In situ revascularization with silver-coated polyester grafts to treat aortic infection: early and midterm results

Endovascular wall-grafting for mycotic common iliac pseudo-aneurysm: Systemic mycoses

Mycotic pseudoaneurysms of the iliac arteries are extremely rare and are caused by infection of the artery wall. It is difficult to diagnose early due to its silent manifestation. We present a case of a 64-year-old man with an isolated left common iliac artery pseudoaneurysm caused by Candida albicans who presented with thrombophlebitis, abdominal pain, nausea and vomiting associated with fever, which was successfully treated with interposition grafting and antibiotic therapy. We present this case to highlight that aneurysms and other vascular lesions can affect different arteries in the body and may therefore only be discovered during routine investigations of non-specific symptoms.

Contemporary outcomes for arterial reconstruction with non-saphenous vein cryo-preserved conduits

OBJECTIVE

Cryopreserved (CP) products are utilized during challenging cases when autogenous or prosthetic conduit use is not feasible. Despite decades of experience with cadaveric greater saphenous vein (GSV), there is limited available data regarding the outcomes and patency of other CP products, specifically arterial and deep venous grafts. This study was designed to evaluate outcomes of non-GSV CP conduits in patients undergoing urgent, emergent, and elective arterial reconstruction at our institution. We hypothesized that non-GSV CP allografts have adequate patency and outcomes and are therefore a feasible alternative to GSV in settings where autologous graft is unavailable or prosthetic grafts are contraindicated.

METHODS

This study was approved by the Institutional Review Board at our institution. We retrospectively reviewed charts of patients undergoing arterial reconstructions using CP conduits from 2010 to 2022. Data collected included demographics, comorbidities, smoking status, indications for surgery, indication for CP conduit use, anatomic reconstruction, urgency of procedure, and blood loss. Time-to-event outcomes included primary and secondary graft patency rates, follow-up amputations, and mortality; other complications included follow-up infection/reinfection and 30-day complications, including return to the operating room and perioperative mortality. Time-to-event analyses were evaluated using product-limit survival estimates.

RESULTS

Of 96 identified patients receiving CP conduits, 56 patients received non-GSV conduits for 66 arterial reconstructions. The most common type of non-GSV CP product used was femoral artery (31 patients), followed by aorto-iliac artery (22 patients), and femoral vein (19 patients), with some patients receiving more than one reconstruction or CP product. Patients were mostly male (75%), with a mean age of 63.1 years and a mean body mass index of 26.7 kg/m2. Indications for CP conduit use included infection in 53 patients, hostile environment in 36 patients, contaminated field in 30 patients, tissue coverage concerns in 30 patients, inadequate conduit in nine patients, and patient preference in one patient. Notably, multiple patients had more than one indication. Most surgeries (95%) were performed in urgent or emergent settings. Supra-inguinal reconstructions were most common (53%), followed by extra-anatomic bypasses (47%). Thirty-day mortality occurred in 10 patients (19%). Fifteen patients (27%) required return to the operating room for indications related to the vascular reconstructions, with 10 (18%) cases being unplanned and five (9%) cases planned/staged. Overall survival at 6, 12, and 24 months was 80%, 68%, and 59%, respectively. Primary patency at 6, 12, and 24 months was 86%, 70%, and 62%, respectively. Amputation freedom at 6 months, 12 months, and 24 months was 98%, 95%, and 86%, respectively for non-traumatic indications.

CONCLUSIONS

Non-GSV CP products may be used in complex arterial reconstructions when autogenous or prosthetic options are not feasible or available.

Performance of the BioIntegral Bovine Pericardial Graft in Vascular Infections: VASCular No-REact Graft Against INfection Study

BACKGROUND

Vascular graft and endograft infections (VGEI) and native vessel infections (NVI) remain considerable challenges in vascular surgery, leading to high mortality and morbidity rates. Although in situ reconstruction is the preferred treatment, the material of choice is still a source of debate. Autologous veins are considered the first choice; however, xenografts may be an acceptable alternative. The performance of a biomodified bovine pericardial graft is assessed when implemented in an infected vascular area.

METHODS

This is a prospective multicenter cohort study. Patients who underwent reconstruction for VGEI or NVI with a biomodified bovine pericardial bifurcated or straight tube graft were included from December 2017 until June 2021. The primary outcome measure was reinfection at mid-term follow-up. Secondary outcome measures included mortality, patency, and amputation rate.

RESULTS

Thirty-four patients with vascular infections were included, of which 23 (68%) had an infected Dacron prosthesis after primary open repair and 8 (24%) had an infected endovascular graft. The remaining 3 (9%) had infected native vessels. At secondary repair, 3 (7%) patients had an in situ aortic tube reconstruction, 29 (66%) had an aortic bifurcated reconstruction, and 2 (5%) had an iliac-femoral reconstruction. At 1-year follow-up after the BioIntegral bovine pericardial graft reconstruction, the reinfection rate was 9%. The 1-year infection-related and procedure-related mortality rate was 16%. The occlusion rate was 6% and in total 3 patients underwent a lower limb amputation during the 1-year follow-up period.

CONCLUSIONS

In situ reconstruction as treatment of (endo)graft and native vessel infections remains a challenge and reinfection looms as a potential consequence. In cases where time is of essence or when autologous venous repair is not feasible, a swift available solution is needed. The BioIntegral biomodified bovine pericardial graft may be an option as it shows reasonable results in terms of reinfection, in aortic tube and bifurcated grafts.

A review on the deeper understanding of inflammation and infection of the thoracic aorta

OBJECTIVE

To review the current literature regarding infection and inflammation of the thoracic aorta and to summarise its aetiologies, pathogenesis and clinical presentation. Additionally, the authors sought to compare diagnostic methods and to analyse the different management options.

