Prosthetic Graft Infection Research Articles

Results of infrainguinal revascularization with bypass surgery using a heparin-bonded graft for disabling intermittent claudication due to femoropopliteal occlusive disease

BackgroundThe purpose of this study was to analyze the results of infrainguinal revascularization for disabling intermittent claudication (IC) due to femoropopliteal occlusive disease using bypass graft (BPG) surgery with a heparin-bonded expanded polytetrafluoroethylene (HB-ePTFE) graft. MethodsBetween 2002 and 2016, we performed 1400 BPGs with HB-ePTFE interventions in patients with femoropopliteal occlusive disease, of which IC was an indication in 485 (34.6%) patients. Early major end points were in-hospital mortality and major complications; late major end points were primary patency, freedom from redo bypass, freedom from progression to critical limb ischemia, and freedom from above-knee amputation or prosthetic graft infection. ResultsWe performed 200 (41.2%) above-knee BPGs and 231 (47.6%) below-knee BPGs; 54 (11.1%) BPGs targeted a tibial artery. In-hospital death occurred in two (0.4%) patients. Overall, the major complication rate was 4.3%. The median duration of follow-up was 33 months (range, 1-150 months; interquartile range [IQR], 14-62.8 months); the cumulative follow-up index for survival was 0.75 ± 0.25. During the follow-up, 56 (11.6%) patients died. Estimated primary patency of the BPG was 86.1% ± 1.6% (95% confidence interval [CI], 82.7-88.9) at 12 months, 68.4% ± 2.4% (95% CI, 63.5-72.9) at 36 months, and 57.7% ± 2.9% (95% CI, 52.0-63.2) at 60 months. On multivariate analysis, runoff status (no or one vessel), site of the distal anastomosis (below the knee), and postoperative medical treatment (oral anticoagulants) impaired primary patency. Estimated freedom from redo bypass was 96.1% ± 0.9% (95% CI, 93.9-97.5) at 12 months, 84.8% ± 1.9% (95% CI, 80.7-88.2) at 36 months, and 76.4% ± 2.6% (95% CI, 71.0-81.1) at 60 months. Both the runoff status (no or one vessel) and the diameter of the graft (6 mm) were significantly associated with the need for redo bypass. Freedom from progression to critical limb ischemia was 86.1% ± 2.2% (95% CI, 81.2-89.9) at 60 months. During the follow-up, there were 20 (4.1%) above-knee amputations, which occurred at a median of 33 months (range, 2-107 months; IQR, 14-63 months) after the indexed BPG intervention. Prosthetic graft infection occurred in seven (1.4%) patients, with a median delay from index procedure to presentation with graft infection of 33 months (range, 1-72 months; IQR, 14-62.5 months), resulting in a freedom from prosthetic graft infection rate of 98.2% ± 2% (95% CI, 95.8-99.2) at 60 months. ConclusionsIn patients suffering from lifestyle-disabling IC with long or complex occlusive lesions of the femoropopliteal segment, open BPG surgery with Hb-ePTFE graft had an acceptably low mortality rate. A poor runoff status was a significant predictor of loss of graft patency, especially after a below-knee anastomosis, as was the need for redo bypass. Dual antiplatelet therapy had significantly better results against follow-up thrombosis, and 8-mm grafts showed better freedom from redo bypass compared with 6-mm grafts.

Efficacy of Antiseptic Solutions in Treatment of Staphylococcus Aureus Infected Surgical Wounds with Patches of Vascular Graft: An Experimental Study in Rats.

