Predicting the need for subclavian artery revascularization in thoracic endovascular aortic repair: A systematic review and meta-analysis.

OBJECTIVE: This systematic review and meta-analysis aims to investigate the effectiveness of left subclavian artery revascularization compared with non-revascularization in thoracic endovascular aortic repair, and to summarize the current evidence on its indications. METHODS: A computerized search was conducted across multiple databases, including MEDLINE, SCOPUS, Cochrane Library, and Web of Science, for studies published up to November 2023. Study selection, data abstraction, and quality assessment (using the Newcastle-Ottawa Scale) were independently conducted by two reviewers, with a third author resolving discrepancies. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were calculated using random-effects models and publication bias was assessed using funnel plots. RESULTS: In the 76 included studies, left subclavian artery revascularization was associated with reduced risks of stroke (OR, 0.67; 95% CI, 0.45-0.98; n = 15,331), spinal cord ischemia (OR, 0.75; 95% CI, 0.56-0.99; n = 11,995), and arm ischemia (OR, 0.09; 95% CI, 0.01-0.59; n = 8438). No significant reduction in paraplegia (OR, 0.56; 95% CI, 0.21-1.47; n = 1802) or mortality (OR, 0.77; 95% CI, 0.53-1.12; n = 11,831) was observed. Moreover, the risk of endoleak was comparable in both groups (OR, 1.25; 95% CI, 0.55-2.84; P = .60; n = 793), whereas the risk of reintervention was significantly higher in the revascularization group (OR, 1.98; 95% CI, 1.03-3.83; P = .04; n = 272). Both groups had similar risks of major (OR, 0.45; 95% CI, 0.19-1.09; P = .08; n = 1113), minor (OR, 0.21; 95% CI, 0.01-3.45; P = .27; n = 183), renal (OR, 0.61; 95% CI, 0.12-3.06; P = .55; n = 310), and pulmonary (OR, 0.59; 95% CI, 0.16-2.15; P = .42; n = 8083) complications. The most frequent indications for left subclavian artery revascularization were primary prevention of spinal cord ischemia, augmentation of the landing zone, and primary stroke prevention. CONCLUSIONS: Left subclavian artery revascularization in thoracic endovascular aortic repair was associated with reduced neurological complications but was not found to impact mortality. The study highlights important indications for revascularization as well as significant predictors of complications, providing a basis for clinical decision-making and future research.

Trends in operative case volumes of Canadian vascular surgery trainees.

OBJECTIVE: Vascular surgery has evolved with increasing use of endovascular therapies and a decline in open surgery. The influence of these changes, in addition to a new vascular surgery training program introduced in 2012, on case volumes of vascular trainees is not known. We sought to evaluate trends in operative case volumes of Canadian vascular surgery trainees. METHODS: A survey was administered to graduates of the Canadian Royal College-accredited Vascular Fellowships (VFs) and Integrated Vascular Surgery Residency (IVSR) programs (2007-2019) to record cases performed during their final 2 years of training. Procedures of interest were open abdominal aortic aneurysm (oAAA) repair, open thoracic/thoracoabdominal aortic (oTAA/TAAA) repair, lower extremity bypass (LEB), carotid endarterectomy (CEA), lower extremity endovascular intervention (LEEI), and endovascular abdominal, advanced, and thoracic aortic repair (EVAR, aEVAR, and TEVAR). Case volumes were analyzed overall, and by graduation year, type of training program, and resident demographics. RESULTS: A total of 60 participants (10% female) from all the 10 Canadian training institutions responded (response rate, 63%). There was a declining trend in overall procedures performed since the introduction of IVSR in 2012 (median, 427 [interquartile range (IQR), 304-496] in 2007-2012 vs median, 342 [IQR, 279-405] in 2013-2019; P = .055), driven by a significant decline in open vascular surgery cases (median, 273 [IQR, 221-339] in 2007-2012 vs median, 156 [IQR, 128-181] in 2013-2019; P = .001). Case volumes of oAAA, LEB, and CEA declined by 44%, 40%, and 45%, respectively. Compared with vascular fellows, IVSR residents logged ∼2.5 times more aEVARs (median, 8; IQR, 2-11 vs median, 19; IQR, 8-27; P = .001) and ∼1.5 times more LEEIs (median, 60; IQR, 40-99 vs median, 93; IQR, 69-120; P = .018). Trainees were most confident (range, 90%-100%) in performing oAAA, EVAR, LEB, LEEI, and CEA after training, and least confident in performing oTAA/TAAA and aEVAR (20% and 49% confidence, respectively). CONCLUSIONS: Operative case volumes of Canadian vascular surgery trainees since the introduction of IVSR program in 2012 have decreased, driven by declining exposure to open cases. However, trainees continue to receive adequate operative exposure to perform most standard vascular procedures confidently upon graduation.

