Acute coagulopathy after reperfusion of the liver graft in children correction with recombinant activated factor VII

Coagulopathy and transfusion therapy in pediatric liver transplantation

Bleeding and coagulopathy are critical issues complicating pediatric liver transplantation and contributing to morbidity and mortality in the cirrhotic child. The complexity of coagulopathy in the pediatric patient is illustrated by the interaction between three basic models. The first model, "developmental hemostasis", demonstrates how a different balance between pro- and anticoagulation factors leads to a normal hemostatic capacity in the pediatric patient at various ages. The second, the "cell based model of coagulation", takes into account the interaction between plasma proteins and cells. In the last, the concept of "rebalanced coagulation" highlights how the reduction of both pro- and anticoagulation factors leads to a normal, although unstable, coagulation profile. This new concept has led to the development of novel techniques used to analyze the coagulation capacity of whole blood for all patients. For example, viscoelastic methodologies are increasingly used on adult patients to test hemostatic capacity and to guide transfusion protocols. However, results are often confounding or have limited impact on morbidity and mortality. Moreover, data from pediatric patients remain inadequate. In addition, several interventions have been proposed to limit blood loss during transplantation, including the use of antifibrinolytic drugs and surgical techniques, such as the piggyback and lowering the central venous pressure during the hepatic dissection phase. The rationale for the use of these interventions is quite solid and has led to their incorporation into clinical practice; yet few of them have been rigorously tested in adults, let alone in children. Finally, the postoperative period in pediatric cohorts of patients has been characterized by an enhanced risk of hepatic vessel thrombosis. Thrombosis in fact remains the primary cause of early graft failure and re-transplantation within the first 30 d following surgery, and it occurs despite prolongation of standard coagulation assays. Data, however, are currently lacking regarding the use of anti-aggregation/anticoagulation therapies and how to best monitor for thrombosis in the early postoperative period in pediatric patients. Therefore, further studies are necessary to elucidate the interaction between the development of the coagulation system and cirrhosis in children. Moreover, strategies to optimize blood transfusion and anticoagulation must be tested specifically in pediatric patients. In conclusion, data from the adult world can be translated with difficulty into the pediatric field as indication for transplantation, baseline pathologies and levels of pro- and anticoagulation factors are not comparable between the two populations.

Outcomes of patients with benign liver diseases undergoing living donor versus deceased donor liver transplantation

BACKGROUND/AIMS

The number of people undergoing living donor liver transplantation (LDLT) has increased rapidly in many transplant centres. Patients considering LDLT need to know whether LDLT is riskier than deceased donor liver transplantation (DDLT). The aim of this study was to compare the outcomes of patients undergoing LDLT versus DDLT.

METHODS

A total of 349 patients with benign liver diseases were recruited from 2005 to 2011 for this study. LDLT was performed in 128 patients, and DDLT was performed in 221 patients. Pre- and intra-operative variables for the two groups were compared. Statistically analysed post-operative outcomes include the postoperative incidence of complication, biliary and vascular complication, hepatitis B virus (HBV) recurrence, long-term survival rate and outcomes of emergency transplantation.

RESULTS

The waiting times were 22.10±15.31 days for the patients undergoing LDLT versus 35.81±29.18 days for the patients undergoing DDLT. The cold ischemia time (CIT) was 119.34±19.75 minutes for the LDLT group and 346±154.18 for DDLT group. LDLT group had higher intraoperative blood loss, but red blood cell (RBC) transfusion was not different. Similar ≥ Clavien III complications, vascular complications, hepatitis B virus (HBV) recurrence and long-term survival rates were noted. LDLT patients suffered a higher incidence of biliary complications in the early postoperative days. However, during the long-term follow-up period, biliary complication rates were similar between the two groups. The long-term survival rate of patients undergoing emergency transplantation was lower than of patients undergoing elective transplantation. However, no significant difference was observed between emergency LDLT and emergency DDLT.

CONCLUSIONS

Patients undergoing LDLT achieved similar outcomes to patients undergoing DDLT. Although LDLT patients may suffer a higher incidence of early biliary complications, the total biliary complication rate was similar during the long-term follow-up period.

Recombinant activated factor VII usage in life threatening hemorrhage: a pediatric experience

OBJECTIVE

To determine the safety and efficacy of off label usage of Recombinant activated factor VII (rFVIIa) in children with severe bleeding in non-hemophiliac children with diverse etiologies like leukemia, post hematopoietic stem cell transplantation, dengue shock syndrome and Glanzmann thrombasthenia.

