Ambiguous terms such as “close margin” or “inconclusive” further contribute to the unclarity of margin evaluation and decision-making. The search of surgical procedures that better preserve function and quality of life, parallel to technological progress,

has led to the development of endoscopic approaches in head and neck surgical oncology. Strong described the first use of endoscopic CO2 laser resection of glottic cancer in 1975.2 With further development over the next decades, the technique became one of the mainstay treatments for early laryngeal cancer.3–6 Transoral robotic surgery (TORS) for the resection of supraglottic Inhibitors,research,lifescience,medical cancer was introduced in 2007 by Weinstein et al.7 overcoming some of the limitations concerning visualization, maneuvering, and accessibility in transoral laser microsurgery (TLM). The growing practice of endoscopic surgeries resulted in a change in the therapeutic LY2157299 management of selected head and neck cancers, replacing the external approach in early stages.5 The aim of this review was to summarize the literature Inhibitors,research,lifescience,medical considering the assessment and feasibility of negative margins in transoral

laser and robotic surgery. BASIC PRINCIPLES IN ENDOSCOPIC SURGERY Transoral laser microsurgery is minimally invasive and is performed under direct suspension laryngoscopy with an operating microscope that grants the surgeon a high-power magnification of vision, therefore a superior detailed Inhibitors,research,lifescience,medical quality compared to that obtained by external approach. In TORS one of the arms holds a high-definition endoscopic camera, enabling an excellent three-dimensional magnified vision which can be moved during the surgery. However, the tactile feedback in endoscopic operation is limited Inhibitors,research,lifescience,medical or not possible; therefore assessment of tumor penetration is hampered. In order Inhibitors,research,lifescience,medical to overcome its limitations, and fully utilize its advantages, transoral surgery dictates some changes and emphasizes different principles during the operation. Exposure Obtaining good exposure of the lesion is an important principle in surgical oncology; it is a key parameter to the success of the endoscopic procedure. Several

studies have found the surgeon’s judgment of complete resection of glottic below cancer in TLM to be superior to violated margins in the histopathology report.8–11 The surgeon’s assessment of the neoplasm borders, based on the excellent view, necessitates as clear and complete a view of the lesion as possible. From setting up the patient in the correct position, through using the different kinds of laryngoscopes or retractors, setting up the microscope and robotic arms in the limited transoral field of surgery, although time-consuming, is part of the transoral surgery. Depending on the site of the tumor, especially in transoral laser cordectomy, exposure can necessitate resection of obscuring tissue such as false vocal cord or petiole of the epiglottis.