Oral bleeding in hemophilia: treatment with epsilon aminocaproic acid and replacement therapy

Antifibrinolytic therapy for preventing oral bleeding in patients with haemophilia or Von Willebrand disease undergoing minor oral surgery or dental extractions

BACKGROUND

Minor oral surgery or dental extractions (oral or dental procedures) are widely performed and can be complicated by hazardous oral bleeding, especially in people with an inherited bleeding disorder such as haemophilia or Von Willebrand disease (VWD). The amount and severity of singular bleedings depend on disease-related factors, such as the severity of the haemophilia, both local and systemic patient factors (such as periodontal inflammation, vasculopathy or platelet dysfunction) and intervention-related factors (such as the type and number of teeth extracted or the dimension of the wound surface). Similar to local haemostatic measures and suturing, antifibrinolytic therapy is a cheap, safe and potentially effective treatment to prevent bleeding complications in individuals with bleeding disorders undergoing oral or dental procedures. However, a systematic review of trials reporting outcomes after oral surgery or a dental procedure in people with an inherited bleeding disorder, with or without, the use of antifibrinolytic agents has not been performed to date. This is an update of a previously published Cochrane Review.

OBJECTIVES

Primarily, we aim to assess the efficacy of antifibrinolytic agents to prevent bleeding complications in people with haemophilia or VWD undergoing oral or dental procedures.Secondary objectives are to assess if antifibrinolytic agents can replace or reduce the need for clotting factor concentrate therapy in people with haemophilia or VWD and to establish the effects of these agents on bleeding in oral or dental procedures for each of these patient populations.

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group's Coagulopathies Trials Register, compiled from electronic database searches of the Cochrane Central Register of Controlled Trials (CENTRAL), of MEDLINE and from handsearching of journals and conference abstract books. We additionally searched the reference lists of relevant articles and reviews. We searched PubMed, Embase, Cinahl and the Cochrane Library. Additional searches were performed in ClinicalTrials.gov, WHO International Clinical Trials Registry Platform (ICTRP).Date of last search of the Cystic Fibrosis and Genetic Disorders Group's Coagulopathies Trials Register: 01 March 2019.

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials in people with haemophilia or VWD undergoing oral or dental procedures using antifibrinolytic agents (tranexamic acid or epsilon aminocaproic acid (EACA)) to prevent perioperative bleeding compared to no intervention or usual care with or without placebo.

DATA COLLECTION AND ANALYSIS

Two authors independently screened the titles and abstracts of all identified articles. Full texts were obtained for potentially relevant abstracts and two authors independently assessed these for inclusion based on the selection criteria. A third author verified trial eligibility. Two authors independently performed data extraction and risk of bias assessments using standardised forms.

MAIN RESULTS

While there were no eligible trials in people with VWD identified, two randomised, double-blind, placebo-controlled trials (total of 59 participants) in people with haemophilia undergoing dental extraction were included. One trial of tranexamic acid published in 1972 included 28 participants with mild, moderate or severe haemophilia A and B and one of EACA published in 1971 included 31 people with haemophilia with factor VIII or factor IX levels less than 15%. Overall, the two included trials showed a beneficial effect of tranexamic acid and EACA, administered systemically, in reducing the number of bleedings, the amount of blood loss and the need for therapeutic clotting factor concentrates. Regarding postoperative bleeding, the tranexamic acid trial showed a risk difference (RD) of -0.64 (95% confidence interval (CI) -0.93 to - 0.36) and the EACA trial a RD of -0.50 (95% CI 0.77 to -0.22). The combined RD of both trials was -0.57 (95% CI -0.76 to -0.37), with the quality of the evidence (GRADE) for this outcome is rated as moderate. Side effects occurred once and required stopping EACA (combined RD of -0.03 (95% CI -0.08 to 0.13). There was heterogeneity between the two trials regarding the proportion of people with severe haemophilia included, the concomitant standard therapy and fibrinolytic agent treatment regimens used. We cannot exclude that a selection bias has occurred in the EACA trial, but overall the risk of bias appeared to be low for both trials.

