The palatine tonsils and adenoids are classified as mucosaassociated lymphoid tissues located at the entrance to the upper airway. Their main role is to protect the body from the entry of exogenous material and infectious organisms such as bacteria through mucosal sites, especially in childhood [1]. At birth, the tissue size is very small, but increases as the child grows reaching peak size and immune function at 2-5 years old. It then becomes smaller at puberty as other lymphoid organs change [2]. Normally, in children, the adenoid forms a soft mound on the roof and posterior wall of the nasopharynx, just above and behind the uvula.

Chronic upper airway obstruction in childhood, followed by tonsil and adenoid hypertrophy can cause sleep-disordered breath, obstructive sleep apnea, mouth breathing, daytime sleepiness and simple snoring. Complications such as hypertension, heart failure, nocturia, activity disorder or learning disorder can also develop [3-5]. Growth retardation is another possible complication due to increased energy consumption or decreased growth hormone secretion during sleep and pain or discomfort with eating due to inflammation and a narrow oropharyngeal space [6-8].

Because immune function or upper respiratory tract starts to decline after 3 years of age, adenotonsillectomy is thought to have no significant effect on the immune system [9]. So, tonsillectomy can be recommended as a first-line treatment in chronic cases. There have been many studies regarding the effects on growth pattern after childhood tonsillectomy, and some authors have reported that height and weight growth patterns normalized after tonsillectomy [10-13]. However, there are few studies on the long-term effects on growth or presenting symptoms. Furthermore, it is also unclear impact on growth according to preoperative growth status. Therefore, the present study was conducted to evaluate the long-term effects of adenotonsillectomy on growth according to preoperative growth status and symptoms.

There are many heterogeneous clinical manifestations of adenoid hypertrophy according to patient age, general condition, and nasopharynx size. The most common symptom is nasal obstruction, which can present as snoring or mouth breathing. Hypertrophied adenoids can also block the orifice of the Eustachian tube, resulting in inflammation in the middle ear, or obstruct normal ventilation of the paranasal sinuses, resulting in sinusitis. Thus, inflammatory conditions of the tonsils and adenoids tend to increase the frequency of infectious complications and the chance of contracting an upper airway infection [1,3,5]. Adenotonsillar hypertrophy also causes snoring or sleep apnea, which result in growth retardation [6,8,15].

Adenotonsillectomy has been considered most effective treatment for adenotonsillar hypertrophy and chronic tonsillitis. Adenotonsillar hypertrophy with obstructive sleep apnea, failure to thrive, upper airway blockage and dysphagia are mainly observed in pediatric patients and candidates for adenotonsillectomy [16].

Growth improvement in children after tonsillectomy and/or adenoidectomy have been reported by several authors. In a study conducted in 29 children with obstructive adenotonsillar hypertrophy, increased weight and height standard deviation scores, energy intake and serum insulin-like growth factor 1 (IGF-1) were reported 6 months after adenotonsillectomy [12]. A retrospective study of 115 pediatric patients with sleep apnea or recurrent tonsillitis showed that the weight and body mass index gain after adenotonsillectomy was more effective in a younger age group, especially under the age of 6 years [13]. A prospective study in 22 patients to evaluate the effect of adenotonsillectomy revealed that children that underwent adenotonsillectomy had more height and weight gain after 6 months later [10]. Recently, Katz, et al. [11] conducted randomized controlled study to compare the effect on growth of adenotonsillectomy and watchful waiting in 464 children who had obstructive sleep apnea. Their results showed that adenotonsillectomy for children with sleep apnea results in significantly greater weight gain than watchful waiting 7 months after surgery.

Growth improvement after adenotonsillectomy could be explained by several reasons including improvement of dysphagia, sleep apnea and increased growth hormone. In a study prospective study using questionnaire in 85 children who underwent tonsillectomy, swallowing related quality of life, ability to tolerate a regular diet and weight percentile for age were improved whether the reason they referred was dysphagia or not [17]. Conley, et al. [18] reported improved dysphagia and sleep apnea even in children with neurologically impaired swallowing using video swallow study, polysomnography and telephone survey.

Improvement in sleep parameters including apnea/hypopnea index and minimum oxygen saturation after adenotonsillectomy in children with obstructive sleep apnea was also reported [19]. Furthermore, several studies showed that serologic changes after tonsillectomy or adenoidectmy. Increased IGF-1 mediating the anabolic effects of growth hormone and insulin-like growth factor-binding protein 3 (IGFBP-3) which is main binding protein of IGF-1 after tonsillectomy was reported [20,21]. Reduction in tumor necrosis factor-α (TNG-α), proinflammatory cytokine, and increased CD4+/CD8+ T lymphocyte ratio after adenotonsillectomy was also reported [22,23].

However, most of the studies on growth, symptom and laboratory changes after tonsillectomy included small number of patients and short-term follow-up periods, and there have been few studies on long-term effects on growth or symptom changes.

In this study, we analyzed long-term growth changes at 5 years after adenotonsillectomy. There were significant improvements in height percentile regardless of pre-operative height percentile. Furthermore, height percentile increase was greater in patients whose pre-operative height percentile was below 50. It might imply that the growth could be markedly improved after adenotonsillectomy in children having delayed growth due to adenotonsillar disease. Weight and BMI percentile were also increased in patients whose preoperative weight percentile was below 50. Interestingly, weight, and BMI percentile decreased in patients whose pre-operative weight percentile was 50 or more. It can be assumed that some obese children subsequently lost their weight due to improvement of sleep-disordered breathing or decreased frequency of upper respiratory infections resulting in increased activity levels.

In the view point of preoperative symptoms, many patients had 2 or more preoperative symptoms although indication of surgery was snoring or sleep apnea in most cases. There were significant improvements in URI frequency and appetite as well as snoring or sleep apnea although preoperative presenting symptoms may be affected by many confounding factors for 5 years. We also analyzed the growth changes according to the presenting symptoms, but height percentile was significantly increased regardless of presenting symptoms.

This study has some limitations in this study. First, we investigated postoperative growth status and symptoms by telephone based survey instead of office based physical examination and survey. However, recall bias could be minimal because preoperative data was based on the medical records and the items surveyed using telephone were height, weight, and symptoms at the time of survey. Second, we assumed that children will remain on the same height and weight percentile unless they undergo adenotonsillectomy. There might be many confounding factors because the growth and symptoms could be influenced by various factors and we investigated the growth status 5 years later after surgery. However, this is an important study that showed long-term effect of adenotonsillectomy on growth because there is few study about longterm effect of adenotonsillectomy on growth.

In conclusion, adenotonsillectomy can improve snoring or sleep apnea, URI frequency and appetite for a long time. Furthermore, it has long-term positive effects on height growth in children with adenotonsillar hypertrophy. The impacts of adenotonsillectomy on growth are more prominent in patients who have lower height percentile preoperatively. Weight gain also can be expected in low-weight children before surgery.