Thromboelastometry as a Predictor of Thrombotic Complications During Pediatric Recipient Liver Transplantation

Study Overview
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Brief Summary
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The study aims to correlate the perioperative results of a device called thromboelastogram, which is used to detect coagulation abnormalities, with thrombotic complications during pediatric recipient liver transplantation.

Detailed Description
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Pediatric patients undergoing liver transplant are at risk for significant bleeding and thrombotic complications. Studies in both pediatric and adult cohorts estimate an incidence of thrombotic events in up to 26% of cases. Hepatic artery and portal vein thrombosis (PVT) are reported at rates of 5-15% in pediatric cohorts, which is three to four times the incidence in adults. Bleeding estimates are harder to quantify given variability in the definition of major bleeding, but range from approximately 5 to 9%.The contribution of bleeding to morbidity is difficult to quantify, but thrombotic complications are known to reduce graft survival and contribute significantly to adverse outcomes, with mortality rates approaching 50% in those with hepatic artery thrombosis. Thromboelastometry offers rapid, comprehensive, and global clinical assessment of the patients' coagulation status, as demonstrated by several studies. Little data exists in the use of thromboelastography (TEG) in pediatric liver transplantation. In 2011, Curiel et al implemented pre-transplant TEGs for patients listed for liver transplantation. The invistigators sought to examine if there were any correlations with preoperative hypercoagulable indices on the TEG and postoperative thrombotic complications.The invistigators have identified that a preoperative hypercoagulable TEG portends to thrombotic complications in pediatric liver transplant patients. Further studies are needed to explore perioperative management strategies for high risk patients to prevent the development of postoperative thrombotic complications based upon preoperative TEG studies. That's why the invistigators will study the perioperative thromboelastometry as a predictor of thrombotic complications during pediatric recipient liver transplantation.

Official Title
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Perioperative Thromboelastometry as a Predictor of Thrombotic Complications During Pediatric Recipient Liver Transplantation

Conditions
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Pediatric Liver Transplantation

Intervention / Treatment
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* Procedure: Pediatric Liver transplantation


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Male or female participant must be between 3 months and 15 years of age. Participant is a recipient of a first liver allograft from living donors. Participant is a single-organ recipient (liver only). Participants' parent/guardian is capable of understanding the purposes and risks of the study and must sign an informed consent for the study. Exclusion Criteria: Pre-existing blood disease. A history of liver transplantation. Multivisceral transplantation. Participants' parent/guardian refused to participate in the study.