METHOD

Medical records of 16 non-hemophiliac children with 20 bleeding episodes where rFVIIa was administered only after failure of standard measures to control bleeding were retrospectively reviewed and data collected regarding patient demographics, diagnosis and location of bleeding. Blood counts, coagulation and other lab parameters, both pre and post rFVIIa, were also noted. Severity of bleeding was assessed using a scoring system used previously by Nevo S et al. A record of usage of the amount of blood components (red blood cells, platelets, fresh frozen plasma, and cryoprecipitate) 24 h pre and post rFVIIa was also made. The dose of rFVIIa and any adverse side effects were recorded.

RESULTS

Bleeding sites were gastrointestinal (13/20), pulmonary hemorrhage (6/20) and intracranial hemorrhage (1/20). Thrombocytopenia (platelet count <50,000/cumm) was present in 50% episodes and five had refractory low platelets. Usage of packed red cells and platelets was significantly less after usage of rFVIIa (p value 0.001 and 0.006, respectively). Mean dosage of rFVIIa was 77 μgm/kg/dose (range 60 to 90 μgm/kg/dose). The bleeding stopped completely in 11(55%), decreased to minimal in 2 (10%), reduced but transfusions needed in 4 (20%) and did not stop in 3 (15%) episodes. Five patients (31%) did not survive the bleeding episode. None of the patients developed thrombosis.

CONCLUSIONS

rFVIIa appears to be safe and effective in controlling life-threatening bleed in non-hemophiliac children.

Applicability and safety of recombinant activated factor VII to control non-haemophilic haemorrhage: investigational experience in 265 children

Experience of recombinant activated factor VII (rFVIIa, NovoSeven; Novo Nordisk A/S, Bagsvaerd, Denmark) to control haemorrhage in non-haemophilic children is limited. The object of this study was to examine the applicability and safety of rFVIIa amongst a group of non-haemophilic paediatric subjects. Details of all non-haemophilic children < or =16 years receiving rFVIIa whose data were recorded in the investigational, internet-based registry, haemostasis.com were analysed. A total of 265 children (mean age 7.7 years) were treated with rFVIIa; the median dose administered was 78.4 microg kg(-1) body weight (range 9.0-393.4) and the median total dose received 100.0 microg kg(-1) body weight (range 10.9-1341.2). Therapeutic areas included surgery (34.5%), coagulopathy (including thrombocytopenia; 29.0%), spontaneous bleeding (17.2%), trauma (8.4%) and intracranial haemorrhage (4.5%). Two patients experienced thromboembolic events following administration of rFVIIa. Thirty-nine patients died on account of haemorrhage or complications relating to their underlying condition; neither the thromboembolic events nor the deaths were related to rFVIIa administration. Bleeding stopped in 118/237 (49.8%), markedly decreased in 54/237 (22.8%), decreased in 51/237 (21.5%), remained unchanged in 13/237 (5.5%) and increased in 1/237 (0.4%) patients. These results suggest that rFVIIa is safe and widely applicable in children to control non-haemophilic haemorrhage.

Activated recombinant factor VII in orthotopic liver transplantation

Orthotopic liver transplantation (OLT) is affected by important alterations of hemostasis. The aim of this study was to evaluate the efficacy of recombinant factor VII activated (rFVIIa) to reduce intraoperative bleeding during OLT.

METHODS

Twenty OLT patients were assigned in double-blind way to a rFVIIa group or a control group. Inclusion criteria were hemoglobin > 8 g/dL: INR > 1,5 and fibrinogen > 100 mg/dL. We administered a single bouls of rFVIIa (40 microg/kg) or placebo. We determined INR, partial thromboplastin time, fibrinogen, ATIII, and blood cell counts. Blood products were administered as follows: 4 units of fresh frozen plasma when INR > 1.5, and 1 unit of RBC for Hb < 10 g/dL. The study ended 6 hours after the bolus.

RESULTS

No thromboembolic events occurred. The INR was different between rFVIIa group and the controls at T0 (1.9 vs 1.6 P < .021) and during T1 (1.2 vs 1.6 P < .004). The total transfused red blood cells was 300 mL +/- 133 in rFVIIa group and 570 mL +/- 111 in control group (P < .017). The total fresh frozen plasma was 600 mL +/- 154 in rFVIIa group and 1400 mL +/- 187 in control group (P < .001). Total blood loss was greater in the control group than the rFVIIa group: 1140 mL +/- 112 vs 740 mL +/- 131 (P < .049).

