Presenting as a Giant Renal Artery Aneurysm: A Case Report and Review of Literature

OBJECTIVES

To discuss an unusual presentation of solitary fibrous tumor (SFT) as well as the first description of SFT originating from the renal vein.

CASE REPORT

In this article, we report the case of a 56-year-old man who presented with nonspecific epigastric pain and was found on computed tomography to have a large 10-cm renal artery aneurysm with evidence of contained rupture, segmental ischemia of the kidney, and suggestion of renal vein thrombosis. This was treated by a multidisciplinary team of urologists, vascular surgeons, and interventional radiologists with both renal artery coil embolization and radical nephrectomy. The thrombosis was found on pathologic review to be a malignant SFT originating from the renal vein with likely erosion into the renal artery.

CONCLUSION

This report describes the first case of SFT originating from the renal vein and demonstrates the potential for mimicry as a giant renal artery aneurysm.

Renal Pelvis Carcinoma with Renal Vein or Inferior Vena Cava Involvement Linked to Early-onset Lung Metastasis Based on CT Scan Diagnosis

BACKGROUND/AIM

Renal pelvis cancer with invasion of the renal vein or inferior vena cava (IVC) carries a poor prognosis. The present study investigated whether early-onset lung metastasis in these patients contributes to their poor outcome.

PATIENTS AND METHODS

Data were retrospectively collected from hospitalized patients with metastatic renal pelvis urothelial cancer. The parameters used to estimate the risk of lung metastasis were based on computed tomographic (CT) scans. The parameters included sex, age (≤65 years or >65 years), site (right or left side), metastasis to para-aortic lymph nodes (LNs), suspicion of peritoneal spread, IVC involvement, and renal vein involvement. There were 71 cases including: 40 (56%) patients with lung metastasis (22 early-onset and 18 late-onset), 68 (96%) with suspicion of peritoneal spread, 38 (54%) with para-aortic LN metastasis, 10 (14%) with IVC involvement, and 53 (74%) with renal vein involvement. Sixty-four cases were evaluated to estimate the risk of lung metastasis.

RESULTS

Tumor involvement in the IVC (p=0.01) and in the renal vein (p<0.00001) were high risk factors for lung metastasis.

CONCLUSION

Tumor involvement of the renal vein or IVC is linked to early-onset lung metastasis in renal pelvis cancer based on CT scan diagnosis.

[Aggressive renal angiomyolipoma extending to the renal vein: about a case and literature review]

Renal angiomyolipoma is a benign tumor. It is characterized of three different components: muscular, vascular and greasy. Their distribution is variable. Diagnosis is based on the identification of the intratumoral greasy component on CT scan and MRI. In exceptional circumstances, this tumor may be aggressive with locoregional and venous extension (renal vein and inferior vena cava). We here report the case of a 37-year old patient with voluminous renal angiomyolipoma extending to the renal vein.

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.

Technical Intraoperative Maneuvers for the Management of Inferior Vena Cava Thrombus in Renal Cell Carcinoma

Introduction

Renal vein or inferior vena cava (IVC) invasion by neoplastic thrombus in patients with renal cell carcinoma (RCC) is not an obstacle for radical oncological treatment. The aim of this study is to present our technical maneuvers for complete removal of the intracaval thrombus without compromising hemodymanic stability of the patient.

Materials and methods

Between 2000 and 2014, 15 RCC patients with IVC involvement of levels I–III were treated with curative intent and were prospectively studied. The operative technique varied according to thrombus extent. For type I, extraction of the thrombus is facilitated by a 2–3 cm longitudinal incision on the IVC that begins at the level of the renal vein and extends cranially, encompassing a vessel wall rim of the orifice of the resected renal vein. For type II cases, the IVC is clamped above the neoplastic thrombus, and for type III, the IVC clamping is combined with hepatic blood flow control with “Pringle maneuver.” For type IV, the IVC is clamped above the diaphragm, or if the thrombus extends into the right atrium cardiothoracic input is appropriate.

Results

The main operative steps include preparation and control of the renal vessels and the IVC. Occasionally, for type III tumor thrombi, the patient becomes hemodynamically unstable when IVC is clamped suprahepatically. In such a case, a novel operative maneuver of milking the thrombus below the orifice of the hepatic veins, and subsequently the IVC clamp also beneath the hepatic veins, allowing release of the “Pringle maneuver” is performed. This operative step restores hepatic blood flow and hemodynamic stability and is based on the floating nature of the thrombus into the IVC. Mean operative time was 120 min (range from 90 to 180 min), and average liver and renal warm ischemia time was 20 min (range from 15 to 35 min). Postoperative overall hospital stay ranged from 7 to 13 days.

