Investigation of operational fundamentals for vacuum-assisted headspace high-capacity solid-phase microextraction and gas chromatographic analysis of semivolatile compounds from a model solid sample.

Vacuum-assisted headspace solid-phase microextraction (Vac-HS-SPME) is a technique used to enhance SPME sampling of semi-volatile organic compounds. Here, it was combined with a high-capacity SPME Arrow, which features a larger volume of extraction phase and a more rugged configuration than traditional extraction fibers. An in-depth assessment of the critical parameters was conducted to achieve optimal extraction of representative compounds from a model solid sample matrix (Ottawa sand). Operational fundamentals investigated included the types of seals needed to create a leak-free environment under vacuum conditions; the magnitude of the vacuum applied and time needed to activate the Vac kinetics; order of sample vial preparation methods (VPMs); and other standard variables associated with extract analysis by gas chromatography-mass spectrometry. When exploring the limits of sample VPMs, results indicated an ideal workflow requires the solid sample to be spiked before sealing the vial, allow the sample to rest overnight, then apply vacuum at a pressure of -677 mbar (out of -789 mbar maximum possible vacuum with pump and compressor used), exerted on the vial for 90 s. This work provides the necessary workflow for the optimization of Vac-HS-SPME sampling of analytes from solid matrices.

Review of the literature supporting international clinical practice guidelines on iliac venous stenting and their applicability to Australia and New Zealand practice.

BACKGROUND: The overall goal of this report is to provide a high-level, practical approach to managing venous outflow obstruction (VOO). METHODS: A group of vascular surgeons from Australia and New Zealand with specific interest, training, and experience in the management of VOO were surveyed to assess current local practices. The results were analyzed and areas of disagreement identified. After this, the group performed a literature review of consensus guidelines published by leading international organizations focused on the management of chronic venous disease, namely, the Society for Vascular Surgery, American Venous Forum, European Society for Vascular Surgery, American Vein and Lymphatic Society, Cardiovascular and Interventional Radiology Society of Europe, and American Heart Association. These guidelines were compared against the consensus statements obtained through the surveys to determine how they relate to Australian and New Zealand practice. In addition, selected key studies, reviews, and meta-analyses on venous stenting were discussed and added to the document. A selection of statements with >75% agreement was voted on, and barriers to the guideline's applicability were identified. The final recommendations were further reviewed and endorsed by another group of venous experts. RESULTS: The document addresses two key areas: patient selection and technical aspects of venous stenting. Regarding patient selection, patients with clinically relevant VOO, a Clinical-Etiologic-Anatomic-Physiologic score of ≥3 or a Venous Clinical Severity Score for pain of ≥2, or both, including venous claudication, with evidence of >50% stenosis should be considered for venous stenting (Level of Recommendation Ib). Patients with chronic pelvic pain, deep dyspareunia, postcoital pain affecting their quality of life, when other causes have been ruled out, should also be considered for venous stenting (Level of Recommendation Ic). Asymptomatic patients should not be offered venous stenting (Level of Recommendation IIIc). Patients undergoing thrombus removal for acute iliofemoral deep vein thrombosis, in whom a culprit stenotic lesion of >50% has been uncovered, should be considered for venous stenting (Level of Recommendation Ib). CONCLUSIONS: Patients with VOO have been underdiagnosed and undertreated for decades; however, in recent years, interest from physicians and industry has grown substantially. International guidelines aimed at developing standards of care to avoid undertreating and overtreating patients are applicable to Australia and New Zealand practice and will serve as an educational platform for future developments.

A Cost-Consequence Analysis Comparing Balloon-Expandable Covered Stents for the Management of Aortoiliac Occlusive Disease.

PURPOSE: To compare procedural and long-term costs associated with the use of Balloon-Expandable Covered Stents (BECS) in the management of Aortoiliac Occlusive Disease (AIOD). MATERIALS AND METHODS: A cost-consequence model was developed to simulate the intra- and post-operative management of patients with AIOD from the perspective of private health-payers. The study assessed the costs of the LifeStream (BD, Franklin Lakes, New Jersey), iCAST/Advanta V12 (Getinge, Goteborg, Sweden), BeGraft Peripheral (Bentley, Hechingen, Germany), and Viabahn Balloon Expandable (VBX) (W.L. Gore, Flagstaff, Arizona) BECS devices. Device costs were identified from the Australian Prosthesis List, whereas clinical outcomes of BECS were estimated from a systematic review of the literature. Costs were calculated over 24 and 36 month time horizons and reported in US dollars. RESULTS: Long-term, per-patient cost of each device at 24 and 36 months was $6253/$6634 for the LifeStream; $6359/$6869 for the iCAST/Advanta V12; $4806 (data available to 24 months) for the BeGraft Peripheral; and $4839/$5046 for the Viabahn VBX, respectively. Most of the cost difference was attributed to the number of stents required per treated limb and frequency of clinically-driven target lesion revascularization events. CONCLUSIONS: Best-available clinical evidence and economic modeling demonstrates that the BeGraft Peripheral and Viabahn VBX were of similar cost and the least costly options at 24 months, whereas at 36 months, the lowest cost BECS option for the treatment of AIOD was the Viabahn VBX. CLINICAL IMPACT: This analysis supports economically informed decision-making for health-payers managing systems that care for patients with AIOD. Stent length and avoiding reintervention were identified as key areas of cost-saving for future BECS development.

