10.7\ Tonsillectomy

and Adenoidectomy

10.7.1  Discussion

Tonsillectomy and adenoidectomy are two of the most commonly performed pediatric surgical procedures. The main indications for tonsillectomy and adenoidectomy include adenotonsillar hyperplasia with obstructive sleep apnea, failure to thrive, or abnormal dentofacial growth; malignant neoplasms; and adenotonsillar hyperplasia with upper airway obstruction, dysphagia, or speech impairment and halitosis. Furthermore, otitis media and recurrent or chronic rhinosinusitis or adenoiditis are indications for adenoidectomy, but not tonsillectomy, while recurrent or chronic pharyngotonsillitis, peritonsillar abscess, and streptococcal carriage are indications for tonsillectomy, but not adenoidectomy. Frequently, the appearance on postoperative imaging is that of asymmetric absence of Waldeyer ring tissue, whereby the residual normal tissue can hypertrophy and should not be mistaken for a lesion (Fig. 10.50). Sometimes, the trace amounts of residual Waldeyer ring tissues can regrow over the course of years after tonsillectomy/adenoidectomy, such that the effects of surgery are not noticeable. As in many other parts of the head and neck, when more extensive surgeries are performed for tumor resection, the resulting defects may be reconstructed using soft tissue flaps (Fig. 10.51).

Among patients who underwent tonsillectomy for obstructive apnea, cine MRI is a useful modality for evaluating anatomy and function when there are recurrent symptoms. Potential causes include glossoptosis, hypopharyngeal collapse, recurrent and enlarged adenoids and lingual tonsils, and macroglossia. If lingual tonsils were greater than 10 mm in diameter and abutted both the posterior border of the tongue and the posterior

pharyngeal wall, they can be considered markedly enlarged (Fig. 10.52). On the other hand, patients can develop velopharyngeal insufficiency following excessive removal of adenoid tissues. This can manifest as a gap between the pharynx and soft palate on cine MRI, which can be treated via palatoplasty or pharyngeal augmentation with substances, such as hydroxyapatite filler (Fig. 10.53).

Among patients who underwent tonsillectomy/ adenoidectomy for neoplasm, 18FDG-PET/CT is useful for evaluating recurrent tumor. However, infection at the site of surgery can manifest as focal hypermetabolism (Fig. 10.54). Noninfectious inflammation and granulation tissue at the surgical site can also yield false-positive results on 18FDGPET/CT. However, as opposed to tumor recurrence, activity on 18FDG-PET/CT should decrease over time with infection and inflammation.

Fig.10.50  Tonsillectomy. Axial fat-suppressed T2-weighted MRI shows the absence of the right lingual tonsil and a remaining hypertrophied left anterior palatine tonsil (arrow). The postoperative changes are otherwise virtually imperceptible

Fig. 10.51  Tonsillectomy with flap reconstruction. Axial CT images show flap reconstruction of the right tonsillectomy defect (arrow), after resection of an invasive squamous cell carcinoma. There is nevertheless a relative paucity of tissue on the right side

Fig. 10.52  Recurrent enlargement of adenoids and tonsils. Cine MRI in a child with obstructive apnea previously treated with adenotonsillectomy shows enlarged adenoid and lingual tonsils associated with airway narrowing (encircled)

Fig. 10.53  Velopharyngeal insufficiency after adenoidectomy. The patient underwent a Furlow palatoplasty to repair a submucosal cleft with marked improvement but persistent velopharyngeal insufficiency with fatigue at the end of the day. Posterior pharyngeal wall pharyngoplasty with calcium hydroxyapatite filler injection augmentation was then performed. Sagittal cine MR image (a) after adenoidectomy and palatoplasty shows velopharyngeal

gap that persists throughout the cycle (arrow). Sagittal MR image (b) obtained after adenoid augmentation shows increased bulk of the adenoids with no residual velopharyngeal gap. Axial CT image (c) in a different patient shows the high attenuation Radiesse within the retropharyngeal space at the level of the oroand nasopharynx (arrow)

Fig. 10.54  Postoperative infection mimicking tumor recurrence. Contrast-enhanced CT (a) shows asymmetric edema of the pharyngeal mucosal and parapharyngeal spaces (arrow), but no distinct mass. 18FDG-PET/CT (b) obtained soon after shows focal hypermetabolism in the

left oropharyngeal surgical bed (arrow). The lesion proved to be fungal pharyngitis, and follow-up 18FDGPET/CT (c) obtained 6 months later showed resolution of the lesion