Effect of EDTA with porous balloon on calcified lesion: An atherosclerotic cadaver study.

BACKGROUND: Ethylene diamine tetra-acetic acid (EDTA) is a chelating agent used to dissolve calcium deposits but evidence in decalcifying atherosclerotic lesions is limited. AIMS: We assessed the feasibility and efficacy of EDTA delivered via porous balloon to target calcified lesions in cadaveric below-the-knee (BTK) arteries. METHODS: Using porcine carotid arteries, EDTA concentration was measured in the arterial wall and outside the artery at the 0-, 0.5-, 4-, and 24-h circulation after the injection through a porous balloon. In cadaver BTK samples, the proximal and distal anterior tibial artery (ATA) and distal posterior tibial artery (PTA) were studied. EDTA-2Na/H2O or EDTA-3Na/H2O were administrated using a porous balloon, then circulated for 6 h for EDTA-3Na/H2O and 24 h for EDTA-2Na/H2O and EDTA-3Na/H2O. Micro-CT imaging of the artery segments before and after the circulation and cross-sectional analyses were performed to evaluate calcium burden. RESULTS: In the porcine carotid study, EDTA was delivered through a porous balloon present in the arterial wall and was retained there for 24 h. In BTK arteries, cross-sectional analyses of micro-CT revealed a significant decrease in the calcium area in the distal ATA segment under 24-h circulation with EDTA-2Na/H2O and in the distal ATA segment under 24-h circulation with EDTA-3Na/H2O. The proximal ATA segment under 6-h circulation with EDTA-3Na/H2O showed no significant change in any parameters of calcium CONCLUSION: EDTA-3Na/H2O or EDTA-2Na/H2O with longer circulation times resulted in greater calcium reduction in atherosclerotic lesion. EDTA may have a potential therapeutic option for the treatment of atherosclerotic calcified lesions.

Paclitaxel coated balloon versus conventional balloon angioplasty in dysfunctional dialysis arteriovenous fistula: a systematic review and meta-analysis of randomized controlled trials.

PURPOSE: To compare the efficacy and safety between paclitaxel coated balloon (PCB) angioplasty and conventional balloon (CB) angioplasty in the treatment of dysfunctional arteriovenous fistula (AVF). METHODS: We searched four major electronic databases (PubMed, EMBASE, Web of Science and the Cochrane Library) for randomized controlled trials (RCTs) published from inception through November 28, 2021. Outcomes of interest included target lesion primary patency (TLPP), technical success and all-cause mortality. The STATA package version 15.1 was utilized to undertake meta-analyses. RESULTS: Fourteen RCTs totaling 1535 patients were analyzed. The available data showed that there were no significant differences of TLPP rates at 3, 6, 9 and 12 months between the PCB group and the CB group (risk ratio (RR) 1.00, 95% confidence interval (CI) 0.93-1.07, p = 1.000, I2 = 33.5%, Cochrane Q test p = 0.185, fixed-effect model; RR 1.17, 95% CI 0.99-1.39, p = 0.065, I2 = 75.4%, Cochrane Q test p = 0.000, random-effect model; RR 0.81, 95% CI 0.35-1.89, p = 0.625, I2 = 62.8%, Cochrane Q test p = 0.045, random-effect model; RR 1.19, 95% CI 0.97-1.47, p = 0.096, I2 = 40.5%, Cochrane Q test p = 0.071, random-effect model). In addition, two groups had similar technical success rates (RR 1.00, 95% CI 0.97-1.03, p = 1.000, I2 = 0.0%, Cochrane Q test p = 0.596, fixed-effect model) and all-cause mortality rates (RR 1.00, 95% CI 0.54-1.84, p = 1.000, I2 = 0.0%, Cochrane Q test p = 0.599, fixed-effect model). CONCLUSIONS: PCB angioplasty did not appear to convey any obvious advantage over CB angioplasty in the treatment of dysfunctional AVF. However, further multi-center, large-scale and well-designed RCTs are needed to prove outcomes.

