INTRODUCTION Transoral laser microsurgery (TLM) is a minimally invasive surgical approach to functional organ preservation for cancer of the upper aerodigestive tract. It involves tumour resection using specialized endoscopic instruments, microscopes and lasers, with the wound bed often left to heal by secondary intention.1 The term TLM was rst coined by John Salassa of Mayo Clinic in the 1990s to distinguish this technique from the more generic endoscopic laser surgery by virtue of using an operating microscope to closely examine the host-disease interface following principles established by Wolfgang Steiner.2 This affords the advantage of binocular vision and stereoscopic depth perception, combined with the superb optics of modern microscopes, making it truly a microsurgical technique. In contrast to non-surgical radiation and chemoradiation-based protocols, TLM places no limit on treatment options in the event of recurrent, persistent or second primary disease and avoids the long-term iatrogenic sequelae of denitive radiotherapy. TLM differs from traditional surgical oncology by departing from the classic Halstedian principle of en bloc resection. Instead, tumour is often divided with the laser and the tumour margin followed under the microscope, with frozen-section control, allowing piecemeal resection via the endoscope. The aim
is to ensure a tumour-free margin in all dimensions with minimal excision of normal tissue. TLM also has a diagnostic element, as it precisely denes tumour extent at the time of surgery and provides maximal tissue for pathological assessment. Transoral minimally invasive techniques will likely become more widespread in the future as advances in technology continue to improve endoscopic access to the pharynx and larynx. This chapter describes the current state of surgical laser technology, its application to head and neck cancer, and provides a framework for the TLM approach to tumours at each major head and neck subsite.