Outcomes After Neuraxial or Regional Anaesthesia Instead of General Anaesthesia for Lower Limb Revascularisation Surgery: A Systematic Review and Meta-Analysis of Randomised and Non-Randomised Studies.

OBJECTIVE: To determine whether receipt of neuraxial or regional anaesthesia instead of general anaesthesia for lower limb revascularisation surgery affects patient outcomes. DATA SOURCES: MEDLINE, EMBASE, Evidence Based Medicine Reviews, and Google Scholar. REVIEW METHODS: After protocol registration, the data sources were searched for randomised and non-randomised studies comparing neuraxial or regional anaesthesia with general anaesthesia for lower limb revascularisation surgery in adults. Two investigators independently selected articles, extracted data, and assessed risks of bias. Data were pooled using random effects models. GRADE was used to assess certainty in cumulative evidence. RESULTS: From 10 755 citations identified, five randomised (n = 970) and 13 non-randomised (n = 96 800) studies were included. Use of neuraxial instead of general anaesthesia for lower limb revascularisation surgery was associated with no statistically significant reduction in short term (in hospital or 30 day) mortality in randomised studies (pooled odds ratio [OR] 0.77; 95% confidence interval [CI] 0.33 - 1.81; low certainty) and a statistically significant reduction in adjusted short term mortality in non-randomised studies (pooled OR 0.67; 95% CI 0.56 - 0.81; low certainty). Adults allocated to neuraxial anaesthesia in randomised studies had fewer pulmonary complications (pooled OR 0.35; 95% CI 0.16 - 0.76; low certainty). In non-randomised studies, neuraxial instead of general anaesthesia was associated with a lower adjusted odds of any morbidity (pooled OR 0.66; 95% CI 0.52 - 0.84), cardiac complications (pooled OR 0.68; 95% CI 0.58 - 0.79), pneumonia (pooled OR 0.81; 95% CI 0.64 - 1.02), prolonged mechanical ventilation (OR 0.09; 95% CI 0.002 - 0.55), and bypass graft thrombosis (OR 0.70; 95% CI 0.59 - 0.85), as well as a shorter operative duration (low certainty for all). Use of a nerve block instead of general anaesthesia was associated with a lower adjusted odds of delirium (OR 0.16; 95% CI 0.06 - 0.42) and a shorter operative duration (low certainty for both). CONCLUSION: Randomised and non-randomised data suggest that neuraxial anaesthesia for lower limb revascularisation surgery reduces morbidity and possibly mortality. Until randomised trials with a low risk of bias become available, this study supports use of neuraxial anaesthesia for these procedures where appropriate.

Canadian Cardiovascular Society 2022 Guidelines for Peripheral Arterial Disease.

Patients with widespread atherosclerosis such as peripheral artery disease (PAD) have a high risk of cardiovascular and limb symptoms and complications, which affects their quality of life and longevity. Over the past 2 decades there have been substantial advances in diagnostics, pharmacotherapy, and interventions including endovascular and open surgical to aid in the management of PAD patients. To summarize the evidence regarding approaches to diagnosis, risk stratification, medical and intervention treatments for patients with PAD, guided by the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) framework, evidence was synthesized, and assessed for quality, and recommendations provided-categorized as weak or strong for each prespecified research question. Fifty-six recommendations were made, with 27% (15/56) graded as strong recommendations with high-quality evidence, 14% (8/56) were designated as strong recommendations with moderate-quality evidence, and 20% (11/56) were strong recommendations with low quality of evidence. Conversely 39% (22/56) were classified as weak recommendations. For PAD patients, strong recommendations on the basis of high-quality evidence, include smoking cessation interventions, structured exercise programs for claudication, lipid-modifying therapy, antithrombotic therapy with a single antiplatelet agent or dual pathway inhibition with low-dose rivaroxaban and aspirin; treatment of hypertension with an angiotensin converting enzyme or angiotensin receptor blocker; and for those with diabetes, a sodium-glucose cotransporter 2 inhibitor should be considered. Furthermore, autogenous grafts are more effective than prosthetic grafts for surgical bypasses for claudication or chronic limb-threatening ischemia involving the popliteal or distal arteries. Other recommendations indicated that new endovascular techniques and hybrid procedures be considered in patients with favourable anatomy and patient factors, and finally, the evidence for perioperative risk stratification for PAD patients who undergo surgery remains weak.

Physician-modified Steerable Endovascular Catheter.

