Prophylactic use of the silver-acetate–coated graft in arterial occlusive disease: A retrospective, comparative study

The Role of the Omniflow II Biosynthetic Graft in Postoperative Wound Problems After Lower Limb Revascularization: A Single Center Prospective Registry

OBJECTIVE

To investigate the role of the Omniflow II prosthesis in the prevention of vascular graft infection (VGI) in patients with peripheral arterial disease and to report on short-and mid-term graft-related morbidity.

MATERIAL AND METHODS

Patients were included in prospective registry between October 2019 and March 2023. The primary endpoint was to report infection-related problems, operation-related wound problems, and short- and mid-term graft-related morbidity. Secondary endpoint was to report the bypass patency rates and limb salvage rates.

RESULTS

A total of 146 Omniflow II grafts were implanted in 125 patients. Sixty-seven patients (45.9%) received a femoral interposition graft, and 77 patients (52.7%) underwent ipsilateral bypass surgery (femoropopliteal or femorocrural). Forty-one patients (28.1%) underwent crural bypass surgery. Seventy-six patients (52.1%) had previous vascular operation in the groin. The mean follow-up time was 352 days (range 0-1108 days). 3.4% of the patients suffered a wound infection limited to the dermis, and in 8.2%, the subcutaneous tissue was involved. Five early VGI (3.4%) and one late VGI (0.7%) occurred. One year primary patency rate of above-the-knee bypass was significantly better compared to the bypass below the knee (74.5% ± 0.131 versus 54% ± 0.126 (P = 0.049)). This difference was not significantly different when below-the-knee bypass surgery was compared with crural bypass surgery (54% ± 0.126 versus 23.8% ± 0.080 (P = 0.098)).

CONCLUSIONS

The performance of the Omniflow II prosthesis in the preventive setting is highly influenced by the anatomic location of the distal anastomosis. No influence on the incidence of postoperative wound problems could be observed. The rate of Omniflow II VGI in a high-risk population is similar to reported outcomes in other prosthetic grafts.

Use of a Silver-Impregnated Vascular Graft: Single-Center Experience

INTRODUCTION

Vascular graft infection is a life threatening situation with significant morbidity and mortality. Bacterial graft infection can lead to false aneurysms, bleeding and sepsis. There are a lot of risky situations where grafts can become infected. It is therefore highly desirable to have a vascular graft that is resistant to infection. In this retrospective clinical study, a silver-impregnated vascular graft was evaluated in various indications.

METHODS

Our study included a total of 71 patients who received a silver-impregnated vascular graft during the period from 2013 to 2018. Patients had an aortoiliac localization of vascular graft in 61 cases (86%), and a peripheral localization on the lower limbs in 10 cases (14%). Indications for the use of these special vascular grafts were trophic lesions or gangrene in the lower limbs in 24 cases (34%), suspicious mycotic abdominal aortic aneurysm (mAAA) in 4 cases (5.5%), salmonela aortitis or aneurysms in 4 cases (5.5%), infection of the previous vascular graft in 11 cases (15.5%), other infections in 12 cases (17%), AAA rupture in 10 cases (14%) and other reasons (pre-transplant condition, multiple trauma, graft-enteric fistula) in 6 cases (8.5%). Thirty-day mortality, morbidity, the need for reintervention and amputation, primary and secondary graft patency, and finally the presence of a proven vascular graft infection were evaluated.

RESULTS

The 30-day mortality was 19.7%, and morbidity was 42.2%. The primary patency of the vascular graft was 91.5%. Reoperation was necessary in 10 cases (14%) and amputation was necessary in 10 cases (14%). The median length of hospital stay was 13 days and the mean follow-up period was 48 ± 9 months. During the follow-up period, six patients (8.5%) died from reasons unrelated to surgery or without any relation to the vascular graft. Secondary patency after one year was 88%. Infection of the silver graft was observed in three patients (4.2%).

CONCLUSIONS

Based on our results, the silver graft is a very suitable alternative for solving infectious, or potentially infectious, situations in vascular surgery. In particular, in urgent or acute cases, a silver graft is often the only option.

