Treatment of Aorto-iliac and Infrainguinal Vascular Infections with a Prefabricated Bovine Pericardial Graft

BACKGROUND

The use of biological grafts provides acceptable mid- and long-term results in native or prosthetic vascular infections. Several reports describe the successful use of bovine pericardium in case of vascular infections, mainly as a large patch to be sutured as a tubular graft. Recently, a novel prefabricated bovine pericardium graft (Biointegral Surgical No-React® Inc, Mississauga, ON, Canada) has been introduced in clinical practice with promising results. In this study, we report our preliminary experience utilizing Biointegral Surgical graft in case of native and or prosthetic aorto-iliac and infrainguinal infection.

METHODS

We retrospectively analyzed data from 20 patients with native or prosthetic aorto-iliac and infrainguinal infection who underwent in situ reconstruction (ISR) with a Biointegral Surgical No-React bovine pericardium prosthesis between October 2020 and February 2023 at the Vascular Surgery Unit of the Fondazione Policlinico Universitario Gemelli - IRCCS in Rome, Italy. All patients followed a standardized protocol including postoperative anticoagulation and long-term intravenous antibiotics.

RESULTS

The indication for surgery was: mycotic aortic aneurysm in 4 patients (20%), graft infection after abdominal aortic repair in 11 patients (55%), peripheral graft infection in 5 patients (25%). Complete excision of the infected aorta or prosthetic graft, surgical debridement and ISR were performed in all patients. Hospital mortality rate was 5% (n = 1) and graft-related mortality of 0%. During follow-up (median 13 months, range 6-34 months), reinfection was 5.2% and primary graft patency 94.7%.

CONCLUSIONS

The use of prefabricated bovine pericardial grafts represents a promising option for the treatment of native and prosthetic aorto-iliac and infrainguinal infections. The application of this biological graft with a standardized postoperative protocol has been associated with a satisfactory patency and reinfection rate without increased bleeding complications.

Early and Mid-Term Results of Native and Abdominal Aortic Graft Infection Treatment via Surgeon-Constructed Porcine Pericardial Aortic Tubes

The search for optimal material for aortic infection reconstruction is ongoing. Our study presents the early and mid-term results of surgeon-constructed porcine pericardial tubes in the in-situ reconstruction of abdominal aortic infections, focusing on the safety as well as the durability of surgeon-created tubes. We performed a retrospective analysis of 8 patients treated for native aortic (n = 3) and aortic graft infections (n = 5) with surgeon-created tubes made of porcine pericardium patch (8 × 14 cm NO-REACT Ⓡ, BioIntegral Surgical Inc., Mississauga, ON, Canada). There were 7 males and 1 female, aged 68.5 (±4.8 years). Three patients had an aorto-enteric fistula. Technical success was obtained in all patients. Thirty-day mortality was 12.5% (n = 1). Mid-term follow-up was 12 months (2-63 months). One-year mortality was 37.5% (n = 3). Reintervention rate was 28.5% (n = 2). False aneurysm rate in the follow-up was 14.2% (n = 1). Surgeon-constructed porcine pericardial tubes seem to be a promising alternative as a replacement for native as well as graft-related abdominal aortic infections. The mid-term durability is encouraging, once the infection is controlled in cases with successful fistula repair and in native aortic infections patients. Further observations on larger groups, in longer follow-ups are necessary to confirm these preliminary observations.

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.

Outcomes of Candida and Non-Candida Aortic Graft Infection

OBJECTIVE

To evaluate and compare the outcomes of Candida- and non-Candida-associated aortic graft infections.

METHODS

We retrospectively analyzed the data from patients treated for aortic graft infection from 2015 to 2021 in our hospital.

RESULTS

A total of 66 patients (56 men; median age, 69 years; range, 50-87 years) were admitted with aortic graft infection, including 21 (32%) patients in the Candida group and 45 (68%) in the non-Candida group. The average time between initial operation and presentation of aortic graft infection was 50 months (range, 1-332 months). Graft-enteric fistulas (GEFs) were more often in the Candida group (57% vs 27%, P = .017). The most proven causative fungal specimen was C. albicans in 16 (76%) patients. Non-albicans Candida was found in 9% of all patients and 29% of the Candida patients. The median ICU length of stay was longer in the Candida group than non-Candida (10 vs 9 days, P = .012). Additionally, the median hospital length of stay was longer in the Candida group (33 vs 22 days, P = .048). There were no statistically significant differences between Candida and non-Candida groups according to the in-hospital mortality (24% vs 24%, P = .955), and 1-year mortality (38% vs 38%, P = .980).

