Abstract: To explore the factors of post-adenoidectomy occipital hyperplasia. METHODS: Forty-one children with post-adenoidectomy occipital hyperplasia underwent allergen testing and medical record review to clarify the diagnosis, and pathological examination of the hyperplastic occipital tissue was performed. Forty children who did not have round occipital hyperplasia six months after adenoidectomy were selected as controls. Results: The allergen positivity rate of the round occipital hyperplasia group was 85%, of which 49% were perennial allergens, 41% were a mixture of perennial and seasonal, and 10% were seasonal allergens. The allergen positivity rate of the control group was 5%. Conclusion: Allergic rhinitis may be the main cause of round occipital hyperplasia after adenoidectomy.
Keywords: adenoidectomy, allergic, rhinitis, round pillow, hyperplasia In recent years, more and more children need surgery due to adenoid hypertrophy affecting breathing, and the surgical method has been changed from traditional adenoids scraping with a spoon to nasal endoscopic low-temperature plasma resection or aspiration drill resection, the latter two methods can accurately and completely remove the adenoids and reduce the chance of recurrence. Despite this, some children still develop hypoventilation or delayed middle ear complications after surgery, and these children are found to have a wider round occipital area than before surgery. It has been noted that the incidence of adenoid hypertrophy in children with allergic rhinitis is higher than that in children with non-allergic rhinitis, and the incidence in children with allergic rhinitis has gradually increased in recent years.
1. Data and methods 1.1. Clinical data From February 2007 to November 2009, 41 cases of post-adenoidectomy occipital hyperplasia were seen in our department, 25 males and 16 females, aged 3 to 11 years, with an average age of 5.1±2.4 years. The other 40 children who did not have round occipital hyperplasia six months after adenoidectomy were selected as controls, 26 males and 14 females, aged from 3 to 11 years old, with an average age of (5.2±2.6).
1.2, Methods All cases were diagnosed by nasal endoscopy of the nasopharynx, and a round occipital width of more than two times normal was considered as round occipital hyperplasia (Figure 1). In two groups of children, allergens were detected by skin prick method with Aroger’s allergen skin test solution or by pharmacia cap system to detect specific IgE. In one case of round occipital hyperplasia obstructing the posterior nostril, low temperature plasma was used to remove the hyperplastic tissue and remove the round occipital tissue for pathological examination. The medical records were reviewed to determine if the patient had allergic rhinitis or chronic rhinitis or sinusitis before surgery.
2. Results Among 41 children with round occipital hyperplasia, 26 cases were positive for allergens and 8 cases had increased or significantly increased specific IgE. Among them, perennial allergens accounted for 49%, mixed perennial and seasonal accounted for 41%, and seasonal allergens 10%. Allergens were ranked as follows: mold spp. (71%), dust mite and house dust mite (46%), animal hair (27%), weeds (38%), and trees (29%). Pathological findings: the hyperplastic round occipital tissue was covered with pseudocomplexed columnar ciliated epithelium, with massive lymphoid tissue hyperplasia in the lamina propria, increased glands, and edematous thickening of the basement membrane (Figure 2a-2b) The children tested positive for allergens. 21 cases were diagnosed with allergic rhinitis before surgery, and the remaining 20 cases had a history of chronic rhinitis before surgery. None of these children were given effective postoperative anti-allergic and anti-inflammatory treatment. In the control group, 2 cases were positive for allergens, both were weeds and trees, and the rest were negative. 2 cases were diagnosed with chronic sinusitis by preoperative CT examination, and 4 cases had a history of chronic rhinitis. 2 children with sinusitis were given sinus negative pressure replacement and anti-inflammatory treatment after surgery, 2 children with allergic rhinitis were given oral loratadine tablets and nasal spray of mometasone furoate after surgery, and the remaining 4 children with chronic rhinitis were treated with oral nasal abdomen and orifice granules .
3. Conclusion The above results show that more than 85% of children with round occipital hyperplasia suffered from allergic rhinitis and the remaining 15% suffered from chronic rhinitis or chronic rhinosinusitis. Perennial allergic rhinitis may be the main cause of post-adenoidectomy round occipital hyperplasia, and chronic rhinitis or chronic sinusitis that persists is also an important cause. Allergic rhinitis is an important risk factor for adenoid hypertrophy. The adenoids and tonsils are the lymphoid tissues closest to the nasal mucosa in humans, and studies have found that allergen-related lymphocytes and cytokines are higher in the adenoids of children with allergic rhinitis than in those with non-allergic disease. After adenoidectomy, lymphocytes in the nasopharynx, mainly in the round occipital tissue, can proliferate reactively in response to allergen stimulation. The round occipital mucosa is a continuation of the nasal mucosa, and its structure is basically the same as that of the nasal mucosa. When allergic rhinitis occurs, the basement membrane of the round occipital mucosa thickens due to the increase of glands in the lamina propria and the accumulation of a large number of inflammatory mediators, which can also thicken the round occipital mucosa edema. In this group of cases, not only the round occipital area was hyperplastic, but also the residual adenoid tissue was hyperplastic in some cases. Pathological examination confirmed lymphocyte hyperplasia, increased glandularity, and thickened basement membrane edema in the hyperplastic circular occipital mucosa. In order to prevent the postoperative hyperplasia of the round occipital and residual adenoid tissue in children with adenoid hypertrophy combined with allergic rhinitis, routine antiallergic treatment, especially nasal spray glucocorticoids, should be used after adenoidectomy to reduce round occipital edema and hyperplasia. In this paper, we report 41 cases of children with round occipital hyperplasia without corresponding formal treatment. After systematic outpatient anti-allergic and anti-inflammatory treatment, nasopharyngeal secretions were significantly reduced, and round occipital hyperplasia was significantly reduced and most of them returned to normal. For the round occipital tissue that affected the function of the eustachian tube and blocked the posterior nostril, it was removed layer by layer from outside to inside with Evag70 low-temperature plasma knife until the round occipital muscle contracted. In the control group, eight children with allergic rhinitis or chronic rhinitis or sinusitis did not have postoperative round occipital hyperplasia because of the effective treatment given after surgery.