Stenosis to stented: decrease in flow disturbances following stent implantation of a diseased arteriovenous fistula.

The arteriovenous fistula (AVF) is commonly faced with stenosis at the juxta-anastomotic (JXA) region of the vein. Implantation of a flexible nitinol stent across the stenosed JXA has led to the retention of functioning AVFs leading to the resulting AVF geometry being distinctly altered, thereby affecting the haemodynamic environment within it. In this study, large eddy simulations of the flow field within a patient-specific AVF geometry before and after stent implantation were conducted to detail the change in flow features. Although the diseased AVF had much lower flow rates, adverse flow features, such as recirculation zones and swirling flow at the anastomosis, and jet flow at the stenosis site were present. Larger velocity fluctuations (leading to higher turbulent kinetic energy) stemming from these flow features were apparent in the diseased AVF compared to the stented AVF. The unsteadiness at the stenosis created large regions of wall shear stress (WSS) fluctuations downstream of the stenosis site that were not as apparent in the stented AVF geometry. The larger pressure drop across the diseased vein, compared to the stented vein, was primarily caused by the constriction at the stenosis, potentially causing the lower flow rate. Furthermore, the WSS fluctuations in the diseased AVF could lead to further disease progression downstream of the stenosis. The change in bulk flow unsteadiness, pressure drop, and WSS behaviour confirms that the haemodynamic environment of the diseased AVF has substantially improved following the flexible stent implantation.

Robotic tomographic ultrasound and artificial intelligence for management of haemodialysis arteriovenous fistulae.

BACKGROUND: Arteriovenous fistulae (AVF) and Arteriovenous Grafts (AVG) may present a problematic vascular access for renal replacement therapy (RRT), reliant on recurrent specialist nurse and medical evaluation. Dysfunctional accesses are frequently referred 'out of the dialysis clinic' for specialist sonographic examination, with associated delays potentiating loss of vascular access viability and/or need for emergency intervention. Definitive anatomical and functional diagnostics based in the dialysis unit may help to solve these delays and associated complications. OBJECTIVES: This publication reports a novel vascular access monitoring concept, Robotic Tomographic Ultrasound (RTU). RESEARCH DESIGN: Robotic Tomographic Ultrasound incorporates a semi-autonomous, robotic vascular ultrasound system and purpose designed analysis software that can be deployed at the point of care. Three-dimensional scan data, as well as conventional B-Mode and Doppler data are obtained by the system and transferred to a cloud based reporting and analysis software. Scans are remotely annotated and interpreted by a sonographer, with diagnostic data presented securely to clinicians on their preferred web based application/web connected device. RESULTS: Software developed specifically for pre AVF mapping, maturation and monitoring protocols, analyse the data and then present interpreted results to all caring clinicians to assist with decision making. Vascular access planning can be determined with high confidence with data from the Map module. Maturation data can be presented in line with institutional requirements to the dialysis nurse, facilitating precocious needle access. CONCLUSION: Robotic Tomographic Ultrasound is a novel approach to vascular access management that may reduce the risk of loss of functional access by regular monitoring with the system; automated alerts guiding clinicians to the need for pre-emptive intervention, and the potential to increase longevity of the vascular access.

A sex-based analysis of 5-year outcomes following stenting for the treatment of aorto-iliac occlusive disease.

