Multi-omics analysis of renal vein serum with Ischemia-Reperfusion injury.

BACKGROUND: Acute kidney injury (AKI) is frequently caused by renal ischemia-reperfusion injury (IRI). Identifying potential renal IRI disease biomarkers would be useful for evaluating AKI severity. OBJECTIVE: We used proteomics and metabolomics to investigate the differences in renal venous blood between ischemic and healthy kidneys in an animal model by identifying differentially expressed proteins (DEPs) and differentially expressed protein metabolites (DEMs). METHODS: Nine pairs of renal venous blood samples were collected before and at 20, 40, and 60 min post ischemia. The ischemia time of Group A, B and C was 20,40 and 60 min. The proteome and metabolome of renal venous blood were evaluated to establish the differences between renal venous blood before and after ischemia. RESULTS: We identified 79 common DEPs in all samples of Group A, 80 in Group B, and 131 in Group C. Further common DEPs among all three groups were Tyrosineprotein kinase, GPR15LG, KAZALD1, ADH1B. We also identified 81, 64, and 83 common DEMs in each group respectively, in which 30 DEMs were further common to all groups. Bioinformatic analysis of the DEPs and DEMs was conducted. CONCLUSION: This study demonstrated that different pathological processes occur during short- and long-term renal IRI. Tyrosine protein kinase, GPR15LG, Kazal-type serine peptidase inhibitor domain 1, and all-trans-retinol dehydrogenase are potential biomarkers of renal IRI.

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.

Impact of Left Renal Vein Ligation on Renal Function Following En Bloc Resection of Segmental Inferior Vena Cava and Right Kidney.

BACKGROUND: Renal function after left renal vein (LRV) ligation following en bloc resection of segmental inferior vena cava (IVC) and right kidney is understudied. We assessed the impact of LRV ligation on postoperative renal function following en bloc resection of segmental IVC and right kidney. METHODS: We retrospectively reviewed 28 patients who underwent LRV ligation during en bloc resection of segmental IVC and right kidney. Patient demographics, tumor characteristics, intraoperative factors, complications, length of hospital and intensive care unit (ICU) stay, and patient survival were collected. Pre- and postoperative renal function was retrospectively analyzed. RESULTS: Twenty patients underwent robot-assisted surgery and eight patients underwent open surgery. The median operative time was 162 min and estimated blood loss was 350 mL. Ten patients had normal renal function and 12 patients had an initial increase in creatinine but improved gradually. Six patients developed acute renal failure; five patients gradually recovered in 5-32 days after temporary hemodialysis. Renal replacement therapy significantly correlated with maximal anterior-posterior diameter of the LRV (p = 0.001). Complications were observed in 11 cases, four of which were Clavien-Dindo grades I-II. Thirteen patients were alive with no recurrence, nine patients were alive with metastasis, and six cases died during the follow-up period. CONCLUSIONS: LRV ligation following en bloc resection of segmental IVC and right kidney is feasible, with no significant long-term impact on renal function. The maximum anterior-posterior diameter of the LRV is a reliable method for predicting renal replacement therapy in the absence of collateral circulation.

Surgical management of renal cell carcinoma with subhepatic inferior vena cava tumor thrombus: a case report and review of the literature.

BACKGROUND: Renal cell carcinomas are the most common form of kidney cancer in adults. In addition to metastasizing in lungs, soft tissues, bones, and the liver, it also spreads locally. In 2-10% of patients, it causes a thrombus in the renal or inferior vena cava vein; in 1% of patients thrombus reaches the right atrium. Surgery is the only curative option, particularly for locally advanced disease. Despite the advancements in laparoscopic, robotic and endovascular techniques, for this group of patients, open surgery continues to be among the best options. CASE REPORT: Here we present a case of successful tumor thrombectomy from the infrahepatic inferior vena cava combined with renal vein amputation and nephrectomy. Our patient, a 58 year old Albanian woman presented to the doctors office with flank pain, weight loss, fever, high blood pressure, night sweats, and malaise. After a comprehensive assessment, which included urine analysis, complete blood count, electrolytes, renal and hepatic function tests, as well as ultrasonography and computed tomography, she was diagnosed with left kidney renal cell carcinoma involving the left renal vein and subhepatic inferior vena cava. After obtaining informed consent from the patient we scheduled her for surgery, which went well and without complications. She was discharged one week after to continue treatment with radiotherapy, chemotherapy, and immunotherapy. CONCLUSION: Open surgery is a safe and efficient way to treat renal cell carcinoma involving the renal vein and inferior vena cava. It is superior to other therapeutic modalities. When properly done it provides acceptable long time survival and good quality of life to patients.

