Patterns of cortical oxygenation may predict the response to stenting in subjects with renal artery stenosis: A radiomics-based model.

BACKGROUND: Percutaneous-transluminal renal angioplasty (PTRA) and stenting aim to halt the progression of kidney disease in patients with renal artery stenosis (RAS), but its outcome is often suboptimal. We hypothesized that a model incorporating markers of renal function and oxygenation extracted using radiomics analysis of blood oxygenation-level dependent (BOLD)-MRI images may predict renal response to PTRA in swine RAS. MATERIALS AND METHODS: Twenty domestic pigs with RAS were scanned with CT and BOLD MRI before and 4 weeks after PTRA. Stenotic (STK) and contralateral (CLK) kidney volume, blood flow (RBF), and glomerular filtration rate (GFR) were determined, and BOLD-MRI R2 * maps were generated before and after administration of furosemide, a tubular reabsorption inhibitor. Radiomics features were extracted from pre-PTRA BOLD maps and Robust features were determined by Intraclass correlation coefficients (ICC). Prognostic models were developed to predict post-PTRA renal function based on the baseline functional and BOLD-radiomics features, using Lasso-regression for training, and testing with resampling. RESULTS: Twenty-six radiomics features passed the robustness test. STK oxygenation distribution pattern did not respond to furosemide, whereas in the CLK radiomics features sensitive to oxygenation heterogeneity declined. Radiomics-based model predictions of post-PTRA GFR (r = 0.58, p = 0.007) and RBF (r = 0.68; p = 0.001) correlated with actual measurements with sensitivity and specificity of 92% and 67%, respectively. Models were unsuccessful in predicting post-PTRA systemic measures of renal function. CONCLUSIONS: Several radiomics features are sensitive to cortical oxygenation patterns and permit estimation of post-PTRA renal function, thereby distinguishing subjects likely to respond to PTRA and stenting.

[Clinical value of renal artery resistance index and urinary angiotensinogen in early diagnosis of acute kidney injury in patients with sepsis].

OBJECTIVE: To investigate the value of renal artery resistance index (RRI) and urinary angiotensinogen (UAGT) in the early diagnosis of acute kidney injury (AKI) in patients with sepsis. METHODS: A prospective study was conducted. Seventy-eight patients with sepsis admitted to the department of critical care medicine of General Hospital of Ningxia Medical University from January to September 2021 were enrolled. Patients were observed for the development of AKI within 1 week. General data [gender, age, body mass index (BMI), major infection sites and critical illness related scores], laboratory indicators [mean arterial pressure (MAP), central venous pressure (CVP), procalcitonin (PCT), arterial blood lactic acid (Lac), etc.], duration of mechanical ventilation and length of intensive care unit (ICU) stay were recorded. After hemodynamic stabilization of the patients, renal ultrasound was performed to measure the RRI within 24 hours after ICU admission. Urine samples were taken immediately after diagnosis, and the level of UAGT was detected by enzyme-linked immunosorbent assay (ELISA). The above parameters were compared between the two groups. Multivariate Logistic regression was used to analyze the risk factors of AKI in patients with sepsis. Receiver operator characteristic curve (ROC curve) was drawn to analyze the predictive value of related indicators for AKI in sepsis. RESULTS: A total of 78 patients were finally enrolled, of which 45 developed AKI and 33 did not. Compared with the non-AKI group, the rates of vasoactive drugs use, 28-day mortality, sequential organ failure assessment (SOFA) score, acute physiology and chronic health evaluation II (APACHE II) score, PCT, Lac, RRI and UAGT were significantly higher in the AKI group [rates of vasoactive drugs use: 68.9% vs. 39.4%, 28-day mortality: 48.9% vs. 24.2%, SOFA score: 12.0 (10.5, 14.0) vs. 8.0 (7.0, 10.0), APACHE II score: 22.0 (18.0, 27.5) vs. 16.0 (15.0, 18.5), PCT (µg/L): 12.5±2.6 vs. 10.9±2.8, Lac (mmol/L): 2.6 (1.9, 3.4) vs. 1.9 (1.3, 2.6), RRI: 0.74±0.03 vs. 0.72±0.02, UAGT (µg/L): 75.16±19.99 vs. 46.28±20.75, all P < 0.05], the duration of mechanical ventilation and the length of ICU stay were significantly prolonged [duration of mechanical ventilation (days): 8.0 (7.0, 12.0) vs. 5.0 (4.0, 6.0), length of ICU stay (days): 14.0 (10.0, 16.0) vs. 9.0 (8.0, 11.5), both P < 0.01], and MAP was significantly lowered [mmHg (1 mmHg ≈ 0.133 kPa): 68.5±11.2 vs. 74.2±12.8, P < 0.05]. There was no significant difference in other parameters between the two groups. Multivariate Logistic regression analysis showed that SOFA score [odds ratio (OR) = 2.088, 95% confidence interval (95%CI) was 1.322-3.299], APACHE II score (OR = 1.447, 95%CI was 1.134-1.845), RRI (OR = 1.432, 95%CI was 1.103-1.859), and UAGT (OR = 1.077, 95%CI was 1.035-1.121) were independent risk factors for sepsis complicated with AKI (all P < 0.01). ROC curve analysis showed that SOFA score, APACHE II score, RRI and UAGT had certain predictive value for AKI in septic patients, the area under the ROC curve (AUC) were 0.814 (95%CI was 0.716-0.912), 0.804 (95%CI was 0.708-0.901), 0.789 (95%CI was 0.690-0.888), and 0.840 (95%CI was 0.747-0.934), respectively, and the AUC of RRI combined with UAGT was 0.912 (95%CI was 0.849-0.974), which was better than the above single index (all P < 0.05). CONCLUSIONS: RRI combined with UAGT has a high early predictive value for septic AKI.

