Efficacy of Amicar for Children Having Craniofacial Surgery

The purpose of this study is to determine whether Amicar (ε-aminocaproic acid) is effective in reducing blood loss in children undergoing craniofacial reconstruction surgery. The investigators hypothesize that Amicar will decrease intraoperative blood loss and decrease the need for perioperative blood product administration in children undergoing craniofacial surgery.

Craniosynostosis is a condition in which there is premature fusion of one or more of the sutures between the bones of the skull. Premature fusion of sutures in the skull limits the ability of the cranial vault to expand to accommodate the rapidly growing brain in infancy and early childhood and leads to bony deformation. Left uncorrected, craniosynostosis may adversely impact both neurologic and psychosocial development and in some cases, can result in high intracranial pressure and blindness. Craniofacial (CF) reconstructive surgery is performed in young children with craniosynostosis to improve physical appearance, prevent functional neurologic disturbances, and enhance psychosocial development. Due to the complexities of the surgery as well as the young age and size of the patients, CF reconstruction carries potential life threatening risks and can result in significant morbidity. Reported complications include massive intraoperative hemorrhage, intraoperative cardiac arrest, transfusion-related reactions, venous air embolism, hypotension, coagulopathy, bradycardia, postoperative seizures, surgical site infections, facial swelling with airway compromise, and unplanned postoperative mechanical ventilation. The most severe and most common perioperative issues relate to the rate and extent of blood loss. Fibrinolysis, which impairs adequate hemostasis, has been shown to occur in children during CF reconstruction. This most certainly contributes to the magnitude of blood loss in these types of operations. Thus, targeting this defect in clot hemostasis with the use of antifibrinolytics is a reasonable therapeutic approach. Amicar (ε-aminocaproic acid) is a synthetic lysine analog that blocks the lysine binding sites on plasminogen, resulting in antifibrinolytic activity through inhibition of plasmin formation. We have chosen to study Amicar in this clinical context for a number of reasons. First, major hemorrhage continues to be a significant perioperative issue in this cohort. Secondly, Amicar is commonly and safely administered to children undergoing other types of high-risk surgery (i.e., spinal fusion surgery and open heart surgery). In addition, Amicar is inexpensive and easily administered, making it a viable and novel therapeutic option if shown to be effective for this type of surgery.

Treatment group 1: Amicar 100 mg/kg (0.4 mL/kg) IV loading dose, followed by an intraoperative continuous infusion at 40 mg/kg/hr (0.16 mL/kg/hr) to be continued until skin closure.

Treatment group 2: Equal volume of normal saline (placebo control) at the same rate as treatment group 1.

As estimated blood loss is known to be inaccurate in this setting, mean intraoperative blood loss (in mL/kg) will be calculated using a formula previously described in this population.

To establish that intraoperative administration of Amicar decreases perioperative blood donor exposure and need for transfusion following craniofacial reconstructive surgery

Inclusion Criteria: Any child diagnosed with craniosynostosis in need of surgical repair Males and females between the ages of 2 - 36 months (minorities will be included) Surgical procedure involving complex craniofacial reconstruction and craniotomy Written informed consent from parent/guardian Exclusion Criteria: Subjects with known or suspected hypersensitivity reaction to Amicar or history of prior Amicar exposure Presence or prior history of a known coagulation disorder or hypercoagulable state Preoperative laboratory values that indicate clinically significant hematologic disease (hemoglobin, platelet count, prothrombin time, or partial thromboplastin time outside of normal range) Subjects who are on anticoagulant therapy (Coumadin, heparin, aspirin, etc.) Subjects with a prior history of a thrombotic event History of renal malformation Presence of hematuria History of abnormal renal function - serum creatinine or blood urea nitrogen (BUN) value greater than 1.5 times the upper limit of the normal range Craniofacial reconstruction surgery performed in conjunction with an additional surgical procedure associated with blood loss Subjects who have been previously enrolled in this protocol may not be enrolled again

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