Regional citrate anticoagulation vs systemic heparin anticoagulation for double-filtration plasmapheresis.

INTRODUCTION: Double-filtration plasmapheresis (DFPP) has been utilized for immunomodulation in kidney transplantation. Anticoagulation is important to maintain circuit patency during DFPP. We aimed to compare the efficacy and safety of regional citrate anticoagulation (RCA) with systemic heparin anticoagulation during DFPP in kidney transplant recipients. METHODS: A retrospective cohort study was conducted to compare the efficacy and safety of RCA (RCA-DFPP) to systemic heparin anticoagulation (Hep-DFPP) for DFPP among kidney transplant recipients in a single tertiary center. RESULTS: A total of 112 sessions of DFPP were performed for 23 subjects, of which 62 sessions were RCA-DFPP and 50 sessions were Hep-DFPP. There were 13 sessions (11.6%) of premature circuit clotting, 10 sessions (16.1%) for RCA-DFPP and 3 sessions (6.0%) for Hep-DFPP (P = .10). All premature circuit clotting episodes occurred in subjects who underwent DFPP through a vascular catheter. Premature circuit clotting was associated with the use of a vascular catheter (odds ratio [OR] 14.2, 95% confidence interval [CI] 2.7-73.7; P < .01) and high postfilter ionized calcium (OR 12.7, 95% CI 1.4-112.5; P < .01). There was no major bleeding event. Hep-DFPP was associated with higher occurrence of hypocalcemia (OR 1.1, 95% CI 1.0-1.2; P < .01) and metabolic acidosis (OR 1.4, 95% CI 1.2-2.0; P = .04), while hypomagnesemia was more common for RCA-DFPP (OR 2.9, 95% CI 1.1-7.4; P = .03). CONCLUSION: Amongst kidney transplant patients who receive DFPP therapy, RCA-DFPP may be comparable to Hep-DFPP for the maintenance of circuit patency. Functioning vascular access is vital in avoiding premature clotting of the circuit. Close monitoring of electrolyte imbalances and coagulopathy related to DFPP is recommended.

Single-Center Prospective Pilot Study of Sirolimus Drug-Coated Balloon Angioplasty in Maintaining the Patency of Thrombosed Arteriovenous Graft.

PURPOSE: To investigate the use of a sirolimus drug-coated balloon (DCB) in the management of a thrombosed arteriovenous graft (AVG). MATERIALS AND METHODS: A single-center prospective pilot study was conducted between October 2018 and October 2019. Twenty patients (age = 67.0 years ± 10; male = 35%; mean time on dialysis = 31 months) with thrombosed upper limb AVG were enrolled. After successful pharmacomechanical thrombectomy and adequate treatment of the graft vein junction, sirolimus DCB angioplasty was performed at the graft vein junction. The patients were followed-up for 6 months, and all adverse events occurring during the study period were recorded. RESULTS: The primary circuit patency rates at 3 and 6 months were 76% and 65%, respectively, while the assisted-primary circuit patency rates at 3 and 6 months were 82% and 65%, respectively. The 3- and 6-month secondary circuit patency rates were 88% and 76%, respectively. Using Kaplan-Meier analyses, the estimated mean primary, assisted-primary, and secondary patencies were 285 days (95% confidence interval (CI) = 194-376 days), 319 days (95% CI = 221-416 days), and 409 days (95% CI = 333-485 days). No adverse event directly related to sirolimus DCB use was observed. CONCLUSIONS: The results of this pilot study suggest that the application of sirolimus DCB at the graft vein junction after the successful thrombectomy of AVG may be a feasible option to improve patency outcomes.

Single Asian Center Experience Using the Flixene™ Early Cannulation Graft for Hemodialysis Access Creation.

