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Biomedical subjects

G J Jako

Publications and source records attributed to G J Jako.

At least 37 records · Page 2Linked to original sources

The anatomic limitations of CO2 laser cordectomy.

The anatomical limitations of CO2 laser cordectomy in an experimental setting with maximal exposure are presented. The major limitation is the thyroid cartilage. This is reached in the area of anterior commissure tendon by removal of only 2 to 3 mm of soft tissue. Most posteriorly in the larynx, the distance to the thyroid cartilage becomes progressively greater, being 5.3 mm at mid-cord and 9.0 mm at the anterior end of the vocal process of the arytenoid. The inferior limitation is the cricothyroid membrane. Anteriorly this is avoided by not extending laser excision more inferiorly than 5 mm's. Posterolaterally, the limitation is the para-arytenoid musculature. Excisional biopsy or staging with the laser must be within the framework of these limitations.

Biopsy↗

Development of a carbon dioxide laser cystoscope.

CO2 laser lesions were created at varying power densities on the exteriorized canine bladders. A 50-watt carbon dioxide continuous laser coupled to a Zeiss surgical microscope was used. A schematic power curve was developed indexing depth of bladder penetration by the laser against laser energy output. Once the optimal power settings for the carbon dioxide laser were established, vertical heat transmission, hemostasis, and healing were studied. A prototype carbon dioxide laser cystoscope was then constructed that allowed endoscopic delivery of the CO2 laser beam into the intact canine bladder. The beam was focussed by a germanium lens and directed out the end of the endoscope, using a movable mirror. Eight dogs were then endoscopically studied in vivo.

Animals↗

Transoral management of localized carcinoma of the oral cavity using the CO2 laser.

Since 1972 we have been cautiously exploring the use of CO2 laser in the management of carefully selected cases of localized carcinoma of the oral cavity. At the present time our experience is based on the treatment of 57 patients with cancer of the oral cavity. The CO2 laser has been found to be an indispensable tool in the transoral management of T1 carcinomas, multiple superficial carcinoma, extensive leukoplakia and verrucous carcinoma. The laser allows precise excision of the lesion and involved mucosa and provides and excellent specimen for histologic verification of the margins. The morbidity of laser excision is minimal, so that a tracheotomy is not needed and patients can almost always be discharged on the following day. (Follow-up data on those patients at risk for 30 months indicate excellent control rates).

Adult↗

Laryngeal carcinoma: transoral treatment utilizing the CO2 laser.

The CO2 laser has been found to be a useful adjunct in our efforts to treat laryngeal carcinoma. Utilized endoscopically, it has been of help in establishing the proper staging, in diagnosing recurrence after radiation therapy, in reestablishing airways blocked with tumor, in debulking tumor mass prior to radiation and/or chemotherapy, and as a primary mode of excisional therapy, all accomplished with minimal morbidity. Most patients may return home the first postoperative day, eating, with serviceable voice, and requiring no tracheotomy or analgesics, all of which provide a significant cost benefit.

Carbon Dioxide↗

Development of a carbon dioxide laser cystoscope.

A 50-watt carbon dioxide continuous laser coupled to a Zeiss surgical microscope was used to study the characteristics of laser-induced lesions on the exteriorized canine bladder. The relationship of energy to the depth of the lesion created by the laser was evaluated. Healing, vertical temperature transmission and hemostasis were studied. A prototype carbon dioxide laser cystoscope then was constructed and used endoscopically to create surgical lesions in the intact canine bladder.

Animals↗

Laser surgery in otolaryngology: interaction of CO2 laser and soft tissue.

The sequence of histological change induced by CO2 laser irradiation was discussed in terms of two factors: the physiomechanical factor and the physiochemical factor. At sufficiently high heat energy levels, the immediate findings are characterized by crater formation resulting from rapid vaporization of the water and ejection of the solid component. In the immediate vicinity of the crater edge, the maximum tissue temperature rise is 65 degrees C above the 32 degrees C ambient tissue temperature and it decreases to the primary tissue temperature within a distance of 2 mm. The healing process of CO2 laser induced lesions proceeds with minimal delay. The lymphatic and vascular channels are occluded in the marginal area of coagulation resulting in a marked hemostatic effect. This sealing effect increases the margin of safety in preventing possible dissemination of tumor cells. By selecting the appropriate power, time, and focus cone angle, precise destruction of preselected areas of tissue can be achieved with an extraordinary hemostatic effect without damaging the underlying tissue. These advantages are especially helpful in function-preserving surgery.

Animals↗