Current Techniques of Adenoidectomy





Introduction


The clinical significance of adenoid hypertrophy was not truly appreciated until the mid-19th century. This was due to the adenoids’ relatively inaccessible location given the technology available at that time. Once discovered, various techniques for the removal of the adenoids were developed. Some of these basic techniques have remained with us since that time.


Although commonly known for causing chronic sinonasal symptoms or influencing chronic ear disease, enlargement of the adenoids can play a prominent role in obstructive sleep apnea.





Patient Selection


Children with signs and symptoms of obstructive sleep apnea or those with polysomnogram-proven disease should have their adenoids evaluated as part of a routine workup. This can be done in a number of ways. In very young children or older cooperative children, flexible fiber-optic nasopharyngoscopy provides the most direct means of evaluation. A camera and monitor attached to the scope can provide families with visual reinforcement. In the child who will not tolerate a flexible examination in the office, a lateral plain film of the nasopharynx can demonstrate adenoid hypertrophy and resultant compromise of the nasal air column. Although not routinely obtained to evaluate for adenoid hypertrophy, computed tomography scans and magnetic resonance imaging can also demonstrate enlargement of the adenoid pad.


Adenoid hypertrophy is classically graded on a scale of 1 to 4+, with each grade describing the percentage of the adenoid hypertrophy obstructing the nasopharynx on nasal endoscopy. Grade 1 describes the adenoid occupying less than 25% of the choanal area. Grade 2 adenoids occupy 25% to 50% of the choanal area. Grade 3 adenoids occupy 50% to 75% of the choanal area. Grade 4 adenoids occupy 75% to 100% of the choanal area. Having the patient sniff versus phonate can best show the nasopharyngeal opening based on the position of the soft palate, which is maximally open with a sniff and closed while phonating.


Adenoidectomy must be carefully considered in children with a history of cleft palate, overt or submucous, or those with a history of velopharyngeal insufficiency. A balance between relief of obstruction and the creation of velar incompetence is crucial. Families must be counseled as to the increased risk for this potentially significant complication, even if a limited procedure is performed, such as a superior adenoidectomy.


Very commonly, adenoidectomy is performed in concert with tonsillectomy as the most common surgical procedure to treat obstructive sleep apnea.





Outline of Procedures


Various options for airway management exist, and it is important for the surgical and anesthesia teams to decide on this before the procedure begins. A straight endotracheal tube, laryngeal mask airway, or oral Ring–Adair–Elwyn tube may be used. The surgeon must consider factors such as other procedures (i.e. tonsillectomy) being performed when deciding on the type of airway management.


Historically, adenoidectomy was performed with the surgeon facing the patient, who was sitting upright. Some surgeons still currently employ an orientation similar to that of endoscopic sinus surgery. Today, the Rose position is commonly used in which the patient’s head and neck are extended and the surgeon sits behind the patient. A small shoulder roll may aid in this positioning. The eyes are protected, and the patient is sterilely draped. A mouth gag, such as the Crowe–Davis or McGyver, is then carefully inserted into the mouth, and the oropharynx is exposed. The mouth gag can be suspended per surgeon preference. The soft palate should then be visually inspected and palpated before mouth gag extension to ensure that a submucous cleft is not present. Visualization of the nasopharynx can be easily achieved using a defogged #5 laryngeal mirror and a headlight. Exposure can be enhanced using either one or two red rubber catheters. These are placed transnasally, retrieved from the oropharynx, and then clamped back on themselves, effectively retracting the soft palate. This retraction with red rubber catheters may aid in protecting the posterior surface of the soft palate from scarring, and hence nasopharyngeal stenosis, as well as aid in visualization of the nasopharynx.


The adenoidectomy is performed to the lateral boundary of the nasopharynx at the torus tubarius of the eustachian tube orifice. Care should be taken to avoid the eustachian tube orifice to avoid scaring and future eustachian tube dysfunction. The anterior border is defined by the posterior septum, or vomer, and the bony choana. Avoiding injury to the lateral bony choana can avoid unnecessary bleeding from branches of the sphenopalatine artery. The posterior/inferior border is defined by Passavant ridge, where the soft palate approximates for closure of the nasopharynx. Leaving a modest cuff of adenoid centrally along the inferiormost portion of the adenoid bed can protect from concerns of postoperative velopharyngeal insufficiency. Due to the curved nature of the roof of the nasopharynx, the depth of adenoidectomy can be a challenge to define. Deep to the adenoids are prevertebral muscles, which on deep cautery can lead to scarring, fibrosis, abscess, and even Grisel syndrome, defined by neck pain, stiffness, and atlantoaxial subluxation.



Curette Adenoidectomy


The use of a curette to remove the adenoids dates back to some of the earliest attempts at this procedure and remains an incredibly popular technique worldwide. The original design of Jacob Gottenstein has been modified, and many different lengths, widths, and curvatures are available. The basic principle is that of a sharp horizontal knife edge that is designed to cut through the base of the adenoid bed. The instrument is designed to follow the natural curvature of the nasopharyngeal skull base ( Fig. 70.1 ).




FIG. 70.1


Placement of adenoid curette. Note how curve of instrument approximates contour of skull base for effective removal of tissue without damage to underlying structures.


The curette may be passed blindly into the nasopharynx, or the laryngeal mirrors may be used to guide the cutting edge into position. Visualization of the fossa of Rosenmuller helps determine the appropriate curette size. The curette is placed against the vomer and then pushed through the adenoid tissue to the more resistant deeper layers. The handle is pulled toward the head, and the surgeon’s other hand acts as a fulcrum at approximately the level of the incisors. The curette is swept in an arc through the adenoid tissue until the level of Passavant ridge, which is the inferior aspect of the dissection. After the initial pass, the adenoid bed is inspected for the completeness of the procedure. If residual adenoid tissue is left behind, it must be removed using a smaller curette or St. Claire-Thompson forceps or Meltzer adenoid punch forceps. A tonsil sponge is then generally placed into the nasopharynx to aid in hemostasis. These sponges may contain medications such as oxymetazoline or can be used alone. It is the author’s preference to finalize hemostasis using a suction monopolar cautery using mirror guidance, although other techniques, including pressure packing, bismuth subgallate, and silver nitrate, have been described. Once final hemostasis is achieved, the nasopharynx and oropharynx should be irrigated and the stomach emptied of its contents before extubation.



Suction Cautery and Ablation Adenoidectomy


The widespread use of the suction monopolar cautery unit to achieve hemostasis after adenoidectomy naturally led to its use as a primary means of reducing adenoid tissue. With the patient in the Rose position, as described earlier, the adenoid pad is viewed with a mirror. The monopolar cautery unit, generally set at 30 to 40 watts, can then be shaped to fit the patient’s unique anatomy. The unit is gently bent to match the curve of the adenoid suction, allowing for better reach of the nasopharynx. Starting at the choana and working inferiorly, the adenoids are sequentially ablated using the cautery unit ( Fig. 70.2 ). As the tissue fluid is vaporized, there is a dramatic reduction in the size of the adenoid tissue. Care is taken to avoid inadvertent cautery of nonadenoidal tissue. Bleeding tends to be minimal using this technique and can be controlled with any of the methods described earlier.


Jun 10, 2019 | Posted by in OTOLARYNGOLOGY | Comments Off on Current Techniques of Adenoidectomy
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