Intravascular ultrasonic catheter/probe and method for treating intravascular blockage

An ultrasonic apparatus for the treatment of a patient having blood vessels obstructed by deposits of atherosclerotic plaque or blood clots, comprising:

• an ultrasonic energy source;
• an elongated, solid, flexible probe having first and second ends and coupled at the first end to the ultrasonic energy source and having a tip at the second end, the probe length selected so as to provide both longitudinal and transverse motion of the probe tip, the probe tip having a blunt, rounded shape formed to be substantially free of any tendency to perforate a blood vessel and the probe having a degree of flexibility selected to prevent perforation of the blood vessel upon contact with the probe tip;
• and
• a hollow catheter having first and second ends, internally carrying a portion of the probe, the tip of the probe having a diameter less than the internal diameter of the hollow catheter, the second end of the probe adapted to be inserted into the blood vessel to be treated;
• the catheter having an inflatable annular balloon around the outer circumference of the second end of the catheter.

An apparatus for use with an ultrasonic energy source and capable of being advanced in a blood vessel to the site of a blockage due to atherosclerotic plaque or blood clot for the treatment of the blockage, comprising:

• a flexible, elongated metal wire probe having one end adapted to be coupled to the ultrasonic energy source and having a tip at the other end, and the length of the probe being selected so that the probe length is an acoustical length of a whole number multiple of a one-half wavelength of the frequency of the ultrasonic energy source in the material of which the probe is constructed, with the tip of the probe located at an antinode of the probe length, the tip having a blunt, rounded shape formed to be substantially free of any tendency to perforate a blood vessel and the probe having a degree of flexibility selected to prevent perforation of the blood vessel upon contact with the probe tip;
• a hollow catheter comprised of a flexible material having an inside diameter sufficient to internally carry the blunt, rounded tip of the probe, adapted to be inserted into the blood vessel at one end, and having an inflatable cuff at the inserted end that may be inflated to axially center the catheter and probe in the blood vessel;
• and
• means, coupled to the catheter, for introducing fluid into the blood vessel through the catheter.

A method of treating a patient suffering from partial or total blood vessel blockage due to the deposition of fibrous or calcified plaque or a blood clot on the blood vessel interior wall, the method comprising the steps of:

• (a) providing an ultrasonic energy source;
• an elongated, hollow catheter;
• and an elongated, solid, flexible probe carried internally within the catheter;
• (b) providing the probe with a blunt, rounded tip having a diameter less than the internal diameter of the hollow catheter and with a length that results in both longitudinal and transverse motion of the probe tip, the blunt, rounded tip being formed to be substantially free of any tendency to perforate a blood vessel and the probe having a degree of flexibility selected to prevent perforation of the blood vessel upon contact with the probe tip;
• (c) attaching a first end of the catheter and probe to the ultrasonic energy source such that a second end of the probe is coextensive with a second end of the catheter;
• (d) making an incision in the outer skin of the patient down to a blood vessel;
• (e) introducing the catheter carrying the probe into the blood vessel and advancing the catheter and probe to the site of blockage by viewing a real-time x-ray image of the catheter and probe in the blood vessel;
• (f) extending the probe from the end of the catheter and thereby making contact with the fibrous or calcified plaque or blood clot at the site of blockage;
• and
• (g) transmitting ultrasonic energy along the probe so as to vibrate the probe tip at ultrasonic frequencies in the longitudinal and transverse directions, thereby breaking up and pulverizing the blockage.