OBJECTIVES: The aim of this study was to evaluate the impact of sex on mid-term outcomes following stenting for aorto-iliac occlusive disease (AIOD). METHODS: The Covered versus Balloon Expandable Stent Trial (COBEST) compared the safety and efficacy of the covered stent (CS) with those of the bare metal stent (BMS) in the treatment of hemodynamically significant AIOD. It was identified that CS provided a significant benefit. The primary endpoint of our analysis was the rate of primary patency 5 years following stenting for AIOD (inclusive of both CS and BMS) in both sexes. RESULTS: Of the 168 lesions treated, 103 (61%) were present in men and 65 (39%) were present in women. Of the concomitant comorbidities, diabetes mellitus was significantly more common in women (17.5% vs 41.5%, p = .006). Although chronic limb threatening ischemia (CLTI) at the time of intervention was more common in women, the difference was not significant (16.5% vs 24.6%, p = .395). Sex was not associated with the primary patency rate (male; 0.70, 95% confidence interval [CI]: 0.23-2.19, p = .543). When considering both male sex and the utilization of BMS, no significant impact was found on the primary patency rate (hazard ratio [HR]: 3.43, 95% CI: 0.69-17.10, p = .133). All-cause mortality at 60 months was 22.6% in men compared to 19.4% in women (p = .695). CONCLUSIONS: No significant difference was identified in the primary patency rate between the sexes. Further investigation is warranted to ascertain whether sex-specific interventional guidelines are required in this regard.

RETRACTED: Australian and New Zealand Society for Vascular Surgery clinical practice guidelines on venous outflow Obstruction of the femoral-iliocaval veins.

BACKGROUND: The overall goal of this report is to provide a high-level, practical approach to managing venous outflow obstruction (VOO) in Australia and New Zealand. METHODS: A group of vascular surgeons from the Australian and New Zealand Society for Vascular Surgery with specific interest, training, and experience in the management of VOO were surveyed to assess current local practice. The results were analyzed and areas of disagreement identified. Following this, the group performed a literature review of consensus guidelines published by leading international organizations focused on the management of chronic venous disease, namely the Society for Vascular Surgery, American Venous Forum, European Society for Vascular Surgery, American Vein and Lymphatic Society, Cardiovascular and Interventional Radiology Society of Europe, and American Heart Association. These guidelines were compared against the consensus statements obtained through the surveys to determine how they relate to Australian and New Zealand practice. In addition, selected key studies, reviews, and meta-analyses on venous stenting were discussed and added to the document. Finally, a selection of statements with >75% agreement was voted on, and barriers to the guideline's applicability were identified. RESULTS: The document addresses two key areas: patient selection and technical aspects of venous stenting. Regarding patient selection, patients with a CEAP (Clinical-Etiologic-Anatomic-Physiologic) score of ≥3 or a venous clinical severity score for pain of ≥2, or both, and evidence of >50% stenosis on venography, computed tomography venography, magnetic resonance venography, and/or intravascular ultrasound should be considered for venous stenting (level of recommendation Ib) Patients undergoing thrombus removal for acute iliofemoral deep vein thrombosis, in whom a culprit stenotic lesion has been uncovered, should be considered for venous stenting (level of recommendation Ib). Patients with chronic pelvic pain, deep dyspareunia, postcoital pain affecting their quality of life, when other causes have been ruled out, should be considered for venous stenting (level of recommendation Ic). Asymptomatic patients should not be offered venous stenting (level of recommendation IIIc). CONCLUSIONS: Patients with deep VOO have been underdiagnosed and undertreated for decades; however, in recent years, interest from physicians and industry has grown substantially. The advent of simpler and safer treatment options has revolutionized its management, but, unfortunately, formal training for venous disease has not grown at the same rate. Simplifying the technology and training required can result in inconsistent outcomes. These guidelines are aimed at developing standards of care and will serve as an educational platform for future developments.

Solid phase extraction as sample pretreatment method for top-down quantitative analysis of low molecular weight proteins from biological samples using liquid chromatography - triple quadrupole mass spectrometry.

Targeting and quantifying intact proteins from biological samples is still a very challenging research area. Several crucial steps exist in the analytical workflow, including development of a reliable sample preparation method. Here, we developed and applied for the first time a non-immunoaffinity sample preparation method based on a generally widely available micro-elution solid phase extraction (µSPE) strategy for the extraction of multiple lower molecular weight intact proteins (<30 kDa) from various biological matrices. Omission of a time-consuming drying and reconstitution step after extraction resulted in a more simple and rapid sample preparation procedure. A model set of eleven intact proteins (molecular weights: 5.5-29 kDa; isoelectric points: 4.5-11.3) were analyzed in multiple biological fluids using reversed-phase liquid chromatography with a triple quadrupole mass spectrometer operated in multiple reaction monitoring mode. Various sample pre-treatment reagents, sorbent types, and washing and elution solvents were experimentally tested and optimized to obtain the µSPE clean-up condition for a broad mixture of intact proteins having variable physicochemical properties. 1% trifluoroacetic acid and 0.2% Triton 100-X were selected as suitable sample pre-treatment reagents for releasing protein-protein interactions in human serum/plasma and human urine, respectively. Hydrophilic lipophilic balanced µSPE sorbent was selected as a high performing stationary phase. Addition of 1% trifluoroacetic acid to all washing and elution solutions showed the most beneficial effect for the extraction recovery of the proteins. Under the optimized conditions, reproducible extraction recoveries >65% for all targeted proteins (up to 30 kDa) in human urine and >50% for most of the proteins in serum/plasma were achieved. The selected conditions were applied also for the analysis of clinical serum and urine samples to demonstrate the feasibility of the developed method to target intact proteins directly by more affordable µSPE sample preparation and triple quadrupole mass spectrometry, which could be beneficial in many application fields.

