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Biomedical subjects

G Onik

Publications and source records attributed to G Onik.

46 records · Page 3Linked to original sources

Sonographic monitoring of hepatic cryosurgery in an experimental animal model.

Several cryosurgical techniques for freezing hepatic parenchyma have been developed. To assess the efficacy of sonographic monitoring of hepatic cryosurgery, an experimental animal model was devised. Real-time sonography was used to monitor the in vivo evolution of hypothermically induced hepatic cryolesions in four mongrel dogs. The results suggest that sonography is an effective and accurate means of monitoring the entire freezing and thawing cycle in hepatic cryosurgery.

Animals↗

Ultrasonic characteristics of frozen liver.

The recent development of new ultrasound probes has made real-time intraoperative monitoring of cryosurgery, and thermocouple placement a possibility. It is shown that frozen tissue and thermocouple needles have acoustic characteristics that enable them to be easily visualized by ultrasound examination. Further in vivo animal studies are needed to examine temperature characteristics of visualized cryolesions, to develop scanning techniques, and to correlate ultrasonic findings with histologic changes in tissue.

Animals↗

Hydropneumothorax: detection on supine radiographs.

Hydropneumothorax may be diagnosed on a supine radiograph by recognition of a pleural line with increased density lateral to it in the pleural space. Recognition of this condition may have implications for therapeutic chest tube placement.

Adolescent↗

Image-guided prostate cryosurgery: state of the art.

BACKGROUND: Cryosurgery was first used to treat prostate cancer in the early 1970s but it was not until 1993, when the results from percutaneous ultrasound-guided cryosurgery were published, that the potential advantages of this treatment became apparent. Changes in equipment and techniques have improved the results of cryosurgery, in both tumor control and lower morbidity. METHODS: The author has reviewed data of his own and those of others concerning the changes in techniques employed and outcomes from prostate cryosurgery. RESULTS: Ultrasound-guided percutaneous transperineal placement of the cryoprobes allows monitoring of freezing in real time. Monitoring temperature at critical locations, separating the rectum and prostate by saline injection, and using argon gas rather than liquid nitrogen-based equipment have improved results and lowered complication rates. The technique produces outcomes similar to those obtained with brachytherapy and three-dimensional conformal radiation therapy. CONCLUSIONS: Advantages of cryosurgery include the ability to re-treat patients without added morbidity and to treat salvage postradiation patients with acceptable results and morbidity. The recent demonstration that "nerve-sparing" cryosurgery is possible suggests that cryosurgery may be used more often.

Cryosurgery↗

Far-lateral disk herniation: treatment by automated percutaneous diskectomy.

Automated percutaneous diskectomy has certain advantages over other surgical approaches to the treatment of far-lateral disk herniation; primarily, the procedure can be performed under local anesthesia without soft-tissue disruption. We describe four patients with far-lateral herniations who were successfully treated with the procedure.

Adult↗

MR body stereotaxis: an aid for MR-guided biopsies.

The use of a new body stereotactic system to facilitate magnetic resonance (MR) guided biopsies is described. A skin entry point is first found using a localizer MR scan. The articulating arm of the stereotactic unit is then used to aim the MR needle at the entry point and accurately maintain the needle at the correct angle to intersect the target area. Complex angles may be used to allow needle passes outside the scan plane. This is accomplished by angling the arm out of the plane of the section.

Biopsy↗