[The use of thrombin to decrease postoperative hemorrhage after total hip and knee replacement]

We used thrombin locally in order to decrease the post-operation hemorrhage in 25 patients after total hip and knee prosthesis. Thrombin application reduced post-operation hemorrhage by 70-80%. There was no negative impact of thrombin on wound healing.

Use of fibrin glue (beriplast) in the management of bleeding gastric varices

BACKGROUND AND AIMS

Gastric variceal bleeding is a serious complication of portal hypertension. The optimum endoscopic treatment of bleeding gastric varices is yet to be defined. We evaluated the use of Beriplast, which is a solution of fibrinogen and thrombin, in controlling gastric variceal bleeding.

PATIENTS AND METHODS

Fifteen patients presenting with gastric variceal bleeding were entered into an open trial of endoscopic gastric intravariceal injection treatment with Beriplast (fibrin sealant) and followed for up to 1 month after endoscopic treatment.

RESULTS

There was failure to control bleeding in one patient. Four patients had rebleeding after the index bleed. All four were reinjected with Beriplast, and the bleeding was controlled in three. All patients were followed for 30 days, and the 30-day mortality following injection treatment was one. Fourteen patients were discharged from the hospital after the first episode of gastric variceal bleeding. None of the patients had injection-induced complications.

CONCLUSIONS

These results show that Beriplast is a safe and simple endoscopic treatment option and is very effective in controlling gastric variceal bleeding.

Decrease of hemostatic cardiovascular risk factors by aggressive vs. conventional atorvastatin treatment in patients with Type 2 diabetes mellitus

BACKGROUND

Patients with Type 2 diabetes mellitus have increased levels of hemostatic risk variables for cardiovascular disease, such as fibrinogen, von Willebrand factor (VWF), factor (F)VIIa, d-dimer and plasminogen activator inhibitor-1 (PAI-1).

OBJECTIVES

To evaluate the effect of aggressive vs. standard dose atorvastatin on hemostatic cardiovascular risk factors in patients with Type 2 diabetes mellitus.

PATIENTS AND METHODS

The effect of 30 weeks of treatment with atorvastatin 10 and 80 mg on hemostatic cardiovascular risk factors was assessed in a randomized double-blind placebo-controlled trial on 217 patients with Type 2 diabetes mellitus and dyslipidemia.

RESULTS AND CONCLUSIONS

Atorvastatin 10 and 80 mg dose-dependently reduced d-dimer (7.4% and 8.5%, respectively, P for trend = 0.004) and PAI-1 antigen levels (9.0% and 18%, respectively, P for trend = 0.021). Levels of fibrinogen, VWF, tissue-type plasminogen activator and FVIIa were not influenced by atorvastatin. In conclusion, in patients with Type 2 diabetes mellitus, atorvastatin dose-dependently improved the levels of the hemostatic risk variables d-dimer and PAI-1.

Effects of topically applied biomaterials on paranasal sinus mucosal healing

BACKGROUND

Recently, nasal packing made of absorbable biomaterial has become increasingly popular. Although absorbable packs are effective for hemostasis, their impact on healing mucosa is unknown. Some have felt that a biocompatible sinus dressing actually may enhance healing, particularly in areas where the mucosa has been stripped. The aim of this study was to determine the effect of topical MeroGel and FloSeal on paranasal sinus mucosal healing in a rabbit model.

METHODS

Bilateral maxillary sinuses of 12 New Zealand white rabbits were surgically opened and stripped of mucosa. The left maxillary sinus of six rabbits had sterile saline-soaked MeroGel placed in the antrum, and the other six rabbits received FloSeal. The right maxillary sinuses of all 12 animals were stripped and otherwise untreated to serve as stripped controls. The animals were killed at 2 weeks and specimens were examined by light microscopy.