We demonstrate a simple, intraoperative modification to a 65 cm Beacon Tip Kumpe catheter (Cook Medical) using readily-available components in order to increase its functionality during endovascular procedures. The steerable endovascular catheter has near-spherical range, improving accessibility to challenging anatomy over conventional catheters as demonstrated by our qualitative modeling. In addition, the modification provides structural reinforcement at the catheter tip leading to precise wire advancement. Use of the steerable catheter was demonstrated in vivo during contralateral gate cannulation of an endovascular aneurysm repair, however it holds broad applications in visceral, branched and fenestrated cannulations. Physician-modified devices offer the potential to improve endovascular techniques and reduce additional procedure costs while avoiding regulatory board approval required of novel steerable endovascular devices.

Outcomes After Receipt of Neuraxial or Regional Anesthesia Instead of General Anesthesia for Lower Limb Revascularization Surgery: Protocol for a Systematic Review and Meta-analysis.

BACKGROUND: Patients undergoing lower limb revascularization surgery for peripheral artery disease (PAD) have a high risk of perioperative morbidity and mortality and often have long hospital stays. Use of neuraxial or regional anesthesia instead of general anesthesia may represent one approach to improving outcomes and reducing resource use among these patients. OBJECTIVE: The aim is to conduct a systematic review and meta-analysis to determine whether receipt of neuraxial or regional anesthesia instead of general anesthesia in adults undergoing lower limb revascularization surgery for PAD results in improved health outcomes and costs and a shorter length of hospitalization. METHODS: We will search electronic bibliographic databases (MEDLINE, EMBASE, the seven databases in Evidence-Based Medicine Reviews, medRxiv, bioRxiv, and Google Scholar), review papers identified during the search, and included article bibliographies. We will include randomized and nonrandomized studies comparing the use of neuraxial or regional anesthesia instead of general anesthesia in adults undergoing lower limb revascularization surgery for PAD. Two investigators will independently evaluate the risk of bias. The primary outcome will be short-term (in-hospital or 30-day) mortality. Secondary outcomes will include longer-term mortality; major adverse cardiovascular, pulmonary, renal, and limb events; delirium; deep vein thrombosis or pulmonary embolism; neuraxial or regional anesthesia-related complications; graft-related outcomes; length of operation and hospital stay; costs; and patient-reported or functional outcomes. We will calculate summary odds ratios (ORs) and standardized mean differences (SMDs) using random-effects models. Heterogeneity will be explored using stratified meta-analyses and meta-regression. We will assess for publication bias using the Begg and Egger tests and use the trim-and-fill method to estimate the potential influence of this bias on summary estimates. Finally, we will use Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) methodology to make an overall rating of the quality of evidence in our effect estimates. RESULTS: The protocol was registered in the International Prospective Register of Systematic Reviews (PROSPERO). We executed the peer-reviewed search strategy on March 2, 2021. We completed the review of titles and abstracts on July 30, 2021, and plan to complete the review of full-text papers by September 30, 2021. We will complete full-text study data extraction and the risk-of-bias assessment by November 15, 2021, and conduct qualitative and then quantitative data synthesis and GRADE assessment of results by January 1, 2022, before drafting the manuscript. We anticipate that we will be able to submit the manuscript for peer review by the end of February 2022. CONCLUSIONS: This study will synthesize existing evidence regarding whether receipt of neuraxial or regional anesthesia instead of general anesthesia in adults undergoing lower limb revascularization surgery for PAD results in improved health outcomes, graft patency, and costs and a shorter length of hospital stay. Study results will be used to inform practice and future research, including creation of a pilot and then multicenter randomized controlled trial. TRIAL REGISTRATION: Prospero CRD42021237060; https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=237060. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): PRR1-10.2196/32170.

From cellular function to global impact: the vascular perspective on COVID-19.

Since COVID-19 was declared a pandemic a year ago, our understanding of its effects on the vascular system has slowly evolved. At the cellular level, SARS-CoV-2 - the virus that causes COVID-19 - accesses the vascular endothelium through the angiotensin-converting enzyme 2 (ACE-2) receptor and induces proinflammatory and prothrombotic responses. At the clinical level, these pathways lead to thromboembolic events that affect the pulmonary, extracranial, mesenteric, and lower extremity vessels. At the population level, the presence of vascular risk factors predisposes individuals to more severe forms of COVID-19, whereas the absence of vascular risk factors does not spare patients with COVID-19 from unprecedented rates of stroke, pulmonary embolism and acute limb ischemia. Finally, at the community and global level, the fear of COVID-19, measures taken to limit the spread of SARS-CoV-2 and reallocation of limited hospital resources have led to delayed presentations of severe forms of ischemia, surgery cancellations and missed opportunities for limb salvage. The purpose of this narrative review is to present some of the data on COVID-19, from cellular mechanisms to clinical manifestations, and discuss its impact on the local and global surgical communities from a vascular perspective.

