Healing after transoral carbon dioxide laser surgery for early glottic cancer.

OBJECTIVE: This study aimed to evaluate the clinical significance of granulation tissue after endoscopic carbon dioxide laser surgery for glottic cancer. METHOD: This was a retrospective review of 36 patients who underwent endoscopic carbon dioxide laser surgery for T1 and T2 glottic cancer. Post-operative, endoscopic examinations were rated by three blinded otolaryngologists for time to heal and presence of granulation. Patient and surgical factors were compared with time to heal and granulation. RESULTS: A total of 16 of 36 wounds (44 per cent) developed granulation tissue, and 24 wounds (67 per cent) healed without requiring surgical intervention. A total of 7 of 8 wounds biopsied more than 3.5 months after surgery had persistent cancer versus 1 of 4 wounds biopsied at equal to or less than 3.5 months (85.7 per cent vs 25 per cent; p = 0.03). Biopsy at more than 3.5 months was associated with 28-fold increased odds of cancer in biopsy compared with biopsy at equal to or less than 3.5 months (odds ratio, 28.0; 95 per cent confidence interval, 1.088-373.3). CONCLUSION: After carbon dioxide laser surgery for glottic cancer, development of granulation tissue is common. Granulation that persists for more than 3.5 months necessitates biopsy because of increased risk of persistent cancer.

Gratings for integrated optics by electron lithography.

The electron lithographic fabrication of high quality diffraction gratings with periods in the 0.25-microm < a(o) < 1.5-microm range is reported. The negative electron resist employed is a copolymer of glycidyl methacrylate and ethyl acrylate with a sensitivity about 15 times better than that of poly(methyl methacrylate), a positive resist. A new scan generator with linearity accurate to 1 part in 10(4) and locked onto the 60-Hz power supplies is described. Gratings with up to 3000 lines were fabricated with long range order deltaa(o)/a(o)