Microbiology of periprosthetic infections following implant-based breast reconstruction surgery: a multicentric retrospective study.

Introduction: Implant-based breast reconstruction (IBR) is the predominant breast reconstruction technique post-mastectomy, with bacterial infections being a significant complication affecting patient recovery and quality of life. The following study aimed to determine the microbiological features of the causative agents responsible for breast implant infections, with more attention paid to the comparative analysis of Gram-positive and Gram-negative bacteria and their presentation. Methods: We conducted a retrospective analysis of 214 patients who presented with periprosthetic infection and underwent implant removal following implant-based breast reconstruction at Humanitas Research Hospital and Istituto Europeo di Oncologia between January 2018 and March 2024. Results: The study revealed that Gram-positive bacteria were more prevalent, with Staphylococcus species, particularly Staphylococcus aureus, being the most isolated pathogen in both institutions (∼39.96%). In contrast, Gram-negative bacteria were less frequent, with a higher proportion of these pathogens being multi-resistant strains. A significant difference was observed (p = 0.007), indicating that individuals with normal BMI have a higher prevalence of Gram-positive infections (88.46%), whereas obese and overweight patients had higher proportions of Gram-negative infections (23.53% and 28.89%, respectively). In addition, smoking status was also significantly associated with pathogen distribution (p = 0.032), with active and past smokers being related to higher percentages of polymicrobial infections. Furthermore, positive prophylactic MSSA/MRSA swabs were significantly more associated with Staphylococcus aureus infections compared to those with negative results (p = <0.001). Conclusions: Gram-positive bacteria, especially Staphylococcus species, dominate the microbiological landscape of implant-based breast reconstruction (IBR) infections. Our findings provide insights into this critical issue, facilitating a more precise choice of empiric antibiotic treatment and prevention strategies. This analysis underscores the necessity for prophylactic protocols and therapeutic approaches tailored to the predominant bacterial groups. Further research is needed to explore long-term trends and resistance mechanisms to improve patient management.

Perioperative infection prevention during inflatable penile prosthesis surgery: a narrative review.

Background and Objective: Penile prostheses are an option for the management of erectile dysfunction (ED). Over the years penile prosthesis surgery has become increasingly safe owing to improvements such as antibiotic usage, coated devices, and surgical techniques. However, infection remains a dreaded complication during prosthesis surgery. Efforts to minimize risk of infection in the perioperative period have been extensively studied. Herein, we performed a narrative review on preoperative, intraoperative, and postoperative strategies for infection prevention during placement of a penile prosthesis with a comparison of infection prevention strategies to other surgical fields. Methods: A literature review was performed using PubMed and Google Scholar. Studies evaluating perioperative management of penile prosthesis infection were included. The following search terms were used to for our literature search: penile prosthesis, inflatable penile prosthesis, infection, prevention, perioperative management. Articles were graded based on the 2011 Oxford Centre for Evidence Based Medicine (OCEBM) guidelines and a table was generated with each intervention discussed and its level of evidence based on current literature. Key Content and Findings: Optimization of patient's comorbid conditions can help reduce risk during prosthesis operations. Monitoring and optimizing a patient's glycemic control has been investigated, but the current literature does not necessarily support a strict hemoglobin A1c (HbA1c) or pre-operative blood glucose level. Surgical field preparation using chlorhexidine-based solutions has been shown to be superior to iodine-based solutions. Appropriately selected peri-operative antibiotics have also been shown to reduce infection risk. Intraoperatively, the use of coated devices in addition to a 'no touch' technique have been shown to significantly reduce the risk of inflatable penile prosthesis (IPP) infection. Post operatively, available evidence of antibiotic use has not been demonstrated to be effective in reducing infection rates. Conclusions: Surgical infection following placement of an IPP is a devastating and morbid complication with infection rate up as high as 1-3% in virgin cases and 7-18% in revision cases. While perioperative techniques exist and have reduced risk of infection, more prospective data is needed to evaluate the clinical significance of these different approaches. More research in these areas, along with future options such as nanoparticles, antibiotic coated suture, and next generation sequencing (NGS) for bacterial pathogens, may shed light on further ways to optimize infection reduction strategies for prosthesis surgery.

Study on the Antibacterial Activity and Bone Inductivity of Nanosilver/PLGA-Coated TI-CU Implants.

