Ultra high frequency ultrasound enables real-time visualization of blood supply from chorioallantoic membrane to human autosomal dominant polycystic kidney tissue.

Ultra high frequency (UHF) ultrasound enables the visualization of very small structures that cannot be detected by conventional ultrasound. The utilization of UHF imaging as a new imaging technique for the 3D-in-vivo chorioallantoic membrane (CAM) model can facilitate new insights into tissue perfusion and survival. Therefore, human renal cystic tissue was grafted onto the CAM and examined using UHF ultrasound imaging. Due to the unprecedented resolution of UHF ultrasound, it was possible to visualize microvessels, their development, and the formation of anastomoses. This enabled the observation of anastomoses between human and chicken vessels only 12 h after transplantation. These observations were validated by 3D reconstructions from a light sheet microscopy image stack, indocyanine green angiography, and histological analysis. Contrary to the assumption that the nutrient supply of the human cystic tissue and the gas exchange happens through diffusion from CAM vessels, this study shows that the vasculature of the human cystic tissue is directly connected to the blood vessels of the CAM and perfusion is established within a short period. Therefore, this in-vivo model combined with UHF imaging appears to be the ideal platform for studying the effects of intravenously applied therapeutics to inhibit renal cyst growth.

Sepsis induces heterogeneous transcription of coagulation- and inflammation-associated genes in renal microvasculature.

BACKGROUND: Acute kidney injury (AKI) in sepsis patients increases patient mortality. Endothelial cells are important players in the pathophysiology of sepsis-associated AKI (SA-AKI), yet knowledge regarding their spatiotemporal involvement in coagulation disbalance and leukocyte recruitment is lacking. This study investigated the identity and kinetics of responses of different microvascular compartments in kidney cortex in response to SA-AKI. METHODS: Laser microdissected arterioles, glomeruli, peritubular capillaries, and postcapillary venules from kidneys of mice subjected to cecal ligation and puncture (CLP) were analyzed using RNA sequencing. Differential expression and pathway enrichment analyses identified genes involved in coagulation and inflammation. A selection of these genes was evaluated by RT-qPCR in microvascular compartments of renal biopsies from patients with SA-AKI. The role of two identified genes in lipopolysaccharide-induced endothelial coagulation and inflammatory activation were determined in vitro in HUVEC using siRNA-based gene silencing. RESULTS: CLP-sepsis in mice induced altered expression of approximately 400 genes in the renal microvasculature, with microvascular compartments exhibiting unique spatiotemporal responses. In mice, changes in gene expression related to coagulation and inflammation were most extensive in glomeruli at early and intermediate time points, with high induction of Plat, Serpine1, Thbd, Icam1, Stat3, and Ifitm3. In human SA-AKI, PROCR and STAT3 were induced in postcapillary venules, while SERPINE1 expression was diminished. IFITM3 was increased in arterioles and glomeruli. In vitro studies revealed that STAT3 and IFITM3 partly control endothelial coagulation and inflammatory activation. CONCLUSION: Renal microvascular compartments in mice and humans exhibited heterogeneous changes in coagulation- and inflammation-related gene expression in response to SA-AKI. Additional research should aim at understanding the functional consequences of the here described heterogeneous microvascular responses to establish the usefulness of identified genes as therapeutic targets in SA-AKI.

The prevalence of accessory renal arteries in sudanese population in Khartoum State: a cross-sectional CT study from 2017 to 2020.

BACKGROUND: Renal artery variations are clinically significant due to their implications for surgical procedures and renal function. However, data on these variations in Sudanese populations are limited. This study aimed to determine the prevalence and characteristics of renal artery variations in a Sudanese population. METHODS: A cross-sectional retrospective study was conducted in Khartoum state from October 2017 to October 2020. A total of 400 Sudanese participants who underwent abdominal CT scans were included. Data on demographic characteristics, kidney measurements, and renal vasculature were collected and analyzed using descriptive statistics and inferential tests. RESULTS: The mean age of participants was 46.7 ± 18 years, with a nearly equal gender distribution. Overall, renal artery variations were present in 11% of participants, with accessory renal arteries observed in 6% of the study population. Among those with accessory vessels, 50% were on the right side, 29.2% on the left, and 20.8% bilateral, distributed across hilar 29.2%, lower polar 29.2%, and upper polar 41.7% regions. No significant associations were found between accessory renal arteries and age or gender (p-value > 0.05). However, participants with accessory renal arteries exhibited significantly narrower width 5.0 ± 1.4 than those with no with accessory renal arteries 5.8 ± 1.1 (p-value 0.002) Early dividing renal arteries were found in 5% of participants, with nearly half being bilateral. No significant associations were found between the presence of early dividing renal arteries and demographic or renal measurements (p-value > 0.05). CONCLUSION: This study provides valuable insights into the prevalence and characteristics of renal artery variations in a Sudanese population. The findings contribute to our understanding of renal anatomy in this demographic and can inform clinical practice and surgical planning, particularly in renal transplantation and other renal procedures.