Depuis que la COVID-19 s'est vu donner le statut de pandémie il y a 1 an, notre connaissance des effets de cette maladie sur le système vasculaire a évolué. À l'échelle cellulaire, le SRAS-CoV-2 ­ le virus qui cause la COVID-19 ­ accède à l'endothélium vasculaire par le récepteur de l'enzyme de conversion de l'angiotensine-2 (ACE-2) et provoque des réponses proinflammatoires et prothrombotiques. À l'échelle clinique, ces réponses peuvent mener à une activité thromboembolique touchant les vaisseaux pulmonaires, extracrâniens, mésentériques et des membres inférieurs. À l'échelle populationnelle, la présence chez certaines personnes de facteurs de risque vasculaires les prédispose à une forme plus grave de la COVID-19, mais l'absence de ces facteurs n'empêche pas les patients atteints de la COVID-19 de présenter des taux sans précédent d'AVC, d'embolie pulmonaire et d'ischémie aiguë aux membres. Enfin, à l'échelle locale et mondiale, la peur entourant la COVID-19, les mesures prises pour en endiguer la propagation et le redéploiement des ressources limitées des hôpitaux ont mené au report de visites à l'hôpital pour des formes graves d'ischémie, à l'annulation de chirurgies et à des occasions manquées de préserver des membres. La présente revue non systématique a pour objectif de présenter une partie des données sur la COVID-19, de ses mécanismes cellulaires à ses manifestations cliniques, et de discuter des répercussions de la crise sur les communautés chirurgicales locales et mondiales, dans une optique vasculaire.

Antithrombotic regimens in females with symptomatic lower extremity peripheral arterial disease: protocol for a systematic review and meta-analysis.

INTRODUCTION: Patients with peripheral arterial disease (PAD) are at increased risk for systemic arterial thromboembolic events. Females represent a unique subset of patients with PAD, who differ from males in important ways: they have smaller diameter vessels, undergo lower extremity bypass less frequently and experience higher rates of graft occlusion, amputation and mortality than males. Females also trend towards higher rates of major coronary events and cardiovascular mortality. Current guidelines recommend monoantiplatelet therapy (MAPT) for secondary prevention in patients with symptomatic PAD. However, indications for more intensive antithrombotic therapy in this cohort-especially among females who are frequently under-represented in randomised controlled trials (RCTs)-remain unclear. As newer antithrombotic therapies emerge, some RCTs have demonstrated differential effects in females versus males. A systematic review is needed to quantify the rates of arterial thromboembolic and bleeding events with different antithrombotic regimens in females with symptomatic PAD. METHODS AND ANALYSIS: We will search MEDLINE, Embase and the Cochrane Central Register of Controlled trials for published RCTs that include females with symptomatic PAD and compare full dose anticoagulation±antiplatelet therapy, dual pathway inhibition or dual antiplatelet therapy with MAPT. Title, abstract and full-text screening will be conducted in duplicate by three reviewers. Authors will be contacted to obtain sex-stratified outcomes as needed. Risk of bias will be assessed using the Cochrane Risk of Bias tool. Data will be extracted by independent reviewers and confirmed by a second reviewer. Quantitative synthesis will be conducted using Review Manager (RevMan) V.5 for applicable outcomes data. Planned subgroup analysis by PAD severity, vascular intervention and indication for antithrombotics will be conducted where data permits. ETHICS AND DISSEMINATION: Ethics approval is waived as the study does not involve primary data collection. This review will be submitted for publication in a peer-reviewed journal and for presentation at national and international scientific meetings. TRIAL REGISTRATION NUMBER: This protocol was registered with the PROSPERO International Prospective Register of Systematic Reviews (ID# CRD42020196933).

A Canadian multicenter experience describing outcomes after endovascular abdominal aortic aneurysm repair stent graft explantation.