RESULTS

MeroGel-treated mucosa showed extensive fibrosis of the basal lamina and lamina propria, complete loss of surface epithelium, and loss of the mucociliary blanket. There was minimal resorption of the MeroGel, and MeroGel fibers were frankly incorporated into the regenerated epithelium, associated with an exuberant lymphocytic infiltrate. FloSeal-treated mucosa showed similar fibrosis of the basal lamina and lamina propria with loss of the mucociliary blanket, although to a lesser degree than the MeroGel- treated group. FloSeal showed similar incorporation into the healed mucosa with lymphocytosis. Controls showed expected submucosal gland reduction, lamina propria fibrosis, and loss of cilia, but the lamina propria fibrosis seen in the MeroGel and FloSeal groups was markedly more prominent.

CONCLUSION

In a rabbit model, MeroGel and FloSeal appear to increase reactionary fibrosis of healing mucosa. These agents also appear to be incompletely resorbed and grossly incorporated into healing tissue. Mucosal healing may be impaired by the application of these agents.

The management of inhibitors in haemophilia A: introduction and systematic review of current practice

Haemophilia is the commonest bleeding disorder in the UK, affecting approximately 5400 people, almost all of them male. In haemophiliacs, reduced levels, or absence, of factor VIII (FVIII) cause bleeding episodes, typically into joint spaces or muscles. Haemophilia is generally treated with exogenous FVIII. However, in some haemophiliacs, therapeutically administered FVIII comes to be recognized as a foreign protein, stimulating the production of antibodies (inhibitors), which react with FVIII to render it ineffective. Alternative treatment strategies then have to be used to manage bleeding episodes. In addition, strategies have been developed to attempt to abolish inhibitor production through the induction of immune tolerance. A systematic review was undertaken of current international practice for the clinical management of haemophilia A patients with inhibitors to FVIII, concentrating on literature published from 1995 onwards. Although it can be difficult to determine what constitutes current practice, current guidelines indicate that immune tolerance induction is seen as desirable, with the choice of regimen dependent on patient characteristics, familiarity with regimens and cost. Various approaches, based on similar factors, are used to control bleeding episodes.

Control of bleeding in patients with haemophilia A with inhibitors: a systematic review

This paper reports a systematic review of the best available evidence of clinical effectiveness in the treatment of acute bleeding in haemophilia A patients with inhibitors. Because of the lack of randomized controlled trials (RCTs) on this topic, broad inclusion criteria with regard to study design were applied in order to assess the best available evidence for each intervention. Because of the clinical and methodological heterogeneity of the evidence, it was not appropriate to pool data across studies; instead, data were synthesized using tabulation and qualitative narrative assessment. No evidence was found to support the use of high-dose factor VIII (FVIII) in bleeding episodes. However in surgery it was found to be highly successful (100%) for low-titre, low-responding inhibitors although not reliable for high-responding inhibitors. Porcine FVIII (pFVIII) was effective in the control of severe bleeding episodes with high-titre or high-responding inhibitors (100%) and in 60-90% of surgical procedures. Activated prothrombin complex concentrates (APCCs) appear to be more effective than prothrombin complex concentrates (PCCs) in the control of mild to severe bleeding episodes. There was no good evidence for the use of PCCs in surgery. APCCs controlled bleeding in approximately 90% of surgical episodes. Recombinant factor VIIa (rFVIIa) controlled 70-100% of mild to severe bleeding episodes with high-responding inhibitors, and achieved better results when used early. It was effective in 60-100% of surgical episodes. Doses varied from study to study, and side-effects from mild to infrequent but serious adverse events were reported. The quality of the evidence is variable. Limited evidence relating to other treatment options is also included in the review.

[Lepirudin during cardiopulmonary bypass in a patient with heparin-induced thrombocytopenia]