Conclusion

The technical solutions employed in the current study allow successful removal of neoplastic thrombi from the IVC in most cases, associated with minimal perioperative complication rate even for patients who due to multiple comorbidities would be considered otherwise inoperable.

Cadaveric Study of Mode of Termination of Gonadal Veins: Implications for Procedures Utilizing Terminal Ends of Gonadal Veins as Entry Portals

CONTEXT

The terminal ends of gonadal veins act as an entry portal in gonadal embolization procedures used for treating varicocele in males and pelvic congestion disease in females. Here, we studied the modes of termination of gonadal veins in adult cadavers.

MATERIALS AND METHODS

Thirty-five adult formalin-fixed cadavers (seventy sides) were studied over a period of 4 years. The modes of termination of gonadal veins were observed under the following study variables: (a) number, (b) locale of termination, and (c) termination angle.

RESULTS

Variations in study parameters were observed in eight sides of seven cadavers (seven unilateral and one bilateral). Double veins at termination were observed in six cadavers; anomalous termination was observed in three cadavers. Angle of termination differed from normal in 3 cadavers. In one of these cadavers, the left ovarian vein drained into the left suprarenal vein.

CONCLUSION

Duplication of terminal ends, anomalous drainage site, and varied angles of termination call for caution to ensure the success of procedures, which use terminal ends of gonadal veins as entry portals.

A Detailed Study of Multiple Vascular Variations in the Upper Part of Abdomen

Introduction:

Knowledge of vascular variations near the kidney is of importance to many clinical disciplines such as nephrologists, radiologists, gastroenterologists, and general surgeons. Variant branches of the abdominal aorta and renal arteries are the victims of iatrogenic bleeding during surgery. We found multiple vascular variations in the upper part of the abdomen during our dissection classes.

Methods:

During the dissection classes of the abdomen for undergraduate medical students, we observed multiple vascular variations in the abdomen of an adult male cadaver. The vessels and surrounding viscera were cleaned using dissection instruments. Variations observed were photographed.

Results:

The right kidney had its hilum directed posteriorly. There were two right renal veins and a partially doubled left renal vein (LRV). The left suprarenal and gonadal veins drained into the upper LRV. There were two right renal arteries. Upper right renal artery gave origin to the right inferior phrenic and middle suprarenal arteries. There were two renal arteries on the left side also. The left upper renal artery gave a polar branch to the left kidney and divided into two branches before entering the kidney. The left inferior phrenic artery (IPA) gave two gastric branches to the fundus of the stomach.

Conclusions:

The variations noted by us are of tremendous surgical application. The variant vessels might get damaged during surgical procedures if the surgeons are not aware of these variations. The most important among the variations reported here is the gastric branch of the IPA, which has not been reported yet.

Thrombosis of the Abdominal Veins in Childhood

Abdominal venous thrombosis is a rare form of venous thromboembolic disease in children. While mortality rates are low, a significant proportion of affected children may suffer long-term morbidity. Additionally, given the infrequency of these thrombi, there is lack of stringent research data and evidence-based treatment guidelines. Nonetheless, pediatric hematologists and other subspecialists are likely to encounter these problems in practice. This review is therefore intended to provide a useful guide on the clinical diagnosis and management of children with these rare forms of venous thromboembolic disease. Herein, we will thus appraise the current knowledge regarding major forms of abdominal venous thrombosis in children. The discussion will focus on the epidemiology, presentation, diagnosis, management, and outcomes of (1) inferior vena cava, (2) portal, (3) mesenteric, (4) hepatic, and (5) renal vein thrombosis.

Leiomyosarcoma of the renal vein: analysis of outcome and prognostic factors in the world case series of 67 patients

Background

Leiomyosarcoma is a rare malignant mesenchymal tumour. Some cases of leiomyosarcoma of the renal vein (LRV) have been reported in the literature, but no analysis of data and search for prognostic factors have been done so far. The aim of this review was to describe the LRV, to analyse overall survival (OS), local recurrence free survival (LRFS) and distant metastases free survival (DMFS) in LRV world case series and to identify significant predictors of OS, LRFS and DMFS.

Methods

Cases from the literature based on PubMed search and a case from our institution were included.