BACKGROUND: Most studies describing the outcomes after endovascular abdominal aortic aneurysm repair (EVAR) explantation have been from single, high-volume, centers. We performed a multicenter cross-Canadian study of outcomes after EVAR stent graft explantation. Our objectives were to describe the outcomes after late open conversion and EVAR graft explantation at various Canadian centers and the techniques and outcomes stratified by the indication for explant. METHODS: The Canadian Vascular Surgery Research Group performed a retrospective multicenter study of all cases of EVAR graft explantation at participating centers from 2003 to 2018. Data were collected using a standardized, secure, online platform (RedCap [Research Electronic Data Capture]). Univariate statistical analysis was used to compare the techniques and outcomes stratified the indication for graft explantation. RESULTS: Patient data from 111 EVAR explants collected from 13 participating centers were analyzed. The mean age at explantation was 74 years, the average aneurysm size was 7.5 cm, and 28% had had at least one instructions for use violation at EVAR. The average time between EVAR and explantation was 42.5 months. The most common indication for explantation was endoleak (n = 66; type Ia, 46; type Ib, 2; type II, 9; type III, 2; type V, 7), followed by infection in 20 patients; rupture in 18 patients (due to type Ia endoleak in 10 patients, type Ib in 1, type II in 1, type III in 2, and type V in 1), and graft thrombosis in 7 patients. The overall 30-day mortality was 11%, and 45% of the patients had experienced at least one major perioperative complication. Mortality was significantly greater for patients with rupture (33.3%) and those with infection (15%) compared with patients undergoing elective explantation for endoleak (4.5%; P = .003). The average center volume during the previous 15 years was 8 cases with a wide range (2-19 cases). A trend was seen toward greater mortality for patients treated at centers with fewer than eight cases compared with those with eight or more cases (19% vs 9%). However, the difference did not reach statistical significance (P = .23). Overall, 41% of patients had undergone at least one attempt at endovascular salvage before explantation, with the highest proportion among patients who had undergone EVAR explantation for endoleak (51%). Only 22% of patients with rupture had undergone an attempt at endovascular salvage before explantation. CONCLUSIONS: The performance of EVAR graft explantation has increasing in Canada. Patients who had undergone elective explantation for endoleak had lower mortality than those treated for either infection or rupture. Thus, patients with an indication for explanation should be offered surgery before symptoms or rupture has occurred. A trend was seen toward greater mortality for patients treated at centers with lower volumes.

Declining institutional memory of open abdominal aortic aneurysm repair.

OBJECTIVE: Since its introduction, endovascular aneurysm repair (EVAR) has become a mainstay in the treatment of abdominal aortic aneurysms (AAAs), resulting in the decline of open aneurysm repairs. The objective of this study was to determine whether reduced open aneurysm repair frequency has led to a reduction in perioperative efficiency and increase in postsurgical complications. METHODS: A retrospective cohort study compared perioperative data and complications of 49 consecutive juxtarenal AAA (<1-cm neck) open repairs performed between 2014 and 2017 and 53 consecutive juxtarenal AAA controls (2005-2007) at The Ottawa Hospital. There was no change in surgical personnel during this 10-year comparison. RESULTS: The Ottawa Hospital experienced a 61% decline in the number of open AAA repairs between the two time periods examined; 541 open AAA repairs and 86 EVARs were performed between 2005 and 2007, whereas 358 open AAA repairs and 385 EVARs were performed between 2014 and 2017. Age of participants significantly decreased in the 2014 to 2017 group (P = .01), as did the number of women undergoing open juxtarenal AAA repair (P = .05). Total operating room time and anesthesia time were longer in the 2014-2017 group (P = .02; P = .01), whereas surgical times remained consistent (P = .13). Suprarenal clamp time and blood loss during the procedure were decreased in the 2014-2017 group (P < .01; P < .01). Intensive care unit stay and overall hospital stay were not significantly different between groups (P = .77; P = .87); however, there were large standard deviations observed for the 2014-2017 group. As well, 18.4% of patients in the 2014-2017 group experienced postsurgical complications of Clavien-Dindo grade IIIa or higher compared with 11.3% of patients in the historical control group (P = .07). Mortality also trended toward an increase in the 2014-2017 group (P = .43). CONCLUSIONS: The reduced rate of open repair performance at The Ottawa Hospital reflects the global trend toward EVAR. Anesthesia and operating room times increased during the period examined, reflecting a possible loss of expertise in the last decade. Complications also increased during this time for anatomically similar patients. Taken together, these findings may reflect a decreased institutional familiarity with open aneurysm repair and postsurgical care.

Carotid Endarterectomy Versus Carotid Artery Stenting: Survey of the Quality, Readability, and Treatment Preference of Carotid Artery Disease Websites.

