Coagulation abnormalities can present as a diagnostic challenge during pre-operative workup. We r... more Coagulation abnormalities can present as a diagnostic challenge during pre-operative workup. We report a case of a 71-year-old man with isolated prolonged activated partial thromboplastin time (APTT) noted in the setting of pre-proctocolectomy workup. There was no previous history of clinically significant bleeding apart from intermittent gastrointestinal bleeding in the setting of severe Crohn's disease. He had undergone previous laparoscopic high anterior resection of the bowel with no prolonged surgical bleeding. Extended coagulation testing including testing with multiple APTT reagents and mixing studies were performed. Despite the mixing studies correcting on 1:1 mix with normal pooled plasma indicating a possible factor deficiency, intrinsic factors (Factors VIII, IX, XI and XII) and contact factor (prekallikrein) studies were within normal limits. Lupus anticoagulant testing performed using two different methods were negative although false negative results are possible given the heterogeneity of these autoantibodies and a weaker lupus anticoagulant may be missed. Overall, commercial laboratory coagulation testing was not helpful in achieving a final diagnosis and we utilised a combination global coagulation assays including whole blood thromboelastography and platelet-poor plasma thrombin generation using calibrated automated thrombogram and ST Genesia for his peri-operative decision making. Interestingly, the patient demonstrated hypercoagulable global coagulation assay parameters including increased endogenous thrombin potential (ETP) and maximum amplitude (MA) on thromboelastography. While extensive testing was inconclusive, global coagulation assays provided reassurance that the patient is unlikely to have an underlying bleeding phenotype.
Coagulation abnormalities can present as a diagnostic challenge during pre-operative workup. We r... more Coagulation abnormalities can present as a diagnostic challenge during pre-operative workup. We report a case of a 71-year-old man with isolated prolonged activated partial thromboplastin time (APTT) noted in the setting of pre-proctocolectomy workup. There was no previous history of clinically significant bleeding apart from intermittent gastrointestinal bleeding in the setting of severe Crohn's disease. He had undergone previous laparoscopic high anterior resection of the bowel with no prolonged surgical bleeding. Extended coagulation testing including testing with multiple APTT reagents and mixing studies were performed. Despite the mixing studies correcting on 1:1 mix with normal pooled plasma indicating a possible factor deficiency, intrinsic factors (Factors VIII, IX, XI and XII) and contact factor (prekallikrein) studies were within normal limits. Lupus anticoagulant testing performed using two different methods were negative although false negative results are possible given the heterogeneity of these autoantibodies and a weaker lupus anticoagulant may be missed. Overall, commercial laboratory coagulation testing was not helpful in achieving a final diagnosis and we utilised a combination global coagulation assays including whole blood thromboelastography and platelet-poor plasma thrombin generation using calibrated automated thrombogram and ST Genesia for his peri-operative decision making. Interestingly, the patient demonstrated hypercoagulable global coagulation assay parameters including increased endogenous thrombin potential (ETP) and maximum amplitude (MA) on thromboelastography. While extensive testing was inconclusive, global coagulation assays provided reassurance that the patient is unlikely to have an underlying bleeding phenotype.
Uploads
Papers by Niki Lee