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Polysomnography outcomes for partial intracapsular versus total tonsillectomy
International Journal of Pediatric Otorhinolaryngology 74 (2010) 1361–1366
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Polysomnography outcomes for partial intracapsular versus total tonsillectomy§,§§ Jason Mangiardi a,1, Katharina D. Graw-Panzer b, Jeremy Weedon c, Theresa Regis a, Haesoon Lee b, Nira A. Goldstein a,* a
Division of Pediatric Otolaryngology, State University of New York Downstate Medical Center, 450 Clarkson Avenue, Box 126, Brooklyn, NY 11203, United States Division of Pediatric Pulmonology, State University of New York Downstate Medical Center, 450 Clarkson Avenue, Box 49, Brooklyn, NY 11203, United States c Scientific Computing Center, State University of New York Downstate Medical Center, 450 Clarkson Avenue, Box 7, Brooklyn, NY 11203, United States b
A R T I C L E I N F O
A B S T R A C T
Article history: Received 2 July 2010 Received in revised form 30 August 2010 Accepted 3 September 2010 Available online 28 September 2010
Objective: To demonstrate similar improvement in pediatric sleep-disordered breathing (SDB) as determined by polysomnography (PSG) with microdebrider-assisted partial intracapsular tonsillectomy and adenoidectomy (PITA) versus Bovie electrocautery complete tonsillectomy and adenoidectomy (T&A). Methods: In this retrospective cohort study, 30 children found to have SDB by PSG who have undergone either PITA (15 participants) or T&A (15 participants) as treatment were evaluated with standardized history and physical examination and unattended home overnight PSG. Results: Median change in apnea–hypopnea index (AHI) was 1.7 ( 4.9 to 29.8) for the PITA group and 2.3 ( 10.9 to 64.1) for the T&A group, although there was substantially more variability in the T&A group. A mixed linear model evaluating the relation of surgical group with change in AHI demonstrated no significant differences in group means (F[1,13] = 0.31, P = .590) but the variances differed significantly (residual likelihood ratio chi-square = 5.24, df = 1, P = .022). Five of 15 (33%) PITA patients and 4 of 15 (27%) T&A patients had postoperative AHI scores of 5; this difference was not statistically significant (Fisher exact test P = 1.000). There was no significant interaction or substantial confounding effect of age, sex, race, preoperative tonsil size, preoperative AHI, or body mass index in the model relating surgery type to reduction of postoperative AHI to 5. Conclusions: Our study demonstrates no clinically or statistically significant differences in PSG and clinical outcomes between PITA and T&A for treatment of pediatric SDB in otherwise healthy children. ß 2010 Elsevier Ireland Ltd. All rights reserved.
Keywords: Sleep-disordered breathing Obstructive sleep apnea Tonsillectomy Polysomnography
1. Introduction Pediatric sleep-disordered breathing (SDB) is a continuum of pathology including primary snoring, increased upper airway resistance syndrome and obstructive sleep apnea (OSA) with OSA being the most severe form [1]. Estimates place the prevalence of pediatric SDB at 1–3% of the preschool and school-age populations [2]. Treatment of SDB with tonsillectomy and adenoidectomy (T&A) is successful in resolution of abnormal polysomnographic
§ Presented at the American Society of Pediatric Otolaryngology Annual Meeting, May 2, 2010; Las Vegas, NV, United States. §§ Trial Registration: clinicaltrials.gov Identifier: NCT00887471. * Corresponding author at: Department of Otolaryngology, State University of New York Downstate Medical Center, 450 Clarkson Avenue, Box 126, Brooklyn, NY 11203, United States. Tel.: +1 718 270 1638; fax: +1 718 270 3924. E-mail address: [email protected] (N.A. Goldstein). 1 Current address: New York Otolaryngology Group, 501 Seaview Avenue, Staten Island, NY 10305, United States.
