Repair of abdominal aortic aneurysm in severe Factor VII deficiency

Congenital Factor VII deficiency is a rare disorder associated with reduced levels of Factor VII activity. Replacement therapy is necessary to control hemorrhaging or if surgery is needed. We report operative treatment of one case of chronic abdominal aortic aneurysm in a patient affected by a severe form of congenital Factor VII deficiency (endogenous FVII level <1%). The operation was carried out after the administration of Factor VII concentrate raised the Factor VII concentration to hemostatic levels. The patient continued to receive the concentrate every 6 hrs during the first three postoperative days. Dosage was assessed to obtain Factor VII levels not lower than 25%. No postoperative bleeding or thrombotic events were observed. The patient was discharged in excellent condition.

[New possibilities in the management of hemorrhagic diathesis caused by factor deficiency and thrombocytopenia: recombinant active factor VII concentrate]

Recombinant Factor VIIa, a new therapeutic tool to treat severe bleeding caused by inhibitory haemophilia cases, some cases of thrombocytopenia and thrombocytopathy (e.g. severe type III von Willebrand disease) receives growing attention in clinical practice. Exogeneous FVIIa-in a supraphysiological concentration (clearly over 6 U/ml) seems to be able to generate quickly and safely (without thrombotic side effects) thrombin--the final enzyme of clotting--in physiological, or pathological conditions. A concise review about the possible mechanisms of action, indications, monitoring and clinical experience gained sofar with FVIIa is given in this report.

Clinical picture and treatment strategies in factor VII deficiency

Factor VII is a trace protein required for normal haemostasis. Deficiency of factor VII comprises a highly heterogeneous disease group. Factor VII deficiency can cause bleeding, in particular if factor VII is extremely low, but a few cases lacking factor VII function entirely or subtotally may not present with a history of bleeding. Bleeding problems are not often reported in patients having a factor VII:C level at 10-15% of normal or more. Bleeding is frequently of mucocutaneous type, but the whole array of haemophilic bleeding may also occur. To control bleeding, during surgery in particular, substitution is required in the severe case of factor VII deficiency, but clinical studies documenting which correctional levels of factor VII:C to aim are lacking. It appears that a critical low level (trough) value at 10-15% may be anticipated, but clear documentation does not exist. Substitution programmes may include plasma or plasma derived factor IX concentrates of lower degrees of purity, so-called prothrombin complex concentrates that also are relatively impure, and pure factor VII concentrates. An alternative is a recombinant factor VIIa molecule. However, this concentrate has not received license in a number of countries. Thrombotic manifestations appear to occur more often than expected in the factor VII deficient patients, some have been linked to the use of impure concentrates, others to preexisting thrombophilic risk factors, but some are unexplained and may bear a relationship to the deficiency state of factor VII itself. Controlled clinical trials are highly warranted in this rare bleeding condition.

Congenital factor VII deficiency in a patient with an abdominal aortic aneurysm

A patient with congenital factor VII deficiency underwent surgery for an inflammatory abdominal aortic aneurysm. No references in the literature have been found on the management of this coagulation defect in patients who require vascular surgery. We present one such case, with special reference to the perioperative management of factor VII replacement therapy.

Hereditary factor VII deficiency in pregnancy: peripartum treatment with factor VII concentrate

This report describes pregnant sisters with severe factor VII deficiency and peripartum management with factor VII concentrate. In this family, two affected members had previously developed severe postpartum hemorrhage when managed with fresh frozen plasma. Therapy-related complications owing to plasma infusion included viral disease transmission and pulmonary edema. Therefore, to lessen the risks of complications, specific factor therapy was initiated shortly before parturition in both patients. Factor VII concentrate was administered prior to delivery and every 6 hr for the next 72 hr to keep trough levels at approximately 10%. Based on peak and trough levels, the mean factor VII half-lives were determined to be 3.6 and 5.7 hr. Use of the concentrate was associated with uncomplicated delivery and minimal postpartum bleeding.

