Use of dextran and post-primary antibody fixation in immunoperoxidase staining of fresh frozen tissue. Detection of immunoglobulin associated with squamous carcinomas of the head and neck.

Use of unfixed fresh frozen tissue sections for immunocytochemical studies reduces the possibility of denaturation of antigenic determinants compared to formalin fixation and paraffin embedding procedures. However, tissue and cellular morphology can be extensively altered in the numerous application and washing steps with frozen tissue sections. We tested a number of buffer solutions and showed that the use of dextran-containing buffers and fixation by glutaraldehyde after primary antibody application preserves tissue morphology. The procedures described here are also applicable to ascertaining the presence of Fc receptors of leukocytes in sections of carcinoma tissues. The buffered dextran washes and post-primary antibody fixation method was used to demonstrate the presence of immunoglobulin associated with squamous carcinoma cells. The immunoglobulin was not removed by washing of tissue sections at 37 degrees C but could be removed by low or high pH buffer washes, suggesting that the immunoglobulin is bound in a specific manner.

Hoarseness.

The voice is the primary means of communication for humans socially and in the workplace. Although rarely life-threatening, voice problems cause tremendous alteration in daily living and should not be underestimated as a medical disorder. Besides affecting useful communication, voice problems may also signify the presence of more serious medical illnesses, such as malignancy or airway compromise. This article describes normal vocal anatomy and physiology and outlines a practical approach in evaluating patients with voice disorders.

Custom designed acoustic pulses.

We have used a tunable, infrared, free-electron laser with a Pockels cell controlled pulse duration to generate photoacoustic pulses with separate variable rise times (from 15 to 100 ns), durations (100-400 ns), and amplitudes (0.005-0.1 MPa). The tunability of the free-electron laser across water absorption bands allows the rise time of the thermal-elastically generated acoustical pulsed to be varied, while a Pockels cell controls the duration and cross polarizers control the pressure amplitude. The mechanical effects of pressure transients on biological tissue can have dramatic consequences. In addition to cell necrosis, carefully controlled pressure transients can also be used for therapeutic applications, such as drug delivery and gene therapy. This technique permits systemic probing of how biological tissue is affected by stress transients. © 1999 Society of Photo-Optical Instrumentation Engineers.

Preoperative combination chemotherapy for advanced stage head and neck cancer. Promising early results.

We treated 19 consecutive patients with cisplatin, bleomycin, and methotrexate before definitive surgery or radiation therapy. Fourteen patients (74 percent) had partial or complete tumor regression after chemotherapy. With a minimum follow-up time of 27 months, none of the 4 patients who had a major histologic response relapsed, and only 2 of the remaining 15 patients continued disease-free. The achievement of a complete histologic response after preoperative chemotherapy may correlate with long-term disease-free survival after surgery and radiation therapy for head and neck cancer.

The advantages of laser treatment of tumors of the larynx.

The carbon dioxide (CO2) laser is safe and efficacious when used in conjunction with endoscopic excision of selected premalignant and malignant tumors of the larynx. Cure rates parallel those obtained with traditional surgical instruments. Advantages of laser excision of early glottic carcinomas include greater accuracy in establishing the true extent of the disease, minimal morbidity, and cost effectiveness.

Laser surgery for benign laryngeal disease. Conservation and ergonomics.

In surgery, the era of tissue conservation and advanced engineering ergonomics has arrived. As a surgical tool, lasers will undergo extensive development. The most precise of surgical tools, its ability to focus to spots equal to its wavelength will permit intracellular surgery. A new technology must be mastered by the operator, who must have a solid foundation in laser physics. The small spot size possible with the new laser laryngoscopy coupler introduces one more refinement in the growing trend toward "conservational" surgery of the larynx for both benign and malignant laryngeal disease.

Instrumentation for CO2 laser surgery of the larynx and tracheobronchial tree.

This article discusses the safety principles necessary in laser surgery of the aerodigestive tract, and reviews the instrumentation currently used in microlaryngeal and bronchoscopic laser surgery that satisfies these criteria. Such use will contribute to reduction of morbidity rates associated with laser surgery in these procedures.

Laser safety in otolaryngology--head and neck surgery: anesthetic and educational considerations for laryngeal surgery.

Two investigations concerning anesthetic and educational considerations for laser safety in microlaryngeal carbon dioxide laser surgery have been performed. The first study demonstrated that attendance at a "hands-on" laser surgery course that stressed safety precautions was associated with a reduced rate of laser-related complications in the selected group of otolaryngologists who participated in the course, when compared to another selected group of otolaryngologists who were members of a senior otolaryngology society, and surveyed solely on the basis of their society membership. The second series of studies compared the incendiary characteristics of three endotracheal tubes in various mixtures of oxygen, diluted with either helium or nitrogen. It was determined that the polyvinyl chloride tube should not be used for laser surgery, even when wrapped with reflective, metallic tape. The safest anesthetic gas mixture was found to be 30% oxygen in helium; the addition of 2% halothane did not have an adverse effect, as had been previously reported. Both the Xomed Laser-Shield and Rusch red rubber endotracheal tubes were found to be safe, when used with the laser in the pulsed mode in an atmosphere of 100% oxygen. When the laser was used in the continuous mode, both tubes ignited in an atmosphere of 30% oxygen in helium. These findings challenged the previously reported levels of safety associated with the use of an unwrapped Xomed tube. Based on the results of this investigation, it has been concluded that both the Rusch red rubber tube and the Xomed Laser-Shield tube should be wrapped with reflective, metallic tape, when used for cases of microlaryngeal surgery with the carbon dioxide laser.