0165-5876/$ – see front matter ß 2010 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.ijporl.2010.09.003
indices in 80% of otherwise healthy children [3,4]. However, standard methods of tonsillectomy are riddled with postoperative complications including high risks of bleeding, burdensome postoperative pain and significant delays in return to regular activity. Recently, some centers have advocated partial intracapsular tonsillectomy and adenoidectomy (PITA) as treatment for pediatric SDB [5,6]. In the PITA procedure, only part of the tonsil is removed with the extent of dissection varying by surgeon. This allows the remainder of the tonsil to serve as a ‘‘biologic dressing’’ over the tonsillar fossa musculature. Advocates of this method cite lower postoperative pain rates because of decreased thermal injury to the underlying musculature with a correspondingly improved rate of return to regular activity [5]. However, opponents worry that the residual tonsil tissue could regrow leading to a recurrence in symptoms. Symptomatic tonsillar regrowth with microdebriderassisted PITA has been found to be less than 1% [7] and higher with other PITA techniques [8]. Studies regarding the postoperative hemorrhage rate and regrowth potential of PITA patients are
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difficult to perform given the large sample sizes required to show any substantial difference between PITA and T&A children. The largest, a retrospective study of 870 children from 3 different medical centers, reported a postoperative hemorrhage rate (95% CI) of 0.5% (0, 1.4), readmission rate (95% CI) of 0.7% (0, 1.9) and a regrowth rate (95% CI) of 0.46% (0.009, 0.9) over a mean follow-up of 1.2 years [7]. The rates of bleeding and readmission were significantly lower than those in a comparison group of 1121 children undergoing conventional T&A. Retrospective comparisons between differing techniques for PITA have shown microdebrider-assisted procedures preferable to electrocautery and harmonic scalpel techniques in the domains of postoperative pain and return to normal diet and activity [9]. Prospective studies have shown improved median days to regular activity (2.5 versus 4 days for microdebrider-assisted PITA versus electrocautery tonsillectomy respectively) and median days to last pain medication dose (4 versus 6.5 days) [10]. Two studies have evaluated SDB-related quality of life in otherwise healthy children undergoing PITA using the validated quality of life survey, the OSA-18. Colen et al. [11] reported large and significant improvements in both the total and individual domain scores for 50 children with SDB (42% with positive preoperative polysomnography [PSG]) at 3-months and 1-year after surgery and Tunkel et al. [12] reported similar findings for 14 children, all with positive preoperative PSG, at 5–10 weeks after surgery. The improvements in OSA-18 scores in both studies were similar to studies reporting changes in quality of life in children undergoing conventional T&A. Since its first description in children in 1975, the gold standard for evaluation of OSA has been PSG [13,14]. There are two previous studies evaluating PSG outcomes in otherwise healthy PITA patients. In the uncontrolled before-after study by Tunkel et al. [12] described above, 14 children with moderate OSA (apnea– hypopnea index [AHI] between 5 and 20) demonstrated significant improvement in AHI on laboratory-based PSG and 13 of 14 patients had complete cure of their OSA (AHI 1) with one patient having mild residual OSA (AHI > 1 and < 5) at a follow-up of 5–10 weeks after surgery. Reilly et al. [15] performed a retrospective review of 26 children treated by microdebrider tonsillectomy and electrodessication adenoidectomy who had both pre- and postoperative laboratory-based PSG. The authors found statistically significant improvements in both AHI and AI at mean follow-up of <2 years, with complete resolution of OSA (AHI 1) in 50% and persistent mild residual OSA (AHI > 1 and <5) in 50%. The current study aims to further validate PITA as a treatment modality for pediatric SDB by demonstrating similar home PSG outcomes between PITA and T&A at one to 6-year follow-up. 2. Methods 2.1. Participants This is a retrospective cohort study of children with SDB who have undergone either PITA or T&A as treatment. The protocol was approved by the Institutional