Estimation of risk for major bleeding in native kidney biopsies in patients with multiple risk factors.

BACKGROUND AND AIMS: Individuals undergoing kidney biopsy are increasingly older and may have concurrent illnesses that cause deranged hematological and renal parameters that are associated with post-biopsy bleeding. We aimed to develop a clinical risk model to quantify bleeding risks in high-risk individuals with multiple risk factors. METHODS: Single-center retrospective cohort study of consecutive adults with serum creatinine ≥ 2 mg/dL (176 µmol/L) and had ultrasound-guided percutaneous native kidney biopsies between June 2011 and July 2015 in our tertiary referral center. The primary outcome was major bleeding, defined as need for red cell transfusion, radiological or surgical intervention, or if bleeding led to death within 7 days after kidney biopsy. RESULTS: Among 184 native kidney biopsies with serum creatinine ≥ 2 mg/dL, median age was 54.1 years and eGFR was 18.8 ml/min/1.73 m2. Major bleeding occurred in 19 biopsies (10.3%). Multivariate analysis accounting for age, weight, hemoglobin, platelet, prothrombin time and urea found that higher hemoglobin (adjusted OR 0.51, 95% CI 0.33-0.79, p = 0.003) and platelet (adjusted OR 0.99, 95% CI 0.98-0.99, p = 0.01) were independently associated with reduced major bleeding. A risk model that included (1) age ≥ 62 years old, (2) hemoglobin < 10 g/dL and (3) platelets ≤ 216 × 109/L as categorical variables predicted major bleeding post-biopsy. CONCLUSION: We developed a risk model that included multiple risk factors to quantify bleeding risks in native kidney biopsies with renal impairment.

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.

Early (6 months) results of a pilot prospective study to investigate the efficacy and safety of sirolimus coated balloon angioplasty for dysfunctional arterio-venous fistulas: MAgicTouch Intervention Leap for Dialysis Access (MATILDA) Trial.

BACKGROUND: The aim of this pilot study was to evaluate the safety and efficacy of the MagicTouch™ sirolimus-coated balloon (SCB) catheter (Concept Medical Inc., Tampa, FL, US) on improving the patency of failing arterio-venous fistulas (AVF) with de novo and recurrent stenoses. MATILDA reports early outcomes at 3- and 6 months post intervention. METHODS: Single-centre, single-arm prospective pilot study of 33 (18 males; mean age 64.7±11.6 years) end-stage renal failure Asian patients with a dysfunctional AVF, who underwent SCB angioplasty between May 2019-January 2020. All procedures were performed under local anaesthetic without sedation and as day surgery. All patients were prescribed dual antiplatelet therapy for 3 months and followed up with Duplex ultrasound at 3 and 6 months. RESULTS: 47 stenotic target lesions treated and 24/33 (72.7%) patients were for restenosis. Main indications for intervention was low/dropping access flow (21/33; 63.6%) and most common target lesion was in the juxta-anastomosis (19/47; 40.4%). There was 100% technical and procedural success. There were no peri-procedural complications related to the SCB. The target lesion primary patency rates at 3 and 6 months were 46/47 (97.9%) and 29/35 (82.9%) respectively. Circuit access patency rates at 3 and 6 months were 31/33 (93.9%) and 17/25 (68%) respectively. There was one (2.9%) death at 6 months and 4/33 (12.1%) overall to date, all from patients' underlying co-morbidities. CONCLUSIONS: SCB angioplasty for dysfunctional AVF circuits is a safe and efficacious modality in Asian haemodialysis patients at six months comparable if not better than the paclitaxel data reported to date in the literature.

Study protocol of a pilot study on sirolimus-coated balloon angioplasty in salvaging clotted arteriovenous graft.

BACKGROUND: In arteriovenous graft (AVG) for haemodialysis, the primary cause of failure is venous stenosis of the graft-vein junction from neointimal hyperplasia (NIH), resulting in thrombosis. While interventions to salvage clotted AVG are known to have high clinical success rates, long-term patency rates have been suboptimal. Drug-coated balloon (DCB) has been used to treat stenosed arteriovenous access in recent years with encouraging results but data on its effect in clotted AVG is unavailable. METHODS: This is an investigator-initiated, single-center, single-arm prospective pilot study to determine the safety and outcome of the sirolimus-coated balloon (SCB) in the salvage of thrombosed AVG. Twenty patients who undergo successful percutaneous thrombectomy will receive treatment with SCB at the graft vein junction. The patients will be followed-up for 6-months. The primary endpoint is the patency rates at 3-month while the secondary endpoints are the patency rates and the number of interventions needed to maintain patency at 6-month. DISCUSSION: Unremitting efforts have been made to prolong the patency of AV accesses over the years. DCB angioplasty combines mechanical and biological treatment for vascular stenosis. Sirolimus, being a cystostatic anti-proliferative agent, has been successfully used in coronary artery interventions. As the primary pathology of vascular stenosis in the dialysis circuit is neointimal hyperplasia, the use of sirolimus in balloon angioplasty may be effective. With this prospective study, we evaluate the efficacy and safety of SCB in patients with clotted AVG. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT03666208 on 11 September 2018.