Insights from intravascular pressure measurement of renal artery revascularization in patients with fibromuscular dysplasia: The DYSART study.

OBJECTIVE: The indication of percutaneous renal transluminal angioplasty (PTRA) in fibromuscular dysplasia (FMD) is mainly based on renal artery stenosis (RAS) due to atherosclerosis criteria, which are not specific to FMD. Consequently, the selection of patients who could benefit from this treatment and its effectiveness remain uncertain. The aims of this study were to: (1) report the effects of PTRA guided by trans-stenotic pressure measurements on hypertension 7 months after treatment; (2) assess the impact of pressure measurement to guide treatment efficacy in comparison to visual angiographic parameters; and (3) evaluate the reproducibility and accuracy of the stenosis measurement using a 4F catheter in comparison to a pressure guidewire. METHODS: This prospective multi-centric study analyzed 24 patients with hypertension with RAS due to FMD that required PTRA. Clinical, duplex ultrasound, and angiographic indices were collected, and patients were followed up for 7 months (±1 month). Angiographic indices were measured twice both by a pressure guidewire and a 4F catheter. Assessment of procedural and clinical success of angioplasty was performed for all patients. RESULTS: Twenty-three patients (96%) had procedural success (considered as a post-PTRA translesional systolic gradient ≤10 mmHg or reduced by at least 80%) with a significant decrease in the systolic gradient after angioplasty (26.50 mmHg; [interquartile range, 16.75-38.75] vs 0.00 [interquartile range, 0.00-2.00]; P < .01). Three patients (12%) had complications, including two renal artery dissections and one partial renal infarction. Twenty-one patients (88%) were clinical responders to angioplasty at follow-up. Visual stenosis assessment showed a poor correlation with systolic gradient measurement before and after PTRA (R from -0.05 to 0.41; P = 0.06-0.82). High correlations were found between pressure measurements made by a 4F catheter and guidewire (R from 0.64 to 0.89; P ≤ .003). CONCLUSIONS: In patients selected by clinical indicators and duplex ultrasound, reaching a translesional systolic gradient ≤10 mmHg or reduced by at least 80% after angioplasty, promotes a high success rate for PTRA in hypertension due to FMD RAS.

Intentional Bilateral Renal Artery Coverage During Ruptured Endovascular Paraanastomotic Pseudoaneurysm Repair.

The development of a paraanastomotic pseudoaneurysm is a serious complication after open prosthetic reconstruction of the aorta for occlusive or aneurysmal disease. Open repair of these lesions has previously been associated with high rates of morbidity and mortality. Endovascular repair may provide suitable treatment for proximal paraanastomotic aortic bypass graft pseudoaneurysms in patients who are poor candidates for open surgery. Bilateral renal artery coverage may be necessary to achieve adequate fixation and seal during life-threatening emergency cases of pseudoaneurysm rupture. Due to the infrequency of reported cases, the consequences of bilateral renal artery occlusion during these complex procedures are poorly understood. We present a case of a proximal paraanastomotic aortobifemoral bypass pseudoaneurysm rupture that was managed using endovascular repair with intentional coverage of both renal arteries. We also review the contemporary literature on endovascular management of paraanastomotic aneurysms and discuss the role of bilateral renal artery coverage in treating select patients with complex ruptured aortic pathology.

