CN113057732A - A laser ablation catheter - Google Patents

Abstract

Translated fromChinese

本发明公开了一种激光消蚀术导管，包括一个细长的导管和光纤束，光纤束装在导管中，导管两端分为导管近端和导管远端，导管近端为脉冲激光的输入端，导管远端为脉冲激光的输出端；在所述导管远端的导管壁上开有侧壁孔；将所述光纤束分成两类，第一类光纤束的光束出射面与导管远端端面对齐，使第一类光纤束中传输的光束前向出射；第二类光纤束的远端端面为斜面，并在斜面上镀上反射膜，使第二类光纤束中传输的光束在该斜面上发生反射，使光束从光纤的侧面出射，并通过导管远端的导管壁上的侧壁孔侧向出射导管。从第一类光纤束中出射的光束可以处理位于导管远端前方的病灶斑块，从第二类光纤束中出射的侧向光束用于处理血管的环形钙化病变。

The invention discloses a laser ablation catheter, which comprises an elongated catheter and an optical fiber bundle. The optical fiber bundle is installed in the catheter. The two ends of the catheter are divided into a proximal end of the catheter and a distal end of the catheter. , the distal end of the catheter is the output end of the pulsed laser; a side wall hole is opened on the catheter wall at the distal end of the catheter; the fiber bundle is divided into two categories, the beam exit surface of the first type fiber bundle and the end face of the distal end of the catheter Alignment, so that the light beam transmitted in the first type of optical fiber bundle exits forward; the distal end face of the second type of optical fiber bundle is an inclined plane, and a reflective film is coated on the inclined surface, so that the light beam transmitted in the second type of optical fiber bundle is on the inclined plane. Reflection occurs on the optic so that the beam exits the side of the fiber and exits the catheter laterally through a sidewall hole in the catheter wall at the distal end of the catheter. The beam from the first type of fiber optic bundle can treat the focal plaque located in front of the distal end of the catheter, and the side beam from the second type of fiber optic bundle is used to treat the annular calcified lesions of the blood vessel.

Description

Laser ablation catheter

Technical Field

The invention belongs to the technical field of medical instruments, and particularly relates to a laser ablation catheter.

Background

Percutaneous Coronary Intervention (PCI) is a minimally invasive procedure, which is a treatment method for improving myocardial perfusion by dredging a narrow or even an occluded coronary artery lumen through a catheter technique. Conventional treatment means include angioplasty or stent implantation. However, coronary calcified lesions increase the difficulty of interventional treatment, increase the incidence of immediate surgical complications and major adverse cardiovascular events in early and late stages. The reason for this is that calcified lesions are high-resistance lesions and the balloon requires very high pressure (sometimes up to 10 to 15 atm, even 30 atm). Such pressure will generally increase the probability of rebound stenosis, dissection, perforation, rupture of the vessel significantly. Such surgical events are particularly severe in the case of eccentric calcified lesions, since the pressure of the balloon is exerted on the soft tissue without calcification.

Plaque ablation is a cardiac intervention assisted treatment technique, which includes rotational atherectomy, orbital atherectomy, laser ablation, etc. of plaque in the coronary artery. The main purpose is to achieve the effects of ablating calcified tissues and restoring lumen area through mechanical means or energy conversion. In recent years, Excimer Laser (Excimer Laser) intracoronary plaque ablation uses an ultraviolet light source, a catheter design, and a pulsed cold light source, which improves the effectiveness and safety of the surgery. The ultraviolet laser light source can be effectively absorbed by biological tissues and can provide enough energy to destroy intermolecular forces of surface tissues. At the same time, the absorption of light by the tissue causes a local temperature rise and causes photo-acoustic and photo-thermal ablation effects. These effects occur only in a thin layer on the surface of the biological tissue, with little effect on the surrounding tissue. After the catheter smoothly passes through the pathological changes, the balloon can be used for fully expanding and implanting the stent, and the revascularization can be completed.

