Intrarenal Resistance Research Articles

Rapid adaptation of the intrarenal resistance index after living donor kidney transplantation

Limited data exist concerning changes of renal perfusion directly after kidney transplantation. Colour-coded duplex sonography is the accepted method to assess kidney perfusion after transplantation. A widely used, although unspecific, Doppler parameter is the intrarenal resistance index (RI). The aim of this study was to clarify the influence of different patient- and procedure-related factors on RI before and immediately after living kidney transplantation. In a prospective study, 80 living kidney transplantation donor-recipient pairs were included. RI was measured in the donor 1 to 3 days before nephrectomy and in the recipient during the first hour after transplantation to examine the influence of age, heart rate, duration of cold and warm ischaemia time and immunosuppressive medications. Mean RI did not differ between donors and recipients. RI correlated with age, both in donors (r = 0.58, P < 0.001) and recipients (r = 0.39, P < 0.001). In recipients, 10 or more years younger than their donors (n = 24), an average decrease of 0.05 in RI compared to the donors' value was observed (P = 0.01). Heart rate, cold and warm ischaemia time and immunosuppressive medications had no influence on the recipient RI. In patients with delayed graft function, a significant increase in RI within 14 days was observed. However, the initial RI was not predictive of graft function. The transplanted kidney seems to be able to adjust its RI within a short time despite several potential harmful factors that can occur during the transplantation.

Renal Hemodynamics and Renoprotection

Background: Angiotensin II (AII) is the well-known determinant of kidney damage increasing intraglomerular pressure, matrix expansion and fibroblast proliferation. Renin-angiotensin system (RAS) inhibition, limiting the hemodynamic effects of AII, reduces proteinuria and is renoprotective in the long term. Methods: We studied 15 chronic proteinuric patients by Doppler ultrasonography to clarify the intrarenal hemodynamic changes during RAS blockade by Benazepril (10–20 mg/day) alone and combined with Valsartan (80–160 mg/day). We also investigated the correlation between hemodynamic indices, RAS components and antiproteinuric effect. Results: After 1 month of Benazepril proteinuria, resistive index (RI) and pulsatility index (PI) significantly decreased and proteinuria reduction was directly correlated to decrease in RI (r = 0.55, p = 0.03). Contrarily, after 1 month of combined therapy, RI and PI restored to baseline and progressively increased in the following 3 months, while proteinuria decreased. Increase in RI was directly correlated to concomitant increase in plasma renin activity (r = 0.65, p = 0.01) suggesting a direct role of renin in restoring intrarenal resistances. Conclusion: The hemodynamic changes caused by RAS inhibitors partially contribute to the antiproteinuric effect. Other RAS components, such as renin, may contribute to renal vasoconstriction and could be a further determinant of kidney damage besides a promising target for renoprotection.

Increased flow‐mediated vasodilation in cirrhotic patients with ascites: relationship with renal resistive index

Peripheral vasodilation is the key factor in the development of hyperdynamic circulation, sodium retention and functional renal failure in patients with cirrhosis. Brachial artery flow-mediated dilation (FMD) after transient vascular occlusion is a non-invasive method to assess the shear stress-induced arterial vasodilation. To evaluate FMD in cirrhotic patients with and without ascites and to assess the relationship between FMD and intrarenal resistances. Flow-mediated dilation was determined in 32 cirrhotic patients (22 with ascites) and 12 healthy controls and correlated with the intrarenal resistive index (RI) assessed by Doppler exploration. Basal diameter of the brachial artery was similar in healthy controls and in cirrhotic patients, whereas FMD was significantly higher in patients with cirrhosis and ascites [29.5% (range 10.3-50%)] than in pre-ascitic patients [17.3% (range 2.4-48.5%)] and healthy control subjects [11.6% (range 5.1-17.8%)] (P<0.001). Intrarenal RI was significantly higher in patients with cirrhosis than in healthy subjects, and a direct relationship existed between FMD and intrarenal RI (r=0.66; P<0.00001). These findings in vivo demonstrate that cirrhotic patients with ascites have an enhanced shear stress-induced peripheral vasodilation, which is closely related to intrarenal vasoconstriction.

