High Primary Failure Rate Research Articles

Standardization of Pre-operative Evaluation to Improve the Outcome of Arteriovenous Fistula for Vascular Access of Hemodialysis: A Review of 700 Cases.

Background With the advent of COVID-19, mortality rates of end-stage kidney disease (ESKD) rose by 37% which makes its treatment an important part of healthcare. Arteriovenous fistula (AVF) is linked to higher patient survival rates. Cimino-Brescia fistula is the most effective vascular access technique, but it has a high rate of primary failure (PF) and a several-week maturation period before it can be used. The current study aims to verify the preoperative evaluation in improving survival among AVF patients. Methodology The current study is a retrospective analysis of the hospital database from Jan 2022 to July 2023, with patients of a mean age of 60.2 years. The sample size was around 700, including the patients indicated for long-term hemodialysis (HD) with an estimated GFR of less than 20 mm/min/1.73m². Following AVF surgery, post-operative outcomes, PF, and maturation time were considered. Results Among the 757 AVF procedures, 588 (82%) were new cases, and 112 (16%) had prior AVF history on the same side. PF was observed in 126 (18%) AVFs, while 574 (84%) achieved maturation. Age at surgery did not correlate with PF. Male sex and brachiocephalic AVF (BCAVF) had lower PF rates, while female gender, non-BCAVF, and vascular chronic kidney disease (CKD) were independent predictors. Proximal fistulas had a higher failure risk (32%). During surgery, the PF occurred six times more frequently in patients with veins and arteries under 2 mm and without a bruit. Conclusion AVF maturation aims to achieve a functional AVF for easy dialysis, requiring meticulous vein selection, doppler vascular mapping, and a standardized process to reduce PF rates. Factors determining PF include thrill and bruit, flow rates, and comorbidities. These findings can help clinicians make informed decisions and improve outcomes for patients undergoing fistula surgery.

#5088 ARTIFICIAL INTELLIGENCE APPLIED TO VASCULAR DOPPLER ULTRASOUND MODELS FOR PREDICTING UNDERDEVELOPMENT OF VASCULAR ACCESS IN NEPHROLOGY

Abstract Background and Aims The vascular access of choice for hemodialysis patients is the arteriovenous fistula (AVF). There is a high rate of early primary failure and loss of primary AVF patency. Monitoring of vascular access is essential for early diagnosis of complications and prolonging survival. Models based on Artificial Intelligence (AI) and Machine Learning (ML) can be used for this. Method Retrospective descriptive study of the Vascular Doppler Ultrasound (VDU) in adults carried out since January 2019 to January 2022 in our AVF follow-up nephrology clinic. We analyze the results and create AI-based AVF underdevelopment prediction models. We included clinical, demographic and ultrasound variables. Patients were undergoing AVF post-surgery follow-up (VDU by protocol at 3-4 weeks after AVF surgery) or were referred to the clinic with signs of AVF dysfunction. The insufficient development of the vascular access is established as an objective variable. SPSS 20 Statistical Package. Automated Learning Analysis (ML) with Orange ML and BigML. Results 243 VDU were performed. Of the total, 139 (57%) were follow-up post-surgical VDU per protocol and 104 (43%) were AVF dysfunction VDU. Using supervised ML Analysis techniques with random sampling of 80% of the instances for Training and 20% for Test, we obtain prediction models for the underdevelopment (UD) attribute of FAV: Decision tree algorithm, Area under the curve (AUC) 89%, Classification accuracy (CA) 90%, Precision 90%. Random Forest Algorithm (RF) (AUC) 95%, (CA) 86%, Accuracy 81%. Near Neighbor Algorithm (K-NN) (AUC) 88%, CA 82%, Accuracy 78%. Convolutional Neural Networks (NNC) (AUC) 82%, CA 74%, Accuracy 60%. Algorithm with unsupervised technique of clustering in k-Means 3 clusters are obtained. The variables that best correlate with the objective variable are access flow, vein diameter, resistance index (RI) proximal, (RI) distal, and diameter of the anastomosis. Conclusion The vascular ultrasound systematized by the nephrologist facilitates the early diagnosis of complications that lead to early intervention. Analysis of the data with techniques (ML) can facilitate early diagnosis AVF poor development requiring close monitoring or intervention. The development of a nephrology clinic for monitoring vascular access could avoid invasive and unnecessary procedures for the patient.