Differential contribution of renal cytochrome P450 enzymes to kidney endothelial dysfunction and vascular oxidative stress in obesity.

Arachidonic acid (AA)-derived cytochrome P450 (CYP) derivatives, epoxyeicosatrienoic acids (EETs) and 20-hidroxyeicosatetranoic acid (20-HETE), play a key role in kidney tubular and vascular functions and blood pressure. Altered metabolism of CYP epoxygenases and CYP hydroxylases has differentially been involved in the pathogenesis of metabolic disease-associated vascular complications, although the mechanisms responsible for the vascular injury are unclear. The present study aimed to assess whether obesity-induced changes in CYP enzymes may contribute to oxidative stress and endothelial dysfunction in kidney preglomerular arteries. Endothelial function and reactive oxygen species (ROS) production were assessed in interlobar arteries of obese Zucker rats (OZR) and their lean counterparts lean Zucker rats (LZR) and the effects of CYP2C and CYP4A inhibitors sulfaphenazole and HET0016, respectively, were examined on the endothelium-dependent relaxations and O2- and H2O2 levels of preglomerular arteries. Non-nitric oxide (NO) non-prostanoid endothelium-derived hyperpolarization (EDH)-type responses were preserved but resistant to the CYP epoxygenase blocker sulfaphenazole in OZR in contrast to those in LZR. Sulfaphenazole did not further inhibit reduced arterial H2O2 levels, and CYP2C11/CYP2C23 enzymes were downregulated in intrarenal arteries from OZR. Renal EDH-mediated relaxations were preserved in obese rats by the enhanced activity and expression of endothelial calcium-activated potassium channels (KCa). CYP4A blockade restored impaired NO-mediated dilatation and inhibited augmented O2- production in kidney arteries from OZR. The current data demonstrate that both decreased endothelial CYP2C11/ CYP2C23-derived vasodilator H2O2 and augmented CYP4A-derived 20-HETE contribute to endothelial dysfunction and vascular oxidative stress in obesity. CYP4A inhibitors ameliorate arterial oxidative stress and restore endothelial function which suggests its therapeutic potential for the vascular complications of obesity-associated kidney injury.

Refractory hypertension secondary to renal artery stenosis with a honeycomb-like structure.

BACKGROUND: A honeycomb-like structure (HLS) is a rare abnormality characterized by a braid-like appearance. Angiograph and intravascular examination, including coherence tomography and intravascular ultrasound (IVUS), can further confirm the multiple intraluminal channels or honeycomb structure, which can also be described as looking like 'swiss cheese', a 'spider web' or a 'lotus root'. Previous studies have mostly reported this abnormality in coronary arteries, with a few cases in renal arteries. More information about the characteristics and development of HLS is needed. CASE PRESENTATION: A 69-year-old Han man with resistant hypertension received abdominal enhanced computerised tomography and was revealed to have left renal artery stenosis with the possibility of left renal infarction. Renal artery angiography confirmed a 95% stenosis located in the proximal segment of the left renal artery, and the middle segment was blurred with multi-channel-like blood flow. Further IVUS was performed and identified multiple channels surrounded by fibrous tissue. It was a rare case of HLS in the renal artery secondary to the thrombus, with organisation and recanalisation. Balloon dilatation and stent implantation at the proximal segment of the left renal artery were performed successfully. Blood pressure was well controlled after the procedure. CONCLUSIONS: The IVUS findings are helpful for forming interventional therapeutic strategies for HLS lesions in the renal artery.

Renal Artery Reconstruction for Refractory Hypertension Caused by Congenital Renal Artery Deficiency.

