Ventricular assist device-related infections and solid organ transplantation-Guidelines from the American Society of Transplantation Infectious Diseases Community of Practice

Fungal Foe and Mechanical Hearts: A Retrospective Case Series on Candida auris Bloodstream Infection With Left Ventricular Assist Devices

No guidelines currently exist for the management of Candida auris bloodstream infection in patients with left ventricular assist devices (LVADs). We aim to share our management experience through this retrospective case series outlining 15 episodes of C auris candidemia identified in 7 patients over 18 months. The initial source of candidemia was central venous catheter in 5 patients, driveline exit site infection in 1 patient, and possible pump infection in 1 patient. All patients were initially treated with micafungin. Despite susceptibility to micafungin, 4 patients experienced recurrent C auris candidemia. All patients died within 1 year of their first episode of C auris candidemia. Source control is challenging in patients with LVADs, and strict infection prevention measures should be practiced. More studies are needed to evaluate the role of newer antifungal agents, use of combination antifungal regimens, and impact on morbidity in patients with LVADs.

Management of infectious disease syndromes in thoracic organ transplants and mechanical circulatory device recipients: a Delphi panel

PURPOSE

Antimicrobial misuse contributes to antimicrobial resistance in thoracic transplant (TTx) and mechanical circulatory support (MCS) recipients. This study uses a modified Delphi method to define the expected appropriate antimicrobial prescribing for the common clinical scenarios encountered in TTx and MCS recipients.

METHODS

An online questionnaire on managing 10 common infectious disease syndromes was submitted to a multidisciplinary Delphi panel of 25 experts from various disciplines. Consensus was predefined as 80% agreement for each question. Questions where consensus was not achieved were discussed during live virtual live sessions adapted by an independent process expert.

RESULTS

An online survey of 62 questions related to 10 infectious disease syndromes was submitted to the Delphi panel. In the first round of the online questionnaire, consensus on antimicrobial management was reached by 6.5% (4/62). In Round 2 online live discussion, the remaining 58 questions were discussed among the Delphi Panel members using a virtual meeting platform. Consensus was reached among 62% (36/58) of questions. Agreement was not reached regarding the antimicrobial management of the following six clinical syndromes: (1) Burkholderia cepacia pneumonia (duration of therapy); (2) Mycobacterium abscessus (intra-operative antimicrobials); (3) invasive aspergillosis (treatment of culture-negative but positive BAL galactomannan) (duration of therapy); (4) respiratory syncytial virus (duration of antiviral therapy); (5) left ventricular assist device deep infection (initial empirical antimicrobial coverage) and (6) CMV (duration of secondary prophylaxis).

CONCLUSION

This Delphi panel developed consensus-based recommendations for 10 infectious clinical syndromes seen in TTx and MCS recipients.

Pericardial Closure With Expanded Polytetrafluoroethylene Patch in Left Ventricular Assist Device Surgery

To reduce adhesions after left ventricular assist device (LVAD) implantation, pericardial closure using an expanded polytetrafluoroethylene (ePTFE) patch has been suggested. However, as foreign material, ePTFE patches could increase the risk of infectious complications. In this single-center retrospective study, we investigated outcomes of pericardial closure using an ePTFE patch in LVAD implantation. We included all patients who underwent LVAD implantation at our center between 2011 and 2020 (n = 166). Primary endpoint was development of mediastinitis at any point of time between LVAD implantation and heart transplantation (HTx) or death. Secondary endpoint was overall survival. Preoperative and postoperative clinical data were collected to ensure comparability between the groups. We included 166 patients with LVAD. A total of 116 patients (70%) underwent pericardial closure using an ePTFE patch. There were significant differences between the groups in treatment setting, previous cardiac surgery, Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) level, development of driveline infection, and HTx. Patients with an ePTFE patch developed mediastinitis more frequently (16%) than patients without ePTFE patch (4%) ( p = 0.039). A significant difference in overall survival between the groups could not be confirmed ( p = 0.29). The use of PTFE patches for pericardial closure in LVAD implantation was associated with a higher incidence of mediastinitis, but not with a difference in overall survival.