BACKGROUND: The aim of this study was to review the efficacy of the Flixene™ (Atrium™, Hudson, NH, USA) hemodialysis arterio-venous graft (AVG) in a multiethnic Asian cohort of patients with end-stage renal failure (ESRF). Primary outcome was graft primary patency rate and secondary end points included graft usability, time to cannulation, reinterventions required for access salvage, complications, and patient mortality. METHODS: Single-center, single-arm, multi-investigator nonrandomized retrospective study. Patients with ESRF who underwent Flixene™ graft implantation over a two-year period (January 2017 - December 2018) were included to allow at least one-year follow-up. Demographics, procedural and follow-up data were collected from the hospital electronic medical records. RESULTS: About 48 patients (49 AVG) were included. There were 24 (50%) men; mean age 63.7 (IQR 58.2-71.3) years. Technical success rate was 45/49 (91.8%); 4/49 (8.2%) AVG created did not reach cannulation. 11/49 (22.4%) and 28/49 (57.1%) achieved cannulation within 1 and 2 weeks, respectively. 6- and 12- month primary patencies were 33.5% and 19.6%, respectively. Primary-assisted patency rates were 46.6% and 29.6% at the same time intervals. Secondary patency rate was 77.6% and 63.9% at 6 and 12 months, respectively. There were 6 (12.2%) graft infections requiring explant and one-year mortality was 14%. CONCLUSIONS: Our experience with the Flixene™ early cannulation graft is comparable with other AVGs in terms of patency and infection rates. However, early cannulation rates are lower than in other case series.

Effect of short-term low molecular weight heparin on patency following successful salvage of arteriovenous access with recurrent thrombosis.

AIM: This study aims to investigate the effect of low molecular weight heparin (LMWH) in maintaining the patency of arteriovenous (AV) access with recurrent thrombosis. METHODS: Following successful thrombectomy, 66 patients with recurrent thrombosis were included in the study. The primary, assisted primary and secondary patency rates of patients who received LMWH (n = 24) were compared with those who did not receive anticoagulant (n = 42) using Kaplan-Meier analysis. Cox-regression analysis was performed to investigate potential predictors of patency rates. RESULTS: The mean dose of enoxaparin used was 40 ± 13.1 mg or 0.74 ± 0.2 mg/kg daily for a median duration of 14 (IQR 7,28) days. The mean trough anti-Xa concentrations measured after two doses of LMWH was 0.17 ± 0.13 IU/mL. Kaplan-Meier analyses for mean primary, assisted primary and secondary patency rates of LMWH vs no anticoagulation groups were 149 (95% CI: 91 - 207) vs 87 (95% CI: 42-132) days (P < .006), 230 (95% CI: 142-320) vs 107 (95% CI: 62-150) days (P = .01) and 438 (299-579) vs 294 (95% CI: 197-392) days (P = .08) respectively. LMWH remained a significant protective predictor of primary (HR: 0.49; 95% CI: 0.25-0.86; P = .02) and assisted primary patency rates (HR: 0.51; 95% CI: 0.27-0.98; P = .04) after adjusting for patient age, access age, type of AV access, presence of peripheral vascular disease and haemoglobin levels. CONCLUSION: LMWH may improve short and mid-term patency rates for AV accesses with recurrent thrombosis.

Outcomes of endovascular salvage of clotted arteriovenous access and predictors of patency after thrombectomy.

OBJECTIVE: This study aimed to report the outcomes of endovascular salvage of clotted arteriovenous (AV) accesses and to determine potential predictors of poor patency rates after thrombectomy. METHODS: Records of hemodialysis patients who underwent endovascular salvage of clotted AV access were reviewed retrospectively. Technical and clinical success rates, complication rates, and 3- and 6-month patency rates were determined. Multivariate analysis was performed to determine the predictors of patency after thrombectomy. RESULTS: A total of 294 patients underwent endovascular salvage of clotted AV access during the study period; 156 patients had arteriovenous fistula, whereas the remaining 138 were arteriovenous grafts (AVGs). The technical and clinical success rates were 96.3% and 93.2%; the major and minor complication rates were 0.7% and 9.9%. Post-thrombectomy primary, assisted primary, and secondary patency rates were 62.9%, 76.2%, and 77.6% at 3 months and 43.9%, 59.5%, and 61.6% at 6 months. The patency rates were significantly better for arteriovenous fistula than for AVG except for 6-month assisted primary and secondary patency. Multivariate Cox regression analysis showed that prior thrombosis within 90 days was significantly associated with loss of primary patency (hazard ratio [HR], 1.90; 95% confidence interval [CI], 1.21-2.98; P < .01), assisted primary patency (HR, 2.42; 95% CI, 1.42-4.13; P < .01), and secondary patency (HR, 2.52; 95% CI, 1.40-4.53; P < .01). Having an AVG was also negatively associated with primary patency. CONCLUSIONS: Most clotted AV accesses can be salvaged by endovascular technique. Recurrent thrombosis within 90 days is associated with poor short- and long-term patency even after successful endovascular reinterventions.