Background: Implants are widely used in the field of orthopedics and dental sciences. Titanium (TI) and its alloys have become the most widely used implant materials, but implant-associated infection remains a common and serious complication after implant surgery. In addition, titanium exhibits biological inertness, which prevents implants and bone tissue from binding strongly and may cause implants to loosen and fall out. Therefore, preventing implant infection and improving their bone induction ability are important goals. Purpose: To study the antibacterial activity and bone induction ability of titanium-copper alloy implants coated with nanosilver/poly (lactic-co-glycolic acid) (NSPTICU) and provide a new approach for inhibiting implant-associated infection and promoting bone integration. Methods: We first examined the in vitro osteogenic ability of NSPTICU implants by studying the proliferation and differentiation of MC3T3-E1 cells. Furthermore, the ability of NSPTICU implants to induce osteogenic activity in SD rats was studied by micro-computed tomography (micro-CT), hematoxylin-eosin (HE) staining, masson staining, immunohistochemistry and van gieson (VG) staining. The antibacterial activity of NSPTICU in vitro was studied with gram-positive Staphylococcus aureus (Sa) and gram-negative Escherichia coli (E. coli) bacteria. Sa was used as the test bacterium, and the antibacterial ability of NSPTICU implanted in rats was studied by gross view specimen collection, bacterial colony counting, HE staining and Giemsa staining. Results: Alizarin red staining, alkaline phosphatase (ALP) staining, quantitative real-time polymerase chain reaction (qRT-PCR) and western blot analysis showed that NSPTICU promoted the osteogenic differentiation of MC3T3-E1 cells. The in vitro antimicrobial results showed that the NSPTICU implants exhibited better antibacterial properties. Animal experiments showed that NSPTICU can inhibit inflammation and promote the repair of bone defects. Conclusion: NSPTICU has excellent antibacterial and bone induction ability, and has broad application prospects in the treatment of bone defects related to orthopedics and dental sciences.

Prophylactic absorbable antibiotic beads for prepectoral implant-based breast reconstruction: A single institution early experience.

Infection after implant-based breast reconstruction remains challenging, with infection rates up to 24%. Best clinical practice indicates prophylactic oral antibiotics are ineffective at preventing infection. Absorbable antibiotic beads have been routinely used in other surgical subspecialties such as orthopedic and vascular procedures for continuous local antibiotic delivery to the surgical site when implants are placed. Biodegradable calcium sulfate antibiotic beads have been shown to normalize incidence of infection when used prophylactically for a high-risk prepectoral patient population. The purpose of this study is to evaluate the effect of prophylactic biodegradable antibiotic beads when used non-selectively for all prepectoral immediate tissue expander (TE) reconstruction. Patients who underwent mastectomy and immediate prepectoral TE reconstruction on the same day between 2018 and 2024 were reviewed. Patients were divided into two groups: those who received antibiotic beads (Group 1) and those who did not (Group 2). Absorbable calcium-sulfate beads were reconstituted with 1 g vancomycin and 240 mg gentamicin. There were 33 patients (63 TEs) in Group 1 and 330 patients (545 TEs) in Group 2. TE loss was present in 1.5% (1/65 TEs) Group 1 compared to 9.4% (51/545 TEs) in Group 2 (p = 0.032). The mean follow-up time was 178 days (range 93-266 days). Prophylactic biodegradable antibiotic beads used during immediate tissue expander reconstruction decreased implant loss rate. There was one occurrence of SSI in the antibiotic bead group. Antibiotic beads may potentially decrease complications in immediate TE reconstruction when used non-selectively for all patients.

Reconstructive breast implant-related infections: Prevention, diagnosis, treatment, and pearls of wisdom.

Implant-based reconstructions are increasingly utilized following mastectomy in the prevention and treatment of breast cancer. However, these implants are associated with a high rate of infection, which is a major complication that can lead to implant removal, delay in adjuvant radiation and chemotherapy, and increase in health care costs. Early clinical signs and symptoms of infection, such as erythema, warmth, and tenderness, are challenging to discern from expected postsurgical responses. Furthermore, when atypical features are present or the patient's condition does not improve on adequate antimicrobials, the clinician should be prompted to consider an alternative noninfectious etiology. Herein we highlight the key elements of the preventive, diagnostic, and multidisciplinary therapeutic approach to salvaging the infected breast implant; review several infectious disease mimickers; and provide many pearls of wisdom that the practicing clinician must be familiar with and be able to manage in an effective and successful manner.