Clinical outcomes by SF3B1 mutation status in patients (pts) with lower-risk myelodysplastic syndrome (LR-MDS) retreated with erythropoiesis-stimulating agents (ESAs).

7071 Background: Pts with SF3B1-mutated LR-MDS often have a more favorable prognosis versus those with SF3B1 wildtype. A sizeable number of pts with LR-MDS undergo ESA treatment even after experiencing ESA failure in first line. This study evaluated the outcomes of pts with LR-MDS retreated with ESAs in routine clinical practice, stratified by SF3B1 status. Methods: This retrospective cohort study included pts with LR-MDS in the US community setting who initiated ESAs as first-line therapy between January 1, 2016 and June 30, 2019, and were followed through June 30, 2021. Eligible pts discontinued ESAs (treatment gap ≥ 3 wk for epoetin alfa or ≥ 6 wk for darbepoetin alfa) and subsequently reinitiated ESA therapy at least once during follow-up. Ring sideroblasts (RS) ≥ 15% served as a surrogate for pts with unknown SF3B1 mutation status. Outcomes included ESA switches, dose reductions and escalations, ESA failure, and overall survival (OS). Primary ESA failure was defined as no rise in hemoglobin (Hb) ≥ 1.5 g/dL or no decrease in RBC transfusion requirement by 8 wk of treatment. Transfusion-dependent (TD) status was evaluated for pts who were transfusion independent (TI) at baseline. Results: A total of 82 pts with LR-MDS and repeat ESA treatment were included. Median age at start of ESA treatment was 79 y (interquartile range [IQR], 72–85). Diagnosis of MDS-RS, MDS with isolated del(5q), MDS with multilineage dysplasia, and MDS with single lineage dysplasia was reported in 30 (36%), 7 (9%), 9 (11%), and 9 (11%) pts, respectively; 27 (33%) had unknown classification. Median follow-up was 26 mo (IQR, 13–38) with 65% failing ESA therapy by 8 wk. Table shows pts’ SF3B1 mutation status, median OS, pts who had an ESA switch, dose reduction or escalation, experienced ESA failure, and pts who were TI at baseline and became TD during follow-up. Results were similar when RS was not used as a surrogate, and when analyses were limited to pts who were treated with ESAs only throughout follow-up. Conclusions: In this study of pts with LR-MDS retreated with ESAs, primary ESA failure was high with nearly half of TI pts becoming TD during follow-up. OS was poor regardless of SF3B1 status – 2–4 times lower than the remaining life expectancy for a 79-y-old (108 mo for men; 125 mo for women). Although treatment options were limited during the study period, the high primary failure rate suggests that pts with LR-MDS may benefit from alternatives to ESAs. [Table: see text]

Endovascular creation of hemodialysis arteriovenous fistulae: the current status and future perspective-a literature review.

End-stage renal disease (ESRD) is increasingly prevalent among Americans. Traditionally, the gold standard of dialysis fistulae creation is surgical arteriovenous fistulae (AVF), which is preferred over central venous catheter (CVC) and arteriovenous graft (AVG). However, it is associated with many challenges, particularly its high primary failure rate, which is partially attributed to neointimal hyperplasia. Endovascular creation of arteriovenous fistulae (endoAVF) is a recently emerging method, and is thought to circumvent many of the surgical challenges. It is theorized to reduce the peri-operative trauma to the vessel, thus reducing the amount of neointimal hyperplasia. In this article, we aim to review the current status and future perspectives of endoAVF. An electronic search was performed on MEDLINE and Embase to identify relevant articles from 2015 to 2021. The initial trial data has been promising, resulting in the increased adoption of endoAVF devices in clinical practice. Further, short- and mid-term data has shown that endoAVF has been associated with good maturation rate, re-intervention rate, primary and secondary patency rates. In comparison to historical surgical data, endoAVF has been shown to be comparable in certain aspects. Lastly, endoAVF has been used in an increasing range of clinical applications, including wrist AVF and two-stage transposition procedure. Although current data has been promising, endoAVF is associated with a host of unique challenges, and the current data has mostly been derived from selective patient population. Further studies are required to further assess its usefulness and its role in the dialysis care algorithm.

