Hemophilia B, an X-linked recessive deficiency of factor IX, is present in 1 in 25,000 to 30,000 male births. Hemophilia B patients exhibit a range of clinical severity that correlates with factor levels and can be mild (>5%), moderate (1 to 5%), or severe (<1%). Severe hemophilia B typically presents with spontaneous hemorrhage before age 2. Patients with mild-to-moderate disease are more likely to present later in childhood or teenage years with median age of diagnosis of 11.5 years.
The available guidelines are helpful in guiding perioperative hemostasis for most surgeries, as well as managing bleeding complications including intracranial hemorrhage. Unfortunately, very little prospective data exist to guide elective high risk neurosurgeries. This paucity has resulted in a reluctance to offer these patients desperately needed interventions.
We report a unique case of undiagnosed mild hemophilia B that was found incidentally at age 64 during pre-operative workup. Additionally, we describe this patient’s successful peri-operative care.
A 64 year-old man with intractable Parkinson’s disease was referred to the hematology clinic following a neurosurgical evaluation for deep brain stimulator implantation. His preoperative laboratory studies revealed a prolonged aPTT, and normal PT/INR.Past surgeries included uncomplicated knee arthroscopy and appendectomy.
The patient has a life-long history of easy bruising, yet no history of spontaneous or provoked bleeding. There were no immediate family members with known bleeding disorders; however the patient described a history of excessive bleeding in his maternal grandfather.
Further laboratory evaluation revealed an aPTT of 45.9 seconds and a factor IX level of 13%. Laboratory results were repeated at a separate institution and a reference laboratory for confirmation. Inhibitor studies were negative.Antiphospholipidantibodies were also negative. PTT 1:1 mixing study shoed full correction. Factor II, VII, X, and XI studies were normal. Given the patient’s laboratory findings and positive family history,he was diagnosed with inherited hemophilia B.
In preparation for bilateral sub-thalamic stimulator implantation, a Factor IX replacement protocol was devised to minimize the risk of intracranial hemorrhage.
The patient was admitted one day prior to surgery. Factor IX concentrates (AlphaNineâ) were utilized. Factor IX was dosed to achieve a preoperative trough factor level of over 100%. Factor IX maintenance was started promptly and doses to achieve a trough level of 80% to 100% for the next 14 days, then to achieve a trough level of 50% for 7 additional days for a total factor support of 21 days. Peak and trough levels were monitored. The patient had 2 sequential surgeries in order to implant deep brain stimulation electrodes in the left and right sub-thalamic nuclei, respectively. Subsequently, a third surgery was required for implantation of the pulse generator and tunneled extension wires. Following the initial seven days of postoperative therapy, the patient was discharged with daily self-administered factor IX. The three-stage surgical approach was successful and no bleeding events were observed during the peri-operative and follow up period. Family counseling and testing was initiated for male family members.
Hemophilia is a rare disease and often presents early in life. This unique patient had minimal surgical and traumatic exposure, resulting in a subclinical bleeding disorder that remained undisclosed until advanced age. In fact, this report represents one of the oldest age at presentation of Hemophilia B in literature.
Although this rare case benefitted from extensive pre-operative bleeding assessment, we do not advocate changing current guidelines regarding peri-operative risk assessment and evaluation. However, this case highlighted the occasional significance of persistent prolonged aPTT and need for evaluation by a hematologist, especially if high-risk invasive intervention is contemplated.
Multidisciplinary care and appropriate factor support for patients with hemophilia can reduce their operative bleeding risk, as we demonstrated in this case. A diagnosis of hemophilia should not preclude elective surgical intervention provided that this is performed at a tertiary center that is equipped with resources and expertise to meet the special needs of this patient population.
No relevant conflicts of interest to declare.
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