Surgical Management of Wilms Tumors with Intravenous Extension: A Multicenter Analysis of Clinical Management with Technical Insights.

BACKGROUND: About 5% of Wilms tumors present with vascular extension, which sometimes extends to the right atrium. Vascular extension does not affect the prognosis, but impacts the surgical strategy, which is complex and not fully standardized. Our goal is to identify elements of successful surgical management of Wilms tumors with vascular extensions. PATIENTS AND METHODS: A retrospective study of pediatric Wilms tumors treated at three sites (January 1999-June 2019) was conducted. The inclusion criterion was the presence of a renal vein and vena cava thrombus at diagnosis. Tumor stage, pre and postoperative treatment, preoperative imaging, operative report, pathology, operative complications, and follow-up data were reviewed. RESULTS: Of the 696 pediatric patients with Wilms tumors, 69 (9.9%) met the inclusion criterion. In total, 24 patients (37.5%) had a right atrial extension and two presented with Budd-Chiari syndrome at diagnosis. Two died at diagnosis owing to pulmonary embolism. All patients received neoadjuvant chemotherapy and thrombus regressed in 35.6% of cases. Overall, 14 patients had persistent intra-atrial thrombus extension (58%) and underwent cardiopulmonary bypass. Most thrombi (72%) were removed intact with nephrectomy. Massive intraoperative bleeding occurred during three procedures. Postoperative renal insufficiency was identified as a risk factor for patient survival (p = 0.01). With a median follow-up of 9 years (range: 0.5-20 years), overall survival was 89% and event-free survival was 78%. CONCLUSIONS: Neoadjuvant chemotherapy with proper surgical strategy resulted in a survival rate comparable to that of children with Wilms tumors without intravascular extension. Clinicians should be aware that postoperative renal insufficiency is associated with worse survival outcomes.

Anatomy and anatomical variations of adrenal veins and its application to adrenal venous sampling.

PURPOSE: Our aim was to study the anatomy of the left and right main adrenal veins (LAV and RAV) and to identify their anatomical variations in order to see the practical application of these findings to adrenal venous sampling (AVS). METHODS: Our work is based on dissection of 80 adrenal glands from fresh corpses in the forensic medicine department. We studied the number, the drainage, the direction and the level of termination of the main adrenal veins. RESULTS: The average length of the LAV was 21 mm. It ended in 100% of cases at the upper edge of the left renal vein with a mean connection angle of 70° and after an anastomosis with the lower phrenic vein in 36 cases(90%). The average length of the RAV was 9 mm. It ended in 100% of cases at the level of the retro hepatic inferior vena cava (IVC) mainly on its posterior face in 21 cases (53%) and on its right lateral border in 18 cases (45%). The mean angle of the RAV in relation to the vertical axis of the IVC was 40°, with extremes ranging from 15° to 90°. CONCLUSIONS: AVS seems to be easier on the left than on the right side because of the greater length of the adrenal vein (21 mm vs. 9 mm) and a greater angle of connection (70° with the left renal vein vs. 40° with the IVC), which explains the lower success rate of cannulation and the more frequent occurrence of blood sample contamination on the right side.

Renal vein valves: a prevalence, microanatomical and histological study.

