A Novel Approach for the Treatment of Nutcracker Syndrome: A Case Report.

We describe a case of nutcracker syndrome in a 35 year-old male that was treated with a left renal vein transposition via an open retroperitoneal approach. Our case highlights some of the advantages of the retroperitoneal approach, which may decrease the risk of postoperative complications when compared to the traditional midline abdominal transperitoneal approach. The patient agreed to publish the case details and images included below.

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.

Nutcracker syndrome.

This study represents a concise review of Nutcracker syndrome with its history, incidence, clinical presentation and currently available diagnostic criteria and treatment options. This should help any clinician identify and better serve patients with rare venous disorders such as this. Although the literature is scarce, clinicians should be keen to diagnose and treat patients with this potentially debilitating syndrome.

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.

The use of venous Doppler to predict adverse kidney events in a general ICU cohort.

BACKGROUND: Changes in Doppler flow patterns of hepatic veins (HV), portal vein (PV) and intra-renal veins (RV) reflect right atrial pressure and venous congestion; the feasibility of obtaining these assessments and the clinical relevance of the findings is unknown in a general ICU population. This study compares the morphology of HV, PV and RV waveform abnormalities in prediction of major adverse kidney events at 30 days (MAKE30) in critically ill patients. STUDY DESIGN AND METHODS: We conducted a prospective observational study enrolling adult patients within 24 h of admission to the ICU. Patients underwent an ultrasound evaluation of the HV, PV and RV. We compared the rate of MAKE-30 events in patients with and without venous flow abnormalities in the hepatic, portal and intra-renal veins. The HV was considered abnormal if S to D wave reversal was present. The PV was considered abnormal if the portal pulsatility index (PPI) was greater than 30%. We also examined PPI as a continuous variable to assess whether small changes in portal vein flow was a clinically important marker of venous congestion. RESULTS: From January 2019 to June 2019, we enrolled 114 patients. HV abnormalities demonstrate an odds ratio of 4.0 (95% CI 1.4-11.2). PV as a dichotomous outcome is associated with an increased odds ratio of MAKE-30 but fails to reach statistical significance (OR 2.3 95% CI 0.87-5.96), but when examined as a continuous variable it demonstrates an odds ratio of 1.03 (95% CI 1.00-1.06). RV Doppler flow abnormalities are not associated with an increase in the rate of MAKE-30 INTERPRETATION: Obtaining hepatic, portal and renal venous Doppler assessments in critically ill ICU patients are feasible. Abnormalities in hepatic and portal venous Doppler are associated with an increase in MAKE-30. Further research is needed to determine if venous Doppler assessments can be useful measures in assessing right-sided venous congestion in critically ill patients.

Chronic elevation of renal venous pressure induces extensive renal venous collateral formation and modulates renal function and cardiovascular stability in rats.

Acutely increased renal venous pressure (RVP) impairs renal function, but the long-term impact is unknown. We investigated whether chronic RVP elevation impairs baseline renal function and prevents exacerbation of renal dysfunction and cardiovascular instability upon further RVP increase. RVP elevation (20-25 mmHg) or sham operation (sham) was performed in rats. After 1 wk (n = 17) or 3 wk (n = 22), blood pressure, RVP, renal blood flow (RBF), renal vascular conductance (RVC), and glomerular filtration rate (GFR) were measured at baseline and during superimposed RVP increase. Chronic RVP elevation induced extensive renal venous collateral formation. RVP fell to 6 ± 1 mmHg at 1 wk and 3 ± 1 mmHg at 3 wk. Baseline blood pressure and heart rate were unaltered compared with sham. RBF, RVC, and GFR were reduced at 1 wk but normalized by 3 wk. Upon further RVP increase, the drop in mean arterial pressure was attenuated at 3 wk compared with 1 wk (P < 0.05), whereas heart rate fell comparably across all groups; the mean arterial pressure-heart rate relationship was disrupted at 1 and 3 wk. RBF fell to a similar degree as sham at 1 wk (-2.3 ± 0.7 vs. -3.9 ± 1.2 mL/min, P = 0.066); however, at 3 wk, this was attenuated compared with sham (-1.5 ± 0.5 vs. -4.2 ± 0.7 mL/min, P < 0.05). The drop in RVC and GFR was attenuated at 1 and 3 wk (P < 0.05). Thus, chronic RVP elevation induced by partial renal vein ligation elicits extensive renal venous collateral formation, and although baseline renal function is impaired, chronic RVP elevation in this manner induces protective adaptations in kidneys of healthy rats, which attenuates the hemodynamic response to further RVP increase.

