Successful treatment with recombinant factor VIIa of therapy-resistant severe bleeding in a patient with acquired von Willebrand disease

Acquired von Willebrand syndrome: focused for hematologists

The acquired von Willebrand syndrome (AvWS) is a rare bleeding disorder with laboratory findings similar to those of inherited von Willebrand disease. However, unlike the inherited disease, AvWS occurs in persons with no personal and family history of bleeding and is often associated with a variety of underlying diseases, most frequently lymphoproliferative, myeloproliferative and cardiovascular disorders. After the presentation of a typical case, in this narrative review we discuss the more recent data on the pathophysiology, clinical, laboratory and therapeutic aspects of this acquired bleeding syndrome. We chose to focus particularly on those aspects of greater interest for the hematologist.

Acquired von Willebrand syndrome and lymphoproliferative disorders: A case report

Acquired von Willebrand syndrome is a rare bleeding disorder often secondary to an underlying lymphoproliferative disorder. We report a case in whom response of both the acquired von Willebrand syndrome and smoldering multiple myeloma persist 14 months after daratumumab treatment discontinuation.

A role for recombinant activated factor VII in trauma?

It is possible that recombinant activated factor VII (rFVIIa) could revolutionize the medical and surgical management of haemorrhage following trauma due to its ease of administration and mechanism of action. This article reviews the evidence for the use of rFVIIa as a procoagulant, its mechanism of action and its potential role in blunt and penetrating trauma. The role of rFVIIa in the emergency room or operating theatre and in the pre-hospital environment is discussed. Administration of rFVIIa `at the roadside’ may have signifi cant potential implications, especially for the trauma surgeon and even for strategic planners. Finally, the areas where further research is needed to provide objective evidence of its effi cacy are elaborated.

Acquired von Willebrand syndrome and mitral valve prosthesis leakage. A pilot study

BACKGROUND

Of patients with severe aortic stenosis, 15-25% present with bleeding episodes possibly attributable to acquired von Willebrand syndrome (AVWS). AVWS associated with mitral valve prosthesis leakage has not been reported.

METHODS AND RESULTS

Five patients receiving appropriate oral anticoagulation showed mitral valve prosthesis leakage and bleeding episodes; all of them required hospitalization and two blood transfusions, and a von Willebrand factor (VWF) analysis was performed. Two patients with normal functioning metallic prosthesis valves were included as controls. Before surgery, after cessation of acenocumarol, the patients had prolonged activated partial thromboplastin time; four had prolonged closure time (CT) from the platelet function analyzer. Factor VIII procoagulant activity (FVIII:C), VWF ristocetin cofactor activity (VWF:RCo), and VWF collagen binding (VWF:CB) were considerably elevated, while VWF antigen (VWF:Ag) was most elevated. Disproportionate VWF:RCo/VWF:Ag and VWF:CB/VWF:Ag ratios were seen with the loss of large VWF multimers. Following surgery, all parameters were markedly increased and the ratios, CT, and multimeric VWF profile became normal.

CONCLUSIONS

Acquired VWF qualitative alterations in mitral valve prosthesis leakage may be associated with or contribute to bleeding diathesis. AVWS should be taken into consideration in patients with mitral valve prosthesis leakage with bleeding diathesis not explained by excessive oral anticoagulation.

Resuscitation and monitoring in gastrointestinal bleeding

INTRODUCTION

Gastrointestinal bleeding is a common life-threatening problem, causing significant mortality, costs and resource allocation. Its management requires a dynamic multidisciplinary approach that directs diagnostic and therapeutic priorities appropriately.

MATERIALS AND METHODS

Articles published within the past 15 years, related to gastrointestinal bleeding, were reviewed through MEDLINE search, in addition to current guidelines and standards.

