The effect of gamma and microwave radiation sterilization on periodontological grafts for microbiological evaluation.

Periodontological grafts are materials used in dentistry to regenerate lost gingival soft tissues or bone parts. In the case of direct contact with blood, the possibility of disease transmission from the source to the patient is high. This source can be an animal or a human. Therefore, the sterilization of grafts before implanting to the patient is of significant importance. The purpose of this study was to evaluate gamma radiation and microwave sterilization processes from microbiological and sterility perspectives and to compare the effectiveness of these two sterilization methods. Grafts were irradiated with 2, 4, 5, 10, 25 and 50 kGy doses of gamma radiation. Another group of same materials was irradiated by microwave for 1, 2, 3 and 4 min at 24,500 MHz and 900 W. Gamma radiation and microwave sterilization methods were evaluated as successful at minimum doses as 5 kGy and 3 min, respectively. Both gamma and microwave sterilization successfu lly sterilized periodontological grafts coded as PBG1, HBG1, HL1, PDG1, MBG3, MDG2 and PDG3. Moreover, microwave sterilization can be used as an alternative novel method to gamma radiation sterilization.

Editor's Choice - Validation of the Management of Aortic Graft Infection Collaboration (MAGIC) Criteria for the Diagnosis of Vascular Graft/Endograft Infection: Results from the Prospective Vascular Graft Cohort Study.

OBJECTIVE: The timely management of vascular graft/endograft infection (VGEI) is crucial to a favourable outcome, yet can be challenging as there is no validated gold standard diagnostic test. Recently, a new case definition has been proposed by the Management of Aortic Graft Infection Collaboration (MAGIC) to close the diagnostic gap. The aim of this study was to validate the MAGIC criteria as a suggested diagnostic standard for the diagnosis of suspected VGEI in the prospective Vascular Graft Cohort study (VASGRA). METHODS: VASGRA is an open, prospective, observational cohort study. Prospective participants in VASGRA between 2013 and 2019 were included (257 patients; 137 with VGEI). The accuracy of the MAGIC criteria for a diagnosis of VGEI was evaluated retrospectively by calculating the sensitivity and specificity vs. the consensually adjudicated VASGRA infection status. RESULTS: The VASGRA cohort categorised 137 (53.3%) patients as "diseased" and 120 patients as "not diseased"; using the MAGIC criteria, 183/257 (71.2%) patients were considered to be "diseased". Thus, for the MAGIC criteria, a sensitivity of 99% (95% confidence interval [CI] 96-100) and a specificity of 61% (95% CI 52-70) were calculated. Considering suspected VGEI according to the MAGIC criteria as "not diseased" achieved congruent assessments of the VASGRA team and the MAGIC criteria, with a sensitivity of 93% and a specificity of 93%. The accuracy of the MAGIC criteria for the different graft locations were also compared. If the suspected VGEIs were assigned to the "not diseased" group, VGEIs of the thoracic aorta seemed to have a poorer sensitivity (86%; 95% CI 73-95) than the other graft locations. CONCLUSION: The current MAGIC criteria offer good sensitivity and specificity in the context of true infections but a reduced specificity for a possible VGEI.

Genetic diversity of clinical and environmental Mucorales isolates obtained from an investigation of mucormycosis cases among solid organ transplant recipients.

Mucormycoses are invasive infections by Rhizopus species and other Mucorales. Over 10 months, four solid organ transplant (SOT) recipients at our centre developed mucormycosis due to Rhizopus microsporus (n=2), R. arrhizus (n=1) or Lichtheimia corymbifera (n=1), at a median 31.5 days (range: 13-34) post-admission. We performed whole genome sequencing (WGS) on 72 Mucorales isolates (45 R. arrhizus, 19 R. delemar, six R. microsporus, two Lichtheimia species) from these patients, from five patients with community-acquired mucormycosis, and from hospital and regional environments. Isolates were compared by core protein phylogeny and global genomic features, including genome size, guanine-cytosine percentages, shared protein families and paralogue expansions. Patient isolates fell into six core phylogenetic lineages (clades). Phylogenetic and genomic similarities of R. microsporus isolates recovered 7 months apart from two SOT recipients in adjoining hospitals suggested a potential common source exposure. However, isolates from other patients and environmental sites had unique genomes. Many isolates that were indistinguishable by core phylogeny were distinct by one or more global genomic comparisons. Certain clades were recovered throughout the study period, whereas others were found at particular time points. In conclusion, mucormycosis cases could not be genetically linked to a definitive environmental source. Comprehensive genomic analyses eliminated false associations between Mucorales isolates that would have been assigned using core phylogenetic or less extensive genomic comparisons. The genomic diversity of Mucorales mandates that multiple isolates from individual patients and environmental sites undergo WGS during epidemiological investigations. However, exhaustive surveillance of fungal populations in a hospital and surrounding community is probably infeasible.

