lithotripsy device for tunneling a vascular occluded area

Abstract

A lithotripsy device for tunneling a vascular occlusion comprises a tunneling catheter including a tunneling catheter shaft having a distal end and a proximal end. A tunneling probe is positioned on the distal end of the tunneling catheter shaft. The tunneling probe has a pair of electrodes; each electrode is operably connected to an electric lead within the tunneling catheter shaft. The leads are configured to be operably connected to an external pulse generator. Activation of the external pulse generator operably connected to the leads causes repeated electrical discharges between the electrodes. When the electrodes are in a fluid, the repeated electrical discharges generate repeated hydraulic shock waves directed away from the electrical discharge within the fluid. When the repeated hydraulic shock waves strike calcified tissue, the calcified tissue is fragmented into a deformed plaque. The deformed plaque has lower resistance to mechanical displacement than the original calcified tissue.

Description

Technology Field

[0001] Cross-reference regarding related applications

[0002] This application claims priority to U.S. Provisional Application No. 63 / 620,667 (Atty. Dkt. No. VJYR60-35815), filed on January 12, 2024, under the title “LITHOTRIPSY DEVICE FOR TUNNELING THROUGH VASCULAR OCCLUSIONS,” the entirety of which is incorporated by reference into this application.

[0003] Technology field

[0004] The following disclosure relates to a therapeutic system for percutaneous coronary angioplasty or percutaneous peripheral angioplasty, in which a tunneling device is used to form an initial path across an occluded lesion to enable subsequent crossing by a guidewire, dilation catheter, and / or other interventional equipment. In particular, the tunneling device may be customized to move through a calcified occluded lesion. Background Technology

[0005] A treatment system in which a dilation catheter is used to pass through a lesion to dilate the lesion and restore normal blood flow within the vessel is known as percutaneous coronary angioplasty or percutaneous peripheral angioplasty. If the lesion is calcified or hardened in other ways, the dilation catheter may include a balloon that can operate at high pressure to crush the calcified or hardened plaque and push it toward the vessel wall. However, using a high-pressure balloon to crush and open calcified or hardened plaque carries the risk of causing trauma or damage to the artery or vessel wall, including perforation.

[0006] To reduce the risk of damage to artery or vessel wall during angioplasty of calcified or sclerotic lesions, a so-called endovascular lithotripsy (hereinafter referred to as lithotripsy) treatment system is used, wherein a balloon dilation catheter further comprises a lithotripsy generator placed within a fluid-filled balloon, the lithotripsy generator forms a bubble that rapidly expands and collapses within the balloon to form a mechanical shock wave within the balloon, and this shock wave travels through the balloon to adjacent tissue. The shock wave generated by this lithotripsy system is delivered to the calcified lesion through the fluid, through the balloon, through the blood, and through the vessel wall, so that the energy will crush the sclerotic plaque without applying excessive pressure to the wall of the artery or vessel by the balloon. Examples of such lithotripsy treatment systems are described in U.S. Patents No. 9,072,534 and No. 11,020,135 assigned to Shockwave Medical, Inc.

[0007] To effectively use known lithotripsy treatment systems, a treatment device (collectively referred to as a "lithotripsy dilation balloon") comprising an uninflated balloon and a lithotripsy generator must be positioned within the site of occlusion of an artery or blood vessel and at least partially filled with a fluid (e.g., saline, contrast agent solution, etc.) before the shockwave generator is activated to produce the desired therapeutic effect, namely the fragmentation of calcified or hardened plaque using lithotripsy energy. However, in some cases, the target plaque present within the artery or blood vessel causes a very extensive occlusion, so the remaining passage may be too small in diameter or too tortuous to allow the passage of the guidewire and / or lithotripsy dilation catheter required for the shockwave dilation balloon to pass through the target plaque. When faced with such extensive occlusion, it becomes necessary to first create a pilot passageway through the target plaque that has both a sufficient diameter and a sufficiently straight path to allow the passage of the guidewire required for the uninflated lithotripsy dilation balloon. In some cases, a guideway may be created by forcibly pushing an appropriately sized guidewire or catheter into the occluded tissue using mechanical force sufficient to fragment and pass through until a guideway of sufficient diameter and straightness is established. However, using mechanical force to push or puncture the wire to pass through calcified or hardened plaque carries the risk that the occlusion may deflect the wire toward the arterial wall or cause it to suddenly rupture, resulting in the stressed guidewire overshooting into the arterial wall; in either case, there is a possibility of perforating all three layers of the artery or vessel wall, or causing other trauma and damage to the vessel. In many cases, the wire cannot simply pass through these calcified occlusions, so the condition cannot be treated percutaneously.Therefore, there is a need for a treatment system that can create a straight guide passage through calcified or hardened lesions using low mechanical force that minimizes damage to the blood vessels without perforating the artery or blood vessel wall. means of solving the problem

[0008] In one embodiment, a treatment system is provided comprising a lithotripsy catheter having a lithotripsy tunneling probe at its distal end capable of rupturing a calcified lesion while creating a new lumen (i.e., "passage lumen") capable of receiving a guidewire in a penetrating state within a true lumen space (i.e., "vascular lumen"). In one embodiment, the new lumen is capable of receiving a guidewire of 0.014" or more in a penetrating state.

[0009] In another embodiment, a treatment system is provided comprising a lithotripsy catheter having a lithotripsy tunneling probe at the distal end that can create a passage through a calcified lesion while minimizing the amount of distal atheroemboli.

[0010] In another embodiment, a treatment system is provided comprising a lithotripsy catheter having a lithotripsy tunneling probe at its distal end that can create a passage through a calcified lesion without remaining within the vascular structure or perforating all three layers of the vascular wall.

[0011] In another embodiment, a treatment system is provided comprising a support balloon or other support structure for orienting a lithotripsy tunneling probe at the distal end of a lithotripsy catheter toward the center of the occluded lesion and toward the wall of the vessel. In one embodiment, the support balloon is positioned at the distal end of the support catheter. In another embodiment, the distal end of the support catheter is the support structure. In another embodiment, orienting the lithotripsy tunneling probe comprises positioning the distal end of the tunneling probe at a predetermined distance and orientation relative to the proximal face of the occluded lesion.

[0012] In another embodiment, a treatment system is provided comprising a support catheter and a lithotripsy catheter having a lithotripsy tunneling probe at a distal end. The support catheter has a lumen sized to accommodate the lithotripsy catheter within it. The support catheter and the lithotripsy catheter can be inserted into a blood vessel, and the support catheter is fixed to the body, thereby enabling the lithotripsy catheter to be moved to or withdrawn from the body while the support catheter remains in a fixed position within the blood vessel (i.e., while forming the "base of operations"), and then enabling the lithotripsy catheter to be exchanged within the support catheter with a guidewire of 0.035" or less.

[0013] In another embodiment, a treatment system is provided comprising a support catheter and a lithotripsy catheter having a lithotripsy tunneling probe at the distal end, wherein the support catheter receiving the lithotripsy catheter is compatible with a sheath of size 4 Fr ("French") (or larger). In one embodiment, the system is configured to be used in a retrograde fashion from the tibial artery. In another embodiment, the lithotripsy catheter is placed inside the support catheter (mother / daughter), and these catheters are removablely connected to each other by a screw interlocking system.

[0014] In another embodiment, a treatment system is provided comprising a support catheter and a lithotripsy catheter having a lithotripsy tunneling probe at its distal end, wherein the distal end of the support catheter is angulated to selectively orient the tunneling probe circumferentially or directionally around the proximal or distal end of the occlusion (when performing a retrograde approach). In one embodiment, the angulated support catheter may be rotated within the vessel to change the aim of the tunneling probe. In another embodiment, the system also includes a fixture to enable selective rotation of the angulated support catheter within the vessel while maintaining the axial position of the support catheter within the vessel.

[0015] In another embodiment, a treatment system is provided comprising a support catheter and a lithotripsy catheter having a lithotripsy tunneling probe at the distal end, wherein the distal end of the support catheter is radiopaque and the distal end of the lithotripsy catheter is radiopaque and the distal end of the support catheter is distinguishable from the distal end of the lithotripsy catheter by radiography.

[0016] In another embodiment, a lithotripsy device for tunneling a vascular occluded area comprises a tunneling catheter including a tunneling catheter shaft having a distal end and a proximal end. A tunneling probe is positioned on the distal end of the tunneling catheter shaft. The tunneling probe has a pair of electrodes; each electrode is operably connected to an electric lead within the tunneling catheter shaft. The lead is configured to be operably connected to an external pulse generator. Activation of the external pulse generator operably connected to the lead causes repeated electrical discharges between the electrodes. When the electrodes are in a fluid, the repeated electrical discharges generate repeated hydrostatic shock waves directed away from the electrical discharge within the fluid. When the repeated hydrostatic shock waves strike calcified tissue, the calcified tissue is fragmented into a modified plaque. The modified plaque has lower resistance to mechanical displacement than the original calcified tissue.

[0017] In one embodiment, the tunneling probe is configured to have a raised rim on the distal end; and the electrodes are inset within the raised rim.

[0018] In another embodiment, the electrodes are arranged concentrically within the raised rim.

[0019] In another embodiment, the electrodes are configured in an opposing arched arrangement within the raised rim.

[0020] In another embodiment, the tunneling probe is configured to have a tapering conical face on the distal end; and the electrodes are configured in a spaced-apart arrangement on the tapering conical face.

[0021] In another embodiment, the tapered conical surface of the tunneling probe ends at a flat face; and the electrodes are exposed on the flat face.

[0022] In another embodiment, the tapered conical surface of the tunneling probe ends at a rounded end; and the electrodes are not exposed on the rounded end.

[0023] In another embodiment, the lithotripsy device further comprises a guidewire lumen formed through the catheter shaft and having an outlet on the distal end. The tunneling probe is configured to have a flat surface on the distal end, and the electrodes protrude over the flat surface.

[0024] In another embodiment, the exit of the guide wire lumen is positioned at the center of the flat surface of the distal end, and the electrodes are configured in an opposing arched arrangement on the opposing sides of the exit.

[0025] In another embodiment, the exit of the guidewire lumen is offset from the center of the flat surface of the distal end, and the electrodes are composed of adjacent studs on one side of the exit.

[0026] In another embodiment, the exit of the guide wire lumen is positioned at the center of the flat surface of the distal end, and the electrodes are composed of studs on the opposing sides of the exit.

[0027] In another embodiment, the lithotripsy device further includes a positioning balloon operably attached to the tunneling catheter shaft near the distal end. The positioning balloon can be optionally inflated to position the catheter tunneling probe at a desired location within the cross-section of the blood vessel.

[0028] In another embodiment, the lithotripsy device further comprises a support catheter having a distal end and a proximal end, and including a support catheter shaft forming an internal lumen configured to receive the tunneling catheter passing through the interior. When the support catheter is positioned such that the distal end is located near the occlusion of the calcified tissue, the proximal end may be fixed at the introduction position. When the support catheter is fixed at the introduction position, the tunneling catheter may be selectively inserted and withdrawn through the internal lumen to reach the occlusion of the calcified tissue with the distal end having the tunneling probe.

[0029] In another embodiment, the support catheter further comprises a positioning balloon operably attached to the support catheter shaft near the distal end. The positioning balloon may be optionally inflated to position the distal end of the support catheter at a desired location within the cross-section of the blood vessel. When the tunneling catheter is introduced through the support catheter, the tunneling probe of the tunneling catheter protrudes from the support catheter at the desired location within the cross-section of the blood vessel.

[0030] In another embodiment, the lithotripsy device further includes a pulse generator operably connected to the electric lead.

[0031] In another embodiment, a lithotripsy device for tunneling a vascular occlusion of calcified tissue within a fluid environment of a blood vessel is provided. The lithotripsy device comprises a tunneling catheter comprising a tunneling catheter shaft having a distal end and a proximal end. A tunneling probe is disposed on the distal end of the tunneling catheter shaft, and the tunneling probe comprises a pair of electrodes, each electrode operably connected to an electric lead within the tunneling catheter shaft; a raised rim on the distal end, wherein the electrodes are inset into the raised rim; and a flexible diaphragm attached across the raised rim. The raised rim and the flexible diaphragm form a probe cavity that accommodates the electrodes, and the probe cavity is fluidly isolated from the fluid environment outside the probe cavity. The lead is configured to be operably connected to an external pulse generator. Activation of an external pulse generator operably connected to the lead causes repeated electrical discharges between the electrodes. When the probe cavity contains the working fluid, the repeated electrical discharges generate repeated primary shock waves that cause the flexible diaphragm to vibrate repeatedly within the working fluid. The repeated vibration of the flexible diaphragm generates repeated secondary shock waves that propagate into the fluid environment outside the probe cavity. When the repeated secondary shock waves strike the calcified tissue within the fluid environment, the calcified tissue is fractured into deformed plaques. The deformed plaques have lower resistance to mechanical displacement than the original calcified tissue.

[0032] In one embodiment, the flexible diaphragm is formed of a metal or a metal alloy.

[0033] In another embodiment, the flexible diaphragm is formed of plastic, polymer, elastomer, or other non-metallic material.

[0034] In another embodiment, the lithotripsy device further includes a fluid lumen formed within the tunneling catheter shaft and fluidly connecting the probe cavity to a source of fresh working fluid in order to circulate fresh working fluid through the probe cavity during the repeated electrical discharge.