MO779: Benefits of a Nefrovascular Ultrasound Consultation: Results of 2 Years of Follow-Up

Abstract BACKGROUND AND AIMS The main vascular access for haemodialysis patients is the arteriovenous fistula (AVF). There is a high rate of early primary failure and loss of primary patency, therefore, vascular access monitoring is essential for the early diagnosis of complications and prolonging their survival. Our objective is to analyse the results of a consultation for the review and follow-up of AVFs using colour-Doppler ultrasound, performed by the nephrologist. METHOD Retrospective descriptive study of vascular ultrasounds performed from January 2019 to January 2021. Including clinical and demographic variables of the patients, as well as ultrasound parameters. Data from the Review group were compared; ultrasounds performed 3–4 weeks after performing vascular access; versus Dysfunction group; whose patients were referred from the advanced chronic kidney disease (ACKD) consultations or from the different dialysis centres upon detecting any data of suspected vascular access dysfunction. RESULTS A total of 166 vascular ultrasounds were performed: 106 (64%) in the Review group and 60 (36%) in the Dysfunction of the AVF group. A higher proportion of women was found in the Dysfunction group and upper mean age, close to the significance, P = 0.06 and P = 0.059 respectively. No significant differences were found with respect to other demographic characteristics in both groups (hypertension, diabetes, anticoagulant treatment and aetiology of kidney disease). Regarding the type of vascular access, a lower proportion of radiocephalic AVFs was observed in the Revision group (65% versus 50%) and a greater number of elbow AVFs (humero cephalic, humero basilic and humero median) in the Dysfunction group (35% versus 50%) with differences close to significance, P = 0.057. In the Review group, in 70.8% the findings were normal, in 24.5% lack of development was found, thrombosis in 9.4%, stenosis 6.6%, aneurysm 6%, oedema 17% and haematoma 6.6%. A 43% of the patients did not require to implement measures, in 42% exercise was recommended, in 6% repose of the AVF and 6 patients were requested fistulography and 3 were referred to cardiovascular surgery (CCV). In the Access Dysfunction group, the ultrasound diagnosis was normal in 28%, thrombosis was objective in 25%, stenosis 37%, aneurysm 42%, oedema 17%, haematoma 22%. 37% were referred for fistulography and 15% for revision by CCV. Regarding the ultrasound parameters, significant differences (P > 0.05) were found in terms of AVF flow, proximal and distal resistance index and vein calibre, but not in terms of vein depth and anastomosis diameter. A total of 28 fistulograms were performed, finding 86% agreement with the ultrasound findings. And in 93% the intervention was successful. Only 24% of the patients referred to the consultation required some type of intervention, and up to 65% were able to save the AVF, avoiding the realization of a new vascular access. CONCLUSION The systematic review after performing the vascular access made it possible to diagnose complications early and allow early intervention. It might be necessary to establish predictive criteria for vascular access dysfunction to individualize the follow-up for each patient, such as age, sex, or type of vascular access. Systematized vascular ultrasound by the nephrologist is very useful to preserve the functionality of the vascular access. On the other hand, the Vascular Nephrodiagnosis Consultation can avoid performing invasive and unnecessary procedures for the patient.

High pulse pressure predicts primary arteriovenous fistula failure within 1 year.

The arteriovenous fistula is the preferred access route for hemodialysis, although its high primary failure rate remains a clinical challenge. Multiple studies have attempted to determine the risk factors for primary arteriovenous fistula failure; however, none have identified pulse pressure as a potential predictive marker. High pulse pressure is a surrogate poor arterial compliance endpoint and leads to inferior cardiovascular outcomes. Our aim was to determine whether elevated pulse pressure indicates poor arteriovenous fistula maturation. We retrospectively reviewed 274 patients who underwent an arteriovenous fistula index operation between September 1, 2018 and May 31, 2019. Demographic, clinical data, and operative parameters were collected and analyzed. The maximum follow-up period was 365 days. Arteriovenous fistula failure was defined as the inability to achieve functional use during the follow-up period. We identified risk factors for arteriovenous fistula failure by performing a multivariate logistic regression analysis using backward elimination procedures. A total of 274 patients were included in the study. The patients' average age was 61.3 ± 14.0 years, approximately half of the patients (n = 161, 58.8%) were male, and the majority had hypertension. At the end of the follow-up period, 68 (24.8%) had arteriovenous fistula failure. The proportion of patients with pulse pressure values of >60 mmHg was significantly higher in the failure group than in the maturation group (66.0% vs 80.9%; p = 0.021). A PP value of >60 mmHg (odds ratio = 2.25; 95% confidence interval = 1.14-4.42; p = 0.019) and coronary artery disease or myocardial infarction (odds ratio = 1.97; 95% confidence interval = 1.01-3.84; p = 0.045) were found to be independent risk factors for primary arteriovenous fistula failure. High pulse pressure is an independent risk factor for primary arteriovenous fistula failure.

