Driveline Exit Site Infections Research Articles

TB or Non-TB, How to Treat These Infections in a Heart Transplant Patient (That is the Question!)

<h3>Introduction</h3> Driveline exit site infections (DLESi) are common complications of left ventricular assist device (LVAD) therapy. Rarely, non-tuberculosis mycobacteria (NTB) cause such infections. We present a case showing successful treatment of a DLESi due to <i>Mycobacterium chelonae</i> which first became clinically apparent after orthotopic heart transplant (OHT). <h3>Case Report</h3> A 61-year-old male with a dilated cardiomyopathy received a Heartmate 3 LVAD followed 4 years later by OHT. Prior to OHT, no infections were reported. Two months after OHT, an abdominal wall abscess at the former driveline exit site was treated with incision and drainage. Abdominal wound drainage continued, with appearance of satellite lesions and chest wall nodules. Although initial cultures were negative, wound cultures collected 3 months later, grew <i>M. chelonae</i>. For rare NTM related DLESi, a standardized regimen is not established. Hence, commonly used macrolide, quinolone, and linezolid were started. Azithromycin was initially chosen over the more frequently studied clarithromycin due to the latter's interaction with tacrolimus. Linezolid was stopped due to pancytopenia and the ensuing susceptibility report showed quinalone resistance. As a result, the patient was functionally on macrolide monotherapy which led to a recurrence of nodules. Thus, multiple antibiotic regimens were started in succession (Figure). The final clofazimine, azithromycin, and tigecycline based regimen was clinically effective, but caused intolerable diarrhea that led to self-discontinuation of treatment after ∼9 months of therapy. He remains asymptomatic 1-year since antibiotic termination. <h3>Summary</h3> Picking an antibiotic regimen for rare, difficult-to-treat NTB related DLESi involves using the sensitivity analysis while accounting for drug-drug interactions with immunosuppressive medications. Our case demonstrates efficacy of a macrolide and clofazimine based regimen for treatment of a LVAD associated NTB infection in an OHT patient.

Effect of Ventricular Assist Device Self-care Simulation-Based Mastery Learning on Driveline Exit Site Infections: A Pilot Study.

Ventricular assist device simulation-based mastery learning (SBML) results in better patient and caregiver self-care skills compared with usual training. The aim of this study was to evaluate the effect of SBML on driveline exit site infections. We compared the probability of remaining infection free at 3 and 12 months between patients randomized to SBML or usual training. The SBML-training group had no infections at 3 months and 2 infections at 12 months, yielding a Kaplan-Meier estimate of the probability of remaining infection free of 0.857 (95% confidence interval [CI], 0.692-1.00) at 12 months. The usual-training group had 6 infections at 3 months with no additional infections by 12 months. Kaplan-Meier estimates of remaining infection free at 3 and 12 months were 0.878 (95% CI, 0.758-1.00) and 0.748 (95% CI, 0.591-0.946), respectively. Time-to-infection distributions for SBML versus usual training showed a difference in 12-month infection rates of 0.109 (P = .07). Ventricular assist device self-care SBML resulted in fewer 12-month infections.