Background and objectives: Treatment of a prosthetic vascular graft infection (PVGI) remains a challenging problem in vascular surgery. The aim of this study was to design a novel rat model for treatment of peripheral vascular prosthesis infection caused by Staphylococcus aureus (S. aureus) and to determine the efficacy of different antiseptic solutions in suppressing or eradicating infection from the wound and the graft material itself. Materials and methods: A piece of Dacron vascular prosthesis was surgically implanted at the dorsum of 48 Wistar rats and the wounds were infected with 5 McFarland standard inoculum of S. aureus. Suppurating wounds were daily irrigated with different antiseptic solutions: octenidine dihydrochloride, povidone-iodine, chlorhexidine digluconate, and sterile saline. The antimicrobial action of antiseptics was defined according to their capability to eradicate bacteria from the graft surroundings and bacteriological examination of the graft itself. Extended studies on wound microbiology, cytology, and histopathology were performed with an additional group of 10 rats, treated with the most effective antiseptic-octenidine dihydrochloride. Results: Four-day treatment course with octenidine, povidone-iodine, and chlorhexidine resulted in 99.98% (p = 0.0005), 90.73% (p = 0.002), and 65.97% (p = 0.004) decrease in S. aureus colonies in wound washouts, respectively. The number of S. aureus colonies increased insignificantly by 19.72% (p = 0.765) in control group. Seven-day treatment course with octenidine eradicated viable bacteria from nine out of 10 wound washouts and sterilized one vascular graft. Conclusions: A reproducible rat model of PVGI with a thriving S. aureus infection was designed. It is a first PVGI animal model where different antiseptic solutions were applied as daily irrigations to treat peripheral PVGI. Seven-day treatment with octenidine eradicated bacteria from the wound washouts for 90% of rats and one vascular graft. Further studies are needed to investigate if irrigations with octenidine could properly cure vascular bed from infection to assure a successful implantation of a new synthetic vascular substitute.

Surgical Principles for the Management of Peripheral Graft Infections

Prosthetic graft infections remain one of the most significant complications encountered by vascular surgeons given the high rate of morbidity and limb loss. Graft infections involving the lower extremity have a reported incidence of 2 to 6%. Presentation can include an indolent infection, septic shock, or frank hemorrhage. The goals of therapy are minimizing morbidity and mortality, preventing recurrent infection, and limb salvage. The gold standard in management is complete graft excision; however, this may not always be feasible or necessary. Various techniques such as partial preservation with concomitant revascularization may be appropriate in selected circumstances. A thorough understanding of the pathophysiology, extent of infection, and the patient’s overall clinical picture are necessary so that a patient-specific approach can be implemented. This review contains 4 figures, 1 table, and 31 references. Keywords: cryopreserved cadaveric graft, extracavitary graft, graft excision, graft infection, graft preservation, lower-extremity bypass graft, lateral femoral bypass, prosthetic vascular graft

Value of 18F-FDG PET/CT in diagnosis of prosthetic vascular graft infection after endovascular aortic repair

Objective To study the features and clinical value of 18F-fluorodeoxyglucose (FDG) PET/CT in prosthetic vascular graft infections (PVGIs) after endovascular aortic repair (EVAR). Methods Data of 27 patients (22 males and 5 females, age range: 21-77 years, average age: 42 years) who underwent PET/CT imaging after EVAR from October 2011 to January 2017 were studied retrospectively. A total of 11 cases were finally diagnosed as PVGIs (PVGIs group), and the remaining 16 cases were defined as the negative group. PET/CT imaging features were compared between two groups. The detection rates of PET/CT and aortic CT angiography (CTA) for PVGIs were calculated and compared. Two-sample t test and Fisher exact test were used for data analysis. Results Significant uptake of FDG around the stents was detected by PET/CT in all patients in PVGIs group. The maximum standardized uptake value (SUVmax ) of 11 patients in early imaging was 14.9±3.3 (10.8-21.8) and that of 9 patients in delayed imaging was 13.8±3.4 (10.6-19.1). Six patients of the negative group underwent the delayed imaging. No uptake or mild uptake of FDG around the stents was observed in negative group, with the SUVmax of 1.7±0.8(1.0-2.9) in early imaging and 1.6±0.7(1.1-2.5) in delayed imaging. SUVmax in negative group was significantly lower than that in PVGIs group (t values: 12.6 and 11.8, both P<0.001). Five patients in PVGIs group were diagnosed as graft infections by the aortic CTA, while the remaining 6 cases showed no definitive infection signs on aortic CTA. The detection rate of aortic CTA was 5/11, which was significantly lower than that of PET/CT (P<0.05). In negative group, 6 patients had abnormal FDG uptakes in other areas and were finally confirmed as infectious lesions (n=3) or malignant tumors (n=3). Conclusion Compared with aortic CTA, 18F-FDG PET/CT is more sensitive and accurate in detection and diagnosis of PVGIs after EVAR. Key words: Aortic disease; Surgical procedures, operative; Blood vessel prosthesis; Infection; Positron-emission tomography; Tomography, X-ray computed; Deoxyglucose