Robust Rat and Mouse Models of Bilateral Renal Ischemia Reperfusion Injury.

BACKGROUND/AIM: Acute and chronic kidney diseases are a major contributor to morbidity and mortality worldwide, with no specific treatments currently available for these. To enable understanding the pathophysiology of and testing novel treatments for acute and chronic kidney disease, a suitable in vivo model of kidney disease is essential. In this article, we describe two reliable rodent models (rats and mice) of efficacious kidney injury displaying acute to chronic kidney injury progression, which is also reversible through novel therapeutic strategies such as ischemic preconditioning (IPC). MATERIALS AND METHODS: We utilized adult male Lewis rats and adult male wildtype (C57BL/6) mice, performed a midline laparotomy, and induced warm ischemia to both kidneys by bilateral clamping of both renal vascular pedicles for a set time, to mimic the hypoxic etiology of disease commonly found in kidney injury. RESULTS: Bilateral ischemia reperfusion injury caused marked structural and functional kidney injury as exemplified by histology damage scores, serum creatinine levels, and kidney injury biomarker levels in both rodents. Furthermore, this effect displayed a dose-dependent response in the mouse model. CONCLUSION: These rodent models of bilateral kidney IRI are reliable, reproducible, and enable detailed mechanistic study of the underlying pathophysiology of both acute and chronic kidney disease. They have been carefully optimised for single operator use with a strong track record of training both surgically trained and surgically naïve operators.

Noninvasive measurement of tracer extraction efficiency in tissue, illustrated with Tc-99m-MAG3.

OBJECTIVE: The aim of this study is to develop a noninvasive technique for measuring tissue tracer extraction efficiency ( E ) and illustrate it for Tc-99m-mercaptoacetyltriglycine (MAG3) and kidney. METHODS: E was measured in 10 patients with normal MAG3 renography. E is the ratio of tissue clearance-to-blood flow ( Ki/F ). For single-photon tracers, attenuation constants are unknown, so Ki and F cannot be separately measured. However, by deriving attenuation-uncorrected Ki' and F' from the same regions of interests (ROIs), these constants cancel out, giving E . Using a lung ROI for blood activity, F was measured from first-pass and Ki' from Gjedde-Patlak-Rutland (GPR) analysis up to 130 s. Because of interference from right ventricle, a left ventricular ROI (LV) is unsuitable for F' but was used in GPR analysis, making an adjustment for the ratio of respective blood pool signals arising from lung and LV ROIs in early frames (60-90 s). RESULTS: A lung ROI underestimates F' by 4% at normal LV function. Chest wall interstitial activity ( I ), which does not affect F' , amounted to 53 and 30% of the lung and LV signals at 20 min, and 12 and 6% at 130 s, resulting in underestimations of Ki of 4 and 2%, respectively. Ignoring these opposing errors, E based on lung ROI for left and right kidneys was 43.5 (SD 8)% and 47.3 (9)%, and based on LV ROI for GPR analysis was 44.5 (10.9)% and 48.3 (10.6)%. CONCLUSION: E can be measured by combining blood flow from first-pass with clearance from GPR analysis, and has potential value both clinically and in clinical research.

Long-Term Safety and Efficacy of Transcatheter Microwave and Radiofrequency Denervation in a Chronic Ovine Model.

