Study protocol for a Prospective, Randomized controlled trial of stEnt graft and Drug-coated bAlloon Treatment for cephalic arch stenOsis in dysfunctional arteRio-venous fistulas (PREDATOR).

BACKGROUND: Treatment of cephalic arch stenosis (CAS) is associated with high risk of failure and complications. Although stent-graft (SG) placement has improved patency rates, stent edge restenosis has been raised as a potential limiting factor for SG usage in CAS. This study aims to evaluate the safety and efficacy of combining stent graft placement with paclitaxel-coated balloon (PCB) angioplasty versus PCB alone in the treatment of CAS. METHODS: This is an investigator-initiated, prospective, international, multicenter, open-label, randomized control clinical trial that plans to recruit 80 patients, who require fistuloplasty from dysfunctional arteriovenous fistula (AVF) from CAS. Eligible participants are randomly assigned to receive treatment with SG and PCB or PCB alone in a 1:1 ratio post-angioplasty (n = 40 in each arm). Randomization is stratified by de novo or recurrent lesion, and the participants are followed up for 1 year. The primary endpoints of the study are target lesion primary patency (TLPP) and access circuit primary patency (ACPP) rates at 6-months. The secondary endpoints are TLPP and ACPP at 3- and 12-month; target lesion and access circuit assisted primary and secondary patency rates at 3, 6, and 12-months and the total number of interventions; complication rate; and cost-effectiveness. DISCUSSION: This study will evaluate the clinical efficacy and safety of combination SG and PCB implantation compared to PCB alone in the treatment of CAS for hemodialysis patients.

Sirolimus-coated balloon angioplasty in maintaining the patency of thrombosed arteriovenous graft: 1-year results of a prospective study.

BACKGROUND: A prospective, pilot study was designed to test the feasibility of using sirolimus-coated balloon (SCB) to treat graft vein junction of thrombosed arteriovenous graft (AVG) following successful pharmacomechanical thrombectomy. The present report provides the 1-year results of this study. METHODS: This is a 1-year follow-up of a single, prospective, single-arm study that was conducted from 2018 to 2019 in 20 patients who presented to a tertiary institution with thrombosed AVG. The recruited patients received SCB angioplasty at the graft-vein junction following successful endovascular thrombectomy of a thrombosed AVG. One year after recruitment, there were three deaths, one AVG revision, and one AVG explantation among the participants recruited. The outcomes of 15 subjects at 1-year following the index procedure obtained from electronic medical records were re-examined. RESULTS: The 1-year access circuit primary patency rate was 40%, while assisted primary and secondary patency rates were 46.7% and 73.3%, respectively. A total of 16 interventions (4 angioplasties, 12 thrombectomies) were performed in 9 patients over the 12 months. Four AVGs were abandoned. The median number of interventions per patient was 1 (0-3) per year. Using Kaplan-Meier analysis, the mean estimated post-intervention access circuit primary patency was 230 (95% CI: 162-300) days, while access circuit assisted primary patency was 253 (95% CI: 187-320) days, and access circuit secondary patency was 292 (95% CI: 230-356) days. Sub-group analysis did not show a significant difference in the mean estimated primary patency between AVG with de novo and recurrent stenosis (245 days, 95% CI: 151-339 vs 210 days, 95% CI: 113-307; p = 0.29). CONCLUSIONS: SCB may help sustain the patency of thrombosed AVG following successful thrombectomy.

Cost-Effectiveness of Drug-Coated Balloon Angioplasty Compared With Conventional Balloon Angioplasty for Arteriovenous Access Flow Dysfunction.