Outcome after early thrombotic occlusion of arteriovenous fistulas.

Arteriovenous fistulas (AVFs) are considered the first choice for venous access in end-stage renal disease patients, however, they are also known to have a high primary failure rate (early thrombosis and maturation failure). Of these, the outcome of thrombosed immature AVFs is not well known. This study aimed to investigate the outcome of AVFs with early thrombosis. Patients who underwent AVF creation from January 2009 to December 2019 at Seoul National University Hospital or Seoul Metropolitan Government - Seoul National University Boramae Medical Center were retrospectively reviewed. Patients who received salvage operations due to early thrombosis within 30 days after access creation were analyzed. During the study period, a total of 45 patients (radiocephalic 26; brachiocephalic 19) developed early thrombosis and underwent salvage operations. The median age of patients was 61.0 (54.5-69.5) years, and 51.1% were male. The first salvage operation was performed on the median 1.0 (0.0-4.5) day after AVF creation. The most common cause for early thrombosis was venous stenosis (64.4%) and followed by poor arterial inflow (28.9%), especially in radiocephalic AVFs. About 20 AVFs were salvaged to maturation (46.5%). Post-salvage primary patency and secondary patency at 1 year was 72.6% and 100%. In a multivariate logistic regression, significant risk factors for maturation failures were minimum venous outflow diameter ⩽2.5 mm (OR, 4.433; 95% CI, 1.039-18.921; p = 0.044) and lower in patients with hypertension (OR, 0.064; 95% CI, 0.006-0.637; p = 0.019). Thrombosed immature AVFs are associated with a high failure rate after salvage operation. However, if the salvage operation is successfully performed, it is associated with an acceptable 1-year outcome.

Cephalic Vein Distensibility as a Predictor of Arteriovenous Fistula

Background: A significant limitation of arteriovenous fistulas (AVF) is their high primary failure rate due to non-maturation. Dilation of the vein is an important feature, which occurs as a response to increased blood flow and consequent shear stress after creation of a fistula. We studied the influence of cephalic vein distensibility on fistula maturation.

Initial Outcomes Following Introduction of Percutaneous Arteriovenous Fistula Program with Comparison to Historical Surgically Created Fistulas