[0035] In another embodiment, a method for using a lithotripsy device for tunneling a vascular occlusion of calcified tissue within a fluid environment of a blood vessel comprises: providing a lithotripsy tunneling catheter and a support catheter; introducing a guidewire into a fluid-filled vascular system and guiding the guidewire into a blood vessel having a calcified tissue occlusion; introducing the support catheter into the vascular system on the guidewire to the location of the calcified tissue occlusion; inflating a positioning balloon on the support catheter within the blood vessel; fixing the support catheter at the introduction position to minimize axial movement of the support catheter within the blood vessel; withdrawing the guidewire from the lumen of the support catheter; introducing the tunneling catheter through the support catheter to the location of the calcified tissue occlusion and positioning a tunneling probe within a blood vessel adjacent to the calcified tissue; and generating an electrical discharge between electrodes on the tunneling probe to generate a hydraulic shock wave within the fluid of the blood vessel. The method comprises the step of directing a shock wave generated by the above-mentioned electric discharge into the calcified tissue of the occluded portion through the fluid within the blood vessel to fragment the calcified tissue into a deformed plaque; and the step of channeling the deformed plaque by penetrating it with reduced mechanical force to create a channel passing through the calcified tissue of the occluded portion along a desired line.

[0036] In another embodiment, the lithotripsy catheter is provided with a sealed chamber "drum" type tunneling probe. The catheter end effector consists of a rigid outer "can" (a metal hypo tube and metal washer laser-welded together), two electric leads with exposed ends (electrodes), a multiluminal shaft (fluid inlet lumen, fluid outlet lumen, and two electric lead lumens), and a membrane (a polymer with low acoustic impedance thermally or adhesively attached to the "can"). The chamber is filled with a fluid (e.g., saline or a saline-contrast agent mixture) circulating through the multiluminal shaft to expel air bubbles and cool the end effector components. Energy transferred by a generator to the exposed ends (i.e., electrodes) of the electric leads creates an electric discharge and subsequent fluid cavitation within the chamber. A hydraulic shock wave is formed, focused axially forward through a membrane with low acoustic impedance by an external rigid (metal) tube with high acoustic impedance, and then propagates into calcified tissue. Repeated exposure of calcified tissue to the hydraulic shock wave creates a modified plaque that is more easily displaced than the original calcified tissue.

[0037] In another embodiment, the lithotripsy catheter is provided with a sealed chamber "drum" type tunneling probe. The catheter end effector consists of a rigid outer "can" (metal inner and outer hypo tubes and two metal washers laser-welded together), two electric leads having exposed ends (electrodes), a multiluminal shaft (fluid inlet lumen, fluid outlet lumen, and two electric lead lumens), and a membrane (a polymer having low acoustic impedance attached thermally, mechanically, or adhesively to the "can"). The chamber is filled with a fluid (e.g., saline or a saline-contrast agent mixture) circulating through the multiluminal shaft to expel air bubbles and cool the end effector components. Energy delivered by a generator to the exposed ends (i.e., electrodes) of the electric leads creates an electric discharge and subsequent fluid cavitation within the chamber. A hydraulic shock wave is formed, focused axially forward through a membrane with low acoustic impedance by an external rigid (metal) tube with high acoustic impedance, and then propagates into calcified tissue. Repeated exposure of calcified tissue to the hydraulic shock wave creates a modified plaque that is more easily displaced than the original calcified tissue.

[0038] In another embodiment, the lithotripsy catheter is provided with a sealed chamber "drum" type tunneling probe. The catheter end effector consists of a rigid outer "can" (metal inner and outer hypo tubes and metal washers laser-welded together), two electric leads having exposed ends (electrodes), a multiluminal shaft (fluid inlet lumen, fluid outlet lumen, and two electric lead lumens), and a membrane (a polymer having low acoustic impedance attached thermally, mechanically, or adhesively to the "can"). The chamber is filled with a fluid (e.g., saline or a saline-contrast agent mixture) circulating through the multiluminal shaft to expel air bubbles and cool the end effector components. Energy delivered by a generator to the exposed ends (i.e., electrodes) of the electric leads creates an electric discharge and subsequent fluid cavitation within the chamber. A hydraulic shock wave is formed, focused axially forward through a membrane with low acoustic impedance by an external rigid (metal) tube with high acoustic impedance, and then propagates into calcified tissue. Repeated exposure of calcified tissue to the hydraulic shock wave creates a modified plaque that is more easily displaced than the original calcified tissue.

[0039] In another embodiment, the lithotripsy catheter is provided with a sealed chamber "drum" type tunneling probe. The catheter end effector consists of a rigid outer tube (a metal hypo tube attached adhesively, mechanically, or thermally to the membrane and shaft), two electric leads having exposed ends (electrodes), a multiluminal shaft (fluid inlet lumen, fluid outlet lumen, and two electric lead lumens), and a "sock-type" membrane (a polymer having low acoustic impedance thermally adhesively attached to the shaft). The chamber is filled with a fluid (e.g., saline or a saline-contrast agent mixture) circulating through the multiluminal shaft to expel air bubbles and cool the end effector components. Energy transferred by a generator to the exposed ends (i.e., electrodes) of the electric leads creates an electrical discharge and subsequent fluid cavitation within the chamber. A hydraulic shock wave is formed, focused axially forward through a membrane with low acoustic impedance by an external rigid (metal) tube with high acoustic impedance, and then propagates into calcified tissue. Repeated exposure of calcified tissue to the hydraulic shock wave creates a modified plaque that is more easily displaced than the original calcified tissue.

[0040] In another embodiment, the lithotripsy catheter is provided with a sealed chamber "drum" type tunneling probe. The catheter end effector consists of a rigid outer "can" (metal inner and outer hypo tubes), a single lumen shaft, and a membrane (a polymer with low acoustic impedance attached thermally, mechanically, or adhesively to the "can"). The shaft and chamber are filled with a fluid (e.g., saline or a saline-contrast agent mixture) that transmits high-frequency hydraulic pulsating pressure waves. An external generator uses compressed CO2 to generate pulsating waves through a diaphragm within the handle of the device. A hydraulic shock wave is formed, focused axially forward through a membrane with low acoustic impedance by an outer rigid (metal) tube with high acoustic impedance, and then propagated into calcified tissue. Repeated exposure of calcified tissue to hydraulic shock waves generates modified plaque that is more easily displaced than the original calcified tissue. Brief explanation of the drawing

[0041] For a more complete understanding, the following description is taken into account in conjunction with the attached drawings briefly described herein. FIG. 1 illustrates a lithotripsy catheter having a cannon / bumper type tunneling probe having no central lumen and concentric electrodes according to one embodiment. The probe may include a rigid outer tube having internal electrodes / emitters located proximal to the distal end of the probe. The rigid outer tube directs the shock wave distally (end emission), and the inset emitter helps the user position the catheter at an optimal distance from the calcified lesion for therapeutic effect. FIG. 2 is a drawing illustrating another lithotripsy catheter having a cannon / bumper tunneling probe having a central lumen and arched electrodes according to another embodiment. FIG. 3 is a drawing illustrating a lithotripsy catheter having a tapered end tunneling probe having a flat tip without a central lumen and narrow lateral electrodes having ends exposed on the flat tip, according to another embodiment. FIG. 4 is a drawing illustrating another lithotripsy catheter having a tapered end tunneling probe with a round tip having no central lumen and wide lateral electrodes according to another embodiment. FIG. 5 is a drawing illustrating another lithotripsy catheter having a tapered end tunneling probe having a flat tip without a central lumen and wide lateral electrodes having ends exposed on the flat tip, according to another embodiment. FIG. 6 is a drawing illustrating a lithotripsy catheter having an over-the-wire tunneling probe having an arched electrode protruding from the end and having a central lumen, according to another embodiment. FIG. 7 is a drawing illustrating another lithotripsy catheter having an over-the-wire tunneling probe having a D-shaped lumen and adjacent stud electrodes protruding from the end, according to another embodiment. FIG. 8 is a drawing illustrating another lithotripsy catheter having an over-the-wire tunneling probe having a central lumen and opposing electrodes protruding from the end, according to another embodiment. FIG. 9 is a drawing illustrating a lithotripsy catheter having a sealed chamber "drum" type tunneling probe according to another embodiment. Figure 10 is a cross-sectional view of the sealed chamber "drum" type tunneling probe of Figure 9. FIG. 11 is a drawing illustrating another lithotripsy catheter having a positioning balloon according to another embodiment. Figures 12a, 12b, and 12c illustrate the use of a lithotripsy catheter having the positioning balloon of Figure 11 in a blood vessel completely occluded by calcified tissue. FIGS. 12d and 12e illustrate the use of a lithotripsy catheter having the positioning balloon of FIG. 11 in a blood vessel in which the lumen is substantially narrowed by calcified tissue. FIG. 13 is a drawing illustrating a positioning support catheter for use in connection with a lithotripsy tunneling catheter according to another embodiment. Figures 14a, 14b, 14c, and 14d illustrate the use of a lithotripsy tunneling probe and guidewire and the positioning support catheter of Figure 13 within a blood vessel completely occluded by calcified tissue. FIGS. 14e and 14f illustrate the use of a lithotripsy tunneling probe and guidewire and the positioning support catheter of FIG. 13 in a blood vessel in which the lumen is substantially narrowed by calcified tissue. FIG. 15 is a drawing illustrating an alternative centering support catheter for use in connection with a lithotripsy tunneling catheter according to another embodiment. Figures 16a and 16b illustrate the use of a lithotripsy tunneling probe and an alternative positioning support catheter of Figure 15 within a blood vessel occluded by calcified tissue. FIG. 17 is a drawing illustrating a straight support catheter for use in connection with a lithotripsy tunneling catheter according to another embodiment. FIG. 18 is a drawing illustrating a curved support catheter for use in connection with a lithotripsy tunneling catheter according to another embodiment. FIG. 19 is a block diagram illustrating a method of using a lithotripsy device to tunnel a vascular occlusion formed by calcified tissue. FIG. 20 is a front perspective view of a lithotripsy catheter having a sealed chamber "drum" type tunneling probe according to another embodiment. FIG. 21 is an anterior perspective view of the lithotripsy catheter of FIG. 20, with the anterior membrane retainer shown transparently for illustrative purposes. Fig. 22 is a partial side view of the lithotripsy catheter of Fig. 20. FIG. 23 is a front perspective view of a lithotripsy catheter having a sealed chamber "drum" type tunneling probe according to another embodiment. FIG. 24 is an anterior perspective view of the lithotripsy catheter of FIG. 23, with the anterior membrane retainer shown transparently for illustrative purposes. Fig. 25 is a partial side view of the lithotripsy catheter of Fig. 23. FIG. 26 is a partial side cross-sectional view of a lithotripsy catheter having a sealed chamber "drum" type tunneling probe according to another embodiment. FIG. 27 shows a prototype tunneling catheter according to the embodiment of FIG. 26. FIG. 28 shows a prototype tunneling catheter according to the embodiments of FIG. 29 to FIG. 33. FIG. 29 is a front view of a lithotripsy catheter having a sealed chamber "sock" type tunneling probe according to another embodiment. Fig. 30 is an anterior perspective view of the lithotripsy catheter of Fig. 29. Fig. 31 is a side cross-sectional view of a "sock" type membrane suitable for use in the lithotripsy catheter of Fig. 29. Fig. 32 is a side cross-sectional view of an enlarged portion of the lithotripsy catheter of Fig. 29. Fig. 33 is a side cross-sectional view of another part of the lithotripsy catheter of Fig. 29. FIG. 34 is a side cross-sectional view of a lithotripsy catheter having a sealed chamber "sock" type tunneling probe suitable for use with an external high-frequency hydraulic pulsating pressure wave generator. FIG. 35 is a frontal perspective view of the lithotripsy catheter of FIG. 34, with the length of the catheter reduced for illustrative purposes. Specific details for implementing the invention

[0042] Referring to FIGS. 1 through 11, various embodiments of a lithotripsy device for tunneling a vascular occluded area are provided. As a standard for the electrical design embodiment of the system, an electrical pulse generator system derived from a conventional electrohydraulic lithotripsy ("EHL") device is suitable. However, in order to optimize the system to tunnel a calcified and hardened lesion found to be occluding the vascular system while minimizing the possibility of damage to the actual artery or blood vessel, a new configuration for the probe and a new design for the electrical pulse waveform and the corresponding hydraulic pressure shock wave are provided.

[0043] Some embodiments of a lithotripsy device for tunneling a vascular occluded area include a tunneling catheter (including a tunneling shaft and a tunneling probe) having an outer diameter ("OD") of 6 French ("Fr") or less and configured to be compatible (i.e., to pass through) an introducer sheath ("ID") of 6 Fr inner diameter. Some embodiments of a lithotripsy device include a tunneling catheter having an OD of 4 Fr or less and configured to be compatible with a 4 Fr ID introducer sheath. Some embodiments of a lithotripsy device include a support catheter and a tunneling catheter, wherein the support catheter has an ID of 6 Fr or less and is configured to be compatible with an introducer sheath having an ID of 8 Fr or less, and the tunneling catheter (including a tunneling shaft and a tunneling probe) is configured to be compatible with the ID of 6 Fr or less of the support catheter. An additional embodiment of a lithotripsy device comprises a support catheter and a tunneling catheter, wherein the support catheter is configured to be compatible with an introducer sheath having an ID of 6 Fr or less, and the tunneling catheter is configured to be compatible with the ID of the support catheter.

[0044] To be clear, the tunneling lithotripsy device of the present invention is not intended to substantially expand calcified or hardened lesions in order to restore blood flow. Even if the tunneling lithotripsy device includes any type of balloon, that balloon is not an expansion balloon. Rather, the tunneling lithotripsy device of the present invention operates to cleave, crush, pulverize, or soften calcified or hardened lesions solely to facilitate the passage of a guidewire necessary for the subsequent effective expansion of the lesion by a separate expansion balloon. The separate expansion balloon may be a conventional high-pressure expansion balloon or a shockwave generator type expansion balloon (though not limited thereto).

