Femoral Cannulation for CPB: Tips and Discussion…

Editors Note:

I got this email today:

“Respected Sir / Mam,

This is Shahriar from Bangladesh. I am interested to know about femoral bypass technique.  Awaiting for your kind suggestion.

Regards,

Towfiq Shahriar Islam Khan, Perfusionist

IBN SINA Hospital (Cardiac Centre) Bangladesh”

Hence, the following article.

Please feel free to add suggestions or advise as you see fit.

Femoral Cannulation: Tips and Discussion…

Peripheral cannulation is the historical route for connecting the pump-oxygenator to the vasculature of the patient in order to establish partial or complete cardiopulmonary bypass. Although most open heart procedures are nowadays realized with central cannulation, there is renewed interest in remote cannulation through the femoral, iliac, axillary, subclavian and jugular vessels. Remote cannulation is not only of interest in hemodynamically unstable patients who can be put on cardiopulmonary bypass in local anesthesia, and stabilized prior to intubation, but also for complex procedures like replacement of the thoracoabdominal aorta, acute type A aortic dissections, complex redo open heart surgery, extracorporeal membrane oxygenation, and more recently, small access open heart surgery, robotic surgery, and others.

Open Femoral Cannulation Approach

Examples of traditional cannulas for peripheral cannulation: (top) original Bardic cannula : straight design with a shoulder.  A connector with a sidearm and a Luer lock two way stopcock have been added. (Center) modern straight cannula : straight design without shoulder. (Bottom) wire supported cannula with light house tip and end hole – this design is guide wire compatible) or others.

Usually, an arterial cannula slightly smaller than the arterial diameter is selected (typical size for adult males is 24 F and 22 F for adult females).

Percutaneous Femora Arterial Cannulation Approach

High pressure backflow of red blood (pulsatile jet) has to be witnessed prior to insertion of a guide wire

Thin wall percutaneous arterial cannula (above) allowing for full flow. Typical size for this purpose is 21F which allows for flows of 4 l/min and more

The common femoral artery is punctured in the middle between the inguinal ligament and the deep femoral artery, provided the vessel wall is soft and free from major atheromatous lesions.

A J-type guide wire (typical radius 3.5 mm) is inserted through the hollow needle and advanced into the iliac vessels.

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A percutaneous cannula stiffened by its corresponding mandrel is inserted over the guide wire and positioned with all its orifices within the artery.

A 21F thin wall percutaneous arterial cannula is usually sufficient for flows up to 4 l/min. Once in position, the cannula can be secured in various fashions: a suture to the skin, a snare and a tie, or a tape.

Femoral Venous Cannulation

Adequate venous blood drainage is one of the main challenges for conversion of partial cardiopulmonary bypass into full cardiopulmonary bypass. In the past we relied for this purpose on percutaneous venous cannulas which were positioned in trans-femoral fashion into the right atrium. At best, approximately 90% of target flow can be achieved with the best traditional percutaneous cannulas provided venous return is augmented with a centrifugal pump, vacuum or other suitable means.

For percutaneous venous cannulation, the common femoral vein is punctured in a relatively flat angle with reference to the vessel and in such a fashion that its wall is penetrated roughly in the middle, between the inguinal ligament and the deep femoral vein.

Examples of venous cannulas for open peripheral cannulation: (top) Chest tube (24 F); (center) (32 F); (bottom) smart canula^® expands from 18 F to 36 F.

Typically, a venous cannula slightly smaller than the venous diameter is selected (typical size for adult males is 28 F and 24 F for adult females).

Percutaneous Venous Cannulation

Some current percutaneous venous cannulae

Newer Technologies:  Smart Expanding Percutaneous Catheters