Case of Isolated Absence of the Azygos Vein: Evaluation Using Photon-counting Detector CT.

The isolated absence of the azygos vein was incidentally found on computed tomography (CT) examination in a 60-year-old female. The exact anomaly can be evaluated on high-resolution images of 0.4-mm slice thickness with low keV using photon-counting detector CT. The azygos vein, including the azygos arch, was absent, and a mildly dilated hemiazygos vein flowed to the left brachiocephalic vein through the left superior intercostal vein. A hemiazygos vein connected the left renal vein at the level of the first lumbar vertebra. This patient was the second patient to undergo evaluation using volume rendering images. High-resolution maximum-intensity projection images were useful for assessing the anatomy. Radiation dose was decreased compared with that in conventional CT.

A new notable compression source of left renal vein entrapment: right renal artery.

PURPOSE: To estimate the incidences of left renal vein (LRV) entrapment by right renal artery (RRA), a phenomenon primarily reported as case reports. METHODS: The cross-sectional study consecutively screened renal vessel CT data of 38 (Renal) patients with nephropathy and 305 (Non-renal) patients with peripheral arterial diseases in a teaching hospital in northeast China between November 2018 and March 2023. The LRV compression by adjacent anatomical structures, including but not limited to RRA and multiple compression-related parameters, were investigated through multiplanar analysis of the CT data. RESULTS: The overall LRV entrapment rates by adjacent structures were 41.93% (12/31) and 24.00% (6/25), the rates of RRA-sourced LRV compression 22.58% (7/31) and 20.00% (5/25), and the rates of compression by superior mesenteric artery (SMA) 16.13% (5/31) and 4.00% (1/25) in the Renal and Non-renal groups, respectively, with no significance. The venous segments distal to the RRA-compressed site had a significantly larger transectional lumen area than those of the non-compressed veins in both groups (3.09 ± 1.29 vs. 1.82 ± 0.23, p < 0.001 and 4.30 ± 2.65 vs. 2.12 ± 0.55, p = 0.006; maximum-to-minimum area ratios in Renal and Non-renal groups, respectively). Nearly 80% of RRAs were found arising anteriorly rightwards instead of passing straight to the right. CONCLUSION: RRA-sourced LRV compression was not rare, and its incidence was higher than that of the compression by SMA in both patient cohorts. RRA could be a more common compression source than SMA concerning LRV entrapment. Further investigations involving different populations, including healthy individuals, are needed.

Transarterial Embolization of Renal Arteriovenous Malformations: Treatment Outcomes According to Angiographic Classification.

PURPOSE: To assess the different adjunctive catheter techniques required to achieve complete occlusion of renal arteriovenous malformations (rAVMs) of different angioarchitectural types. MATERIALS AND METHODS: Overall, data on 18 patients with rAVM (Type 1, n = 7; Type 2, n = 2; Type 3, n = 9; mean age, 53.8 years) who underwent 25 procedures between 2011 and 2022 were reviewed. The clinical presentations, endovascular techniques, arteriovenous malformation (AVM) occlusion rate, adverse events (including the incidence of renal infarction), and clinical symptoms and outcomes (including recurrence/increase of AVM) were analyzed according to the Cho-Do angioarchitectural classification. Posttreatment renal infarction was classified as no infarction, small infarction (<12.5%), medium infarction (12.5%-25%), and large infarction (>25%) using contrast-enhanced computed tomography or magnetic resonance imaging. RESULTS: Hematuria and heart failure were presenting symptoms in 10 and 2 patients, respectively. The embolic materials used were as follows: Type 1 rAVM, coils alone or with n-butyl-2-cyanoacrylate (nBCA); Type 2 rAVM, nBCA alone or with coils; and Type 3 rAVMs, nBCA alone. Fourteen patients underwent adjunctive catheter techniques, including flow control with a balloon catheter and multiple microcatheter placement, alone or in combination. Immediate postprocedural angiography revealed complete occlusion in 15 patients (83%) and marked regression of rAVM in 3 (17%). Small asymptomatic renal infarctions were observed in 6 patients with Type 3 rAVMs without any decrease in renal function. No major adverse events were observed. All symptomatic patients experienced symptom resolution. Recurrence/increase of rAVM was not observed during the mean 32-month follow-up period (range, 2-120 months). CONCLUSIONS: Transarterial embolization using adjunctive catheter techniques according to angioarchitectural types can be an effective treatment for rAVMs.