OBJECTIVES: This study aimed to determine the cost-effectiveness of drug-coated balloon (DCB) angioplasty compared with conventional balloon angioplasty (cPTA) in patients with arteriovenous fistulas (AVFs) and arteriovenous grafts (AVGs) dysfunction from a Singapore healthcare perspective. METHODS: Existing cost-effectiveness studies comparing DCB and cPTA have not incorporated AVF/AVG abandonment costs. This Markov model-based economic evaluation incorporated AVF/AVG creation and maturation costs on top of routine intervention costs to model a hypothetical cohort of 60-year-old AVF/AVG flow dysfunction patients. Effectiveness was measured in quality-adjusted life-years. Cost-effectiveness was assessed using incremental net monetary benefit (NMB) at a Singapore willingness-to-pay threshold of Singapore dollar (S$)87 000. Deterministic and probabilistic sensitivity analyses were performed to examine parameter uncertainty. To test hypotheses regarding cost-effectiveness, intervention counts per patient, cumulative incidence functions of AVF/AVG abandonment, and survival curves of death were compared between DCB and cPTA. RESULTS: DCB was not cost-effective at 3-year horizon (NMB = -S$1424), but was cost-effective at 1- and 6-year horizons (NMB = S$356 and S$3738, respectively). At 3 years, there was a 34.5% probability of DCB being cost-effective, but at 1- and 6-year horizons there was, respectively, 58.6% and 59.9% probability of DCB being cost-effective. DCB had graphically less AVF/AVG-abandonments, but this was not statistically significant (P = .21). Differences in other parameters were neither graphically nor statistically significant. CONCLUSIONS: With AVF/AVG abandonment considered, DCB may be weakly cost-effective compared with cPTA in treating AVF/AVG flow dysfunction. AV access creation and maturation costs could have important explanatory value in assessing DCB cost-effectiveness.

The Role of Catheter-Directed CT-Angiography in Radioembolisation.

Radioembolisation is an established transarterial therapy for hepatocellular carcinoma and liver metastasis. Success of radioembolisation depends on meticulous angiography and accurate dosimetry. Intra-procedure catheter-directed CT-angiography is commonly performed to improve the efficacy and safety of radioembolisation. This review article will (1) introduce the differences between cone beam CT and hybrid angiography-CT, and (2) describe the benefits of catheter-directed CT-angiography in radioembolisation from both an interventional radiology and nuclear medicine perspective.

Cost-Effectiveness of Drug-Coated Balloon Angioplasty Versus Conventional Balloon Angioplasty for Treating Below-the-Knee Arteries in Chronic Limb-Threatening Ischemia: The SINGA-PACLI Trial.

PURPOSE: Drug-coated balloon angioplasty (DCBA) has been studied as a potentially superior option compared to conventional percutaneous transluminal angioplasty (PTA) in treating below-the-knee (BTK) arteries in chronic limb-threatening ischemia (CLTI). The aim of this study is to examine the cost-effectiveness of DCBA versus PTA in BTK arteries based on a randomized controlled trial. MATERIAL AND METHODS: A prospective economic study was embedded in a randomized controlled trial of 138 patients with CLTI. Resource use and health outcomes were assessed at baseline, and at 3, 6 and 12 months post-intervention. Costs were calculated from a societal perspective and health outcomes measured using quality-adjusted life years with probabilistic sensitivity analysis performed to account for subject heterogeneity. RESULTS: Compared with participants randomized to receive PTA, participants randomized to DCBA gained an average baseline-adjusted quality-adjusted life years (QALYs) of .012 while average total costs were USD$1854 higher; this translates to an incremental cost-effectiveness ratio (ICER) of US$154,500 additional cost per QALY gained. However, the estimate of ICER had substantial variance with only 48% of bootstrap ICERs meeting a benchmark threshold of US$57,705 (the average gross domestic product (GDP) per capita of Singapore). CONCLUSION: The use of DCBA in BTK arteries in CLTI patients was not cost-effective compared with PTA. LEVEL OF EVIDENCE: 2, Randomized trial.

SIroliMus coated angioPlasty versus plain balloon angioplasty in the tREatment of dialySis acceSs dysfunctION (IMPRESSION): study protocol for a randomized controlled trial.

