European Journal of Cardiovascular Medicine

Chronic otitis media (COM) is a long-standing infection and inflammation of the middle ear cleft characterised by persistent or recurrent ear discharge through a perforated tympanic membrane, usually of more than three months' duration. The World Health Organization identifies chronic suppurative otitis media as a major public health problem, and estimates that the burden of disease is highest in South-East Asia, the Western Pacific and sub-Saharan Africa, where poverty, overcrowding, poor hygiene and limited access to health care persist [1]. Systematic reviews describe COM as a disease that is both common and under-treated in resource-limited settings, with hearing loss as its most frequent sequel [2].

In India, the prevalence of COM is substantial, particularly in rural and low-income populations. Community-based work from southern India documented considerable otitis media and associated hearing impairment among rural school children [3], and tertiary hospitals across the country continue to receive large numbers of patients with chronic

ear disease, many of whom present late after repeated inadequate treatment. Nutritional deficiency, recurrent upper respiratory tract infection, adenoid hypertrophy, delay in seeking care and the widespread practice of self-medication and instillation of home remedies are important contributors.

Clinically, COM is classically divided into the tubotympanic (mucosal, "safe") type and the atticoantral (squamosal, "unsafe") type. The latter is associated with cholesteatoma, granulation tissue and osteitis, which progressively destroy the ossicular chain and the bony walls that separate the middle ear and mastoid from the labyrinth, facial canal, dura of the middle and posterior cranial fossae and the sigmoid sinus [4]. Tubotympanic disease is generally benign, but acute exacerbations with virulent organisms and thrombophlebitis can also lead to complications.

Complications of COM are conventionally classified as extracranial (extratemporal and intratemporal), including postaural and Bezold abscess, coalescent mastoiditis, facial nerve palsy, labyrinthine fistula, labyrinthitis and petrositis, and intracranial, including extradural abscess, subdural empyema, meningitis, brain abscess, lateral (sigmoid) sinus thrombophlebitis and otitic hydrocephalus. Although the incidence has fallen markedly with antibiotics, the problem has not disappeared, and complications continue to be reported from both developed and developing nations [5–7]. Reported mortality from intracranial extension remains significant, particularly with brain abscess and delayed presentation.

Indian series have repeatedly shown that patients with complicated disease are predominantly young, from rural backgrounds and have unsafe disease with cholesteatoma [8–10]. Because the clinical presentation of a complication may be subtle and can be masked by prior antibiotic therapy, a high index of suspicion, early imaging and aggressive multidisciplinary treatment are needed. Regional data on the clinical profile and outcome of treatment help tertiary centres plan referral pathways, surgical expertise and preventive strategies. The present prospective study was therefore undertaken to describe the clinical profile of complications of COM and to evaluate the management and outcome in a tertiary care centre.

AIMS AND OBJECTIVES

• To study the clinical profile and demographic distribution of patients with complications of chronic otitis media.
• To determine the types and frequency of extracranial and intracranial complications.
• To identify the bacteriological profile and antibiotic sensitivity pattern in complicated COM.
• To evaluate the surgical and medical management and the outcome at follow-up.

Study design and setting

This was a hospital-based prospective observational study conducted in the Department of Otorhinolaryngology and Head & Neck Surgery of a tertiary care teaching hospital over a period of 12 months, from January 2019 to December 2019. Institutional Ethics Committee approval was obtained before commencement, and written informed consent (or consent from parents or guardians for minors) was taken from all participants.

Study population and sample size

All consecutive patients of any age and sex diagnosed with COM and at least one extracranial or intracranial complication, presenting to the outpatient department, emergency department or referred from peripheral centres, were screened. During the study period 1,246 patients with COM were evaluated, of whom 80 fulfilled the criteria and were included. A consecutive sampling method was used for the entire study period.