Laser ablation can remove various lesions in the stenosed blood vessel, with the direction of laser light exiting the optical waveguide medium being substantially forward. In the ablation catheters used at present, the light path outlet of the light guide medium is at the tip of the catheter, so that only the tissue at the front end of the catheter can be ablated. This results in a laser ablated lumen area comparable to the cross-sectional area of the catheter. This is not ideal for the treatment of a wide range of calcified lesions, especially calcified rings. If one wants to treat lesions in a larger diameter range, one of the methods is to replace one larger size ablation catheter. The invention changes the light propagation direction of a part of the light guide, so that the light is emitted from the side surface of the guide tube. Lateral emergent light can act on the pathological tissue on the side surface of the catheter, particularly the calcification ring, can shatter or soften the calcification ring, can play a role similar to a spinous process saccule, and therefore preparation is made for expansion of the focus in the next step.

Disclosure of Invention

The invention aims to design a laser ablation catheter, which changes the light propagation direction of a part of optical fiber bundle so that the light beam is emitted from the side surface of the catheter.

The technical scheme of the invention is that the laser ablation catheter comprises a slender catheter and an optical fiber bundle, wherein the optical fiber bundle is arranged in the catheter, two ends of the catheter are divided into a catheter proximal end and a catheter distal end, the catheter proximal end is an input end of pulse laser, and the catheter distal end is an output end of the pulse laser; a side wall hole is arranged on the wall of the catheter at the far end of the catheter; the optical fiber bundles are divided into two types, the light beam emergent surface of the first type of optical fiber bundle is aligned with the distal end surface of the catheter, so that the light beams transmitted in the first type of optical fiber bundle are emitted in the forward direction; the far end face of the second type of optical fiber bundle is an inclined plane, and a reflecting film is plated on the inclined plane, so that the light beams transmitted in the second type of optical fiber bundle are reflected on the inclined plane, and are emitted out from the side face of the optical fiber and out of the catheter through the side wall hole on the catheter wall at the far end of the catheter.

An adjustable baffle is arranged in front of the input end of the pulse laser of the second type of optical fiber bundle.

The adjustable baffle is made of graphite material.

The number of side wall holes on the wall of the catheter at the far end of the catheter is 2-4, the second type of optical fiber bundle is divided into 2-4 bundles, and the second type of optical fiber bundle corresponds to the side wall holes on the wall of the catheter at the far end of the catheter.

The incident angle of the light beam transmitted in the second type of optical fiber bundle at the inclined plane is 20-70 degrees.

The preferred angle of incidence of the light beams transmitted in the second type of fiber optic bundle at the inclined plane is 50 ° to 60 °.

The distance from the light beam reflection inclined plane of the second type optical fiber bundle to the far end face of the catheter is 2 mm to 10 mm.

The preferred distance from the beam reflecting bevel of the second type of fiber optic bundle to the distal end face of the catheter is 3 mm to 5 mm.

The laser ablation catheter provided by the invention has the following advantages:

the invention provides a laser ablation catheter, wherein a side wall hole is formed in the wall of the catheter at the far end of the catheter; the optical fiber bundles in the catheter are divided into two types, the light beam emergent surface of the first type of optical fiber bundle is aligned with the distal end face of the catheter, and the direction of the light beam emergent from the light beam emergent surface of the first type of optical fiber bundle is basically parallel to the axial direction of the optical fiber, so that the light beam transmitted in the first type of optical fiber bundle is emergent in the forward direction; the far end face of the second type of optical fiber bundle is an inclined plane, and a reflecting film is plated on the inclined plane, so that the light beams transmitted in the second type of optical fiber bundle are reflected on the inclined plane, and are emitted out from the side face of the optical fiber and out of the catheter through the side wall hole on the catheter wall at the far end of the catheter.

The light beams emitted from the first type of optical fiber bundles are used for treating stenotic lesions of blood vessels, lesion plaques in front of the far end of the catheter can be well treated, a lumen with the size of the cross section of the catheter is formed in a narrow annular calcified area, and a necessary lumen area is provided for subsequent treatment. The lateral light beams emitted from the second type of optical fiber beams are used for treating annular calcified lesions of blood vessels, and can carry out laser ablation on lesion tissues around the wall of the catheter, particularly calcified rings, so as to shatter or soften the calcified rings, so that a lesion stenosis can be easily expanded subsequently, and the balloon expansion or stent placement is facilitated.

An adjustable baffle is arranged in front of the input end of the pulse laser of the second type of optical fiber bundle, and an operator can control the baffle to be opened or closed according to needs so as to control the output or non-output of the light beams in the second type of optical fiber bundle.