Renovascular hypertension is a common cause of secondary hypertension. According to the epidemiological survey, the prevalence of renovascular hypertension accounts for 1-5% of the population with hypertension. Most of the cases are associated with atherosclerosis and Fibromuscular Dysplasia (FMD). Owing to the lack of standard treatment, they will eventually develop into chronic kidney disease, which significantly affects the patient's quality of life. Hypertension is considered a prerequisite for renal artery surgery; renal function research is used to guide the treatment of unilateral lesions because endovascular intervention can only slightly improve hypertension and renal function. We advocate open surgery for patients with congenital dysplasia of renal vascular hypertension, in which the most common surgical operations are aortorenal artery bypass, renal artery endarterectomy, and renal artery replantation. This paper reports a rare case of renovascular hypertension. The patient was a 13-year-old female, and the operation was risky and complicated. He was diagnosed with a congenital absence of the right renal artery. The right renal function was recovered, and the blood pressure was well controlled after the Aorta-Right Renal Artery Bypass.

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.

Blunted natriuretic response to saline loading in sheep with hypertensive kidney disease following radiofrequency catheter-based renal denervation.

Renal sympathetic nerves contribute to renal excretory function during volume expansion. We hypothesized that intact renal innervation is required for excretion of a fluid/electrolyte load in hypertensive chronic kidney disease (CKD) and normotensive healthy settings. Blood pressure, kidney hemodynamic and excretory response to 180 min of isotonic saline loading (0.13 ml/kg/min) were examined in female normotensive (control) and hypertensive CKD sheep at 2 and 11 months after sham (control-intact, CKD-intact) or radiofrequency catheter-based RDN (control-RDN, CKD-RDN) procedure. Basal blood pressure was ~ 7 to 9 mmHg lower at 2, and 11 months in CKD-RDN compared with CKD-intact sheep. Saline loading did not alter glomerular filtration rate in any group. At 2 months, in response to saline loading, total urine and sodium excretion were ~ 40 to 50% less, in control-RDN and CKD-RDN than intact groups. At 11 months, the natriuretic and diuretic response to saline loading were similar between control-intact, control-RDN and CKD-intact groups but sodium excretion was ~ 42% less in CKD-RDN compared with CKD-intact at this time-point. These findings indicate that chronic withdrawal of basal renal sympathetic activity impairs fluid/electrolyte excretion during volume expansion. Clinically, a reduced ability to excrete a saline load following RDN may contribute to disturbances in body fluid balance in hypertensive CKD.

Acute Beetroot Juice Ingestion Does Not Alter Renal Hemodynamics during Normoxia and Mild Hypercapnia in Healthy Young Adults.

Arterial hypercapnia reduces renal perfusion. Beetroot juice (BRJ) increases nitric oxide bioavailability and may improve renal blood flow. We tested the hypothesis that acute consumption of BRJ attenuates both decreases in blood velocity and increases in vascular resistance in the renal and segmental arteries during acute hypercapnia. In fourteen healthy young adults, blood velocity and vascular resistance were measured with Doppler ultrasound in the renal and segmental arteries during five minutes of breathing a carbon dioxide gas mixture (CO2) before and three hours after consuming 500 mL of BRJ. There was no difference between pre- and post-BRJ consumption in the increase in the partial pressure of end-tidal CO2 during CO2 breathing (pre: +4 ± 1 mmHg; post: +4 ± 2 mmHg, p = 0.4281). Segmental artery blood velocity decreased during CO2 breathing in both pre- (by -1.8 ± 1.9 cm/s, p = 0.0193) and post-BRJ (by -2.1 ± 1.9 cm/s, p = 0.0079), but there were no differences between pre- and post-consumption (p = 0.7633). Segmental artery vascular resistance increased from room air baseline during CO2 at pre-BRJ consumption (by 0.4 ± 0.4 mmHg/cm/s, p = 0.0153) but not post-BRJ (p = 0.1336), with no differences between pre- and post-consumption (p = 0.7407). These findings indicate that BRJ consumption does not attenuate reductions in renal perfusion during acute mild hypercapnia in healthy young adults.

The long-term fate of renal and visceral vessel reconstruction after open thoracoabdominal aortic aneurysm repair.