Treatment of vascular graft infections: gentamicin-coated ePTFE grafts reveals strong antibacterial properties in vitro

Vascular graft infections (VGI) are severe complications in prosthetic vascular surgery with an incidence ranging from 1 to 6%. In these cases, synthetic grafts are commonly used in combination with antimicrobial agents. Expanded polytetrafluoroethylene (ePTFE) is in clinical use as a synthetic graft material and shows promising results by influencing bacterial adhesion. However, the literature on antibiotic-bound ePTFE grafts is scarce. Gentamicin is a frequently used antibiotic for local treatment of surgical site infections, but has not been evaluated as antimicrobial agent on ePTFE grafts. In this study, we examine the antimicrobial efficacy and biocompatibility of novel types of gentamicin-coated ePTFE grafts in vitro. ePTFE grafts coated with gentamicin salt formulations with covalently-bound palmitate were evaluated in two drug concentrations (GP1.75% and GP3.5%). To investigate effects from types of formulations, also suspensions of gentamicin in palmitate as well as polylactide were used at comparable levels (GS + PA and GS + R203). Antibacterial efficacies were estimated by employing a zone of inhibition, growth inhibition and bacterial adhesion assay against Staphylococcus aureus (SA). Cytotoxicity was determined with murine fibroblasts according to the ISO standard 10993-5. Gentamicin-coated ePTFE grafts show low bacterial adherence and strong antibacterial properties in vitro against SA. Bactericidal inhibition lasted until day 11. Highest biocompatibility was achieved using gentamicin palmitate GP1.75% coated ePTFE grafts. ePTFE grafts with gentamicin-coating are effective in vitro against SA growth and adherence. Most promising results regarding antimicrobial properties and biocompatibility were shown with chemically bounded gentamicin palmitate GP1.75% coatings. Graphical abstract.

Pre-clinical In Vitro Models of Vascular Graft Coating in the Prevention of Vascular Graft Infection: A Systematic Review

OBJECTIVE

Vascular graft infection (VGI) is a feared complication. Prevention is of the utmost importance and vascular graft coatings (VGCs) could offer a potential to do this, with in vitro research a first crucial step. The aim of this study was to summarise key features of in vitro models investigating coating strategies to prevent VGI in order to provide guidance for the setup of future translational research.

DATA SOURCES

A comprehensive search was performed in MEDLINE, Embase, and Web of Science.

METHODS

A systematic review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. For each database, a specific search strategy was developed. Quality was assessed with the Toxicological data Reliability Assessment Tool (ToxRTool). In vitro models using a VGC and inoculation of the graft with a pathogen were included. The type of graft, coating, and pathogen were summarised. The outcome assessment in each study was evaluated.

RESULTS

In total, 4 667 studies were identified, of which 45 papers met the inclusion criteria. The majority used polyester grafts (68.2%). Thirty-one studies (68.9%) included antibiotics, and nine studies (20%) used a commercial silver graft in their protocol. New antibacterial strategies (e.g., proteolytic enzymes) were investigated. A variety of testing methods was found and focused mainly on bacterial adherence, coating adherence and dilution, biofilm formation, and cytotoxicity. Ninety-three per cent of the studies (n = 41) were considered unreliable.

CONCLUSION

Polyester is the preferred type of graft to coat on. The majority of coating studies are based on antibiotics; however, new coating strategies (e.g., antibiofilm coating) are coming. Many in vitro setups are available. In vitro studies have great potential, they can limit the use, but cannot replace in vivo studies completely. This paper can be used as a guidance document for future in vitro research.

Clinical Studies Reporting on Vascular Graft Coatings for the Prevention of Aortic Graft Infection: A Systematic Review and Meta-Analysis

OBJECTIVE

The aim of this study was to investigate the efficacy of vascular graft coatings used in the aortic position to prevent vascular graft infection (VGI).

METHODS

A systematic review was conducted in accordance with the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines using a pre-registered protocol (CRD42020206436). Eligible studies used a vascular graft coating in the aortic position and reported on VGI. A search was performed in MEDLINE (PubMed), Embase, Web of Science, and the Cochrane Library. Primary outcome parameters were VGI, patency, and mortality. Pooled estimates of VGI were calculated using odds ratio (OR) and 95% confidence intervals (CIs) wherever possible. Quality assessment was performed with the Newcastle-Ottawa Assessment Scale and the Revised Cochrane risk of bias tool for randomised trials.

