Describes a technical modification to create a hook-tail closed-end catheter for safer percutaneous selective cardioangiography.
Percutaneous catheterization is widely employed in various forms of angiography; it is not as well accepted for selective cardioangiography because an open end-hole catheter can cause severe injury within the heart. As a closed-end catheter is frequently preferable for intra-cardial contrast injections, catheter modifications have been suggested. The tip may leave the catheter through them. The catheter thus functions as a closed-end one—only a very small amount of the contrast agent emerges from the end in a retrograde direction. Types and Preparation of Catheters Polyethylene catheter material can be tapered to fit tightly around a leader if the has been occluded after its introduction into the vessel (11, 12, 16, 17), or a closed-tip catheter has been introduced percu-taneously by various means (3, 6, 10, 11). To make use of the advantageous percutaneous technic, a modification of the commonly used polyethylene (PE) catheter was made. This catheter has the distal end tapered and drawn out 3 to 5 cm. Both the inner diameter (ID) and the outer diameter (OD) of the taper are thus markedly reduced. Proximal to the taper, 5 or more side-holes are made so the major portion of the injected contrast medium tubing is cold drawn over it (14). Traction on the catheter over a leader will cause an abrupt change of the ID as well as the OD of the catheter; the length of the tapered part varies and depends somewhat on the force applied. A thinned section 10 cm long can be made easily, but for practical reasons a 3 to 5 cm length is enough. Since the PE catheter, when cold drawn, adapts snugly to any wire introduced, the ID and OD of the tapered part can be varied according to the requirements of the study. The 0.7 mm (0.027 in.) and 0.9 mm (0.035 in.) guide wires (Kifa) were used in this series, the 0.7 mm for the smaller catheters. The type of catheter employed varied with the age of the patient, size of the punctured vessel, and site of the intended injection of contrast material (Table I, Fig. 1). The most commonly used catheters were the gray ödman-Ledin and a specially made thin-walled catheter with the same outer diameter as the red radiopaque ödman-Ledin, herein labeled red thin-wall special. The catheters were prepared in lengths of about 60 and 100 cm. Immediately proximal to the tapered part, 4 to 10 side-holes were made with a perforator—Kifa size 1–2 for the small catheters and size 3 for the large ones. Immediately prior to use, the selected catheter was shaped according to the anticipated vascular anatomy. The drawn-out part of the distal end was warmed for an instant in hot water and shaped into a 180° bend. During this maneuver, a leader was passed through this part to avoid the kinking which otherwise would result. When the thinned part is heated in water, it decreases in length and the lumen increases slightly in diameter.
Boijsen et al. (Tue,) studied this question.