RESULTS

Decisions of ICU admission and blood transfusion must be individualized based on the extent of bleeding, hemodynamic profile and comorbidities of the patient and the risk of rebleeding. A secure airway may be required to optimize oxygenation and to prevent aspiration. Doses of induction agents must be reduced due to the changes in volume of distribution. Volume replacement is the cornerstone of resuscitation in profuse bleeding, but nontargeted aggressive fluid resuscitation must be avoided to allow clot formation and to prevent increased bleeding. Decision to give blood transfusion must be based on physiologic triggers rather than a fixed level of hemoglobin. Coagulopathy must be corrected and hypothermia avoided. Need for massive transfusion must be recognized as early as possible, and a 1:1:1 ratio of packed red blood cells, fresh frozen plasma and platelets is recommended to prevent dilutional coagulopathy. Tromboelastography can be used to direct hemostatic resuscitation. Transfusion related lung injury (TRALI) is a significant problem with a mortality rate approaching 40%. Prevention of TRALI is important in patients with gastrointestinal bleeding, especially among patients having end-stage liver disease. Preventive strategies include prestorage leukoreduction, use of male-only or never-pregnant donors and avoidance of long storage times. Management of gastrointestinal bleeding requires delicately tailoring resuscitation to patient needs to avoid nonspecific aggressive resuscitation. "Functional hemodynamic monitoring" requires recognition of indications and limitations of hemodynamic measurements. Dynamic indices like systolic pressure variation are more reliable predictors of volume responsiveness. Noninvasive methods of hemodynamic monitoring and cardiac output measurement need further verification in patients with gastrointestinal bleeding.

CONCLUSIONS

Management of gastrointestinal bleeding requires a dynamic multidisciplinary approach. The mentioned advances in management of hemorrhagic shock must be considered in resuscitation and monitoring of patients with GI bleeding.

Management of acquired bleeding problems in cancer patients

Cancer patients can have acquired bleeding problems for many reasons. In this review, an approach to the evaluation and management of the bleeding patient is discussed. Specific issues including coagulation defects, thrombocytopenia, platelet dysfunction, and bleeding complications of specific hematological malignancies due to anticoagulation, are discussed.

Management of acquired bleeding problems in cancer patients

Cancer patients can have acquired bleeding problems for many reasons. In this review, an approach to the bleeding patient in the Emergency Department is discussed. Specific issue including coagulation defects, thrombocytopenia, platelet dysfunction, bleeding complications of specific hematological malignancies and due to anticoagulation, are discussed.

Pathogenesis and management of bleeding and thrombosis in plasma cell dyscrasias

Unexpectedly high rates of venous thromboembolic events (VTE) concurrent with the introduction of highly effective immune modulating drugs thalidomide and lenolidomide for treatment of multiple myeloma have focused attention on the incidence and underlying pathophysiology of VTE in patients with plasma cell dyscrasias, and on thromboprophylaxis approaches. While bleeding complications are relatively uncommon in patients with lymphoproliferative disorders, acquired von Willebrand syndrome, typically occurring in patients with monoclonal gammopathy of unknown significance, and acquired coagulopathies associated with primary amyloidosis can present with haemorrhagic complications and both are challenging to manage. This review highlights these important haemostasis-related complications of plasma cell dyscrasias and provides an overview of other uncommon bleeding and thrombotic events that can affect diagnostic and therapeutic management of clonal plasma cell disorders. Due to the infrequency of most of these haemostasis complications, available information is typically based on retrospective cases or series.

The Role Of von Willebrand Factor In Hemorrhagic And Thrombotic Disorders

von Willebrand factor (VWF) is a multimeric plasma protein that mediates platelet adhesion as well as platelet aggregation at sites of vascular injury and acts as a carrier of factor VIII. Although acquired or inherited VWF deficiency is associated with a bleeding tendency, there is increasing evidence that VWF has a pivotal role in thrombogenesis. In fact, while the presence in the plasma of unusually large VWF multimers, due to a congenital or acquired deficiency of a VWF-cleaving metalloprotease, has been implicated in the pathogenesis of thrombotic thrombocytopenic purpura, high plasma levels of VWF have been associated with an increased risk of both arterial and venous thrombosis. The role of VWF in normal and pathological hemostasis is discussed in this review, and important advances in the pathophysiology, diagnosis, and treatment of VWF-associated disorders are also described.

Use of recombinant activated factor VII to arrest uncontrolled bleeding: a case series

A retrospective analysis is described to assess the effects of using recombinant activated factor VII to control bleeding in a series of patients who had failed to respond to conventional hemostatic measures. In all, 18 patients (aged 16-65 years) with a range of conditions resulting in bleeding refractory to conventional methods of control were treated with recombinant activated factor VII (60-120 Amicrog/kg; 1-4 doses). The effects of recombinant activated factor VII on bleeding were noted together with the patients' transfusion requirements and hematological parameters. Administration of recombinant activated factor VII successfully stopped bleeding in 17 of the 18 patients. Therapy with recombinant activated factor VII significantly decreased transfusion requirements for packed red blood cells, fresh frozen plasma, platelets, and cryoprecipitate compared with pretreatment values along with significant improvement in hemostasis. In various serious bleeding situations, treatment with recombinant activated factor VII may effectively arrest bleeding, which has remained refractory to conventional methods of control.

