Surgical wound infections after peripheral vascular surgery

Prediction Models for Forecasting Risk of Development of Surgical Site Infection after Lower Limb Revascularization Surgery: A Systematic Review

BACKGROUND

Surgical site infections (SSIs) are a common and potentially preventable complication of lower limb revascularization surgery associated with increased healthcare resource utilization and patient morbidity. We conducted a systematic review to evaluate multivariable prediction models designed to forecast risk of SSI development after these procedures.

METHODS

After protocol registration (CRD42022331292), we searched MEDLINE, EMBASE, CENTRAL, and Evidence-Based Medicine Reviews (inception to April 4th, 2023) for studies describing multivariable prediction models designed to forecast risk of SSI in adults after lower limb revascularization surgery. Two investigators independently screened abstracts and full-text articles, extracted data, and assessed risk of bias. A narrative synthesis was performed to summarize predictors included in the models and their calibration and discrimination, validation status, and clinical applicability.

RESULTS

Among the 6,671 citations identified, we included 5 studies (n = 23,063 patients). The included studies described 5 unique multivariable prediction models generated through forward selection, backward selection, or Akaike Information Criterion-based methods. Two models were designed to predict any SSI and 3 Szyilagyi grade II (extending into subcutaneous tissue) SSI. Across the 5 models, 18 adjusted predictors (10 of which were preoperative, 3 intraoperative, and 5 postoperative) significantly predicted any SSI and 14 adjusted predictors significantly predict Szilagyi grade II SSI. Female sex, obesity, and chronic obstructive pulmonary disease significantly predicted SSI in more than one model. All models had a "good fit" according to the Hosmer-Lemeshow test (P > 0.05). Model discrimination was quantified using the area under the curve, which ranged from 0.66 to 0.75 across models. Two models were internally validated using non-exhaustive twofold cross-validation and bootstrap resampling. No model was externally validated. Three studies had a high overall risk of bias according to the Prediction model Risk Of Bias ASsessment Tool (PROBAST).

CONCLUSIONS

Five multivariable prediction models with moderate discrimination have been developed to forecast risk of SSI development after lower limb revascularization surgery. Given the frequency and consequences of SSI after these procedures, development and external validation of novel prediction models and comparison of these models to the existing models evaluated in this systematic review is warranted.

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.

Improving Compliance with Preoperative Nasal Povidone-Iodine to Prevent Surgical Site Infection in Vascular and Neurosurgery Services in a Community Teaching Hospital

Surgical site infections (SSI) remain a cause of morbidity, prolonged hospitalization, surgical readmission, and death. Nasal colonization with methicillin-resistant Staphylococcal aureus is a frequent cause of device-related SSI and nasal mupirocin has been used for prevention. More recently, povidone-iodine nasal swabs have become an alternative. It is cheaper, ensures compliance and there are no concerns regarding antimicrobial resistance. However, its adoption was suboptimal in a community hospital system in southwestern Ohio, especially in neurosurgery and vascular surgery. Quality improvement techniques, including solicitation of stakeholder input, surgeons and perioperative nurses' education, and the use of reminders to order and administer the povidone-iodine nasal swabs improved physician ordering and nurse administration compliance, leading to fewer infections. The interventions continued after the project was completed, sustaining decreases in neurosurgery and vascular surgery, and fewer SSI through the first years of the pandemic. Despite the complexity of these surgeries, simple interventions were effective in addressing the problem.

Effectiveness of negative-pressure wound therapy to standard therapy in the prevention of complications after vascular surgery

Wound complications are common after vascular surgery and many may be preventable. Negative pressure wound therapy (NPWT) dressings may be able to reduce wound complications relating to closed incisions following vascular surgery and several devices are currently available along with a large body of literature. This review article will describe the use of NPWT dressings in vascular surgery. We will summarize the currently available systems, the likely mechanism of action of NWPT, the published studies to date and we will give our recommendations regarding the priorities for future research on this topic.