Aortic reconstruction in infected aortic pathology by femoral vein “neo-aorta”

The use of autologous femoral veins for in situ reconstruction of the aortoiliac segment is an effective technique to treat native aorta or prosthetic graft infections. The indications, technical details, and outcomes of this procedure are detailed. Graft infection involving the aortic segment, while rare, remains one of the most challenging vascular surgery conditions to treat. The original technique of "neo-aortoiliac surgery" with in situ autologous vein grafts has evolved over the past 25 years and remains a worthwhile alternative for the treatment of aortic graft infections, with lower mortality rates compared with other extra-anatomic or in situ surgical options. Acceptance of this surgical option is due to low graft re-infection rates, rare graft disruption, and low long-term aneurysmal degeneration. Excision of the femoral veins is associated with acceptable rates of lower limb edema. The use of an autologous femoral vein graft can be considered the standard of care in selected patients for the management of aortic graft infections. Optimal management of patients with aortic graft infections requires consideration of all potential therapeutic options because no single modality can be used, and individualizing treatment according to the clinical condition will yield the best patient outcomes.

Infectious diseases physician attitudes to long-term antibiotic use.

Background In Australia, it is not known how much antibiotic prescribing by infectious diseases physicians is long-term, or how confident they are with the evidence behind this practice. Objective Survey Australian infectious diseases physicians to assess attitudes and prescribing practice prescribing prolonged courses of antibiotics. Methods An online questionnaire was distributed to the mailing group for the Australian Society of Infectious Diseases. Responses were collected from 29th October to 12th November 2015. Results The majority of respondents practiced in Australia as Infectious Diseases physicians, microbiologists, or trainees. 88% had prescribed long-term antibiotics. Heterogeneity was noted in the indications for prescription, including recurrent UTIs, cellulitis or chest infections, prosthetic joint infection and vascular graft infection. Beta-lactams antibiotics were prescribed most frequently. 22% of respondents had prescribed rifampicin/fusidic acid most frequently, while 11% could not identify a single antibiotic that they used most frequently, due to the heterogeneity of indications for prescribing. 95% stated that they would stop long-term antibiotic therapy if appropriate, and 74% were willing to enrol their patients into a randomised control trial looking at stopping long-term therapy. Conclusion Most infectious diseases physicians who responded to the survey prescribe long-term antibiotics, with great heterogeneity in the indications for which these antibiotics are prescribed.

Invited commentary

This basic science study's goal is to address an area of clinical ambiguity: how to coat an endovascular stent graft with rifampin in a standard and optimized manner for immediate use in an infected field. It optimizes two variables, concentration and incubation period, in an ex vivo experiment and on the basis of the results suggests a rapid real-time perioperative protocol. The graft chosen to study is a standard Dacron endograft of various diameters and lengths. There are reports of using a rifampin-coated endograft in an infected field with preparation extrapolated from methods used during open operation (60 mg/mL rifampin incubated for 1 hour). A dedicated scientific study to determine optimal endograft coating would allow a more reasonable comparison of results when applied in the clinical condition. This study demonstrates that a rifampin solution of 10 mg/mL delivered as one 20-mL aliquot with an incubation time of 10 minutes will provide a well-coated endograft, not improved by higher concentrations or longer periods of intubation. This allows the surgeon to save both resources (drug, supplies) and time during an urgent or emergent case. An overnight bathing in methanol solvent demonstrates that the concentration or incubation time had no effect on the amount of rifampin trapped (coating) on the graft. Bathing in a saline bath demonstrates that the coated rifampin is essentially gone at 50 hours. The well-coated endograft does not retain as much rifampin as a similarly coated control graft, probably because the control graft is a gelatin-sealed graft. The endograft is not made with a gelatin coating, so the authors have no control of this processing step, and the comparison is somewhat artificial. As with most good basic research, more questions come to mind than are answered by the original work. This study does not evaluate the prepared graft under conditions that might greatly influence its performance in the clinical situation. The lack of evaluation in a flow chamber does not allow an estimate of rifampin loss over time from both the flow and sac surface. Dacron endografts generally leak through the material interstices until anticoagulation is reversed, so the loss may be rapid from both surfaces. Under such circumstances, what antimicrobial activity remains even minutes after deployment? In vivo animal experiments with implantation in an infected field would yield some estimate of the potential clinical impact of this method of in situ repair. Would presealing with a gelatin coating before rifampin coating better mimic the open scenario and improve the results? All these factors being considered, this study does provide a logical basic science first step to a clinical problem that can now be further studied to provide greater insight into its clinic use. The opinions or views expressed in this commentary are those of the authors and do not necessarily reflect the opinions or recommendations of the Journal of Vascular Surgery or the Society for Vascular Surgery Optimization of rifampin coating on covered Dacron endovascular stent grafts for infected aortic aneurysmsJournal of Vascular SurgeryVol. 69Issue 1PreviewIn the treatment of an infected aorta, open repair and replacement with a rifampin-impregnated Dacron vascular graft decrease the risk of prosthetic graft infections, with several protocols available in the literature. We hypothesize that the same holds true for endovascular aneurysm repair, and after studying and optimizing rifampin solution concentration and incubation period to maximize the coating process of rifampin on Dacron endovascular stent grafts (ESGs), we propose a rapid real-time perioperative protocol. Full-Text PDF Open Archive

