Venous Cannulation
◆ 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
