title: Effects of Aspirin Therapy on Ultrasound-Guided Renal Allograft Biopsy Bleeding Complications.
abstract: OBJECTIVE
  To determine if patient aspirin exposure and timing affect bleeding risk after renal allograft biopsy.
  
  
  METHODS
  Review of 6,700 renal allograft biopsies (in 2,362 unique patients) was performed. Median patient age was 53.0 years [interquartile range 43.0, 62.0]; 56.2% of patients were male. Of biopsies, 4,706 (70.2%) were performed in patients with no aspirin exposure within 10 days of biopsy; 664 (9.9%), were performed within 8-10 days of aspirin exposure; 855 (12.8%), within 4-7 days; and 475 (7.1%), within 0-3 days. Follow-up to 3 months after the procedure was completed in all patients. Biopsies were categorized as protocol or indication; 19.7% were indication biopsies. Bleeding complications were graded based on SIR criteria. Logistic regression models examined the association between aspirin use and bleeding events.
  
  
  RESULTS
  Rate [95% confidence interval] of major bleeding complications was 0.24% [0.14, 0.39], and rate of any bleeding complication was 0.66% [0.46, 0.90]. Bleeding events were significantly associated with patients undergoing indication biopsies compared with protocol biopsies (odds ratio [OR] 2.27, P = .012). Patient factors associated with major bleeding complications in multivariate models included estimated glomerular filtration rate (OR 0.61, P = .016) and platelet count (OR 0.64, P = .033). Aspirin use was not significantly associated with increased risk of bleeding complication except for use of 325 mg of aspirin within 3 days of biopsy (any complication OR 3.87 [1.12, 13.4], P = .032; major complication OR 6.30 [1.27, 31.3], P = .024).
  
  
  CONCLUSIONS
  Renal allograft biopsy bleeding complications are very rare, particularly for protocol biopsies. Use of 325 mg of aspirin within 3 days of renal allograft biopsy was associated with increased bleeding complications.
authors.affiliation: Department of Radiology, 200 First Street SW, Rochester, MN 55905. Electronic address: baffour.francis@mayo.edu.
authors.forename: Francis I
authors.initials: FI
authors.lastname: Baffour
authors.affiliation: Division of Nephrology and Hypertension, 200 First Street SW, Rochester, MN 55905.
authors.forename: LaTonya J
authors.initials: LJ
authors.lastname: Hickson
authors.affiliation: Department of Medicine, Division of Transplant Surgery, 200 First Street SW, Rochester, MN 55905.
authors.forename: Mark D
authors.initials: MD
authors.lastname: Stegall
authors.affiliation: Department of Medicine, Division of Transplant Surgery, 200 First Street SW, Rochester, MN 55905.
authors.forename: Patrick G
authors.initials: PG
authors.lastname: Dean
authors.affiliation: Department of Surgery, Division of Biomedical Statistics and Informatics, 200 First Street SW, Rochester, MN 55905.
authors.forename: Tina M
authors.initials: TM
authors.lastname: Gunderson
authors.affiliation: Division of Ultrasound, 200 First Street SW, Rochester, MN 55905.
authors.forename: Thomas D
authors.initials: TD
authors.lastname: Atwell
authors.affiliation: Division of Ultrasound, 200 First Street SW, Rochester, MN 55905.
authors.forename: A Nicholas
authors.initials: AN
authors.lastname: Kurup
authors.affiliation: Division of Abdominal Imaging, 200 First Street SW, Rochester, MN 55905.
authors.forename: John J
authors.initials: JJ
authors.lastname: Schmitz
authors.affiliation: Division of Surgery Research Services, 200 First Street SW, Rochester, MN 55905; Department of Health Sciences Research, and William J. von Liebig Center for Transplantation and Clinical Regeneration, Mayo Clinic, 200 First Street SW, Rochester, MN 55905.
authors.forename: Walter D
authors.initials: WD
authors.lastname: Park
authors.affiliation: Division of Abdominal Imaging, 200 First Street SW, Rochester, MN 55905.
authors.forename: Grant D
authors.initials: GD
authors.lastname: Schmit
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D064591:Allografts; D001241:Aspirin / Q000008:administration & dosage / Q000009:adverse effects*; D001777:Blood Coagulation / Q000187:drug effects*; D016009:Chi-Square Distribution; D004334:Drug Administration Schedule; D005260:Female; D005919:Glomerular Filtration Rate; D006470:Hemorrhage / Q000139:chemically induced*; D006801:Humans; D061705:Image-Guided Biopsy / Q000009:adverse effects*; D007668:Kidney / Q000473:pathology* / Q000503:physiopathology; D016030:Kidney Transplantation / Q000009:adverse effects; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D016017:Odds Ratio; D010975:Platelet Aggregation Inhibitors / Q000008:administration & dosage / Q000009:adverse effects*; D010976:Platelet Count; D012189:Retrospective Studies; D012307:Risk Factors; D012737:Sex Factors; D013997:Time Factors; D016896:Treatment Outcome; D018084:Ultrasonography, Interventional / Q000009:adverse effects*
chemical_list: D010975:Platelet Aggregation Inhibitors; D001241:Aspirin