METHOD

A comprehensive electronic search using PubMed, MEDLINE, Scopus and Google Scholar was conducted to find relevant journal articles with key search terms including: 'aortitis', 'thoracic aortic infection' and 'surgical management of infected thoracic aortic aneurysms'. Prominent publications from 1995 till present (2021) were analysed to achieve a deeper understanding of thoracic aorta infection and inflammation, and the information was then collated to form this review.

RESULTS

The literature review revealed that infectious causes are more prominent than non-infectious causes, with Gram positive bacteria such as Staphylococcus, Enterococcus and Streptococcus accounting for approximately 60% of the infections. The authors also noted that Staphylococcus Aureus was associated with poorer outcomes. Key diagnostic tools include MRI and multi-slice CT imaging, which are useful imaging modalities in defining the extent of the disease thus allowing for planning surgical intervention. Surgical intervention itself is extremely multifaceted and the rarity of the condition means no large-scale comparative research between all the management options exists. Until more large-scale comparative data becomes available to guide treatment, the optimal approach must be decided on a case-by-case basis, considering the benefits and drawback of each treatment option.

CONCLUSION

A high index of suspicion and a comprehensive history is required to effectively diagnose and manage infection and inflammation of the thoracic aorta. Differentiating between infectious and inflammatory cases is crucial for management planning, as infectious causes typically require antibiotics and surgical intervention. Over the years, the post treatment results have shown significant improvement due to earlier diagnosis, advancement in surgical options and increasingly specific microbial therapy.

Reconstruction of primary and secondary aortic infections with an antimicrobial graft

INTRODUCTION

In situ reconstruction (ISR) with autologous veins is the preferred method in infectious native aortic aneurysms (INAAs) or vascular (endo)graft infection (VGEI). However, access to biological substitutes can prove difficult and lacks versatility. This study evaluates survival and freedom from reinfection after ISR of INAA/VGEI using the antimicrobial Intergard Synergy graft combining silver and triclosan.

METHODS

From February 2014 to April 2020, 86 antimicrobial grafts were implanted for aortic infection. The diagnosis of INAA/VGEI and reinfection was established based on the Management of Aortic Graft Infection Collaboration criteria. Survival was analyzed using the Kaplan-Meier method and log-rank P values.

RESULTS

The antimicrobial graft was implanted in 32 cases of INAA, 28 of VGI, and 26 of VEI. The median age was 69.0 (interquartile range: 62.0; 74.0), with a history of coronary artery disease (n = 21; 24.4%), chronic kidney disease (n = 11; 12.8%), cancer (n = 21; 24.4%), and immunosuppression (n = 27; 31.4%). Imaging showed infiltration (n = 14; 16.3%), air (n = 10; 11.6%), and rupture (n = 16; 18.6% including 22 aortoenteric fistulae [AEnF]). Symptoms included fever (n = 37; 43.0%), shock (n = 11; 12.8%), and pain (n = 47; 54.7%). Repair was undertaken through a midline laparotomy in 75 cases (87.2%) and coeliac cross-clamping in 19 (22.1%), suprarenal in 26 (30.2%), plus celiac trunk (n = 3), mesenteric (n = 5), renal (n = 13), or hypogastric (n = 4) artery reconstruction, and omental flap coverage (n = 41; 48.8%). For AEnF, the gastrointestinal tract was repaired using direct suture (n = 14; 16.3%) or resection anastomosis (n = 8; 9.3%). Causative organisms were identified in 74 patients (86.0%), with polymicrobial infection in 32 (37.2%) and fungal coinfection in 7 (8.1%). Thirty-day and in-hospital mortality were 14.0% and 22.1% (n = 12 and 19, respectively, 3 INAA [9.4%], 7 VGI [25.0%], and 9 VEI [34.6%]). Seventy patients (81.4%) had a postoperative complication, 44 (51.2%) of whom returned to the operative room. The 1- and 2-year survival rates were 74.0% (95% confidence interval [CI]: 63.3-82.1) and 69.8% (95% CI: 58.5-78.5), respectively. Survival was significantly better for INAA vs VGEI (P = .01) and worse for AEnF (P = .001). Freedom from reinfection was 97.2% (95% CI: 89.2-99.3) and 95.0% (95% CI: 84.8-98.4) with six reinfections (7.0%) requiring two radiological/six surgical drainage and two graft removals. Primary patency was 88.0% (95% CI: 78.1-93.6) and 79.9% (95% CI: 67.3-88.1) with no significant difference between INAA and VGEI (P = .16).

CONCLUSIONS

ISR of INAA or VGEI with the antimicrobial graft showed encouraging early mortality, comparable to the rates found in femoral vein (9%-16%) and arterial allograft (8%-28%) studies, as well as mid-term reinfection. The highest in-hospital mortality was noted for VEI including nearly 50% of AEnF.

Bacteriophages for the Treatment of Graft Infections in Cardiovascular Medicine

Bacterial infections of vascular grafts represent a major burden in cardiovascular medicine, which is related to an increase in morbidity and mortality. Different factors that are associated with this medical field such as patient frailty, biofilm formation, or immunosuppression negatively influence antibiotic treatment, inhibiting therapy success. Thus, further treatment strategies are required. Bacteriophage antibacterial properties were discovered 100 years ago, but the focus on antibiotics in Western medicine since the mid-20th century slowed the further development of bacteriophage therapy. Therefore, the experience and knowledge gained until then in bacteriophage mechanisms of action, handling, clinical uses, and limitations were largely lost. However, the parallel emergence of antimicrobial resistance and individualized medicine has provoked a radical reassessment of this approach and cardiovascular surgery is one area in which phages may play an important role to cope with this new scenario. In this context, bacteriophages might be applicable for both prophylactic and therapeutic use, serving as a stand-alone therapy or in combination with antibiotics. From another perspective, standardization of phage application is also required. The ideal surgical bacteriophage application method should be less invasive, enabling highly localized concentrations, and limiting bacteriophage distribution to the infection site during a prolonged time lapse. This review describes the latest reports of phage therapy in cardiovascular surgery and discusses options for their use in implant and vascular graft infections.