Improving haemodialysis fistula maturation following early ultrasound vascular mapping: 'The Venous Preservation Scan'.

AIM: Formation of autogenous arteriovenous fistula (AVF) in patients with chronic kidney disease (CKD) is complicated by a high primary failure rate. We hypothesized that early (months to years before AVF creation) Venous Preservation Scan (VPS) followed by vasculature preservation is effective in protecting the patient's best 'for fistula' vasculature. This study was performed to evaluate the impact of VPS on AVF outcomes. METHODS: The case records of 123 patients who underwent ultrasound mapping for AVF creation in a district hospital were reviewed. Ninety-seven were VPS and 26 were Routine Pre-Operative Planning Scan (RPOPS) performed immediately prior to surgery. Outcomes of 21 patients who went onto AVF creation in the VPS group were compared to 23 patients in the RPOPS group. RESULTS: Success and complication rates for AVF placement in patients who underwent VPS versus RPOPS were 100% versus 91.3% (P = 0.27) and 0 versus 8.7% (P = 0.23). A greater proportion of AVF created following RPOPS required intervention before maturation (47.6% vs 19%, P = 0.05). The median primary patency of AVF created following VPS versus RPOPS was 492 (IQR 222, 1219) versus 169 (IQR 116, 414) days (P = 0.02). The cumulative patency did not differ between the two groups (median = 807 (IQR 499, 1308) versus 1059 (IQR 331, 1263) days, P = 0.26). CONCLUSIONS: This small study suggests that VPS may favourably influence the survival of primary AVF and reduce the need for assisted interventions. However, confirmation with larger randomized controlled trial is warranted.

Paclitaxel-coated balloon in the treatment of recurrent dysfunctional arteriovenous access, real-world experience and longitudinal follow up.

AIM: Dysfunctional arteriovenous (AV) access remains a significant cause of morbidity and hospital admission for patients with end stage renal failure on haemodialysis. This study was performed to evaluate the impact of paclitaxel-coated Balloon (PCB) on the patency of AV access with recurrent stenoses. METHODS: We retrospectively studied haemodialysis patients who presented to our centre with recurrent AV access dysfunction and compared intervention-free patency using plain balloon versus PCB. RESULTS: A total of 147 patients were followed up longitudinally. Intervention-free patency was better following PCB compared to previous intervention using plain balloons (6.4 ± 5.8 versus 4.0 ± 3.7, P < 0.01). The 3- and 6-month patency rates after PCB were significantly better compared to standard plain angioplasty balloon: 69.4% versus 52.4%, P < 0.01 and 42.9% versus 15.6%, P < 0.01 respectively. Kaplan-Meier survival analysis of circuit patency demonstrated the superiority of PCB over plain balloon angioplasty in both arteriovenous fistula and arteriovenous graft (P < 0.01 and P = 0.01 respectively) although the patency of arteriovenous fistula remained significantly better than arteriovenous graft following interventions with PCB (P < 0.01). Age of AV access and the number of previous interventions were found to be significant predictors of patency following PCB intervention. CONCLUSION: Arteriovenous access intervention with PCB was shown to be superior compared to plain balloon in the treatment of both non-thrombosed and thrombosed AV accesses in our multi-ethnic population.

A prospective study of clinical characteristics and outcomes of acute kidney injury in a tertiary care Centre.

BACKGROUND: Acute kidney injury (AKI) is a major global health problem. We aim to evaluate the epidemiology, risk factors and outcomes of AKI episodes in our single centre. METHODOLOGY: We prospectively identified 422 AKI and acute on chronic kidney disease episodes in 404 patients meeting KDIGO definitions using electronic medical records and clinical data from 15th July to 22nd October 2016, excluding patients with baseline estimated GFR (eGFR) of < 15 mL/min. Patients were followed up till 6 months after AKI diagnosis. RESULTS: The mean age was 65.8 ± 14.1. Majority of patients were male (58.2%) of Chinese ethnicity (68.8%). One hundred and thirty-two patients (32.6%) were diagnosed in acute care units. Seventy-five percent of patients developed AKI during admission in a non-Renal specialty. Mean baseline eGFR was 50.2 ± 27.7 mL/min. Mean creatinine at AKI diagnosis was 297 ± 161 µmol/L. Renal consultations were initiated at KDIGO Stages 1, 2 and 3 in 58.9, 24.5 and 16.6% of patients, respectively. Three hundred and ten (76.7%) patients had a single etiology of AKI with the 3 most common etiologies of AKI being pre-renal (27.7%), sepsis-associated (25.5%) and ischemic acute tubular necrosis (15.3%). One hundred and nine (27%) patients received acute renal replacement therapy. In-hospital mortality was 20.3%. Six-month mortality post-AKI event was 9.4%. On survival analysis, patients with KDIGO Stage 3 AKI had significantly shorter survival than other stages. CONCLUSION: AKI is associated with significant in-hospital to 6-month mortality. This signifies the pressing need for AKI prevention, early detection and intervention in mitigating reversible risk factors in order to optimize clinical outcomes.

