Catheter Shape Research Articles

An ideal catheter: the simple curve.

A complex variety of catheter shapes has developed in the short period since Seldinger first introduced percutaneous angiography. The author has discovered in the course of several thousand selective arteriograms that only only one cartheter is needed: the original simple curve.

Adrenal venography; improvement of the shape of catheter and its clinical application (author's transl)

The preoperative identification of adrenal tumor is essential to correct diagnosis and appropriate treatment. Adrenal venography is one of the most useful adjuncts for this purpose, but catheters of various types introduced in the past are not necessarily well configured to catheterize adrenal veins. The catheter newly designed by us made catheterization of the left adrenal vein much easier even for unskilled hands. Our new catheter has been used in 20 of 55 venographical studies which have been carried out in our service. Determination of cortisol concentrations in adrenal venous blood which was performed in 6 cases failed to give any clue to determine the laterality of the existing adrenal tumor.

New Preformed Catheter Shape for Right Adrenal Venography

A new preformed catheter shape for right adrenal venography is presented. It makes this operation much easier and more successful than any catheter described previously.

Versatile catheter tip for selective angiography.

Since the inception of selective angiography, many different catheter shapes have been designed to permit catheterization of specific arteries. Based upon the principle that each tributary of the aorta represents discontinuity in its circumference, we have designed a general catheter shape which may be used to catheterize all the branches of the aorta from the sinuses of Valsalva to the internal iliac arteries. Figure 1, A demonstrates the versatile catheter shape for selective angiography. Segment AB is 2 mm long. The segment BC is equal to the distance CE which is just less than the estimated diameter of the aorta in the region of the specific artery to be catheterized. Segment BC of the catheter is parallel to segment EF. The portion of the catheter EFG is gently curved as shown. The arcs of the catheter ABC and EFG are so shaped as to put tension on the two parallel segments BC and EF. When the catheter is in the aorta (Fig. 1, B), the projecting tip AB is used to probe the aortic wall. When the tip of the catheter encounters the mouth of a branch of the aorta, the tension of the major arc causes the tip of the catheter to spring into the orifice (Fig. 1, C). Pulling the catheter distally straightens the curves, and the catheter slips further into the vessel. The angiographer varies the distance the tip of the catheter extends into the artery by the extent of withdrawal of the catheter. The parallel sides BC and EF aid in determining the direction the tip of the catheter is facing when approaching the mouth of the desired artery. As one rotates the catheter and observes the direction of motion of the segments he can readily determine whether the tip is facing anteriorly or posteriorly. Often the catheter resumes the shape indicated in Figure 1, D. Despite this, it may be easily manipulated, and the tip will enter the desired branch when it is approached from below. For the internal iliac artery catheterization a caudal motion facilitates the insertion of the catheter tip. Nevertheless, we have found it easier to selectively catheterize arteries utilizing the shape shown in Figure 1, B. Therefore, we frequently convert the shape in Figure 1, D to the preferential shape by catheterizing the renal or lumbar arteries and then pushing the catheter cephalad. This restores the preshaped curves as desired. If segment CDE has been made too wide for the aorta and is unsuitable for selective arterial catheterization, a replacement is shaped and inserted. Even if the aorta is markedly plagued by arteriosclerotic changes, selective catheterization is much easier when this versatile tip is employed. Summary The authors describe a catheter shape which has markedly shortened the time required for selective angiography, lessened the trauma at the puncture site from prolonged manipulations, and decreased patient morbidity. During the catheterization of more than one artery in the same patient, this catheter shape expedites the examination by eliminating the need for changing catheters.

CAVAL CATHETER MODIFICATIONS. OPEN-HEART SURGERY.

Refinements in the small details of instituting cardiopulmonary bypass enable this surgical procedure to progress more smoothly, prevents occasional but often troublesome complications, and allows the surgeon to concentrate on less routine problems. Insertion, positioning, and securing the caval catheters is a standard maneuver. The following modifications have made easier placement and removal of these catheters. The catheter is first formed into a right angle by autoclaving the catheter in the metal catheter former* (Fig 1). The plastic will maintain this shape on cooling and removal. The metal formers prevent wall kinking and obstruction of the lumen of the catheter at the right angle. This shape of catheter has proved much easier to insert into the cava openings. The two catheters then lay side by side to the Y connector. This enables a smooth lie on the operative field. The major problem after positioning of the caval catheters is to