Measurement of the intrarenal arterial resistance index for the identification and prediction of diabetic nephropathy

Background and Aims High intrarenal resistance index (RI) predicts renal function in several conditions; its use in the prediction of diabetic nephropathy (DN) is little explored. We aimed (1) to compare RI in diabetic and non diabetic hypertensive patients, and (2) to evaluate whether high RI is associated with clinical signs of DN and its progression over time. Methods and Results Design: observational, prospective. Participants: 92 type 2 diabetic patients and 37 non-diabetic controls aged 40–70, with hypertension and normal renal function. We measured ultrasound RI and, among others, creatinine, estimated glomerular filtration rate and urinary albumin excretion rate (AER) at baseline and after 4.5 years follow-up. Progression of albuminuric state (i.e., transition from baseline normo-microalbuminuria to follow-up micro-macroalbuminuria) was evaluated. RI was significantly higher in diabetic than non-diabetic participants (0.69 ± 0.05 vs 0.59 ± 0.05, p < 0.001). Diabetic patients with RI ≥ 0.73, i.e., above the 80th percentile of the RI distribution, had significantly higher baseline AER and a more frequent progression of the albuminuric state compared to patients with RI < 0.73 (27.7 μg/mg [12.1–235.4] vs 15.1 μg/mg [8.6–33.4]; 52.9% vs 9.5%, respectively). AER increased significantly from baseline to follow-up in patients with RI ≥ 0.73 (from 27.7 μg/mg [12.1–235.4] to 265.0 μg/mg [23.8–1018.1], p < 0.01), but not in those with RI < 0.73 (from 15.1 μg/mg [8.6–33.4] to 16.1 μg/mg [10.7–67.2], ns). OR for progression of albuminuric state, adjusted for established predictors of DN, including baseline AER, was 5.01 (1.4–17.7, 95% CI) for patients with RI ≥ 0.73 vs <0.73. Findings were confirmed in patients with normoalbuminuria at baseline. Conclusions In diabetic patients, high RI (≥0.73) is associated with features of DN and its progression over time, independent of albuminuria.

Color‐coded duplex ultrasound for diagnosis of renal artery stenosis and as follow‐up examination after revascularization

Currently, angiography is still considered to be the gold standard for the diagnosis of a renal artery stenosis (RAS). However, angiography is invasive and carries the potential risk of haematoma, pseudoaneurysm, contrast agent induced nephropathy, and athermanous embolization. Color-coded duplex ultrasound is a noninvasive frequently repeatable bed-side examination and is currently the only diagnostic method to reliably differentiate between a hemodynamically relevant or irrelevant stenosis using the side-to-side difference of the intrarenal resistance index (RI). There is a highly specific correlation between a side difference of the RI of >0.05 and an at least 70% angiographic diameter stenosis. All other duplex parameters like a peak systolic flow velocity >200 cm/sec or a renal aortic flow velocity ratio >3.5 are correlated to a 50 or 60% angiographic diameter stenosis and offer therefore indeed a high sensitivity in terms of detecting a RAS; however, the specificity detecting a hemodynamically relevant RAS is low. Provided that duplex ultrasound is performed by an experienced physician with an adequate machine it should be the preferred imaging method. The present article gives an overview about the literature related to duplex based diagnosis of RAS and as a follow-up diagnostic procedure following RAS revascularization.

Renal Scintigraphy Findings in Allograft Recipients With Increased Resistance Index on Doppler Sonography

Aim The measurement of intrarenal resistance indices (RIs) by doppler ultrasound plays an important role in the evaluation of renal transplant recipients. Although an elevated RI was initially considered to be specific for rejection, later studies revealed this parameter as a nonspecific marker of transplant dysfunction. In this study, we analysed Tc-99m DTPA renal scintigraphy findings in patients with increased RI during the early posttransplantation period. Methods This study included 22 patients with increased RI on doppler sonography during the first week after transplantation. Twenty-two recipients with uncomplicated early postoperative courses were used as a control group. An RI value >0.7 was considered pathologic. All patients underwent Tc-99m DTPA renal scintigraphy just after doppler sonography. In addition to visual interpretation of images, renogram curves were evaluated for patterns suggestive of acute tubular necrosis and acute rejection. Glomerular filtration rate (GFR) was calculated using computer software. Perfusion time-activity curves were assessed for the presence of peak and plateau patterns to calculate this ratio (P:PL). Results The mean value for P:PL in patients with increased RI and in the control group were 1.37 ± 0.33 and 1.53 ± 0.47, respectively ( P < .05). The mean value for GFR was significantly lower in the patient group compared with control subjects. Six patients had normal perfusion and function (27%). Perfusion pattern and renogram changes were suggestive of acute tubular necrosis in 5 patients and acute rejection in 6 patients. These diagnoses were confirmed later with serial scintigraphic changes or biopsy results. Three patients had an accumulation pattern on the renogram suggesting partial obstruction. Conclusion During the early posttransplantation period an increased RI on doppler sonography was seen in both normal functioning grafts and those with allograft dysfunction. Renal scintigraphy with perfusion and renogram patterns highly suggestive of specific allograft pathologies seemed to provide useful information to distinguish early postoperative renal allograft pathologies.