A pilot study on adjunctive use of parametric colour-coded digital subtraction angiography in endovascular interventions of haemodialysis access.

BACKGROUND: Two-dimensional digital subtraction angiography (DSA) is the gold standard for angiographic evaluation of dysfunctional haemodialysis access. We aim to investigate the utility of parametric colour coded DSA in providing hemodynamic analysis during haemodialysis access interventions. METHODS: We retrospectively studied 20 patients who underwent access intervention and applied parametric colour-coding on selected DSA acquisitions before and after percutaneous transluminal angioplasty (PTA). The difference in time to peak (dTTP) contrast enhancement and time attenuation curve (TAC) of pre- and post-stenotic regions of interest (ROIs) were obtained and compared after treatment. RESULTS: Improvements were seen in mean percent of stenosis after PTA (p < 0.0001) for all cases. Median dTTP improved from 0.52 (IQR 0.26, 0.8) to 0.25 (IQR 0, 0.26) seconds (p = 0.001). Median 50% contrast washout time improved from 0.77 (IQR 0.39, 1.17) to 0.42 (IQR 0.23, 0.59) seconds (p = 0.031). Significant correlation was seen for dTTP vs. percent of stenosis (r = 0.723, p = 0.043) pre-PTA and for change in dTTP vs. percent change in stenosis post-PTA (r = 0.786, p = 0.021) for inflow lesions. Such correlation was however not seen in outflow lesions. CONCLUSIONS: Adjunctive use of parametric colour-coded DSA may provide potentially useful hemodynamic information during vascular access interventions. Larger prospective studies are needed to validate our findings.

Impact of simulation-based learning on immediate outcomes of temporary haemodialysis catheter placements by nephrology fellows.

AIM: Traditional apprenticeship model (AM) of teaching in invasive procedures such as temporary haemodialysis catheter (THDC) insertion can result in propagation of errors and complications. Simulation-based learning (SBL) offers standardization of skills and allows trainees to repeatedly practice invasive procedures prior to performing them on actual patient. METHODS: Retrospective cohort study of first-, second- and third-year Nephrology Fellows from a tertiary teaching hospital from September 2008 to September 2015. The intervention group (n = 9) received simulation training in ultrasound-guided THDC placement. The historical control group (n = 12) received training through traditional AM. The primary and secondary outcomes were the immediate complications and success rates of THDC insertion. RESULTS: A total of 2481 THDCs were placed in 1787 patients. Success rate of internal jugular THDC placement for AM vs. SBL Fellow was 99.8% versus 100% (P = 0.90), while the success rate for femoral THDC placement was 99.6% versus 99.2% (P = 0.53). SBL Fellows reported fewer overall peri-procedure complications (8.3% vs. 11.2%, P = 0.02) and mechanical complications (1% vs. 2.4%, P = 0.02) compared to AM Fellows. The rate of reported technical difficulty was similar (7.5% vs. 9.2%, P = 0.17). After adjusting for side and site of THDC placement, body mass index and laboratory indices, THDC inserted by AM Fellows were independently associated with increased overall peri-procedure complications (OR = 1.396, 95% CI: 1.052-1.854, P = 0.02) and mechanical complications (OR = 2.481, 95% CI: 1.178-4.810, P = 0.02). CONCLUSIONS: Simulation-based learning was associated with lower procedure related complications and should be an integral component in the teaching of procedural skills in Nephrology.

Predictors of low estimated glomerular filtration rate after living kidney donation in a Southeast Asian population from Singapore.