Long-term Results of Interwoven Nitinol Stents to Treat the Radiocephalic Anastomotic Arteriovenous Fistula Stenosis.

INTRODUCTION: Juxta-anastomotic stenosis (JXAS) is a common problem afflicting the arteriovenous fistula (AVF). This study aimed to evaluate the safety and long-term efficacy of an interwoven nitinol stent (Supera, Abbott Vascular, Santa Clara, CA, USA) in the treatment of radiocephalic AVF JXAS. METHODS: A single-center, retrospective, observational study was conducted of patients with failing AVF due to JXAS treated with an interwoven nitinol stent. End points included JXAS target lesion primary patency, access circuit primary patency, assisted access circuit primary patency, and endovascular intervention rate (EIR). RESULTS: Sixty patients were treated with a Supera stent in the JXAS between February 2014 and March 2020. One patient was excluded (AVF used for illicit drug use), leaving 59 patients (67.8% male, mean age 66.9 ± 11.4 years [range: 40-84]) with typical medical comorbidities. Overall, 45.8% of patients had previous AVF intervention. The stent was inserted with a 100% technical success rate with a mean follow-up of 729.6 ± 456.0 days (range: 5-2182 days). Juxta-anastomotic stenosis target lesion primary patency was 68.2 ± 6.6%, 53.3 ± 7.5%, and 46.2 ± 8.1% at 12, 24, and 36 months, respectively. The EIR was .64 (0-3.29) procedures/patient/year, after which the assisted access circuit primary patency rate was 94.3 ± 3.2% at 12, 24, and 36 month time points. Three thrombosed circuits occurred which were all successfully salvaged with no difference in patency by indication for procedure and no AVFs lost/abandoned out to 3 years. Avoidance of stent post-dilatation and the presence of stent mal-apposition were associated with improved primary patency, and reduced EIR, which may suggest an importance in vessel preparation prior to stent implantation. CONCLUSION: Interwoven nitinol stent treatment of the failing AVF with JXAS results in promising 3 year JXAS patency, with a low rate of endovascular re-intervention for those circuits developing restenosis. All AVFs were maintained over 3 years, demonstrating this treatment allows for long-term radiocephalic AVF vascular access.

Arteriovenous fistula formation with adjuvant endovascular maturation.

BACKGROUND: The clinical utility of the native arteriovenous fistula (AVF) has been limited by the prolonged time required for maturation, the low overall maturation rate, and subsequent abandonment. Endovascular intervention has been increasingly accepted as the first-line therapy for AVF stenosis. The objective of the present study was to evaluate the AVF formation outcomes when early endovascular intervention was selectively performed to bring about timely AVF maturation. METHODS: We performed a retrospective study (February 2014 to February 2020) of 82 AVF consecutive patients (mean age, 62.5 ± 13.5 years; range, 17-83; 58 men [70.7%]) with end-stage renal failure who had undergone vascular access construction at a single institution. The 4-year AVF patency, vascular diameters, hemodialysis parameters, reintervention rate, and mortality were analyzed. RESULTS: Radiocephalic AVF was the most common fistula constructed (71 patients; 88.6%). The evaluation at a mean of 46.2 ± 56.0 days (range, 5-343 days) after AVF formation revealed 33 immature AVFs (40.2%). Subsequently, 19 patients had undergone endovascular procedures, including angioplasty and/or stenting of the juxta-anastomosis, cannulation zones, and/or outflow segments to bring about timely maturation of the AVF. Hence, 93.9% of the AVFs had reached functional patency (maturation) by 6 months after formation, with a mean time to maturation of 67.8 ± 65.9 days (range, 5-320 days). After reaching maturation, the primary access functional patency was 82% ± 4.3% at 6 months, 58% ± 5.5% at 12 months, and 34% ± 6.8% at 48 months. The primary assisted access functional patency was 95% ± 2.4% at 6 months, 90% ± 3.3% at 12 months, and 83% ± 4.7% at 48 months. A total of 121 endovascular interventions were performed to maintain patency, equating to an endovascular reintervention rate of 0.37 procedure/patient year. The mean arterial, venous, and brachial flow rates did not change significantly after maturation with a mean AVF (primary assisted functional patency) survival time of 5.9 ± 0.26 years (range, 5.33-6.36 years) from maturation. Only 12 thromboses had occurred after the first follow-up review after AVF formation. These were all salvaged using endovascular techniques, leading to 100% total secondary functional patency at 4 years. The 5-year estimated all-cause mortality was 45.6% ± 12.7%. CONCLUSIONS: The AVF maturation rate and interval to maturation were improved when early endovascular intervention was selectively performed after AVF formation. This allowed for near universal maturation. In addition, once matured, the use of ongoing endovascular reinterventions allowed for a low reintervention rate and long-term patency, providing reliable long-term renal vascular access.