Use of Recombinant Factor VIIa in Inherited and Acquired von Willebrand Disease

Recombinant factor VIIa (rFVIIa) is increasingly used outside the labeled indications for the treatment of life-threatening bleeding episodes after failure of respective standard therapy. In this article, the authors focus on the use of the agent in patients with inherited or acquired von Willebrand disease (vWD). Although the current experience is sparse, published cases indicate the high efficacy of rFVIIa for the treatment of patients refractory to conventional treatment. The agent may be used in patients with congenital vWD complicated by alloantibodies directed against substituted von Willebrand factor or in the presence of concomitant hemostatic defects as well as acquired vWD with hitherto limited therapeutic options. Controlled clinical studies are necessary to define the use of rFVIIa in this clinical setting.

Acquired von Willebrand syndrome: an update

Acquired von Willebrand syndrome (aVWS) is a rare bleeding disorder with laboratory findings similar to those for congenital von Willebrand disease (VWD). However, unlike congenital VWD, it arises in individuals with no personal or family history of bleeding. aVWS occurs in association with a variety of underlying disorders, most frequently in lymphoproliferative disorders, myeloproliferative disorders, and cardiovascular diseases. Through an analysis of the more recent literature data, the pathophysiology and the clinical, laboratory, and therapeutic aspects of this syndrome are concisely reported in this review.

Recent acquisitions in acquired and congenital von Willebrand disorders

von Willebrand factor is a multimeric plasma protein that mediates platelet adhesion as well as platelet aggregation at sites of vascular injury and, moreover, acts as a carrier of factor VIII. Its deficiency is associated with a bleeding tendency. The progresses in the pathophysiology, diagnosis and management of inherited von Willebrand disease and acquired von Willebrand syndrome will be discussed in this review.

Bleeding and Thrombosis Risks in Plasma Cell Dyscrasias

Major, spontaneous bleeding is uncommon in patients with plasma cell dyscrasias despite frequent abnormal screening hemostasis tests. However, acquired von Willebrand deficiency and light-chain (AL) amyloidosis, and amyloidosis complicating multiple myeloma can present with serious hemorrhagic complications that are challenging to manage. While patients with monoclonal gammapathy of undetermined significance and multiple myeloma share an intrinsic increased risk of venous thromboembolic events (VTE), treatment with thalidomide and lenalidomide increases the incidence of VTE in certain multiple myeloma patient subsets. Our understanding of the complex interactions among malignant plasma cells, inflammatory and hemostasis pathways, and treatment modalities that combine to produce thrombotic complications is incomplete. Prospective, randomized trials are clearly needed to assist clinicians in providing optimal VTE prophylaxis to their patients with plasma cell dyscrasias.

The use of recombinant activated factor VII in congenital and acquired von Willebrand disease

Recombinant activated factor VII (NovoSeven), a novel hemostatic agent originally developed for the treatment of bleeding episodes in hemophilia A or B patients with inhibitors, has been recently employed with benefit for the management of hemorrhages in other nonhemophilic congenital and acquired hemostatic abnormalities. This review focuses on the use of this drug in acquired and congenital von Willebrand disease. The analysis of the literature data shows that recombinant activated factor VII is an effective agent for the treatment of refractory bleeding in von Willebrand disease patients and for the treatment or prevention of bleeding in those patients with alloantibodies or autoantibodies against von Willebrand factor. Further studies are needed, however, to assess its safety and to optimize the dosages and regimens of therapy in such patients.

A cerebrovascular event after single-dose administration of recombinant factor VIIa in a patient with esophageal variceal bleeding

Upper gastrointestinal bleeding (UGIB) is a life-threatening complication of cirrhosis that develops from esophageal varices in almost 70% of patients. The mortality rate from the bleeding episodes is reported to be 30% [1-4]. Standard management of UGIB of cirrhotic patients is vasoactive therapy combined with endoscopic procedures such as endoscopic sclerotherapy and band ligation [5]. Currently, it is reported that recombinant activated fVIIa (Novoseven, NovoNordisc) can correct the prothrombin time in decompensated cirrhotic patients and also can be used safely in Child's B and C cirrhotic patients with UGIB [6-8]. Herein, we describe the first case report in the literature of a cerebrovascular event after the administration of a single dose of fVIIa in a cirrhotic patient with esophageal variceal bleeding.