Lymphatics of the floor of the mouth and neck: anatomical studies related to contralateral drainage pathways.

An anatomical study was made to determine the role of the regional lymphatic drainage pathways in contralateral flow from the floor of the mouth in the dog. Microsurgical techniques were used to cannulate and perfuse a lymphatic vessel. Following a two hour infusion, bilateral radical neck dissections were performed. An efferent upper jugular communicating pathway was repeatedly identified which crossed the midline and drained into the contralateral subdigastric group of nodes. These studies demonstrate a precise role for the regional lymphatic drainage pathways in contralateral flow from the floor of the mouth.

Soft-tissue complications of laser surgery for recurrent respiratory papillomatosis.

Twenty-two patients with recurrent respiratory papillomatosis underwent 105 carbon dioxide (CO2) laser microlaryngoscopic and tracheobronchoscopic operations from July 1986 through February 1990. All soft-tissue complications, whether intraoperative or delayed secondary to laser surgery, were retrospectively analyzed. The intraoperative laser-related soft-tissue complication rate was zero. Two of the 22 patients acquired slight unilateral true vocal cord scar tissue and 1 patient developed a small posterior laryngeal web. The delayed soft-tissue complication rate was 13.6%, which compares favorably with published reports of 28.7% and 45%. This low complication rate has resulted from the selection of appropriate CO2 laser emission parameters and the use of the microspot micromanipulator, which help minimize lateral and/or deep thermal damage at the site of laser impact.

Prevention of pharyngocutaneous fistulas by means of laser-weld techniques.

Although much has been written on methods of dealing with pharyngocutaneous fistulas once they have formed, there are few reports of methods of preventing fistula formation from occurring. We examined the use of laser-weld techniques with the neodymium:yttrium aluminum garnet (Nd:YAG) and diode lasers to seal pharyngotomy closures. Laser-weld techniques have been used successfully in many other tissues, but reports documenting use in the upper aerodigestive tract are minimal. Indocyanine-green dye-enhanced collagen and fibrinogen were studied as laser solder materials for the diode laser. Twenty-nine experimental animals were studied. Neither the Nd:YAG nor the diode laser was successful in preventing fistula formation. Tensiometric studies documented significant strength of the laser welds ex vivo, but this finding was not clinically significant.

Medial microflap for excision of benign vocal fold lesions.

The goal of microlaryngeal surgery is to treat the pathology while preserving or improving vocal function. The medial microflap technique was thus developed. An incision is made over or abutting the lesion, which is then dissected from the vocal ligament and overlying mucosa. Seventeen patients underwent medial microflap excision of their lesions. Postoperative videostroboscopic examinations revealed the presence of mucosal wave and improved glottic closure in 15 of the 17 patients. Acoustic and perceptual analyses revealed improved voice quality. The medial technique is a modification of the previously described lateral microflap technique. Patients whose stroboscopic examination implies lack of involvement of the vocal ligament are candidates for this technique. By identifying normal histologic planes without extensive dissection, lesions can be excised with minimal interruption of vibratory mechanics.

A compendium of intranasal flaps.

The reconstructive surgeon is frequently called upon to repair intranasal defects which require the use of grafts and/or flaps. In general, flaps are difficult to design and utilize because of 1. limited intranasal exposure and 2. the complex design requirements for movement of the flap through three dimensions. Intranasal exposure is increased by the transoral premaxillary approach, the lateral alotomy, the lateral rhinotomy, the transethmoid, and the open rhinoplasty. The flaps to be designed all utilize the basic principles for skin flaps. However in contrast to movement on a relatively two-dimensional surface, they frequently require movement in the three dimensions, i.e., from the floor of the nose up to the septum, from the side to the center, etc. We review the following flaps: 1. mucoperichondrial advancement and rotation flaps of the septum, 2. composite septal flap, 3. inferior turbinate flaps, 4. nasal floor mucoperiosteal flaps, 5. middle turbinate flaps, 6. composite lateral cartilage flaps, 7. buccal sulcus flaps, and 8. nasolabial flaps.

Computer-assisted surgical techniques using the Vanderbilt Free Electron Laser.

The Vanderbilt Free Electron Laser (FEL) is capable of lasing between 2.0 and 8.0 microns with a high peak intensity pulsed structure. The FEL is used to investigate potential applications in otolaryngology. Charring of temporal bones and thermal stress patterns in Plexiglas indicate thermal buildup at 20 and 10 Hz repetition rates of the laser. Also, transient temperature changes measured with thermocouples in a gelatin model reveal that significant heat production occurs at these laser repetition rates. To utilize the fastest laser repetition rates and maintain minimal lateral thermal damage, a computer-controlled scanning system was devised. The authors have also used the computer control with the carbon dioxide laser and experienced improved ablation.

