Management of cephalic arch stenosis in hemodialysis access: Updated systematic review and meta-analysis.

INTRODUCTION: Cephalic arch stenosis (CAS) is often recurrent, resistant to treatment and the intervention outcome is not well validated so far. We purposed to assess the clinical outcomes of CAS treatment in patients with hemodialysis access. METHODS: Electronic bibliographic sources were searched up to December 4 2023 to identify studies reported outcome after treating CAS. Direct and indirect evidence was combined to compare odds ratios (OR) and surfaces under the cumulative ranking curves across the different treatment modalities through meta-analysis and network meta-analyses (NMA). This systematic review was conducted in accordance with the PRISMA-P. The review is registered in PROSPERO (CRD42022296513). RESULTS: Four randomized controlled trials (RCTs) and 15 non-RCTs were included in the analysis. The study population differed in fistula type, restenosis or thrombosis, and significant heterogeneity was observed among the publications. The risk of bias was low to serious. Meta-analysis found no significant difference between DCB and PTA in primary patency at 6 and 12 months (OR 1.16 and 0.60, respectively; low certainty of evidence). Favorable result with STG compared to stent or PTA at 3, 6, and 12 month was observed (OR 4.28, 5.13, and 13.12, and 4.28, 5.13, 13.12, respectively; low certainty of evidence). Regarding primary patency, the treatment rankings, from highest to lowest, were STG (92.7%), transposition (76.0%), stent (67.5%), DCB (46.3%), and PTA (64.5%) at 12 months. CONCLUSION: Despite data limitations, the low-quality evidence suggests that STG may merit consideration as a primary treatment option when all alternatives are applicable, given their potential for better primary patency and higher treatment ranking.

Efficiency and safety of microvascular anastomotic coupler for wrist revascularization in traumatic injuries.

Introduction: Effective vascular anastomosis is crucial for successful hand surgery, particularly in traumatic injuries where rapid restoration of blood flow is essential. The Synovis microvascular anastomotic coupler system presents a novel approach by potentially offering faster and more reliable outcomes than traditional suturing methods. This study was conducted to assess the effectiveness and safety of the Synovis coupler for microvascular anastomoses in the wrist, evaluating anastomosis time, patency rates, and complication rates. Methods: This retrospective study examined 25 microvascular anastomoses (22 arteries and 3 veins) in 24 patients at a major trauma center. The primary outcomes measured were anastomosis time and vascular patency, which were assessed immediately post-operation and at subsequent follow-ups. Results: The average time required for anastomosis using the coupler was 7.3 min. Immediate post-operative vascular patency was 100%, with a long-term patency rate of 88%. Complications included arterial narrowing at the coupler site in 3 arteries, and complete occlusion in 3 arteries, accounting for a 12% long-term complication rate. Conclusion: Although the Synovis coupler demonstrated a significant reduction in anastomosis time and high patency rates, our data suggest that its effectiveness is more pronounced in venous anastomoses. The higher complication rates in arterial anastomoses warrant cautious use in these cases. Further research, including prospective randomized controlled trials, is needed to validate these findings and optimize patient selection criteria for using couplers in microvascular surgery.

A Systematic Review and Meta-analysis of 24 Month Patency After Endovenous Stenting of Superior Vena Cava, Subclavian, and Brachiocephalic Vein Stenosis.

OBJECTIVE: This systematic review and meta-analysis aimed to appraise recent evidence assessing patency outcomes at various time points in patients with superior vena cava, subclavian, and brachiocephalic vein stenosis who had undergone stenting. DATA SOURCES: PubMed, Scopus, and Cochrane Library databases were searched for studies up to December 2022. REVIEW METHODS: Measured outcomes included technical success rate, primary, primary assisted, and secondary patency at various time points. A subgroup analysis was also conducted to compare malignant and benign obstruction. GRADE was used to assess the certainty of evidence. RESULTS: Thirty nine studies reporting outcomes in 1 539 patients were included in the meta-analysis. Primary patency up to one year after the procedure was 81.5% (95% CI 74.5 - 86.9%). Primary patency declined after one year to 63.2% (95% CI 51.9 - 73.1%) at 12 - 24 months. Primary assisted patency and secondary patency at ≥ 24 months were 72.7% (95% CI 49.1 - 88.0%) and 76.6% (95% CI 51.1 - 91.1%). In the subgroup analysis, primary patency was significantly higher in patients with a malignant stenosis compared with a benign stenosis at 1 - 3 and 12 - 24 months. No significant difference was seen for pooled secondary patency rates when comparing the malignant and benign subgroups. GRADE analysis determined the certainty of evidence for all outcomes to be very low. CONCLUSION: Stenting is an effective intervention for benign and malignant stenosis of the superior vena cava, subclavian, and brachiocephalic veins. Primary patency rates were good up to one year after the procedure, with 81.5% of stents retaining patency at 6 - 12 months. Patency rates declined after one year, to 63.2% primary and 89.3% secondary patency at 12 - 24 months, showing improved outcomes following re-intervention. High quality evidence is lacking. More research is needed to investigate patency outcomes and the need for surveillance or re-intervention programs.