RESULTS

In total, 6 873 papers were identified. Only eight studies were included. Six of eight studies (75%) reported on known antimicrobial coating strategies such as antibiotics (n = 3) and silver (n = 3). In the other two studies, polymer coated grafts were used. Only three of eight studies compared coated with uncoated grafts (two antibiotic and one silver). Two randomised controlled trials reported on the effect of rifampicin soaked (1 mg/mL) grafts and showed no significant effect in the early (2 months; OR 0.69, 95% CI 0.29 - 1.62) or late (2 years; OR 0.73, 95% CI 0.23 - 2.32) post-operative periods. A retrospective cohort study focusing on the effect of silver coated grafts did not reveal any advantage (OR 0.19, 95% CI 0.02 - 1.64). Two polymer coated grafts were not considered to have a potential benefit in the prevention of VGIs.

CONCLUSION

Clinical studies reporting on the antibacterial effect of vascular graft coatings in the aortic position to prevent VGI are scarce. For silver and antibiotic coatings, no significant protection for VGI was observed. New types of grafts or long acting coating strategies are mandatory to prevent this complication in the future.

How to Prevent Surgical Site Infection in Vascular Surgery: A Review of the Evidence

BACKGROUND

This review aims to identify and review the current evidence for preventing postoperative surgical site infections in abdominal aortic aneurysm surgery or infrainguinal arterial surgery.

METHODS

Extended literature review of clinical trials that examined the prevention of postoperative surgical site infections in abdominal aortic aneurysm or infrainguinal arterial surgery. Searches were conducted on Ovid MEDLINE (1950 - 13 March 2020) using key terms for vascular surgery, surgical site infections and specific preventative techniques. Articles were included if they discussed a relationship between a preventative technique and surgical site infections in abdominal aortic aneurysm or infrainguinal arterial surgery. The GRADE guidelines were used to assess the quality of evidence.

RESULTS

21 techniques and 81 studies were included. Prophylactic antibiotics and negative pressure wound therapy have a high quality of evidence for the prevention of surgical site infections in abdominal aortic aneurysm or infrainguinal arterial surgery. A moderate quality evidence base was identified for gentamicin containing collagen implant (confined to high surgical site infection risk centers). Currently, there is a low or very low quality of evidence to suggest a reduction in the surgical site infection rate for combination therapy, glycaemic control, Methicillin-resistant Staphylococcus aureus screening and absorbable suture. Evidence suggests no beneficial effect for nutritional supplementation, chlorhexidine bath, hair removal therapy, Staphylococcus aureus nasal eradication, cyanoacrylate microsealant, silver grafts, rifampicin bonded grafts, triclosan coated suture and postoperative wound drains. Endoscopic saphenous vein harvest may reduce surgical site infection rate (very low quality of evidence) but may lower long-term patency. Autologous vein grafts may increase surgical site infections (very low quality of evidence) but may provide better long-term patency rates in above-knee infrainguinal bypass surgery. There was no identified evidence for perioperative normothermia, electrosurgical bipolar vessel sealer or Dermabond and Tegaderm for surgical site infection prevention in vascular surgery.

CONCLUSIONS

Prophylactic antibiotics and postoperative negative pressure wound therapy are effective in the prevention of postoperative surgical site infection in abdominal aortic aneurysm or infrainguinal arterial surgery. There exists a significant risk of bias in the literature for many preventative techniques and further studies are required to investigate the efficacy of gentamicin containing collagen implant, and specific combination therapies.

A systematic review of preclinical data regarding commercial silver-coated vascular grafts

OBJECTIVE

Vascular graft infection (VGI) is a serious complication with high mortality and morbidity rates. Several measures could be taken to decrease this risk, including the use of silver-containing vascular grafts. However, to date, no clinical advantages have been reported. This study reviews the outcome of preclinical studies focusing on the role of commercially available silver-coated grafts in the prevention of VGI.