Outcomes of abdominal aortic aneurysm repair among patients with rheumatoid arthritis.

OBJECTIVE: In the present study, we compared the outcomes of elective abdominal aortic aneurysm (AAA) repair in patients with and without rheumatoid arthritis (RA) stratified by the type of surgery. METHODS: A retrospective population-based cohort study was conducted from 2003 to 2016. Linked administrative health data from Ontario, Canada were used to identify all patients aged ≥65 years who had undergone elective open or endovascular AAA repair during the study period. Patients were identified using validated procedure and billing codes and matching using propensity scores. The primary outcome was survival. The secondary outcomes were major adverse cardiovascular events (MACE)-free survival (defined as freedom from death, myocardial infarction, and stroke), reintervention, and secondary rupture. RESULTS: Of 14,816 patients undergoing elective AAA repair, a diagnosis of RA was present for 309 (2.0%). The propensity-matched cohort included 234 pairs of RA and control patients. The matched cohort was followed up for a mean ± standard deviation of 4.93 ± 3.35 years, and the median survival was 6.76 and 7.31 years for the RA and control groups, respectively. Cox regression analysis demonstrated no statistically significant differences in the hazards for death, MACE, reintervention, or secondary rupture. Analysis of the differences in outcomes stratified by repair approach also showed no statistically significant differences in the hazards for death, MACE, reintervention, or secondary rupture. CONCLUSIONS: We found no statistically significant differences in survival, MACE, reintervention, or secondary rupture among patients with RA undergoing elective AAA repair compared with controls. Further studies are required to evaluate the impact of comorbidities and antirheumatic medications on the outcomes of elective AAA repair.

A systematic review and meta-analysis of plain versus drug-eluting balloon angioplasty in the treatment of juxta-anastomotic hemodialysis arteriovenous fistula stenosis.

OBJECTIVE: Owing to the lack of comparative evidence between the endovascular technologies for arteriovenous fistula (AVF) stenosis treatments, we sought to summarize the reported data comparing the effectiveness of different endovascular approaches for the treatment of AVF stenoses at the juxta-anastomotic site. METHODS: We performed a systematic review in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The MEDLINE, Embase, and Cochrane Central Register of Controlled Trials databases were searched from inception to June 12, 2018 for observational and randomized studies that had examined the effectiveness of AVF stenosis treatment using plain percutaneous balloon angioplasty (PTA), cutting balloon angioplasty, drug-eluting balloon (DEB) angioplasty, high-pressure balloon angioplasty, and stenting. Bias was assessed using the Newcastle-Ottawa scale for observational studies and the Cochrane Collaboration tool for randomized studies. Article screening, full-text review, assessment of bias, and data collection were conducted in duplicate, with a third reviewer to reconcile any discrepancies. We conducted a qualitative synthesis of the available evidence and a quantitative meta-analysis for the primary assisted patency outcome. The meta-analysis was conducted using Review Manager, version 5.3, using random effects models, with the I2 statistic used to assess heterogeneity. Statistical significance was set at P < .05. RESULTS: Our search yielded 3683 reports. Of these, three randomized trials and three observational studies were included. Three studies with 342 patients had described the effectiveness of high-pressure balloon angioplasty, conventional PTA, and stenting and had analyzed the data qualitatively. Three studies with 141 patients had investigated native AVF patency after DEB angioplasty and conventional PTA and were included in the meta-analysis. DEB angioplasty showed significantly greater primary assisted patency rates at 12 months after treatment compared with PTA (odds ratio, 3.66; 95% confidence interval, 1.32-10.14; I2 = 49%). No statistically significant differences were found in 6-month primary assisted patency among the treatment groups (odds ratio, 2.03; 95% confidence interval, 0.64-6.45; I2 = 50%). A total of 58 of 72 AVFs remained patent 6 months after DEB angioplasty compared with 45 of 69 at 6 months after PTA. At 12 months after treatment, 48 of 72 AVFs remained patent after DEB angioplasty compared with 23 of 69 AVFs after PTA. CONCLUSIONS: Our findings suggest DEB angioplasty is a more effective treatment option for AVF stenosis at the juxta-anastomotic site compared with PTA. Although DEB angioplasty might provide longer term patency than other endovascular treatments, further high-quality data are needed to confirm this finding.

