Skull base osteomyelitis secondary to malignant otitis externa

PURPOSE OF REVIEW

Skull base osteomyelitis secondary to malignant otitis externa was first described in 1959. Since then, advances have been made in the diagnosis, treatment, and clinical outcomes of this condition.

RECENT FINDINGS

This review discusses the pathophysiology and microbiology of malignant otitis externa. The review highlights the sometimes subtle presenting symptoms and recent advances in imaging and their practical application to diagnosing and monitoring the disease. Therapy for malignant otitis externa has changed since this entity was first described; this article reviews the medical, surgical, and adjuvant therapies and the relevant controversies.

SUMMARY

The review discusses the history, pathogenesis, diagnosis, and treatment of skull base osteomyelitis in the context of malignant otitis externa with particular emphasis on HIV, children, and other immunodeficient states.

Complications of chronic suppurative otitis media and their management

OBJECTIVE

The objective of this is to determine the incidence of otogenic complications of chronic suppurative otitis media (CSOM) and its management.

STUDY DESIGN

The authors conducted a retrospective study.

METHODS

The study was conducted at the tertiary referral and teaching hospital. An analysis was made about the clinical and operative findings, surgical techniques and approaches, the overall management and recovery of the patients. The data were then compared with the relevant and available literature.

RESULTS

Of the 70 cases, 47 (67%) had a single complication, of which eight (11%) had intracranial and 39 (56%) had extracranial complications. Twenty-three (33%) had two or more complications. The commonly encountered intracranial complications were otitic meningitis, lateral sinus thrombosis, and cerebellar abscess, which were seen in 13 (19%), 10 (14%), and 6 (9%) cases, respectively. Among the extracranial complications, mastoid abscess, postauricular fistula, and facial palsy were encountered in 26 (37%), 17 (24%) and 10 (14%) patients, respectively. Surgeries were the main mode of treatment for these conditions. According to severity, we found four different types of the lateral sinus involvement. Three patients with otitic facial palsy failed to regain full facial function despite surgery. A total of nine patients with the diagnosis of otitic meningitis, lateral sinus thrombosis and interhemispheric abscess expired. It constituted the mortality rate of 13% in our study.

CONCLUSION

CSOM complications, despite its reduced incidence, still pose a great challenge in developing countries as the disease present in the advanced stage leading to difficulty in management and consequently higher morbidity and mortality.

Endolymphatic sac tumors: radiologic appearance

PURPOSE

To evaluate the radiologic appearance of endolymphatic sac tumors (ELSTs).

MATERIALS AND METHODS

Four patients with ELST underwent computed tomography (CT), and two of the four also underwent magnetic resonance (MR) imaging. Their radiologic studies were reviewed for characteristic findings of ELST.

RESULTS

Retrolabyrinthine bone destruction was centered at the external aperture of the vestibular aqueduct in all four patients. CT showed irregular bone margins and prominent intratumoral bone in all four patients. At MR imaging, one tumor was almost homogeneous and isointense to gray matter with T1 weighting, and the other was heterogeneous and contained hyper-, hypo-, and isointense foci with T1 and T2 weighting.

CONCLUSION

These radiologic changes may help distinguish ELSTs from other tumors of the temporal bone and posterior fossa.

Cholesteatoma in children

The 65 cholesteatomas operated on in children showed a more expansive and rapid growth than those in adults. In one fifth of the cases cholesteatoma filled the whole air-cell area, which was wide in half of the children. Fifty-two ears of these children had an attic or a posterosuperior perforation. One case was complicated by a fistula in the horizontal semicircular canal, and the ossicular chain was unbroken in 23 cases (35%). Thus, the findings support the idea of the primary soft-tissue spread of cholesteatoma in children. Five ears (8%) discharged postoperatively, and three ears (5%) were reoperated on and showed residual tympanal cholesteatoma. Cavity obliteration with canal wall down technique proved safe, even in the cases of the most extensive and active cholesteatoma.