CONCLUSIONS

Patients with bacterial and fungal aortic graft infections have high rates of morbidity and mortality. We found no significant differences in postoperative morbidity and mortality between Candida and non-Candida patients. However, the ICU and hospital length of stay were longer in the Candida group.

Complications related to the access site after transaxillary implantation of a microaxial left ventricular assist device

BACKGROUND

Impella 5.0 and 5.5 (summarized as Impella 5+) are microaxial, catheter-based left ventricular assist devices (LVAD) that are implanted via a vascular graft sutured to the axillary artery and provide blood flow of up to 5.5 liter/min. This study aims to investigate the incidence of long-term complications following circulatory support with Impella 5+.

METHODS

A single-center retrospective analysis of 203 consecutive adult patients treated between January 2017 and September 2021 with a surgically implanted Impella 5.0 or 5.5 via a vascular graft sutured to the axillary artery.

RESULTS

The median Impella support duration was 8 days. Of 203 patients, 78 (38.4%) died while on temporary mechanical circulatory support. Fifty-five (27.1%) were successfully weaned from Impella 5+ and 70 (34.5%) were bridged to a durable LVAD with a median follow-up time of 232 (IQR 68.5, 597) days after Impella 5+ explantation. In 119 of these patients, the Impella was explanted and the vascular graft was shortened, ligated, and pushed under the pectoralis muscle; in 6 patients early graft infection prompted complete graft removal during explantation. In addition, 13 patients (10.9%) developed a late-onset graft infection after a median of 86 days, requiring complete (n = 10) or partial (n = 2) explantation of the retained graft. In 1 patient, the graft infection was successfully treated by conservative therapy. Our analysis identified no specific risk factors for graft infections. Of the 203 patients, 5 (2.5%) developed a brachial plexus injury resulting in neurological dysfunction.

CONCLUSIONS

In 10.9% of patients, retaining the vascular graft was complicated by a late graft infection. Complete explantation of the graft prosthesis may decrease the infection rate, but may in turn increase the risk of brachial plexus injury. On the other hand, this method offers the possibility of bedside explantation.

Use of 3D Printing for the Development of Biodegradable Antiplatelet Materials for Cardiovascular Applications

Small-diameter synthetic vascular grafts are required for surgical bypass grafting when there is a lack of suitable autologous vessels due to different reasons, such as previous operations. Thrombosis is the main cause of failure of small-diameter synthetic vascular grafts when used for this revascularization technique. Therefore, the development of biodegradable vascular grafts capable of providing a localized and sustained antithrombotic drug release mark a major step forward in the fight against cardiovascular diseases, which are the leading cause of death globally. The present paper describes the use of an extrusion-based 3D printing technology for the production of biodegradable antiplatelet tubular grafts for cardiovascular applications. For this purpose, acetylsalicylic acid (ASA) was chosen as a model molecule due to its antiplatelet activity. Poly(caprolactone) and ASA were combined for the fabrication and characterization of ASA-loaded tubular grafts. Moreover, rifampicin (RIF) was added to the formulation containing the higher ASA loading, as a model molecule that can be used to prevent vascular prosthesis infections. The produced tubular grafts were fully characterized through multiple techniques and the last step was to evaluate their drug release, antiplatelet and antimicrobial activity and cytocompatibility. The results suggested that these materials were capable of providing a sustained ASA release for periods of up to 2 weeks. Tubular grafts containing 10% (w/w) of ASA showed lower platelet adhesion onto the surface than the blank and grafts containing 5% (w/w) of ASA. Moreover, tubular grafts scaffolds containing 1% (w/w) of RIF were capable of inhibiting the growth of Staphylococcus aureus. Finally, the evaluation of the cytocompatibility of the scaffold samples revealed that the incorporation of ASA or RIF into the composition did not compromise cell viability and proliferation at short incubation periods (24 h).

Inferior Vena Cava Leiomyosarcoma: What Method of Reconstruction for Which Type of Resection?