Epidemiology and Risk Factors for Nosocomial Infections in Left Ventricular Assist Device Recipients

Left ventricular assist devices (LVADs) have been increasingly used as a valid option to improve the prognosis and reduce the symptoms of end-stage heart failure. However, long-term complications, mostly infections and coagulation disorders, are frequent. We described the epidemiology and risk factors for nosocomial infections (NIs) in a cohort of adult patients who underwent continuous-flow LVAD implant between January 2010 and December 2017 in Turin, Italy. Secondary outcomes were the prevalence of multidrug-resistant (MDR) bacteria and mortality. Results: Overall, 64 LVADs were implanted. A total of 32 (50%) patients experienced at least one episode of NI, with a total of 46 infectious events. VAD-related infections occurred in 22 patients (68.8%). Non VAD-related NIs occurred in 12 patients (37.5%), mainly low respiratory tract infections. Length of intensive care unit admission was a risk factor for NI (OR 1.224, 95%CI; 1.049, 1.429). Gram-negative bacilli were responsible for 58.8% of VAD-related infections and 79.5% of non-VAD related infections. In sixteen patients (50%), at least one episode of infection was related to an MDR strain. INTERMACS class and length of MV were independent risk factors for NIs by MDR strains (respectively, OR 2.12, 95%CI: 1.08, 6.80; p = 0.02 and OR 1.46, 95%CI: 1.07, 5.52, p = 0.047). In-hospital mortality was 6.3%. No differences in mortality were observed between infected and non-infected patients (p = 0.61) even when caused by MDR strains (p = 0.143). Conclusion: the rate of nosocomial infections in LVAD patients is associated with the length of ICU admission, and the etiology of nosocomial infection after LVAD implant is mainly due to GNB, including a high rate of MDR strains, especially KPC-KP and MDR PA.

Controlling infections in hospitalized pretransplant candidates

PURPOSE OF REVIEW

Infections in hospitalized patients awaiting solid organ transplantation can pose complicated diagnostic and therapeutic challenges. Goals of management include stabilizing the patient, treating or controlling infections, and decreasing the risk of reactivation of infection after transplant.

RECENT FINDINGS

Groups such as The Organ Procurement and Transplantation Network, American Society of Transplantation Infectious Diseases Community of Practice and the European Society of Clinical Microbiology and Infectious Diseases have updated their guidelines on screening and treatment of infection in transplant candidates. There are also recent developments in therapeutic options for tuberculosis, COVID-19, Clostridioides difficile colitis, bloodstream infections, and other common infections.

SUMMARY

Ideally, antimicrobial therapy should be complete prior to transplantation. In situations in which completion of therapy prior to transplant is not feasible, therapy may need to be prolonged or modified. In most situations, infections can be managed similarly to the general population, although some infections, particularly fungal and mycobacterial, require a different management approach. We review disease- and organ-specific management.

Candida Infectious Endocarditis and Implantable Cardiac Device Infections

Intravascular diseases due to Candida species, including endocarditis and cardiac device-associated infections, are rare yet devastating manifestations of invasive candidiasis affecting an already vulnerable population. Despite their significant associated morbidity and mortality, limited prospective data exist to inform the optimal diagnostic and therapeutic approaches to these entities. Herein, we review the existing literature pertaining to the epidemiology, diagnosis, and management of infectious endocarditis, rhythm management device infections, and circulatory support device infections caused by Candida species and suggest areas for future research.

Infections in Patients With Left Ventricular Assist Devices: Current State and Future Perspectives

Mechanical circulatory support is increasingly being used as bridge-to-transplant and destination therapy in patients with advanced heart failure. Technologic improvements have led to increased patient survival and quality of life, but infection remains one of the leading adverse events following ventricular assist device (VAD) implantation. Infections can be classified as VAD-specific, VAD-related, and non-VAD infections. Risk of VAD-specific infections, such as driveline, pump pocket, and pump infections, remains for the duration of implantation. While adverse events are typically most common early (within 90 days of implantation), device-specific infection (primarily driveline) is a notable exception. No diminishment over time is seen, with event rates of 0.16 events per patient-year in both the early and late periods postimplantation. Management of VAD-specific infections requires aggressive treatment and chronic suppressive antimicrobial therapy is indicated when there is concern for seeding of the device. While surgical intervention/hardware removal is often necessary in prosthesis-related infections, this is not so easily accomplished with VADs. This review outlines the current state of infections in patients supported with VAD therapy and discusses future directions, including possibilities with fully implantable devices and novel approaches to treatment.

