Risk Factors for Surgical Site Infection after Lower Limb Revascularisation Surgery: a Systematic Review and Meta-Analysis of Prognostic Studies.

OBJECTIVE: To systematically review and meta-analyse adjusted risk factors for surgical site infection (SSI) after lower limb revascularisation surgery. DATA SOURCES: MEDLINE, Embase, Evidence Based Medicine Reviews, and the Cochrane Central Register of Controlled Trials (inception to 28 April 2022). REVIEW METHODS: Systematic review and meta-analysis conducted according to PRISMA guidelines. After protocol registration, databases were searched. Studies reporting adjusted risk factors for SSI in adults who underwent lower limb revascularisation surgery for peripheral artery disease were included. Adjusted odds ratios (ORs) were pooled using random effects models. GRADE was used to assess certainty. RESULTS: Among 6 377 citations identified, 50 studies (n = 271 125 patients) were included. The cumulative incidence of SSI was 12 (95% confidence interval [CI] 10 - 13) per 100 patients. Studies reported 139 potential SSI risk factors adjusted for a median of 12 (range 1 - 69) potential confounding factors. Risk factors that increased the pooled adjusted odds of SSI included: female sex (pooled OR 1.41, 95% CI 1.20 - 1.64; high certainty); dependent functional status (pooled OR 1.18, 95% CI 1.03 - 1.35; low certainty); being overweight (pooled OR 1.82, 95% CI 1.29 - 2.56; moderate certainty), obese (pooled OR 2.20, 95% CI 1.44 - 3.36; high certainty), or morbidly obese (pooled OR 1.65, 95% CI 1.08 - 2.52; moderate certainty); chronic obstructive pulmonary disease (pooled OR 1.42, 95% CI 1.17 - 1.71; high certainty); chronic limb threatening ischaemia (pooled OR 1.67, 95% CI 1.22 - 2.29; moderate certainty); chronic kidney disease (pooled OR 2.13, 95% CI 1.18 - 3.83; moderate certainty); intra-operative (pooled OR 1.23, 95% CI 1.02 - 1.49), peri-operative (pooled OR 1.92, 95% CI 1.27 - 2.90), or post-operative (pooled OR 2.21, 95% CI 1.44 - 3.39) blood transfusion (moderate certainty for all); urgent or emergency surgery (pooled OR 2.12, 95% CI 1.22 - 3.70; moderate certainty); vein bypass and or patch instead of endarterectomy alone (pooled OR 1.86, 95% CI 1.33 - 2.59; moderate certainty); an operation lasting ≥ 3 hours (pooled OR 1.86, 95% CI 1.33 - 2.59; moderate certainty) or ≥ 5 hours (pooled OR 1.60, 95% CI 1.18 - 2.17; moderate certainty); and early or unplanned re-operation (pooled OR 4.50, 95% CI 2.18 - 9.32; low certainty). CONCLUSION: This systematic review identified evidence informed SSI risk factors following lower limb revascularisation surgery. These may be used to develop improved SSI risk prediction tools and to identify patients who may benefit from evidence informed SSI prevention strategies.

Association Between Complications after Vascular Surgery and Prolonged Postoperative Opioid Use.

BACKGROUND: Few studies have looked at the long-term risk of opioid use following major vascular surgery and no study has investigated the potential association between major complications and prolonged opioid use. We analyzed a population-based database linked to a prescription database to investigate factors associated with prolonged opioid use following major vascular surgery. METHODS: This population-based cohort study included all adults who underwent open lower extremity revascularization (LER) or nonruptured abdominal aortic aneurysm repair (open [AAA] and endovascular [EVAR]) in the province of Ontario, Canada, between 2013 and 2018. Prolonged opioid use was defined as 2 or more opioid prescriptions filled 6-12 months following surgery. Potential predictors of prolonged use were explored using modified Poisson regression with a generalized estimating equation approach to account for the clustering of patients within physicians and institutions. RESULTS: This study included a total of 11,104 patients with 5,652 patients undergoing open LER, 3,285 patients undergoing EVAR, and 2,167 patients undergoing AAA. The rates of prior opioid use were 35.4% for LER, 15.8% for AAA and 14.3% for EVAR. Major complication rates following each procedure were 59.5% for AAA, 35.1% for LER, and 21.0% for EVAR. Following surgery, prolonged opioid use was identified in 26.1% of LER, 13.2% of AAA, and 11.6% of EVAR patients. The strongest predictor of prolonged opioid use was prior use with an odds ratio (OR) of 13.27 (95% CI: 10.63-16.57) for AAA, 11.24 (95% CI: 9.18-13.75) for EVAR, and 4.69 (95% CI: 4.16-5.29) for LER. The occurrence of a major complication was only associated with prolonged opioid use for patients undergoing LER (OR 1.10; 95% CI: 1.03-1.19), while it had a protective effect on patients undergoing EVAR (OR 0.83; 95% CI: 0.69-0.99) and no association for patients undergoing open AAA repair (OR 1.11; 95% CI: 0.95-1.29). Older age was also protective with a reduced rate of prolonged opioid use for every 10 years of age increase: AAA (OR 0.87; 95% CI: 0.77-0.99); EVAR (OR 0.83; 95% CI: 0.76-0.91); and LER (OR 0.91; 95% CI: 0.87-0.94). CONCLUSIONS: Prolonged opioid use is common following major vascular surgery, occurring in over 10% of patients undergoing either open or endovascular aneurysm repair and over 25% of patients undergoing open LER. Prior opioid use is the strongest predictor for prolonged use, while the occurrence of postoperative complications is associated with a slight increased risk of prolonged use in patients undergoing LER. These patient populations should be targeted for multimodal methods of opioid reduction following their procedures.

