Cardioplegia Cannulation and Venting
◆ A
purse-string suture (4-0 polypropylene) is placed on the right atrial wall,
caudal to the IVC cannulation site and about 1 cm from the atrioventricular
junction, at the level of the acute margin of the right ventricle (Fig. 2.13).
◆ The
cannula is passed through a stab in the purse string and is rotated so that the
tip abuts on the atrial septum at a point just medial to the IVC and curls
toward the left shoulder as the cannula is advanced. Proper placement is
indicated by easy passage of the cannula tip and by external palpation of the
cannula in the coronary sinus medial to the IVC. The pressure tracing from the
tip of the cannula will also be characteristic, and the position can be
confirmed using TEE.
◆ If
the cannula cannot be easily inserted, after snaring down the two single-stage
cannulae, a small transverse atriotomy (1.5 cm) may be made and a purse-string
suture placed around the coronary sinus ostium to secure the retrograde cannula
after insertion under direct vision.
◆ A
purse-string suture (4-0 polypropylene) is placed on the right superior
pulmonary vein with the medial suture line placed into the left atrium (Fig.
2.14).
◆ The
vent can be placed prior to or after cross-clamp application. If the vent is
placed prior to application of the cross-clamp, the surgeon must ensure that
the left ventricle is not ejecting to avoid possible air embolization during
vent placement.
◆ The
venting cannula can be tailored by creating a question mark curve to allow for
placement of the cannula into the left ventricle through the left atrium and
mitral valve. The cannula is passed through a no. 11 blade stab in
the pulmonary vein purse string, and the cannula is gently advanced in a left
inferolateral direction. If feasible, the surgeon’s hand can be placed behind
the heart in the oblique sinus and can palpate and guide the cannula through
the mitral valve.
◆ To
achieve effective venting and minimize bleeding during aortic procedures, the
cannula should sit in the left ventricle.
◆ Less
common alternative sites for ventricular venting include the superior aspect of
the left atrium, the pulmonary artery, and the foramen ovale.
 |
Similar image to Figure 2.13 but showing the right superior pulmonary vein and a cannula being advanced to the apex of
| the LV. A gloved hand can be placed behind the heart. |
Keywords : Cannulation
Techniques for Cardiopulmonary Bypass, cannulation techniques,
cardiopulmonary bypass, Surgical Anatomy, Operative Steps, Postoperative Care,
Pearls and Pitfalls, Ascending Aorta, Femoral and Iliac Vessels, Axillary
Artery
