◆ We prefer to use a long double-stage or multi-stage venous cannula because it may be used for definitive perfusion. We do not routinely place tapes proximally and distally, thus avoiding posterior dissection. Two purse-string sutures (4-0 polypropylene) are placed around the target, and a 14 F needle is inserted approximately 3 mm from the caudal apex of the diamond. A guidewire is inserted cephalad, up to the superior vena cava (SVC). The cannula is inserted over the wire, with further minor opening of the vein wall with a scalpel superiorly, up to 3 mm from the apex of the diamond. Further advancement of the cannula is guided by TEE to ensure that the tip is just inside the SVC.
◆ At the completion of the procedure, the purse strings can be gently snared as the cannula is removed and then tied, with little compromise of the femoral vein lumen.
◆ Usually, a double-stage venous cannula is inserted through the right atrial appendage. The edges of the atrium can be gently grasped on each side, with an incision made using a scalpel or scissors. The cannula is introduced with the tip directed posteriorly so that it is gently guided into the inferior vena cava (IVC). Occasionally, digital manipulation at the level of the IVC below the heart is necessary to guide the cannula into the correct position, with or without confirmation by TEE.
◆ If two single-stage venous cannulae are required, we generally place one cannula (IVC) through the atrial appendage. The second purse string is placed approximately 1.5 cm posterior and caudal to this point so that the second cannula (SVC) crosses the IVC cannula. This orientation facilitates exposure of the tricuspid valve and coronary sinus and provides good retraction of a left atriotomy when the caval cannulae are pulled to the left side of the incision. During preparation for orthotopic heart transplantation, both purse strings should be placed as posterior in the atrial wall as comfortably possible (without a crossover orientation) to allow for the preparation of an appropriate cuff of native right atrium to facilitate the atrial anastomosis.
◆ If necessary, snares can be placed around the SVC and IVC after gentle circumferential dis- section. We do not routinely snare for mitral valve surgery.
◆ Direct cannulation of the SVC may be necessary, particularly with high atrial septal defects (e.g., sinus venosus). The purse string should be placed in a diamond fashion on the anterior surface of the SVC, well above the sinoatrial node, but in a location such that the snare will include flow through the azygos vein. The two sides of the purse string are held with forceps by the surgeon and assistant, and a vertical venotomy is completed. A right-angled cannula is inserted directly and twisted cephalad, and the purse strings are tightened. For orthotopic heart transplantation using bicaval cannulation, SVC cannulation can be achieved as described previously; IVC cannulation can be achieved by venous cannulation arising from the femoral vein.
Keywords : Cannulation Techniques for Cardiopulmonary Bypass, cannulation techniques, cardiopulmonary bypass, Surgical Anatomy, Operative Steps, Arterial Canulation, Venous Cannulation, Postoperative Care, Pearls and Pitfalls, Ascending Aorta, Femoral and Iliac Vessels, Axillary Artery