Use of a photoangiolytic diode laser in temporal bone paraganglioma surgery: experience and prospects

Introduction. Over the past few decades, the laser surgery has revolutionized the clinical practice of physicians of various specialties, including otorhinolaryngologists. Some of the most advantageous properties of photoangiolytic lasers, when properly used: coagulation of the superficial and subepithelial blood vessels without damage and destruction of the superficial epithelium, decrease in the energy absorption by the surrounding tissue, and minimization of the coagulation of the perivascular tissue around the target blood vessels. In addition, photoangiolytic lasers allow contactless delivery of a laser pulse through a very small fiberglass (300 or 400 μm). The surgeons can (and should) choose between a cutting laser (usually a carbon dioxide laser) or a photoangiolytic laser (PDL, KTP). During our work, we used a 445 nm wavelength photoangiolytic laser for the surgical treatment of a vascularized tumor – temporal bone paraganglioma. Objective of the study: to analyze the effectiveness of combined surgical treatment of temporal bone paragangliomas with the use of a photoangiolytic laser.

Material and methods. Sixty seven patients diagnosed with temporal bone paraganglioma types A and B underwent surgical treatment at the Federal State Budgetary Institution National Medical Research Center for Otorhinolaryngology of the Federal Medico Biological Agency of Russia, Moscow. In 30 cases, surgical treatment was performed with the use of a photoangiolytic diode laser with a wavelength 445 nm; in 37 cases, surgical treatment was performed with the use of standard methods. We set up high power at 445 nm photoangiolytic diode laser and shortened the working cycles at the highest power to 4 W, 20 ms pulses (5–40 ms), 150 ms pauses (150–300 ms), 400 μm fiberglass diameter with a very short pulse duration and a distance of 1–3 mm from the target tissue for photoangiolysis. Results. All sixty seven patients were at the age of (49.50±8.00). Their case history duration ranged from 15 days to 6 years. All patients complained of pulsatile tinnitus, and 80% of patients with affected ears suffered varying degrees of hearing loss. After using the modified temporal bone paraganglioma excision method with the photoangiolytic laser, there were no postoperative complications in all cases, and the external auditory canal and the incision behind the ear healed satisfactorily. There were no recurrences during the follow up. The anatomical results of myringoplasty in both groups were comparable and accounted for 100% of cases, respectively. In the early (6 months) and late (36 months and more) postoperative period, auditory and vestibular functions were not impaired in any of the groups, which is confirmed by the data of tone threshold audiometry and the absence of vestibular disorders in all patients of the experimental and control groups. There was no facial nerve dysfunction in any of the studied groups; the average blood loss during surgery in patients of the control group was 214.2±63.5 mL, a value significantly higher than that in the experimental group, which was 20.2±4.5 mL; The duration of hospitalization in the experimental group was shorter for 7 days on average than in the control group. Conclusions. Removal of the middle ear tumor was performed with minimal blood loss in the pre and postoperative period, without damage to the surrounding structures of the inner and middle ear. In the future, it is planned to analyze long term postoperative changes both at the tissue and functional levels. Such data will be available only after 36 months from the moment of surgery, as well as when the required number of operations using this technique is reached.

Key words: hearing, ossicular chain, laser surgery, surgical management of paraganglioma, tympanojugular paraganglioma, bleeding
Conflicts of interest. The authors have no conflicts of interest to declare.
Funding. Federal budget.