Assessment of Sirolimus- vs. paCLitaxEl-coated balloon angioPlasty In atherosclerotic femoropopliteal lesiOnS (ASCLEPIOS Study): preliminary results.

BACKGROUND: There appears to be an association between paclitaxel-coated devices and increased 5-year all-cause mortality. METHODS: We are conducting a prospective, randomized, controlled, single-center, noninferiority study. All consecutive patients with femoropopliteal arterial disease who fulfilled the inclusion/exclusion criteria are sequentially and consecutively assigned to either paclitaxel (Ranger, Boston Scientific) or sirolimus (MagicTouch, Concept Medical) coated balloon angioplasty treatment. The primary outcome are procedural success and primary vessel patency at index procedure. The secondary outcomes are 30-day and 12-month freedom from MAEs (amputation, death, TLR/TVR, MI, distal embolization that requires a separate intervention or hospitalization), procedural success (≤30% residual diameter stenosis or occlusion after the procedure), Rutherford category improvement (reduction ≤1 category) and ABI improvement (increase ≥0.10 from baseline). RESULTS: A total of six patients have been enrolled in the present study up to now. The mean age was 72.6 years old and five were male. All patients had angiographic evidence of isolated occlusion in the transition segment of the distal femoral superficial artery in the popliteal artery. The mean length was 109 mm. Three patients were treated by sirolimus-coated (group A) and three by paclitaxel coated balloon angioplasty (group B). The primary patency and procedural success was in two of three and three of three patients, for group A and B, respectively. CONCLUSIONS: Preliminary results show safety and feasibility of the Sirolimus-coated balloon angioplasty. Further investigation and increase of sample size will allow for more sustained conclusions regarding patency and procedural success of this type of balloons for the endovascular treatment of peripheral arterial disease.

Covered Stents vs. Angioplasty for Common Iliac Artery In Stent Restenosis: A Retrospective Comparison.

OBJECTIVE: The optimal endovascular treatment for common iliac artery in stent re-stenosis has yet to be assessed. Treatment options include, among others, angioplasty alone and repeated stenting with covered stents. METHODS: This study retrospectively compared patency and target lesion revascularisation of these treatments. All patients who underwent endovascular treatment of common iliac artery in stent re-stenosis between 2007 and 2017 were included retrospectively. The primary end point was freedom from re-stenosis. Secondary endpoints were target lesion revascularisation rate (TLR) and freedom from occlusion during follow up. RESULTS: Seventy-four interventions were included, consisting of 37 angioplasties and 37 covered stent placements in 57 patients. Freedom from re-stenosis at four years was 72.6% (95% confidence interval [CI] 51.8% - 88.7%) in the covered stent group vs. 43.5% (95% CI 25.9% - 59.8%) in the percutaneous transluminal angioplasty (PTA) group (p = .003). The target lesion revascularisation (TLR) rate was 16.4% (95% CI 7.1% - 35.6%) and 43.6% (95% CI 28.0% - 63.2%) respectively (p = .020). There was no difference in freedom from occlusion; this was 90.8% (95% CI 73.9% - 97.0%) in the covered stent group and 79.1% (95% CI 58.4% - 90.3%) in the PTA group (p = .49). The difference in freedom from re-stenosis and TLR remained significant after sensitivity and multivariable analyses. CONCLUSION: Covered stents offer better outcomes for common iliac artery in stent re-stenosis than angioplasty alone.

Vascular Response Toward an Absorbable Sirolimus-eluting Polymeric Scaffold for Vascular Application in a Model of Normal Porcine Carotid Arteries.

