Congenital aortic stenosis is usually diagnosed by Echocardiography. Patients will be coming to the cath lab to determine if the aortic valve is suitable for ballooning.
- Indeflator devise.
- 0.35 x 260 Teflon or super stiff Exchange wire x 1.
- 50- cc, leur Lock syringe.
- Balloons as required and listed in the PULMONARY VALVE BALLOON section.
Prepare balloon by either aspiration or flushing air from a balloon as outlined in the PULMONARY
VALVE BALLOON section. Use a dilution of 1.8 of Omniopaque 350 and saline.
Give Inj Heparin 50/100 units per kg. The venous sheath will be used for a right heart cath.
should there be a left to right communication, LV pressure will be recorded and LV/ aorta
gradient will be recorded. If there is no patient foramen ovale (PFO) a transeptal puncture
may be done. A femoral arterial sheath will be inserted and a retrograde approach to the LV
will be attempted. An additional femoral arterial leader catheter will be inserted in left femoral
artery and connected to line# 3. Angiograms in the ascending aorta (PA/ LAT.) will be done.
Crossing the aortic valve will be very difficult. It is very important that all exams be done quickly
and efficiently. LV/ femoral artery pressure gradient is recorded, LV sao2 taken and LV
angiogram is done.
A JR.4 catheter (5 Fr) and a TERUMO hydrophilic coated 0.038 straight guide wire or a 0.035 Benson type heparin coated guide wire is usually very effective for crossing an aortic valve.
The size of the aortic valve is measured using the catheter for comparison. The measurement is taken perpendicular to, and at the level of the cusps.
The largest diameter exchange wire that will fit the balloon should be chosen to give optimal support.
Insert an exchange wire into the LV and remove the catheter and the femoral sheath. It is very important that the wire remains in the LV. Apply sufficient pressure on the site to maintain hemostasis. Insert the balloon over the wire across the aortic valve.
Curling the soft end of the exchange wire before inserting or J tip wire will:
1. Greatly reduce the ventricular ectopics caused by the tip irritating the myocardium.
2. Allow more of the wire to be in the LV. During the exchange procedure.
3. Position the stiffer portion of the wire across the valve, give greater support for the balloon.
While holding the balloon in place very quickly inflate the balloon to its nominal pressure. This step should be signed to record the inflation. Quickly deflate the balloon. This step may be repeated 1 or 2 times.
Expect arrhythmias and drop in pressure while the balloon is inflated. Resuscitation may be necessary but usually, these will abate spontaneously.
It may be necessary to use a 50- ml syringe attached to the vent or Indeflator port to create greater negative pressure while deflating the balloon.
If it is not possible to cross the aortic valve it is possible to position a balloon wedge catheter through the transeptal access site and manipulate it into the ascending aorta. A snare device will be used to trap the wire in the aorta and
pull it through the valve into the LV. Removed the balloon maintaining the exchange wire in the LV slight twisting of the balloon will be necessary to withdraw from the femoral puncture site. A sheath of the same size, or slightly larger than the balloon will be inserted over the wire and an end hole catheter positioned across the valve.
The pressure gradient across the aortic valve will be measured. If a satisfactory reduction in LV pressure is obtained, a pullback across the aortic valve is done to determine the gradient again. It may be necessary to repeat the ballooning using a larger balloon. Repeat LV or aortic angiogram to check the final result.
Note: Anesthesia standby is required for possible intubation and ventilation, and depending on weight, babies under1 year should be ventilated under general anesthesia.
On completion of procedure access lines are removed lines are removed as required. If the patient is intubated and is returning to the ICU for ventilation, the arterial leader catheter may remain in situ.