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Location of the adenoid
Location of the adenoid
Adenoidectomy surgical removal of the adenoids for reasons which include impaired breathing through the nose, chronic infections, or recurrent earaches. The surgery is less commonly performed in adults in whom adenoids are considered vestigial and purposeless. It is most often done on an outpatient basis under general anesthesia. Post-operative pain is generally minimal and reduced by icy or cold foods. The procedure can be combined with tonsillectomy if indicated and recovery time can range from several hours to two or three days (though as age increases so does recovery time).
Adenoidectomy is not often performed under one year of age as adenoid function is part of the body's immune system but its contribution to this decreases progressively beyond this age.
In the early 1900s, adenoidectomies began to be routinely combined with tonsillectomy. Initially, the procedures were performed by otolaryngologists, general surgeons, and general practitioners but over the past 30 years have been performed almost exclusively by otolaryngologists.
Then, adenoidectomies were performed as treatment of anorexia nervosa, mental retardation, and enuresis or to promote 'good health'. By current standards, these indications seem odd but may be explained by the hypothesis that children might have failed to thrive if they had chronically sore throats or severe obstructive sleep apnea (OSA). Also, children who heard poorly because of chronic otitis media might have had unrecognized speech delay mistaken for mental retardation. Adenoidectomy might have helped to resolve ear fluid problems, speech delays, and consequent perceptions of low intelligence.
The relationship between enuresis and obstructive apnea, and the benefit of adenoidectomy by implication, is complex and controversial. On one hand, the frequency of enuresis declines as children grow older. On the other, the size of the adenoids, and again by implication, any obstruction that they might be causing, also declines with increasing age. These two factors make it difficult to distinguish the benefits of adenoidectomy from age-related spontaneous improvement. Further, most of the studies in the medical literature which appear to show benefit from adenoidectomy have been case reports or case series. Such studies are prone to unintentional bias. Finally, a recent study of six thousand children has not shown an association between enuresis and obstructive sleep in general but an increase with advancing severity of obstructive sleep apnea, observed only in girls.
A decline in the frequency of the procedure started in the 1930s as its use became controversial. Tonsillitis and adenoiditis requiring surgery became less frequent with the development of antimicrobial agents and a decline in upper respiratory infections among older school-aged children. Also, several studies had shown that adenoidectomy and tonsillectomy was ineffective for many of the indications used at that time as well as the suggestion of an increased risk of developing poliomyelitis after the procedure, later disproved. Prospective clinical trials, performed over the last 2 decades, have redefined the appropriate indications for tonsillectomy and adenoidectomy (T&A), tonsillectomy alone, and adenoidectomy alone.
In 1971, more than one million Americans underwent tonsillectomies and/or adenoidectomies, of which 50,000 consisted of adenoidectomy alone.
By 1996, roughly a half million children underwent some surgery on their adenoids and/or tonsils in both outpatient and inpatient settings. This included approximately 60,000 tonsillectomies, 250,000 combined tonsillectomies and adenoidectomies, and 125,000 adenoidectomies. By 2006, the total number had risen to over 700,000 but when adjusted for population changes, the tonsillectomy "rate" had dropped from 0.62 per thousand children to 0.53 per thousand. A larger decline for combined tonsillectomy and adenoidectomy was noted - from 2.20 per thousand to 1.46. There was no significant change in adenoidectomy rates for chronic infectious reasons (0.25 versus 0.21 per 1000.
The indications for adenoidectomy are controversial. Widest agreement surrounds their removal for obstructive sleep apnea, usually combined with tonsillectomy. Even then, it has been observed that a significant percentage of the study population (18%) did not respond. There is also support for adenoidectomy in recurrent otitis media in children previously treated with tympanostomy tubes. Finally, the effectiveness of adenoidectomy in children with recurrent upper respiratory tract infections has been questioned with the outcome, in some studies, being no better than watchful waiting.
Adenoids develop from a subepithelial infiltration of lymphocytes after the 16th week of embryonic life. They are part of the so-called Waldeyer ring of lymphoid tissue which includes the palatine tonsils and the lingual tonsil.
After birth, enlargement begins and continues until aged 5 to 7 years. Symptomatic enlargement between 18 to 24 months of age is not uncommon, meaning that snoring, nasal airway obstruction and obstructed breathing may occur during sleep. However, this may be reasonably expected to decline when children reach school age, and progressive shrinkage may be expected thereafter.
The establishment of the upper respiratory tract is initiated at birth. Species of bacteria such as lactobacilli, anaerobic streptococci, actinomycosis, Fusobacterium species, and Nocardia are normally present by 6 months of age. Normal flora found in the adenoid consists of alpha-hemolytic streptococci and enterococci, Corynebacterium species, coagulase-negative staphylococci, Neisseria species, Haemophilus species, Micrococcus species, and Stomatococcus species.
It is currently believed that bacterial biofilms play an integral role in the harboring of chronic infection by tonsil and adenoid tissue so contributing to recurrent sinusitis and recurrent or persistent ear disease. Also, enlarged adenoids and tonsils may lead to the obstruction of the breathing patterns in children, causing apnea during sleep.
The most common bacteria isolated are Haemophilus influenzae, group A beta-hemolytic Streptococcus, Staphylococcus aureus, Moraxella catarrhalis, and Streptococcus pneumoniea. Heamophilus influenza, Moraxella catarrhalis and Streptococcus pneumonia are the three most resistant pathogens of otitis and rhinosinisitis in children suffering from these diseases.