Diagnosis and treatment of ear canal exostoses

Egzostoze vanjskog zvukovoda su ireverzibilne, benigne, bilateralne i simetrične koštane izrasline. Etiopatogeneza nije još u potpunosti objašnjene, no većina studija jasno pokazuje povezanost čestog izlaganja zvukovoda hladnoj vodi s povećanom pojavnosti egzostoza. (1) Stoga se često termin “surfersko uho” ili rijeđe “ronilačko uho” koristi za opis ove bolesti. Razlog je visoka prevalencija egzostoza u ljudi koji su često izloženi hladnoj vodi, poput; surfera, ronilaca, plivača, spasilaca na plaži. Učestalost pojave egzostoza u općoj populaciji je 3–6%. Uobičajeno egzostoze ostaju male, asimptomatske i slučajno dijagnosticirane tijekom rutinskog otoskopskog pregleda. No progresivni razvoj okluzije zvukovoda, potaknut cerumenom ili stranim materijalom, može dovesti do klinički značajne upale vanjskog slušnog kanala, provodnog gubitka sluha, bolnosti i tinnitusa. Opstrukcija zvukovoda od najmanje 80% postaje klinički relevantna te može uzrokovati simptome. (2) Dijagnoza egzostoza zvukovoda se postavlja prevenstveno pomoću otoskopskog pregleda. Ozbiljnost egzostoza tj. stupanj opstrukcije ocjenjuje se od 0 do 3, na temelju postotka okluzije slušnog kanala, koji se vidi na fizičkom pregledu. Nemogućnost identifikacije egzostoze otoskopskim pregledom je stupanj 0, okluzija od 33% je blagi oblik egzostoze (stupanj 1), okluzija od 33% do 66% je umjereni oblik (stupanj 2), a egzostoza s okluzijom više od 66% smatra se teškim oblikom (stupanj 3). Za daljnju procjenu i dijagnozu zlatni standard je slikanje pomoću CT-a. Radi se CT temporalne kosti, tj. vanjskog slušnog kanala. Stanja koja potencijalno mogu proizvesti najsličniju simptomatologiju i slike na CT-u s egzostozama zvukovoda su osteom vanjskog uha, kolesteatom, keratosis obturans i fibroza medijalnog kanala. Terapija egzostoza vanjskog zvukovoda može biti konzervativna i kirurška. U večini slučaja se liječenje započinje konzervativno, tj liječe se novonastali simptomi, a ako izostanu rezultati, nastavlja se kirurškim pristupom. U slučaju potpune obliteracije zvukovoda egzostozama jedini izbor je kirurško liječenje. Pristup na egzostoze može biti kroz zvukovod (transmeatalno), endauralno ili retroaurikularno. Najčeće komplikacije neliječenih egzostoza su rekurentni otitis externa, potpuna obliteracija zvukovoda i konduktivni gubitak sluha.Exostoses of the external auditory canal are irreversible, benign, bilateral and symmetrical bone growths. The etiopathogenesis has not yet been fully explained, but most studies clearly show the connection between frequent exposure of the ear canal to cold water and an increased incidence of exostoses. (1) Therefore, the term "surfer's ear" or more rarely "diver's ear" is often used to describe this disease. The reason is the high prevalence of exostoses in people who are often exposed to cold water, such as; surfers, divers, swimmers, lifeguards on the beach. The frequency of occurrence of exostoses in the general population is 3–6%. Usually, exostoses remain small, asymptomatic and incidentally diagnosed during a routine otoscopic examination. But the progressive development of ear canal occlusion, induced by cerumen or foreign material, can lead to clinically significant inflammation of the external auditory canal, conductive hearing loss, pain and tinnitus. An ear canal obstruction of at least 80% becomes clinically relevant and may cause symptoms. (2) The diagnosis of ear canal exostosis is made preventively using an otoscopic examination. The severity of exostoses, i.e. the degree of obstruction, is graded from 0 to 3, based on the percentage of occlusion of the auditory canal, which can be seen on physical examination. The inability to identify the exostosis by otoscopic examination is grade 0, an occlusion of 33% is a mild form of exostosis (grade 1), an occlusion of 33% to 66% is a moderate form (grade 2), and an exostosis with an occlusion of more than 66% is considered a severe form ( degree 3). For further evaluation and diagnosis, the gold standard is CT imaging. A CT scan of the temporal bone, i.e. the external auditory canal, is performed. Conditions that can potentially produce the most similar symptomatology and images on CT with exostoses of the ear canal are osteoma of the external ear, cholesteatoma, keratosis obturans and fibrosis of the medial canal. Therapy of exostosis of the external auditory canal can be conservative or surgical. In most cases, the treatment is started conservatively, i.e. new symptoms are treated, and if there are no results, it is continued with a surgical approach. In case of complete obliteration of the ear canal by exostoses, the only choice is surgical treatment. Access to exostoses can be through the ear canal (transmeatal), endaural or retroauricular. The most common complications of untreated exostoses are recurrent otitis externa, complete obliteration of the ear canal and conductive hearing loss