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.

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.

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.

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.

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.

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.

Alterations in Doppler-derived renal venous stasis index during recompensation of right heart failure and fluid overload in a patient with pulmonary hypertension.

Renal congestion is becoming recognized as a potential contributor to cardiorenal syndromes. Adequate control of congestion with simultaneous preservation of renal function has been proposed as a central goal of the management of heart failure. We report our care of a 48-year-old woman suffering from right heart failure and massive fluid overload due to severe pulmonary hypertension secondary to a combination of left-heart disease and status after recurrent pulmonary embolisms. Alterations in Doppler-derived intrarenal venous flow patterns and a novel renal venous stasis index were used to evaluate improvement in renal venous congestion during recompensation. Due to refractory congestion despite optimal medical treatment and continuous veno-venous hemodialysis, a peritoneal dialysis catheter was placed to relieve the massive ascites. The paracentesis of ascites led to a significant loss of weight, normalization of hydration status with subsequent termination of continuous veno-venous hemodialysis, and a significant improvement in clinical and echocardiographic parameters. Renal Doppler ultrasonography showed continuous improvement in intrarenal venous flow patterns and the renal venous stasis index indicative of effective decongestion up to a normal intrarenal venous flow pattern and renal venous stasis index. Furthermore, residual renal function increased during follow-up. This case demonstrates the feasibility of renal Doppler ultrasonography as a simple, non-invasive, and integrative measure of renal congestion. The renal venous stasis index and intrarenal venous flow patterns may be useful to evaluate the treatment response and to guide therapy in patients with right heart failure.

Stent Placement Across the Renal Vein Inflow in Patients Undergoing Venous Reconstruction Preserves Renal Function and Renal Vein Patency: Experience in 93 Patients.

PURPOSE: To determine if stent placement across the renal vein inflow affects kidney function and renal vein patency. METHODS: Between June 2008 and September 2016, 93 patients (mean age 39 years, range 15-70; 54 women) with iliocaval occlusion underwent venous stent placement and were retrospectively reviewed. For this analysis, the patients were separated into treatment and control groups: 51 (55%) patients had suprarenal and infrarenal iliocaval venous disease requiring inferior vena cava stent reconstruction across the renal vein inflow (treatment group) and 42 (45%) patients had iliac vein stenting sparing the renal veins (control group). Treatment group patients received Wallstents (n=15), Gianturco Z-stents (n=24), or suprarenal and infrarenal Wallstents such that the renal veins were bracketed with a "renal gap" (n=12). Stenting technical success, stent type, glomerular filtration rate (GFR), and creatinine before and after stent placement were recorded, along with renal vein patency and complications. RESULTS: All procedures were technically successful. In the 51-patient treatment group, 15 (29%) patients received Wallstents and 24 (47%) received Gianturco Z-stents across the renal veins, while 12 (24%) were given a "renal gap" with no stent placement directly across the renal vein inflow. In the control group, 42 patients received iliac vein Wallstents only. Mean prestent GFR was 59±1.8 mL/min/1.73 m2 and mean prestent creatinine was 0.8±0.2 mg/dL for the entire cohort. Mean prestent GFR and creatinine values in the Wallstent, Gianturco Z-stent, and "renal gap" subgroups did not differ from the iliac vein stent group. Mean poststent GFR and creatinine values were 59±3.3 mL/min/1.73 m2 and 0.8±0.3 mg/dL, respectively. There were no differences between mean pre- and poststent GFR (p=0.32) or creatinine (p=0.41) values when considering all patients or when comparing the treatment subgroups and the control group. There were no differences in the poststent mean GFR or creatinine values between the Wallstent (p=0.21 and p=0.34, respectively) and Gianturco Z-stent (p=0.43 and p=0.41, respectively) groups and the "renal gap" group. One patient with a Wallstent across the renal veins developed right renal vein thrombosis 7 days after the procedure. CONCLUSION: Stent placement across the renal vein inflow did not compromise renal function. A very small risk of renal vein thrombosis was seen.

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.

Endovascular Therapy of a Giant Renal Artery Aneurysm Combined With High-Flow Renal Arteriovenous Fistula Using a Patent Ductus Arteriosus Occluder.