Intervention on Spontaneous Splenorenal Shunt May Decrease the Incidence of Acute Kidney Injury After Liver Transplant.

OBJECTIVES: Spontaneous splenorenal shuntis a type of portosystemic shunt that develops frequently in the setting of chronic portal hypertension. It remains controversial whether shuntinterventions during liver transplant improve transplant outcomes. MATERIALS AND METHODS: We conducted a retrospective comparison between deceased-donor liver transplant recipients who received spontaneous splenorenal shunt intervention and those who did not at a tertiary center between 2012 and 2017. Primary outcomes of interest included intraoperative transfusion requirement, hospital length of stay, acute kidney injury posttransplant, portal vein thrombosis, thrombocytopenia, and 1-year graft and patient survival. RESULTS: Of 268 liver transplant recipients, 50 (18.6%) had large spontaneous splenorenal shunts pretransplant, with 45 patients having available radiologic and outcome data. Nine of 45 patients (20%) received shunt intervention, including pretransplant balloonoccluded retrograde transvenous obliteration (n = 5), intraoperative ligation of the left renal vein (n = 3), and intraoperative direct shunt ligation (n = 1). Demographic data, clinical characteristics, and Model for End-Stage Liver Disease scores were not different between the intervention and the nonintervention groups. Intraoperative transfusion, length of hospitalization, portal vein thrombosis, thrombocytopenia, and 1-year graft and patient survival were also similar between the 2 groups. However, the rate of posttransplant acute kidney injury was significantly lower in patients in the intervention group (0 cases vs 12 cases; odds ratio = 0.73; 95% confidence interval, 0.59-0.90). Patients with no SRS intervention (n = 36) were followed radiologically for 1 year posttransplant, with follow-up data showing complete resolution of spontaneous splenorenal shunt in just 4 patients (15%) and no changes in the remaining patients. CONCLUSIONS: Peritransplant interventions for spontaneous splenorenal shunt may reduce posttransplant acute kidney injury. In patients without intervention, spontaneous splenorenal shunt predominantly persisted 1 year posttransplant.

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.

Salvage Renal Autotransplant Following Previous Renal Vein Stenting in Nutcracker Syndrome.

OBJECTIVES: Nutcracker syndrome is rare, and a proportion of patients with this syndrome continue to have intractable pain and symptoms. Due to the heterogeneity of patients' chief complaints and symptoms, the surgeon's preferred approach may be inherently different but is of paramount importance to the outcome. MATERIALS AND METHODS: We present 4 cases in which renal autotransplant with extraction and ligation of previously placed gonadal coils was performed following previously attempted renal vein stenting or combined renal vein transposition followed by renal vein stenting. RESULTS: Autotransplant resulted in flank pain resolution with improvement in symptoms associated with pelvic congestion syndrome. CONCLUSIONS: The approach to such cases requires meticulous and adequate vena cava exposure, with preparation for potential caval reconstruction. No firm inferences can be made from such a small series; however, we believe in renal autotransplant as first-line therapy, and failure after an initial renal vein stent should be salvaged by renal autotransplant over further endovascular attempts.

The Effect of Left Renal Vein Division on Renal Function Following Open Abdominal Aortic Surgery Using Propensity Score Matching Analysis.