[0045] Now, referring specifically to FIG. 1, a lithotripsy tunneling catheter according to a first embodiment is illustrated. The tunneling catheter (100) comprises a catheter shaft (102) and a tunneling probe (104) on a distal end. The tunneling probe (104) comprises a raised or protruding rim (105) that forms an electrode cavity (107) inside. Concentric electrodes (106, 108) are positioned on the base of the electrode cavity (107) so as to face the open distal end. In this way, the concentric electrodes (106, 108) are recessed by a predetermined distance from the distal end of the probe (104). In some embodiments, the protruding rim (105) of the probe (104) is formed by a rigid outer tube, and the internal electrodes / emitters (106, 108) are positioned proximally relative to the distal end of the probe. The rigid outer tube directs the shock wave distally (end emission), and the inset emitter helps the user position the catheter at an optimal distance from the calcified lesion for therapeutic effect. In the illustrated embodiment, the tunneling catheter (100) does not include a communicating central lumen. Unless otherwise noted, the term "communicating" lumen refers to a lumen that is open at the distal end of the catheter shaft to allow the passage of a guidewire and / or the passage of perfusion or aspiration. The tunneling catheter (100) also includes an electrical lead (not shown) configured to be operablely connected to electrodes (106, 108) and operablely connected to an external pulse generator.

[0046] By activating a pulse generator connected to electrodes (106, 108), a series of short electrical discharges is initiated between the electrodes. Each electrical discharge evaporates the surrounding fluid (e.g., plasma) to form gas bubbles that rapidly expand and collapse at the discharge site. As the gas bubbles expand and collapse, a hydraulic shock wave is formed that propagates from the discharge site through the fluid to adjacent tissues. While such shock waves are generally harmless to soft (i.e., flexible) tissues, they can rupture calcified or otherwise hardened tissues, such as plaque lesions. In a preferred embodiment, the pulse generator is operably connected to a pulse controller that can selectively change the power, frequency, duration, waveform, and other characteristics of the electrical discharge initiated by the pulse generator to generate shock waves suitable for tunneling various types of lesions. In some embodiments using a pulse controller, the pulse generator and the pulse controller are separate units, whereas in other embodiments, they are combined into a single unit. After the calcified or hardened occluded tissue is fragmented by a shock wave, the tunneling catheter (100) can be advanced into the softened tissue to form a channel through the occluded area. Alternatively, after softening the occluded tissue with a shock wave, the tunneling catheter (100) can be withdrawn and replaced with a guide wire to form a channel into the softened material of the occluded area. After the desired channel through the calcified material is formed, the tunneling catheter (100) is withdrawn and the expansion of the occluded area can be performed by a separate expansion balloon.

[0047] Now, referring specifically to FIG. 2, another lithotripsy tunneling catheter according to a second embodiment is illustrated. The tunneling catheter (200) comprises a catheter shaft (202) and a tunneling probe (204) on a distal end. The tunneling probe (204) comprises a raised or protruding rim (205) that forms an electrode cavity (207) inside. Arched electrodes (206, 208) are positioned on the base of the electrode cavity (207) on opposite sides of the central lumen (210) to which they communicate. The central lumen (210) may be operably connected to the proximal end of the shaft (202) to allow the passage of a guide wire. In some embodiments, the central lumen (210) may enable fluid perfusion and / or fluid aspiration to be provided to an area adjacent to the tunneling probe (204). The tunneling catheter (200) also includes an electric lead (not shown) configured to be operablely connected to electrodes (206, 208) and connected to an external pulse generator. By activating the pulse generator, an electric discharge is generated between the electrodes (206, 208), forming a hydraulic shock wave that propagates from the discharge location and tunnels into the calcified occluded tissue by crushing it as previously described. After the desired channel is formed by penetrating, or partially penetrating, the tunneling catheter (200) is withdrawn, and expansion of the occluded portion can be performed by a separate expansion balloon.

[0048] The tunneling catheters (100, 200) all have a "cannon / bumper" type tunneling probe configuration in which a rigid outer tube having electrodes is recessed into an electrode cavity formed by a raised rim on the end of the probe. The raised rim propagates the shock wave generated from the electrode cavity generally in the axial direction (i.e., parallel to the central axis of the catheter). Additionally, the raised rim prevents the electrodes from coming into direct contact with the occluded tissue. Furthermore, the raised rim ensures that the shock wave is generated at a predetermined distance from the occluded area (assuming the distal end of the probe is in contact with the occluded area or is positioned at a predetermined distance from the occluded area). Advantages of a cannon / bumper-style tunneling probe include (but are not limited to) excellent directionality of the shock wave, a constant distance between the electrodes and the lesion when the distal end of the catheter is pressurized against the lesion, and the ability to use the central lumen (210) for guidewire or perfusion / aspiration (only applicable to the catheter (200)). Disadvantages of a cannon / bumper-style probe include that electrical arcing in blood has not been verified and may present functional or safety (thrombotic) risks to the patient under certain conditions, and that interactions between the guidewire (if present) and the electrodes may cause safety risks. It should be noted that, where present, these disadvantages can be mitigated or overcome by developing appropriate usage protocols and / or additional features.

[0049] Now, referring specifically to FIG. 3, a lithotripsy tunneling catheter according to a third embodiment is illustrated. The tunneling catheter (300) comprises a catheter shaft (302) and an exposed tunneling probe (304) having a tapered distal end (303) and a flat tip (305). The tunneling probe (304) comprises narrow lateral electrodes (306, 308) having exposed ends on the flat tip (305). There is no communicating central lumen. The tunneling catheter (300) also comprises an electric lead (not illustrated) configured to be operablely connected to the electrodes (306, 308) and connected to an external pulse generator. By activating the pulse generator, an electrical discharge is generated between the electrodes (306, 308). When the flat tip (305) is spaced apart from the lesion, the electrical discharge from the electrodes (306, 308) can travel through the surrounding fluid and generate a shock wave that propagates away from the probe as previously described. When the flat tip (305) is pressurized against the lesion, at least a portion of the electrical discharge can travel through the contact area of ​​the lesion between the exposed ends of the electrodes (306, 308), thereby directly destroying the contact area through cauterization. Using lithotripsy and thermal energy, the probe (304) tunnels in by crushing the calcified occluded tissue as previously described. After the desired channel is formed by penetrating, or partially penetrating, the tunneling catheter (300) is withdrawn, and expansion of the occluded area can be performed by a separate expansion balloon.

[0050] Now, referring specifically to FIG. 4, a lithotripsy tunneling catheter according to a fourth embodiment is illustrated. The tunneling catheter (400) comprises a catheter shaft (not illustrated) and an exposed tunneling probe (404) having a tapered distal end (403) and a round tip (405). The tunneling probe (404) comprises a wide lateral electrode (406, 408) positioned on the tapered end (403) and not extending over the round tip (405). There is no communicating central lumen. The tunneling catheter (400) also comprises an electric lead (not illustrated) configured to be operablely connected to the electrode (406, 408) and connected to an external pulse generator. By activating the pulse generator, an electrical discharge is generated between the electrodes (406, 408), creating a shock wave that propagates into the occluded tissue in a direction away from the probe as previously described. Using lithotripsy, the probe (404) tunnels in by crushing the calcified occluded tissue as previously described. After the desired channel is formed by penetrating the calcified material, or partially penetrating it, the tunneling catheter (400) is withdrawn and the occluded area can be expanded by a separate expansion balloon.

[0051] Now, referring specifically to FIG. 5, a lithotripsy tunneling catheter according to a fifth embodiment is illustrated. The tunneling catheter (500) comprises a catheter shaft (not illustrated) and an exposed tunneling probe (504) having a tapered distal end (503) and a flat tip (505). The tunneling probe (504) comprises wide lateral electrodes (506, 508) having exposed ends on the flat tip (505). There is no communicating central lumen. The tunneling catheter (500) also comprises an electric lead (not illustrated) configured to be operablely connected to the electrodes (506, 508) and connected to an external pulse generator. By activating the pulse generator, an electrical discharge is generated between the electrodes (506, 508). Similar to the probe (300), when the flat tip (505) is spaced apart from the lesion, the electrical discharge from the electrodes (506, 508) can generate a shock wave that travels through the surrounding fluid and propagates away from the probe, but when the flat tip is pressurized against the lesion, at least a portion of the electrical discharge can travel between the exposed ends of the electrodes through the contact portion of the lesion. Using shock wave and thermal energy, the probe (504) tunnels in by crushing the calcified occluded tissue as previously described. After the desired channel is formed by penetrating, or partially penetrating, the tunneling catheter (500) is withdrawn and expansion of the occluded area can be performed by a separate expansion balloon.

[0052] All tunneling catheters (300, 400, 500) feature a "tapered" type tunneling probe configuration in which the distal end of the tunneling probe is tapered to improve the ability to mechanically push through the lesion after cracking caused by lithotripsy shockwaves. Advantages of the tapered type tunneling probe include (but are not limited to) a simple design without multiple lumens and the ability to mechanically open a channel after cracking of the calcified portion. Disadvantages of the tapered type probe include reduced directionality (i.e., of the shockwave), the fact that the small overall scale of the probe reduces the value of the tapered tip, the fact that the tapered tip may increase the risk of perforation, and (as previously mentioned) that electrical arcing in blood has not been verified and may present functional or safety risks to the patient under certain conditions. It should be noted that these disadvantages, where present, can be mitigated or overcome by developing appropriate usage protocols and / or additional features.

[0053] Now, referring specifically to FIG. 6, another lithotripsy tunneling catheter according to the sixth embodiment is illustrated. The tunneling catheter (600) comprises a catheter shaft (602) and a protruding tunneling probe (604) on the distal end. The tunneling probe (604) comprises arched electrodes (606, 608) positioned on opposing sides of the central lumen (610). The central lumen (610) can move over a guidewire (not illustrated). In one embodiment, the guidewire may be a 0.014" inch guidewire. The tunneling catheter (600) also includes an electric lead (not shown) configured to be operablely connected to electrodes (606, 608) and connected to an external pulse generator. By activating the pulse generator, an electric discharge occurs between the electrodes (606, 608), generating a shock wave that propagates from the probe (604) through the surrounding fluid to crack or break a calcified or inflexible occlusion. After the desired channel is formed by penetrating, or partially penetrating, the tunneling catheter (600) is withdrawn, and expansion of the occlusion can be performed by a separate expansion balloon.

[0054] Now, referring specifically to FIG. 7, another lithotripsy tunneling catheter according to the seventh embodiment is illustrated. The tunneling catheter (700) comprises a catheter shaft (702) and a tunneling probe (704) protruding from the distal end. The tunneling probe (704) comprises a pair of parallel stud-type electrodes (706, 708) offset from a lumen (710) positioned on one side of the tunneling probe (704). In the illustrated embodiment, the offset lumen (710) is in the shape of a "D" (in cross-section), but in other embodiments, the offset lumen may have a different shape. The offset lumen (710) may move over a guide wire (not illustrated). In one embodiment, the guidewire may be a 0.014" inch guidewire. The tunneling catheter (700) also includes an electric lead (not shown) configured to be operablely connected to electrodes (706, 708) and connected to an external pulse generator. By activating the pulse generator, an electric discharge occurs between the electrodes (706, 708), generating a shock wave that propagates from the probe (704) through the surrounding fluid to rupture or fragment the occluded sclerosed tissue. After the desired channel is formed by penetrating, or partially penetrating, the tunneling catheter (700) is withdrawn, and expansion of the occluded portion can be performed by a separate expansion balloon.

[0055] Now, referring specifically to FIG. 8, another lithotripsy tunneling catheter according to the eighth embodiment is illustrated. The tunneling catheter (800) comprises a catheter shaft (802) and a tunneling probe (804) protruding on the distal end. The tunneling probe (804) comprises a pair of stud-type electrodes (806, 808) positioned on both sides of the central lumen (810). The central lumen (810) can move over a guidewire (not illustrated). In one embodiment, the guidewire may be a 0.014" inch guidewire, but may accommodate up to a 0.035" inch guidewire. The tunneling catheter (800) also comprises an electric lead (not illustrated) configured to be operablely connected to the electrodes (806, 808) and connected to an external pulse generator. By activating the pulse generator, an electric discharge occurs between the electrodes (806, 808), generating a shock wave that propagates from the probe (804) through the surrounding fluid to crack or fragment the occluded hardened tissue. After the desired channel is formed by penetrating the calcified material, or partially penetrating it, the tunneling catheter (800) is withdrawn and the expansion of the occluded area can be performed by a separate expansion balloon.

[0056] The tunneling catheters (600, 700, 800) all have an "over-the-wire" type tunneling probe configuration in which each electrode extends beyond the distal end of the shaft and the probe moves along a guide wire. In some embodiments, the central lumen may enable fluid irrigation or fluid suction to be provided to an area adjacent to the tunneling probe. Compared to cannon / bumper type probes (100, 200) having a raised rim at the end of the probe, the over-the-wire type probes (600, 700, 800) do not have a raised rim and therefore do not have an electrode cavity for focusing shock waves axially. Thus, the over-the-wire type tunneling probes (600, 700, 800) can propagate shock waves axially as well as radially outward from the probe. Other advantages of the over-the-wire type tunneling probe include (but are not limited to) faster and easier exchange of the lithotripsy catheter with other devices, such as high-pressure dilation catheters, shockwave dilation catheters, etc. Additional advantages include the so-called "inchworm" function, in which the tunneling probe is used to soften a first portion of the lesion, then a guidewire is used to form a channel in the first softened portion, then the tunneling probe is incrementally advanced into the newly created channel to soften an additional second portion of the lesion, and this process is repeated until the desired channel is completed by penetrating the lesion. As described above, the central lumen can also facilitate fluid perfusion or fluid aspiration in the affected region adjacent to the tunneling probe.The disadvantages of over-the-wire type tunneling probes are similar to those of cannon / bumper-style probes, including the fact that electrical arcing in blood has not been verified and may pose functional or safety risks to the patient under certain conditions, and that interactions between the guidewire and the electrode may present safety risks. An additional disadvantage is the small diameter of the guidewire that can be accommodated within the guidewire lumen, considering the overall dimensional constraints of the tunneling catheter. It should be noted that, where present, these disadvantages can be mitigated or overcome by developing appropriate usage protocols and / or additional features.

