Renal Venous Research Articles

Abstract 13330: Intrarenal Doppler Ultrasonography Reflects Hemodynamics and Predicts Prognosis in Patients With Heart Failure

Introduction: We aimed to clarify clinical implications of intrarenal hemodynamics (congestion and hypoperfusion) assessed by intrarenal Doppler ultrasonography (IRD) and their prognostic impacts in patients with heart failure (HF). Methods and Results: We performed IRD and measured interlobar renal artery velocity time integral (VTI) and intrarenal venous flow (IRVF) patterns (monophasic or non-monophasic pattern) to assess intrarenal hypoperfusion and congestion in HF patients (n=341). These patients were categorized based on 1) VTI: high VTI (VTI ≥ 14.0 cm, n=231) or low VTI (VTI < 14.0 cm, n=103); and 2) IRVF: monophasic (n=36) or non-monophasic (n=305) pattern. We performed right-heart catheterization, and examined post-discharge cardiac event rate such as cardiac death and rehospitalization due to worsening HF. Regarding renal perfusion, cardiac index was positively correlated with VTI (R=0.270, P=0.040). Concerning renal congestion, levels of right atrial pressure were higher in monophasic pattern than in non-monophasic pattern (9.0 vs. 7.2 mmHg, P=0.029). Importantly, HF patients with low VTI and a monophasic IRVF pattern (subset 4) had the highest cardiac event rate ( Figure ). In the Cox proportional hazard analysis, the combination of low VTI and a monophasic IRVF pattern was found to be a strong predictor of cardiac events (HR 8.357, 95% CI 3.365-20.752). Conclusion: Intrarenal hypoperfusion and congestion assessed by IRD imaging reflected cardiac output and right atrial pressure, and was useful to risk-stratify HF patients.

Doppler Interrogation of the Femoral Vein in the Critically Ill Patient: The Fastest Potential Acoustic Window to Diagnose Right Ventricular Dysfunction?

To report the use of common femoral vein Doppler interrogation as a simple technique to diagnose right ventricular dysfunction. Case report. Cardiac surgical ICU. Postoperative cardiac surgical patients. Common femoral pulsed-wave and color Doppler examination associated with hepatic, portal, and renal venous Doppler measurement were obtained in both patients and before and after treatment in patient number 1. In addition, right ventricular pressure waveform examination was obtained in patient number 2. The technique to obtain common femoral venous Doppler is described. Two cases of patients presenting with right ventricular dysfunction and fluid overload with portal and renal venous congestion in the perioperative period undergoing complex multivalvular cardiac surgery are presented. Hemodynamic waveform monitoring was performed alongside echocardiographic, hepatic, and renal venous flow Doppler assessment, and spectral Doppler profiles of the common femoral veins were examined. Those findings were useful in confirming our diagnosis and guiding our response to treatment. An algorithm was developed and tested on two additional hemodynamically unstable patients. Doppler examination of the common femoral vein is a simple, fast, and noninvasive technique that could be useful to rule in the presence of right ventricular dysfunction with venous congestion and help guide the management of such patients.

The Effect of Decongestion on Intrarenal Venous Flow Patterns in Patients With Acute Heart Failure

BackgroundDiscontinuous intrarenal venous flow patterns, as assessed by renal Doppler ultrasound examination, are associated with changes in hemodynamics such as volume expansion and poorer diuretic response in patients with heart failure (HF). We aimed to study intrarenal venous and arterial flow patterns after decongestive treatment in patients with acute HF. Methods and ResultsFifteen patients with acute HF were enrolled. Intrarenal venous and arterial flow patterns were assessed at baseline, 1 hour after administration of loop diuretics, at day 2 and day 3. Among patients hospitalized for acute HF, 13 (87%) had a discontinuous venous flow pattern at admission. After decongestive treatment, a significant improvement of the venous impedance index (P = .021) and venous discontinuity index (P = .004) was observed at day 3 compared with baseline. There was no effect on the intrarenal arterial flow patterns. ConclusionsIn patients who exhibit discontinuous renal venous flow patterns hospitalized for decongestive treatment owing to acute HF led to a normalization of intrarenal venous flow to a continuous pattern.

Value of Renal Vascular Doppler Sonography in Cardiorenal Syndrome Type 1.