BACKGROUND: Open surgery of abdominal aortic aneurysm (AAA) or aortoiliac occlusive disease (AIOD) sometimes requires left renal vein division (LRVD) to gain adequate exposure of the abdominal aorta. The aim of this study is to evaluate the effect of LRVD on the postoperative renal function using propensity score matching (PSM). METHODS: From July 1996 to January 2018, we retrospectively reviewed 698 patients who underwent open aortic surgery, including 543 AAAs and 155 AIODs, at a single institution. 66 patients (9.6%, 47 AAAs, 19 AIODs) needed LRVD during the operation. A 1:3 ratio PSM was used to control the selective bias between the LRVD and non-LRVD groups. We investigated preoperative and postoperative renal function including serum creatinine (sCr) level and estimated glomerular filtration rate (eGFR, mL/min/1.73 m2). Major complications, long-term renal function, and 30-day mortality were also compared. RESULTS: The LRVD group had a significantly higher rate of renal artery reconstruction (15.2% vs. 3.3%, P < 0.001) and suprarenal clamping (54.6% vs. 9.5%, P < 0.001) and higher incidence of juxtarenal AIOD (24.2% vs. 5.4%, P < 0.001). With PSM, 63 patients in the LRVD group and 144 patients in the non-LRVD group were enrolled in this study. The baseline characteristics were well balanced in the groups after PSM. There were no significant differences in preoperative eGFR (72.4 ± 21.3 vs. 76.1 ± 25.0, P = 0.306) and postoperative eGFR on day 3 (69.5 ± 26.6 vs. 77.5 ± 28.5, P = 0.065), day 7 (73.3 ± 24.8 vs. 78.5 ± 27.4, P = 0.264), and in the long-term follow-up period (69.0 ± 22.2 vs. 68.9 ± 27.1, P = 0.986, 50.2 month ± 45.50) in the 2 groups. Only the sCr level (1.40 ± 0.59 vs. 1.21 ± 0.62, P = 0.045) and eGFR (59.5 ± 23.9 vs. 71.4 ± 26.0, P = 0.002) were significantly worse on postoperative day 1 in the LRVD than in the non-LRVD group. There were no significant differences in 30-day mortality (1.6% vs. 1.6%, P = 1.00). CONCLUSIONS: The patients in the LVRD group underwent initial drop in renal function; however, eGFR improved during the follow-up period. There was no difference in renal function and postoperative mortality between LRVD and non-LRVD groups. Therefore, LRVD is a safe and durable procedure during complex abdominal aortic surgery.

Nutcracker Syndrome as an Unusual Cause of Postprandial Pain.

Nutcracker syndrome is a rare entity in which compression of the left renal vein (LRV), usually by the overlying superior mesenteric artery (SMA), results in renal venous congestion and reflux in the left ovarian vein (LOV). Patients may present with hematuria, left flank pain, dyspareunia, and vaginal or abdominal wall varicose veins. We report a patient with nutcracker syndrome who presented atypically with left flank pain that was exacerbated in the postprandial state. We hypothesize that the physiologic dilation of the SMA after oral intake caused increased LRV compression at that site and augmented lateral LRV distention. The patient had no evidence of SMA syndrome or chronic mesenteric insufficiency. Her symptoms resolved after we performed an LOV to inferior vena cava transposition.

Outcomes of left renal vein stenting in patients with nutcracker syndrome.

BACKGROUND: Nutcracker syndrome (NCS) is a rare condition that can be manifested with hematuria, flank pain, pelvic varicosities, or chronic pelvic congestion related to left renal vein (LRV) compression. Open surgery, specifically LRV transposition, has been the mainstay of treatment, but in the past few years, LRV stenting has emerged as a less invasive alternative without sufficient evidence to support it. This study aimed to assess outcomes of renal vein stenting in the treatment of NCS. METHODS: A retrospective chart review of patients with NCS who underwent LRV stenting between 2010 and 2018 was performed. End points were perioperative adverse outcomes, symptom relief, and stent patency. Symptom resolution was classified as complete, partial, and none on the basis of the interpretation of medical records on clinical follow-up. Standard descriptive statistics and survival analysis were used. RESULTS: Eighteen patients (17 female; mean age, 38.1 ± 16.9 years) diagnosed with NCS and treated with LRV stenting were identified. Five of these had a prior LRV transposition that had failed within a mean of 7.0 ± 4.9 months, manifested by symptom recurrence (or no improvement) along with imaging evidence of persistently severe renal vein stenosis. Twelve patients had coexisting pelvic congestion syndrome treated with gonadal vein embolization. The most frequent sign and symptom were hematuria (10/18 patients) and flank pain (15/18 patients), respectively. All patients received self-expanding stents (mean diameter, 12.8 ± 1.6 mm), the smaller ones typically placed in the previously transposed LRVs. No perioperative complications occurred. Nine patients were discharged on the same day; the remaining patients stayed longer for pain control (mean hospital stay, 1.0 ± 1.3 days). At an average follow-up of 41.4 ± 26.6 months, 13 (72.2%) patients had symptoms resolved or improved (9 complete, 4 partial). Three of the five patients whose symptoms remained unchanged had previous LRV transposition surgery, and two of these three patients eventually required renal autotransplantation. Six of 10 patients who presented with hematuria had it resolved. Three patients underwent a stent reintervention at 5.8 months, 16.8 months, and 51.7 months because of symptom recurrence or stent restenosis. The two early ones required balloon venoplasty and the third one restenting. Two-year primary and primary assisted patency was 85.2% and 100%, respectively. No stent migration occurred. CONCLUSIONS: Endovascular treatment with renal vein stenting is safe, providing encouraging results with good midterm patency rates and symptom relief. Minimally invasive approaches may have a potential role in the treatment of NCS. Larger series and longer follow-up are needed to better assess the comparative performance against LRV transposition.