Efficacy of Strategies Intended to Prevent Surgical Site Infection After Lower Limb Revascularization Surgery: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

OBJECTIVE: The objective of this study is to evaluate the efficacy of strategies intended to prevent surgical site infection (SSI) after lower limb revascularization surgery. BACKGROUND: SSIs are common, costly complications of lower limb revascularization surgery associated with significant morbidity and mortality. METHODS: We searched MEDLINE, EMBASE, CENTRAL, and Evidence-Based Medicine Reviews (inception to April 28, 2022). Two investigators independently screened abstracts and full-text articles, extracted data, and assessed the risk of bias. We included randomized controlled trials (RCTs) that evaluated strategies intended to prevent SSI after lower limb revascularization surgery for peripheral artery disease. We used random-effects models to pool data and GRADE to assess certainty. RESULTS: Among 6258 identified citations, we included 26 RCTs (n=4752 patients) that evaluated 12 strategies to prevent SSI. Preincision antibiotics [risk ratio (RR)=0.25; 95% CI, 0.11-0.57; n=4 studies; I2 statistic=7.1%; high certainty] and incisional negative-pressure wound therapy (iNPWT) (RR=0.54; 95% CI, 0.38-0.78; n=5 studies; I2 statistic=7.2%; high certainty) reduced pooled risk of early (≤30 days) SSI. iNPWT also reduced the risk of longer-term (>30 days) SSI (pooled-RR=0.44; 95% CI, 0.26-0.73; n=2 studies; I2 =0%; low certainty). Strategies with uncertain effects on risk of SSI included preincision ultrasound vein mapping (RR=0.58; 95% CI, 0.33-1.01; n=1 study); transverse groin incisions (RR=0.33; 95% CI, 0.097-1.15; n=1 study), antibiotic-bonded prosthetic bypass grafts (RR=0.74; 95% CI, 0.44-1.25; n=1 study; n=257 patients), and postoperative oxygen administration (RR=0.66; 95% CI, 0.42-1.03; n=1 study) (low certainty for all). CONCLUSIONS: Preincision antibiotics and iNPWT reduce the risk of early SSI after lower limb revascularization surgery. Confirmatory trials are required to determine whether other promising strategies also reduce SSI risk.

Microcirculation surrounding end-stage human chronic skin wounds is associated with endoglin/CD146/ALK-1 expression, endothelial cell proliferation and an absence of p16Ink4a.

Angiogenesis is an essential part of normal skin healing, re-establishing blood flow in developing granulation tissue. Non-healing skin wounds are associated with impaired angiogenesis and although the role of re-establishing macroscopic blood flow to limbs to prevent wound chronicity is well investigated, less is known about vascular alterations at the microcirculatory level. We hypothesised that significant phenotypic changes would be evident in blood vessels surrounding chronic skin wounds. Wound edge tissue, proximal to wound (2 cm from wound edge) and non-involved skin (>10 cm from wound edge) was harvested under informed consent from 20 patients undergoing elective amputation due to critical limb ischemia. To assess blood vessel structure and viability, tissue was prepared for histological analysis and labelled with antibodies specific for PECAM-1 (CD31), CD146, endoglin, ALK-1, ALK-5, and p16Ink4a as a marker of cellular senescence. Density of microvasculature was significantly increased in wound edge dermis, which was concomitant with increased labelling for endoglin and CD146. The number of CD31 positive vessel density was unchanged in wound edge tissue relative to non-involved tissue. Co-labelling of endoglin with the transforming growth factor receptor ALK-1, and to a lesser extent ALK-5, demonstrated activation of endothelial cells which correlated with PCNA labelling indicative of proliferation. Analysis of p16Ink4a staining showed a complete lack of immunoreactivity in the vasculature and dermis, although staining was evident in sub-populations of keratinocytes. We conclude that the endoglin-ALK-1-endothelial proliferation axis is active in the vasculature at the edge of chronic skin wounds and is not associated with p16Ink4a mediated senescence. This information could be further used to guide treatment of chronic skin wounds and optimise debridement protocols.

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.

A Meta-Analysis to Derive Population-Based Quality Benchmarks of the Incidence of Surgical Site Infection after Lower Limb Revascularization Surgery.

