Pedicle flap coverage for infected ventricular assist device augmented with dissolving antibiotic beads: Creation of an antibacterial pocket

Plastic Surgery Involvement With Surgical Management of Infected Ventricular Assist Devices Decreased Lifetime Return to Operating Room and 90-Day Infectious Complications

BACKGROUND

The use of left ventricular assist devices (LVADs) for patients with end-stage cardiac failure awaiting heart transplantation has become increasingly common. However, ventricular assist device-related infections remain a major problem complicating their long-term use. Retrospective review has previously shown a decrease in lifetime return to operating room (RTOR) with no change in 90-day complications when a muscle or omental flap is used for coverage after washout for infection. We wished to determine if early plastic surgery intervention led to a decreased length of stay for these patients.

METHODS

Patients with LVAD readmitted for LVAD infection at a single institution from 2008 to 2021 were identified using a preexisting database. Patients were followed retrospectively for an average of 3.2 years. Patient demographics, preoperative diagnosis/disease state, type of ventricular assist device inserted, postoperative day of ventricular assist device infection onset, definitive device coverage, timing of coverage procedure after the initial washout for infection, type of flap used for coverage, 90-day complications after definitive coverage, and lifetime return to operating room for infection were reviewed. Comparison analysis with χ2 and analysis of variance testing was used to analyze outcomes.

RESULTS

Of 568 patients admitted with an LVAD infection, 104 underwent operative debridement and closure by plastic and reconstructive surgery (PRS) or cardiothoracic surgery (CTS). Fifty-three underwent PRS closure, and 51 underwent CTS closure. There was an increased incidence of diabetes among the PRS group (P < 0.001); otherwise, there was no difference in baseline characteristics. There was increased RTOR over a lifetime with CTS closure compared with PRS (P = 0.03) and increased 90-day risk of infection (P = 0.007). Patients with PRS closure had an increased risk of postoperative hematoma (P = 046). Plastic and reconstructive surgery was typically consulted on hospital day 10. Both PRS and CTS closure patients were discharged on postoperative day 7, on average (P = 0.542).

CONCLUSIONS

Plastic surgery involvement with surgical decision making and closure of infected LVAD devices has a decrease in lifetime RTOR and decreased 90-day complications related to infections. There may be a benefit to earlier PRS consultation for coverage assessment.

Clinical Outcomes of Left Ventricular Assist Device Pump Infection

Few studies have focused on the clinical outcomes and risk factors of left ventricular assist device (LVAD) pump infection, and no standard treatment for LVAD pump infection has been established. Therefore, we used a therapeutic flowchart to manage LVAD pump infections. We retrospectively evaluated 220 patients who underwent continuous-flow LVAD implantation between January 2005 and March 2021 at Osaka University, Japan. First, we performed wound debridement, negative-pressure wound therapy, antibiotic treatment, and omental flap transposition. Subsequently, we administered conservative treatment, scheduled implantable LVAD exchange, or emergent removal of the implantable LVAD and exchange for extracorporeal LVAD or percutaneous LVAD (IMPELLA). Pump infections occurred in 32 patients. The survival rates of patients with pump infections during LVAD support were 93%, 74%, and 61% at 180 days, 1 year, and 2 years after LVAD pump infection, respectively. Fifteen patients underwent successful heart transplantation. Bridge-to-bridge surgery, preoperative use of venoarterial extracorporeal membrane oxygenation or percutaneous LVAD, high lactate dehydrogenase levels, and driveline infection were significantly associated with pump infection. Our study reveals that poor preoperative condition and driveline infection were significant risk factors for LVAD pump infection.

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.

Flap Coverage of Infected Ventricular Assist Devices Influences Patient Outcomes

BACKGROUND

The use of left ventricular assist devices (LVADs) for patients with end-stage cardiac failure awaiting heart transplantation has become increasingly common. However, ventricular assist device-related infections remain a major problem complicating their long-term use. Poor data exist to determine how to manage these infections after operative debridement.

