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.

A systematic review and meta-analysis of outcomes associated with development of surgical site infection after lower-limb revascularization surgery.

OBJECTIVES: Although surgical site infection (SSI) is a commonly used quality metric after lower-limb revascularization surgery, outcomes associated with development of this complication are poorly characterized. We conducted a systematic review and meta-analysis of studies reporting associations between development of an SSI after these procedures and clinical outcomes and healthcare resource use. METHODS: We searched MEDLINE, Embase, CENTRAL, and Evidence-Based Medicine Reviews (inception to April 4th, 2023) for studies examining adjusted associations between development of an SSI after lower-limb revascularization surgery and clinical outcomes and healthcare resource use. Two investigators independently screened abstracts and full-text citations, extracted data, and assessed risk of bias. Data were pooled using random-effects models. Heterogeneity was assessed using I2 statistics. GRADE was used to assess estimate certainty. RESULTS: Among 6671 citations identified, we included 11 studies (n = 61,628 total patients) that reported adjusted-associations between development of an SSI and 13 different outcomes. Developing an SSI was associated with an increased adjusted-risk of hospital readmission (pooled adjusted-risk ratio (aRR) = 3.55; 95% CI (confidence interval) = 1.40-8.97; n = 4 studies; n = 13,532 patients; I2 = 99.0%; moderate certainty), bypass graft thrombosis within 30-days (pooled aRR = 2.09; 95% CI = 1.41-3.09; n = 2 studies; n = 23,240 patients; I2 = 51.1%; low certainty), reoperation (pooled aRR = 2.69; 95% CI = 2.67-2.72; n = 2 studies; n = 23,240 patients; I2 = 0.0%; moderate certainty), bleeding requiring a transfusion or secondary procedure (aRR = 1.40; 95% CI = 1.26-1.55; n = 1 study; n = 10,910 patients; low certainty), myocardial infarction or stroke (aRR = 1.21; 95% CI = 1.02-1.43; n = 1 study; n = 10,910 patients; low certainty), and major (i.e., above-ankle) amputation (pooled aRR = 1.93; 95% CI = 1.26-2.95; n = 4 studies; n = 32,859 patients; I2 = 83.0; low certainty). Development of an SSI >30-days after the index operation (aRR = 2.20; 95% CI = 1.16-4.17; n = 3 studies; n = 21,949 patients; low certainty) and prosthetic graft infection (aRR = 6.72; 95% CI = 3.21-12.70; n = 1 study; n = 272 patients; low certainty) were both associated with an increased adjusted-risk of major amputation. Prosthetic graft infection was also associated with an increased adjusted-risk of mortality >30-days after the index procedure (aRR = 6.40; 95% CI = 3.32-12.36; n = 1 study; n = 272 patients; low certainty). CONCLUSIONS: This systematic review and meta-analysis suggests that development of an SSI after lower-limb revascularization surgery significantly increases patient morbidity and healthcare resource use. SSI is therefore a valuable quality metric after these surgeries. However, current estimates are based on heterogenous, low-to-moderate certainty evidence and should be confirmed by large, multicenter, cohort studies.

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.

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.

Development and evaluation of an evidence-based, theory-grounded online Clinical Frailty Scale tutorial.

INTRODUCTION: Frailty is a robust predictor of adverse outcomes in older people. Practice guidelines recommend routine screening for frailty; however, this does not occur regularly. The Clinical Frailty Scale (CFS) is a validated, feasible instrument that can be used in a variety of clinical settings and is associated with many adverse outcomes. Our objective was to develop and evaluate an online training module to guide frailty assessment using the CFS. METHODS: A multidisciplinary team of clinical experts developed an evidence-based, theory-grounded online training module for users who wished to perform frailty assessment using the CFS. The module was prospectively evaluated for user satisfaction, effectiveness and feasibility using a standardised questionnaire. Qualitative feedback was analysed with thematic analysis. RESULTS: Version 1 of the CFS module was used 627 times from 21 October 2019 to 24 March 2020. Satisfaction, effectiveness and feasibility of the module were positively rated (≥4/5 on a 5-point Likert scale n = 582 [93%], n = 507, [81%], n = 575, [91%], respectively). Qualitative feedback highlighted ease of use, likelihood of users to share the module with others and opportunities to increase multimedia content. CONCLUSION: An online tutorial, designed using evidence and theory to guide frailty assessment using the CFS, was positively rated by users. The module's content and structure was rated effective and feasible, and users were satisfied with, and likely to share, the module. Research evaluating the module's impact on the accuracy of frailty assessment is required.

Structure, processes, and initial outcomes of The Ottawa Hospital Multi-Specialist Limb-Preservation Clinic and Programme: A unique-in-Canada quality improvement initiative.