Structural design and mechanical performance of composite vascular grafts

This study reviews the state of the art in structural design and the corresponding mechanical behaviours of composite vascular grafts. We critically analyse surface and matrix designs composed of layered, embedded, and hybrid structures along the radial and longitudinal directions; materials and manufacturing techniques, such as tissue engineering and the use of textiles or their combinations; and the corresponding mechanical behaviours of composite vascular grafts in terms of their physical–mechanical properties, especially their stress–strain relationships and elastic recovery. The role of computational studies is discussed with respect to optimizing the geometrics designs and the corresponding mechanical behaviours to satisfy specialized applications, such as those for the aorta and its subparts. Natural and synthetic endothelial materials yield improvements in the mechanical and biological compliance of composite graft surfaces with host arteries. Moreover, the diameter, wall thickness, stiffness, compliance, tensile strength, elasticity, and burst strength of the graft matrix are determined depending on the application and the patient. For composite vascular grafts, hybrid architectures are recommended featuring multiple layers, dimensions, and materials to achieve the desired optimal flexibility and function for complying with user-specific requirements. Rapidly emerging artificial intelligence and big data techniques for diagnostics and the three-dimensional (3D) manufacturing of vascular grafts will likely yield highly compliant, subject-specific, long-lasting, and economical vascular grafts in the near-future.

Graphic abstract

Tobramycin Supplemented Small-Diameter Vascular Grafts for Local Antibiotic Delivery: A Preliminary Formulation Study

Peripheral artery occlusive disease is an emerging cardiovascular disease characterized by the blockage of blood vessels in the limbs and is associated with dysfunction, gangrene, amputation, and a high mortality risk. Possible treatments involve by-pass surgery using autologous vessel grafts, because of the lack of suitable synthetic small-diameter vascular prosthesis. One to five percent of patients experience vascular graft infection, with a high risk of haemorrhage, spreading of the infection, amputation and even death. In this work, an infection-proof vascular graft prototype was designed and manufactured by electrospinning 12.5% w/v poly-L-lactic-co-glycolic acid solution in 75% v/v dichloromethane, 23.8% v/v dimethylformamide and 1.2% v/v water, loaded with 0.2% w/w_PLGA. Polymer and tobramycin concentrations were selected after viscosity and surface tension and after HPLC-UV encapsulation efficiency (EE%) evaluation, respectively. The final drug-loaded prototype had an EE% of 95.58% ± 3.14%, with smooth fibres in the nanometer range and good porosity; graft wall thickness was 291 ± 20.82 μm and its internal diameter was 2.61 ± 0.05 mm. The graft's antimicrobic activity evaluation through time-kill assays demonstrated a significant and strong antibacterial activity over 5 days against Staphylococcus aureus and Escherichia coli. An indirect cell viability assay on Normal Human Dermal Fibroblasts (NHDF) confirmed the cytocompatibility of the grafts.

Citrobacter koseri Surgical Site Infection after Femoropopliteal Vein Bypass for Popliteal Artery Aneurysm Treated with a Graft Preserving Strategy

Background: A 69-year-old man underwent ligation and evacuation of a popliteal artery aneurysm with a femoral-to-popliteal vein bypass. He had a history of Citrobacter koseri prostatitis two months prior to the surgery. One month postoperatively, he presented with extremity swelling, redness, and fluid collections around the graft. Methods: A graft preserving strategy was adopted. The patient underwent operative drainage, washing, and received long-term antibiotic therapy. Fluid culture grew Citrobacter koseri, previously not reported as cause of surgical site infection with infrainguinal graft involvement. Results: The infection was treated successfully, and the patient is remains symptom free 18 months post-operatively. Conclusions: This case highlights the importance of considering culturing the aneurysm content in the presence of infectious history.

Cryopreservation moderates the thrombogenicity of arterial allografts during storage

INTRODUCTION

Management of vascular infections represents a major challenge in vascular surgery. The use of cryopreserved vascular allografts could be a feasible therapeutic option, but the optimal conditions for their production and use are not precisely defined.

AIMS

To evaluate the effects of cryopreservation and the duration of storage on the thrombogenicity of femoral artery allografts.

METHODS

In our prospective study, eleven multi-organ-donation-harvested human femoral arteries were examined at five time points during storage at -80°C: before cryopreservation as a fresh native sample and immediately, one, twelve and twenty-four weeks after the cryopreservation. Cross-sections of allografts were perfused with heparin-anticoagulated blood at shear-rates relevant to medium-sized arteries. The deposited platelets and fibrin were immunostained. The thrombogenicity of the intima, media and adventitia layers of the artery grafts was assessed quantitatively from the relative area covered by fibrin- and platelet-related fluorescent signal in the confocal micrographs.

