Prospective case series.
Area involved on otoscopy. PS indicates posterosuperior.
Pathologic findings. C indicates cholesteatoma; G, granulation tissue.
Ossicular involvement. N indicates normal; I, involved.
Defects. Others indicates facial nerve, posterior meatal wall, and lateral semicircular canal.
Outcome. Asterisks refer to prognostic indicators.
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Kurien M, Job A, Mathew J, Chandy M. Otogenic Intracranial Abscess: Concurrent Craniotomy and Mastoidectomy—Changing Trends in a Developing Country. Arch Otolaryngol Head Neck Surg. 1998;124(12):1353–1356. doi:10.1001/archotol.124.12.1353
OTITIS MEDIA is common in India. In a survey of a rural primary school in southern India, the prevalence of otitis media was 17.6%.1 In the last 4 decades, the prevalence of intracranial complications (ICCs) following suppurative middle ear disease has declined from 4% to 0.24%, and the mortality has decreased from 25% to 8%.2-6 Two prospective studies of the microbial pattern of brain abscess reported in this decade showed chronic suppurative otitis media (CSOM) to be the most common predisposing factor in 48% of the patients in India7 and in 22.7% of the patients in Malaysia.8
This report represents a prospective case series from Christian Medical College and Hospital in Vellore, in the southern part of India. It is a tertiary academic teaching center with 1700 inpatients. The Ear, Nose, and Throat Department treats approximately 45,000 patients each year. The incidence of CSOM is about 30%.9,10 Fifty-one percent of the ear, nose, and throat emergencies in our hospital are cases of CSOM with complications. The purpose of this study was to evaluate the incidence, clinical profile, treatment, and outcome of patients admitted with otogenic intracranial abscess and to highlight the advantages of concurrent craniotomy and mastoidectomy.
This prospective case series included patients who were admitted to our hospital between January 1990 and June 1996 with clinically diagnosed otogenic intracranial abscess that was confirmed by computed tomographic scanning. All the patients underwent definitive neurosurgical intervention (total or subtotal excision of the abscess and/or drainage of empyema) and mastoidectomy during the same procedure. A canal wall down procedure with a meatoplasty was performed in all patients by means of an endaural approach. The operative findings and outcome were evaluated in both adults and children. All patients received 1 to 5 years of follow-up.
There were 157 patients diagnosed as having intracranial abscess during the study period. Thirty-six cases (23%) were of otogenic origin. Twenty-one patients (58%) were children (patients aged 16 years and older were considered adults), and there was a male preponderance in both the adult and the pediatric groups (Figure 1). The children ranged in age from 7 to 16 years (mean age, 12 years) and the adults from 16 to 53 years (mean age, 19 years). Although a small percentage in both groups had bilateral CSOM, the left ear was the affected side in 80% of the children and in 60% of the adults (Figure 2). Posterosuperior or attic retraction was seen more commonly in both groups. Nineteen percent of the children also had combined attic and posterosuperior involvement. Total perforation with secondary acquired cholesteatoma was relatively less common (<14%) (Figure 3).
Although one third of the children showed only granulation tissue on otoscopy, all the patients had cholesteatoma with or without granulation tissue detected at surgery (Figure 4). The malleus was least affected (67%) and the incus was the most affected (100%) in both groups. However, there was significantly more stapedial involvement in the children (95%) than in the adults (67%) (Figure 5). Sinus plate defects were more common than tegmental defects in both groups, while bony defects in the Trautmann triangular space were seen only in children. Also, more than 1 bony defect was seen in 14% of the children, whereas no bony defects were identified in 20% of the adults (Figure 6).
