Surgery – Diagnostic testing – Sampling nonliquid body material
Reexamination Certificate
1999-04-06
2002-01-08
Lacyk, John P. (Department: 3736)
Surgery
Diagnostic testing
Sampling nonliquid body material
Reexamination Certificate
active
06336904
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to medical devices and methods. More particularly, the present invention relates to devices and methods for localizing lesions and other target sites in solid tissue, such as breast tissue.
Radiography is quite effective in determining the presence, size, and general location of tumors and other lesions in breast and other solid tissues. Relying directly on radiographic images to locate the site of a lesion in surgical and biopsy procedures, however, can be very difficult. In particular, since tissue is soft and subject to deformation when accessed with scalpels and other surgical instruments, the lesion can move from an initial location indicated in the radiographic image, making surgical access very difficult.
To at least partly alleviate this problem, tissue localization wires have been developed. Such wires are small diameter, flexible rods having a barb, hook, or other anchor at their distal tips. Such wires can be introduced through a needle or cannula under fluoroscopic guidance so that the tip can be anchored immediately adjacent to the site of the lesion. The surgeon can then follow the shaft of the wire to its tip, and remove the lesion adjacent to the tip with a reasonably high degree of precision.
While the use of such tissue localization wires has been a significant improvement, the need to follow the shaft of the wire to its distal end is problematic. Most surgical procedures for removing tumors and other lesions still rely on manual use of a scalpel to access the lesion site. Following the wire shaft with a scalpel is difficult, and the surgeon will often inadvertently and excessively cut into healthy tissue surrounding the shaft. Moreover, the presence of the shaft can damage the scalpel blade and interfere in other ways with the procedure being performed. In addition, the need to follow the wire shaft precludes alternate access routes that may be advantageous, e.g., by providing a more direct access route or by passing through less healthy tissue.
In addition to biopsy and removal of primary lesions, breast cancer surgery often involves the removal of lymph nodes which may have received metastatic cells as the result of lymph drainage. While it is most common to remove all of a patient's axillary nodes when nodal involvement is suspected, such removal is associated with significant morbidity and patient discomfort. A less traumatic alternative is to remove only those lymph nodes which have received lymphatic drainage from the primary lesion. These lymph nodes, referred to as the sentinel node(s), may be identified by injecting a radioisotopic or other detectable marker to the region of the primary lesion and detecting to which node(s) the marker drains. It has been found that the lymph drainage path from a primary tumor will usually go to one or a very few of such sentinel node(s). When using radioactive markers, the sentinel node(s) can then be generally located using a scintillation counter passed over the patient's skin. The node(s) can then be surgically removed using a scalpel, but such removal can be difficult since lymph nodes are hard to locate.
For these reasons, it would be desirable to provide improved methods and devices for localizing target tissue sites within solid tissue particularly including tumors and other lesions within breast tissue. The localization methods and devices will preferably permit visual or optical detection of the target site without the need to surgically follow the shaft or other path created by a localization wire. In particular, it would be desirable to provide localization markers which are visible through relatively thick layers of solid tissue in order to permit surgical access over preferred routes without interference from localization wires or other physical structure. Such improved methods and devices for localizing target tissues should be useful for the identification of sentinel node(s) which have previously been marked with a radioisotopic or other marker, as well as with primary tumors and other lesions. At least some of these objectives will be met by the invention described hereinafter.
2. Description of the Background Art
Breast lesion localization and/or biopsy devices are described in U.S. Pat. Nos. 5,660,185; 5,647,674; 5,556,410; 5,409,004; 5,353,804; 5,221,269; 5,197,482; 4,966,583; 4,774,948; and 4,592,356. U.S. Pat. No. 5,158,084 discloses a particular localization wire having palpable markers for assisting a surgeon in locating the site of a lesion.
The use of infrared light for illuminating the ureter during abdominal surgery is described in U.S. Pat. Nos. 5,517,997 and 5,423,321. The purpose of the illumination is to warn the surgeon of the ureter location and avoid accidental injury to the ureter.
The use of infrared and other light radiation for imaging and/or evaluating tissue structures is described in U.S. Pat. Nos. 5,792,215; 5,014,713; 4,817,622; 4,813,422; 4,541,438; and 4,248,214.
The removal of a sentinel lymph node in breast cancer surgery is described in Krag (1999) J. Natl. Cancer Inst. 91:302-303; Veronesi et al. (1999) J. Natl. Cancer Inst. 91:368-373; and McMasters (1998) N. Engl. J. Med. 339:990-995.
The full disclosures of each of the above listed U.S. patents are incorporated herein by reference.
SUMMARY OF THE INVENTION
The present invention provides improved methods, devices, and kits for localizing target sites in solid tissue. While the present invention is particularly useful for marking tumors and other lesions in breast tissue to facilitate subsequent biopsy and/or tissue removal, it will also find use in the marking of virtually any fluoroscopically visible target site in any type of solid tissue for virtually any purpose. A significant advantage of the present invention is that the localization may be performed visually or optically and does not depend on surgically following a path defined by the shaft of a localization wire. While in most cases a wire will be employed to mark the target site, surgical access to the site can be obtained from virtually any direction and does not need to follow the shaft of the localization wire itself. Moreover, even in cases where it is desired to follow the shaft to the target site, the ability to concurrently visualize or optically detect the target site facilitates following the shaft.
A method according to the present invention for localizing a target site in solid tissue comprises percutaneously introducing an illumination source, and detecting the emitted illumination transmitted through tissue to mark the target site therein. Usually, the method will further comprise removing a portion of the solid tissue in the region of the emitted illumination, either for purposes of biopsy or for removal of a tumor or other diseased tissue. The removal step may comprise manually cutting tissue while detecting the emitted illumination, where the direction of cutting is based at least in part on the observed position within the tissue of the emitted illumination, i.e., the illumination acts as a beacon guiding the surgeon to the target site.
In a first exemplary embodiment, the introducing step comprises anchoring a wire in the solid tissue, where the wire carries the illumination source. The illumination source may be a passive source for transmitting externally generated illumination down the wire to an emitting element, such as an optical fiber having a dispersive element therein. Alternatively, the illumination source may comprise an active element, such as a light generating element, typically a light emitting diode.
Usually, the illumination source will be a point source. By point source, it is meant that the illumination source is not extended or distributed along a significant length or area. In particular, the point source will usually have a maximum width, length, or other dimension of 1 cm, preferably being less than 0.5 cm. Also preferably, the point or other illumination source will emit radiation isotropically, i.e., generally
Banner & Witcoff , Ltd.
Lacyk John P.
Pro Duct Health, Inc.
Szmal Brian
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