Brief Report: Willingness to Accept HIV-Infected and Increased Infectious Risk Donor Organs Among Transplant Candidates Living With HIV.

BACKGROUND: HIV-infected (HIV+) donor to HIV+ recipient (HIV D+/R+) transplantation might improve access to transplantation for people living with HIV. However, it remains unknown whether transplant candidates living with HIV will accept the currently unknown risks of HIV D+/R+ transplantation. METHODS: We surveyed transplant candidates living with HIV from 9 US transplant centers regarding willingness to accept HIV+ donor organs. RESULTS: Among 116 participants, the median age was 55 years, 68% were men, and 78% were African American. Most were willing to accept HIV+ living donor organs (87%), HIV+ deceased donor organs (84%), and increased infectious risk donor organs (70%). Some (30%) were concerned about HIV superinfection; even among these respondents, 71% were willing to accept an HIV D+ organ. Respondents from centers that had already performed a transplant under an HIV D+/R+ transplantation research protocol were more willing to accept HIV+ deceased donor organs (89% vs. 71%, P = 0.04). Respondents who chose not to enroll in an HIV D+/R+ transplantation research protocol were less likely to believe that HIV D+/R+ transplantation was safe (45% vs. 77%, P = 0.02), and that HIV D+ organs would work similar to HIV D- organs (55% vs. 77%, P = 0.04), but more likely to believe they would receive an infection other than HIV from an HIV D+ organ (64% vs. 13%, P < 0.01). CONCLUSIONS: Willingness to accept HIV D+ organs among transplant candidates living with HIV does not seem to be a major barrier to HIV D+/R+ transplantation and may increase with growing HIV D+/R+ transplantation experience.

Human microbiota-transplanted C57BL/6 mice and offspring display reduced establishment of key bacteria and reduced immune stimulation compared to mouse microbiota-transplantation.

Transplantation of germ-free (GF) mice with microbiota from mice or humans stimulates the intestinal immune system in disparate ways. We transplanted a human microbiota into GF C57BL/6 mice and a murine C57BL/6 microbiota into GF C57BL/6 mice and Swiss-Webster (SW) mice. Mice were bred to produce an offspring generation. 56% of the Operational Taxonomic Units (OTUs) present in the human donor microbiota established in the recipient mice, whereas 81% of the C57BL/6 OTUs established in the recipient C57BL/6 and SW mice. Anti-inflammatory bacteria such as Faecalibacterium and Bifidobacterium from humans were not transferred to mice. Expression of immune-related intestinal genes was lower in human microbiota-mice and not different between parent and offspring generation. Expression of intestinal barrier-related genes was slightly higher in human microbiota-mice. Cytokines and chemokines measured in plasma were differentially present in human and mouse microbiota-mice. Minor differences in microbiota and gene expression were found between transplanted mice of different genetics. It is concluded that important immune-regulating bacteria are lost when transplanting microbiota from humans to C57BL/6 mice, and that the established human microbiota is a weak stimulator of the murine immune system. The results are important for study design considerations in microbiota transplantation studies involving immunological parameters.

Abdominal Aortic Graft Infection Caused by stG485.0, ST29 Streptococcus dysgalactiae subsp. equisimilis.