Review Boards of the State University of New York Downstate Medical Center and the Long Island College Hospital and informed consent was obtained from the parents or legal guardians of the participants. Between July 2003 and January 2008, 149 children underwent PITA while 455 underwent T&A by the senior investigator at the Long Island College Hospital or the University Hospital of Brooklyn in Brooklyn, NY. PITA was offered as an alternative to T&A to all the parents of children with SDB but no history of recurrent tonsillitis. The potential benefits of PITA as well as the potential risk of tonsil regrowth were explained and the procedure was chosen by the parent or caretaker. The medical records of the 149 children who underwent PITA were reviewed to
identify children with positive preoperative PSG (laboratorybased, home or nap). All patients with positive studies were offered participation. Of these, 15 completed all aspects of the study. PITA participants were randomly 1–1 matched by age, sex, time since procedure and PSG results (AHI within 5) to 15 children who underwent T&A. Children with recurrent tonsillitis, craniofacial syndromes, neuromuscular disorders and sickle cell disease were excluded. 2.2. Interventions All participants underwent a standardized history and physical examination, by either the primary investigator or first author, and home overnight PSG. The history determined the presence of snoring, apneic pauses, restless sleep, frequent awakenings, neck extension, enuresis for children 4 years of age and older, daytime sleepiness, behavior/learning problems, and mouthbreathing. The physical examination included height, weight, tonsil size and the presence of mouthbreathing, hyponasality, and adenoid facies (open mouth, long face, mandibular hypoplasia). BMI was calculated by dividing the child’s weight in kilograms by the square of the height in meters and compared to standard percentiles for age and sex. Tonsil size was graded as the reduction in pharyngeal luminal diameter: 1+, 0–25%; 2+, 26–50%; 3+, 51– 75%; and 4+, 76–100% as described by Brodsky [16]. The patient’s office and hospital charts were reviewed to record the preoperative symptoms and physical examination findings. Entry and preoperative symptom scores were calculated as the sum of all positive history items divided by the total number of items with valid responses. Due to the sequential nature of the study, examiners were not blinded to the type of surgery performed. Unattended home overnight PSG was performed. Studies consisted of respiratory rate, pulse rate, pulse oximetry, inductive plethysmography of the chest and abdomen and the mathematical sum of the 2 for respiratory effort, and oronasal airflow from a loose mask or nasal cannula. Obstructive apnea was defined as the cessation of oronasal airflow with continued respiratory effort for at least 2.5 times the typical breath interval, and obstructive hypopnea was defined as a decrease in amplitude of oronasal airflow of at least 50% with no decrease in respiratory effort for the same duration with at least 4% desaturation. PSG was considered positive for OSA when the number of obstructive apneas plus hypopneas per hour of sleep (AHI) was >5, the number of apneas per hour of sleep (apnea index, AI) was >1, or the minimum oxygen saturation was less than 92% [14]. This definition of a positive PSG was used as these are the traditional criteria for which surgical treatment is recommended. The pre- and postoperative sleep studies were analyzed by a pediatric pulmonologist blinded to treatment group and to pre- or postoperative signs and symptoms. Unattended home PSG has been found to be accurate and practical in the routine evaluation of pediatric OSA [17]. It is advantageous in that it allows children to sleep in their own environment, leading to longer sleep duration, higher sleep efficiency, and fewer laboratory-induced arousals. Home sleep study also increases patient compliance and retention through all aspects of the study. 2.3. Statistical methods Patients who enrolled and completed the study, patients who withdrew and patients not offered enrollment were compared in terms of age at surgery, current age, time since surgery, preoperative AHI and preoperative lowest oxygen saturation using the Kruskal–Wallis test and in terms of age, race and surgical group using the generalized Fisher exact test.
