What are adenoids? Adenoid Hypertrophy, Clinical features and Adenoidectomy

• Adenoids are part of Waldeyer’s ring of lymphoid tissue at entry of upper respiratory tract. These are sites of first immunological contact for inhaled antigen in childhood.
• The word adenoid was coined by Wilhelm Meyer. They are also known as Lushka’s tonsil (by Santorini), Nasopharyngeal vegetations/ and nasopharyngeal tonsils.

Anatomy

• Adenoids consists of vertical ridges of lymphoid tissues separated by deep clefts and covered by ciliated epithelium.
• Unlike palatine tonsils, adenoids have no crypts or capsules.

Development

• By around 4-6 weeks of gestational age, lymphoid tissues can be identified with in mucus membrane of roof and posterior wall of nasopharynx.
• These lymphoid tissues may extend to fossa of Rossenmuller and to eustachian tube orifice (Tubal tonsils / Gerlach’s tonsil)
• Adenoids can be identified by MRI from 4th month in 18% children and by 5th month in all children.
• Growth continues rapidly during infancy and plateaus between 2-14 years.
• Largest in 7th year, but clinical symptoms are more common in young age group due to
  • Relatively small volume of nasopharynx
  • Increased frequency of Upper respiratory tract infections
• Regression occurs rapidly after 15 years and completely disappears by 20 years.

Blood supply and Venous drainage

• Blood supply via
  • Ascending palatine branch of facial artery
  • Ascending pharyngeal branch of External Carotid Artery (ECA)
  • Pharyngeal branch of third part of maxillary artery
  • Ascending cervical branch of inferior thyroid artery of thyrocervical trunk
• Venous drainage to IJV and Facial vein.
• Lymphatic drainage to retropharyngeal LN, upper deep cervical LN (post triangle)
• Nerve supply – Sensory branches of vagus and glossopharyngeal.

Functions of adenoid

• Produce B cells, producing IgG, IgA Ab.
• Forms immunologic memory in younger children.

Pathological effects

• Can act as a focus of sepsis / infection.
• Recurrent Otitis Media with Effusion (OME)
  • Due to anatomical obstruction of eustachian tube along with recurrent Acute or chronic inflammation of adenoid and increased bacterial load (particularly H. influenza).
  • Biofilm formation
    • Biofilms are structured bacterial cells enclosed in a self-produced polymeric matric, adherent to an inert of living surface)
    • Causes squamous cell metaplasia – reticular epithelium extension – fibrosis of interfollicular connective tissues – reduced mucociliary clearance – biofilm formation.
  • Chronic GERD is also implicated in inflammation of nasopharynx and adenoids leading to recurrent OME.
• Recurrent Acute Otitis Media (AOM)
  • Evidence says that adenoidectomy is not effective in reducing episode of AOM in children <2 years.
  • Low dose prophylactic antibiotics, until maturation of immune system is preferred to adenoidectomy in these children to prevent recurrence.
• Upper airway obstruction
  • Nasal obstruction is the most common symptom.
  • Mouth breathing interferes with feeding or suckling in child leads to failure to thrive.
• Obstructive Sleep Apnea (OSA)
  • Incidence of OSA in children is approximately 1% with equal sex ratio.
  • Peak incidence at 3-6 years.
  • Airway obstruction by adenoid causes – decreased PaO2, Increased PaCO2, and decreased IGF-1. All returns to normal after adenoidectomy.
  • Radiographic findings of adenoids correlate well with PSG findings.
• Rhinitis
  • Due to choanal obstruction, normal nasal secretions cannot drain into nasopharynx.
• Chronic rhinosinusitis
  • Improvement noted in majority of children following adenoidectomy.
  • Due to biofilm formation
• Olfaction
  • Olfactory sensitivity is reduced in relation to adenoid size and improves after adenoidectomy.
  • May be leads to poor appetite in children with adenoid hypertrophy.
• Nocturnal enuresis
  • Significant relief after adenoidectomy.
  • Adenotonsillectomy can improve bedwetting in kids – Read article.
    • Upper airway obstruction causes deep inspiration, leads to increased venous return to mediastinum. This will cause dilatation of atrial muscles, which in turn cause release of ANP/BNP. As a result, diuresis happens.
• Pulmonary hypertension
  • In long standing nasal obstruction.
• Neoplasia
  • Unsuspected neoplasia of adenoid and tonsil in childhood is rare.
  • Atypical lymphadenopathy, persistent and asymmetric enlargement of adeno-tonsills in absence of infection are suspicious of malignant transformation – needs early imaging and biopsy.
  • Diagnosis is mainly overlooked for infections.

Assessment and Management

• Clinical history
  • Full pediatric ENT history
  • Special attention to symptoms of middle ear disease, nasal obstruction.
  • Specific questions regarding sleep disturbances, eating and atopic symptoms.
  • Aprosexia – loss of concentration.
  • Full history of previous treatment and medications.
  • Family history of unusual bleeding / bleeding tendency, if planning for surgery.
• Examination
  • Adenoid facies
    • Due to chronic nasal obstruction and mouth breathing.
    • Elongated face with dull expression, dark circles under eyes.
    • Open mouth, Retrognathic mandible, hitched up upper lip, prominent and crowded upper teeth, pinched up nose (due to disuse atrophy of alae nasi).
    • High arched / Gothic palate due to loss of molding action of tongue on palates.
    • External nose – skin crease in supratip region indication frequent rubbing due to rhinitis.
    • Anterior rhinoscopy – Cold spatula test, using Lack’s tongue depressor to assess airway patency.
    • Diagnostic Nasal Endoscopy with topical intranasal anesthetic spray is the gold standard.
      • Well tolerated in children
      • For treatment decision prior to adenoidectomy
      • Endoscopic grading system co-relates well with symptoms of nasal obstruction, snoring, tympanometry. But no co-relation with purulent rhinorrhea.
• Imaging

  • 

    Soft tissue Xray neck Lateral View is also a good alternative to nasal endoscopy, indicated if child is not co-operative for nasal endoscopy.
    (Click here to read doctor’s own study on this subject.)

