UNASSIGNED: Oscillatory wall shear stress and related metrics have been identified as potential predictors of dialysis access outcomes; however, the absence of a simple non-invasive method for measuring these haemodynamic forces has been prohibitive to their adoption into routine clinical practice. We present a computationally enhanced, single patient case study, offering a unique insight into the haemodynamic environment surrounding the development of flow limiting neointimal hyperplasia within the efferent vein of a previously functional arteriovenous fistula (AVF).
UNASSIGNED: Computational fluid dynamics (CFD) simulations were used to create a quantitative map of oscillatory shear stress as well as enabling visualisation of streamline patterns within the AVF. CFD data was compared to ultrasound-based turbulence quantification and examined alongside structural and functional changes in the access site over time.
UNASSIGNED: This work further supports the notion that flow limiting neointimal hyperplasia development in vascular access fistulae, occurs in response to oscillatory wall shear stress, and provides proof of concept for the idea that non-invasive ultrasound turbulence quantification tools could play a role in predicting vascular access outcomes.
UNASSIGNED: In addition to providing insight into the haemodynamic environment surrounding the development of flow limiting neointimal hyperplasia, we hope that this paper will promote discussion and further thinking about how our learnings from in-silico studies can be incorporated into clinical practice through novel uses of existing diagnostic tools.

OBJECTIVE: To compare the primary patency and restenosis rates in treatment naieve dialysis arteriovenous fistulas (AVFs) after drug-coated balloons (DCB) versus plain balloon angioplasty (PTA).
METHODS: This retrospective study included 157 patients who underwent AVF angioplasty for treatment-native AVF stenosis between January 2012 to 2022. The fistulas were Brachiocephalic (75%), Brachiobasilic (17%), and radiocephalic (8%). The index intervention was with either DCB or percutaneous transluminal angioplasty (PTA) with subsequent follow up. Patients with central venous stenosis, thrombosed fistula, fistula stents, AV graft or surgical intervention after the index procedure were excluded.
RESULTS: Arteriovenous fistula angioplasty was done in 28 patients using DCB and in 129 patients using PTA. A total of 108 patients presented with a single stenosis, 42 with 2 stenoses, and 7 with 3 stenoses. The location of these stenoses was in the venous outflow (57%), the juxta anastomotic segment (31%), and cephalic arch (12%). The median time to re-intervention for the PTA was 216 days compared to 304 days for the DCB (p=0.079). Primary patency at 6 months was 60.4% for PTA and 75% for DCB (p=0.141) CONCLUSION: Although DCB angioplasty of treatmentnaïve dysfunctional AVF tends to improve the time to intervention and 6-month primary patency compared to PTA, this difference did not reach statistical significance.

We present the case of a 38-year-old man with end-stage renal disease receiving hemodialysis via a left femoral loop graft who developed debilitating back pain. During a maintenance fistulogram, we found a completely occluded inferior vena cava and engorged lumbar veins. The patient underwent inferior vena cava reconstruction with stenting, which resulted in complete resolution of the engorged lumbar veins on venography and a significant reduction in his back pain. Engorgement of the lumbar veins can cause significant pain, and treatment of the underlying pathology can alleviate these symptoms.

BACKGROUND: Central venous catheters may become embedded due to the formation of adhesions between the indwelling catheter and the vein wall.
METHODS: A 49-year-old patient with bacteraemia was referred for retrieval of an embedded internalised central venous dialysis catheter. Recently the catheter had been surgically ligated at the venotomy site internalising the intravascular catheter component, which precluded antegrade ballooning through the catheter hub. Seldinger technique was used to access the catheter lumen within the left internal jugular vein and through and through access was established across the catheter. Retrograde endoluminal balloon dilation was performed to disrupt adhesions and free the catheter. The catheter was snared over the wire and removed from the right femoral vein.
CONCLUSIONS: This case report outlines an effective, minimally invasive retrieval method in a rare case of an embedded internalised central venous catheter.

Pulmonary hypertension (PH) is often present in patients presenting for kidney transplant listing. While PH can complicate kidney transplant (KTx), with multidisciplinary management that includes both the transplant center and pulmonary hypertension center or experts both pre- and post-transplant. This review summaries the approach and management of PH in KTx candidates and recipients, along with expected outcomes and controversies surrounding arteriovenous fistula and graft management.