Recently, there has been an abundance of encouraging data regarding the creation of percutaneous arteriovenous fistulas. Despite promising data regarding their clinical maturation, a paucity of data exists which provides direct comparison between percutaneously created AVFs (pAVF) and open surgically created AVFs (sAVF). This study has 2 primary objectives: First, to compare clinical outcomes of pAVFs to sAVFs, with emphasis on clinical maturation and frequency of postoperative interventions to facilitate maturation. Second, to contribute toward the evidence-based incorporation of the pAVF procedure into the hemodialysis access algorithm. A single-center retrospective review was performed on all consecutive patients undergoing surgically created brachiocephalic arteriovenous fistula (BC-AVF, sAVF group) from January 1, 2018 to December 31, 2018 and Ellipsys-created percutaneous arteriovenous fistula (pAVF group) from January 1, 2019 to December 31, 2019. Comparative analysis between groups was performed. A total of 24 patients underwent Ellipsys-created pAVF with mean age of 56.7 ± 22.6 years (12 males [50%], 12 females [50%]) and 62 patients underwent surgically created BC-AVF with mean age of 62.5 ± 13.2 years (32 males [52%], 30 females [48%]). Both the pAVF and sAVF groups had comparable mean operating times (60 ± 40 vs. 56 ± 25 min, P = 0.67) and frequency of procedural technical success (23 [96%] vs. 62 [100%], P = 0.28), respectively. The pAVF group had a lower clinical maturation rate (12 [52%] vs. 54 [87%], P = 0.003) and a higher primary failure rate (9 [39%] vs. 6 [10%], P = 0.003) when compared to the sAVF group. The pAVF group had an increased overall rate of undergoing a postoperative intervention (18 [78%] vs. 13 [21%], P< 0.001), as well as an increased number of total postoperative interventions (1.1 ± 0.9 vs. 0.3 ± 0.6 interventions, P< 0.001) compared to the sAVF group. Percutaneous transluminal angioplasty of the juxta anastomotic segment was the most prevalent postoperative intervention performed in the pAVF group and occurred at a significantly increased frequency when compared to the sAVF group rate (13 [57%] vs. 5 [8%], P< 0.001). In our single-center retrospective review, patients undergoing Ellipsys-created pAVF in the first year following introduction of percutaneous endovascular had inferior rates of clinical maturation and underwent more postoperative interventions when compared to historical patients undergoing surgically created BC-AVF. Outcome discrepancies compared to previously reported Ellipsys data demonstrate a need for further studies examining the practical translatability of the pAVF.

Is the Fistula First Approach still valid?

ABSTRACTThe Fistula First Breakthrough Initiative, founded in 2003, was responsible for changing the access profile in the United States, increasing the prevalence of arteriovenous fistulas (AVFs) by 50% and reducing that of arteriovenous grafts (AVGs). However, the concept that AVFs are always the best access for all patients has been challenged. Discussion points are: (1) the questionable survival benefit of AVFs over AVGs, if one takes into account the high rates of primary AVF failure; (2) the potential benefits of using AVGs for greater primary success; and (3) the questionable benefit of AVFs over AVGs in patients with shorter survival, such as the elderly. The high rate of primary failure and maturation procedures leads to prolonged use of catheters, and it is one of the weaknesses of the fistula first strategy. AVGs proved to be better than AVFs as a second access after the failure of a first AVF, and in patients with non-ideal vessels, with greater primary success and reduced catheter times. AVGs appear to have a similar survival to AVFs in patients older than 80 years, with less primary failures and interventions to promote maturation. The most recent KDOQUI guidelines suggest an individualized approach in access planning, taking into account life expectancy, comorbidities and individual vascular characteristics, with the aim of chosing adequate access for the right patient, at the right time, for the right reasons.

Drug survival of biologic treatments in Turkish patients with psoriasis.

Psoriasis is a chronic, immune-mediated disease deriving from a polygenic predisposition. Treatment paradigm of the moderate to severe psoriasis has changed in the last two decades as biologics have been developed. Real-world data concerning biologics in the treatment vary from country to country. We aimed to investigate the efficacy and drug survival of biologic agents in patients treated in our clinic in Turkey. Data for 211 biologic protocols were examined for 125 patients treated with a biologic at least once for a minimum duration of 16 weeks at our department. The drug survival rate for 3 years was highest among ustekinumab (UST) users. The primary failure rate in the present study was higher among tumor necrosis factor-alpha inhibitors compared to UST (P < .0001). The higher primary failure rate was found in etanercept users and the highest secondary failure rate was observed in infliximab, while the lowest primary and secondary failure rates were determined in UST users. UST use and articular involvement emerged as significant positive predictors of drug survival in naïve patients. Our study is the first study presenting real-life data and biologic survival in the treatment of psoriasis in Turkey, and UST exhibited significantly higher drug survival scores, particularly in naive patients.

Vessel Preservation in Chronic Kidney Disease.

Chronic kidney disease (CKD) is a major noncommunicable disorder and has become the 9th leading cause of death in the United States. Most patients with CKD in the United States choose hemodialysis as their treatment of choice. A functioning arteriovenous access is essential to reduce dependence on central venous catheters. An arteriovenous fistula (AVF), though the preferred access, has a major limitation with a high primary maturation failure rate. A functioning AVF requires well-preserved vessels, both arteries and veins, along with an acceptable cardiac pump function. Vessel preservation is crucial from a surgeon's perspective to create an AVF but is also relevant for maturation. More recently, concerns regarding the sequelae of transradial approach for percutaneous cardiac interventions have been raised. Educating and empowering the patient is the first step, but equally important is to educate all caregivers involved in providing care to a patient with advanced CKD. The current review evaluates the strategies used to preserve peripheral veins, central veins, and peripheral arteries.