Surgical and medical interventions for abdominal aortic graft infections

BACKGROUND

Abdominal aortic graft infections are a major complication following abdominal aortic aneurysm surgery, with high morbidity and mortality rates. They can be treated surgically or conservatively using medical management. The two most common surgical techniques are in situ replacement of the graft and extra-anatomical bypass. Medical management most commonly consists of a course of long-term antibiotics. There is currently no consensus on which intervention (extra-anatomical bypass, in situ replacement, or medical) is the most effective in managing abdominal aortic graft infections. Whilst in emergency or complex situations such as graft rupture surgical management is the only option, in non-emergency situations it is often personal preference that influences the clinician's decision-making.

OBJECTIVES

To assess and compare the effects of surgical and medical interventions for abdominal aortic graft infections.

SEARCH METHODS

The Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, CENTRAL, MEDLINE, Embase, and CINAHL databases and WHO ICTRP and ClinicalTrials.gov trials registers to 2 December 2019. We also reviewed the bibliographies of the studies identified by the search and contacted specialists in the field and study authors to request information on any possible unpublished data.

SELECTION CRITERIA

We aimed to include all randomised controlled trials that used surgical or medical interventions to treat abdominal aortic graft infections. The definitions of abdominal aortic graft infections were accepted as presented in the individual studies, and included secondary infection due to aortoenteric fistula. We excluded studies presenting data on prosthetic graft infections in general, unless data specific to abdominal aortic graft infections could be isolated.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed all studies identified by the search. We planned to independently assess risk of bias of the included trials and to evaluate the quality of the evidence using the GRADE approach. Our main outcomes were overall mortality, amputation, graft re-infection, overall graft-related complications, graft-related mortality, acute limb ischaemia, and re-intervention.

MAIN RESULTS

We identified no randomised controlled trials to conduct meta-analysis.

AUTHORS' CONCLUSIONS

There is currently insufficient evidence to draw conclusions to support any treatment over the other. Multicentre clinical trials are required to compare different treatments for the condition.

In situ revascularization with rifampicin-soaked silver polyester graft for aortic infection: Results of a retrospective monocentric series of 18 cases

OBJECTIVE

To evaluate the short and long-term results of in situ prosthetic graft treatment using rifampicin-soaked silver polyester graft in patients with aortic infection.

MATERIAL AND METHOD

All the patients surgically managed in our center for an aortic infection were retrospectively analyzed. The primary endpoint was the intra-hospital mortality, secondary outcomes were limb salvage, persistent or recurrent infection, prosthetic graft patency, and long-term survival.

RESULTS

From January 2004 to December 2015, 18 consecutive patients (12 men and 6 women) were operated on for aortic infection. Six mycotic aneurysms and 12 prosthetic infections, including 8 para-entero-prosthetic fistulas, were treated. In 5 cases, surgery was performed in emergency. During the early postoperative period, we performed one major amputation and two aortic infections were persistent. Intra-hospital mortality was 27.7%. The median follow-up among the 13 surviving patients was 26 months. During follow-up, none of the 13 patients presented reinfection or bypass thrombosis.

CONCLUSION

This series shows that in situ revascularization with rifampicin-soaked silver polyester graft for aortic infection have results in agreement with the literature in terms of intra-hospital mortality with a low reinfection rate.

Systematic Review and Meta: Analysis of Aortic Graft Infections following Abdominal Aortic Aneurysm Repair

Introduction. Aortic graft infection (AGI) is a rare complication following AAA repair and is associated with high morbidity and mortality. Management is variable, and there are no evidence-based guidelines. The aim of this study was to systematically review and analyse management options for AGI.

Twenty-year experience with cryopreserved arterial allografts for vascular infections

OBJECTIVES

The aim of this study was to analyse outcomes over 2 decades using cryopreserved vascular allografts to treat vascular infection.

METHODS

We conducted a retrospective study of patients identified from our institutional database who were treated for primary or secondary vascular infection using implanted allografts.

RESULTS

Between October 1992 and May 2014, 54 patients underwent surgery for vascular infection out of 118 patients implanted with cryopreserved vascular allografts. The 52 patients for whom we had full information form the basis of the study with a 96% follow-up. The average age was 64 ± 11 years; 87% were men; 65% had previous vascular surgery; 19% had emergency operations. A total of 75% of the patients had aortoiliofemoral infections. Five patients underwent surgery with cardiopulmonary bypass. Fifty percent required more than 1 allograft and 15% had concomitant procedures. Seventy-three percent (38/52) of specimen cultures yielded positive results with polymicrobial flora in 29%. Surgical specimens most frequently grew coagulase-negative staphylococci. The early postoperative reoperation rate was 15% for allograft-related complications. There were 20 (38%) early deaths, including deaths of acute myocardial infarction, anastomosis rupture and persistent sepsis and shock. Uncontrolled infection leading to septic shock and multiple organ failure was the cause of death in 50% of the cases. The mean duration of freedom from allograft reintervention was 12.2 years. The mean duration of freedom from allograft occlusion or limb loss was 12.1 years [95% confidence interval (CI) 9.9-14.4]. Of the 32 surviving patients, we had patency information for 66% obtained by angiography or computed tomography. The mean survival for the cohort was 5.9 years (95% CI 3.9-7.8). Mean freedom from cardiovascular infection-related death was 9.3 years (95% CI 7.2-11.4).

CONCLUSIONS

Allografts can be indicated for treatment of primary/secondary infection and have remarkable results in multimorbid patients. Patients with vascular infection have a high-risk profile, around 40% mortality during the first 6 months, with reduction in overall mortality thereafter. We believe that allografts may play a role in the surgical treatment of vascular infection.

