What is the role of the adenoid in pediatric chronic rhinosinusitis?

Pediatric chronic rhinosinusitis (CRS) is broadly defined as 90 or more uninterrupted days of respiratory symptoms with corresponding endoscopic and/or computed tomography (CT) scan findings. It is a common yet difficult problem in the pediatric population. Otolaryngologists agree on initial medical management with nasal saline irrigations, nasal steroid sprays, and an antibiotic directed at the most common sinonasal pathogens. The majority of pediatric patients do not require surgery for CRS. In children with sinus disease refractory to medical therapy, there is controversy regarding surgical management. Surgical options include adenoidectomy and endoscopic sinus surgery (ESS). The goal of surgery is to improve quality of life and prevent further disease. It is preferable to avoid the need for additional or revision surgeries. This review describes the evidence regarding the role of the adenoid in pediatric CRS. Of note, pediatric CRS associated with cystic fibrosis, immunodeficiency, nasal polyposis, allergic fungal disease, and/or ciliary dyskinesia is generally not treated with adenoidectomy alone; these patients are excluded from the discussion below. The adenoid has been implicated in sinus disease because it harbors bacteria within biofilms. Shin et al.1 published a retrospective chart review of prospectively collected data in 2008 that examined adenoid size and bacteriology in relation to pediatric CRS. The authors included 410 children less than 14 years of age who underwent adenoidectomy for symptoms of adenoid hypertrophy. Each child had a preoperative paranasal sinus X-ray within 10 days of surgery, a lateral radiograph to assess adenoid size using an adenoidal–nasopharyngeal ratio, and a culture taken from the adenoid tissue. Bacteria was isolated from 79.3% of the specimens; the most common pathogens were Haemophilus influenzae (28.5%), Streptococcus pneumoniae (21.7%), and Streptococcus pyogenes (21.0%). The rate of bacterial isolation from the adenoid cultures correlated with the severity of sinus disease as seen on Waters' view, which was statistically significant (P = 0.0000). There was a statistically significant increase in the preoperative radiographic severity of sinus disease in patients who grew H. influenzae and S. pneumoniae. There was no statistically significant correlation between adenoid size and severity of sinus disease on radiograph. These authors suggest that in the setting of CRS, the adenoid may act as a reservoir for pathogenic bacteria rather than a source of obstruction. In 2007, Coticchia et al.2 compared the surface area of adenoid tissue covered by a biofilm in patients who had an adenoidectomy for obstructive sleep apnea (OSA) to patients who underwent adenoidectomy for CRS. This study demonstrated a statistically significant difference in the percentage of mucosal surface area covered by biofilm between these two groups. Adenoid tissue removed from patients with a diagnosis of CRS had a mean surface area of 94.9% of their mucosal surface covered with mature biofilms, compared with a mean of 1.9% in patients with OSA. The authors conclude that persistent biofilms explain the cycle of recurrent symptoms of CRS despite medical therapy, and that mechanical debridement of the adenoid tissue is the sole solution to removing this nidus of infection. A prospective cohort study that was published in 1995 introduced a stepped protocol for the management of refractory pediatric CRS in patients aged 2 to 13 years (median age 6 years, interquartile range 3.5–9.5 years).3 All 41 patients enrolled in the study were initially treated with additional antibiotics. Patients with chronic symptoms (n = 27) received 3 weeks of antibiotic therapy and a nasal steroid preparation. Sinusitis prone patients (n = 14) who had three or more annual recurrences of sinusitis received prophylactic antibiotics nightly at half the usual dose for 2 months or longer. Fifteen patients (37%) responded to antibiotics alone, as determined by their sinusitis response score. Patients subsequently had an adenoidectomy (n = 10, 24%) if they failed antibiotic therapy and had adenoid tissue present. ESS was the third step of the protocol and was reserved for patients who had no adenoid tissue (either due to involution or excision prior to enrollment in the study) or those who failed adenoidectomy. Eighteen patients (44%) ultimately underwent ESS; of those, six had an adenoidectomy either prior to or during the study. Overall, the adenoidectomy success rate was 57%. Based on these findings, the author suggests additional antibiotic therapy and adenoidectomy before ESS in pediatric CRS. The clinical outcome of pediatric patients who underwent adenoidectomy for refractory rhinosinusitis was evaluated in a recent meta-analysis.4 Studies written in English and published prior to September 2007 were included if they reported the success of adenoidectomy alone in patients less than 18 years of age and included five or more patients. Nine studies met inclusion criteria, and the grand mean age of patients was 5.8 years (range 4.4–6.9 years). Patient/caregiver reports of symptom improvement were the main outcome measure. Eight studies were similar enough to undergo random effects modeling. The summary estimate of patients who symptomatically improved following adenoidectomy alone was 69.3% (95% CI = 56.8–81.7%, P < 0.001). The authors note that the same author published three articles included within their analysis. When these publications were excluded, the summary estimate of improvement rose to 83.4% (95% CI = 74.5–92.2%, P < 0.001). Their results strongly suggest adenoidectomy as the first-line surgical management of refractory pediatric CRS. A retrospective chart review by Ramadan et al.5 published in 2007 focused on patients who failed initial adenoidectomy for the treatment of CRS. They discovered a roughly 50% failure rate, consistent with previous studies, with a mean failure time of 23.7 months (range 4.4–77.4 months). Of all the patient characteristics reviewed, only an age less than 7 years and asthma were predictors of an earlier failure rate. Gender, Lund-McKay stage, and history of allergies had no bearing on failure time. Based on these findings, the authors conclude that adenoidectomy is a reasonable first step for the treatment of certain patients with CRS, and knowledge of those patients at higher risk to fail adenoidectomy may be helpful for caregiver counseling. Based on the current evidence, bacteria harbored within adenoid biofilms contribute to pediatric CRS, even in the absence of obstructive adenoid hypertrophy. Adenoidectomy is a reasonable first-line surgical option for pediatric patients with CRS that is refractory to medical therapy. The majority of studies that examine the role of adenoidectomy alone for pediatric CRS are limited to younger patients; therefore, its role in adolescents has yet to be determined. This is a difficult topic with many directions for future research. A prospective study with a validated quality-of-life questionnaire and long-term follow-up is necessary to define which subgroup of pediatric patients benefit from adenoidectomy alone. Three of the studies are level 3 evidence (retrospective reviews); one is level 2 (prospective cohort study); and one is not defined (meta-analysis).