Adenoidectomy

Anatomy and Physiology

The adenoid is a proliferation of lymphoid tissue lining the posterior wall of the nasopharynx, forming the superior aspect of Waldeyer’s lymphatic ring.[2] Identifiable from 6 weeks gestation, it receives its blood supply from branches of the facial and maxillary arteries and the thyrocervical trunk. The adenoid enlarges rapidly during early childhood and reaches its largest size by age seven before regressing.[3] A relative mismatch between an enlarged adenoidal pad and a small nasopharynx in the pediatric population can result in choanal obstruction, leading to chronic mouth-breathing, sleep-disordered breathing, and obstructive sleep apnea. Left untreated, chronic mouth-breathing is postulated to affect midfacial growth and dental occlusion, leading to adenoid facies. This concists of a chronically open mouth, protruding teeth, a high-arched palate, an everted upper lip, and loss of the nasolabial fold.[4] Obstruction of the Eustachian tube orifice, in conjunction with the presence of an increased bacterial load in the adenoid, is thought to produce a biofilm implicated in the pathogenesis of otitis media with effusion.[5][6]

Indications

The main, evidence-based indications for adenoidectomy are the treatment of otitis media with effusion and obstructive sleep-disordered breathing in children. The latter procedure is often performed in conjunction with tonsillectomy in cases of gross tonsillar hypertrophy, or concurrent history of recurrent tonsillitis meeting the Paradise criteria.[7]

Less frequent indications for adenoidectomy are in the holistic management of rhinosinusitis, hyposmia or anosmia, and suspected malignancy.[2] The decision to operate should always be based on a clear positive history, clinical examination, and appropriate investigations individualized to each patient. In otitis media with effusion, this includes audiometry and tympanometry, and in cases of sleep-disordered breathing, polysomnography or sleep endoscopy can be used to confirm the clinical diagnosis if needed.

Contraindications

Whilst there are no absolute contraindications to adenoidectomy, careful consideration must be given to palatal insufficiency. Individuals with a known cleft palate or occult submucosal cleft palate are at a significantly increased risk of developing velopharyngeal insufficiency following adenoidectomy which can result in persistent hypernasal speech and nasal regurgitation. In such individuals a partial adenoidectomy limited to the lower third of the choana has been proposed.[8] Other relative contraindications to adenoidectomy include significant bleeding diathesis and active infection.[9]

Equipment

A range of instruments is currently used to carry out adenoidectomy.  These instruments include monopolar suction diathermy, curettage, powered micro-debrider, coblation, and laser techniques. All can be used successfully, and it is left to the operating surgeon which instruments they prefer to use.

Personnel

Adenoidectomy can be performed with the support of a scrub nurse and an anesthetist, a surgical assistant is not required.

Preparation

Following induction and intubation (an oral Rae tube is often helpful), the patient is laid supine with an appropriately-sized shoulder bolster placed to facilitate neck extension. If myringotomy and grommet insertion are to be performed concurrently, this usually precedes adenoidectomy, whereas concurrent tonsillectomy can be performed either before or after adenoidectomy.

A Crowe-Davis gag is inserted and opened to achieve good visualization of the oropharynx, the gag is suspended to maintain an optimal position. The McIvor mouth gag may be used in edentulous patients. This can be achieved via a rolled towel, a Mayo stand eedge, or Draffin rods. The soft palate should always be palpated for a submucosal cleft, and the postnasal space may also be palpated to assess adenoid size and to evaluate fo pulsations that can indicate aberrant medialization of the carotid arteries.

A nasal suction catheter is introduced, and its tip is withdrawn from the oropharynx. The 2 ends are then clipped under moderate tension adjacent to the alar cartilage to retract the soft palate anteriorly. A tonsil swab may be positioned between the catheter and nose to prevent pressure necrosis.

Technique or Treatment

A wide range of techniques for adenoidectomy exist, including laser ablation, coblation, endoscopic excision, and power-assisted (microdebrider) excision. Ultimately the decision rests with the operating surgeon, as similar successful outcomes have been well-documented with all of these methods.[10]

Monopolar Suction Diathermy

The monopolar suction diathermy device is bent to 70 to 90 degrees approximately 2 centimeters from its tip and the stylet then removed. Under indirect visualization with an anti-fogged laryngeal mirror, suction-diathermy (current 35 to 38 W) is carried out systematically, superiorly to inferiorly, from the choanal to the velopharyngeal portion of the adenoid. Lateral adenoidal tissue can be suctioned medially before ablation, avoiding trauma and scarring of the tubal cushion or damage to the torus tubarius. The procedure is completed when a comprehensive view of the choana is achieved, the nasopharynx has a smooth contour, and hemostasis ensured. Care should be taken to leave  a small remnant of adenoid tissue at Passavant's ridge to avoid postoperative velopharyngeal insufficiency. Nasal packing is rarely required.

