Geza J. Jako

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.

Laser surgery in the aerodigestive tract

Summary The conventional management of certain problems in the aerodigestive tract has been either inconvenient or ineffective. Seventy-five cases have been treated with the continuous wave CO 2 laser in an attempt to identify the advantages and limitations of laser surgery. It has been found that the CO 2 laser provides a practical method of tissue ablation or excision which can be carried out with excellent control. The laser beam is directed with a handpiece in the oral cavity, with the surgical microscopic laser attachment in the nose, pharynx, and larynx, and with the endoscope-bronchoscope assembly in the tracheobronchial tree. Laser surgery appears to be most valuable when precise surgery is needed to preserve function.

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.

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.

Complications of CO2 laser surgery of the aerodigestive tract: experience of 4416 cases.

The CO2 laser was first Introduced for surgery of the aerodigestive tract in 1971. Since that time, great advances in application have been made in both the adult and pediatric population. Recent reports of isolated complications have appeared in the literature. However, a realistic complication rate in a large series of patients has yet to be reported. This report relates the combined experience of the authors in a total of 4416 cases during the 11–year period from 1971 to 1982. There were nine instances of complications, representing a complication rate of 0.2%. These complications provided a unique learning experience for the authors, and led to the establishment of certain basic principles that should be followed in all laser operations. This survey indicates that the CO2 laser is a safe, extremely useful surgical modality in the aerodigestive tract.

Management of choanal atresia with the carbon dioxide laser.

Congenital choanal atresia frequently demands immediate recognition in the newborn, and provision of a nasal airway as soon as possible. A variety of techniques are available to correct this problem, but none is entirely satisfactory. Transpalatal procedures are associated with significant morbidity in the newborn, and transnasal microsurgical procedures are less predictable when a thick bony plate is present in the choanal obstruction. Transnasal resection with the CO2 laser has been carried out in seven patients (ten sides), whose ages ranged from 16 hours to 14 years. From this early experience, it appears that the procedure is entirely feasible and convenient. It seems to have significant advantages over conventional microsurgical techniques. Eight out of ten choanae have remained patent for four months or more. A lumen keeper is needed during the immediate postoperative period for at least two to three weeks. The procedure is associated with minimal morbidity.

Familial paragangliomas : Linkage to chromosome 11q23 and clinical implications

Familial paragangliomas (PGL), or glomus tumors, are slow-growing, highly vascular, generally benign neoplasms usually of the head and neck that arise from neural crest cells. This rare autosomal-dominant disorder is highly penetrant and influenced by genomic imprinting through paternal transmission. Timely detection of these tumors affords the affected individual the opportunity to avoid the potential morbidity associated with surgical removal, and mortality that may accompany local and distant metastases. Linkage to two distinct chromosomal loci, 11q13.1 and 11q22.3-q23, has been reported, suggesting heterogeneity. We evaluated three multigenerational families with hereditary PGL, including 19 affected, and 59 unaffected and potentially at-risk individuals. Numerous microsatellite markers corresponding to each candidate region were tested in all members of the three families. Confirmation of linkage to 11q23 was established in all three families. The inheritance pattern was consistent with genetic imprinting. Using these data, we were able to provide presymptomatic diagnosis with subsequent removal of tumor from one individual, and to start several others on an MRI surveillance protocol.

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 mms. Posterolaterally, the limitation is the para‐arytenoid musculature. Excisional biopsy or staging with the laser must be within the framework of these limitations.

Anesthesia for carbon dioxide laser microsurgery on the larynx and trachea.

General anesthesia for laser microsurgery of the larynx and trachea included nitrous oxide (N?O), oxygen (02), halothane or enfiurane, and succinylcholine in children, and thiopental, N,O, 02, fentanyl, and succinylcholine in adults. During 392 procedures on 140 patients over a 28-month period, no side effects related to the procedure were seen nor were there any injuries to patients or personnel.

The Control Of Neodymium YAG Laser Fiber Optics Hyperthermia With Magnetic Resonance Imaging

Experiments were performed to investigate the feasibility of combining laser heating of tissues while controlling the temperature changes by magnetic resonance imaging (MRI). A great potential exists for applications in cancer treatment and in scientific research.