Continuous infusion during total joint arthroplasty in Japanese haemophilia A patients: comparison study among two recombinants and one plasma-derived factor VIII

Rates of venous thromboembolism and use of thromboprophylaxis after major orthopedic surgery in patients with congenital hemophilia A or B: a systematic review

BACKGROUND

Venous thromboembolism (VTE) is a well-recognized complication after total joint replacement (TJR). Persons with hemophilia A or B are considered at low postoperative VTE risk due to their coagulation factor deficiencies, and administering pharmacologic thromboprophylaxis is often considered contraindicated. However, using factor replacement therapy could increase the postoperative VTE risk.

OBJECTIVES

To analyze best available evidences of VTE rates in persons with hemophilia A or B undergoing lower limb TJR and the use of postoperative pharmacologic thromboprophylaxis.

METHODS

We systematically screened 4 online biomedical databases to identify studies reporting VTE rates in patients with hemophilia after TJR. Case reports and case series with less than 10 patients were excluded.

RESULTS

Twenty-six observational studies were included in this systematic review, reporting 1181 TJRs in patients with hemophilia A or B. Eight studies had VTE rates as the primary outcome. Five studies reported screen-detected VTE, while 21 reported symptomatic VTE events. Overall, 17 VTE events were reported (1.4%; 95% CI, 0.9%-2.3%), including 10 (6.6%) after 151 surgeries with postoperative VTE screening and 7 (0.7%) after 1080 surgeries without postoperative screening. Thromboprophylaxis protocols were specified in 21 studies; postoperative thromboprophylaxis was used in 15 (1.3%) surgeries. This information was not available for 29.0% of the analyzed population.

CONCLUSION

Despite the low thromboprophylaxis use in patients with hemophilia, rates of symptomatic VTE after TJR appeared to be low. We also highlighted the need to better report the thrombotic outcome in persons with hemophilia to face the ongoing changes in the hemophilia landscape.

Continuous Infusion of Factor VIII and von Willebrand Factor in Surgery: Trials with pdFVIII LFB or pdVWF LFB in Patients with Bleeding Disorders

INTRODUCTION

A plasma-derived factor VIII product (pdFVIII, Factane 100 or 200 IU/mL) and a plasma-derived von Willebrand factor product (pdVWF, Wilfactin 100 IU/mL) are approved for replacement therapy by intravenous bolus injections in haemophilia A (HA) and von Willebrand disease (VWD), respectively. However, in situations requiring intensive treatment, continuous infusion (CI) may be desirable to better control target plasma factor levels.

AIM

To evaluate the perioperative haemostatic efficacy and safety of these concentrates administered by CI.

METHODS

Three phase III trials were conducted. Adults with HA (FVIII:C <1%) (Studies 1 and 2) or VWD (VWF:RCo <20%) (Study 3) received a preoperative bolus followed by CI of undiluted concentrate for at least 6 days. Bolus doses and CI rates were based on individual recovery and clearance, respectively. Initial infusion rate had to be higher for 48 hours for HA and 24 hours for VWD patients to anticipate potential fluctuations of factor concentrations during major surgery. Target levels of FVIII:C in HA and VWF:RCo in VWD were 80 and 70 IU/dL, respectively. Efficacy was assessed using a global haemostatic efficacy score.

RESULTS

Studies 1, 2, and 3 included 12, 4 and 6 patients, respectively. Efficacy outcomes were excellent/good in all 22 major surgeries including 18 orthopaedic procedures. Most daily measured FVIII and VWF levels (92%) were on target. No safety concerns, thrombotic events or inhibitors were identified.

CONCLUSION

pdFVIII and pdVWF administered by CI represent an effective and safe alternative to bolus injections in patients with severe HA or VWD undergoing surgery.

Stability of Turoctocog Alfa, a Recombinant Factor VIII Product, during Continuous Infusion In Vitro

Objective  Turoctocog alfa is a recombinant factor VIII (rFVIII) for the prevention and treatment of bleeding in patients with hemophilia A, including those undergoing surgery and invasive medical procedures. This in vitro study evaluated the physical and chemical stability of turoctocog alfa during continuous infusion (CI) over 24 hours at 30°C.