BACKGROUND: Transcatheter renal denervation (RDN) has had inconsistent efficacy and concerns for durability of denervation. We aimed to investigate long-term safety and efficacy of transcatheter microwave RDN in vivo in normotensive sheep in comparison to conventional radiofrequency ablation. METHODS AND RESULTS: Sheep underwent bilateral RDN, receiving 1 to 2 microwave ablations (maximum power of 80-120 W for 240 s-480 s) and 12 to 16 radiofrequency ablations (180 s-240 s) in the main renal artery in a paired fashion, alternating the side of treatment, euthanized at 2 weeks (acute N=15) or 5.5 months (chronic N=15), and compared with undenervated controls (N=4). Microwave RDN produced substantial circumferential perivascular injury compared with radiofrequency at both 2 weeks [area 239.8 (interquartile range [IQR] 152.0-343.4) mm2 versus 50.1 (IQR, 32.0-74.6) mm2, P <0.001; depth 16.4 (IQR, 13.9-18.9) mm versus 7.5 (IQR, 6.0-8.9) mm P <0.001] and 5.5 months [area 20.0 (IQR, 3.4-31.8) mm2 versus 5.0 (IQR, 1.4-7.3) mm2, P=0.025; depth 5.9 (IQR, 1.9-8.8) mm versus 3.1 (IQR, 1.2-4.1) mm, P=0.005] using mixed models. Renal denervation resulted in significant long-term reductions in viability of renal sympathetic nerves [58.9% reduction with microwave (P=0.01) and 45% reduction with radiofrequency (P=0.017)] and median cortical norepinephrine levels [71% reduction with microwave (P <0.001) and 72.9% reduction with radiofrequency (P <0.001)] at 5.5 months compared with undenervated controls. CONCLUSIONS: Transcatheter microwave RDN produces deep circumferential perivascular ablations without significant arterial injury to provide effective and durable RDN at 5.5 months compared with radiofrequency RDN.

RAS protein activator-like 2 (RASAL2) initiates peritubular capillary rarefaction in hypoxic renal interstitial fibrosis.

The progression of chronic kidney disease (CKD) often involves renal interstitial fibrosis (RIF) and subsequent loss of peritubular capillaries (PTCs), which enhances disease severity. Despite advancements in our understanding of fibrosis, effective interventions for reversing capillary loss remain elusive. Notably, RIF exhibits reduced capillary density, whereas renal cell carcinoma (RCC) shows robust angiogenesis under hypoxic conditions. Using RNA sequencing and bioinformatics, we identified differentially expressed genes (DEGs) in hypoxic human renal tubular epithelial cells (HK-2) and renal cancer cells (786-0). Analysis of altered Ras and PI3K/Akt pathways coupled with hub gene investigation revealed RAS protein activator-like 2 (RASAL2) as a key candidate. Subsequent in vitro and in vivo studies confirmed RASAL2's early-stage response in RIF, which reduced with fibrosis progression. RASAL2 suppression in HK-2 cells enhanced angiogenesis, as evidenced by increased proliferation, migration, and branching of human umbilical vein endothelial cells (HUVECs) co-cultured with HK-2 cells. In mice, RASAL2 knockdown improved Vascular endothelial growth factor A (VEGFA) and Proliferating cell nuclear antigen (PCNA) levels in unilateral ureteral occlusion (UUO)-induced fibrosis (compared to wild type). Hypoxia-inducible factor 1 alpha (HIF-1α) emerged as a pivotal mediator, substantiated by chromatin immunoprecipitation (ChIP) sequencing, with its induction linked to activation. Hypoxia increased the production of RASAL2-enriched extracellular vesicles (EVs) derived from tubular cells, which were internalized by endothelial cells, contributing to the exacerbation of PTC loss. These findings underscore RASAL2's role in mediating reduced angiogenesis in RIF and reveal a novel EV-mediated communication between hypoxic tubular- and endothelial cells, demonstrating a complex interplay between angiogenesis and fibrosis in CKD pathogenesis.

Retrospective analysis of the perioperative outcome in living donor kidney transplantation with multiple renal arteries: does accessory vessel ligation affect the outcome?