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.

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.

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.

Comparison of alteplase and urokinase for pharmacomechanical thrombolysis of clotted hemodialysis access.

BACKGROUND: Percutaneous pharmacomechanical thrombolysis is increasingly used to salvage thrombosed hemodialysis access. We aim to evaluate the effectiveness of alteplase compared to urokinase in percutaneous pharmacomechanical thrombolysis clotted access. METHODS: Records of patients who underwent pharmacomechanical thrombolysis at Interventional Nephrology Suite in a tertiary teaching hospital from 1 January 2016 to 31 December 2016 were reviewed. Technical and clinical success rates, thrombosis-free and cumulative survivals, procedure time, and radiation dose imparted to patients were compared for pharmacomechanical thrombolysis with urokinase versus alteplase. RESULTS: A total of 122 incident patients underwent pharmacothrombolysis (n = 53 for urokinase, n = 69 for alteplase) during the study period. The mean dose of urokinase and alteplase used was 176,897 ± 73,418 units and 3.7 ± 0.8 mg, respectively. Pharmacomechnical thrombolysis using urokinase versus alteplase has similar technical success rate (98.1% vs 97.1%, p = 0.599), clinical success rate (88.7% vs 97.1%, p = 0.068), complication rate (9.4% vs 13.0%, p = 0.373), and primary patency rates at 3 months (57.1% vs 70.1%, p = 0.106). Thrombosis-free survivals of the vascular access were 113.2 (35.3, 196) days versus 122 (84, 239) days (p = 0.168). Cumulative survivals were 239 (116, 320) vs 213 (110.5, 316.5) days (p = 0.801). Procedure time, fluoroscopy time, skin dose, and dose were significantly lower for pharmacomechanical thrombolysis using alteplase compared to urokinase (p = 0.045, p < 0.0001, p = 0.006, p = 0.001, respectively). Stenting was found to be associated with successful dialysis following thrombolysis on univariate analysis (odds ratio: 9.167, 95% confidence interval: 1.391-19.846, p = 0.021), although this was no longer significant in multivariate analysis (p = 0.078). CONCLUSION: Alteplase is an effective and safe alternative to urokinase for pharmacomechanical thrombolysis of clotted vascular access.

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.

Time delay and its effect on survival in malaysian patients with non-small cell lung carcinoma.

While evidence indicates that early stage disease has better prognosis, the effect of delay in presentation and treatment of patients with non-small cell lung cancer (NSCLC) on survival is debatable. A retrospective study of 122 Malaysian patients with NSCLC was performed to examine the presentation and treatment delay, and its relation with patient survival. Median (25-75% IQR) interval between onset of symptoms and first hospital consultation (patient delay) and between first hospital consultation and treatment or decision to treat (doctor delay) were 2 (1.0- 5.0) and 1.1 (0.6-2.4) months respectively. The median survival rates in patient delay of <1, 1 to 3, and >3 months were 4.1 (9.9-1.7), 5.1 (10.9-3.2) and 5.7 (12.3-2.1) months respectively (log rank p=0.648), while in doctor delay, <30, 30-60, >60 days, the rates were 4.1 (10.8-1.8), 7.6 (13.7-3.2) and 5.3 (16.0-3.0) months respectively (p=0.557). Most patients presented and were treated in a relatively short time, and delays did not appear to influence survival. This Asian data is consistent with those from Western population, reiterating the need for public health measures that can identify disease early..

Survival in Patients with Non-Small Cell Lung Cancer Who Opted out of Cancer-Specific Therapy.

In Malaysia, many patients opted out of cancer-specific treatment for various reasons. This study was undertaken to investigate the survival rate of patients with stages I to III non-small cell lung cancer (NSCLC) who opted out of treatment, compared with those who accepted treatment. Case records of 119 patients diagnosed with NSCLC between 1996 and 2003 in two urban-based hospitals were retrospectively examined. Survival status was ascertained from follow-up medical clinic records or telephone contact with patients or their next-of-kin. Median (25-75% IQR) survival rate for 79 patients who accepted and 22 patients who opted out of treatment, were 8.6 (16.0-3.7) and 2.2 (3.5-0.8) months respectively [log rank p< 0.001, Kaplan-Meier survival analysis]. Except for proportionately more patients with large cell carcinoma who declined treatment, there was no significant difference between the two groups in relation with age, gender, ethnicity, tumour stage, and time delays between symptom onset and treatment or decision-to-treat. We concluded that there was a small but significant survival benefit in accepting cancer-specific treatment. The findings imply that there is no effective alternative therapy to cancer-specific treatment in improving survival. However, overall prognosis for patients with NSCLC remains dismal.