Orthostatic proteinuria due to inferior vena cava interruption without nutcracker phenomenon in an old obese female: a case report and literature review.

BACKGROUND: Nutcracker syndrome (NCS) caused by left renal vein (LRV) entrapment, is one of the most common causes of orthostatic proteinuria. In stereotype, orthostatic proteinuria is often accompanied by left renal vein obstruction and is found in young and underweight individuals. Here, we report a rare case with orthostatic proteinuria in an old obese female caused by a rare type of congenital inferior vena cava (IVC) interruption. CASE PRESENTATION: A 65-year-old obese woman, who suffered from fluctuated proteinuria, had been misdiagnosed as chronic glomerulitis for 30 years. Instead of having any sign of NCS, she had a unique type of IVC interruption. Most venous blood from infrarenal IVC and right kidney drained into her LRV, and then through the expanded communicating vessel, drained into the left ascending lumbar vein which extended as hemiazygos vein. To the best of our knowledge, this is one of the first cases reported of orthostatic proteinuria attributed to the subsequent hemodynamic irregularity caused by IVC interruption without nutcracker phenomenon. CONCLUSION: Adult-onset orthostatic proteinuria is relatively rare, hard to be recognized and could be misdiagnosed as chronic glomerulonephritis. The case provided a novel differential diagnostic condition for those who suffered from fluctuated proteinuria of unknown causes.

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.

An Uncommon Variant of Nutcracker Syndrome Secondary to Left Renal Vein Compression Between the Right Renal Artery and The Proper Hepatic Artery.

Nutcracker syndrome refers to the compression of the left renal vein between the abdominal aorta and the superior mesenteric artery. The subsequent venous congestion of the left kidney, when symptomatic, could be associated with left flank pain, hematuria, varicocele, dyspareunia, dysmenorrhea, and proteinuria. Here we describe a 42-year-old female patient with simultaneous Dunbar syndrome and a rare variant of nutcracker syndrome in which the left renal vein (LRV) compression is secondary to the unusual path of the vein between the right renal artery and the proper hepatic artery. For both the nutcracker syndrome and the Dunbar syndrome, open approach by median mini-laparotomic access for transposition of LRV, and resection of the diaphragmatic pillars and arcuate ligament was attempted. During the intervention, due to anatomical issues, the LRV transposition was converted to endovascular stenting of the LRV, moreover the implanted stent was transfixed with an external non-absorbable suture to avoid migration. At the 12 months follow-up the patient was asymptomatic, and the duplex scan confirmed the patency of the celiac trunk without re-stenosis and a correct position of the LRV stent with no proximal or distal migration.

Triple Retroaortic Renal Vein With Tumor Thrombus.

A case report of a 51-year-old man with left renal tumor and level II vena cava tumor thrombus (thrombus extending >2 cm above the renal vein, but below the hepatic veins) in a rare anatomical variant of renal vein. In nonmetastatic patients, aggressive surgical resection is widely accepted as the standard management option, but some doubts about the best practice in these patients are relevant. Surgical approach on those patients is a challenge for the surgeons, and anatomical variants make the procedure even more difficulty. These patients should be referring to a tertiary center because of the potential perioperative complexity.

Endovascular management of a patient with massive renal arteriovenous fistula: challenges and tricks.

We describe the endovascular management of a patient with a massive renal arteriovenous fistula and a huge venous aneurysmal sac, who presented with features of cardiac failure and fever. The challenges faced and the outcomes are discussed with relevant literature review.

Hypertension Caused by Renal Arteriovenous Fistula with Multiple Renal Artery Aneurysms.

Renal arteriovenous fistula with renal artery aneurysms and dilated renal veins presents as an infrequent lesion. Endovascular therapy has recently been considered the first-line treatment for these conditions. We report a case of a patient with idiopathic renal arteriovenous fistula concomitant with multiple renal artery aneurysms that was successfully treated by the placement of a covered stent.

Coexistence of a rare type of ectopic kidney with atypical renal vasculature.

Knowledge of anatomical anomalies is significant for all specialists in clinical practice and may prevent serious complications following medical procedures. This report presents the rare crossed fused renal ectopia (CFRE) with atypical renal vasculature in cadaver of a 68-year-old man. The ectopic kidney was located on right side with four renal veins, three renal arteries, two ureters, where one of them is double. The embryological background, as well as the potential clinical significance of this morphological variation, is discussed. An interventional radiological and surgical procedure should be appropriately implemented to treat anomalies of vessels and CFRE.