BACKGROUND: Fully absorbable polymeric scaffolds, as a potential alternative to permanent metallic stents, are entering the clinical field. The aim of this study is to assess the in vivo biocompatibility of a novel Sirolimus-eluting (SIR) absorbable scaffold based on poly(L-lactide) (PLLA) and poly(4-hydroxybutyrate) (P4HB) for interventional application. METHODS: Absorbable PLLA/P4HB scaffolds either loaded with SIR coating or unloaded scaffolds were implanted interventionally into common carotid arteries of 14 female. Bare metal stents (BMS) served as control. Peroral dual anti-platelet therapy was administered throughout the study. Stented common carotid arteries segments were explanted after 4 weeks, and assessed histomorphometrically. RESULTS: The absorbable scaffolds showed a decreased residual lumen area and higher stenosis after 4 weeks (PLLA/P4HB: 6.56 ± 0.41 mm² and 37.56 ± 4.67%; SIR-PLLA/P4HB: 6.90 ± 0.58 mm² and 35.60 ± 3.15%) as compared to BMS (15.29 ± 1.86 mm² and 7.65 ± 2.27%). Incorporation of SIR reduced the significantly higher inflammation of unloaded scaffolds however not to a level compared to bare metal stent (PLLA/P4HB: 1.20 ± 0.19; SIR-PLLA/P4HB: 0.96 ± 0.24; BMS: 0.54 ± 0.12). In contrast, the BMS showed a slightly elevated vascular injury score (0.74 ± 0.15), as compared to the PLLA/P4HB (0.54 ± 0.20) and the SIR-PLLA/P4HB (0.48 ± 0.15) groups. CONCLUSION: In this preclinical model, the new absorbable polymeric (SIR-) scaffolds showed similar technical feasability and safety for vascular application as the permanent metal stents. The higher inflammatory propensity of the polymeric scaffolds was slightly reduced by SIR-coating. A smaller strut thickness of the polymeric scaffolds might have been a positive effect on tissue ingrowth between the struts and needs to be addressed in future work on the stent design.

Comparison of functional patency rates between paclitaxel-eluting versus plain balloon angioplasty in hemodialysis patients with central venous stenosis: An intra-individual comparison study.

Central venous stenosis (CVS) is usually a late-diagnosed clinical entity that is common in hemodialysis patients. It causes various problems ranging from hemodialysis difficulty to loss of the arterio-venous (A-V) fistula. In the present study, we aimed to determine the effect of drug eluting balloon while excluding the influence of other variable factors by evaluating the same individuals with plain and paclitaxel-eluting balloons. This research was a prospective study of 18 symptomatic hemodialysis patients (age 50.9 ± 14.0 years, range 32-72 years; 11 male, 7 female) with CVS who underwent treatment by plain balloon angioplasty (PBA) and paclitaxel-eluting balloon angioplasty (PEBA) in our hospital from January 2016 to June 2017. First, third and sixth month central vein patency rates were compared. The median patency rates of central veins were 109.0 (range: 10-324) days after PBA and 238.5 (range: 157-501) days after PEBA (p < 0.001). There was no statistically significant difference between PBA and PEBA angioplasty in one-month patency (p Ëƒ 0.05). By contrast, a statistically significant difference was found between 3- and 6-month patency rates (p = 0.031 and p Ë‚ 0.001, respectively). Kaplan-Meier analysis revealed that the primary cumulative patency rate of PEBA was significantly longer than that of PBA (p ˂ 0.001). In this prospective study, PEBA patency is superior to PBA patency in the treatment of CVS in dialysis patients.

Editor's Choice - Risk of Major Amputation Following Application of Paclitaxel Coated Balloons in the Lower Limb Arteries: A Systematic Review and Meta-Analysis of Randomised Controlled Trials.