Assessment of arterial supply to the stomach after bariatric surgery using multidetector CT arteriography.

PURPOSE: To describe residual arterial supply to the stomach after bariatric surgery via a systematic arterial-phase CT assessment approach that can aid in diagnosis and treatment of postoperative complications and facilitate planning for future procedures. METHODS: Arterial-phase CT of 46 patients who underwent Roux-en-Y gastric bypass (RYGB) or sleeve gastrectomy (SG) at 3 academic institutions were retrospectively reviewed to assess patency of left gastric artery (LGA), right gastric artery (RGA), gastroepiploic artery (GEA), and left inferior phrenic artery (LIPA) and presence of gastric perforators. RESULTS: In 25 RYGB and 21 SG patients, mean diameters were LGA 2.2 ± 0.4 mm, RGA 1.6 ± 0.5 mm, and GEA 1.7 ± 0.4 mm. On RYGB scans, all LGAs, RGAs, and 24/25 (96%) of GEAs were identified. Excellent to good patency was seen in 20/25 (80%) LGAs, 21/25 (84%) RGAs, and 23/24 (96%) GEAs. On SG scans, all LGAs, 18/21 (86%) of RGAs, and 20/21 (95%) GEAs were identified. Excellent to good patency was seen in 17/21 (81%) LGAs, 15/18 (83%) RGAs, and 20/20 (100%) GEAs. In terms of gastric perforators, LGA supply was seen on 23/25 (92%) of RYGB and 17/17 (100%) of SG scans. RGA supply was seen on 13/21 (62%) RYGB and 9/18 (50%) SG scans. GEA supply was seen on 19/23 (83%) RYGB scans. No gastric supply via GEA was seen on SG scans. CONCLUSION: In this study, arterial supply to the stomach through the LGA was consistently identified in all RYGB and SG cases, indicating an uncomplicated surgical approach with regard to preserving the LGA. Dedicated CT angiography protocol or catheter-directed angiography is recommended for accurate and comprehensive assessment of the gastric blood supply, particularly before surgical re-intervention.

Outcomes of Cold Stored Saphenous Vein Allografts for Haemodialysis Vascular Access.

OBJECTIVE: The aim of this study was to evaluate the outcomes of cold stored saphenous vein allografts (CSVAs) for haemodialysis vascular access. METHODS: A retrospective, two centre study was conducted between January 2016 and December 2020 of all patients who had CSVA placement for haemodialysis vascular access. Primary, primary assisted, and secondary patency were analysed, as well as procedural complications and re-interventions. RESULTS: One hundred and nine patients (n = 55 women) with a mean age of 67.2 ± 13.6 years, with no options for creating an autogenous arteriovenous fistula, were included in the study. At one year, primary, primary assisted, and secondary patency were 37.6%, 59.0%, and 73.3%, respectively; and at two years 19.9%, 42.5%, and 54.9%, respectively. During a mean follow up period of 26 ± 18 months, five patients (4.6%) had an access infection, with no related death. During the follow up period, 32 patients (29.4%) died and 13 patients (11.9%) underwent a kidney transplant. None of these patients showed immunoconversion before transplantation. The cumulative incidence of adverse events by the Fine-Gray method was calculated. Considering competing risks (death and renal transplantation), 9.2% of patients lost their vascular access at one year and 18% at two years. Moreover, 57.8% patients had stenosis, mainly on the outflow (45.9%), and 49.5% had thrombosis. CONCLUSION: With a comparable patency rate associated with a low infection rate, CSVA offers a potential alternative to expanded polytetrafluoroethylene grafts. This creates haemodialysis vascular access when the venous capital is exhausted in patients with reported risk factors for vascular access infection, i.e., insertion in the thigh, advanced age, diabetes mellitus, immunocompromised state, obesity, or revision of an infected prosthetic graft.