584. Ventricular assist device infections with Pseudomonas aeruginosa

BackgroundInfection is a leading cause of morbidity and mortality in ventricular assist device (VAD) recipients. Pseudomonas aeruginosa (PA) is the second most common organism implicated in VAD infections, occurring in 10–50% of infections. The epidemiology of VAD recipients with PA infection are poorly described.MethodsWe identified patients (pts) at Northwestern Memorial Hospital with a VAD-specific PA infection from January 1, 2012 to Dec 31, 2019. VADs included the Heartmate II, Heartmate 3, and Heartware HVAD devices. VAD-specific infections were defined according to the 2013 ISHLT Guidelines.ResultsSeventeen out of 91 (18.7%) VAD infections were due to PA. Infections of the driveline exit site (DLES) occurred most commonly (n=15, 88.2%), followed by pocket (n=2, 11.8%) and pump (n=2, 11.8%) infections. Median time to infection after VAD implantation was 295 days (IQR 154 – 440 days). Eight (47.1%) pt isolates were not fluoroquinolone (FQ) susceptible. Resistance to multiple antibiotic classes was observed in pts in whom serial cultures were obtained. Median antibiotic treatment was 107 days (IQR 55 – 183 days, maximum 775 days). Five (29.4%) pts received FQ monotherapy on initial diagnosis, 3 (60%) of whom required change to a different class for resistance. Surgical debridement and VAD exchange were performed in 5 (29.4%) and 3 (17.6%) pts respectively. Co-pathogens were identified in 9 (52.9%) pts, the most common being Staphylococcus aureus (n=2) and Enterococcus spp (n=2). A total of 5 (29.4%) pts went on to successful heart transplantation; one had recurrent PA infection at the prior DLES requiring prolonged antibiotics and removal of retained DL material. All cause 1-year mortality rate was 11.7% (n = 2), both of whom died from cerebrovascular accidents.ConclusionVAD-specific infections with PA occurred late after device implantation and required prolonged antibiotic courses. Antimicrobial resistance was high at diagnosis and worsened in pts on prolonged therapy. Morbidity and mortality in pts with PA VAD infections were high. The preponderance of DLES infections warrants further study and highlights the need for improvements in DLES care and infection prevention strategies.Disclosures All Authors: No reported disclosures

Treatment of chronic left ventricular assist device infection with local application of bacteriophages.

Left ventricular assist device-associated infections represent a major complication during long-term support. Driveline exit site infections harbour the risk of ascending into the pump, causing deep-seated infections. We report on the successful treatment of a chronic recurrent left ventricular assist device pump-associated infection by the local application of bacteriophages as adjunct to standard surgical and antimicrobial treatment.

Showering with the Driveline Exit Site Exposed to Well Water Does Not Increase Rates of Driveline Exit Site Infection

Purpose Determine the effects of showering on rates of driveline exit site infections (DLESI). Methods Prospective analysis of all durable left ventricular assist device (LVAD) patient implants at a single academic center from June 2011 to June 2018. All patients who were provided instructions for showering were included in this analysis (n=164). Exclusion criteria included patients that expired before 90 days of support and those not discharged prior to transplant (n=30). Patients were instructed to shower without a dressing covering their DLES, to use antibacterial soap and then immediately apply a sterile dressing using a standard kit of supplies. Infections were diagnosed with positive exit site cultures. Self-reported household water sources, well water vs municipal water, were used to compare the rates of DLESI. Our overall DLESI infection rates were compared to STS INTERMACS data. SPSS was used to analyze statistics. Results Overall at our center, 77% of the patients were free of DLESI. Demographics, duration of support, indication for LVAD and payer source for the well water and municipal water groups were similar except the well water group was older (p=0.003). Freedom from DLESI was 83% (n=38/46) & 74% (n=65/88) of patients who showered with well & municipal water respectively (p=0.254). Kaplan Meier curves are similar (p=0.151). The mean time to DLESI is 90 days and 87 days in the well and municipal water groups respectively (p=0.153). The late phase infection rate (after the first three months) per 100 pt months at our center is 1.16 compared to STS INTERMACS at 1.38. Conclusion At a single center, LVAD patients showering with different water sources have comparable rates of freedom from DLESIs. LVAD patients who follow a DLES management protocol that includes showering have comparable rates of DLESI when compared to STS INTERMACS data.

A Comprehensive In Vitro Evaluation of Medihoney as an Anti-Biofilm Agent in Preventing Ventricular Assist Device Driveline Infections