Worsening of renal function in a patient with acute decompensated heart failure is called cardiorenal syndrome (CRS) type 1. Recent studies have shown an association of persistent systemic venous congestion with renal dysfunction. This trial was set up to investigate the changes of renal Doppler parameters with diuretic therapy in patients with CRS type 1. Cases of CRS type 1 were identified among patients hospitalized for decompensated heart failure. Serial measurements of the renal venous impedance index (VII) and arterial resistive index (ARI) were calculated by pulsed wave Doppler sonography. A total of 30 patients who had creatinine improvement with diuresis (group 1) and 34 patients without any improvement (group 2) were analyzed. Patients in group 1 had higher median VII and ARI (VII, 0.86 versus 0.66; P < .001; ARI, 0.78 versus 0.65; P < .001) on admission. A high ARI on admission (odds ratio, 6.25; 95% confidence interval, 1.84-14.3; P = .003) predicted the improvement of serum creatinine levels with diuretic therapy independent of confounding factors in patients with CRS type 1. Renal vascular Doppler parameters might offer guidance on the diagnostic and therapeutic strategies in prescribing decongestive therapy for decompensated heart failure.

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

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

P0201ASSOCIATION OF INTRARENAL VEIN FLOW PATTERNS WITH CARDIAC FUNCTION IN OUTPATIENTS WITH CHRONIC KIDNEY DISEASE AND HEART FAILURE

Abstract Background and Aims In patients with chronic kidney disease (CKD) and heart failure (HF), renal venous congestion plays a key role in determining renal dysfunction and a worse prognosis. Αim of this ongoing study is to identify Doppler intrarenal venous flow patterns reflecting renal congestion in patients with CKD and HF and to detect possible associations with cardiac function parameters. Prognostic implications will be evaluated at a next stge. Method We prospectively enroll outpatients affected by CKD stages 3-4 and HF, in stable clinical conditions and in conventional therapy. All patients undergo clinical evaluation, routine biochemistry, transthoracic echocardiogram and renal echo-Doppler. Pulsed Doppler flow recording is performed at the level of the right interlobular renal veins at the end-expiratory phase. The intrarenal venous flow patterns are divided into five types according to the waveforms of the flow. Type A and B are characterized by a continuous flow and considered normal waveforms. Type C is characterized by a short interruption and/or reversal flow during the end-diastolic or protosystolic phase. Type D and E are characterized by a wide interruption and/or reversal flow, respectively. Types C, D and E are considered abnormal and reflect increasing venous pressure within the kidneys. Results Until now, 36 patients (27males / 9 females), 13 (36%) diabetics, aged 69.4±10.6 years old, have been included, and baseline characteristics are presented. Twenty patients (55%) have CKD stage 3, and 16 patients CKD stage 4 (45%). Fifteen (40%) of these patients have HF New York Heart Association (ΝΥΗA) class II, 18 (50%) ΝΥΗΑ class ΙΙΙ and 3 (10%) ΝΥΗΑ class IV. Mean ejection fraction (EF) is 34.5±7.8%, moderately reduced in 9 (25%) and severely reduced in 27 (75%) of these patients. By analyzing the waveforms, we noticed that 27 patients (75%) had venous patterns of continuous flow (type A 18% and type B 57%) and 9 (25%) had venous patterns with not continuous flows (21% type C and 4% type D). The patients with renal venous patterns A and B had higher EF than those with renal venous patterns C and D (36±8% vs. 30±5%, p=0.045). We have also observed that worsening HF according to NYHA classification was significantly associated to more pathological renal venous patterns (rho=0.402, p=0.034) Conclusion In patients with CKD and HF we may observe abnormal intrarenal vein flow patterns, in the context of renal congestion, related to the functional state of the heart. Further studies will indicate the clinical and prognostic significance of these measurements to better characterize patients with cardio-renal syndrome.