Delphi Consensus Study Toward a Comprehensive Classification System for Angioplasty-Induced Femoropopliteal Dissection: The DISFORM Study.

OBJECTIVES: The aim of this study was to seek expert consensus regarding the features that predict adverse outcomes in order to develop a dedicated angiographic classification system for femoropopliteal artery dissection. BACKGROUND: Dissection of the femoral and popliteal arteries is common after percutaneous angioplasty. Its classification is important. However, all current classification systems have significant limitations. METHODS: Delphi consensus methodology was performed over 3 rounds, using an expert panel of 17 interventionalists. Each was asked to rank dissection features with the potential to lead to acute technical failure and/or early restenosis and then which combination of features would require the placement of a metallic scaffold to avoid those outcomes. Results were used to develop a novel grading system and dissection treatment algorithm. RESULTS: Four main characteristics were identified from a comprehensive preliminary list. There was a good level of agreement between panelists from 773 responses (48 combinations). All panelists recommended scaffolding if a dissection produced a ≥50% diameter reduction (100%). Most recommended scaffolding if the dissection had a spiral shape (73%-100%), was severely flow limiting (93%-100%), or had complex morphology defined by long and multiple dissections (65%-100%). Multiple combinations of those features were more likely to receive a recommendation to scaffold. CONCLUSIONS: Scaffolding of a postangioplasty dissection is recommended in the presence of significant diameter reduction, spiral shape, flow impairment, or adverse morphology (DISFORM). The DISFORM classification system has been developed as a tool to provide uniform language to standardize reporting and for discussion of dissection treatment and prognosis.

Infective thrombophlebitis after great saphenous vein cyanoacrylate embolization.

The use of cyanoacrylate embolization has increased in interest as a safe, effective, and minimally invasive method to treat symptomatic saphenous reflux. The procedure is generally well tolerated by patients, and complications such as phlebitis are minor and usually self-limiting. Postprocedural infections have been described but occur infrequently and usually in the early postoperative course. In the present case report, we have described a late-onset infective thrombophlebitis of the great saphenous vein after cyanoacrylate embolization, requiring surgical excision of the treated vein.

Mortality Rates After Paclitaxel-Coated Device Use in Patients With Occlusive Femoropopliteal Disease: An Updated Systematic Review and Meta-Analysis of Randomized Controlled Trials.

PURPOSE: A late increased mortality risk has been reported in a summary level meta-analysis of patients with femoropopliteal artery occlusive disease treated with paclitaxel-coated angioplasty balloons and stents. However, at the longer follow up timepoints that analysis was limited by small trial numbers and few participants. The aim of this study was to report an updated summary level risk of all-cause mortality after treatment with paclitaxel-coated devices in that same patient group. MATERIALS AND METHODS: We performed a systematic review and meta-analysis of randomized controlled trials to investigate the mortality outcomes associated with paclitaxel-coated devices used to treat patients with occlusive disease of femoropopliteal arteries (last search date December 10, 2020). The single primary endpoint was all-cause mortality. RESULTS: We identified 34 randomized controlled trials (7654 patients; 84% intermittent claudication). There were 622 deaths among 4147 (15.0%) subjects in the paclitaxel device group and 475 deaths among 3507 (13.5%) subjects in the noncoated control group [relative risk ratio (RR) 1.07, 95% confidence interval (CI) 0.96 to 1.20, p=0.20, I2=0%). All-cause mortality was similar between groups at 12 months (34 studies, 7654 patients; RR 0.99, 95% CI 0.81 to 1.22, p=0.94, I2=0%), 24 months (20 studies, 3799 patients; RR 1.16, 95% CI 0.87 to 1.55, p=0.31, I2=0%), and 60 months (9 studies, 2288 patients; RR 1.19, 95% CI 0.98 to 1.45, p=0.08, I2=0%). CONCLUSION: This updated meta-analysis with included additional trials and larger patient numbers shows no evidence of increased risk of all-cause mortality in patients treated with paclitaxel-coated devices, compared with uncoated devices for femoropopliteal disease at all time points to 60 months. There is therefore no justification to limit their use, or alter regulatory body follow-up recommendations in this patient population. SYSTEMATIC REVIEW REGISTRATION: CRD42020216140.