Atorvastatin Reduces In Vivo Fibrin Deposition and Macrophage Accumulation, and Improves Primary Patency Duration and Maturation of Murine Arteriovenous Fistula.

Arteriovenous fistulas placed surgically for dialysis vascular access have a high primary failure rate resulting from excessive inward remodeling, medial fibrosis, and thrombosis. No clinically established pharmacologic or perisurgical therapies currently address this unmet need. Statins' induction of multiple anti-inflammatory and antithrombotic effects suggests that these drugs might reduce arteriovenous fistula failure. Yet, the in vivo physiologic and molecular effects of statins on fistula patency and maturation remain poorly understood. We randomized 108 C57Bl/6J mice to receive daily atorvastatin 1.14 mg/kg or PBS (control) starting 7 days before end-to-side carotid artery-jugular vein fistula creation and for up to 42 days after fistula creation. We then assessed longitudinally the effects of statin therapy on primary murine fistula patency and maturation. We concomitantly analyzed the in vivo arteriovenous fistula thrombogenic and inflammatory macrophage response to statin therapy, using the fibrin-targeted, near-infrared fluorescence molecular imaging agent FTP11-CyAm7 and dextranated, macrophage-avid nanoparticles CLIO-VT680. In vivo molecular-structural imaging demonstrated that atorvastatin significantly reduced fibrin deposition at day 7 and macrophage accumulation at days 7 and 14, findings supported by histopathologic and gene-expression analyses. Structurally, atorvastatin promoted favorable venous limb outward remodeling, preserved arteriovenous fistula blood flow, and prolonged primary arteriovenous fistula patency through day 42 (P<0.05 versus control for all measures). These findings provide new in vivo evidence that statins improve experimental arteriovenous fistula patency and maturation, indicating that additional clinical evaluation of statin therapy in patients on dialysis undergoing arteriovenous fistula placement is warranted.

Influence of cephalic vein dilation on arteriovenous fistula maturation in patients with small cephalic veins.

A substantial limitation of dialysis fistulas is their high primary failure rate due to nonmaturation. Various studies have documented that patients with larger vein diameters exhibit reduced risks for nonmaturation. Nevertheless, some patients have small veins. Few studies have focused on patients with small veins. We hypothesize that sufficient venous dilation contributes to fistula maturation. Therefore, we studied the influence of cephalic vein dilation on fistula maturation in patients with small veins.Patients with small cephalic veins (diameter <2 mm) undergoing initial arteriovenous fistulae (AVF) operation were included. A total of 72 patients were enrolled in this study. A prospective study was performed, and the patients were followed for 6 weeks after surgery. Preoperative and postoperative duplex ultrasound mapping of veins was performed, and dilation of the cephalic vein was evaluated.The fistula maturation rate was 44.44%. Multivariate logistic regression analysis revealed a significant relationship between fistula maturation and preoperative cephalic vein dilation. Based on the results of ROC analysis, the fistula maturation rate in patients with vein dilation greater than or equal to the cut-off was 57.14% in the training data set and 54.55% in the testing data set. The independent influencing factors for fistula maturation were used to establish a combined index with logistic regression analysis. The fistula maturation rate in patients with combined indexes greater than or equal to the cut-off was 80.95% in the training data set and 77.78% in the testing data set.Our results demonstrated that preoperative venous dilation was associated with AVF maturation. For patients with small veins, venous distensibility needs to be carefully assessed before surgery, as it may be a better predictor of AVF maturation than venous diameter.