Renal artery aneurysm (RAA) concomitant with a renal arteriovenous fistula (RAVF) is extremely rare. A 32-year-old man suffered from a giant RAA combined with high-flow RAVF. The computer tomographic angiography (CTA) demonstrated a RAA, which is 6.3 cm in length and 2.1 cm in diameter, combined with an arteriovenous fistula between the right renal artery and right renal vein (fistula area:1.05 cm × 1.0 cm). After a comprehensive preoperative assessment, a patent ductus arteriosus occluder (PDAO) was implanted. At a 1-year follow-up, the CTA study showed that the PDAO was in situ and there was no recanalization of the lesion. At a third-year follow-up, ultrasound examination showed an image of right renal atrophy. The results of long-term follow-up demonstrate that PDAO is safe and effective for the management of RAAs combined with high-flow RAVF.

Robot-Assisted Laparoscopic Left Renal Vein Transposition for the Treatment of Nutcracker Syndrome: A Preliminary Experience.

BACKGROUND: The aim of this study was to describe our robot-assisted laparoscopic left renal vein (LRV) transposition experiences for nutcracker syndrome treatment. METHODS: From August 2016 through May 2017, three patients with nutcracker syndrome underwent robot-assisted laparoscopic LRV transpositions. The patient demographics, surgical outcomes, and postoperative morbidities were reviewed. RESULTS: Successful surgical procedures were performed in all three patients. The operative times for the three cases were 150, 175, and 162 minutes, respectively, while the LRV anastomosis times were 19, 22, and 13 minutes, respectively. No major perioperative complications were encountered, and the hematuria and flank pain were resolved in all three cases. At the 6-month follow-up, the computed tomography scan showed that the LRV narrowing had disappeared in two of the patients. Although one patient still exhibited LRV flattening, his symptoms were also relieved, and the varicose tributaries spontaneously ceased. CONCLUSIONS: Robot-assisted laparoscopic LRV transposition can be a viable minimally invasive treatment option for patients with nutcracker syndrome.

Endovascular Stent-graft Repair of Combined Renal Artery Aneurysm and Arteriovenous Fistula.

Renal artery aneurysm with concomitant presence of arteriovenous fistula is an extremely rare entity. Few reports have been described in the literature. Nowadays, endovascular repair with covered stents or transarterial embolization with coils or glue has become the first line of treatment. We present the successful repair of a distal renal artery aneurysm combined with arteriovenous fistula with stent graft.

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.

Duplex scan and histologic assessment of acute renal injury in a kidney-kidney crosstalk swine experimental model.

OBJECTIVE: The objective of this study was to identify the effect of two left renal vasculature occlusion strategies on the duplex ultrasound-assessed rheology and histology of the contralateral kidney. METHODS: Pigs were randomly assigned to one of two groups: left renal artery-only clamping (A group, n = 8) or left renal artery and vein clamping (AV group, n = 9). Bilateral renal parenchymal biopsy specimens were taken every 10 minutes for 90 minutes. Duplex ultrasound resistive index (RI) and pulsatility index (PI) were measured. Mixed models with normal distribution and first-order autoregressive correlation structure and generalized estimating equation models were used. Results are presented as adjusted means with standard errors, estimated proportions with standard errors, and line plots with 95% confidence intervals. RESULTS: RI and PI increased in the nonischemic kidney. In A group animals, RI values increased significantly (P < .01) after 30 minutes of ischemia and PI increased significantly (P < .04) from 30 to 60 minutes of ischemia. The number of histologic abnormalities was higher in A group than in AV group biopsy specimens. The percentage of lesions increased significantly after 10 minutes in A group nonischemic kidneys (P < .02) and between 50 and 80 minutes in AV group nonischemic kidneys (P < .01). CONCLUSIONS: Nonischemic kidneys were acutely affected by contralateral ischemia. Their function was more adversely affected by unilateral renal artery occlusion with preserved renal vein patency (A group).

Long-term fate of renal function after open surgery for juxtarenal and pararenal aortic aneurysm.