PURPOSE: Accurate surgical reconstruction of arterial vascular supply is a crucial part of living kidney transplantation (LDKT). The presence of multiple renal arteries (MRA) in grafts can be challenging. In the present study, we investigated the impact of ligation versus anastomosis of small accessory graft arteries on the perioperative outcome. METHODS: Clinical and radiological outcomes of 51 patients with MRA out of a total of 308 patients who underwent LDKT with MRA between 2011 and 2020 were stratified in two groups and analyzed. In group 1 (20 patients), ligation of accessory arteries (ARAs) and group 2 (31 patients) anastomosis of ARAs was performed. RESULTS: Significant differences were observed in the anastomosis-, surgery-, and warm ischemia time (WIT) in favor of group 1. Students t-test showed comparable serum creatinine levels of 2.33 (± 1.75) to 1.68 (± 0.83) mg/dL in group 1 and 2.63 (± 2.47) to 1.50 (± 0.41) mg/dL in group 2, were seen from 1 week to 1 year after transplant. No increased rates of Delayed graft function (DGF), primary transplant dysfunction and transplant rejection were seen, but graft loss and revision rates were slightly higher when the ARAs were ligated. Analysis of Doppler sonography revealed that segmental perfusion deficits tend to regenerate during the clinical course. CONCLUSION: Ligation of smaller accessory renal arteries may not affect the outcome of living kidney transplantation, except for a minor increase in the reoperation rate. Segmental perfusion deficits of the graft seem to regenerate in most cases as seen in Doppler sonography.

Renal vascular control during normothermia and passive heat stress does not differ between healthy younger men and women.

Men are likely at greater risk for heat-induced acute kidney injury compared with women, possibly due to differences in vascular control. We tested the hypothesis that the renal vasoconstrictor and vasodilator responses will be greater in younger women compared with men during passive heat stress. Twenty-five healthy adults [12 women (early follicular phase) and 13 men] completed two experimental visits, heat stress or normothermic time-control, assigned in a block-randomized crossover design. During heat stress, participants wore a water-perfused suit perfused with 50°C water. Core temperature was increased by ∼0.8°C in the first hour before commencing a 2-min cold pressor test (CPT). Core temperature remained clamped and at 1-h post-CPT, subjects ingested a whey protein shake (1.2 g of protein/kg body wt), and measurements were taken pre-, 75 min, and 150 min post-protein. Beat-to-beat blood pressure (Penaz method) was measured and segmental artery vascular resistance (VR, Doppler ultrasound) was calculated as segmental artery blood velocity ÷ mean arterial pressure. CPT-induced increases in segmental artery VR did not differ between trials (trial effect: P = 0.142) nor between men (heat stress: 1.5 ± 1.0 mmHg/cm/s, normothermia: 1.4 ± 1.0 mmHg/cm/s) and women (heat stress: 1.4 ± 1.2 mmHg/cm/s, normothermia: 2.1 ± 1.1 mmHg/cm/s) (group effect: P = 0.429). Reductions in segmental artery VR following oral protein loading did not differ between trials (trial effect: P = 0.080) nor between men (heat stress: -0.6 ± 0.8 mmHg/cm/s, normothermia: -0.6 ± 0.6 mmHg/cm/s) and women (heat stress: -0.5 ± 0.5 mmHg/cm/s, normothermia: -1.1 ± 0.6 mmHg/cm/s) (group effect: P = 0.204). Renal vasoconstrictor responses to the cold pressor test and vasodilator responses following an oral protein load during heat stress or normothermia do not differ between younger men and younger women in the early follicular phase of the menstrual cycle.NEW & NOTEWORTHY The mechanisms underlying greater heat-induced acute kidney injury risk in men versus women remain unknown. This study examined renal vascular control, including both vasodilatory (oral protein load) and vasoconstrictor (cold presser test) responses, during normothermia and heat stress and compared these responses between men and women. The results indicated that in both conditions neither renal vasodilatory nor vasoconstrictor responses differ between younger men and younger women.

The renal vasodilatation from ß-adrenergic activation in vivo in rats is not driven by KV7 and BKCa channels.