Cryopreserved Venous Allografts in Supra-inguinal Reconstructions: A Single Centre Experience

OBJECTIVE

This study introduces a novel technique for supra-inguinal arterial reconstructions with cryopreserved femoral vein and caval allografts with a low re-infection rate and an acceptable graft re-intervention rate on early mid term analysis.

METHODS

Patients treated from February 2012 to March 2018 with cryopreserved venous allograft reconstructions owing to infection in the supra-inguinal area were reviewed retrospectively. The primary end points were re-infection and the treatment related mortality rate. Secondary end points were 30 and 90 day and overall mortality and graft re-intervention rate.

RESULTS

Of the 23 patients treated with cryopreserved venous allografts for infection in aorto-iliac area, 21 (91%) patients underwent reconstruction with cryopreserved femoral veins and two (9%) with vena cava. Indications for treatment were aortic graft infections (n = 12 [52%]), mycotic aneurysms (n = 5 [22%]), femorofemoral prosthetic infections (n = 3 [13%]), anastomotic pseudo-aneurysms (n = 2 [9%]), and aortic thrombosis with intestinal spillage (n = 1 [4%]). In hospital and 90 day mortality were 9% (n = 2); overall treatment related mortality during the median follow up of 15 months was 13% (n = 3). During the follow up, two allografts were re-operated on owing to anastomotic dilatation and one because of re-infection, resulting in a re-intervention rate of 13% (n = 3). None of the grafts was lost and there were no amputations. At the end of follow up 17 patients (74%) were alive. Kaplan-Meier estimation for survival was 76% (95% confidence interval [CI] 57%-95%) at one year and 70% (95% CI 49%-91%) at two years.

CONCLUSION

Cryopreserved venous allografts appear to be an infection resistant and reasonably safe reconstruction material in the aorto-iliac axis based upon the early mid term analysis from a single centre experience. Further research is needed to compare their performance with other biological reconstruction material.

Recommendations for management of infected aortic pathology based on current evidence

The management of infection involving the abdominal aorta requires clinical decisions based on patient factors and the nature of the infectious process. Any infection occurring after endovascular aortic aneurysm repair or open aortic replacement grafting should be treated promptly with appropriate systemic antibiotic therapy. Once a vascular prosthesis becomes infected, surgical treatment is necessary. There should be a low threshold for graft excision and extra-anatomic bypass in the presence of fistula or abscess cavity, when feasible entire graft should be excised. In selected patients, graft excision with in situ aorta reconstruction is an appropriate option using an autogenous femoral vein, cryopreserved allograft, or a prosthetic graft impregnated with antibiotic. The replaced in situ aortic graft should be covered with an omental pedicle. For primary aortic graft infections, endovascular treatment may act as a bridge to more definitive treatment; or, in the absence of gross retroperitoneal infections, endovascular grafting alone with prolonged systemic antibiotic therapy is a viable option, particularly in patients not fit for open surgical procedures.

Collagen-Based Tissue Engineering Strategies for Vascular Medicine

Cardiovascular diseases (CVDs) account for the 31% of total death per year, making them the first cause of death in the world. Atherosclerosis is at the root of the most life-threatening CVDs. Vascular bypass/replacement surgery is the primary therapy for patients with atherosclerosis. The use of polymeric grafts for this application is still burdened by high-rate failure, mostly caused by thrombosis and neointima hyperplasia at the implantation site. As a solution for these problems, the fast re-establishment of a functional endothelial cell (EC) layer has been proposed, representing a strategy of crucial importance to reduce these adverse outcomes. Implant modifications using molecules and growth factors with the aim of speeding up the re-endothelialization process has been proposed over the last years. Collagen, by virtue of several favorable properties, has been widely studied for its application in vascular graft enrichment, mainly as a coating for vascular graft luminal surface and as a drug delivery system for the release of pro-endothelialization factors. Collagen coatings provide receptor-ligand binding sites for ECs on the graft surface and, at the same time, act as biological sealants, effectively reducing graft porosity. The development of collagen-based drug delivery systems, in which small-molecule and protein-based drugs are immobilized within a collagen scaffold in order to control their release for biomedical applications, has been widely explored. These systems help in protecting the biological activity of the loaded molecules while slowing their diffusion from collagen scaffolds, providing optimal effects on the targeted vascular cells. Moreover, collagen-based vascular tissue engineering substitutes, despite not showing yet optimal mechanical properties for their use in the therapy, have shown a high potential as physiologically relevant models for the study of cardiovascular therapeutic drugs and diseases. In this review, the current state of the art about the use of collagen-based strategies, mainly as a coating material for the functionalization of vascular graft luminal surface, as a drug delivery system for the release of pro-endothelialization factors, and as physiologically relevant in vitro vascular models, and the future trend in this field of research will be presented and discussed.

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.

A meta-analysis of outcomes of in-situ reconstruction after total or partial removal of infected abdominal aortic graft

INTRODUCTION

There is currently a lack of evidence for the relative effectiveness of partial resection (PR) and total resection (TR) before managing abdominal aortic graft infection (AGI). Most authorities agree that TR is mandatory for intracavitary AGI in patients with favorable conditions but there is an increasing number of patients with severe comorbidities for whom this approach is not suitable, resulting in a prohibitive mortality rate. The purpose of this study was to determine the most appropriate indication for TR or PR.

EVIDENCE ACQUISITION

A meta-analysis was conducted on the rates of early/late mortality, amputations and reinfection. A meta-regression was performed with eight variables: patient age, male prevalence, presence of virulent or nonvirulent organisms, urgency, omentoplasty and follow-up.