BACKGROUND: Although the indications for endovascular aneurysm repair for abdominal aortic aneurysm have been expanding, our primary strategy for pararenal and juxtarenal abdominal aortic aneurysm (P/JRAA) is open surgery (OS). One consequence of OS for P/JRAA is transient renal ischemia owing to renal artery clamping, which can be followed by acute kidney injury (AKI). Prior studies referred to the impact of renal ischemia on AKI, but they have rarely evaluated longer-term renal function. This study focused on a chronic renal decline (CRD) during follow-up. METHODS: A retrospective review of our series of P/JRAA treated with OS from 2007 to 2015. Patients on hemodialysis at the time of surgery were excluded. Preoperative renal function was estimated using the chronic kidney disease (CKD) staging system. Postoperative AKI was defined by the RIFLE criteria (Risk, Injury, Failure, Loss of function, End-stage renal disease). CRD was defined as progression in CKD stage or estimated glomerular filtration rate (eGFR) decline of >20%. RESULTS: Among 451 elective OS, 111 underwent repair for P/JRAA. Three patients were excluded because of preoperative hemodialysis. Consequently, 108 patients were enrolled. Preoperatively, 41 patients (38.0%) had CKD stage 3 (eGFR < 60 mL/min/1.73 m2). Eight patients (7.2%) were in stage 4 (eGFR < 30 mL/min/1.73 m2). Proximal clamping was supraceliac (6 patients), suprarenal (34 patients), and inter-renal (68 patients). The median renal ischemic time was 33 minutes. The left renal vein was divided in 24 patients. Fourteen renal arteries in 14 patients were revascularized. Cold renal perfusion was applied in 11 patients. One in-hospital death was excluded from these analyses. AKI was observed in 20 patients (18.7%). One patient required temporary hemodialysis. During a median renal function follow-up for 24.5 months (interquartile range, 3.34-48.4), 17 patients (15.9%) had CRD. One patient required hemodialysis 5 years after surgery. In univariate analysis, CKD stages 3 and 4 were significant predictors for CRD (P = .014 and P < .001, respectively). Cold renal perfusion was associated with a higher risk of CRD (P = .047). On multivariate analysis, preoperative CKD stage 3 (hazard ratio, 4.22; 95% confidence interval, 1.10-16.3; P = .036) and stage 4 (hazard ratio, 59.72; 95% confidence interval, 10.13-352.0; P < .001) were identified as risk factors. In patients with CKD stage ≤2, the estimated freedom from CRD at 5 years was 96.6 ± 3.4%. CONCLUSIONS: CKD stage ≥3 was a significant risk for CRD after OS for P/JRAA. Renal artery clamping seemed innocuous for patients with a preoperative eGFR of ≥60 mL/min/1.73 m2 in terms of CRD. No significant impact of left renal vein division on CRD was confirmed.

Acute Renal Vein Thrombosis: A Case Report of Successful Treatment with Mechanical Thromboaspiration.

Treatment of renal vein thromboses has previously been limited to conventional anticoagulation. We describe a case of successful treatment of acute native renal vein thrombosis (RVT) in a 61-year-old fit-and-well female using mechanical thromboaspiration without the use of thrombolysis. The report demonstrates the computed tomographic appearances of an acute RVT, the venographic images taken before and after thromboaspiration, and the magnetic resonance imaging of the kidney performed 3 months later, showing complete resolution of the thrombus and normal appearances of the kidney. We believe this case to be the first published case of a safe and successful treatment of acute native RVT using the Penumbra Indigo® mechanical aspiration system, highlighting the importance of access to skilled interventional radiologists for treatment of this rare condition.

Role of intratubular pressure during the ischemic phase in acute kidney injury.

Acute kidney injury (AKI) induced by clamping of renal vein or pedicle is more severe than clamping of artery, but the mechanism has not been clarified. In the present study, we tested our hypothesis that increased proximal tubular pressure (Pt) during the ischemic phase exacerbates kidney injury and promotes the development of AKI. We induced AKI by bilateral clamping of renal arteries, pedicles, or veins for 18 min at 37°C, respectively. Pt during the ischemic phase was measured with micropuncture. We found that higher Pt was associated with more severe AKI. To determine the role of Pt during the ischemic phase on the development of AKI, we adjusted the Pt by altering renal artery pressure. We induced AKI by bilateral clamping of renal veins, and the Pt was changed by adjusting the renal artery pressure during the ischemic phase by constriction of aorta and mesenteric artery. When we decreased renal artery pressure from 85 ± 5 to 65 ± 8 mmHg, Pt decreased from 53.3 ± 2.7 to 44.7 ± 2.0 mmHg. Plasma creatinine decreased from 2.48 ± 0.23 to 1.91 ± 0.21 mg/dl at 24 h after renal ischemia. When we raised renal artery pressure to 103 ± 7 mmHg, Pt increased to 67.2 ± 5.1 mmHg. Plasma creatinine elevated to 3.17 ± 0.14 mg·dl·24 h after renal ischemia. Changes in KIM-1, NGAL, and histology were in the similar pattern as plasma creatinine. In summary, we found that higher Pt during the ischemic phase promoted the development of AKI, while lower Pt protected from kidney injury. Pt may be a potential target for treatment of AKI.