Biosynthetic vascular graft: a valuable alternative to traditional replacement materials for treatment of prosthetic aortic graft infection?

To report the experience of a tertiary vascular surgery center using Omniflow II® biosynthetic vascular grafts for treatment of prosthetic aortic graft infection. Retrospective analysis of all patients with prosthetic graft infections who underwent in situ aortic reconstruction using Omniflow II® grafts or other conduits between March 2015 and May 2017. Early and late mortality, perioperative complications, and reinfection rate were analyzed. Sixteen patients (14 males, median age 68.5, range 57-89) with prosthetic aortic graft infection were treated at our center. Eight patients received an Omniflow II® biosynthetic graft, two patients silver-triclosan coated grafts, three patients bovine pericardial tube grafts, and three patients composite bovine pericardial tube grafts with Omniflow II® graft extensions. Perioperative complications occurred in seven patients (43.8%). Early mortality rate was 18.7% (n = 3). In addition, four patients died during follow-up after a median of 11 months (range 0-34 months). We did not observe any reinfections. Bypass grafts were patent in all patients. No major limb amputations were performed during follow-up. Treatment of prosthetic aortic graft infection with Omniflow II® vascular grafts is feasible. Graft material seems to have an excellent resistance to infection and might be a valuable alternative to traditional replacement materials. Especially long-term durability has to be continuously monitored and documented.

Infections of Prosthetic Grafts and Patches Used for Infrainguinal Arterial Reconstructions

Prosthetic grafts are often used as alternative conduits in patients with peripheral vascular disease who do not have an adequate autologous vein for bypass. Prosthetic grafts, unfortunately, carry an increased risk of infection and are associated with increased morbidity and mortality. The goal of this study was to identify potential risk factors and subsequent outcomes associated with lower extremity prosthetic graft infections. Two hundred seventy-two lower extremity prosthetic bypasses and patches were performed at an academic medical center between 2014 and 2016. A retrospective review of patients' demographics, comorbidities, indication for surgery, type of procedures performed, and procedural characteristics was conducted. Outcomes, including limb loss and mortality, were analyzed. Forty-three (15.8%) patients with graft infections were identified during a median follow-up of 668days (interquartile range [IQR]=588). The median time to graft infection was 43days (IQR=85) with Staphylococcus being the most common bacteria cultured. Infections were associated with a 30.2% rate of limb loss and a 34.9% rate of mortality. The risk of infection was 2.4 times greater among those with a history of redo surgery (95% confidence interval [CI] of the hazard ratio [HR]: 1.3, 4.3) and 2.1 times greater in women (95% CI: 1.1, 3.8), by multivariable statistics. A 1g/dL increase in albumin level was associated with a 33.5% decrease in hazard of infection (HR: 0.67, 95% CI: 0.46, 0.96) in the multivariable model. The estimated cumulative incidence of infection for female patients with hypertension and mean albumin of 3.36 undergoing redo surgery was 19.4% at 30days after surgery (95% CI: 10.6, 35.6) and 39.9% at 1year (95% CI: 26.8, 59.3). Female gender, redo surgery, and malnutrition are associated with increased risk of prosthetic graft infections leading to a high rate of limb loss and mortality. Endovascular interventions and bypasses with vein conduits should be considered in these patients.