In 2017, The Ottawa Hospital initiated a unique-in-Canada quality improvement initiative by opening a novel, multi-specialist limb-preservation clinic. We sought to describe the structure, processes, and initial outcomes of the clinic and evaluate whether it is achieving its mandate of providing high-quality wound clinical care, education, and research. We conducted a descriptive prospective cohort study alongside a nested study of 162 clinic patients requiring serial assessments. There have been 1623 visits, mostly (72.2%) from outpatients. During 17.8% of visits, patients were evaluated by >1 specialist. Therapies provided most often included negative-pressure wound therapy (32.7%), biological wound dressings (21.6%), and total contact casting (18.5%). Furthermore, 1.2% underwent toe/ray amputations or skin grafting in clinic and 22.8% were initiated on antimicrobials. Mixed-effects models suggested that mean wound volumes for those requiring serial assessments decreased by 1.6 (95% confidence interval = -0.86 to -2.27) cm3 between visits. The clinic provided seven rotations to vascular surgery, infectious diseases, dermatology, and palliative care physicians; three nursing preceptorships; and two educational workshops. It also initiated provincial and national vascular health and wound care research initiatives. This study may be used to guide development of other limb-preservation clinics and programmes. Findings support that our programme is achieving its mandate.

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.

Characteristics of high-cost inpatients with peripheral artery disease.

OBJECTIVE: Inpatient treatment of peripheral artery disease (PAD) is more than six times as costly as that of the general inpatient population. Our objective was to describe factors associated with hospital cost for patients admitted for PAD, the characteristics of high-cost patients, and their outcomes including amputations and death. METHODS: We performed a retrospective cohort study of admitted patients receiving a procedure for PAD at The Ottawa Hospital between 2007 and 2016. Demographics, comorbidity, inpatient events, and hospital cost data during the index admission were collected. We defined high-cost patients as those whose total costs of index admission were in the tenth percentile and above. Features associated with high-cost status were examined using logistic regression with elastic net regularization. We used generalized linear models to examine overall drivers of cost. RESULTS: We identified 3084 eligible patients, incurring $72.2 million in hospital costs. The mean cost of the most expensive 10% of patients was $88,076 (standard deviation, $54,720), more than five times the mean cost of $16,217 (standard deviation, $10,322) for nonhigh-cost patients. High-cost patients were more likely to present urgently (odds ratio [OR], 1.63; 95% confidence interval [CI], 1.16-2.25; P < .01). After adjustment for preadmission factors, high-cost patients were more likely to have experienced an adverse patient safety incident (OR, 13.49; 95% CI, 6.97-24.8; P < .01), amputation (OR, 2.79; 95% CI, 1.68-4.49; P <.01), intensive care unit admission (OR, 6.42; 95% CI, 3.62-10.2; P < .01), and disposition barriers requiring alternate level of care status (OR, 10.44; 95% CI, 6.42-15.2; P < .01). The high-cost group was more likely to have received hybrid revascularization (OR, 7.07; 95% CI, 3.34-13.6; P < .01). High-cost patients had higher than predicted in-hospital mortality (18% vs 9.2% predicted) compared with the low-cost group (3.0% vs 2.7%; P < .001), and fewer than half of high-cost patients were discharged home. CONCLUSIONS: Providing hospital care for the top 10% most expensive patients in our cohort was more than five times as costly per patient than providing care for the nonhigh-cost patients. Whereas pre-existing factors may predispose a patient to require expensive care, there are potentially modifiable factors during the admission that could reduce costs of these patients.

Hospital resource use and costs among abdominal aortic aneurysm repair patients admitted to the intensive care unit.

BACKGROUND: Abdominal aortic aneurysm (AAA) repair is associated with significant morbidity and mortality. As a result, many of these patients are monitored postoperatively in the intensive care unit (ICU). However, little is known about resource utilization and costs associated with ICU admission in this population. We sought to evaluate predictors of total costs among patients admitted to the ICU after repair of nonruptured or ruptured AAA. METHODS: We retrospectively analyzed prospectively collected data (2011-2016) of ICU patients admitted after AAA repair. The primary outcome was total hospital costs. We used elastic net regression to identify pre-ICU admission predictors of hospitalization costs separately for nonruptured and ruptured AAA patients. RESULTS: We included 552 patients in the analysis. Of these, 440 (79.7%) were admitted after repair of nonruptured AAA, and 112 (20.3%) were admitted after repair of ruptured AAA. The mean age of patients with nonruptured AAA was 74 (standard deviation, 9) years, and the mean age of patients with ruptured AAA was 70 (standard deviation, 8) years. Median total hospital cost (in Canadian dollars) was $21,555 (interquartile range, $17,798-$27,294) for patients with nonruptured AAA and $33,709 (interquartile range, $23,173-$53,913) for patients with ruptured AAA. Among both nonruptured and ruptured AAA patients, increasing age, illness severity, use of endovascular repair, history of chronic obstructive pulmonary disease, and excessive blood loss (≥4000 mL) were associated with increased costs, whereas having an anesthesiologist with vascular subspecialty training was associated with lower costs. CONCLUSIONS: Patient-, procedure-, and clinician-specific variables are associated with costs in patients admitted to the ICU after repair of AAA. These factors may be considered future targets in initiatives to improve cost-effectiveness in this population.