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[New methods for minimal invasive assessment of uncertain mammography and MRI tomography findings].

Results of 3 minimal invasive techniques for breast biopsy of clinically occult lesion are presented. 1. Mammographically guided Site-Select biopsies allow removal of tissue in one piece using a large diameter core biopsy instrument (similar to the ABBI-principle). However the overlying subcutaneous tissue is saved. No technical problems occurred in 13/13 diagnostic biopsies. Complete removal was, however, only possible in 2/4 tumors < 1 cm due to tissue shift during insertion of the instrument. 2. Mammographically guided vacuum biopsy also allows contiguous removal of areas of 1.2-1.8 cm diameter, while blood is suctioned out, as well. 3 stereotaxic miscalculations were immediately recognized. Diagnostic accuracy in 405 biopsies so far is 100%. The examination was very well tolerated by the patients. 3. By means of a specially developed biopsy coil and vacuum biopsy percutaneous in- or excisional biopsy of enhancing lesions visible by MRI alone has been realized by us for the first time. 24/25 diagnoses are definitely representative--as proven by lack of enhancement after biopsy. One diagnosis, which was uncertain due to overlying blood, is being followed. Minimal invasive methods may open up new perspectives.

Biopsy, Needle↗

Magnetic Resonance Imaging (MRI) stereotaxis using the Patil System. A technical note.

Magnetic Resonance Imaging (MRI) scanning would prove useful for lesions that are not visualized on computed tomography (CT) scan or are better defined on MRI scan. The problem of reference marker visualization can be overcome by coating them with mineral oil or by placing paramagnetic fluid filled rods on them. The unique construction of the Patil System permits its use even in a strong magnetic field. The technique of MRI stereotaxis using this stereotaxic system without any modification is described.

Brain Diseases↗

Stereotactic histologic biopsy in breasts with implants.

PURPOSE: To describe our experience with stereotactic histologic biopsy in patients with breast implants. MATERIALS AND METHODS: Thirty-one (1.3%) of 2,399 consecutive lesions on which stereotactic histologic biopsy was performed were in breasts containing implants. Biopsy difficulties were evaluated for lesions in breasts with and breasts without implants. Biopsy was performed on lesions in patients with implants prone on a dedicated table, with automated large-core (n = 13) or directional vacuum-assisted (n = 18) devices. Follow-up was surgical (11 of 11 malignancies and two of three high-risk lesions) and mammographic (one of three high-risk lesions and 17 of 17 benign lesions). RESULTS: There were no implant ruptures, hematomas requiring drainage, infections requiring treatment, false-negative findings, or histologic underestimations. Difficulties with stereotactic histologic biopsy were more prevalent in breasts with implants and included positioning problems in 10 (50%) of 20 lesions in breasts with subglandular implants and zero (0%) of 10 with subpectoral implants, lesions seen on only one view in four (13%) of 31 lesions, specimen radiographs negative for calcifications in two (10%) of 20 lesions, prominent bleeding in two (6%) of 31 lesions, and suboptimally small tissue samples in three (10%) of 31 lesions. CONCLUSION: Stereotactic histologic biopsy is safe in breasts with implants. Compared with that in breasts without implants, biopsy is often technically more difficult and may eventually prove less accurate.

Adult↗

Craniofacial postherpetic neuralgia managed by stereotactic spinal trigeminal nucleotomy.

Postherpetic craniofacial neuralgias are notoriously difficult to deal with. Nevertheless, stereotactic spinal trigeminal nucleotomy seems to be a rational approach, as both experimental and clinical data strongly suggest the relevance of nucleus caudalis for certain facial neurogenic pain phenomena. From a series of 136 consecutive nucleotomies, 80 were performed for deafferentation pain. The long-term results of 25 such cases, who underwent this procedure for postherpetic neuralgia, are reported. Their pain was referred to the Vth, to the VII, IX and Xth, and to the C2-3 dermatomes. Abolition of the allodynia, and disappearance of, or marked reduction in, the deep background pain was achieved in 76% of the cases overall. The follow-up period ranged from 1 to 13 years. There was no untoward side-effects. Technical and electrophysiological data germane to accurate target placement are discussed. Spinal trigeminal nucleotomy is then a specially suitable procedure for postherpetic craniofacial dysaesthesiae.

Follow-Up Studies↗

Interventional breast procedures.