[0057] In some embodiments, each lumen (610, 710, 810) of each over-the-wire catheter (600, 700, 800) may further include two separate fluid passages within the lumen. When two separate fluid passages are provided, one fluid passage may be used for fluid inflow and the other fluid passage may be used for fluid outflow. In some embodiments, the fluid inflow passage may be used for perfusion (e.g., using saline) of the area directly surrounding the tunneling probe before, during, or after the lithotripsy operation. In some embodiments, the fluid outflow passage may be used for aspiration (e.g., aspiration of blood or saline containing lithotripsy debris) of the area directly surrounding the tunneling probe before, during, or after the lithotripsy operation. In some embodiments, simultaneous perfusion and aspiration may be provided to provide controlled circulation of fluid through the lithotripsy area to remove heated fluid and / or debris induced by electric discharge during lithotripsy operation.

[0058] Now, referring specifically to FIGS. 9 and FIGS. 10, another lithotripsy tunneling catheter according to the ninth aspect is illustrated. The tunneling catheter (900) comprises a catheter shaft (902) and a tunneling probe (904) on the distal end. Similar to the probe (200) described previously, the tunneling probe (904) also comprises a raised or protruding rim (905) forming an electrode cavity (907) inside, and electrodes (906 and 908 (shown by dashed lines)) are positioned at the base of the electrode cavity. However, unlike the probe (200), the tunneling probe (904) further comprises a flexible diaphragm (912) attached across the distal end of the probe to fluidly isolate the electrode cavity (907) from the blood vessel, thereby forming a "drum" configuration. In other words, the electrode cavity (907) can be filled with a fluid that is isolated from the fluid within the blood vessel (e.g., plasma), such as physiological saline or a contrast agent solution. The tunneling catheter (900) also includes an electrical lead wire (not shown) configured to be operablely connected to the electrodes (906, 908) and connected to an external pulse generator.

[0059] By activating the pulse generator connected to the probe (904), an electric discharge occurs between the electrodes (906, 908), generating a primary shock wave that propagates into the fluid within the electrode cavity (907). This primary shock wave strikes one side of the diaphragm (912), causing the diaphragm to bend or vibrate relative to the blood vessel fluid on the other side, thereby generating a secondary shock wave that propagates into the blood vessel fluid while still maintaining fluid isolation between the two fluids. Since the fluid within the electrode cavity (907) is always isolated from the blood vessel, any undesirable thermal or physical effects of a direct electric discharge within a blood-filled blood vessel are prevented. The diaphragm (912) may be made of any fluid-impermeable flexible material, including elastomers, polymers, and thin metals. Depending on the stiffness of the material used for the diaphragm (912), the secondary shock wave may be amplified or attenuated relative to the primary shock wave. However, potential attenuation can be compensated by increasing the output of the primary shock wave or by changing the discharge pulse using a pulse controller. Depending on the individual acoustic impedance of the electrode cavity (907) and the fluid within the vessel, the secondary shock wave may be attenuated compared to the primary shock wave. However, this attenuation can be compensated by increasing the output of the primary shock wave or by changing the discharge pulse using a pulse controller.

[0060] In some embodiments, the tunneling catheter (900) may also include at least one lumen (910) communicating with a sealed electrode cavity (907). The lumen (910) may be used to fill the electrode cavity (907) with fluid. In some embodiments, two lumens communicating with the sealed electrode cavity (907), such as 910' and 910", may be provided. For example, when two lumens (910', 910") are provided, one lumen may be used for fluid filling and the other lumen may be used for fluid withdrawal. In some embodiments, continuous circulation of fluid may be provided through a sealed electrode cavity (907) using two lumens (910', 910") during the lithotripsy operation. In other embodiments, periodic circulation of fluid may be provided through a sealed electrode cavity (907) using two lumens (910', 910") during the lithotripsy operation. Continuous or periodic circulation of fluid through the sealed electrode cavity (907) during the lithotripsy operation may remove heat introduced from the electrical discharge to control the temperature of the fluid within the electrode cavity and / or replace the fluid as needed if the fluid deteriorates due to the electrical discharge. Additionally, continuous or periodic circulation of fluid through the sealed electrode cavity (907) during the lithotripsy operation may remove residual air or bubbles from the cavity that, if not done so, could interfere with the delivery of lithotripsy shockwaves or impede the optimal therapeutic effect. In some embodiments, when a lumen (910) or a lumen (910', 910") is provided, each lumen may be configured with a high fluid inductance to prevent significant fluid backflow from shock waves generated in the electrode cavity (907). In other embodiments, when a lumen (910) or a lumen (910', 910") is provided, a flow control unit may be provided to allow flow through each lumen between shock waves and to stop flow in the lumen during shock waves.After the tunneling probe (904) penetrates the calcified material, or partially penetrates it, to form a desired channel, the tunneling catheter (900) is withdrawn and the expansion of the occluded portion can be performed by a separate expansion balloon.

[0061] Now, referring to FIG. 11, another lithotripsy tunneling catheter according to the tenth aspect is illustrated. The tunneling catheter (1100) comprises a catheter shaft (1102) and a tunneling probe (1104) on the distal end. The tunneling probe (1104) may be configured in any configuration of the previously described probes (104, 204, 304, 404, 504, 604, 704, 804, and 904) (but is not limited thereto). The tunneling catheter (1100) also comprises a positioning balloon (1115) attached to the catheter shaft behind the tunneling probe (1104) (i.e., proximal). The positioning balloon (1115) can be inflated with an expansion fluid (e.g., physiological saline) through an expansion lumen (not shown) within the catheter shaft (1102). In the illustrated embodiment, the positioning balloon (1115) is configured to extend uniformly around the catheter shaft (1102) to center the tunneling probe (1104) within the lumen of the blood vessel. In another embodiment, the positioning balloon (1115) may be configured to extend non-uniformly around the catheter shaft (1102) to offset the tunneling probe (1104) from the centerline of the lumen of the blood vessel.

[0062] Now, referring to FIGS. 12a, 12b, and 12c, the use of a tunneling catheter (1100) within an artery or blood vessel completely occluded by calcified tissue is illustrated. The blood vessel (1200) comprises a blood vessel wall (1202) forming an inner lumen (1203) filled with fluid (e.g., blood). The blood vessel wall (1202) comprises a plurality of layers including an intima (1204), a media (1206), and an externa (1208). Regions of calcified plaque (1210) within the blood vessel wall (1202) form an occlusion that reduces or blocks blood flow through the blood vessel. In the embodiments illustrated in FIGS. 12a through 12c, the blood vessel is completely blocked.

[0063] Now, referring specifically to FIG. 12a, a tunneling catheter (1100) is shown positioned within a blood vessel (1200) near an occlusion (1210). A positioning balloon (1115) can be inflated to center a tunneling probe (1104) within the lumen (1203) of the blood vessel. The tunneling catheter (1100) can be advanced through the lumen (1203) until the tunneling probe (1104) is adjacent to a calcified plaque (1210). By activating a pulse generator, an electrical discharge occurs between the electrodes of the tunneling probe (1104), sending a hydraulic shock wave into the adjacent calcified material (1210). This shock wave cracks, grinds, or crushes the calcified material near the plaque (1210), transforming it into weakened material or a "modified plaque." The deformed plaque has less strength and / or cohesion than the original calcified material, and accordingly has less resistance to mechanical displacement (i.e., being pushed sideways or pushed through) than the original calcified material. Now, referring to FIG. 12b, after the operation of the tunneling probe (1104), portions of the calcified plaque (1210) within the effective range of the tunneling probe are crushed into a "pocket" of the deformed plaque (1214) by the shock wave. Then, the deformed plaque (1214) can be penetrated or pushed sideways (i.e., displaced) to form a channel penetrating the calcified plaque (1210) using substantially less force than is required to penetrate or push sideways the original calcified plaque.

[0064] Now, referring to FIG. 12c, in some cases, the tunneling probe (1104) itself may be used to push through or drive out the deformed plaque (1214) to form a channel within the calcified tissue. In some embodiments, for example, where the tunneling probe (1104) includes a guidewire lumen (e.g., probes (204, 604, 704 and 804)), a guidewire (1226) may be introduced through the catheter shaft (1102) and the tunneling probe as shown in FIG. 12c to penetrate the deformed plaque and form a channel. In other cases, the tunneling probe (1104) may be withdrawn from the blood vessel, and a guidewire (1226) or other tool may be inserted separately to penetrate the deformed plaque and form a channel.

[0065] Now, referring to FIGS. 12d and 12e, the use of a tunneling catheter (1100) in an artery or blood vessel having a lumen that is substantially narrowed (i.e., not completely blocked) by calcified tissue is illustrated. First, referring to FIG. 12d, the tunneling catheter (1100) is shown placed within a blood vessel (1200') near an occlusion formed by calcified tissue (1210). A positioning balloon (1115) can be inflated to position the tunneling probe (1104) at a desired location within the blood vessel lumen (1203) so that the tunneling probe (1104) is adjacent to the narrowed lumen portion (1212). When the pulse generator is activated, an electrical discharge occurs between the electrodes of the tunneling probe (1104) to send a hydraulic shock wave along the narrowed lumen portion (1212) into the adjacent calcified material (1210). These shock waves crush the calcified material near the plaque (1210), transforming it into a deformed plaque. Now, referring to FIG. 12e, after the operation of the tunneling probe (1104), portions of the calcified plaque (1210) along the narrowed lumen (1212) are crushed into a "pocket" of the deformed plaque (1214) by the shock waves. The deformed plaque (1214) is then penetrated or pushed aside (i.e., displaced) to form a channel that penetrates the calcified plaque (1210) using substantially less force than is required to penetrate or push aside the original calcified plaque.

[0066] After advancing the tunneling catheter (1100) to position the tunneling probe (1104) within the newly formed channel through the deformed plaque (1214) along the narrowed portion (1212) of the lumen, the pulse generator can be activated once again so that the tunneling probe (1104) can fragment additional calcified tissue (1210) into additional deformed plaque. Subsequently, this newly deformed plaque (1214) can be channeled as described above. This process is repeated to incrementally extend the channel until the channel passes through the occlusion. In many cases, the activated tunneling probe (1104) will naturally follow the path of least resistance along the narrowed portion (1212) of the lumen as it advances through the calcified tissue (1210) to form the channel.

[0067] In some cases, the tunneling catheter (1100) may include a suction and / or perfusion lumen, in which case the tunneling process may include using a perfusion fluid to loosen the deformed plaque (1214) and / or using a suction to remove the crushed or deformed plaque. If necessary, the tunneling process may include alternating multiple times of impacting the calcified plaque (1210) and channeling the deformed plaque (1214) using the tunneling probe (1104) until a channel (indicated by the dashed line 1216) is formed by penetrating the occlusion (1212) or partially penetrating it. After a suitable channel is formed within the calcified plaque (1210) of the occlusion (1212), the tunneling catheter (1100) is withdrawn, and expansion of the occlusion may be performed by a separate expansion balloon.

[0068] Now, referring to FIG. 13, a centering support catheter according to another embodiment for use in connection with a lithotripsy tunneling catheter comprising (but not limited to) tunneling catheters (100, 200, 300, 400, 500, 600, 700, 800, and 900) is illustrated. The support catheter (1300) comprises a catheter shaft (1302) forming an internal lumen (1314) and a positioning balloon (1315) positioned adjacent to the distal end (1316) of the support catheter. The positioning balloon (1315) may be inflated with an inflating fluid (e.g., physiological saline) through an inflating lumen (not illustrated) within the catheter shaft (1302). In the illustrated embodiment, the positioning balloon (1315) is configured to extend uniformly around the catheter shaft (1302) to center the distal end (1316) within the lumen of the blood vessel. In another embodiment, the positioning balloon (1315) may be configured to extend non-uniformly around the catheter shaft (1302) to offset the distal end (1316) from the centerline of the lumen of the blood vessel. The support catheter (1300) does not include a tunneling probe, but is instead configured to receive each lithotripsy tunneling catheter into the lumen (1314) and guide the tunneling catheter through the lumen until the tunneling probe extends from the distal end (1316).

[0069] Now, referring to FIGS. 14a, 14b, 14c and 14d, the use of a support catheter (1300) and a lithotripsy tunneling catheter (1420) within an artery or blood vessel completely occluded by calcified material is illustrated. The blood vessel (1400) comprises a blood vessel wall (1402) forming an inner lumen (1403) filled with fluid (e.g., blood). The blood vessel wall (1402) comprises a plurality of layers including an intima (1404), a media (1406), and an adventitia (1408). Regions of calcified plaque (1410) within the blood vessel wall (1402) form an occlusion (1412) that reduces or blocks blood flow through the blood vessel. In the illustrated embodiments of FIGS. 14a through 14d, the blood vessel is completely blocked. The tunneling catheter (1420) may be configured as any of the configurations described above for the tunneling catheter (100, 200, 300, 400, 500, 600, 700, 800, and 900), having a tunneling catheter shaft (1422) having a lithotripsy tunneling probe (1424) at a distal end (but is not limited thereto). The lithotripsy tunneling probe (1424) may be configured as any of the configurations described above for the tunneling probe (104, 204, 304, 404, 504, 604, 704, 804, and 904) (but is not limited thereto).