A Budget Impact Model for the use of Drug-Eluting Stents in Patients with Symptomatic Lower-Limb Peripheral Arterial Disease: An Australian Perspective.

PURPOSE: Improvement in long-term outcomes through innovative, cost-effective medical technologies is a focus for endovascular procedures aimed at treating symptomatic lower-limb peripheral arterial disease (PAD). The advent of drug-eluting stents (DES) has improved symptomatic PAD treatment via a reduction in high rates of target lesion revascularisation (TLR). The present study aimed to compare the 5-year financial impact of treatment with Eluvia, a new paclitaxel-eluting stent, versus treatment with Zilver PTX, a drug-coated stent, among patients in Australia by developing a budget impact model (BIM). METHODS: A BIM was developed from an Australian public hospital payer perspective using Australian national cost weights (AUD), published literature, and public hospital audit data. Clinical outcomes, including clinically driven TLRs (CD-TLRs), adverse events, and length of stay, were based on the 2-year results of the IMPERIAL trial, which compared Eluvia DES to Zilver PTX. RESULTS: Assuming EVP eligibility rate of 80% and DES uses rate ranging from 10 to 28% (superficial femoral artery lesions only), the 5-year model forecasted a treatment population between 14,428 and 40,399 patients. The model estimated 1499-4198 fewer CD-TLRs and 16,515-46,243 fewer hospital days with Eluvia DES use. This translated to 5-year potential savings of $4.3-$12.1 million to the Australian public hospital payer attributable to reduced CD-TLRs for Eluvia DES and $33.1-$92.6 million to Australian public hospitals owing to reduced adverse events and hospital bed days. CONCLUSION: Eluvia DES use as treatment for symptomatic lower-limb PAD could lead to potential savings for the Australian public healthcare system based on improved patient outcomes.

Trends and outcomes in Australian carotid artery revascularization surgery: 2010-2017.

BACKGROUND: Carotid endarterectomy (CEA) and carotid artery stenting (CAS) reduce the risk of stroke in patients with severe carotid stenosis. The aim was to compare contemporary treatment trends and outcomes after CEA and CAS between states of Australia. METHODS: A retrospective analysis was conducted on data from the Australasian Vascular Audit between 2010 and 2017. The primary endpoint was perioperative stroke or death (S/D). We also analysed stroke and death independently and revascularization rates per 100 000 population. RESULTS: A total of 15 413 patients underwent carotid revascularization (CEA 14 070; CAS 1343). S/D rates were similar for CEA and CAS (1.9% versus 1.8%; P = 0.37; symptomatic 2.1% versus 2.3%; P = 0.12; asymptomatic 1.5% versus 1.1%; P = 0.67). Patients ≥80 years (2.7% versus 1.7%; P = 0.01), those who had shunts (2.2% versus 1.7%; P = 0.03) or surgery in teaching hospitals (2.6% versus 1.4%; P = 0.02) had higher rates of S/D after CEA. Patients whose proceduralist used a cerebral protection device had lower S/D rates after CAS for symptomatic disease (4.8% versus 2.2%; P = 0.03). There was a wide variation in practice between states, where CAS as a proportion of total carotid procedures ranged from 0% to 17%, and a wide variation in outcomes, with rates of S/D varying between 1.4-6.6% for CEA and 0-6.7% after CAS. CONCLUSION: Outcomes after CAS are equivalent to CEA when performed by vascular surgeons, however significant variation exists for both choice of revascularization procedure and perioperative outcomes between states. Further investigation is needed to determine whether clinical care pathways should be revised to achieve consistency and quality of outcomes.

The Relationship Between Carotid Revascularization Procedural Volume and Perioperative Outcomes in Australia and New Zealand.