Epidemiology, Diagnosis and Management of Neonatal Thrombosis

Introduction: Current research on neonatal thrombosis is limited. It relies heavily on individual case reports and much of the data is extrapolated from the adult scientific literature. The aim of this descriptive study is to review the epidemiology, diagnosis and management of neonatal thrombosis at a single tertiary care institution. Methods: This is a retrospective study of apatients admitted to McMaster Children's Hospital, neonatal intensive care unite from 2005 to 2018. Data on patient demographics, diagnostic imaging, thrombophilia testing, co-morbidities, treatment, outcomes were collected from health records. Results: A total of 242 neonatal patients were included. The distribution of 251 thrombotic episodes was: 144 portal vein, 15 cerebral sino-venous, 12 cardiac, 2 pulmonary embolisms, 5 renal vein, 40 extremity and central venous and 13 arterial. Additionally, 20 cases categorized as miscellaneous, consisted of clots in sites such as the basilic vein or umbilical artery, among other locations. Male and female percentages were 55% and 45%, respectively. Preterm to term infant ratio was 1.5:1. The average age at diagnosis was 13.2 days. 70% of thrombotic episodes were line-related, while infection and surgery were associated with 19% and 12% of episodes, respectively. 52% of the patients were blood group O. 30% of the patients received initial anticoagulation treatment, while the rest were managed conservatively. There was a trend towards higher rate of complete clot resolution in patients who received anticoagulation (48%) compared to those who did not (40%). Conclusion: This is one of the largest, single institution, epidemiologic studies of neonatal thrombosis. In our group of patients, portal vein thrombosis was most prevalent compared to other sites of thrombosis and catheterization was the commonest risk factor. There was a trend towards improved resolution with anticoagulation. Further prospective studies are required to confirm these findings. Disclosures No relevant conflicts of interest to declare.

Ultrasound guidance for volume management in patients with heart failure.

Congestion is one of the most prominent characteristics of patients presented with decompensated heart failure and it implies unfavorable prognosis for the heart failure patient. Neurohumoral and immuno-inflammatory activation secondary to cardiac dysfunction constitute the pivotal mechanisms driving the heart failure syndrome that results in progressive fluid accumulation. In addition, fluid redistribution between different vascular compartments in human body guided from sympathetic activity constitutes another mechanism for heart failure decompensation. Ultrasound applied in the form of echocardiography provides invaluable data for the assessment of intracardiac filling pressures. The type of renal venous flow can provide the degree of renal congestion and probably insight into the pathophysiology of the decompensation of heart failure. Assessment of lung congestion in the patient with heart failure can be accomplished by lung ultrasonography. Additionally, clinical studies on the role of ultrasound in the management and prognosis of the congested patient are reviewed. Special heart failure population supported with left ventricular assist devices and extracorporeal membrane oxygenation support constitute an area where ultrasound guidance of fluid management has gained important role.

P2599Echo color doppler evaluation of renal hemodynamic during acute heart failure

Abstract Background Acute heart failure (AHF) is often accompanied by impairment in renal function. A profound derangement of normal abdominal haemodynamic is always present during this clinical phase. Methods 14 patients (6 F – mean age 80 – mean EF 0.39) admitted for acute heart failure underwent cardiac and renal Echo Doppler examination at day 1-3-5 of Hospital stay. Parameters of arterial and venous flow within cortical right kidney were recorded. Venous Doppler Profile (VDP) was classified as: continuous (C), pulsatile (P), biphasic (B) or monophasic (M) according to the growing degree of derangement. Arterial resistive index (RI) &gt;0.8 was considered elevated. Correlation between renal hemodynamic (and its changes) with biohumoral and echo parameters was sought. Outcome At day 1 VDP was M or B in 8 patients (57%) and in four (50%) of them dropped to C or P at day 5. RI was elevated in 8 patients at day 1 while only in 4 at day 5. VDP and RI were not related to EF or BNP values. One patient died before day 5, no other worsening heart failure episodes occurred. Two patients (14%) developed acute kidney injury but their VDP and RI were normal and did not change. Three patients (21%) did not improve their BNP (decrease &gt;30%) but this was not associated with VDP or RI changes. Elevated derived pulmonary artery systolic pressure (&gt;40 mmHg) was present in 6 out of 8 patients (75%) with M or B VDP and in all 4 patients with both elevated RI and M or B VDP. Venous Pattern Day 1 Day 3 Day 5 Continous 2 8 5 Pulsatile 4 2 4 Biphasic 2 1 2 Monophasic 6 3 2 Arterial RI &gt;0.8 8 6 4 BNP, pg/ml 1060±1180* 372±281* 424±213* Creatinine, mg/dl 1.4±0.6 1.5±0.6 1.3±0.6 Hb, g/dl 12.1±2.3 12.3±3.6 13.2±2.3 *p&gt;0.05. Conclusions This is the first study exploring changes in renal hemodynamic by echo Doppler during AHF. With respect to previous studies among stable patients, our preliminary data shows a higher proportion of deranged renal venous and/or arterial pattern. After diuretic therapy a trend towards improvement in VDP was recorded. No clear association with other clinical and hemodynamic parameters seems evident.

