Eagle's Syndrome Treated With Transoral Robotic Surgery Approach: A Single Centre Experience and Literature Review

摘要

Eagle syndrome (ES) gained recognition through the work of American otorhinolaryngologist Watt Weems Eagle in 1937 [1]. It is characterised by the symptomatic elongation of the styloid process and the calcification of the stylohyoid ligament [1, 2]. In anatomical studies on cadavers by an Italian surgeon from the 1600s named De Marchetti, a professor of anatomy at the Faculty of Medicine in Padua, there is evidence of the intuition that the styloid process has a growth trend throughout life, although he did not hypothesise a connection between this finding and symptoms, which was done in a very explanatory and intuitive way by Watt Weems Eagle [3]. The styloid process, extending from the temporal bone, projects anteriorly and inferiorly into the parapharyngeal space and lies close to the latero-cervical compartments, including the internal carotid artery, internal jugular vein, glossopharyngeal, vagus, accessory, and hypoglossal nerves. The stylopharyngeus, styloglossus, and stylohyoid muscles, primarily involved during swallowing and chewing, are closely associated with the process [4]. This anatomical configuration and its variations can impede the normal function of the adjacent latero-cervical regions. Patient symptoms may include neck pain (sore throat but also painful lateral head and neck movements), hypopharyngeal globus sensation, dysphagia, ear pain (and tinnitus), dysphonia, and various degrees of discomfort and/or pain in the cricopharyngeal regions [5]. Headaches or focal neurological symptoms, such as transient ischemic attacks or strokes, may occur in the clinical presentation of Eagle syndrome, known as stylocarotid syndrome. This happens when the elongated and deviated styloid process impacts and runs above the internal carotid artery [6] The styloid process is considered elongated when it exceeds 30 mm in length. This condition has a prevalence that can reach 33.4% of the population, yet only a few cases become symptomatic [7]. It can be unilateral or bilateral, as described in the literature [8, 9]. This condition is more frequently found in women than in men (3:1 ratio) [10]. Diagnosis typically occurs between the fourth and sixth decades of a patient's life [11]. Usually, the medical history includes tonsillectomy (31.3% of patients), dental procedures, blunt traumas such as motor vehicle crashes, as the hypothetical pathogenesis of this occurrence may be possibly explained by the process of scarring in the tonsillar fossa close to the stylohyoid system [12-14]. Today, we recognise different presentations of ES. The first, also known as the classic form, is characterised by secondary neuralgia attributed to the styloid, mainly distinguished by pain in the cervical and facial regions. The carotid form involves the internal carotid, and the jugular form involves conflict between the styloid, jugular vein, and often the transverse process of the cervical vertebra. ES can be treated either conservatively or by surgical styloidectomy. Conservative treatments include systemic use of nonsteroidal anti-inflammatory drugs, steroids, or antidepressants, as well as local injection of steroids or anaesthetics like lidocaine [15]. Surgical management is reserved for patients in whom conservative treatments fail and consists of the shortening of the styloid process (partial styloidectomy) by transcervical open approach or transoral approach [16]. In recent years, transoral robotic surgery (TORS) has been proposed as an alternative to traditional transoral styloidectomy [8, 17]. The transcervical approach begins with an incision in the submandibular skin, typically a few centimetres below the mandible's inferior border, to safeguard the facial nerve's marginal mandibular branch. The landmarks to follow to perform the incision are the mastoid tip, the anterior margin of the sternocleidomastoid muscle, following a virtual line connecting it to the hyoid bone. After incising the platysma and superficial cervical fascia, acc