The mechanisms behind renal vasodilatation elicited by stimulation of ß-adrenergic receptors are not clarified. As several classes of K channels are potentially activated, we tested the hypothesis that KV7 and BKCa channels contribute to the decreased renal vascular tone in vivo and in vitro. Changes in renal blood flow (RBF) during ß-adrenergic stimulation were measured in anaesthetized rats using an ultrasonic flow probe. The isometric tension of segmental arteries from normo- and hypertensive rats and segmental arteries from wild-type mice and mice lacking functional KV7.1 channels was examined in a wire-myograph. The ß-adrenergic agonist isoprenaline increased RBF significantly in vivo. Neither activation nor inhibition of KV7 and BKCa channels affected the ß-adrenergic RBF response. In segmental arteries from normo- and hypertensive rats, inhibition of KV7 channels significantly decreased the ß-adrenergic vasorelaxation. However, inhibiting BKCa channels was equally effective in reducing the ß-adrenergic vasorelaxation. The ß-adrenergic vasorelaxation was not different between segmental arteries from wild-type mice and mice lacking KV7.1 channels. As opposed to rats, inhibition of KV7 channels did not affect the murine ß-adrenergic vasorelaxation. Although inhibition and activation of KV7 channels or BKCa channels significantly changed baseline RBF in vivo, none of the treatments affected ß-adrenergic vasodilatation. In isolated segmental arteries, however, inhibition of KV7 and BKCa channels significantly reduced the ß-adrenergic vasorelaxation, indicating that the regulation of RBF in vivo is driven by several actors in order to maintain an adequate RBF. Our data illustrates the challenge in extrapolating results from in vitro to in vivo conditions.

Spontaneous renal tumour regression following an aortic dissection.

Spontaneous tumour regression is a rare but well-documented phenomenon, especially for renal cell carcinomas. We describe the case of a 60-year-old male who presented with chest pain and shortness of breath. He was diagnosed with a large type A aortic dissection and an incidental right renal mass, highly suspicious of a renal cell carcinoma. Following repair of the dissection, subsequent imaging showed that the renal mass had largely resolved. Spontaneous tumour regression is commonly thought to occur through immunological mechanisms. A vascular cause of tumour regression through infarction is postulated in this case. Although angioembolisation is a well-recognised management option in the context of palliative treatment of symptomatic renal tumours, this case suggests an extended role for angioembolisation in the treatment of small renal masses.

Changes in renal microcirculation in patients with nephrotic and nephritic syndrome: The role of resistive index.

BACKGROUND: Renal Resistive Index (RRI) is an important and non-invasive parameter of renal damage and it is associated with abnormal microcirculation or to a parenchymal injury. The aim of our study was to compare the RRI in a cohort of patients with renal diseases categorized in three groups: nephrotic syndrome (NS), acute nephritic syndrome (ANS) and patients with urinary abnormalities (UA). METHODS: Four hundred eighty-two patients with median age of 48 years (IQR 34-62) with indications for kidney disease were included in the study. Biochemical analyses, clinical assessment with detection of NS, ANS and UA and comorbidities were reported. Renal Doppler ultrasound with RRI was evaluated in all patients at the time of enrolment. RESULTS: NS was present in 81 (16.8 %) patients while ANS in 81 (16.8 %) and UA in 228 (47.3 %) patients. Patients with ANS showed significant higher RRI compared to both patients with NS [0.71 (IQR 0.67-0.78) vs 0.68 (0.63-0.73), p < 0.001] and UA [0.71 (0.67-0.78) vs 0.65 (0.61-0.71), p < 0.001]; RRI was higher in NS patients than in patients with UA [0.68 (0.63-0.73) vs 0.65 (0.61-0.71), p < 0.001]. Patients with ANS had significantly lower median estimated glomerular filtration rate (eGFR) compared respectively to NS and UA patients [19.7 ml/min vs 54.8 ml/min and vs 72.3 ml/min, p < 0.001], while renal length was significantly higher in patients with NS compared to both patients with ANS and UA [111.88 mm vs 101.98 mm and vs 106.15, p < 0.001]. Patients with ANS had more frequently hematuria and RRI ≥ 0.70 (p < 0.001) compared to both patients with NS and patients with UA. The multiple regression analysis, weighted for age, showed that RRI inversely correlates with eGFR (ß coefficient = -0.430, p < 0.001). CONCLUSIONS: Higher and pathological RRI were found in ANS than NS and UA. Renal resistive index in ANS reflects changes in intrarenal perfusion and microvascular dysfunction related to disease characteristics.

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.

Human Kidney Proximal Tubule-Microvascular Model Facilitates High-Throughput Analyses of Structural and Functional Effects of Ischemia-Reperfusion Injury.