PURPOSE: In the modern era of robotic renal procedures and diagnostics, an even more detailed anatomical understanding than hitherto is necessary. Valves of the renal veins (RVV) have been underemphasized and have been disputed by some authors, and few textbooks describe them. The current anatomical study was performed to address such shortcomings in the literature. METHODS: One hundred renal veins were studied in fifty adult formalin-fixed cadavers. Renal veins were removed from the abdomen after sectioning them flush with their entrance to the renal hilum. The inferior vena cava was then incised longitudinally and opened, and RVV were examined grossly and histologically. A classification scheme was developed and applied to our findings. RESULTS: Nineteen RVVs were observed in the fifty cadavers (38%). Four (8%) valves were found on right sides and fifteen (30%) on left sides. The valves were seen as cord/band-like, folds, and single and double leaflets. Histologically, they were all extensions of the tunica intima. CONCLUSION: On the basis of our study, RVV are not uncommon. They were more common on left sides, and on both sides, they were found within approximately one centimeter of the junction of the inferior vena cava and renal vein. Although the function of such valves cannot be inferred from this anatomical study, the structures of the Single leaflet valve (TS2) and Double leaflet valve (TS3) valves suggest they could prevent venous reflux from the IVC into the kidney.

Postpartum ovarian vein thrombosis with left renal venous infarction after vaginal delivery.

A primipara in her late 20s presented with abdominal pain and pain in the left flank 14 days after a ventouse delivery. She was treated with antibiotics, antiemetics and analgesics with the initial differential diagnosis of cystitis, pyelonephritis or nephrolithiasis. Despite the treatment, the patient experienced increased colic pain and nausea. An ultrasound showed an enlarged left kidney, suggesting pyelonephritis, and thereby, the antibiotic treatment was adjusted accordingly. Despite additional pain medication, pain relief could not be achieved. The diagnosis of ovarian venous thrombosis was considered, and an abdominal CT scan confirmed the diagnosis. The patient was treated with anticoagulant therapy. Hypercoagulability work-up revealed a heterozygous mutation of the Factor V Leiden. Our patient awaits a haematologic follow-up.

Resection of primary left renal vein leiomyosarcoma with renal preservation following an unusual clinical presentation.

An elderly man was referred to vascular surgery on incidental discovery of a left retroperitoneal mass ultimately found to be of left renal vein (LRV) origin. He initially presented with recurring lower back pain. CT of the abdomen/pelvis showed a 6.0×5.5 cm lobulated retroperitoneal mass anterior to the infrarenal aorta. Resection of the mass necessitated a multidisciplinary team consisting of medical oncologists, radiation oncologists, urologists and vascular surgeons. In efforts to obtain an R0 margin, en-bloc resection of the LRV from its confluence with the inferior vena cava (IVC) was necessary. A primary repair of the IVC was performed with preservation of the left kidney. The patient's back pain has since resolved after the surgery. A literature search found IVC reconstructions to be safe and effective in the removal of vascular leiomyosarcomas.

[A rare malignant tumor of the renal vein]. / Une tumeur maligne rare de la veine rénale.

The renal vein is an exceptional location for leiomyosarcoma, an aggressive malignant tumor of smooth-muscle origin with a poor prognosis. We report the case of a 55-year-old female patient who consulted for left flank pain that had been present for 6 months. A CT scan revealed a 9.4cm left retroperitoneal mass in contact with the psoas muscle, left kidney, stomach, spleen, left colon and extending up to the pancreas, raising the suspicion of a tumour originating in the retroperitoneal tissues. A biopsy revealed a smooth-muscle cell tumour with a degree of malignancy difficult to define. The patient underwent a monobloc left compartmentectomy, which led to the diagnosis of leiomyosarcoma of the left renal vein. A review of the literature on these rare tumours in this location is presented.

Pre-operative colour Doppler ultrasound for the prevention of bleeding complications after renal biopsy: A rare case of left renal lower pole vein.