Drawings

Fig. 1 is a schematic cross-sectional view of a laser ablation catheter.

Fig. 2 is a schematic cross-sectional view of the distal end of a laser ablation catheter.

Fig. 3 is a perspective view of the distal end of a laser ablation catheter.

Fig. 4 is a schematic cross-sectional view of a catheter proximal joint of a laser ablation catheter.

The reference numbers illustrate:

100. catheter, 101, catheter proximal end, 102, catheter distal end, 103, catheter wall, 104, first type fiber bundle, 105, second type fiber bundle, 106, pulse laser, 107, guidewire lumen, 108, catheter distal end face, 109, side wall aperture, 110, bevel, 111, catheter proximal end fitting, 112, adjustable baffle, 113, beam exit face of first type fiber bundle, 114, transmission beam in second type fiber bundle, 115, exit beam in second type fiber bundle, 116, guidewire, 117, visualization ring, 118, rectangular fixture, positioning device,

Detailed Description

In order to make the implementation objects, technical solutions and advantages of the present invention clearer, the technical solutions in the embodiments of the present invention will be described in more detail below with reference to the accompanying drawings in the embodiments of the present invention. It should be emphasized that the following description is merely exemplary in nature and is not intended to limit the scope of the invention or its application.

Examples

A laser ablation catheter of the type described in this example is shown in figures 1 to 4.

As shown in fig. 1, the laser ablation catheter according to the embodiment includes anelongated catheter 100 and a fiber bundle, the fiber bundle is installed in thecatheter 100, two ends of thecatheter 100 are divided into a catheterproximal end 101 and a catheterdistal end 102, the catheterproximal end 101 is an input end of a pulse laser, and the catheterdistal end 102 is an output end of the pulse laser; aside wall hole 109 is arranged on thecatheter wall 103 of the catheterdistal end 102; the optical fiber bundles are divided into two types, the light beamemergent surface 113 of the first typeoptical fiber bundle 104 is aligned with the far-end face 108 of the catheter, the direction of the light beam emergent from the light beamemergent surface 113 of the first typeoptical fiber bundle 104 is basically parallel to the axial direction of the optical fiber, and the light beam transmitted in the first typeoptical fiber bundle 104 is emergent in the forward direction; the distal end face of the second typeoptical fiber bundle 105 is aninclined surface 110, and a reflective film is coated on theinclined surface 110, so that thelight beam 114 transmitted in the second typeoptical fiber bundle 105 is reflected on theinclined surface 110, and thelight beam 115 is emitted from the side surface of the optical fiber and is emitted out of the catheter through theside wall hole 109 on thecatheter wall 103 of thedistal end 102 of the catheter.

Thecatheter 100 is provided with aguide wire lumen 107, one end of theguide wire lumen 107 being open at the catheterdistal end face 108, the other end of theguide wire lumen 107 being open at thecatheter wall 103. The fiber bundle at theproximal end 101 of the catheter is connected with apulse laser 106 through aproximal catheter connector 111, and the pulse laser output by thepulse laser 106 is transmitted through a firsttype fiber bundle 104 and a secondtype fiber bundle 105, and is emitted in the forward direction at thedistal end face 108 of the catheter and is emitted in theside wall hole 109 on thecatheter wall 103 at thedistal end 102 of the catheter. Theinclined plane 110 of the beam exit surface of the second typeoptical fiber bundle 105 can be formed by grinding, and a dielectric film can be coated on the groundinclined plane 110 by ion beam sputtering deposition to form a reflective film surface, so that the beam is reflected on theinclined plane 110 and exits from the side surface of the optical fiber.