Nontuberculous Mycobacterial Infections Associated With Left Ventricular Assist Devices in 3 Patients

Durable left ventricular assist devices (LVADs) provide circulatory support in patients with end-stage heart failure; however, complications include infection of the driveline exit site. Nontuberculous mycobacterial infections are rare in patients with LVADs, but they should be considered in those who have undergone device exchanges and have bacterial infections with driveline exit-site discharge but no fever or leukocytosis. We reviewed the charts of patients who had an LVAD implanted at our institution from January 2009 through December 2019, to identify those with a device-related nontuberculous mycobacterial infection. Collected data included patient demographics, premorbid conditions, infection type, previous device complications, treatment, and outcomes. We identified infections in 3 patients (mean age, 41 yr): Mycobacterium abscessus in 2 and M. chimaera in 1. All had a HeartMate II device and had undergone device exchanges for pump thrombosis or for driveline fault or infections. All presented with driveline exit-site discharge without fever or leukocytosis. The mean time between initial device implantation and diagnosis of a nontuberculous mycobacterial infection was 55 months. All 3 patients were treated with antibiotics and underwent localized surgical débridement; one underwent an additional device exchange. The M. abscessus infections disseminated, and both patients died; the patient with M. chimaera infection continued to take suppressive antibiotics. Nontuberculous mycobacterial infections are associated with high morbidity and mortality rates, warranting prompt diagnosis and treatment.

Infections in LVAD patients

Infections in LVAD patients continue to be a major cause of morbidity and mortality. One needs to separate between early infections which are mostly driven by the general state of the patient before implant, and infections during long term support, mostly related to drive line issues. A diligent risk stratification before implant and close follow up after implant will help to reduce the incidence of infection.

Infections in LVAD patients

Infections in left ventricular assist device (LVAD) patients remain common. Differentiating into device related and non-device related infection is crucial. The incidence of non-device related infections seems to be more determined by the overall condition of the LVAD recipient. Device related infections can be treated by innovative surgical approaches or by transplant. Infection increases the risk of mortaility while on LVAD.

Single-Center Experience With Protocolized Treatment of Left Ventricular Assist Device Infections

Purpose

Because of the current lack of evidence-based antimicrobial treatment guidelines, Left Ventricular Assist Device (LVAD) infections are often treated according to local insights. Here, we propose a flowchart for protocolized treatment, in order to improve outcome.

Methods

The flowchart was composed based on literature, consensus and expert opinion statements. It includes choice, dosage and duration of antibiotics, and indications for suppressive therapy, with particular focus on Staphylococcus aureus (SA) (Figure 1). The preliminary treatment results of 28 patients (2 from start cephalexin suppressive therapy) after implementation in July 2018 are described.

Results

Cumulative incidence for first episode of infection in a 3-year time period was 27% (26 of 96 patients with an LVAD). Twenty-one of 23 (91%) first episodes of driveline infection (10 superficial and 13 deep; nine of 13 caused by SA) were successfully treated with antibiotics according to flowchart with complete resolution of clinical signs and symptoms. For two patients with deep driveline infections, surgery was needed in addition. There were no relapses of deep driveline infections, and only 2 SA deep driveline re-infections after 6 months. Nine patients received cephalexin of whom four patients (44%) developed a breakthrough infection with cephalexin-resistant gram-negative bacteria.

Conclusions

The first results of this protocolized treatment approach of LVAD infections are promising. Yet, initiation of cephalexin suppressive therapy should be carefully considered given the occurrence of infections with resistant micro-organisms. The long-term outcome of this approach needs to be established in a larger number of patients, preferably in a multi-center setting.

Bring it on: Top five antimicrobial stewardship challenges in transplant infectious diseases and practical strategies to address them

Antimicrobial therapies are essential tools for transplant recipients who are at high risk for infectious complications. However, judicious use of antimicrobials is critical to preventing the development of antimicrobial resistance. Treatment of multidrug-resistant organisms is challenging and potentially leads to therapies with higher toxicities, intravenous access, and intensive drug monitoring for interactions. Antimicrobial stewardship programs are crucial in the prevention of antimicrobial resistance, though balancing these strategies with the need for early and frequent antibiotic therapy in these immunocompromised patients can be challenging. In this review, we summarize 5 frequently encountered transplant infectious disease stewardship challenges, and we suggest strategies to improve practices for each clinical syndrome. These 5 challenging areas are: asymptomatic bacteriuria in kidney transplant recipients, febrile neutropenia in hematopoietic stem cell transplantation, antifungal prophylaxis in liver and lung transplantation, treatment of left-ventricular assist device infections, and Clostridioides difficile infection in solid-organ and hematopoietic stem-cell transplant recipients. Common themes contributing to these challenges include limited data specific to transplant patients, shortcomings in diagnostic testing, and uncertainties in pharmacotherapy.