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The relationship of surgical group with AHI change was evaluated by constructing a mixed linear model (MLM). The dependent variable was the logarithm of the ratio of postoperative AHI score to preoperative AHI score; this transformation was chosen in order to minimize skew of model residuals. Surgical group was introduced as a fixed factor; subject pairs constituted levels of a random (blocking) factor. Variance was estimated separately for each surgical group; a residual likelihood ratio test was conducted to test differing variance between groups. Two outlying change scores were excluded from inferential analysis. A similar analysis was constructed for symptom change score, but this time the dependent variable was a simple preoperative minus postoperative difference score; no cases were excluded. The relationship of surgical group with postoperative AHI 5 was evaluated by exact conditional logistic regression, predicting AHI 5 from surgical group with subject pairs as strata. A similar model was used to determine if any of the following covariates were predictive of postoperative AHI 5: age, sex, race, preoperative tonsil size, preoperative AHI and entry percentile BMI category. A P value < .05 was considered statistically significant. SAS Release 9.2 (SAS Institute, Cary NC) and LogXact Release 7 (Cytel Corp., Cambridge MA) software were used. 3. Results Review of surgical case logs identified 45 patients with positive PSG who had undergone PITA and 101 with positive PSG who had undergone T&A. Of these 15 PITA patients entered and completed the study and 15 matched T&A patients entered and completed the study. An additional 8 patients (7 PITA, 1 T&A) were enrolled but withdrew prior to completion. One additional T&A patient completed the study but was not included because his matched PITA patient withdrew. There was no significant difference in age at surgery (P = .453), current age (P = .508), sex (P = .951), race (P = .495), time since surgery (P = .541), preoperative AHI (P = .407) and preoperative lowest oxygen saturation (P = .681) among patients who completed the study, patients who withdrew, and patients who were not offered enrollment. PITA patients were significantly more likely to withdraw than T&A patients (P < .001). Patient demographics for the 15 PITA and 15 T&A patients that completed the protocol are presented in Table 1. Mean (SD) age at surgery was 5.33 (3.65) years for the PITA patients and 6.15 (3.29) years for the T&A patients. 80% of the PITA patients were male as compared to 47% of the T&A patients. BMI was measured only at entry into the study due to a large number of missing heights and weights in the patients’ charts at the time of surgery. 67% of the PITA patients and 71% of the T&A patients were overweight or obese. Time between surgery and study entry was about 4 years for both groups. History and physical examination findings are presented in Table 2. Data are missing for some of the preoperative measures due to incomplete information in the patients’ charts. All patients snored preoperatively while snoring was found in 73.3% of the PITA patients and 40.0% of the T&A patients at study entry. Apneic pauses were reported for 80.0% of the PITA patients and 93.3% of the T&A patients preoperatively and 0% of the PITA patients and 14.3% of the T&A patients at study entry. Preoperative tonsil size was 3+ or 4+ for about 80% of patients in both groups. Residual 1+ tonsils were found for 33.3% of the PITA patients and 13.3% of the T&A patients at study entry. The mean (SD) symptom change score was 0.38 (0.31) for the PITA patients and 0.44 (0.28) for the T&A patients (P < .001 for both). No significant difference was found between groups in either mean (F[1,14] = 0.24, P = .630) or variance (chi-square = 0.116, df = 1, P = .733). Preoperative studies consisted of 5 overnight laboratorybased studies, 3 overnight home studies, and 7 nap studies for
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Table 1 Patient demographics.
Age at surgery, y n Mean (SD) Range Sex, no. (%) n Male Female Race, no. (%) n White Black Hispanic Asian Postoperative BMI percentile, no. (%) n Underweight, <5th percentile Healthy, 5th & <85th percentile Overweight, 85th & <95th percentile Obese, 95th percentile Time since surgery, y n Mean (SD) Range
PITA
Total T&A
15 5.33 (3.65) 1.31–13.92
15 6.15 (3.29) 1.07–12.38
15 12 (80.0) 3 (20.0)
15 7 (46.7) 8 (53.3)
15 2 (13.3) 12 (80.0) 0 1 (6.7)
15 2 (13.3) 11 (73.3) 2 (13.3) 0
9 0 3 (33.3) 3 (33.3) 3 (33.3) 15 4.04 (1.39) 1.63–5.72
14 1 3 3 7
(7.1) (21.4) (21.4) (50.0)
15 3.84 (1.85) 0.90–6.26
Abbreviations: PITA, partial intracapsular tonsillectomy and adenoidectomy; Total T&A, total tonsillectomy and adenoidectomy.