As shown in fig. 2, this is a schematic cross-sectional view of thedistal end 102 of the catheter and indicates the direction of propagation of the light beam in dashed lines. The optical fiber bundle in the invention can be formed by slender optical fibers with circular cross sections, and also can be formed by slender optical fibers with other cross section shapes. In this embodiment, a fiber bundle is composed of slender optical fibers having a circular cross section. The optical fiber bundle is composed of at least two optical fibers so as to divide the optical fiber bundle into two types of optical fiber bundles for emitting a forward light beam and a side light beam. In this embodiment, 3side wall holes 109 are adopted, the optical fiber bundle is composed of at least 4 optical fibers, one optical fiber emits forward light beams, and 3 optical fibers emit lateral light beams, and the actual number of the optical fibers can be determined by actual needs. As can be seen in fig. 2, the lightbeam exit face 113 of the first-type fiber bundle 104 is aligned with the catheterdistal end face 108, so that the light beams transmitted in the first-type fiber bundle 104 exit in the forward direction. Thelight beam 114 transmitted in thebundle 105 of the second type is reflected at theinclined surface 110, so that theoutgoing light beam 115 in the bundle of the second type exits from the side of the optical fiber and exits the catheter laterally through theside wall hole 109 in thecatheter wall 103 at thedistal end 102 of the catheter. The angle of incidence of thelight beam 114 transmitted in thesecond type 105 on theinclined surface 110 is between 20 ° and 70 °, preferably between 50 ° and 60 °, which ensures that theoutgoing light beam 115 is deflected by 40 ° to 140 °, or preferably by 100 ° to 120 °, in this embodiment 55 °, and theoutgoing light beam 115 is deflected by 110 ° with respect to the fiber axis. The distance from thebeam exit ramp 110 of the second type of fiberoptic bundle 105 to thedistal end face 108 of the catheter is between 2 mm and 10 mm, preferably between 3 mm and 5 mm. In this embodiment, the distance from the lightbeam exit bevel 110 of the second typeoptical fiber bundle 105 to thedistal end face 108 of the catheter is 4 mm.

This is a perspective view of thedistal end 102 of the catheter, as shown in fig. 3. Aguidewire 116 is threaded into theguidewire lumen 107 of thecatheter 100, and theguidewire 116 guides thecatheter 100 along theguidewire 116 into the blood vessel and proximate the lesion area. The lightbeam exit face 113 of the first-type bundle 104 is aligned with the catheterdistal end face 108, and the light beam transmitted in the first-type bundle 104 exits forward. The light beams transmitted in the second type of fiber optic bundle 105 (not labeled in fig. 3) exit the catheter laterally fromside wall apertures 109 in thecatheter wall 103 at thedistal end 102 of the catheter. Since the second-type fiber bundle 105 does not reach the catheterdistal end face 108, thebeam exit face 113 of the first-type fiber bundle 104 on the catheterdistal end face 108 cannot completely cover the catheterdistal end face 108. The catheterdistal end 102 is also fitted with avisualization ring 117 so that the catheterdistal end 102 is visible in angiographic imaging.

This is a schematic cross-sectional view of the catheterproximal hub 111, as shown in fig. 4. Thefirst type 104 andsecond type 105 optical fiber bundles are bundled at theproximal end 101 of the catheter. The bundled fiber bundle arrangement should match the shape of the exit aperture of thepulsed laser 106. In the present exemplary embodiment, the exit aperture of thepulse laser 106 may be rectangular. Thefirst type 104 andsecond type 105 optical fiber bundles are thus arranged substantially in a rectangle and are fixed in shape and position by arectangular fixing device 118.

In the present exemplary embodiment, the present invention is illustrated by representing the second type offiber bundle 105 with three fibers. The second type offiber optic bundle 105 is arranged at a lateral position. The selective switching of the delivery of the side-emitting pulsed laser light by the second-typefiber optic bundle 105 is accomplished by whether the optical input of the second-typefiber optic bundle 105 at theproximal end 101 of the catheter is blocked. When the catheterproximal end 101 input light of the second typefiber optic bundle 105 is blocked, the second typefiber optic bundle 105 will not emit pulsed laser light. The shield may be a mechanical device or a photoelectric effect device. In the exemplary embodiment, this shielding is illustrated by a rotatableadjustable bezel 112. Anadjustable baffle 112 is installed in front of the input end of the pulse laser of the second typeoptical fiber bundle 105. When theadjustable stop 112 is in the current position of FIG. 4, it does not block the second type offiber optic bundle 105. When theadjustable stop 112 is rotated to the rectangular dashed line position, it can block the secondtype fiber bundle 105 without affecting the firsttype fiber bundle 104. Theadjustable stop 112 may be made of a light absorbing material such as graphite to attenuate reflected light, reduce the energy of the light reflected back to thepulsed laser 106, and protect thepulsed laser 106.