2141. Characteristics and Prognosis of Patients with a Prosthetic Vascular Graft Infection (PVGI): A Prospective Cohort of 200 patients

BackgroundThe aim of the present study was to describe the characteristics and prognosis of patients admitted for a PVGI and to assess the factors associated with the death of these patients.MethodsAll consecutive patients admitted in our department between January 1, 2000 and January 1, 2018 for a PVGI were enrolled in the present prospective cohort study. PVGIs were divided into extracavitary (femoro-femoral, femoro-popliteal and axillo-femoral) and cavitary (aorto-iliac, aorto-femoral, ilio-femoral, aortic); into “early” infection (<4 months) and late. Patients’ baseline characteristics and their follow-up were described, and factors associated with death were assessed by using a logistic multivariate regression model.ResultsOverall, 200 patients were included during this period. The median age of patients was 69 years [IQR: 61–78], mainly of men (86%). One hundred and sixteen patients had an intracavitary PVGI (58%). Enterobacteriaceae and MSSA were the most frequent pathogens (n = 60 and 59), followed by coagulase negative staphylococci (n = 30), Streptococcus (n = 26) and enterococcus (n = 25). Surgery with replacement of the infected prosthesis was performed in 102 patients (53%). Culture of material samples taken during surgery were plurimicrobial in 67 patients (34%). After surgery, the median follow-up of patients was 7.5 months [IQR: 2–19] during which 30 presented a failure (15%) and 85 patients died, 41 due to the PVGI (21%). Factors independently associated with death in multivariate analysis were: to be over 70 years old (OR = 8.2; P < 0.01), to stay in ICU for more than 6 days (OR = 5.9; P = 0.01) and to have an intracavitary PVGI (OR = 9.0; P = 0.02). Antibiotic therapy regimen combining rifampicin to another antibiotic was associated with a decreased mortality (OR = 0.11; P < 0.01).ConclusionOur results suggest that the prognostic of patients admitted for PVGI depends on the site of infection and the occurrence of a shock after the admission. We found a better prognosis for patients with an extracavitary PVGI, without sepsis. Finally, PVGI treated with an antibiotic combination including rifampicin had a better outcome.Disclosures All authors: No reported disclosures.

Lateral femoral bypass for prosthetic arterial graft infections in the groin

ObjectiveProsthetic arterial graft infections (PAGIs) in the groin pose significant challenges in terms of revascularization options and risk of limb loss as well as associated morbidities. Although obturator canal bypass (OCB) has been suggested for revascularization of the extremity in these cases, moderate success rates and technical challenges have limited widespread use. Our study analyzed lateral femoral bypass (LFB) as an alternative approach for the treatment of groin PAGIs. MethodsThis is a retrospective review of a prospectively maintained database of patients who underwent LFB for groin PAGIs at a single center from 2000 to 2017. Patients' data including demographics, comorbidities, perioperative complications, graft patency, and need for reintervention were used. Patients were observed after LFB with duplex ultrasound surveillance in an accredited noninvasive vascular laboratory every 3 months during the first year, followed by every 6 months for the second year and yearly thereafter. After isolation of the infected wound with sterile dressings, remote proximal and distal arterial exposure incisions were made. LFBs were tunneled under the inguinal ligament and lateral to the infected wound from an uninvolved inflow artery or bypass graft to an uninvolved outflow vessel. ResultsA total of 19 LFBs were performed in 16 patients (mean age, 69 ± 12.6 years). Three LFBs were performed urgently for acute bleeding. Choice of conduit included 6 (31.6%) autogenous vein grafts, 10 (52.6%) cadaveric grafts, 2 (10.5%) rifampin-soaked Dacron grafts, and 1 (5.3%) polytetrafluoroethylene graft. Average follow-up was 33 months (range, 0-103 months). Major adverse events occurring within 30 days of the operation included one (5.3%) death and one (5.3%) graft excision for pseudoaneurysm. Primary patency and primary assisted patency at 12 and 24 months were 73% and 83%, respectively. One patient required an amputation 17 months after surgery after failure of repeated revascularization attempts. Overall limb salvage was 93.8% during this follow-up period. ConclusionsIn this series, LFB for management of groin PAGIs demonstrated higher patency and limb salvage rates compared with previous reports of OCB. Diligent postoperative duplex ultrasound surveillance is critical to the achievement of limb salvage and maintenance of graft patency. These results suggest that LFB, which is technically less complex than OCB, should be considered the first choice for revascularization in select cases of PAGIs involving the groin.