P1676De novo aortic insufficiency following long term LVAD support can be successfully treated with TAVI and a pre-stenting technique

Abstract Background/Introduction Long-term continuous flow left ventricular assist device (cf-LVAD) can result in the development of relevant aortic regurgitation (AR). Although its impact on survival is still controversial, it causes heart failure related symptoms. Current evidence for less invasive strategies to treat AR in cf-LVAD patients is limited. Purpose This study sought to investigate the value of transcatheter aortic valve implantation (TAVI) to treat severe de novo AR in patients on long-term cf-LVAD support. Methods We performed a retrospective analysis of 13 patients with severe AR following cf-LVAD implantation treated with TAVI between 2010 and 2019. TAVI's were performed via transfemoral (n=11), transapical (n=1) and transaxillary (n=1) access route. CoreValve (n=2), LotusValve (n=1), SapienXT (n=1) and Sapien3 (n=9) were used as transcatheter heart valves. In 4 patients, a new off-label strategy using landing-zone pre-stenting with a Sinus-XL stent was used (Figure 1). Results The median time interval from LVAD-implantation to TAVI was 1.7 years [interquartile range (IQR): 1.0 - 3.1]. Median age was 62 years [IQR: 57 - 67]. No procedural mortality or stroke was observed. Overall, device success according to VARC-II criteria was low due to a high rate of second valve necessity (54%). In contrast to the standard implantation technique, device success was 100% when the newly developed pre-stenting technique was applied (Table 1). Aortic regurgitation at discharge was none/trace in all patients. Valve function remained stable in all patients during a median echocardiographic follow-up time of 105 days [IQR: 11 - 298]. Table 1 Overall Sinus-XL prestenting (n=4) NO prestenting (n=9) Device success 7 (54) 4 (100) 3 (33) Procedural mortality 0 (0) 0 (0) 0 (0) Correct positioning of a single valve 7 (54) 4 (100) 3 (33) Intended valve performance 13 (100) 4 (100) 9 (100) Moderate or severe aortic regurgitation 0 (0) 0 (0) 0 (0) Figure 1 Conclusions Transcatheter aortic valve implantation is an efficient tool to treat cf-LVAD induced severe AR. The challenging anatomy of the non-calcified device landing zone causes a relatively high rate of primary device failure, which could be overcome with a pre-stenting technique. Acknowledgement/Funding None

Hitting back at lymphoma: How do modern diagnostics identify high-risk diffuse large B-cell lymphoma subsets and alter treatment?

Diffuse large B-cell lymphoma (DLBCL) is a clinically and biologically heterogeneous disease. Diagnostic tools in the clinic can now identify distinct subsets characterized by unique molecular features, which are increasingly transforming how these patients are managed. Activated B-cell-like DLBCL is characterized by NF-κB activation and chronic B-cell receptor signaling and may be targeted with lenalidomide or ibrutinib in the relapsed setting. Germinal center-like DLBCL is enriched for activating EZH2 mutations, and encouraging activity has been observed for the EZH2 inhibitor tazemetostat, which now has a fast-track US Food and Drug Administration designation. Double-hit lymphoma is a high-grade B-cell lymphoma characterized by translocations of MYC and BCL2 and/or BCL6 and carries a poor prognosis. Intensive chemoimmunotherapy strategies appear to be superior to standard R-CHOP (rituximab combined with cyclophosphamide, doxorubicin, vincristine, and prednisone) as initial therapy, and anti-CD19 chimeric antigen receptor T cells are inducing remission in patients with relapsed/refractory disease who previously had few available options. Primary mediastinal (thymic) large B-cell lymphoma is a molecularly distinct large-cell lymphoma with clinical and molecular features that overlap with those of classical Hodgkin lymphoma. R-CHOP has been associated with an unacceptably high rate of primary treatment failure in this young population, whereas dose-adjusted EPOCH-R (etoposide, prednisone, vincristine, cyclophosphamide, and doxorubicin plus rituximab) produces durable remissions without the need for radiotherapy in most patients. For relapsed/refractory disease, immune checkpoint inhibitors targeting PD-1 have shown promising activity in chemotherapy-refractory disease, as have anti-CD19 chimeric antigen receptor T cells. Additional therapeutic targets, including JAK2, continue to be evaluated. The identification of discrete biological subsets is steadily moving us away from a "one-size-fits-all" approach in DLBCL.

Pre-existing arterial pathologic changes affecting arteriovenous fistula patency and cardiovascular mortality in hemodialysis patients.