EVIDENCE SYNTHESIS

Twenty-one studies and 1052 patients were included. For TR and PR, the rates of early mortality and reinfection were 16.8% and 10.5%, 11% and 27%, respectively. For TR urgency and male gender were associated with increased rate of early mortality and male gender, PDF and virulent organisms were associated with increased risk of reinfection. For PR no statistical correlation was analyzable except for PDF with increased risk of reinfection.

CONCLUSIONS

Early mortality rates are higher for TR and reinfection rates are higher for PR. For TR early mortality increases in urgent cases and it is suggested that alternative option must be discussed, reinfection decreases in the presence of nonvirulent organisms and TR seems optimal. For TR and PR reinfection increases in presence of PDF and alternative technique may be more appropriate.

[Treatment of radiation-induced iliofemoral arterial complications with groin radionecrosis]

Long-term iliofemoral complications induced by radiation include vascular (arterial and venous) lesions, nervous lesions and soft tissue loss that can be cutaneous and subcutaneous and potentially lead to radionecrosis with vessel exposure. We present five cases of groin radionecrosis. There were three men and two women (age 30-73 years). Radiotherapy had been delivered 15 years earlier in three cases, and 2 years earlier in two cases. Symptoms were intermittent claudication (n=1), critical ischemia (n=1), and septic hemorrhage (n=1). Two patients had no vascular symptoms. Four patients underwent scheduled surgery after complete cardiac and cardiovascular evaluation with duplex-Doppler, CT scan and/or intra-arterial angiography. One woman underwent emergency surgery after septic hemorrhage of a previous in situ femoral revascularization fashioned 2 months earlier. Revascularization was achieved with trans-iliac (n=3), trans-muscular (n=1, and in situ (n=1) iliofemoral bypass. A retroperitoneal approach with section of large muscles was used. In three cases, a trans-iliac route was used by perforating the iliac wing with a 8-mm PTFE graft. Proximal anastomosis was done on the abdominal aorta (n=1) and the homolateral common iliac artery (n=2). Distal anastomosis was done on the distal profunda artery and popliteal artery (n=1) and on the distal femoral superficial artery (n=2). In two cases, an iliofemoral bypass was done with a 7-mm PTFE vascular graft. The proximal anastomosis was done on the proximal external iliac artery and the distal anastomosis on the proximal superficial femoral artery. A plastic procedure was performed in four cases. Three patients had a homolateral (n=1) or controlateral (n=2) rectus abdominis flap. In one case, plastic coverage was done with an antebrachial flap (Chinese flap), which has been released at 6 weeks. One patient had post-radiotherapy iliofemoral vascular disease, but there was no vascular exposure, and no plastic coverage was necessary. The postoperative course was uneventful in four cases. The patient treated with an in situ bypass developed septic hemorrhage at day 10, requiring revision. The patient died of multiple organ system failure, with a patent graft and a viable flap. The other four patients had no early or late complications. These patients have been followed annually for clinical examinations and duplex scans, and angio-scans. One patient died of ischemic heart disease. The three other patients are alive with a patent bypass with 11, 8 and 3 years follow-up. One patient had a late occlusion of the bypass treated by thrombectomy after 7 and 10 years. In conclusion, patients with femoral radionecrosis can be treated by an extra-anatomic bypass, with plastic coverage. The trans-iliac is a relatively simple and safe procedure.

A Meta-Analysis of Outcomes After In Situ Reconstructions for Aortic Graft Infection

OBJECTIVE

To confirm the advantage of in situ reconstruction (ISR) over extra-anatomic reconstruction (EAR) for aortic graft infection and determine the most appropriate conduit including autogenous veins, cryopreserved allografts, and synthetic prosthesis (standard, rifampicin of silver polyesters).

METHODS

A meta-analysis was conducted with rate of mortality, graft occlusion, amputation, and reinfection. A meta-regression was performed with 4 factors: patients' age, presence of prosthetic-duodenal fistula (PDF), virulent organisms, or nonvirulent organisms.

RESULTS

In situ reconstruction over EAR seems to favor all events. For the 5 conduits used for ISR, according to operative mortality, age of the patients looks to have a positive correlation only for silver polyester and no conduit present any advantage in the presence of PDF. Reinfection seems to be not significantly different for the 5 conduits, and only autogenous veins appear to have a positive correlation with infecting organisms.

CONCLUSION

In situ reconstruction may be considered as first-line treatment. Our results suggest that silver polyesters appear to be most appropriate for older patients, and in order to limit reinfection, autogenous veins are probably the most suitable conduit.

Xenopericardial self-made tube grafts in infectious vascular reconstructions: Preliminary results of an easy and ready to use surgical approach

PURPOSE

Infections are a major setback of vascular reconstruction and associated with considerable morbidity and mortality. We evaluated retrospectively our results with self-made bovine pericardial grafts in infected vessel revascularization versus standard graft material.

BASIC METHODS

Retrospective analysis of 9 patients with bovine reconstruction and 10 patients with miscellaneous grafts (vein, homograft) for vascular infections.

PRINCIPAL FINDINGS

Infection-free rate of the pericardial group was 100% in 17 months. For patients after reconstructions with miscellaneous grafts, the infection-free rate was 82% in 45 months. Overall in-hospital mortality was 10.5%. There were no in-hospital deaths in the pericardial group. Graft patency of the whole cohort was 100%. The median follow up was 11.74 months.

CONCLUSION

Self-made bovine pericardial tube grafts can be crafted to almost any size and adjusted to complex anatomic requirements. The use was feasible in various situations and was associated with good preliminary results concerning patency and reinfection.