METHODS

Patients who underwent insertion of a ventricular assist device and had a subsequent readmission for LVAD infection at the University of Rochester Medical Center from 2012 to 2022 were identified through accessing the medical records archives of the hospital. Patients were followed retrospectively for an average of 3.2 years. Patient demographics, preoperative diagnosis/disease state, type of ventricular assist device inserted, postoperative day of ventricular assist device infection onset, infectious organism identified at initial washout, infectious organism identified at time of definitive device coverage, timing of coverage procedure after the initial washout for infection, type of flap used for coverage, 90-day complications after definitive coverage, and lifetime return to operating room for infection were reviewed. Comparison analysis with a χ2 test was used to analyze outcomes.

RESULTS

Of 568 patients admitted with an LVAD-related infection 117 underwent operative debridement. Of these, 34 underwent primary closure, 31 underwent closure with secondary intention (negative pressure wound therapy with split thickness skin grafting), and 52 were closed with a flap (pectoralis, omental, latissimus, or vertical rectus abdominus musculocutaneous flap). There was a statistically significant higher incidence of return to the operating room (RTOR) for infection over a lifetime with primary closure compared with secondary intention and flap reconstruction (P = 0.01, 0.02), but no difference in 90-day complications (P = 0.76, P = 0.58). Eighty-three patients had a positive culture upon definitive coverage with 24 having a postsurgical complication, 15 of which required lifetime RTOR for infection. Thirty four were closed with negative cultures with 9 having a complication and 4 requiring RTOR for infection. This was not statistically significant for complications or RTOR (P = 0.79, 0.40). Culture data were further substratified into bacterial cultures (n = 73) versus fungal cultures (n = 10), and there was no statistically significant difference between these compared with complications or RTOR (P = 0.40, 0.39).

CONCLUSIONS

Coverage of infected LVADs with locoregional flaps or allowing to granulate using wound vac therapy has a decreased lifetime RTOR for future infections for these patients without increase in 90-day complications. Timing of RTOR should not be impacted by positive cultures provided there is healthy granulation tissue in the wound.

In-vitro model for bacterial growth inhibition of compartmentalized infection treated by an ultra-high concentration of antibiotics

BACKGROUND

Pseudomonas aeruginosa (P. aeruginosa), Escherichia coli (E. coli), and Staphylococcus aureus (S. aureus) are common pathogens encountered in infected cardiovascular-implantable electronic device (CIED). Continuous, in-situ targeted, ultra-high concentration antibiotic (CITA) treatment is a novel antibiotic treatment approach for localized infections. CITA provides sufficient local antibiotic concentrations to heavily infected cavities while avoiding systemic toxicity.

AIM

In-vitro confirmation of the efficacy of the CITA treatment approach in simulated compartmentalized infections.

MATERIALS AND METHODS

A rapid automated bacterial culture analyzing system) Uro4 HB&L™ (was applied to compare the efficacy of selected antibiotics at a standard minimal inhibitory concentration (1MIC), 4MIC, and CITA at 103MIC, for growth inhibition of high bacterial loads (106 colony-forming-units/ml) of ATCC strains of P. aeruginosa, E. coli, and S. aureus.

RESULTS

The addition of gentamicin and amikacin at 1MIC concentrations only temporarily inhibited the exponential growth of E. coli and P. aeruginosa. 4MIC level extended the delay of exponential bacterial growth. Increasing concentrations of vancomycin similarly temporarily delayed S. aureus growth. All tested antibiotics at CITA of 103MIC totally inhibited the exponential growth of the tested bacteria through 72 hours of exposure. (P<0.001).

CONCLUSION

In this in-vitro model, CITA at 103MIC effectively inhibited exponential bacterial growth of high loads of P. aeruginosa, E. coli, and S. aureus. This model offers preliminary laboratory support for the benefit of the in-situ antibiotic treatment, providing ultra-high concentrations directly at the compartmentalized infection site, not achievable by the conventional intravenous and oral routes.