A New Technique: Laparoscopic Resection of Fibrous Ring and Placing Extravascular Stent in Patients With Nutcracker Syndrome: A Report of 5 Cases

ObjectiveTo evaluate the feasibility and safety of a new laparoscopic technique for resection of a fibrous ring and extravascular stent implantation in patients with nutcracker syndrome (NCS). Material and MethodsWe retrospectively reviewed data of 5 patients diagnosed with NCS between March 2010 and February 2016. The mean age of the patients (4 male and 1 female) was 34 years (range, 28-40 years). All 5 patients underwent laparoscopic resection of the narrow fibrous ring around the left renal venous (LRV) and for extravascular stent implantation in the LRV for management of NCS. ResultsThe average operating time was104 minutes and the average blood loss during surgery was 59 mL. The average length of the postoperative hospital stay was 6 days (range, 4-8 days). In all 5 patients, the symptoms of macroscopic hematuria started decreasing gradually and resolved after surgery. Postoperative computed tomography showed that the blood outflow from the LRV was smooth. The ratio of the dilated segment's inner diameter to the diameter of the strictured segment decreased from 3.4 to 9.5, preoperatively to 1.1-2.0, postoperatively. The mean follow-up period was 17.6 months (range, 8-24 months).One patient's varicocele was cured and symptoms in all 5 patients resolved after surgery. None of the patients showed symptom recurrence. ConclusionLaparoscopic surgery, for the placement of an extravascular stent and resection of the fibrous ring around the end of the LRV outflow to the inferior vena cava appears feasible and safe and offers an alternative minimally invasive for the management of NCS.

Sonographic Venous Velocity Index Identifies Patients with Chronic Kidney Disease and Severe Diastolic Dysfunction

ObjectiveDiagnosing cardiorenal syndrome (CRS) in patients with chronic kidney disease (CKD) continues to remain challenging in outpatient practice. In this study, we investigate whether a newly developed venous velocity ultrasound index (VVI) can differentiate between patients with CRS and patients with CKD of other cause or normal renal function (NRF).Methods Patients with CRS (n = 30), CKD (n=30), and NRF (n=30) were included in the study. For each patient, duplex ultrasound scans of intrarenal segmental veins were retrospectively analyzed. The VVI was calculated from the renal venous doppler curve as the ratio of the maximal positive venous velocity to the maximal negative venous velocity. Patients with CRS were compared to age-matched controls with NRF and to GFR-matched controls with CKD. Results:The GFRs of patients with CRS and those with CKD were comparable (26.4±5 and 25.6±7 ml/min/m2), as was the age in patients with CRS and NRF (6 ±12 years and 68±16 years, respectively). There was no significant difference in ejection fraction between patients with CRS and those with CKD (44.2±6.2% vs. 47.4 ±7.2), but there was a significant decrease compared to those with NRF (52.6 ±5.1, p<0.01). The VVI was significantly higher in the CRS group (0.81± 0.18) compared to the CKD group (0.18± 0.17, p<0.01) or NRF group (0.22± 0.20, p<0.01). The positive predictability of CRS was 96.4% in patients with VVI values of >0.6.ConclusionThe newly developed VVI was useful in successfully predicting severe diastolic dysfunction (CRS) in patients with severe kidney injury in outpatient care.

