WO1994003227A1

WO1994003227A1 - Steerable cardiac catheter

Info

Publication number: WO1994003227A1
Application number: PCT/GR1993/000015
Authority: WO
Inventors: Christodoulos Stefanadis; Pavlos Toutouzas
Original assignee: Christodoulos Stefanadis; Pavlos Toutouzas
Priority date: 1992-07-31
Filing date: 1993-07-29
Publication date: 1994-02-17

Abstract

Steerable cardiac catheter for the retrograde (via the left ventricle) catheterization of the left atrium which consists of a catheter (1, 5) that has in its proximal part a steering arm (8) which passes through the lumen of the catheter shaft, emerges a short distance from the distal end of catheter shaft and is fixed to the distal end of the catheter (1, 2, 5, 6). When the steering arm (8) is advanced (2), by external manipulations, the angle of the curve of the distal part of the shaft is increased (1), and when the steering arm (8) is retracted (6), the angle of the curve of the distal part of the catheter is closed (5). These manipulations, in combination with the appropriate rotation of the catheter shaft around its longitudinal axis, again by external manipulations, make it possible for the catheter to find access to the left atrium, when the catheter has been advanced to the left ventricle retrogradely.

Description

STEERABLE CARDIAC CATHETER

Technical Field

The invention concerns a cardiac catheter for the retrograde catheterization of the left atrium of the heart. Background Of The Invention

Catheterization of the left atrium presents great interest and it is performed for diagnostic, research (function of the left atrium, hemodynamic studies, secretory capacity) and therapeutic (balloon mitral valvuloplasty) purposes. Particularly, catheterization of the left atrium became a nessecity with the establishment of percutaneous mitral valvuloplasty as an important therapeutic modality for the nonsurgical treatment of rheumatic mitral stenosis. Retrograde (via the left ventricle) catheterization of the left atrium, however, presents certain difficulties, and has the risk of damage to the subvalvular apparatus. These result from the position of the mitral ring relative to the left atrial cavity. To approach the mitral orifice, the catheter must bend through a large angle. Apart from this, the mitral subvalvular system itself (papillary muscles, cordae tendineae) impedes access to the left atrium. The first attempt for the retrograde catheterization of the left atrium (E. Shirey et al, Retrograde transaortic and mitral valve catheterization. Am J Cardiol 1966; 18:745), did not catch on, probably because it was unsuccessful in many cases, particularly in patients with mitral stenosis. Attempts of balloon mitral valvuloplasty using a purely retrograde route by means of conventional (Buchler JR, et al. Percutaneous mitral valvuloplasty in rheumatic stenosis by isolated transarterial approach: A new feasible technique. Jpn Heart J 1987;28:790) or preshaped (Orme EC, et al. Balloon mitral valvuloplasty via retrograde left atrial catheterization. Am Heart J 1989; 117:680) catheters, have met with limited success. Thus, the inability to achive a controlled retrograde approach to the mitral valve and, through it, to the left atrium, has led to the universal adoption of the antegrade transseptal approach for left atrial catheterization, usually with concomitant dilatation of the interatrial septum. However, this method is rather complicated, requires great skills on the part of the operator, and may be accompanied by serious complications, such as perforation of the heart and hemodynamically significant left-to-right atrial shunt, (for example: The National Heart, Lung and Blood Insitute Balloon Valvuloplasty registry Participants: Multicenter experience with balloon mitral commissurotomy. NHBLI balloon valvuloplasty registry report on immediate and 30-day follow-up results. Circulation 1992;85:448 / Crawford MH. Iatrogenic Lutembacher's syndrome revisited. Circulation 1990;81:1422-1424 / Bairn DS, Grossmann W. Percutaneous approach and transseptal catherization. In: Grossman W, ed. Cardiac Catheterization and Angiography. Philadelphia: Lea and Febiger, 1986:71-75). For these reasons, a simple method for the retrograde catheterization of the left atrium would be desirable. Summary of the invention

The present invention is a safe and effectives means for the successful retrograde catherization of the left atrium that bypassess the serious disadvantages of the transseptal catheterization. The present invention has the advantage that manipulation of a steering arm enables the configuration of the catheter tip to be changed by remote control, so that the tip may assume different forms. A forwardly movement of the steering arm along the longitudinal axis of the shaft increases the angle of the curve of the distal part of the shaft and the reawardly movement of the steering arm along the longitudinal axis of the shaft reduces the angle of the distal part of the shaft. This, in combination with the appropriate rotation of the catheter shaft around its longitudinal axis, again by external manipulations, makes it possible for the catheter tip to point towards the mitral valve annulus and find access to the left atrium, when the catheter has been advanced to the left ventricle retrogradely. The main advantages of the steerable cardiac catheter for the retrograde catheterization of the left atrium is its effectiveness (offers a consistent entering to the left atrium under any circumstances) and safety (avoids damage to the subvalvular apparatus while it obviates the need for transseptal catheterization and its inherent complications). For these reasons, the present invention provides a safe and effective means for the retrograde catheterization of the left atrium for diagnostic, research and therapeutic purposes. Brief Description Of The Drawings

FIGURE 1 shows the distal of a catheter embodying the present invention in a straightened configuration;

FIGURE 2 shows the distal part of the same catheter as in FIGURE 1, but in an intermediately curved configuration;

FIGURE 3 shows the distal part of a catheter of this invention in its completely curved configuration;

FIGURE 4 shows the proximal part of a catheter provided with a steering system that enables the configuration of the distal part of the catheter to be altered by remote control thereof as shown in FIGURES 1-3, as above Descrition Of The Prefered Embodiment

The present invention is described in detail below with reference to the aforementioned drawings which illustrate one specific embodiment.

The drawings illustrate the steerable catheter for the catheterization of the left atrium, which consists of a cardiac catheter (1,3,5) that has in its proximal part (7) a steering arm or wire (8) which passes through the lumen of the catheter shaft and emerges a short distance from the distal end of catheter shaft. The distal end region of the the arm or wire is attached to the distal end of the catheter as shown in

FIGURE 1. When the steering arm or wire (8) is advanced, by external manipulations, the angle of the curve of the distal part of the shaft is increased, until the distal part of the catheter acquires, at the forewardmost advancement of the steering arm or wire (2), a straigtened configuration (1) which facilitates insertion of the catheter to the femoral artery and advancement to the left ventricle. When the steering arm or wire (8) is retracted (4), again by external manipulations, the angle of the curve of the distal part of the catheter is closed (3), up to the completely curved configuration (5) at the rearwardmost retraction of the steering arm or wire

(6). These manipulations, in combination with the appropriate rotation of the catheter shaft around its longitudinal axis, again by external manipulations, make it possible for the catheter tip to point towards the mitral valve annulus and find access to the left atrium, when the catheter has been advanced to the left ventricle retrogradely. To remove the catheter from the patient, the steering wire (8) is advanced and the distal part of the catheter is straightened (1).

The foregoing discussion and the accompanying drawings are intended to be illustrative and are not to be taken as limiting. Still other variations within the spirit and score of this invention are possible and will readily present themselves to those skilled in the art.

Claims

A steerable cardiac catheter for the catheterization of the left atrium suitable for diagnostic, research and therapeutic purposes, which comprises an elongated, flexible hollow shaft; and a steering arm for said shaft so that a forwardly movement of the steering arm along the longitudinal axis of the shaft increases the angle of the curve of the distal part of the shaft and the reawardly movement of the steering arm along the longitudinal axis of the shaft reduces the angle of the distal part of the shaft.