Posture commonly and considerably modifies stenosis of left common iliac and left renal veins in women diagnosed with pelvic venous disorder.

OBJECTIVE: Pelvic venous incompetence or pelvic congestion syndrome (commonly referred to as pelvic venous disorder [PVD]) is increasingly diagnosed, especially in multiparous women. This may be either primary or secondary to pelvic venous outflow obstruction-left common iliac vein (LCIV) or left renal vein (LRV) stenosis. Intravascular ultrasound (IVUS) examination performed in the supine position is commonly used for diagnosis of LRV and LCIV stenosis; however, body position may affect the cross-sectional area (CSA) of both of these veins during IVUS. The aim of the study was to test the hypothesis that postural changes may significantly affect the CSA of the LRV and LCIV. METHODS: A single-arm, single-center cohort study of women suffering from PVD was performed at a tertiary hospital in Poland. It comprised consecutive patients with either pelvic vein reflux or suggestion of LCIV or LRV obstruction but no signs of deep venous thrombosis. IVUS examination of the iliac veins, inferior vena cava, and LRV was performed in the supine position. IVUS of the LRV and LCIV was performed also with a Valsalva maneuver and with patients lying on the left side and standing. A 60% CSA reduction was used as a cutoff value between significant and nonsignificant vein stenosis. RESULTS: A total of 41 women were examined. Significant stenosis of the LRV was seen in 22 patients (55%) supine but in only 4 (10%) patients studied when lying on the left side and in 27 (67.5%) patients studied while standing. Significant stenosis of the LCIV was seen in 26 supine patients (63.4%), in 8 lying on the left side (19.5%), and in 10 (24.4%) standing. CONCLUSIONS: Postural changes dramatically affect CSA of the LCIV and LRV and thus the degree of stenosis in women diagnosed with PVD. Stenosis found in patients while supine often disappears when the position is changed to lying on the left side or to standing. Therapeutic decisions based on assessment of CSA reduction in the supine position are likely to be inadequate.

Effect of Intraoperative Division of the Left Renal Vein on the Fate of Renal Function and Left Renal Volume After Open Repair of Para- and Juxtarenal Aortic Aneurysm.

BACKGROUND: The effect of left renal vein division (LRVD) during open surgery (OS) for pararenal and juxtarenal abdominal aortic aneurysm (P/JRAA) on postoperative renal function remains controversial, so we focused on chronic renal decline (CRD) and separately examined renal volume as a surrogate index of split renal function.Methods and Results:The 115 patients with P/JRAA treated with OS from June 2007 to January 2017 were reviewed: 26 patients without LRVD were matched to 27 patients with LRVD according to preoperative chronic kidney disease (CKD) stage and proximal clamp sites. The effect of LRVD on CRD was investigated by a time-to-event analysis. During a median follow-up of 23.5 months, CRD occurred in 5 patients with LRVD and in 4 patients without LRVD. Comparison of freedom from CRD showed no significant difference between the matched groups (P=0.870). The separate renal volumes were evaluated before surgery and at 1 and 2 years of follow-up using CT images from 18 patients with LRVD. At 2 years, the mean renal volume had decreased by 15% in the left kidney and by 9% in the right kidney (P=0.052 and 0.148, respectively), but the left-to-right renal volume ratio showed no significant change (P=0.647). CONCLUSIONS: LRVD had no significant effect on CRD or left renal volume relative to the right renal volume for up to 2 years.

