The validity of canine platelet aggregometry in predicting vascular graft patency.
Several laboratories have found canine platelet aggregometry predictive of thrombotic potential in vascular grafts. Adenosine diphosphate (ADP) is a frequently used agonist, often at unspecified or differing concentrations. This study was designed to evaluate the predictive value of ADP-induced platelet aggregometry and the validity of the methodology. Platelet aggregometry in response to 2 x 10(-5) M ADP was assayed in 70 dogs. Twenty-six percent were aggregators, 51% were non-aggregators, and 20% were indeterminant. All dogs were then treated with aspirin and dipyridamole. Vascular prostheses were implanted bilaterally (aorto-iliac) and anti-platelet therapy continued for two weeks. Dose-response to ADP was studied at three concentrations in 20 dogs. At 2 x 10(-5) 1/20 aggregated, at 4 x 10(-5) 3/19 aggregated and at 2 x 10(-4) 15/20 aggregated. Time between samples and study was evaluated in 11 dogs, with 2/11 changing from non-aggregator to aggregator at two or three hours. Daily reproducibility was studied in 70 dogs, 14 of which changed aggregation status between days. Patency was 58/68 (85%) for non-aggregators, 23/34 (68%) for aggregators (p = 0.038). Platelet aggregometry has significant predictive value for graft patency but methodology must be specified and standardized.
Greisler
H P
HP
Department of Surgery, Loyola University Medical Center, Maywood, Illinois.
McGurrin
J F
JF
Klosak
J J
JJ
Tattersall
C W
CW
Ellinger
J
J
Henderson
S C
SC
Cabusao
E A
EA
D000244:Adenosine Diphosphate / Q000008:administration & dosage / Q000502:physiology / Q000627:therapeutic use; D000818:Animals; D001241:Aspirin / Q000008:administration & dosage / Q000627:therapeutic use; D001807:Blood Vessel Prosthesis / Q000145:classification; D004176:Dipyridamole / Q000008:administration & dosage / Q000627:therapeutic use; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D005069:Evaluation Studies as Topic; D006083:Graft Occlusion, Vascular / Q000097:blood / Q000188:drug therapy / Q000453:epidemiology*; D010974:Platelet Aggregation / Q000187:drug effects / Q000502:physiology*; D010976:Platelet Count; D011237:Predictive Value of Tests; D011379:Prognosis; D015203:Reproducibility of Results
D000244:Adenosine Diphosphate; D004176:Dipyridamole; D001241:Aspirin