BACKGROUND: The reported incidence of surgical site infection (SSI) after lower limb revascularization surgery varies. We conducted a systematic review and meta-analysis of population-based studies reporting the incidence of SSI in adults who underwent these surgeries in high-income countries to derive SSI quality benchmarks. METHODS: We searched MEDLINE, EMBASE, CENTRAL, and Evidence-Based Medicine Reviews (inception-to-April 28th, 2022) for population-based studies estimating the cumulative incidence of SSI among adults who underwent lower limb revascularization surgery for peripheral artery disease (PAD) in high-income countries. Two investigators independently screened abstracts and full-text articles, extracted data, and assessed risks of bias. We used random-effects models to pool data and GRADE to assess certainty. RESULTS: Among 6,258 citations, we included 53 studies (n = 757,726 patients); 8 of which (n = 435,769 patients) reported nonoverlapping data that were meta-analyzed. The pooled cumulative incidence of any SSI was 6.0 in 100 patients [95% confidence interval (CI) = 4.3-8.0 in 100 patients; n = 8 studies; n = 435,769 patients; moderate certainty]. The cumulative incidence of Szilagyi grade I (cellulitis), grade II (subcutaneous tissue), and grade III (prosthetic graft) SSI was 6.5 in 100 patients (95% CI = 4.3-8.6 in 100 patients; n = 2 studies; n = 39,645 patients; low certainty), 2.1 in 100 patients (95% CI = 2.0-2.3 in 100 patients; n = 2 studies; low certainty), and 0.4 in 100 patients (95% CI = 0.4-0.4 in 100 patients; n = 1 study; n = 333,275 patients; low certainty), respectively. The pooled cumulative incidence of any early (in-hospital/≤30-days) and late (>30-days) SSI was 6.2 in 100 patients (95% CI = 4.4-8.0 in 100 patients; n = 7 studies; n = 431,273 patients; moderate certainty) and 3.7 in 100 patients (95% CI = 2.2-5.2 in 100 patients; n = 2 studies; n = 10,565 patients; low certainty), respectively. CONCLUSIONS: This systematic review derived population-based benchmarks of the incidence of any SSI; Szilagyi I, II, and III SSI; and early and late SSI after lower limb revascularization surgery. These may be used by practicing surgeons and healthcare leaders/administrators to guide quality improvement efforts in the United States and perhaps other countries.

Defining major surgical complications using administrative data in Ontario: a validation study.

BACKGROUND: Although surgical complications are often included as an outcome of surgical research conducted using administrative data, little validation work has been performed. We sought to evaluate the diagnostic performance of an algorithm designed to capture major surgical complications using health administrative data. METHODS: This retrospective study included patients who underwent high-risk elective general surgery at a single institution in Ontario, Canada, from Sept. 1, 2016, to Sept. 1, 2017. Patients were identified for inclusion using the local operative database. Medical records were reviewed by trained clinicians to abstract postoperative complications. Data were linked to administrative data holdings, and a series of code-based algorithms were applied to capture a composite indicator of major surgical complications. We used sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy to evaluate the performance of our administrative data algorithm, as compared with data abstracted from the institutional charting system. RESULTS: The study included a total of 270 patients. According to the data from the chart audit, 55% of patients experienced at least 1 major surgical complication. Overall sensitivity, specificity, PPV, NPV and accuracy for the composite outcome was 72%, 80%, 82%, 70% and 76%, respectively. Diagnostic performance was poor for several of the individual complications. CONCLUSION: Our results showed that administrative data holdings can be used to capture a composite indicator of major surgical complications with adequate sensitivity and specificity. Additional work is required to identify suitable algorithms for several specific complications.

The Society for Vascular Surgery clinical practice guidelines on popliteal artery aneurysms.

The Society for Vascular Surgery clinical practice guidelines on popliteal artery aneurysms (PAAs) leverage the work of a panel of experts chosen by the Society for Vascular Surgery to review the current world literature as it applies to PAAs to extract the most salient, evidence-based recommendations for the treatment of these patients. These guidelines focus on PAA screening, indications for intervention, choice of repair strategy, management of asymptomatic and symptomatic PAAs (including those presenting with acute limb ischemia), and follow-up of both untreated and treated PAAs. They offer long-awaited evidence-based recommendations for physicians taking care of these patients.

Malperfusion syndrome in acute type A aortic dissection: Thinking beyond the proximal repair.