Continuous-flow left ventricular assist device: Current knowledge, complications, and future directions

Long-term continuous-flow left ventricular assist devices have become a real alternative to heart transplantation in patients with advanced heart failure, achieving a promising 2-year event-free survival rate with new-generation devices. Currently, this technology has spread throughout the world, and any cardiologist or cardiac surgeon should be familiar with its fundamentals and its possible complications as well as the advances made in recent years. The aim of this review is to describe current knowledge, management of complications, and future directions of this novel heart-failure therapy.

Impact of Ventricular Assist Device-Specific Infections on Post-Heart Transplant Infections: A Retrospective Single-Center Study

BACKGROUND

Patients with a ventricular assist device (VAD) who are awaiting heart transplant (HTx) are susceptible to infections. Such infections, especially at the site of the VAD, may increase the risk of severe post-transplant infections and mortality. Information on the characteristics of VAD-specific infections and outcomes in HTx recipients after prolonged periods of LVAD therapy is scarce.

PURPOSE

We aimed to assess the impact of active VAD-specific infections on the incidence of early post-transplant infections and patient survival.

METHODS

We conducted a retrospective review of adult HTx cases at our center between April 2011 and October 2020. Informed consent was waived due to study design. A total of 86 patients were included in this study, among whom 94.2% (n = 81) were bridged with a VAD, and the median VAD support period was 1089 days.

RESULTS

Patients with active VAD-specific infections were significantly more likely to develop severe acute mediastinitis [odds ratio (OR) 14.8, 95% confidence interval (CI) 4.83-45.4, P < .01]. Active VAD infections were significantly related to increased length of intensive care unit stay (22.1 days vs 13.0 days, P = .016) and longer mechanical ventilation periods (324.7 hours vs 113.2 hours, P = .03). The 30-day survival rates for patients with and without post-transplant infections were 100% and 97.1%, respectively.

CONCLUSION

Compared to other risk factors, the presence of active VAD-specific infections increases the risk of early post-heart transplant infections and morbidity, without affecting mortality.

Cefazolin plus ertapenem and heart transplantation as salvage therapy for refractory LVAD infection due to methicillin-susceptible Staphylococcus aureus: A case series

The use of left ventricular assist devices (LVADs) is increasingly more common as the availability of donor organs in relation to failing hearts is outstandingly limited. Infections are the most common complications in LVAD recipients, particularly those caused by Staphylococcus spp. Refractory LVAD-related infections are not uncommon as achieving adequate source control is often not feasible before heart transplantation. Evidence suggest that cefazolin plus ertapenem is effective in refractory methicillin-susceptible Staphylococcus aureus (MSSA) bacteremia, but this approach has not been described in LVAD recipients. In this article, we report two cases of refractory MSSA bacteremia in LVAD recipients that were successfully treated with salvage therapy with cefazolin plus ertapenem and subsequent heart transplantation. This treatment strategy should be considered in patients with refractory LVAD-associated infection due to MSSA that are not responding to standard treatment.

Ventricular Assist Device Driveline Infections: A Systematic Review

Infection is the most common complication in patients undergoing ventricular assist device (VAD) implantation. Driveline exit site (DLES) infection is the most frequent VAD infection and is a significant cause of adverse events in VAD patients, contributing to morbidity, even mortality, and repetitive hospital readmissions. There are many risk factors for driveline infection (DLI) including younger age, smaller constitution of patients, obesity, exposed velour at the DLES, longer duration of device support, lower cardiac index, higher heart failure score, DLES trauma, and comorbidities such as diabetes mellitus, chronic kidney disease, and depression. The incidence of DLI depends also on the device type. Numerous measures to prevent DLI currently exist. Some of them are proven, whereas the others remain controversial. Current recommendations on DLES care and DLI management are predominantly based on expert consensus and clinical experience of the certain centers. However, careful and uniform DLES care including obligatory driveline immobilization, previously prepared sterile dressing change kits, and continuous patient education are probably crucial for prevention of DLI. Diagnosis and treatment of DLI are often challenging because of certain immunological alterations in VAD patients and microbial biofilm formation on the driveline surface areas. Although there are many conservative and surgical methods described in the DLI treatment, the only possible permanent solution for DLI resolution in VAD patients is heart transplantation. This systematic review brings a comprehensive synthesis of recent data on the prevention, diagnostic workup, and conservative and surgical management of DLI in VAD patients.