Acquired von Willebrand syndrome: features and management

Acquired von Willebrand syndrome (AvWS) is not a well-known bleeding disorder among clinicians and is associated with various underlying diseases. The clinical manifestations are similar to congenital von Willebrand disease. Diagnosis is confirmed mainly by a decrease of ristocetin cofactor activity (vWF:RCo) and/or collagen binding activity (vWF:CBA) and by vWF multimeric analysis, usually with a selective loss of large multimers. Plasma von Willebrand factor propeptide (vWF:AgII) is a good marker of vWF synthesis. Various pathogenic mechanisms have been proposed, including development of autoantibodies to the von Willebrand factor (vWF), adsorption of vWF onto tumor cells or activated platelets, increase of vWF proteolysis, and mechanical destruction of vWF under high shear stress. Treatment of the underlying disorder may resolve AvWS. Desmopressin (DDAVP) is a first-line therapeutic option. Factor VIII/vWF concentrates and high-dose immunoglobulin infusions are reserved for patients unresponsive to DDAVP.

Acquired von Willebrand Syndrome: An Underdiagnosed and Misdiagnosed Bleeding Complication in Patients With Lymphoproliferative and Myeloproliferative Disorders

Acquired von Willebrand syndrome (AVWS) is a rare bleeding disorder with laboratory findings similar to those for congenital von Willebrand disease (VWD). Unlike the congenital disease, AVWS usually occurs in individuals with no personal or family history of bleeding. The prevalence of AVWS in the general population is unknown because data from large prospective studies of this syndrome are not available. Although AVWS is particularly frequent in lymphoproliferative or myeloproliferative disorders, it can also be associated with solid tumors, immunologic and cardiovascular disorders, and other miscellaneous conditions. Diagnosis of AVWS is based on assays measuring the activity of von Willebrand factor (VWF). This tends to be abnormally low, but factor VIII (FVIII) coagulant activity can sometimes be normal. FVIII/VWF inhibiting activity is found in only a minority of cases. Bleeding episodes in patients with AVWS are mostly of the mucocutaneous type and can be managed with desmopressin, plasma-derived FVIII/VWF concentrates, and intravenous immunoglobulin (IVIg). Recombinant activated factor VII can be useful in patients unresponsive to standard therapy. An updated version of the International Registry on AVWS, recently available online, will provide more information on this rare, but underdiagnosed and misdiagnosed, disorder.

Management of bleeding emergencies: when to use recombinant activated Factor VII

Recombinant activated Factor VII (rVIIa) was originally released as a clotting factor, with use limited to a select group of patients who had few other treatment options. Due to the apparent ability of rVIIa to stop bleeding, no matter what the underlying cause, there is great interest in use of rVIIa in a wide range of bleeding patients. This article discusses rVIIa and its uses in a variety of patients, especially liver disease and trauma patients, and makes suggestions for appropriate use. Although most of the reports on rVIIa are anecdotes and case series, there is increasing data for clinical trials to help guide usage.

Management of acquired von Willebrand's sryndrome in a patient requiring major surgery

We present the case of a patient with acquired von Willebrand's syndrome and a monoclonal gammopathy of undetermined significance who required cystectomy for relapsed transitional cell carcinoma (TCC) of the bladder. We demonstrated that infused von Willebrand factor (VWF) containing factor VIII concentrates had an unacceptably short half-life, but that this was significantly prolonged following combined therapy with plasma exchange and intravenous immunoglobulin (IVIgG). This approach was successfully utilized peri-operatively, with the total surgical blood loss less than would be expected even for a haemostatically normal patient. Trough VWF antigen and Ristocetin co-factor activity levels fell on the second postoperative day and we therefore administered further IVIgG. Levels again fell on the fifth postoperative day with the development of a Staphylococcus aureus septicaemia. At this point bleeding occurred from a surgical drain site requiring 'factor VIII inhibitor bypass activity' to secure haemostasis while further plasma exchange and IVIgG were administered. Now 5 years later, there is no evidence of recurrence of the TCC or progression of the monoclonal gammopathy.