BACKGROUND AND OBJECTIVE: Malperfusion syndrome (MPS) is associated with the highest mortality and major morbidity risk in patients with acute Type A aortic dissection (TAAD). The timing of the open proximal aortic repair in the presence of MPS remains debatable given variability in clinical presentation and different local treatment algorithms. This paper provides an up to date and comprehensive overview of published outcomes and available techniques for addressing malperfusion in the setting of acute TAAD. METHODS: We have reviewed published data from the major aortic dissection registries including the International Registry of Acute Aortic Dissection, the German Registry for Acute Aortic Dissection In Type A, and the Nordic Consortium for Acute Type A Aortic Dissection, as well as the most up to date literature involving malperfusion in the setting of acute TAAD. This data highlights unique strategies that have been adopted at aortic centers internationally to address malperfusion in this setting pre-, intra-, and postoperatively, which are summarized here and may be of great clinical benefit to other centers treating this disease with more traditional methods. RESULTS: The review of the available data has definitively shown an increased mortality up to 43% and morbidity in patients presenting with MPS in the setting of acute TAAD. More specifically, preoperative MPS has been shown to be an independent predictor of mortality with mesenteric malperfusion associated with the worst mortality outcomes from 70% to 100%. Addressing MPS pre or intraoperatively is associated with significantly reduced mortality outcomes down to 4%-13%. CONCLUSION: Adapting a dynamic and easily accessible diagnostic method for the comprehensive assessment of different forms of malperfusion (dynamic/static) and incorporating it within the surgical plan is the first step toward early diagnosis and prevention of malperfusion related complications.

Systematic Review of the Long-Term Effects of Presurgical Orthopedic Devices on Patient Outcomes.

OBJECTIVE: To perform a systematic review of the literature to identify the long-term effects of presurgical orthopedic (PSO) device use on patient outcomes. DESIGN: A comprehensive literature review of Embase and Ovid databases was performed to identify all English-language publications related to unilateral cleft lip and palate, presurgical devices, and patient outcomes. Studies were excluded if they did not report patient outcomes beyond 2 years of age, did not describe the use of a PSO device, were case reports (n < 10), or were purely descriptive studies. MAIN OUTCOME MEASURES: Reported patient outcomes following the use of PSO devices. RESULTS: Following a review of all articles by 2 independent reviews, 30 articles were selected for inclusion. Overall, there was no reported consensus as to the long-term effects of PSO devices. Furthermore, this study identified that only 10% of published research controlled for confounding factors that could influence the reported results. Confounding factors that were identified included different operating surgeon, different surgical protocols, and different rates of revision surgeries. CONCLUSIONS: Overall, this systematic review identified 2 important conclusions. Firstly, there is no consensus in the literature about the long-term effects of PSO devices on long-term patient outcomes. Secondly, research in this domain is limited by confounding factors that influence the applicability of the reported results.

Onyx versus coil embolization for the treatment of type II endoleaks.

OBJECTIVE: Little evidence is available supporting the optimal treatment of type II endoleaks associated with aortic sac growth. Previous studies have lacked comparisons between treatment methods and long-term follow-up. The purpose of the present study was to review our center's experience with the treatment of type II endoleaks comparing Onyx (a liquid embolization agent consisting of ethylene vinyl alcohol; Medtronic, Minneapolis, Minn) embolization and coil embolization. METHODS: A retrospective review of prospectively collected data from a vascular surgery database was performed to identify all patients who had undergone embolization of a type II endoleak for aortic sac growth after endovascular aneurysm repair from 2005 to 2018. The Onyx and coil embolization groups were compared using univariate statistics. RESULTS: A total of 58 patients had undergone 77 embolization procedures for type II endoleaks with either Onyx (27 patients; 37 procedures) or coils (31 patients; 40 procedures). The average aneurysm size at embolization was larger in the Onyx group (77.9 ± 15.1 mm) compared with coil embolization (73.4 ± 11.9 mm). The mean follow-up was 57 months for the Onyx group and 74 months for the coil embolization group. Of the 27 patients who had undergone Onyx embolization, 2 (7.4%) had required graft explantation compared with 5 of the 31 patients (16.1%) who had undergone coil embolization (P = .33). The results of the per-patient analysis showed that the coil embolization group had a significantly greater rate of the need for further reintervention compared with the Onyx group (55% vs 19%; P < .01). Clinical success was observed in 13 patients (48%) in the Onyx embolization group compared with 10 patients (32%) in the coil embolization group (P = .04). Two patients in each group had presented with secondary rupture of the aneurysm sac after attempted embolization. CONCLUSIONS: Type II endoleaks associated with sac growth treated with Onyx were less likely to require further reinterventions than were those treated with coil embolization. A trend was found toward a greater need for endovascular aneurysm repair explant after coil embolization. With a high rate of further reintervention and potential for sac rupture, diligent follow-up is required after attempted type II embolization, regardless of the technique used.

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.

Systematic Review and Meta-Analysis of Preventative Strategies for Acute Kidney Injury in Patients Undergoing Abdominal Aortic Aneurysm Repair.