Meningitis was the most common associated ICC, with adults being more affected than children. Cerebellar abscess was the most common intracranial abscess (48%). Temporal abscess and subdural empyema were relatively less common. Perisinus abscess and lateral sinus thrombosis were seen only in children, and hydrocephalus was noted only in adults (Figure 7). More than two thirds of the patients in both groups had more than 1 ICC at the time of admission. In one third of the patients, definitive surgical intervention (Figure 8), consisting of either craniotomy and excision of the abscess and/or drainage of empyema, followed by mastoidectomy (endaural approach, canal wall down procedure with meatoplasty), was performed in 1 procedure in the first 24 hours. The duration of surgery ranged from 6 to 9 hours (mean, 8.2 hours). Four children (19%) and 2 adults (13%) who came to the emergency department with seizures underwent an emergency burr hole procedure in the intensive care unit, and then underwent the above-mentioned procedure after they were stabilized.
There was no significant intraoperative or postoperative morbidity or mortality. The total duration of hospital stay was 4 to 31 days, with approximately one third in both groups staying fewer than 10 days (Figure 8). Gram-negative organisms were isolated in the intracranial specimens from the majority of the patients in both groups: the pus cultures from 57% of the children and 33% of the adults yielded more than 1 organism (Table 1). The patients continued to receive antibiotics and antiedema agents (mannitol and dexamethasone) postoperatively for about 1 week, followed by 6 weeks of oral antibiotics and antiseizure medication. All but 2 adults (94%) belonged to a very poor socioeconomic group and had no medical insurance. Follow-up of these patients showed that none of them had a recurrence of ICCs or residual neurological deficits. However, 3 children (14%) showed evidence of recidivism cholesteatoma, and revision surgery had to be performed.
Chronic suppurative otitis media with ICCs, though on the decline,2-6 continues to be an important health issue in developing countries. Two large series reported incidence rates of 42%5 and 56%,6 with the peak being in the first and second decades of life.4-6 Our series also demonstrated that the peak occurred in the early second decade of life and that males were predominantly affected. To our knowledge, laterality of the ear in relation to the ICCs has not been noted previously. In our series, 80% of the children had CSOM in the left ear and 60% of the adults had it in the right ear.
Chronic suppurative otitis media with ICCs has been reported in cholesteatomatous (58%)5,6 and noncholesteatomatous ears (21%5 and 42%6). Cholesteatoma was seen in 67% of the ears of patients who were surgically treated at our institution in an earlier study of otogenic meningitis,11 a percentage that was similar to those given in previous reports.5,6 However, in our present study of otogenic intracranial abscess, 100% of the patients had cholesteatoma. This is the same percentage as that reported by Kangsanarak et al.5 In the white population, cholesteatoma is typically the primary acquired type, with attic perforation/retraction or posterosuperior retraction,9,10 and in the Asian population, it is predominantly the secondary acquired type.12 In our study of intracranial abscess, more than 85% of both groups had attic or and posterosuperior involvement with total perforation. The incus was involved in all patients in both groups, while the malleus was involved in the fewest patients (67%) in both groups. This observation has been noted by other investigators.9,10 The stapes was affected in the majority of the children (95%) and less involved in the adults (67%). This finding has not been reported previously, to our knowledge. Meningitis was the most commonly reported ICC, followed by brain abscess.4,5 In our series, meningitis was also the most common coexisting ICC, noted in 9 adults (60%) and 9 children (43%). In an earlier study of otogenic meningitis, coexisting ICCs were reported in 36% of the patients.5 Cerebellar abscess was the most common intracranial abscess in our series. This finding was contrary to those of 2 previous studies in which a temporal lobe abscess predominance was noted at ratios of 2:113 and 1:1.6 Subdural empyema was relatively less common, similar to previous reports.6 Defects of the sinus plate were the most common bony defects in both groups in our study, followed by defects of the tegmen plate, with defects of the Trautmann triangular space seen only in the pediatric group. Children had a greater risk of having more than 1 bony defect, and adults had a greater chance of having no identifiable bony defects. These observations have not been previously reported, to our knowledge. In a previous study of otogenic meningitis at our institution,11 bony defects were seen in only 33% of the ears. This finding supports the theory that intracranial spread can occur through routes other than bony defects.9,10
In CSOM with ICCs, local treatment of complications is generally carried out immediately, followed as soon as possible by mastoidectomy to remove the source of infection, to prevent further ICCs and reinfection in the ear, to arrest the progress of the ear disease, and to preserve useful hearing.5,6,9-11,14 In our series, definitive surgical intervention (both neurosurgery and ear, nose, and throat surgery) was undertaken in less than 24 hours in only one third of the cases in both groups, in direct correlation with the presence of fewer than 1 ICC. In the remaining two thirds of the cases, in which there were more than 1 ICC, surgery was delayed for more than 24 hours, until the patient was stabilized. All patients underwent craniotomy and excision of the abscess and/or drainage of empyema, followed by mastoidectomy, in the same procedure.