  • Clemens et al radiographic grading
    • Grade I – Adenoid tissue filling 1/3rd of vertical portion of choanae.
    • Grade II – Adenoid tissue filling 1/3rd to 2/3rd of vertical portion of choanae.
    • Grade III – Adenoid tissue filling 2/3rds to nearly complete obstruction of choanae.
    • Grade IV – Complete choanal obstruction
  • Acoustic rhinomanometry and MRI are not applicable in clinical practice.

Adenoidectomy

• Surgical procedure for removing of enlarged adenoids (Adenoid Hypertrophy).
• Unless specifically indicated, combining tonsillectomy with adenoidectomy is not recommended. This is because compared to adenoidectomy, tonsillectomy is associated with a significantly increased mortality of 1:10,000 to 1:35,000, increased complication rates, treatment costs and with a post op bleeding rate of 0.6% to 4%, occurring in the immediate perioperative period and up to two weeks postoperatively.
• Indications
  • Symptomatic patients.
  • Generally, if >45% obstruction of airway is there (Grade 2 adenoids), it is considered as an indication.
• Impact of adeno-tonsillectomy
  • Adenoid hyperplasia in childhood is common and self-limiting usually.
  • Removal at young age (< 3 years) may be immunologically undesirable, unless highly indicated.
  • Between 4-10 year, adeno-tonsillectomy doesn’t cause immune deficiency.
• Procedure
  • Under General Anesthesia with child in tonsillectomy position (Rose’s position).
  • Traditionally
    • Assessment of adenoids done by digital palpation and soft palate for any submucosal cleft.
    • Removal is by blind curettage with St. Clair Thomson’s curette with guard – chance of left over tissue, leading to recurrence.
    • Hemostasis achieved by gauze swab tamponade.
    • More blood loss (>50ml)
  • Other options
    • Under Endoscopic Visualization
      • Less blood loss (<4ml)
      • Near total removal – very minimal chance of recurrence.
      • Avoiding trauma to eustachian tube
    • Microdebrider – 20% faster
    • Suction coagulator – significantly cheaper than debrider
    • Coblation assisted – costly, but less painful.
    • KTP laser – High incidence of post op nasopharyngeal stenosis – not recommended.
• Complications
  • Dental trauma
    • Usually rare.
    • May be accidental due to slippage of gag or support.
    • When loose dentition present, needs to be removed prior to surgery.
    • Parents should be warned about damage to teeth.
  • Bleeding
    • Primary / Reactionary hemorrhage (within 6-24 hours) is less than 0.7%
    • If severe, Posterior nasal packing for 4 hours has shown same efficacy as 24hours. Immediate return to theatre also needed.
    • Less chance following endoscopic resection.
    • Usually due to bleeding from aberrant ascending pharyngeal artery
    • Secondary hemorrhage (after 24 hours) is rare.
    • Clotting disorders – Needs hematological advice.
  • Retained swab.
    • Count should be made before removal of gag and reversal of anesthesia.
    • Swab may be retained in nasopharynx or laryngopharynx.
  • Nasopharyngeal blood clot
    • Gentle suction before removal of gag.
    • If not done, clot will fall to larynx during extubating causing fatal acute airway obstruction – Coroner’s Clot.
  • Infections
    • Uncommon.
    • Fetor (bad breath) may be common for a week.
    • Rarely retropharyngeal and mediastinal abscess ay occur due to trauma and secondary infection of adenoid bed.
  • Cervical spine injury
    • Griesel syndrome – non-traumatic atlanto axial subluxation is rare.
    • Mostly due to spasm of paraspinal muscles – associated with overuse of diathermy – minimum power settings are recommended.
    • More prone in patients with Down syndrome – due to laxity of ligaments. Prior plain imaging of cervical spine needed.
    • Patient present with torticollis, neck pain.
    • Velopharyngeal dysfunction
    • Severe dysfunction seen in 1:1500-10,000 cases.
  • Velopharyngeal Insufficiency
    • Hypo nasal speech, swallowing, nasal regurgitation of food.
    • Prior to surgery, palate and uvula needs to assess for submucosal cleft, palatal dysfunction.
    • In children with bifid uvula or with submucosal cleft, partial removal under endoscopic guidance with clearing of choanal airway but leaving adenoid intact at velopharyngeal junction is done by some – controversial.
    • Long term velopharyngeal insufficiency is rare, reconstructive surgery to correct hyper nasal speech and swallowing.
  • Other complications
    • Injury to eustachian tube
    • Injury to pharyngeal musculature and vertebrae
  • Regrowth
    • If needed, repeat surgery can be done.
    • More in traditional blind curettage
• Post op care
  • Mostly day care procedure
  • Based on social & geographic factors, surgical & anesthetic techniques, fluid replacement, Antibiotics & analgesia – child can be discharged within 6 hours.