In recent years, the prevalence of invasive Streptococcus dysgalactiae subsp. equisimilis (SDSE) infections has increased gradually throughout the world, including Japan. Here, we report the case of an abdominal aortic graft infection caused by stG485.0, ST29 SDSE in an elderly patient with diabetes. The patient was an 86-year-old man who had undergone surgery 10 years ago for treating a non-infected abdominal aortic aneurysm using a bifurcated graft. He was referred to our hospital after being suspected of having an abdominal aortic graft infection based on computed tomography (CT) scans. He underwent surgery to drain the pus that had accumulated between the aneurysm and graft. Although blood cultures were negative, the surgical specimen culture was positive for a ß-hemolytic group G streptococci, which was subsequently identified as SDSE using 16S ribosomal RNA sequencing. Genetic relationships deduced from emm and multilocus sequence typing revealed the isolate to be types stG485.0 and ST29, respectively. Although aortic aneurysm graft infection has a poor prognosis, we successfully rescued the patient through prompt surgery and identification of the responsible pathogen. This case indicates that attention must be paid toward possible SDSE infections in the field of vascular surgery.

Encuesta sobre el manejo de injertos del ligamento cruzado anterior contaminados accidentalmente / Survey on management of accidentally contaminated anterior cruciate ligament grafts

OBJETIVO: Encuestar a cirujanos de rodilla en Chile, sobre su conducta en contaminaciones accidentales del injerto, en reconstrucciones de ligamento cruzado anterior (LCA). MÉTODOS: Se realizó una encuesta anónima en relación a la incidencia, tratamiento y resultados clínicos de los injertos de LCA contaminados, a todos los médicos pertenecientes al área de traumatología y ortopedia asistentes al congreso Ateneo de rodilla 2015. RESULTADOS: Se encuestaron 54 médicos, 33 (61%) especialistas en cirugía de rodilla y 21 (39%) médicos en formación. De los cirujanos de rodilla, 15 (45%) reportaron al menos un caso de contaminación, de los cuales 12 (80%) informaron un único evento, 3 (20%) indicaron la eventualidad en 2, 3 y 5 ocasiones respectivamente, para un total de 22 injertos contaminados. De los cirujanos que reportaron injertos contaminados, 11 (73%) realizan 50 o más reconstrucciones al año. La decisión tomada en los casos de contaminación fue en 13 oportunidades (59%), lavar el injerto y utilizarlo de acuerdo al plan inicial; en 6 casos (27%), utilizar aloinjerto; en 2 ocasiones (9%), utilizar autoinjerto alternativo; y en 1 oportunidad (5%); triplicar el semitendinoso. Ninguno de los casos de contaminación reportó infecciones. CONCLUSIONES: En casos de una contaminación accidental, la mayoría de los cirujanos encuestados prefieren optar por la descontaminación del injerto y su utilización en la reconstrucción de acuerdo al plan inicial; para lo cual la clorhexidina y antibióticos sería la solución a usar de preferencia. NIVEL DE EVIDENCIA: Nivel V, opinión de experto.

OBJECTIVE: To survey knee surgeons who perform anterior cruciate ligament (ACL) reconstruction in Chile, about the management when ACL graft contamination occurs. METHODS: An anonymous survey was conducted to all physicians belonging to the area of traumatology and orthopedics who attended the 2015 annual Chilean Knee Society meeting. The survey questioned the incidence, treatment, and outcomes of ACL graft contaminations. RESULTS: Fifty-four physicians were surveyed, of which 33 (61%) where knee surgeons and 21 (39%) physicians in training. Of the 33 knee surgeons, 15 (45%) reported at least one contamination during their career. Of those 15, 12 (80%) had one event, and three surgeons (20%) informed having 2, 3, and 5 episodes respectively, for a total of 22 reported contaminated grafts. Of the surgeons who reported a contaminated graft, 11 (73%) performed 50 or more ACL reconstructions annually. In 13 opportunities (59%) the management for a contaminated graft was cleansing the graft and proceeding as planned. In 6 cases (27%) an allograft was used, in 2 occasions (9%) a different graft was harvested, and in 1 opportunity (5%) a semitendinosus graft triplication was performed. No infections in any of the contaminated grafts were reported. CONCLUSIONS: In case of accidental graft contamination during an ACL reconstruction, knee surgeons most often preferred disinfecting the graft and using it as the initial plan. LEVEL OF EVIDENCE: Level V, expert opinion.

