Cerebral Oximetric Monitoring of the Posterior Circulation
Condition: Congenital Heart Disease
MeSH terms: Heart Diseases; Heart Defects, Congenital
Study type: Observational

Summary: 
      One known risk of pediatric heart surgery is the possibility for brain damage. This problem
      results from a lack of oxygen rich blood flow to the brain during surgery. In order to
      provide the patient's brain with blood during this operation, selective cerebral perfusion is
      sometimes used. This technique allows for adequate blood flow to the brain, and is monitored
      using special sticker sensors. The sensors are applied to the patient's forehead, and a
      corresponding monitor indicates oxygen levels in the front part of the brain. The goal of
      this study is to find out if these same stickers can be applied to the base of the skull to
      measure cerebral oxygenation at the back of the brain, and to determine if the back of the
      brain is adequately oxygenated during selective cerebral perfusion in patients undergoing
      complex aortic arch reconstruction.
    

Detailed description: 
      One known risk of pediatric heart surgery is the possibility for brain damage. In may cases
      this problem results from a lack of oxygen rick blood flow to the brain during surgery.
      Recently, a technique has been developed that allows for adequate blood flow to the brain
      during surgery, thus decreasing the chances that brain injury will occur as a result of heart
      surgery. This technique, called selective cerebral perfusion, is not the technique of choice
      for surgeons operating to repair the aortic arch, but it is sometimes used. The aorta is the
      main artery that comes out of the heart and carries oxygen rick blood to the body. This large
      vessel is connected to the heart on one end and then extends upward and forms an arch. At the
      top of the arch, three vessels branch off and provide the upper part of the body, including
      the brain, with blood.

      In a patient with a deformity in the aortic arch, it is necessary to operate to ensure that
      the flow of blood to the body is adequate and uninterrupted. In order to provide the baby's
      brain with blood during this operation, the technique mentioned earlier called selective
      cerebral perfusion is used. In order to understand how selective cerebral perfusion works, it
      is important to know that the patient will be placed on cardiopulmonary bypass during
      surgery. During cardiopulmonary bypass, a machine is used to pump blood to the body. This
      allows the surgeon to work on the heart and surrounding arteries while still providing blood
      flow of he brain and body. In the past, when surgery involved correction of abnormalities of
      the aortic arch, cardiopulmonary bypass would have to be stopped and the arch drained of
      blood, meaning there would be periods of time where the baby's brain would not receive any
      blood flow. With selective cerebral perfusion, a small Gore-Tex shunt is attached to one of
      the blood vessels that branch off of the aortic arch. Blood from the cardiopulmonary bypass
      machine is them pumped into the shunt where it enters the artery that branches off of the
      aorta and eventually travels up the neck and into the brain. Other studies have shown that
      pumping blood into this vessel allows the front portion of the brain to receive blood while
      the aortic arch abnormality is being corrected. These studies have shown this by using two
      stickers with special sensors on them that are connected to a monitor. These stickers, when
      placed on the baby's forehead, show on the monitor whether or not the front part of the brain
      is receiving blood.

      There are two parts to this study, with part 1 used to assess feasibility:

      Part 1: The goal of part one is to find out if these stickers can accurately show whether or
      not blood is getting to the back of the brain. Patients undergoing heart surgery who are not
      getting complex aortic arch reconstruction will be enrolled for part 1.

      Part 2: If it is found that the stickers do work, part 2 will enroll patients who are
      undergoing complex aortic arch reconstruction. The goal of part 2 is to find out if the
      technique known as selective cerebral perfusion is effective at getting blood to the back of
      the brain during complex aortic arch reconstruction.

      The study procedures for part 1 and 2 will be the same, with one sticker being placed in the
      normal position of the forehead, and the other sticker placed at the base of the skull.
      Application and data collected from the stickers in parts 1 and 2 will not affect surgical
      treatments.
    

Intervention name(s): Cerebral oximeter sensor
Intervention type(s): Device
Intervention description(s): The INVOS Cerebral Oximeter utilizes two electrodes to monitor cerebral oxygenation. The recommended placement of these electrodes is on the forehead to monitor the frontal cortex. In this study, one electrode will be placed in the normal position on the forehead, and the other will be placed at the base of the skull. The stickers will be placed on the patient at the beginning of surgery and removed at the end. The maximum amount of time that they will be on the patient's skin is approximately six hours. Application of the stickers and the data they provide will not alter the provider's treatment plan. This procedure will be used for all enrolled patients, whether they are enrolled in Part I or Part II.
Observational model: Cohort
Time perspective: Prospective
Sampling method: Probability Sample
Study population: 
        Neonates or infants undergoing heart surgery
      
Keywords: Aortic Arch