AIM: Post-donation kidney function has not been well characterized in the Southeast Asian population. We studied a retrospective cohort of 174 living kidney donors at Singapore General Hospital between 1976 and 2012, evaluated patterns of change in kidney function using quantile regression analysis and investigated for predictors of low estimated glomerular filtration rate (eGFR) < 60 mL/min per 1.73m2 . Median follow-up time (range) was 7.8 (0.1-33.8) years following donor nephrectomy. RESULTS: Of the donors, 43.1% regained 75% or more of pre-nephrectomy eGFR after 5 years post-donation; 9.8% exhibited 100% recovery to pre-nephrectomy eGFR. High pre-nephrectomy eGFR was protective for risk of low post-donation eGFR, with a 6% risk reduction for each unit increase in pre-nephrectomy eGFR (odds ratio, 0.94; 95% confidence interval, 0.91-0.97; P = 0.002). This relationship was stronger in the short term (>6 months to < 5 years) than medium to long term (5 years or longer) (interaction P = 0.052). CONCLUSION: In general, kidney function is well preserved following kidney donation in Southeast Asian donors. Pre-nephrectomy eGFR is a good predictor of post-donation eGFR, especially in the short-term.

Outcomes of arteriovenous fistula creation, effect of preoperative vein mapping and predictors of fistula success in incident haemodialysis patients: A single-centre experience.

AIM: Vascular access in haemodialysis is critical for effective therapy. We aim to evaluate the outcomes of arteriovenous fistula (AVF) creation in incident haemodialysis patients, impact of preoperative vein mapping and predictors of successful AVF maturation in our centre. METHODS: Data of End-stage Renal Disease (ESRD) patients initiated on haemodialysis from January 2010 to December 2012 in our centre were retrospectively obtained from electronic medical records and clinical notes. Demographic characteristics, medical comorbidities, perioperative details were collected, and patients were followed up until 1 January 2014. RESULTS: A total of 708 patients (median age 64, IQR 55-72) were included with mean duration of follow up of 2.3 ± 1.2 years, with access of AVF and arteriovenous graft (AVG) in 694 (98%) and 14 (2%) patients respectively. Eight patients were lost to follow-up. Successful AVF maturation was achieved in 542 patients (78%), with 1-year cumulative patency rate of 74%. Multivariate analysis revealed male gender, upper arm AVF and good postoperative thrill and pulse as predictors of successful AVF maturation. Preoperative vein mapping was performed in 42.5% (295/694) of patients, with mean vein diameter of 2.44 ± 0.82 mm. Maturation rates with and without vein mapping were 72.2% and 82.4%, respectively, (P = 0.001). In patients with vein diameters of <2 mm and ≥2 mm, there was no statistically significant difference in maturation rates (71.3% vs. 72.6%; P = 0.887) and median maturation time (66 vs. 78 days; P = 0.73). CONCLUSION: Arteriovenous fistula can be successfully created in most incident haemodialysis patients. Routine vein mapping is not necessary if veins are suitable on physical examination alone, and vein sizes of <2 mm on ultrasound is not associated with lower AVF maturation rate.

Endovascular salvage of failing arterio-venous fistulas utilising sirolimus eluting balloons: Six months results from the ISABELLA trial.

BACKGROUND: Aim of this pilot clinical study was to evaluate the safety and efficacy of the Selution Sustained Limus Release (SLR)™ sirolimus-eluting balloon (SEB) for improving failing arterio-venous fistulas (AVF) patency in Asian haemodialysis patients. METHODS: Prospective single-centre, multi-investigator, non-consecutive, non-blinded single arm trial. Forty end-stage renal failure Asian patients with a dysfunctional AVF underwent SEB angioplasty between May and November 2020. All stenotic lesions were prepared with high pressure non-compliant balloon angioplasty prior to SEB angioplasty. Endpoints of interest included target lesion primary patency and circuit access patency and safety through 30 days. All patients received dual antiplatelet therapy for 1 month and were followed up with Duplex ultrasound at 6 months. RESULTS: There was one subject dropout so final n = 39 patients (mean age 65.0 ± 11.9; males = 26 (66.7%)) and n = 43 target lesions treated. Main indication for intervention was dropping access flow (24/39; 61.5%) and most common target lesion was in the juxta-anastomosis (24/43; 54.5%). There was 100% technical and procedural success. There were no adverse events related to the SEB. Target lesion primary patency rates at 3 and 6 months were 39/41 (95.1%) and 28/39 (71.8%) respectively. Access circuit patency rates at 3 and 6 months were 35/37 (94.6%) and 22/35 (62.9%) respectively. There were 3 (7.7%) deaths all attributable to patients' underlying co-morbidities. CONCLUSIONS: Fistuloplasty using the novel Selution SLR™ SEB for dysfunctional AVF circuits seems a safe and effective modality in Asian haemodialysis patients at 6 months but larger randomised controlled studies are required now to determine its true efficacy against plain balloon angioplasty.