the PITA patients and 9 overnight laboratory-based studies, one overnight home study and 5 nap studies for the T&A patients. All postoperative studies were home overnight studies. Mean sleep time was shorter in the preoperative studies for both groups because a large number of patients had nap PSG (Table 3). Median preoperative AHI was 8.3 for the PITA patients and 10.9 for the T&A patients, while median postoperative AHI was 5.9 for the PITA patients and 8.1 for the T&A patients (Table 3). Postoperative AHIs were generally higher than expected from previous literature that reported values using laboratory-based PSG. Lowest oxygen saturation improved in both groups postoperatively. Although median AHI change score was very similar between groups, there was substantially more variability of the response in the T&A group. The MLM showed that the group mean change in AHI did not differ significantly (F[1,13] = 0.31, P = .590), but the variances differed significantly between groups (chi-square = 5.24, df = 1, P = .022). Adjusting for subject pairings, the mean decline in AHI was estimated at 27% for the PITA patients (P = .036) and 36% for the T&A patients (P = .085). Although the mean change was greater for the T&A patients, the P value is larger because of the greater variability in scores for the T&A patients. Five of 15 (33%) PITA patients and 4 of 15 (27%) T&A patients had a postoperative AHI 5; this difference was not statistically significant (Fisher exact test P = 1.000). There was no significant interaction or substantial confounding effect for age, sex, race, preoperative tonsil size, preoperative AHI, and postoperative body mass index category in the model relating surgery type to reduction of postoperative AHI to 5. Improvement in PSG indices was lower than expected in both groups. All children with AHI > 5 were recommended to have repeat overnight laboratory PSG. Only 2 patients (1 PITA patient [AHI 15.4], 1 T&A patient [AHI 12.6]) complied as the other patients were symptomatically improved. These 2 patients had normal laboratory-based studies (AHI 0.9 and 1.6, respectively). One PITA patient with a higher postoperative AHI than on entry (change in AHI = 3.8) underwent a completion tonsillectomy with resultant resolution of his symptoms.
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Table 2 Preoperative and postoperative clinical assessment. PITA Variable History Snoring Apnea Restless sleep Frequent awakenings Neck extension Enuresis Daytime sleepiness Behavior problems Mouthbreathing Physical examination Tonsil size 4+ 3+ 2+ 1+ 0 Mouthbreathing Hyponasality Adenoid facies
Total T&A
Preop, n
Preop, no. (%)
Postop, n
Postop, no. (%)
Preop, n
Preop, no. (%)
Postop, n
Postop, no. (%)
15 15 14 13 14 10 13 9 15
15 12 10 9 7 5 1 7 14
(100.0) (80.0) (71.4) (69.2) (50.0) (50.0) (7.7) (77.8) (93.3)
15 15 15 15 14 13 15 15 15
11 0 7 1 4 3 2 5 5
(73.3) (0) (46.7) (6.7) (28.6) (23.1) (13.3) (33.3) (33.3)
15 15 14 13 14 14 13 11 14
15 14 14 7 9 8 7 5 10
15 14 15 15 14 15 15 15 15
6 2 10 4 1 1 5 7 3
(40.0) (14.3) (66.7) (26.7) (7.1) (6.7) (33.3) (46.7) (20.0)
5 8 2 0 0 10 0 5
(33.3) (53.3) (13.3) (0) (0) (71.4) (0) (55.6)
0 0 0 5 10 2 2 2
(0) (0) (0) (33.3) (66.7) (13.3) (13.3) (13.3)
0 0 0 2 13 2 0 1
(0) (0) (0) (13.3) (86.7) (13.3) (0) (6.7)
15
14 4 9
15
15
15 15 15
PITA
Symptom score
*
(100.0) (93.3) (100.0) (53.8) (64.3) (57.1) (53.8) (45.5) (71.4)
14 10 12
15 8 4 3 0 0 7 1 1
(53.3) (26.7) (20.0) (0) (0) (50.0) (10.0) (8.3)
15 15 15
Total T&A
n
Preop, mean (SD)
Postop, mean (SD)
Change, mean (SD)
n
Preop, mean (SD)
Postop, mean (SD)
Change, mean (SD)
15
0.69 (0.19)
0.31 (0.26)
0.38 (0.31)
15
0.73 (0.18)
0.30 (0.22)
0.44 (0.28)
Abbreviations: PITA, partial intracapsular tonsillectomy and adenoidectomy; Total T&A, total tonsillectomy and adenoidectomy; Preop, preoperative; Postop, postoperative. * Sum of all positive history items divided by total number of items with valid responses. There was no significant difference between groups in either mean (F[1,14] = 0.24, P = .630) or variance (chi-square = 0.116, df = 1, P = .733).
