Characterization of infected, explanted ventricular assist device drivelines: The role of biofilms and microgaps in the driveline tunnel

Yue Qu, David McGiffin, Christopher Hayward, Janelle McLean, Courtney Duncan, Desiree Robson, Christina Kure, Rong Shen, Helen Williams, Sherry Mayo, Helmut Thissen, Silvana Marasco, Adam Zimmet, Justin Negri, Paul Jansz, Kumud Dhital, David M. Kaye, Anton Y. Peleg

Research output: Contribution to journalArticleResearchpeer-review

Abstract

BACKGROUND: Driveline infections remain a major complication of ventricular assist device (VAD) implantation. This study aimed to characterize in vivo microbial biofilms associated with driveline infections and host tissue integration of implanted drivelines. METHODS: A total of 9 infected and 13 uninfected drivelines were obtained from patients with VAD undergoing heart transplantation in Australia between 2016 and 2018. Each driveline was sectioned into 11 pieces of 1.5 cm in length, and each section was examined by scanning electron microscopy (SEM) and viable counts for microbial biofilms. Microorganisms were cultured and identified. Host tissue integration of clinical drivelines was assessed with micro–computed tomography (CT) and SEM. An in vitro interstitial biofilm assay was used to simulate biofilm migration in the driveline tunnel, and time-lapse microscopy was performed. RESULTS: Of the 9 explanted, infected drivelines, all had organisms isolated from varying depths along the velour section of the drivelines, and all were consistent with the swab culture results of the clinically infected exit site. SEM and micro-CT suggested insufficient tissue integration throughout the driveline velour, with microgaps observed. Clinical biofilms presented as microcolonies within the driveline tunnel, with human tissue as the sub-stratum, and were resistant to anti-microbial treatment. Biofilm migration mediated by a dispersal-seeding mechanism was observed. CONCLUSIONS: This study of explanted infected drivelines showed extensive anti-microbial–resistant biofilms along the velour, associated with microgaps between the driveline and the surrounding tissue. These data support the enhancement of tissue integration into the velour as a potential preventive strategy against driveline infections by preventing biofilm migration that may use microgaps as mediators.

Original languageEnglish
Pages (from-to)1289-1299
Number of pages11
JournalThe Journal of Heart and Lung Transplantation
Volume39
Issue number11
DOIs
Publication statusPublished - Nov 2020

Keywords

  • biofilms
  • driveline infections
  • in vivo
  • microgaps
  • tissue integration
  • ventricular assist device

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