METHODS

A systematic review was performed with a focus on the preclinical role of commercially available silver-coated vascular grafts in the prevention and treatment of VGI. A comprehensive search was conducted in Medline, Embase, and Web of Science.

RESULTS

Nine in vitro and five in vivo studies were included. Two commercial grafts were used (INTERGARD SILVER and Silver Graft). In vitro studies used both gram-positive and gram-negative strains. A positive antimicrobial effect was observed in seven of nine studies (77.8%). A delayed antifungal effect against Candida species was observed in vitro, but disappeared when adding serum proteins. In vivo studies witnessed a microbicidal effect in two out of five studies (40%), but only tested a single causative pathogen (ie, Staphylococcus aureus).

CONCLUSIONS

Both in vitro and in vivo studies demonstrated conflicting and mixed results concerning the antimicrobial efficacy of commercially available silver-containing grafts in the prevention of VGI. In general, the study setup was heterogeneous in the different articles. Given the lack of convincing preclinical evidence and their poor performance in clinical studies, more data are needed at this time to guide the appropriate use of silver grafts.

Pre-clinical in vivo Models of Vascular Graft Coating in the Prevention of Vascular Graft Infection: A Systematic Review

OBJECTIVE

Vascular graft infection (VGI) remains an important complication with a high mortality and morbidity rate. Currently, studies focusing on the role of vascular graft coatings in the prevention of VGI are scarce. Therefore, the aims of this study were to survey and summarise key features of pre-clinical in vivo models that have been used to investigate coating strategies to prevent VGI and to set up an ideal model that can be used in future preclinical research.

DATA SOURCES

A systematic review was conducted in accordance with the Preferred reporting items for Systematic Reviews and Meta-Analysis guidelines. A comprehensive search was performed in MEDLINE (PubMed), Embase, and Web of Science.

REVIEW METHODS

For each database, a specific search strategy was developed. Quality was assessed with the Toxicological data Reliability Assessment Tool (ToxRTool). The type of animal model, graft, coating, and pathogen were summarised. The outcome assessment in each study was evaluated.

RESULTS

In total, 4 667 studies were identified, of which 94 papers focusing on in vivo testing were included. Staphylococcus aureus was the organism most used (n = 65; 67.7%). Most of the graft types were polyester grafts. Rifampicin was the most frequently used antibiotic coating (n = 43, 48.3%). In the outcome assessment, most studies mentioned colony forming unit count (n = 88; 91.7%) and clinical outcome (n = 72; 75%). According to the ToxRTool, 21 (22.3%, n = 21/94) studies were considered to be not reliable.

CONCLUSION

Currently published in vivo models are very miscellaneous. More attention should be paid to the methodology of these pre-clinical reports when transferring novel graft coatings into clinical practice. Variables used in pre-clinical reports (bacterial strain, duration of activity coating) do not correspond well to current clinical studies. Based on the results of this review, a proposal for a complete and comprehensive set up for pre-clinical invivo testing of anti-infectious properties of vascular graft coatings was defined.

Single and multi-functional coating strategies for enhancing the biocompatibility and tissue integration of blood-contacting medical implants

Device-associated clot formation and poor tissue integration are ongoing problems with permanent and temporary implantable medical devices. These complications lead to increased rates of mortality and morbidity and impose a burden on healthcare systems. In this review, we outline the current approaches for developing single and multi-functional surface coating techniques that aim to circumvent the limitations associated with existing blood-contacting medical devices. We focus on surface coatings that possess dual hemocompatibility and biofunctionality features and discuss their advantages and shortcomings to providing a biocompatible and biodynamic interface between the medical implant and blood. Lastly, we outline the newly developed surface modification techniques that use lubricant-infused coatings and discuss their unique potential and limitations in mitigating medical device-associated complications.

Silver-Impregnated Dressing Does Not Decrease Incidence of Surgical Site Infection After Adult Cardiac Surgery

OBJECTIVE

Sternal wound infections complicate 1% to 8% of cardiac surgeries and carry significant morbidity. We investigated the utility of silver-impregnated dressing in decreasing sternal wound infections after sternotomy cases.

