Primary Assisted Patency Research Articles

Medium Term Outcomes of Deep Venous Stenting in the Management of Venous Thoracic Outlet Syndrome

Venous thoracic outlet syndrome (vTOS) is a relatively rare condition associated with significant morbidity. Its management continues to evolve, with increasing use of endovascular adjuncts, such as percutaneous thrombectomy and angioplasty, in addition to first rib resection. The utility of stenting residual venous stenotic lesions is poorly defined within the literature. This study sought to review the medium term patency rates of upper limb deep venous stenting in the management of vTOS. A single centre, retrospective review of patients managed for vTOS with first rib resection followed by upper limb deep venous stenting between January 2012 and February 2021 was conducted. Post-procedural ultrasounds were reviewed to determine stent patency. Twenty-six patients were included, with 33 stents placed. The median duration of follow up was 50 months. On venous duplex ultrasound at three years post-operatively, primary patency rates were 66%, primary assisted patency rates were 88%, secondary patency rates were 91%, and total occlusion rates were 9%. After stent placement, 80% of patients remained asymptomatic with regard to compression symptoms. Upper limb deep venous stenting is an effective adjunct to surgical decompression in the management of vTOS. Stent medium term patency rates are promising; however, further studies with longer follow up and larger cohorts with multicentre results are required to confirm these early findings.

577 Infra-Inguinal Bypass Graft Surveillance Is an Opportunity to Optimise Statin and Antiplatelet Therapy to Reduce 12-Month Major Amputation and Mortality Rates

Abstract Aim Infra-inguinal bypass graft failure within the first two postoperative years can result from stenotic lesions within the conduit and near anastomosis. This study assesses graft surveillance uptake, patency, amputation, and death rates among infra-inguinal bypass surgery patients at 1, 6 and 12-months postoperatively. Method Patients undergoing infra-inguinal bypass at a single vascular centre between 1st January 2018 and 31st December 2019 were identified from the prospectively collected database. Primary outcomes at 1, 6 and 12-months postoperatively included: duplex-ultrasound (DUS) surveillance uptake, patency, major amputations, and death rates. Statistical analysis with SPSS® was performed using chi-squared tests and paired sample t-tests. Results Of the 91 patients included, 79.1% were men and median(IQR) age was 71(62–76). At 1, 6 and 12 months, DUS uptake was 74.2%, 77.5% and 73.3% respectively, primary-assisted patency rates were 88.2%, 78.8% and 65.3% respectively and secondary patency rates were 97.6%, 96.3% and 96.3% respectively. Major amputation rates at 1, 6 and 12 months were 5.4%, 8.6%, 8.6% respectively. Death rates at 1, 6 and 12 months were 3.2%, 5.4% and 10.8% respectively. Patients on statin therapy post-operatively had lower 12-month mortality than those not on statin therapy (7.7% vs 30.0%, p=.028). Major amputation rate at 12 months was lower among patients prescribed antiplatelet therapy (6.3% vs 40%, p=.008). Conclusions DUS graft surveillance is a vital opportunity to adequately optimise statin and antiplatelet therapy post-revascularisation to reduce 12-month major amputation and mortality rates.

Use of Covered Stents in Cannulation Sites as a Last Option to Salvage Failing Vascular Access

Purpose: Controversy exists regarding the treatment of recurrent stenosis in vascular access at cannulation sites with a covered stent as repeated cannulation may damage the stent. The purpose of this study was to review covered stent placement at cannulation sites to salvage failing vascular access. Materials and methods: A total of 11 patients were included for the purpose of this study. Eight patients (72.7%) received a covered stent due to recurrent stenosis, 2 (18.2%) due to an acute occlusion, and in 1 case (9.1%), the covered stent was used to repair a damaged polytetrafluoroethylene arteriovenous graft (PTFE AVG). Results: Primary patency after stent placement was 40.9% at 6 months, primary-assisted patency was 79.5% at 12 months, and secondary patency was 80% at 24 months. No significant problems were observed during the dialysis sessions after stent placement. The intervention rate per patient-year was not significantly different before or after covered stent placement, at 3.8 (IQR=9.5) interventions per year versus 2.5 (IQR=3.0) interventions per year (p=0.280). Conclusion: In conclusion, treating failing vascular access with problems at cannulation sites with covered stents can be considered. Clinical Impact Treating vascular access stenosis at cannulation sites with covered stents can successfully prolong vascular access life.