BACKGOUND: To assess the effect of various preventative interventions for reducing the incidence of postoperative acute kidney injury (AKI) in patients undergoing elective abdominal aortic aneurysm (AAA) repair. METHODS: We included randomized controlled trials of 10 patients or more which tested a preventative intervention versus standard therapy or placebo in patients undergoing elective AAA repair using the open or endovascular approach. Studies including mixed patient populations such as those with aortic occlusive disease, thoracoabdominal aneurysms or ruptured aneurysms were ineligible for review. We searched Medline (1966-2019), EMBASE (1947-2019), CINAHL (1961-2019), Web of Science (1945-2019), Scopus (1966-2019), and The Cochrane Library (1996-2019) for trials available as published manuscripts in English. Study quality was assessed using the Cochrane Collaboration risk of bias tool. Where possible we pooled the results of similar interventions using random effects meta-analysis. RESULTS: We included 17 trials involving 1443 participants. Most trials were small, single-center studies, with varying definitions of AKI and a high or moderate risk of bias. The preventative strategies with possible protective effects were mannitol, a composite of antioxidant supplements, an open extraperitoneal approach, and human atrial natriuretic peptide (hANP). Curcumin, methylprednisolone, carbon dioxide contrast medium, hemodynamic monitoring and N-acetylcysteine were found to be ineffective. Six trials with a total of 355 participants reported on remote ischemic preconditioning (RIPC) and our meta-analysis showed no statistically significant difference between RIPC and standard treatment (OR 1.20, 95% CI 0.37, 3.89); although the results should be interpreted with caution due to considerable statistical heterogeneity (I2 = 70%). None of the interventions studied significantly reduced receipt of renal replacement therapy (RRT). CONCLUSIONS: Interventions that have shown some potential to reduce AKI after AAA repair include mannitol, a composite of antioxidant supplements, an open extraperitoneal approach and hANP. These conclusions are limited by the small size, high risk of bias and inconsistency of the included trials. Large, high quality, multi-center randomized trials will help determine which interventions are effective in reducing the incidence of postoperative AKI among patients undergoing elective AAA repair.

Variability in research productivity among Canadian surgical specialties.

Background: Academic productivity, as measured by number and impact of publications, is central to the career advancement and promotion of academic surgeons. We compared research productivity metrics among specialties and sought factors associated with increased productivity. Methods: Academic surgeons were identified through departmental webpages and their scholarly metrics were collected through Scopus in a standardized fashion. We collected total number of documents, h-index, and average number of publications per year in the preceding 5 years. We explored whether presence of a training program, graduate degree, academic rank and size of the clinical group affected productivity metrics. Linear regression was used for multivariable analysis. Results: We collected data on 2172 surgeons from 15 separate academic centres across Canada. Wide variability existed in metrics among specialties, with cardiac and neurosurgery being the most productive, and vascular surgery and plastic surgery being the least productive. The average number of publications was 71, and the average h-index was 18.7. The average h-index for cardiac surgery was 25.7 compared with 8.3 for vascular surgery (p < 0.001). Our multivariable model identified academic rank, surgical specialty, graduate degree, presence of a training program, and larger clinical group as being associated with increased academic productivity. Conclusion: There is variability in research productivity among Canadian surgical specialties. Cardiac surgery and neurosurgery are productive, whereas vascular surgery and plastic surgery are less productive than other surgical disciplines. Obtaining a research-oriented graduate degree, being part of a larger clinical group, and presence of a training program were all associated with higher productivity, even after adjusting for academic rank and specialty.

Contexte: La productivité universitaire, évaluée selon le nombre de publications et leurs retombées, est déterminante pour la carrière et l'avancement des professeurs de chirurgie. Nous avons comparé des indicateurs de la productivité en recherche de diverses spécialités et cherché les facteurs liés à une productivité accrue. Méthodes: Nous avons identifié les professeurs de chirurgie dans les pages Web de départements, et recueilli dans Scopus, de manière normalisée, les données : nombre total de documents, indice h et nombre moyen de publications par année dans les 5 dernières années. Nous avons cherché à savoir si l'existence d'un programme de formation, le diplôme d'études supérieures, le rang professoral et la taille du groupe clinique avaient une incidence sur les indicateurs de productivité. L'analyse multivariable a été faite au moyen d'une régression linéaire. Résultats: Nous avons recueilli des données sur 2172 chirurgiens de 15 différents centres universitaires du Canada. Les indicateurs variaient grandement selon la spécialité. La productivité la plus élevée était associée à la chirurgie cardiaque et à la neurochirurgie, et la productivité la moins élevée, à la chirurgie vasculaire et à la chirurgie plastique. Le nombre moyen de publications était de 71 et l'indice h moyen, de 18,7. L'indice h moyen pour la chirurgie cardiaque était de 25,7, comparativement à 8,3 pour la chirurgie vasculaire (p < 0,001). Notre modèle multivariable a montré que le rang professoral, la spécialité chirurgicale, le diplôme d'études supérieures, l'existence d'un programme de formation et un grand groupe clinique sont liés à une productivité universitaire accrue. Conclusion: La productivité en recherche varie en fonction de la spécialité chirurgicale au Canada. La chirurgie cardiaque et la neurochirurgie sont productives, tandis que la chirurgie vasculaire et la chirurgie plastique le sont moins que d'autres spécialités. L'obtention d'un diplôme d'études supérieures axées sur la recherche, l'appartenance à un grand groupe clinique et l'existence d'un programme de formation étaient toutes associées à une productivité supérieure, même après correction pour tenir compte du rang professoral et de la spécialité.

Long-term outcomes comparing endovascular and open abdominal aortic aneurysm repair in octogenarians.