BACKGROUND: Percutaneous transluminal angioplasty is the current standard treatment for arteriovenous fistula (AVF) stenosis. The mid- and long-term patency with plain balloon angioplasty (PBA) is however far from satisfactory. While paclitaxel-coated balloon angioplasty has been shown to be superior to PBA, concern over its safety profile has recently arisen after a reported possible increased mortality risk with a meta-analysis of large lower limb studies. An angioplasty balloon with a new type of drug coating, the sirolimus-coated balloon (SCB), has been proven to improve patency in the coronary arteries. However, its effect on AV access has yet to be studied. METHODS/DESIGN: This is an investigator-initiated, prospective, multicenter, double-blinded, randomized controlled clinical trial to assess the effectiveness of SCB compared to PBA in improving the patency of AVF after angioplasty. A total of 170 patients with mature AVF that requires PTA due to AVF dysfunction will be randomly assigned to treatment with a SCB or PBA at a 1:1 ratio, stratified by location of AVF and followed up for up to 1 year. The inclusion criteria include [1] adult patient aged 21 to 85 years who requires balloon angioplasty for dysfunctional arteriovenous fistula [2]; matured AVF, defined as being in use for at least 1 month prior to the angioplasty; and [3] successful angioplasty of the underlying stenosis with PBA, defined as less than 30% residual stenosis on digital subtraction angiography (DSA) and restoration of thrill in the AVF on clinical examination. The exclusion criteria include thrombosed or partially thrombosed access circuit at the time of treatment, presence of symptomatic or angiographically significant central vein stenosis that requires treatment with more than 30% residual stenosis post angioplasty, and existing stent placement within the AVF circuit. The primary endpoint of the study is access circuit primary patency at 6 months. The secondary endpoints are target lesion primary patency; access circuit-assisted primary patency; access circuit secondary patency at 3, 6, and 12 months; target lesion restenosis rate at 6 months; total number of interventions; complication rate; and cost-effectiveness. The trial is supported by Concept Medical. DISCUSSION: This study will evaluate the clinical efficacy and safety of SCB compared to PBA in the treatment of AVF stenosis in hemodialysis patients. TRIAL REGISTRATION: ClinicalTrials.gov NCT04409912 . Registered on 1 June 2020.

Drug Coated Balloons for Dysfunctional Haemodialysis Venous Access: A Patient Level Meta-Analysis of Randomised Controlled Trials.

OBJECTIVE: To perform an individual patient data level meta-analysis of randomised controlled trials comparing drug coated balloon angioplasty (DCB) against conventional percutaneous transluminal angioplasty (PTA) in the treatment of dysfunctional haemodialysis venous access. METHODS: A search was conducted from inception to 13 November 2020. Kaplan-Meier curves comparing DCB with PTA by target lesion primary patency (TLPP) and access circuit primary patency (ACPP) were graphically reconstructed to retrieve patient level data. One stage meta-analyses with Cox models with random effects shared frailties were conducted to determine hazard ratios (HRs). Dynamic restricted mean survival times (RMST) were conducted in view of violation of the proportional hazards assumption. Conventional two stage meta-analyses and network meta-analyses under random effects Frequentist models were conducted to determine overall and comparative outcomes of paclitaxel concentrations used. Where outliers were consistently detected through outlier and influence analyses, sensitivity analyses excluding those studies were conducted. RESULTS: Among 10 RCTs (1 207 patients), HRs across all models favoured DCB (one stage shared frailty HR 0.62, 95% CI 0.53 - 0.73, p < .001; two stage random effects HR 0.60, 95% CI 0.42 - 0.86, p = .018, I2 = 65%) for TLPP. Evidence of time varying effects (p = .005) was found. TLPP RMST was + 3.54 months (25.0%) longer in DCB treated patients compared with PTA (p = .001) at three years. TLPP at six months, one year, and two years was 75.3% vs. 58.1%, 51.1% vs. 37.1%, and 31.4% vs. 26.0% for DCB and PTA, respectively. The P-Scores within the Frequentist network meta-analysis suggest that higher concentrations of paclitaxel were associated with better TLPP and ACPP. Among six RCTs (854 patients), the one stage model favoured DCB (shared frailty HR 0.72, 95% CI 0.60 - 0.87, p < .001) for ACPP. Conversely, the two stage random effects model demonstrated no significant difference (HR 0.76, 95% CI 0.35 - 1.67, p = .41, I2 = 81%). Sensitivity analysis excluding outliers significantly favoured DCB (HR 0.61, 95% CI 0.41 - 0.91, p = .027, I2 = 62%). CONCLUSION: Overall evidence suggests that DCB is favoured over PTA in TLPP and ACPP.

Randomized Controlled Trial Comparing Drug-coated Balloon Angioplasty versus Conventional Balloon Angioplasty for Treating Below-the-Knee Arteries in Critical Limb Ischemia: The SINGA-PACLI Trial.

