Visualization of Pyriform Sinus During Nasopharyngeal Laryngoscopy
Yes, the pyriform sinus can be visualized during nasopharyngeal (flexible) laryngoscopy, and this is explicitly recommended as part of a complete examination of the hypopharynx. 1
Guideline-Based Recommendations
The American Academy of Otolaryngology-Head and Neck Surgery guidelines explicitly state that visual examination of the hypopharynx should include the pyriform sinuses and posterior pharyngeal wall as essential components of a targeted physical examination. 1 This examination is performed using either mirror laryngoscopy or endoscopy (flexible or rigid scope), with the method left to clinician discretion. 1
Anatomical Structures Visualized
During flexible nasopharyngeal laryngoscopy, the following structures can be examined:
- Nasal cavity (septum, floor, turbinates)
- Nasopharynx (eustachian tube orifices, superior and posterior walls)
- Hypopharynx (pyriform sinuses, posterior pharyngeal wall) 1
- Larynx (epiglottis, vocal folds, subglottis) 1
Technical Optimization for Pyriform Sinus Visualization
Head positioning maneuvers significantly improve pyriform sinus visualization:
- Right head turn increases visualization of the left pyriform sinus (P = 0.00001) 2
- Left head turn increases visualization of the right pyriform sinus (P = 0.0001) 2
These maneuvers should be employed when detailed examination of the pyriform sinuses is needed, particularly when evaluating for masses or malignancy. 2
Clinical Context and Importance
The ability to visualize the pyriform sinuses during flexible laryngoscopy is critical because:
- Pyriform sinus lesions (including carcinoma) require direct visualization for detection 1
- Imaging alone is not a substitute for direct mucosal examination 1
- Multiple studies confirm that pyriform sinuses are well-visualized by both rigid telescopic videolaryngoscopy and flexible laryngoscopy 3, 4
Common Pitfalls
Inadequate head positioning is the most common reason for suboptimal pyriform sinus visualization. 2 Clinicians should actively employ contralateral head turn maneuvers rather than relying solely on neutral positioning. 2
Failure to examine the pyriform sinuses in patients at risk for head and neck malignancy represents a missed opportunity for early cancer detection, as the American Academy of Otolaryngology-Head and Neck Surgery explicitly includes this as part of the essential examination. 1