Hollow catheter with more than two radiopaque markers for the measurement of arterial or venous segments in association with use of X-radiation

Technical field

Search of new devices for vessels catheterization.

This is a new version of hollow catheters usable during cardiac or body catheterization and interventions. These catheters are equipped with more than two radiopaque markers placed on millimetered monorail or over-the-wire devices pushable on metallic guidewires.

Moreover, this system can also be equipped with (or without) an inflatable balloon at the tip of the catheter to perform transluminal arterial stenosis dilatation.

This invention allows a precise and accurate length and diameter evaluation of coronary (arterial or venous) segments during cardiac catheterization.

Background of the invention

Since the use of X-radiation can potentially alter real dimensions of anatomical regions, commonly used allows just for a qualitative analysis. In contrast, a quantitative analysis for vessel structures, such as coronary arteries or peripheral arterial segments, represent a mandatory issue in order to obtain a precise and reliable diagnosis that is essential for the efficacy of therapy. Indeed, deliver of metallic coronary endovascular prothesis, namely stents, requires an accurate and precise evaluation of the dimensions (e.g. length and diameter) of needed-to-treat vessels. Currently, in most catheter laboratories worldwide, stent delivery is performed by solely visual evaluation of stenosis severity

and length based on the experience of the operator. In order to overcome this issue, several tools able to objectively assess the real vessels' dimensions have been introduced in the clinical scenario. The most used technique is quantitative angiographic analysis (QSA) which is based on radiographic evaluation of vascular segments by measuring the dimension of well known angiographic catheter dimensions. The principal drawbacks of this system pertain to both catheter and vessel edge detection, and mostly to 3-D spazial resolution of the coronary (or arterial) tree.

Therefore, a reliable and reproducible quantitative system for precise and accurate arterial and venous segments during catheterization procedures is required in the clinical setting.

Brief description of figures

Figure 1 shows a schematic diagram of the catheter with radiopaque markers. Figure 2 displays a schematic catheter with radiopaque markers equipped with an end- tip balloon for arterial stenosis dilatation or endoprothesis deployment.

Description of the invention

This invention is composed of hollow monorail or over-the-wire (OTW) millimetered catheter, with or without an inflatable balloon at the tip, equipped with radiopaque markers along its length. Depending on procedural requirements, markers number can be chosen, more than 2 (from 3 to N), at known predetermined distance. The material of which the catheter is made confers to the catheter plastic and flexible properties, together with radiolucent features. In contrast, markers are designed in radiopaque material (e.g. platinum/iridium) in order to be visible using X-rays

Currently available catheters offer only one, maximum two, of radiopaque markers located at the end-tip, without conferring any capability of vessel measurement because vessels have a three-dimensional (3-D) layout. Therefore, both precision and accuracy in vessels' dimensions cannot be achieved, due to vessels' 3-D spatial layout. The novelty of our invention, compared to already used catheter, is conferred by the capability of determining the exact dimensions of the studied coronary segment, due to the presence in its terminal part of more than two radiopaque markers, which are located at a known, either regular or irregular distance on the catheter.

Applications a) This invention can be applied in different catheterization procedures, therefore achieving a precise and accurate assessment of both vessel (or body) segments' length and diameter.

b) The tip-end-balloon equipped version of the catheter allows arterial stenosis dilatation, thus providing an established therapeutical option (stenosis dilation) in addition to a precise and accurate evaluation of the vessels to be treated. Moreover, this invention also allows the treatment of long stenosis or severely disease vessels in difficult clinical settings.

Additional applications a) Because of its usefulness in calibrating different kind of body conduits/segments such as vein grafts, aorta, oesophagus, urethras, etc.

Features

Use of hollow millimetered catheters with contextual application of radiopaque markers for precise and accurate length and diameter assessment of vessels' segments or hollow organs in association to X-rays use.

The features of this invention include diagnostic catether with radiopaque markers use and therapeutic tip-end inflatable balloon use for coronary stenosis dilatation.

Experimental strategy

The experimental strategy has been drawn as follows: 1. A prototype has been realized (see figure) and in vitro evaluation of all technical features such as markers witth radiopaque properties, pushability, trackability, crossability has been performed. 2. Precision and accuracy have been tested in experimental animal models.