title: Recurrent white thrombi formation in hemodialysis tubing: a case report.
abstract: BACKGROUND
  While the appearance of red clots in the dialyzer is a common phenomenon in every hemodialysis unit, the occurrence of white thrombi in the tubing is relatively rare.
  
  
  METHODS
  We describe an adolescent male with recurrent white thrombi formation in the hemodialysis tubing. This patient had chronic renal failure from focal segmental glomerulosclerosis, but was no longer nephrotic at the time of the thrombi formation. He had a history of recurrent thrombosis of his vascular access. However, no pro-thrombotic risk factors could be identified. White particulate matter, measuring 1 to 3mm in size, and adherent to the arterial and venous blood tubing lines was found during the rinse back of a hemodialysis session. This was associated with a 60% decrease in his platelet count. Light microscopic examination of the deposits revealed the presence of platelet aggregates. He subsequently developed thrombosis of his arteriovenous graft six hours later. The white thrombi recurred at the next dialysis session, as well as six months later. These episodes occurred regardless of the type of dialysis machine or tubing, and appeared to resolve with an increase in heparin dose.
  
  
  CONCLUSIONS
  Recurrent white thrombi formation can occur in the hemodialysis tubing of a patient with no identifiable pro-thrombotic factors. The white thrombi may be a harbinger of arteriovenous graft thrombosis and may be prevented by an increase in heparin dose.
authors.forename: Kiran P
authors.initials: KP
authors.lastname: Sathe
authors.forename: Wee-Song
authors.initials: WS
authors.lastname: Yeo
authors.forename: Isaac Desheng
authors.initials: ID
authors.lastname: Liu
authors.forename: Sudha
authors.initials: S
authors.lastname: Ekambaram
authors.forename: Mohammed
authors.initials: M
authors.lastname: Azar
authors.forename: Hui-Kim
authors.initials: HK
authors.lastname: Yap
authors.affiliation: Shaw-NKF-NUH Children's Kidney Centre, Khoo Teck Puat-National University Children's Medical Institute, National University Health System, Level 12 NUHS Tower Block, 1E Kent Ridge Road, Singapore 119228, Singapore. kar_hui_ng@nuhs.edu.sg.
authors.forename: Kar-Hui
authors.initials: KH
authors.lastname: Ng
mesh_terms: D000293:Adolescent; D005923:Glomerulosclerosis, Focal Segmental / Q000150:complications; D006801:Humans; D007676:Kidney Failure, Chronic / Q000209:etiology / Q000628:therapy*; D008297:Male; D012008:Recurrence; D006435:Renal Dialysis / Q000009:adverse effects* / Q000295:instrumentation*; D013927:Thrombosis / Q000209:etiology*; D062666:Vascular Access Devices / Q000009:adverse effects