RESULTS

Regression analysis of the fibrin and platelet coverage in the course of the 24-week storage excluded the possibility for increase in the graft thrombogenicity in the course of time and supported the hypothesis for a descending trend in fibrin generation and platelet deposition on the arterial wall. The fibrin deposition in the cryopreserved samples did not exceed the level detected in any of the three layers of the native graft. However, an early (up to week 12) shift above the native sample level was observed in the platelet adhesion to the media.

CONCLUSIONS

The hemostatic potential of cryopreserved arterial allografts was retained, whereas their thrombogenic potential declined during the 6-month storage. The only transient prothrombotic change was observed in the media layer, where the platelet deposition exceeded that of the fresh native grafts in the initial twelve weeks after cryopreservation, suggesting a potential clinical benefit from antiplatelet therapy in this time-window.

Benefit of Negative Pressure Dressings in Vascular Surgery Patients with Infra-Inguinal 1 Incisions after short-term followupAssessing the Benefit of Incisional Negative Pressure 2 Dressings in Community-Based Vascular Surgery Patients with Infra-Inguinal Incisions

OBJECTIVES

Within the vascular patient population there is increased risk of developing wound complications especially in infra-inguinal incisions. There has been increasing interest in using closed incisional negative pressure dressings to decrease the risk of wound complications. To assess the efficacy of these incisional wound dressings we studied surgical site infections and seroma rates of infrainguinal incisions in our vascular patient population.

METHODS

This was a multi-institutional, retrospective study from July 2015- June 2019. In 2017 our institution began using the Prevena incisional wound system. Wound complication rates were compared to the non Prevena group prior to 2017. There was a total of 100 infrainguinal incisions (left and right combined) that received the Prevena wound system and 138 infrainguinal incisions that had not. The primary endpoint was to assess for wound complication rates including surgical site infections and seroma formation. Surgical site infections were graded based on the ACS-NSQIP SSI criteria. Seroma formation was diagnosed based on clinical diagnosis, imaging studies (ultrasound, CT) or needle aspiration of fluid collection.

RESULTS

Analysis showed a statistically significant decrease in the rate of SSIs in the Prevena group when compared to the non Prevena group (p=0.012). There was no statistical difference between the two groups in the rate of seroma formation (p=0.155). Of the 100 incisions that received the Prevena wound system 1.2% (1/82) had a femoral SSI and 22% (4/18) had a popliteal SSI. For seroma formation 24.4% (20/82) had a femoral seroma and 11.1% (2/18) had a popliteal seroma. Of the 138 incisions that did not have the Prevena wound system, 9.6% (10/104) had a femoral SSI, and 8.8% (3/34) had a popliteal SSI. For seroma formation 24.0% (25/104) had a femoral seroma and 8.8% (3/34) had a popliteal seroma. Comorbid conditions were assessed in the two study groups and there was no statistical significance regarding rates of surgical site infections between the groups.

CONCLUSIONS

The use of an incisional negative pressure dressing decreases the rate of surgical site infections in infrainguinal incisions. Regarding the use of these wound systems for seromas; our study did not show a statistical significance in decreasing seroma rates.

Healthcare professionals' experiences of being observed regarding hygiene routines: the Hawthorne effect in vascular surgery

Background

The Hawthorne Effect is the change in behaviour by subjects due to their awareness of being observed and is evident in both research and clinical settings as a result of various forms of observation. When the Hawthorne effect exists, it is short-lived, and likely leads to increased productivity, compliance, or adherence to standard protocols. This study is a qualitative component of an ongoing multicentre study, examining the role of Incisional Negative Pressure Wound Therapy after vascular surgery (INVIPS Trial). Here we examine the factors that influence hygiene and the role of the Hawthorne effect on the adherence of healthcare professionals to standard hygiene precautions.

Methods

This is a qualitative interview study, investigating how healthcare professionals perceive the observation regarding hygiene routines and their compliance with them. Seven semi-structured focus group interviews were conducted, each interview included a different staff category and one individual interview with a nurse from the Department for Communicable Disease Control. Additionally, a structured questionnaire interview was performed with environmental services staff. The results were analysed based on the inductive qualitative content analysis approach.