Current Emerging Concepts on the Pathogenesis of Periimplant Diseases: A Narrative Review.

PURPOSE: To describe the emerging evidence concerning etiologic factors and pathophysiologic mechanisms involved in peri-implant inflammatory diseases. MATERIALS AND METHODS: An electronic search for articles published until November 2022 was conducted in MEDLINE by three independent reviewers to identify the manuscripts' reporting data on etiologic factors and pathophysiologic mechanisms associated with peri-implant diseases. RESULTS: Current evidence suggests that peri-implant mucositis and peri-implantitis are inflammatory conditions linked to a microbial challenge. However, in recent years there has been increasing evidence indicating that certain peri-implant inflammatory conditions may not be primarily related to biofilm-mediated infectious processes but rather to other biologic mechanisms, such as a foreign body response. CONCLUSIONS: Current evidence in the dental and medical literature opens new avenues for a more complex interpretation of the etiopathogenetic factors involved in peri-implant diseases. A better understanding of various factors related to the host response, including dysbiosis mechanisms associated with changes in microbiota composition, is necessary for a more precise physiopathologic characterization of these diseases.

Antibacterial activities of titanium dioxide (TiO2) nanotube with planar titanium silver (TiAg) to prevent orthopedic implant infection.

BACKGROUND: Orthopedic implant infection has become a common catastrophic complication after various orthopedic implants, which can lead to prolonged use of antibiotics and even surgical failure. The quality of care (QoC) of orthopedic implant infection is very important. METHODS: Titanium dioxide (TiO2) nanotube array with planar TiAg was prepared, and their antibacterial rates were tested. 400 patients hospitalized in the Department of Orthopedics of Wuhan Fourth Hospital from May 2019 to May 2020 were selected as controls (before QoC evaluation system of orthopedics), and 400 patients hospitalized from June 2020 to June 2021 were selected as observation group (after QoC evaluation system of orthopedics). RESULTS: Regardless of Staphylococcus aureus or Escherichia coli, the antibacterial rate of TiO2 nanotube array with planar TiAg was clearly higher than that of pure iron film on the 10th and 20th days (P < 0.05). The accuracy of hospitalization assessment, disease assessment, adverse event intervention, nursing record filing and nursing satisfaction in observation group were higher as against controls (P < 0.05). CONCLUSION: The TiO2 nanotube array with planar TiAg has good antibacterial property, which can effectively prevent orthopedic implant infection. The construction of QoC evaluation system for orthopedic specialists can effectively improve the QoC of orthopedic specialists.

Listeria innocua infection in an old case of total knee replacement - an unusual case report.

Prosthetic implant-associated arthritis due to Listeria is mostly reported for Listeria monocytogenes. Here, we describe a patient who underwent total knee replacement 12 years ago and presented with pain, tenderness, redness and local rise in temperature in the right knee. Purulent fluid was aspirated. Upon microbiological analysis, culture yielded Listeria innocua. L. innocua is rare. Listeria is not reported as a contaminant and routine cultures may be negative. Because of the long interval between surgery and the onset of symptoms, clinical suspicion, radiological investigations and analysing multiple samples are of immense help.

Staphylococcus aureus surface attachment selectively influences tolerance against charged antibiotics.