The steps are virtually identical if using plasma ablation (Coblator), microdebrider, or laser removal, with the exception that these devices do not require custom bending.[11]

Curettage

An adenoid curette is introduced to the postnasal space and engages with the adenoid pad. A dental mirror can be used to facilitate indirect visualization and confirmation of positioning. The adenoids are removed superior to inferiorly in a single, firm movement, with the head stabilized by the non-dominant hand. The process may be repeated, and the nasopharynx re-examined either by palpation or with a mirror to ensure completeness of excision. The postnasal space may be packed with swabs to achieve hemostasis while a tonsillectomy is performed.  These must be removed at the end of the procedure.

On completion of adenoidectomy, it is essential to suction any clots from the postnasal space using a nasal suction catheter and to ensure that hemostasis has been achieved. Care must be taken when removing the gag to ensure that the endotracheal tube has not herniated into the blade, to prevent inadvertent extubation.

Complications

Common

Pain is self-limiting, and a short course of simple analgesics such as paracetamol and non-steroidal anti-inflammatory medications is usually sufficient.

An altered voice is usually the resolution of preexisting hyponasal speech and is often seen as a benefit rather than a complication.

Adenoid regrowth is noted in a small number of patients, and occasionally a revision adenoidectomy is necessary, particularly in patients having undergone adenoidectomy for infectious/otitis media indications[12].

Rare

Dental trauma and minor injuries to the lips and tongue can occur following adenoidectomy and tonsillectomy. The surgeon must enquire preoperatively about loose teeth and fillings, and exercise caution when introducing and opening the Crowe-Davis mouth gag to minimize these risks.

Intraoperative bleeding can result in the formation of a "coroner's" clot in the nasopharynx that can dislodge and result in fatal aspiration. For this reason, it is mandatory to suction the postnasal space before completing the surgery.

Postoperative bleeding is rare, and with the widespread adoption of diathermy and techniques involving direct visualization, rates have declined to as low as 0.07%.[13] Management of bleeding depends on the degree of bleeding. Incidental and self-limited bleeding may be managed expectantly with observtion and topical nasal oxymetazoline. Bleeding that is ongoing may require a return to the operating room. The nasopharynx is examined and any identified bleeding is cauterized under direct or endoscopic visualization. If this cannot control the bleeding, the patient may be kept intubated and packing of the postnasal space introduced. If this still fails to control the bleeding, embolization by interventional radiology or neck exploration and major vessel ligation may be required. This is extraordinarily rare. [14]

Atlantoaxial subluxation (Grisel syndrome) is a rare but serious complication following adenoidectomy. Pre-existing laxity of the anterior spinal ligament (associated with Down syndrome) and excessive use of diathermy are recognized risk factors. Management consists of analgesia, immobilization, and neurosurgical intervention in refractory cases.[15]

Long-term velopharyngeal insufficiency is rare, occurring in between 1 in 1,500 and 1 in 10,000 cases. It results in hypernasal speech and nasal regurgitation. Risk factors include a known cleft palate or an occult submucosal cleft palate. A partial adenoidectomy retaining tissue at the velopharyngeal junction should be considered in these cases to minimize the risk. Rarely, reconstructive surgery is required to improve severe speech and swallowing impairment.[16]

Clinical Significance

Adenoidectomy is an important surgical procedure and has high-quality evidence for its use in the treatment of pediatric otitis media with effusion as an adjuvant to myringotomy and grommet insertion (Level 1a)[17][18][19] and sleep-disordered breathing.[20][21][22]

Enhancing Healthcare Team Outcomes

Glue ear (severe, longstanding OME) and sleep-disordered breathing are complex disease processes that can have a profound impact on the psychological, social, and biological development of a child, and an interprofessional approach to management is key to achieving optimal outcomes. While general practitioners will often refer directly to otolaryngologists, the involvement of pediatricians and audiologists, as well as speech/languange pathologists to assess global development, the presence of any underlying systemic conditions, and in the perioperative care of children is often essential.

Respiratory and sleep medicine specialists are frequently invaluable in the diagnosis and treatment of sleep-disordered breathing and associated respiratory illness, and in arranging polysomnography. Audiologists perform audiometry and tympanometry and are therefore essential in diagnosing glue ear and assessing the degree of conductive hearing loss.

Perioperative management requires excellent communication between surgeon and anesthetist, particularly in relation to determining whether surgery should be planned as a day case or with an overnight stay for monitoring for oxygen desaturations. Intraoperative communication between surgeon and anesthetist is crucial during the insertion and removal of the mouth gag which if carelessly applied can inadvertently compress or extrude the endotracheal tube.

Throughout any admission or clinic, close involvement of pediatric nurses is vital to ensure that patients are stable and to pick up any early signs of deterioration. Finally, optimal care in the management of otitis media with effusion in patients with cleft palate or Down syndrome is achieved through an interprofessional team with appropriate expertise in the condition (Level V).[23]