Use of recombinant activated factor VII for bleeding in pancreatitis: a case series

OBJECTIVES

To describe the effects of recombinant activated factor VII (rFVIIa) in the treatment of bleeding in a series of patients with acute or chronic pancreatitis.

METHODS

Twelve patients (age, 2.5-65 years) with pancreatitis and bleeding were treated with 18.5 to 120 microg/kg of rFVIIa. Eight patients also had sepsis/infection and/or disseminated intravascular coagulation (DIC). The effects of rFVIIa on bleeding, coagulation status, and transfusion requirements were noted.

RESULTS

Bleeding stopped in 4 patients, was markedly reduced in 4 patients, was reduced in 3 patients, and was remained unchanged in 1 patient. For most patients with pre- and post-rFVIIa data, coagulation parameters improved and transfusion requirements reduced. No thrombotic adverse events occurred. Seven patients died for reasons considered to be unrelated to rFVIIa treatment.

CONCLUSIONS

This case series indicates that rFVIIa may be an effective hemostatic treatment of patients with pancreatitis suffering from massive bleeding. There were no thromboembolic events in any patient, including those with sepsis or DIC.

Recombinant factor VIIa enhances platelet adhesion and activation under flow conditions at normal and reduced platelet count

BACKGROUND

Recombinant factor VIIa (rFVIIa), which was developed for treatment of inhibitor-complicated hemophilia, appears suitable as prohemostatic agent in other clinical disorders including patients with thrombocytopenia. It is generally accepted that rFVIIa functions by enhancement of thrombin generation at the site of injury. It is, however, unknown if and how this affects platelet adhesion and aggregation.

OBJECTIVES

To determine the effect of rFVIIa-mediated thrombin generation on platelet adhesion and aggregation under flow conditions at normal and reduced platelet counts.

METHODS

Washed platelets and red cells were combined to obtain plasma-free blood with different platelet counts. The reconstituted blood was perfused over a collagen- or fibrinogen-coated surface in the absence or presence of a thrombin generating system consisting of purified coagulation factors rFVIIa, factor (F)X and prothrombin.

RESULTS

Addition of coagulation factors rFVIIa, FX and prothrombin to washed platelets and red cells enhanced platelet adhesion and aggregation to collagen and adhesion and spreading to fibrinogen at normal platelet count and at platelet numbers as low as 10 000 microL(-1). rFVIIa-mediated thrombin generation enhanced the activation state of platelets as measured by intracellular calcium fluxes, and enhanced the exposure of procoagulant phospholipids as measured by annexin A5 binding.

CONCLUSIONS

Taken together, increased platelet adhesion and aggregation by rFVIIa-mediated thrombin formation may explain the therapeutic effects of rFVIIa in thrombocytopenic conditions and in patients with a normal platelet count by (i) enhancement of primary hemostasis and (ii) enhancement of procoagulant surface leading to elevated fibrin formation.

Use of Intravenous Immunoglobulin in Patients With Acquired von Willebrand Syndrome

Acquired von Willebrand syndrome (AVWS) is a rare bleeding disorder with laboratory findings similar to those for congenital von Willebrand disease. Unlike the congenital form, AVWS usually occurs in individuals with no personal or family history of bleeding disorders. According to an international registry, AVWS is mainly associated with lymphomyeloproliferative, immunologic, and cardiovascular disorders, as well as with solid tumors and other miscellaneous conditions; however, the prevalence of AVWS in these underlying disorders is still unknown. von Willebrand factor (VWF) is synthesized normally in most AVWS patients, and the low plasma VWF levels are from its accelerated removal from plasma by five different mechanisms, including autoantibodies. Because of the reduced half-life of endogenous-exogenous plasma VWF, bleeding of AVWS cannot be managed with desmopressin or factor VIII/VWF concentrates. Clinical use of intravenous immunoglobulin (IVIg) in AVWS has been reported since 1988. IVIg is most effective in AVWS with type immunoglobulin (Ig) G monoclonal gammopathies of undetermined significance and in other cases with IgG autoantibodies. IVIg can correct factor VIII and von Willebrand factor complex activities for about 15-20 days, and repeated injections induce remission of AVWS in these patients. Prospective studies are required to evaluate the efficacy and safety of IVIg in AVWS.