Results

The analysis revealed four themes and 12 subthemes. Communication and hindering hierarchy were found to be crucial. Healthcare professionals sought more personal and direct feedback. All participants believed that there were routines that should be adhered to but did not know where to find information on them. Staff in the operating theatre were most meticulous in adhering to standard hygiene precautions. The need to give observers a clear mandate and support their work was identified. The staff had different opinions concerning the patient’s awareness of the importance of hygiene following surgery. The INVIPS Trial had mediated the Hawthorne effect.

Conclusion

The results of this study indicate that the themes identified, encompassing communication, behaviour, rules and routines, and work environment, influence the adherence of healthcare professionals to standard precautions to a considerable extent of which many factors could be mediated by a Hawthorne effect. It is important that managers within the healthcare system put into place an improved and sustainable hygiene care to reduce the rate of surgical site infections after vascular surgery.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-021-06097-5.

Management of Vascular Infections in Low- and Middle-Income Countries

Background: Vascular infections are rare and challenging conditions with significant deaths and morbidity. Their management necessitates a multi-disciplinary approach and substantial human and financial resources. The management selected may be influenced by the available resources in low- and middle-income countries (LMICs), where such resources may be variable. Methods: We reviewed the published literature and reviewed the management options for various vascular infections with a focus on carotid, aortic, infrainguinal, and dialysis access infections. Results: Recommendations related to prevention and treatment will be offered from the perspective of LMICs. The general principles for prevention are in compliance with established surgical site infection guidelines and minimize the use of prosthetic material. Early detection and intervention by removing all infected prosthetic material, debridement, drainage, and coverage of the infected field with vascularized tissue are essential steps in the management of the infection. Revascularization using an extra-anatomic or in situ approach is individualized based on the resources and expertise available. Conclusions: The prevention and management of vascular infections in LMICs are effective by adhering to time-proven principles even with limited resources.

Discharge to a Post-Acute Care Facility after Emergent Femoral Artery Repair is Not Protective Against Wound Complications

BACKGROUND

Access site complication is the most common adverse event after endovascular intervention, and when emergent operative repair of the common femoral artery (CFA) is needed, patient morbidity can be significantly increased. The intent of this project was to identify predictors of wound events after emergent operative repair of the CFA due to an access site complication. It was hypothesized that patients discharged to a facility would benefit from an ongoing relationship with healthcare professionals as evidenced by more consistent follow-up and lower wound complication rates.

METHODS

Patients who had a percutaneous CFA access complication and required emergent open CFA repair at an academic medical institution between 2015 and 2018 were included, and the charts were reviewed retrospectively. Primary outcomes included wound complication and outpatient compliance with vascular surgery clinic visit. Dichotomous groups were evaluated by the chi-squared test, and continuous variables were evaluated by Student's t-test. Univariate and multivariate regression analyses were completed to assess risk factors contributing to wound event or failure of clinic follow-up.

RESULTS

Forty-four patients were identified with emergent CFA repair due to an access complication between July 2015 and June 2018. Among this population, 33% of patients had wound complications and 27% were discharged to a facility. Among those discharged to a facility, the rate of follow-up to the vascular surgeon's clinic was significantly lower than those discharged to home (40% vs. 85%, P < 0.05), and the incidence of wound complications appeared greater but did not reach statistical significance (50% vs. 27%, P = 0.11). Univariate analysis indicated that kidney disease, albumin <3 g/dL, and current smoking were predictive of wound complication, whereas on multivariate analysis, only kidney disease remained predictive (P < 0.05, odds ratio = 22). The modified frailty index (mFI) was not predictive of wound complications or compliance with follow-up. However, mFI did approach statistical significance when predicting discharge to a facility.

CONCLUSIONS

Despite the availability of medical personnel to arrange transportation and provide wound care in post-acute care facilities, patients who were discharged to a facility after CFA injury requiring emergent repair experienced lower compliance with clinic follow-up and may have suffered more wound complications. Strategies to improve compliance with patient follow-up and wound healing in patients sent to post-acute care facilities are warranted.