OBJECTIVE: Patients older than 80 years have significantly lower early mortality with endovascular aneurysm repair (EVAR) compared with open repair for abdominal aortic aneurysms (AAAs), but long-term results remain poorly studied. We analyzed the results of both emergent and elective AAA repair in patients aged 80 years or older who had at least 5 years of follow-up. METHODS: Retrospective review of a prospectively collected vascular surgery database was performed to identify all patients who underwent elective repair of an AAA between 2007 and 2012 and were 80 years of age or older at the time of surgery. Open and EVAR groups were compared using univariate statistics. RESULTS: The study cohort was composed of 314 patients 80 years of age or older (median, 83 years; interquartile range, 5 years) who underwent repair (96 open, 218 EVAR). The groups had similar comorbidities, except that EVAR patients were more likely to be male and open repair patients were more likely to have larger aneurysms. Compared with open repair, elective early postoperative mortality was significantly lower for EVAR patients (1% vs 14%; P < .001). Overall mean life expectancy was 5.9 years (EVAR, 5.8 years; open repair, 5.8 years; P = .98). The 1-year survival was significantly higher for EVAR (92.9%) than for open repair (84.1%; P = .02). The 2-year survival (EVAR, 83.4%; open repair, 74.6%; P = .07) and 5-year survival (EVAR, 57.8%; open repair, 60.3%; P = .98) did not differ between EVAR and open repair. Reintervention rates (EVAR, 18%; open repair, 2%; P = .05) were higher in the endovascular treatment group. CONCLUSIONS: EVAR results in an improved 1-year mortality in octogenarians compared with open repair, although 5-year survival is similar between the groups. With average life expectancies of >5 years and an 18% reintervention rate, diligent follow-up is required after EVAR even in elderly patients.

A systematic review and meta-analysis of endovascular juxtarenal aortic aneurysm repair demonstrates lower perioperative mortality compared with open repair.

OBJECTIVE: The objectives of the present study were to summarize and pool the available data from studies that had directly compared endovascular and open repair of juxtarenal aortic aneurysms. METHODS: OVID Medline and Embase were searched for studies from January 2000 to December 2018 that had compared endovascular vs open repair of juxtarenal aortic aneurysms. Studies that had included patients with pararenal and suprarenal aneurysms were also included. The endovascular interventions included short-neck standard endovascular aneurysm repair (EVAR), parallel grafts, and fenestrated/branched EVAR. The primary outcomes were 30-day mortality, perioperative reinterventions, acute renal failure, permanent dialysis, stroke, and spinal cord ischemia. The secondary outcomes were myocardial infarction, bowel and limb ischemia, length of stay, and long-term survival. The data were pooled, and a meta-analysis using a random effects model was performed. RESULTS: A total of 20 studies met the inclusion criteria. Of the 20 studies, five had contained duplicated data and one had included only 2-year follow-up data. Therefore, 14 studies with 5121 patients (1506 endovascular, 3615 open) were included for analysis. The patients undergoing endovascular repair were older (mean difference, 3.42; 95% confidence interval [CI], 2.54-4.3; P < .001; I2 = 56%), more likely to be men (odds ratio [OR], 1.33; 95% CI, 1.02-1.73; P = .04; I2 = 33%), and more likely to have diabetes (OR, 1.24; 95% CI, 1.04-1.50; P = .02; I2 = 0%), coronary artery disease (OR, 1.64; 95% CI, 1.03-2.62; P = .04; I2 = 75%), and chronic kidney disease (OR, 1.52; 95% CI, 1.07-2.15; P = .02; I2 = 50%). Endovascular repair was associated with significantly decreased 30-day mortality (OR, 0.50; 95% CI, 0.34-0.74; P < .001; I2 = 0%). This remained significant when including only fenestrated EVAR (OR, 0.55; 95% CI, 0.36-0.85; P = .007; I2 = 0%). Endovascular repair also resulted in a significantly decreased incidence of acute renal failure (OR, 0.50; 95% CI, 0.28-0.89; P = .02; I2 = 67%), an increased incidence of spinal cord ischemia (OR, 3.14; 95% CI, 1.08-9.09; P = .03; I2 = 0%), a decreased incidence of bowel ischemia (OR, 0.50; 95% CI, 0.24-1.05; P = .07; I2 = 7%), and decreased length of stay (mean difference, -5.99 days; 95% CI, -7.42 to -4.57 days; P < .00001; I2 = 78%). No significant differences were found for the other outcomes. Of the nine studies that had reported long-term survival (1-7 years of follow-up), eight had found no significant differences between groups (data not pooled) and one study had found improved long-term survival in the open repair group. Reinterventions during follow-up were increased in the endovascular group. CONCLUSIONS: Pooling data from 14 studies, we found endovascular repair was associated with lower 30-day mortality, acute renal failure, bowel ischemia, and length of stay but with increased spinal cord ischemia. These data were limited by the risk of bias of the included studies. Further long-term studies are needed to determine whether these differences persist during long-term follow-up.

