Fontan Operation
Conditions
Brief summary
The purpose of this study is to compare the liver stiffness, which can be caused by congestion and fibrosis in pediatric patients before and after a Fontan heart operation. A new form of ultrasound elastography (Acoustic Radiation Force Impulse, or ARFI) will measure liver stiffness.
Detailed description
The Fontan repair for single ventricle congenital heart lesions consists of three stages. This surgery has enable pediatric patients who have the repair to live into adulthood. Stage 3 of the surgery introduces immediate congestion of blood in the liver by increasing central venous pressure (CVP). CVP is the blood pressure within the vena cava, a major blood vessel in the body. Many patients later develop progressive liver fibrosis (stiffness) possibly as a result of increased blood pressure. Liver stiffness is increased both by congestion and fibrosis. Liver fibrosis has significant health risks and may complicate the patient's future healthcare. There are no established, noninvasive means of detecting the liver fibrosis until it becomes severe. Acoustic radiation force impulse (ARFI) elastography, an ultrasound technique, can measure the stiffness of the liver safely from outside the body. The investigators hypothesize that liver stiffness will be increased by stage 3 of the Fontan operation due to onset of liver congestion. Using ARFI, the investigators will measure liver stiffness before and immediately after stage 3 of the Fontan operation, when congestion of blood is likely the only contributor to any change in liver stiffness. The investigators will follow the trend of liver stiffness at six months by repeating the ARFI imaging.
Interventions
DEVICEARFI Ultrasound
This research scan uses acoustic radiation force impulse (ARFI) shear wave velocity imaging (SVI). This is a new ultrasound technology in which unique sound waves create the images/pictures of the liver beng examined/scanned. This ultrasound scan will take approximately 10 minutes to complete.
Sponsors
University of Michigan
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
DIAGNOSTIC
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
No minimum to 17 Years
Healthy volunteers
No
Inclusion criteria
* Pediatric patients ages 0-17 * Patients presenting to the University of Michigan for evaluation just before undergoing stage 3 of the Fontan operation
Exclusion criteria
* Patients over the age of 17 * Patients who have chronic liver disease (elevation of ALT, AST, or Bilirubin greater than two times the upper limits of normal \>4 weeks) * Patients who have evidence of liver enlargement or nodularity on prior ultrasound imaging * Patients who have a history of portal vein or hepatic vein thrombosis * Patients (parents) who are unwilling to read and sign the informed consent document
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Shear Wave Speed (Liver Stiffness) | 0-6 months | ARFI shear wave speed measurements were done on the right lobe of the liver. Measurement units are m/s (meters per second). A total of 8 measurements were performed on each subject at each time point.The 8 values were performed on each subject and averaged. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| IVC Pressure | Baseline and Follow Up Number 1 (approximately 24 -72 hours later) | Blood pressure in the IVC, the interior vena cava, was measured from a central line placed for patient care. |
Countries
United States
Participant flow
Participants by arm
| Arm | Count |
|---|---|
| ARFI Ultrasound Subjects were pediatric patients who had undergone a Fontan operation. Subjects underwent an ultrasound before and after the Fontan operation. The ultrasound scan used acoustic radiation force impulse (ARFI) shear wave velocity imaging (SVI). This is a non-invasive scan that uses sound waves to create images of the liver and measure the stiffness of the tissue. | 18 |
| Total | 18 |
Withdrawals & dropouts
| Period | Reason | FG000 |
|---|---|---|
| Follow-up #1 (24-72 Hours Post-surgery) | Lost to Follow-up | 1 |
| Six Month Follow-up | Lost to Follow-up | 12 |
| Time of Enrollment | Withdrawal by Subject | 3 |
Baseline characteristics
| Characteristic | ARFI Ultrasound |
|---|---|
| Age by Sex Age of Female Subjects | 33 Months |
| Age by Sex Age of Male Subjects | 34 Months |
| Age, Continuous | 33.5 Months STANDARD_DEVIATION 10.5 |
| Sex: Female, Male Female | 6 Participants |
| Sex: Female, Male Male | 12 Participants |
Adverse events
| Event type | EG000 affected / at risk |
|---|---|
| deaths Total, all-cause mortality | 0 / 18 |
| other Total, other adverse events | 0 / 18 |
| serious Total, serious adverse events | 0 / 18 |
Outcome results
Primary
Shear Wave Speed (Liver Stiffness)
ARFI shear wave speed measurements were done on the right lobe of the liver. Measurement units are m/s (meters per second). A total of 8 measurements were performed on each subject at each time point.The 8 values were performed on each subject and averaged.
Time frame: 0-6 months
Population: As shown in the participant flow, data was not captured for follow up time points 1 and 2 for 1 participant. At time point 3 data is only available for 5 participants.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| ARFI Ultrasound | Shear Wave Speed (Liver Stiffness) | Liver Stiffness at baseline | 1.18 meters per second | Standard Deviation 0.29 |
| ARFI Ultrasound | Shear Wave Speed (Liver Stiffness) | Liver Stiffness follow-up tim1 (24-72 hours later) | 2.28 meters per second | Standard Deviation 0.31 |
| ARFI Ultrasound | Shear Wave Speed (Liver Stiffness) | Liver Stiffness follow-up time 2 (7 days later) | 2.22 meters per second | Standard Deviation 0.38 |
| ARFI Ultrasound | Shear Wave Speed (Liver Stiffness) | Liver stiffness follow-up time 3 (6 months) | 2.08 meters per second | Standard Deviation 0.24 |
Comparison: Comparison of Baseline and Follow-up #1p-value: <0.0001Mixed Models Analysis
Comparison: Comparison of Baseline vs. Follow up #2p-value: <0.0001Mixed Models Analysis
Comparison: Comparison of Baseline vs. Follow-up #3p-value: <0.0001Mixed Models Analysis
Secondary
IVC Pressure
Blood pressure in the IVC, the interior vena cava, was measured from a central line placed for patient care.
Time frame: Baseline and Follow Up Number 1 (approximately 24 -72 hours later)
Population: Subjects who had undergone the Fontan operation and who had a central line placed. Blood pressure values were obtained from chart review.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| ARFI Ultrasound | IVC Pressure | IVC pressure before Fontan operation | 7.2 mmHg | Standard Error 2.6 |
| ARFI Ultrasound | IVC Pressure | IVC pressure after Fontan operation (24-72 hours) | 16.44 mmHg | Standard Error 3.3 |
p-value: <0.05Wilcoxon (Mann-Whitney)