Perioperative systemic haemostatic agents

Skilful surgery combined with blood-saving methods and careful management of blood coagulation will all help reduce unnecessary blood loss and transfusion requirements. Excessive surgical bleeding causes hypovolaemia, haemodynamic instability, anaemia and reduced oxygen delivery to tissues, with a subsequent increase in postoperative morbidity and mortality. The role of anaesthetists in managing surgical blood loss has increased greatly in the last decade. Position of the patient during surgery and the provision of a hypotensive anaesthetic regimen were once considered the most important contributions of the anaesthetist to decreasing blood loss. Now, several pharmacological haemostatic agents are being used by anaesthetists as blood-saving agents. After a brief discussion of the physiology of haemostasis, this article will review the evidence for the role of such agents in reducing perioperative blood loss and transfusion requirements.

Recombinant factor VIIa for upper gastrointestinal bleeding in patients with cirrhosis: a randomized, double-blind trial

BACKGROUND & AIMS

Upper gastrointestinal bleeding (UGIB) is a severe and frequent complication of cirrhosis. Recombinant coagulation factor VIIa (rFVIIa) has been shown to correct the prolonged prothrombin time in patients with cirrhosis and UGIB. This trial aimed to determine efficacy and safety of rFVIIa in cirrhotic patients with variceal and nonvariceal UGIB.

METHODS

A total of 245 cirrhotic patients (Child-Pugh < 13; Child-Pugh A = 20%, B = 52%, C = 28%) with UGIB (variceal = 66%, nonvariceal = 29%, bleeding source unknown = 5%) were randomized equally to receive 8 doses of 100 microg/kg rFVIIa or placebo in addition to pharmacologic and endoscopic treatment. The primary end point was a composite including: (1) failure to control UGIB within 24 hours after first dose, or (2) failure to prevent rebleeding between 24 hours and day 5, or (3) death within 5 days.

RESULTS

Baseline characteristics were similar between rFVIIa and placebo groups. rFVIIa showed no advantage over standard treatment in the whole trial population. Exploratory analyses, however, showed that rFVIIa significantly decreased the number of failures on the composite end point (P = 0.03) and the 24-hour bleeding control end point (P = 0.01) in the subgroup of Child-Pugh B and C variceal bleeders. There were no significant differences between rFVIIa and placebo groups in mortality (5- or 42-day) or incidence of adverse events including thromboembolic events.

CONCLUSIONS

Although no overall effect of rFVIIa was observed, exploratory analyses in Child-Pugh B and C cirrhotic patients indicated that administration of rFVIIa significantly decreased the proportion of patients who failed to control variceal bleeding. Dosing with rFVIIa appeared safe. Further studies are needed to verify these findings.

The potential use of recombinant activated factor VII in trauma and surgery

It is possible that recombinant activated factor VII (rFVIIa) could revolutionise the medical and surgical management of haemorrhage following trauma and surgery due to its ease of administration and mechanism of action. This article reviews the evidence for the use of rFVIIa as a pro-coagulant, its mechanism of action, safety and recent research into its use in blunt and penetrating trauma and haemorrhage. The potential role of rFVIIa, both in the pre-hospital environment and in the emergency room or operating theatre, is discussed. Administration of rFVIIa at the roadside, on the battlefield or in a trauma centre may have significant potential implications, especially for the paramedical and surgical teams and even for strategic planners. Finally, the areas where further research is needed to provide objective evidence of its efficacy are elaborated. The potential thromboembolic complications of systemic administration of rFVIIa need to be carefully monitored but the high cost of this drug is likely to be the limiting factor in its widespread use.

Treatment of Bleeding in Severe Hemorrhagic Pancreatitis with Recombinant Factor VIIa

Recombinant factor VIIa (rFVIIa) has been used to treat bleeding complications in patients with hemophilia. It acts at the site of vessel injury, forming a complex with tissue factor to activate the clotting cascade. Recent reports have shown rFVIIa may be a useful hemostatic agent in patients after obstetrical, urologic, trauma, or transplant procedures. We report the first documented case of bleeding from hemorrhage pancreatitis treated with rFVIIa.