Carotid endarterectomy (CEA) and carotid artery stenting (CAS) prevent stroke in selected patients. However, each intervention carries a risk of perioperative complications including stroke or death (S/D). We aimed to determine the relationship between operator volume, hospital volume, and the perioperative risk of S/D in carotid revascularization in Australia and New Zealand. Retrospective analysis was performed on prospectively collected data extracted from the Australasian Vascular Audit between 2010 and 2017. Annual caseload volume was analyzed in quintiles (Q) using multivariate regression to assess its impact on perioperative S/D. Carotid endarterectomy procedures (n = 16 765) demonstrated higher S/D rates for lower-volume operators (2.21% for Q1-Q3 [1-17 annual cases] vs 1.76% for Q4-Q5 [18-61 annual cases]; odds ratio [OR]: 1.28; 95% CI: 1.001-1.64; P = .049). Carotid artery stenting procedures (n = 1350) also demonstrated higher S/D rates for lower-volume operators (2.63% for Q1-Q3 [1-11 annual cases] vs 0.37% for Q4-Q5 [12-31 annual cases]; OR: 6.11; 95% CI: 1.27-29.33; P = .024). No significant hospital volume-outcome effect was observed for either procedure. An inverse relationship was demonstrated between operator volume and perioperative S/D rates following CEA and CAS. Consideration of minimum operator thresholds, restructuring of services and networked referral pathways of care in Australia and New Zealand, would likely result in improved patient outcomes.

Long-term results of a prospective, single-arm evaluation of everolimus-eluting bioresorbable vascular scaffolds in infrapopliteal arteries.

OBJECTIVES: The aim of this study was to perform a long-term evaluation of an everolimus eluting, bioresorbable vascular scaffold (BVS) in the treatment of de novo atherosclerotic disease within crural arteries. METHODS: A prospective, single-arm study was performed enrolling patients with chronic lower limb ischemia between 2013 and 2018. RESULTS: Fifty-five limbs in 48 patients (56% male; mean age 82.1 ± 8.0 years, range 65-97) were treated for critical limb ischemia (72.7%) or severe claudication (27.3%). Seventy-one scaffolds were used to treat 61 lesions with a mean length of 20.1 ± 10.8 mm. During a mean follow-up period of 35.2 ± 20.4 months, 22 (45.8%) patients had died. No late or very-late scaffold thrombosis was observed. Overall, clinical improvement was observed in 90.9% and a limb-salvage rate of 100% was observed. Binary restenosis was detected in 11/71(15.5%) scaffolds. Primary patency and freedom from clinically driven target lesion revascularization rates at 12, 24, 36, 48, and 60 months were 90.8% (95% confidence interval 80.7-95.8), 90.8% (80.7-95.8), 79.7% (65.8-88.4), 76.3% (61.1-86.2), 72.3% (55.5-83.4) and 97.2% (89.2-99.3), 97.2% (89.2-99.3), 90.7% (78.7-96.1), 90.7% (78.7-96.1), and 90.7% (78.7-96.1), respectively. CONCLUSIONS: This long-term study shows excellent rates of patency and freedom from target lesion revascularization using the absorb BVS below-the-knee. This proof of concept study lays the foundation for the next generation of BVS to be evaluated in infrapopliteal arteries.

Safety and feasibility report on nonimplantable endovenous valve formation for the treatment of deep vein reflux.

OBJECTIVE: Definitive treatment techniques for symptomatic deep venous reflux have been relegated to complex and invasive open surgery which is rarely performed today. The BlueLeaf System provides an endovenous method for the formation of deep venous valves without an implant, avoiding the complications associated with permanent foreign materials. The system has the adaptability to form valves within the femoral and popliteal veins at multiple levels in a single procedure. The aim was to determine the midterm safety and efficacy of this novel device in an early feasibility study. METHODS: Feasibility of endovenous deep venous valve formation was assessed in patients with chronic venous insufficiency (Clinical, Etiologic, Anatomic, Pathophysiologic [CEAP] 4-6). Follow-up was completed through 1 year, assessing vein patency and reflux time (RT) with duplex ultrasound examination. Venous clinical improvement was evaluated using the revised Venous Clinical Severity Scale. RESULTS: Of the 14 patients, 13 (93%) had successful formation of at least one monocuspid valve, with a mean number of 1.4 valves (range, 0-3 valves) per patient. There were no device-related serious adverse events during the index procedure. There were no deep venous thromboses reported at any time point, including 10 patients through the 1-year follow-up. In patients with at least one valve formed, site reported duplex ultrasound examination measured the average RT in the popliteal vein below valve formations, was 3.0 ± 1.0 seconds at baseline, 3.9 ± 3.1 seconds at 30 days, and 3.6 ± 2.1 seconds at 360 days. The revised Venous Clinical Severity Scale improved in all 13 successfully treated patients, decreasing from 15.0 ± 6.0 at baseline to 11.6 ± 5.5 at 30 days, 10.7 ± 5.3 at 210 days, and 9.4 ± 5.0 at 360 days (P = .0002; baseline to 360 days). Among the five patients with an ulcer who reached the 360-day follow-up visit, all (100%) healed at least one ulcer. Two patients (40%) healed all ulcers and three patients (60%) had a decrease in ulcers number but remained at C6 at 360 days. The five patients with a total of nine active ulcers at baseline had four active ulcers at 360 days. CONCLUSIONS: The BlueLeaf System holds promise as a minimally invasive means to safely form fully autogenous deep venous valves. Reconstructed deep veins remained patent, without deep venous thrombosis and symptomatic improvement was consistently observed; however, a decrease in the RT was not. Incremental device design improvements have been undertaken to improve valve function. The results of these iterations await further clinical evaluation.