OBJECTIVE: There have been concerns about the long term safety of paclitaxel coated devices in the lower limbs. A formal systematic review and meta-analysis of randomised controlled trials (RCTs) was performed to examine the long term risk of major amputation using paclitaxel coated balloons in peripheral arterial disease (PAD). METHOD: This systematic review was registered with PROSPERO (ID 227761). A broad bibliographic search was performed for RCTs investigating paclitaxel coated balloons in the peripheral arteries (femoropopliteal and infrapopliteal) for treatment of intermittent claudication or critical limb ischaemia (CLI). The literature search was last updated on 20 February 2021 without any restrictions on publication language, date, or status. Major amputations were analysed with time to event methods employing one and two stage models. Sensitivity and subgroup analyses, combinatorial meta-analysis, and a multivariable dose response meta-analysis to examine presence of a biological gradient were also performed. RESULTS: In all, 21 RCTs with 3 760 lower limbs were analysed (52% intermittent claudication and 48% CLI; median follow up two years). There were 87 major amputations of 2 216 limbs in the paclitaxel arms (4.0% crude risk) compared with 41 major amputations in 1 544 limbs in the control arms (2.7% crude risk). The risk of major amputation was significantly higher for paclitaxel coated balloons with a hazard ratio (HR) of 1.66 (95% CI 1.14 - 2.42; p = .008, one stage stratified Cox model). The prediction interval was 95% CI 1.10 - 2.46 (two stage model). The observed amputation risk was consistent for both femoropopliteal (p = .055) and infrapopliteal (p = .055) vessels. Number needed to harm was 35 for CLI. There was good evidence of a significant non-linear dose response relationship with accelerated risk per cumulative paclitaxel dose (chi square model p = .007). There was no evidence of publication bias (p = .80) and no significant statistical heterogeneity between studies (I2 = 0%, p = .77). Results were stable across sensitivity analyses (different models and subgroups based on anatomy and clinical indication and excluding unpublished trials). There were no influential single trials. Level of certainty in evidence was downrated from high to moderate because of sparse events in some studies. CONCLUSION: There appears to be heightened risk of major amputation after use of paclitaxel coated balloons in the peripheral arteries. Further investigations are warranted urgently.

Retrograde Recanalization for Proximal Occlusion of the Right Renal Artery through a Compensated Collateral Artery in a 10-year-old Patient.

BACKGROUND: To describe a retrograde recanalization for the proximal occluded lesion in right renal artery (RRA) in young patient with fibromuscular dysplasia (FMD). METHODS: A 10-year-old girl presented to our hospital with proximal RRA occlusion and refractory hypertension though she took anti-hypertension medicines. Her renin and aldosterone were beyond the normal level in both base state and excited state. Her glomerular filtration rate at right kidney was only 18.4 ml/min. Angiography revealed proximal RRA occlusion and a compensated collateral artery (CCA) from the infrarenal aorta to the RRA. She was thus diagnosed with focal FMD. A retrograde recanalization was performed through this CCA. RESULTS: Angioplasty and stenting were successfully performed to treat the proximal RRA occlusion. Postoperatively, the glomerular filtration rate in the right kidney improved. One-year follow-up revealed that, the blood pressure maintained at normal range without any antihypertensive agents. No other discomfort was complained. CONCLUSIONS: It is feasible to establish a working pathway with patient's compensated collateral artery to treat the renal artery occlusion.

Effects of Peripheral Arterial Disease Interventions on Survival: A Propensity-Score Matched Analysis Using VQI Data.

BACKGROUND: Atherectomy is currently being used extensively for occlusive peripheral artery disease (PAD) interventions without proven benefits. This analysis examines the effects of atherectomy and other endovascular interventions on patient survival. OBJECTIVES: The aim of this study is to compare overall survival for patients undergoing PAD endovascular interventions, such as plain old balloon angioplasty (POBA), stent deployment and atherectomy. METHODS: Propensity score matched cohorts were constructed to conduct pairwise comparisons of overall survival in patients who underwent stenosis and occlusive PAD interventions between May 2011 and February 2020 using Vascular Quality Initiative (VQI) regional registry data. Inverse probability treatment weighting method was used to compare secondary outcomes of in-hospital mortality, length of stay, complications and major amputations. Comparative analysis was performed for POBA vs stenting, POBA vs atherectomy, and stenting vs atherectomy. RESULTS: A total number of 15281 eligible cases were identified. After propensity score matching, 6094, 4032, and 3312 cases were used to compare POBA versus stent deployment, POBA versus atherectomy and stent versus atherectomy, respectively. Stent deployment had significantly better overall survival compared with POBA and atherectomy (P < 0.001). Multivariable Cox proportional hazard models suggested stenting was associated with a reduction in mortality hazard by 30% compared with POBA (HR: 0.7; 95% CI: 0.6-0.82; P < 0.001) and a 40% mortality reduction compared with atherectomy (HR: 0.6; 95% CI: 0.48-0.75; P < 0.001). No significant difference was found between POBA and atherectomy. There was no statistical difference in other secondary outcomes which were comparable among all cohorts. CONCLUSIONS: Stent deployment was significantly superior to POBA and atherectomy in terms of overall survival with comparable complication and amputation rates. The natural history of PAD patients presenting with claudication is associated with an extremely low annual mortality risk. Therefore, further examinations of outcomes, especially in regards to mortality rates, both POBA and atherectomy on the management of PAD patients especially those presenting with claudication is warranted.