Background There is a paucity of randomized trials demonstrating superior efficacy of drug-coated balloon angioplasty (DCBA) compared with conventional percutaneous transluminal angioplasty (PTA) for below-the-knee arterial disease in patients with -critical limb ischemia. Purpose To compare DCBA versus PTA for below-the-knee lesions in participants with critical limb ischemia through 12 months. Materials and Methods In this prospective, randomized, two-center, double-blind superiority study, participants with critical limb ischemia with rest pain or tissue loss with atherosclerotic disease in the native below-the-knee arteries were randomly assigned (in a one-to-one ratio) to DCBA or PTA after stratification for diabetes and renal failure between November 2013 and October 2017. The primary efficacy end point was angiographic primary patency at 6 months analyzed on an intention-to-treat basis. Secondary end points through 12 months were composed of major adverse events including death and major amputations, wound healing, limb salvage, clinically driven target-lesion revascularization, and amputation-free survival. Primary and binary secondary end points, analyzed by using generalized-linear model and time-to-event analyses, were estimated with Kaplan-Meier survival curves and hazard ratios (Cox regression). Results Seventy participants (mean age, 61 years ± 10 [standard deviation]; 43 men) in the DCBA group and 68 (mean age, 64 years ± 10; 50 men) in the PTA group were evaluated. The percentage of patients with angiographic primary patency at 6 months was 43% (30 of 70) in the DCBA group and 38% (26 of 68) in the PTA group (P = .48). Through 12 months, the percentage of deaths was similar: 21% in the DCBA group and 16% in the PTA group (P = .43). Amputation-free survival rate assessed with Kaplan-Meier curves differed through 12 months: 59% (41 of 70) in the DCBA group compared with 78% (53 of 68) in the PTA group (P = .01). Conclusion In participants with critical limb ischemia, the drug-coated balloon angioplasty group and the conventional percutaneous transluminal angioplasty group had similar primary patency rates at 6 months after treatment of below-the-knee arteries. Amputation-free survival rates through 12 months were higher in the percutaneous transluminal angioplasty group. © RSNA, 2021 Online supplemental material is available for this article.

Hepatic venous-portal gradient (HVPG) measurement: pearls and pitfalls.

Hepatic venous pressure gradient (HVPG) is the gold-standard for measurement of portal hypertension, a common cause for life-threatening conditions such as variceal bleeding and hepatic encephalopathy. HVPG also plays a crucial role in risk stratification, treatment selection and assessment of treatment response. Thus recognition of common pitfalls and unusual hepatic venous conditions is crucial. This article aims to provide a radiographical and clinical guide to HVPG with representative clinical cases.

A survey of anxiety and burnout in the radiology workforce of a tertiary hospital during the COVID-19 pandemic.

INTRODUCTION: We aimed to study anxiety and burnout among Division of Radiological Sciences (RADSC) staff during the COVID-19 pandemic and identify potential risk and protective factors. These outcomes were compared with non-RADSC staff. METHODS: A cross-sectional online study was conducted between 12 March and 20 July 2020 in the largest public tertiary hospital receiving COVID-19 cases. Burnout and anxiety were assessed with the Physician Work-Life Scale and the Generalized Anxiety Disorder-7 Scale, respectively. Workplace factors were examined as potential risk and protective factors using multivariable ordinary least squares regression analyses, adjusting for pertinent demographic characteristics. RESULTS: RADSC staff (n = 180) and non-RADSC staff (n = 1458) demonstrated moderate-to-severe anxiety rates of 6.7 and 13.2 % and burnout rates of 17.8 and 23.9 %, respectively. RADSC staff reported significantly lower anxiety (mean ± SD: 4.0 ± 3.7 vs 4.9 ± 4.5; P-value < 0.05), burnout (mean ± SD: 1.9 ± 0.7 vs 2.1 ± 0.8; P-value < 0.01), increased teamwork (82.2% vs 74.1%; P-value < 0.05) and fewer night shifts (36.7% vs 41.1%; P-value < 0.01). Among RADSC staff, higher job dedication was associated with lower anxiety (b (95% CI) = -0.28 (-0.45, -0.11)) and burnout (b (95% CI) = -0.07 (-0.11,-0.04)), while longer than usual working hours was associated with increased anxiety (b (95% CI) = 1.42 (0.36, 2.45)) and burnout (b (95% CI) = 0.28 (0.09, 0.48)). CONCLUSIONS: A proportion of RADSC staff reported significant burnout and anxiety, although less compared to the larger hospital cohort. Measures to prevent longer than usual work hours and increase feelings of enthusiasm and pride in one's job may further reduce the prevalence of anxiety problems and burnout in radiology departments.

Management of arterial dissections in 12 patients during transarterial chemoembolization and yttrium-90 selective internal radiotherapy for primary and secondary liver tumours.

