Cannulation of the Left Inferior Pulmonary Vein For Left Atrial-Femoral Artery Bypass

Abstract

Cannulation of the inferior pulmonary is not trivial (Plate 31). In opening the pulmonary vein, one is entering the left side of the circulation, often with the heart beating. This confers susceptibility to left-sided air embolism. This can, and has been, catastrophic. The heart fibrillates immediately if a bolus of air enters the RCA. Immediate remedy of such embolism may be difficult, especially in the right-side down position for descending aortic surgery. This complication is best avoided.

Questions and Answers

• SP: What is your landmark for finding the left inferior pulmonary vein ?

• JAE: As we all learn via our general thoracic experience, a lymph node usually marks the lower border of the inferior pulmonary vein. This helps immensely to locate the vein as one works one’s way up dissecting the inferior pulmonary ligament.

• SP: Is there an alternative route you can use instead of inferior pulmonary vein for left heart bypass?

• JAE: Yes. You name it, and I have used it. The left atrial appendage is an obvious alternative. The superior pulmonary vein is fine. One can cannulate the body of the left atrium. Applying the Seldinger technique can sometimes be helpful in cannulating a small superior or inferior pulmonary vein.

• SP: You state you worry about air emboli, but what about tearing of this vein, how common is that and have you run into this issue before during cannulation? What do you do to repair it if it tears?

• JAE: The vein is delicate, and it can tear. If this happens, my focus is on preventing air entry through the tear. Bleeding can be controlled by finger pressure. The anesthesiologist should be alerted, so that he can keep the patient “full”, thus assuring that blood will come out rather than air go in. I use a pledgeted stitch always for the original pursetring to discourage tissue tearing. Tying this stitch down usually provides at least a modicum of hemostatic control.