[Arthroscopically controlled screw placement for osteosynthesis of acetabular fractures]. / Arthroskopisch kontrollierte Schraubenpositionierung bei Osteosynthese einer Acetabulumfraktur.

In the surgical treatment of acetabular fractures via a ventral approach the hip joint is not visible. Hip arthroscopy can be an alternative tool instead of 3-D fluoroscope-based navigation to exclude intra-articular perforation of the screws.

PET and SPECT for radiation treatment planning.

Positron emission tomography (PET) and single photon computed emission tomography (SPECT) have been evaluated in several studies for radiation treatment planning in patients with primary brain tumors. PET with the glucose analogue fluorodeoxyglucose has been found to be of limited use for radiation treatment planning because the high physiologic glucose use of normal gray matter makes delineation of tumors challenging. In contrast, there is considerable evidence that PET or SPECT with radiolabeled amino acid or amino acid analogues provides valuable information for the delineation of gliomas. Increased amino acid uptake has been found to be a more specific marker for viable tumor tissue than signal abnormalities on MRI. In addition, increased amino acid uptake is frequently observed in tumor areas that have not caused a disruption of the blood brain barrier. Therefore, PET and SPECT with radiolabeled amino acids provide a unique opportunity to visualize the infiltrative growth of gliomas and use this information for radiation treatment planning.

Stereotaxic vacuum core breast biopsy--experience of 560 patients.

The purpose of our study was the assessment of the diagnostic value of vacuum core biopsy, which promises high accuracy. The material used were a digital stereotaxic biopsy table (Fischer Imaging) and a Mammotome-gun (Biopsys). A total of 560 patients with 594 predominantly indeterminate lesions underwent vacuum core biopsy (VCB). Verification was a follows: (a) demonstration of complete or partial removal of the lesion or replacement of the lesion by a small hematoma by comparison of the pre- and post-VCB mammogram; (b) reexcision of 105 malignant and 13 borderline lesions; (c) radiologic-histologic correlation; (d) 6-month-follow-up mammograms in 460 cases. Five puncture errors occurred which, however, were immediately recognized and VCB was repeated. Based on the above verification a 100% accuracy was achieved. Only one relevant hematoma that required surgical excision occurred. Except for one case mammographically any severe scaring was visible. Based on the excellent accuracy and excellent tolerance of the procedure VCB appears to be the future method of choice for the workup of those indeterminate mammographically detected lesions that up to now have still required surgical biopsy.

[Direct in-vitro measurement of ultrasound velocity in carcinomas, mastopathic tissue, fatty tissue and fibroadenomas of the female breast]. / Direkte In-vitro-Messung der Ultraschallgeschwindigkeit in Karzinomen, mastopathischem Gewebe, Fettgewebe und Fibroadenomen der weiblichen Brustdrüse.

PURPOSE: The study aimed to investigate ultrasound velocity (SV) in carcinomas, fibrocystic changes, fibroadenomas and fatty tissue of the female breast by means of direct in-vitro measurements. We intended to test whether or not differences in SV exist between the various types of tissue and whether the SV is a useful criterion to differentiate the different tissues. METHOD: SV was measured by comparing transmission time of the ultrasound beam through the specimen and through water. Altogether 40 specimens (12 cancer, 14 fibrocystic changes = FCD, 10 fatty tissues, 3 fibroadenomas, and 1 mixed tissue) were analysed. RESULTS: Velocity differed significantly between fat (1478.5 +/- 6.5 m/s) and tumor (1523.1 +/- 5.9 m/s) (p approximately 10(-11)) and between fat and FCD (1526.0 +/- 9.0 m/s) (p approximately 10(-12)). No significant differences and much overlap were seen between the ultrasound velocities of tumors and FCD. Ultrasound velocity in fibroadenomas (1533.2 +/- 3.8 m/s) was comparable with that in carcinomas and FCD. CONCLUSIONS: We conclude that ultrasound velocity may add complementary information to echogenicity (B-scan). Thus, a locally exact correlation of echogenicity and sound velocity might allow for an improved tissue characterization.