O069 Infra-inguinal bypass graft surveillance is an opportunity to optimise statin and antiplatelet therapy to reduce 12-month major amputation and mortality rates

Abstract Introduction Infra-inguinal bypass graft failure within the first two postoperative years can result from stenotic lesions within the conduit and near anastomosis. This study assesses graft surveillance uptake, patency, amputation and death rates among infra-inguinal bypass surgery patients at 1, 6 and 12-months postoperatively. Methods Patients undergoing infra-inguinal bypass at a single vascular centre between 1st January 2018 and 31st December 2019 were identified from the prospectively collected database. Primary outcomes at 1, 6 and 12-months postoperatively included: duplex-ultrasound (DUS) surveillance uptake, patency, major amputations and death rates. Statistical analysis with SPSS® was performed using chi-squared tests and paired sample t-tests. Results Of the 91 patients included, 79.1% were men and median (IQR) age was 71(62–76). At 1, 6 and 12 months, DUS uptake was 74.2%, 77.5% and 73.3% respectively, primary-assisted patency rates were 88.2%, 78.8% and 65.3% respectively and secondary patency rates were 97.6%, 96.3% and 96.3% respectively. Major amputation rates at 1, 6 and 12 months were 5.4%, 8.6%, 8.6% respectively. Death rates at 1, 6 and 12 months were 3.2%, 5.4% and 10.8% respectively. Patients on statin therapy post-operatively had lower 12-month mortality than those not on statin therapy (7.7% vs 30.0%, p=.028). Major amputation rate at 12 months was lower among patients prescribed antiplatelet therapy (6.3% vs 40%, p=.008). Conclusion DUS graft surveillance is a vital opportunity to adequately optimise statin and antiplatelet therapy post-revascularisation to reduce 12-month major amputation and mortality rates. Take-home message Infra-inguinal bypass graft surveillance is an opportunity to optimise statin and antiplatelet therapy to reduce 12-month major amputation and mortality rates.

Clinical outcomes of endovascular therapy with vascular stents for central venous obstruction in hemodialysis patients

BackgroundSymptomatic central venous obstruction (CVO) is sometimes observed in patients undergoing hemodialysis. Angioplasty is generally performed for salvage purposes, and stent implantation is performed as a last resort to prevent permanent venous occlusion. However, published reports about the clinical outcomes of stenting for CVO have been limited by the small number of included patients and the relatively old generation of analyzed stents. This study aimed to clarify the safety and efficacy of endovascular therapy (EVT) using stents for symptomatic CVO in contemporary practice. MethodsThis retrospective review was performed between May 2012 and August 2021. We retrospectively analyzed consecutive 31 lesions (31 patients, 64 ± 10.7 years old) treated with a vascular stent for elastic recoil after balloon angioplasty or recurrent stenosis <3 months after angioplasty. The primary outcome was primary patency, defined as freedom from target lesion revascularization. The secondary outcome was assisted primary patency, defined as freedom from permanent occlusion of the target stents. ResultsIn all cases, stents were successfully deployed on the target lesions. No EVT-related complications were observed. Self-expandable and balloon-expandable stents were used in 26 and 5 lesions, respectively. The median follow-up period was 18 months (interquartile range, 7–40). Kaplan-Meier analysis revealed that the primary patency rates were 66.1 % at 6 months, 61.7 % at 12 months, and 38.4 % at 24 months after EVT. The assisted primary patency rate was 70.3 % 24 months after EVT. In the multivariate analysis, younger age was the only independent predictor of target lesion revascularization (hazard ratio: 0.92, 95 % CI: 0.85–0.99, p = 0.04). ConclusionsStent implantation for CVO that is resistant to standard angioplasty seems safe and effective.

A Single-Center Experience with Forearm Arteriovenous Loop Grafts for Hemodialysis

Autogenous arteriovenous fistula (AVF) remains the standard of hemodialysis (HD) access; however, it cannot be reasonably obtained in all patients. For patients with contraindications to AVFs, prosthetic arteriovenous graft (AVG) remains an alternative. AVGs are plagued by high failure rates; however, there is a paucity of literature examining this. This study aims to examine a single-center review of outcomes of forearm loop AVGs in patients requiring HD access. A single institution, retrospective chart review was completed from 2012 to 2019, including demographics, end-stage renal disease etiology, brachial vessel diameters, and comorbidities. Logistic regression and Cox proportional hazard models were evaluated. Outcomes were defined as primary patency (time elapsed from graft creation until it was utilized as the patient's primary access), primary-assisted patency (time from primary access to intervention to maintain patency), and functional patency (time from graft placement until graft failure). Additionally, multinomial regression models were used to evaluate associations with categorical number of required interventions. Ninety-eight patients [mean age 61.8 (13.9) years, 42.9% female] were identified as having brachial artery to brachial vein AVG creation during the study period, of which 75% achieved primary patency. Primary-assisted patency was 0.36 [standard error (SE) 0.07] at 6months and 0.12 (SE 0.05) at 1year. Functional patency was 0.75 (SE 0.07) at 6months and 0.43 (SE 0.09) at 1year. No association between preoperative vessel diameters and primary-assisted or functional patency was observed. Interestingly, there was a significant negative association between previous ipsilateral access and achievement of primary patency with a 60% decrease in odds of achieving primary patency in patients with previous ipsilateral access [odds ratio 0.4, 95% confidence interval (CI) 0.1-0.9, P=0.03]. There was also noted to be a significant association between the presence of an ipsilateral catheter and increased risk of subsequent abandonment of the AVG (hazard ratio 2.6, 95% CI 1.1-5.8, P=0.02). Prosthetic forearm loop AVGs remain hindered in their utility as they show high rates of graft failure within a year of creation. A significant patient-specific factor leading to this was not clearly demonstrated. As guidelines change regarding the nature of dialysis access for patients on HD, these results draw into question the utility of prosthetic forearm loop grafts in patients requiring long-term HD access.

