Surgery – Instruments – Means for removing tonsils – adenoids or polyps
Reexamination Certificate
2000-08-10
2002-05-07
Truong, Kevin (Department: 3731)
Surgery
Instruments
Means for removing tonsils, adenoids or polyps
C606S127000, C606S200000
Reexamination Certificate
active
06383196
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention generally relates to medical instruments and more specifically to an extractor for removing an object from a body, particularly calculi that can form in the biliary and urinary systems.
2. Description of Related Art
Recently developed medical instruments reduce the invasiveness and potential trauma previously associated with various medical procedures. The removal of calculi in the form of kidney stones, gallstones and the like from the body is one area where this effort is meeting with success. Various instruments now permit the removal of kidney stones and gallstones without the need for major surgery. Some of these instruments incorporate miniaturized grasping forceps. This invention, however, is directed to an alternative set of instruments that utilize mechanical retrieval baskets.
The following United States Letters Patents and United States Patent Application describe various types of such retrieval baskets:
U.S. Pat. No. 4,346,846 (1982) Dormia
U.S. Pat. No. 4,590,938 (1986) Segura et al.
U.S. Pat. No. 4,611,594 (1986) Grayhack et al.
U.S. Pat. No. 4,625,726 (1986) Duthoy
U.S. Pat. No. 4,807,626 (1989) McGirr
U.S. Pat. No. 5,064,428 (1991) Cope et al.
Ser. No. 08/258,121 (1994) Bates et al.
Dormia discloses a retrieval basket at a distal end of a surgical extractor selectively extended beyond a tube in an enlarged condition. The retrieval basket comprises a plurality of wire pairs with the wires in the pairs extending in opposite helical wound paths to provide relatively closer wire spacings in the distal end of the enlarged retrieval basket compared to the proximal end. The differential wire spacing promotes the capture of objects in the middle portion of the retrieval basket and entrapment of such objects in the distal end of the retrieval basket.
Segura et al. disclose a medical retrieval device that can be inserted through the working channel of an endoscope for removing stones and the like from the kidneys or the ureter or biliary duct. A retrieval basket of relatively large diameter extends from the distal end of a sheath and collapses into a compact form when drawn into the sheath. Individual outwardly bowed spring strips form the retrieval basket. These strips extend generally axially of the sheath and join at respective distal and proximal ends. The retrieval basket has a generally bulbous form which is relatively stiff due to the spring strip construction and facilitates dislodgment and capture of stones.
The Grayhack et al. patent discloses another retrieval basket that is useful during the removal and/or destruction of calculi. A smooth outer tubular sheath overlies and contains a stranded wire cable terminating in a protective tip at the working or distal end of the device. When the cable is extended distally, the individual spring wire strands at the working end of the cable expand to form a retrieval basket. The distal end of this device additionally includes an expandable distal portion for protecting surrounding tissue during withdrawal of the device and calculi.
The Duthoy patent discloses an extraction device that includes a retrieval basket formed from a plurality of individual wires spaced about and outwardly from an imaginary extension of the center line of a hollow cable. A filiform extends distally from the distal end of the retrieval basket to extend past a stone and to allow the basket to be threaded around and onto the calculi.
The McGirr patent discloses an extractor including a self-closing retrieval basket at the distal end of a catheter with a flexible control line for opening the retrieval basket from the proximal end of the catheter. The retrieval basket assumes a normal position wherein it is in a compact closed form. Pulling on the control line flexes individual strips which define the retrieval basket to open the retrieval basket, when the control line is released, the strips relax and surround the calculi or object being removed.
Cope et al. disclose a stone retrieval basket having superelastic individual wire loops secured together at the apex of the loops to define a distal end of a retrieval basket which can be insert through and beyond a distal end of an elongated tube. Sleeves which secure the wires in a spaced relation and defines the proximal end of the retrieval basket, so the retrieval basket has a bulbous shape.
Bates et al. disclose, in a co-pending patent application commonly assigned with this application, a surgical retrieval basket comprising axially extending wires that are grouped in sets of filaments. The wires are normally maintained in an overlying sheath in a compact condition and form an enlarged retrieval basket upon retraction of the sheath. The individual filaments in a set are relatively closely angularly spaced with the sets being relatively widely spaced to provide a greater number of contact points with entrapped calculi without significantly increasing the manipulations necessary to capture such calculi in the retrieval basket.
These and other surgical extractors using retrieval baskets have certain common characteristics. Each retrieval basket comprises a plurality of filaments in the form of individual strands, strips or wires that extend from a proximal end of the retrieval basket to the distal end of the retrieval basket and, as disclosed by Cope et al., back to the proximal end. In some retrieval baskets the strands are formed along substantially straight lines when the retrieval basket is in a compact form; in others, along a generally helical path. Each instrument includes a plurality of three or more such individual strands to provide contact points for entrapping objects and between which the objects must pass for capture within the retrieval basket.
Retrieval baskets preferably include sufficient numbers of closely spaced wires to provide an enclosure for retaining objects captured within such retrieval baskets while having relatively few widely spaced wires for promotion of capture of such objects. Additionally, the overall size or diameter of an extractor and ancillary equipment, such as an endoscopic device, can impose upper limits on the number of wires and the size of the individual wires. Thus, the design of such baskets involves a compromise between the numbers of wires needed to retain objects and to promote capture of such objects and the overall size of such wires for sufficient strength of the basket.
The following United States Letters Patents and United States Patent Application describe retrieval baskets that include a material coating over the distal end of the baskets to encapsulate objects to be removed from the body:
U.S. Pat. No. 3,472,230 (1969) Fogarty
U.S. Pat. No. 4,790,812 (1988) Hawkins, Jr. et al.
Fogarty discloses a surgical retrieval basket that extends from the distal end of a catheter and comprises four spring wires that to a slide. An umbrella of suitable flexible material is connected to the distal portion of the wires so that upon deployment of the retrieval basket the edges of the umbrella form a circular scrapper. Retracting the retrieval basket from a deployed condition toward and then into a proximal sheath removes debris from a body passage with the umbrella retaining and then closing upon the captured debris.
Hawkins, Jr. et al. disclose a parachute retrieval basket deployed from the end of a catheter. The retrieval basket comprises four individual helically wound spring wires that extend between proximal to distal ends of the basket. A thin, porous fabric web secures and covers the distal portion of the wires to thereby prevent passage of debris, such as emboli or atheroma therethrough.
These and other surgical extractors having a unitary material web at the distal end have certain common characteristics. Each retrieval basket comprises a plurality of filaments in the form of individual strands, strips or wires that extend from a proximal end to the distal end of the retrieval basket. Like the previously described retrieval baskets, the strands lie either along substantially straight l
Bates James S.
Leslie Stephen W.
Scimed Life Systems Inc.
Testa Hurwitz & Thibeault LLP
Truong Kevin
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