[Optical mammography in preoperative patients]. / Optische Mammographie an präoperativen Patientinnen.

AIM: Research concerning alternative methods of breast imaging that may supplement or even replace mammography appears interesting for further improvement of diagnostic accuracy, for possible cost reduction and increased patient acceptance and compliance. METHOD/PATIENTS: 119 pre-operative patients (59 carcinomas, 60 benign lesions) were examined on a prototype breast scanner in this fundamental research project. Images of the compressed breast that display light transmission and phase shift at wavelengths of 690, 750, 790 and 860 nm were obtained with scanning steps every 2 mm. Based on these images we could calculate further images. RESULTS: Images displaying the division of two original transmission images appeared most useful, whereas phase images generally did not yield relevant additional information. A total of 51 out of 59 carcinomas (mean diameter: 21 mm) were visualised and diagnosed. Specificity in respect of lesion diagnosis was 28%. If surrounding tissue was included in the evaluation, the specificity dropped to 9%. DISCUSSION: The method is not sufficiently developed and well-tried for clinical use. Future research might consider the development of tumour-specific contrast media.

[Vacuum punch biopsy under digital stereotaxic control, a new procedure in percutaneous diagnostic incision and excision biopsy of mammographic findings: initial experience]. / Vakuumstanzbiopsie unter digitaler Stereotaxie--ein neues Verfahren zur perkutanen diagnostischen Inzisions- und Exzisionsbiopsie mammographischer Befunde--erste Erfahrungen.

PURPOSE: To evaluate a digital, stereotactically controlled vacuum punch biopsy method. MATERIAL AND METHOD: In 60/61 female patients a vacuum punch biopsy (14 G) was performed under digital stereotactic control; by means of a single biopsy 1-2 cm3 of tissue was obtained. In one patient the examination could not be carried out because of insufficient microcalcification. Excision biopsies were performed because of doubtful microcalcification (24), focal lesions (35) or abnormal tissue architecture (1). RESULTS: 48 of the biopsies proved benign, 2 showed dysplasias, 5 in situ and 5 invasive carcinomas. In all cases the histological and radiological diagnoses were in agreement. The possibility of a non-presentative biopsy could be excluded with a high degree of certainty because of the accurate localisation and the coherent tissue samples; this produced significant increase in diagnostic certainty. Subsequent haematomas seen mammographically (58/60) are smaller (1-1.5 cm) than for conventional percutaneous punch biopsies because of the effect of suction. The examination was well tolerated (there were no significant haematomas and no infection). Problems consisted of one case of bleeding (due to little experience) and one incorrect localisation which was immediately recognised. DISCUSSION: If the high degree of accuracy, which is expected, can be confirmed, the procedure would appear suitable for replacing diagnostic operative biopsies of non-characteristic mammographic finding.

A new method for conservative renal surgery--experimental and first clinical results.

So far two methods for prolonging the tolerance of renal ischemia are available: 1) surface cooling with crushed ice and 2) perfusion cooling with an extracellular-like solution. Both methods use only the principle of reducing metabolism through cooling. While rewarming during surgery the ischemic protection is lost, or the kidney must be cooled once again. Therefore, a new preservation solution should reduce energy consumption due to its composition in addition to cooling. For open heart surgery, the HTK solution by Bretschneider is already used clinically. In 71 dog kidney experiments, the ischemic time kidneys could tolerate was prolonged by this solution from 15 to 120 min at 35 degrees C and from 45 to 360 min at 25 degrees C. After 2 h of ischemia at 30 degrees C glomerular filtration rate was about 20 ml/min.100gww within 3 h of reperfusion. After six postoperative days the filtration rate was 40 ml/min.100 gww. No ischemic damage could be recognized by histological investigations. The clinical effectiveness of this method was shown in 7 clinical applications. Ischemic duration lasted up to 113 min, and blood creatinine was between 0.8 and 2.4 mg% at the 6th postoperative day. Use of this preservation technique thus leads to improved kidney function immediately following operation. Longer ischemia can be tolerated by a kidney thus protected, and using this technique excellent visibility can be achieved during intrarenal surgery, simplifying, for example, tumor extirpation.