Drug-Eluting Stents are Associated with Superior Mid-Term Outcomes for the Treatment of Infrainguinal Bypass Graft Stenoses

We previously demonstrated that everolimus drug-eluting stents (eDES) have reasonable short-term patency for the treatment of infrainguinal bypass stenoses. The aim of this study is to compare mid-term outcomes of eDES, plain balloon angioplasty (PTA), percutaneous cutting balloon (PCB), and drug-coated balloon (DCB) interventions for failing infrainguinal bypasses. We conducted a retrospective review of patients with infrainguinal bypass stenoses treated by endovascular intervention (August 2010-August 2021). The primary outcome was primary patency (PP). Secondary outcomes were primary-assisted patency (PAP), secondary patency (SP), limb salvage (LS), and mortality. Outcomes were compared by treatment using Kaplan-Meier curves with log-rank tests and Cox proportional hazards models adjusting for baseline differences between groups. Seventy-two consecutive patients with 152 discrete infrainguinal bypass graft stenoses were identified. Mean age was 65.1±10.6years, 55.6% were male, and 48.6% were Black. In total, 81.9% of patients were originally treated for chronic limb-threatening ischemia, and 57.2% of distal anastomoses were to tibial or pedal targets. Of 152 lesions, 44.1% (n=67) were treated with PTA, 17.8% (n=27) with PCB, 20.4% (n=31) with DCB, and 17.8% (n=27) with eDES. Median follow-up was 28.5months (interquartile range 11.5-51.9). There was no difference in bypass configuration, conduit choice, or stenosis location (proximal anastomosis, mid-bypass, distal anastomosis) between groups. At 24 months postintervention, PP was significantly better for eDES (72.9%, 95% confidence interval [CI] 49.8-85.6), followed by PCB (55.9%, 95% CI 34.2-72.9), PTA (34.4%, 95% CI 21.7-47.4), and DCB (33.6%, 95% CI 14.5-53.9) (P=0.03). PAP, LS, and mortality did not significantly differ between modalities (P>0.05). After risk adjustment, eDES was associated with the lowest risk of PP loss (hazard ratio versus PTA 0.15, 95% CI 0.05-0.47). eDES is associated with superior 24-month patency rates compared to other endovascular technologies, and should be considered a primary therapy modality for the treatment of infrainguinal bypass graft stenoses.

The efficacy and safety of blunt impingement followed by a sharp recanalization technique in hemodialysis patients with refractory central vein occlusion: a single-center experience.

BackgroundCentral vein occlusion (CVO) is a serious problem in hemodialysis patients. There is an unsatisfactory result for refractory CVO by sharp recanalization alone. This study evaluated the efficacy and safety of blunt impingement followed by sharp recanalization for the treatment of CVO in hemodialysis patients.MethodsThis study retrospectively examined hemodialysis patients with CVO who failed to recanalize using standard guidewire and catheter techniques in our department. In the first instance, all CVOs were recanalized using blunt impingement techniques, including a 6-Fr long sheath (Cook Incorporated, Bloomington, IN USA) and an 8-Fr sheath of Rosch-Uchida Transjugular Liver Access Set (RUPS-100; Cook Incorporated, Bloomington, IN, USA). If this was not successful, sharp recanalization devices were applied, including the stiff tip of a guidewire (Terumo, Tokyo, Japan), the RUPS-100, and the percutaneous transhepatic cholangial drainage (PTCD) needle (Cook Incorporated, USA). All patients were followed up at least 4 months postoperatively. The technical success rate, arteriovenous access patency rates, and operation-related complications were analyzed.ResultsThe procedural success rate was 100.0% (30 of 30). Thirty patients with CVO underwent blunt impingement with a technique success rate of 70.0% (21 of 30), and 9 patients received sharp recanalization after failed blunt impingement, with a technique success rate of 100.0% (9 of 9). The primary patency rates at 6 and 12 months postoperatively were 86.7% and 53.3%, respectively. The primary assisted patency rates were 93.3% and 63.3%, and the secondary patency rates were 93.3% and 70.0% at 6 and 12 months, respectively. One major procedure-related complication was detected, namely, a small injury of the superior vena cava (SVC) wall in a patient receiving recanalization via the stiff end of a guidewire, but this did not require further treatment.ConclusionsIt is potentially effective and safe for interventionalists to use blunt impingement followed by sharp recanalization techniques to treat chronic CVO that is refractory to traversal using traditional catheter and guidewire techniques.