Long-term survival after endovascular and open repair in patients with anatomy outside instructions for use criteria for endovascular aneurysm repair.

BACKGROUND: Randomized controlled trials of long-term survival for infrarenal abdominal aortic aneurysms have compared open surgical repair (OSR) with endovascular aneurysm repair (EVAR) in patients with suitable aortic anatomy for EVAR. However, in clinical practice, patients who do not meet instructions for use (IFU) criteria are often still treated by EVAR despite that some studies show higher graft-related adverse events. The goal of this study was to compare the long-term survival of EVAR and OSR in patients with anatomy outside IFU criteria for EVAR. METHODS: This multicenter retrospective cohort study included patients with at least one anatomic IFU violation for EVAR undergoing either elective EVAR or elective OSR for abdominal aortic aneurysm. Demographics, anatomic data, and follow-up data of patients were collected from three academic centers from 2003 to 2016. Device-specific IFU were used for EVAR patients, whereas generic IFU for EVAR were applied to the OSR patients. The primary outcomes were 30-day mortality and long-term all-cause mortality. Secondary outcomes were aneurysm-related mortality and perioperative complications at 30 days. Kaplan-Meier survival and Cox proportional hazards modeling were performed. Inverse propensity score weights were used to adjust for differences in treatment selection. RESULTS: The study population included 202 EVAR patients and 224 OSR patients with at least one anatomic IFU violation for EVAR. EVAR patients were older (78.1 ± 7.3 vs 70.9 ± 7.0 years; P < .001) and less likely to be hypertensive (69.3% vs 79.0%; P = .02) compared with OSR patients. OSR patients were more likely to have proximal aortic neck IFU violations (75.0% vs 47.1%; P < .001) and were less likely to have iliac IFU violations (65.2% vs 79.2%; P < .001). All-cause mortality was 37.6% in the EVAR group and 24.1% in the OSR group with a median follow-up time of 5.2 (3.5-7.2) and 5.4 (2.8-9.3) years, respectively (P < .002). Kaplan-Meier survival analysis revealed a significant association between patients undergoing OSR and increased long-term survival (log-rank P < .0001). When adjusted for possible confounders and weighted for propensity for treatment through Cox hazard modeling, the association remained significant (hazard ratio, 0.6; 95% confidence interval, 0.4-0.9). Aneurysm-related mortality was 3.5% in the EVAR group and 2.2% in the OSR group during long-term follow-up (P < .001). CONCLUSIONS: Our study identified that patients with IFU violations have higher overall long-term survival with open surgery compared with EVAR. Caution should be applied in considering standard EVAR for patients with anatomy outside of IFU.

Editor's Choice - Infrainguinal Bypass Following Failed Endovascular Intervention Compared With Primary Bypass: A Systematic Review and Meta-Analysis.

OBJECTIVES: Patients with infrainguinal peripheral arterial disease often undergo multiple revascularisation procedures. Although many centres have adopted an endovascular first approach, some are reluctant to do so for fear of compromising the outcomes of any subsequent bypasses. All studies that compared the outcomes of primary infrainguinal bypass with bypass after failed endovascular intervention were analysed. METHODS: A systematic review was conducted of MEDLINE, EMBASE, and CENTRAL databases for studies comparing outcomes of primary infrainguinal bypass with bypass after failed endovascular intervention for peripheral arterial disease. Abstracts and full text studies were screened independently by two reviewers with data abstraction done in duplicate. Dichotomous outcome measures were reported using the OR and 95% CI, and pooled using random effects models. RESULTS: Abstracts were screened (2,528), with 50 selected for full text review. Of these, 15 studies involving 11,886 patients met the inclusion criteria. Pooling the results of studies comparing primary bypass with bypass after failed endovascular intervention showed no significant difference in 30 day mortality (OR 1.00; 95% CI 0.65-1.54), or 30 day amputation rates (OR 1.26; 95% CI 0.95-1.65). Interestingly, one year amputation free survival was higher in the patients who had primary bypass (OR 1.30; 95% CI 1.10-1.52) compared with patients who had bypass after failed endovascular therapy. There was also worse one year primary patency (OR 1.65; 95% CI 1.04-2.62) for patients with prior failed endovascular intervention. The review demonstrated a trend towards higher rates of early graft occlusion (OR 4.54; 95% CI 0.97-21.28). CONCLUSIONS: Meta-analysis of the existing literature comparing primary bypass with bypass following failed endovascular intervention shows worse one year amputation free survival and worse primary patency in those patients who undergo bypass after failed endovascular intervention. There is also a trend towards higher rates of early graft occlusion, although these results were not statistically significant. These conclusions are limited by observational study design, inconsistent patient selection, and significant heterogeneity between studies.

Association between known or strongly suspected malignant hyperthermia susceptibility and postoperative outcomes: an observational population-based study.