Pharmacological strategies to decrease transfusion requirements in patients undergoing surgery

Surgical procedures are inevitably associated with bleeding. The amount of blood loss may vary widely between different surgical procedures and depends on surgical as well as non-surgical factors. Whereas adequate surgical haemostasis may suffice in most patients, pro-haemostatic pharmacological agents may be of additional benefit in patients with (diffuse) surgical bleeding or in patients with a specific underlying haemostatic defect. In general, surgical haemostasis and pharmacological therapies can be complementary in controlling blood loss. The use of pharmacological therapies to reduce blood loss and blood transfusions in surgery has historically been restricted to a few drugs. Antifibrinolytic agents (aprotinin, tranexamic acid and aminocaproic acid) have the best evidence supporting their use, especially in cardiac surgery, liver transplantation and some orthopaedic surgical procedures. Meta-analyses of randomised, controlled trials in cardiac patients have suggested a slight benefit of aprotinin, compared with the other antifibrinolytics. Desmopressin is the treatment of choice in patients with mild haemophilia A and von Willebrand disease. It has also been shown to be effective in patients undergoing cardiac surgery who received aspirin up to the time of operation. However, overall evidence does not support a beneficial effect of desmopressin in patients without pre-existing coagulopathy undergoing elective surgical procedures. Topical agents, such as fibrin sealants have been successfully used in a variety of surgical procedures. However, only very few controlled clinical trials have been performed and scientific evidence supporting their use is still limited. Novel drugs, like recombinant factor VIIa (eptacog alfa), are currently under clinical investigation. Recombinant factor VIIa has been introduced for the treatment of haemophilia patients with inhibitors, either in surgical or non-surgical situations. Preliminary data indicate that it may also be effective in surgical patients without pre-existing coagulation abnormalities. More clinical trials are warranted before definitive conclusions can be drawn about the safety and the exact role of this new drug in surgical patients. Only adequately powered and properly designed randomised, clinical trials will allow us to define the most effective and the safest pharmacological therapies for reducing blood loss and transfusion requirements in surgical patients. Future trials should also consider cost-effectiveness because of considerable differences in the costs of the available pro-haemostatic pharmacological agents.

Effect of recombinant activated factor VII on perioperative blood loss in patients undergoing retropubic prostatectomy: a double-blind placebo-controlled randomised trial

BACKGROUND

Recombinant activated factor VII (factor VIIa) has prohaemostatic effects in bleeding patients with coagulation abnormalities. We aimed to test the hypothesis that recombinant factor VIIa could reduce perioperative blood loss in patients with normal coagulation systems. Therefore, we assessed safety and efficacy of this drug in patients undergoing retropubic prostatectomy, which is often associated with major blood loss and need for transfusion.

METHODS

In a double-blind, randomised placebo-controlled trial, we recorded blood loss and transfusion requirements in 36 patients undergoing retropubic prostatectomy, who were randomised to receive an intravenous bolus of recombinant factor VIIa (20 microg/kg or 40 microg/kg) or placebo in the early operative phase.

FINDINGS

Median perioperative blood loss was 1235 mL (IQR 1025-1407) and 1089 mL (928-1320) in groups given recombinant factor VIIa 20 microg/kg and 40 microg/kg, respectively, compared with 2688 mL (1707-3565) in the placebo group (p=0.001). Seven of twelve placebo-treated patients were transfused, whereas no patients who received 40 microg/kg recombinant factor VIIa needed transfusion. The odds ratio for receiving any blood product in patients treated with recombinant factor VIIa compared with control patients was 0 (95% CI 0.00-0.33) No adverse events arose.

INTERPRETATION

An injection of recombinant factor VIIa can reduce perioperative blood loss and eliminate the need for transfusion in patients undergoing major surgery.

Efficacy of NovoSeven during surgery on a haemophiliac with previous history of inhibitors

Management of bleeding in haemophiliacs with a history of inhibitor remains problematic. With infusion of factor VIII (FVIII), development of an anamnestic response and possible appearance of high-titre inhibitor remains a valid concern. We report a case of a haemophiliac with a history of moderately high-titre FVIII inhibitor that had become undetectable. He had not received FVIII since 1997, when he became inhibitor negative. He had been managed during his bleeding episodes with prothrombin complex factor concentrates, which became less effective in controlling his bleeding. The patient had a history of recurrent, spontaneous shoulder joint dislocations with bleeding, pain and significant disability. Shoulder joint replacement surgery was suggested. Replacement therapy was discussed with the patient, who refused treatment with human FVIII because of his concern for possible anamnestic response and inhibitor rebound. Porcine FVIII was not acceptable due to his poor response when used once in the past, and his history of moderate allergic reaction. Therefore, recombinant factor VIIa (NovoSeven, Novo Nordisk, Princeton, NJ) was considered to be an acceptable option for the contemplated shoulder surgery. The patient underwent 2.5 h of surgery with NovoSeven infusion. The surgeons were impressed with the lack of bleeding in this traumatic surgery. Despite the continuously prolonged activated partial thromboplastin time and low FVIII levels, the patient maintained a remarkably dry surgical field. Effective haemostasis was achieved during and after this procedure. This case illustrates the usage of NovoSeven as an effective treatment modality in a haemophilia A patient with past history of inhibitor undergoing joint surgery.