Forearm Arteriovenous Fistula Maturation Delay due to Juxta-Anastomotic Stenosis: Role of Percutaneous Angioplasty

Introduction: Arteriovenous fistula is the optimal vascular access for hemodialysis as it has the best long-term patency rate and the lowest complication rate. Although we are still lacking consensus, surgery has been advocated as the best treatment option for maturation delay. We proposed to evaluate the results of endovascular approach of arteriovenous fistula’s maturation delay in our hospital. Methods: We conducted a retrospective study, selecting patients referred to our diagnostic and therapeutic angiography unit due to arteriovenous fistula delayed maturation, between April 2017 and June 2020. Results: Thirty-four patients were referred to our center due to maturation delay, of which six (17.7%) were excluded as the diagnosis was not confirmed and six (17.7%) because the lesions were not suitable for percutaneous angioplasty. The other 22 patients (64.7%) were subjected to percutaneous endovascular treatment. Mean age was 67.3 ± 13.8 years. Eighteen patients (81.8%) had maturation delay due to peri-anastomotic stenosis; 12 (66.7%) were forearm fistulas (all radio-cephalic). Mean follow-up time was 21.2 ± 11.2 months. Eleven (91.7%) fistulas were salvaged, although four (33.3%) needed reintervention. Primary and assisted primary patencies at 6 and 12 months were 66.7% vs 91.7% and 58.3% vs 91.7%, respectively. Conclusion: Our results point out that endovascular treatment is a good treatment option for maturation delay of forearm arteriovenous fistulas due to juxta-anastomotic stenosis. Even though surgical treatment appears to have better primary patency, a step-by-step approach seems to be a valid strategy, as our assisted primary patency shows.

Retrospective evaluation of early thrombosis in transjugular intrahepatic portosystemic polytetrafluoroethylene-coated shunts under 2-day postinterventional heparinization

The development of acute thrombosis within the TIPS tract may be prevented by prophylactic anticoagulation; however, there is no evidence of the correct anticoagulation regimen after TIPS placement. The purpose of this single-center retrospective study was to evaluate the short-term occlusion rate of transjugular intrahepatic portosystemic shunts (TIPSs) with polytetrafluorethylene (PTFE)-coated stents under consequent periprocedural full heparinization (target partial thromboplastin time [PTT]: 60–80 s). We analyzed TIPS placements that were followed up over a six-month period by Doppler ultrasound in 94 patients and compared the study group of 54 patients who received intravenous periprocedural full heparinization (target PTT: 60–80 s) without any other anticoagulation to patients with prolonged anticoagulation medication. The primary endpoint was TIPS patency after six months. The primary patency rate was 88.3% overall, and in the study group, 90.7%, with an early thrombosis rate of 3.2% (study group: 1.9%) and a primary assisted patency rate of 95.7% (study group: 96.3%). In the study group, one case of TIPS thrombosis occurred on the 23rd day after TIPS placement. Two patients underwent reintervention because of stenosis or buckling. Moreover, the target PTT was not attained in 8 of the 54 patent TIPSs. Four patients had an increased portosystemic pressure gradient, without stenosis, and the flow rate was corrected by increasing the TIPS diameter by dilation. Two-day heparinization seems sufficient to avoid early TIPS thrombosis over a six-month period.

A randomised control trial protocol of MuST for vascular access cannulation in hemodialysis patients (MuST Study): contributions for a safe nursing intervention

