CO2 Laser Surgery in Patients with Otosclerosis

PICHON RIVIERE, A.; AUGUSTOVSKI, F.; GARCIA MARTI, S.; GLUJOVSKY, D.; ALCARAZ, A.; LOPEZ, A.; BARDACH, A.; CIAPPONI, A; VALANZASCA, P

Documento de Evaluación de tecnologías Sanitarias

IECS

Año: 2013 p. 1 - 30

1668-2793

Otosclerosis is a condition which produces the highest number of hearing losses in white people and it is estimated that 1 every 1,000 individuals suffers otosclerosis symptoms. Otospongiosis is the formation of foci in the inner ear in which bone reabsorption is produced and later more dense and mature new bone tissue is formed (otosclerosis). In 90% of the cases, the stapedial footplate is the location of these foci producing the invasion of it and the later immobilization of the stapes. When the focus immobilized the stapedial-vestibular joint, ?conductive hearing loss? develops. Treatment may include the use of hearing aids, drugs or surgery. Disease progression may be stopped or some symptoms may improve, but it cannot be cured (mainly hypoacusis). In the conductive clinical forms (stapedial fixation) and the mixed forms (stapedial fixation and partial cochlear alterations), there is a chance of recovering hearing loss by microsurgery where the stapes, fixed because of the disease, is removed and substituted by a prostheses. Stapedotomy consists of making a calibrated perforation in an area of the stapedial footplate through which the distal end of the prostheses is passed. This perforation may be carried out using conventional ?micro-scissors?, ?micro-drill? or other mechanical means or laser (CO2, Argon and potassium?-titanyl?phosphate [KTP], among others). It is proposed that CO2 laser surgery would produce less inner ear damage, provide greater precision when perforating the stapedial footplate and the hearing results would be similar to those obtained with conventional tools.TechnologyCO2 laser is based on carbonic gas which is excited by electrical stimulation. It has a wave length of 10,600 nm and it is invisible. It is well absorbed by tissues (collagen, bone and perilymph), has low penetration and an acceptable coagulation capacity by thin vessels.PurposeTo assess the available evidence on the efficacy, safety and coverage related aspects regarding CO2 laser surgery use in patients with otosclerosis.MethodsA bibliographic search was carried out on the main databases: DARE, NHS EED, on Internet general search engines, in health technology evaluation agencies and health sponsors. Priority was given to the inclusion of systematic reviews; controlled, randomized clinical trials (RCTs); health technology assessments and economic evaluations; clinical practice guidelines and coverage policies of other health systems.ResultsNo randomized clinical trials, systematic reviews, coverage policies or clinical practice guidelines were found. Two comparative non-controlled trials, 3 case series which assessed CO2 laser alone or with conventional treatment were found.In the 2 experimental studies, CO2 laser was compared with mechanical techniques (micro-drill or manual perforators) in patients with otosclerosis. The air and bone conduction thresholds, the bone conduction and air-bone gap were calculated before and after surgery for the following frequencies: 250, 500, 1,000; 2,000 and 4,000 Hz. Neither of the 2 studies showed significant differences in the hearing results between the surgeries performed using mechanical techniques and CO2 laser. The case series which evaluated CO2 laser and micro-drill showed no statistically significant differences regarding hearing results.ConclusionsThere is no adequate quality evidence comparing CO2 laser with conventional surgical techniques. The studies found seem to suggest that the safety and hearing results obtained in patients with otosclerosis undergoing CO2 laser would be similar to those obtained with mechanical techniques.