Procedure
The patient’s body was tilted to the left, and the right side of the
back was slightly elevated. TTE was used to determine the position of
the trans intercostal incision based on the location of VSD and the main
direction of blood flow. A surgical incision ≤ 1 cm in length (the
minimum incision in this study was 0.7 cm) was made at the left margin
of sternum of the 3rd to the 5th intercostal spaces, normally the 4th
intercostal space (Fig.2B, Fig.2C).
The subcutaneous soft tissues were opened by blunt dissection without
entering into the pleural cavity. The pericardium was transversely
incised and hung with 4-5 sutures (Fig.2A). TEE was used to determine
the position of the purse-string suture on the right ventricular
surface. With the real-time guidance of TEE, the cardiac surgeon moved
the tweezers in order for the tweezers’ head to point toward the PmVSD
and the main direction of blood flow. An optimal angle from the selected
site toward the VSD facilitated the guidewire passing through the VSD.
After heparin (1mg/kg) was administered, a purse-string suture was made
at the position of the tweezers’ head under direct visualization. TEE
was placed at a suitable angle for real-time monitoring and guidance. A
punch needle was inserted into the right ventricle through the pouch.
Then, the guidewire was sent to the left ventricle through the PmVSD
(Fig. 3b). The delivery sheath and the dilator were introduced to the
left ventricle over the guidewire after the puncture needle was
withdrawn. If the defect diameter of VSD was too small , surgeon should
expand VSD using the bigger dilator so that the delivery sheath pass
through the PmVSD smoothly. While the top of the sheath was confirmed to
be in the left ventricle, the guidewire and the dilator were withdrawn
(Fig. 3C. The short loading sheath was then connected to the long
delivery sheath. The occluder was pushed to released the left disk from
the sheath (Fig. 3D). According to the shape of PmVSD and AMS, the left
disk was placed on the left ventricular side of PmVSD or pulled all or
partly into the aneurysm. Then, the delivery sheath was withdrawn back
to the right ventricle, and the waist of the device and the right disk
were fully released (Fig. 3E).
TEE was immediately performed. If the device were perfectly released
without complications such as device dislocation, residual shunt,
device-related valve regurgitation (especially the tricuspid valve) and
arrhythmia, the device was inspected repeatedly by a push-pull maneuver
and unscrewed from the delivery
cable. Otherwise, the occluder was adjusted, withdrawn, or replaced if
complications arose.
After the occluder was released and unscrewed from the delivery cable,
the protective device suture contributed to the retrieval of the device
through a larger delivery sheath if the device was found to be displaced
by TEE . If all went well, the suture was gently pulled out from the
device and the delivery device was withdrawn. The last steps were to
ligate the purse-string suture and close the incision in layers
(Fig. 3).
ECG monitor was used to monitor heart rhythm and blood pressure during
the operation. During the surgery, care should be taken in monitoring
heart rhythm, blood pressure, oxygen saturation, blood gas analysis and
airway management. If these indications are abnormal, the procedure
should be discontinued and should even be cancelled.