Systems of conductive skin for power transfer in clinical applications

The primary aim of this article is to review the clinical challenges related to the supply of power in implanted left ventricular assist devices (LVADs) by means of transcutaneous drivelines. In effect of that, we present the preventive measures and post-operative protocols that are regularly employed to address the leading problem of driveline infections. Due to the lack of reliable wireless solutions for power transfer in LVADs, the development of new driveline configurations remains at the forefront of different strategies that aim to power LVADs in a less destructive manner. To this end, skin damage and breach formation around transcutaneous LVAD drivelines represent key challenges before improving the current standard of care. For this reason, we assess recent strategies on the surface functionalization of LVAD drivelines, which aim to limit the incidence of driveline infection by directing the responses of the skin tissue. Moreover, we propose a class of power transfer systems that could leverage the ability of skin tissue to effectively heal short diameter wounds. In this direction, we employed a novel method to generate thin conductive wires of controllable surface topography with the potential to minimize skin disruption and eliminate the problem of driveline infections. Our initial results suggest the viability of the small diameter wires for the investigation of new power transfer systems for LVADs. Overall, this review uniquely compiles a diverse number of topics with the aim to instigate new research ventures on the design of power transfer systems for IMDs, and specifically LVADs.

Prevention of infection and optimizing vaccination in the solid organ transplant candidate and recipient

PURPOSE OF REVIEW

Infections can result in serious complications in solid organ transplant (SOT) patients. The need to remain up to date on recommendations on screening, vaccinations, and chemoprophylaxis is paramount in the management of SOT patients. The goal of this review is to provide an overview of current recommendations for the prevention of infections and optimization of vaccinations from the pretransplant through posttransplant periods.

RECENT FINDINGS

There is an emphasis on thorough pretransplant evaluation to guide clinicians and pretransplant testing based on epidemiological and endemic risk factors. Additionally, recent studies on vaccine safety and efficacy of newer vaccine formulations in SOT recipients are addressed.

SUMMARY

This review provides insight on updated recommendations for pretransplant screening, new data on vaccine optimization in SOT recipients and posttransplant prophylaxis. Further research is needed in order to improve preventive measures including screening tests, vaccines, and chemoprophylaxis.

Contemporary Management Strategies in VAD Infection

PURPOSE OF REVIEW

The use of durable ventricular assist devices (VAD) to manage end-stage heart failure is increasing, but infection remains a leading cause of morbidity and mortality among patients with VAD. In this review, we synthesize recent data pertaining to the epidemiology, diagnosis, management, and prevention of VAD infections, discuss transplant considerations in patients with VAD infections, and highlight remaining knowledge gaps. We also present a conceptual framework for treating clinicians to approach these infections that draws on the same principles that guide the treatment of analogous infections that occur in patients without VAD.

RECENT FINDINGS

Despite advances in device design, surgical techniques, and preventative interventions, more than a third of VAD recipients still experience infection as an adverse outcome. Positron emission tomography has emerged as a promising modality for identifying and characterizing VAD infections. High-quality data to support many of the routine therapeutic strategies currently used for VAD infections-including suppressive antibiotic therapy, surgical debridement/device exchange, and novel antimicrobials for emerging multidrug-resistant organisms-remain limited. Although pre-transplant VAD infection may impact some early transplant outcomes, transplantation remains a viable option for patients with most types of VAD infection. Standardized definitions of VAD infection applied to large registry datasets have yielded key insights into the epidemiology of infectious complications among VAD recipients, but more prospective studies are needed to evaluate the effectiveness of existing and novel diagnostic and therapeutic strategies.