The threat of infection during implant placement surgery remains a considerable burden for millions of patients worldwide. To combat this threat, clinicians employ a range of anti-infective strategies and practices. One of the most common interventions is the use of prophylactic antibiotic treatment during implant placement surgery. However, these practices can be detrimental by promoting the resilience of biofilm-forming bacteria and enabling them to persist throughout treatment and re-emerge later, causing a life-threatening infection. Thus, it is of the utmost importance to elucidate the events occurring during the initial stages of bacterial surface attachment and determine whether any biological processes may be targeted to improve surgical outcomes. Using gene expression analysis, we identified a cellular mechanism of S. aureus which modifies its cell surface charge following attachment to a medical grade titanium surface. We determined the upregulation of two systems involved in the d-alanylation of teichoic acids and the lysylation of phosphatidylglycerol. We supported these molecular findings by utilizing synchrotron-sourced attenuated total reflection Fourier-transform infrared microspectroscopy to analyze the biomolecular properties of the S. aureus cell surface following attachment. As a direct consequence, S. aureus quickly becomes substantially more tolerant to the positively charged vancomycin, but not the negatively charged cefazolin. The present study can assist clinicians in rationally selecting the most potent antibiotic in prophylaxis treatments. Furthermore, it highlights a cellular process that could potentially be targeted by novel technologies and strategies to improve the outcome of antibiotic prophylaxis during implant placement surgery. STATEMENT OF SIGNIFICANCE: The antibiotic tolerance of bacteria in biofilm is a well-established phenomenon. However, the physiological adaptations employed by Staphylococcus aureus to increase its antibiotic tolerance during the early stages of surface attachment are poorly understood. Using multiple techniques, including gene expression analysis and synchrotron-sourced Fourier-transform infrared microspectroscopy, we generated insights into the physiological response of S. aureus following attachment to a medical grade titanium surface. We showed that this phenotypic transition enables S. aureus to better tolerate the positively charged vancomycin, but not the negatively charged cefazolin. These findings shed light on the antibiotic tolerance mechanisms employed by S. aureus to survive prophylactically administered antibiotics and can help clinicians to protect patients from infections.

Extracellular Proteins Isolated from L. acidophilus as an Osteomicrobiological Therapeutic Agent to Reduce Pathogenic Biofilm Formation, Regulate Chronic Inflammation, and Augment Bone Formation In Vitro.

Periprosthetic joint infection (PJI) is a challenging complication that can occur following joint replacement surgery. Efficacious strategies to prevent and treat PJI and its recurrence remain elusive. Commensal bacteria within the gut convey beneficial effects through a defense strategy named "colonization resistance" thereby preventing pathogenic infection along the intestinal surface. This blueprint may be applicable to PJI. The aim is to investigate Lactobacillus acidophilus spp. and their isolated extracellular-derived proteins (LaEPs) on PJI-relevant Staphylococcus aureus, methicillin-resistant S. aureus, and Escherichia coli planktonic growth and biofilm formation in vitro. The effect of LaEPs on cultured macrophages and osteogenic, and adipogenic human bone marrow-derived mesenchymal stem cell differentiation is analyzed. Data show electrostatically-induced probiotic-pathogen species co-aggregation and pathogenic growth inhibition together with LaEP-induced biofilm prevention. LaEPs prime macrophages for enhanced microbial phagocytosis via cathepsin K, reduce lipopolysaccharide-induced DNA damage and receptor activator nuclear factor-kappa B ligand expression, and promote a reparative M2 macrophage morphology under chronic inflammatory conditions. LaEPs also significantly augment bone deposition while abating adipogenesis thus holding promise as a potential multimodal therapeutic strategy. Proteomic analyses highlight high abundance of lysyl endopeptidase, and urocanate reductase. Further, in vivo analyses are warranted to elucidate their role in the prevention and treatment of PJIs.

Ultrasound-Stimulated "Exocytosis" by Cell-Like Microbubbles Enhances Antibacterial Species Penetration and Immune Activation Against Implant Infection.

Host immune systems serving as crucial defense lines are vital resisting mechanisms against biofilm-associated implant infections. Nevertheless, biofilms hinder the penetration of anti-bacterial species, inhibit phagocytosis of immune cells, and frustrate host inflammatory responses, ultimately resulting in the weakness of the host immune system for biofilm elimination. Herein, a cell-like construct is developed through encapsulation of erythrocyte membrane fragments on the surface of Fe3 O4 nanoparticle-fabricated microbubbles and then loaded with hydroxyurea (EMB-Hu). Under ultrasound (US) stimulation, EMB-Hu undergoes a stable oscillation manner to act in an "exocytosis" mechanism for disrupting biofilm, releasing agents, and enhancing penetration of catalytically generated anti-bacterial species within biofilms. Additionally, the US-stimulated "exocytosis" by EMB-Hu can activate pro-inflammatory macrophage polarization and enhance macrophage phagocytosis for clearance of disrupted biofilms. Collectively, this work has exhibited cell-like microbubbles with US-stimulated "exocytosis" mechanisms to overcome the biofilm barrier and signal macrophages for inflammatory activation, finally achieving favorable therapeutic effects against implant infections caused by methicillin-resistant Staphylococcus aureus (MRSA) biofilms.

Defeating the Hidden Foe: Antibiotic Therapy and Clinical Outcomes of Cutibacterium acnes Spinal Implant Infections.