Sample preparation and fractionation techniques for intact proteins for mass spectrometric analysis.

The analysis of proteins in biological samples is highly desirable, given their connection to myriad biological functions and disease states, as well as the growing interest in the development of protein-based pharmaceuticals. The introduction and maturation of "soft" ionization methods, such as electrospray ionization and matrix-assisted laser desorption/ionization, have made mass spectrometry an indispensable tool for the analysis of proteins. Despite the availability of powerful instrumentation, sample preparation and fractionation remain among the most challenging aspects of protein analysis. This review summarizes these challenges and provides an overview of the state-of-the-art in sample preparation and fractionation of proteins for mass spectrometric analysis, with an emphasis on those used for top-down proteomic approaches. Biological fluids, particularly important for clinical and pharmaceutical applications and their characteristics are also discussed. While immunoaffinity-based methods are addressed, more attention is given to non-immunoaffinity-based methods, such as precipitation, coacervation, size exclusion, dialysis, solid-phase extraction, and electrophoresis. These techniques are presented in the context of a significant number of studies where they have been developed and utilized.

The Relationship Between Operative Volume and Peri-operative Mortality After Non-elective Aortic Aneurysm Repair in Australia.

OBJECTIVE: Hospital and surgeon operative caseload is thought to be associated with peri-operative mortality following the non-elective repair of aortic aneurysms; however, whether such an association exists within the Australian healthcare setting is unknown. METHODS: The Australasian Vascular Audit was interrogated to identify patients undergoing non-elective (emergency [EMG] or semi-urgent [URG]) aortic aneurysm repair between 2010 and 2016, as well as their treating surgeon and hospital. Hierarchal logistic regression modelling was used to assess the impact of caseload on outcomes after both endovascular (EVAR) and open surgical repair (OSR). RESULTS: Volume counts were determined from 14 262 patients (4 121 OSR and 10 141 EVAR). After exclusion of elective procedures and duplicates, 1 153 EVAR (570 EMG and 583 URG) and 1 245 OSR (946 EMG and 299 URG) non-elective cases remained for the analysis. Crude mortality was 24.0% following OSR (EMG 29.2%; URG 7.7%) and 7.5% following EVAR (EMG 12.6%; URG 2.4%). Univariable analysis demonstrated an association between OSR mortality and hospital volume (quintile [Q] 1: 25.3%, Q2: 27.8%, Q3: 23.9%, Q4: 27.0%, Q5: 16.2%; p = .030), but not surgeon (Q1: 25.2%, Q2: 27.4%, Q3: 26.0%, Q4: 21.4%, Q5: 19.5%, p = .32). Multivariable analysis confirmed this association (odds ratio (OR) [95% CI]; Q1 vs 5: 1.91 [1.13-3.21], Q2 vs. 5: 2.01[1.24-3.25], Q3 vs. 5: 1.41 [0.86-2.29], Q4 vs. 5: 1.92 [1.17-3.15]; p = .020). The difference was most pronounced in the EMG OSR group [Q1 - 3 vs. 4-5] (OR 1.63 [1.07-2.48]; p = .020). Mortality after EVAR was not associated with either hospital (Q1: 6.3%, Q2: 10%, Q3: 6.8%, Q4: 4.5%, Q5: 10%; p = .14) or surgeon volume (Q1: 9.3%, Q2: 5.7%, Q3: 8.1%, Q4: 7.0%, Q5: 7.3%; p = .67). CONCLUSION: There is an inverse correlation between hospital volume and peri-operative mortality following EMG open repair of aortic aneurysm. These data support restructuring Australian pathways of care to direct suspected ruptured aneurysm to institutions that reach a minimum volume threshold.