Histological and Mechanical Assessment of Decellularized Porcine Biografts, and Its Biological Evaluation following Aortic Implantation during Mid-Term Follow-Up

Aims: Prosthetic graft infection frequently requires graft replacement. Among other options, a biological graft could serve as an alternative choice. Decellularization reduces tissue immunogenicity. Our aim was to determine an efficient decellularization method and to evaluate the decellularized porcine biografts’ adaptability. Methods: Four different protocols were implemented to decellularize porcine aortic segments (n = 4). Cell removal effectiveness and matrix structure preservation were histologically examined. Mechanical tests were performed. Decellularized porcine grafts were interpositioned in a porcine aorta. After a 6-month period, implanted samples were removed and evaluated using light and electron microscopy. Results: Histological results showed complete removal of cells and preserved connective tissue fiber structure following decellularization, using sodium dodecyl sulfate and sodium azide. Pressure tests demonstrated similar compliance to fresh vessels. In 9 out of 10 cases, pigs survived the follow-up period. Graft rejection, intimal hyperplasia, reocclusion and/or aneurysm formation were not observed. Presence of host cells and neoendothelialization were microscopically confirmed. Conclusions: This decellularization protocol enables a cost-effective preparation of biological grafts featuring reduced immunogenicity. The implanted grafts did not degenerate during the 6-month follow-up period, the lack of graft rejection suggests acceptable immunological tolerance, while recipient cells migrate into, proliferate and differentiate, thus creating the possibility for further use as an optional vascular graft.

Determining the Diagnostic Value of 18F-Fluorodeoxyglucose Positron Emission/Computed Tomography in Detecting Prosthetic Aortic Graft Infection

To determine the diagnostic value of 18F-fluorodeoxyglucose positron emission/computed tomography (FDG PET/CT) in detecting prosthetic aortic graft infection (AGI). Twenty-one patients with prosthetic grafts for abdominal aortic aneurysms underwent FDG PET/CT scans for suspected graft infection over a 15-month period. Images were evaluated for tracer pattern and grade of FDG uptake in addition to measuring the maximal standardized uptake value (SUVmax). Two independent nuclear medicine physicians retrospectively evaluated all imaging. The images from a control group of patients with aortic grafts who underwent FDG PET/CT scans for onco-hematological indications were evaluated to establish radiological characteristics of asymptomatic grafts. Secondary parameters that are associated with graft infection such as components of the peripheral blood count were collected. Graft infection status was determined using microbiological outcomes following graft explantation or radiological drainage of perigraft collections and correlated with results of the FDG PET/CT scans to determine infective status. In the control group, the pattern of FDG uptake was homogenous and diffuse. The mean SUVmax was 3.5 (±1.3). Thirteen out of 21 grafts were confirmed as infected. Tracer uptake in infected grafts displayed an intense and focal pattern, with a median grade of uptake of 4 vs. 2 on a validated 4 point grading scale. The area under the receiver operating curve for FDG PET/CT in detecting infection was 0.85 (±0.15) P=0.01. Sensitivity was 92%, specificity 63%, and positive and negative predictive values of 80% and 83%, respectively. The SUVmax was significantly higher in infected than noninfected grafts, (10.3±4.2 vs. 5.4±3.4) P=0.02. According to the receiver operating characteristic analysis, SUVmax greater than 6.3 represented the optimal cutoff between infective and noninfective outcome. Of the secondary parameters collected, grade of uptake and SUVmax were the only significant predictors of infection (odds ratio 2.5, 1.5 respectively) P=0.05. White cell count, erythrocyte sedimentation rate, and C-reactive protein demonstrated nonsignificant odds ratios of 1.4, 0.9, and 1.0, respectively. FDG PET/CT is a valuable diagnostic test for identifying AGI. Infected grafts display significantly greater FDG uptake in a distinctive intense focal perigraft pattern and distribution. SUVmax greater than 6.3 is a good cutoff to determine infective status.