AUTHORS' CONCLUSIONS

Despite the discovery of a beneficial effect of systemically administered tranexamic acid and EACA in preventing postoperative bleeding in people with haemophilia undergoing dental extraction, the limited number of randomised controlled trials identified, in combination with the small sample sizes and heterogeneity regarding standard therapy and treatment regimens between the two trials, do not allow us to conclude definite efficacy of antifibrinolytic therapy in oral or dental procedures in people with haemophilia. No trials were identified in people with VWD.

Antifibrinolytic therapy for preventing oral bleeding in patients with haemophilia or Von Willebrand disease undergoing minor oral surgery or dental extractions

BACKGROUND

Minor oral surgery or dental extractions (oral or dental procedures) are widely performed and can be complicated by hazardous oral bleeding, especially in people with an inherited bleeding disorder such as haemophilia or Von Willebrand disease. The amount and severity of singular bleedings depend on disease-related factors, such as the severity of the haemophilia, both local and systemic patient factors (such as periodontal inflammation, vasculopathy or platelet dysfunction) and intervention-related factors (such as the type and number of teeth extracted or the dimension of the wound surface). Similar to local haemostatic measures and suturing, antifibrinolytic therapy is a cheap, safe and potentially effective treatment to prevent bleeding complications in individuals with bleeding disorders undergoing oral or dental procedures. However, a systematic review of trials reporting outcomes after oral surgery or a dental procedure in people with an inherited bleeding disorder, with or without, the use of antifibrinolytic agents has not been performed to date.

OBJECTIVES

The primary objective was to assess the efficacy of local or systemic use of antifibrinolytic agents to prevent bleeding complications in people with haemophilia or Von Willebrand disease undergoing oral or dental procedures. Secondary objectives were to assess if antifibrinolytic agents can replace or reduce the need for clotting factor concentrate therapy in people with haemophilia or Von Willebrand disease and to further establish the effects of these agents on bleeding in oral or dental procedures for each of these populations.

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group's Coagulopathies Trials Register, compiled from electronic database searches of the Cochrane Central Register of Controlled Trials (CENTRAL), of MEDLINE and from handsearching of journals and conference abstract books. We additionally searched the reference lists of relevant articles and reviews. We searched PubMed, Embase and The Cochrane Library. Additional searches were performed in ClinicalTrials.gov, WHO International Clinical Trials Registry Platform (ICTRP).Date of last search of the Cystic Fibrosis and Genetic Disorders Group's Coagulopathies Trials Register: 14 December 2015.

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials in people with haemophilia or Von Willebrand disease undergoing oral or dental procedures using antifibrinolytic agents (tranexamic acid or epsilon aminocaproic acid) to prevent perioperative bleeding compared to no intervention or usual care with or without placebo.

DATA COLLECTION AND ANALYSIS

Two authors independently screened the titles and abstracts of all identified articles. Full texts were obtained for potentially relevant abstracts and two authors independently assessed these for inclusion based on the selection criteria. A third author verified trial eligibility. Two authors independently performed data extraction and risk of bias assessments using standardized forms.

