Fontan Operation Clinical Trial
Official title:
Long-term Effects on Pulmonary Function in Post- Fontan Operation
Developed in the early 1970s, Fontan Operation has provided palliative care for patients
with single ventricle physiology. Single ventricle is a rare subclass of the
atrioventricular (AV) alignment abnormalities double inlet and common inlet ventricles (and
rarely, straddling tricuspid valve), in which there is only one ventricular sinus [1]. Most
patients present with symptoms of congestion , low cardiac output, and deep cyanosis
immedietly after birth. Untreated, these heart anomalies are highly lethal. Neonatal heart
transplantation is implacable because of shortage of donors. Fontan operation is a three
staged palliative procedure: the single ventricle pumping blood to the systemic circulation
, while blood flows laminarly to the lungs through direct anastomosis of the superior and
inferior vena cavae (total cavo pulmonary connections), inevitably by-passing the right
heart .
This procedure has been shown to immediately correct the mixed venous blood dysfunction,
providing treatment for the prominent signs of cyanosis.
Along with its beneficial outcomes, Fontan circulation patients have been documented to have
a variety of post-operative late complications. Of most substantial, increased systemic
vascular resistance (mean of 10-15 mmHg higher) [2], systolic dysfunction as a result of
decreased preload and increase afterload [3], and atrial arrhythmias [4].
With the advent of bypassing right-heart circulation with Fontan operation, the pulmonary
vascular bed is exposed to a new atmosphere of blood flow. Instead of physiological
pulsatile flow in normal circulation, the pulmonary vasculature is receiving slow velocity,
laminar flow [5]. Patients post-Fontan operations have been documented to have
restrictive-type pulmonary function, but still yet to be correlated with Fontan circulation
or as a possible result of prior lung tissue injury from the pre/intra-operation high volume
blood flow. Regardless, Fontan patients are described to have decreased pulmonary function.
The purpose of this research effort is to document and analyze the pulmonary function of
those patients post-Fontan operation. It is still unclear as to what the long-term effects
of Fontan operation are towards the pulmonary vascular bed, leaving us questions about the
effects on lung capacities, ventilation-perfusion efficiency, and oxygen saturation.
Generation of Data:
1. Spirometry-Spirometry will be performed in accordance with ATS/ERS (American Thoracic
Society/ European Respiratory Society) Task Force using a KoKo spirometer (KoKo system,
PDS Inc., Ferraris Cardiopulmonary System Group; Louisville, CO, USA). Each maneuver
will be repeated for at least three technically acceptable FEFV curves; the best
results were used for analysis. [6]
2. Whole Body Plethysmography- FRCpleth will be measured in a commercial, whole body
ZAN500 constant volume body plethysmograph (ZAN-Messgeraete GmbH, Germany); the
surrounded glassed cabin of 980 L includes a chair with adjustable height, all meeting
the ATS/ERS recommendations for plethysmography measurements [7,8]. The flow, volume,
cabin pressure, and mouth pressures are automatically calibrated. BTPS conditions for
lung volumes are automatically corrected. According to the manufacturer, environmental
interference is automatically reduced by a numeric-drift-compensation, enabling quick
stable signals for immediate testing.
3. MCT - Methacholine challenge tests will be performed in a designated room at the
Pediatric Pulmonary Unit, Meyer Children's Hospital, Haifa, Israel. MCT was performed
with double doses of fresh methacholine solutions in saline. Solutions were driven by
KoKo-PDS dosimeter via mouthpiece. The MCT will end when FEV1 dropped by more 20% from
baseline FEV1 values or when a methacholine concentration of 16 mg/ml was reached. The
exact PC20 value will be then calculated by the program according to the
log-transformed formula, as described in the guidelines for methacholine.[9] Airway
hyper-reactivity was defined as PC20 <8 mg/ml. Oxygen saturation and heart rate were
monitored by pulse oximetry (Nonin Wrist Ox 3100, Nonin Medical, Inc., Plymouth, MN,
USA).
4. FENO: Measurement of FENO will be performed by portable electrochemical analyzer NIOX
MINO (Aerocrine AB, Smidesvägen, Sweden),[10] and according to ATS recommendations .
The measurement procedure includes a deep inhalation to total lung capacity followed by
exhalation for 10 seconds at a mouth flow rate of 50 mL/sec and a pressure of 10
cmH2O.[11] Analysis of Data: Subjects of study will be patients post-Fontan operation
over the age of 6 years in order to fulfill the cooperation requirement necessary to
obtain data. Patients should be in general good health without any ongoing acute
pulmonary disease.
;
Observational Model: Cohort, Time Perspective: Prospective
| Status | Clinical Trial | Phase | |
|---|---|---|---|
| Completed |
NCT02269709 -
Stage 3 Fontan Operation Liver Ultrasound Study
|
N/A | |
| Recruiting |
NCT02414321 -
The Role of the Pulmonary Vasculature in the Fontan Circulation
|
||
| Not yet recruiting |
NCT05474664 -
Camostat Mesylate for Protein-losing Enteropathy After Fontan Operation
|
Phase 2 |