Harmonic scalpel versus flexible CO2 laser for tongue resection: a histopathological analysis of thermal damage in human cadavers.

BACKGROUND: Monopolar cautery is the most commonly used surgical cutting and hemostatic tool for head and neck surgery. There are newer technologies that are being utilized with the goal of precise cutting, decreasing blood loss, reducing thermal damage, and allowing faster wound healing. Our study compares thermal damage caused by Harmonic scalpel and CO2 laser to cadaveric tongue. METHODS: Two fresh human cadaver heads were enrolled for the study. Oral tongue was exposed and incisions were made in the tongue akin to a tongue tumor resection using the harmonic scalpel and flexible C02 laser fiber at various settings recommended for surgery. The margins of resection were sampled, labeled, and sent for pathological analysis to assess depth of thermal damage calculated in millimeters. The pathologist was blinded to the surgical tool used. Control tongue tissue was also sent for comparison as a baseline for comparison. RESULTS: Three tongue samples were studied to assess depth of thermal damage by harmonic scalpel. The mean depth of thermal damage was 0.69 (range, 0.51 - 0.82). Five tongue samples were studied to assess depth of thermal damage by CO2 laser. The mean depth of thermal damage was 0.3 (range, 0.22 to 0.43). As expected, control samples showed 0 mm of thermal damage. There was a statistically significant difference between the depth of thermal injury to tongue resection margins by harmonic scalpel as compared to CO2 laser, (p = 0.003). CONCLUSION: In a cadaveric model, flexible CO2 laser fiber causes less depth of thermal damage when compared with harmonic scalpel at settings utilized in our study. However, the relevance of this information in terms of wound healing, hemostasis, safety, cost-effectiveness, and surgical outcomes needs to be further studied in clinical settings.

Retro-auricular video-assisted "gasless" thyroidectomy: feasibility study in human cadavers.

BACKGROUND: In recent years, there has been a surge of interest in developing alternative surgical approaches to the thyroid gland with a focus on cosmesis. Approaches can be either complete endoscopic approaches using CO(2) insufflation or endoscopy-assisted approaches. We describe a novel approach for thyroidectomy via a retro-auricular incision without gas insufflation using endoscopic assistance. METHODS: Six fresh human cadavers were utilized. Four head and neck specimens were used to assess the retro-auricular approach and the creation of surgical space in the lower neck. Three hemithyroidectomy in two fresh human cadavers procedures were performed via a retro-auricular approach. The end-point of the study was successful removal of the hemithyroid gland with preservation of the recurrent laryngeal nerve. RESULTS: In all cases, the retro-auricular flap and subplatysmal plane could be achieved without difficulty. Three hemithyroid specimens were successfully removed in two cadaveric specimens using the retro-auricular approach with endoscopic guidance. Thyroid gland resection with identification and preservation of the recurrent laryngeal nerve could be achieved in all three procedures (100%). CONCLUSION: The retro-auricular approach or the "Walvekar approach" permits adequate working space and an excellent endoscopic surgical view for removal of the ipsilateral hemithyroid gland with an option for a bilateral approach using a "gasless technique."