Innovative algorithm for treating patients with temporal bone paragangliomas

Background. According to global literature, paraganglioma is a relatively rare tumor that arises from nonchromaffin paraganglion cells, also called glomus bodies, and therefore has many synonyms: glomus tumor, glomus tympanicum and glomus jugulare tumor, chemodectoma, nonchromaffin paraganglioma, etc. The overall incidence of head and neck paraganglioma ranges from 1 per 30,000 to 1 per 100,000 of the population. Temporal bone paraganglioma is a benign tumor characterized by slow growth, a tendency to invade bone structures and the dura mater, abundant vascularization, and frequent recurrence. All these properties make glomus tumors one of the most difficult diseases in otologic surgery. Given the complexity of the temporal bone and jugular foramen anatomy, as well as the presence of vital anatomical structures involved in the pathological process, we developed and applied an innovative algorithm for managing patients with temporal bone paragangliomas which allowed to provide the most accurate diagnostics and effective differentiated surgical treatment while preserving the middle ear function and the temporal bone architecture. Material and methods. During the period from February 2015 to May 2025, 272 patients with temporal bone paragangliomas (53 men and 219 women) aged 18 to 89 were examined and operated on at the National Medical Research Center for Otorhinolaryngology. To assess the extent of tumor spread, involvement of vital anatomical structures, and to choose the optimal surgical strategy, all patients underwent preoperative CT of temporal bones and MRI of the head in different modes. In advanced cases, angiography combined with embolization of the tumor-feeding vessels was also used. An innovative algorithm of management of patients with temporal bone paragangliomas was developed and applied on the basis of the National Medical Research Center for Otorhinolaryngology of the Federal Medical-Biological Agency.
Results. In the course of our work using an innovative algorithm of treatment of patients with temporal bone paragangliomas, we evaluated the early postoperative and long-term results, assessed the quality of tumor removal based on radiological diagnostic methods of MRI in the postoperative period, and evaluated the auditory function and the function of the lower cranial nerves. In the postoperative period, according to the data of threshold and pure tone audiometry, there was improvement of hearing in patients with types A–B1 paragangliomas, while hearing remained at the same level or there was a slight decrease due to the increase of sound conduction thresholds in case of type B3 paraganglioma, by the mean of 10–15 dB. In the early and late postoperative period, no facial nerve weakness was observed in patients with type A and B paragangliomas. Ten patients with type C1–C2 paragangliomas had House-Brackmann grade 2–3 facial palsy after surgery. Six patients with type C3–C4 tumors had House-Brackmann grade 4–5 facial nerve dysfunction with a tendency to gradual recovery after surgical treatment. In the long-term postoperative period (6–24 months), the facial nerve function recovered completely in patients with types C1 and C2 paragangliomas and to the level of House-Brackmann grade 2 in patients with type C3 tumors. The mean blood loss during surgery varied depending on the use of preoperative embolization of tumor-feeding vessels, so the difference of blood loss was 100–150 mL for type B3 tumors, and 350–750 mL for type C paragangliomas. Most patients did not develop a recurrence during the long-term follow-up, except for 5 patients with type C3 who were diagnosed with a recurrence according to MRI findings. The mean duration of hospitalization was 7 calendar days.
Conclusion. An innovative algorithm for the management of patients with temporal bone paraganglioma opens new horizons in the field of diagnosis and treatment of this disease. Timely radiological diagnostics using contrastenhanced MSCT of the temporal bone and MRI of the brain and neck at the first complaints of pulsatile noise provide earlier diagnosis of temporal bone paragangliomas and allows for better surgical intervention planning, considering the extent of the process and the involvement of anatomical structures of the temporal bone. The use of preoperative angiography with selective embolization of tumor-feeding vessels and occlusion of venous sinuses with a coil reduces intraoperative blood loss and decreases the duration of surgical interventions. Intraoperative use of neuromonitoring of the inferior cranial nerves and the use of electromagnetic navigation during tumor removal aims to avoid damage to anatomically vital structures of the temporal bone. The use of modern microscopy equipment together with intraoperative videoendoscopy allows the use of modified minimally invasive surgical accesses with preservation of the function of middle ear structures and temporal bone architectonics. The use of an angiolytic laser to remove tumors directly adjacent to the internal carotid artery allowed the tumor to be removed without damaging the vessel. The use of high-tech modern equipment and the selection of adequate minimally invasive surgical access allow good results to be achieved in the treatment and further observation of patients with paragangliomas of the temporal bone.
Key words: innovative treatment algorithm, retrofacial approach, modified infratemporal approach, angiolytic laser, blood loss, hearing
Conflict of interest. The authors declare that there is no conflict of interest.
Funding. The study has not received any funding.