Effect of coarctation of aorta anatomy and balloon profile on the outcome of balloon angioplasty in infantile coarctation.

OBJECTIVE: Coarctation of the Aorta (CoA) is a relatively common cardiovascular disorder. The present study aimed to evaluate the effect of COA anatomy and high versus low-pressure balloons on the outcome of balloon angioplasty among neonates and infants. METHODS: In this retrospective study, the neonates and infants undergoing balloon angioplasty at Namazi hospital were enrolled. After balloon angioplasty, immediate data results were promptly recorded.Moreover, midterm echocardiographic information was collected via electronic cardiac records of pediatric wards and clinical and echocardiographic data at least 12 months after balloon angioplasty. Finally, data were analyzed using SPSS-20. RESULTS: In this study, 42 infants were included. The median age at the time of balloon angioplasty was 1.55 (range 0.1-12) months and 66.7% of the patients were male. The mean pressure gradient of coarctation was 38.49 ± 24.97 mmHg, which decreased to 7.61 ± 8.00 mmHg (P < 0.001). A high-pressure balloon was used in 27, and a low-pressure balloon was used in 15 patients. COA's pressure gradient changed 30.89 ± 18.06 in the high-pressure group and 24.53 ± 20.79 in the low-pressure balloon group (P = 0.282). In the high-pressure balloon group, 14.81% and in the low-pressure group, 33.33% had recoarctation and need second balloon angioplasty (p < 0.021). The infant with discrete coarctation had a higher decrease in gradient and lower recoarctation. CONCLUSION: Recoarctation rate was lower in the high-pressure balloon. The infant with discrete COA had a better response to the balloon with more decrease in gradient and lower recoarctation rate. Therefore, the stenotic segment anatomy needs to be considered in the selection of treatment methods.

Refractory hypertension secondary to renal artery stenosis with a honeycomb-like structure.

BACKGROUND: A honeycomb-like structure (HLS) is a rare abnormality characterized by a braid-like appearance. Angiograph and intravascular examination, including coherence tomography and intravascular ultrasound (IVUS), can further confirm the multiple intraluminal channels or honeycomb structure, which can also be described as looking like 'swiss cheese', a 'spider web' or a 'lotus root'. Previous studies have mostly reported this abnormality in coronary arteries, with a few cases in renal arteries. More information about the characteristics and development of HLS is needed. CASE PRESENTATION: A 69-year-old Han man with resistant hypertension received abdominal enhanced computerised tomography and was revealed to have left renal artery stenosis with the possibility of left renal infarction. Renal artery angiography confirmed a 95% stenosis located in the proximal segment of the left renal artery, and the middle segment was blurred with multi-channel-like blood flow. Further IVUS was performed and identified multiple channels surrounded by fibrous tissue. It was a rare case of HLS in the renal artery secondary to the thrombus, with organisation and recanalisation. Balloon dilatation and stent implantation at the proximal segment of the left renal artery were performed successfully. Blood pressure was well controlled after the procedure. CONCLUSIONS: The IVUS findings are helpful for forming interventional therapeutic strategies for HLS lesions in the renal artery.

Percutaneous Closure of Paravalvular Regurgitation After Third-Generation Transcatheter Aortic Valve Replacement.

Significant paravalvular leak regurgitation (PVLR) after transcatheter aortic valve replacement (TAVR) is a well-known complication associated with disabling symptoms related to heart failure and hemolysis or both, with poor prognostic implications. Although challenging and technically demanding, percutaneous closure is an effective treatment option for high-risk patients with symptomatic PVLR. Here, we present two cases of transcatheter PVLR closure after replacement of third-generation (one self-expandable and one balloon-expandable) transcatheter aortic valves, each with peculiar challenges, and the strategies adopted to increase the success rate of percutaneous closure.