BACKGROUND: The internet is becoming increasingly more important in the new era of patient self-education. Carotid endarterectomy (CEA) and carotid artery stenting (CAS) are recognized interventions to treat patients with carotid artery stenosis. Using the Google search platform, patients encounter many websites with conflicting information, which are sometimes difficult to understand. This lack of accessibility creates uncertainty or bias toward interventions for carotid artery disease. The quality, readability, and treatment preference of carotid artery disease (CAD) websites have not yet been evaluated. OBJECTIVE: This study aimed to explore the quality, readability, and treatment preference of CAD websites. METHODS: We searched Google Canada for 10 CAD-related keywords. Returned links were assessed for publication date, medical specialty and industry affiliation, presence of randomized controlled trial data, differentiation by symptomatic status, and favored treatment. Website quality and readability were rated by the DISCERN instrument and Gunning Fog Index. RESULTS: We identified 54 unique sites: 18 (33.3%) by medical societies or individual physicians, 11 (20.4%) by government organizations, 9 (16.7%) by laypersons, and 1 (1.9%) that was industry-sponsored. Of these sites, 26 (48.1%) distinguished symptomatic from asymptomatic CAD. A majority of sites overall (57.4%) and vascular-affiliated (72.7%) favored CEA. In contrast, radiology- and cardiology-affiliated sites demonstrated the highest proportion of sites favoring CAS, though they were equally likely to favor CEA. A large proportion (21/54, 38.9%) of sites received poor quality ratings (total DISCERN score <48), and the majority (41/54, 75.9%) required a reading level greater than a high school senior. CONCLUSIONS: CAD websites are often produced by government organizations, medical societies, or physicians, especially vascular surgeons. Sites ranged in quality, readability, and differentiation by symptomatic status. Google searches of CAD-related terms are more likely to yield sites favoring CEA. Future research should determine the extent of website influence on CAD patients' treatment decisions.

A Novel Recurrent COL5A1 Genetic Variant Is Associated With a Dysplasia-Associated Arterial Disease Exhibiting Dissections and Fibromuscular Dysplasia.

OBJECTIVE: While rare variants in the COL5A1 gene have been associated with classical Ehlers-Danlos syndrome and rarely with arterial dissections, recurrent variants in COL5A1 underlying a systemic arteriopathy have not been described. Monogenic forms of multifocal fibromuscular dysplasia (mFMD) have not been previously defined. Approach and Results: We studied 4 independent probands with the COL5A1 pathogenic variant c.1540G>A, p.(Gly514Ser) who presented with arterial aneurysms, dissections, tortuosity, and mFMD affecting multiple arteries. Arterial medial fibroplasia and smooth muscle cell disorganization were confirmed histologically. The COL5A1 c.1540G>A variant is predicted to be pathogenic in silico and absent in gnomAD. The c.1540G>A variant is on a shared 160.1 kb haplotype with 0.4% frequency in Europeans. Furthermore, exome sequencing data from a cohort of 264 individuals with mFMD were examined for COL5A1 variants. In this mFMD cohort, COL5A1 c.1540G>A and 6 additional relatively rare COL5A1 variants predicted to be deleterious in silico were identified and were associated with arterial dissections (P=0.005). CONCLUSIONS: COL5A1 c.1540G>A is the first recurring variant recognized to be associated with arterial dissections and mFMD. This variant presents with a phenotype reminiscent of vascular Ehlers-Danlos syndrome. A shared haplotype among probands supports the existence of a common founder. Relatively rare COL5A1 genetic variants predicted to be deleterious by in silico analysis were identified in ≈2.7% of mFMD cases, and as they were enriched in patients with arterial dissections, may act as disease modifiers. Molecular testing for COL5A1 should be considered in patients with a phenotype overlapping with vascular Ehlers-Danlos syndrome and mFMD.

Physiologic perfusion monitoring methods during endovascular revascularization for atherosclerotic peripheral arterial disease: protocol for a systematic review.