Ultra-high-resolution photon-counting detector CT in evaluating coronary stent patency: a comparison to invasive coronary angiography.

OBJECTIVES: To determine the diagnostic accuracy of ultra-high-resolution photon-counting detector CT angiography (UHR PCD-CTA) for evaluating coronary stent patency compared to invasive coronary angiography (ICA). METHODS: Consecutive, clinically referred patients with prior coronary stent implantation were prospectively enrolled between August 2022 and March 2023 and underwent UHR PCD-CTA (collimation, 120 × 0.2 mm). Two radiologists independently analyzed image quality of the in-stent lumen using a 5-point Likert scale, ranging from 1 ("excellent") to 5 ("non-diagnostic"), and assessed all coronary stents for the presence of in-stent stenosis (≥ 50% lumen narrowing). The diagnostic accuracy of UHR PCD-CTA was determined, with ICA serving as the standard of reference. RESULTS: A total of 44 coronary stents in 18 participants (mean age, 83 years ± 6 [standard deviation]; 12 women) were included in the analysis. In 3/44 stents, both readers described image quality as non-diagnostic, whereas reader 2 noted a fourth stent to have non-diagnostic image quality. In comparison to ICA, UHR PCD-CTA demonstrated a sensitivity, specificity, and accuracy of 100% (95% CI [confidence interval] 47.8, 100), 92.3% (95% CI 79.1, 98.4), and 93.2% (95% CI 81.3, 98.6) for reader 1 and 100% (95% CI 47.8, 100), 87.2% (95% CI 72.6, 95.7), and 88.6% (95% CI 75.4, 96.2) for reader 2, respectively. Both readers observed a 100% negative predictive value (36/36 stents and 34/34 stents). Stent patency inter-reader agreement was 90.1%, corresponding to a substantial Cohen's kappa value of 0.72. CONCLUSIONS: UHR PCD-CTA enables non-invasive assessment of coronary stent patency with high image quality and diagnostic accuracy. CLINICAL RELEVANCE STATEMENT: Ultra-high-resolution photon-counting detector CT angiography represents a reliable and non-invasive method for assessing coronary stent patency. Its high negative predictive value makes it a promising alternative over invasive coronary angiography for the rule-out of in-stent stenosis. KEY POINTS: • CT-based evaluation of coronary stent patency is limited by stent-induced artifacts and spatial resolution. • Ultra-high-resolution photon-counting detector CT accurately evaluates coronary stent patency compared to invasive coronary angiography. • Photon-counting detector CT represents a promising method for the non-invasive rule-out of in-stent stenosis.

Chronic inflammatory diseases increase the risk of post-thrombotic syndrome: A prospective cohort study.

BACKGROUND: Clinical management of patients with deep vein thrombosis (DVT) is centered around their risk of recurrent venous thromboembolism (VTE) and post-thrombotic syndrome (PTS). While chronic inflammatory disease (CID) has been established as a risk factor of (recurrent) VTE, research about its potential impact on PTS is lacking. OBJECTIVES: We aimed to assess the risk of PTS in patients with CID, stratifying for the use of anti-inflammatory treatment. PATIENTS/METHODS: Consecutive patients with proximal DVT and no active cancer between 2003 and 2018 received a two-year prospective follow-up. CID included inflammatory bowel disease, rheumatic diseases, and gout. Residual venous obstruction (RVO) was assessed by compressive ultrasound after 3-6 months. PTS was diagnosed using the Villalta score after 6-24 months. Hazard ratios (HR) and odds ratios (OR) were adjusted for patient characteristics. The medical ethics committee approved this study. RESULTS: In total 82 of 801 patients had CID (10.2 %). PTS more often developed in patients with CID (35.4% vs. 18.9 %, p < 0.001) than in those without CID (HR 1.72 [1.15-2.58]). The prevalence of RVO was similar in patients with and without CID (36.8% vs. 41.4 %), and RVO was strongly associated with PTS in patients with CID (OR 3.21 [1.14-9.03]). Moreover, patients with untreated CID (44 %, n = 36) more often had RVO than those with treated CID (51.6% vs. 26.7 %, p = 0.027), and accordingly had a higher risk of PTS (HR 2.18 [1.04-4.58]). CONCLUSIONS: Patients with CID had an increased risk of developing PTS, especially those without anti-inflammatory treatment, possibly due to an unfavorable impact on RVO-related venous pathology.