4. Discussion Current literature establishes a strong argument for PITA procedures based on reduced perioperative morbidities and complications along with postoperative quality of life considerations. Tunkel et al. [12] and Reilly et al. [15] also demonstrated significant improvement in PSG indices in children undergoing PITA. Our study endeavored to compare clinical and PSG outcomes between PITA and T&A. Although this study was not designed as an equivalence study and sample size is insufficient to make a definitive statement, there is little evidence in terms of either clinical or statistical significance in these data to suggest that PITA might be an inferior procedure. Success of surgery was not influenced by the patient’s age, tonsil size, severity of the AHI or BMI. There are a few notable limitations to the study. The complexity of patient enrollment and the staged nature of the study prohibited interviewer blinding to procedure type. However, the pulmonologist evaluating the sleep studies was
blinded to the patient’s history and procedure type. There was also a risk of selection bias. To investigate this potential bias, we compared the groups offered enrollment, those who dropped out and those who completed the study. We found no difference in preoperative data between these groups. Refusals to participate were rare, however, drops-outs were more common. The most common reasons for dropping out were difficulty in arranging a visit for completing the standardized history and physical examinations or completing home PSG. BMI was measured only at entry and may not have been reflective of the patient’s preoperative status as an average of 4 years had elapsed between surgery and entry into the study. Preoperative PSG consisted of overnight laboratory, overnight home and nap studies as these were what were available to the patients based on the treating institution and their insurance status. The distribution of studies was not that different for the 2 groups and the AHI for nap and home studies should approximate those of laboratory-based studies [18].
Table 3 Preoperative and postoperative polysomnography results. PITA (n = 15)
Total T&A (n = 15)
Variable
Preop, mean (SD) Median, range
Postop, mean (SD) Median, range
Change, mean (SD) Median, range
Preop, mean (SD) Median, range
Postop, mean (SD) Median, range
Change, mean (SD) Median, range
Sleep time (min.)
295.8 (188.6) 404, 51–558 11.3 (10.0) 8.3, 3.4–44.1 88.0 (9.3) 93,67–95 Preop AHI 5, No. (%)a 1 (6.7)
499.0 (146.1) 529, 92–668 7.5 (4.3) 5.9, 3.5–16.0 92.3 (4.1) 95, 82–95 Postop AHI 5, No. (%)a 5 (33.3)
–
297.6 (166.4) 328, 67–604 16.8 (16.6) 10.9, 1.7–67.0 87.7 (9.4) 90 (62–95) Preop AHI 5, No. (%)a 2 (13.3)
509.4 (139.6) 560, 94–651 8.8 (4.7) 8.1, 2.5–18.5 90.3 (7.5) 95, 70–95 Postop AHI 5, No. (%)a 4 (26.7)
–
AHI Lowest Saturation (%)
Result
3.8 (8.5) 1.7, 4.9 to 29.8* –
8.0 (18.7) 2.3, 10.9 to 64.1* –
Abbreviations: PITA, partial intracapsular tonsillectomy and adenoidectomy; Total T&A, total tonsillectomy and adenoidectomy; Preop, preoperative; Postop, postoperative; AHI, apnea–hypopnea index. * No significant difference in group means (F[1,13] = 0.31, P = .590) but variances between groups differed significantly (residual likelihood ratio chi-square = 5.24, df = 1, P = .022). a Difference between groups is not statistically significant (exact test, P = 1.000).