Medical treatment of prosthetic vascular graft infections: Review of the literature and proposals of a Working Group

More than 400000 vascular grafts are inserted annually in the USA. Graft insertion is complicated by infection in 0.5-4% of cases. Vascular graft infections (VGIs) are becoming one of the most frequent prosthesis-related infections and are associated with considerable mortality, ranging from 10 to 25% within 30 days following the diagnosis. Treatment of VGI is based on urgent surgical removal of the infected graft followed by prolonged antibiotherapy. Data regarding the best antibiotherapy to use are lacking since no well designed trial to study antimicrobial treatment of VGI exists. Moreover, since VGIs demonstrate very specific pathophysiology, guidelines on other material-related infections or infective endocarditis treatment cannot be entirely applied to VGI. A French multidisciplinary group gathering infectious diseases specialists, anaesthesiologists, intensivists, microbiologists, radiologists and vascular surgeons was created to review the literature dealing with VGI and to make some proposals regarding empirical and documented antibiotic therapy for these infections. This article reveals these proposals.

Surgical and antimicrobial treatment of prosthetic vascular graft infections at different surgical sites: a retrospective study of treatment outcomes

Objective

Little is known about optimal management of prosthetic vascular graft infections, which are a rare but serious complication associated with graft implants. The goal of this study was to compare and characterize these infections with respect to the location of the graft and to identify factors associated with outcome.

Methods

This was a retrospective study over more than a decade at a tertiary care university hospital that has an established multidisciplinary approach to treating graft infections. Cases of possible prosthetic vascular graft infection were identified from the hospital's infectious diseases database and evaluated against strict diagnostic criteria. Patients were divided into groups according to the locations of their grafts: thoracic-aortic, abdominal-aortic, or peripheral-arterial. Statistical analyses included evaluation of patient and infection characteristics, time to treatment failure, and factors associated specifically with cure rates in aortic graft infections. The primary endpoint was cure at one year after diagnosis of the infection.

Results

Characterization of graft infections according to the graft location did show that these infections differ in terms of their characteristics and that the prognosis for treatment seems to be influenced by the location of the infection. Cure rate and all-cause mortality at one year were 87.5% and 12.5% in 24 patients with thoracic-aortic graft infections, 37.0% and 55.6% in 27 patients with abdominal-aortic graft infections, and 70.0% and 30.0% in 10 patients with peripheral-arterial graft infections. In uni- and multivariate analysis, the type of surgical intervention used in managing infections (graft retention versus graft replacement) did not affect primary outcome, whereas a rifampicin-based antimicrobial regimen was associated with a higher cure rate.

Conclusions

We recommend that future prospective studies differentiate prosthetic vascular graft infections according to the location of the grafts and that rifampicin-based antimicrobial regimens be evaluated in clinical trials involving vascular graft infections caused by staphylococci.

Intra-abdominal aortic graft infection: prognostic factors associated with in-hospital mortality

BACKGROUND

Mortality associated with aortic graft infection is considerable. The gold standard for surgical treatment remains explantation of the graft. However, prognostic factors associated with early mortality due to this surgical procedure are not well-known.

METHODS

Retrospective analysis of patients admitted in our center between January 2006 and October 2011 for aortic graft infection. The primary endpoint was in-hospital mortality. A bivariate analysis of characteristics of patients associated with in-hospital outcome was performed.

RESULTS

Twenty five evaluable patients were studied. All patients were male. Their mean age was 67 ± 8.4 years. Most of them (92%) had severe underlying diseases. An in situ prosthetic graft replacement, mainly using cryopreserved arterial allografts, was performed in all patients, excepted one who underwent extra-anatomic bypass. Causative organisms were identified in 23 patients (92%). The in-hospital mortality rate was 48%. Among pre-operative characteristics, age ≥ 70 years, creatinine ≥ 12 mg/L and C reactive protein ≥ 50 mg/L were significantly associated with in-hospital mortality. Hospital mortality rates increased with the number of risk factor present on ICU admission, and were 0%, 14.3%, 85.7% and 100% for 0, 1, 2 and 3 factors, respectively. The only intra-operative factor associated with prognosis was an associated intestinal procedure due to aorto-enteric fistula. SAPS II, SOFA score and occurrence of medical or surgical complications were postoperative characteristics associated with in-hospital mortality.

CONCLUSION

Morbidity and mortality associated with surgical approach of aortic graft infections are considerable. Age and values of creatinine and C Reactive protein on hospital admission appear as the most important determinant of in hospital mortality. They could be taken into account for guiding the surgical strategy.

Acute and subacute toxicity in vivo of thermal-sprayed silver containing hydroxyapatite coating in rat tibia

To reduce the incidence of implant-associated infection, we previously developed a novel coating technology using hydroxyapatite (HA) containing silver (Ag). This study examined in vivo acute and subacute toxicity associated with the Ag-HA coating in rat tibiae. Ten-week-old rats received implantation of HA-, 2% Ag-HA-, or 50% Ag-HA-coated titanium rods. Concentrations of silver in serum, brain, liver, kidneys, and spleen were measured in the acute phase (2-4 days after treatment) and subacute phase (4-12 weeks after treatment). Biochemical and histological examinations of those organs were also performed. Mean serum silver concentration peaked in the acute phase and then gradually decreased. Mean silver concentrations in all examined organs from the 2% Ag-HA coating groups showed no significant differences compared with the HA coating group. No significant differences in mean levels of glutamic-oxaloacetic transaminase, glutamic-pyruvic transaminase, lactate dehydrogenase, creatinine, or blood urea nitrogen were seen between the three groups and controls. Histological examinations of all organs revealed no abnormal pathologic findings. No acute or subacute toxicity was seen in vivo for 2% Ag-HA coating or HA coating. Ag-HA coatings on implants may represent biologically safe antibacterial biomaterials and may be of value for reducing surgical-site infections related to implantation.

In situ revascularisation for femoropopliteal graft infection: ten years of experience with silver grafts

Purpose

The purpose of this study was to analyze clinical outcome of patients for femoropopliteal graft infection who were treated by in situ reconstruction with a silver-coated prosthesis.