Population-based long-term outcomes of open versus endovascular aortic repair of ruptured abdominal aortic aneurysms.

OBJECTIVE: Existing data regarding endovascular aortic repair (EVAR) of ruptured abdominal aortic aneurysm (rAAA) are conflicting in their findings. The purpose of this paper was to determine the long-term outcomes of EVAR vs open surgical repair (OSR) for treatment of rAAA. METHODS: A population-based retrospective cohort study of all patients 40 years or more that underwent OSR or EVAR of rAAA in Ontario, Canada, from 2003 to 2016 was conducted. Administrative data from the province of Ontario was used as the data source. The propensity for repair approach was calculated using a logistic regression model including all covariates and used for inverse probability of treatment weighting. Cox proportional hazards regression was conducted using the weighted cohort to determine the survival and major adverse cardiovascular event (MACE)-free survival of EVAR relative to OSR for rAAA up to 10 years after repair. RESULTS: A total of 2692 rAAA (261 EVAR [10%] and 2431 OSR [90%]) repairs were recorded from April 1, 2003, to March 31, 2016. Mean follow-up for the entire cohort was 3.4 years (standard deviation [SD], 3.9 years), with a maximum follow-up of 14.0 years. OSR patients were followed for a mean of 3.5 years (SD, 4.0 years) and maximum of 14.0 years, and EVAR patients were followed for a mean of 2.7 years (SD, 2.7 years) and a maximum of 11.4 years. Median survival was 2.7 years overall, and 2.5 and 3.7 years for OSR and EVAR patients, respectively. There were no significant baseline differences between EVAR and OSR patients after inverse probability of treatment weighting. EVAR patients were at lower hazard for all-cause mortality (hazard ratio, 0.49; 95% confidence interval, 0.37-0.65; P < .01), and MACE (hazard ratio, 0.51, 95% confidence interval, 0.40-0.66; P < .01) within 30 days of repair. There were no statistically significant differences between EVAR and OSR in the hazard for all-cause mortality or MACE from 30 days to 5 years, and 5 to 10 years. Despite this, the upfront mortality and MACE benefits of EVAR persisted for more than 4.5 years after repair. CONCLUSIONS: This population-based cohort study using administrative data from Ontario, Canada, demonstrated lower hazards for all-cause mortality and MACE within 30 days of operation in favor of EVAR, but no differences in the mid- or longer-term results. More work is needed to understand and improve the long-term outcomes of ruptured endovascular aortic aneurysm repair and ruptured open surgical repair.

Short-term outcomes of combined neuraxial and general anaesthesia versus general anaesthesia alone for elective open abdominal aortic aneurysm repair: retrospective population-based cohort study†.