Albeit rare, renal vein abnormalities on autopsy and in cases of abdominal surgery complications have been reported and should be kept in mind when performing invasive procedures, such as renal biopsy. We detected a rare renal vein abnormality on colour Doppler ultrasound before renal biopsy, thereby, avoiding a haemorrhagic complication. A 10-year-old boy presented to our department for the first time because of incidental findings of haematuria and proteinuria. We suspected chronic glomerulonephritis and scheduled an ultrasound-guided percutaneous renal biopsy. A simple screening ultrasound at the initial visit revealed no renal or vascular abnormalities. The day before the renal biopsy, we confirmed the biopsy site by performing a colour Doppler ultrasound, which showed abnormal blood flow from the lower pole of the left kidney, which was the planned puncture site; therefore, we changed the biopsy site to the right and completed the examination. Subsequent computed tomography angiography depicted two renal veins; one was the usual left renal vein draining from the kidney hilum, and the second was an accessory vein draining from the inferior pole of the left kidney and entering the inferior vena cava through the dorsal side of the aorta. Although rare, abnormalities in the renal vessels on the inferior pole of the kidney, which is the usual site of renal biopsy, are essential to rule out preoperatively by colour Doppler ultrasound, because these can cause significant bleeding during renal biopsy if not recognized.

Patient-Reported Outcomes for Robot-Assisted Laparoscopic Extravascular Renal Vein Stent Placements for Nutcracker Syndrome.

Introduction: Nutcracker phenomenon is the compression of the left renal vein between the superior mesenteric artery (SMA) and the abdominal aorta. Nutcracker syndrome refers to the presence of nutcracker phenomenon with symptoms. Between 2016 and 2022, we performed 18 robot-assisted laparoscopic extravascular renal vein stent (RALERVS) placements. We sought to assess patient-reported outcomes of RALERVS placement by a single institution. Methods: We performed a single-center retrospective review of 18 patients with a minimum of 3 months follow-up. Symptoms were assessed utilizing a questionnaire conducted with a 5-point Likert scale at a minimum of 3 months postoperatively. Five on the Likert scale was severe while 1 was none. Primary study outcomes compared pre- and postoperative patient-reported symptom scores. Results: Twelve out of 18 patients responded to the survey. The average length of time from date of operation to completion of survey was 2.6 years. Average age of the cohort was 36 years with a mean BMI of 19.4 kg/m2. There was only one man. Mean operative time was 137 minutes and mean estimated blood loss was 12 mL. Mean preoperative SMA angle was 19° and mean postoperative SMA angle was 36°. Patients reported that flank pain, abdominal pain, nausea, headaches, back pain, pelvic pain, and early satiety improved (p < 0.05). Ten of 12 respondents would recommend RALERVS for nutcracker syndrome. Conclusion: RALERVS demonstrates an effective treatment for nutcracker syndrome. Patients reported improved symptoms at 3 months postoperatively across multiple domains. Further studies need to be conducted to assess long-term durability of the extravascular renal vein graft.

Role of Renal Venous Oxygen Pressure for Renal Function Monitoring After Related Living-Donor Kidney Transplantation: Cohort Study.

BACKGROUND: Monitoring of renal function after kidney transplantation (KT) is performed by measuring serum creatinine (SCr), urine volumes (UV), and glomerular filtration rate (GFR). Other methods based on oxygen metabolism, such as the renal venous oxygen pressure (PrvO2), may be useful. The aim of this study was to explore the correlation between PrvO2 and SCr, UV, and GFR 5 days after KT (SCr5, UV5, and GFR5, respectively). METHODS: We conducted a prospective cohort study in adults scheduled for living donor KT. A venous blood sample was taken from the renal vein after declamping the renal artery, and blood gas determinations were made. Correlation analyses between PrvO2 and SCr5, UV5, and GFR5 were done by calculating Spearman's correlation coefficient with generalized linear models (GLM). A Spearman's correlation analysis was performed between the percentage decrease in SCr (%ΔSCr) and PrvO2. A GLM was also performed to determine the association of PrvO2 with slow graft function (SGF). RESULTS: The study included 42 patients, of whom 67% were men. The median age was 31 years (IQR, 27-43.5). PrvO2 was negatively correlated with SCr5 (ρ = -0.53, P = .003), and positively correlated with GFR5 (ρ = 0.49, P = .001) and %ΔSCr (ρ = 0.47, P = .002). A higher PrvO2 was associated with an increase in GFR in univariable (ß = 1.24, 95% CI, 0.56-1.93, P = .001) and multivariable (ß = 1.24, 95% CI, 0.53-1.94, P = .001) analyses. No association was found between PrvO2 and SGF. CONCLUSION: PrvO2 could be used to monitor renal function in the first 5 days after related living-donor KT, given its good correlation with SCr and GFR.