Ilio-femoral venous stenting for post-thrombotic syndrome in women of childbearing age: efficacy and impact of pregnancy-a multi-center study by the French Society of Cardiovascular Imaging.

OBJECTIVE: We investigated the efficacy of iliofemoral venous stenting in women of childbearing age treated for post-thrombotic syndrome (PTS) and assessed the influence of pregnancy on stent occlusion. METHODS: A retrospective analysis was conducted on women of childbearing age who underwent endovascular stenting for PTS due to chronic iliocava occlusion across 15 centers from 2009 to 2020. The study assessed pregnancy rates, primary patency rates, secondary patency rates, and clinical efficacy using the Villalta score for PTS severity and the Chronic Venous Disease Quality of Life Questionnaire - version 20 (CIVIQ-20), 6-12 months after the procedure. The impact of pregnancy on stent occlusion was analyzed using classical and multi-state survival analyses. Prophylactic low-molecular-weight heparin or fondaparinux was administered to patients during pregnancy until 6 weeks post-partum. RESULTS: In total, 211 women with PTS underwent endovascular stenting, with a median age of 31 years (range: 16-42). Following recanalization, significant improvements were observed in the Villalta score (p < 0.0001) and the CIVIQ-20 score (p < 0.0001). Thirty-seven (17.6%) women became pregnant and 49 (23.2%) experienced stent occlusions. The 1-year and 5-year occlusion-free survival probabilities were 80.6% (95% confidence interval [CI]: 75.1-86.4%) and 66.6% (95% CI: 57.4-77.4%), respectively. There was no significant association between pregnancy and stent occlusion-free survival (hazard ratio = 1.00 [95% CI: 0.11-8.92], p = 0.9930). CONCLUSION: Iliofemoral venous stenting in women of childbearing age was an effective treatment for post-thrombotic syndrome, and it did not increase the risk for stent occlusion during pregnancy when accompanied by appropriate anticoagulation. CLINICAL RELEVANCE STATEMENT: This study demonstrates that pregnancy following iliofemoral venous stenting for post-thrombotic syndrome does not elevate the risk for stent occlusion. KEY POINTS: • The severity of post-thrombotic syndrome and the quality of life, as measured using the Villalta score and Chronic Venous Disease Quality of Life Questionnaire - version 20, respectively, showed significant improvements 6-12 months after iliofemoral venous stenting. • The occurrence of pregnancy after recanalization in women of childbearing age did not lead to a significant increase in the risk for stent occlusion.

A collaborative model between dialysis clinics and a hospital center improves the quality of vascular access care and intervention for hemodialysis patients.

BACKGROUND: This study reports the outcomes of a collaborative program between dialysis clinics and a referral hospital, which consisted of clinical monitoring and supplementary routine surveillance, for improving the quality of vascular access care. METHODS: This retrospective observational study was performed at five dialysis clinics as part of a 2-year collaborative program (2019-2020) in conjunction with a hospital-based dialysis access management center. A total of 392 hemodialysis patients (arteriovenous fistula [AVF], n = 339 and arteriovenous graft [AVG], n = 53) were included. Outcome measures included the prognosis of vascular access, clinic satisfaction, and referral rate to the hospital. RESULTS: Increased vascular access flow was observed and critical flow events decreased from the first to the second year (AVF: 18.3% vs. 12.7%, p < 0.001; AVG: 26.2% vs. 20.1%, p = 0.30). There were fewer percutaneous transluminal angioplasty events in the AVG group (0.77 per person-year vs. 0.51 per person-year, p = 0.005). New AVF or AVG creation events also remained low. All dialysis clinics were satisfied with the program. The overall referral rate from the participating clinics increased (65.7% vs. 72.0%) during the study period independently of the physical distance between the dialysis clinic and the hospital. CONCLUSION: The collaboration between dialysis clinics and a referral hospital for improving the quality of vascular access care was successful in this study, and the model can be used by other clinics and hospitals looking to improve care coordination in dialysis patients.

Comparison between canine and porcine models of chronic deep venous thrombosis.

OBJECTIVE: To first induce chronic deep venous thrombosis in the left iliac veins of canines and porcines and then compare these two models to validate endovascular treatment devices. METHODS: Thrombin and fibrinogen were used to produce a solid thrombus in the left iliac veins of a stenosis model. The researchers used venous angiography and histological staining to investigate the progression of thrombosis. RESULTS: A left iliac vein thrombus was successfully formed in all experimental animals, including six Labrador dogs and three Bama miniature pigs, and there was minimal surgical bleeding. All dogs survived until 90 days, and three pigs died on Days 29, 33, and 58. CONCLUSION: The researchers first established the models and then observed the progression of chronic deep venous thrombosis of the iliac vein in large animals for up to 90 days. Dogs are better suited for chronic deep venous thrombosis models due to their uncomplicated anatomy, excellent obedience, and proneness to physical activity compared with pigs.