BACKGROUND: Use of neuraxial anaesthesia for open abdominal aortic aneurysm repair is postulated to reduce mortality and morbidity. This study aimed to determine the 90-day outcomes after elective open abdominal aortic aneurysm repair in patients receiving combined general and neuraxial anaesthesia vs general anaesthesia alone. METHODS: A retrospective population-based cohort study was conducted from 2003 to 2016. All patients ≥40 yr old undergoing open abdominal aortic aneurysm repair were included. The propensity score was used to construct inverse probability of treatment weighted regression models to assess differences in 90-day outcomes. RESULTS: A total of 10 447 elective open abdominal aortic aneurysm repairs were identified; 9003 (86%) patients received combined general and neuraxial anaesthesia and 1444 (14%) received general anaesthesia alone. Combined anaesthesia was associated with significantly lower hazards for all-cause mortality (hazard ratio [HR]=0.47; 95% confidence interval [CI], 0.37-0.61) and major adverse cardiovascular events (HR=0.72; 95% CI, 0.60-0.86). Combined patients were at lower odds for acute kidney injury (odds ratio [OR]=0.66; 95% CI, 0.49-0.89), respiratory failure (OR=0.41; 95% CI, 0.36-0.47), and limb complications (OR=0.30; 95% CI, 0.25-0.37), with higher odds of being discharged home (OR=1.32; 95% CI, 1.15-1.51). Combined anaesthesia was also associated with significant mechanical ventilation and ICU and hospital length of stay benefits. CONCLUSIONS: Combined general and neuraxial anaesthesia in elective open abdominal aortic aneurysm repair is associated with reduced 90-day mortality and morbidity. Neuraxial anaesthesia should be considered as a routine adjunct to general anaesthesia for elective open abdominal aortic aneurysm repair.

Ticagrelor as an Alternative Antiplatelet Therapy in Cardiac Patients Non-Sensitive to Aspirin.

Background and Objectives: Aspirin (acetylsalicylic acid-ASA) is a first-line antiplatelet therapy provided to patients with coronary artery disease (CAD). However, it has been demonstrated that 20-30% of these patients are non-sensitive to their ASA therapy. ASA non-sensitivity is a phenomenon where low-dose ASA (81-325 mg) does not completely inhibit arachidonic-acid-induced platelet aggregation, putting patients at risk of adverse cardio-thrombotic events. Ticagrelor is a P2Y12 receptor inhibitor and alternative antiplatelet that has been approved to reduce the risk of stroke, myocardial infarction, and overall cardiovascular-related death. In this study, we aimed to identify ASA non-sensitive patients and evaluate if they would be sensitive to ticagrelor. Materials and Methods: For this pilot study, thirty-eight patients with CAD taking 81 mg ASA were recruited. Blood samples were collected from each patient and platelet rich plasma (PRP) from each sample was isolated. Light-transmission aggregometry (LTA) was used to determine baseline ASA sensitivity in each patient using 0.5 mg/mL arachidonic acid as a platelet agonist. Patients with ≥20% maximal platelet aggregation after activation were considered ASA non-sensitive. Fresh PRP samples from all patients were then spiked with a clinical dosage of ticagrelor (3 µM-approximately equivalent to a loading dose of 180 mg ticagrelor). Sensitivity was determined using LTA and 5 µM ADP as a platelet agonist. Patients with ≥46% maximal platelet aggregation were considered ticagrelor non-sensitive. Results: Of the 38 CAD patients taking 81 mg ASA, 32% (12/38) were non-sensitive to their 81 mg ASA therapy. All 38 of the recruited patients (100%) were sensitive to ticagrelor ex vivo. In conclusion, we were able to identify ASA non-sensitivity using LTA and determine that ASA non-sensitive patients were sensitive to ticagrelor. Conclusions: Our results suggest that ticagrelor is a promising alternative therapy for patients who are non-sensitive to ASA.

Optimization of rifampin coating on covered Dacron endovascular stent grafts for infected aortic aneurysms.