OBJECTIVES: In the ever-advancing era of endovascular thoracoabdominal aneurysm (TAAA) repair, understanding long-term patency of renovisceral reconstructions after open TAAA repair provides important benchmarks. METHODS: Institutional open TAAA repair patient data were queried. Patients dying during index admission or with incomplete operative detail were excluded. Visceral and renal reconstructions were categorized as bypass, incorporation into a proximal or distal beveled aortic anastomosis, inclusion button, Carrel patch, or hybrid stent along with endarterectomy/stent adjuncts. Axial imaging or angiography determined long-term patency. Vessel event was defined as new occlusion or reintervention after repair. Overall time-to-event analysis was performed as well as separate analyses for each vessel (celiac, superior mesenteric artery [SMA], right renal, left renal) by reconstruction type utilizing Kaplan-Meier methods. Log-rank testing was employed to compare reconstructive strategies. RESULTS: Over 28 years, 604 repairs (type I, 106 [18%]; type II, 73 [12%]; type III, 195 [32%]; and type IV, 230 [38%]) were identified. Follow-up (median, 500 days) was available in 410/570 (72%) celiac, 406/573 (71%) SMA, 379/532 (71.2%) right renal, and 370/515 (72%) left renal reconstructions. There were five celiac, one SMA, eight right renal, and 10 left renal events. No type of reconstruction or adjunct was significantly associated with event. Overall 5-year patency of all renal/visceral reconstructions was 94% (95% confidence interval, 90%-96%). Estimated 5-year patency of the celiac, SMA, left renal, and right renal were similar, and were 99%, 100%, 97%, and 96%, respectively (P = .09). CONCLUSIONS: Visceral and renal long-term patency after open TAAA repair is excellent regardless of reconstructive technique. No differences are appreciated even when target vessel disease is addressed at the time of reconstruction. These findings continue to substantiate the effective long-term durability of open TAAA repair and are particularly germane to the ongoing evolution of endovascular strategies.

Diagnostic value of doppler ultrasound indices of maternal renal interlobar vasculature in the prediction of preeclampsia.

We aimed to determine the diagnostic accuracy of maternal renal vasculature Doppler ultrasound indices in the prediction of preeclampsia. A total of 40 pregnant women with a gestational age of more than 20 weeks were included and followed. The pregnant women underwent a Doppler ultrasound examination to measure the resistance index (RI) of the interlobar arteries of right and left kidneys and the renal interlobar vein impedance index (RIVI). Of the included women, 15 patients developed preeclampsia based on clinical and laboratory criteria. The renal vascular Doppler ultrasound indices were compared between the two groups. Then, using the Receiver Operating Characteristic (ROC) analysis, the diagnostic accuracy of interlobar artery RI and RIVI were investigated in the prediction of preeclampsia occurrence. RIVI values of right and left kidneys were significantly higher in the preeclampsia group compared to the normal pregnancy group. The left kidney interlobar artery RI at a cut-point of 0.59 had a sensitivity of 100% and a specificity of 40% (area under curve=0.7, P-0.03) in the prediction of preeclampsia. The RIVI of the left kidney (adjusted odds ratio=17.14, 95% CI = 3.46 to 47.28) was statistically significant in predicting preeclampsia (P-0.006). We found that, besides other routine methods, using Doppler ultrasound and measuring RIVI can be reliable in the prediction of preeclampsia.

Vascular tone regulation in renal interlobar arteries of male rats is dysfunctional after intrauterine growth restriction.

Intrauterine growth restriction (IUGR) due to an adverse intrauterine environment predisposes to arterial hypertension and loss of kidney function. Here, we investigated whether vascular dysregulation in renal interlobar arteries (RIAs) may contribute to hypertensive glomerular damage after IUGR. In rats, IUGR was induced by bilateral uterine vessel ligation. Offspring of nonoperated rats served as controls. From postnatal day 49, blood pressure was telemetrically recorded. On postnatal day 70, we evaluated contractile function in RIAs and mesenteric arteries. In addition, blood, urine, and glomerular parameters as well as renal collagen deposition were analyzed. IUGR RIAs not only showed loss of stretch activation in 9 of 11 arteries and reduced stretch-induced myogenic tone but also showed a shift of the concentration-response relation of acetylcholine-induced relaxation toward lower concentrations. However, IUGR RIAs also exhibited augmented contractions through phenylephrine. Systemic mean arterial pressure [mean difference: 4.8 mmHg (daytime) and 5.7 mmHg (night)], mean glomerular area (IUGR: 9,754 ± 338 µm2 and control: 8,395 ± 227 µm2), and urinary protein-to-creatinine ratio (IUGR: 1.67 ± 0.13 g/g and control: 1.26 ± 0.10 g/g) were elevated after IUGR. We conclude that male IUGR rat offspring may have increased vulnerability toward hypertensive glomerular damage due to loss of myogenic tone and augmented endothelium-dependent relaxation in RIAs.NEW & NOTEWORTHY For the first time, our study presents wire myography data from renal interlobar arteries (RIAs) and mesenteric arteries of young adult rat offspring after intrauterine growth restriction (IUGR). Our data indicate that myogenic tone in RIAs is dysfunctional after IUGR. Furthermore, IUGR offspring suffer from mild arterial hypertension, glomerular hypertrophy, and increased urinary protein-to-creatinine ratio. Dysregulation of vascular tone in RIAs could be an important variable that impacts upon vulnerability toward glomerular injury after IUGR.