Inferior vena cava leiomyosarcoma (IVCL) is a rare tumor with a poor prognosis, and its surgical resection remains a challenge. To date, surgery is the only potentially curative treatment for IVCL with a 5-year survival rate of 55%. The main challenge is to combine oncological surgery with clear margins and vascular reconstruction of the inferior vena cava (IVC). In this review, we discuss the different approaches to vascular reconstruction after IVCL resection, using a prosthetic or autologous patch, direct suture or simple ligation without IVC reconstruction. The reconstruction of IVC depends of tumor location and its extension. We recommend no reconstruction if venous collaterality is well-established. When vascular reconstruction is required, we prefer prosthetic PTFE graft. These patients should be referred to high-volume centers with a multidisciplinary team of sarcoma surgeons with cardiothoracic, vascular and hepatic specialties.

Fused deposition modelling for the development of drug loaded cardiovascular prosthesis

Cardiovascular diseases constitute a number of conditions which are the leading cause of death globally. To combat these diseases and improve the quality and duration of life, several cardiac implants have been developed, including stents, vascular grafts and valvular prostheses. The implantation of these vascular prosthesis has associated risks such as infection or blood clot formation. In order to overcome these limitations medicated vascular prosthesis have been previously used. The present paper describes a 3D printing method to develop medicated vascular prosthesis using fused deposition modelling (FDM) technology. For this purpose, rifampicin (RIF) was selected as a model molecule as it can be used to prevent vascular graft prosthesis infection. Thermoplastic polyurethane (TPU) and RIF were combined using hot melt extrusion (HME) to obtain filaments containing RIF concentrations ranging between 0 and 1% (w/w). These materials are capable of providing RIF release for periods ranging between 30 and 80 days. Moreover, TPU-based materials containing RIF were capable of inhibiting the growth of Staphylococcus aureus. This behaviour was observed even for TPU-based materials containing RIF concentrations of 0.1% (w/w). TPU containing 1% (w/w) of RIF showed antimicrobial properties even after 30 days of RIF release. Alternatively, these methods were used to prepare dipyridamole containing TPU filaments. Finally, using a dual extrusion 3D printer vascular grafts containing both drugs were prepared.

Ruptured mycotic common iliac aneurysm due to Capnocytophaga canimorsus, acquired from dog saliva: A case report

INTRODUCTION

Mycotic arterial aneurysm occurs secondary to infection of the arterial wall Dubois et al. (2010). It is a serious clinical condition associated with significant morbidity and mortality. Various pathogens can be responsible but the most commonly isolated causative organisms are Staphylococcus spp. and Salmonella spp. Brown et al. (1984). An extremely uncommon causative pathogen is Capnocytophaga canimorsus, a commensal bacterium found in the normal gingival flora of canines.

PRESENTATION OF CASE

We describe the case of a ruptured mycotic common iliac aneurysm presenting with acute haemodynamic instability and femoral nerve impairment due to compression secondary to extensive haematoma. Rupture was preceded by a four-week history of left hip/groin discomfort with an abrasion to the left upper limb exposed to dog saliva in the weeks prior to symptom onset. Open debridement, revascularisation, and aggressive antimicrobial therapy was utilised with microbiological culture revealing Capnocytophaga canimorsus as the causative pathogen.

DISCUSSION

Successful repair was achieved surgically with a prosthetic bypass, followed by a 6-week course of intravenous antibiotics. Lifelong oral suppressant antibiotic treatment was then commenced. At 6-month follow up, the patient was free from clinical or radiological recurrence of infection or aneurysm.

CONCLUSION

This case highlights an extremely rare aetiology for ruptured common iliac aneurysm in the form of Capnocytophaga canimorsus. It highlights the importance of a thorough history, including pet exposures, for patients with infected aneurysms and the need to ensure appropriate specimens are collected when a mycotic aneurysm is suspected.

Microbial evolution of vascular graft infections in a tertiary hospital based on positive graft cultures

BACKGROUND

Vascular graft infections are a serious complication in vascular surgery. Correct antibiotic therapy targeted to the most likely infecting species is essential to treat these patients, although the bacterial epidemiology and pathogenesis are still not completely understood. We analyzed the behavior of vascular graft infections and the microbiologic patterns of resistance.

METHODS

A 10-year (2008-2018), single-center, retrospective cohort study was performed of all patients admitted with vascular graft infection identified by positive direct graft cultures. An extensive microbiologic study was performed to analyze the bacterial strains, antibiotic resistance and sensitivity, and prevalence stratified by the year.