Efficacy of Preoperative Antibiotic Therapy for the Treatment of Vascular Graft Infection

Objective: We aimed to assess the efficacy of preoperative antibiotic therapy for the treatment of prosthetic graft infection.Materials and Methods: We retrospectively analyzed the treatment strategies used for managing patients with prosthetic vascular graft infections between 2000 and 2016. The patients were divided into two groups: early antibiotic (EA) group, those who were administered with antibiotics ≥2 weeks preoperatively and late antibiotic (LA) group, those who were administered with antibiotics <2 weeks preoperatively. We evaluated the outcomes including surgical procedures, length of hospital stay, and surgical revision.Results: All the surgical procedures performed in the EA group were elective surgeries. Three of the 11 surgeries performed in the LA group were emergency surgeries (P=0.16). No significant differences were observed in the operative procedure (P=0.64), operation time (P=0.37), and blood loss (P=0.63) of the two groups. Although the length of postoperative hospital stay did not significantly differ (P=0.61), the total length of hospital stay was longer in the EA group (P=0.02). Surgical revisions were performed for five patients in the LA group and for none in the EA group (P=0.04).Conclusion: Preoperative antibiotic therapy provided excellent outcomes in terms of avoiding surgical revisions in the treatment of vascular graft infection.

IF11. Good Early Results of Negative Pressure Wound Nonexcisional Treatment for Prosthetic Graft Infection Are Durable: It Is a Game Changer

IF11. Good Early Results of Negative Pressure Wound Nonexcisional Treatment for Prosthetic Graft Infection Are Durable: It Is a Game Changer

Trombosis de prótesis aórtica supracoronaria por Aspergillus

Infection of prosthetic vascular grafts of fungal etiology are rare entities, requiring high diagnostic suspicion and carry a high mortality. We present the case of patient with supracoronary dacron graft with thrombosis by Aspergillus flavus. Aspergillus is a filamentous fungus whose primary mode of transmission is via inhalation of spores. It has a predilection for infection of prosthetic left valves, forming large, friable and high risk of embolism vegetations, with a mortality rate of up to 80-90%. Main complication is septic embolization. It is hardly detected in normal blood cultures. The treatment is based on intensive antifungal therapy and surgery.

Organization model for allotransplantations of cryopreserved vascular grafts in Czech Republic

The transplantation of fresh or cryopreserved vascular allografts in patients with a prosthetic graft infection or critical limb ischemia is necessary for their limb salvage and, in many cases, represents a lifesaving procedure. While transplantation of fresh allografts has a long history in the Czech Republic, the standard use of cryopreserved vascular allografts was introduced into the clinical practice in 2011 as a result of the implementation of EU Directive 2004/23/EC into national legislation (Human Cell and Tissue Act No. 296/2008 Coll.). The authors present an organizational model based on cooperation between the majority of Czech Transplant Centers with a tissue establishment licensed by the national competent authority. In various points, we are addressing individual aspects of experimental and clinical studies which affect clinical practice. Based on experimental and clinical work, the first validation of cryopreserved arterial and venous grafts for clinical use was performed between 2011 and 2013. The growing number of centers participating in this programme led to a growing number of patients who underwent transplantation of vascular allografts. In 2015 the numbers of transplanted fresh versus cryopreserved allografts in the Czech Republic were almost equal. Cooperation of the participating centers in the Czech Republic with the licensed Tissue Establishment made it possible to achieve a full compliance with the European Union Directives, and harmonized national legal norms and assured a high quality of cryopreserved vascular allografts.