MAIN RESULTS

While there were no eligible trials in people with Von Willebrand disease identified, two randomised, double-blind, placebo-controlled trials (total of 59 participants) in people with haemophilia undergoing dental extraction were included. One trial of tranexamic acid published in 1972 included 28 participants with mild, moderate or severe haemophilia A and B and one of epsilon aminocaproic acid published in 1971 included 31 people with haemophilia with factor VIII or factor IX levels less than 15%. Overall, the two included trials showed a beneficial effect of tranexamic acid and EACA, administered systemically, in reducing the number of bleedings, the amount of blood loss and the need for therapeutic clotting factor concentrates. Regarding postoperative bleeding, the tranexamic acid trial showed a risk difference of -0.64 (95% confidence interval -0.93 to - 0.36) and the EACA trial a risk difference of -0.50 (95% confidence interval 0.77 to -0.22). The combined risk difference of both trials was -0.57 (95% confidence interval -0.76 to -0.37), with the quality of the evidence (GRADE) for this outcome is rated as moderate. Side effects occurred once and required stopping epsilon aminocaproic acid (combined risk difference of -0.03 (95% CI -0.08 to 0.13). There was heterogeneity between the two trials regarding the proportion of people with severe haemophilia included, the concomitant standard therapy and fibrinolytic agent treatment regimens used. We cannot exclude that a selection bias has occurred in the epsilon aminocaproic acid trial, but overall the risk of bias appeared to be low for both trials.

AUTHORS' CONCLUSIONS

Despite the discovery of a beneficial effect of systemically administered tranexamic acid and epsilon aminocaproic acid in preventing postoperative bleeding in people with haemophilia undergoing dental extraction, the limited number of randomised controlled trials identified, in combination with the small sample sizes and heterogeneity regarding standard therapy and treatment regimens between the two trials, do not allow us to conclude definite efficacy of antifibrinolytic therapy in oral or dental procedures in people with haemophilia. No trials were identified in people with Von Willebrand disease.

The role of recombinant factor VIIa (FVIIa) in fibrin structure in the absence of FVIII/FIX

Patients with hemophilia have an impaired thrombin generation and therefore form loose fibrin hemostatic plugs that are easily dissolved by fibrinolysis. This prevents maintained hemostasis in these patients, resulting in a severe bleeding disorder. Recombinant (F)VIIa has been shown to enhance thrombin generation on already thrombin-activated platelets in the absence of FVIII and FIX. An efficacy rate of 80-90% has been found in hemophilia patients with inhibitors against FVIII or FIX both in association with major surgery and in the treatment of serious bleedings. In a model measuring fibrin clot permeability in a platelet-containing system described by Blombäck et al. (1994) this was demonstrated to be dependent on the concentration of FVIII and FIX. The addition of rFVIIa in concentrations of 1.9, 4.8 and 9.6 microg mL(-1) normalized fibrin clot permeability. The concentration of 1.9 microg mL(-1) of rFVIIa normalized clot permeability in this system and the higher concentrations of rFVIIa added only slightly to the effect. No further decrease in clot permeability was found when rFVIIa in a concentration of 1.9 microg mL(-1) was added to a sample with a normal concentration (100%) of FVIII or FIX. Higher concentrations of rFVIIa added to the plasma containing 100% of FVIII or FIX induced only a slight further decrease of fibrin permeability constant, arguing against any unwanted effect of extra rFVIIa on clot permeability in the case of a normal hemostasis. Furthermore, the fibrin network was studied with 3D microscopy and the loose network found in the absence of FVIII or FIX increased in density with increasing FVIII or FIX concentrations. The addition of rFVIIa to FVIII- or FIX-deficient systems altered the network structure, making the fibers thinner and more tightly packed.

Evidence that less replacement therapy is required for dental extractions in hemophiliacs

The requirements for factor VIII (AHF) or factor IX (PTC) of hemophilic patients undergoing dental extractions were evaluated to determine the minimum effective regimen. Sixteen patients underwent 19 operative procedures. The mean total dose of factor VIII or IX was 45.8 U/kg for 11 procedures with preoperative replacement therapy and 34.5 U/kg for the 8 without. Four patients received no replacement therapy at all. Our results compared favorably to published studies employing factor replacement alone or in combination with antifibrinolytic agents such as epsilon-amino-caproic acid (EACA), with respect to blood products utilized and duration of hospitalization. However, our patients received less factor replacement than usually suggested. General anesthesia with intubation, a common recommendation, was not required in any patients. Dental extractions can be carried out in hemophiliacs using less replacement therapy than currently recommended. In some circumstances, no replacement therapy may be necessary. The reported efficacy of antifibrinolytic agents in reducing the requirement for replacement therapy is difficult to assess because of the relatively large amount of prophylactic factor replacement used in conjunction with these agents.