[0070] Now, referring specifically to FIG. 14a, the support catheter (1300) can be introduced into the blood vessel (1400) with or without a guidewire. Preferably, the positioning balloon (1315) is not inflated during introduction to facilitate movement through the intervening lumen of the body. Once the support catheter (1300) is positioned at a desired location near the occlusion (1412), the positioning balloon (1315) can be inflated to center or position the distal end (1316) of the support catheter within the blood vessel (1400). The support catheter (1300) can optionally be fixed in place (e.g., at the point of introduction) to prevent unintended movement within the blood vessel (1400) during subsequent operation. Once the support catheter (1300) is positioned at the desired location, the guidewire can be withdrawn (if used).

[0071] Now, referring also to FIG. 14b, the tunneling catheter (1420) can be introduced through the lumen (1314) of the support catheter (1300) and advanced through the lumen by pushing the catheter shaft (1422) until the tunneling probe (1424) extends from the distal end (1316) to a desired position adjacent to the calcified plaque (1410) of the occlusion (1412). By activating the pulse generator, an electrical discharge is generated between the electrodes of the tunneling probe (1424), releasing a hydraulic shock wave into the adjacent calcified material (1410). This shock wave breaks down parts of the calcified material (1410) within the effective range of the tunneling probe (1424) into the deformed plaque (1414) as described above. In the illustrated embodiment of FIG. 14b, the tunneling probe (1424) has an effective range (indicated as “D1” and illustrated by a dashed line) that extends axially mainly forward of the probe, creating a pocket of the deformed plaque (1414) having a depth of “D1”. In other embodiments, the shock wave emitted from the tunneling probe (1424) may have a different effective range and / or a different orientation, and thus may create a pocket of the deformed plaque (1414) having a different shape or dimension. The deformed plaque (1414) may be penetrated or pushed aside to form a channel through the calcified plaque (1410) using substantially less force than that required to penetrate or push aside the original calcified plaque.

[0072] Now, referring also to FIG. 14c, after operating the tunneling probe (1424) to crush the calcified material (1410) to a depth of D1 into a deformed plaque (1414), a channel may be formed within the deformed plaque by pushing the deformed plaque aside. In some cases, the tunneling probe (1424) itself may be used to push through or drive out the newly deformed plaque (1414) to form a channel. In other cases, a guide wire may be used to penetrate the deformed plaque to form a channel. For example, in an embodiment having a tunneling probe (1424) including a guidewire lumen (e.g., probes (204, 604, 704 and 804)), the tunneling catheter (1420) may be maintained in a position within the support catheter (1300), and a guidewire (1426) may be introduced through the tunneling catheter shaft (1402) and the tunneling probe to form a channel through the deformed plaque. In another embodiment having a tunneling probe (1424) not including a guidewire lumen (e.g., probes (104, 204, 404, 504 and 904)), the tunneling catheter (1420) may be withdrawn from the support catheter (1300), and a guidewire (1426) may be introduced through the support shaft (1302) to form a channel through the deformed plaque. In the illustrated embodiment of FIG. 14c, the tunneling catheter (1420) is temporarily withdrawn from the support catheter (1300) so that a separate guide wire (1426) or other tool can be reinserted into the occluded area (1412) and used to form a channel by penetrating the deformed plaque (1414) to a depth of D1. Using the guide wire (1426) for channeling can prevent the tunneling probe (1424) from being damaged during channeling of the calcified material (1410).In another embodiment, the tunneling catheter (1420) may be temporarily withdrawn from the support catheter (1300) so that a tool catheter having a perfusion and / or suction lumen can be reinserted into the occlusion site (1412) and used to channel through the deformed plaque (1414) using perfusion and / or suction.

[0073] Now, referring also to FIG. 14d, after performing initial channeling to a depth D1, the tunneling catheter (1420) can be reinserted (if withdrawn) into the occluded area (1412) through the support catheter (1300) and advanced to the end of the channel. Then, the tunneling process is resumed by reactivating the tunneling probe (1424) and applying shock to the next section, indicated as D2, so that additional calcified plaque (1410) can be broken into deformed plaque (1414). After applying shock to section D2 with the tunneling probe (1424), section D2 can be channeled as described above. The process of first using shock waves to break calcified tissue and then channeling through the deformed plaque is repeated until a channel of the desired length (indicated by the dashed line 1416) is formed through the occluded area (1412). In a preferred embodiment, the support catheter (1300) acts as a "base of operations" that remains fixed in place throughout the entire tunneling process, including during the use of the tunneling probe (1424) and during the replacement between the tunneling catheter (1420), guidewire (1426), and tool catheter (if used), in order to protect the wall (1402) of the blood vessel. After a suitable channel (1416) is formed within the calcified plaque (1410) of the occlusion (1412), the tunneling catheter (1420) may be withdrawn from the support catheter (1300) so that the expansion of the occlusion may be performed by a separate expansion balloon. In some cases, the support catheter (1300) may be used to guide the separate expansion balloon to the occlusion location, whereas in other cases, the support catheter may be withdrawn before the expansion balloon is inserted.

[0074] Now, referring to FIGS. 14e and 14f, the use of a support catheter (1300) and a tunneling catheter (1420) in an artery or blood vessel having a lumen that is substantially narrowed (i.e., not completely blocked) by calcified tissue is illustrated. First, referring to FIG. 14e, the support catheter (1300) is placed within a blood vessel (1400') near the occlusion formed by calcified tissue (1410). A positioning balloon (1315) can be inflated to position the support catheter (1300) at a desired location and orientation within the blood vessel lumen (1403) so that the distal end (1316) of the support catheter is adjacent to the narrowed lumen portion (1412). In the illustrated embodiment of FIG. 14e, the positioning balloon (1315) is optionally inflated and manipulated so that the distal end (1316) of the support catheter (1300) can be positioned offset from the center of the lumen (1403). Now, referring also to FIG. 14f, after positioning the support catheter (1300), the tunneling catheter (1420) is introduced through the support catheter shaft (1302), and the tunneling probe (1424) can be advanced until it extends from the support catheter to a position adjacent to the narrowed lumen portion (1412) formed by the calcified tissue (1410). When the pulse generator is activated, an electrical discharge occurs between the electrodes of the tunneling probe (1104) to send a hydraulic shock wave into the adjacent calcified material (1410) along the narrowed lumen portion (1412). These shock waves crush the calcified material near the plaque (1410), transforming it into a deformed plaque. After the operation of the tunneling probe (1104), portions of the calcified plaque (1410) along the narrowed lumen (1412) are crushed into a "pocket" of the plaque (1414) deformed by the shock waves.After that, the deformed plaque (1414) can be penetrated or pushed sideways (i.e., displaced) to form a channel penetrating the calcified plaque (1410) using substantially less force than is required to penetrate or push sideways the original calcified plaque.

[0075] After advancing the tunneling catheter (1420) to position the tunneling probe (1424) within the newly formed channel through the deformed plaque (1414) along the narrowed portion (1412) of the lumen, the pulse generator can be activated once again so that the tunneling probe (1424) can fragment additional calcified tissue (1410) into additional deformed plaque. Subsequently, this newly deformed plaque (1414) can be channeled as described above. This process is repeated to incrementally extend the channel until the channel passes through the occlusion. In many cases, as the activated tunneling probe (1424) advances through the calcified tissue (1410) to form the channel, it will naturally follow the path of least resistance along the narrowed portion (1412) of the lumen.

[0076] Now, referring to FIG. 15, an alternative centering support catheter according to another embodiment for use in connection with a lithotripsy tunneling catheter comprising (but not limited to) tunneling catheters (100, 200, 300, 400, 500, 600, 700, 800, and 900) is illustrated. The alternative support catheter (1500) comprises a catheter shaft (1502) forming an internal lumen (1514), and a positioning balloon (1515) positioned adjacent to the distal end (1516) of the support catheter. The positioning balloon (1515) may be inflated with an expansion fluid through an expansion lumen (not illustrated) within the catheter shaft (1502). The distal end (1516) of the alternative support catheter (1500) further includes a guide tip (1517) that redirects the internal lumen (1514) in a predetermined manner. In the illustrated embodiment, the guide tip (1517) is curved at an angle of 34 degrees with respect to the longitudinal axis (1518) of the support catheter shaft (1502). In another embodiment, the guide tip (1517) may be curved at an angle within the range of 20 to 40 degrees with respect to the longitudinal axis (1518) of the support catheter shaft (1502). In yet another embodiment, the guide tip (1517) may be curved at an angle within the range of 10 to 50 degrees with respect to the longitudinal axis (1518) of the support catheter shaft (1502).

[0077] Now, referring also to FIGS. 16a and 16b, the use of an alternative support catheter (1500) and a lithotripsy tunneling catheter (1420) within an occluded artery or blood vessel is illustrated. Unless otherwise specified, the blood vessel (1400) and the lithotripsy tunneling catheter (1420) are as described above.

[0078] Referring first to FIG. 16a, an alternative support catheter (1500) can be introduced into a blood vessel (1400) with or without a guide wire. Preferably, the positioning balloon (1515) is not inflated during introduction to facilitate movement through the intervening lumen of the body. The alternative support catheter (1500) is positioned within the blood vessel (1400) such that the guide tip (1517) is oriented in the desired direction. Once the alternative support catheter (1500) is positioned at the desired location near the occlusion (1412), the positioning balloon (1515) can be inflated to center or position the distal end (1516) and the guide tip (1517) within the blood vessel (1400). In some embodiments, the guide tip (1517) is made of a radiopaque material or has a radiopaque marking so that the exit direction of the guide tip (1517) can be imaged by radiography. In some embodiments, the direction of the guide tip (1517) may be optionally changed by twisting the catheter shaft (1502) before the inflation of the positioning balloon (1515), as indicated by directions A and B in FIG. 16a. In some embodiments, the direction of the guide tip (1517) may be optionally changed by twisting the catheter shaft (1502) even after the inflation of the positioning balloon (1515). Once the alternative support catheter (1500) is positioned at the desired location, the guide wire can be withdrawn (if used).

[0079] Now, referring also to FIG. 16b, the tunneling catheter (1420) can be introduced through the lumen (1514) of the support catheter (1500) and advanced through the lumen by pushing the catheter shaft (1422) until the tunneling probe (1424) extends from the guide tip (1517) of the distal end (1516). Since the guide tip (1517) is curved at a constant angle with respect to the longitudinal axis (1518) of the support catheter shaft (1502), the distal end of the tunneling catheter (1420) containing the tunneling probe (1424) will exit the guide tip at a similar relative angle and in a similar direction. Then, the tunneling probe (1424) can be advanced from the guide tip (1517) to a desired position adjacent to the calcified plaque (1410) of the occlusion (1412). By activating the pulse generator, an electrical discharge is generated between the electrodes of the tunneling probe (1424) as described above, except that the shock wave can now be directed to an uncentered position and a selected angle within the blood vessel (1400), thereby releasing a hydraulic shock wave into the adjacent calcified material (1410). Using the tunneling catheter (1420) with an alternative support catheter (1500) is substantially similar to using the support catheter (1300) described above.

[0080] Now, referring to FIG. 17, another support catheter according to another embodiment for use in connection with a lithotripsy tunneling catheter (1420) is illustrated. The straight support catheter (1700) includes a catheter shaft (1702) forming an internal lumen (1714) as described above, but does not include a positioning balloon. After positioning the distal end (1716) of the catheter shaft (1702) at a desired location adjacent to the occlusion (1412), the proximal end (not illustrated) can be fixed at the introduction position so that the distal end remains fixed relative to the occlusion. Then, the tunneling catheter (1420) can be introduced through the straight support catheter (1700) until the tunneling probe (1424) is adjacent to the calcified tissue (1410). Accordingly, the straight support catheter (1700) can serve as a "base of operations" that remains fixed in place throughout the entire tunneling process, including during the use of the tunneling probe (1424) and during the replacement between the tunneling catheter (1420), guidewire (1426), and tool catheter (if used), in order to protect the wall (1402) of the blood vessel. After a suitable channel (1416) is formed within the calcified plaque (1410) of the occlusion (1412), the tunneling catheter (1420) can be withdrawn from the straight support catheter (1700) so that the expansion of the occlusion can be performed by a separate expansion balloon. Although the straight support catheter (1700) does not provide the centering function of the support catheter (1300), it is simpler to operate and generates fewer steps in the workflow. Therefore, the straight support catheter (1700) is suitable for use within smaller blood vessels or when additional centering of the tunneling probe is not required.

[0081] Now, referring to FIG. 18, another support catheter according to another embodiment for use in connection with a lithotripsy tunneling catheter (1420) is illustrated. The curved support catheter (1800) includes a catheter shaft (1802) forming an internal lumen (1814) as described above, but does not include a positioning balloon. The curved support catheter (1800) further includes a curved guide tip (1817) on its distal end (1816), similar to the guide tip (1517) of the alternative support catheter (1500). The curved support catheter (1800) does not include the centering function provided by the centering balloon (1515) of the alternative support catheter, but can be used to orient the tunneling catheter (1420) having the tunneling probe (1424) to a desired position at a desired angle, substantially the same as described for the alternative support catheter (1500). Thus, the curved support catheter (1800) can serve as a "base of operations" that remains fixed in place throughout the entire tunneling process, including during the use of the tunneling probe (1424) and during the replacement between the tunneling catheter (1420), the guidewire (1426), and the tool catheter (if used), in order to protect the wall (1402) of the blood vessel. After a suitable channel (1416) is formed within the calcified plaque (1410) of the occluded portion (1412), the tunneling catheter (1420) can be withdrawn from the curved support catheter (1800) so that the expansion of the occluded portion can be performed by a separate expansion balloon. The curved support catheter (1800) does not provide the centering function of the support catheter (1300), but it is simpler to operate and generates fewer steps in the workflow.