BackgroundThe vascular access preservation and the maintenance of a complication-free fistula remains an Achilles’ heel of hemodialysis in chronic kidney patients due to its substantial contribution to the morbidity and mortality. Systematic studies in the area of examining cannulation practices, achieving complication-free cannulation, and strategies to improve fistula survival are needed. For this reason, we consider it essential to create and investigate new methodologies for approaching fistula in patients on regular HD.The Multiple Single Cannulation Technique (MuST) is based on the association between the rope-ladder (RL) using the arteriovenous vessel through progressive rotation, and the buttonhole (BH) since there are three specific cannulation sites for each cannulation day during the week. The MuST is simple to implement and seems to be a very promising technique in terms of patient safety. Previous studies already showed an arteriovenous fistula survival similar to RL but significantly higher than BH.MethodsThis MuST study is a multicenter, prospective, non-blind, parallel-group, randomized controlled trial with the intervention group submitted to MuST and a control group undergoing the rope-ladder, up to 100 subjects for each group. Patients will be randomized 1:1 to one of two cannulation technique (CT), and the follow-up period of this study will be 12 months. Primary outcome is to evaluate the arteriovenous fistula survival rate at 12 months determined by the percentage of fistulas in use from the beginning of the study to the date of the first clinical intervention by angioplasty or vascular surgery, to maintain or restore patency (unassisted patency). Secondary outcome is to evaluate arteriovenous fistula survival rate at 12 month determined by the percentage of fistulas in use from the study start to the date of access abandonment due to dysfunction, patient abandonment, or death, treatment change modality or study end. We will also evaluate the assisted primary patency and include the following secondary outcomes associated with the cannulation technique: Infection, Hematoma, Aneurysm development, and pain.DiscussionThe study will investigate whether fistula survival can be improved when using cannulation by MuST compared to the RL. MuST study will provide important information on fistula survival when cannulated by MuST but also information related to its use in fistulas previously cannulated by other CTs.Trial registrationClinicalTrials.gov identifier NCT05081648 registered on 18 October 2021.

Comparison between transposed arteriovenous fistulas and arteriovenous graft for the hemodialysis patients: A meta-analysis and systematic review.

It is challenging for a surgeon to determine the appropriate vascular access for hemodialysis patients whose cephalic vein is usually inaccessible. The purpose of the study is to compare the complications and patency rates between transposed arteriovenous fistulas (tAVF) and arteriovenous graft (AVG) for the hemodialysis patients. Studies were recruited from PubMed, Cochrane library, EMBASE, the web of science databases, and reviewing reference lists of related studies from the inception dates to September 2, 2021. Statistical analyses were conducted using the statistical tool Review Manager version5.3 (Cochrane Collaboration, London, UK). I2 > 50% was defined as a high degree of heterogeneity, and then a random-effects model was used. Otherwise, the fixed-effects model was used. Odds ratio with its 95% confidence interval (95% CI) was used. Thirty-three trials (26 retrospective studies, four randomized controlled trials, two prospective trials, and one controlled-comparative study) with 6430 enrolled participants were identified in our analysis. The results showed that tAVF was accompanied with lower thrombosis rate (103/1184 (8.69%) vs 257/1367 (18.80%); I2 = 45%; 95% CI, 0.34 (0.26, 0.45)) and infection rate (43/2031 (2.12%) vs 180/2147 (8.38%); I2 = 0%; 95% CI, 0.20 (0.14, 0.30)) than arteriovenous graft. The significantly better primary patency rates, secondary patency rates, and primary assisted patency rates during follow-up were found in tAVF. However, the failure rate and the prevalence of hematoma were significantly lower in AVG group. No evidence showed the rate of overall mortality, steal syndrome, and aneurysm reduced in tAVF. Our results showed that tAVF is a promising vascular access technique for hemodialysis patients whose cephalic vein is inaccessible. Our data showed that tAVF has less thrombosis, infection risk, and better patency rates when compared with AVG. However, more attentions need to be paid to transposed arteriovenous fistulas maturation and hematoma.

Factors Affecting Patency of In Situ Saphenous Vein Bypass: Two Year Results from LIMBSAVE (Treatment of critical Limb Ischaemia with infragenicular Bypass adopting in situ SAphenous VEin technique) Registry

The aim was to demonstrate contemporary outcomes of in situ saphenous vein bypass using a valvulotome. Analysis of two year outcomes of a multicentre registry based on the treatment of critical Limb Ischaemia with infragenicular Bypass adopting in situ SAphenous VEin technique (LIMBSAVE). Between January 2018 and December 2019, 541 patients in 43 centres were enrolled. In all patients an innovative valvulotome was used. Early outcomes were assessed. Two year outcomes according to Kaplan-Meier curves in terms of patency and limb salvage were evaluated. Associations between patient and procedure variables were analysed with univariable and multivariable analyses. In all cases, a valvulotome was able to lyse the valves. Vein injury due to the in situ technique was 3.5%. Thirty day mortality and major amputation rates were 3% and 0.9%, respectively. Mean follow up was 12.1 months. Two year estimated primary patency, primary assisted patency, secondary patency, and limb salvage were 69.1%, 81.4%, 86.5%, and 94.5%, respectively. Multivariable analysis showed an association between pre-operative vein diameter < 3 mm and lower primary patency (hazard ration [HR] 14.3, p < .001), primary assisted patency (HR 9.4, p= .002), secondary patency (HR 7.2, p= .007), and limb salvage (HR 7.8, p= .005) rates. Distal anastomosis to a tibial or foot vessel was also associated with lower primary patency (HR 4.8, p= .033), and primary assisted patency (HR 6, p= .011) rates. Use of a suprafascial tributary collateral as a graft was associated with lower primary patency (HR 6.7, p= .013), and primary assisted patency (HR 4.2, p= .042) rates. Vein diameter < 3 mm, distal anastomosis on a tibial or foot vessel, and use of a suprafascial tributary collateral as a graft were significantly associated with loss of patency and limb loss during follow up.