CT and MR imaging after middle ear surgery

This article describes the current value of imaging in patients after stapes surgery and surgery after chronic otitis media including cholesteatoma. Possibilities and limits of computed tomography (CT) and MRI are described and most important investigation parameters are mentioned. After otosclerosis surgery, CT is the method of first choice in detection of reasons for vertigo and/or recurrent hearing loss in the later postoperative phase. CT may show the position and condition of prosthesis, scarring around the prosthesis and otospongiotic foci. Sometimes, it gives indirect hints for perilymphatic fistulas and incus necrosis. MRI is able to document inner ear complications. CT has a high negative predictive value in cases with a free cavity after mastoidectomy. Localized opacities or total occlusion are difficult to distinguish by CT alone. MRI provides important additional information in the differentiation of cholesterol granuloma, cholesteatoma, effusion, granulation and scar tissue.

Mastoid obliteration: autogenous cranial bone pAte reconstruction

OBJECTIVE

To review the outcome in consecutive patients who have undergone complete epitympanic and mastoid obliteration and concurrent tympanic membrane reconstruction over a 53-month period.

STUDY DESIGN

Retrospective review.

SETTING

Tertiary referral center.

PATIENTS

Sixty-two ears in 56 sequential patients undergoing mastoid obliteration with major indications including recurrent infection, debris trapping in the canal wall-down cavity, intolerance of water exposure, calorically induced vertigo in an existing cavity, a semicircular canal fistula, and inability to wear a hearing device. Thirty-six ears in 33 patients who underwent second-stage surgery for ossicular reconstruction during the same time period are also reviewed.

INTERVENTION

Transplanted autogenous cranial bone is used to induce osteoneogenesis resulting in complete obliteration of the epitympanic and mastoid spaces while maintaining a mesotympanic space.

MAIN OUTCOME MEASURES

Success of obliteration, incidence of symptoms prompting intervention, hearing outcome, incidence of recurrent cholesteatoma, and incidence of eustachian tube dysfunction necessitating treatment and need for revision surgical procedures.RESULTS Complete take of the bony obliteration occurs in over 95% of cases; 90% of treated patients enjoy complete absence of original symptoms, whereas symptoms improved in the remainder. For over 95% of patients, existing eustachian tube function has been adequate after obliteration. To date, no patient has required revision surgical intervention.

CONCLUSION

Mastoid obliteration with autogenous cranial bone is a safe and extremely effective option for treatment of problematic canal wall-down mastoid cavities. Surgical techniques that include sterile harvest of the cranial bone graft mixed with antibiotic, revision of the cavity to expose viable native bone, inclusion of the epitympanic spaces in the obliteration, and complete coverage of the pAte with autogenous fascia have proven critical to successful outcome.

Ear canal cholesteatoma

Although cholesteatomas are more commonly found in the middle ear and the mastoid, the disease can occur in the external ear canal. All cases of ear canal cholesteatoma treated by the author were reviewed. There were nine ears in seven patients, who had an average age of 62 years. The lesions ranged in size from a few millimeters to extensive mastoid destruction. Smaller lesions can be managed by frequent cleaning as an office procedure. Larger lesions require surgery, either canaloplasty or mastoidectomy. The otolaryngologist should suspect this disease in the elderly. Microscopic examination of the ear with meticulous cleaning of all wax, especially in elderly patients, is most useful in detecting early disease. Frequent applications of mineral oil to the canal should be used in the management of the disease and to prevent recurrence.

Acute and latent mastoiditis in children

During the period from 1974 to 1981, surgery for acute mastoiditis was performed on 12 ears, giving an annual incidence of 0.004 per cent among cases of acute otitis media. All ears made a full long-term recovery. The low incidence is ascribed to the world-wide early use of antibiotics. During the same period 52 ears with secretory otitis media (SOM) underwent mastoidectomy. Histologically extensive mastoid inflammation was found in 96 per cent. The changes appeared as formation of secretory cells and cysts, resorption of bone, and infiltration of soft tissues with both mononuclear cells and polymorphonuclear leucocytes. The number of SOM patients undergoing mastoid operations account for 1.4 per cent of the patients admitted to hospital because of SOM. Thirty-four ears (65 per cent) have healed during the follow-up period (mean 2.9 years), while the tympanostomy tube is still in place in 18 ears (35 per cent). In the latter group, factors causing oedema in the pharyngeal end of the Eustachian tube are apparently still present.