A method of treating a patient suffering from partial or total blockage of a blood vessel due to the deposition of fibrous or calcified plaque or a blood clot on the blood vessel interior wall, the method comprising the steps of:

• (a) providing an ultrasonic apparatus comprising an ultrasonic energy source;
• an elongated, solid, flexible probe coupled at a first end to the ultrasonic energy source and having a tip at a second end;
• a hollow catheter for internally carrying a portion of the probe such that the catheter is adapted to be coupled at a first end to means for introducing fluid into the catheter and inserted at a second end of the catheter into the blood vessel to be treated, and means to slide the probe within the catheter and to extend the probe from the second end of the catheter into a mass of atherosclerotic plaque or blood clot;
• (b) providing the probe tip with a blunt, rounded shape having a diameter less than the internal diameter of the hollow catheter and formed to be substantially free of any tendency to perforate a blood vessel and the probe having a degree of flexibility selected to prevent perforation of the blood vessel upon contact with the probe tip, and the probe is selected to have a length that results in both longitudinal and transverse motion at the tip;
• (c) inserting the probe within the catheter and attaching the first end of the probe to the ultrasonic energy source such that the second end of the probe is coextensive with the second end of the catheter;
• (d) making an incision in the outer skin of the patient down to a blood vessel and inserting a self-sealing sheath into the blood vessel;
• (e) introducing the catheter carrying the probe through the self-sealing sheath and into the blood vessel, and advancing the catheter and probe to the site of blockage by viewing a real-time x-ray image of the catheter and probe in the blood vessel;
• (f) extending the probe from the end of the catheter so that the probe tip makes contact with the fibrous or calcified plaque or blood clot at the site of arterial blockage;
• and
• (g) transmitting ultrasonic energy along the probe so as to vibrate the probe tip at ultrasonic frequencies in the longitudinal and transverse directions, thereby breaking up and pulverizing the fibrous or calcified plaque or blood clot.

An ultrasonic apparatus for the treatment of a patient having blood vessels obstructed by deposits of atherosclerotic plaque of blood clots, comprising:

• an ultrasonic energy source;
• an elongated, solid, flexible probe having first and second ends and coupled at the first end to the ultrasonic energy source and having a tip at the second end, the probe length selected so as to provide both longitudinal and transverse motion of the probe tip, the probe tip having a blunt, rounded shape formed to be substantially free of any tendency to perforate a blood vessel and the probe having a degree of flexibility selected to prevent perforation of the blood vessel upon contact with the probe tip;
• a hollow catheter for internally carrying a portion of the probe, the catheter having first and second ends;
• and
• means adapted to slide the probe within the catheter and to extend the probe from the second end of the catheter into a mass of atherosclerotic plaque or blood clots, and means to reduce and control the temperature of said tip including means connected to said source for causing said source to supply pulsed ultrasonic energy to said probe.

An ultrasonic apparatus for the treatment of a patient having blood vessels obstructed by deposits of atherosclerotic plaque or blood clots, comprising:

• an ultrasonic energy source;
• an elongated, solid, flexible probe having first and second ends and coupled at the first end to the ultrasonic energy source and having a tip at the second end, the probe length selected so as to provide both longitudinal and transverse motion of the probe tip, the probe tip having a blunt, rounded shape formed to be substantially free of any tendency to perforate a blood vessel and the probe having a degree of flexibility selected to prevent perforation of the blood vessel upon contact with the probe tip;
• and
• a hollow catheter having first and second ends, internally carrying a portion of the probe, the second end of the probe adapted to be inserted into the blood vessel to be treated;
• the catheter having an inflatable annular balloon around the outer circumference of the second end of the catheter, and means to reduce and control the temperature of said tip including means connected to said source for causing said source to supply pulsed ultrasonic energy to said probe.

