Robert C. Sprecher

Objectives/Hypothesis: The goal is to review the efficacy and safety of bioabsorbable miniplates as an alternative to autologous grafts in single‐stage laryngotracheal reconstruction for subglottic stenosis.Study Design: Case series.Methods: A standard approach to the laryngotracheal complex is performed. The cricoid cartilage and first two tracheal rings are incised vertically, including the tracheostoma if present. A poly‐L‐lactic‐acid‐polyglycolic‐acid bioabsorbable miniplate was cut to an approximate 1‐ to 1.5‐cm length and 3‐ to 4‐mm width, and placed over the cricoid defect. This plate was sutured in place using 4‐0 undyed nylon sutures, securing the plate at each end to the cricoid cartilage. Care was taken to place these sutures submucosally in the tracheal lumen. If there was concern for suprastomal collapse, additional plates were placed inferiorly. The patient was taken back to the intensive care unit with a penrose drain in place and left sedated and intubated for 1 week and then re‐evaluated in the operating room.Results: The procedure has been performed on 10 patients. All patients had a well‐healed and fully mucosalized anterior tracheal wall with no evidence of plate or suture exposure at the time of extubation. There were no postoperative complications directly attributable to the use of the absorbable plate. All patients were successfully decannulated at the time of discharge. Long‐term follow‐up ranges from 14 to 63 months. No patients have required revision laryngotracheal reconstruction or repeat tracheostomy.Conclusions: This study demonstrates that the use of bioabsorbable plates in select patients is a safe and effective alternative to the use of autologous cartilage grafts for single‐stage laryngotracheal reconstruction for anterior subglottic stenosis. Donor site morbidity is eliminated, and operative time is decreased. Laryngoscope, 2010

Objectives/Hypothesis: To evaluate the efficacy of photodynamic therapy (PDT) with the phthalocyanine photosensitizer Pc 4 for treating an animal model of recurrent respiratory papillomatosis (RRP). Methods: Rabbit skin was grafted onto the dorsum of severe combined immunodeficient mice, two xenografts per animal. After the graft healed, it was inoculated with cottontail rabbit papillomavirus (CRPV). When papillomas developed, Pc 4 (0.6 or 1.0 mg/kg) was administered systemically, and 48 hours later, one papilloma of the two on each animal was exposed to 675‐nm photoactivating light at either 100 or 150 J/cm². In addition to the contralateral tumors, which received Pc 4 but no light, other controls included animals receiving light only or neither agent. Response was assessed by measuring papilloma size with a caliper. Some papillomas and residual skin were harvested for histological assessment. Results: For the lower‐dose PDT regimens, papilloma growth rates were not significantly different from the controls. In contrast, 13 of 15 papillomas receiving the higher Pc 4 dose (1.0 mg/kg) and the higher light fluence (150 J/cm²) regressed completely and did not regrow within the observation period of up to 79 days. The response of these papillomas was significantly different from the controls (P < .001). Histological analysis confirmed the absence of residual tumor following complete response and replacement with near‐normal epithelium. Conclusions: Pc 4‐PDT is highly effective in treating virally induced (CRPV) papillomas in a murine model of RRP, and thus warrants further study as a treatment for HPV‐induced papillomas. Laryngoscope, 2010

Photodynamic therapy (PDT) of cancer is an experimental tumor therapy which is based on the combined use of a systemically administered photo-sensitizer to a tumor-bearing host and local illumination of the lesion by a high-intensity visible light source, typically a tunable argon dye laser. Human squamous cell carcinoma (HSCC) is the most frequently encountered malignancy of the head and neck. In this study, responses of HSCC cells to PDT were examined in in vitro and in vivo systems. In in vitro studies, the HSCC cells showed a positive photodynamic response with Photofrin-II® (Pf-II), chloroaluminum phthalocyanine tetrasulfonate (AIPcTS), and a newly synthesized silicon phthalocyanine (SiPc IV). Single cell suspension of HSCC injected subcutaneously on the back of athymic nude mice resulted in a well-circumscribed tumor mass. The animals required a low tumor dose for the successful establishment of a tumor. The tumor was minimally immunogenic and showed neither macroscopic signs of early metastasis to lung, kidney, liver, or spleen nor evidence of surrounding erythema, fluctuation, or tenderness until the late stages of necrosis. Intraperitoneal administration of AlPcTS or SiPc IV to tumor-bearing mice resulted in rapid uptake of the photosensitizers in liver, skin, and tumor tissue. Twenty-four hours following the intraperitoneal administration of AlPcTS or SiPc IV to tumor-bearing animals, the tumor to normal skin ratio of the photo-sensitizer was 1.6 or 1.5, respectively. Administration of Pf-H (5 mg/kg) to tumor-bearing animals followed 24 hours later by irradiation of the tumor (135 J/cm², 630 nm light from an argon pumped-dye laser) resulted in greater than 80% ablation in tumor volume 24 hours post-PDT. These characteristics make this tumor model system suitable for PDT studies of human tumor cells in vitro as well as in vivo.