OBJECTIVE: In the treatment of an infected aorta, open repair and replacement with a rifampin-impregnated Dacron vascular graft decrease the risk of prosthetic graft infections, with several protocols available in the literature. We hypothesize that the same holds true for endovascular aneurysm repair, and after studying and optimizing rifampin solution concentration and incubation period to maximize the coating process of rifampin on Dacron endovascular stent grafts (ESGs), we propose a rapid real-time perioperative protocol. METHODS: Several prepared rifampin solutions, including a negative control solution, were used to coat multiple triplicate sets of Dacron endovascular aortic stent grafts at different but set incubation periods. Rifampin elution from the grafts was studied by spectroscopic analysis. Once an optimized solution concentration and incubation time were determined, the elution of rifampin over time from the graft and the graft's surface characteristics were studied by ultraviolet-visible spectroscopy and atomic force microscopy. RESULTS: All coated ESGs with any concentration of prepared rifampin solution, regardless of incubation time, immediately demonstrated a visible bright orange discoloration and subsequently after elution procedures returned to the original noncolored state. At the 25-minute incubation time (standard flush), there was no statistical difference in the amount of rifampin coated to the ESGs with 10-mg/mL, 30-mg/mL, and 60-mg/mL solutions (0.06 ± 0.01, 0.07 ± 0.05, and 0.044 ± 0.01, respectively; P > .05). This was also true for a 10-minute incubation time (express flush) of 10-mg/mL and 60-mg/mL rifampin solution concentrations (0.04 ± 0.007 and 0.066 ± 0.014, respectively; P = .22). The elution-over-time of coated rifampin ESG, although not statistically significant, did seem to plateau and to reach a steady state by 50 hours and was confirmed by surface characteristics using atomic force microscopy. CONCLUSIONS: Having studied two variables of rifampin coating techniques to Dacron ESGs, the authors propose a rapid real-time perioperative coating protocol by using a 10-mg/mL rifampin solution for a 10-minute incubation period. As rifampin loosely binds to Dacron ESGs by weak intermolecular forces, a rifampin-coated ESG would need to be inserted in a timely fashion to treat the diseased aorta and to deliver its antibiotic affect. A rapid perioperative coating protocol followed by immediate deployment makes our proposed technique especially useful in an urgent and unstable clinical scenario.

A systematic review and meta-analysis of the long-term outcomes of endovascular versus open repair of abdominal aortic aneurysm.

OBJECTIVE: This study synthesized the literature comparing the long-term (5-9 years) and very long-term (≥10 years) all-cause mortality, reintervention, and secondary rupture rates between endovascular aneurysm repair (EVAR) and open surgical repair (OSR) of abdominal aortic aneurysm (AAA). METHODS: MEDLINE, Embase, and CENTRAL databases were searched from inception to May 2018 for studies comparing EVAR to OSR with a minimum follow-up period of 5 years. Study selection, data abstraction, and quality assessment were conducted by two independent reviewers, with a third author resolving discrepancies. Study quality was assessed using the Cochrane and Newcastle-Ottawa scales. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were calculated using random-effects models. Heterogeneity was quantified using the I2 statistic, and publication bias was assessed using funnel plots. RESULTS: Our search yielded 3431 unique articles. Three randomized controlled trials and 68 observational studies comparing 151,092 EVAR to 148,692 OSR patients were included. Inter-rater agreement was excellent at the screening (κ = 0.78) and full-text review (κ = 0.89) stages. Overall, the risk of bias was low to moderate. For long-term outcomes, 54 studies reported all-cause mortality (n = 203,246), 23 reported reintervention (n = 157,151), and 4 reported secondary rupture (n = 150,135). EVAR was associated with higher long-term all-cause mortality (OR, 1.19; 95% CI, 1.06-1.33; P = .003, I2 = 91%), reintervention (OR, 2.12; 95% CI, 1.67-2.69; P < .00001, I2 = 96%), and secondary rupture rates (OR, 4.84; 95% CI, 2.63-8.89; P < .00001, I2 = 92%). For very long-term outcomes, 15 studies reported all-cause mortality (n = 48,721), 9 reported reintervention (n = 7511), and 1 reported secondary rupture (n = 1116). There was no mortality difference between groups, but EVAR was associated with higher reintervention (OR, 2.47; 95% CI, 1.71-3.57; P < .00001, I2 = 84%) and secondary rupture rates (OR, 8.10; 95% CI, 1.01-64.99; P = .05). Subanalysis of more recent studies, with last year of patient recruitment 2010 or after, demonstrated no long-term mortality differences between EVAR and OSR. CONCLUSIONS: EVAR is associated with higher long-term all-cause mortality, reintervention, and secondary rupture rates compared with OSR. In the very long-term, EVAR is also associated with higher reintervention and secondary rupture rates. Notably, EVAR mortality has improved over time. Vigilant long-term surveillance of EVAR patients is recommended.

Validation of abdominal aortic aneurysm repair codes in Ontario administrative data.