Accurate Risk Assessment of Patients with Pathologic T3aN0M0 Renal Cell Carcinoma

To develop a more precise risk-stratification system by investigating the prognostic impact of tumor growth within fatty tissues surrounding the kidney and/or renal vein. We conducted a retrospective review of the medical records of 211 patients with a pathologic diagnosis of T3aN0M0RCC among 4,483 renal cell carcinoma (RCC) patients from February 1988 to December 2015 according to the number of T3a pathologies—extrarenal fat invasion (EFI) and/or renal venous invasion (RVI). During a mean follow-up duration of 38.8 months, the patients with both pathologies (EFI + RVI) had lower recurrence free survival (RFS) rate than those with only a single pathology (p = 0.001). Using multivariable Cox regression analysis, the presence of both factors was shown to be an independent predictor of RFS (HR = 1.964, p = 0.032); cancer specific survival rate was not different among patients with EFI and/or RVI. Patients with pathologic T3aN0M0 RCC presenting with both EFI and RVI were at an increased risk of recurrence following nephrectomy. Therefore, pathologic T3a RCC could be sub-divided into those with favorable and unfavorable disease according to presence of EFI and/or RVI pathologies.

Doppler-Based Renal Venous Stasis Index as a New Prognostic Marker in Right Heart Failure

Background: Persistent congestion with deteriorating renal function is an important cause of adverse outcomes in heart failure. Renal Doppler ultrasonography has been proposed to assess renal congestion but is not fully characterized, and current approaches do not reflect the full continuum of renal congestion. We aimed to characterize new approaches to evaluate renal congestion using Doppler ultrasonography. Methods: We enrolled 205 patients with suspected or pre-diagnosed pulmonary hypertension (PH) undergoing right heart catheterization. PH is the most common precursor to right ventricular failure, and thus represents an ideal scenario to study congestion. Patients underwent renal Doppler ultrasonography and assessment of invasive cardiopulmonary haemodynamics, echocardiography, renal function, intra-abdominal pressure, and hormonal and hydration status. Four renal venous flow patterns (RVFPs) and a novel renal venous stasis index (RVSI) were defined. The rate of PH-related morbidity and all-cause mortality (composite endpoint) was evaluated for 1 year post-discharge. Associations with outcome were assessed using Cox proportional hazard models. Prognostic utility of RVSI and RVFP was compared using receiver operating characteristic (ROC) curves. Findings: RVSI increased across the RVFPs (p<0*0001), and was significantly associated with right heart and renal function, intra-abdominal pressure, and hormonal and hydration status. During follow-up, the morbidity/mortality endpoint occurred in 91 patients and was independently predicted by RVSI (RVSI in 3rd tertile vs RVSI=0: hazard ratio 4*72 [95% confidence interval 2*10-10*59; p<0*0001]). ROC curves suggested superiority of RVSI to RVFPs in predicting outcome (area under curve: 0*789 and 0*761, respectively). Interpretation: We describe four RVFPs, and we propose RVSI as a conceptually new, non-invasive, objective, and reproducible Doppler index of renal congestion. RVSI might provide additional information to stratify vulnerable patients with right heart failure. Clinical Trial Number: The study is registered at www.ClinicalTrials.gov (NCT03039959). Funding: This study was funded by the German Research Foundation (DFG) SFB1213, projects B08 and B07. Declaration of Interests: Dr. Seeger disclosed personal fees for consulting from Bayer Pharma AG, from Liquidia Technologies, Inc, and from United Therapeutics Corporation outside the submitted work. Dr. Gall discloses personal fees and non-financial support from Actelion, AstraZeneca, Bayer, BMS, GlaxoSmithKline, Janssen Cilag, Lilly, MSD, Novartis, Pfizer, and United Therapeutics/OMT outside the submitted work. Dr. Gofrani discloses grants from German Research Foundation (DFG) during the conduct of the study, and personal fees from Actelion, Bayer, GSK, Novartis, Pfizer, Bellerophon Pulse Technologies, and MSD Merck Sharpe & Dohme outside the submitted work. None of the other authors declare any competing interests. Ethical Approval Statement: The study was approved by the local Human Research Ethics Committee (AZ 237/16) and complied with the Declaration of Helsinki. All participants gave signed informed consent and were included in the Giessen PH registry.