Materials and Methods  The study was performed at 30°C ( ± 2°C). A CI system with pump speed set at either 0.6 or 1.5 mL/h was used to evaluate the stability of three turoctocog alfa strengths (500, 1,000, and 3,000 IU), equating to doses of 1.1 to 16.1 IU/h per kilogram of body weight. The following parameters were evaluated at selected time points between 0 and 24 hours: appearance of solution, clarity, pH, potency, purity, content, total high molecular weight proteins (HMWPs), and oxidized rFVIII.

Results  The mean potency of turoctocog alfa was maintained within the predefined acceptance criteria during CI for both pump speeds with all three strengths at 6, 12, or 24 hours (500 IU: ≥484 IU/vial; 1,000 IU: ≥1,014 IU/vial; and 3,000 IU: ≥3,029 IU/vial). Furthermore, the appearance of solution, clarity, pH, purity, content of turoctocog alfa, total HMWP, and oxidized forms were also within the predefined limits, and comparable to the reference samples (time = 0 hours) for the pump speeds and product strengths assessed.

Conclusion  Physical and chemical stability of turoctocog alfa was maintained during CI over 24 hours. There was only minor degradation or changes in any of the parameters tested. Potency was within the prespecified acceptance limits throughout 24 hours of infusion. These findings confirm the suitability of turoctocog alfa for CI.

Continuous infusion of coagulation factor concentrates during intensive treatment

In clinical management of bleeds and surgical procedures in patients suffering from bleeding disorders either repetitive bolus injections (BI) or continuous infusion (CI) can be used for coagulation factor replacement. Continuous infusion seems to be an attractive route of administration and may be considered if replacement therapy is required for more than 3 days. The strongest argument favouring continuous infusion is its superiority in providing the patient with a safe and constant level of the deficient coagulation factor by balancing input with clearance. Furthermore, several studies have shown that coagulation factor consumption may be reduced by CI compared to repetitive bolus injections (BI) since unnecessary peaks of factor level are avoided. Concerns have been raised whether continuous infusion of coagulation concentrates is associated with an increased risk of developing inhibitors. However, available data have so far not shown an increased risk for inhibitor development in severe haemophilia patients with more than 50 exposure days of coagulation factor concentrates. Further, previously reported complications when using CI such as phlebitis at the infusion site and pump failure are nowadays very seldom seen when small amounts of heparin are added to the infusion bag, and increased quality of the pumps are available. Over the last decades, numerous reports have confirmed CI to be a safe and effective mode of coagulation factor replacement even in the most challenging surgical procedures, such as total joint arthroplasties.

Comparison of continuous infusion versus bolus injection of factor concentrates for blood management after total knee arthroplasty in patients with hemophilia

Background

Total knee arthroplasty (TKA) has become the treatment of choice for end-stage hemophilic arthropathy of the knee. Theoretically in hemophilia A, perioperative continuous infusion (CI) of factor VIII (FVIII) would provide a more consistent FVIII level than general bolus injections (BI) in TKA. Current study was designed to evaluate the effectiveness of CI of coagulation factor concentrates during the perioperative period compared to BI.

Methods

A total of 42 TKAs were performed in 31 patients with severe hemophilia A. Under the supervision of a multidisciplinary hemophilia team, CI and BI were monitored during application of a standardized regimen. Perioperative clinical parameters including postoperative hemoglobin drop, drained blood volume, transfusion rate, total consumption of FVIII, and perioperative complications were assessed.

Results

The difference in the postoperative hemoglobin drop was significant between two groups with a lower decrease in the CI group (p = 0.002). The drained blood volume for postoperative 24 h was significantly lower in the CI than the BI groups (p = 0.037). Total consumption of factor concentrates for postoperative 5 days was greater in the CI group than in the BI group (p = 0.000). One postoperative hematoma and wound dehiscence occurred in BI group and no other complication developed.