The radiocephalic arteriovenous fistula (AVF) provides optimal vascular access for hemodialysis; it has a higher long-term patency rate and fewer complications than other vascular access methods. However, the AVF has a high primary failure rate. The presence of small-diameter vessels at anastomosis sites is an important risk factor for AVF failure. However, in a recent study, despite selecting an adequate artery and vein for creating an AVF by routine preoperative vascular mapping, AVF maturation and primary failure occurred. Thus, pre-existing arteriosclerosis at AVF anastomosis sites likely contributes to AVF failure. In this review, we discuss the relationship between pathologic changes and AVF patency in hemodialysis patients. Because arteriosclerosis of the major arteries such as the coronary and carotid arteries is associated with cardiovascular mortality, we also review the impact of arteriosclerosis of upper arm arteries at AVF anastomosis sites on cardiovascular mortality in hemodialysis patients.

A Review of Arteriovenous Fistulae Creation in Octogenarians

To analyze the outcomes of arteriovenous fistulae (AVFs) creation in octogenarians. A retrospective study of 47 AVFs created in patients aged 80years and above from 2008 to 2014. Patient and AVF characteristics and outcomes were evaluated. Predictors of patency were analyzed with multivariate analysis and Kaplan-Meier patency, and survival analysis was performed. Forty-seven of 1,259 AVFs created were for octogenarians (4%). Mean age was 83years old (range: 80-91 years), with 27 male (57%) and 35 with tunneled dialysis catheters in situ (75%). There were a total of 15 (32%) radiocephalic AVFs, 30 (64%) brachial-cephalic AVFs, and 2 (4%) brachial-basilic transposition AVFs. At 12months, assisted primary patency rate was 28% (13 patients) while primary failure rate was 72% (34 patients). Subset analysis showed brachial-cephalic AVFs to have the highest assisted primary patency rate at 33%. Within 24months, tunneled dialysis catheter-related sepsis rate was 31% (11 patients). Multivariate analysis did not reveal any factor to be statistically significant in predicting AVF patency. Kaplan-Meier survival curve showed a 50% survival rate at 63months after AVF creation. In view of high AVF primary failure rate and relatively low tunneled dialysis catheter bacteremia rate, long-term tunneled dialysis catheters as the main form of hemodialysis renal access may be a viable option. However, with 50% of end-stage renal failure patients surviving up to 63months after AVF creation, the risks and benefits of long-term tunneled dialysis catheters must be balanced against those of AVF creation.

Nonmaturing Fistulae: Epidemiology, Possible Interventions, and Outcomes

Autogenous arteriovenous fistulae are the best method for prolonged, successful dialysis access. However, a substantial limitation of dialysis fistulae is their high primary failure rate, estimated to be as high as 70% for radiocephalic fistulae. Fistula maturation is influenced by demographic risk factors as well as anatomical barriers, the latter of which can be readily identified by noninvasive ultrasound imaging and physical examination. These barriers can be categorized as inflow problems (native arterial disease, arteriovenous anastomotic stenosis, and juxta-anastomotic stenosis) or outflow problems (proximal venous stenosis or collateral veins). Venous stenoses represent the most commonly observed barrier to fistula maturation. By treating these barriers with a systematic approach, interventionalists can significantly improve the likelihood of a fistula's usability for dialysis.

Fistula Eligibility: A Work in Progress

Effective hemodialysis requires a reliable vascular access. Clinical practice guidelines strongly recommend the fistula as the preferred option followed by arteriovenous (AV) grafts, with central venous catheters being least preferred. Recently, there has been a growing awareness of the limitations of the fistula, its high rate of primary failure and that a fistula may not be appropriate for all patients initiating or on hemodialysis. However, determinates for fistula eligibility have not been clearly defined. The creation and use of a fistula requires the complex integration of patient, biological, and surgical factors, none of which can be easily predicted or planned. There have been several successful initiatives over the last decade addressing patient suitability for AV access, but none have validated defined criteria for fistula eligibility. We discuss these initiatives by addressing: 1) process of care, 2) radiological and nonradiological tests and procedures, and 3) alternative surgical approaches. Careful clinical judgment, appropriate vascular access assessment and placement, and an individualized approach to the risks and benefits will optimize patient health outcomes while minimizing prolonged catheter dependence among hemodialysis patients.