Background: Cutibacterium acnes can cause spinal implant infections. However, little is known about the optimal medical management and outcomes of C. acnes spinal implant infections (CSII). Our study aims to describe the management of patients with CSII and evaluate the clinical outcomes. Methods: We performed a retrospective cohort study of patients aged 18 years or older who underwent spinal fusion surgery with instrumentation between January 1, 2011, and December 31, 2020, and whose intraoperative cultures were positive for C. acnes. The primary outcome was treatment failure based on subsequent recurrence, infection with another organism, or unplanned surgery secondary to infection. Results: There were 55 patients with a median follow-up (interquartile range) of 2 (1.2-2.0) years. Overall, there were 6 treatment failures over 85.8 total person-years, for an annual rate of 7.0% (95% CI, 2.6%-15.2%). Systemic antibiotic treatment was given to 74.5% (n = 41) of patients for a median duration of 352 days. In the subgroup treated with systemic antibiotics, there were 4 treatment failures (annual rate, 6.3%; 95% CI, 1.7%-16.2%), all of which occurred while on antibiotic therapy. Two failures occurred in the subgroup without antibiotic treatment (annual rate, 8.8%; 95% CI, 1.1%-31.8%). Conclusions: Our study found that the estimated annual treatment failure rate was slightly higher among patients who did not receive antibiotics. Of the 6 failures observed, 4 had recurrence of C. acnes either on initial or subsequent treatment failures. More studies are warranted to determine the optimal duration of therapy for CSII.

Comparing the efficacy of antimicrobial pocket-irrigation protocols in an in vivo breast implant infection model.

BACKGROUND: Breast implant infection and biofilm formation are major concerns in reconstructive and esthetic breast surgery, with significant medical and economic consequences. Staphylococcus is the common pathogen, with rapidly increasing rates of methicillin-resistant Staphylococcus aureus (MRSA). There is no consensus on prevention practices. This study compares the effect of several pocket irrigation and antibiotic prophylaxis regimens on implant colonization and biofilm formation in an established rat model of MRSA-infected silicone breast implants. METHODS: Silicone discs were inserted in a sub-pectoral pocket in 57 rats (114 implants). Implant infection was induced by injection of free planktonic MRSA into the surgical pocket. Rats were allocated to study groups treated by different antimicrobial protocols: pocket irrigation with vancomycin, povidone-iodine, or saline. Each group was divided into subgroups treated with or without additional peri-operative systemic vancomycin. Implant colonization or overt infection was assessed at post-operative day 14 both clinically and by cultures. RESULTS: Pocket irrigation with vancomycin prevented contamination in 87% of implants. Irrigation and systemic vancomycin prevented contamination in 100% of implants with no difference between a single preoperative dose and a 48-h regimen. Systemic vancomycin alone or irrigation with povidone-iodine alone resulted in 100% contamination rates. CONCLUSIONS: In this in vivo model, combination of systemic vancomycin with vancomycin pocket irrigation was the most effective regimen, preventing contamination in 100% of implants. Continuation of post-operative antibiotic treatment showed no added advantage.

Chitosan Sponges Are Associated With Higher Rates of Wound Complications Compared to Calcium Sulfate Beads.

Background In this study, we aimed to determine if there is a difference in the rates of wound dehiscence, delayed union, nonunion, and unanticipated surgery after the use of bioabsorbable local antibiotic-delivery systems (LADS), specifically comparing antibiotic-impregnated calcium sulfate pellets (Osteoset-T, Wright Medical Technology Inc., Arlington, TN, USA, hereafter referred to as beads) and chitosan sponge (Sentrex BioSponge, Bionova Medical, Germantown, TN, USA, hereafter referred to as sponges) in the management of acute and chronic extremity wounds. Methodology We conducted a retrospective comparative cohort study in the setting of a level 1 trauma center. All patients who received either beads or sponges as an adjunct to surgical debridement from January 2010 to December 2017 were included, and 136 patients met the inclusion criteria. The intervention studied was extremity wounds that were treated with bioabsorbable LADS, either beads or sponges. The main outcome measurement was wound dehiscence and the need for unanticipated surgery. Results Of the 136 patients in the study cohort, 78% (106/136) were treated with beads, and 22% (30/136) were treated with sponges. Of the 136 patients, 50 (37%) experienced wound dehiscence, and 49 patients required unanticipated surgery. Overall, 62% (31/50) of patients with wound dehiscence and 67.4% (33/49) of patients requiring unanticipated surgery were seen in the bead cohort (p = 0.0001 and 0.025, respectively). However, in multivariable analyses, we found that the odds of having wound dehiscence and undergoing unanticipated surgery were, respectively, 4.9 (p = 0.001) and 2.8 (p = 0.021) times more likely to occur in the sponge than in the bead group. Conclusions Sentrex sponges appear to be associated with higher rates of wound dehiscence and the need for unanticipated surgery compared to Osteoset beads.