PURPOSE: To determine the positive predictive values (PPV) of Ontario administrative data codes for the identification of open (OSR) and endovascular (EVAR) repairs of elective (eAAA) and ruptured (rAAA) abdominal aortic aneurysms. METHODS: We randomly identified 319 eAAA and rAAA repairs at two Toronto hospitals between April 2003 and March 2015, using administrative health data in Ontario, Canada. International Statistical Classification of Diseases and Related Health Problems 10th Revision (ICD-10) codes I71.3 and I71.4, were used to identify rAAA and eAAA patients, respectively. A blinded retrospective chart review was conducted and served as the gold standard comparator. Re-abstracted records were compared to Canadian Classification of Health Interventions (CCI) and Ontario Health Insurance Plan (OHIP) codes in the Canadian Institute for Health Information Discharge Abstract Database (CIHI-DAD) and OHIP databases. We calculated the PPV and 95% confidence intervals (95% CI) of individual and combined procedure and billing codes for elective and ruptured OSR and EVAR (eOSR, eEVAR, rOSR, and rEVAR). RESULTS: Permutation of codes allowed identification of eOSR with 95% PPV (95% CI 88, 98), eEVAR with 96% PPV (95% CI 90, 99), rOSR with 87% PPV (95% CI 79, 93) and rEVAR with 91% PPV (95% CI 59, 100). CONCLUSIONS: Diagnostic, procedure and billing code combinations allow identification of eOSR, eEVAR, rOSR and rEVAR patients in Ontario administrative data with a high degree of certainty.

True Ulnar Artery Aneurysm in the Proximal Forearm: Case Report and Literature Review.

BACKGROUND: Ulnar artery aneurysms are rare with less than 150 previously reported. Previously ulnar aneurysms have been most commonly noted as occurring in the distal ulnar artery close to the palmar arch. METHODS: We present the case of a 47-year-old male with a background history of human immunodeficiency virus (HIV) who attended our outpatient clinic with symptoms of distal embolization from a proximal ulnar artery aneurysm. RESULTS: Preoperatively, the aneurysm was thought to arise from the distal brachial artery, and only intraoperatively was the diagnosis of ulnar aneurysm made. The aneurysm was excised, and a reverse vein bypass graft anastomosed end to side on the brachial artery, and end to end on the distal ulnar. True ulnar artery aneurysms also involving the more proximal ulnar artery have been previously reported associated with vasculitic disorders. HIV has been previously associated with aneurysm formation in a number of anatomical locations. This case is noteworthy as it reports on the presentation and successful operative management of a true ulnar artery aneurysm arising in the proximal forearm in the setting of HIV, which has not been previously reported in medical literature. CONCLUSIONS: We present successful operative management of a true ulnar aneurysm in the proximal forearm using a reverse venous interposition bypass. Diagnosis of a proximal ulnar artery aneurysm may represent a diagnostic challenge given its rarity as it may mimic brachial artery aneurysm.

Angio-Seal Closure for Traumatic Left Subclavian Artery Pseudoaneurysm: A Case Report.

Subclavian artery pseudoaneurysms are rare and associated with high morbidity and mortality. Alternative approaches to open surgical repair can include endovascular repair or ultrasound-guided thrombin injection. Here, we describe a safe and novel technique of closure of a subclavian artery pseudoaneurysm with Angio-Seal that was unresponsive to thrombin injection and in a difficult location for open repair.

Chromatographic Enantiomer Separation Using 9-Amino-9-(deoxy)-epiquinine-derived Chiral Selectors: Control of Chiral Recognition via Introduction of Additional Stereogenic Centers.