A laser ablation catheter of the present embodiment is used in conjunction with avascular guidewire 116 during a procedure for treating a diseased plaque in a blood vessel. The tip of theguidewire 116 at the focal region to be treated is inserted into theguidewire lumen 107 from the catheterdistal end face 108 and thecatheter 100 is advanced over theguidewire 116 to the vicinity of the lesion. When a stenosis is encountered and thecatheter 100 cannot pass through, thepulsed laser 106 may be turned on to perform laser ablation on the lesion. The light beam emitted from the first typeoptical fiber bundle 104 is used for treating the stenosis of the blood vessel, so that lesion plaque positioned in front of thedistal end 102 of the catheter can be well treated, a lumen with the size of the cross section of thecatheter 100 is opened in the annular calcified area of the stenosis, and a necessary lumen area is provided for subsequent treatment. Theside light beam 115 emitted from the second typeoptical fiber bundle 105 is used for treating annular calcified lesion of blood vessel, and can perform laser ablation on lesion tissue around thecatheter wall 103, especially calcified ring, according to requirements, so as to crack or soften the calcified ring, so that the lesion stenosis can be easily expanded subsequently, and the balloon expansion or stent placement is facilitated.

Thepulsed laser 106 used for laser ablation has a wavelength between 300 nanometers and 420 nanometers. Optionally, the pulsed laser is a Nd: YAG third harmonic laser with a wavelength of 355 nm. When the wavelength is used, the energy flux of each pulse emitted by the optical fiber bundle is at least 50mJ/mm²I.e. a sufficient amount of light energy per unit area is required. The pulse frequency emitted by the optical fiber bundle is at least 10Hz, and preferably between 25Hz and 40 Hz. Optionally, thepulsed laser 106 is an excimer laser with a wavelength of 308 nm. When the wavelength is used, the energy flux of each pulse emitted by the optical fiber bundle is at least 30mJ/mm². The pulse frequency emitted by the optical fiber bundle is at least 10Hz, and preferably between 25Hz and 40 Hz.

Finally, it should be pointed out that: the above examples are only for illustrating the technical solutions of the present invention, and are not limited thereto. Although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.

Claims (8)

1. A laser ablation catheter comprises a slender catheter and an optical fiber bundle, wherein the optical fiber bundle is arranged in the catheter, two ends of the catheter are divided into a catheter proximal end and a catheter distal end, the catheter proximal end is an input end of pulse laser, and the catheter distal end is an output end of the pulse laser; the method is characterized in that: a side wall hole is arranged on the wall of the catheter at the far end of the catheter; the optical fiber bundles are divided into two types, the light beam emergent surface of the first type of optical fiber bundle is aligned with the distal end surface of the catheter, so that the light beams transmitted in the first type of optical fiber bundle are emitted in the forward direction; the far end face of the second type of optical fiber bundle is an inclined plane, and a reflecting film is plated on the inclined plane, so that the light beams transmitted in the second type of optical fiber bundle are reflected on the inclined plane, and are emitted out from the side face of the optical fiber and out of the catheter through the side wall hole on the catheter wall at the far end of the catheter.

2. A laser ablation catheter as in claim 1, wherein: an adjustable baffle is arranged in front of the input end of the pulse laser of the second type of optical fiber bundle.

3. A laser ablation catheter as claimed in claim 2, wherein: the adjustable baffle is made of graphite material.

4. A laser ablation catheter as in claim 1, wherein: the number of side wall holes on the wall of the catheter at the far end of the catheter is 2-4, the second type of optical fiber bundle is divided into 2-4 bundles, and the second type of optical fiber bundle corresponds to the side wall holes on the wall of the catheter at the far end of the catheter.

5. A laser ablation catheter as in claim 1, wherein: the incident angle of the light beam transmitted in the second type of optical fiber bundle at the inclined plane is 20-70 degrees.

6. A laser ablation catheter as in claim 5, wherein: the preferred angle of incidence of the light beams transmitted in the second type of fiber optic bundle at the inclined plane is 50 ° to 60 °.

7. A laser ablation catheter as in claim 1, wherein: the distance from the light beam reflection inclined plane of the second type optical fiber bundle to the far end face of the catheter is 2 mm to 10 mm.

8. A laser ablation catheter as in claim 7, wherein: the preferred distance from the beam reflecting bevel of the second type of fiber optic bundle to the distal end face of the catheter is 3 mm to 5 mm.

Images