Do ultrasound renal resistance indices reflect systemic rather than renal vascular damage in chronic kidney disease?

In patients suffering from chronic kidney disease (CKD), ultrasound renal resistance indices predict progression of kidney disease and death. Although ultrasound resistance indices were initially considered to directly reflect intrarenal vascular resistance, they are complex composite parameters that are influenced by various vascular factors. We hypothesized that renal resistance indices reflect systemic vascular disease rather than local renal damage in patients with CKD. In 140 patients suffering from CKD not receiving renal replacement therapy, intrarenal resistance indices were measured in interlobar arteries. For assessment of systemic atherosclerotic disease, common carotid intima-media thickness (IMT) and ankle-brachial blood pressure index were determined. Categories of risk for coronary heart diseases were defined by Framingham risk scoring. Increased renal resistance indices were associated with high Framingham risk scores and with the presence of atherosclerotic disease. In addition, ultrasound renal resistance indices progressively increased with the stage of renal function impairment, and patients suffering from diabetic nephropathy had higher resistance indices than patients suffering from other renal diseases. In a multivariate linear regression analysis, IMT, Framingham risk score, renal function, presence of diabetic nephropathy and pulse pressure independently predicted resistance indices. However, when additionally adjusting for age, IMT and Framingham risk score were no longer independent predictors of resistance indices. In patients suffering from CKD, intrarenal resistance indices are independently associated with cardiovascular risk score and systemic vascular disease as well as with aetiology and stage of CKD. This may explain their strong association with both impaired renal outcome and death.

Duplex Ultrasound and Renin Ratio Predict Treatment Failure After Revascularization for Renal Artery Stenosis

The aim of this study was to find predictors to identify patients with hypertension who will not improve after removal of renal artery stenosis (RAS). Prospective study of patients with unilateral stenosis (>60% diameter reduction) and hypertension in 24-h measurements despite antihypertensive drugs, who underwent revascularization (surgery/angioplasty). Examinations were performed before treatment and after 3 and 6 months after exclusion of restenosis. Studies included 24-h blood pressure, creatinine clearance, 99Tc MAG3 scintigraphy, and measurements of renal vein plasma renin activity (PRA). Intrarenal resistance indices (RI) were determined with duplex ultrasound before and 30 min after administration of intravenous enalaprilat. Improvement of hypertension was defined by a score consisting of 24-h mean arterial pressure and the number of antihypertensive drugs. From December 2000 to December 2003, 50 patients completed the study. Improvement of hypertension was observed in 18 patients (36%). Comparison between responders (n = 18) and nonresponders (n = 32) revealed significant differences only for RI and PRA measurements. The largest area under the curve in receiver-operating characteristic (ROC) analysis for prediction of no improvement of hypertension was found for RI (stenosis side), which was nearly identical for measurements before and after administration of angiotensin-converting enzyme (ACE) inhibitor. The highest sensitivities and specificities predicting which patients will not improve were found for RIs > or = 0.55. The highest univariate odds ratio (OR 44, confidence interval [CI] 4.8-404) was found for the parameters of RI > or = 0.55 and a renin ratio of <1:1.5. Resistance indices of the poststenotic kidney above 0.55 and a negative renin ratio can predict a poor outcome concerning arterial blood pressure response after restoration of renal blood flow for unilateral renal artery stenosis.

The Intrarenal Vascular Resistance Parameters Measured by Duplex Doppler Ultrasound Shortly After Kidney Transplantation in Patients With Immediate, Slow, and Delayed Graft Function