Incidence and Risk Factors for Systemic Infection in Deceased Donors.

BACKGROUND: Organ donation shortage is the primary barrier to all organ transplantations.Infectious disease transmission through transplantation is considered controversial for organ retrieval. Donors with bacteremia and sepsis are considered controversial for organ retrieval due to potential transmission of an infectious agent to the recipient. METHODS: We retrospectively reviewed the results of bacterial culture of the donor's blood from peripheral venous or central venous catheter, urine, and bronchial aspiration from the organ donation registries of 102 potential donors from the Ministry of Health and Tissue Transplant Coordination Center of Istanbul Region in 2015. RESULTS: Of the 102 deceased donors included in the analysis, 24 (23.5%) had infection. The most common sites of infection were the bloodstream (41.6%) and the respiratory system (37.5%). The most common isolated pathogens of the bacterial cultures were Gram-positive bacteria (21), Gram-negative microorganisms (14), and Candida (1). The significant risk factor for infection was duration of stay at the intensive care unit (median: 5 day; 25-75%: 3-5 day) (odds ratio, 2.94; 95% confidence interval, 1.06-8.12; P < .05). The presence of infection in the donor accounted for a significant part of the reasons why the organs were not accepted for transplantation (kidneys 9%, liver 4%, heart 6%). CONCLUSIONS: The study showed that deceased donors with prolonged stays in the intensive care unit have an increased risk for developing nosocomial infections; so there is a need for establishing and enforcing the prevention and control of infection in possible donors.

Glomerulonephritis triggered by chronical aortic graft infection in a male with Loeys-Dietz syndrome: A case report.

RATIONALE: Glomerulonephritis triggered by a chronically infected graft is increasingly identified because of widely used implanted device. Removal of the aortic graft and sustained antibiotic therapy is the usual approach to maximize the chance of renal recovery, but as this case shows graft removal is not always possible. PATIENT CONCERNS: A 35-year-old man with intractable and recurrent fever had acute renal failure in sustained antibiotic therapy. DIAGNOSES: Renal biopsy suggested crescentic glomerulonephritis. fluorodeoxyglucose/positron emission tomography-computed tomography showed increased metabolic activity at the site of aortic graft, reminding that chronic infection of an implanted graft can lead to severe glomerulonephritis. TGFBR2 c.1133G>T mutation was observed in mutation analysis, which was reported to be associated with Loeys-Dietz syndrome. INTERVENTIONS: Although infection was properly controlled with appropriate antimicrobial treatment, his renal dysfunction did not improve. A short-term inclusion of low-dose corticosteroid significantly benefit without introducing harm. OUTCOMES: He partly recovered from renal injury. LESSONS: In patients with glomerulonephritis triggered by a long-duration infection, low-dose corticosteroid therapy may be considered when renal dysfunction secondary to nephritis does not improve after appropriate antimicrobial treatment.

A reliable method to avoid contamination during cartilage graft preparation in septorhinoplasty.

PURPOSE: The aim of the study is to determine the risk of contamination in the cartilage graft materials prepared on the swester table and those prepared in a sterile package, and to reveal a more reliable method by performing the microbiological examination of these materials. METHODS: Cartilages removed from the nasal septum were divided into four pieces. The first part (Sample A) was directly placed into the medium. Sample B was prepared by being crushed in a sterile package. Sample C was prepared on the auxiliary swester table, and Sample D was prepared on the main swester table actively used by surgery team. All samples were transferred in a 1 ml brain heart(BH) liquid medium. From each BH medium, 100 µl culture was performed on blood agar, eosin-methylene blue-lactose-sucrose agar and chocolate agar. RESULTS: Bacterial growth was detected in 2 of the samples A, in 4 of the samples B, in 24 of the samples C, and in 36 of the samples D. The number of patients with bacterial growth in the samples C and/or D despite no growth in the sample B was 35. When the samples A/B and C/D were compared in terms of bacterial growth, a significant difference was found in all matchings (p < 0.001 for all comparisons).  CONCLUSION: These findings showed that preparation of the cartilage grafts on the swester table was extremely risky for microbiological contamination. Arslan and his colleagues suggest that preparing a graft material in a sterile package is extremely simple, cheap, and it also reduces contamination risk significantly.

