Either femoral may be used, but the left femoral is preferable owing to the fact that, the angle at the bifurcation of the ascending vena cava is more obtuse.
If the operator desires to remove blood from the heart, we believe that the indirect method is the better way. By the use of the direct method to draw blood from the right auricle by means of the trocar there is always danger of rupturing the circulation. The aorta may be accidently pierced. When the trocar is inserted from below to reach the right ventricle the stomach may be punctured and the liver and diaphragm will have to be pierced which, too, may mean an injured circulation. If any accidental damage has been done, it can not be remedied. The direct method is a blind procedure and is always uncertain. On the other hand if the flexible rubber drainage tube is inserted into the vein it must follow the channel of that vein. It is more certain than the trocar method and there is no danger of rupturing the circulation.
The basilic or axillary vein may be used to remove blood from the heart instead of the femoral. These veins should be used on the left side of the body owing to the fact that the angle at the junction of the subclavian and internal jugular veins is not so acute as on the right side.
Removal of Blood by the Use of the Femoral Vein.
—The use of the femoral vein is considered by some operators a very good method. The femoral should be employed in the upper third. Make the incision in the center of Scarpa's triangle, just below Poupart's ligament. The incision should be about two inches in length, the length of the incision usually depends upon the size and thickness of the thigh and the depth of the vein in the tissue. Expose the artery and the vein. The vein at this point will lie to the inside of and a little below the femoral artery. Open the artery and inject about a pint of fluid to cause a pressure on the venous system.
Have all the blood drainage outfit in readiness then open the vein and quickly insert the drainage tube. Any of the drainage tubes now commonly sold on the market are good. For the femoral, though, the flexible rubber drainage tube seems to be the best, because the femoral vein dips deep down into the posterior part of the abdomen after it leaves the Poupart's ligament. The flexible rubber drainage tube will follow this bend and can be pushed as far as is desired by the operator, in contrast the steel drainage tube could only be pushed into the vein for a few inches.
Blood ought to drain out into the blood bottle, if it does not, inject a little more fluid to cause more pressure on the venous system, and if it will not flow by the drainage method or any of its modifications try the aspirator. If blood still will not flow, it may mean that there is a clot ahead of the drainage tube. Pump some fluid through the drainage tube into the vein, to see if the tube is open, then let the fluid drain out which usually will bring some blood. After you have tried all the methods, if blood still does not flow, it will indicate that the blood is either in a coagulated condition, or there is not very much blood in that particular vein, which in this case is the femoral. The blood may be more in the dependent parts of the body.
Removal of Blood from the Axillary Vein.
—The axillary vein is of large size, and is formed by the junction of the venae comites or deep brachial veins with the basilic. The axillary vein begins at the lower part of the axillary space, increases in size as it ascends by receiving tributaries corresponding in name with the branches of the axillary artery and terminates immediately beneath the clavicle at the outer margin of the first rib where it becomes the subclavian vein. To remove blood from the axillary vein, raise the vein to the surface, and insert the drainage tube. The Eckels-Genung steel drainage tube will perhaps be the best tube to use. Insert the drain tube high up in the arm pit, pass through the subclavian, to beyond the valve located in the subclavian vein outside the point at which the internal jugular vein unites with the subclavian to form the innominate. There being no more valves the blood should pass out freely. If the blood does not flow, raise the axillary artery, begin the injection of fluid which will tend to cause a pressure through the capillaries on the venous system pressing the blood back to the right auricle of the heart as in life, and as there is no obstructed passage the blood should flow freely from the tube. The vein tube is of metal having a plunger rod within, and a Y attachment at the upper end. The blood runs from the Y shaped attachment into a rubber tube which is connected with the blood bottle. A flexible arterial tube should be used in the artery, which will measure eight to ten inches in length and constructed with a shut-off valve. The tube will reach the innominate artery close to the arch of the aorta. With these arterial and drainage tubes the arms can be folded and placed in position, with the hands over the abdomen and the tubes will extend out over the upper border of the arm. This method will enable the operator to inject the body and have the arms in their natural position. If a short circuit through the internal mammary vessels occurs, and this will be evidenced by the premature flow of thin blood, close the vein tube now and then during the operation, continuing the injection until the proper results are obtained.