METHODS

A single-institution cohort study was performed as part of a quality improvement trial of a new sternal dressing. Five hundred fifty-seven sternotomy cases were performed in 2015 with application of a traditional gauze dressing. In 2016, 682 sternotomy cases were performed with the use of a commercially available silver-impregnated dressing. Prospectively identified metrics were analyzed for each patient population along with nursing assessments and structured questionnaires.

RESULTS

Baseline characteristics of patients in traditional gauze and silver-impregnated dressing groups were similar. Morbidity and mortality were similar. Nine (1.6%) and 12 (1.8%) sternal wound infections were reported in traditional gauze and silver-impregnated dressing groups, respectively. There was no difference in the rate of sternal wound infections (P = 0.80). The number of organ space infections (3) and deep sternal wound infections (3) was the same; however, the number of superficial infections was greater in the silver-impregnated dressing cohort (3 vs. 6). Among patients in either group with sternal wound infection, there were no differences in the proportion of superficial infections (44% vs. 50%, P = 0.8) or the organism cultured (67% vs. 50% staphylococcus, P = 0.45). A total of 22% of patients reported "not satisfied" with silver-impregnated dressing.

CONCLUSIONS

Silver dressings did not reduce sternal wound infection after sternotomy for cardiac surgery in a large-cohort study. We discontinued the routine use of silver dressings for adult cardiac surgery based on these results because traditional gauze likely represents an equally effective and less costly alternative.

How to best treat infectious complications of open and endovascular thoracic aortic repairs

Infectious complications of open and endovascular procedures for descending thoracic aortic disease are relatively rare, affecting 1% to 6% of treated patients. However, the number of thoracic aortic procedures, especially endovascular, is increasing continuously, and infectious complications involving the graft or endograft have been observed more frequently in recent years. Several causative factors may play a role in thoracic aortic prosthetic infections, including hematogenous seeding, local bacterial translocation, and iatrogenous contamination. In addition, the development of a fistula between the aortic graft and the esophagus or the bronchial tree is a common associated finding, representing a dramatic event that further increases mortality rates and requires multidisciplinary management. Treatment of these conditions is demanding, often including a number of pharmacological, surgical, and endovascular options. Because there are several different surgical strategies and timing modalities that are chosen according to the surgeon's experience, the results of different treatment options are difficult to summarize, and no consensus exists on a standardized paradigm of treatment. In this review, published reports regarding clinical outcomes related to thoracic graft and endograft infections are discussed, including our personal experience with surgical and endovascular management of this condition.

Prevention of perioperative vascular prosthetic infection with a novel triple antimicrobial-bonded arterial graft

OBJECTIVE

Previously, we investigated a locally developed technique of bonding arterial grafts with three antimicrobials to protect against early (within 2 weeks) perioperative bacterial contamination encountered occasionally during aortic graft prosthetic reconstruction. Vascular graft infections are classified by their appearance time (early [<4 months] vs late [>4 months] after graft implantation), degree of incorporation into the surrounding vessel wall, connectivity to the postoperative wound, and extent of graft involvement. In the current phase of testing, we evaluated the ability of our novel triple antimicrobial-bonded graft to prevent infection in the first 8 weeks after implantation.

METHODS

In nine Sinclair miniature pigs, we surgically implanted a 6-mm vascular Dacron patch graft in the infrarenal abdominal aorta. Five pigs received grafts chemically bonded with a 60-mg/mL solution of rifampin, minocycline, and chlorhexidine, and four pigs received unbonded grafts. Before implantation, the five bonded grafts and three of the unbonded grafts were immersed for 15 minutes in a 2-mL solution containing 1-2 × 10⁷ colony-forming units (CFUs)/mL of Staphylococcus aureus (ATCC 29213); the fourth unbonded graft served as a control.

RESULTS

At week 9, all of the grafts were explanted. All S aureus-inoculated bonded grafts (n = 5) showed no bacterial growth. The unbonded, uninoculated graft (n = 1) showed low-level bacterial growth (<1.2 × 10³ CFUs); S cohnii spp urealyticus, but not S aureus, was isolated, which suggested accidental direct perioperative contamination. Two pigs that received S aureus-inoculated, unbonded grafts were euthanized because of severe S aureus infection (<6.56 × 10⁸ CFUs per graft). Results of histopathologic analysis were concordant with the microbiologic findings. Most intergroup differences were observed in the inflammatory infiltrate in the aortic wall at the site of graft implantation. In all pigs that received bonded grafts, Gram staining showed no bacteria.