Caval replacement strategy in pediatric retroperitoneal tumors encasing the vena cava: a single-center experience and review of literature

BackgroundComplete encasement of the inferior vena cava by retroperitoneal tumors is rare. Although replacement of the vena cava has been considered for various conditions in adults, it is rarely used in children except for challenging resections and as a last chance approach – often aiming more at debulking than cure. Materials and methodsFrom January 2009 to February 2017, 4 patients (2 adrenal neuroblastomas, 1 renal cell carcinoma, 1 infantile fibrosarcoma) underwent elective en-bloc resection of tumor and of the infrahepatic portion of the inferior vena cava (IVC), with planned IVC prosthetic replacement. In three cases a portion of the left renal vein had to be resected as well, with the vein reanastomosed onto the prosthesis, and a concomitant auto-transplantation of the right kidney was associated in one neuroblastoma patient. ResultsAll patients had an uncomplicated postoperative course. In one patient, the prosthetic conduit is patent at long-term (43 months), while the middle portion of the prosthesis did eventually thrombose at mid-term after surgery in the three others – with no related symptoms. Interestingly, all renal venous reconstructions remain patent. Three patients (2 neuroblastomas and 1 infantile fibrosarcoma) are alive and disease-free at 43, 74 and 108 months after surgery, respectively. One patient with renal cell carcinoma died of recurrence of the disease 21 months after surgery. ConclusionResection and reconstruction of the vena cava, including the renal vein portion, can be considered and planned electively in case of tumoral encasement. This strategy is associated with good tolerance of the operation, low morbidity and satisfactory long-term function, even in cases with progressive and/or secondary partial thrombosis. Level of EvidenceIV

The dark side of the kidney in cardio-renal syndrome: renal venous hypertension and congestive kidney failure.

Renal involvement in some forms of acute or chronic diseases, such as heart failure or sepsis, presents with a complex pathophysiological basis that is not always clearly distinguishable. In these clinical settings, kidney failure is traditionally and almost exclusively attributed to renal hypoperfusion and it is commonly accepted that causal elements are pre-renal, such as a reduction in the ejection fraction or absolute or relative hypovolemia acting directly on oxygen transport mechanisms and renal autoregulation systems, causing a reduction of glomerular filtration rate. Nevertheless, the concept emerging from accumulating clinical and experimental evidence is that in complex clinical pictures, kidney failure is strongly linked to the hemodynamic alterations occurring in the renal venous micro and macrocirculation. Accordingly, the transmission of the increased venous pressure to the renal venous compartment and the consequent increasing renal afterload has a pivotal role in determining and sustaining the kidney damage. The aim of this review was to clarify the physiopathological aspects of the link between worsening renal function and renal venous hypertension, analyzing the prognostic and therapeutic implications of the so-called congestive kidney failure in cardio-renal syndrome and in other clinical contexts of its possible onset.

Correction to: Altered oscillation of Doppler-derived renal and renal interlobar venous flow velocities in hypertensive and diabetic patients.

In the original publication of this paper the legend of Fig.1 should read as: Fig.1 Pulsed Doppler flow velocity recordings of the aorta (a), right renal artery (b), right renal interlobar artery (c), inferior vena cava (d), right renal vein (e), and right renal interlobar vein (f). PSV peak systolic velocity, EDV end-diastolic velocity, V MAX maximum velocity, V MIN minimum velocity.

Acute Kidney Injury in Heart Failure Revisited-The Ameliorating Impact of "Decongestive Diuresis" on Renal Dysfunction in Type 1 Acute Cardiorenal Syndrome: Accelerated Rising Pro B Naturetic Peptide Is a Predictor of Good Renal Prognosis.

There is mounting evidence that forward heart failure as manifested by low cardiac output alone does not define the degree of renal dysfunction in cardiorenal syndrome. As a result, the term “congestive renal failure” was coined in 2012 by Ross to depict the role of renal venous hypertension in type 1 acute cardiorenal syndrome. If so, aggressive decongestive therapies, either through mechanical ultrafiltration with dialysis machines or pharmacologic ultrafiltration with potent diuretics, would lead to improved cardio and renal outcomes. Nevertheless, as recently as 2012, a review of this literature had concluded that a renal venous hypertension-directed approach using diuretics to manage cardio-renal syndrome was yet to be fully investigated. We, in this review, with three consecutive case series, describe our experience with pharmacologic decongestive diuresis in this paradigm of care and argue for studies of such therapeutic interventions in the management of cardiorenal syndrome. Finally, based on our observations in the Renal Unit, Mayo Clinic Health System, in Northwestern Wisconsin, we have hypothesized that patients with cardiorenal syndrome presenting with accelerated rising Pro B Naturetic Peptide levels appear to represent a group that would have good cardio- and renal-outcomes with such decongestive pharmacologic therapies.