Posttransplant complications in adult recipients of intestine grafts without bowel decontamination.

BACKGROUND: Selective digestive decontamination is commonly used to decrease lumenal bacterial flora. Preoperative bowel decontamination may be associated with a lower wound infection rate but has not been shown to decrease risk of intra-abdominal abscess or lower leak rate for enteric anastomoses. Alternatively, the decontamination disrupts the normal flora of the gastrointestinal tract and may affect normal physiology, including immunologic function. This study reports complication rates of an intestine transplant program that has never used bowel decontamination. METHODS: All adult patients who underwent intestine transplant from 2003 to 2015 at a single center were reviewed. Posttransplant complications included intra-abdominal abscess, enteric fistula, and leak from the enteric anastomosis. Viral, fungal, and bacterial infections in the first year after transplant are reported. RESULTS: There were 184 adult patients who underwent deceased donor intestine transplant during the study period. Among these patients, 30% developed an infected postoperative fluid collection, 4 developed an enteric fistula (2%), and 16 had an enteric or anastomotic leak (8%). The rate of any bacterial infection was 91% in the first year, with a wound infection rate of 25%. Fungal infection occurred in 47% of patients. Rejection rates were 55% at 1 y for isolated intestine patients and 17% for multivisceral (liver inclusive) patients. CONCLUSIONS: Among this population of intestine transplant patients in which no bowel decontamination was used, rates of surgical complications, infections, and rejection were similar to those reported by other centers. Bowel decontamination provides no identifiable benefit in intestine transplantation.

Donor-Derived Candida dubliniensis Resulting in Perigraft Abscesses in a Liver Transplant Recipient Proven by Whole Genome Sequencing: A Case Report.

BACKGROUND: The transmission of fungi via transplant, although well-known, has not often been molecularly proven. We describe a case of donor-derived candidiasis verified by whole genome sequencing. CASE DESCRIPTION: The multiorgan donor was a 42-year-old woman with subdural hemorrhage. Procurement of the thoracic organs was performed followed by the abdominal organs. Tissue from the left bronchus grew Candida dubliniensis. The liver recipient was a 63-year-old woman with cryptogenic liver cirrhosis. She was noted to have worsening leukocytosis on postoperative day (POD) 9. Computed tomography of the abdomen and pelvis showed multiple rim-enhancing collections around the graft. Percutaneous drainage was performed. Fluid cultures grew C dubliniensis. C dubliniensis isolated from the donor's left bronchus and the liver recipient's abscesses were verified to be related by whole genome sequencing. We postulate that C dubliniensis colonizing the donor's transected trachea could have contaminated the inferior vena cava when the former was left open after explant of the donor's lungs. A portion of the donor's contaminated inferior vena cava was transplanted along with the liver graft, resulting in the infected collections in the recipient. CONCLUSIONS: Our case report highlights the importance of maintaining a sterile field during organ procurement, especially in a multiorgan donor whose organs are explanted in succession.

Fatal Fusarium infection manifesting as osteomyelitis following previous treatment with amphotericin B in a multi-visceral transplant: Case report and review of Fusarium infections in solid organ transplantation.

Invasive fusariosis in solid organ transplant is uncommon and usually presents as localized infection with favorable outcomes compared to hematologic malignancies or bone marrow transplants. We report the first case of Fusarium osteomyelitis in a patient following multi-visceral transplant and review Fusarium in organ transplant recipients and Fusarium bone and joint infections. Our case underscores the importance of early recognition and multidisciplinary approach to treatment and highlights potential failure to eradicate with amphotericin B monotherapy.

Post-keratoplasty Endophthalmitis by Multidrug-resistant Pseudomonas Aeruginosa With Positive Culture of the Contralateral Donor Cornea: A Case Report.