Renal autotransplantation results in pain resolution after left renal vein transposition.

Left renal vein transposition is often the preferred treatment of nutcracker syndrome. However, pain returns in some patients despite surgery. One solution to this problem is renal autotransplantation. Here we report our initial results of renal autotransplantation in patients with persistent flank pain despite a previous left renal vein transposition. We used the University of Wisconsin loin pain hematuria syndrome test as a diagnostic maneuver to determine who may benefit from renal autotransplantation; this procedure subsequently resulted in complete pain resolution in all three patients. All patients underwent successful renal autotransplantation and remain pain free. These cases support the test as a diagnostic maneuver to determine which patients may benefit from renal autotransplantation.

Pathogenesis and Management of Acute Kidney Injury in Patients with Nephrotic Syndrome Due to Primary Glomerulopathies.

Acute kidney injury in the context of nephrotic syndrome is a serious and alarming clinical problem. Largely, acute kidney injury is a relatively frequent complication among patients with comorbidities while it has been independently associated with an increased risk of adverse outcomes, including death and chronic kidney disease. Nephrotic syndrome, without hematuria or with minimal hematuria, includes a list of certain glomerulopathies; minimal change disease, focal segmental glomerulosclerosis and membranous nephropathy. In the light of primary nephrotic syndrome, pathophysiology of acute kidney injury is differentiated by the nature of the primary disease and the severity of the nephrotic state. This review aims to explore the clinical circumstances and pathogenetic mechanisms of acute kidney injury in patients with nephrotic syndrome due to primary glomerulopathies, focusing on newer perceptions regarding the pathogenesis and management of this complicated condition, for the prompt recognition and timely initiation of appropriate treatment in order to restore renal function to its baseline level. Prompt recognition of the precise cause of acute kidney injury is crucial for renal recovery. Clinical characteristics, laboratory and serological findings along with histopathological findings, if required, will reveal the implicated pathway leading to individualized approach and management.

Unusual Drainage of the Bifurcated Left Renal Vein Into a Dilated Lumbar Azygos Vein and Inferior Vena Cava.

We report a unique case of unusual drainage of the bifurcated retroaortic left renal vein, with the cranial wider branch draining into a dilated lumbar azygos vein and caudal thinner branch connecting with the inferior vena cava. The right renal vein was duplicated. The anomaly was discovered on multimodal 18F-labeled fluorodeoxyglucose positron emission tomography/computed tomography performed for oncological purposes. The basis enabling occurrence of such variation was probably persistent developmental extra left-right venous connections, intercardinal, or intersupracardinal, depending on the theory. The embryology of the chest and abdominal veins is a complicated process and there is no unanimity concerning its concepts. The old models are currently being questioned and reevaluated. Knowledge of possible variants of renal and azygos veins course is important from clinical, imaging, and surgical points of view. The retroaortic left renal veins course may sometimes cause pain, hematuria, proteinuria, and pelvic congestion syndromes. Dilated parts of uncommonly located veins, because of assuming a nodular shape on transverse images, may be mistaken for abnormal lymph nodes, other tumors or aneurysms on imaging. During a variety of surgical procedures, including venous sampling, renal transplantation, or any retroperitoneal surgery, knowledge of an aberrant venous course may be important for the success of the procedure and may be crucial even earlier during the qualification process.

Renal Vein Thrombosis After Open Repair of Abdominal Aortic Aneurysm Successfully Treated by Direct Oral Anticoagulants.

INTRODUCTION: Venous thromboembolism (VTE) of the lower extremities frequently occurs after surgery. It is unknown whether the complication of renal vein thrombosis (RVT) develops after an open repair (OR) for abdominal aortic aneurysm (AAA). Furthermore, anticoagulation therapy with apixaban, a direct oral anticoagulant (DOAC), has not been described as treatment for RVT in such cases. CASE: A 64-year-old man underwent OR for AAA. Postoperative computed tomography revealed RVT in the left renal vein. Apixaban (5 mg twice a day) therapy was initiated. Six months later, we discontinued anticoagulation therapy and observed no recurrence. Following OR, our patient developed RVT for which DOACs were very useful. CONCLUSION: Thus, RVT can manifest as VTE after OR and direct anticoagulants can be considered as a therapeutic option.