[0082] Now, referring to FIG. 19, a method of using a lithotripsy device to tunnel a vascular occlusion formed by calcified tissue is illustrated. The method (1900) includes the step of providing a lithotripsy tunneling catheter (1420) and a support catheter (1300) as described above. Block 1902 is the step of introducing a guidewire (1426) into a fluid-filled vascular system and guiding the guidewire into a blood vessel (1400) having a calcified tissue occlusion (1410, 1412). Block 1904 is the step of introducing the support catheter (1300) over the guidewire (1426) into the vascular system (1400) to the location of the calcified tissue occlusion (1410, 1412). Block 1906 is a step of inflating a positioning balloon (1315) on a support catheter (1300) within a blood vessel (1400). Block 1908 is a step of fixing the support catheter (1300) at the introduction position to minimize axial movement of the support catheter within the blood vessel (1400). Block 1910 is a step of withdrawing a guide wire (1426) from the lumen (1314) of the support catheter (1300). Block 1912 is a step of introducing a tunneling catheter (1420) through the support catheter (1300) to the location of a calcified tissue occlusion (1412) and positioning a tunneling probe (1424) within a blood vessel (1400) adjacent to the calcified tissue (1410). Block 1914 is a step of generating an electric discharge between electrodes (e.g., 706, 708) on a tunneling probe (1424) to generate a hydraulic shock wave within the fluid of the blood vessel (1400). Block 1916 is a step of directing the shock wave generated by the electric discharge through the fluid within the blood vessel (1400) into the calcified tissue (1410) of the occluded portion (1412) to break the calcified tissue (1414).Block 1918 is a step of channeling through a deformed plaque (1414) with reduced mechanical force to create a channel that passes through the calcified tissue (1410) of the occlusion (1412) along the desired line (1416).

[0083] The method (1900) may be modified in the order and details of the steps according to the prior disclosure. For example, the step (1916) of crushing the calcified tissue (1410) into the deformed plaque, and the step (1918) of channeling through the deformed plaque (1414) with reduced force to create a channel through the calcified tissue may be repeated as needed. Additionally, the method (1900) may have steps according to the prior disclosure added or deleted. For example, in some embodiments, after the step (1916) of crushing the calcified tissue (1410) into the deformed plaque (1414), a new step may follow in which a tunneling catheter (1420) is withdrawn from the support catheter (1300) and a guide wire (1426) is inserted to perform the step (1918) of channeling through the deformed plaque. Many different methods of using a lithotripsy device to tunnel a vascular occlusion formed by calcified tissue are disclosed through a review of the previously disclosed content.

[0084] Now, referring to FIGS. 20 through 22, a lithotripsy catheter having a sealed chamber "drum" type tunneling probe according to another embodiment is illustrated. Unless otherwise described, this embodiment operates in a manner similar to the embodiment described above in relation to FIGS. 9 and FIGS. 10. The tunneling lithotripsy catheter (2000) comprises a multiluminal catheter shaft (2002) and a tunneling probe (or "end effector") (2004) fixed on the distal end of the catheter shaft.

[0085] As best illustrated in FIGS. 21 and 22, a multiluminal catheter shaft (2002) forms one or more electrode lumens (2006) and one or more fluid lumens (2008) that extend through from its proximal end to its distal end. An electrode (2010) extends from the distal end of the catheter shaft (2002) and can be electrically connected to an external power supply (not shown) via an electric lead (not shown) extending through the electrode lumen (2006). In the illustrated embodiment, two electrodes (2010), two electrode lumens (2006), and two fluid lumens (2008) are provided, but in other embodiments, the catheter shaft (2002) may provide a different number of electrode lumens and / or fluid lumens. In the illustrated embodiment, the first fluid lumen (2008') may be a supply fluid lumen, and the second fluid lumen (2008") may be a discharge fluid lumen. The fluid lumen (2008) may be fluid-fluidly connected to an external fluid pump system (not illustrated) to circulate a fluid, such as physiological saline, through the resonating chamber of the end effector (2004). The multi-lumen catheter shaft (2002) may be manufactured from Pebax® (Arkema trademark) brand thermoplastic elastomer, other thermoplastic elastomers, or other polymers or materials used in conventional catheter shafts. The supply and discharge fluid lumens (2008', 2008") are connected through the catheter lumen to maintain the circulation pump pressure at a manageable level and to prevent excessive static pressure within the resonating chamber (2014) that could cause rupture of the flexible membrane (2024). It must have a selected diameter to provide a manageable pressure drop to the circulating working fluid. Other variables may require optimization equations.The lumen (2008) must be large enough to reduce the pump pressure for an optimal fluid flow rate to cool the electrode (2010) and discharge bubbles from the resonance chamber (2014). If the lumen (2008) is too large, more bubbles may be introduced. Therefore, the fluid lumen (2008) must have a selected diameter to provide a manageable pressure drop, facilitate active cooling of the electrode (2010), and discharge bubbles generated by electrical discharge and subsequent cavitation. In the illustrated embodiment, the supply and discharge fluid lumens (2008', 2008") each have an individual diameter of about 0.5 mm. D FS and D FD has.

[0086] The tunneling probe (2004) of the lithotripsy catheter assembly (2000) further comprises a rigid outer shell or "can" (2012) that forms a resonance chamber (2014) and an ejection hole (2016) inside. The ejection hole (2016) is generally opened distally along the central (longitudinal) axis of the catheter shaft. In the illustrated embodiment, the can (2012) comprises a rigid tube portion (2018) and a rigid annular retainer ring (2020) fixed perpendicularly to the distal end of the tube portion. The central opening of the retainer ring (2020) forms the ejection hole (2016). In the illustrated embodiment, the tube portion (2018) may be formed of a stainless steel tube, such as a hypo tube, and the retainer ring (2020) may be made of a stainless steel ring, such as a washer. In other embodiments, the tube portion (2018) and / or the retainer ring (2020) may be formed from other rigid materials. In the illustrated embodiment, the first joint (2022) between the retainer ring (2020) and the tube portion (2018) is formed using laser welding, but in other embodiments, the first joint may be formed using other forms of welding, adhesive, or other known joining or bonding methods. In yet another embodiment, the retainer ring (2020) may be formed integrally from the tube portion (2018) by spin forming a portion of the sidewall (of the tube portion) from an axial orientation to a radial orientation (with respect to the central axis).

[0087] Referring further to FIGS. 20 through 22, a flexible membrane (2024) is attached to a can (2012) to cover an emission hole (2016). The membrane (2024) must be elastic to provide good transmission of pressure pulses generated in the resonance chamber (2014), but at the same time must be strong enough to resist rupture. Generally speaking, the softer the material of the flexible membrane (2024), the better the transmission of pressure pulses from the resonance chamber (2014) to an external medium having target tissue. In some embodiments, the membrane (2024) is formed of an elastomer material having a hardness (durometer) in the range of 50 Shore A to 35 Shore D. In some preferred embodiments, the membrane (2024) is formed of an elastomer material having a hardness in the range of 80 Shore A to 90 Shore A. In some embodiments, the elastomer material of the membrane (2024) is a polyurethane material, but in other embodiments, other elastomer or polymer materials may be used. In another embodiment, if the membrane (2024) provides sufficient axial flexibility to transmit acoustic pressure waves, the membrane may be made of a thin metal diaphragm or other non-polymer material.

[0088] As best illustrated in FIG. 22, in the illustrated embodiment, the membrane (2024) is preferably attached to the proximal side of the retainer ring (2020) by a second joint (2026) that is fluid-sealing and mechanically rigid. In this illustrated embodiment, the second joint (2026) is formed using thermal bonding, but in other embodiments, the second joint may be made using an adhesive or other known bonding or joining method. The distal end of the catheter shaft (2002) is inserted into the proximal end of the tube portion (2018), and a third joint (2028) is formed between them to secure the can (2012) in place on the catheter shaft. This third joint (2028) is generally formed after the flexible membrane (2024) is secured to the can (2012) by the second joint (2026). In the illustrated embodiment, the third joint (2028) is a thermal joint or an adhesive joint, but in other embodiments, the third joint may be formed using welding or other known joining or bonding methods. The third joint (2028) must be sufficient to provide a fluid seal and mechanical bond between the catheter shaft (2002) and the can (2012), but does not need to extend along the entire longitudinal interface between the shaft (2002) and the can (2012).

[0089] When a flexible membrane (2024) is fixed to a can (2012) and the can is fixed over a multi-lumen shaft (2002), a resonance chamber (2014) is formed between the distal end of the shaft, the wall of the can, and the membrane. The can (2012) also forms an emission hole (2016) covered by the flexible membrane (2024) to seal the resonance chamber from the external environment.

[0090] During operation, the resonance chamber (2014) is filled with a working fluid (e.g., physiological saline or a physiological saline-contrast agent mixture) circulating through multiple lumen shafts (2002) to discharge bubbles and cool the end effector components. Energy transferred by a generator to the exposed end of an electric lead (i.e., electrode (2010)) creates an electric discharge through the working fluid and generates subsequent fluid cavitation within the working fluid. A hydraulic shock wave is formed from this cavitation and travels through the working fluid within the resonance chamber, is focused axially forward (i.e. distally) into the external medium through a flexible membrane (2024) (having a relatively low acoustic impedance) by a relatively rigid tube portion (2018) (having a relatively high acoustic impedance), and subsequently propagates from the external medium to the target calcified tissue. Repeated exposure of calcified tissue to hydraulic shock waves generates deformed plaques that are more easily displaced than the original calcified tissue.

[0091] The current design parameters for the lithotripsy catheter (2000) at this point in time are as follows: the inner diameter of the resonance chamber (2014). D RC It is influenced by the size of the expected body structure that must be passed through to access the treatment site. For some peripheral vascular applications and / or coronary vascular applications, an overall diameter (outer diameter) of 2.5 mm or less of the catheter (2000) is preferred. Accordingly, in some embodiments, the inner diameter of the resonance chamber (2014) D RC has a value within the range of 1.00 mm to 2.00 mm. In some preferred embodiments D RC It has a value within the range of 1.50 mm to 1.70 mm. Inner diameter in some currently preferred embodiments. D RC It has a value of approximately 1.60 mm. For other applications, the allowable outer diameter of the catheter (2000) may be larger, and thus the inner diameter D RC It can be proportionally larger.

[0092] Diameter of the discharge hole (2016) D EA It must be as large as possible to reduce the attenuation of the hydrostatic pulse (i.e., acoustic pressure wave) when the hydrostatic pulse is transmitted through the flexible membrane (2024). Therefore, ideally, the ratio of the emission hole diameter to the resonance chamber diameter should approach 1.0 (i.e., D EA / D RC -> a value of 1.0). However, since there must be a sufficient area on the exposed proximal side of the retainer ring (2020) to accommodate the second joint (2026) that holds the membrane (2024) during use, this design D EA / D RC The value must be less than 1.0. Inner diameter within the range of 1.0 mm to 2.0 mm. D RC In the case of an embodiment of a catheter (2000) having, the ratio D EA / D RC It can have a value within the range of 0.4 to 0.8. Inner diameter within the range of 1.0mm to 2.0mm. D RC In the case of some preferred embodiments of the catheter (2000) having, the ratio D EA / D RC It can have a value within the range of 0.5 to 0.6. Chamber diameter of approximately 1.6 mm. D RC In some currently preferred embodiments having, D EA It is about 0.9mm.

[0093] The flexible membrane (2024) of the catheter (2000) must be as thin as possible (i.e., axially) to reduce the attenuation of hydraulic pulses / acoustic pressure waves transmitted through the membrane. Nevertheless, the membrane (2024) must be thick enough to resist damage during use. Inner diameter within the range of 1.0 mm to 2.0 mm D RC In the case of an embodiment of a catheter (2000) having, the thickness of the membrane (2024) T M It can have a value within the range of 0.050 mm to 0.254 mm. Inner diameter within the range of 1.0 mm to 2.0 mm. D RC In the case of some preferred embodiments of the catheter (2000) having, thickness T M It can have a value within the range of 0.127 mm to 0.152 mm.

[0094] Length of the resonance chamber (2014) L RC must be selected based on multiple factors. First, length L RC As the value of increases, there exists a longer distance over which the relatively violent / sharp pressure wave generated at the electrode (2010) is attenuated or dampened before reaching the relatively fragile flexible membrane (2024). Therefore, of a larger value L RC ) extends the lifespan (i.e., reliability) of the flexible member (2024). However, the length L RC If the value of is too large, it may cause excessive attenuation / decrease of the acoustic pressure wave before the acoustic pressure wave reaches the flexible member (2024), resulting in reduced efficiency and / or effect of the acoustic wave transmitted to the target calcified tissue by the catheter (2000). Inner diameter within the range of 1.0 mm to 2.0 mm D RC In the case of an embodiment of a catheter (2000) having, a resonance chamber length having a value within the range of 1.0 mm to 6.0 mm L RC Acceptable membrane life (or reliability) and acoustic efficiency can be achieved. Inner diameter within the range of 2.0 mm to 4.0 mm D RC In the case of some preferred embodiments of the catheter (2000) having, the resonance chamber length L RC has a value within the range of 2.0 mm to 4.0 mm. In the illustrated embodiment, the length L RC For ease of measurement, it is measured axially (i.e., longitudinally) from the distal surface of the catheter shaft (2002) to the distal surface of the membrane (2024). In another embodiment, the length L RC It is measured axially from the distal surface of the catheter shaft (2002) to the proximal surface of the membrane (2024). The thickness of the membrane (2024). T M this L RC When it is smaller compared to, the selection of the measurement surface has a reduced effect.