Prognostic Factors for Restenosis of Superficial Femoral Artery after Endovascular Treatment.

High incidence of superficial femoral artery (SFA) restenosis after percutaneous transluminal angioplasty (PTA) poses a persistent challenge in peripheral arterial disease (PAD) treatment. We studied how the patients' and lesions' characteristics, thrombin generation, overall haemostatic potential (OHP), and single nucleotide polymorphisms (SNPs) of the NR4A2 and PECAM1 genes affected the likelihood of restenosis. In total, 206 consecutive PAD patients with limiting intermittent claudication due to SFA stenosis who were treated with balloon angioplasty with bailout stenting when necessary were included. Patients' clinical status and patency of the treated arterial segment on ultrasound examination were assessed 1, 6, and 12 months after the procedure. Restenosis occurred in 45% of patients, with less than 20% of all patients experiencing symptoms. In the multivariate analysis, predictors of restenosis proved to be poor infrapopliteal runoff, higher lesion complexity, absence of treated arterial hypertension, delayed lag phase in thrombin generation, and higher contribution of plasma extracellular vesicles to thrombin concentration. Poor infrapopliteal runoff increased the risk of restenosis in the first 6 months, but not later. The negative effect of poor infrapopliteal runoff on SFA patency opens questions about the potential benefits of simultaneous revascularisation of below-knee arteries along with SFA revascularisation.

Stent Graft vs Drug-Coated Balloon in Endovascular Treatment of Complex Femoropopliteal Artery Lesions: A 2-Center Experience.

OBJECTIVE: Both stent grafts (SG) and drug-coated balloons (DCBs) have shown to be effective treatments for long and complex femoropopliteal (FP) lesions. However, there has not been a clinical trial comparing the 2 treatments directly. This study aims to compare the primary patency (PP) and clinical outcomes of SG and DCB for endovascular treatment of complex FP Trans-Atlantic Inter-Society Consensus (TASC) C/D lesions in patients. METHODS: From July 2013 to May 2019, a retrospective study was conducted at 2 medical centers to compare the clinical outcomes of Viabahn SG and DCB angioplasty in patients with TASC C/D FP lesions. The study used overlap weighting to adjust for differences in baseline characteristics and to reduce the impact of confounding factors and selection bias between the 2 groups. The primary endpoint was PP through 24 months, and the secondary endpoints included freedom from clinical-driven target lesion revascularization (CD-TLR), all-cause of death rate, and major amputation rate. RESULTS: A total of 161 limbs in 150 patients with TASC C/D FP lesions were treated either with Viabahn SGs (67 limbs, 65 patients) or DCBs (94 limbs, 85 patients). In the DCB group, 22 target vessels (23.4%) underwent directional atherectomy before DCB angioplasty and 37 target vessels (39.4%) underwent bail-out bare-metal stent implantation for early recoil or severe dissection. The SG group had significantly higher PP rates at both the 12 and 24 months than in the DCB group (75.8% vs 39.2%, p=0.02; 64.1% vs 31.9%, p=0.02), respectively. However, there were no significant differences between the 2 groups in terms of CD-TLR, death rate, and major amputation rate. According to the results of multivariate analysis, DCB angioplasty was the only independent predictor associated with restenosis (hazard ratio [HR]=0.264, 95% confidence interval [CI]=0.100-0.696, p=0.007). CONCLUSIONS: This study showed that SG was associated with a significantly higher PP rate in complex long FP lesions compared with DCB angioplasty. However, there was no significant difference in the freedom from CD-TLR and major amputation rate. It is important to follow the criteria for using SG strictly to avoid early restenosis, which can lead to acute thrombosis and severe limb ischemia. Closer monitoring is recommended for patients who undergo SG implantation. CLINICAL IMPACT: There has no head-to-head clinical trial that compares DCB and SG in complex long FP lesions. This study showed that SG following the criteria was associated with a significantly higher PP rate compared with DCB angioplasty. Closer monitoring is recommended for patients with SG to avoid acute thrombosis. Randomized controlled trials comparing SG and DCB are necessary.