Usefulness of delayed postcontrast magnetic resonance imaging in the detection of residual cholesteatoma after canal wall-up tympanoplasty

OBJECTIVES/HYPOTHESIS

Imaging takes an increasing place in the follow-up of patients who have undergone surgery for cholesteatoma, with computed tomography (CT) as the first line imaging technique. However, in case of complete opacity of the tympanomastoid cavities, CT is not able to differentiate residual cholesteatoma from postoperative scar tissue. The aim of this study was to assess the usefulness of magnetic resonance imaging (MRI) using delayed postcontrast T1-weighted images for the detection of residual cholesteatoma after canal wall-up tympanoplasty (CWU) in cases where CT was not conclusive.

STUDY DESIGN

Prospective study.

METHODS

MRI, with delayed postcontrast T1-weighted images (30-45 minutes after contrast injection), was performed before revision surgery in 41 consecutive patients who had undergone CWU for cholesteatoma and presenting with a nonspecific complete opacity of the mastoid bowl on CT. In all the cases, imaging results were compared with operative findings at surgical revision.

RESULTS

A residual cholesteatoma was found in 19 of 41 patients at revision surgery and was correctly detected on MRI in 17 patients. In the two remaining cases, cholesteatoma pearls smaller than 3 mm were not seen. There was no false-positive case. Statistics were as follows: sensitivity 90%; specificity 100%; positive predictive value 100%; negative predictive value 92%.

CONCLUSION

When postoperative CT is not conclusive because of complete opacity of the tympanomastoid cavities, MRI with delayed postcontrast T1-weighted images is a reliable additional technique for the detection of a residual cholesteatoma when its diameter is at least 3 mm.

Schneiderian-type mucosal papillomas of the middle ear and mastoid

Five cases of schneiderian-type mucosal papillomas arising in the middle ear space are reported. The patients were all women, ranging in age from 19 to 57 years (median, 31 years). Clinical complaints--unilateral conductive hearing loss, pain, or otorrhea--ranged from those lasting several months to recurrent problems spanning 20 years. All of the patients had a history of chronic otitis media predating the development of the papillomas; none of the patients had a history of sinonasal or nasopharyngeal schneiderian-type papillomas. Clinically, three patients had intact tympanic membranes, while the other two patients had perforated tympanic membranes through which a bulging polypoid mass was identified. Radiographic studies showed opacification of the middle ear space without evidence of osseous destruction. The intraoperative findings were of polypoid lesions filling the middle ear space, including involvement of the eustachian tube orifice. Histologically, the tumors were identical to sinonasal schneiderian papillomas. Immunohistochemical evaluation for human papillomavirus was negative. Surgical excision is the treatment of choice. In four of the patients, recurrent tumor was identified, necessitating additional surgery. In only one patient did the initial surgery result in complete ablation of the tumor. All patients are alive and free of recurrent disease over periods ranging from 6 months to 120 months (median, 84 months).

The correlation of middle ear aeration with mastoid pneumatization. The mastoid as a pressure buffer

Atelectatic ears, which by definition are poorly aerated, are also usually associated with poor mastoid pneumatization. On the other hand, otosclerotic patients, whose middle ears are usually exceptionally well aerated, also have excellent mastoid pneumatization. Three unusual cases are presented, in which partial atelectasis developed in stapedectomized patients. In each case the mastoid was later found to be nonpneumatized, and further analysis revealed that their stapes fixation had in effect most probably been of non-otosclerotic origin. Thus, although these three cases had at first appeared to represent exceptions to the general rule of otosclerotics having a well-aerated middle ear, in fact they support the association between atelectasis and poor pneumatization. The linkage of good middle ear aeration with large mastoid pneumatization and vice versa may suggest that the mastoid plays a role of a pressure buffer in the middle ear, which is a system of a gas pocket with fluctuating pressures. Also, otosclerosis may be considered to be an unlikely cause of conductive deafness in cases of poor pneumatization.