Three new cinchona-type chiral selectors have been prepared by attaching N-pivaloyl-glycine, N-pivaloyl-(S)-valine and N-pivaloyl-(R)-valine segments to the C9-amino function of 9-amino-9-(deoxy)-epiquinine (eAQN), and immobilized to silica to provide the corresponding chiral stationary phases (CSPs). Evaluation of the chromatographic enantioseparation characteristics of these CSPs with a broad assortment of N-carbamoyl protected amino acids under polar organic mobile phase conditions revealed modest chiral recognition capabilities for N-Fmoc-, N-Cbz- and N-Boc-derivatives. It was found that the enantioselective analyte binding to these CSPs is strictly controlled by the absolute stereo-chemistry of the amino acid functionalities attached to the C9-amino group of the eAQN framework. Specifically, the CSP derived from (S)-valine-based selector exhibits preferential binding of N-carbamoyl-(S)-amino acids, while the CSPs featuring (R)-valine- and the glycine-derived selectors show opposite enantioselective binding preference. The observed impact of analyte structure on enantioselectivity and the specific preferences in enantioselective binding point to chiral recognition mechanisms capitalizing on intermolecular ion pairing, hydrogen bonding and subtle steric interactions, with the latter making the crucial contributions to stereodiscrimination. The finding that the chiral recognition characteristics of epiquinine can be readily controlled via incorporation of additional stereogenic centers remote from the cinchona scaffold might be useful information for the design of new enantioselective receptors and organocatalysts.

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.

Predictors of peri-opertative morbidity and liver dysfunction after hepatic resection in patients with chronic liver disease.

BACKGROUND: Hepatic resection in patients with chronic liver disease (CLD) is associated with a risk of post-operative liver failure and higher morbidity than patients without liver disease. There is no universal risk stratification scheme for CLD patients undergoing resection. OBJECTIVES: The aim of the present study was to evaluate the association between routine pre-operative laboratory investigations, model for end-stage liver disease (MELD), indocyanine green retention at 15 min (ICG15) and post-operative outcomes in CLD patients undergoing liver resection. METHODS: A retrospective review of patients undergoing resection for hepatocellular carcinoma (HCC) at the University Health Network was preformed. ICG15 results, pre- and post-operative laboratory results were obtained from clinical records. Adjusted odds ratios (AOR) were calculated for associations between pre-operative factors and post-operative outcomes using multivariate logistic regression adjusting for patient age and number of segments resected. RESULTS: Between 2001 and 2005, 129 CLD patients underwent surgical resection for HCC. Procedures included 51 (40%) resections of ≤ 2 segments, 52 (40%) hemihepatectomies and 25 (19%) extended hepatic resections. Thirty- and 90-day post-operative mortality was 1.6% and 4.1%, respectively. Prolonged (>10 days) hospital length of stay (LOS) was independently associated with an ICG15 >15% {AOR [95% confidence interval (CI)]= 8.5 (1.4-51)} and an international normalized ratio (INR) > 1.2 [AOR (95% CI) = 5.0 (1.4-18.6)]. An ICG15 > 15% and MELD score were independent predictors of prolonged LOS. An ICG15 > 15% was also independently associated with MELD > 20 on post-operative day 3 [AOR (95% CI) = 24.3 (1.8-319)]. CONCLUSIONS: Elevated ICG retention was independently associated with post-operative liver dysfunction and morbidity. The utility of ICG in combination with other biochemical measures to predict outcomes after hepatic resection in CLD patients requires further prospective study.

Harnessing the full potential of hospital-based data to support surgical quality improvement.

Surgical departments commonly rely on third-party quality improvement registries. As electronic health data become increasingly integrated and accessible within an institution, alternatives to these platforms arise. We present the conceptualization and implementation of an in-house quality improvement platform that provides real-time reports, is less onerous on clinicians and is tailored to an institution's priorities of care.

Gender differences in faculty rank among academic physicians: a systematic review and meta-analysis.