Early experience with venous arterialization for limb salvage in no-option patients with chronic limb-threatening ischemia

ObjectiveChronic limb-threatening ischemia (CLTI) is associated with adverse limb outcomes and increased mortality. However, a small subset of the CLTI population will have no feasible conventional methods of revascularization. In such cases, venous arterialization (VA) could provide an alternative for limb salvage. The objective of the present study was to review the outcomes of VA at our institution. MethodsWe performed a single-institution review of 41 patients who had been followed up prospectively and had undergone either superficial or deep VA. The data collected included patient demographics, comorbidities, VA technique (endovascular vs hybrid), and WIfI (wound, ischemia, and foot infection) limb staging. Data were collected at 1-month, 6-month, and 1-year intervals and included the following outcomes: patency, wound healing, major adverse limb events, major amputation, and death. Descriptive statistics were used for analysis. ResultsThe study group included 41 patients who had undergone successful open hybrid superficial or deep endovascular VA; 21 (51.2%) had undergone a purely endovascular procedure and 20 (48.8%), hybrid VA. The WIfI clinical stage was as follows: stage 4, 33 (80.5%); stage 3, 6 (14.6%); and stage 2, 1 (2.4%). Of the 41 patients, 24 (58.5%) had completed follow-up at 6 months and 16 (39%) at 1 year. At 1 year, the VA primary patency was 28.6% (95% confidence interval [CI], 0.15%-0.43%), primary assisted patency was 44.3% (95% CI, 0.27%-0.60%), and secondary patency was 67% (95% CI, 0.49%-0.80%). The complete wound healing rate was 2.7% (n = 1) at 1 month, 62.5% (n = 15) at 6 months, and 18.8% (n = 3) at 1 year. Overall wound healing at 1 year was 46.3% (n = 19). The number of major adverse limb events at 1 year was 15 (36.5%) and included 8 reinterventions (19.5%) and 7 major amputations (17%). The number of deaths was zero (0%) at 1 month and four (19%) at 6 months. Two deaths (9.5%) were attributed to COVID-19 (coronavirus disease 2019). No further deaths had occurred within 1 year. The limb salvage survival probability at 1 year was 81%. ConclusionsThese findings suggest that for a select subset of CLTI patients presenting with a high WIfI clinical limb stage and no viable options for conventional open or endovascular arterial revascularization, superficial and deep VA are feasible options to achieve limb salvage.

Endovascular bypass as a strategy for long femoropopliteal lesions.

Endovascular treatment has become the predominant treatment modality for femoropopliteal lesions. In longer and more complex lesions advanced technology is often required to improve results, with the endovascular bypass being one of them. A systematic review of the literature was performed to determine the clinical and technical outcomes of the latest generation endoprosthesis, with heparin bioactive surface and contoured proximal edge. 13 articles were enrolled: 3 randomized controlled trials, 4 prospective multicenter trials and 6 retrospective studies. The VIASTAR trial showed that the endoprosthesis has a better two-year primary patency compared to bare metal stenting, especially in long lesions (62% vs. 27%, P=0.004). The SUPERB trial showed that the endoprosthesis had similar results compared to bypass surgery, albeit with less complications (31% vs. 55%, P=0.048). The RELINE study showed that treatment with an endoprosthesis had a better one-year primary patency compared to balloon angioplasty for in-stent restenosis (75% vs. 28%, P<0.001). In the cohort studies one-year patency rates ranged from 61% to 86% for primary patency, from 65% to 92% for primary assisted patency, and from 83% to 95% for secondary patency. For long femoropopliteal lesions, the heparin-bonded endoprosthesis is related to better outcomes compared to bare nitinol stents, and comparable outcomes as with the femoropopliteal bypass, but with less complications. There is a wide range in primary patency rates, with consistent high secondary patency rates. The endovascular bypass can be considered an appropriate strategy in these patients.

The role of vacuum-assisted mechanical thrombectomy in the management of acutely thrombosed arteriovenous fistulas and grafts.