PURPOSE: Whether current standards of care management for malignant hyperthermia (MH)-susceptible patients result in acceptable postoperative clinical outcomes at a population level is not known. Our objective was to determine if patients with susceptibility to MH experienced similar outcomes as patients without MH susceptibility after surgery under general anesthesia. METHODS: This was a retrospective, population-based cohort study from 1 April 2009 until 31 March 2016 in the Canadian province of Ontario. Participants were adults who underwent common in- or outpatient surgeries under general anesthesia. The exposure studied was either known or strongly suspected MH susceptibility as determined by usage of a specific physician billing code. The primary outcome was a composite of all-cause death, hospital readmission, or major postoperative complications, all within 30 postoperative days. Separate analyses were employed, based on whether a patient had in- or outpatient surgery. Inverse probability of exposure weighting based on the propensity score was used to estimate adjusted exposure effects. RESULTS: The cohort included 957,876 patients (583,254 in- and 374,622 outpatients). There were 2,900 (0.3%) patients with a known or strong suspicion of MH susceptibility. For inpatients, the primary outcome occurred in 146,192 (25.1%) of the non-MH-susceptible group and in 337 (20.1%) of the MH-susceptible group (unadjusted risk difference [RD], -5.0%; 95% confidence interval [CI], -6.9 to -3.1%; P < 0.001). In outpatients, the primary outcome occurred in 9,146 (2.4%) of the non-MH-susceptible group and in 32 (2.6%) of the MH-susceptible group (RD, 0.2%; 95% CI, -0.7 to 1.1%; P = 0.72). After adjustment, MH susceptibility was not associated with the primary outcome in either the inpatients (adjusted risk difference [aRD], 1.2%; 95% CI, -1.3 to 3.6%; P = 0.35) or outpatients (aRD, -0.1%; 95% CI -1.0 to 0.9%; P = 0.90). CONCLUSIONS: Among adults in Ontario who underwent common surgeries under general anesthesia from 2009 to 2016, known or strongly suspected MH was not associated with a higher risk of adverse postoperative outcomes. These findings support the current standard of care management for MH-susceptible patients.

RéSUMé: OBJECTIF: Nous ignorons si les normes actuelles de gestion des soins de patients susceptibles d'hyperthermie maligne (HM) aboutissent à des résultats cliniques postopératoires acceptables à l'échelle d'une population. Notre objectif a été de déterminer si des patients présentant une susceptibilité à l'HM présentaient une évolution comparable à celle des patients non connus susceptibles après chirurgie sous anesthésie générale. MéTHODES: Il s'agissait d'une étude de cohorte rétrospective, basée sur une population de la province canadienne de l'Ontario allant du 1er avril 2009 au 31 mars 2016. Les participants étaient des adultes, hospitalisés ou ambulatoires, ayant subi des interventions sous anesthésie générale. L'exposition étudiée était une susceptibilité à l'HM connue ou fortement suspectée, déterminée par l'utilisation d'un code de facturation spécifique des médecins. Le critère d'évaluation principal était un critère composite incluant les décès toutes causes confondues, les réadmissions hospitalières ou les complications postopératoires majeures qui étaient survenus dans un délai de 30 jours postopératoires. Des analyses séparées ont été utilisées, selon que les patients avaient été hospitalisés ou opérés en chirurgie d'un jour. La probabilité inverse de la pondération de l'exposition basée sur le score pour la propension a servi à estimer les effets ajustés de l'exposition. RéSULTATS: La cohorte a inclus 957 876 patients (583 254 patients hospitalisés et 374 622 patients ambulatoires). Parmi eux, 2 900 patients (0,3 %) avaient une susceptibilité à l'HM connue ou fortement suspectée. Pour les patients hospitalisés, le critère d'évaluation principal est survenu chez 146 192 (25,1 %) des patients du groupe non susceptible d'HM et chez 337 (20,1 %) patients du groupe susceptible d'HM (différence de risques [DR] non ajustée : −5,0 %; intervalle de confiance [IC] à 95 % : −6,9 % à −3,1 %; P < 0,001). Pour les patients ambulatoires, le critère d'évaluation principal est survenu chez 9 146 (2,4 %) des patients du groupe non susceptible d'HM et chez 32 (2,6 %) patients du groupe susceptible d'HM (différence de risques [DR] non ajustée : 0,2 %; IC à 95 % : −0,7 % à 1,1 %; P = 0,72). Après ajustement, la susceptibilité à l'HM ne s'est pas avérée associée au critère d'évaluation principal dans le groupe de patients hospitalisés (différence de risques ajustée [DRa], 1,2 %; IC à 95 % : −1,3 % à 3,6 %; P = 0,35) ou dans le groupe de patients ambulatoires (DRa : −0,1 %; IC à 95 % : −1,0 % à 0,9 %; P = 0,90). CONCLUSIONS: Parmi les adultes de la province de l'Ontario ayant subi des interventions chirurgicales usuelles sous anesthésie générale entre 2009 et 2016, l'HM connue ou fortement suspectée n'a pas été associée à un plus grand risque d'évolution postopératoire défavorable. Ces constatations sont en faveur du maintien des normes des soins actuels pour la gestion des patients susceptibles d'HM.