Impact of Renal Pelvic Denervation on Systemic Hemodynamics and Neurohumoral Changes in a Porcine Model.

INTRODUCTION: The blood pressure (BP) response to arterial renal denervation (RDN) is variable. METHODS: This study examined the effectiveness of renal pelvic denervation (RPD) on BP, heart rate (HR), norepinephrine (NE), and histopathology in 42 swine. NE levels were measured immediately, 7, 14, 30, and 90 days after RPD. Intra-arterial BP and HR were measured throughout RPD and after 14 days in 5 swine. RESULTS: During the procedure, RPD immediately reduced systolic BP (-20.6 ± 18.3 mm Hg), diastolic BP (-6.0 ± 8.3 mm Hg), and HR (-5.4 ± 5.6 bpm), which remained decreased at follow-up. The porcine kidneys had a mean NE reduction of 76% directly post procedure and 60% after 7 days, 64% after 14 days, 57% after 30 days, and 65% after 90 days. Histopathological examination confirmed nerve ablation. CONCLUSIONS: These preliminary findings suggest that the renal pelvis nerve ablation is an encouraging target for RDN. Clinical trials are required to test the feasibility of RPD in human hypertension.

Renal Outcome and New-Onset Renal and Extrarenal Dissections in Patients With Nontrauma Renal Artery Dissection Associated With Renal Infarction.

[Figure: see text].

Transplant Renal Artery Stenosis: A Case Report of Functional Recovery Six Months After Angioplasty.

Transplant renal artery stenosis (TRAS) is a common vascular complication after kidney transplantation, leading to worsening or refractory hypertension, deterioration in renal function, and possible cause of graft loss. Early diagnosis and an appropriate treatment are crucial for organ preservation. Endovascular treatment, including percutaneous transluminal angioplasty and stent implantation, is considered the first-line therapy for TRAS. Here we report the case of a 69-year-old woman with end-stage renal disease for chronic kidney disease not biopsy proven, who underwent a kidney transplant from expanded criteria donors on December 2018. Postoperative course was characterized by delayed graft function. Doppler ultrasonography (US) showed an increase of peak systolic velocity at the origin of the renal artery, and parvus-tardus waveform in periferic graft arteries and an abdominal computed tomography scan confirmed a stenosis at the origin of the main renal artery (TRAS). The patient underwent a percutaneous transluminal angioplasty. It was not possible to place a stent at the particular location of the stenosis at the anastomosis. Despite the improvement of the graft's perfusion, monitored with Doppler US, the patient showed a very poor improvement in renal function and remained on hemodialysis for months. A percutaneous needle biopsy reported a normal renal parenchyma and excluded acute rejection. During this period, the patient received immunosuppressive therapy. About 6 months after the transplant, the patient had an unexpected and slow renal function recovery until she was weaned completely from hemodialysis.

Renal artery stenosis.

Renal artery stenosis is the most common secondary cause of hypertension and predominantly caused by atherosclerosis. In suspected patients, a non-invasive diagnosis with ultrasound is preferred. Asymptomatic, incidentally found RAS does not require revascularization. In symptomatic patients requiring revascularization, renal artery stenting is the preferred therapy. Selecting appropriate patients for revascularization requires careful consideration of lesion severity and is optimized with a multidisciplinary team. All patients with atherosclerotic RAS should be treated with guideline-directed medical therapy, including hypertension control, diabetes control, statins, antiplatelet therapy, smoking cessation and encouraging activity.

Value of renal resistive index in covid-19 ARDS patients: an early inflammation alert for the lung-kidney cross-talk?