An Antibacterial Polypeptide Coating Prepared by In Situ Enzymatic Polymerization for Preventing Delayed Infection of Implants.

Delayed implant-associated infection is an important challenge, as the treatment involves a high risk of implant replacement. Mussel-inspired antimicrobial coatings can be applied to coat a variety of implants in a facile way, but the adhesive 3,4-dihydroxyphenylalanine (DOPA) group is prone to oxidation. Therefore, an antibacterial polypeptide copolymer poly(Phe7-stat-Lys10)-b-polyTyr3 was designed to prepare the implant coating upon tyrosinase-induced enzymatic polymerization for preventing implant-associated infections. Both poly(Phe7-stat-Lys10) and polyTyr3 blocks have specific functions: the former provides intrinsic antibacterial activity with a low risk to induce antimicrobial resistance, and the latter is attachable to the surface of implants to rapidly generate an antibacterial coating by in situ injection of polypeptide copolymer since tyrosine could be oxidized to DOPA under catalyzation of skin tyrosinase. This polypeptide coating with excellent antibacterial effect and desirable biofilm inhibition activity is promising for broad applications in a multitude of biomedical materials to combat delayed infections.

Did the National Ban on Bacitracin Irrigation Affect Infection Rates in Implant-Based Breast Reconstruction? An Analysis of a National Database.

INTRODUCTION: The current standard of practice in implant-based breast reconstruction is irrigation of the mastectomy pocket with antimicrobial solution before implant placement. Prior to being banned and formally recalled in January 2020, bacitracin was a very commonly utilized antibiotic. This study characterizes the effects of the national bacitracin ban on implant-based breast reconstruction infection rates by using a nationwide database to compare complication rates before and after bacitracin was banned. MATERIALS AND METHODS: The American College of Surgeons National Surgical Quality Improvement (ACS-NSQIP) database was queried retrospectively for all patients who underwent implant-based breast reconstruction before the bacitracin ban (2012-2019) and afterwards (2020). Demographics, comorbidities, and complications were collected. Univariate analysis and multivariate analysis were conducted to determine if there were significant changes in wound complications, local wound infections, and systemic infections between the 2 case-control matched cohorts. RESULTS: A total of 37,126 patients were in the pre-ban cohort and 6333 patients were in the post-ban cohort. Before matching, there were significant differences in race distribution, BMI, ASA class, inpatient vs. outpatient status, preoperative smoking, and preoperative diabetes mellitus (all P < .05). After case-control matching, there were 6313 patients in each cohort. Univariate analysis revealed differences in postoperative superficial and organ space surgical site infection, wound complications/infections, all cause complications, and reoperations (all P < .05). Multivariate analysis showed that patients who underwent breast reconstruction before the ban had decreased odds of having wound infections, related infections, all cause complications, and reoperations (all P < .05). CONCLUSION: This study provides a macroscopic view into the effects of the formal injectable bacitracin ban on breast reconstruction outcomes. Patients who underwent implant-based breast reconstruction after the ban of injectable bacitracin had higher odds of developing wound infections, related infections, and reoperations. More study into suitable alternatives to injectable bacitracin for surgical site antimicrobial irrigation is warranted.

A case of mediastinal abscess and infected aortic aneurysm caused by dissemination of Mycobacterium abscessus subsp. massiliense pulmonary disease.