OBJECTIVE: To describe rates and management strategies of arterial dissections in transarterial chemoembolization (TACE) and Yttrium-90 selective internal radiotherapy (90Y SIRT) for primary and secondary liver tumours. MATERIALS AND METHODS: This retrospective review included 1377 hepatic angiographies between May 2010 and June 2015 in a single centre for TACE and 90Y SIRT of liver tumours. The angiogram results, management, treatment outcomes and follow-up angiography/imaging findings were recorded. RESULTS AND DISCUSSION: Twelve cases of arterial dissections (12/1377, 0.87%) were documented. Three dissections (3/633, 0.47%) occurred during TACE, seven (7/449, 1.56%) during pre-treatment planning angiographies (PTPA) for 90Y SIRT, and two (2/249, 0.80%) during the treatment procedure of 90Y SIRT. The preferred management strategy was to manoeuvre past the dissection and complete the procedure, which was achieved in six patients (50%). Angioplasty with stenting was performed in one patient. In three patients, the procedure was held off for up to 3 months to allow the dissection to heal before repeating the procedure. A dissection that occurred during PTPA was detected only when the patient returned for 90Y SIRT. PTPA was immediately repeated for this patient. The last patient opted for sorafenib. Residual 50% stenosis was seen in one patient on follow-up hepatic angiography, but he was otherwise asymptomatic. In the remaining patients, no residual dissection or clinical sequelae was observed on follow-up. CONCLUSION: Arterial dissection is a rare but important complication of transarterial locoregional therapy. Where possible, attempts should be made at completing the therapy. Deferring treatment can be considered as dissections usually heal within 3 months. LEVEL OF EVIDENCE: Level 4, case series.

Repurposing the power injectable peripherally inserted central catheter as a tunnelled, non-cuffed, centrally inserted central venous catheter in oncological patients for short- to mid-term vascular access: A pilot study.

OBJECTIVES: Usual short- to mid-term vascular accesses for oncologic patients include the peripherally inserted central catheter and non-tunnelled centrally inserted central catheters, inserted in the supraclavicular or infraclavicular area. Peripherally inserted central catheters can be restrictive in active patients; supraclavicular non-tunnelled centrally inserted central catheters are not ideal in terms of exit site location and cosmesis, while infraclavicular non-tunnelled centrally inserted central catheters may be associated with puncture-related complications. In this pilot study, we have evaluated the off-label use of peripherally inserted central catheters as a tunnelled supraclavicular centrally inserted central catheter. METHODS: Ten patients were recruited for this prospective study. A non-cuffed, power injectable peripherally inserted central catheter was inserted via a short subcutaneous tunnel into the internal jugular vein using the peel-away sheath and introducer as a tunneller. Puncture wounds were closed with tissue glue. Patients were followed up for comfort scores, dwell time and complications. RESULTS: The median dwell time was 94 days (mean of 113 days). One catheter was removed due to systemic fungemia, resulting in an acceptable complication rate of 0.97 per 1000 catheter days.Mean patient-reported comfort scores was 16 (out of 20). Pressurised injections for computer tomography imaging were performed in five patients without complications. CONCLUSION: Despite limited numbers, this method appears to be safe and well accepted with low complication rates. This modified vascular access is low profile, easily concealed, readily removable and compatible with pressure injector and uses a commonly found catheter in a modified fashion. Larger prospective trials will be needed to ascertain if it can be a standard of care for oncological patients.

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.

Letter to the editor: Comment on a case report of thermal injury to spinal cord, a rare complication of percutaneous microwave spine tumour ablation.

Microwave ablation of the spine is an effective treatment option for patients with symptomatic osseous metastases. It is an increasingly common procedure in clinical practice and can be performed in conjunction with other procedures such as vertebroplasty and nerve root blocks. Multiple studies have demonstrated the safety and efficacy of the percutaneous ablation; however potential complications can arise. Thermal injury to the spinal cord is a rare but serious known complication which has severe consequences to the patient. Multiple strategies can be adopted to reduce the rate of complications. We aim to discuss the various technical considerations when performing percutaneous ablation of spinal tumours to decrease the risks of complications.

Outcome and Distal Access Patency in Subintimal Arterial Flossing with Antegrade-Retrograde Intervention for Chronic Total Occlusions in Lower Extremity Critical Limb Ischemia.