We analysed RRI and other hemodynamic, re-spiratory and inflammation parameters in critically ill pa-tients affected by severe covid-19 with acute distress respi-ratory syndrome (ARDS) aiming at verifying their modifica-tions during supine and prone positioning and any mutual correlation or interplay with RRI.

Vitamin D Deficiency Cause Gender Specific Alterations of Renal Arterial Function in a Rodent Model.

Vitamin D deficiency shows positive correlation to cardiovascular risk, which might be influenced by gender specific features. Our goal was to examine the effect of Vitamin D supplementation and Vitamin D deficiency in male and female rats on an important hypertension target organ, the renal artery. Female and male Wistar rats were fed with Vitamin D reduced chow for eight weeks to induce hypovitaminosis. Another group of animals received normal chow with further supplementation to reach optimal serum vitamin levels. Isolated renal arteries of Vitamin D deficient female rats showed increased phenylephrine-induced contraction. In all experimental groups, both indomethacin and selective cyclooxygenase-2 inhibition (NS398) decreased the phenylephrine-induced contraction. Angiotensin II-induced contraction was pronounced in Vitamin D supplemented males. In both Vitamin D deficient groups, acetylcholine-induced relaxation was impaired. In the female Vitamin D supplemented group NS398, in males the indomethacin caused reduced acetylcholine-induced relaxation. Increased elastic fiber density was observed in Vitamin D deficient females. The intensity of eNOS immunostaining was decreased in Vitamin D deficient females. The density of AT1R staining was the highest in the male Vitamin D deficient group. Although Vitamin D deficiency induced renal vascular dysfunction in both sexes, female rats developed more extensive impairment that was accompanied by enzymatic and structural changes.

Splanchnic occlusive disease predicts for spinal cord injury after open descending thoracic and thoracoabdominal aneurysm repair.

OBJECTIVE: In the present study, we sought to discern the effects of splanchnic occlusive disease (SOD; renal, superior mesenteric, and/or celiac axis arteries) on spinal cord injury (SCI; paraparesis or paraplegia) and major adverse events (MAE) after descending thoracic aneurysm (DTA) and thoracoabdominal aortic aneurysm (TAAA) open repair. METHODS: Patients who had undergone DTA/TAAA repair at our institution were dichotomized according to the presence of SOD, which was investigated as a predictive factor of our primary (SCI) and secondary (operative mortality, myocardial infarction, stroke, tracheostomy, de novo dialysis, MAE, survival) endpoints. Risk adjustment used both propensity score matching and multivariable logistic regression. RESULTS: From July 1997 to October 2019, 888 patients had undergone DTA/TAAA repair, of whom 19 were excluded from our analysis for missing data. SOD was absent in 712 patients and present in 157 patients. The patients with SOD had presented with a greater incidence of preoperative renal impairment (61 [38.9%] vs 175 [24.6%]; P < .01) and peripheral arterial disease (60 [38.2%] vs 162 [22.8%]; P < .01] and decreased left ventricular ejection fraction (45%; interquartile range, 10%; vs 50%; interquartile range, 4%; P < .01). The etiology of aortic disease was more frequently dissection in the SOD group (56.1% vs 43.7%) and more frequently nondissecting aneurysm in the non-SOD group (56.3% vs 43.9%; P < .01). Patients without SOD had presented with aneurysms more cranially located (DTA, 34.0% vs 7.6%; extent I TAAA, 44.0% vs 7.6%). In contrast, patients with SOD had presented with aneurysms more caudally located (extent II TAAA, 36.9% vs 8.6%; extent III TAAA, 30.6% vs 11.0%; extent IV TAAA, 17.2% vs 2.5%; P < .01). Propensity score matching led to 144 pairs, with SOD significantly associated with SCI (10 [6.9%] vs 2 [1.4%]; P = .03) and MAE (47 [32.6%] vs 26 [15%]; P < .01). Ten-year survival was reduced in those with SOD (31.5% vs 45.2%; P < .01). Conditional multivariable regression confirmed SOD to be a predictor of SCI in the matched sample (odds ratio, 6.60; P = .02). CONCLUSIONS: Our results have shown that SOD is a significant predictor of SCI in patients undergoing open DTA/TAAA repair. The investigation of measures to prolong neuronal ischemia tolerance (eg, hypothermia) is warranted for such patients.