Operating Otoscope for Foreign Body Removal
An operating otoscope (also called an otomicroscope or binocular microscope) is the type of otoscope that can be used with forceps to remove foreign bodies from the ear, as it provides stereoscopic magnification and allows both hands to be free for instrumentation.
Visualization Equipment Options
The American Academy of Otolaryngology-Head and Neck Surgery identifies three appropriate instruments for visualization during manual removal of ear foreign bodies 1:
- Handheld speculum or standard otoscope 1
- Headlamp or head mirror 1
- Binocular microscope (otomicroscope) - offers the distinct advantage of stereoscopic magnification 1
Why the Otomicroscope is Superior for Instrumented Removal
The binocular microscope/otomicroscope is specifically advantageous because it provides stereoscopic magnification while keeping both hands free to manipulate instruments 1. This is critical when using forceps or other instruments for foreign body extraction.
Evidence Supporting Otomicroscopy
A prospective study of 85 pediatric ear foreign bodies demonstrated that implementation of a dedicated otomicroscope in the emergency department resulted in 2:
- 76% successful removal rate for complex foreign bodies 2
- Low complication rate with only 23% experiencing any complications (mostly minor EAC lacerations) 2
- No tympanic membrane perforations 2
- Mean of only 1.65 attempts needed for removal 2
Instruments Used with the Otomicroscope
When performing manual removal under otomicroscopic visualization, the following instruments are appropriate 1:
- Alligator or cup forceps (most commonly used for foreign bodies) 1, 3
- Metal or plastic curette loop or spoon 1
- Right-angled hook (particularly useful for small objects) 1, 3
- Angulated suction tips (French size 3,5,7) 1
- Jobson-Horne probe 1
- Straight applicator with cotton wool 1
Clinical Pearls
When Otomicroscopy is Essential
Otomicroscopy becomes particularly important in 2, 3:
- Foreign bodies touching the tympanic membrane (31% in one series) 2
- Hard or spherical objects that are difficult to grasp 3
- Cases with previous failed removal attempts 2, 3
- Presence of external auditory canal comorbidities (associated with higher complication rates) 2
Advantages Over Standard Otoscopy
The otomicroscope is most useful for 1:
- Assessing tympanic membrane abnormalities (perforation, atrophy, tympanosclerosis, atelectasis, retraction pockets) 1
- Providing direct visualization throughout the removal process to assess when removal is complete 1
- Allowing atraumatic cleaning with aural suctioning under microscopic guidance for high-risk patients 4
Important Caveats
Limitations
- Requires special equipment and training, which often limits examination to secondary care settings 1
- May require sedation in young children, particularly when multiple attempts are needed 2
- Referral to otolaryngology is warranted for hard or round objects, failed previous attempts, or ear trauma to avoid worsening the foreign body position 3