DISCUSSION

The use of rFVIIa during OLT can reduce the risk of bleeding during surgery. The literature has described cases who did not benefit from the treatment. An adequate cut-off of INR, allowed us to treat only patients at greater bleeding risk.

Successful use of recombinant activated FVII and aminocaproic acid in four neonates with life-threatening hemorrhage

Reports on the use of recombinant activated factor VII (rFVIIa) to counteract hemorrhagic shock in neonates and preterm infants are increasing. rFVIIa enhances thrombin generation in situations with impaired thrombin formation and, since thrombin has a crucial role in providing hemostasis, rFVIIa is regarded as a general hemostasis agent. Full thrombin generation is necessary for the formation of a stable fibrin plug resistant to premature fibrinolysis. Antifibrinolytic drugs are not recommended for the treatment of acute bleeding. We report four neonates (one with massive postsurgical hemorrhage after ileostomy and three with severe pulmonary hemorrhage in the course of mechanical ventilation for meconium aspiration syndrome, congenital heart disease and during postoperative resuscitation after cardiac surgery for congenital heart disease) who were successfully treated with multiple administration of rFVIIa (120 microg/kg per dose) and antifibrinolytic therapy - aminocaproic acid (100 mg/kg per dose). In a fibrinolytic environment therapeutic concentrations of rFVIIa may sometimes be insufficient to produce adequate amounts of thrombin necessary for stable clot structure. Laboratory data in three of our patients with pulmonary hemorrhage (low fibrinogen levels with slightly prolonged prothrombin time) supported this thesis, so we blocked fibrinolysis with aminocaproic acid and achieved a complete clinical and laboratory therapeutic effect.

Recombinant activated factor VII (rFVIIa) treatment in infants with hemorrhage

BACKGROUND

Recombinant activated factor VII (rFVIIa) is approved by the FDA for the treatment of bleeding episodes in patients with hemophilia A or B with inhibitors to factor VIII or factor IX. In addition to the FDA-approved indications, rFVIIa has been anecdotally reported effective for profound bleeding episodes in adult patients without hemophilia, and proven beneficial for adults with intracranial hemorrhage. In the pediatric literature, case reports have been made with apparent clinical improvement seen after the use of rFVIIa for acute life-threatening bleeding; however, there are limited data regarding its use in infants<4 months of age. We report our experience with rFVIIa in nine infants with severe hemorrhage of diverse etiologies.

METHODS

This case series of infants under 4 months with coagulopathy and bleeding treated with rFVIIa was collected from two institutions. We report the age, weight and pre-rFVIIa laboratory values of the patients as well as the clinical scenario and outcomes.

RESULTS

The nine infants all suffered acute life-threatening hemorrhage. Two patients were postoperative from cardiac surgery, two with Vitamin K deficiency and intracranial hemorrhage, three with suspected necrotizing enterocolitis and abdominal hemorrhage, and two with pulmonary hemorrhage. The patients ranged in age from 2 days to 4 months, (average age 1 month and average weight 3.3+/-1.0 kg). Seven of the nine patients had frozen plasma, cryoprecipitate, or platelet administration in failed attempts to correct the coagulation defect prior to receiving rFVIIa. The dose range used in this series was 90-100 microg.kg-1, with 90 microg.kg-1 being the most commonly used dose. The average pre-rFVIIa INR was 8.7+/-5.1. Four patients had an immeasurably high INR. All patients had clinical resolution of bleeding after receiving rFVIIa, and seven of nine patients survived.

CONCLUSIONS

rFVIIa is a powerful hemostatic drug whose mechanism of action provides a theoretical specificity to sites of tissue injury. In addition to its FDA-approved uses in hemophiliac patients, this drug has a potential role in the treatment of life-threatening hemorrhage from multiple causes.

Recombinant factor VIIa reduces transfusion requirements in liver transplant patients with high MELD scores