Background Evaluation of pulsatility (PI) and resistive (RI) indexes by duplex Doppler ultrasound shortly after kidney transplantation reflects the exacerbation of interstitial edema. The aim of study was to characterize factors that influence PI and RI in patients with immediate (IGF), slow (SGF), or delayed (DGF) kidney graft function. Patients and methods PI and RI were measured in 200 transplanted patients at 2 to 4 days postoperatively. We excluded patients with acute rejection episodes within the first month. IGF, which was defined as serum creatinine <264 μmol/L at 3 days, SGF, which was defined as creatinine >264 μmol/L by day 3 with a maximum of one dialysis, and DGF, which was defined as more than 1 dialysis were observed in 33.3%, 41.5%, and 25.2% of patients, respectively. The examined donor parameters were age, hypotensive episodes, catecholamine infusion, central venous pressure, and glomerular filtration rate. The recipient factors were age, history of hypertension, diabetes mellitus, ischemic heart disease, and stroke. Additionally cold ischemia time (CIT), HLA mismatch, and PRA were analyzed. Results The lowest PI and RI values were observed among patients with IGF (PI 1.37 [1.28 to 1.46]; RI 0.72 [0.69 to 0.74]); moderate values in SGF (PI 1.65 [1.52 to 1.78]; RI 0.78 [0.76 to 0.80]) and the highest values in DGF (PI 2.09 [1.83 to 2.35]; RI 0.83 [0.80 to 0.86]) differences that were highly significant. Hypotensive episodes and catecholamine infusion in the preharvest period had essential impacts on PI or RI values in the early posttransplant period. There was no significant correlation between PI or RI values and CIT. A slower ATN resolution was observed in DGF patients with higher PI values. Conclusion Ischemic injury, which occured mainly prior to organ harvesting, played a dominant role determining intrarenal resistance in the early posttransplant period.

What do Doppler indices of renal perfusion tell us for the evaluation of renal disease?

What do Doppler indices of renal perfusion tell us for the evaluation of renal disease?

Renal Doppler resistance indices are associated with systemic atherosclerosis in kidney transplant recipients

In kidney transplant recipients, increased intrarenal resistance indices measured by duplex ultrasound are associated with poor subsequent allograft performance. It remains unclear whether high resistance indices rather reflect local renal damage or systemic vessel disease. We hypothesized that resistance indices are associated with cardiovascular risk factors and with subclinical systemic atherosclerosis in transplant recipients. In 105 renal transplant recipients, categories of risk for coronary heart disease were determined by Framingham risk scoring. Intrarenal resistive index (RI) and pulsatility index (PI) were measured in segmental arteries at five representative locations. For assessment of subclinical atherosclerosis, common carotid intima-media thickness, and ankle-brachial blood pressure index (ABI) were determined. Transplant recipients with high coronary risk had higher intrarenal resistance indices than low-risk patients. Higher age, female gender, and lower body mass index were independently associated with increased resistance indices. Renal resistance indices were correlated with common carotid intima-media thickness [RI: r= 0.270 (P= 0.005); PI: r= 0.355 (P < 0.001)]. This association remained significant after adjusting for renal function. Renal resistance indices were increased in patients with pathologic ankle-brachial-indices compared to patients with physiologic ankle-brachial-indices [RI: 73.3 +/- 7.1 vs. 70.2 +/- 6.9 (P= 0.03); PI: 146.4 +/- 29.9 vs. 131.4 +/- 25.9 (P= 0.01)]. Renal resistance indices were neither significantly correlated with glomerular filtration rate (GFR), nor with donor age. Intrarenal resistance indices are a complex integration of arterial compliance, pulsatility, and peripheral resistance. They are associated with traditional cardiovascular risk factors as well as with subclinical atherosclerotic vessel damage and should thus not be considered specific markers of renal damage.

Acute effect of CyA A (Neoral®) on large artery hemodynamics in renal transplant patients

