Anatomy and Physiology of the operated larynx

Fig. 1. Pre-operative CT: patient with laryngeal cancer (indication to SCL-CHEP) and DISH syndrome. Treatment of this latter condition takes place at the same time as the laryngeal cancer operation. Correct knowledge of the anatomy and physiology of the operated larynx is crucial to the success of functional la-ryngeal cancer surgery. A fundamental distinction must be made between procedures involving the removal, to a greater or lesser extent 1 , of the vocal fold and those that not only alter the endolaryngeal soft tissues, but also entail the reductive remodelling of the laryngeal framework and repositioning of the neolarynx within the neck. it addition to the morphology of the neolarynx, other pre-existing and/or post-surgical anatomic and functional elements that can prove decisive to the success of the procedure must also be considered. of these, the most important are the presence of spinal cord disease, laryn-gopharyngeal reflux (lPr), any upper respiratory and digestive tract disorders following radiotherapy, salivary flow alterations and, last but not least, the patient's psychological conditions. Cervical spinal disease can take the form of cumbersome bone spurs on the vertebral bodies in severe spinal arthritis or concomitant diffuse idiopathic Skeletal hyperosto-sis (diSh). These conditions must be taken into consideration when planning surgery and be sometimes treated surgically during the laryngeal cancer procedure (Fig. 1). Bruno et al. 2 identified a number of quantitative parameters , visible on pre-operative computed tomography (CT) scans, that can be useful in pinpointing the position of the neolarynx in the neck following crico-hyoido-epiglot-topexy (ChEP), of prognostic importance as far as concerns post-operative functional recovery. The role of lPr in glottic tissue repair processes and, more generally, in all procedures involving laryngeal and/or laryngotracheal reconstructions, deserves special mention. The negative influence of lPr in glottic repair processes has been analysed in studies on animals and, more recently, in clinical studies on humans. in animal studies 3 , irrigation using hydrochloric acid with a ph of 3 and pepsin was administered for 4 or 8 weeks after vocal cord stripping. This group of animals experienced delayed healing, intense inflammation, epithelial erosion and formation of granular tissue, with distant sequelae that evolved into rigid scar tissue, with significant dense collagen deposition. This immediate and delayed tissue damage was evaluated quantitatively and showed a clear statistical significance compared to the control group receiving sterile saline solution irrigations. in a recent clinical study 4 , healing after vocal …