Treatment of Nutcracker Syndrome with Left Renal Vein Transposition and Endovascular Stenting.

BACKGROUND: Nutcracker syndrome is a rare condition that occurs as a result of the entrapment of the left renal vein (LRV) between the aorta and the superior mesenteric artery. It is typically associated with symptoms such as left flank pain, hematuria, proteinuria, and pelvic congestion. The current treatment approach may be conservative in the presence of tolerable symptoms, and surgical or hybrid and stenting procedures in the order of priority in the presence of intolerable symptoms. The aim of this study is to review our experiences to evaluate the results of both methods in this series in which we have a greater tendency toward surgery instead of stenting. METHODS: The clinical data of consecutive patients with nutcracker syndrome who underwent LRV transposition and LRV stenting between July 2019 and October 2023 were retrospectively reviewed. The patients were divided into 2 groups based on the methods of treatment: surgical and stenting. For procedure selection, LRV transposition was primarily recommended, with stenting offered to those who declined. Primary end points were morbidity and mortality. Secondary end points included late complications, patency, freedom from reintervention, and resolution of symptoms. Standard basic statistics and survival analysis methods were employed. RESULTS: Nineteen patients with nutcracker syndrome (female: 100%) were treated with LRV stentings (n = 5) and LRV transposition (n = 14). The mean age was 24 (20-27, interquartile range [IQR]) years. The mean follow-up was 23 (9-32, IQR) months. There were no major complications and mortality after both procedures. The most frequent sign and symptom associated with LRV entrapment were left flank pain 100% (n = 19), proteinuria 88% (n = 15), and hematuria 47% (n = 9). The mean peak velocity ratio on Doppler ultrasound was 6.13 (6-6.44, IQR). Aortomesenteric angle, beak angle (beak sign), and mean diameter ratio on computed tomography were 26° (22.6-28.5, IQR), 25° (23.9-28, IQR), and 5.3 (5-6, IQR), respectively. Venous pressure measurements were only used to confirm the diagnosis in 5 patients in the stenting group. The measured renocaval gradient was 4 (3.9-4.4, IQR) mm Hg. After both procedures, the classical symptoms, including left flank pain, proteinuria, and hematuria, resolved in 89.5% (n = 17), 57.8% (n = 11), and 82.3% (n = 15) of the cases, respectively. A total of 4 patients required reintervention, 3 patients after LRV transposition (occlusion, n = 2; stenosis, n = 1), and 1 patient after stenting (occlusion, n = 1). The 1-year and 3-year primary patency for the 19 patients was 87% and 80%, respectively. Three-year primary-assisted patency was 100%. Similarly, the 1-year and 3-year freedom from reintervention rate was 83% and 72%, respectively. Additionally, the 1-year and 3-year primary patency for the surgical group was 91% and 81%, respectively, and the 1-year and 3-year primary patency for the stenting group was 75%. CONCLUSIONS: Nutcracker syndrome should be kept in mind in cases where flank pain and hematuria cannot be associated with kidney diseases. Radiographic evidence must be accompanied by serious symptoms to initiate the treatment of nutcracker syndrome with LRV transposition and endovascular stenting procedures. Both procedures, along with their respective advantages and disadvantages, can be preferred as primary treatments for nutcracker syndrome. Our study demonstrates that both procedures can be safely and effectively performed, yielding good outcomes.