Lepirudin is an alternative anticoagulant therapy in heparin-induced thrombocytopenia (HIT) during cardiopulmonary bypass (CPB). We report a case of a female patient with HIT referred for aortocoronary bypass graft despite persistence of antibodies to platelet factor 4-heparin complexes. Anticoagulation management is described. Whole blood hirudin concentration attempted during CPB was above 4 microg ml(-1). To obtain this concentration, lepirudin administration was managed as follows: 0.1 mg kg(-1) h(-1) lepirudin during preoperative course, 0.2 mg kg(-1) bolus just before CPB and 0.2 mg kg(-1) in the priming solution, complementary boluses of 5 and 10 mg during procedure (according to whole blood ecarin clotting time). Aprotinin was administered simultaneously according to Royston protocol. Anticoagulation was monitored with whole blood ecarin time performed in the operation room (patient's whole blood was diluted one half and one third with normal whole blood; in vitro calibration curve was constructed using normal whole blood spiked with lepirudin). CPB duration was 73 min. When measured, whole blood hirudin concentration was 3.8-5.8 microg ml(-1). Total lepirudin administration was 44 mg. No haemorrhagic or thrombotic events were observed during surgical procedure and postoperative course. Despite lepirudin administration is not yet clearly precise for CPB procedure, its use seems adapted and safe in subjects without renal insufficiency but requiring precise coordination for anaesthesiological, surgical and biological teams.

Bone conditioning to enhance implant osseointegration: an experimental study in pigs

PURPOSE

Osseointegration of implants depends on time and the local bone conditions regarding quality and quantity. This led to the bone classification by Lekholm and Zarb. The aim of the present study was to enhance osseointegration of implants through conditioning of the bone bed and to compare in this context the efficacy of bone condensation, an osteoinductive collagen (Colloss), and platelet-rich plasma (PRP).

MATERIALS AND METHODS

Porcine frontal skull bone was used for the preparation of Identical-size implant beds. Before placement of the implants (Ankylos, 3.5 x 4 mm), the implant beds were untreated (control) or conditioned with condensation, Colloss, or PRP. The animals were sacrificed after 2, 4, and 8 weeks. The specimens were then compared and analyzed by microradiography, and statistical analysis was performed using the Wilcoxon signed rank test.

RESULTS

At the early observation times, significant effects on the sites of topical bone conditioning in comparison to the control group could be seen regarding the implant-bone interface (2 weeks: control 31%, Colloss 60%, condensation 73%, PRP 47%; 4 weeks: control 39%, Colloss 51%, condensation 40%, PRP 42%) and peri-implant bone density (2 weeks: control 31%, Colloss 48%, condensation 59%, PRP 39%; 4 weeks: control 47%, Colloss 53%, condensation 41%, PRP 50%). A leveling of the results between groups was found at 8 weeks (implant-bone interface: control 51%, Colloss 58%, condensation 55%, PRP 62%; peri-implant bone density: control 50%, Colloss 55%, condensation 51%, PRP 51%).

DISCUSSION

Overall, bone condensation and Colloss apparently influenced bone formation process from the onset, but over the entire 8-week healing period, differences in bone formation were not significant

CONCLUSION

It can be stated that, in the initial healing phase, an effect of topical bone conditioning may be achieved by the different described methods.

Economic modelling of different treatment strategies for haemophilia A with high-responding inhibitors

This paper reports a systematic review of the cost-effectiveness of treatment options in patients with haemophilia A with inhibitors. As very little relevant published evidence was identified, an economic modelling exercise was undertaken to calculate the cost-effectiveness of different strategies in the treatment of high-responding haemophilia A patients with inhibitors. A decision analysis approach was used to model the expected lifetime clinical outcomes and costs of the more common regimens currently used in UK in treating severe haemophiliacs with inhibitors. The model attempts to reflect the outcomes of clinical events, costs and life expectancy for each different treatment regimen for haemophilic boys with inhibitors who are high responders (defined as inhibitor level >/=10 BU) throughout their life. The basic model structure is centred on a Markov decision process, which was used to simulate, at quarter-yearly intervals, the movement through discrete health states and their complications. The model allows a comparison of cost-effectiveness between three immune tolerance induction (ITI) regimens (Bonn, Mälmo and Low-Dose protocols) and against a relevant 'on-demand' (OD) regimen. It also shows the cost-effectiveness of different OD regimens using different bypassing agents. The results of the economic modelling indicate that treating haemophilia A patients who have high-responding inhibitors OD with recombinant activated factor VII is cost-effective compared to treatment with activated prothrombin complex concentrates. However, when OD treatment regimens are compared with the three ITI protocols, the Malmö ITI protocol is the preferred treatment strategy, generating more quality adjusted life-years (QALYs) and less cost than either an OD regimen or the Bonn or Low-Dose ITI protocols.