The prognostic role of RBP-4 and adiponectin in patients with peripheral arterial disease undergoing lower limb endovascular revascularization.

BACKGROUND: RBP4 is an adipokine with an established role in atherosclerosis, while adiponectin has unique anti-inflammatory properties. We investigated the association of RBP4 and adiponectin with the presence of symptomatic peripheral artery disease (PAD) and their possible prognostic role in major adverse cardiovascular events (MACE). METHODS: We enrolled 168 consecutive patients with symptomatic, established PAD, requiring revascularization by endovascular means of any or both of their lower limbs. 88 age- and sex-matched subjects with less than 2 classical cardiovascular risk factors served as controls. Clinical parameters, glycemic and lipid profile, RBP4 and adiponectin levels were assayed. The occurrence of MACE was recorded during the 6-month follow-up and patients were assigned to MACE and non-MACE subgroups. RESULTS: The presence of symptomatic PAD was significantly correlated with age, diabetes, hsCRP, RBP4 and low adiponectin levels (p < 0.05). After adjustment for age, RBP4 (ß = 0.498, p < 0.001), and adiponectin (ß = -0.288, p < 0.001) levels remained as independent predictors of PAD presence in the whole study cohort. At baseline, MACE subgroup appeared with higher RBP-4 and hsCRP serum levels than non-MACE subgroup (p < 0.001), but no differences were detected for adiponectin (p = 0.758). Serum RBP4 levels remained independent predictor of MACE (ß = 0.455, p < 0.001) after adjustment for traditional cardiovascular risk factors. CONCLUSIONS: High RBP4 and low adiponectin serum levels are independently associated with PAD presence. In addition, RBP4 is an independent predictor of MACE incidence in symptomatic PAD patients.

3D modelling of drug-coated balloons for the treatment of calcified superficial femoral arteries.

BACKGROUND/OBJECTIVES: Drug-coated balloon therapy for diseased superficial femoral arteries remains controversial. Despite its clinical relevance, only a few computational studies based on simplistic two-dimensional models have been proposed to investigate this endovascular therapy to date. This work addresses the aforementioned limitation by analyzing the drug transport and kinetics occurring during drug-coated balloon deployment in a three-dimensional geometry. METHODS: An idealized three-dimensional model of a superficial femoral artery presenting with a calcific plaque and treated with a drug-coated balloon was created to perform transient mass transport simulations. To account for the transport of drug (i.e. paclitaxel) released by the device, a diffusion-reaction equation was implemented by describing the drug bound to specific intracellular receptors through a non-linear, reversible reaction. The following features concerning procedural aspects, pathologies and modelling assumptions were investigated: (i) balloon application time (60-180 seconds); (ii) vessel wall composition (healthy vs. calcified wall); (iii) sequential balloon application; and (iv) drug wash-out by the blood stream vs. coating retention, modeled as exponential decay. RESULTS: The balloon inflation time impacted both the free and specifically-bound drug concentrations in the vessel wall. The vessel wall composition highly affected the drug concentrations. In particular, the specifically-bound drug concentration was four orders of magnitude lower in the calcific compared with healthy vessel wall portions, primarily as a result of reduced drug diffusion. The sequential application of two drug-coated balloons led to modest differences (~15%) in drug concentration immediately after inflation, which became negligible within 10 minutes. The retention of the balloon coating increased the drug concentration in the vessel wall fourfold. CONCLUSIONS: The overall findings suggest that paclitaxel kinetics may be affected not only by the geometrical and compositional features of the vessel treated with the drug-coated balloon, but also by balloon design characteristics and procedural aspects that should be carefully considered.

A retrospective cohort study comparing high and low balloon inflation pressure on technical success and patency for treating central venous lesions in patients on chronic hemodialysis.