Inclusion and exclusion criteria

Inclusion criteria: (a) patients with clinically diagnosed COM (tubotympanic or atticoantral) with perforation and ear discharge, with or without cholesteatoma; (b) presence of one or more complications confirmed clinically and/or radiologically; (c) consent to participate and to follow-up.

Exclusion criteria: (a) acute otitis media or acute mastoiditis without a background of chronic disease; (b) post-traumatic or congenital causes of facial palsy, meningitis or brain abscess of non-otogenic origin; (c) patients with previous mastoid surgery presenting with recurrent disease only (without complication); (d) patients unwilling to participate.

Clinical evaluation

A structured proforma was used to record age, sex, residence, socioeconomic status (modified Kuppuswamy scale), duration of disease, presenting symptoms and prior treatment. Otoscopy and otomicroscopy were carried out to document the type of perforation, presence of cholesteatoma, granulations, polyp and foul-smelling discharge. Tuning fork tests (Rinne, Weber, absolute bone conduction), facial nerve function (House–Brackmann grading), fistula test, cerebellar signs, fundus examination, neck stiffness and Kernig's sign were assessed in every patient. Postaural region was examined for swelling, tenderness, sagging of the posterosuperior canal wall and neck extension of an abscess.

Investigations

Routine haematological and biochemical investigations were done in all patients. Pure tone audiometry was performed in patients fit for testing. Ear discharge or intraoperative pus was sent for aerobic and anaerobic culture, fungal smear and antibiotic sensitivity by the Kirby–Bauer disc diffusion method as per CLSI guidelines. High-resolution computed tomography (HRCT) of the temporal bone with 0.625 mm slices in axial and coronal planes was obtained in all patients. Contrast-enhanced CT or MRI with MR venography of the brain, and lumbar puncture with CSF analysis (when not contraindicated), were performed in those with clinical suspicion of an intracranial complication.

Management protocol

All patients were admitted and started on intravenous broad-spectrum antibiotics (a third-generation cephalosporin with metronidazole, with an anti-pseudomonal agent added where indicated), later modified according to culture and sensitivity. Patients with raised intracranial pressure received osmotic agents and anticonvulsants as required. Surgery was planned after stabilisation and was individualised: cortical mastoidectomy, canal wall up mastoidectomy, canal wall down (modified radical) mastoidectomy or radical mastoidectomy, with exposure of the dura or sigmoid sinus and drainage of extradural collections when required. Brain abscess and subdural empyema were managed in collaboration with the neurosurgical team by burr-hole aspiration or craniotomy. Tympanoplasty or ossiculoplasty was deferred to a later stage where indicated.

Follow-up and outcome measures

Patients were followed at 1 week, 1 month and 3 months after discharge. Outcome measures were resolution of the complication, status of the ear (dry or discharging), residual hearing loss on audiometry, residual facial weakness (House–Brackmann grade), residual neurological deficit, duration of hospital stay and mortality.

Statistical analysis

Data were entered in Microsoft Excel and analysed using SPSS software version 26.0. Categorical variables are expressed as frequencies and percentages, and continuous variables as mean ± standard deviation. The chi-square test or Fisher's exact test was used for comparison of proportions and the independent t-test for comparison of means. A p-value of less than 0.05 was considered statistically significant.

During the 24-month study period, 1,246 patients with COM were evaluated, of whom 80 (6.4%) had one or more complications and formed the study population. A total of 87 complications were recorded; 73 patients (91.3%) had a single complication and 7 patients (8.8%) had two complications.

Age and sex distribution

The age of the patients ranged from 4 to 68 years (mean 24.6 ± 14.2 years). The maximum number of patients belonged to the 11–20-year age group (30.0%), followed by the 21–30-year group (25.0%); 70.0% of patients were below 30 years of age. There were 46 males (57.5%) and 34 females (42.5%), giving a male-to-female ratio of 1.35:1 (Table 1).