RESULTS

A total of 72 vascular graft infections with positive graft cultures occurring in 65 patients were found. Their mean age was 67 ± 9.6 years, and 85% were men. Infection-related mortality was 11%. Of the 65 patients, 14 had undergone aortobifemoral bypass, 13 axillofemoral bypass, 5 femorofemoral bypass, 27 femoropopliteal bypass, and 4 femoral endarterectomy with synthetic patch angioplasty. The median interval from the index procedure to infection was longer for intracavitary than for extracavitary grafts (P = .011). Of the 72 infections, 48 were monomicrobial and 24 were polymicrobial. Gram-negative bacteria were predominantly identified in intracavitary graft infections (54%). In contrast, gram-positive bacteria were most frequent in the extracavitary graft group (58%). Multidrug-resistant bacterial species occurred more frequently in early graft infections (P = .002). Throughout the study duration, an overall decrease in gram-positive infections and an increase in gram-negative infections was observed, especially in extensively drug-resistant strains. A similar progression was found in all nosocomial infections.

CONCLUSIONS

The present study has shown that vascular graft infection microbiology changed in accordance with graft location and interval to infection from revascularization surgery and had also evolved over the study period with patterns similar to those for all nosocomial infections. This highlights the importance of studying the specific microbiology of each healthcare center and its relationship to vascular graft infections to achieve the best treatment possible.

Community Hospital Experience With Bovine Tissue in Infected Vascular Fields

BACKGROUND

Vascular prosthetic graft infections are rare but associated with high morbidity and mortality. Treatment involves removal of the infected graft requiring arteriotomy closure. Previously this was performed with autologous graft, but bovine tissue has increasingly been used. The objective of this paper is to review the community hospital experience with bovine tissue repair in an infected vascular field.

MATERIALS AND METHODS

A retrospective review of all cases performed by a single surgeon in a community hospital for infected prosthetic grafts was completed. Sixteen cases were included where bovine tissue was used for repair. Presentation, location of graft, and causative organism were reviewed, and outcomes including reoperation and mortality were recorded.

RESULTS

Of the 16 patients, 15 (94%) had positive cultures of the graft. Methicillin-Resistant Staph Aureus was the most commonly isolated organism (50%). There were 3 unplanned reoperations including a revision from below to above knee amputation, drainage of a hematoma, and a wound debridement within the first year. Over the 1 year follow up period, 3 patients died for a mortality of 19%. There were no reinfections during follow-up.

DISCUSSION

Prosthetic graft infection is a rare but serious vascular surgery complication. The causative organism has shifted in the last few years to become increasingly drug resistant. Treatment requires excision, and bovine tissue has been demonstrated to provide a safe and durable method of repair.

A systematic review and meta-analysis of 18F-fluoro-d-deoxyglucose positron emission tomography interpretation methods in vascular graft and endograft infection

OBJECTIVE

Vascular graft and endograft infection (VGEI) has high morbidity and mortality rates. Diagnosis is complicated because symptoms vary and can be nonspecific. A meta-analysis identified ¹⁸F-fluoro-d-deoxyglucose positron emission tomography-computed tomography (¹⁸F-FDG PET/CT) as the most valuable tool for diagnosis of VGEI and favorable to computed tomography as the current standard. However, the availability and varied use of several interpretation methods, without consensus on which interpretation method is best, complicate clinical use. The aim of this study was to evaluate the diagnostic performance of different interpretation methods of ¹⁸F-FDG PET/CT in diagnosis of VGEI.

METHODS

A systematic review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Data sources included PubMed/MEDLINE, Embase, and Cochrane Library. A meta-analysis was conducted on the different interpretation methods for ¹⁸F-FDG PET/CT in diagnosis of VGEI, including visual FDG uptake intensity, visual FDG uptake pattern, and quantitative maximum standardized uptake (SUVmax).

RESULTS

Of 613 articles, 13 were included (10 prospective and 3 retrospective articles). The FDG uptake pattern method (I² = 26.2%) showed negligible heterogeneity, whereas the FDG uptake intensity (I² = 42.2%) and SUVmax (I² = 42.1%) methods showed moderate heterogeneity. The pooled sensitivity for FDG uptake intensity was 0.90 (95% confidence interval [CI], 0.79-0.96); for uptake pattern, 0.94 (95% CI, 0.89-0.97); and for SUVmax, 0.95 (95% CI, 0.76-0.99). The pooled specificity for FDG uptake intensity was 0.59 (95% CI, 0.38-0.78); for FDG uptake pattern, 0.81 (95% CI, 0.71-0.88); and for SUVmax, 0.77 (95% CI, 0.63-0.87). The uptake pattern interpretation method demonstrated the best positive and negative post-test probability, 82% and 10%, respectively.