Long Term Follow Up, Causes for Re-intervention, and Consequences for Surveillance After Stenting for Proximal Deep Vein Obstruction.

OBJECTIVE: Venous stenting is performed increasingly for acute deep vein thrombosis (DVT) and post-thrombotic syndrome (PTS) with good short term patency results, but long term data are scarce. The purpose of this study was to evaluate long term outcome of stenting for acute DVT and PTS and to study causes of re-intervention. METHODS: All patients stented for acute DVT and PTS between May 2006 and November 2021 were included retrospectively in this single centre cohort study. Patency was studied by duplex ultrasound (DUS) or computed tomography. The primary endpoint was stent patency. Re-intervention free survival was calculated using Kaplan-Meier methods. Secondary endpoints were causes of re-intervention, using the Pouncey classification system (2022). Binary logistic regression was used to calculate odds ratios for predictors of re-intervention. RESULTS: A total of 114 patients were included, with 129 limbs involved (acute DVT n = 53; 41%), PTS n = 76; 59%). Median follow up was 2.3 years (interquartile range [IQR] 2.3) for acute DVT and 5.2 years (IQR 7.1) for PTS. Primary patency, secondary patency, and permanent occlusion were 73.5%, 98.1%, and 1.9% for acute DVT, and 63.2%, 92.1%, and 7.9% for PTS limbs. Overall, 41 limbs underwent at least one re-intervention: 14 in the acute DVT group and 27 for PTS. Most re-interventions (82.9%) were performed within the first year after stenting. Missed inflow, insufficient flow, and thrombosis despite anticoagulation were the most common causes of re-intervention. The strongest predictor for re-intervention for PTS was inflow disease (odds ratio 3.57, 95% confidence interval 1.26 - 10.13, p= .017). CONCLUSION: Long term patency of deep venous stenting is good. Re-interventions are typically performed in the first year and are potentially preventable by improving the procedure and patient selection. Since secondary patency rates are excellent, selected patients may be considered for discharge from long term surveillance.

Long-Term Results of Femorodistal Sequential Composite-Bypass Combining Heparin-Bonded PTFE-Prosthesis and Autologous Vein Using the Deutsch Bridge Technique in Critical Limb-Threatening Ischemia.

BACKGROUND: Autologous vein bypass provides excellent long-term results in critical limb-threatening ischemia (CLTI), but a substantial portion of patients have insufficient vein length. In limbs with two distal outflow vessels and limited vein length, a vascular prosthesis may be combined with autologous vein for a sequential composite bridge bypass (SCBB). Results regarding graft function, limb salvage and reinterventions are presented. METHODS: Between January 2010 and December 2019, 47 consecutive SCBB operations with a heparin-bonded PTFE-prosthesis and autologous vein were performed. Grafts were followed with a duplex scan with prospective documentation in a computerized vascular database. Retrospective analysis of graft patency, limb salvage and patient survival was performed. RESULTS: Mean follow-up was 34 months (range 1-127 months). 30-day mortality was 10.6% and 5-year patient survival 32%. Postoperative bypass occlusion occurred in 6.4% and late occlusions or graft stenoses in 30%. Two prostheses developed late infection and seven legs were amputated. Primary, primary assisted, secondary patency and limb salvage rate were 54%, 63%, 66% and 85% after 5 years, respectively. CONCLUSIONS: SCBB patency and limb salvage were good despite a high early postoperative mortality. Combination of a heparin-bonded PTFE-prosthesis and autologous vein appears to be a valuable tool in CLTI in case of insufficient vein.

Bare-Metal Stent in Dysfunctional Hemodialysis Access: An Assessment of Circuit Patency according to Access Type and Stent Location.

Purpose: To evaluate the circuit patency after nitinol bare-metal stent (BMS) placement according to the type of access and location of the stent in dysfunctional hemodialysis access. Materials and Methods: Between January 2017 and December 2019, 159 patients (mean age, 64.1 ± 13.2 years) underwent nitinol BMS placement for dysfunctional access. The location of stents was as follows: 18 brachiocephalic vein, 51 cephalic arch, 40 upper arm vein, 10 juxta-anastomotic vein, 7 arteriovenous (AV) anastomosis, and 33 graft-vein (GV) anastomosis. Circuit patency was evaluated by the Kaplan-Meier method, and cox regression model. Results: A total of 159 stents were successfully deployed in 103 AV fistula (AVF) and 56 AV graft (AVG). AVG showed lower primary and secondary patency at 12-months compared with AVF (primary patency; 25.0% vs. 44.7%; p = 0.005, secondary patency; 76.8% vs. 92.2%; p = 0.014). Cox regression model demonstrated poorer primary patency at 12 months after stenting in the cephalic arch and GV anastomosis compared with the other sites. Conclusion: AVF showed better primary and secondary circuit patency at 12 months following the placement of BMS compared with AVG. Stents in the cephalic arch and GV anastomosis were associated with poorer primary patency at 12 months compared to those in other locations.