Conclusions

Although good control of hemostasis could be achieved using either method during the perioperative period of TKA, CI seems more tolerable and effective than BI to provide perioperative blood management undergoing TKA in patients with hemophilia.

Trial registration

The study was retrospectively registered in WHO ICTRP under identifier KCT0002404 (date of registration: August 04, 2017).

Perioperative treatment of hemophilia A patients: blood group O patients are at risk of bleeding complications

ESSENTIALS: Targeting of factor VIII values is a challenge during perioperative replacement therapy in hemophilia. This study aims to identify the extent and predictors of factor VIII underdosing and overdosing. Blood group O predicts underdosing and is associated with perioperative bleeding. To increase quality of care and cost-effectiveness of treatment, refining of dosing is obligatory.

SUMMARY

BACKGROUND

Perioperative administration of factor VIII (FVIII) concentrate in hemophilia A may result in both underdosing and overdosing, leading to respectively a risk of bleeding complications and unnecessary costs.

OBJECTIVES

This retrospective observational study aims to identify the extent and predictors of underdosing and overdosing in perioperative hemophilia A patients (FVIII levels < 0.05 IU mL(-1)).

PATIENTS AND METHODS

One hundred nineteen patients undergoing 198 elective, minor, or major surgical procedures were included (median age 40 years, median body weight 75 kg). Perioperative management was evaluated by quantification of perioperative infusion of FVIII concentrate and achieved FVIII levels. Predictors of underdosing and (excessive) overdosing were analyzed by logistic regression analysis. Excessive overdosing was defined as upper target level plus ≥ 0.20 IU mL(-1).

RESULTS

Depending on postoperative day, 7-45% of achieved FVIII levels were under and 33-75% were above predefined target ranges as stated by national guidelines. A potential reduction of FVIII consumption of 44% would have been attained if FVIII levels had been maintained within target ranges. Blood group O and major surgery were predictive of underdosing (odds ratio [OR] 6.3, 95% confidence interval [CI] 2.7-14.9; OR 3.3, 95% CI 1.4-7.9). Blood group O patients had more bleeding complications in comparison to patients with blood group non-O (OR 2.02, 95% CI 1.00-4.09). Patients with blood group non-O were at higher risk of overdosing (OR 1.5, 95% CI 1.1-1.9). Additionally, patients treated with bolus infusions were at higher risk of excessive overdosing (OR 1.8, 95% CI 1.3-2.4).

CONCLUSION

Quality of care and cost-effectiveness can be improved by refining of dosing strategies based on individual patient characteristics such as blood group and mode of infusion.

Perioperative management of hemophilia patients receiving total hip and knee arthroplasty: a complication report of two cases

It has been recognized that perioperative hemostasis management after joint-replacement surgery for hemophilia patients is complicated and cumbersome, due to the necessity of rigorous monitoring for clotting-factor levels throughout the infusion. Between 2005 and 2014, we examined seven patients with hemophilia A (ten joints: six hips and four knees) receiving total hip or knee arthroplasty (THA or TKA) for hemophilic arthropathy. One male patient (31 years old) showed an intra-articular hematoma formation after THA (case 1). In another male patient (46 years old) receiving TKA, the postoperative trough factor VIII level became lower significantly than reference levels (80%–100% for the 5–10 postoperative days) recommended by the guidelines from the Japanese Society on Thrombosis and Hemostasis, despite sufficient coagulant based on the guidelines being administered (case 2). In the latter patient, deep infection and hematoma formation were observed postoperatively. In this article, we provide a detailed clinical report regarding these two complication cases at the early postoperative periods, and the management of bleeding control for hemophilia patients is discussed.

