title: Comparing velour versus silicone interfaces at the driveline exit site of HeartMate II devices: infection rates, histopathology, and ultrastructural aspects.
abstract: BACKGROUND
  Driveline exit site (DLES) infection is a major complication of ventricular assist devices (VADs). Differences in the sheath material interfacing with exit site tissue appear to affect healing time and infection risk more than site hygiene, but the mechanistic basis for this is not clear.
  
  
  METHODS
  Health record data from Utah Artificial Heart Program patients with HeartMate II (HMII) devices implanted from 2008 to 2012 were retrospectively reviewed, with particular attention to interface type, incorporation (healing) time, and infections. Tissue samples from the DLES were collected at the time of VAD removal in a small subset. These samples were examined by routine histology and environmental scanning electron microscopy (ESEM).
  
  
  RESULTS
  Among 57 patients with sufficient data, 15 had velour interfaces and 42 had silicone. Indications for and duration of support were similar between the groups. The silicone group had shorter incorporation time (45 ±22 vs. 56 ±34 days, P=.17) and fewer DLES infections (20% vs. 1.7%, P=.026, for patient infections and 0.0340 vs. 0.166, P=.16, for infections per patient-year). Tissues from five patients, three with velour, were examined. Velour interfaces demonstrated more hyperkeratosis, hypergranulosis, and dermal inflammation. By ESEM, the silicone driveline tracts appeared relatively smooth and flat, whereas the velour interface samples were irregular with deep fissures and globular material adhering to the surface.
  
  
  CONCLUSIONS
  Using the silicone portion of the HMII driveline at the DLES was associated with fewer infections and a trend toward faster healing in this small retrospective series. Whether the intriguing microscopic differences directly account for this needs further study on a larger scale.
authors.affiliation: Utah Artificial Heart Program, Intermountain Medical Center and Intermountain Healthcare, Salt Lake City, Utah.
authors.forename: Sean P
authors.initials: SP
authors.lastname: McCandless
authors.affiliation: Utah Artificial Heart Program, Intermountain Medical Center and Intermountain Healthcare, Salt Lake City, Utah.
authors.forename: Ian D
authors.initials: ID
authors.lastname: Ledford
authors.affiliation: Utah Artificial Heart Program, Intermountain Medical Center and Intermountain Healthcare, Salt Lake City, Utah.
authors.forename: Nathan O
authors.initials: NO
authors.lastname: Mason
authors.affiliation: Department of Cardiology, Intermountain Medical Center and Intermountain Healthcare, Salt Lake City, Utah.
authors.forename: Rami
authors.initials: R
authors.lastname: Alharethi
authors.affiliation: Department of Critical Care Intensive Medicine, Intermountain Medical Center and Intermountain Healthcare, Salt Lake City, Utah.
authors.forename: Brad Y
authors.initials: BY
authors.lastname: Rasmusson
authors.affiliation: Department of Cardiology, Intermountain Medical Center and Intermountain Healthcare, Salt Lake City, Utah.
authors.forename: Deborah
authors.initials: D
authors.lastname: Budge
authors.affiliation: Utah Artificial Heart Program, Intermountain Medical Center and Intermountain Healthcare, Salt Lake City, Utah.
authors.forename: Sandi L
authors.initials: SL
authors.lastname: Stoker
authors.affiliation: Department of Cardiothoracic Surgery, Intermountain Medical Center and Intermountain Healthcare, Salt Lake City, Utah.
authors.forename: Stephen E
authors.initials: SE
authors.lastname: Clayson
authors.affiliation: Department of Cardiothoracic Surgery, Intermountain Medical Center and Intermountain Healthcare, Salt Lake City, Utah.
authors.forename: John R
authors.initials: JR
authors.lastname: Doty
authors.affiliation: Department of Critical Care Intensive Medicine, Intermountain Medical Center and Intermountain Healthcare, Salt Lake City, Utah.
authors.forename: George E
authors.initials: GE
authors.lastname: Thomsen
authors.affiliation: Department of Cardiothoracic Surgery, Intermountain Medical Center and Intermountain Healthcare, Salt Lake City, Utah.
authors.forename: William T
authors.initials: WT
authors.lastname: Caine
authors.affiliation: Department of Cardiology, Intermountain Medical Center and Intermountain Healthcare, Salt Lake City, Utah.
authors.forename: Abdallah G
authors.initials: AG
authors.lastname: Kfoury
authors.affiliation: Department of Cardiothoracic Surgery, Intermountain Medical Center and Intermountain Healthcare, Salt Lake City, Utah.
authors.forename: Bruce B
authors.initials: BB
authors.lastname: Reid
authors.affiliation: Department of Pathology, Intermountain Medical Center and Intermountain Healthcare, Salt Lake City, Utah. Electronic address: Dylan.Miller@imail.org.
authors.forename: Dylan V
authors.initials: DV
authors.lastname: Miller
mesh_terms: D005260:Female; D006353:Heart-Assist Devices / Q000009:adverse effects*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011091:Polyesters / Q000009:adverse effects*; D016459:Prosthesis-Related Infections / Q000453:epidemiology / Q000209:etiology*; D012828:Silicones / Q000009:adverse effects*
chemical_list: D011091:Polyesters; D012828:Silicones; C020542:velour
keywords: Driveline exit site; HeartMate II; Infection; SEM; VAD