Purpose Medihoney is routinely applied to the exit site of Ventricular Assist Device (VAD) drivelines in patients in many Australian hospitals to prevent driveline infections. Its effectiveness as a prophylactic measure remains unclear. We performed a comprehensive in vitro study using microbiological assays that closely mimic the in vivo environment of the driveline exit-site to assess the effectiveness of medihoney in preventing biofilm-related driveline infections. Methods Antimicrobial efficacy testing of medihoney was performed against 24 clinically-relevant bacterial and fungal strains grown as planktonic and biofilm cells. The minimum inhibitory concentration (MIC), minimum biofilm inhibitory concentration, minimum eradication concentration of medihoney, and the activity of individual components of medihoney were assessed. A colony biofilm assay and a drip-flow biofilm reactor assay that mimic chronic wounds and the driveline exit site were used to evaluate medihoney activity in inhibiting early adherent organism monolayers and mature biofilms. Results Medihoney demonstrated activity against planktonic organism cells in 5/6 S. aureus strains, 6/6 of S. epidermidis strains, 1/6 of P. aeruginosa strains and 4/6 of Candida strains using a qualitative disk diffusion susceptibility assay and a quantitative broth microdilution assay [MICs, 10% weight/volume (W/V) medihoney concentrations]. Higher concentrations of medihoney (30-50%, W/V) were required to inhibit the growth of biofilm cells. Eradication of biofilms could not be achieved by medihoney, even at the highest concentration studied. The antibiofilm properties of medihoney were multi-faceted, including sugar content, pH, osmolality and the proposed active ingredient, methylglyoxal (MGO). MGO actually played a less important role than other medihoney characteristics. The colony biofilm assay and the drip flow biofilm reactor showed that medihoney was unable to prevent the maturation of biofilms after early organism adherence, and only had a weak activity against established biofilms. Conclusion Our work suggests a suboptimal effectiveness of medihoney in preventing driveline exit site infections due to biofilm development, warranting further clinical trials before its widespread use can be justified.

Comparing the rates of driveline exit site infections in LVAD patients showering with different water sources.

Background Infections at the driveline exit site (DLES) is a common complication following left ventricular assist device (LVAD) implantation. This project examined rates of freedom from DLES infection in patients who were taught to shower following LVAD surgery. The water source the patients reported using was compared. Methods All durable LVAD patient implants at a single center from June 2011 to April 2017 were retrospectively reviewed (n = 135). Patients were instructed to shower with no dressing covering their DLES, to use antibacterial soap and then immediately apply a sterile dressing using a standard kit of supplies. Upon follow up, fourteen patients were excluded due to not surviving index hospitalization. An additional three were excluded due to incomplete information. Patients self-reported the source of their home water-well or municipal water on their home safety check list. Infections were diagnosed with positive exit site cultures. Data were analyzed using chi-square statistics. Conclusions In conclusion, patients who are provided instruction to shower have comparable rates of DLES infections despite the source of shower water. Results DLES infections were documented in 28 of 118 patients. 84% and 72% of patients who showered with well water (n = 32/38) and municipal water (58/80) were free of DLES infections respectively (p = 0.16). Comparing the rates of driveline exit site infections in LVAD patients showering with different water sources.

Sunshine Heart C-Pulse: device for NYHA Class III and ambulatory Class IV heart failure.

Advanced heart failure (HF) patients not meeting criteria for ventricular assist device or heart transplant with life-limiting symptoms are limited to medical and resynchronization therapy. The Sunshine Heart C-Pulse, based on intra-aortic balloon pump physiology, provides implantable, on-demand, extra-aortic counterpulsation, which reduces afterload and improves cardiac perfusion in New York Heart Association Class III and ambulatory Class IV HF. The C-Pulse reduces New York Heart Association Class, improves 6-min walk distances, inotrope requirements and HF symptom questionnaires. Advantages include shorter operative times without cardiopulmonary bypass, no reported strokes or thrombosis and no need for anticoagulation. Driveline exit site infections, inability to provide full circulatory support and poor function with intractable arrhythmias remain concerns. Current randomized controlled studies will evaluate long-term efficacy and safety compared with medical and resynchronization therapy.

Ultraviolet Radiation Affects Thoratec HeartMate II Driveline Mechanical Properties: A Pilot Experiment.