Acute mastoiditis: a 10 year retrospective study

This retrospective study reviews our experience in the management of acute otomastoiditis over 10 years. During the study period we identified 40 cases in children aged 3 months-15 years with a peak incidence in the second year of life. Sixty per cent of them had a history of acute otitis media (AOM). All the children were already receiving oral antibiotic therapy. Otalgia, fever, poor feeding and vomiting were the most common symptoms, all the children had evidence of retroauricolar inflammation. Computerized tomography (CT) and magnetic resonance imaging (MRI) were used to support the diagnosis and to evaluate possible complications. Streptococcus pneumoniae was the most common isolated bacterium. All the patients received intravenous antibiotics, 65% of children received only medical treatment, 35% also underwent surgical intervention. Mean length of hospital stay was 12.3 days. Cholesteathoma was diagnosed in one child. We conclude from our study that acute otomastoiditis is a disease mainly affecting young children, that develops from AOM resistant to oral antibiotics. Adequate initial management always requires intravenous antibiotics, conservative surgical treatment with miryngotomy is appropriate in children not responding within 48 h from beginning of therapy. Mastoidectomy should be performed in all the patients with acute coalescent mastoiditis or in case of evidence of intracranial complications.

Anatomic landmarks of the glossopharyngeal nerve: a microsurgical anatomic study

OBJECTIVE

Compared with other lower cranial nerves, the glossopharyngeal nerve (GPhN) is well hidden within the jugular foramen, at the infratemporal fossa, and in the deep layers of the neck. This study aims to disclose the course of the GPhN and point out landmarks to aid in its exposure.

METHODS

The GPhN was studied in 10 cadaveric heads (20 sides) injected with colored latex for microsurgical dissection. The specimens were dissected under the surgical microscope.

RESULTS

The GPhN can be divided into three portions: cisternal, jugular foramen, and extracranial. The rootlets of the GPhN emerge from the postolivary sulcus and course ventral to the flocculus and choroid plexus of the lateral recess of the fourth ventricle. The nerve then enters the jugular foramen through the uppermost porus (pars nervosa) and is separated from the vagus and accessory nerves by a fibrous crest. The cochlear aqueduct opens to the roof of this porus. On four sides in the cadaver specimens (20%), the GPhN traversed a separate bony canal within the jugular foramen; no separate canal was found in the other cadavers. In all specimens, the Jacobson's (tympanic) nerve emerged from the inferior ganglion of the GPhN, and the Arnold's (auricular branch of the vagus) nerve also consisted of branches from the GPhN. The GPhN exits from the jugular foramen posteromedial to the styloid process and the styloid muscles. The last four cranial nerves and the internal jugular vein pass through a narrow space between the transverse process of the atlas (C1) and the styloid process. The styloid muscles are a pyramid shape, the tip of which is formed by the attachment of the styloid muscles to the styloid process. The GPhN crosses to the anterior side of the stylopharyngeus muscle at the junction of the stylopharyngeus, middle constrictor, and hyoglossal muscles, which are at the base of the pyramid. The middle constrictor muscle forms a wall between the GPhN and the hypoglossal nerve in this region. Then, the GPhN gives off a lingual branch and deepens to innervate the pharyngeal mucosa.

CONCLUSION

Two landmarks help to identify the GPhN in the subarachnoid space: the choroid plexus of the lateral recess of the fourth ventricle and the dural entrance porus of the jugular foramen. The opening of the cochlear aqueduct, the mastoid canaliculus, and the inferior tympanic canaliculus are three landmarks of the GPhN within the jugular foramen. Finally, the base of the styloid process, the base of the styloid pyramid, and the transverse process of the atlas serve as three landmarks of the GPhN at the extracranial region in the infratemporal fossa.

Role of the mastoid in tympanic membrane reconstruction

Otologists have long debated the importance of the mastoid in determining the success or failure of tympanic membrane reconstruction. The pneumatic spaces within the mastoid represent an "air reservoir" which can be drawn upon during periods of eustachian tube dysfunction and buffer the middle ear against the development of detrimental negative pressures. Mastoid inflammatory disease, if untreated, may result in recurrent suppuration and graft failure. Small mastoid volume, aside from its well known association with chronic infectious middle ear disease, has been shown to effect adversely graft survival following myringoplasty. In 48 patients undergoing myringoplasty with simple mastoidectomy, neither small mastoid size nor inflammatory mastoid disease significantly decreased the rate of graft healing. This suggests that simple mastoidectomy is an effective means of repneumatizing the mastoid and eradicating mastoid sources of infection. The successful surgical creation of a pneumatized mastoid cavity in communication with the middle ear was confirmed by postoperative computerized tomographic (CT) scans. In failed cases, CT scanning predictably identified residual mastoid disease. Simple mastoidectomy is considered to be a safe and useful adjunct to myringoplasty in selected cases of chronic otitis media with perforation.