Reversal of the International Normalized Ratio with recombinant activated factor VII in central nervous system bleeding during warfarin thromboprophylaxis: clinical and biochemical aspects

Major bleeding is a frequent and hazardous complication associated with thromboprophylaxis using vitamin-K antagonists (VKA). Suggested regimens for control of highly elevated International Normalized Ratio (INR) and hemorrhagic events during VKA treatment include administration of vitamin K, infusion of fresh frozen plasma (FFP) or a prothrombin complex concentrate (PCC). In contrast, this communication present the first report on the efficacious use of recombinant factor VIIa (rFVIIa) as additional therapy in seven patients presenting with central nervous system (CNS) bleeding emergencies. Pre-treatment INRs ranged from 1.7 to 6.6, and 10 min after a single dose of rFVIIa (10-40 microg/kg) all INRs were </= 1.5. Six patients underwent drainage of the CNS hematoma and all patients survived. No untoward biochemical signs of coagulation activation were detected and no incidence of thromboembolism was observed. In ex-vivo experimental studies, profiles of continuous whole blood clot formation were evaluated by thrombelastography in 25 patients on VKA treatment (INR 1.7-4.3), demonstrating a significantly prolonged initiation phase and diminished propagation of clot formation. Ex-vivo supplementation with rFVIIa to blood of six patients returned a distinct reduction of the prolonged initiation but variable changes in the maximum velocity of clot formation. The ex-vivo experiments and our clinical data support recent suggestions that rFVIIa might substitute for infusion of FFP or PCC in acute reversal of VKA treatment.

Somatostatin therapy ameliorates chronic and refractory gastrointestinal bleeding caused by diffuse angiodysplasia in a patient on anticoagulation therapy

We present a patient receiving chronic anticoagulant treatment with recurrent and intractable gastrointestinal bleeding due to diffuse angiodysplasia. Following failure of previous medical and surgical treatment, and in light of the patient's need for chronic anticoagulation due to mechanical heart valve, she was treated with somatostatin analogue, octreotide s.c. 100 microg on alternate days for 28 months. Treatment significantly decreased the occurrence of bleeding episodes, the need for hospitalization and blood transfusion requirements despite continued anticoagulant therapy. Octreotide treatment should be considered in patients with refractory gastrointestinal bleeding due to angiodysplasia in particular in those who need anticoagulant treatment.

Hemostatic effects of polymerized albumin particles bearing rGPIa/IIa in thrombocytopenic mice

The recombinant fragment of the platelet membrane glycoprotein Ia/IIa (rGPIa/IIa) was conjugated to the polymerized albumin particles (polyAlb) with the average diameter of 180 nm. The intravenous administration of rGPIa/IIa-polyAlb to thrombocytopenic mice ([platelet] = 2.1+/-0.3 x 10(5) particles/ microL) with three doses of ca. 2.4 x 10(10), 7.2 x 10(10), and 2.4 x 10(11)particles/kg, respectively, significantly reduced their bleeding time to 426+/-71, 378+/-101, and 337+/-46 s, respectively, whereas that of the control groups (PBS) was 730+/-198 s. The injection of rGPIa/IIa-polyAlb (2.4 x 10(11)particles/kg) was approximately equal to the effect of the injection of the mouse platelets at a dose of 2.0 x 10(10) particles/kg. It was confirmed that rGPIa/IIa-polyAlb had a recognition ability against collagen and could contribute to the hemostasis in the thrombocytopenic mice as a platelet substitute.

General haemostatic agents--fact or fiction?

