Tonsillectomy has been widely done for many years in the otolaryngologic fields. Complications of this operation are bleeding, dehydration, pain, and oral feeding discomfort. Conventional extracapsular tonsillectomy and adenoidectomy (ECTA) means total removal of tonsillar tissue, including capsule of tonsils [1]. On the other hand, intracapsular tonsillectomy preserves the tonsillar capsule, which results in less postoperative pain and faster recovery than ECTA [2]. There are several technique used for intracapsular tonsillectomy; however the use of a powered microdebrider to remove tonsils was first reported by Koltai, et al. [3]. In this technique, the microdebrider removes tonsil, with leaving the lymphatic tissue on the capsule. This preserved tissue and tonsillar capsule function as a “biologic dressing,” which protects the pharyngeal muscles overlying the tonsillar fossa [4]. However, powered intracapsular tonsillectomy and adenoidectomy (PITA) is not performed in patients with recurrent tonsillitis due to the possibility of residual tonsils.

The large tonsils and adenoids can obstruct the pharyngeal airway and consequently cause obstructive sleep apnea (OSA), which is especially important in children. Therefore, adenotonsillectomy is an effective treatment for pediatric OSA and the application of PITA for the treatment of OSA has been reported in many studies [5-7]. However, the efficacy of PITA is still on debate [8]. There is also a lack of studies that directly compare PITA using microdebrider and ECTA’s functional outcomes let alone prospective studies.

The study was done to compare the clinical outcomes and complications of PITA with those of ECTA in treatment of pediatric OSA. We hypothesized that PITA is an effective, safe and less painful treatment in pediatric OSA patients and we want to prove these advantages by comparing with ECTA.

A total of 81 patients participated in the study, 46 of whom were in the PITA group, and 35 of whom were in the ECTA group. Demographic characteristics of patients were shown in Table 1. There was male dominant in both groups. A mean age of patients was 7.1 years in PITA group and 8.3 years in ECTA group. However, there was no statistical difference between the two groups for age and sex. There was a statistical difference between two groups in terms of tonsil size. Tonsil size of grade 3 or 4 was more common in the PITA group, but there was no difference in adenoid size between two groups (Table 1). Polysomnography was not performed on any of the subjects.

The severity of OSA was assessed by measuring the patients’ quality of life using the KOSA-18 questionnaire. The preoperative KOSA-18 score was 73.8 in the PITA group, and 58.6 in the ECTA group. However, there was no statistically significant difference of preoperative KOSA-18 between PITA and ECTA group (p=0.08). The postoperative KOSA-18 score was 28.5 in the PITA group, and 33.2 in the ECTA group respectively. Significant reduction of KOSA-18 scores was shown in the both groups after operation (p<0.01, p<0.01 respectively; Fig. 1).

Postoperative pain was evaluated by VAS score. The average score at postoperative day 1, 3, and 7 were significantly lower in the PITA group compared to the ECTA group (p=0.03, p<0.01, and p<0.01 respectively; Fig. 2).

Postoperative bleeding was 1 case in the PITA group, and 2 cases in the ECTA group (Table 2). All 3 cases had bleeding on tonsillectomy sites. One case in the ECTA group needed readmission to control bleeding, but there was no case of reoperation. Although bleeding was more common in the ECTA group, there was no significantly difference.

Because obstruction of the airway due to hypertrophy of the tonsils and adenoids is the main cause of OSA in children, adenotonsillectomy is the first treatment option in pediatric OSA. It can relieve airway obstruction associated with sleep [12,13].

Several attempts have been made to perform surgery using different tools and technology. However, there is still a dilemma for efficacy and safety [14]. The first introduction of PITA was reported by Koltai, et al. [3] and several studies have proven the effectiveness and safety of this procedure [2,14].

Sleep apnea is closely related to quality of life because it induces daytime sleepiness and depressive mood [15,16]. In our study, we found that KOSA-18 scores were significantly reduced regardless of intracapsular or extracapsular tonsillectomy. It is consistent with the previous meta-analysis study [1]. These results showed that quality of life was improved after surgery in pediatric patients. Although it is a subjective evaluation method, it can be considered as a meaningful result.

Because tonsillar capsule is left during PITA, the underlying vessels can be preserved. Therefore, PITA reduces the risk of postoperative bleeding [17]. Incidence of postoperative bleeding was lower in the PITA group compared with the ECTA group, but there was no statistical difference in this study. But bleeding was significantly less in the PITA group in a previously published study [14]. This difference is probably because our study was small-sized.

Tissue between tonsil and pharyngeal muscle acts a role in protecting the muscle from thermal damage caused by electrocautery [2,4]. Postoperative pain is caused by damage to the tonsillar fossa musculature [1]. Damage of musculature can be minimized during PITA. Our study found significant decrease of VAS score in the PITA group. Less pain is important because it enables an earlier return to normal diet and life after surgery [4,18].

Our study showed patients who received PITA had less postoperative pain. However, as the choice of surgical procedure was determined by the number of episodes of acute tonsillitis, it can be suspected that the ECTA group was more susceptible to postoperative pain. A study by Zagólski, et al. [19] shows that the general perception of patients with recurrent tonsillitis having more post-operative pain may be due to intra-operative trauma rather than past medical history. When patients with or without recurrent tonsillitis received the same surgical technique which eliminated forceful dissection, the group with recurrent tonsillitis experienced less pain. Thus it can be argued that the PITA group experienced less pain due to its surgical procedure.

Our study has several limitations. Although the gold standard diagnostic method of OSA is polysomnography, we diagnose OSA subjectively using history taking, physical examination, and questionnaire. Polysomnography is expensive and difficult to perform for younger children because they can’t cooperate. Second, we followed up patients until 1 mouth after surgery in outpatient, so our study did not include long-term outcome of PITA. PITA has several advantages because it preserves the tonsillar capsule, but it may lead to a residual tonsil tissue. This residual tonsil enables regrowth and can cause repeated tonsillitis and recurrent of OSA. Therefore, long-term outcome is important, but it was not evaluated in this study. Long-term studies in larger group patients are needed. Third, as complete blindfold could not be achieved by study design, there may be some placebo effect in place. Fourth, as patients with a history of recurrent tonsillitis was enrolled for ECTA rather than PITA, the study may be influenced by selection bias.

In conclusion, PITA is shown to be effectiveness and efficiency in pediatric OSA with fewer complications. Especially, when PITA was performed, there was less postoperative pain, which allowed the children to have a faster return to normal diet and activity after surgery. PITA should be considered more in the treatment of pediatric OSA patients because it is a procedure that gives more satisfaction to both parents and children.