Surgery – Instruments – Stereotaxic device
Reexamination Certificate
1999-11-26
2001-07-17
Smith, Jeffrey A. (Department: 3732)
Surgery
Instruments
Stereotaxic device
Reexamination Certificate
active
06261299
ABSTRACT:
TECHNICAL FIELD OF THE INVENTION
This invention relates generally to apparatus and methods useful in scientific research and interventional medicine, and useful in the visualization and analysis of organic tissues and bodies; and to research into the cause and symptoms of disease, its diagnosis and treatment. The invention particularly concerns apparatus which may be advantageously utilized by a researcher, physician or health care professional, in cooperation with types of medical imaging equipment, such as computed tomography (CT) imaging equipment or magnetic resonance (MR) imaging equipment, plain film or fluoroscopy. The invention may be utilized to conveniently and accurately aid in timely (real time), manually, truly, and physically accomplishing the steps of locating, vectoring, and inserting an object such as a probe or other needle-like medical device at, toward, and in a patient's targeted anatomic feature, particularly in the breast of a female patient for purposes of performing a breast biopsy.
BACKGROUND OF THE INVENTION
This invention relates to a stereotactic device for use with an imaging apparatus (such as magnetic resonance, CT imaging, and fluoroscopy) useful in the visualization and analysis of organic tissues and bodies, and to research into the cause and symptoms of disease, its diagnosis and treatment.
It is often necessary to sample or test a portion of tissue from humans and other animals, particularly in diagnosing and treating patients with tumors. When a physician establishes that suspicious circumstances exist, a biopsy is typically performed to determine whether the cells are cancerous. A biopsy may be accomplished by an open or percutaneous technique. Open biopsy removes part or all of the potentially cancerous mass. Percutaneous biopsy is usually done with a needle-like instrument and may be either a fine needle aspiration (FNA) or a core biopsy. In FNA biopsy, individual cells or cell clusters are obtained for cytologic examination. In core biopsy, a core or fragment of tissue may be obtained for histologic examination that may be accomplished utilizing a frozen section or paraffin section.
The biopsy done depends a lot on the surrounding circumstances. No single procedure is ideal for all cases.
To properly diagnose a questionable mass, tissue is needed from an organ or lesion within the body. Usually only part of the organ or lesion needs to be examined. The sample extracted must, however, be representative of the organ or lesion as a whole. In the past, surgery was necessary to locate, identify and remove the sample. With the advent of medical imaging equipment such as x-rays, fluoroscopy, ultrasound, and magnetic resonance imaging, it became possible to identify tiny abnormalities embedded deep within the body. Definitive characterization, though, still requires adequate sampling to characterize the histology of the organ or lesion.
As an example, mammography can often identify non-palpable breast abnormalities earlier than they could be diagnosed by physical examination. Although most non-palpable breast abnormalities are benign, some may be malignant. If breast cancer can be diagnosed before it becomes palpable, the subsequent mortality rate can be reduced. However, it is often difficult to determine whether or not pre-palpable breast abnormalities are malignant, as some benign lesions have mammographic features which mimic malignant lesions and some have features which mimic benign lesions.
To reach a definitive diagnosis, tissue from within the breast must be removed and examined under a microscope. Prior to the late 1980's, reaching a definitive tissue diagnosis for non-palpable breast disease required a mammographically-guided localization, either with a wire device, visible dye, or carbon particles, followed by an open, surgical biopsy utilizing one of these methods to guide the surgeon to the non-palpable lesion within the breast.
In one open method of the prior art, a breast is pierced with a localization wire to position the large diameter section of the wire through the center of the lesion, acting as a temporary marker. Tissue is then removed around the area marked by the localization wire. The tissue is prepared and sectioned for evaluation. Such an open surgical breast biopsy can have many drawbacks. Open biopsies can be disfiguring, expensive, and are imperfect. Any of a number of possible errors may lead to an incorrect diagnosis of a lesion. Open surgical biopsies also carry a small mortality risk due to the risk of anesthesia, and a moderate morbidity rate including bleeding, infection, and fracture or migration of the localizing wire. In cases where multiple lesions are present, a surgeon may be reluctant to biopsy each lesion due to the large tissue mass that must be extracted from the breast. The most convenient lesion is typically taken which results in an incomplete diagnosis. Finally, surgical breast biopsies are extremely common. In the United States alone it is estimated that open, surgical breast biopsies are performed on over 500,000 women annually. A less invasive alternative has long been sought.
In 1988, two stereotactic guidance systems were modified to allow the guiding portion of each system to accommodate spring powered devices. In 1989, free-hand ultrasound guidance techniques were developed to guide the stereotactic guidance systems to breast lesions seen by ultrasound. With the introduction of stereotactic and ultrasound guided percutaneous breast biopsies, an alternative to open, surgical breast biopsy was obtained.
In the use of magnetic resonance imaging (“MRI”) for breast biopsies, there is a serious problem with the interventional procedures. The problem is that the probe cannot be seen, and therefore its location is unknown at the moment before it is to enter the patient. This is one of the most important reasons why MRI has not been used extensively for interventional procedures.
There are many imaging stereotactic devices currently available. Despite the incredible power of existing imaging technologies however, very few procedures are actually done using the existing technology in a routine clinical setting. There are several reasons for the lack of general acceptance of these devices in existing markets.
Most of the systems are expensive, and normally this expense cannot be justified in terms of usage or benefit for the large capital investment required. Physicians and hospitals are generally not prepared in today's economic climate to make a large investment for a system that may only be used intermittently and may become quickly outdated.
Most existing systems are electronic and use optical and computer interfaces. The majority of these systems do not function in a real-time setting, but rather use special post-processed acquired image information. This information is then used to direct the procedure at a different time and place.
Many of the systems are imager proprietary or dependent, so it is possible that only a few units may be able to use a specific technology. Though these systems claim to have very high real-space accuracy, in reality, they have only limited real-space correlation since there is no live (real-time) imaging to confirm the progress of the procedure.
Most stereotactic units are complex and have multiple components. Some of the systems envelop the patient, for example, through the use of head frames that are bolted directly to the skull. If there is any change in the components of such a rigid system at the time and place of the actual intervention, the previously obtained information that forms the basis for the intervention is no longer valid. These systems also rely on gathering many images to direct the operation, rather than needing only a few. Because of this, the process can be very slow, since a large amount of data needs to be acquired to direct the process.
A number of existing stereotactic systems utilize fiducials that are placed on the patient or the stereotactic frame. These are image-conspicuous markers that are seen in the image space an
Robert Eduardo C.
Smith Jeffrey A.
Standley & Gilcrest LLP
The Ohio State University
LandOfFree
Stereotactic apparatus and methods does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Stereotactic apparatus and methods, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Stereotactic apparatus and methods will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2505474