Haemophilia is the most serious bleeding model that nature has provided us with, indicating the importance of factor FVIII and FIX in haemostasis. According to current knowledge, haemostasis is initiated by the formation of a complex between tissue factor (TF), exposed as a result of a vessel wall injury, and activated FVII (FVIIa) that is normally present in circulating blood. The TF-FVIIa complexes convert FX into FXa on the TF-bearing cell. FXa then activates prothrombin into thrombin. This limited amount of thrombin activates FVIII, FV, FXI and platelets. Thrombin-activated platelets change shape, resulting in exposure of negatively-charged phospholipids, which form the perfect template for full thrombin generation involving FVIII and FIX. In patients with haemophilia FVIII or FIX is missing. These individuals generate only initial limited amounts of thrombin as its generation is dependent on the presence of FVIII and FIX. Full thrombin generation is necessary for complete activation of FXIII and thrombin activatable fibrinolytic inhibitor to occur. Furthermore, full thrombin generation is important for the fibrin structure of the haemostatic plug. In the case of impaired thrombin generation, fibrin plugs will be loose and highly permeable. Such fibrin plugs are easily dissolved by normal fibrinolytic activity and thus prevent full and maintained haemostasis from occurring. The addition of rFVIIa to FVIII- or FIX-deficient plasma has been shown to increase thrombin generation in a cell-based in vitro model. Furthermore, extra rFVIIa was found to normalise fibrin clot permeability in vitro and to tighten the fibrin structure as studied by three-dimensional confocal microscopy. These findings indicate that administration of rFVIIa is capable of compensating for the lack of FVIII and FIX. Accordingly, the administration of exogenous rFVIIa has been found to stop bleedings in haemophilia patients and, provided it is given in doses high enough, to allow major surgery to be performed in severe haemophiliacs with inhibitors. As rFVIIa enhances thrombin generation on already activated platelets, it has been suggested that rFVIIa may also help to improve haemostasis in other situations involving impaired thrombin generation, such as platelet disorders (thrombocytopenia and functional platelet defects). Preliminary clinical data appear to support this. Patients with profuse bleeding due to extensive surgery or trauma often develop a complex coagulation pattern which includes reduced plasma levels of fibrinogen, FVIII and FV, and decreased platelet counts. These patients may well have an impaired capacity to generate thrombin. Consequently, they may benefit from one or two doses of rFVIIa in order to assist in the generation of a thrombin peak sufficient to form a firm, stable fibrin haemostatic plug and thereby reduce bleeding. This would facilitate any mechanical repair necessary for full haemostasis. Preliminary results in a few patients may support such an effect for rFVIIa. As thrombin has such a crucial role in providing haemostasis, any agent that enhances the thrombin generation in situations with an impaired thrombin formation may be characterised as a 'general haemostatic agent'. Let us look forward to more 'facts' through the 'evidence-based route'.

[The influence of contrykal on intraoperative blood loss during endoprosthesis implantation of the hip joint]

Application of the proteases inhibitors constitutes one of possible pharmacologic methods of the blood loss compensation during performance of operative intervention in orthopedics, especially for endoprosthesis of the main joints. Application of contrykalum for endoprosthesis of the hip joint is expedient, if prognosticated intraoperative blood loss exceeds 1000 ml. Efficacy of preparation was not established for the lesser blood loss cases.

Can epsilon-aminocaproic acid balance the off-pump bleeding advantage?

BACKGROUND

Aprotinin improved the control of bleeding in patients undergoing surgery with cardiopulmunary bypass, but its use was halted because of the risk of bovine spongiform encephalopathy. We then started to use epsilon-aminocaproic acid and the results in the control of bleeding were satisfactory. To assess its effectiveness in the control of postoperative bleeding precisely, we compared the results for patients operated on for myocardial revascularization on-pump and treated with epsilon-aminocaproic acid with those for patients who decidedly bleed less: off-pump patients.

METHODS

Two groups of patients who had had either on- or off-pump double aortocoronary bypass surgery were retrospectively reviewed for postoperative bleeding. These two almost homogeneous group had two grafts only: left anterior descending and circumflex arteries operated on with cardiopulmonary bypass and treated with the epsilon-aminocaproic acid, and left anterior descending and right coronary arteries operated on off-pump.

RESULTS

Postoperative bleeding through chest drainage at 4 h was 265+/-91.7 mL in the off-pump group and 328.4+/-131.4 mL in the on-pump group (p=0.004). But at 24 h it was 671.6+/-311.5 mL in the off-pump group and 827.8+/-514.4 mL in the on-pump group (p=0.07).

