Figure 1
The rigid 3 mm diameter linear cryoprobe used to place linear cryolesions. Two of these probes are essential for performing the Cryosurgical Maze Procedure in association with Mitral Valve Surgery.

Figure 2
A purse-string suture is placed in the posterior-lateral right atrium and a linear cryoprobe is inserted through the purse-string into the inside of the right atrium.
A cryolesion is placed superiorly to the SVC.

Figure 3
Using the same purse-string suture, a second cryolesion is placed down to the IVC to complete the longitudinal lesion from the SVC to the IVC.

Figure 4
The first purse-string suture is tied down and a second is placed near the AV groove. The cryoprobe is inserted through this second purse-string suture and the "T" lesion is placed across the lower right atrium.

Figure 5
Using the same purse-string suture, the "T" linear cryolesion is extended down to the level of the tricuspid valve annulus.

Figure 6
The second purse-string suture is tied down and a third purse-string suture is placed in the right atrial appendage. A lateral right atrial cryolesion is then placed, leaving at least 3 cm between its tip and the "T" cryolesion.

Figure 7
Using the same purse-string suture in the right atrial appendage, a cryolesion is placed from the appendage down to the antero-medial tricuspid valve annulus.

Figure 8
The inter-atrial groove is then dissected completely and the right superior and right inferior pulmonary veins are dissected free anteriorly and posteriorly.

Figure 9
One linear cryoprobe is placed posterior to the right pulmonary veins as they enter the left atrium. A second identical cryoprobe is placed on the anterior surface of the veins in the same plane. Cardiopulmonary bypass is instituted. The cryoprobes are then "squeezed" together firmly.

Figure 10
This results in a circumferential, Tranmural cryolesion around the orifices of the right pulmonary veins.

Figure 11
The surgeon then retracts the ventricles out of the pericardium with his left hand to expose the intra-pericardial segments of both left pulmonary veins.

Figure 12
After minimal dissection around the left pulmonary veins, the two cryoprobes are "clamped" around both left pulmonary veins as they enter the left atrium posteriorly. This result in a circumferential, transmural cryolesion around the orifices of the left pulmonary veins.

Figure 13
A purse-string suture is then placed in the tip of the left atrial appendage and a linear cryoprobe is inserted inside the atrial appendage. A cryolesion is placed from the tip of the appendage to the left superior pulmonary vein orifice.

Figure 14
The heart is cardioplegically arrested and the aortal is cross-clamped. The linear Cryoplrobes are placed on both sides of the atrial septum. The resultant atrial septal cryolesion is transmural and extends down as far as the two cryoprobes are inserted.

Figure 15
Once the left atrium is opened to expose the mitral valve, a linear cryolesion is placed between the two inferior pulmonary veins. The probe is placed outside the atrium so that the surgeon can be certain that this lesion is transmural.

Figure 16
The cryoprobe is then turned down to the level of the mitral valve annulus epicardially. This traverses the coronary sinus and freezes it transmurally. A corresponding cryolesion is placed in exactly the same plane endocardially to complete the Maze procedure. Mitral valve surgery can then commence.

Figure 17
Summary of the cryolesions that are performed during cardioplegic arrest.