The capability to provide histologic diagnoses of nonpalpable lesions by performance of percutaneous needle biopsy has revolutionized breast imaging in the past decade. The radiologist who performs percutaneous breast biopsies assumes an increased level of responsibility for the patient regarding patient selection, lesion selection, performance of the biopsy procedure, interpretation of results, and patient follow-up. With variable and increasingly numerous options for the biopsy of breast lesions, careful attention must be paid to the selection of patients and types of lesions for different procedures. Critical technical considerations affect whether biopsy of a lesion can be optimally performed percutaneously, and these considerations must be factored into the recommendations for patient treatment. In addition, a limited preprocedural clinical assessment of the patient will allow a safer procedure to be performed expeditiously. Most breast abnormalities classified by using the ACR Lexicon as 4 (suggestive) or 5 (highly suggestive, likely malignant) are suitable for either percutaneous breast needle biopsy or needle localization and excisional biopsy. In general, those lesions classified as 3 (probably benign) carry a recommendation for early follow-up and not biopsy, because the likelihood of malignancy is small. A particular advantage of percutaneous biopsy is in the diagnosis of multicentric breast cancer. Core biopsy is less invasive and less costly than surgical biopsy, and it can be used to demonstrate multicentric disease, saving the patient a two-step surgery. However, several lesions are better treated by excision than by percutaneous biopsy. Among these are architectural distortion or loosely arranged, segmental or regional microcalcifications. For nonpalpable breast lesions visualized on mammography, sonography, or both, imaging-guided localization is required for precise needle placement either for wire localization or for percutaneous breast biopsy. The selection of which modality to use for guidance depends on (1) the adequacy of visualization of the lesion by the modality used, (2) the position of the lesion, (3) the ease of positioning the patient, (4) the skill of the operator, (5) the need to reduce radiation exposure, (6) the overall patient condition, and (7) size of the lesion. Fine-needle aspiration biopsy (FNAB) has a high sensitivity and specificity in the diagnosis of palpable breast lesions when the procedure is properly performed and interpreted. Variable results have been achieved with FNAB of nonpalpable breast lesions under imaging guidance. Three critical components are necessary to achieve reliable results by using FNAB. These include the following: (1) accuracy in needle placement, (2) skill in performance of FNAB, and (3) expert cytopathologic analysis. Accurate preoperative needle localization of nonpalpable breast lesions allows the radiologist to guide the surgeon performing an open biopsy and helps to ensure that the surgical procedure can be performed quickly and can be accomplished with the best possible cosmetic result for the patient. Lesions selected for needle localization and biopsy should undergo a complete tailored imaging evaluation before the needle localization is scheduled. Specimen radiography should be performed for all nonpalpable lesions. Once the lesion has been identified on specimen radiography, the radiologist can assist the pathologist in identifying the lesion microscopically by marking the lesion within the surgical specimen. We cover the technical and interpretative aspects of percutaneous breast biopsy and needle localization for surgical biopsy.

Biopsy, Needle↗

Surgical approaches to epilepsy.

Medically intractable epilepsy may be treated successfully with surgery in a high proportion of patients following appropriate clinical and diagnostic evaluation. Recent technical advances provide more precise diagnostic methods, especially for localizing the areas of seizure origin in the cerebral cortex. The excision of epileptogenic cortex remains the main surgical treatment for partial forms of epilepsy, while commissurotomies are appropriate for some patients with a secondary, generalized type of epilepsy. Limited experience with a variety of stereotaxic lesions and the modality of cerebellar stimulation has not yet provided definite evidence of efficacy of these techniques. Following surgical excisions, two thirds of the patients are significantly improved and over one third become seizure free, with morbidity-mortality rates of less than 0.5%.

Cerebral Cortex↗

Stereotactic transsylvian, transinsular approach for deep-seated lesions.

BACKGROUND: Lesions located deep within the frontal and parietal lobes adjacent to the internal capsule are often considered surgically inaccessible. We have used intraoperative stereotactic lesion localization in conjunction with microsurgical dissection of the lateral sylvian fissure to accurately and atraumatically approach such lesions through the insular cortex. METHODS: When possible, the sylvian fissure is widely opened using standard microsurgical technique. However, exploration through a precisely placed exposure no more than 1.0 cm in length is still feasible. Repeated intraoperative lesion localization employing ultrasound, frame-based or frameless stereotaxis was used to guide dissection deep to the Insular cortex. RESULTS: Using this approach we have resected five cavernous angiomas, three plexiform AVMs and 2 low-grade gliomas. There was a single case of transient dysphasia in seven dominant hemisphere explorations and a single case of transient somatosensory impairment. Otherwise, there were no new transient or permanent postoperative neurologic deficits. In two cases, hemiparesis present prior to surgery improved following resection of a cavernous angioma. CONCLUSIONS: The transsylvian, transinsular approach can be employed to safely expose lesions deep within the cerebral hemisphere. Anatomic considerations, surgical technical refinements, and clinical results are the subject of this report.