CONCLUSIONS

epsilon-Aminocaproic acid is effective in controlling postoperative bleeding in patients operated on for myocardial revascularization with the aid of cardiopulmonary bypass.

Update on Novo Nordisk's clinical trial programme on NovoSeven®

Recombinant coagulation factor VIIa (rFVIIa; Novoseven, Novo Nordisk A/S, Bagsvaerd, Denmark) is registered in most regions of the world for the treatment of bleeding episodes in haemophilia patients with inhibitors to factor VIII or IX. Since its initial availability, there have been several case stories on the investigational use of rFVIIa as a haemostatic agent in a variety of bleeding patients. Novo Nordisk recognizes the need to establish clinical guidance, and when possible, regulatory approvals for indications with bleeding episodes of various aetiologies. Currently, the safety and efficacy of rFVIIa is being investigated in 11 multinational, phase II trials, involving more than 1500 patients. Most of these trials have been designed to establish the efficacy of rFVIIa as a rescue treatment in episodes of severe life-threatening (upper gastrointestinal bleeding, stem cell transplantation, intra-cerebral haemorrhage and trauma). The remaining focus is on the prophylactic use of rFVIIa to improve haemostasis during surgery (orthotopic liver transplantation and liver resection), with the aim of avoiding or reducing the need for blood transfusions. In addition, Novo Nordisk is also continuing studies in haemophilia patients with inhibitors to increase therapeutic knowledge within this indication. Studies addressing dosages and regimens in subpopulations are presently ongoing.

Comparative analysis of hemostatic agents in a swine model of lethal groin injury

BACKGROUND

Techniques for better hemorrhage control after injury could change outcome. A large-animal model of lethal, uncontrolled hemorrhage was developed to test whether the use of various hemostatic agents would decrease bleeding and improve early survival.

METHODS

A complex groin injury was created in 30 Yorkshire swine (42-55 kg) to produce uncontrolled hemorrhage. This injury included semitransection of the proximal thigh and complete division of the femoral artery and vein. After 5 minutes, the animals were randomized to (n = 6 animals per group) no dressing (ND), standard dressing (SD), SD and Rapid Deployment Hemostat (RDH) bandage, SD and QuikClot hemostatic agent (QC), or SD and TraumaDEX (TDEX). Limited volume 0.9% saline (1,000 mL over 30 minutes) resuscitation was started 30 minutes after injury. We measured blood loss, early mortality (180 minutes), and physiologic markers of hemorrhagic shock (e.g., cardiac output, blood pressure, hemoglobin, metabolic acidosis).

RESULTS

Application of wound dressing decreased mortality in all groups compared with the ND group (83% mortality). However, this difference was significant (p < 0.05) only for the QuikClot hemostatic agent (0% mortality). Before the application of dressing (first 5 minutes), there were no differences in blood loss between the groups. After application of dressings, the QC group had the lowest blood loss (4.4 +/- 1.4 mL/kg).

CONCLUSION

Of the hemostatic agents tested, QuikClot improved survival and decreased bleeding in a swine model of lethal vascular and soft tissue injury.

Analysis and results of the recombinant factor VIIa extended-use registry

This paper describes the analysis of recombinant factor VIIa (rFVIIa; NovoSeven; Novo Nordisk, Bagsvaerd, Denmark) use in 40 patients with intractable bleeding in the UK. All cases were reported on the 'rFVIIa extended use database' (Traumanet) between its launch in February 1999 and 12 March 2002. Twenty-one other cases reporting rFVIIa use in different circumstances were excluded from the analysis. Recombinant FVIIa was effective in stopping or markedly reducing blood loss in 80% of patients; 20% of patients did not respond to treatment. Non-responders tended to have more deranged coagulation and lower platelet counts compared with responders. Despite a wide range of underlying illnesses, including malignancy and sepsis, few patients suffered adverse events. Thrombotic events occurred in three of 40 (7.5%) patients and these patients were considered as already at risk of thrombosis from other causes. The data suggest that rFVIIa is safe and effective therapy in patients with uncontrollable haemorrhage.