CONCLUSIONS

Our triple-bonded aortic graft prevented perioperative aortic graft infection for at least 8 weeks in a porcine model. The synergistic antimicrobial activity of this graft was sufficient to prevent and/or eradicate infection during that period. Further studies are needed to assess the graft's ability to combat early-onset vascular graft infection for up to 4 months.

[Dilemmas of the reconstruction of the major pelvic artery due to infectious aortic graft complication]

INTRODUCTION

In the pelvic region thrombendarterectomy and bypass procedures are the most commonly performed procedures to treat peripheral artery occlusive diseases with chronic, severe circulation failure caused by atherosclerosis. Biologic and synthetic grafts can also be used in bypass surgeries. Application of synthetic grafts can acutely increase the development of the infectious graft complication and its mortality is still between 70 and 75% in pelvic processes. We describe the difficulties and dilemmas of an infectious aortobifemoral graft.

CASE PRESENTATION

58-year-old female patient with right lower limb trophic ulcer underwent a DSA examination showing a bilateral iliac occlusion and aortobifemoral bypass surgery with Dacron graft implantation was performed. Re-occlusion and infection of the graft led to an in situ silver Dacron graft replacement. Due to the one-sided re-occlusion, a femoro-femoral crossover bypass surgery applying silver graft was performed. Despite the previously described procedures the infectious process got worse and autologous deep vein reconstruction was required beside the removal of the infectious synthetic grafts at the same time.

DISCUSSION

There are local and extraanatomical solutions to reduce infectious graft complication. In pelvic infections bypass surgeries using autologous deep vein can show the best results. This procedure is the trustworthiest but also the most straining technique due to the extension of surgical time and increased blood loss. The proper surgical strategy should be selected on individual bases including cardiopulmonary load ability, patient age and technical/infrastructural possibilities.

Results from the International Silver Graft Registry for high-risk patients treated with a metallic-silver impregnated vascular graft

The purpose of this postmarket surveillance registry was to document the efficacy of a vascular prosthesis coated with metallic silver in high-risk patients undergoing vascular reconstructions. Patency (primary endpoint) and freedom from graft infection (secondary endpoint) data were assessed at a minimum of 12 months in patients with significant co-morbidity and/or confirmed graft infections or infected native vessels. Between November 2006 and December 2009, 230 patients with high-risk factors underwent aortic, peripheral and/or extra-anatomic reconstructions with Silver Graft® (SG) in six German, one French and one Polish vascular center. All participating centers used the metallic silver-coated polyester graft (SG) in various diameters and lengths including tubular and bifurcate vascular grafts. Doppler ultrasound follow-ups to determine graft patency were planned at 12 months or done at an earlier time in case the patient became symptomatic. A total of 230 patients were studied. Ten of these 230 patients had graft infections at baseline whereas the remaining 220 subjects had significant risk factors such as coronary artery disease (62.7%, 138/220), vascular access in scar tissue (27.3%, 60/220), Fontaine III/IV (38.2%, 84/220), chronic renal insufficiency (26.8%, 59/220) and diabetes (21.0%, 46/220). The long-term follow-up at 15.5 ± 8.3 months revealed a secondary patency rate of 93.2% (205/220) and an ‘all cause’ mortality rate of 18.6% (41/220). There was a freedom from de novo graft infection rate of 95.9% (211/220) in the high-risk group without graft infections at baseline. One regraft infection occurred distal of the revisional reconstruction in the 10 patients with graft infection at baseline. The presence of perigraft fluid at follow-up and Fontaine III/IV at baseline were found to be predictors for graft patency whereas perigraft fluid presence was the only predictor for de novo graft infections. This registry revealed favorable patency and freedom from de novo infections rates in a ‘high-risk’ population with significant co-morbidities.

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.

[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.