Results

Sixty-seven patients with a mean age of 56.6 years were identified; 76.1% were women. Mean tumour size was 8.9 cm; in 68.7% located on the left side. Tumour thrombus extended into the inferior vena cava lumen in 13.4%. All patients but one underwent surgery (98.5%). After a median follow up of 24 months, the OS was 79.5%. LRFS was 83.5% after a median follow up of 21.5 months and DMFS was 76.1% after a median follow up of 22 months. Factors predictive of OS in univariate analysis were surgical margins, while factors predictive of LRFS were inferior vena cava luminal extension and grade. No factors predictive of DMFS were identified. In multivariate analysis none of the factors were predictive of OS, LRFS and DMFS.

Conclusions

Based on the literature review and presented case some conclusions can be made. LRV is usually located in the hilum of the kidney. It should be considered in differential diagnosis of renal and retroperitoneal masses, particularly in women over the age 40, on the left side and in the absence of haematuria. Core needle biopsy should be performed. Patients should be managed by sarcoma multidisciplinary team. LRV should be surgically removed, with negative margins.

A case of renal cell carcinoma with an extensive inferior vena cava thrombosis

Renal cell carcinoma (RCC) is the most prevalent primary renal malignant neoplasm in adults. Most of the cases are usually found incidentally. It is commonly associated with venous thrombosis. We demonstrate a case of a RCC which was associated with an extensive thrombus that reached the upper part of the inferior vena cava (IVC). We also perform a brief literature review about the association between RCC and IVC thrombosis.

Evaluation of renal vascular anatomy in live renal donors: Role of multi detector computed tomography

Background:

Evaluation of renal vascular variations is important in renal donors to avoid vascular complications during surgery. Venous variations, mainly resulting from the errors of the embryological development, are frequently observed.

Aim:

This retrospective cross-sectional study aimed to investigate the renal vascular variants with multidetector computed tomography (MDCT) angiography to provide valuable information for surgery and its correlations with surgical findings.

Materials and Methods:

A total of 200 patients underwent MDCT angiography as a routine work up for live renal donors. The number, course, and drainage patterns of the renal veins were retrospectively observed from the scans. Anomalies of renal veins and inferior vena cava (IVC) were recorded and classified. Multiplanar reformations (MPRs), maximum intensity projections, and volume rendering were used for analysis. The results obtained were correlated surgically.

Results:

In the present study, out of 200 healthy donors, the standard pattern of drainage of renal veins was observed in only 67% of donors on the right side and 92% of donors on the left side. Supernumerary renal veins in the form of dual and triple renal veins were seen on the right side in about 32.5% of donors (dual right renal veins in 30.5% cases and triple right renal veins in 2.5% cases). Variations on the left side were classified into four groups: supernumerary, retro-aortic, circumaortic, and plexiform left renal veins in 1%, 2.5%, 4%, 0.5%, cases respectively.

Conclusions:

Developmental variations in renal veins can be easily detected on computed tomography scan, which can go unnoticed and can pose a fatal threat during major surgeries such as donor nephrectomies in otherwise healthy donors if undiagnosed.

Ex Vivo Resection and Renal Autotransplantation for the Treatment of a Large Renal Vein Aneurysm Causing Recurrent Pulmonary Embolism and a Coexisting Vascular Malformation: A Case Report

A 36-year-old young woman with a medical history of recurrent pulmonary embolism and chronic pelvic pain was admitted to our hospital. Contrast-enhanced imaging techniques revealed a large left renal vein aneurysm with a coexisting vascular mass. The patient was operated on electively, and the left kidney was autotransplanted to the right ileac fossa following the ex vivo resection of the vascular mass and the left renal vein aneurysm. Herein, we report an unusual coexistence of a vascular mass and recurrent pulmonary embolism treated successfully with our surgical treatment strategy.

Portal-systemic shunt through the right renal vein developing following portal tumor thrombus

Despite the semi-routine use of color Doppler sonography for evaluating portal circulation abnormalities, there is a relative paucity of information on portal-systemic (P-S) shunt through the right renal vein (P-SR shunt). We report such a case. The patient was a 60-year-old woman with hepatocellular carcinoma on liver cirrhosis. Serial sonography showed an aggravation in findings; an increase in the size of the tumor was followed by formation of a portal tumor thrombus, and then occurrence of a P-SR shunt. We present this case, with a comparison between the patient's clinical course and the color Doppler results. To our knowledge, this is the first report to make such a comparison in a P-SR shunt case. We also briefly review the literature.