BACKGROUND: We aimed to analyze the success rates and the access patency rates at 12 months between patients on chronic hemodialysis with symptomatic central venous stenosis (CVS) or occlusion (CVO), receiving high or low balloon inflation pressure for treatment. METHODS: We performed a retrospective study in which angioplasty balloons were inflated using a low-pressure or a high-pressure for the management of hemodialysis patients with CVS/CVO. The outcomes of this study were the success rate and the access patency rates at 12 months after balloon angioplasty, and the differences between groups were compared. RESULTS: We included a total of 74 patients on hemodialysis and assigned them to the low-pressure or the high-pressure groups. Success rates in patients of the high-pressure group (94.12%) were higher than those in patients of the low-pressure group (67.50%) (p = 0.005). With a total of 59 patients with technical success, at 6 and 12 months after angioplasty, the rates of access patency in the low-pressure group were 68 and 48%, respectively; on the other hand, the primary patency rates in the high-pressure group were 86.67% (6-months) and 76.67% (12-months). The 6 and 12 months post-interventional patency rates were higher in patients of the high-pressure group than those in patients of the low-pressure group (p = 0.10 at 6 months and p = 0.03 at 12 months). CONCLUSIONS: Compared to balloon angioplasty using a low inflation pressure, hemodialysis patients with CVS/CVO receiving angioplasty using a high inflation pressure have significantly higher technical success and 12-month patency rates.

Editor's Choice - Paclitaxel Coated Balloon Angioplasty vs. Plain Balloon Angioplasty for Haemodialysis Arteriovenous Access Stenosis: A Systematic Review and a Time to Event Meta-Analysis of Randomised Controlled Trials.

OBJECTIVE: A systematic review and meta-analysis of randomised controlled trials (RCTs) was performed to determine the effectiveness and safety of drug coated balloon (DCB) angioplasty compared with uncoated plain balloon (PB) angioplasty in treating arteriovenous access stenosis. METHODS: MEDLINE, Embase, Scopus, and the Cochrane Central Register of Controlled Trials were searched for RCTs comparing paclitaxel coated DCB and PB angioplasty for arteriovenous access stenosis. The last date of the literature search was 31 December 2020. Risk of bias of the retrieved studies was assessed with the Cochrane Collaboration tool for assessing risk of bias (RoB 2.0). The random effects model was used to estimate the risk of loss of target lesion patency (six and 12 months) and circuit patency (six and 12 months). Procedure related adverse events and mortality rate were also compared. Patency results were pooled using the time to event meta-analytical method and the quality of evidence was assessed according to the GRADE approach. RESULTS: Sixteen eligible trials, including 1 682 lesions, were included in the quantitative analysis for the efficacy and safety of paclitaxel coated DCBs. DCBs were associated with a lower risk of loss of target lesion patency at six months (HR 0.53, 95% CI 0.42 - 0.66) and 12 months (HR 0.60, 95% CI 0.47 - 0.76), and were also associated with improved six and 12 month circuit patency. Overall quality of evidence was moderate to low. Procedural complications were rare, and the risk of death up to 12 months was similar between the two groups (OR 1.03, 95% CI 0.68 - 1.56). CONCLUSION: Paclitaxel coated DCBs reduced the risk of loss of target lesion patency and circuit patency in arteriovenous access stenosis compared with PBs. Considering the heterogeneity of the included trials, there is a need to investigate optimal treatment regimens regarding drug dose and agent of the DCB and the treatment procedure.

Endovascular Release of a 50-Year-Old Adams-Deweese IVC Clip to Facilitate Percutaneous Repair of Mitral Valve Regurgitation.

Percutaneous mitral valve (MV) repair using MitraClip requires large-caliber venous access. We describe a patient with a ligated inferior vena cava due to an Adams-DeWeese clip placed 50 years prior, who had progressive shortness of breath and lower extremity symptoms secondary to severe mitral regurgitation and chronic iliocaval deep venous thrombosis. Due to comorbidities, MitraClip was recommended over surgery for MV repair. Caval luminal gain was required to facilitate endovascular access for the MitraClip system. Stent-mediated release of the inferior vena cava clip allowed successful passage of the delivery sheath from the common femoral vein to MV and subsequent valve repair.

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.