Adolescent↗

Stereotactic evacuation of large intracerebral hematoma.

Despite the declining incidence of strokes, statistics regarding intracerebral hemorrhage indicate a relatively stable incidence in this form of cerebral insult over the past 20 years. Intracerebral hemorrhage accounts for 10% of all strokes, and is fatal to 50-60% of its victims. Until the advent of computer-assisted tomography, surgical intervention offered little benefit to patients suffering primary hemorrhage within the deep gray structures of the cerebral hemispheres. Technical advances in both diagnostic and therapeutic instrumentation now permit stereotactic subtotal evacuation of deep intracerebral hematomas.

Adult↗

Intraoperative use of Doppler ultrasound and endoscopic monitoring in the stereotactic biopsy of malignant brain tumors. Technical note.

An intraoperative monitoring tool is described that prevents mechanical injury to intracerebral vessels during stereotactic surgery. The method, which combines pulse Doppler ultrasonography and fiberendoscopy, allowed stereotactic biopsy to be performed without serious intracerebral bleeding in 25 patients with hypervascular malignant brain tumors, 13 with glioblastoma multiforme, five with anaplastic astrocytoma, five with metastatic tumor, and two with malignant lymphoma. The ultrasound apparatus has a built-in fast-Fourier transformation system analyzer and an improved filtering system that provide real-time measurement of blood flow velocity. The source of flow (arterial or venous) could be identified by both real-time sonography and acoustic signal frequencies. It was possible to measure the size and distance of a vessel by adjusting the Doppler signal gain dial from initially waxing to waning sounds, because the acoustic signal was adjusted to the axial flow of each vessel in 0.1-mm steps. Each of three Doppler probes (1 mm, 2 mm, and 3 mm in diameter) fit through the outer cannula of the biopsy needle. Vessels located within 7 mm from the tip of these probes could be detected easily and rapidly, so the biopsy needle could be advanced safely to the desired target in 7-mm steps. If sonograms revealed blood flow, indicating the presence of larger vessels in the intended stereotactic trajectory, the angle of the needle was changed slightly to avoid vascular injury. Because the fiberendoscope was connected to a video processor, the vessel could be visualized at a higher magnification on the video display, unless there was active bleeding. This technically simple and reliable system enhances operative safety while maintaining accuracy.

Biopsy↗

[Spontaneous intracerebral hematoma].

The surgical treatment of spontaneous intracerebral hematoma has been a controversial subject since neurosurgery began to develop. In our midst we now feel that the surgical treatment should be done early, when the patient presents with the precise indications, since this is the only way to protect the brain from the more or less sudden mass effect to which it is subjected. We have operated on 47 patients (33 men and 14 women) who were from 14 to 82 years old of age (with an average of 56 years), with an intracerebral hematoma in one or the other of the cerebral or cerebellar hemispheres, of varied etiology (most frequently, arterial hypertension). We analyzed the diagnostic methods and the surgical procedures performed on our patients, and emphasize the importance of other methods, such as stereotaxic localization, which shows much promise, especially for gravely ill patients in whom any conventional intervention carries a great risk. The results were excellent in three patients (6.3%) because they returned to their original occupation; good in 9 (19%), who were able to be gainfully employed; bad in 9 (19%), who remained partially or totally dependent, and 26 patients (55.3%) expired. Today, in spite of technical advances, there has been little change in the morbidity and mortality of patients with hematomas of more than 50 ml.

Adolescent↗

Simple plastic stereotactic unit for use in the computed tomographic scanner.

The marriage of computed tomography (CT) and stereotactic surgery offers an opportunity to provide sophisticated and effective treatment to discrete areas of the brain. An important part of this capability is the development of stereotactic frames that are compatible with the CT scanner, i.e., that do not degrade the CT image. A number of technically elegant and ingenious stereotactic frames have been reported. However, they have the drawback of technical complexity and, particularly, great exposure. We are reporting a simple ball and socket skull-mounted stereotactic device that allows solid fixation of probes for use in brain needle biopsies, ventricular catheterization, and similar activities.

Biopsy↗