CONCLUSIONS

This meta-analysis identified the FDG uptake pattern as the most accurate assessment method of ¹⁸F-FDG PET/CT for diagnosis of VGEI. The optimal SUVmax cutoff, depending on the vendor, demonstrated strong sensitivity and moderate specificity.

A rare case of Listeria monocytogenes causing mycotic aneurysm of the common femoral artery: A case report

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Immunosuppressed patients may not display typical clinical or biochemical features associated with mycotic aneurysms.

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Clinicians should have a high index of suspicion for infective aetiology when treating aneurysmal disease in immunocompromised patients.

•

It is important to obtain intraoperative tissue samples for histopathology and microbiological assessment in immunocompromised patients for detection of rare pathogens.

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Autogenous vein should be used in infected surgical fields to avoid the risk of prosthetic graft infection.

Introduction

Mycotic aneurysms are an uncommon occurrence, withStaphylococcus and Salmonella species found to be the causative pathogen in up to 95% of cases. We believe this is the first described case of a common femoral artery mycotic aneurysm due to Listeria monocytogenes.

Presentation of case

A 66-year-old male presented with a two-month history of an increasing painful mass in his left groin, on the background of immunosuppression treatment for ankylosing spondylitis. He was afebrile on assessment, with a normal white cell count. Contrast enhanced CT scan showed a common femoral artery aneurysm, with no infective features. His aneurysm was excised and repaired with a Dacron tube graft. L. monocytogenes was cultured from the aneurysm tissue, and he was commenced on appropriate antibiotic treatment. The prosthetic graft was also replaced with a venous bypass of the aneurysm.

Discussion

L. monocytogenes is a rare cause of mycotic aneurysm with less than 40 cases reported in the literature. Immunosuppression is a recognised risk factor for Listerial infections. Immunocompromised patients may not display typical clinical or biochemical features associated with a mycotic aneurysm. Prosthetic graft infections are associated with significant mortality, with excision of the prosthetic material and venous reconstruction associated with good outcomes for eradicating infection.

Conclusion

This report highlights the importance of obtaining intraoperative tissue samples for microbiological and histopathological assessment in immunocompromised patients. This is important for the detection of rare organisms such as L.monocytogenes, requiring targeted antibiotic therapy. Inappropriate treatment of Listerial infections can result in serious invasive illness.

Systematic Review and Meta-Analysis on the Management of Open Abdominal Aortic Graft Infections

OBJECTIVE

Aortic graft infection (AGI) is a disastrous complication with an incidence of 0.2-6% in operated patients. With little or no high quality evidence, the best treatment option remains unclear. Therefore, the literature on the management of open abdominal AGI was systematically reviewed to determine optimal treatment.

METHODS

In accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, a systematic review and meta-analysis was conducted for AGI. MEDLINE, Embase, and the Cochrane Database of Systematic Reviews were searched. Methodological quality was assessed using the Methodological Index for Non-randomised Studies (MINORS) score. Primary outcomes were 30 day mortality and one year survival. Secondary outcomes were survival, infection recurrence, limb salvage, and graft patency.

RESULTS

Of 1574 studies identified, 32 papers were included in the study. The overall quality of the studies was moderate, with an average MINORS score of 11.9. Pooled overall 30 day mortality and one year survival were 13.5% (95% CI 10.5-16.4) and 73.6% (95% CI 68.8-78.4), respectively. The lowest 30 day mortality and highest one year survival were found for in situ repair compared with extra-anatomic repair and for prosthetic grafts compared with venous grafts or arterial allografts. The infection recurrence rate was highest for prosthetic grafts.

CONCLUSIONS

There is a lack of well designed, qualitative comparative studies making conclusive recommendations impossible. The current best available data suggests that partial graft removal should be avoided and the lowest 30 day mortality and best one year survival are achieved with in situ repair using prosthetic grafts. Initiatives such as the MAGIC database to collaboratively collect prospective data are an important step forward in obtaining more solid answers on this topic.