The purpose of this study is to evaluate the safety and efficacy of the mechanical thrombectomy with the Indigo System in the treatment of thrombosed arteriovenous fistulas and grafts. A retrospective search of endovascular procedures performed from November 2018 to June 2020 was conducted. Inclusion criteria were: acute arteriovenous fistula or graft thrombosis that underwent endovascular mechanical thrombectomy with Indigo System. The following information was collected from each case: sex, age, fistula modality, fistula location, treatment modality, and outcomes. Endpoints evaluated were: technical and clinical success rates; primary, assisted primary, and secondary patency rates; complication rates. Twenty-six mechanical thrombectomy procedures for declotting of arteriovenous fistula thrombosis, using the Indigo System, were performed in 22 patients. Technical and clinical success was achieved in 23/26 cases (88%). Mean follow-up was 9 months (range 11-539 days). The 6-month primary, primary assisted, and secondary patency rates were 71%, 86%, 93% and the 12-month primary, primary assisted, and secondary patency rates were 71%, 72%, 80%, respectively. No technical or device-related complications were observed during thrombectomy, however two venous ruptures occurred on the angioplasty of the underlying stenosis. In conclusion, vacuum-assisted thrombectomy of acutely thrombosed arteriovenous fistulas and grafts with Indigo System is safe and effective, providing good short term patency rates.

Bypass Versus Interwoven Nitinol Stents for Long Femoro-Popliteal Occlusions: A Propensity Matched Analysis.

To compare femoro-popliteal bypass and interwoven nitinol stenting for long occlusions of the femoro-popliteal segment. Single center retrospective propensity matching analysis of the symptomatic patients with long occlusion of the femoro-popliteal segment (> 20cm), who underwent stenting with interwoven nitinol stent or femoro-popliteal bypass from 2012 to 2020. primary patency, primary-assisted patency, secondary patency. Secondary endpoints: major adverse cardiovascular events, major adverse limb events, primary sustained clinical improvement, survival. A total of 437 patients were enrolled: 294 in the bypass group and 143 in the endovascular therapy (EVT) group. After propensity score matching, 264 and 113 patients remained in the groups, respectively. A median occlusion length was 250mm. One-year and two-year primary and secondary patency rates were comparable in both groups (two-year primary patency: 68.5% for bypass vs. 68.9% for EVT, p = 1.00). In the "above the knee" subgroup analysis, two-year secondary patency was higher in the EVT group than in the bypass group (90.9% vs. 77.5%, p = 0.048). In "below-the-knee" subgroup analysis, primary and primary assisted patency were statistically significantly higher in the EVT group than in artificial bypass subgroup (66.7% vs. 42.4%, p = .046 and 76.7% vs. 45.5%, p = .011, respectively). However, compared to autovenous bypass, the EVT group showed lower primary patency rates, although the differences are not significant. A nonselective endovascular strategy can allow for regular successful treatment of femoro-popliteal lesions longer than 25cm.

Comparison of long occlusive femoropopliteal de novo versus previous endovascularly treated lesions managed with in situ saphenous bypass

BackgroundThe aim of this study was to compare the 2-year outcomes of de novo versus postendovascular lesion treatment of femoropopliteal occlusions included in a national, multicenter, observational, prospective registry based on the treatment of critical Limb-threatening IschaeMia with infragenicular Bypass adopting in situ SAphenous VEin technique (LIMBSAVE) registry. MethodsFrom January 2018 to December 2019, 541 patients from 43 centers have been enrolled in the LIMBSAVE registry. Of these patients, 460 were included in the present study: 341 (74.1%) with de novo lesions (DN group) and 119 (25.9%) with postendovascular treatment lesions (PE group). Initial outcome measures were assessed at 30 days after treatment. Furthermore, at the 2-year follow-up, the estimated outcomes of primary patency, primary-assisted patency, secondary patency, and limb salvage were analyzed with Kaplan-Meier curves and compared between groups with the log-rank test. ResultsBoth groups were homogeneous in terms of demographic data, preoperative risk factors, and clinical presentation. However, compared with DN group, more patients in PE group had a great saphenous vein diameter of less than 3 mm (11.1% vs 21%; P = .007). Intraoperatively, both groups showed similar distal anastomosis sites: below-the-knee popliteal artery (63% DN group, 66.4% PE group) and tibial vessel (37% DN group, 33.6% PE group) (P = .3). The overall mean duration of follow-up was 11.6 months (range, 1-24 months). At the 2-year follow-up, there were no differences between the two groups in terms of primary patency (66.3% DN group vs 74.1% PE group; P = .9), primary-assisted patency (78.2% DN group vs 79.5% PE group; P = .2), secondary patency (85.1% DN group vs 91.4% PE group; P = .2), and limb salvage (95.2% DN group vs 95.1% PE group; P = .9). ConclusionsThe LIMBSAVE registry did not show a worsening of overall patency and limb salvages rates at the 2-year follow-up in patients undergoing in situ saphenous bypass after a failed endovascular approach for long femoropopliteal occlusive disease. This finding is in contrast with what has been published in literature.