PURPOSE: To report the outcome and distal access patency of the Subintimal Arterial Flossing with Antegrade-Retrograde Intervention (SAFARI) technique for chronic total occlusion (CTO) in critical limb ischemia (CLI). MATERIALS AND METHODS: From January 2009 to June 2015, 220 SAFARI procedures were performed for 200 limbs in 191 patients (108 males [56.5%]; median age, 70 years old; range, 36 to 97 years old) with CLI (9.4% were Fontaine classification 3; and 90.6% were Fontaine classification 4). Distal access was obtained from the distal superficial femoral artery (n = 6), popliteal artery (n = 49), anterior tibial artery (n = 56), dorsalis pedis (n = 51), peroneal artery (n = 12), posterior tibial artery (n = 45), and lateral plantar artery (n = 1). Distal access hemostasis was obtained with internal balloon tamponade in 71.4% (n = 157). Outcome measurements were technical success, freedom from major amputation and complications. Preprocedural angiograms of clinically driven repeat interventions were reviewed in 73 cases for distal access patency. RESULTS: Technical success was achieved in 80.5% (n = 177). Reasons for technical failure include inability to obtain distal access (n = 3), cross the occlusion retrogradely (n = 16), re-enter the true lumen (n = 9), and achieve antegrade blood flow after the procedure (n = 15). Freedom from major amputation for technically successful procedures was 84.7%, 82.9%, and 81.9% at 6, 12, and 24 months, respectively. There were 3 cases of distal access bleeding with 1case that required coil embolization. The distal access remained patent in 80.8% of observable cases with repeated endovascular intervention. CONCLUSIONS: Distal retrograde arterial access (SAFARI) technique is safe and effective in the treatment of CTOs in the context of CLI, after failure of antegrade revascularization.

Recanalisation of an axillary vein occlusion jailed by a migrated cephalic arch stent-graft using the TruePath chronic total occlusion drilling device.

BACKGROUND: Stent placement in the cephalic arch is being used with increasing frequency. Late complications of bare metal and stent grafts in dialysis access, in particular stent migration, are often under-reported and can lead to compromise of future dialysis circuits. CASE PRESENTATION: A 52-year-old man developed acute arm swelling 2 days after creation of a left arm brachio-basilic arteriovenous graft. The axillary vein was found to be jailed by a previously deployed cephalic arch stent graft which had migrated into the subclavian vein. There was failure to cross through the fabric of the stent graft using conventional chronic total occlusion wires and techniques. A TruePath device was used successfully to cross through the fabric of migrated cephalic arch stent graft and recanalise the short subclavian-axillary vein occlusion. CONCLUSION: The adapted use of a drilling chronic total occlusion device to drill through the fabric of migrated stent graft was performed successfully to allow complete recanalisation of the occluded axillary vein.

Bioabsorbable radiopaque water-responsive shape memory embolization plug for temporary vascular occlusion.

We describe the preparation, characterization and evaluation of a biodegradable radiopaque water-triggered shape memory embolization plug for temporary vascular occlusion. The shape memory occluding device consists of a composite of a radio-opaque filler and a poly (dl-lactide-co-glycolide) (PLGA) blend, which was coated with a crosslinked poly (ethylene glycol) diacrylate (PEGDA) hydrogel. The mechanical properties, the degradation timeframe, the effect of programming conditions on the shape memory behaviour and the extent of radio-opacity for imaging were evaluated. Based on the tests, the mechanism responsible for the water-induced shape memory effect in such an embolization plug was elucidated. Suitable materials were optimized to fabricate an embolic plug prototype and its in vitro performance was evaluated as an occlusion rate (using a custom-built set up) and its biocompatibility. Finally, a feasibility study was conducted in vivo in a rabbit model to investigate the ease of device deployment, device migration and extent of vessel occlusion. The in vivo results demonstrated that the prototypes were visible under fluoroscopy and complete vascular occlusion occurred within 2 min of deployment of the prototypes in vivo. In conclusion, the developed embolization plug enables controlled and temporary vascular embolization, and is ready for safety studies.

The "SAFARI" technique using retrograde access via peroneal artery access.

The "SAFARI" technique or subintimal arterial flossing with antegrade-retrograde intervention is a method for recanalisation of chronic total occlusions (CTOs) when subintimal angioplasty fails. Retrograde access is usually obtained via the popliteal, distal anterior tibial artery (ATA)/dorsalis pedis (DP), or distal posterior tibial artery (PTA). Distal access via the peroneal artery has not been described and has a risk of continued bleeding, leading to compartment syndrome due to its deep location. We describe our experience in two patients with retrograde access via the peroneal artery and the use of balloon-assisted hemostasis for these retrograde punctures. This approach may potentially give more options for endovascular interventions in lower limb CTOs.