Longevity and quality of life for left ventricular assist device (LVAD) patients are plagued by driveline exit site infections. Ultraviolet (UV) radiation, a current treatment in wound healing clinics, could potentially treat LVAD exit site infections. However, the effect of UV radiation on the tensile properties of HeartMate II (HMII) driveline material is unknown. The sleeve of a single HMII driveline was distributed into six exposure groups (n = 10/group). The six groups were further divided into two treatment cohorts designed to replicate wound treatment schedules of postimplant LVAD patients. Strip biaxial tensile tests were performed on both unexposed and exposed samples to analyze changes in material elasticity (Young's modulus), point of deformation (yield strength), and breaking point. Our data suggest that UV exposure changes the elasticity of the HMII driveline. However, the material endured aberrantly large forces and the properties remained within the safety threshold of device performance. This study warrants further examination of the effect of UV light on driveline material, to determine safety, reliability, and efficacy of UV treatment on exit site infections.

Drive-line infections and sepsis in patients receiving the HVAD system as a left ventricular assist device

Drive-line infections and sepsis lead to significant morbidity and even mortality in patients with ventricular assist devices (VADs). The HeartWare HVAD system is unique compared with other VAD systems in that it has a thin, flexible drive-line and is implanted directly into the pericardial space without the need for a pump pocket. We reviewed 332 patients receiving the HVAD in the pivotal ADVANCE Bridge to Transplant (BTT) trial and Continued Access Protocol (CAP) to determine the incidence of drive-line infections and sepsis. Summary statistics of outcomes and Kaplan-Meier freedom-from-event analyses were performed. The Cochran-Mantel-Haenszel test for homogeneity was used to determine whether there was any site effect on rates of either drive-line exit-site or sepsis infections. Drive-line exit-site infections occurred in 16.9% (56 of 332) of patients (0.25 event per patient-year [EPPY]). These infections were primarily treated with antibiotics and most occurred >30 days post-implant (88%, or 66 of 75 drive-line infections). Sepsis occurred in 17.2% (57 of 332) of patients (0.23 EPPY), and sepsis events occurred more frequently >30 days post-implant (86%, or 60 of 70 sepsis events). Of patients with sepsis, 17.5% (10 of 57) died due to sepsis-related neurologic events (7 of 10) and multisystem organ failure (2 of 10) and cardiopulmonary failure (1 of 10), whereas there were no deaths related to drive-line infections. In addition, 17.5% (10 of 57) of patients had a stroke event while under treatment for sepsis (7 hemorrhagic and 3 ischemic strokes), and 3.5% (2 of 57 patients with sepsis) had a device exchange for VAD thrombus (4 days before and 1 day after sepsis diagnosis). Patients with drive-line infections or sepsis had a larger body mass index compared to those without infection (29.4 vs 27.6 kg/m(2), p = 0.015), and were more frequently diabetic (43.7% vs 31.2%, p = 0.034). Although there was no negative impact on survival in patients with drive-line exit-site infections, there was a trend for reduced survival in patients with sepsis events when compared to those patients without sepsis. The incidence of drive-line infection and sepsis was low in patients receiving the HVAD pump. Despite a trend toward reduced survival in patients with sepsis events, the overall survival of patients with either drive-line infections or sepsis was excellent.

The Effect of Percuatneous Lead Placement on Drive Line Exit Site Infections in HeartMate II Patients

Purpose It has been suggested that aligning the junction of the silicon exterior of the HeartMate II drive line and the flocked portion of the lead with skin level, “Buried”, as opposed to leaving 2-3 inches of the flocking exposed above the skin, “Unburied” reduced DLES infections. Thus, we examined DLES infection rates and causes in a single center, retrospective, non-randomized review. Methods and Materials We compared DLES infection incidence, cause of infection (poor wound healing vs. trauma), time to 1st infection, requirement for advanced measures with the 2 DLES placements in Thoratec HeartMate II recipients. Statistical comparisons were performed using Statica (Statsoft). For this study, we defined a DLES infection as at least one positive wound culture. Results Figure 1 shows the freedom from DLES infections for the 2 approaches. Significantly more, 33% (16/48)) of Unburied had DLES infections than 18% (17/94) of Buried, and the infection duration was longer, 500 vs. 175 days, respectively. The average time to 1st infection was significantly longer, 13 months, for the Unburied vs 7 months for the Buried, related to cause of infection: poor wound healing in 59% of the Buried DLES infections (10/17) vs. 38% (6/16) for the Unburied. Of the 16 Unburied DLES infections, 11 required wound vac, 7 surgical revision, and 3 pump replacements, vs. 9, 7, and 0 respectively for the Buried approach. Conclusions Using the Buried approach may reduce the incidence, severity, and duration of DLES infection, yet, a portion of patients still develop DLES due to poor wound healing and trauma. Alternative approaches to the drive line are likely needed to eliminate this pernicious source of LVAD infections.