Safety and Efficacy of Drug Eluting Stents for Treatment of Transplant Renal Artery Stenosis

Transplant renal artery stenosis (TRAS) after renal transplantation is a common cause of graft dysfunction and failure. Endovascular intervention in the form of percutaneous transluminal angioplasty (PTA) and stenting has rapidly become the dominant treatment modality for the TRAS. There is a paucity of clinical data on the use of drug-eluting stent (DES) for TRAS. We investigated the outcomes of patients with clinically significant TRAS undergoing DES placement. A retrospective review of patients with clinically significant TRAS undergoing PTA with DES placement from June 2014 to April 2021 was conducted. Patients treated for TRAS exhibited uncontrolled hypertension and/or unexplained allograft dysfunction. Patient demographics, procedural details, and follow-up outcomes were collected. Primary endpoints were the in-stent primary patency and graft survival. Secondary endpoints were freedom from reintervention, primary-assisted patency, and access-related complications. Thirteen TRAS in 12 patients with graft function alteration were treated with DES. The median age was 57 years (interquartile range (IQR), 48-63 years), and 9 (70%) patients were male. The median follow-up was 9 months (IQR, 4-52 months). The most common comorbidity was hypertension (100%), coronary artery disease (83%), and diabetes. The median time from deceased donor transplant to intervention was 5.8 months (IQR, 3.5-6.7 months). TRAS was most commonly found at the juxta-ostial segment (77%). The procedure was performed with carbon dioxide angiography with minimal amount of iodinated contrast (median, 3 mL) under local anesthesia in 9 (69%), and general anesthesia in 4 (31%) patients. The median stent diameter was 4.5 mm (IQR, 4-5 mm), and the median stent length was 15 mm (IQR, 15-18 mm). No intraoperative complications occurred. The rates of stenosis-free primary patency of the DES and graft survival were 76% and 100%, respectively. All 3 reinterventions for restenosis resulted from the kinking of the transplant renal artery proximal to the DES, which were treated by extending the stent more proximally 1-2 mm into the external iliac artery. There were no access-related complications. The median time to reintervention was 0.9 months (range, 0.23-2 months). Freedom from reintervention and primary-assisted patency were 76% and 100%, respectively. Our study demonstrates that DES is a safe and effective treatment modality in patients with TRAS at short to mid-term follow-up. As all reinterventions after DES were performed due to kinking of the transplant renal artery proximal to the stent, bridging of the DES 1-2 mm into the external iliac artery is recommended.

Comparative retrospective analysis of the results of open femoral-popliteal bypass grafting and endovascular stenting with an interwoven biomimetic stent in patients with prolonged occlusions of the arteries in the femoropopliteal segment

Introduction. Autovenous graft is considered the gold standard for prolonged occlusive lesions of the arteries in the femoralpopliteal segment. However, the vein is not always anatomically suitable for bypass grafting; it may have been previously used in previous operations, for example, in coronary artery bypass grafting. Open surgery is always more traumatic than endovascular surgery. Conventional nitinol stents show unsatisfactory results in the femoral-popliteal position due to the high percentage of reocclusions associated with their breakage during physiological movements in the leg joints. The modified method of making interwoven nitinol stents allows improving their biomimetic properties and reducing the percentage of breakages and, accordingly, reocclusions.Material and Methods. There was a retrospective analysis of 437 patients with prolonged atherosclerotic occlusive lesion in the femoropopliteal segment (&gt; 20 cm). There were two groups: a group of bypass surgery and a group of endovascular intervention. The pseudo-randomization method of propensity score matching was used to align the groups according to various criteria.Results. Primary and secondary patency rates for one- and two-year follow up were comparable between the two groups. A subgroup analysis of above-knee intervention showed that a two-year secondary patency rate was significantly higher in the endovascular intervention group than in the bypass group (90.9% vs. 77.5%, p = 0.048). The subgroup analysis of interventions below the knee joint showed that the patency rates at two years of primary and primary-assisted patency were significantly higher in the endovascular intervention group than in the bypass group with an artificial expanded polytetrafluoroethylene (ePTFE) graft (66.7% versus 42.4%, p = 0.046 and 76.7% versus 45.5%, p = 0.011, respectively). The autovenous graft showed better results for primary patency compared with the endovascular intervention group, but the difference was statistically insignificant (77.2% versus 66.7%, respectively, p = 0.3).Conclusion. The analysis of obtained results suggests that the primary endovascular strategy may be recommended for all prolonged occlusive lesions of the femoropopliteal segment above the knee joint gap. For lesions below the knee joint, the autovenous bypass grafting remains the operation of choice, but in the absence of a suitable autovenous graft, the primary endovascular strategy may also be recommended. Additional large multicenter randomized trials are required to refine these recommendations.