The natural history of congenital cholesteatoma

OBJECTIVES

To describe the natural history of congenital cholesteatoma (CC) and to determine whether such a description provides clues about the origins and end points of these lesions.

DESIGN

A retrospective qualitative analysis of intraoperative illustrations of 34 consecutive patients with 35 CCs (1 bilateral).

SETTING

Two tertiary care children's hospitals.

PATIENTS

Thirty-four children with CC, mean age, 5.6 years (range, 2-13 years).

RESULTS

Congenital cholesteatoma originates generally, but not universally, in the anterior superior quadrant. The progression of growth is toward the posterior superior quadrant and attic and then into the mastoid. Contact with the ossicular chain generally results in loss of ossicular continuity and in conductive hearing loss.

CONCLUSIONS

Congenital cholesteatoma appears to have a predictable trajectory of growth, starting as a small pearl in the middle ear, eventually growing to involve the ossicles and mastoid, and causing varying degrees of destruction and functional impairment. The clinical picture of a young child with otorrhea, conductive hearing loss, tympanic membrane perforation in a nontraditional location, and a mastoid filled with cholesteatoma may represent the end point in the natural history of CC, despite the fact that this type of lesion is outside the accepted definition of CC.

Use of endoscopes for chronic ear surgery in children

OBJECTIVE

To determine whether an endoscopic second-look examination of the mastoid and middle ear could replace an open second-look mastoidectomy.

DESIGN

Patients were examined endoscopically. The findings were compared with a standard open mastoidectomy procedure during the same operation. The mastoid can be inspected through a small postauricular incision and the middle ear can be inspected through a myringotomy incision or tympanomeatal flap.

PATIENTS

Ten patients aged 6 to 16 years.

RESULTS

Endoscopic findings correlated exactly with open mastoidectomy findings in all cases.

CONCLUSION

In light of this study an open second-look mastoidectomy may be avoided if minimal or no recurrent cholesteatoma is found during the endoscopic exploration. The use of the ridged endoscope has added another dimension to the standard microsurgical techniques used in pediatric otology. The indications, techniques, and findings of otoendoscopy in the management of chronic otitis media in children will be presented.

The mastoid air cell system in ear surgery

Despite the overall high success rate of myringoplasty, the long-term results in ears with preoperative dysfunction of the Eustachian tube and with a small mastoid air cell system are disappointing. In this communication, we report an 83% healing rate after myringoplasty that included mastoidectomy with posterior and anterior tympanotomy in a selected group of patients with poor tubal function and small mastoids.

An assessment of the value of the preoperative computed tomography scans prior to otoendoscopic 'second look' in intact canal wall mastoid surgery

'Second look' surgery following primary intact canal wall mastoid surgery for cholesteatoma is considered mandatory for most cases in modern otological practice. The morbidity of the second look can be reduced by the use of the rigid otoendoscope. Forty-three patients undergoing 'second look' surgery were studied with an average age of 24.7 years. Prior to surgery a computed tomography (CT) scan was performed to assess the anatomy and pneumatisation of the cavity. The mean interval between primary and secondary surgery was 16 months and in all cases CT scans were performed within 6 months of 'second look' surgery. The presence of an opaque mastoid did not correlate with residual or recurrent cholesteatoma. The sensitivity of CT in diagnosing residual or recurrent cholesteatoma was 42.9% with a specificity of 48.3% and a predictive value of 28.6%. These results are explained by the fact that it is radiologically impossible to differentiate between recurrence, scar tissue or fluid with a CT scan. Nevertheless it was possible to inspect the cavity with the otoendoscope even in the presence of an opaque mastoid whether due to scar tissue or residual/recurrent cholesteatoma.