Optimization of rifampin coating on covered Dacron endovascular stent grafts for infected aortic aneurysms

ObjectiveIn the treatment of an infected aorta, open repair and replacement with a rifampin-impregnated Dacron vascular graft decrease the risk of prosthetic graft infections, with several protocols available in the literature. We hypothesize that the same holds true for endovascular aneurysm repair, and after studying and optimizing rifampin solution concentration and incubation period to maximize the coating process of rifampin on Dacron endovascular stent grafts (ESGs), we propose a rapid real-time perioperative protocol. MethodsSeveral prepared rifampin solutions, including a negative control solution, were used to coat multiple triplicate sets of Dacron endovascular aortic stent grafts at different but set incubation periods. Rifampin elution from the grafts was studied by spectroscopic analysis. Once an optimized solution concentration and incubation time were determined, the elution of rifampin over time from the graft and the graft's surface characteristics were studied by ultraviolet-visible spectroscopy and atomic force microscopy. ResultsAll coated ESGs with any concentration of prepared rifampin solution, regardless of incubation time, immediately demonstrated a visible bright orange discoloration and subsequently after elution procedures returned to the original noncolored state. At the 25-minute incubation time (standard flush), there was no statistical difference in the amount of rifampin coated to the ESGs with 10-mg/mL, 30-mg/mL, and 60-mg/mL solutions (0.06 ± 0.01, 0.07 ± 0.05, and 0.044 ± 0.01, respectively; P > .05). This was also true for a 10-minute incubation time (express flush) of 10-mg/mL and 60-mg/mL rifampin solution concentrations (0.04 ± 0.007 and 0.066 ± 0.014, respectively; P = .22). The elution-over-time of coated rifampin ESG, although not statistically significant, did seem to plateau and to reach a steady state by 50 hours and was confirmed by surface characteristics using atomic force microscopy. ConclusionsHaving studied two variables of rifampin coating techniques to Dacron ESGs, the authors propose a rapid real-time perioperative coating protocol by using a 10-mg/mL rifampin solution for a 10-minute incubation period. As rifampin loosely binds to Dacron ESGs by weak intermolecular forces, a rifampin-coated ESG would need to be inserted in a timely fashion to treat the diseased aorta and to deliver its antibiotic affect. A rapid perioperative coating protocol followed by immediate deployment makes our proposed technique especially useful in an urgent and unstable clinical scenario.

Initial Inoculation Concentration Does Not Affect Final Bacterial Colonization of In vitro Vascular Conduits.

Despite improved peri-operative care, prosthetic graft infections continue to cause substantial morbidity and mortality. Contemporary graft infection models have tested a conduit's infectability using varying concentrations without standardization. Using a static assay in vitro model, we sought to evaluate the impact of inoculation concentration on vascular conduit attachment. The 2-hour and 24-hour attachment of Staphylococcus aureus TCH1516 and Pseudomonas aeruginosa PA01-UW were determined on polytetrafluoroethylene (PTFE), Dacron®, nitinol, cobalt chromium, and Viabahn® (W.L. Gore and Associates, Newark, DE) endoprotheses. Individually and in combination, concentrations at 104, 105, 106, 107, and 108 were tested on 2-mm sections of each graft. After each time interval, the prosthetics were rinsed to remove non-attached bacteria, sonicated to release the attached bacteria, spiral plated, and then analyzed for the attached concentration. After two hours, the higher initial inoculation concentration translated into a higher attachment percentage, but the mean attachment percentage was only 14.8% in the 108 group. Pseudomonas aeruginosa had the greatest mean attachment across all material and concentration groups. The sequence of attachment on the conduits followed a constant order: Dacron, PTFE, cobalt, nitinol, and Viabahn with no difference between Dacron and PTFE. Although there were still differences at the 24-hour mark, the median attachment at each concentration was greater than the highest initial concentration (108). Initial attachment percentage is poor consistently regardless of inoculation concentration, however, Staphylococcus aureus and Pseudomonas aeruginosa are still able to achieve full attachment after 24 hours. A concentration of less than 107 should be used in vascular graft infection models to ensure adequate bacterial attachment.

Graft-Sparing Strategy for Thoracic Prosthetic Graft Infection.

Thoracic prosthetic graft infection is a rare but serious complication with no standard management. We reported our surgical experience on graft-sparing strategy for thoracic prosthetic graft infection. This study included patients who underwent graft-sparing surgery for thoracic prosthetic graft infection at Matsubara Tokushukai Hospital in Japan from January 2000 to October 2017. There were 17 patients included in the analyses, with a mean age at surgery of 71.0 ± 10.5 years; 11 were men. In-hospital mortality was observed in five patients (29.4%). Graft-sparing surgery for thoracic prosthetic graft infection is an alternative option particularly for early graft infection after hemiarch replacement.