Entraining biological calculi

Abstract

A medical device for entraining biological stones during medical procedures for the fragmentation of urinary, biliary, pancreatic, and other biological calculi and safely removing them from the body. The device includes a guidewire having a longitudinally-extending wire core. A portion of the wire core more adjacent the distal end thereof than the proximal end thereof is wound to form a helical coil which tapers in diameter from a larger diameter end at the proximal end thereof to a smaller diameter end at the distal end thereof. At least a portion of the core forming said helical coil is made of a super-elastic deformable material which collapses upon retraction into a tubular sheath and which reforms into a coil upon deployment from the sheath.

Description

FIELD OF THE INVENTION [0001] This invention relates to medical treatments for biological concretions and more specifically, to devices and methods for entraining and extracting these concretions such as urinary, biliary, and pancreatic stones, and other calcified material or debris from the body. BACKGROUND OF THE INVENTION [0002] Urolithiasis, or kidney stone disease, is a significant health problem in the United States. It is estimated that between 2-5% of the general population will develop a urinary calculus during their lifetime. Since being introduced in the 1980s, minimally invasive procedures such as lithotripsy as well as ureteroscopy have become the preferred methods for treatment in a majority of cases of stones in the ureter, and have a potential for application to concretions that develop in other parts of the body such as the pancreas and the gallbladder. [0003] Lithotripsy is a medical procedure that uses energy in various forms such as acoustic shock waves, pneumati...

AI Technical Summary

Benefits of technology

[0009] Accordingly, it is an object of the present invention to provide a flexible, form-fitting device which prevents upward migration of biological stones and fragments of stones generated during medical procedures for stone fragmentation. It is another object of the invention to provide a device in which the entraining configuration may be collapsed and redeployed repeatedly as required during a stone fragmentation procedure.

Problems solved by technology

Urolithiasis, or kidney stone disease, is a significant health problem in the United States.

Although these promising new techniques and instrumentation have improved the treatment of kidney and other biological stones, some problems remain.

However, each of these devices suffers from limitations.

The cage or basket-like configuration entrains a single stone within the wire frame; but these prior art devices have rigid frames that lack the maneuverability and flexibility to engage and disengage a stone repeatedly without causing harm to the surrounding tissue, and the entraining portion of these prior art devices are often rigid and are either not collapsible into a smaller configuration or require mechanisms for opening or closing the basket.

If the basket or cage of the device itself has become trapped within the ureter, a second device often must be deployed to retrieve the first basket from the body; and if the basket or coil structure has entrained a stone which is too large to be extracted without further fragmentation, it also may be difficult to disengage the stone without a significant amount of manipulation.

The balloons of such devices are difficult to manipulate and failure to maintain the balloons in the correct spatial position may result in loss of the stone.

Further, if a stone is caught in a narrow passageway during the extraction process, the balloon catheters cannot move the stone away from the exit direction to dislodge it from the passageway; and if the stone is caught in between the lining of the ureteral wall and the balloon, the pressure of the balloon may push the stone into the lining, causing significant damage to the lining.

Also, soft air-inflated balloons are easily punctured when used in conjunction with most types of stone fragmentation procedures.

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