Ranger™ paclitaxel-coated balloon versus conventional balloon angioplasty for treatment of failing arteriovenous fistulas and grafts in haemodialysis patients: A retrospective cohort study.

BACKGROUND: Aim was to compare the safety and patency efficacy outcomes between Ranger™ paclitaxel-coated balloon (PCB)- versus conventional balloon angioplasty (POBA) in the treatment of haemodialysis access-related conduit stenosis. METHODS: Retrospective single-centre, multi-investigator, consecutive, double-arm comparative cohort study. About 130 end-stage renal failure Asian patients with dysfunctional arteriovenous fistula (AVF) or arteriovenous graft underwent PCB or POBA fistuloplasty between November 2018 and June 2020. All stenotic lesions were prepared with high pressure non-compliant balloon angioplasty prior to PCB angioplasty. All patients received at least one antiplatelet agent for 3 months duration post procedure. RESULTS: Mean age was 66.0 ± 10 years and 79/130 (61%) were males. PCB arm (n = 65) versus POBA arm (n = 65). Majority were AVFs circuits (122/130, 94%). Main indication for intervention was dropping access flow (98/130, 76%). About 172 lesions were treated (56% POBA, 44% PCB), and the juxta-anastomosis (JAS) was the main target lesion (87/172, 51%). There were no significant differences in safety outcomes (30-day adverse events, access thrombosis, abandoned AVF and death) between treatment groups. Mean time to target lesion reintervention (TLR) was longer in PCB-treated lesions (7.1 ± 2.7 vs 5.8 ± 3.2 months, p = 0.03), especially amongst recurrent lesions (7.3 ± 2.4 vs 5.7 ± 3.2, p = 0.02). Mean time to circuit reintervention was also longer in PCB-treated circuits (6.9 ± 2.8 vs 5.8 ± 3.7months, p = 0.04). There were 16 deaths (12%), all attributed to patient's underlying comorbidities. CONCLUSIONS: Fistuloplasty with Ranger™ PCB for failing arteriovenous circuits in end-stage renal failure patients, is a safe and efficacious modality compared to POBA in terms of longer freedom from TLR.

Use of the helical SUPERA™ stent and Passeo-18 Lux™ drug-coated balloon to treat recurrent cephalic arch stenosis for dysfunctional brachiocephalic fistulas: 1 year results of the Arch V SUPERA-LUX study.

BACKGROUND: Aim of Arch V SUPERA-LUX was to evaluate the safety and efficacy of the combination therapy of SUPERA™ (Abbott Vascular, Santa Clara, CA, USA) helical stent implantation and Passeo-18 Lux™ (Biotronik Asia Pacific Pte Ltd, Singapore) drug coated balloon (DCB) elution to treat recurrent cephalic arch stenosis (CAS) in the setting of AV access dysfunction. METHODS: Investigator-initiated, single-center, single-arm prospective pilot study of 20 end-stage renal failure Asian patients with a dysfunctional brachiocephalic fistula. All had symptomatic recurrent CAS within 6 months of prior intervention. The lesion was pre-dilated with a standard high-pressure balloon (Biotronik Passeo-35 HP balloon). The DCB (Passeo-18 Lux™) is subsequently inflated and the SUPERA™ stent deployed to sit 2 mm distal to the cephalic arch and covering the CAS but within the DCB zone. All patients were prescribed dual antiplatelet therapy for 3 months and followed up with Duplex ultrasound at 6- and 12-months. RESULTS: There were 9 (45%) males and mean age was 67 ± 11.0 years. Mean time from prior procedure was 113 ± 68 days and main indication for reintervention was high venous pressure (9/20, 45%). Technical success was 100% and there were no peri-procedural complications related to either stent or DCB deployment. Target lesion primary patency at 6- and 12-months was 10/18 (55%) and 5/16 (31%), respectively. Mean time to target lesion re-intervention was 170 ± 82 days. Circuit access patency was 8/18 (44%) and 2/16 (13%) at 6- and 12-months respectively and mortality was 3/20 (15%) attributed to the patients' underlying co-morbidities. CONCLUSION: Dual prong strategy of using SUPERA™ stenting and Passeo-18 Lux™ drug elution for recurrent CAS, although safe, was no more efficacious than conventional balloon angioplasty or stenting alone. Development of an intense inflammatory reaction within the stent led to reinterventions of a number of cases with suboptimal results.