Table 1: Age and sex distribution of patients (n = 80)

Sociodemographic profile and duration of disease

Sixty-five percent of patients resided in rural areas, and nearly half (47.5%) belonged to the lower socioeconomic class. A history of ear discharge for more than five years was present in half of the patients (50.0%), while 11.3% had a disease duration of less than one year (Table 2). Previous treatment from unqualified practitioners or self-medication with ear drops was reported by 38 patients (47.5%).

Table 2: Sociodemographic profile and duration of disease (n = 80)

Presenting symptoms

Ear discharge (92.5%) and hearing loss (85.0%) were the commonest otological symptoms. Among symptoms suggesting a complication, fever (45.0%), headache (41.3%), postaural swelling (27.5%), vomiting (21.3%) and vertigo (22.5%) were prominent. Altered sensorium or neck stiffness was present in 11 patients (13.8%) and facial weakness in 9 patients (11.3%) (Table 3).

Table 3: Presenting symptoms (n = 80; multiple responses)

Type and laterality of disease

Fifty-nine patients (73.7%) had atticoantral disease and 21 (26.3%) had tubotympanic disease. Cholesteatoma was confirmed at surgery in 57 patients (71.3%), granulation tissue or polyp in 41 (51.3%) and ossicular erosion in 49 (61.3%). The left ear was involved in 47.5%, the right ear in 45.0% and both ears in 7.5% of patients (Table 4).

Table 4: Type and laterality of chronic otitis media (n = 80)

Spectrum of complications

Extracranial complications alone were found in 47 patients (58.8%) and intracranial complications (with or without an extracranial complication) in 33 patients (41.3%). Postaural (subperiosteal) abscess was the single commonest complication (22.5%), followed by meningitis (13.8%), facial nerve palsy (11.3%), coalescent mastoiditis (11.3%) and sigmoid sinus thrombophlebitis (11.3%). Brain abscess was seen in 6 patients (4 temporal lobe, 2 cerebellar). The seven patients with combined complications comprised postaural abscess with sigmoid sinus thrombophlebitis (2), extradural abscess with meningitis (2), brain abscess with meningitis (2) and labyrinthine fistula with facial palsy (1). The distribution is shown in Table 5.

Table 5: Distribution of complications (87 complications in 80 patients)

Exceeds 100% because seven patients had two complications each

Radiological and operative findings

HRCT of the temporal bone was performed in all 80 patients. Contrast-enhanced CT or MRI of the brain was obtained in 38 patients, confirming an intracranial complication in 33. Bone erosion of the sinus plate (23.8%) and tegmen tympani (18.8%) correlated with sigmoid sinus and extradural complications respectively, and lateral semicircular canal erosion was present in all six patients with labyrinthine fistula (Table 6).

Table 6: HRCT temporal bone and operative findings (n = 80)

Audiological profile

Pure tone audiometry could be performed in 71 patients; the remaining nine were too ill at presentation. Conductive hearing loss was found in 38 patients (53.5%), mixed hearing loss in 27 (38.0%) and severe-to-profound sensorineural loss in 6 (8.5%), the last group corresponding to patients with labyrinthitis.

Microbiological profile

Culture of ear discharge or intraoperative pus was done in 74 patients, with growth in 61 (82.4%). Pseudomonas aeruginosa was the commonest isolate (31.1%), followed by Staphylococcus aureus (23.0%), of which four isolates were methicillin-resistant (MRSA), and Proteus species (13.1%). Fungal growth was seen in three patients (4.9%) (Table 7). Among the Pseudomonas isolates, sensitivity was highest to imipenem (94.7%), piperacillin-tazobactam (89.5%) and amikacin (84.2%), and lower to ciprofloxacin (78.9%) and ceftazidime (73.7%). All Staphylococcus aureus isolates were sensitive to vancomycin and linezolid.

Table 7: Bacteriological profile (n = 61 positive cultures)

Association of disease type with class of complication

Intracranial complications were more frequent in atticoantral than tubotympanic disease (84.8% versus 15.2% of intracranial cases), but the difference did not reach statistical significance (χ² = 3.57, df = 1, p = 0.059) (Table 8).

