Active squamous chronic otitis media (COM) is a synonym of cholesteatoma which leads to severe destruction with irreversible sequelae of intra or extracranial complications of otogenic origin [1]. Hence, an otogenic abscess is a rare clinical entity (1:10000) but required surgical emergency to be drained out to avoid complications [2].

As per our experience incidences of active squamous COM in spite of improved health education, socioeconomic status, resistance of organism to antibiotics and uncontrolled bacterial infection were noticed [1,3,4]. Due to in judicial use of latest antibiotics the disease has not yet completely regressed. Lifestyle changes attributed to metabolic diseases like diabetes mellitus and increased frequency of ear infections because of recurrent episodes of rhinosinusitis due to fitness activities like swimming, diving. Frequent use of ear plugs, air travels and recently increased use of cotton buds to clean the ear have also at times caused retraction of tympanic membrane.

Infection can spread from middle ear through preformed anatomical or pathological pathways like fracture of temporal bone, dehiscence of the floor of middle ear, non-union petro-squamous suture. Also spreads by 1) pathological implantation or invasion or metaplasia theory leads into bony erosion and osteitis of mastoid bone (tegmen tympani or Trautmann’s triangle) [5,6] or through 2) demineralization of bone or 3) venous thrombophlebitis i.e. connection between tributaries of dural veins with tributaries of Haversian canals; leads into meningitis, lateral sinus thrombophlebitis and finally leads into neurological instability of patients and 4) along with peri-arteriolar Virchow-Robin spaces into cerebral white matter. So squamous active COM can lead to lethal complications hence it’s a potentially serious disease [7].

Middle ear with mastoid erosion leads to collection of pus between the dura and cranium. It gets collected around the lateral sigmoid sinus and due to low host immunity leads to sigmoid sinus thrombosis which may extend down to involve internal jugular vein; it may further lead to complication of pulmonary embolism, ultimately leading to pulmonary infarct which due to early treatment is rare nowadays [5,8,9,10].

Following surgery options: as per patient’s medical treatment and clinical stability:

Fig-1: Surgery options

One staged procedure: Patients who were stable, underwent incision and drainage of extracranial abscess along with canal wall down tympano-mastoidectomy at the same sitting. In each case; pus for culture and sensitivity test (SCAST) collected and post-operatively patients were treated as per SCAST report.

Two staged procedure: Those who had intracranial abscess and unstable were treated by the two stage procedure i.e. initially intracranial abscess drainage with cyst wall excision by neurosurgeon through craniotomy or burr-hole surgery to avoid intracranial spread from infected origin i.e. mastoid followed by canal wall down tympano-mastoidectomy [14].

Sex distribution: Out of 82 patients 52 were male (63.4%) and 30 were female (36.5%). Males were more commonly affected than females [5].

Age distribution: In the present study, any age can be affected but most commonly the age of disease presentation was second decade (34.1%) followed by first decades (26.8%) [15]. While in age group of 31-40 years, 41-50 years and 51-60 years were also affected with number of patients were 12(14.6%), 11(13.4%) and 09 (10.9%) respectively.

Clinical Presentation:

Table-1: Clinical presentation.

mastoidectomy.

1) Patients with intracranial abscess :50

Table-3: Intracranial abscess: Two staged management

For meningitis, sigmoid sinus thrombosis and petrous apex abscess; medical management is the first line treatment. If medical line of treatment of sigmoid sinus thrombosis fails then surgical exploration with removal of thrombus and packing of cavity with gelfoam to block the vessel [17].

It was found (Table 3) that most commonly cerebral abscess (21.9%) in temporo-parietal region and then cerebellar abscess (14.6%). In these cases patients underwent abscess drainage with cyst wall excision through craniotomy or burr-hole surgery. After one week of stability and antibiotic coverage, patients had undergone canal wall down tympano-mastoidectomy.

2) Patients with extracranial abscess: 16

Table-4: Extracranial abscess: Two staged management

While in extracranial abscess, subperiosteal abscess were 9.75% and less number of Citelli’s abscess only 1.21% (Table 4). Extracranial abscess breakthrough mastoid bone and spread into subcutaneous plane (Figure 3) lead into postaural tender swelling.

Fig-5: HRCT Temporal bone: labyrinthine fistula: lateral semicircular canal dehiscence with soft tissue embedded in middle ear and mastoid cavity.

Table 6: Post-operative complications.

In the present study, there was no mortality but had raised morbidity due to intracranial abscess. In 12(14.63%) cases, patients required revision surgery for management of complications. Facial nerve palsy could not be corrected as they were irreversibly damaged by the disease.

In the study of 82 cases of otogenic abscess who presented in our department, the discussion is based on clinical presentations, intra-operative findings and their management.

Squamous active COM with complications is more in developing countries [18]

In the study majority cases were between 10-30 years of age with maximum incidence in second decade (34.1%) followed by first decade (26.8%). Youngest being 12 years and oldest being 58 years. Males were predominantly affected (63.4%) with common presentation of foul smelling otorrhea occasionally blood tinged with hearing loss.

The bacterial etiology was mostly staphylococcus aureus (31.7%), pseudomonas aeroginosa (25.6%) and mycobacterium tuberculosis (10.9%) is also a common entity.

In the present study, the incidence of intracranial complications (60.9%) is more as compared to extracranial (39%) complications. Most common intracranial abscess was cerebral (21.9%) abscess while subperiosteal abscess (9.07%) was common in extracranial abscess.

All the 50 patients with intracranial abscesses had fundoscopy examination and graded accordingly - Grade I papilloedema was commonest 35 cases (42.6%), Grade II papilloedema was seen in 9 cases (10.9%) and Grade III papilloedema was seen in only 1 case (1.21%) of cerebral abscess. No patient showed Grade IV and V papilloedema [14].

Facial canal dehiscence was found in 25 (30.4%) cases without facial nerve palsy. Disease cleared over the exposed facial nerve; in 17 (20.7%) cases only the temporalis fascia graft was kept over the dehiscent bony facial canal. 08 (9.75%) cases required facial nerve decompression along with local steroid application to avoid facial nerve palsy.

Resolution was seen in 04 (3.28%) cases post-operatively with systemic steroidal use and active physiotherapy. Persistent facial palsy in spite of corrective surgery was seen in 04 cases (3.28%).

Incision and drainage of an abscess was followed by eradication of disease from middle ear cleft and mastoid en antrum by canal wall down tympano-mastoidectomy.

In any otogenic abscess, incision and drainage followed by canal wall down tympano- mastoidectomy was the treatment of choice. One or two stage procedure is to be followed as per site of abscess. For effective management antibiotics as per SCAST report to be followed. In developing country tuberculosis should be kept in mind as one of the infective pathology.

Otogenic abscess are common in developing country due to poverty, ignorance towards of ear disease, non-availability of diagnostic as well therapeutic services. Any ear disease should not be neglected to avoid morbid conditions.

After going through the various surgical managements over the years, it can be concluded that in spite of use of various potent antibiotics, spread of information by audio-video techniques, camps, surgical techniques, there is still aura of ignorance and some patients with CSOM comes to hospital with complications.

Canal wall down tympano-mastoidectomy still remains the best procedure for dealing with otogenic abscesses along with medical management with SOS neurosurgeon assistance. Facial nerve palsy once caused is very unlikely to be corrected in some cases. Otogenic abscesses if adequately treated may have presented with persistently discharging ear cavity but abscess formation is extremely rare.