Effect of left renal vein compression stenosis on functional status of left kidney in patients with pelvic venous disorders.

OBJECTIVE: We evaluated the effect of left renal vein (LRV) compression stenosis on the functional state of the left kidney in patients with pelvic venous disorders (PeVDs). METHODS: We examined 162 female patients with PeVD and diagnosed LVR compression stenosis using duplex ultrasound (DUS) in 40. Patients with clinical manifestations of PeVD (n = 26) had symptoms and signs of pelvic venous congestion but without pain in the left flank of the abdomen, typical for nutcracker syndrome (NS). The remaining patients were asymptomatic (n = 14). The parameters measured with DUS included the angle of the superior mesenteric artery (SMA) with the aorta, the LRV diameter (Dhilum/Dstenosis) ratio, and LRV velocity (Vstenosis/Vhilum) ratio. All the patients underwent laboratory testing (complete blood count, urinalysis, and biochemical blood testing) and dynamic renal scintigraphy to assess the secretory and evacuation functions of the renal tubular system. RESULTS: The laboratory tests revealed no abnormalities, including no hematuria or proteinuria, in either group. The Dhilum/Dstenosis and Vstenosis/Vhilum ratios varied from 2.8 to 5.2 and from 2.9 to 8.3, respectively, and did not differ between the symptomatic and asymptomatic patients. All 40 patients with LRV compression stenosis were diagnosed with left gonadal vein reflux with a mean duration of 4.7 ± 0.6 seconds and 2.2 ± 0.6 seconds in the symptomatic and asymptomatic patients, respectively (P = .005). Eight patients had signs of NS on DUS, including five in the symptomatic group (SMA angle, 34.8° ± 2.7°; Dhilum/Dstenosis ratio, 5.2 ± 0.2; and Vstenosis/Vhilum ratio, 5.7 ± 0.4) and three in the asymptomatic group (SMA angle, 35° ± 2.8°; Dhilum/Dstenosis ratio, 5; and Vstenosis/Vhilum ratio, 5 ± 0.5). The groups did not differ significantly in the DUS parameters. Scintigraphy did not reveal any cases of secretory or evacuation dysfunction of the left kidney, including in the patients with DUS signs of NS. The maximum uptake time, elimination half-life, and effective renal plasma flow were within the normal ranges. CONCLUSIONS: LRV compression stenosis without hematuria has no significant effects on the functional state of the left kidney, irrespective of the disease severity. In patients with PeVDs, dynamic renal scintigraphy provides an objective assessment of left kidney function.

Venous vascular reconstruction of a robotically procured right kidney with two renal veins transplanted into a pediatric recipient.

BACKGROUND: Right versus left kidney donor nephrectomy remains a controversial topic in renal transplantation given the increased incidence of right kidney vascular anomalies and associated venous thrombosis. We present the case of a 3-year-old pediatric recipient with urethral atresia and end-stage kidney disease who received a robotically procured living donor right pelvic kidney with two short same-size renal veins and a short ureter. METHODS: We utilized a completely deceased iliac vein system (common iliac vein with both external and internal veins) to extend the two renal veins. Due to the distance between both renal veins, the external iliac vein was anastomosed to the upper hilum renal vein, and the internal iliac vein was anastomosed to the lower hilum renal vein. The donor's short ureter was anastomosed to the recipient's ureter end-to-side. RESULTS: The patient had immediate graft function and there were no post-operative complications. Renal ultrasound was unremarkable at 48 hours post-transplant. Serum creatinine was 0.5 mg/dL at 3 months post-transplant. CONCLUSION: We demonstrate the successful transplantation of a robotically procured right pelvic donor kidney with two short renal veins using a deceased donor iliac vein system for venous reconstruction without increasing technical complications. This technique of venous reconstruction can be used in right kidneys with similar anatomical variations without affecting graft function.