PURPOSE: The aim of this paper is to present the case report of a patient developing endophthalmitis after penetrating keratoplasty caused by a multidrug-resistant Pseudomonas aeruginosa, detected only in the contralateral donor tissue. CASE REPORT: A 77-year-old man underwent an uneventful penetrating keratoplasty with a preoperative culture-negative donor cornea; however, the fellow cornea grew multidrug-resistant Pseudomonas aeruginosa. The patient developed and was treated for endophthalmitis after penetrating keratoplasty, and aqueous and vitreous taps grew P. aeruginosa with antibiotic resistance identical to the isolate from the mate cornea. Sequence analysis of the 16S ribosomal gene from the two isolates and confirmation analyzing the sequence of P. aeruginosa heat shock protein gene (groES) were performed showing the same strain for both organisms. CONCLUSION: This case report documents the presence of the same multidrug-resistant P. aeruginosa causing endophthalmitis after penetrating keratoplasty and in the contralateral donor tissue, suggesting that we must be cautious in deciding to transplant tissues with positive culture in the contralateral donor cornea.

Donor Leucocytosis Predicts Bacterial and Fungal Contamination of the Preservation Solution in Visceral Organ Transplantation.

INTRODUCTION: Contamination of the preservation solution may contribute to septic complications that can occur after transplantation and cause higher morbidity and mortality among recipients. The aim of this study was to determine potential donor-related predictors of positive microbiological findings in the preservation solution. DESIGN: We retrospectively studied 16 donor parameters on data from our center for microbiological findings in the preservation solution used in solid-organ recovery. From January 2008 through December 2011, 976 solid organs were transplanted, and in 167, the solution was positive for contaminants. RESULTS: The most frequently detected contaminant was coagulase-negative staphylococci. Only the donor leucocyte count (cutoff at 9.1 × 109/L) predicted positive microbiological findings in the preservation solution ( P = .0024). Multivariable regression analysis found that donor age, donor sex, intensive care unit stay, total number of organs recovered, and leucocyte count differentiated various categories of potentially pathogenic bacteria. CONCLUSION: Donor leucocyte count higher than 9.1 × 109/L predicts contamination of preservation solution.

Contamination occurs during ACL graft harvesting and manipulation, but it can be easily eradicated.

PURPOSE: Why anterior cruciate ligament (ACL) autograft soaking in a 5 mg/ml vancomycin solution decreases the rate of infection has not been well-explained. One hypothesis is that grafts can be contaminated during harvesting and vancomycin eradicates the bacteria. The purpose of the present study is to assess how the vancomycin solution acts against ACL graft contamination during graft harvesting and preparation. METHODS: The study was carried out in three university hospitals over a period of 6 months. After sample size calculation, 50 patients were included in the study. Three samples were taken from each ACL graft. Sample 1 was obtained immediately after graft harvesting. After graft manipulation and preparation, the remaining tissue was divided into two parts. The raw sample was denominated sample 2 and sample 3 consisted of the rest of the remaining tissue that had been soaked in the vancomycin solution. All the cultures were incubated at 37 °C with 5% CO2 in agar plates for 7 days (aerobically) or 14 days (anaerobically) and inspected daily for microbial growth. Any bacterial growth and the number of colony forming units were reported. RESULTS: In seven cases (14%), either sample 1 or sample 2 was positive. In five of the cases (10%), only the sample after graft preparation was positive (sample 2). In two cases (4%), sample 1 and sample 2 were positive for the same bacteria. Isolated microorganisms corresponded to coagulase-negative staphylococci (CNS) and Propionibacterium acnes. No bacterial growth was observed in sample 3 (p < 0.001). Thus, none of those seven positive cases (0%) were positive after vancomycin soaking (p < 0.001). CONCLUSION: In the series, ACL graft harvesting and manipulation leads to bacterial contamination in 14% of the cases. This contamination is fully eradicated after soaking in the vancomycin solution in this series. LEVEL OF EVIDENCE: Level II.