Basic methods

From December 2001 to December 2011, 27 patients were treated for femoropopliteal graft infection. Twenty patients (74%) were male and seven (26%) were female. Mean age was 65 years. The primary endpoint was recurrence of infection. Secondary endpoints were early and late mortality and morbidity, primary graft patency, major amputation rates and patient survival.

Principal findings

Early reinfection occurred in 11% and late in 8% of patients. Perioperative mortality was 7% and late was 4%. Above-knee amputation was performed in 4% of patients during early postoperative course and in 12% of patients during follow-up. Early and late graft patency was 96% and 72%, respectively.

Conclusions

Results of in situ implantation of silver-coated grafts for femoropopliteal prosthesis infection are according to our opinion acceptable, but the risk of reinfection remains.

In situ repair of a mycotic suprarenal aortic aneurysm using a cryopreserved aortic homograft and visceral debranching in a patient with spondylodiscitis and left psoas muscle abscess

We present a patient with ruptured suprarenal aortic aneurysm, involving origins of visceral and renal arteries. Associated spondylodiscitis and left psoas muscle abscess were also diagnosed. The patient was initially treated with antibiotics. Diagnostic survey showed progression of the aneurysm diameter and enlargement of the psoas muscle abscess. Surgical treatment using a cryopreserved aortic homograft with debranching of visceral arteries was performed. Different modalities of surgical repair within the infected aortic segment and the rationale for usage of cryopreserved homografts are considered. The importance of optimal timing for surgery is emphasized as well.

Use of silver in the prevention and treatment of infections: silver review

BACKGROUND

The use of silver for the treatment of various maladies or to prevent the transmission of infection dates back to at least 4000 b.c.e. Medical applications are documented in the literature throughout the 17th and 18th centuries. The bactericidal activity of silver is well established. Silver nitrate was used topically throughout the 1800 s for the treatment of burns, ulcerations, and infected wounds, and although its use declined after World War II and the advent of antibiotics, Fox revitalized its use in the form of silver sulfadiazine in 1968.

METHOD

Review of the pertinent English-language literature.

RESULTS

Since Fox's work, the use of topical silver to reduce bacterial burden and promote healing has been investigated in the setting of chronic wounds and ulcers, post-operative incision dressings, blood and urinary catheter designs, endotracheal tubes, orthopedic devices, vascular prostheses, and the sewing ring of prosthetic heart valves. The beneficial effects of silver in reducing or preventing infection have been seen in the topical treatment of burns and chronic wounds and in its use as a coating for many medical devices. However, silver has been unsuccessful in certain applications, such as the Silzone heart valve. In other settings, such as orthopedic hardware coatings, its benefit remains unproved.

CONCLUSION

Silver remains a reasonable addition to the armamentarium against infection and has relatively few side effects. However, one should weigh the benefits of silver-containing products against the known side effects and the other options available for the intended purpose when selecting the most appropriate therapy.

Contemporary management of infrarenal aortic graft infection: early and late results in 82 patients

Management of aortic graft infection (AGI) remains contentious. The purpose of this study was to evaluate factors of clinical significance which influence the outcome of different treatment modalities for AGI. From 2000 to 2008, 82 consecutive patients were treated for AGI. In situ reconstruction (ISR) was performed in 63 patients with various conduits, extra-anatomic reconstruction (EAR) in 11, conservative treatment in five and resection without reconstruction in three. The perioperative mortality rate for the series (33%) was similar for EAR and ISR and was higher in patients with secondary aortoenteric fistula ( P < 0.001) in those undergoing emergency aortic reconstruction ( P < 0.001) and in AGI caused by virulent organisms ( P < 0.05). Fifteen (27%) of the surviving patients developed a recurrence of infection (RI). EAR patients were more exposed to RI ( P < 0.04). In conclusion, ISR may be more appropriate for AGI, but this study cannot draw a conclusion relating to the optimal conduit for ISR.

Nanomaterial-based treatments for medical device-associated infections

Bacterial infections remain one of the biggest concerns to our society. Conventional antibiotic treatments showed little effect on the increasing number of antibiotic-resistant bacteria. Advances in synthetic chemistry and nanotechnology have resulted in a new class of nanometer-scale materials with distinguished properties and great potential to be an alternative for antibiotics. In this Minireview, we address the current situation of medical-device-associated infections and the emerging opportunities for antibacterial nanomaterials in preventing these complications. Several important antimicrobial nanomaterials emergent from advances in synthesis chemistry are introduced and their bactericidal mechanisms are analyzed. In addition, concerns regarding the biocompatibility of such materials are also addressed.

Management of the infected aortoiliac aneurysms

PURPOSE

We have reviewed ruptured and nonruptured infected aortoiliac aneurysms to study the clinical presentation, management and eventual outcome of patients managed with in situ prostheses, axillofemoral prostheses grafts and endovascular reconstruction.

DESIGN

A retrospective chart review of 16 cases treated at a single institution.

METHODS

From January 2007 to March 2008, a total of 93 patients with aortoiliac aneurysms underwent surgical repair at our institution. Among these, 16 patients (17.2%) were shown to be infected aneurysms of the infrarenal (n = 6), juxtarenal (n = 2), and pararenal aorta (n = 1); the others were 5 common, 1 external, and 1 internal iliac arteries. Fourteen patients were male and 2 were female with the mean age of 66 years (range, 45-79). In all cases, the diagnosis was confirmed by abdominal computed tomography and empirical parenteral antibiotics were administered at least 1 week, unless in patients need emergency operations. At the time of an operation, all were saccular and were classified as primary infected aortoiliac aneurysms. Thirteen patients had surgical debridement with in situ graft interposition and omental wrapping, 2 underwent aneurysm exclusion and extra-anatomic (axillo-femoral) bypass, 1 underwent aneurysmectomy of left external iliac artery and polytetrafluoroethylene (PTFE) graft interposition, and 1 underwent endovascular exclusion. The parenteral antibiotics were continued in the postoperative period for 4-6 weeks. Chronic renal disease was present in 37.5% (6/16), with diabetes mellitus present in 31.25% (5/16). The most common pathogen was Salmonella sp. (n = 6) and E. coli (n = 5). Thirty-seven percent (6/16) of the patients presented late, with a 37.5% (6/16) incidence of ruptured (4 contained, 2 free ruptured) that needed emergency surgery.