Patients undergoing orthotopic liver transplantation (OLT) often experience significant coagulopathy and remain at risk for excessive blood loss and massive transfusion. The ability of recombinant factor VIIa (rFVIIa) to reduce transfusion requirements during OLT has not been well established. This retrospective study investigates whether rFVIIa reduces transfusion requirements in liver transplant patients with a significantly prolonged prothrombin time (PT) and a model of end-stage liver disease (MELD) score of > 20. Eleven patients received a single dose of rFVIIa (58 +/- 18 microg kg(-1)) at the time of incision. This group was matched with a selected control group that fulfilled all of the inclusion/exclusion criteria. Patient characteristics, pre-operative PT, HCT, PLT and MELD were identical between groups. Prophylactic application of rFVIIA reduced packed red blood cells (3.9 +/- 2.6 versus 6.9 +/- 2.3 U, P = 0.01) and fresh-frozen plasma (FFP) (12.6 +/- 6 versus 19.8 +/- 7 U, P = 0.018) transfusion requirements when compared with the control group. FFP administration in the first 24 h after surgery was also significantly less in the rVIIa group when compared with the control group (388 +/- 385 versus 1225 +/- 701 mL, P = 0.003). Hospital stay following transplantation tended to be shorter in the rFVIIa group, albeit statistical significance was not achieved (11 +/- 7.3 versus 7.9 +/- 2.7, P = 0.2). All but one patient in the control group survived for 30 days after transplantation. In a selected group of patients with prolonged PT and high MELD score, the prophylactic application of rFVIIa at the start of the OLT may reduce perioperative transfusion requirements.

Emerging Off-Label Uses for Recombinant Activated Factor VII: Grading the Evidence

Recombinant activated factor VII (rFVIIa) is currently licensed in the United States for treatment of bleeding episodes in patients with deficiencies of factor VIII (FVIII) or IX (FIX) who are refractory to factor replacement because of circulating inhibitors. A 1999 report of its successful use to stop what was deemed to be lethal hemorrhage after an abdominal gunshot wound in a young soldier without pre-existing coagulopathy has prompted exploration of other uses for rFVIIa. The virtual explosion of proposed uses of rFVIIa raises issues not only regarding our understanding of the coagulation system, but also regarding its efficacy, cost-effectiveness, and safety.

Single pretransplant bolus of recombinant activated factor VII ameliorates influence of risk factors for blood loss during orthotopic liver transplantation

Large blood loss and transfusions during liver transplantation (LTx) may lead to serious complications and have a negative impact on post-transplant mortality and morbidity. In the retrospective study we compared two groups of recipients of primary cadaveric liver transplantation: group I (study group), consisted of 28 patients with preoperative risk of high intraoperative blood loss, including severe uncorrected coagulopathy. This group was given a bolus of recombinant activated factor VII (rFVIIa) just before LTx. Group II (control group) included 61 patients without a particular risk for increased intraoperative blood loss. These patients were not given rFVIIa. We analyzed both groups for: coagulation parameters before, during and after surgery (INR, APTT, factor VII activity), blood and FFP transfusions, operative time, postoperative complications (vascular thrombosis, reoperation for bleeding), postoperative ICU stay, post-transplant hospitalization time and mortality. Patients from the study group (I) had significantly worse coagulation parameters than patients in the control group (II) at the start of the surgical procedure; however, after administration of a bolus of rFVIIa there was immediate correction of coagulation in all recipients. No significant differences in intraoperative blood transfusions were observed between study and control groups (1980 +/- 311.4 mL vs. 1527 +/- 154.2 mL, respectively), operating time (8.7 h vs. 8.9 h) or ICU and hospital stay (7.03 days vs. 6.15 days and 40.89 days vs. 41.1 days). Re-exploration because of bleeding was performed in three patients from group I (10.7%) and in seven patients (11.5%) from group II. No single case of vascular thrombosis was observed in the study group, while in the control group there were three hepatic artery thromboses, two portal vein thromboses and one hepatic vein thrombosis. We conclude that rFVIIa given preoperatively to liver transplant recipients with several risk factors for high intraoperative bleeding adjusts these patients to a normal risk group, without an increased risk for thrombotic complications.

Eficacia del factor VII activado en la hemorragia poscirugía cardíaca y oxigenación con membrana extracorpórea

A 4-year-old girl suffered severe postoperative chest tube drainage bleeding after cardiac transplant surgery requiring extracorporeal membrane oxygenation. Transfusions of platelets and fresh frozen plasma failed to decrease the bleeding. At 2.5 hours a dose of 180 mcg/kg of recombinant activated Factor VII was administered. The hemorrhage decreased from 45 ml/kg/h in the first 2.5 hours to 17 ml/kg/h in the next 2.5 hours. The same dose of recombinant activated Factor VII was administered and the hemorrhage suddenly decreased to 1.5 ml/kg/h in the next 2.5 hours, with subsequent disappearance. No adverse events related to activated Factor VII were observed. Recombinant activated Factor VII may be useful in some cases of severe postoperative bleeding in children after cardiac surgery. Randomized controlled studies are needed to confirm its safety and efficacy, and to evaluate the most suitable dose.