Acute epiglottitis in adults: experience with fifteen cases.

Fifteen adults with acute epiglottitis are discussed. Three required tracheostomy because of delayed diagnosis. There were no deaths. Epiglottitis occurs more often in adults than is generally recognized. The early symptoms of epiglottitis in adults are sore throat and dysphagia. Any patient with acute, painful dysphagia should have indirect laryngoscopy to rule out epiglottitis. Throat and blood cultures were obtained from 14 of our cases. Cultures from only two patients were positive for Hemophilus influenzae, type B; cultures from the other 12 patients did not grow any bacterial pathogens. The primary treatment of adult epiglottitis is intravenous steroids, antibiotics, and humidified oxygen. Observation by the managing physician is mandatory during the first four hours of treatment. Tracheostomy is indicated in progressive disease.

The microtrapdoor technique for the management of laryngeal stenosis.

The use of the carbon dioxide laser as an endoscopic microsurgical instrument has stimulated interest in treating laryngeal and tracheal stenosis. Dedo and Sooy (1984) reported a significant improvement in the management of posterior commissure, subglottic, and high tracheal stenoses with the use of a microtrapdoor flap. A recent laboratory investigation of this method supported the clinical efficacy of this technique. Six patients are evaluated in this report, three with posterior commissure stenosis and three with subglottic or high tracheal lesions. All six patients had a tracheotomy present or performed at the time of their surgical procedures, and each patient had only one procedure. All six had improved airways after the microtrapdoor flaps. Five have been decannulated and one patient with associated hypopharyngeal stenosis still has a tracheostomy because of mild aspiration, although the airway lumen is moderately improved. It is felt that, as a group, the subglottic and high tracheal lesions respond to this technique better than the posterior commissure stenoses. Details of the technique are presented. This brief clinical report supports the efficacy of the microtrapdoor flap procedure in selected laryngeal and tracheal stenoses.

CO2 laser in otolaryngology-head and neck surgery: a retrospective analysis of complications.

A retrospective review was conducted of all patients undergoing CO2 laser surgery by members of the Department of Otolaryngology-Head and Neck Surgery at Northwestern University Medical School from January 1, 1980 through December 31, 1981; 204 cases were identified and all are included in this report. Early in our department's experience with laser surgery, an endotracheal tube fire occurred. This incident precipitated a departmental review of complications associated with the use of the CO2 laser and resulted in the formulation of a laser safety protocol. All patients in this group were treated under the directives of this protocol; the operative complication rate was low. This retrospective analysis of complications associated with the use of the CO2 laser under a strictly applied protocol demonstrates the relative safety associated with judicious use of this instrument.

Histopathology of congenital subglottic stenosis.

Three patients with congenital subglottic stenosis are presented and whole organ serial-section studies of their larynges are discussed. A superiorly displaced first tracheal ring is observed to form a cartilaginous subglottic stenosis in one. This "trapped first ring" is demonstrated in horizontal, sagittal and coronal planes. Subglottic stenosis is a clinical diagnosis which describes multifarious histopathological forms of narrowing within the subglottic larynx.

Thermal injury patterns and tensile strength of canine oral mucosa after carbon dioxide laser incisions.

The amount of collateral damage in laser surgery is affected by the precision of the beam delivery. To test a new control system, the authors of this study produced surgical incisions in the canine oral mucosa and then documented histologic and tensile strength changes during the wound healing process. The incisions were made by three different methods: scalpel, manually controlled carbon dioxide (CO2) laser, and computer-controlled C02 laser. Both types of laser incisions took longer to heal than the scalpel incisions. The laser incisions were accompanied by a zone of thermal damage lateral to the incision. With the computer-controlled laser incision, the area of thermal damage was reduced, the laser-induced delay in wound healing was less, and tensile strength was relatively greater. The data indicate that surgical performance is improved by critical beam control.

Effect of pulse duration on wound healing using a CO2 laser.

The authors investigated wound healing of incisions in the buccal mucosa of a canine model created using a CO2 laser with a short pulse structure (60 micros, 100 micros, and 120 micros) rather than a conventional continuous wave structure in a shuttered mode. The tissue from 10 animals was evaluated histologically and with tensiometry acutely and at postoperative days 3, 7, and 14. A Bonferroni-Dunn corrected ANOVA analysis at a 95% significance level was used to compare the effect of pulse duration on histologic morphology and wound tensile strength. The data indicate that shorter laser pulse durations create less lateral thermal injury (P < .009) and wounds with greater tensile strength (P < .005), resulting in earlier wound healing. The results also show that heat, sufficient to damage tissue, was conducted to adjacent tissue during laser pulses of 100 micros and longer. These results demonstrate that surgical CO2 lasers with a short pulse structure of approximately 60 micros or less could offer more prompt wound healing while maintaining the advantages of a 10.6-microm wavelength laser.