Endovascular treatment of anterior nutcracker syndrome and pelvic varices in a patient with an anterior and a posterior renal vein.

There are few data on endovascular treatment of anterior nutcracker syndrome and pelvic varices in patients with anterior and posterior renal veins. Our objective is to report a case, identify occurrences and compare diagnosis and treatments. A 42-year-old woman presented with flank and pelvic pain and hematuria. She had anterior nutcracker syndrome and pelvic varices with an anterior and a posterior renal vein. A successful complete endovascular approach was done with stent implantation in the anterior renal vein and left gonadal vein embolisation. After 12-month follow-up, the patient remained asymptomatic with good results on CT. Only two case reports of patients with nutcracker syndrome with anterior and posterior renal veins were identified. In both, a self-expanding stent was implanted in the anterior renal vein. In conclusion, endovascular treatment represents a safe and successful option in patients with nutcracker syndrome and pelvic varices with an anterior and a posterior renal vein.

Renal transplantation using vascular conduit reconstruction in deceased kidneys with multiple renal arteries and short renal veins. / Trasplante renal mediante reconstrucción de conducto vascular en riñones de donantes fallecidos con arterias renales múltiples y venas renales cortas.

BACKGROUND: Transplantation of kidneys with vascular anatomical variants remains a challenge. Due to its varying success in regard to graft function after transplantation, these organs have been frequently discarded assuming in advance an unaffordable rate of vascular complications. PATIENTS AND METHODS: We performed three kidney transplants using organs from deceased donors harboring vascular variants (multiple arteries and short veins), including an unsplittable horseshoe kidney. Different grafts harvested from the same donor aorta, common iliac artery, and inferior vena cava, were used to reconstruct the initial vascular configuration by creating single arterial and venous conduits aimed to simplify the vascular anastomoses in the recipient. RESULTS: No post-operative complications were recorded. Warm ischemia times remained comparable to single artery renal allografts. No delayed graft function was noted in any case, and every patient regained normal renal function after transplantation. CONCLUSIONS: Vascular reconstruction using arterial and venous grafts harvested from the same deceased donor may result a helpful tool to simplify vascular anastomoses during transplantation surgery, thus avoiding their discard in advance, minimizing perioperative complications, and enabling normal graft function rates in the long-term follow-up. The successful outcome obtained by using this approach would help to expand the donor criteria for the inclusion of organs containing vascular anatomical variants.

Is a Retroaortic Vein a Risk Factor in Laparoscopic Living Donor Nephrectomy?

INTRODUCTION: In living donor transplantation choosing the right donor and donor side for laparoscopic donor nephrectomy is a challenging task in clinical practice. Knowledge about anomalies in renal blood supply are crucial to evaluate the feasibility of the operative procedure. Few data so far exist whether the existence of a retroaortic left renal vein has an impact on living kidney transplantation outcome for donor and recipient. MATERIALS AND METHODS: We retrospectively analyzed 221 patients who underwent laparoscopic living donor nephrectomy between 2011 and 2017 for existence of a retroaortic left renal vein. Clinical characteristics and operative outcomes for donors and recipients were analyzed. RESULTS: 221 patients underwent donor nephrectomy between 2011 and 2017; 11 patients (4.98%) showed the feature of a retroaortic left renal vein, and in 8 patients (72.7%) out of those 11 the left kidney was chosen for transplantation. Mean preoperative serum creatinine was 0.77 (0.49-0.98) mg/dL and 1.28 (0.97-1.64) mg/dL at discharge. In recipients mean serum creatinine preoperatively, after 1 week, 1 month,1 year, 2 and 3 years of follow-up was 10.36 (6.09-20.77) mg/dL, 1.71 (0.67-2.72), 1.33 (0.70-1.89), 1.31 (0.95-2.13), 1.31 (0.98-2.13) and 1.33 (1.03-1.84), respectively. Neither donors nor recipients suffered from any operative complications. CONCLUSIONS: Laparoscopic living donor nephrectomy of a left kidney with retroaortic renal vein is safe for the donor, without limitation in the outcome for the recipient.

A Case of Nutcracker Syndrome Combined with Wilkie Syndrome with Unusual Clinical Presentation.