BACKGROUND: Endovascular therapy is a fundamental treatment for peripheral arterial disease. However, the success rate of endovascular therapy remains poor, as a third of patients with critical limb ischemia ultimately require a major amputation for gangrene despite endovascular treatment. This failure rate has prompted investigation into methods of determining physiologic procedural success before and after treatment, before clinically apparent outcomes occur such as gangrene. The aim of this systematic review is to evaluate if in patients undergoing endovascular surgery for lower extremity atherosclerotic peripheral arterial disease, do changes in physiologic measures of perfusion during surgery correlate with clinical outcomes. METHODS: We registered and designed a study protocol for a systematic review. Literature searches will be conducted in MEDLINE, EMBASE, and CENTRAL (from January 1977 onwards). Grey literature will be identified through OpenGrey and clinical trial registries, and supplemented by citation searches. We will include randomized controlled trials, quasi-experimental trials, and observational (cohort, case-control) studies conducted in human adults (age 18 or older) who received elective arterial angioplasty for atherosclerotic peripheral vascular disease. The primary outcome of interest will be major adverse limb events. Two investigators will independently screen all citation, full-text articles, and abstract data. The study quality (risk of bias) will be appraised appropriate tools. Data analysis and synthesis will be qualitative; no meta-analysis is planned, as the anticipated homogeneity of measurement and outcome reporting standardization is low. DISCUSSION: The treatment of peripheral arterial disease is unique in that the tissue of the ischemic leg is easily accessible for direct monitoring during procedures. This is contrasted with cardiac and neurologic monitoring during cardiac and cerebral procedures, where indirect or invasive measures are required to monitor organ perfusion. Currently synthesized evidence describing limb perfusion focuses on static states of ischemia, and does not evaluate the value of change in perfusion measurement as an indicator of endovascular treatment success. These methods could potentially be applied to optimize procedural outcomes by guiding perfusion-based decision-making during surgery. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42019138192.

Unintended Consequences: Perils of Renal Revascularization for Severe Hypertension.

Revascularization of atherosclerotic renal artery stenosis may cure hypertension, but paradoxically, improvement in systemic blood pressure in response to successful revascularization may precipitate ischemia in other organs affected by previously silent atherosclerotic disease. We describe bowel ischemia secondary to preexisting celiac artery stenosis after revascularisation. Prior knowledge of multivessel disease facilitated prompt diagnosis and management of this condition.

Wikipedia in Vascular Surgery Medical Education: Comparative Study.

BACKGROUND: Medical students commonly refer to Wikipedia as their preferred online resource for medical information. The quality and readability of articles about common vascular disorders on Wikipedia has not been evaluated or compared against a standard textbook of surgery. OBJECTIVE: The aims of this study were to (1) compare the quality of Wikipedia articles to that of equivalent chapters in a standard undergraduate medical textbook of surgery, (2) identify any errors of omission in either resource, and (3) compare the readability of both resources using validated ease-of-reading and grade-level tools. METHODS: Using the Medical Council of Canada Objectives for the Qualifying Examination, 8 fundamental topics of vascular surgery were chosen. The articles were found on Wikipedia using Wikipedia's native search engine. The equivalent chapters were identified in Schwartz Principles of Surgery (ninth edition). Medical learners (n=2) assessed each of the texts on their original platforms to independently evaluate readability, quality, and errors of omission. Readability was evaluated with Flesch Reading Ease scores and 5 grade-level scores (Flesch-Kincaid Grade Level, Gunning Fog Index, Coleman-Liau Index, Simple Measure of Gobbledygook Index, and Automated Readability Index), quality was evaluated using the DISCERN instrument, and errors of omission were evaluated using a standardized scoring system that was designed by the authors. RESULTS: Flesch Reading Ease scores suggested that Wikipedia (mean 30.5; SD 8.4) was significantly easier to read (P=.03) than Schwartz (mean 20.2; SD 9.0). The mean grade level (calculated using all grade-level indices) of the Wikipedia articles (mean 14.2; SD 1.3) was significantly different (P=.02) than the mean grade level of Schwartz (mean 15.9; SD 1.4). The quality of the text was also assessed using the DISCERN instrument and suggested that Schwartz (mean 71.4; SD 3.1) had a significantly higher quality (P=.002) compared to that of Wikipedia (mean 52.9; SD 11.4). Finally, the Wikipedia error of omission rate (mean 12.5; SD 6.8) was higher than that of Schwartz (mean 21.3; SD 1.9) indicating that there were significantly fewer errors of omission in the surgical textbook (P=.008). CONCLUSIONS: Online resources are increasingly easier to access but can vary in quality. Based on this comparison, the authors of this study recommend the use of vascular surgery textbooks as a primary source of learning material because the information within is more consistent in quality and has fewer errors of omission. Wikipedia can be a useful resource for quick reference, particularly because of its ease of reading, but its vascular surgery articles require further development.

The futility of surveillance for old and small aneurysms.