Intestinal microbiota changes after solid organ transplantation: a systematic review

Introduction: The intestinal microbiota may undergo changes after solid organ transplantation. The purpose of this systematic review was to characterize the intestinal microbiota of patients undergoing solid organ transplantation. Methods: MEDLINE, EMBASE and Cochrane Library databases were searched from inception to July 21, 2017. Studies of patients undergoing solid organ transplantation that evaluated changes in intestinal microbiota composition and one of the following outcomes were included: post-transplant weight, new-onset diabetes after transplantation, delayed graft function, acute rejection, graft and patient survival, and post-transplant infections. Results: Out of 765 studies found in this search, two studies (86 patients) fulfilled inclusion criteria. Both studies assessed kidney transplantation recipients, and a reduction in bacterial species diversity after transplantation was observed. Changes in intestinal microbiota were associated with acute rejection in both studies. One study reported diarrhea and urinary infections, while the other one reported urinary and respiratory infections. None of them reported other outcomes of interest. Conclusion: Changes in intestinal microbiota were observed after kidney transplantation, and they were associated with higher incidence of acute rejection and infections in transplant recipients. However, data are still scarce and more studies are needed to evaluate if microbiota changes have an impact on post-transplant outcomes. (AU)

Vascular Graft Infection: Incidence and Potential Risk Factors.

PURPOSE: The purpose of this study was to identify factors that increase the risk of vascular graft infections (VGI) in patients following abdominal or lower extremity revascularization surgery. DESIGN: Retrospective, descriptive study. METHODS: We reviewed the electronic health records of 223 patients who had undergone abdominal or lower extremity revascularization procedures from July 2012 to November 2014, looking for factors associated with VGI. We reviewed 28 preoperative, intraoperative, and post-operative factors. Descriptive statistics (mean, range, and standard deviation) were used to describe the sample; χ was used to determine correlations between the risk factors and subsequent VGIs. The level of significance was determined at P = .05, with a confidence level of 95%. RESULTS: We identified 33 cases of VGIs for the 223 charts reviewed, yielding an incidence rate of 15%. Seventeen of the 33 patients with VGI (51.5%) were male. The average age of patients who experienced VGI was 60.9 years (standard deviation, 12.2 years, range, 29-81 years). Preoperative factors that were shown to show statistical significance for the development of VGI were sequential procedures (P = .003), diabetes mellitus (P = .002), hemoglobin A1c more than 7.0 (P = .0002), blood glucose more than 180 mg/dL (P = .0006), and lack of mobility (0.0097). Intraoperative factors associated with VGI were hemostatic agents applied to the surgical field intraoperatively (P = .003) and perioperative hypoxemia (P = .027). Postoperative factors associated with VGI were discharge from the hospital to skilled nursing facility or acute rehabilitation facility (P = .005) and unscheduled clinic visits (P = .008). CONCLUSION: We measured a 15% incidence of VGI and identified multiple pre-, intra-, and postoperative associated factors. Vigilance is required to prevent VGI and knowledge of specific risk factors is important.

Validation of microbiological testing in cardiovascular tissue banks: results of a quality round trial.

OBJECTIVES: Surgeons needing human cardiovascular tissue for implantation in their patients are confronted with cardiovascular tissue banks that use different methods to identify and decontaminate micro-organisms. To elucidate these differences, we compared the quality of processing methods in 20 tissue banks and 1 reference laboratory. We did this to validate the results for accepting or rejecting tissue. We included the decontamination methods used and the influence of antibiotic cocktails and residues with results and controls. The minor details of the processes were not included. METHODS: To compare the outcomes of microbiological testing and decontamination methods of heart valve allografts in cardiovascular tissue banks, an international quality round was organized. Twenty cardiovascular tissue banks participated in this quality round. The quality round method was validated first and consisted of sending purposely contaminated human heart valve tissue samples with known micro-organisms to the participants. The participants identified the micro-organisms using their local decontamination methods. RESULTS: Seventeen of the 20 participants correctly identified the micro-organisms; if these samples were heart valves to be released for implantation, 3 of the 20 participants would have decided to accept their result for release. Decontamination was shown not to be effective in 13 tissue banks because of growth of the organisms after decontamination. Articles in the literature revealed that antibiotics are effective at 36°C and not, or less so, at 2-8°C. The decontamination procedure, if it is validated, will ensure that the tissue contains no known micro-organisms. CONCLUSIONS: This study demonstrates that the quality round method of sending contaminated tissues and assessing the results of the microbiological cultures is an effective way of validating the processes of tissue banks. Only when harmonization, based on validated methods, has been achieved, will surgeons be able to fully rely on the methods used and have confidence in the consistent sterility of the tissue grafts. Tissue banks should validate their methods so that all stakeholders can trust the outcomes.