Table 8: Type of COM versus class of complication

Management

All 80 patients received intravenous antibiotics. Seventy-seven patients (96.3%) underwent surgery. Canal wall down mastoidectomy (modified radical) was the commonest operation (55.0%), followed by cortical mastoidectomy (20.0%) and canal wall up mastoidectomy (15.0%). Postaural and Bezold abscesses were incised and drained at the time of mastoidectomy. Extradural abscesses were drained through the eroded tegmen after mastoidectomy, and the sigmoid sinus was exposed and the perisinus pus evacuated in all nine patients with thrombophlebitis. Four patients with brain abscess and one with subdural empyema underwent neurosurgical drainage (burr-hole aspiration in four, craniotomy in one). Three patients who presented in a moribund state with advanced intracranial sepsis were managed conservatively and did not survive to surgery (Table 9).

Table 9: Surgical procedures performed (n = 80)

Neurosurgical procedures (burr-hole aspiration or craniotomy; n = 5) were performed in addition to mastoidectomy in the above patients.

Hospital stay and outcome

The mean hospital stay was 13.1 ± 7.8 days overall, and was significantly longer in patients with intracranial complications (19.4 ± 8.2 days) than in those with extracranial complications alone (8.6 ± 3.1 days) (t = 7.2, p < 0.001) (Table 10). At the three-month follow-up, 62 patients (77.5%) had made a complete recovery with a dry, healed cavity or ear, 9 (11.3%) had residual hearing impairment requiring rehabilitation, 3 (3.8%) had residual facial weakness (House–Brackmann grade III) and 3 (3.8%) had residual neurological deficit. Of nine patients with facial palsy (grade III in four, IV in three and V in two), six recovered to grade I–II after decompression and disease clearance. Three patients died (mortality 3.8%): one with temporal lobe abscess and meningitis, one with cerebellar abscess, and one with subdural empyema; all deaths were in the intracranial group (3/33, 9.1%; Fisher's exact p = 0.066) (Table 11).

Table 10: Duration of hospital stay (days)

Table 11: Outcome at three-month follow-up (n = 80)

Complications of COM are a serious sequel of a disease that is largely preventable and treatable. In this prospective study, 6.4% of COM patients seen at our tertiary centre presented with at least one complication, a figure that reflects the referral nature of the hospital and cannot be extrapolated to the community. Even so, the finding underscores that late presentation and inadequate treatment continue to feed complicated disease in India, as noted in earlier reports from tertiary centres [8–10].

Most of our patients were in the second and third decades of life, with 70.0% below 30 years, and there was a mild male predominance. A similar young age profile and male preponderance have been described in Indian studies of complicated COM [8–10]. Young age at presentation may reflect more aggressive disease, a greater tendency to cholesteatoma growth in the paediatric and adolescent mastoid, and more frequent exposure to upper respiratory infections. The predominance of rural residents (65.0%) and lower socioeconomic class (47.5%) in our series matches the community-level observations of Jacob et al. in southern India [3] and supports the argument that poor access to otological care, malnutrition, crowding and unsupervised treatment drive disease progression. Nearly half of our patients had consulted unqualified practitioners or used self-prescribed ear drops, a finding that emphasises the importance of public education and training of primary care physicians in early referral.

Atticoantral disease was present in 73.7% of our patients and cholesteatoma was confirmed at surgery in 71.3%. Cholesteatoma and associated osteitis are widely regarded as the principal mechanisms of bone erosion leading to complications [4,5,11]. Rupa and Raman, in a classic Indian study from Vellore, found that complicated COM was strongly associated with cholesteatoma and unsafe disease [8], and subsequent work by Vikram et al. and Sharma et al. likewise emphasised the importance of cholesteatoma in patients with complications [9,10]. Our finding that 28 of 33 intracranial complications occurred with atticoantral disease is in keeping with this, although the association with intracranial extension was not statistically significant (p = 0.059), most probably due to

the modest sample size. It is notable that 26.3% of our patients had tubotympanic disease, and five of them developed intracranial complications. This shows that mucosal disease is not always benign, and that acute exacerbations of virulent infection or retrograde thrombophlebitis can produce serious intracranial sepsis even without cholesteatoma.