Current Understanding of Leukocyte Phenotypic and Functional Modulation During Extracorporeal Membrane Oxygenation: A Narrative Review

A plethora of leukocyte modulations have been reported in critically ill patients. Critical illnesses such as acute respiratory distress syndrome and cardiogenic shock, which potentially require extracorporeal membrane oxygenation (ECMO) support, are associated with changes in leukocyte numbers, phenotype, and functions. The changes observed in these illnesses could be compounded by exposure of blood to the non-endothelialized surfaces and non-physiological conditions of ECMO. This can result in further leukocyte activation, increased platelet-leukocyte interplay, pro-inflammatory and pro-coagulant state, alongside features of immunosuppression. However, the effects of ECMO on leukocytes, in particular their phenotypic and functional signatures, remain largely overlooked, including whether these changes have attributable mortality and morbidity. The aim of our narrative review is to highlight the importance of studying leukocyte signatures to better understand the development of complications associated with ECMO. Increased knowledge and appreciation of their probable role in ECMO-related adverse events may assist in guiding the design and establishment of targeted preventative actions.

Loss of daptomycin susceptibility in clinical Staphylococcus epidermidis infection coincided with variants in WalK

Daptomycin (DAP) is key in treating multidrug-resistant Staphylococcus infections. Diminished susceptibility to DAP is emerging among Staphylococcus epidermidis strains although mechanisms for non-susceptibility (NS) remain poorly understood. We report a case of persistent S. epidermidis bacteremia in which loss of DAP susceptibility arose during prolonged treatment. Whole genome sequencing identified two mutations, Q371del and P415L, in a single-affected gene, WalK, that coincided with the emergence of DAP-NS. Protein modeling of the mutations predicted a disruption of WalK protein configuration. The emergence of mutations in a single-gene during DAP exposure raises concerns in an era of increasingly treatment-resistant infections.

Lay summary: Daptomycin is an important antibiotic for fighting Staphylococcus infections. We identified variants in the WalK gene that were coincident with resistance in a clinical Staphylococcus epidermidis infection. Clinicians, hospital epidemiologists, and microbiology laboratories need to be aware of the potential for the evolution of drug resistance during prolonged daptomycin therapy.

Efficacy and safety of chronic antimicrobial suppression therapy for left ventricular assist device driveline infections: A single-center descriptive experience

BACKGROUND

Driveline infection (DLI) is the most common left ventricular assist device (LVAD) infectious complication. Short-term antimicrobial therapy and local debridement are the cornerstones of management for these infections, but the use of chronic antimicrobial suppression (CAS) therapy is not well characterized.

METHODS

To better characterize the efficacy of CAS therapy, we performed a retrospective review of all patients (N = 219) receiving care at our tertiary transplant center with continuous-flow LVADs placed between August 2007 and July 2019.

RESULTS

A total of 24 patients were identified as having received CAS therapy as treatment for DLIs. The mean age was 56 years, 50% were female, and chronic kidney disease affected 63% of patients. Staphylococcus aureus accounted for half of all initial DLIs, and the mean length of CAS therapy was 486 days (range 48-2287 days). All patients received per os regimens as suppression therapy. Adverse events impacted 5 of 24 patients (0.43 events per 1000 days). Overall, the use of CAS therapy led to successful outcomes in 50% of patients and 29% experienced treatment failures. The remaining patients experienced stable symptoms. Relapses were the most common cause of treatment failure, and three patients experienced reinfections while on CAS therapy.

CONCLUSIONS

Our study suggests that CAS therapy for DLIs can be well tolerated, and future studies are needed to determine which patients merit suppression.

Over 870 days of successful antibiotic suppression therapy for VRE-infected left ventricular assist device

Left ventricular assist devices (LVADs) are used in patients with advanced heart failure. Infections are common complications following device placement; however, the efficacy of chronic antimicrobial suppression therapy for deep-seated infections is not well characterized. We report the case of a 49-year-old male with a HeartMate II LVAD who presented with a methicillin-sensitive Staphylococcus aureus pump pocket infection that was subsequently treated with antibiotics and HeartMate III pump exchange. A vancomycin-resistant Enterococcus faecium (VRE) pump pocket infection then developed and responded to surgical drainage followed by long-term suppression with daptomycin then linezolid for over 870 days. A second pump exchange was not required. To our knowledge, this represents the longest reported use of daptomycin (341 days) without symptomatic adverse events. Managing infections caused by multidrug-resistant pathogens presents a clinical challenge. This case demonstrates the potential for antimicrobial suppression therapy to allow for successful retention of a VRE-infected LVAD.