Factor IXa-factor VIIIa-cell surface complex does not contribute to the basal activation of the coagulation mechanism in vivo

We have infused recombinant factor VIIa into patients with hereditary factor VII deficiency with marked reductions in plasma concentrations of factor IX activation peptide (FIXP), factor X activation peptide (FXP), and prothrombin activation fragment F1+2. These investigations show substantial elevations in these markers of coagulation activation and thereby demonstrate that the factor VII-tissue factor pathway is largely responsible for the activation of factor IX as well as factor X in the basal state (ie, the absence of thrombosis or provocative stimuli). We have administered a monoclonal antibody purified factor IX concentrate to individuals with hemophilia B. These studies show an increase in the plasma levels of FIXP that were initially greatly decreased, but no change in FXP or F1+2. We have also infused highly purified factor VIII concentrate into patients with hemophilia A. The data demonstrate no significant changes in the plasma concentrations of FXP and F1+2. The above observations indicate that factor IXa generated by the factor VII-tissue factor pathway is unable to activate factor X under basal conditions. Based upon the above findings, we outline a model of blood coagulation system function under basal conditions, and suggest a process by which the generation of factor Xa and thrombin might be accelerated during normal hemostasis and in the setting of thrombotic disorders.

Acquired factor VII deficiency associated with aplastic anaemia: correction with bone marrow transplantation

We report a patient with severe aplastic anaemia found to have a prolonged prothrombin time due to acquired factor VII deficiency. No evidence for a factor VII inhibitor or inactivator was demonstrable. Laboratory studies identified deficiency both of factor VII activity and factor VII antigen. The factor VII deficiency persisted from clinical presentation until approximately 50 d after allogeneic marrow transplantation when restoration of factor VII activity and antigen was noted. The patient's serum could be depleted of factor VII activity by in vitro incubation with Protein A bound to Sepharose, suggesting the presence of an IgG or IgG containing complex able to bind factor VII, but not neutralize its procoagulant activity. A dual specificity solid phase immunoassay identified a factor VII binding immunoglobulin which was detectable throughout the course of factor VII deficiency. The concordant appearance of this factor VII reactive immunoglobulin and the factor VII deficiency suggested the pathologic role of this immunoglobulin in the aetiology of the factor VII deficiency. This factor VII binding immunoglobulin may have induced rapid plasma clearance of the factor VII molecule or, alternatively, may have modified factor VII synthesis. The immunosuppressive therapy and subsequent lymphohaematopoietic engraftment following allogeneic marrow transplant was accompanied by complete resolution of the factor VII deficiency.

Factor VII deficiency and pregnancy

Hereditary factor VII deficiency is very rare in pregnancy (one in 500,000). However, obstetricians should consider this diagnosis whenever the prothrombin time is prolonged while the activated partial thromboplastin time is normal. The factor VII level increases in normal pregnancy, but the effect of pregnancy upon the factor VII level in deficient individuals is unknown. We report two cases of factor VII deficiency in pregnancy. In both, factor VII levels were 15% or less in the third trimester and were lower postpartum, suggesting that pregnancy does elevate factor VII in deficient individuals as well. Fresh frozen plasma is the treatment of choice. If the level is very low, fresh frozen plasma can be given prophylactically; otherwise, it should be given if blood loss becomes excessive.

[Practical approaches for surgical procedures in congenital factor VII deficiency]

A 33 year old female with a congenital deficit in factor VII underwent four operations, all without any haemorrhage. One of then was carried out using substitutive therapy. She had a non-A non-B hepatitis one month after this treatment. Substitutive therapy depends on the assessment of the risk of haemorrhage, which can be estimated by the concentration of factor VII, the severity of spontaneous haemorrhage, the surgical history, and the planned operation. Since the risk of transmitting viruses with freeze-dried blood products would appear to be virtually nil, since 1985, fresh frozen plasma should be avoided for this type of indication. The doses of concentrated factor VII to be used lie between 20 IU.kg-1 every 4 h and 40 IU.kg-1 every 8 h. Such a dose should be administered in either one or several injections, according to whether the risk of haemorrhage is important or not. Substitutive therapy should be continued as long as the risk persists. Using a test dose of factor VII and, afterwards, measuring its biological activity can help to determine the best time for starting the treatment in order to obtain a level of factor VII greater than the minimum required for surgical haemostasis (10%).

