Pulsed-dye laser and retinoic acid delay progression of oral squamous cell carcinoma: a murine model.

OBJECTIVES/HYPOTHESIS: This study examined the role of the pulsed-dye laser (PDL) at 585 nm coupled with retinoic acid at therapeutic (5.0 mg/kg) and nontherapeutic (0.5 mg/kg) doses to delay the progression of cancer with a two-hit approach. The existing vasculature is selectively targeted by the laser, whereas retinoic acid inhibits future angiogenesis. STUDY DESIGN: Randomized, prospective study in a murine model. METHODS: Twenty-five athymic nude mice were inoculated with oral squamous cell cancers on six flank sites and randomly divided into five groups: 1) control subjects, 2) treatment with 0.5 mg/kg retinoic acid (RA 0.5), 3) treatment with 5.0 mg/kg retinoic acid (RA 5.0), 4) treatment with RA 0.5 + PDL, and 5) treatment with RA 5.0 + PDL. The PDL groups received irradiation after inoculation. The retinoic acid was administered daily. The tumors were counted and measured for 14 days. RESULTS: The control group developed visible tumors in 50% of the inoculation sites at 3 days compared with 3 days (RA 0.5) and 4 days (RA 5.0) for the retinoic acid groups and 9 days (RA 0.5 + PDL) and 10 days (RA 5.0 + PDL) for the laser treatment groups. There was no tumor growth until day 7 in the RA 5.0 + PDL group. The tumor volume was statistically different between the treatment groups. CONCLUSION: This study demonstrated the superiority of a single treatment with the PDL coupled with retinoic acid to delay the progression of cancer when compared with treatment with retinoic acid alone, thus introducing a novel strategy in cancer control.

A new laser treatment for vocal cord papilloma--585-nm pulsed dye.

OBJECTIVES: Microvascular targeting with the 585- nm pulsed dye laser (PDL) may provide a new form of therapy to control symptoms caused by recurrent respiratory papillomatosis (RRP). METHODS: Ten patients with RRP underwent 13 procedures under general anesthesia with the 585-nm PDL. A micromanipulator (11 procedures) and a flexible nasolaryngoscope (2 procedures) were used to deliver the laser pulses. Patients were followed postoperatively according to protocol. RESULTS: Clinical examination revealed regression of papillomas in all patients. Seven patients had complete regression after PDL surgery, and 2 patients had partial response to treatment. One patient was lost to follow-up. No complications were present during this prospective nonrandomized pilot study. CONCLUSION: Patients treated with PDL experienced regression of their papillomas. PDL may provide patients with RRP with an alternative treatment without the risks associated with CO(2) laser surgery. This procedure also has potential to be delivered on an outpatient basis with flexible fiberoptic laryngoscopes.

Anterior window laryngoplasty: a new anatomic approach for posterior glottic and subglottic stensosis.

This study explores the feasibility of an anterior thyroid window as a new approach for posterior glottic stenosis. An anterior window was made on the thyroid cartilage of human cadaver larynges, with its superior edge below the level of the vocal cords and an inferior pedicle composed of the inferior border of the thyroid cartilage attached to the cricothyroid membrane, which was left intact. By obtaining direct exposure of the posterior glottis and cricoarytenoid joints, mucosal graft suturing and exploration of the joints were easily achieved with an operating microscope. This study demonstrates the anatomic feasibility of an anterior window laryngoplasty as an alternative approach to treating posterior glottic stenosis while preserving the cartilage framework and avoiding the anterior commissure. This technique may improve endolaryngeal manipulation by providing a closer and more direct exposure than do endoscopic techniques, and by having fewer possible complications than traditional open techniques.

Preliminary results of intraoperative mitomycin-C in the treatment and prevention of glottic and subglottic stenosis.

Mitomycin-C is an antineoplastic antibiotic that acts as an alkylating agent by inhibiting DNA and protein synthesis. It can inhibit cell division, protein synthesis, and fibroblast proliferation. The purpose of this pilot study is to investigate intraoperative applications of topical mitomycin-C in treatment and prevention of glottic and subglottic stenosis. Eight patients with posterior glottic and/or subglottic stenosis were treated with endoscopic CO2 laser excision followed by topical application of 0.5 cc of 0.4 mg mitomycin-C per milliliter of saline for 4 minutes at the surgical site. After mean follow-up of 15 months (10-20) all patients had clinical improvement of their airway and resolution of their preoperative symptoms. No complications were noted in this study. Although a longer follow-up and further controlled studies are needed, the use of topical mitomycin-C may prove useful in the treatment and prevention of subsequent restenosis and scar formation in the larynx and trachea.

Bronchoscopic management of benign stenosis.

In summary, the use of laser technology in the airway for the treatment of benign lesions has become a standard therapeutic modality for the airway endoscopist. It is extremely important that endoscopists be well acquainted with the laser soft tissue interactions of the laser being used and the safety precautions associated with each individual wavelength. They should be conversant with the indications and contraindications and have the ability to use adjuvant therapeutic modalities, such as stents and medications. As usual, patient selection is one of the key factors related to successful management.