OBJECTIVE: We investigated the yield of ultrasound surveillance for small abdominal aortic aneurysms (AAAs) in patients older than 80 years compared with a younger population for detecting AAA growth reaching the threshold size for repair. Secondary objectives included analysis of the incidence of AAA repair and the cost-benefit of surveillance. METHODS: A retrospective cohort study was performed of all patients undergoing AAA surveillance in Ottawa between 2007 and 2015. Patients were dichotomized by enrollment age (<80 years vs ≥80 years) and stratified by enrollment AAA size. Cohorts were cross-referenced with the Ottawa surgical database, leveraging the common health region to ensure complete data capture. The threshold size for repair was sex specific (female, 5.0 cm; male, 5.5 cm). Factors influencing AAA growth rate were assessed with a general linear multiple mixed model. Analyses with Cox proportional hazards models with competing risk for mortality assessed aorta-related events, and cost-benefit was analyzed by referencing Ontario billing codes. RESULTS: A total of 1231 patients underwent serial ultrasound surveillance, of whom 500 were older than 80 years at some point during the study period. The mean AAA growth rate was 1.63 mm/y (95% confidence interval [CI], 1.54-1.71). Old age and small enrollment aneurysm size were significantly protective against AAA growth. Overall, 357 (29%) patients reached the AAA size threshold for repair, and 272 (22%) underwent AAA repair. Patients older than 80 years were less likely to reach the AAA threshold size for repair compared with their younger counterparts (adjusted hazard ratio, 0.77; 95% CI, 0.61-0.97). Of the 357 patients whose AAA reached the threshold size for repair, octogenarians were substantially less likely to undergo elective AAA repair (adjusted hazard ratio, 0.34; 95% CI, 0.24-0.47). Repair of ruptured AAA was rare (0.8%), and age differences were insignificant. For every octogenarian with an enrollment AAA size between 3.0 and 3.9 cm who ultimately received elective AAA repair, 51 patients were enrolled in surveillance without elective repair. This corresponded to an estimated $33,139 in ultrasound fees. CONCLUSIONS: Surveillance of most patients with small AAA is appropriate. However, patients older than 80 years were significantly less likely than their younger counterparts to experience aortic growth reaching the threshold size for repair. Furthermore, in the unlikely event of AAA growth, patients older than 80 years were substantially less likely to undergo repair. These results suggest that in the context of patient-specific health and wishes, surveillance of AAAs <4 cm in octogenarians is costly and unlikely to be beneficial.

Protocol for a prospective observational diagnostic study: intraoperative simultaneous limb pressure monitoring (INSTANT) study.

INTRODUCTION: Peripheral vascular disease (PVD) is a condition caused by arterial blockages causing inadequate blood flow, resulting in pain and gangrene of the legs. Endovascular therapy, such as angioplasty, can be used to treat PVD, however, the operator feedback during surgery is primarily anatomic based on the angiogram. Because physiologic blood perfusion can be difficult to determine based on anatomic images, we propose introducing physiological measurements into the operating room. This study will investigate whether the change in intraoperative monitoring of haemodynamic measurements such as the Toe-Brachial Index during endovascular surgery for lower extremity atherosclerotic PVD is associated with clinical outcomes such as major adverse limb events (MALEs). METHODS AND ANALYSIS: This study will be a prospective, operator-blinded and blinded endpoint adjudicated observational diagnostic cohort study. A total of 80 legs will be enrolled in the study. Ankle and toe blood pressures will be measured non-invasively at predetermined time points before, during and after surgery, and we will assess associations between changes in intraoperative pressure measurements and postoperative clinical and haemodynamic outcomes. The primary outcome will be MALE within 1 year, and secondary outcomes include follow-up pressure measurements, vessel patency, reintervention, clinical staging improvement, amputation and death. ETHICS AND DISSEMINATION: Regional hospital ethics approval has been granted (Ottawa Hospital Research Institute - Research Ethics Board, Protocol 20180656-01H). On completion of data analysis, the study will submitted for presentation at international vascular surgical society meetings, in addition to submission for publication in publicly accessible medical journals. TRIAL REGISTRATION NUMBER: NCT03875846.

Variability in aneurysm sac regression after endovascular aneurysm repair based on a comprehensive registry of patients in Eastern Ontario.