Treatment of severe pulmonary hemorrhage with activated recombinant factor VII (rFVIIa) in very low birth weight infants

Clinically apparent pulmonary hemorrhage (PH) occurs in 5% to 7% of very low birth weight (VLBW) infants with respiratory distress syndrome (RDS). It is associated with a mortality rate as high as 50% and significant pulmonary and central nervous system morbidities. There is no consensus on treatment modality. We present two VLBW infants with severe PH that did not respond to conventional treatment but were successfully treated with activated recombinant factor VII (rFVIIa). No untoward side effects were noted.

Acquired von Willebrand disease--hemostatic management of major orthopedic surgery with high-dose immunoglobulin, desmopressin, and continuous factor concentrate infusion

Acquired von Willebrand disease (aVWD) is a rare bleeding disorder that mimics congenital VWD in previously healthy individuals; it is most frequently associated with monoclonal gammopathy. Hemostatic therapy of aVWD is challenging due to the extremely shortened half-life of endogenous and exogenous VWF. High-dose intravenous immunoglobulin (ivIG) is recommended as the treatment of choice, usually rapidly normalizing coagulation; but in case of failure, alternative treatment options are not well explored. We report successful major orthopedic surgery in a 61-year-old woman with multiple myeloma IgG lambda and aVWD. IvIG alone failed to correct hemostasis. However, ivIG pretreatment improved the VWF ristocetin cofactor (VWF:RCo) half-life from only 1.5 hr to more than 4 hr, allowing desmopressin infusions twice daily to maintain sufficient VWF:RCo levels. Because of diminishing desmopressin effect, we attempted for the first time in aVWD a continuous VWF/FVIII infusion (Haemate HS), 2.1-2.7 FVIII U/kg/hr or 51-64 U/kg/day, respectively 4.6-6.0 VWF:RCo U/kg/hr or 110-145 U/kg/day) to reach constant factor levels. The steady-state clearance was 2.4 mL/kg/hr for FVIII:C and 13.5 mL/kg/hr for VWF:RCo. During surgery, VWF:RCo, FVIII:C, and PFA-100 closure time were normalized. Until day 5, VWF:RCo was kept above 50%, from day 6 to 10 at least 30% activity were attained. FVIII:C levels were always >70%. The clinical course was uneventful without bleeding. Two weeks after hip surgery the patient was discharged from the hospital without complaints. The therapy described can be recommended as safe and feasible for further evaluation in aVWD patients who are hyporesponsive to ivIG treatment alone. Continuous VWF/FVIII infusion can improve substitution therapy in aVWD.

Mechanism of factor VIIa-dependent coagulation in hemophilia blood

The ability of factor VIIa to initiate thrombin generation and clot formation in blood from healthy donors, blood from patients with hemophilia A, and in anti-factor IX antibody-induced ("acquired") hemophilia B blood was investigated. In normal blood, both factor VIIa-tissue factor (TF) complex and factor VIIa alone initiated thrombin generation. The efficiency of factor VIIa was about 0.0001 that of the factor VIIa-TF complex. In congenital hemophilia A blood and "acquired" hemophilia B blood in vitro, addition of 10 to 50 nM factor VIIa (pharmacologic concentrations) corrected the clotting time at all TF concentrations tested (0-100 pM) but had little effect on thrombin generation. Fibrinopeptide release and insoluble clot formation were only marginally influenced by addition of factor VIIa. TF alone had a more pronounced effect on thrombin generation; an increase in TF from 0 to 100 pM increased the maximum thrombin level in "acquired" hemophilia B blood from 120 to 480 nM. Platelet activation was considerably enhanced by addition of factor VIIa to both hemophilia A blood and "acquired" hemophilia B blood. Thus, pharmacologic concentrations of factor VIIa cannot restore normal thrombin generation in hemophilia A and hemophilia B blood in vitro. The efficacy of factor VIIa (10-50 nM) in hemophilia blood is dependent on TF.