An ultrasonic apparatus for the treatment of a patient having blood vessels obstructed by deposits of atherosclerotic plaque or blood clots, comprising:

• an ultrasonic energy source constituting means for producing pulsed ultrasonic vibrations;
• a flexible, elongated metal wire probe having one end adapted to be coupled to the ultrasonic energy source and having a tip at the other end, and the length of the probe being selected so that the probe length is an acoustical length of a whole number multiple of a one-half wavelength of the frequency of the ultrasonic energy source in the material of which the probe is constructed, with the tip of the probe located at an antinode of the probe length, the tip having a blunt, rounded shape formed to be substantially free of any tendency to perforate a blood vessel and the probe having a degree of flexibility selected to prevent perforation of the blood vessel upon contact with the probe tip;
• a hollow catheter comprised of a flexible material having an inside diameter sufficient to internally carry the blunt, rounded tip of the probe, adapted to be inserted into the blood vessel at one end, and having an inflatable cuff at the inserted end that may be inflated to axially center the catheter and probe in the blood vessel;
• and
• means, coupled to the catheter, for introducing fluid into the blood vessel through the catheter.

A method of treating a patient suffering from partial or total blood vessel blockage due to the deposition of fibrous or calcified plaque or a blood clot on the blood vessel interior wall, the method comprising the steps of:

• (a) providing an ultrasonic energy source;
• an elongated, hollow catheter;
• and an elongated, solid, flexible probe carried internally within the catheter;
• (b) providing the probe with a blunt, rounded tip having a length that results in both longitudinal and transverse motion of the probe tip, the blunt, rounded tip being formed to be substantially free of any tendency to perforate a blood vessel and the probe having a degree of flexibility selected to prevent perforation of the blood vessel upon contact with the probe tip;
• (c) attaching a first end of the catheter and probe to the ultrasonic energy source such that a second end of the probe is coextensive with a second end of the catheter;
• (d) making an incision in the outer skin of the patient down to a blood vessel;
• (e) angiographically introducing the catheter carrying the probe into the blood vessel and advancing the catheter and probe to the site of blockage by viewing a real-time image of the catheter and probe in the blood vessel;
• (f) extending the probe from the end of the catheter and thereby making contact with the fibrous or calcified plaque or blood clot at the site of blockage;
• and
• (g) transmitting pulsed ultrasonic energy along the probe so as to vibrate the probe tip at ultrasonic frequencies in the longitudinal and transverse directions, thereby breaking up and pulverizing the blockage without overheating the probe tip.

A method of treating a patient suffering from partial or total blockage of a blood vessel due to the deposition of fibrous or calcified plaque or a blood clot on the blood vessel interior wall, the method comprising the steps of:

• (a) providing an ultrasonic apparatus comprising an ultrasonic energy source;
• an elongated, solid, flexible probe coupled at a first end to the ultrasonic energy source and having a tip at a second end;
• a hollow catheter for internally carrying a portion of the probe such that the catheter is adapted to be coupled at a first end to means for introducing fluid into the catheter and inserted at a second end of the catheter into the blood vessel to be treated, and means to slide the probe within the catheter and to extend the probe from the second end of the catheter into a mass of atherosclerotic plaque or blood clot;
• (b) providing the probe tip with a blunt, rounded shape formed to be substantially free of any tendency to perforate a blood vessel and the probe having a degree of flexibility selected to prevent perforation of the blood vessel upon contact with the probe tip, and the probe is selected to have a length that results in both longitudinal and transverse motion at the blunt, rounded tip;
• (c) inserting the probe within the catheter and attaching the first end of the probe to the ultrasonic energy source such that the second end of the probe is coextensive with the second end of the catheter;
• (d) mixing an incision in the outer skin of the patient down to a blood vessel and angiographically inserting a self-sealing sheath into the blood vessel;
• (e) introducing the catheter carrying the probe through the self-sealing sheath and into the blood vessel, and advancing the catheter and probe to the site of blockage by viewing a real-time image of the catheter and probe in the blood vessel;
• (f) extending the probe from the end of the catheter so that the probe tip makes contact with the fibrous or calcified plaque or blood clot at the site of arterial blockage;
• and
• (g) transmitting pulsed ultrasonic energy along the probe so as to vibrate the probe tip at ultrasonic frequencies in the longitudinal and transverse directions, thereby breaking up and pulverizing the fibrous or calcified plaque or blood clot without overheating the probe tip.