Kidney ischemia reperfusion injury (IRI) poses a major global healthcare burden, but effective treatments remain elusive. IRI involves a complex interplay of tissue-level structural and functional changes caused by interruptions in blood and filtrate flow and reduced oxygenation. Existing in vitro models poorly replicate the in vivo injury environment and lack means of monitoring tissue function during the injury process. Here, a high-throughput human primary kidney proximal tubule (PT)-microvascular model is described, which facilitates in-depth structural and rapid functional characterization of IRI-induced changes in the tissue barrier. The PREDICT96 (P96) microfluidic platform's user-controlled fluid flow can mimic the conditions of IR to induce pronounced changes in cell structure that resemble clinical and in vivo phenotypes. High-throughput trans-epi/endo-thelial electrical resistance (TEER) sensing is applied to non-invasively track functional changes in the PT-microvascular barrier during the two-stage injury process and over repeated episodes of injury. Notably, ischemia causes an initial increase in tissue TEER followed by a sudden increase in permeability upon reperfusion, and this biphasic response occurs only with the loss of both fluid flow and oxygenation. This study demonstrates the potential of the P96 kidney IRI model to enhance understanding of IRI and fuel therapeutic development.

Renal cortex microperfusion evaluated by laser speckle contrast imaging in an ex vivo perfused kidney model-A proof-of-concept study.

BACKGROUND: Validated quantitative biomarkers for assessment of renal graft function during normothermic machine perfusion (NMP) conditions are lacking. The aim of this project was to quantify cortex microperfusion during ex vivo kidney perfusion using laser speckle contrast imaging (LSCI), and to evaluate the sensitivity of LSCI when measuring different levels of renal perfusion. Furthermore, we aimed to introduce LSCI measurements during NMP in differentially damaged kidneys. METHODS: Eleven porcine kidneys were nephrectomized and perfused ex vivo. Cortex microperfusion was simultaneously monitored using LSCI. First, a flow experiment examined the relationship between changes in delivered renal flow and corresponding changes in LSCI-derived cortex microperfusion. Second, renal cortical perfusion was reduced stepwise by introducing a microembolization model. Finally, LSCI was applied for measuring renal cortex microperfusion in kidneys exposed to minimal damage or 2 h warm ischemia (WI). RESULTS: Cortex microperfusion was calculated from the LSCI-obtained data. The flow experiment resulted in relatively minor changes in cortex microperfusion compared to the pump-induced changes in total renal flow. Based on stepwise injections of microspheres, we observed different levels of cortex microperfusion that correlated with administrated microsphere dosages (r2 = 0.95-0.99). We found no difference in LSCI measured cortex microperfusion between the kidneys exposed to minimal damage (renal cortex blood flow index, rcBFI = 2090-2600) and 2 h WI (rcBFI = 2189-2540). CONCLUSIONS: Based on this preliminary study, we demonstrated the feasibility of LSCI in quantifying cortex microperfusion during ex vivo perfusion. Furthermore, based on LSCI-measurements, cortical microperfusion was similar in kidneys exposed to minimal and 2 h WI.

A Retrospective Analysis of the 1-Year Graft Survival Rate in Indonesian Renal Transplant Recipients With Multiple Renal Arteries.

BACKGROUND: Renal transplantation is the preferred treatment for end-stage renal disease because of its association with improved survival and quality of life. The debate over multiple renal arteries (MRA) vs a single renal artery regarding kidney function, posttransplant complications, and graft and patient survival remains ongoing. Our goal was to determine the 1-year graft survival rate among renal transplant recipients with MRA at Cipto Mangunkusumo Hospital in Jakarta. METHODS: A retrospective study was conducted between January 2012 and December 2020, including all kidney transplant candidates with MRA. Data on graft survival, patient demographics, previous renal transplantation, duration of hemodialysis, and delayed graft function were collected and analyzed using SPSS 24. Kaplan-Meier plots and Cox regression analyses were used to determine risk factors for 1-year survival. RESULTS: Among 752 renal transplant recipients, 104 cases had MRA. The majority were men (71.5%), and the median age of recipients was 47 years. One-year graft survival was observed in 96% of cases, whereas patient survival was 97.7%. No significant difference was found in graft survival based on the number of arteries (single renal artery vs MRA), length of hemodialysis, or previous renal transplantation. However, delayed graft function was significantly associated with graft survival. CONCLUSION: This study highlights that 1-year graft survival in renal transplant recipients with MRA is not significantly affected by the length of hemodialysis before surgery or previous renal transplantation.