Efficacy and safety of low dose, weight-based subcutaneous enoxaparin protocol in recurrent arteriovenous access thrombosis.

BACKGROUND: This study aims to evaluate the safety and efficacy of a short-term, low dose, weight-based subcutaneous enoxaparin protocol (SEP) in maintaining the patency of arteriovenous (AV) access with recurrent thrombosis. METHODS: Prospective follow-up of 25 patients who presented to a tertiary institution with recurrent AV access thrombosis and treated with anticoagulation according to SEP following successful thrombectomy. Patency and safety outcomes of SEP were studied. RESULTS: The participants were 66.4 ± 10.2 years old and predominantly male (60%) and of Chinese ethnicity (72%). The AV accesses had a median age of 1.4 (0.6, 5.6) years with 60% being non-autogenous arteriovenous access while 40% were autogenous arteriovenous access. Thrombolytic agents (urokinase (72%) or alteplase (28%)) were used in all procedures while adjunct thrombectomy device was used in only four procedures. The mean dose of enoxaparin was 36.0 ± 8.2 mg or 0.64 ± 0.1 mg/kg/day for a mean duration 30.0 days (Interquartile range: 27.5, 31.0). One patient developed minor bleeding episode. Kaplan-Meier analysis demonstrated that the mean thrombosis-free survival pre- versus post-SEP adoption was 27.3 (95% CI 17.9-36.7) versus 183.5 (95% CI 100.1-266.9) days (p < 0.001). After adjusting for the type of thrombolytic agent, use of adjunct thrombectomy device, cutting balloon, drug-coated balloon, and stent graft, SEP remained a significant factor associated with longer thrombosis-free patency (HR 0.166: 95% CI 0.070-0.392, p < 0.001). DISCUSSION: SEP appears to be a feasible and safe thromboprophylaxis method to improve thrombosis-free patency for AV access with recurrent thrombosis.

Intervention with selution SLR™ Agent Balloon for Endovascular Latent Limus therapy for failing AV Fistulas (ISABELLA) Trial: Protocol for a pilot clinical study and pre-clinical results.

BACKGROUND: The aim of this pilot clinical study is to evaluate the safety and efficacy of the Selution Sustained Limus Release (SLR)™ sirolimus-coated balloon (M.A. MedAlliance SA, Nyon, Switzerland) for improving the patency of failing arterio-venous fistulas (AVF) in hemodialysis patients. We also present herein a pre-clinical pharmacokinetic and safety evaluation of Selution™ to justify its first use in hemodialysis patients for endovascular access salvage. METHODS AND RESULTS: This is an investigator-initiated prospective single-center, non-blinded single-arm trial. Forty patients with clinically significant de novo or recurrent stenoses in a mature AVF circuit will be recruited. All stenotic lesions will be prepared with high pressure non-compliant conventional balloon angioplasty (CBA) prior to deployment of the Sustained-Release Selution™ sirolimus drug-eluting balloon. The primary efficacy endpoint is 6-month target lesion primary patency and the primary safety endpoint is freedom from localized or systemic serious adverse events through 30 days. Secondary endpoints of interest include technical and clinical success rates and circuit access patency at 3 and 6 months. Follow-up will occur for 2 years for those patients whose AVFs remain patent. Pharmacokinetic and histological animal safety studies performed with the Selution™ coating formulation showed prolonged arterial tissue retention of sirolimus with therapeutic levels up to 60 days and non-toxic and rapidly declining blood levels. Histological results in animal models demonstrated safety, freedom from intraluminal thrombus, reduction in restenosis by sirolimus elution compared to CBA, and no evidence of embolic phenomena indicative of adverse particulate effects. DISCUSSION: Long release sirolimus coated balloons may serve as a promising novel alternative therapy to paclitaxel-based technology for treating conduit stenosis secondary to neointimal hyperplasia. Pre-clinical pharmacokinetic and histological animal data are encouraging and provide suggestion of safety and efficacy in this setting. This single-center trial will provide a first step toward demonstration of efficacy and safety of this device for treatment of stenotic fistulas.