CyA A (CyA) may induce intrarenal vasoconstriction, endothelial dysfunction, and hypertension. There are only two contradictory reports describing the acute effect of CyA on renal resistances measured by color Doppler flowmetry. Therefore, we studied the acute influence of oral CyA on arterial haemodynamics by assessing simultaneous changes in blood pressure, applanation tonometry-derived pulse wave analysis and duplex ultrasound-derived intrarenal resistance indices. Augmentation index (AIx) (difference between the first and second systolic peak on the aortic pressure waveform divided by the pulse pressure = AIx) was determined from contour analysis of arterial waveforms recorded by applanation tonometry using the AtCor device in 18 live-related renal transplants (11 females/7 males, age = 32.0 +/- 8.1 years, transplantation duration = 17.5 +/- 16.1 months, and mean serum creatinine = 133 +/- 70 micromol/L). All studies were performed just before (C0), and 2 hours after (C2) the oral administration of CyA. At the same C0 and C2 moments the resistive index (RI) = (peak systolic frequency shift - minimum diastolic frequency shift)/peak systolic frequency shift, and pulsatility index (PI) = (peak systolic frequency shift - minimum diastolic frequency shift)/mean frequency shift were calculated from Doppler recorded waveforms. Blood pressure and heart rate did not differ significantly at C0 and at C2 serum levels: 134.3/82.9 vs. 128.1/80.0 mm Hg and 72.0 vs. 71.0 beats/min, respectively, despite a marked increase in whole blood concentration (CyA(C0)= 90.8 +/- 45.9 vs. CyA(C2)= 547.4 +/- 251.3 ng/mL) (P= 0.05). Mean AIx fell significantly from 17.2 +/- 13.8 to 12.9 +/- 14.2 (P < 0.0001). There was no correlation between the extent (expressed as absolute or relative change) of the measured alteration in AIx and total administered CyA dose, or increment in blood level between C0 and C2. In support, the intake of CyA did not induce a significant increase in Doppler resistance (RI(C0)= 0.68 +/- 0.08 vs. RI(C2)= 0.70 +/- 0.09) and pulsatility indices (PI(C0)= 1.32 +/- 0.31 vs. PI(C2)= 1.33 +/- 0.28). Finally, three patients were studied twice (>1 week): one under two levels of creatinine, one with no antihypertensives, and a third receiving verapamil initially. All these maintained a significant decrease in AIx at C2 from C0 supporting the reproducibility of the phenomenon. We demonstrate that Neoral CyA acutely improves large arterial compliance function and does not induce an acute rise in intrarenal resistance in stable renal transplant subjects with normal renal function. We speculate that there may be an effect of vitamin E, the diluent vehicle in which CyA is carried (1000 IU/100 mg CyA), shown to improve endothelial function.

Stent-supported angioplasty of severe atherosclerotic renal artery stenosis preserves renal function and improves blood pressure control: long-term results from a prospective registry of 456 lesions.

To report a prospective study evaluating the long-term impact of stent-supported angioplasty on renal function and blood pressure control. In a 6-year period, 456 hemodynamically significant de novo renal artery stenoses > or =70% were treated in 340 consecutive hypertensive patients (223 men; mean age 66+/-10 years, range 44-84) with or without impaired renal function. Baseline data on serum creatinine (sCr), intrarenal resistance index, ambulatory 24-hour blood pressure monitoring, and documentation of the number and dose of antihypertensive drugs were compared to values obtained during follow-up. The primary endpoint was a 10% decrease in sCr; the glomerular filtration rate and changes in blood pressure control were additional outcome measures. During a mean follow-up of 34+/-20 months, sCr decreased significantly from 1.45+/-0.87 to 1.39+/-0.73 mg/dL (p=0.048). In 34% of the patients, sCr decreased >10%, 39% were unchanged, and 27% had an increase >10%. Glomerular filtration rate increased from 59+/-26 to 62+/-26 mL/min/1.73 m(2) (p=0.6). Systolic, diastolic, and mean blood pressure measurements significantly improved immediately after the intervention (132/72/93 versus 144/79/102 mmHg at baseline, p<0.0001) and remained improved during follow-up (p<0.0001). Blood pressure control was improved in 46%, unchanged in 43%, and deteriorated in 11%. Baseline sCr, bilateral intervention, percent diameter stenosis, and 3-vessel coronary disease were independent predictors of improved renal function during follow-up; the number of antihypertensive drugs taken before the intervention predicted improved blood pressure control. Stent-supported angioplasty of renal artery stenoses preserves renal function and improves blood pressure control in a broader spectrum of patients than previously thought.

No rise in renal Doppler resistance indices at peak serum levels of cyclosporin A in stable kidney transplant patients.

The measurement of intrarenal resistance indices by duplex ultrasound plays an important role in the follow-up care of renal transplant patients. Increasing resistance indices indicate rejection episodes, but may also occur e.g. in parenchymal renal diseases. As calcineurin inhibitors induce vasoconstriction both in vivo and in vitro, we studied whether peak serum levels of cyclosporin A led to an acute rise in renal resistance indices via the induction of intrarenal vasoconstriction. The acute impact of peak serum levels of cyclosporin A on intrarenal resistance indices was studied in 36 patients after allogeneic renal transplantation. All patients were transplanted for > 6 months and received an immunosuppressive treatment comprising cyclosporin A. Intrarenal resistance indices were measured by duplex ultrasound immediately before (trough serum level) and 2 h after (peak serum level) the oral intake of cyclosporin A at the individual maintenance dose. Compared with renal resistance indices measured at trough serum levels [resistive index (RI) 0.72 +/- 0.07; pulsatility index (PI) 1.40 +/- 0.27], values remained unchanged at peak serum levels of cyclosporin A (RI 0.72 +/- 0.08; PI 1.43 +/- 0.31). Renal resistance indices correlated with the age of the patients, but not with mean arterial pressure or time since transplantation. The oral intake of cyclosporin A does not induce an acute rise in intrarenal resistance indices in stable transplanted patients. Thus, timing of duplex ultrasound examinations with regard to the intake of cyclosporin A is not necessary in these patients.