BACKGROUND Nutcracker syndrome and Wilkie's syndrome are rare vascular diseases due to the abnormal course of the superior mesenteric artery originating from the abdominal aorta with reduced angle (<22°) and consequent compression of the left renal vein (nutcracker) and duodenum (Wilkie). Here, we report the case of a patient with a rare combination of these 2 syndromes and with unusual clinical manifestation of post-prandial pain. CASE REPORT We describe the case of a young male patient with rapid weight loss, coupled with post-prandial abdominal pain, with sub-acute onset, not associated with other symptoms. The ultrasound examination found an aorto-mesenteric angle of 18° and compression of the left renal vein and left varicocele. A CT study was performed to exclude oncological diseases and/or other pathologies responsible for the pain and weight loss, which confirmed the ultrasound findings and showed compression of the third part of the duodenum. The patient underwent endovascular treatment, with stent placement in the left renal vein, which resolved the vascular compression and of the duodenum, with regression of symptoms. CONCLUSIONS The ultrasound scan promptly highlighted the reduction of the aorto-mesenteric angle and the signs of venous congestion of the left renal vein. Based on this experience, in patients with weight loss and post-prandial pain, in our opinion, diagnostic investigations should also be extended to the study of the aorto-mesenteric angle to confirm or exclude any vascular and/or duodenal compression.

Case Report of a Pelvic Crossed Fused Renal Ectopic Kidney.

Herein we present a case of a horseshoe kidney with crossed fused renal ectopia. Both of these pathologies are congenital anomalies; however, to date, there are few cases that present with both. In this case, discovered during routine dissection, the fused kidney was mostly left-sided and very low in the pelvis. No renal artery arose from the right wall of the abdominal aorta, and the right renal vein drained into the lower part of the inferior vena cava (IVC) where the right and left common iliac veins joined. It is essential for clinicians and surgeons to understand these types of congenital anomalies, as they could impact patient care.

Robotic assisted extravascular stent placement for nutcracker phenomenon of the left renal vein: a case series.

Nutcracker phenomenon of the left renal vein is a rare anatomic anomaly that can present with chronic flank/pelvic pain, pelvic congestion, and hematuria. Conventional treatment options (superior mesenteric artery transposition, endovascular stent placement, auto-transplantation) involve substantial risk, morbidity, or the need for chronic anti-coagulation. We now report our institution's robotic experience with extravascular left renal vein stent placement. A retrospective, single surgeon series from December 2016 to May 2019 was reviewed. After positioning and port placement (three robotic ports, one assistant), the left renal vein was exposed and dissected free circumferentially down to the inferior vena cava insertion. The distance between the renal vein ostium and adrenal vein was measured and a 1 cm-diameter ringed polytetrafluoroethylene vascular stent of this length placed. The stent edges were secured to itself with 3-0 polyglactin sutures. Demographics, surgical, and functional outcomes were collected. Six patients with mean age of 45 ± 6 years and body mass index of 20.3 ± 3.3 g underwent the procedure. Mean operative time was 143 ± 20 min. Estimated blood loss was minimal. Mean graft length utilized was 2.25 ± 0.3 cm. Median day of discharge was 1.5 days (range 1-3). No high-grade complications occurred. All patients received immediate pain relief and 50% also saw other symptomatic improvements. Robotic assisted extravascular left renal vein stent placement appears safe and effective in a small cohort with short follow-up. Further long-term follow-up for pain relief and graft-related complications are needed.

RENAL VEIN THROMBOSIS DUE TO POSTERIOR NUTCRACKER SYNDROME.

Thrombosis of the left renal vein (LRV) is a rare occurrence usually associated with hypercoagulable disorders. It may also be caused by extrinsic compression due to anatomical variations. Such variations, known as nutcracker phenomenon (NP), are usually completely asymptomatic, and they have been described in three variants: a narrowed aortomesenteric angle (AMA) with entrapment of the LRV; a second, rarer variant with an anomalous retro aortic LRV compressed between the abdominal aorta (AA) and the spine (posterior nutcracker syndrome, PNCS); and a third variant with a duplicated LRV with a pre- and retroaortic course, compressed both anteriorly and posteriorly. The development of symptoms secondary to NP is mainly due to renal congestion, often difficult to identify, and includes flank pain, ipsilateral varicocele, hematuria, and orthostatic proteinuria, among others. The most severe complication of NCS is LRV thrombosis with or without associated predisposing prothrombotic factors. The present case associates a PNCS to LRV thrombosis with a floating thrombus in the inferior vena cava and pulmonary embolism.