Turoctocog alfa: an evidence-based review of its potential in the treatment of hemophilia A

Turoctocog alfa is the first B-domain-truncated third generation recombinant coagulation factor VIII (FVIII) product. Nonclinical in vitro and animal model studies have demonstrated that turoctocog alfa has similar functional potency and hemostatic efficacy as comparator FVIII products. With respect to discrepancies in the level of FVIII concentrate in plasma of current FVIII products on comparing measurement results between one-stage clot and chromogenic assays, there was no difference in the in vitro turoctocog alfa study; however, measured FVIII concentrate in field study was higher with the chromogenic assay (1.08 IU/mL) than with one-stage assay (0.83 IU/mL). Two published clinical studies on previously treated patients (PTPs) and clinical pharmacokinetics have described that the pharmacokinetic parameters are similar, and the safety and efficacy for prevention and treatment for bleeding are also similar to those of standard half-life FVIII products. Three clinical trials are ongoing to assess the long-term safety and efficacy of turoctocog alfa for PTPs and previously untreated patients. Those data will be published in the near future, and it will be possible to use turoctocog alfa for all hemophilia patients. However, studies will be needed to confirm the turoctocog alfa profile, such as the stability of dissolved turoctocog alfa over 24 hours at room temperature and post-marketing clinical research aimed at meeting Europe Medicines Agency post-marketing safety and efficacy requirements in PTPs. It is recommended to wait before using turoctocog alfa for previously untreated patients and major surgery until further data have been collected and published.

Progress of in vitro factor VIII coagulant activity from 0 to 8 hours after reconstitution

Background

Continuous infusion of factor VIII (FVIII) is a more cost-effective method for treating hemophilia A than intermittent bolus injection. However, there is currently no specific data in Korea about the progress of in vitro FVIII coagulant activity (FVIII:C) after reconstitution from its lyophilized form.

Methods

Three commercial FVIII concentrate products (two recombinant FVIII and one plasma-derived) were used. In vitro FVIII:C was measured at 0, 2, 4, 6, and 8 hours following reconstitution in both the indoor light-exposed and light-shielded groups.

Results

For the three drugs, in vitro FVIII:C decreased over the 8 hours following reconstitution (P<0.001). The decline of FVIII:C was linear (P<0.001). In vitro FVIII:C for the indoor light-exposed groups was 95.3±1.9% and 90.6±2.5% after 4 and 8 hours following reconstitution, respectively, compared to baseline activity. In the light-shielded group, FVIII:C was 95.4±1.1% and 90.9±1.7% of the baseline activity after 4 and 8 hours, respectively. There was no statistical difference between FVIII:C in the indoor light-exposed and light-shielded groups (P=0.849).

Conclusion

In vitro FVIII:C decreased after reconstitution, but activity was maintained at over 90% of the baseline value during 8 hours. Exposure to indoor light did not accelerate the loss of FVIII:C over the experimental time. This result indicates that CI with FVIII is available in 8-hour intervals, with no indoor light-exposure precautions needed.

Perioperative haemostatic management of haemophilic mice using normal mouse plasma

Intense haemostatic interventions are required to avoid bleeding complications when surgical procedures are performed on haemophilia patients. The objective of this study was to establish an appropriate protocol for perioperative haemostatic management of haemophilic mice. We assessed the prophylactic haemostatic effects of normal mouse plasma (NMP) on haemophilia B (HB) mice for both a skin flap procedure and a laparotomy. When 500 μL of NMP was administered to the mice, plasma factor IX (FIX:C) levels peaked at 15.1% immediately after intravenous (IV) administration, at 6.1% 2 h after intraperitoneal (IP) administration and at 2.7% 6 h after subcutaneous administration. Administering 500 μL of NMP via IP or IV 30 min in advance enabled the skin flap procedure to be performed safely without any complications. After the laparotomy procedure, several mice in the IP administration group exhibited lethal bleeding, but all mice survived in the IV administration group. Anti-mouse FIX inhibitors did not develop, even after repetitive administrations of NMP. However, human FIX concentrates, especially plasma-derived concentrates, elicited the anti-human FIX inhibitors. The results show that administering 500 μL of NMP via IV or IP 30 min in advance enables surgical procedures to be safely performed on HB mice, and that IV administration is more desirable than IP if the procedure requires opening of the abdominal wall.