HRCT of the temporal bone was invaluable in our patients. It demonstrated cholesteatoma-pattern soft tissue, ossicular and bony erosion, sinus plate and tegmen defects, and canal fistulae, and these findings were confirmed at surgery. Gaurano and Joharjy reported characteristic CT findings that allow cholesteatoma to be recognised and its extent defined [12], and we agree that preoperative HRCT guides surgical planning, particularly the safe handling of the dura, sigmoid sinus, facial canal and labyrinth.

In our study, extracranial complications alone accounted for 58.8% of patients, and intracranial complications for 41.3%. The relative frequency of intracranial and extracranial complications varies widely between series. Reviews from Thailand [6] and Turkey [7], and later from Turkey and Brazil [13,14], have reported different proportions depending on referral patterns and the era studied, and Dubey and Larawin observed that extracranial and intracranial complications often coexist in the same patient [5]. In keeping with the latter, 8.8% of our patients had more than one complication, which should always prompt a search for a second site of disease, particularly an intracranial focus in a patient with a postaural or neck abscess.

Postaural subperiosteal abscess was the commonest single complication (22.5%), an observation consistent with several Indian series in which coalescent mastoiditis and postaural abscess form the largest group of extracranial complications [9,10]. Its high frequency probably reflects the dominance of cortical bone erosion by cholesteatoma and osteitis in our referral population. Intracranial complications were led by meningitis (13.8%), sigmoid sinus thrombophlebitis (11.3%) and extradural abscess (10.0%), followed by brain abscess (7.5%). Many series report meningitis as the commonest intracranial complication, while brain abscess, particularly temporal lobe and cerebellar abscess, carries the highest mortality [14,15]. Intracranial complications should be suspected in any COM patient with persistent headache, vomiting, fever, neck stiffness, altered sensorium or focal neurological signs, and a low threshold for contrast imaging is essential.

Facial nerve palsy was seen in 11.3% of our patients and is a well-recognised complication of cholesteatoma, caused by direct erosion of the Fallopian canal or by inflammatory oedema of the nerve [4,16]. In the presence of cholesteatoma, early surgical decompression and disease clearance gave good recovery: six of nine patients recovered to House–Brackmann grade I–II, similar to the generally favourable prognosis reported for facial palsy secondary to COM when surgery is not delayed. Labyrinthine fistula and labyrinthitis occurred in 12.5% of cases. In the presence of a fistula we removed the cholesteatoma matrix with care and covered the exposed membranous labyrinth with fascia, aiming to preserve residual hearing; the six patients with profound sensorineural loss were those with established labyrinthitis [16].

Ear discharge and hearing loss were almost universal, but the symptoms of a complication, namely fever, severe headache, vomiting, vertigo, postaural swelling and facial weakness, were what ultimately brought many patients to hospital. Pre-treatment with oral antibiotics may mask classical signs and cause "latent" or partially treated mastoiditis, which may progress silently to extradural abscess or sinus thrombosis. We found that the clinical suspicion, supported by HRCT and contrast neuroimaging, led to the diagnosis in all but a few patients. The three patients who died had all presented late with advanced sepsis and altered sensorium after prolonged treatment elsewhere, underlining the importance of early referral.

