Cavitation catheter

An assembly comprising:

• a catheter comprising an outer casing and an elongated body configured for navigation through vasculature of a patient, the elongated body comprising an inner wall that defines a lumen extending from a proximal portion to a distal portion, the elongated body configured to pass a fluid through the lumen and out an ejection port at a distalmost end of the catheter, wherein at the distal portion of the elongated body, the inner wall defines a convergent-divergent region such that a diameter of the lumen while moving distally within the elongated body converges from a first lumen diameter to a second lumen diameter and then diverges from the second lumen diameter to a third lumen diameter, wherein the ejection port at the distalmost end of the catheter has a fourth lumen diameter that is greater than the second lumen diameter, wherein outer casing positioned over the inner wall, and wherein the outer casing does not extend distally beyond a distalmost end of the elongate body;
• and
• a pump assembly connected to the proximal portion of the elongated body of the catheter and configured to pump a fluid at a target flow rate through the lumen of the elongated body and out the ejection port, wherein the convergent-divergent region of the elongated body is configured to cause the fluid flowing through the lumen at the target flow rate to cavitate and produce a pressure shockwave as the fluid flows through the convergent-divergent region, and wherein the catheter is configured such that the pressure shockwave emerges from the ejection port at the distalmost end of the catheter.

A method comprising:

• positioning a distal end of a catheter adjacent to a lesion within a vasculature of a patient, wherein the catheter comprises an elongated body comprising an inner wall that defines a lumen extending from a proximal portion to a distal portion, the elongated body configured to pass a fluid through the lumen and out an ejection port at a distalmost end of the catheter, wherein at the distal portion of the elongated body, the inner wall defines a convergent-divergent region such that a diameter of the lumen while moving distally within the elongated body converges from a first lumen diameter to a second lumen diameter and then diverges from the second lumen diameter to a third lumen diameter, wherein the ejection port at the distalmost end of the catheter has a fourth lumen diameter that is greater than the second lumen diameter;
• and
• injecting a fluid into the lumen of the elongated body, wherein injecting the fluid into the lumen at a target flow rate causes the fluid to cavitate as the fluid flows through the convergent-divergent region of the elongated body to form bubbles, wherein the bubbles implode prior to the bubbles exiting out the ejection port and produce a pressure shockwave, wherein the catheter is configured such that the fluid exiting out of the ejection port at the distalmost end of the catheter is unimpeded, and wherein the catheter is configured such that the pressure shockwave emerges from the ejection port at the distalmost end of the catheter.