Intrarenal Flow Alterations During Transition From Euvolemia to Intravascular Volume Expansion in Heart Failure Patients

ObjectivesThe goal of this study was to assess: 1) the intrarenal flow in heart failure (HF) patients during the transition from euvolemia to intravascular volume overload; and 2) the relationship between intrarenal flow and diuretic efficiency. BackgroundIntrarenal blood flow alterations may help to better understand impaired volume handling in HF. MethodsResistance index (RI) and venous impedance index (VII) were assessed in 6 healthy subjects, 40 euvolemic HF patients with reduced ejection fraction (HFrEF), and 10 HF patients with preserved ejection fraction (HFpEF). Assessments were performed by using Doppler ultrasonography at baseline, during 3 h of intravascular volume expansion with 1 l of hydroxyethyl starch 6%, and 1 h after the administration of a loop diuretic. Clinical parameters, echocardiography, and biochemistry were assessed. Urine output was collected after 3 and 24 h. ResultsIn response to volume expansion, VII increased significantly in HFrEF patients (0.4 ± 0.3 to 0.7 ± 0.2; p < 0.001) and in HFpEF patients (0.4 ± 0.3 to 0.7 ± 0.2; p = 0.002) but not in healthy subjects (0.2 ± 0.2 to 0.3 ± 0.1; p = 0.622). This outcome was reversed after loop diuretic administration. In contrast, RI did not change significantly after volume expansion. Echocardiographic-estimated filling pressures did not change significantly. VII during volume expansion was significantly correlated with diuretic response in HF patients independent of baseline renal function (R2 = 0.35; p < 0.001). ConclusionsIn HF patients, intravascular volume expansion resulted in significant blunting of venous flow before a significant increase in cardiac filling pressures could be demonstrated. The observed impaired renal venous flow is correlated with less diuretic efficiency. Intrarenal venous flow patterns may be of interest for evaluating renal congestion.

Renal blood supply and fluid therapy

There are different underlying mechanisms of acute kidney injury (AKI) in various type of shock, but restoration of renal blood flow (RBF) is crucial in prevention of AKI. The first 24-48 hours of shock seem to be critical. Monitoring of global RBF and its intrarenal distribution is not possible in current clinical practice. The only way for optimization of renal blood supply is optimization of macrohemodynamics. In volume-responsive AKI, fluid therapy restores kidney function. Many clinical signs and parameters can be of use in determining the volume status. The accuracy of the assessment may be improved with the help of tools quantifying the clinical parameters (e.g. hypovolemic index – HVI). The basis of intravenous fluid therapy are crystalloids, and their effect is reported to be shorter than 120 min. Every form of hydroxyethyl starch has been shown to be harmful for patients at risk of impaired renal function. In sepsis, the boundary between volume-responsive and volume-unresponsive AKI is blurred. Fluid responsiveness can be lost in the course of AKI as early as on the first day of sepsis. According to the results of the ARDS Network study, the conservative approach in fluid therapy resulted in a shorter time of mechanical ventilation and did not affect the renal function, except for a slight increase of the serum creatinine level. Fluid overload is to be avoided, as renal venous and lymphatic congestion can limit the urine filtration rate, further worsening edema.

Altered oscillation of Doppler-derived renal and renal interlobar venous flow velocities in hypertensive and diabetic patients.

Flow velocity oscillation rate (FVOR) of the renal interlobar vein has been reported to be decreased in patients with urinary obstruction or diabetic nephropathy, and increased in those with hypertension during pregnancy. To clarify the clinical role of the renal interlobar venous FVOR, we investigated the flow velocity patterns of the renal vessels in patients with hypertension (HT) and/or diabetes (DM). Pulsed-wave Doppler sonography was performed in 34 patients: 15 with HT, 10 with DM, and nine with both HT and DM (HT-DM). Each FVOR of the right and left interlobar veins was closely and positively correlated with the ipsilateral interlobar arterial resistive index (RI), especially in the HT group, but not with the estimated glomerular filtration rate. The right interlobar venous FVOR was decreased in the DM and HT-DM groups compared to the HT group. The renal interlobar venous FVOR is strongly influenced by the arterial RI in HT patients, and is reduced in DM patients without an obvious relationship with diabetic nephropathy. These findings should be noted for the clinical application of renal interlobar venous flow analysis.