Renal Arteriovenous Malformations: A Rare Vascular Cause of Back Pain.

BACKGROUND: Renal arteriovenous malformation (AVM) is a very rare phenomenon (fewer than 200 cases in the literature), most commonly (75%) presenting with hematuria in young women. Renal AVMs may be cirsoid (multibranched) or cavernous, with cirsoid morphology predominating 3:1. The historical treatment is partial nephrectomy. Best endovascular therapy is divided among many options. We present 2 cases of large renal AVMs treated with single Amplatzer plugs. METHODS: During a 2-year period (2014-15), 2 patients presented for vascular evaluation of renal AVMs found incidentally on workup for nonspecific abdominal and back pain. Both were the less common cavernous-type AVM. Each noted back pain ipsilateral to the AVM. Neither had a history of trauma or renal procedures. Each underwent angiography and Amplatzer plug placement to occlude flow while preserving parenchyma. RESULTS: Each patient successfully underwent occlusion of the arterial feeding branch of the AVM with immediate angiographic success. Each patient subsequently underwent follow-up imaging that demonstrated absence of filling of the AVM with preservation of healthy renal parenchyma. CONCLUSIONS: Renal AVMs, although very rare, do present to vascular surgeons and may be managed successfully via an endovascular approach with standard techniques. Although renal AVMs are often managed with cyanoacrylate embolization, careful selective arterial catheterization allows for single plug embolization with excellent results and without requiring venous intervention.

Portal systemic shunt between the hepatic portal vein and right renal vein in a patient with multifocal hepatocellular carcinoma: Case report.

Portal hypertension is a clinical syndrome characterized by the development of collateral circulation and portosystemic shunts, as well as ascites and hepatic encephalopathy. We present the case of a large portosystemic shunt between the hepatic portal vein and aneurysmal right renal vein in a cirrhotic 64-year-old man with thrombosis of the portal vein and hepatocellular carcinoma. This is a very rare clinical manifestation which, to our knowledge, has been described only once previously in the literature. © 2017 Wiley Periodicals, Inc. J Clin Ultrasound 45:524-527, 2017.

Endovascular Treatment of Nutcracker Syndrome.

BACKGROUND: Nutcracker syndrome, or mesoaortic compression of the left renal vein (LRV), with associated symptoms related to venous hypertension in the left kidney, is a rare entity that may result in severe symptoms requiring operative intervention. We report on 3 patients who presented with nutcracker syndrome, including one patient with a circumaortic LRV resulting in posterior nutcracker syndrome, who underwent successful endovascular treatment with renal vein stenting. A review of existing literature on endovascular management of nutcracker syndrome follows. METHODS: Three women (age range 28-43 years) presented with symptoms and imaging studies consistent with nutcracker syndrome. Symptoms included pelvic and flank pain in all 3 patients, and episodes of hematuria in 2 patients. Imaging studies demonstrated compression of the LRV between the superior mesenteric artery and aorta in 2 of the patients. The third patient was noted to have a circumaortic LRV. RESULTS: All 3 patients underwent venography and LRV stenting. Stents included a 12 × 40 mm self-expanding nitinol stent, 14 × 60 mm WALLSTENT, and 16 × 40 mm WALLSTENT. All patients were placed on clopidogrel postoperatively. The duration of follow-up ranged from 6 to 27 months. At follow-up, all 3 patients reported significant symptomatic improvement, and duplex ultrasonography demonstrated stent patency in all. CONCLUSIONS: Nutcracker syndrome is a rare condition that can be successfully treated with renal vein stenting via an endovascular approach. Results are encouraging at follow-up periods beyond 2 years.