Staged autogenous to prosthetic hemodialysis access creation strategy to maximize forearm options.

OBJECTIVE: When an adequate cephalic vein is not available for fistula construction, surgeons often turn to basilic vein or prosthetic constructions. Single-stage forearm prosthetic hemodialysis accesses are associated with poor durability, and upper arm non-autogenous access options are often limited by axillary outflow failure, which inevitably drives transition to the contralateral arm or lower extremity. We hypothesized that initial creation of a modest flow proximal forearm arterial-venous anastomosis to dilate ("develop") inflow and outflow vessels, followed by a planned second-stage procedure to create a cannulation zone with a prosthetic graft in the forearm, would result in reliable and durable hemodialysis access in patients with limited options. METHODS: We performed an institutional cohort study from 2017 to 2021 using a prospectively maintained database supplemented with adjudicated chart review. Patients without traditional autogenous hemodialysis access options in the forearm underwent an initial non-wrist arterial-venous anastomosis creation in the forearm as a first stage, followed by a second-stage interposition graft sewn to the existing inflow and venous outflow segments to create a useable cannulation zone in the forearm while leveraging vascular development. Outcomes included time from second-stage access creation to loss of primary and secondary patency, frequency of subsequent interventions, and perioperative complications. RESULTS: The cohort included 23 patients; first-stage radial artery-based (74%) configurations were more common than brachial artery-based (26%). Mean age was 63 years (standard deviation, 14 years), and 65% were female. Median follow-up was 340 days (interquartile range [IQR], 169-701 days). Median time to cannulation from second-stage procedure was 28 days (IQR, 18-53 days). Primary, primary assisted, and secondary patency at 1 year was 16.7% (95% confidence interval [CI], 5.3%-45.8%), 34.6% (95% CI, 15.2%-66.2%), and 95.7% (95% CI, 81.3%-99.7%), respectively. Subsequent interventions occurred at a rate of 3.02 (IQR, 1.0-4.97) per person-year, with endovascular thrombectomy with or without angioplasty/stenting (70.9%) being the most common. There were no cases of steal syndrome. Infection occurred in two cases and were managed with antibiotics alone. CONCLUSIONS: For patients without adequate distal autogenous access options, staged prosthetic graft placement in the forearm offers few short-term complications and excellent durability with active surveillance while strategically preserving the upper arm for future constructions.

Influence of crural vessel run-off on short- and mid-term outcomes following femoro-popliteal bypass grafting.

OBJECTIVES: To determine the influence that the number of patent crural run-off vessels has on short- and mid-term outcomes following femoro-popliteal bypass. METHODS: All patients undergoing index femoro-popliteal bypass grafting between 2013 and 19 at our unit were included. Preoperative imaging was used to stratify patients into cohorts with either one or ≥2 patent run-off vessels. Primary outcomes measures included bypass patency and limb salvage rates at one and 3 years post-operatively. Survival analysis was performed using Kaplan-Meier curves and Logrank test. RESULTS: 147 bypasses performed on 143 patients were included. 24 patients had one-vessel run-off and 123 had ≥2 vessels patent. Patients with one-vessel run-off had a higher proportion of emergency admissions (54% vs 41%) and diabetes (42% vs 31%). 31% of patients underwent diagnostic angiogram imaging in addition to having duplex ultrasound and/or computed tomography angiography. There were no significant differences in primary, primary-assisted or secondary patency rates between the cohorts at 12 or 36 months. Limb salvage rates were significantly higher amongst those with ≥2 vessel run-off at 12 (86% vs 71%, p = 0.03) and 36 (85% vs 71%, p = 0.04) months. For those with occluded grafts, a higher proportion of patients with ≥2 vessel run-off subsequently had an attempt at redo bypass grafting. CONCLUSIONS: Femoro-popliteal bypass is a reasonable treatment option for patients with one-vessel run-off. However, whilst patency rates are comparable, clinicians should be aware of the lower successful limb salvage rates for patients with one patent vessel (especially those presenting with tissue loss).