Duplex ultrasound for follow-up examination after stent-angioplasty of ostial renal artery stenoses

Renal artery stenosis (RAS) may lead to deterioration of renal function and/or hypertension. Stent angioplasty has become the method of choice in the treatment of atherosclerotic ostial RAS. We describe the changes of the following duplex parameters: intrarenal resistance index RI according to Pourcelot and the renal-aortic flow velocity ratio (RAR) directly after intervention and during follow-up (FU). We also examine the value of the method in detecting restenosis. We present the results of a prospective study of 241 patients with stent angioplasty for the treatment of 355 severe RAS (extent of stenosis >/= 70 % of vessel diameter). Duplex examinations during FU were performed before discharge, after 6 and 12 months, and then annually resulting in 1292 examinations. RAR could be calculated in 98.9 % (1278/1292), RI was calculated in 100 % of the examinations. The RAR decreased significantly from 5.9 +/- 2.1 to 1.2 +/- 0.4 after intervention (p < 0.00001) with a slight increase during follow-up. RI increased significantly from 0.64 +/- 0.11 to 0.74 +/- 0.06 after intervention (p < 0.00001), equalling the RI of the contralateral side (0.74 +/- 0.07). During a mean FU of 27 +/- 15 months, 37 restenosis (10.4 %) and 12 re-restenosis were detected and confirmed angiographically, resulting in 48 reinterventions. In case of restenosis, RAR increased from 1.3 +/- 0.4 to 6.3 +/- 2.8 (p < 0.001) with a decrease to 1.3 +/- 0.6 after reintervention (p < 0.001), and RI decreased from 0.75 +/- 0.08 to 0.64 +/- 0.11 (p < 0.001) with an increase to 0.75 +/- 0.07 after reintervention (p < 0.001). Duplex ultrasound is a reliable method for FU of patients after renal artery stent-angioplasty and for detecting restenosis.

Sistema de perfusión hipotérmica de riñón aislado controlado por ordenador

ObjectiveTo evaluate at the laboratory a self-designed computer-controlled kidney perfusion system. A vacuum powered tubular pump with active valves developed by our group is used. This pump is able to produce a flow and pressure patterns very similar to the pulse wave in the human circulatory system. Basic proceduresThis is an experimental study performed with mini-pig kidneys. After transperitoneal bilateral nephrectomy, both organs are sorted either to immediate perfusion or to perfusion after a period of 24 hours of cold storage in Eurocollins solution. The system is able to record continuously perfusion pressure, flow and intrarenal resistance. ResultsA progressive decrease in renal vascular resistance along with an increase in the flow value were observed during the procedures. These dynamic changes become evident both in immediate and deferred renal perfussions. ConclusionsComputer-controlled kidney perfusion system provide us the opportunity of recording in real time renal microcirculatory state modifications during a perfusion. Vascular system seems to be actively modified by the perfusion. This fact should be researched in the next future.

Relationship between intrarenal vascular resistances and plasma levels of endothelins 1 and 3 (ET-I and ET-3) and nitrates/nitrites in liver cirrhosis

Relationship between intrarenal vascular resistances and plasma levels of endothelins 1 and 3 (ET-I and ET-3) and nitrates/nitrites in liver cirrhosis

Significant decrease of intrarenal artery resistance index in cirrhotic patients with ascites responsive to diuretic therapy

Significant decrease of intrarenal artery resistance index in cirrhotic patients with ascites responsive to diuretic therapy

Significant decrease of intrarenal artery resistance index in cirrhotic patients with ascites responsive to diuretic therapy

Significant decrease of intrarenal artery resistance index in cirrhotic patients with ascites responsive to diuretic therapy

Cold ischaemia further increases intrarenal resistance when non-heart-beating kidneys are pulsatile machine perfused

Cold ischaemia further increases intrarenal resistance when non-heart-beating kidneys are pulsatile machine perfused