A Retrospective Chart Review on the Role of Suppressive Therapy in the Management of Spinal Infections Involving Hardware

Suppressive antibiotic treatment (SAT) in the era of MDRO infections: a narrative review

INTRODUCTION

Antibiotics were originally developed to treat acute bacterial infections, and research studies focus their efforts on safety and efficacy in the short term; however, prolonged course of antibiotics has been documented in multiple clinical settings. The aim of this narrative review is to provide a new perspective on SAT and to discuss new therapeuticpossibilities.

AREAS COVERED

We discuss new clinical scenarios in which SAT could be considered. We provided a broad discussion about long-acting agents and new or repurposed oral agents as well as the use of OPAT with elastomeric pumps and an overview of the pipeline of new antifungals. Limitations of SAT are presented in this review and especially patients' adherence issues, possible spread of MDROs, possible rising of the incidence of Clostridioides difficile infections, drug-to-drug interactions and drug-related problems, cost-effectiveness evaluation issues.

EXPERT OPINION

Many research gaps are evident and further studies are needed. Above all, the efficacy and safety of SAT in the different clinical scenarios. Discovery of new molecules against MDROs and ongoing research on PK/PD variables as well as a better understanding of the relationship between SAT and the emergence of resistance could improve SAT usage and reduce the impact of DRPs.

State-of-the-Art Review: Diagnosis and Management of Spinal Implant Infections

Spinal implant infections are a serious complications of instrumented spinal fusion surgeries, carrying high morbidity and complex management challenges. Early postoperative infections may manifest with wound-healing issues, back pain, and fevers. Magnetic resonance imaging (MRI) is the preferred imaging modality, but can be limited by metal artifacts. For cases with stable implants, surgical debridement with implant retention combined with at least 12 weeks of antibiotics is currently considered appropriate treatment. Staphylococcal infections are ideally treated with biofilm-active antibiotics. Suppressive antibiotic therapy can be considered when surgical debridement has been delayed or is incomplete, and for those who are poor surgical candidates for another surgery. Chronic infections may present insidiously with implant failure or pseudarthrosis; implant removal or revision is generally pursued. As current guidance is heavily based on the periprosthetic joint infection literature and low-level studies on spinal implant infections, further research on optimizing diagnostic and treatment approaches is needed.

Clinical impact of the use of chronic suppressive antibiotics against recurrent ventricular assist device infections

Ventricular assist device (VAD) infections are frequent causes of hospital readmission. The risk factors and optimal preventive strategies for such, including chronic suppressive antibiotics (CSA), remain uncertain. We performed a single-center, retrospective, observational cohort study assessing continuous flow VAD recipients who underwent implantation between 2008 and 2018 in Japan. From primary VAD infection (VADI), we followed the patients for recurrent infection, defined as relapsing VAD-specific (e.g., localized infections) or VAD-related (e.g., bacteremia) infections requiring hospital readmission. CSA was defined as the use of oral antimicrobial agents continued beyond initial antibiotic use until transplantation, VAD withdrawal, VADI recurrence, or death. Survival analysis was performed to identify risk factors for recurrent infection accounting for competing risks (e.g., deaths and transplants). Among 163 eligible patients, 76 patients had VADIs. The main causative organism in primary VADI was Staphylococcus aureus (63%, 48/76). Among them, 41 had recurrent infections, whereas 35 had none during the follow-up period (median, 335 days). Thirty-six patients received CSA for a median of 478 days. Although CSA was associated with a decreased risk of recurrent infection [adjusted sub-distribution hazard ratio (SHR), 0.40; 95% confidence interval (CI), 0.18-0.89; P = 0.03], this protective effect was observed only after primary VAD-specific infection (SHR, 0.28; 95% CI, 0.12-0.64; P < 0.01) but not after VAD-related infection. Surgical procedures during primary VADI were associated with an increased risk (SHR, 2.00; 95% CI, 1.10-3.66; P = 0.02). One patient had an adverse drug reaction. CSA may be an effective approach to limit relapsing VADIs following a primary VAD-specific infection with minimal adverse events.

IMPORTANCE

Ventricular assist device infections (VADIs) are a significant complication leading to hospital readmissions. However, the risk factors and optimal preventive strategies for VADI remain unclear. This study investigated the effectiveness of chronic suppressive antibiotic therapy in patients with VADI. We found that the use of chronic suppressive antibiotic therapy was associated with a reduction in the risk of VADI recurrence with few adverse reactions. Our findings suggest the potential benefit of chronic suppressive antibiotics in preventing infections in selected cases. Our findings are relevant for the management of patients with ventricular assist devices awaiting heart transplantation, providing valuable insights for clinical practice.

Dalbavancin as suppressive antibiotic therapy in patients with prosthetic infections: efficacy and safety

Suppressive antibiotic therapy (SAT) is a strategy to alleviate symptoms and/or to reduce the progression of an infection when other treatment options cannot be used. Dalbavancin, due to its prolonged half-life, enables (bi) weekly dosing. Here, we report our multicenter real-life clinical experience with dalbavancin used as SAT in patients with prosthetic joint or vascular infections. Medical records of all adult patients with documented vascular or orthopedic chronic prosthetic infections, who received dalbavancin as SAT between 2016 and 2018 from four Spanish hospitals were reviewed for inclusion. Descriptive analysis of demographic characteristics, Charlson Comorbidity index, Barthel index, isolated pathogens and indication, concomitant antibiotic use, adverse events, and clinical outcome of SAT were performed. Eight patients were eligible for inclusion, where six patients had prosthetic vascular infections (aortic valve) and two patients had knee prosthetic joint infections. The most common pathogens were methicillin-susceptible Staphylococcus aureus and Enterococcus faecium. All patients had a history of prior antibiotic treatment for the prosthetic infection [median duration of antibiotic days 125 days (IQR, 28-203 days)]. The median number of dalbavancin doses was 29 (IQR, 9-61) and concomitant antibiotic use (n = 5, 62.5%). Clinical success was reported in 75% (n = 6) of patients. Adverse events were reported in two patients (mild renal and hepatic impairment). The median estimated cost savings due to the avoided hospital days was €60185 (IQR, 19,916-94984) per patient. Despite the limitations of our study, this preliminary data provides valuable insight to support further evaluation of dalbavancin for SAT in patients with prosthetic infections in the outpatient setting when alternative treatments are not feasible.