Heparin-related thrombosis despite normal platelet counts in vascular surgery.
BACKGROUND
Acute graft thrombosis is a severe complication in vascular surgery that may require limb amputation or even cause death. Because nearly all patients undergoing vascular surgery have had previous exposure to heparin, the presence of heparin-related anti-platelet antibodies typical for heparin-associated thrombocytopenia (HAT) is one underlying possible mechanism of acute graft thrombosis. Although thrombocytopenia is a typical finding of HAT, it is not clear whether the occurrence of clinically important HAT is necessarily associated with thrombocytopenia.


METHODS
Ten out of 246 patients undergoing vascular surgery were diagnosed with HAT because of otherwise unexplained acute graft thrombosis that required recurrent surgical interventions.


RESULTS
In all of the 10 patients, heparin-related anti-platelet antibodies were detected although the platelet counts were within the normal range. When HAT was diagnosed, heparin administration was stopped and, after autoantibody cross-reactivity with the heparinoid Danaparoid had been excluded, anticoagulation was continued using this anticoagulant. After heparin therapy was discontinued none of the 10 patients developed further thrombotic complications.


CONCLUSIONS
The data presented demonstrate clearly that a normal platelet count does not exclude the possibility of HAT. As a consequence of this, HAT should be suspected in patients who develop thrombotic complications during heparin treatment, regardless of the actual platelet counts.
Hach-Wunderle
V
V
Department of Angiology and Vascular Surgery, William Harvey-Klinik, Bad Nauheim, Germany.
Kainer
K
K
Salzmann
G
G
Müller-Berghaus
G
G
Pötzsch
B
B
D000328:Adult; D000368:Aged; D000714:Anastomosis, Surgical; D001157:Arterial Occlusive Diseases / Q000601:surgery*; D001323:Autoantibodies / Q000032:analysis; D001792:Blood Platelets / Q000276:immunology; D001807:Blood Vessel Prosthesis; D002809:Chondroitin Sulfates / Q000008:administration & dosage; D003871:Dermatan Sulfate / Q000008:administration & dosage; D004338:Drug Combinations; D005260:Female; D006083:Graft Occlusion, Vascular / Q000139:chemically induced*; D006493:Heparin / Q000009:adverse effects*; D006496:Heparinoids / Q000008:administration & dosage; D006497:Heparan Sulfate / Q000008:administration & dosage; D006801:Humans; D007431:Intraoperative Complications / Q000139:chemically induced; D008297:Male; D008875:Middle Aged; D010976:Platelet Count; D012086:Reoperation; D013927:Thrombosis / Q000139:chemically induced*; D014654:Vascular Patency
D001323:Autoantibodies; D002809:Chondroitin Sulfates; D003871:Dermatan Sulfate; D004338:Drug Combinations; D006493:Heparin; D006496:Heparinoids; D006497:Heparan Sulfate; C035838:danaparoid