Selection of replacement therapy for patients with severe factor VII deficiency

The risk of significant bleeding in patients with severe Factor VII (FVII) deficiency is well documented. However, controversy regarding management exists not only for the choice of FVII replacement product, but also for the desired hemostatic level of FVII. Two case reports are presented where fresh frozen plasma (FFP) and several Factor IX (FIX) complex concentrates were used to achieve hemostasis. Significantly higher FVII levels were achieved with Proplex (FIX Complex, Hyland Therapeutics) than with other products. Although this and other reports indicate that minor bleeding can be controlled with levels of FVII under 15%, life-threatening hemorrhages require higher FVII levels that can be attained only by using a product with a significant FVII content. It is important to know the FVII content of FIX concentrates in order to plan appropriate therapy for patients with FVII deficiency.

Hereditary factor VII deficiency: report of a case of intracranial hemorrhage

A case of factor VII deficiency in a 52-year-old woman who developed central nervous system hemorrhage is here reported. Screening coagulation tests were all normal except for prothrombin time, normotest and thrombotest. Specific assays of vitamin K-dependent factors revealed that factor VII activity was reduced (11 U/dl). The studies of the family demonstrated that 2 sisters out of 4 were heterozygous for the defect. The activity of factor VII in the offspring, classified as obligatory carriers, ranged between 62 and 78 U/dl, the antigen between 55 and 75 U/dl. The wide variability of factor VII in normal people and the possible compensative effect of normal alleles in carriers do not allow to define the variant, namely if the patient is a CRMR homozygote or a CRMR/CRM-double heterozygote.

A factor VII concentrate for therapeutic use

A concentrate of factor VII suitable for therapeutic use has been prepared from human plasma by a method forming part of a comprehensive scheme of large-scale plasma fractionation. Factor VIII was separated as cryoprecipitate and factors II, IX and X were adsorbed on DEAE-cellulose. Most of the factor VII remained in the supernatant. By batch adsorption on DEAE-Sepharose, followed by elution on a chromatographic column, factor VII was concentrated about 25-fold, and purified about 50-fold compared with original plasma, without the need for further dialysis or concentration steps. Data are presented from 10 batches, each from 80-120 kg plasma. Following doses of factor VII to six congenitally deficient patients, the mean rise in plasma factor VII was 95-100% of theoretical; the half-disappearance time was about 4 h. The treatment of four patients with acquired deficiency of factor VII is also described. No untoward side effects were observed.

Treatment of congenital factor VII deficiency with a new concentrate

A new factor VII concentrate, made from ACD plasma by a process involving successive absorptions of cryoprecipitate supernatant on DEAE Sephadex and of the resulting supernatant on A1(OH)3, was administered to 10 patients with severe factor VII deficiency. 5 patients received only one dose for treatment of a single bleeding episode, the remaining 5 were given multiple infusions (47) for spontaneous hemorrhages or for the prevention of surgical bleeding. In vivo factor VII recovery ranged from 43 to 126% (average 88%) of the assayed in vitro activity of the concentrate. A dose of 0.5 u/kg was found to produce a 1% rise of the plasma factor VII levels. The mean half-life on injected factor VII as assessed in 7 kinetic studies was 205 min (range 168--234). Spontaneous bleeding was easily controlled by the concentrate and major surgical procedures (two tonsillectomies) could be performed without complications. 1 patient developed HBSAg positive hepatitis, but otherwise no serious side effects were observed. Factor VII concentrate reduced the risk of precipitating circulatory overload associated with the use of plasma and avoids the unnecessary rise of factor II, IX and X which follows prothrombin complex concentrates.