This month Barbara A. Konkle, MD, discusses bleeding prevention in a patient undergoing spinal surgery.
And don’t forget to check out next month’s clinical dilemma – send in your responses for a chance to win an ASH Clinical News-themed prize!
I am evaluating a 60-year-old man for cervical spine surgery (disc disease with neurologic symptoms) who has a prolonged prothrombin time (PT). He appears to have mild factor VII (FVII) deficiency. His bleeding history is as follows: catheter ablation for atrial fibrillation (followed by warfarin for 10 months without bleeding), shockwave lithotripsy (no bleeding problems), and tooth extractions about 30 years ago (followed by bleeding for about 2 days, with no need for reevaluation or hemostasis). He has no problems with minor lacerations (e.g., shaving) and is physically active in taekwondo. The initial abnormality that prompted referral was a baseline PT of 15.2 seconds, international normalized ratio (INR) of 1.3, with normal partial thromboplastin time. Repeat PT was 13.8 seconds, INR 1.2, with the following factor levels: FVII 46 percent, factor II 86 percent, factor V 87 percent, and factor X 87 percent. The FVII deficiency literature suggests that surgical bleeding is rare if FVII is above 10 percent. One discussion suggested that 30 percent should be okay, but I am concerned about this being a critical bleeding site.
In determining the risk of bleeding in a patient with a rare factor deficiency, one must consider the factor level, information regarding bleeding risk for the specific deficiency, and the bleeding risk associated with the planned surgery.
Factor VII (FVII) deficiency is a rare bleeding disorder, which in the homozygous or compound heterozygous state has an estimated incidence of 1 in 500,000 individuals.1 Patients with low FVII levels (<10%) commonly have symptoms of mucosal and procedure-related bleeding, and less commonly hemarthroses, hematuria, central nervous system and gastrointestinal bleeding.1,2 The FVII level required for hemostasis is lower than for many other factors, and thus patients can have a FVII level low enough to result in a prolonged prothrombin time, even with a level above what is needed for hemostasis. The FVII hemostatic level generally has been thought to be 10 to 15 percent. The European Network of Rare Bleeding Disorders evaluated the relationship been bleeding and factor activity level in 489 patients with rare bleeding disorders, including 224 with FVII deficiency.3 In FVII deficiency, a trough level greater than 20 percent rendered people asymptomatic.
The patient described above has a FVII level well above the hemostatic level. Care is warranted given the high bleeding risk of the surgery planned. However, there are risks associated with treatment of FVII deficiency using either fresh frozen plasma or recombinant factor VIIa, and one should avoid risks if there are no data to support benefit. That the patient has an essentially negative bleeding history and did well on warfarin, which would lower the FVII level further, provides assurance that he is not at increased bleeding risk. Given the influence of FVII on the prothrombin time, should he require warfarin therapy in the future, another measure of warfarin activity such as the chromogenic FX assay should be used for monitoring.
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- Palla R, Peyvandi F, Shapiro. Rare bleeding disorders: diagnosis and treatment. Blood. 2015;125:2052-61.
- Mariani G, Barnardi F. Factor VII deficiency. Semin Thromb Hemost. 2009;35:400-6.
- Peyvandi F, Palla R, Menegatti M, et al. Coagulation factor activity and clinical bleeding severity in rare bleeding disorders: results from the European Network of Rare Bleeding Disorders. J Thromb Haemost. 2012;10:615-21.
NEXT MONTH'S CLINICAL DILEMMA
I am treating a 67-year-old man who is status/post a liver transplant four months ago. He had transfusion requirements one year prior to transplant, which have now increased. Absolute neutrophil count is variable (700-6,000/mm3). Bone marrow biopsy is hypercellular (70%) with myeloid left shift, but no dysplasia. Flow is negative. Myelodysplastic syndromes FISH panel is negative. Cytogenetics are normal. Myeloid next-generation sequencing shows the following mutations: TET2 (15-35%), ASXL1 (40-50%), and ZRSR2 (80-85%). So, technically he has clonal cytopenias of undetermined significance (CCUS). His erythropoietin level is 680 mU/mL. What therapeutic options are available to reduce his transfusion requirement?
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