Proposed Classification of Incision Complications: Analysis of a Prospective Study on Elective Open Lower-Limb Revascularization

Background: Incision complications (IC) have a significant impact on procedure-related morbidity after lower-limb revascularization. One of the most studied IC is surgical site infection (SSI). Reporting these complications in a uniform way is crucial to evaluate treatment approaches. The aim of this study was to propose a comprehensive classification of IC and apply it to compare SSI with other IC in a trial on elective open lower-limb revascularization procedures. Methods: Two hundred twenty-three eligible patients undergoing elective unilateral inguinal and infra-inguinal arterial vascular surgery were extracted from a randomized controlled trial on incisional negative-pressure wound therapy (NPWT) on inguinal vascular surgical incisions. The IC were classified by grades of severity (grade 0-6) that focused on IC-related consequences such as out-patient treatment (grade 1), prolonged in-patient treatment (grade 2), re-admission (grade 3), and re-operation (grade ≥4). An SSI was defined by the ASEPSIS score criteria. Results: An SSI was diagnosed in 63 patients (28.3%). Thirty-five of 160 patients (21.8%) not suffering from SSI underwent IC treatment. Treatment for IC was recorded for 25/144 patients (17.4%) with satisfactory site healing as judged by the ASEPSIS score. The median incision-related in-hospital stay in those with SSI (n = 79) and disturbed healing (n = 16) according to the ASEPSIS score was 13 days in both groups (p = 0.53). Five patients had peri-vascular SSI (IC grade 4 n = 4; grade 5 n = 1). The proposed classification of IC and the ASEPSIS score correlated highly (r = 0.77; p < 0.001). Inter-rater reliability for IC grading was substantial for three investigators with different levels of experience (k = 0.81, 0.71, and 0.70). Conclusions: The proposed incision classification suggests a comparable clinical significance of vascular IC in terms of IC-related in-patient stay, whether there was a surgical site infection or not. This classification system requires external validation.

[Revascularisation in patients with failed previous arterial reconstructions]

Redo arterial reconstructions are followed by advanced surgical risk or impossible in some cases. Active introduction of endovascular surgery complements the capabilities of conventional surgical approach. It is presented case report of restoration of patency of synthetic femoral-popliteal shunt with previous occlusion for a long time. The technique of recanalization and stenting of allograft is described. Immediate results are favorable but further research is needed.

Antibiotic Prophylaxis With Trimethoprim/Sulfamethoxazole Instead of Cloxacillin/Cefotaxime Increases Inguinal Surgical Site Infection Rate After Lower Extremity Revascularization

Due to the consistently high proportion of surgical site infections (SSI) after vascular surgery, a change of prophylactic antibiotic therapy from cloxacillin/cefotaxime to trimethoprim/sulfamethoxazole (TMP-SMX) was conducted in 2016. The study included consecutive patients undergoing lower extremity revascularization due to acute or chronic lower extremity arterial disease. The antibiotic regime was changed in between the two sampling periods (2014 -2016 versus 2016 -2017). The diagnosis of SSI was based on clinical examination and microbiological results, and severity was classified according to the Szilagyi classification. One hundred and twenty-two patients in the cloxacillin/cefotaxime and 67 patients in the TMP-SMX group were included. The SSI rates were 32.0% and 40.3%, respectively (p=0.25). The proportion of women were higher in the TMP-SMX group (32.8% versus 47.8%, respectively, p=0.043). No other differences between the two groups were found regarding patient, vascular surgery procedure characteristics or severity of SSI. Groin infection rate was higher in the TMP-SMX group (15.4% versus 30.5%, respectively, p=0.022). When adjusting for gender, groin infection was more common in the TMP-SMX group (Odds Ratio 2.5, 95% CI 1.1 -5.4). The groin SSI rate was higher after elective surgery in the TMP-SMX group (13.0% versus 27.8%, respectively, p=0.027), and also after adjusting for gender (Odds Ratio 2.6, 95% CI 1.1 -6.2). The change in antibiotic prophylaxis from Cloxacillin/Cefotaxime to TMP-SMX was associated with an increased rate of inguinal SSI in patients undergoing lower extremity revascularization, despite a possible Hawthorne effect.

Exploration of robotic-assisted surgical techniques in vascular surgery

Robotic-assisted surgical approaches for vascular surgery are feasible regarding minimally invasive exposure, dissection, ligation and skeletonization for varicose vein ligation, anterior spine exposure, femoral-popliteal bypass, femoral vein harvest and aortic aneurysm repair. The authors performed a cadaveric exploration to demonstrate proof of concept and feasibility for a robotic-assisted approached. Surgeon autonomy over endoscopic vision, robotic instrumentation and retraction were noted as key benefits over existing open vascular approaches. Robotic-assisted approaches for vascular surgery enable innovative minimally invasive approaches to disease states not amenable to endovascular repair. Potential reductions in paresthesia through nerve identification were noted during a cadaveric exploration for varicose vein ligation in the setting of chronic venous insufficiency. Minimally invasive femoral artery exposure via a retroperitoneal approach could potentially reduce the morbidity associated with the traditional groin incision. Further exploration and procedure refinement are warranted.