Macroscopic hematuria caused by congenital portosystemic shunt and concomitant nutcracker syndrome

Nutcracker syndrome (NCS) is an uncommon vascular abnormality that causes a variety of symptoms that range from asymptomatic microscopic hematuria to severe pelvic congestion. Congenital portosystemic shunt (CPSS) is an extremely rare anomaly that causes serious complications. Many cases of NCS and CPSS that have presented separately have been reported, but no cases of concomitant NCS and CPSS have been reported. We present a case of intermittent macroscopic hematuria in a patient with both NCS and CPSS. We diagnosed NCS on pressure gradient between the left renal vein (LRV) and the inferior vena cava. The presence of CPSS, which emerged from the LRV and connected to the extrahepatic portal vein, was confirmed on computed tomography. The interaction between NCS and CPSS resulted in mild intermittent macroscopic hematuria only, rather than the more common symptoms that occur when NCS or CPSS present separately.

[Nutcracker syndrome - treated by surgery]

The nutcracker syndrome is caused by tight compression of the left renal vein between the superior mesenteric artery and the abdominal aorta. The consequences may vary between symptomfree conditions through moderate proteinuria and hypertension to severe hematuria. All imaging modalities have been used during diagnostic workup. Wide varieties of surgical and endovascular solutions are reported aiming to achieve decompression of the renal vein like venous or arterial transposition, bypass, renal autotransplantation, stenting, nephrectomy, etc. In our case a 21-year-old man the nutcracker syndrome was successfully solved by transposition of the superior mesenteric artery into the infrarenal aorta.

Left renal vein transposition is effective for posterior nutcracker syndrome

An 8-year-old girl was enrolled in hospital with intermittent gross hematuria in a period of 3 years. Bloody efflux from the left ureteral orifice was diagnosed in this patient with urethrocystoscopy. A retroaortic left renal vein appeared to be compressed by the aorta as detected by computerized tomography. The left renal vein was compressed between the aorta and the spine. A groove in the anterior surface of the left renal vein was detected. A transposition surgery of the left renal vein to a site in front of the aorta was performed for the patient. The patient was discharged after recovery and the hematuria symptom was not found during the 15-month follow-up investigation.

Case report: Varicosity of the communicating vein between the left renal vein and the left ascending lumbar vein mimicking a renal artery aneurysm: Report of an unusual site of varicose veins and a novel hypothesis to explain its association with abdominal pain

A communicating vein between the left renal vein and the left ascending lumbar vein has only rarely been reported in the imaging literature. There are very few reports of varicosity of this communicating vein. Nonetheless, awareness about this communicating vein is of utmost importance for surgeons performing aortoiliac surgeries and nephrectomies as it may pose technical difficulties during surgery or cause life-threatening retroperitoneal hemorrhage. Varicosity of this venous channel may be mistaken for paraaortic lymphadenopathy, adrenal pseudo-mass, or renal artery aneurysm. We report a case of a patient with varicosity of this communicating vein, which mimicked a left renal artery aneurysm. A novel hypothesis is also proposed to explain the relationship with abdominal pain.

The para-aortic ridge plays a key role in the formation of the renal, adrenal and gonadal vascular systems

Renal, adrenal, gonadal, ureteral and inferior phrenic arteries vary in their level of origin and in their calibre, number and precise anatomical relationship to other structures. Studies of the origin and early development of these arteries have evoked sharp disputes. The ladder theory of Felix, which states that 'All the mesonephric arteries may persist; from them are formed the phrenic, suprarenal, renal and internal spermatic arteries' has been generally quoted in the anatomical textbooks without rigorous verification for 100 years. In this study, we re-examined this theory by performing micro-injection of dye and resin into rat (Rattus norvegicus) embryos. Our results revealed that most of the mesonephric arteries had degenerated before the metanephros started its ascent. The definitive renal, adrenal, gonadal, ureteral and inferior phrenic arteries appeared as new branches from the gonadal artery and/or directly from the abdominal aorta to the para-aortic ridge. Coincidental to this, the anatomical architecture of the inter-renal vascular cage, which consists of the interlobar and arcuate arteries and their collateral veins, was completed within the developing metanephros. We demonstrated that the delicate renal vascular cage switched from the primary renal artery to the definitive renal artery and that the route of venous drainage changed from the posterior cardinal vein to the inferior (caudal) vena cava.