Pseudomonas aeruginosa and Staphylococcus aureus were the commonest isolates in our series (31.1% and 23.0%), followed by Proteus and Klebsiella species. Indian bacteriological studies on CSOM from different regions have consistently reported Pseudomonas aeruginosa and Staphylococcus aureus as the predominant pathogens, with a smaller share of Proteus, Klebsiella and E. coli [17–19]. The emergence of MRSA (four isolates, 28.6% of S. aureus) and of resistance to ciprofloxacin and ceftazidime among Pseudomonas isolates supports the view that empirical treatment should be modified promptly according to culture reports, and that topical or systemic quinolones should not be used indiscriminately. Biofilm formation and polymicrobial infection, which impair antibiotic penetration and contribute to persistence, are increasingly recognised as important features of COM [20]. Fungal isolates (4.9%) were seen mostly in patients with a history of prolonged use of topical antibiotic–steroid drops, and we recommend fungal smear and culture in refractory disease.

The principle of management in complicated COM is to combine aggressive medical therapy, including culture-guided intravenous antibiotics and supportive neurological care, with surgical eradication of the primary focus in the temporal bone. The majority of our patients (55.0%) underwent canal wall down mastoidectomy, which is generally preferred in complicated cholesteatoma because it allows wide exteriorisation of disease, easy access to the tegmen, sinus plate and facial canal, and easy long-term surveillance. Canal wall up surgery was reserved for selected patients with extensive pneumatisation and limited disease, such as those with coalescent mastoiditis, in whom a second-look procedure could be planned. The same approach has been advocated by other authors who emphasise that clearance of the primary focus is the key to cure and that the type of mastoidectomy should be dictated by extent of disease [5,10,11].

Neurosurgical collaboration was crucial in the management of brain abscess and subdural empyema. Aspiration through a burr-hole under imaging guidance was effective in our patients with temporal lobe abscess, with mastoid surgery performed once the patient was neurologically stable. The overall mortality of 3.8% in our series, confined to the intracranial group (9.1%), compares favourably with the higher mortality described in earlier decades, and in line with observations that mortality is linked mostly to brain abscess, delayed presentation and altered sensorium at admission [14,15]. Patients with intracranial complications also had a significantly longer hospital stay (19.4 versus 8.6 days), reflecting prolonged intravenous therapy, neurosurgical procedures and monitoring.

Three-quarters of our patients (77.5%) recovered completely, but a significant minority were left with permanent hearing impairment, facial weakness or neurological deficit. Because many patients are young, residual hearing loss is a lifelong problem, and plans for later ossiculoplasty, tympanoplasty or hearing amplification need to be discussed at an early stage. Regular long-term follow-up is essential for patients treated by canal wall down mastoidectomy because of the risk of recurrent cholesteatoma and cavity problems.

Because the majority of complications in our study arose from long-standing, inadequately treated unsafe disease in rural, low-income patients, strategies to reduce the burden should concentrate on early detection and referral. These include school and community ear-screening programmes, training of primary health workers in recognising "danger signs" (postaural swelling, facial weakness, severe headache, vertigo, fever with discharge), discouraging self-medication with ear drops, and ensuring access to safe surgery at district-level centres. The National Programme for Prevention and Control of Deafness in India provides a framework within which these measures can be strengthened.

Limitations

This was a single-centre study with a modest sample size, so the findings reflect referral patterns of a tertiary hospital and cannot be generalised to the community incidence of complications. The three-month follow-up was too short to assess recurrence of cholesteatoma or long-term hearing outcomes. A multicentre study with a longer follow-up and standardised hearing assessment would give more robust data.

Complications of chronic otitis media continue to occur in young, rural and economically disadvantaged patients, mostly with atticoantral disease and cholesteatoma. Postaural abscess, meningitis, facial nerve palsy and sigmoid sinus thrombophlebitis were the most frequent complications in this series, and intracranial complications were associated with longer hospital stay and all the deaths. HRCT of the temporal bone, early contrast neuroimaging, culture-guided intravenous antibiotics, timely mastoid surgery to remove the primary focus and neurosurgical collaboration produced complete recovery in more than three-quarters of patients. Early diagnosis and treatment of COM at the primary care level, public awareness and prompt referral of patients with danger signs remain the most effective ways of preventing these potentially life-threatening complications.

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