Feasibility of an Image-Based Mobile Health Protocol for Postoperative Wound Monitoring

BACKGROUND

Surgical site infection (SSI) is the most common nosocomial infection and the leading cause of readmission among surgical patients. Many SSIs develop in the postdischarge period and are inadequately recognized by patients. To address this, we developed a mobile health protocol of remote wound monitoring using smartphone technology. The current study aims to establish its feasibility among patients and providers.

STUDY DESIGN

We enrolled vascular surgery patients during their inpatient stay. They were trained to use our mobile health application, which allowed them to transmit digital images of their surgical wound and answer a survey about their recovery. After hospital discharge, participants completed the application daily for 2 weeks. Providers on the inpatient team reviewed submissions daily and contacted patients for concerning findings.

RESULTS

Forty participants were enrolled. Forty-five percent of participants submitted data every day for 2 weeks, with an overall submission rate of 90.2%. Submissions were reviewed within an average of 9.7 hours of submission, with 91.9% of submissions reviewed within 24 hours. We detected 7 wound complications with 1 false negative. Participant and provider satisfaction was universally high.

CONCLUSIONS

Patients and their caregivers are willing to participate in a mobile health program aimed at remote monitoring of postoperative recovery, and they are able to complete it with a high level of fidelity and satisfaction. Preliminary results indicate the ability to detect and intervene on wound complications.

Impact of body mass index and gender on wound complications after lower extremity arterial surgery

OBJECTIVE

Wound complications (WCs) after lower extremity arterial surgery (LEAS) are common, resulting in readmissions and reinterventions. Whereas diabetes and obesity are known risk factors for WCs, gender-specific variability in body fat distribution (android vs gynoid) may drive differential risks of WCs after LEAS. We analyzed the independent and synergistic effects of gender and body mass index (BMI) on WCs.

METHODS

We performed a retrospective review of prospectively collected data from a published, randomized, multicenter trial assessing the incidence of WCs (dehiscence, surgical site infections, seroma, and hematoma) after LEAS. Postoperative outcomes were compared between genders. A multivariable regression model assessed the impact of gender and BMI on WCs. Subanalysis focused on the synergy of gender and body habitus, groin-only incisions, and clinical outcomes.

RESULTS

There were 502 patients who underwent LEAS between October 2010 and September 2013. The cohort was elderly (67.6 ± 10.5 years), mostly male (72%), and overweight (BMI, 27.6 ± 5.7); 225 (45%) patients had a groin-only incision. In 171 patients (37.9%), a WC developed within 30 days, 85% of which were infectious in etiology. On multivariable regression, obesity (odds ratio [OR], 2.10; 95% confidence interval [CI], 1.17-3.77), morbid obesity (OR, 2.87; 95% CI, 1.32-6.23), and female gender (OR, 1.17; 95% CI, 1.06-2.75) were independent predictors of infectious WCs at 30 days. When stratified by groin-only incision, BMI was no longer significant, but female gender (OR, 2.70; 95% CI, 1.24-5.87) was predictive of infectious WCs at 30 days. There was no synergistic effect of BMI and gender on WCs.

CONCLUSIONS

WCs are common after LEAS. BMI is an independent risk factor for the development of any WC. Female gender, a potential surrogate for high hip to waist ratio body habitus, is also an independent predictor of groin WCs, suggesting the clinical importance of gynoid vs android fat distribution.