UNASSIGNED: How patient, center, and insertion technique factors interact needs to be understood when designing peritoneal dialysis (PD) catheter insertion pathways.
UNASSIGNED: We undertook a prospective cohort study in 44 UK centers enrolling participants planned for first catheter insertion. Sequences of regressions were used to describe the associations linking patient and dialysis unit-level characteristics with catheter insertion technique and their impact on the occurrence of catheter-related events in the first year (catheter-related infection, hospitalization, and removal). Factors associated with catheter events were incorporated into a multistate model comparing the rates of catheter events between medical and surgical insertion alongside treatment modality transitions and mortality.
UNASSIGNED: Of 784 first catheter insertions, 466 (59%) had a catheter event in the first year and 61.2% of transitions onto hemodialysis (HD) were immediately preceded by a catheter event. Catheter malfunction was less but infection was more common with surgical compared with medical insertions. Participants at centers with fewer late presenters and more new dialysis patients starting PD, had a lower probability of a catheter event. Adjusting for these factors, the hazard ratio for a catheter event following insertion (medical vs. surgical) was 0.70 (95% confidence interval [CI] 0.43 to 1.13), and once established on PD 0.77 (0.62 to 0.96).
UNASSIGNED: Offering both medical and surgical techniques is associated with lower catheter event rates and keeps people on PD for longer.

We report the case of a near fatal arterial injury in a patient undergoing an inside-out catheter placement through an occluded central venous system using the Surfacer device (Bluegrass Vascular). The right internal mammary artery was inadvertently lacerated during the procedure, leading to cardiovascular collapse. The patient was rescued by transfusion, placement of a chest tube, and coil embolization of the right internal mammary artery. Postprocedure analysis of intraoperative cone beam computed tomography revealed that this injury was predictable on imaging, underscoring the need for advanced imaging guidance to enhance the safety of this procedure.

Objectives: In this study, we aim to assess the efficacy of revision using distal inflow (RUDI) in patients with symptomatic dialysis access-associated steal syndrome (DASS). Materials and Methods: All consecutive patients who were diagnosed with grade 3 or 4 DASS and have undergone RUDI in 4 years were included in this study. Results: In total, 35 patients were included in this study; participants had a mean age of 47.5±7.52 years and 54% (n=19) were males. As per our findings, significant improvement was noted in terms of paresthesia (81.2%, p-value: 0.012), coolness (79.4%, p-value: 0.006), pain (78.1%, p-value: 0.006), discoloration (76.4%, p-value: 0.044), paresis (71.4%, p-value: 0.016), and ulcer healing (50%, p-value: 0.044). Gangrene did not further progress in all patients (n=35). Reduction in fistula flow rate after RUDI was 57.5% (682±121 ml/min, p-value: 0.001). Digital systolic pressure was noted to improve by 71.4% (60±9.2 mmHg, p-value: 0.002) after RUDI. Peak systolic velocity increased in both ulnar (66.1±8.2 cm/s, p-value: 0.04) and radial (64.2±7.6 cm/s, p-value: 0.024) arteries of the wrist. Cumulative patency of RUDI graft was 100%, 91.4%, and 85.7% at 3, 6, and 12 months, respectively. Conclusion: RUDI has resulted in significant improvements in terms of DASS symptoms. Using a native vein as conduit, RUDI should be considered a procedure of choice for patients with high-flow DASS.

OBJECTIVE: This cross-sectional survey aimed to determine the prevalence of Interventional Nephrology (IN) practice amongst nephrologists in the Asia-Pacific Region (APR), specifically related to dialysis access (DA).
METHODS: The Association of VA and intervenTionAl Renal physicians (AVATAR) Foundation from India conducted a multinational online survey amongst nephrologists from the Asia-Pacific to determine the practice of IN in the planning, creation, and management of dialysis access. The treatment modalities, manpower and equipment availability, monthly cost of treatment, specifics of dialysis access interventions, and challenges in the training and practice of IN by nephrologists were included in the survey.
RESULTS: Twenty-one countries from the APR participated in the survey. Nephrologists from 18 (85.7%) countries reported performing at least one of the basic dialysis access-related IN procedures, primarily the placement of non-tunnelled central catheters (n-TCC; 71.5%). Only 10 countries (47.6%) reported having an average of <4% of nephrologists performing any of the advanced IN access procedures, the most common being the placement of a peritoneal dialysis (PD) catheter (20%). Lack of formal training (57.14%), time (42.8%), incentive (38%), institutional support (38%), medico-legal protection (28.6%), and prohibitive cost (23.8%) were the main challenges to practice IN. The primary obstacles to implementing the IN training were a lack of funding and skilled personnel.
CONCLUSIONS: The practice of dialysis access-related IN in APR is inadequate, mostly due to a lack of training, backup support, and economic constraints, whereas training in access-related IN is constrained by a lack of a skilled workforce and finances.

Dialysis access maintenance often requires a fistulogram or shuntogram of arteriovenous access. Assessment of the arterial inflow segment and arterial anastomosis is often a critical portion of the procedure. Retrograde occlusive angiography (ROA) is often used to properly assess the inflow. Manual compression using finger compression or a hemostat is often described in the literature. The Fogarty balloon occlusion technique using a 4-Fr Fogarty catheter balloon (Henry Shein) is a simple and cost-effective method that preserves image quality and decreases radiation exposure in retrograde occlusive angiography.