BACKGROUND: Although the absence of aneurysm-related mortality, postimplantation rupture, and reintervention after endovascular aneurysm repair (EVAR) is desirable, it may not necessarily reflect successful aneurysm sac exclusion. Sac regression may be a more sensitive marker for EVAR success and may be influenced by factors beyond the presence or absence of an endoleak. The objective of this study is to determine the rate of overall long-term sac regression after EVAR and the influence of nonanatomic factors, and endograft devices used at our center. METHODS: This retrospective cohort study included all EVARs performed for intact and ruptured abdominal aortic aneurysms (AAAs) at a university teaching hospital. Preoperative, operative, and follow-up data were collected using clinical and radiologic institutional databases. Preoperative and post-EVAR sac diameters were determined by a blinded observer in accordance with Society for Vascular Surgery guidelines. Absolute and relative sac regression was determined at the following intervals: 0 to 6 months, 6 to 12 months, 12 to 18 months, 18 months to 2 years, 2 to 5 years, 5 to 10 years, and more than 10 years. RESULTS: From 1999 to 2015, 1060 patients underwent EVAR for an AAA at the Ottawa Hospital. Procedures were performed using a total of nine unique endograft devices, with five devices (Cook Zenith, n = 398; Medtronic Endurant, n = 375; Medtronic Talent, n = 183; Cook Zenith LP, n = 52; and Terumo Anaconda, n = 23) used in 97% of the procedures. The mean preoperative AAA diameter was 61.2 mm, with no detectable differences between endograft devices with respect to age, preoperative AAA diameter, or rupture diagnosis. Overall mean sac regression increased from -1.3 mm at 6 months, to -14.9 mm beyond 10 years. The majority of sac regression was achieved within 2 years. Only 90 of the 1060 patients (8.5%) experienced sac expansion of greater than 5 mm at some point during their follow-up period. Kaplan-Meier analyses revealed statistically significant device-specific variability in sac regression rates, even in the absence of an endoleak. Cox proportional hazard modeling demonstrated that age less than 75 years (hazard ratio [HR], 1.4; P = .001), female sex (HR, 1.4; P = .003), absence of type I endoleak (HR, 4.6; P < .0001), AAA greater than 70 mm (HR, 1.6; P < .0001), and both the Zenith (HR, 2.0; P < .0001) and Endurant (HR, 1.7; P = .001) devices were associated with shorter time to more than 5 mm sac regression. CONCLUSIONS: This study demonstrated a pattern of sac diameter change after EVAR, with the majority of sac regression occurring within the first 2 years. Variability in sac regression was influenced by nonanatomic variables including age, sex, original AAA diameter, and specific endograft device, even after controlling for the presence or absence of an endoleak. The biophysical relationship between specific endograft design and materials, and sac regression is yet to be determined.

Global Vascular Guidelines on the Management of Chronic Limb-Threatening Ischemia.

GUIDELINE SUMMARY: Chronic limb-threatening ischemia (CLTI) is associated with mortality, amputation, and impaired quality of life. These Global Vascular Guidelines (GVG) are focused on definition, evaluation, and management of CLTI with the goals of improving evidence-based care and highlighting critical research needs. The term CLTI is preferred over critical limb ischemia, as the latter implies threshold values of impaired perfusion rather than a continuum. CLTI is a clinical syndrome defined by the presence of peripheral artery disease (PAD) in combination with rest pain, gangrene, or a lower limb ulceration >2 weeks duration. Venous, traumatic, embolic, and nonatherosclerotic etiologies are excluded. All patients with suspected CLTI should be referred urgently to a vascular specialist. Accurately staging the severity of limb threat is fundamental, and the Society for Vascular Surgery Threatened Limb Classification system, based on grading of Wounds, Ischemia, and foot Infection (WIfI) is endorsed. Objective hemodynamic testing, including toe pressures as the preferred measure, is required to assess CLTI. Evidence-based revascularization (EBR) hinges on three independent axes: Patient risk, Limb severity, and ANatomic complexity (PLAN). Average-risk and high-risk patients are defined by estimated procedural and 2-year all-cause mortality. The GVG proposes a new Global Anatomic Staging System (GLASS), which involves defining a preferred target artery path (TAP) and then estimating limb-based patency (LBP), resulting in three stages of complexity for intervention. The optimal revascularization strategy is also influenced by the availability of autogenous vein for open bypass surgery. Recommendations for EBR are based on best available data, pending level 1 evidence from ongoing trials. Vein bypass may be preferred for average-risk patients with advanced limb threat and high complexity disease, while those with less complex anatomy, intermediate severity limb threat, or high patient risk may be favored for endovascular intervention. All patients with CLTI should be afforded best medical therapy including the use of antithrombotic, lipid-lowering, antihypertensive, and glycemic control agents, as well as counseling on smoking cessation, diet, exercise, and preventive foot care. Following EBR, long-term limb surveillance is advised. The effectiveness of nonrevascularization therapies (eg, spinal stimulation, pneumatic compression, prostanoids, and hyperbaric oxygen) has not been established. Regenerative medicine approaches (eg, cell, gene therapies) for CLTI should be restricted to rigorously conducted randomizsed clinical trials. The GVG promotes standardization of study designs and end points for clinical trials in CLTI. The importance of multidisciplinary teams and centers of excellence for amputation prevention is stressed as a key health system initiative.