Oral bleeding in classic hemophilia

Charts of 132 patients with proved classic hemophilia were reviewed. The diagnosis of hemophilia was most often made after 6 months of age but before 2 years. Persistent oral bleeding led to the diagnosis in 13.6 percent of the cases. The oral site most often involved was the frenum of the lip. In the patient with proven hemophilia, oral bleeding accounted for 9 percent of those bleeding episodes requiring infusion therapy.

Hemophilia

The clinical manifestations of hemophilia depend upon both age and the severity of the factor VIII or IX deficiency. Hemophilia A and B cannot be differentiated on clinical grounds. Laboratory tests include platelet count, prothrombin time, partial thromboplastin time, and bleeding time.

Ocular enucleation in a patient with severe classic hemophilia A

A 27-year-old man with severe classic hemophilia A (antihemophilic globulin level: 1.5% of normal) had blunt trauma to his left eye that produced a corneoscleral laceration with prolapse of the intraocular contents. His left eye was enucleated under management with factor VIII replacement. This consisted of sufficient cryoprecipitate to increase the calculated circulating factor VIII level to 125%, sufficient factor VIII every 12 hours to increase peak postinfusion levels from 100 to 120%, and to maintain minimum levels of 30% immediately before infusion. Because he had developed a gingival hematoma when he was placed on epsilon amino caproic acid after only one day of factor VIII replacement following extraction of mandibular molars, we continued the high level of factor VIII replacement for five days and then began antifibrinolytic epsilon amino caproic acid therapy. His surgical and postoperative course were uneventful on this regimen.

The use of epsilon-aminocaproic acid for the management of hemophilia in dental and oral surgery patients

The use of epsilon-aminocaproic acid has proved to be an efficient and practical method for treating hemophiliacs who require dental work. In the past, patients requiring extractions were admitted to a hospital for approximately ten days and received replacement infusions every 12 hours during their stay. This resulted in a large expense because of the cost of the material and the hospitalization itself, not to mention the trauma sustained by the patient both physically and psychologically. Also, by decreasing the number of factor infusions, the risk of complications such as the transmission of hepatitis, allergic reaction, or inhibitor formation decreased. The same protocol using a single infusion of the appropriate factor replacement with supplementary epsilon-aminocaproic acid can be used for the management of patients with other coagulation disorders such as factor IX deficiency (Christman disease), factor XI deficiency, and von Willebrand's disease. Since this paper was submitted, seven more patients have been treated using this protocol. An additional seven odontectomies, 33 extractions, operative dentistry in 18 quadrants, and alveoloplasties in two full arches have been performed. This brings the total to 23 treatment sesions with 18 patients undergoing 124 procedures. One additional minor bleeding episode occurred, resulting in a total rate of four bleeding episodes in 23 treatment sessions and 124 procedures. Our incidence of complications secondary to epsilon-aminocaproic acid specifically remains zero.

Survival of transfused factor VIII in hemophilic patients treated with epsilon aminocaproic acid

The effect of EACA (epsilon aminocaproic acid) on the survival of factor VIII (F. VIII, antihemophilic factor, AHF) concentrates after infusion in hemophilic subjects was studied using two F. VIII preparations: an intermediate purity "cryoglobulin" and a high purity glycine-precipitated concentrate. In vivo recoveries of F. VIII with both concentrates were found to be close to the values predicted on the basis of concentrate potencies assayed prior to infusion, but not if the labeled potency was used in the calculation. Control studies showed similar first and second phase half-life times and half-disappearance times when the two F. VIII preparations were infused, and both preparations were found to follow a biphasic disappearance curve. The biological half-life (second phase rate of disappearance) was 12 to 13 hours. The administration of EACA in conjunction with the F. VIII concentrates did not prolong the half-life times (first or second phase) or the half-disappearance times.