[0095] Now, referring to FIGS. 23 through 25, a lithotripsy catheter having a sealed chamber "drum" type tunneling probe according to another embodiment is illustrated. Unless otherwise described, this embodiment operates in a manner similar to the embodiment previously described in relation to FIGS. 20 through 22. Components of the description and drawings identified by the same reference numerals are identical or functionally equivalent to those previously described. The tunneling lithotripsy catheter (2300) comprises a multiluminal catheter shaft (2002) and a tunneling probe / end effector (2304) fixed on the distal end of the catheter shaft. The end effector (2304) of this embodiment has a different structure for fixing a flexible membrane (2024).

[0096] As best illustrated in FIGS. 24 and 25, the components of this embodiment, including the multiluminal catheter shaft (2002), electrode lumen (2006), fluid lumen (2008), and electrode (2010), are substantially similar to those previously described. The function and operation of the catheter shaft (2002) for generating electrically induced pressure waves are also similar. The tunneling probe (2304) comprises a rigid outer shell or "can" (2312) that forms a resonance chamber (2014) inside and an ejection hole (2016) that is open distally along the central axis of the catheter shaft. The can (2312) comprises a rigid annular outer retainer ring (2318) that is centered on the proximal face of a rigid annular face ring (2320) and secured by a first joint (2322). The face ring (2320) is fixed vertically to the distal end of the rigid outer tube portion (2324) using the second joint (2326). The rigid annular inner retainer ring (2328) is fixed vertically to the distal end of the rigid inner tube portion (2330) using the third joint (2332). The inner tube portion (2330) has an outer diameter smaller than the inner diameter of the outer tube portion (2324) so ​​that the distal end of the inner tube portion can be inserted into the proximal end of the outer tube portion. In some embodiments, the inner diameter of the outer tube portion (2324) is 1.9 mm and the inner diameter of the inner tube portion (2330) is 1.6 mm, but in other embodiments, other sizes may be used. In the illustrated embodiment, the first, second, and third joints (2322, 2326, and 2332) are formed using laser welding, but in other embodiments, these joints may be formed using other forms of welding, adhesive, or other known joining or bonding methods.

[0097] The tunneling probe (2304) also includes a flexible membrane (2024) that is captured between the proximal surface of the outer retainer ring (2318) and the distal surface of the inner retainer ring (2328) when the inner tube portion (2330) is inserted into the outer tube portion (2324) and secured together using a fourth joint (2334). In the illustrated embodiment, the fourth joint (2334) is formed using laser welding, but in other embodiments, this joint may be formed using other forms of welding, adhesive, or other known joining or bonding methods. The fourth joint (2334) must be sufficient to provide a fluid seal and mechanical bond between the inner and outer tube portions (2330 and 2324), but does not need to extend along the entire longitudinal interface between the tube portions.

[0098] In some embodiments, the inner tube portion (2330) is biased longitudinally toward the outer tube portion (2324) until the flexible membrane (2024) is compressed between the inner retainer ring (2328) and the outer retainer ring (2318) when the fourth joint (2334) is formed. This creates a permanent mechanical bias that compresses the edges of the membrane (2024) to hold it in place. In some embodiments, the flexible membrane (2024) is joined to the outer retainer ring (2318) using the fifth joint (2336) and / or joined to the inner retainer ring (2328) using the sixth joint (2338). In the illustrated embodiment, the fifth and sixth joints (2336 and 2338) are formed using adhesive bonding, but in other embodiments, these joints may be formed using welding, thermal bonding, or other known bonding or joining methods. In some embodiments, both mechanical biasing and bonding are used to secure the flexible membrane to the can (2312), but in other embodiments, only one of the aforementioned fixing types is used.

[0099] The distal end of the catheter shaft (2002) is positioned at the proximal end of the inner tube portion (2330), and a seventh joint (2340) is formed between them to secure the tunneling probe (2304) in place on the catheter shaft. In the illustrated embodiment, the seventh joint (2340) is a thermal or adhesive joint, but in other embodiments, the seventh joint may be formed using welding or other known joining or bonding methods. The seventh joint (2340) must be sufficient to provide a fluid seal and mechanical connection between the catheter shaft (2002) and the can (2312), but does not need to extend along the entire longitudinal interface between the shaft and the can.

[0100] The various rigid and flexible components described herein in relation to the tunneling catheter (2300) may be formed from the same material and using the same parameters as described for the tunneling catheter (2000). Although the joints (2322, 2326, 2332, 2334, 2336, 2338, and 2340) have been designated as “first” through “seventh” joints for convenience, such designation does not imply any limitation on the assembly order of the tunneling catheter (2300), and those skilled in the art will understand that various assembly orders are expected. The method of operation of the catheter (2300) to create a deformed plaque that is more easily displaced than the original calcified tissue is similar to the method of operation of the tunneling catheters described above in this specification.

[0101] Referring now to FIG. 26, a lithotripsy catheter having a sealed chamber "drum" type tunneling probe according to another embodiment is illustrated. The embodiment of FIG. 26 is similar to the embodiment illustrated in FIG. 23 through 25, but uses a modified end effector. Unless otherwise stated, this embodiment operates in a manner similar to the embodiment described in relation to FIG. 23 through 25, and the components of the description and drawings identified by the same reference numerals are identical or functionally equivalent to those previously described. The tunneling lithotripsy catheter (2600) comprises a multiluminal catheter shaft (2002) and a tunneling probe / end effector (2604) fixed on the distal end of the catheter shaft. The end effector (2604) of this embodiment has a different structure for securing a flexible membrane (2024), which includes fewer components and fewer joints than the previous embodiment.

[0102] The multiluminal catheter shaft (2002) of this tunneling catheter (2600) is substantially similar to those described above. The tunneling probe (2604) includes a rigid outer shell or "can" (2612) that forms a resonance chamber (2014) inside and an ejection hole (2016) that is open distally along the central axis of the catheter shaft. The can (2612) includes a rigid annular face ring (2320), an outer tube portion (2324), and an inner tube portion (2330) as in the previous embodiment, but does not require a separate inner or outer retainer ring. The face ring (2320) is fixed perpendicularly to the distal end of the outer tube portion (2324) using a first joint (2626). In the illustrated embodiment, the first joint (2626) is formed using laser welding, but in other embodiments, this joint may be formed using other forms of welding, adhesive, or other known joining or bonding methods. As in the previous embodiment, the inner tube portion (2330) has an outer diameter smaller than the inner diameter of the outer tube portion (2324) so ​​that the distal end of the inner tube portion can be inserted into the proximal end of the outer tube portion.

[0103] The tunneling probe (2604) also includes a flexible membrane (2024) that is captured between the proximal face of the face ring (2320) and the distal face of the inner tube portion (2330) when the inner tube portion is inserted into the outer tube portion (2324) and secured together using a second joint (2640). In the illustrated embodiment, the second joint (2640) is formed using laser welding, but in other embodiments, this joint may be formed using other forms of welding, adhesive, or other known joining or bonding methods. The second joint (2640) must be sufficient to provide a fluid seal and mechanical bond between the inner and outer tube portions (2330 and 2324), but does not need to extend along the entire longitudinal interface between the tube portions.

[0104] In some embodiments, the inner tube portion (2330) is biased longitudinally toward the outer tube portion (2324) until the flexible membrane (2024) is compressed between the inner tube portion and the face ring (2320) when the second joint (2640) is formed. This creates a permanent mechanical bias that compresses the edges of the membrane (2024) to hold it in place. In some embodiments, the flexible membrane (2024) is joined to the inner tube portion (2330) using a third joint (2640) and / or joined to the face ring (2320) using a fourth joint (2644). In the illustrated embodiments, the third and fourth joints (2640 and 2644) are formed using laser welding, but in other embodiments, these joints may be formed using other types of welding, thermal bonding, adhesives, or other known bonding or joining methods. In some embodiments, both mechanical biasing and bonding are used to secure the flexible membrane to the can (2612), but in other embodiments, only one of the aforementioned fixing types is used.

[0105] The distal end of the catheter shaft (2002) is positioned at the proximal end of the inner tube portion (2330), and a fifth joint (2646) is formed between them to secure the tunneling probe (2604) in place on the catheter shaft. In the illustrated embodiment, the fifth joint (2646) is a thermal or adhesive joint, but in other embodiments, the fifth joint may be formed using welding or other known joining or bonding methods. The fifth joint (2646) must be sufficient to provide a fluid seal and mechanical connection between the catheter shaft (2002) and the can (2612), but does not need to extend along the entire longitudinal interface between the shaft and the can.

[0106] The various rigid and flexible components described herein in relation to the tunneling catheter (2600) may be formed from the same materials and using the same parameters as those described for the tunneling catheters (2000 and 2300). Although the joints (2626, 2640, 2642 and 2644) have been designated as “first” through “fourth” joints for convenience, such designation does not imply any limitation on the assembly order of the tunneling catheter (2600), and those skilled in the art will understand that various assembly orders are expected. The method of operation of the catheter (2600) to create a deformed plaque that is more easily displaced than the original calcified tissue is similar to the method of operation of the tunneling catheters described above in this specification.

[0107] Now, referring to FIG. 27, a prototype tunneling catheter (2600) according to the embodiment of FIG. 26 is illustrated.

[0108] Now, referring to FIGS. 28 through 31, a lithotripsy catheter having a sealed chamber "sock" type tunneling probe according to another embodiment is illustrated. FIG. 28 illustrates a prototype tunneling catheter (2900) according to the present embodiment. As further described below, instead of using a flat disk-shaped flexible membrane in the tunneling probe, the tunneling catheter (2900) uses an elongated tubular closed-end flexible membrane resembling a sock (see FIG. 31).

[0109] The lithotripsy catheter (2900) comprises a multiluminal catheter shaft (2002) and a tunneling probe / end effector (2904). The components of this embodiment, including the multiluminal catheter shaft (2002), electrode lumen (2006), fluid lumen (2008), and electrode (2010), are substantially similar to those described above. The function and operation of the catheter shaft (2002) for generating an electrically induced pressure wave are also similar. The tunneling probe (2904) is fixed to the distal end of the catheter shaft (2002) and comprises a rigid can (2912) that accommodates a sock-type flexible membrane (2906) (i.e., "sock").

[0110] Now, referring specifically to FIG. 31, a cross-sectional view of a sock membrane (2906) is shown. The sock (2906) comprises a tubular sidewall (2907) extending from an open proximal end portion (2908) (i.e., "cuff") to a closed distal end portion (2910) (i.e., "toe") along a substantially constant diameter portion (2909) (i.e., "ankle"). In some embodiments, the toe portion (2910) comprises a flat portion (2911) oriented perpendicular to the longitudinal axis of the sock. In some embodiments, the sidewall (2007) of the sock (2009) has a substantially constant wall thickness (in FIG. 32 T M It has (designated as ). For efficient pressure pulse delivery from the resonance chamber (2014) to an external medium having a target calcification, the sock membrane (2906) must be very flexible and / or very thin. In some embodiments, the sock membrane (2906) is formed from an elastomer material having a hardness (durometer) in the range of 50 Shore A to 35 Shore D. In some preferred embodiments, the sock membrane (2906) is formed from an elastomer material having a hardness in the range of 80 Shore A to 90 Shore A. In some embodiments, the elastomer material of the sock membrane (2906) is a polyurethane material, but in other embodiments, other elastomer or polymer materials may be used. In some embodiments, the sock membrane (2906) may be formed by dipping a mandrel into a liquid polymer material and then allowing it to dry / cure. One immersion or multiple immersions may be used to achieve the required thickness. In some embodiments, the sock membrane (2906) may be formed by blow-molding a polymer material. Other methods that may be used in other embodiments to manufacture the sock membrane (2906) include dip casting / molding, injection molding, blow molding, extrusion, and thermal tip forming.

[0111] Now, referring specifically to FIG. 32, a sock membrane (2906) is placed over the distal end of a multiluminal shaft (2002) to form a predetermined first distance (indicated as A in FIG. 32) between the tip of the electrode (2010) and the distal surface of the toe portion (2910). A rigid can (2912) is placed over the distal end of the sock membrane (2906) to form a predetermined second distance (indicated as B in FIG. 32) between the distal surface of the toe portion (2910) and the distal end of the can.

[0112] Now, referring to FIG. 33, the sock membrane (2906) can be joined to the catheter shaft (2002) by a first joint (2916) at the proximal end "cuff" portion (2908), while leaving the central "ankle" portion (2909) of the sock membrane unjoined to both the catheter shaft and the rigid can (2912). Thus, an annular inner gap (2918) (i.e., between the sock sidewall (2907) and the catheter shaft (2002)) and an annular outer gap (2920) (i.e., between the sock sidewall and the rigid can (2912)) extend longitudinally from the distal "toe" end (2910) of the sock membrane (2906) to the proximal "cuff" end (2908). Accordingly, the entire unbonded portion of the sock sidewall (2907) along the ankle portion (2909) is maintained in a radially restricted state by a rigid can (2912) to prevent sidewall blowout, while freely extending longitudinally in response to vibrations induced by pressure waves within the resonance chamber (2014). The unbonded length of the sock membrane (2906) from the toe portion (2910) to the first bonded portion (2916) is the length of the resonance chamber (2014). L RC Because it is substantially larger, the strain per unit length in the unjoined sidewall (2907) caused by vibration (i.e., elongation) of the distal toe end will be substantially smaller than when the same elongation occurs only in the sidewall in contact with the resonance chamber. This "damping" of the strain (and associated stress) in the sock sidewall (2907) improves the reliability of the tunneling probe (2904).