Closed incision negative pressure therapy: international multidisciplinary consensus recommendations

Surgical site occurrences (SSOs) affect up to or over 25% of patients undergoing operative procedures, with the subset of surgical site infections (SSIs) being the most common. Commercially available closed incision negative pressure therapy (ciNPT) may offer surgeons an additional option to manage clean, closed surgical incisions. We conducted an extensive literature search for studies describing ciNPT use and assembled a diverse panel of experts to create consensus recommendations for when using ciNPT may be appropriate. A literature search of MEDLINE, EMBASE and the Cochrane Central Register of Controlled Trials using key words ‘prevention’, ‘negative pressure wound therapy (NPWT)’, ‘active incisional management’, ‘incisional vacuum therapy’, ‘incisional NPWT’, ‘incisional wound VAC’, ‘closed incisional NPWT’, ‘wound infection’, and ‘SSIs’ identified peer‐reviewed studies published from 2000 to 2015. During a multidisciplinary consensus meeting, the 12 experts reviewed the literature, presented their own ciNPT experiences, identified risk factors for SSOs and developed comprehensive consensus recommendations. A total of 100 publications satisfied the search requirements for ciNPT use. A majority presented data supporting ciNPT use. Numerous publications reported SSI risk factors, with the most common including obesity (body mass index ≥30 kg/m²); diabetes mellitus; tobacco use; or prolonged surgical time. We recommend that the surgeon assess the individual patient's risk factors and surgical risks. Surgeons should consider using ciNPT for patients at high risk for developing SSOs or who are undergoing a high‐risk procedure or a procedure that would have highly morbid consequences if an SSI occurred.

Local perivascular adiponectin associates with lower extremity vascular operative wound complications

BACKGROUND

Wound complication rates after lower extremity vascular operative procedures stand as high as 40% and represent a major cause of morbidity, mortality, and cost. In view of increasing recognition of adipose tissue involvement in homeostasis and the response to injury, we hypothesized that adipose phenotype is linked to operative wound outcomes.

METHODS

Clinical history, peripheral blood, and subcutaneous and perivascular adipose tissue were prospectively collected at the time of operation in patients undergoing lower extremity revascularization and lower extremity amputations. Nine biologic mediators (adiponectin; interleukin [IL]-1β, IL-6, and IL-8; leptin; monocyte chemoattractant protein-1; plasminogen activator inhibitor-1; resistin; and tumor necrosis factor) were assayed in the adipose tissues and plasma. The 30-day wound complications were captured in real time. Logarithmic transformation of mediator levels was performed based on positively skewed, non-Gaussian distribution, and data were compared using the Student t test. Bonferroni correction was used for multiple comparisons.

RESULTS

Sixty-six patients undergoing lower extremity revascularization or lower extremity amputations for severe peripheral arterial disease were enrolled. The 30-day follow-up was 92.4%. In total, 19 (29%) patients developed wound complications. Patients who developed wound complications had elevated perivascular adiponectin levels (mean ± standard error, 2,372.45 ± 648.64 ng/mL vs 832.53 ± 180.54 ng/mL, P = .004). Perivascular IL-1β levels were lower among patients with wound dehiscence (0.41 ± 0.004 pg/mL vs 0.73 ± 0.09 pg/mL, P = .001).

CONCLUSION

Local adipose tissue mediator levels at the time of operation demonstrate a previously undescribed compartment-specific relationship to wound outcomes in patients undergoing lower extremity vascular operative procedures. These associations provide fertile directives for defining the mechanisms underlying the pathogenesis of wound complications and their prevention.

Management of infected vascular grafts

Infections of vascular grafts are associated with significant mortality and morbidity risk and cost an estimated $640 million annually in the United States. Clinical presentation varies by time elapsed from implantation and by surgical site. A thorough history and physical examination in conjunction with a variety of imaging modalities is often essential to diagnosis. For infected aortic grafts, there are several options for treatment, including graft excision with extra-anatomic bypass, in situ reconstruction, or reconstruction with the neo-aortoiliac system. The management of infected endovascular aortic grafts is similar. For infected peripheral bypasses, graft preservation techniques can be utilized, but in cases where it is not possible, graft removal and revascularization through uninfected tissue planes is necessary. Infected dialysis access can be surgically treated by complete or subtotal graft excision. Diagnosis, general management, and surgical approaches to infected vascular grafts are discussed in this review.

Predictors of surgical site infection after hospital discharge in patients undergoing major vascular surgery

OBJECTIVE

Surgical site infection (SSI) is one of the most common postoperative complications after vascular reconstruction, producing significant morbidity and hospital readmission. In contrast to SSI that develops while patients are still hospitalized, little is known about the cohort of patients who develop SSI after discharge. In this study, we explore the factors that lead to postdischarge SSI, investigate the differences between risk factors for in-hospital vs postdischarge SSI, and develop a scoring system to identify patients who might benefit from postdischarge monitoring of their wounds.