Ages Eligible for Study
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Minimum Age: 3 Months
Maximum Age: 15 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Thrombosis<br>Patients who will develop thrombosis perioperatively | Procedure: Pediatric Liver transplantation<br>* Pediatric Liver transplantation<br>|
| No thrombosis<br>Patients who will not develop thrombosis perioperatively | Procedure: Pediatric Liver transplantation<br>* Pediatric Liver transplantation<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Intraoperative thrombotic events (hepatic artery or portal vein thrombosis) | Any documented thrombus by imaging or clinical diagnosis made by direct observation during a surgical procedure. This includes both venous and arterial thromboembolic events. | Intraoperative, an average of 12 hours | 
| Thrombotic events (hepatic artery or portal vein thrombosis) | Patients will be screened for hepatic thrombosis regularly with liver Doppler ultrasound during the first week postoperatively, with confirmatory imaging based on identified clinical or imaging concerns. | Postoperative up to 1 week. | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Coagulation Time preoperative. | Coagulation Time (CT, in seconds), the time from the start of measurement until a clot firmness of 2 mm is detected by thromboelastometry preoperatively. | Preoperative up to 1 day before surgery. | 
| Coagulation Time in pre-anhepatic stage. | Coagulation Time (CT, in seconds), the time from the start of measurement until a clot firmness of 2 mm is detected by thromboelastometry during pre-anhepatic stage. | In pre-anhepatic stage, an average of 4 hours. | 
| Coagulation Time in anhepatic stage. | Coagulation Time (CT, in seconds), the time from the start of measurement until a clot firmness of 2 mm is detected by thromboelastometry during anhepatic stage. | In anhepatic stage, an average of 2 hours. | 
| Coagulation Time after reperfusion. | Coagulation Time (CT, in seconds), the time from the start of measurement until a clot firmness of 2 mm is detected by thromboelastometry after reperfusion. | After reperfusion, an average of 4 hours. | 
| Coagulation Time at the end of surgery. | Coagulation Time (CT, in seconds), the time from the start of measurement until a clot firmness of 2 mm is detected by thromboelastometry at the end of surgery. | At the end of surgery, an average of 12 hours. | 
| Clot Formation Time preoperative | Clot Formation Time (CFT, in seconds), the time needed to increase clot firmness from 2 to 20 mm amplitude as detected by thromboelastometry preoperatively. | Preoperative up to 1 day before surgery. | 
| Clot Formation Time in pre-anhepatic stage. | Clot Formation Time (CFT, in seconds), the time needed to increase clot firmness from 2 to 20 mm amplitude as detected by thromboelastometry during pre-anhepatic stage. | In pre-anhepatic stage, an average of 4 hours. | 
| Clot Formation Time in anhepatic stage. | Clot Formation Time (CFT, in seconds), the time needed to increase clot firmness from 2 to 20 mm amplitude as detected by thromboelastometry during anhepatic stage. | In anhepatic stage, an average of 2 hours. | 
| Clot Formation Time after reperfusion. | Clot Formation Time (CFT, in seconds), the time needed to increase clot firmness from 2 to 20 mm amplitude as detected by thromboelastometry after reperfusion. | After reperfusion, an average of 4 hours. | 
| Clot Formation Time at the end of surgery | Clot Formation Time (CFT, in seconds), the time needed to increase clot firmness from 2 to 20 mm amplitude as detected by thromboelastometry at the end of surgery. | At the end of surgery, an average of 12 hours. | 
| Angle α preoperative. | Angle α, the angle of tangent at 2 mm amplitude (ANG α, in degrees) as detected by thromboelastometry preoperatively. | Preoperative up to 1 day before surgery. | 
| Angle α in pre-anhepatic stage. | Angle α, the angle of tangent at 2 mm amplitude (ANG α, in degrees) as detected by thromboelastometry during pre-anhepatic stage. | In pre-anhepatic stage, an average of 4 hours. | 
| Angle α in anhepatic stage. | Angle α, the angle of tangent at 2 mm amplitude (ANG α, in degrees) as detected by thromboelastometry during anhepatic stage. | In anhepatic stage, an average of 2 hours. | 
| Angle α after reperfusion. | Angle α, the angle of tangent at 2 mm amplitude (ANG α, in degrees) as detected by thromboelastometry after reperfusion. | After reperfusion, an average of 4 hours. | 
| Angle α at the end of surgery | Angle α, the angle of tangent at 2 mm amplitude (ANG α, in degrees) as detected by thromboelastometry at the end of surgery. | At the end of surgery, an average of 12 hours. | 
| Maximum Clot Firmness preoperative. | Maximum Clot Firmness (MCF, in millimeters), the maximum amplitude of clot firmness finally achieved as detected by thromboelastography preoperatively. | Preoperative up to 1 day before surgery. | 
| Maximum Clot Firmness in pre-anhepatic stage. | Maximum Clot Firmness (MCF, in millimeters), the maximum amplitude of clot firmness finally achieved as detected by thromboelastography during pre-anhepatic stage. | In pre-anhepatic stage, an average of 4 hours. | 
| Maximum Clot Firmness in anhepatic stage. | Maximum Clot Firmness (MCF, in millimeters), the maximum amplitude of clot firmness finally achieved as detected by thromboelastography during anhepatic stage. | In anhepatic stage, an average of 2 hours. | 
| Maximum Clot Firmness after reperfusion. | Maximum Clot Firmness (MCF, in millimeters), the maximum amplitude of clot firmness finally achieved as detected by thromboelastography after reperfusion. | After reperfusion, an average of 4 hours. | 
| Maximum Clot Firmness at the end of surgery. | Maximum Clot Firmness (MCF, in millimeters), the maximum amplitude of clot firmness finally achieved as detected by thromboelastography at the end of surgery. | At the end of surgery, an average of 12 hours. | 
| Warm ischemic time | in minutes | during the surgery, an average of 2 hours | 
| Length of ICU stay | in days | after the surgery, an average of 1 month | 
| Length of hospital stay | in days | postoperative, an average of 1 month | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Pediatric Liver Transplantation, Thromboelastometry