The mortality rate was 33% in a study by Kangsanarak et al5 from Thailand and 13% in a study by Singh and Maharaj6 from South Africa, with an intracranial recurrence rate of 2%, although aspiration of the abscess and mastoidectomy were both performed during 1 procedure within 12 hours of admission. In our present series, there was no intraoperative or postoperative morbidity or mortality. This result may be attributable to the complete otolaryngological, neurosurgical, and anesthetic evaluations being done before the procedure is performed. The preferred treatment for the unsafe ear9,10 in cases involving otogenic ICCs is radical mastoidectomy5,6,9,10 or modified radical mastoidectomy in cholesteatomatous ears6,11 and cortical mastoidectomy in noncholesteatomatous ears.5,6 None of our patients underwent preoperative audiography, and a mastoid exploration was planned in all of them. Because cholesteatoma was seen in all patients, a canal wall down procedure (modified radical mastoidectomy) was performed. Three children (14%) showed evidence of recurrence. Reports by other authors also showed that children had a greater risk of recurrent cholesteatoma.15
Intracranial abscess secondary to CSOM is a disease of the indigent, and it is prevalent in developing countries. It occurs predominantly in children and young adults, with a male preponderance. Attic and posterosuperior retraction, cholesteatoma, and granulation tissue were commonly noted in our study, and secondary acquired cholesteatoma was relatively rare. Cholesteatoma was seen in all cases, although otoscopy revealed granulation tissue in only one third of the children. Meningitis was the most common coexisting ICC in patients with otogenic intracranial abscess, followed by cerebellar abscess, and sinus plate defects were the most common defects. Intracranial abscess caused by CSOM of the left ear occurred more often in children than in adults, with perisinus abscess and lateral sinus thrombus occurring only in children. On the contrary, it was more common for adults to have intracranial abscess with otitic hydrocephalus caused by CSOM of the right ear. More than two thirds of the patients had more than 1 ICC at the time of admission, and definitive surgical intervention was done more than 24 hours after admission. The presence of multiple ICCs was directly related to the duration of hospital stay, which, unlike bacterial flora, was a prognostic indicator of greater morbidity. The identification and treatment of the associated ICCs, as well as timely surgical intervention, appeared to be of great importance in the patients' prognosis. Canal wall down mastoidectomy was the treatment of choice in patients with intracranial abscess due to cholesteatoma. Children had an increased incidence of recidivism.
In otogenic intracranial abscess, a multidisciplinary approach is essential to reduce the risk of mortality. By performing craniotomy and mastoidectomy concurrently, it is possible to treat ICCs and to remove the source of infection with a single anesthetic procedure during 1 hospital visit. Also, the risk of reinfection is reduced, patient compliance is better, and the hospital stay is more economical. Therefore, concurrent craniotomy and mastoidectomy is a safe, superior, and cost-effective procedure.
Accepted for publication April 23, 1998.
Presented in part at the XVI World Congress of Otorhinolaryngology–Head and Neck Surgery, Sydney, Australia, March 4, 1997.
Corresponding author: Mary Kurien, MS, Ear, Nose, and Throat Department, Christian Medical College and Hospital, Vellore 632,004 (Tamil Nadu), India.
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