Double tunnel technique for the LVAD driveline: improved management regarding driveline infections

A driveline exit site infection is a serious and common complication in long-term left ventricular assist device (LVAD) support. To reduce the incidence and severity of late driveline infections, we modified our surgical technique (double tunnel), and compared it to the conventional short and straight driveline tunnel technique (conventional). We analyzed 43 consecutive patients (37 HeartMate II; 6 Ventrassist) regarding late onset driveline exit site infections after using the surgical driveline tunnel technique after successful LVAD implantation. Of these 43 patients, 11 were treated with the conventional short and straight driveline tunnel technique (conventional), while 32 patients were treated with the modified long subfascial, C-shaped technique (double tunnel). We observed slightly fewer superficial driveline exit site infections in the double tunnel group, even though the difference was not statistically significant (0.638 vs. 1.148 infections/1,000 patient-days; P = 0.22). There were also insignificantly fewer surgical interventions because of exit site infections in the double tunnel group (0.159 vs. 0.581 revisions/1,000 patient-days; P = 0.18). The double tunnel technique offers more surgical options in the case of driveline exit site infections. Due to the long subfascial tunnel, the infected site can be separated from the new driveline exit site, and vacuum-assisted closure therapy can be applied to the infected area. In conclusion, we recommend using the double tunnel driveline technique because of the low infection rate and better treatment options in the case of driveline exit site infection.

8 Differential Infection Rates between Velour Versus Silicone Interface at the HeartMate II Driveline Exit Site: Structural and Ultrastructural Insight into Possible Causes

Prevention of driveline exit site (DLES) infection by attentive wound care is imperative but intrinsic differences in interface material may also influence infectious risk. In this study, we compare DLES infections and structural/ultrastructural differences between silicone and Dacron velour driveline-skin interfaces of the HeartMate II (HMII).

Obesity and Left Ventricular Assist Device Driveline Exit Site Infection

Driveline exit site (DLES) infection is a persistent problem among the left ventricular assist device (LVAD) patients. This study investigated the relationship between obesity and DLES infection. Records of LVAD patients at two institutions from January 1999 to January 2009 were queried. Results were analyzed using t tests. Those with LVAD support > or =90 days were included. The body mass index (BMI) of each patient was measured at the time of implant and at the conclusion of LVAD support or currently, if the patient was ongoing. Other data included preimplant age, ejection fraction, blood urea nitrogen, creatinine, diabetes, New York Heart Association class, pulmonary capillary wedge pressure, VO2 max, and inotrope therapy. The 118 patients who qualified for the study were placed in an infection group (n = 36) or in the control group (n = 82). Both groups had similar preimplant characteristics. Variables with differences statistically significant between the groups included duration of LVAD support, indication for support, device type, and BMI. Patients who developed DLES infections had a significantly higher BMI and continued weight gain over the course of LVAD therapy compared with the control group. Although this association requires further study, implications for clinical practice may include the provision of nutrition and exercise counseling for patients undergoing LVAD therapy, especially if overweight. These results may warrant increased measures to prevent and treat infection in the preimplant and postimplant periods.

Surgical management of Novacor drive-line exit site infections

Implantable left ventricular assist device (LVAD) drive-line exit site infection, an expected consequence of currently available device use, continues to be a significant limiting factor in long-term support. We theorize that the mechanism behind the establishment of the most chronic exit site infections involves a shearing torsion injury that disrupts the tissue adherence interface with the drive-line. The resulting neo-epithelialized drainage tract prevents permanent clearance of the infection with antibiotics alone. The proposed treatment strategy of established infections involves aggressive surgical excision of the involved exit site.