An 81-year-old man was admitted to our hospital because of fever and malaise that had persisted for 3 months. The patient had undergone two aortic valve replacements, 10 and 5 years previously, because of aortic valve regurgitation and infectious endocarditis. He also had had asymptomatic Mycobacterium abscessus complex (MABC) pulmonary disease for the two previous years. Contrast-enhanced computed tomography showed a mediastinal abscess and an ascending aortic aneurysm. Mycobacterium abscessus subsp. massiliense was cultured from his blood, suggesting the aortic aneurysm was secondary to infection of an implanted device. After enlargement over only a few days, a leakage of contrast medium to the mediastinal abscess was found on computed tomography. The patient was diagnosed with rupture of an infectious aortic aneurysm, and emergency aortic replacement and drainage of the mediastinal abscess were successful. The patient was treated with several antibiotics, including meropenem, amikacin, and clarithromycin, and his general condition improved. Cultures from both the mediastinal abscess and a pericardial patch that was placed at the time of surgery 5 years previously revealed MABC. In our case, the infected aortic aneurysm most likely resulted from MABC pulmonary disease rather than from previous intraoperative contamination. This route of infection is rare. Physicians should be aware of the possibility of dissemination and subsequent infection of implants related to MABC pulmonary disease.

Is Instillational Topical Negative Pressure Wound Therapy in Peri-Prosthetic Infections of the Breast Effective? A Pilot Study.

Peri-prosthetic breast infections pose a risk of severe complications after breast implant surgery. The need to remove the breast implant, control the infection and perform additional surgical procedures are the consequences. Reimplantation of an alloplastic implant is only appropriate after an infection-free interval. In this retrospective cohort study, we investigated the effectiveness of negative pressure wound treatment with instillation and dwell time (NPWTi-d) on peri-prosthetic breast infections in combination with implant removal and antibiotic therapy. Twelve patients treated with NPWTi-d due to breast implant infection were included in the study. The bacterial burden was analyzed using wound swabs before and after NPWTi-d. Additionally, laboratory values were determined before NPWTi-d and immediately before wound closure. A total of 13 peri-prosthetic breast infections in 12 patients were treated using implant removal and NPWTi-d. In 76.9% (n = 10) of the cases, the patients had undergone alloplastic breast reconstruction following cancer-related mastectomy, whereas 23.1% (n = 3) of the patients had undergone breast augmentation for cosmetic reasons. The bacterial burden in the breast pocket decreased statistically significant after implant removal and NPWTi-d. No shift from Gram-positive to Gram-negative bacteria was observed. Inflammatory markers rapidly decreased following treatment. NPWTi-d had a positive impact on the healing process after peri-prosthetic breast infections, leading to a decrease in bacterial burden within the wounds and contributing to uneventful healing. Therefore, secondary reimplantation of breast prostheses might be positively influenced when compared to conventional implant removal and simple secondary closure. Further studies are required to conclusively establish the beneficial long-term effects of using NPWTi-d for the treatment of peri-prosthetic breast infections.

Diagnosis of Spinal Infection with Alpha-defensin Lateral Flow Test: A Preliminary Report.

Introduction: The alpha-defensin lateral flow test has been used in periprosthetic joint infection as a diagnostic support tool because of its simplicity and speed. However, the test has not been used to diagnose spinal infections. The purpose of this study was to investigate the efficacy of the alpha-defensin lateral flow test for diagnosing spinal infections. Methods: The subjects were 11 patients who were suspected of having spinal infections from October 2019 to August 2021 and underwent biopsies at a single institution. There were nine male and two female patients, with an average age of 60.7 (14-87) years. For diagnosing infection, the patient's consent for biopsy was obtained, and the sample was collected by computed tomography-guided aspiration biopsy or open biopsy at the site considered to be a possible abscess. The samples were subjected to a bacterial culture test, an acid-fast bacillus culture test, and an alpha-defensin lateral flow test (SynovasureⓇ lateral flow test; Zimmer Biomet, IN, USA). Results: Of the 11 suspected spinal infections, the alpha-defensin lateral flow test was positive in 8 cases, negative in 2 cases, and undeterminable in 1 case. Of the 10 cases excluding the undeterminable case, the definitive diagnosis was 9 cases of spinal infection (spondylitis: 6 cases, spinal implant infection: 3 cases) and 1 case of vertebral body fracture. The alpha-defensin lateral flow test demonstrated a sensitivity of 88.9%, a specificity of 100%, a positive predictive value of 100%, and a negative predictive value of 50%. The biopsy sample culture test demonstrated a sensitivity of 77.8%, a specificity of 100%, a positive predictive value of 100%, and a negative predictive value of 33.3%. Conclusions: We suggested that the alpha-defensin lateral flow test might be useful as a diagnostic support tool for spinal infections.