OBJECTIVE: Many studies have analysed gender bias in academic medicine; however, no comprehensive synthesis of the literature has been performed. We conducted a pooled analysis of the difference in the proportion of men versus women with full professorship among academic physicians. DESIGN: Systematic review and meta-analysis. DATA SOURCES: MEDLINE, Embase, Cochrane Central Register of Controlled Trials, Education Resources Information Center and PsycINFO were searched from inception to 3 July 2020. STUDY SELECTION: All original studies reporting faculty rank stratified by gender worldwide were included. DATA EXTRACTION AND SYNTHESIS: Study screening, data extraction and quality assessment were performed by two independent reviewers, with a third author resolving discrepancies. Meta-analysis was conducted using random-effects models. RESULTS: Our search yielded 5897 articles. 218 studies were included with 991 207 academic physician data points. Men were 2.77 times more likely to be full professors (182 271/643 790 men vs 30 349/251 501 women, OR 2.77, 95% CI 2.57 to 2.98). Although men practised for longer (median 18 vs 12 years, p<0.00002), the gender gap remained after pooling seven studies that adjusted for factors including time in practice, specialty, publications, h-index, additional PhD and institution (adjusted OR 1.83, 95% CI 1.04 to 3.20). Meta-regression by data collection year demonstrated improvement over time (p=0.0011); however, subgroup analysis showed that gender disparities remain significant in the 2010-2020 decade (OR 2.63, 95% CI 2.48 to 2.80). The gender gap was present across all specialties and both within and outside of North America. Men published more papers (mean difference 17.2, 95% CI 14.7 to 19.7), earned higher salaries (mean difference $33 256, 95% CI $25 969 to $40 542) and were more likely to be departmental chairs (OR 2.61, 95% CI 2.19 to 3.12). CONCLUSIONS: Gender inequity in academic medicine exists across all specialties, geographical regions and multiple measures of success, including academic rank, publications, salary and leadership. Men are more likely than women to be full professors after controlling for experience, academic productivity and specialty. Although there has been some improvement over time, the gender disparity in faculty rank persists. PROSPERO REGISTRATION NUMBER: CRD42020197414.

Elevated plasma levels of NT-proBNP in ambulatory patients with peripheral arterial disease.

N-terminal pro B-type natriuretic peptide (NT-proBNP), a cardiac disease biomarker, has been demonstrated to be a strong independent predictor of cardiovascular events in patients without heart failure. Patients with peripheral arterial disease (PAD) are at high risk of cardiovascular events and death. In this study, we investigated levels of NT-proBNP in patients with PAD compared to non-PAD controls. A total of 355 patients were recruited from outpatient clinics at a tertiary care hospital network. Plasma NT-proBNP levels were quantified using protein multiplex. There were 279 patients with both clinical and diagnostic features of PAD and 76 control patients without PAD (non-PAD cohort). Compared with non-PAD patients, median (IQR) NT-proBNP levels in PAD patients were significantly higher (225 ng/L (120-363) vs 285 ng/L (188-425), p- value = 0.001, respectively). Regression analysis demonstrated that NT-proBNP remained significantly higher in patients with PAD relative to non-PAD despite adjusting for age, sex, hypercholesterolemia, smoking and hypertension [odds ratio = 1.28 (1.07-1.54), p-value <0.05]. Subgroup analysis showed elevated NT-proBNP levels in patients with PAD regardless of prior history of CHF, CAD, diabetes and hypercholesteremia (p-value <0.05). Finally, spearmen's correlation analysis demonstrated a negative correlation between NT-proBNP and ABI (ρ = -0.242; p-value < 0.001). In conclusion, our data shows that patients with PAD in an ambulatory care setting have elevated levels of NT-proBNP compared to non-PAD patients in the absence of cardiac symptoms.

Topical Oxygen Therapy Shifts Microbiome Dynamics in Chronic Diabetic Foot Ulcers.

INTRODUCTION: Bacterial biofilm in wounds prevents healing by acting as a physical barrier to wound closure and hyperactivating local inflammatory processes, thus making its removal a high priority. The authors previously have shown that adding topical oxygen to standard wound care increased healing of Texas Grade II and III diabetic foot ulcers (DFUs), which they hypothesized was a result of alterations of the wound microbiome/biofilm. OBJECTIVE: This study aims to determine the mechanism of action of topical oxygen in DFUs by examining the diversity of bacterial genera present in DFUs treated with topical oxygen. MATERIALS AND METHODS: Six patients with chronic DFUs had their wounds swabbed weekly over an 8-week period of continuous topical oxygen treatment, and microbiome diversity was assessed by metagenomic 16S rDNA sequencing using a next-generation sequencing platform. RESULTS: The wound microbiome shifted toward a diverse flora dominated by aerobes and facultative anaerobes with oxygen therapy in 5 healed wounds. In contrast, anaerobic flora persisted in a single nonhealing ulcer in the present study cohort. CONCLUSIONS: Although the sample size was small, this study suggests topical oxygen therapy may have the ability to encourage the growth of aerobic members of the wound microbiome and be an effective alternative to antibiotics in this area.