Multicenter Case Series and Literature Review on Durability of Stents in the Thoracic Outlet.

PURPOSE: The aim of this paper was to report our experience with arterial and venous endovascular stent placement in the thoracic outlet (TO) and review available literature. METHODS: All patients that underwent arterial or venous stent placement in the TO between 2013 and 2020 in 5 Dutch vascular teaching-hospitals were retrospectively identified. Primary endpoint was symptomatic stent failure due to stenosis, chronic or posture dependent compression, fracture, or occlusion of the stent. Secondary endpoints were symptoms at last follow-up and re-interventions. For the literature review, we searched studies reporting on stenting in the TO. RESULTS: Twenty-six patients were included with 11 arterial and 15 venous stents implanted to treat angioplasty resistant stenosis in arterial or venous TO syndrome, iatrogenic or traumatic vascular injury, radiotherapy fibrosis, or arterial dissection. Median follow-up was 19 and 14 months in the arterial and venous-group, respectively. Eight (73%) patients in the arterial, and 9 (60%) in the venous-group suffered symptomatic stent failure. Seven (64%) patients in the arterial, and 9 (60%) in the venous-group required at least 1 re-intervention. When comparing all patients with stent placement after TO decompression (TOD) to patients without, there were substantially more symptomatic stent failures and re-interventions required in the patients without TOD. Six patients (54%) in the arterial-group and 11 (73%) in the venous-group were symptom-free at last follow-up. Five articles describing 51 patients with arterial and 6 articles describing 81 patients with venous stents were included in the literature review. In the arterial-group, no TOD prior to stent placement was performed, while in the venous-group all but 1 article performed TOD prior to stent placement. Results showed comparable rates of symptomatic stent failure (24% vs 30%), and patients requiring re-interventions (29% vs 21%) between groups. CONCLUSION: Based on our multicenter series and review, stents in the TO have a considerable risk of failure, both in the venous and the arterial territory. Especially in patients without TOD: the need for re-interventions is high and half the patients eventually undergo TOD. Based on the currently available data, stenting in the TO should be applied cautiously while TOD should be considered.

Criteria to predict midterm outcome after stenting of chronic iliac vein obstructions (PROMISE trial).

BACKGROUND: Endovenous stent placement has become a first-line approach to prevent post-thrombotic syndrome in patients with chronic post-thrombotic obstruction (PTO) or nonthrombotic iliac vein lesions if conservative management fails. This study aims to identify factors associated with loss of patency to facilitate patient selection for endovenous stenting. METHODS: We retrospectively analyzed 108 consecutive patients after successful endovenous stenting for chronic vein obstruction performed at a single institution from January 2008 to July 2020. Using multivariable logistic regression, we explored potential predictive factors for loss of stent patency, including baseline demographics, post-thrombotic changes, and peak flow velocities measured in the common femoral vein (CFV), deep femoral vein, and femoral vein (FV) using duplex ultrasound examination. RESULTS: The mean follow-up duration was 41 ± 26 months, and participants had a mean age of 47.4 ± 15.4 years with 46.3% women. Ninety (83.3%) patients had PTO and 18 (16.7%) had nonthrombotic iliac vein lesions, predominantly due to May-Thurner syndrome. Loss of patency occurred in 20 (18.5%) patients, all treated for PTO. Comorbidities, side of intervention, and sex did not differ between patients with occluded and patent stents. Stent occlusion was more common with increasing number of stents implanted (P < .001) and with distal stent extension into and beyond the CFV (P < .001). Preinterventional predictive factors for stent occlusion were lower duplex ultrasound peak velocity in the CFV (odds ratio [OR]: 7.52, 95% confidence interval [CI]: 2.54-22.28; P < .001) and FV (OR: 10.75, 95% CI: 2.07-55.82; P < .005), and post-thrombotic changes in the deep femoral vein (OR: 4.51, 95% CI: 1.53-13.25; P = .006) and FV (OR: 3.62: 95% CI: 1.11-11.84; P = .033). Peak velocities of ≤7 cm/s (interquartile range: 0-20 cm/s) in the CVF and ≤8 cm/s (interquartile range: 5-10 cm/s) in the FV were significantly associated with loss of patency. CONCLUSIONS: Insufficient venous inflow as assessed by low peak velocities in the CFV and FV as well as post-thrombotic findings represent reliable risk predictors for stent occlusions, warranting their inclusion into the decision-making process for invasive treatment of PTO.