RESULTS

Disease-specific mortality was 31.25% (5/16). The 30-day mortality rate of ruptured cases is high 67% (4/6), because patients present late in the course of the disease. One patient who underwent aneurysm exclusion and extra-anatomic (axillo-femoral) bypass died 6 months later from burst aortic stump. Salmonella and E. coli are the most common pathogens.

CONCLUSIONS

Early diagnosis followed by surgical intervention with proper antibiotic coverage provides the best results. Mortality rate was still high in patients with sepsis and rupture. An in situ graft interposition and omental wrapping is a safe option for revascularization of infected aneurysms of the iliac arteries and infrarenal aorta.

Primary infected abdominal aortic aneurysm: surgical procedures, early mortality rates, and a survey of the prevalence of infectious organisms over a 30-year period

PURPOSE

The purpose of this study was to analyze the surgical procedures, culture results, and outcomes, and to survey the prevalence of the infectious organisms over a 30-year period in patients with a primary infected abdominal aortic aneurysm (PIAAA).

METHODS

A total of 11 patients (1.8%) with PIAAA were surgically treated between 1982 and June 2009. All patients had back pain, leukocytosis, and elevated C-reactive protein level. All of the patients underwent either urgent or emergency operations.

RESULTS

Cultures of aortic wall specimens and blood were positive in 10 patients and included Salmonella in 2, Streptococcus in 2, Campylobacter fetus in 2, and Listeria, Haemophilus influenzae, Serratia marcescens, Bacteroides thetaiotaomicron, and an unknown organism in 1 patient each. The 10 patients underwent in situ prosthetic grafting with excision of the infected tissue and lavage using 10 l saline solution; omentum plasty was required in four patients. An axillofemoral bypass was performed in one patient with pus surrounding the AAA. All 10 patients with in situ replacement survived and were administered intravenous antibiotic therapy for 1 month postoperatively. All of these patients left the hospital without any further complications. However, one patient who underwent an axillofemoral bypass died of overwhelming sepsis.

CONCLUSION

In situ replacement with excision of infected tissue, lavage using 10 l saline solution, and omentum plasty for PIAAA successfully resolved the condition. High local concentrations of rifampin-soaked grafts or superficial femoral vein may also be an alternative for an in situ replacement conduit.

Surgical outcome in patients with concomitant-infected abdominal aortic aneurysm and spondylitis

The coexistence of infected abdominal aortic aneurysms and spondylitis is rare but challenging. The etiology of the infection is frequently unknown. The aim of this study was to review the outcome of surgical repair of this complex disease. From 2004 to 2006, six patients were identified who underwent surgical repair of concomitant infected abdominal aortic aneurysm and spondylitis. Diagnosis, treatment and intermediate-term results are presented. The clinical manifestation included the signs of ongoing systemic infection, neurological deficit and abdominal or back pain. Computed tomography revealed abdominal aortic aneurysms associated with polysegmental spondylitis. Patients underwent radical debridement and aortic replacement with cryopreserved aortic allografts or silver-coated prostheses followed by antibiotic treatment. Only one patient received a simultaneous anterior vertebral stabilization. Greater omentum was placed in the abscess cavity. Intensive care unit and hospital stay averaged 3.0 and 28.0 days, respectively. Organisms were identified in all but one patient. Over a follow-up period of 4.4 years, four patients are alive and showing freedom from infection, and two patients had died unrelated at seven and eight months. In conclusion, surgical repair of infected aortic aneurysms with resection of infected tissues and implantation of a homograft or a silver-coated prosthesis achieved favorable results in this sick patient group. Simultaneous vertebral stabilization is rarely necessary.

[Mid-term results of silver-coated Dacron graft implantation in aortic and lower extremity revascularization]

BACKGROUND

Prosthetic graft infection or the need for reconstructive arterial surgery in septic condition is a challenging situation in vascular surgery. Recent introduction of silver coated polyester graft has meant a new therapeutic option in selecting the type of graft for revascularization. In this study we analyzed the short and midterm outcome of using silver coated grafts in aortic and lower extremity arterial reconstructions (mortality, graft occlusion, graft infection, amputation).

MATERIALS AND METHODS

In a single center retrospective study we implanted 42 silver coated Dacron grafts (InterGard Silver Dacron prosthesis). The indication of silver graft implantation was graft infection in 17, aorto-duodenal fistula in 7, septic condition caused by gangrene in 16 cases and in 2 cases infection was not established.

RESULTS

Forty silver grafts were implanted in 40 patients with diagnosed infection. The mean age was 62 years (35-81 years), 70% were men. Long term follow-up data were available in 29 patients; the mean follow-up time was 36.76 months. Early (within 30 days of surgery) death occurred in 3 and late death in 11 cases (8 and 38%). Early graft occlusion was noticed in 8 and late occlusion in 2 cases (20 and 7%). Reinfection was diagnosed in 7% of the cases in the early and the midterm period as well. Eight amputations were indicated in the early postoperative period (5 major and 3 minor) and 28% of the patients required major amputation during the follow-up.

CONCLUSIONS

Silver coated Dacron graft means a valuable therapeutic option with good rate of infection control in the treatment of graft infection and septic condition in the lack of autologous graft material in this high risk population.