METHODS

Patients who underwent major vascular surgery from 2005 to 2012 for aneurysm and lower extremity occlusive disease were identified from the American College of Surgeons National Surgical Quality Improvement Program Participant Use Files. Patients were categorized as having no SSI, in-hospital SSI, or SSI after hospital discharge. Predictors of postdischarge SSI were determined by multivariable logistic regression and internally validated by bootstrap resampling. Risk scores were assigned to all significant variables in the model. Summative risk scores were collapsed into quartile-based ordinal categories and defined as low, low/moderate, moderate/high, and high risk. Multivariable logistic regression was used to determine predictors of in-hospital SSI.

RESULTS

Of the 49,817 patients who underwent major vascular surgery, 4449 (8.9%) were diagnosed with SSI (2.1% in-hospital SSI; 6.9% postdischarge SSI). By multivariable analysis, factors significantly associated with increased odds of postdischarge SSI include female gender, obesity, diabetes, smoking, hypertension, coronary artery disease, critical limb ischemia, chronic obstructive pulmonary disease, dyspnea, neurologic disease, prolonged operative time >4 hours, American Society of Anesthesiology class 4 or 5, lower extremity revascularization or aortoiliac procedure, and groin anastomosis. The model exhibited moderate discrimination (bias-corrected C statistic, 0.691) and excellent internal calibration. The postdischarge SSI rate was 2.1% for low-risk patients, 5.1% for low/moderate-risk patients, 7.8% for moderate/high-risk patients, and 14% for high-risk patients. In a comparative analysis, comorbidities were the primary driver of postdischarge SSI, whereas in-hospital factors (operative time, emergency case status) and complications predicted in-hospital SSI.

CONCLUSIONS

The majority of SSIs after major vascular surgery develop following hospital discharge. We have created a scoring system that can select a cohort of patients at high risk for SSI after discharge. These patients can be targeted for transitional care efforts focused on early detection and treatment with the goal of reducing morbidity and preventing readmission secondary to SSI.

Diagnosis and Treatment of Vascular Surgery Related Infection

Surgical site infection (SSI) is an important component of infections acquired from hospital. The most significant feature of vascular surgery different from other surgeries is frequent application of artificial grafts. Once SSI occurs after vascular operations with grafts, it might results in a serious disaster. Staphylococcus aureus and coagulase-negative Staphylococcus are the most common pathogenic bacteria for SSI after vascular surgery. Although SSI in vascular surgery often lacks of typical clinical characters, some clinical symptoms, laboratory data and certain imaging procedures may help to diagnose. In most cases of SSI after vascular procedures, the artificial grafts must be removed and sensitive antibiotics should be administered. However, for different cases, personalized management plan should be made depending on the severity and location of SSI.

Antibiotic Prophylaxis With Trimethoprim/Sulfamethoxazole Instead of Cloxacillin Fails to Improve Inguinal Surgical Site Infection Rate After Vascular Surgery

Background:

Surgical site infections (SSIs) and their prevention continue to be a major point of focus in all surgical specialties today. Antibiotic prophylaxis is one of the mainstays in their prevention. Due to the consistently high proportion of infections caused by intestinal flora from the start of our wound surveillance registry in 2005, we conducted a change in prophylactic antibiotic therapy from cloxacillin in 2012 to trimethoprim/sulfamethoxazole (TMP-SMX) in 2013.

Methods:

The study included all patients undergoing vascular surgery with groin incisions between March 1 and June 30 in 2012 and 2013, respectively, whereby the antibiotic regime was changed in between the 2 sampling periods. The diagnosis of SSI was based on clinical examination and microbiological results.

Results:

Two hundred nineteen patients with inguinal incisions were included in the analysis: 105 in the cloxacillin group of which 19% had SSI and 114 in the TMP-SMX group with an SSI rate of 18% ( P = .77), without differences between the 2 groups regarding age, gender, proportion of emergency surgery, type of surgery, or frequency of concomitant foot ulcers. The high proportion of infections caused by intestinal flora between time periods was unchanged (67% vs 81%, P = .34).

Conclusion:

There was no difference between the 2 groups, suggesting that the choice of antibiotic prophylaxis had a limited role in preventing SSI at our center. Despite this, the lower cost and ease of the administration of TMP-SMX can be seen as convincing advantages.