Intra-renal Arteries in Nephrectomy from a Historical Aspect, a Quest Originated by Medical Illustrations to Reach Modern Angiography.

The aim of the present paper is to contribute to the understanding of the history of the anatomical study of the intra-renal arteries. The vasculature and especially the intra-renal arteries of the kidneys are an intriguing field which was first studied through art and then perfected by medicine. Angiography and microsurgery have resulted in partial nephrectomy techniques for surviving kidneys with adequate functional results. Graves' categorization dating from 1954 opened the way for innovative approaches that have resulted in modern topographical anatomy. CONCLUSION: Our understanding of the anatomy of intra-renal arteries has played a significant role in surgical anatomy and internal medicine.

Radio frequency-based renal denervation: a story of simplicity?

Radio frequency-based renal denervation is a safe and effective way of lowering blood pressure, a common condition associated with high cardiovascular risk. Several catheters have been developed to administer energy to the renal arteries and their side branches, thereby modulating sympathetic renal activity. The Symplicity Flex™ and Symplicity Spyral™ are first- and second-generation devices, respectively, for radio frequency-based renal denervation. There is a continuous need to further improve and adjust interventional antihypertensive therapies. Several randomized controlled trials have been conducted to investigate the safety and efficacy of these catheters and most were able to show radio frequency-based renal denervation to be feasible, safe and effective in lowering blood pressure in hypertensive patients with and without concomitant antihypertensive medication. Herein, the authors discuss the pathophysiologic concepts of renal denervation and its procedural approaches, report catheter designs, summarize clinical trials outcomes and, finally, discuss real-world evidence.

High blood pressure causes illness and death worldwide. Treatment of high blood pressure is usually based on lifestyle modification and blood pressure-lowering drugs. Renal denervation represents a minimally invasive approach to lower blood pressure by interrupting the nerves surrounding the renal arteries. These nerves are involved in the body's fight-or-flight and rest-and-digest systems, the so-called autonomous nervous system. The Spyral™ catheter system uses radio frequency energy to modulate renal nerve activity. Trials have consistently shown that renal denervation is safe. The first-generation catheter was a monoelectrode catheter called Symplicity Flex™ and several points in the renal artery had to be treated. The second-generation device called the Symplicity Spyral™ catheter, on the other hand, has a multielectrode design and consequently fewer ablation points are sufficient for complete denervation. Caused by the positive effects on blood pressure and the consistent safety reports, renal denervation is considered by current guidelines as an alternative and additive treatment approach in patients with high blood pressure.

[Italian Society of Interventional Cardiology (GISE) and Italian Society of Arterial Hypertension (SIIA) Consensus document on the role of renal denervation in the management of the difficult to treat hypertension]. / Documento di consenso della Società Italiana di Cardiologia Interventistica (GISE) e della Società Italiana dell'Ipertensione arteriosa (SIIA) sul ruolo della denervazione renale nella gestione dell'ipertensione arteriosa difficile da trattare.

Arterial hypertension is the most prevalent cardiovascular risk factor worldwide. Despite the availability of many and effective antihypertensive medications, the prevalence of uncontrolled blood pressure (BP) remains high. As sympathetic hyperactivity has long been recognized as a major contributor to resistant hypertension, catheter-based renal denervation (RDN) has emerged as a new strategy to reduce BP. RDN aims to interrupt the activity of renal sympathetic nerves by applying radiofrequency (RF) energy, ultrasound (US) energy, or injection of alcohol in the perivascular space. The Symplicity HTN-3 trial, the largest sham-controlled trial using the first-generation RF-based RDN device, failed to significantly reduce BP. Since then, new devices and techniques have been developed and consequently many sham-controlled trials using second-generation RF or US-based RDN devices have demonstrated the BP lowering efficacy and safety of the procedure. A multidisciplinary team involving hypertension experts, interventionalists with expertise in renal interventions and anesthesiologists, plays a pivotal role from the selection of the patient candidate for the procedure to the post-procedural care. The aim of this consensus document is to summarize the current evidence about the use of RDN in difficult to treat hypertension and to propose a management strategy from the selection of the patient candidate for the procedure to the post-procedural care.