An in vitro Reconstructed Human Skin Equivalent Model to Study the Role of Skin Integration Around Percutaneous Devices Against Bacterial Infection

Percutaneous devices are a key technology in clinical practice, used to connect internal organs to external medical devices. Examples include prosthesis, catheters and electrical drivelines. Percutaneous devices breach the skin's natural barrier and create an entry point for pathogens, making device infections a widespread problem. Modification of the percutaneous implant surface to increase skin integration with the aim to reduce subsequent infection is attracting a great deal of attention. While novel surfaces have been tested in various in vitro models used to study skin integration around percutaneous devices, no skin model has been reported, for the study of bacterial infection around percutaneous devices. Here, we report the establishment of an in vitro human skin equivalent model for driveline infections caused by Staphylococcus aureus, the most common cause of driveline-related infections. Three types of mock drivelines manufactured using melt electrowriting (smooth or porous un-seeded and porous pre-seeded with human fibroblasts) were implanted in human skin constructs and challenged with S. aureus. Our results show a high and stable load of S. aureus in association with the skin surface and no signs of S. aureus-induced tissue damage. Furthermore, our results demonstrate that bacterial migration along the driveline surface occurs in micro-gaps caused by insufficient skin integration between the driveline and the surrounding skin consistent with clinical reports from explanted patient drivelines. Thus, the human skin-driveline infection model presented here provides a clinically-relevant and versatile experimental platform for testing novel device surfaces and infection therapeutics.

In Full Flow: Left Ventricular Assist Device Infections in the Modern Era

With the rising prevalence of heart disease in the United States, there is increasing reliance on durable mechanical circulatory support (MCS) to treat patients with end-stage heart failure. Left ventricular assist devices (LVADs), the most common form of durable MCS, are implanted mechanical pumps that connect to an external power source through a transcutaneous driveline. First-generation LVADs were bulky, pulsatile pumps that were frequently complicated by infection. Second-generation LVADs have an improved design, though infection remains a common and serious complication due to the inherent nature of implanted MCS. Infections can affect any component of the LVAD, with driveline infections being the most common. LVAD infections carry significant morbidity and mortality for LVAD patients. Therefore, it is paramount for the multidisciplinary team of clinicians caring for these patients to be familiar with this complication. We review the epidemiology, prevention, diagnosis, treatment, and outcomes of LVAD infections.

Nontuberculous mycobacterial infections in left ventricular assist device patients

Left ventricular assist devices (LVADs) are integral for the management of medically refractory heart failure, and LVAD infections are common following device placement. Most infections are caused by Staphylococcal spp. and Gram-negative enteric bacteria but nontuberculous mycobacterial (NTM) infections have been reported. We present the second-ever reported case of a driveline infection caused by Mycobacterium fortuitum in a 75-year-old male with a continuous-flow LVAD. After receiving meropenem, azithromycin, and ciprofloxacin, he underwent device exchange and ultimately died after failing to recover neurologically. Management of NTM infections presents a clinical challenge due to the propensity for rapidly growing mycobacterial species to form biofilms and the possibility of negative cultures delaying diagnosis. To address the literature gap surrounding NTM infections in LVAD patients, we performed a systematic review and present all previously reported cases.

Intra-abdominal infections in solid organ transplant recipients: Guidelines from the American Society of Transplantation Infectious Diseases Community of Practice

This new guideline from the AST IDCOP reviews intra-abdominal infections (IAIs), which cause substantial morbidity and mortality among abdominal SOT recipients. Each transplant type carries unique risks for IAI, though peritonitis occurs in all abdominal transplant recipients. Biliary infections, bilomas, and intra-abdominal and intrahepatic abscesses are common after liver transplantation and are associated with the type of biliary anastomosis, the presence of vascular thrombosis or ischemia, and biliary leaks or strictures. IAIs after kidney transplantation include renal and perinephric abscesses and graft-site candidiasis, which is uncommon but may require allograft nephrectomy. Among pancreas transplant recipients, duodenal anastomotic leaks can have catastrophic consequences, and polymicrobial abscesses can lead to graft loss and death. Intestinal transplant recipients are at the highest risk for sepsis, infection due to multidrug-resistant organisms, and death from IAI, as the transplanted intestine is a contaminated, highly immunological, pathogen-rich organ. Source control and antibiotics are the cornerstone of the management of IAIs. Empiric antimicrobial regimens should be tailored to local susceptibility patterns and pathogens with which the patient is known to be colonized, with subsequent optimization once the results of cultures are reported.