[0113] The distal end of the catheter shaft (2002) is disposed within a can (2912), and optionally, a second joint (2922) may be formed between them to secure the can (i.e., outer skin) of the tunneling probe (2904) to the catheter shaft. The second joint (2922) (if present) may be formed anywhere along the shaft (2002) including a hub (not shown) at the proximal end. In the illustrated embodiment, the second joint (2922) is a thermal joint or an adhesive joint, but in other embodiments, the second joint may be formed using welding or other known joining or bonding methods. If present, the second joint (2922) must be sufficient to provide a mechanical connection between the catheter shaft (2002) and the can (2912), but since the fluid seal for the catheter shaft (2002) is provided by the first joint (2916), a fluid-tight seal is not required. In some embodiments, part or all of the can (2912) placed near the resonance chamber may be laser-cut to provide flexibility for better trackability while still providing hoop strength to radially reinforce the sock membrane (2906) and the catheter shaft against internal pressure.

[0114] It is well known that introducing air into the bloodstream can be dangerous to the patient. Therefore, in catheters and other devices having an annular space between an inner member and an outer member, it is common practice to flush the annular space with fluid before use to remove any trapped air. In a lithotripsy catheter (2900), the annular outer gap (2920) between the sock sidewall (2907) and the can (2912) enables flushing the annular space between the sock (2906) and the outer metal tube (2912) and between the outer metal tube and the shaft (2002) to remove any air before use. In an embodiment having a second joint (2922) between the outer metal tube (2912) and the shaft (2002), one or more ports (2924) may be provided into the annular gap through the outer metal tube to facilitate air removal during flushing.

[0115] Now, referring to FIGS. 34 and 35, a lithotripsy catheter having a sealed chamber "sock" type tunneling probe according to another embodiment is illustrated. In this embodiment, the lithotripsy catheter (3400) has an alternative single lumen catheter shaft (3402) and a tunneling probe (3404) similar to that described in relation to previous embodiments. This configuration makes it possible for the lithotripsy catheter (3400) to use an external high-frequency hydraulic pulsatile pressure wave generator to generate the pressure wave used to create deformed plaque.

[0116] A single lumen catheter shaft (3402) contains a single fluid lumen (3408) and does not require any electrode lumen. The fluid lumen (3408) can be operably connected to an external high-frequency hydrostatic pulsating pressure wave generator (not shown), for example, a Pulse IVI™ system manufactured by AVS Pulse, Inc., driven by carbon dioxide. The output of the pressure wave generator is connected to the proximal end of the catheter shaft (3402) using a standard port or other connection hardware. The pressure wave generated by the pressure wave generator is transmitted along the fluid lumen (3408) by an operating fluid, for example saline, to a tunneling probe (3404) placed at the distal end of the catheter shaft.

[0117] The tunneling probe (3404) comprises a rigid can (3412) (i.e., outer skin) and a sock-type flexible membrane (3410) having a tubular sidewall (2907) extending from an open proximal end portion (2908) ("cuff"), similar to the previously described sock membrane (2906), to a closed distal end portion ("toe") (2910) along a substantially constant diameter portion (2909). The sock membrane (3410) is positioned over the distal portion of the catheter shaft (3402) to form a pulsate chamber (3414) by forming a predetermined first distance (indicated as A in FIG. 34) between the distal end of the catheter shaft and the distal surface of the toe (2910). With the central "ankle" portion (2909) of the sock membrane left unattached to the catheter shaft, the sock membrane (3410) is secured to the catheter shaft (3402) by a first attachment (3418) at the proximal end "cuff" portion (2908). A rigid can (3412) is positioned over the distal end of the sock membrane (3410) to form a predetermined second distance (indicated as B in FIG. 34) between the distal surface of the toe portion (2910) and the distal end (3420) of the can. By doing so, the pulsation chamber (3414) is retracted from the distal end (3420) of the can (3412) to protect the flexible membrane (3410) from contact with calcified tissue during operation.

[0118] An annular inner gap (2918) (i.e., between the sock sidewall (2907) and the catheter shaft (3402)) and an annular outer gap (2920) (i.e., between the sock sidewall and the rigid can (3412)) are extended longitudinally from the distal "toe" end (2910) of the sock membrane (3410) to the proximal "cuff" end (2908). Thus, the entire unjoined portion of the sock sidewall (2907) along the ankle portion (2909) is freely extended longitudinally in response to vibrations induced by pressure waves within the pulsation chamber (3414). Optionally, a second joint (3422) may be provided to secure the can (i.e., outer shell) of the tunneling probe (3404) to the catheter shaft (3402). A second joint (3422) (if present) may be formed anywhere along the shaft including a hub (not shown) at the proximal end. In the illustrated embodiment, the second joint (3422) is a thermal joint or an adhesive joint, but in other embodiments, the second joint may be formed using welding or other known joining or bonding methods. If present, the second joint (3422) must be sufficient to provide a mechanical connection between the catheter shaft (3402) and the can (3412), but a fluid seal is not required because the fluid seal for the catheter shaft is provided by the first joint (3418). In some embodiments, part or all of the can (3412) may be laser-cut to provide flexibility for better trackability while still providing hoop strength to radially reinforce the sock membrane (2906) and the catheter shaft against internal pressure. In an embodiment having a second joint (3422) between the outer metal tube (3412) and the shaft (3402), one or more ports (2924) may be provided into the annular gap through the outer metal tube to facilitate air removal during flushing.

[0119] During the operation of the tunneling catheter (3400), a hydraulic shock wave from an external pulsating pressure wave generator travels along the catheter shaft (3402) to the pulsating chamber (3414), is focused axially forward through the flexible membrane (3410) of the tunneling probe, and then propagates to the calcified tissue. Repeated exposure of the calcified tissue to the hydraulic shock wave creates a deformed plaque that is more easily displaced than the original calcified tissue. Additional embodiments are considered within the scope of the invention, for example, tunneling catheters (900, 2000, 2300, 2600, and 2900) may be adapted to use an external pulsating pressure wave generator by replacing each of the multiple lumen catheter shafts in each described embodiment with a single lumen catheter shaft.

[0120] Although preferred embodiments have been described in detail, it should be understood that various changes, substitutions, and modifications may be made without departing from the spirit and scope of the invention as defined by the appended claims.

Claims

Claim 1 A lithotripsy device for tunneling a vascular occlusion of calcified tissue within a fluid environment of a blood vessel, wherein the lithotripsy device comprises: a tunneling catheter, The tunneling catheter above is: A tunneling catheter shaft having a distal end and a proximal end; A tunneling probe having a pair of electrodes disposed on the distal end of the tunneling catheter shaft. Includes, Each electrode is operably connected to an electric lead within the tunneling catheter shaft; A lithotripsy device characterized in that the lead is configured to be operably connected to an external pulse generator; activation of the external pulse generator operably connected to the lead causes repeated electrical discharges between the electrodes; when the electrodes are in a fluid, the repeated electrical discharges generate repeated hydraulic shock waves directed away from the electrical discharges within the fluid; and when the repeated hydraulic shock waves strike calcified tissue, the calcified tissue is fragmented into deformed plaques; and the deformed plaques have lower resistance to mechanical displacement than the original calcified tissue. Claim 2 A lithotripsy device according to claim 1, wherein the tunneling probe is configured to have a raised rim on the distal end; and the electrodes are inset within the raised rim. Claim 3 A lithotripsy device according to paragraph 2, characterized in that the electrodes are arranged concentrically within the raised rim. Claim 4 A lithotripsy device according to paragraph 2, characterized in that the electrodes are arranged in an opposing arched arrangement within the raised rim. Claim 5 A lithotripsy device according to claim 1, wherein the tunneling probe is configured to have a tapering conical face on the distal end; and the electrodes are configured in a spaced-apart arrangement on the tapering conical face. Claim 6 A lithotripsy device according to claim 5, wherein the tapered conical surface of the tunneling probe ends at a flat face; and the electrodes are exposed on the flat face. Claim 7 A lithotripsy device according to claim 5, wherein the tapered conical surface of the tunneling probe ends at a rounded end; and the electrodes are not exposed on the rounded end. Claim 8 A lithotripsy device according to claim 1, further comprising a guidewire lumen formed through the catheter shaft and having an outlet on the distal end; wherein the tunneling probe is configured to have a flat surface on the distal end; and wherein the electrodes protrude over the flat surface. Claim 9 A lithotripsy device according to claim 8, characterized in that the exit of the guidewire lumen is positioned at the center of the flat surface of the distal end, and the electrodes are arranged in an opposing arched arrangement on the opposing sides of the exit. Claim 10 A lithotripsy device according to claim 8, characterized in that the exit of the guidewire lumen is offset from the center of the flat surface of the distal end, and the electrodes are composed of studs adjacent to each other on one side of the exit. Claim 11 A lithotripsy device according to claim 8, characterized in that the exit of the guidewire lumen is positioned at the center of the flat surface of the distal end, and the electrodes are composed of studs on the opposing sides of the exit. Claim 12 A lithotripsy device according to claim 1, further comprising a positioning balloon operably attached to the tunneling catheter shaft near the distal end; wherein the positioning balloon can be optionally inflated to position the catheter tunneling probe at a desired location within the cross-section of a blood vessel. Claim 13 A lithotripsy device according to claim 1, further comprising a support catheter having a distal end and a proximal end and forming an internal lumen configured to receive the tunneling catheter through the interior; wherein when the support catheter is positioned such that the distal end is located near an occlusion of calcified tissue, the proximal end may be fixed at an introduction position; and when the support catheter is fixed at the introduction position, the tunneling catheter may be selectively inserted and withdrawn through the internal lumen to reach the occlusion of the calcified tissue with the distal end having the tunneling probe. Claim 14 A lithotripsy device according to claim 13, further comprising a positioning balloon operably attached to the support catheter shaft near the distal end; wherein the positioning balloon can be optionally inflated to position the distal end of the support catheter at a desired position within the cross-section of a blood vessel; and wherein, when the tunneling catheter is introduced through the support catheter, the tunneling probe of the tunneling catheter protrudes from the support catheter at the desired position within the cross-section of the blood vessel. Claim 15 A lithotripsy device according to claim 1, further comprising a pulse generator operably connected to the electric lead. Claim 16 A lithotripsy device for tunneling a vascular occlusion of calcified tissue within a fluid environment of a blood vessel, wherein the lithotripsy device comprises: a tunneling catheter, The tunneling catheter above is: A tunneling catheter shaft having a distal end and a proximal end; A tunneling probe positioned on the distal end of the tunneling catheter shaft. Includes, The tunneling probe above is: A pair of electrodes, each electrode operably connected to an electric lead within the tunneling catheter shaft; A raised rim on the distal end, wherein the electrodes are inset within the raised rim; and A flexible diaphragm attached across the raised rim above Including; A lithotripsy device characterized in that the raised rim and the flexible diaphragm form a probe cavity that accommodates the electrodes, and the probe cavity is fluidically isolated from a fluid environment outside the probe cavity; the lead is configured to be operably connected to an external pulse generator; activation of the external pulse generator operably connected to the lead causes repeated electrical discharges between the electrodes; when the probe cavity accommodates a working fluid, the repeated electrical discharges generate repeated primary shock waves that cause the flexible diaphragm to vibrate repeatedly within the working fluid; the repeated vibrations of the flexible diaphragm generate repeated secondary shock waves that propagate into a fluid environment outside the probe cavity; and when the repeated secondary shock waves strike calcified tissue within the fluid environment, the calcified tissue is fragmented into a deformed plaque; and the deformed plaque has lower resistance to mechanical displacement than the original calcified tissue. Claim 17 A lithotripsy device according to claim 16, characterized in that the flexible diaphragm is formed of a metal or a metal alloy. Claim 18 A lithotripsy device according to claim 16, characterized in that the flexible diaphragm is formed of plastic, polymer, elastomer, or other non-metallic material. Claim 19 A lithotripsy device according to claim 16, further comprising a fluid lumen formed within the tunneling catheter shaft and fluidly connecting the probe cavity to a source of fresh working fluid in order to circulate fresh working fluid through the probe cavity during the repeated electrical discharge. Claim 20 A method for using a lithotripsy device for tunneling a vascular occlusion of calcified tissue within a fluid environment of a blood vessel, the method comprises: providing a lithotripsy tunneling catheter and a support catheter; introducing a guidewire into a fluid-filled vascular system and guiding the guidewire into a blood vessel having a calcified tissue occlusion; introducing the support catheter into the vascular system on the guidewire to the location of the calcified tissue occlusion; inflating a positioning balloon on the support catheter within the blood vessel; fixing the support catheter at the introduction position to minimize axial movement of the support catheter within the blood vessel; withdrawing the guidewire from the lumen of the support catheter; introducing the tunneling catheter through the support catheter to the location of the calcified tissue occlusion and positioning a tunneling probe within a blood vessel adjacent to the calcified tissue; and generating an electrical discharge between electrodes on the tunneling probe to generate a hydraulic shock wave within the fluid of the blood vessel. A method characterized by comprising: a step of directing a shock wave generated by the above-mentioned electric discharge into the calcified tissue of the occluded portion through the fluid within the blood vessel to fragment the calcified tissue into a deformed plaque; and a step of channeling the deformed plaque by penetrating it with reduced mechanical force to create a channel passing through the calcified tissue of the occluded portion along a desired line.

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