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The sample size also limits the study as it was not powered to detect small differences between the groups and was specifically not designed as an equivalence study; such a study would require a much larger sample, particularly considering the strict matching to which we aspired. There were two main barriers to this type of expansion. First, the cost of obtaining the postoperative PSG is significant. Second, we offered participation to all patients who met our inclusion criteria over a 4 1/2-year period. To substantially increase our patient population would require adding a second surgeon or expanding the time period covered by the study. Adding a second surgeon was not possible without adding an additional clinical site and would limit standardization of the surgery and PSG performed. Patients lost to follow up are a significant problem in a transient urban population and would only have been worsened by expanding the time criteria of the study. Our study was also limited by the use of unattended home PSG instead of laboratory-based PSG. Home PSG was used because it is less expensive, more convenient for patients, and less disruptive of normal sleep. Although two small studies have shown good sensitivity and specificity for home PSG in otherwise healthy children in comparison to laboratory PSG [19], the American Academy of Pediatrics guidelines cautions that the equipment used in these studies was relatively sophisticated and not commercially available and the authors studied a very selected patient population [18]. Additional investigators have cautioned that home PSG has not been adequately validated in children [20,21]. In our study, postoperative AHIs were generally higher than expected, only about 30% of children in both groups had a postoperative AHI 5, and none had AHI < 1, the most stringent definition for cure. Our resolution rate was much lower than rates reported in studies using laboratory-based PSG and calls into question the validity of home PSG. The two children with abnormal postoperative home PSGs who had subsequent laboratory PSG had normal studies. Since both groups had home postoperative PSG, any variability in measurement should have affected both groups equally. It is unlikely that there was an inherent severity of SDB in this patient population. The senior author has performed the identical T&A procedure and published laboratory-based PSG results on a very similar patient population in the past with a 90% rate of resolution of abnormal PSG findings (defined as AHI 5) after T&A at an average follow-up of 8 months [14]. 34% of the patients in the prior study were obese as compared to 42% of the patients in the current study. It was our intent to compare the long-term outcomes between PITA and T&A and the mean time between surgery and postoperative PSG was 4 years. It is possible that the surgical efficacy of both procedures waned over time, but our study was not designed to evaluate time-related changes. In spite of these limitations, our results demonstrate minimal differences in PSG and clinical outcomes between PITA and T&A for treatment of pediatric SDB at relatively long-term follow-up. Our patients were otherwise healthy so the results may not be extrapolated to children with complicated OSA from craniofacial or neuromuscular disorders. Although reduction in perioperative morbidity may be especially beneficial in children with underlying medical problems, the increased scarring associated with conventional tonsillectomy that is not found after PITA may improve the pharyngeal hypotonia in children with underlying neuromuscular disorders. About 70% of our patients were overweight or obese and BMI did not appear to be a confounder. PITA does appear to be as effective as T&A in overweight or obese children. Ideally, our study should be repeated in a larger sample size using pre- and postoperative laboratory-based PSG preferably in a blinded, prospective, randomized fashion with outcomes assessed over time. Special populations of children with complicated OSA
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should also be studied including those with craniofacial abnormalities, neuromuscular disease, hypotonia, Down and other syndromes, sickle cell disease, obesity and children under 2. 5. Conclusions Our results demonstrate similar clinical and unattended home PSG outcomes between PITA and T&A in otherwise healthy children with SDB. Success of surgery was not influenced by the patient’s age, tonsil size, sleep study indices or BMI. Conflict of interest statement None of the authors of this manuscript have any financial or non-financial competing interests to disclose. Acknowledgments This study was supported by a 2006 American Society of Pediatric Otolaryngology Research Grant. The study sponsor had no role in study design, collection, analysis and interpretation of data, writing of the manuscript, and decision to submit the manuscript for publication. We thank Kevin Cary and Advanced Sleep and Breathing for performing the home polysomnography. Results of this study are posted in the ClinicalTrials.gov public trials registry. References [1] M.G. Greene, J.L. Carroll, Consequences of sleep-disordered breathing in childhood, Curr. Opin. Pulm. Med. 3 (1997) 456–463. [2] N.J. Ali, D.J. Pitson, J.R. Stradling, Snoring, sleep disturbance, and behaviour in 4–5 year olds, Arch. Dis. Child. 68 (1993) 360–366. [3] S.E. Brietzke, D. Gallagher, The effectiveness of tonsillectomy and adenoidectomy in the treatment of pediatric obstructive sleep apnea/hypopnea syndrome: a meta-analysis, Otolaryngol. Head Neck Surg. 134 (2006) 979–984. [4] A.J. Lipton, D. Gozal, Treatment of obstructive sleep apnea in children: do we really know how? Sleep Med. Rev. 7 (2003) 61–80. [5] P.J. Koltai, C.A. Solares, J.A. Koempel, K. Hirose, T.I. Abelson, P.R. Krakovitz, et al., Intracapsular tonsillar reduction (partial tonsillectomy): reviving a historical procedure for obstructive sleep disordered breathing in children, Otolaryngol. Head Neck Surg. 129 (2003) 532–538. [6] P.J. Koltai, C.A. Solares, E.J. Mascha, M. Xu, Intracapsular partial tonsillectomy for tonsillar hypertrophy in children, Laryngoscope 112 (2002) 17–19. [7] C.A. Solares, J.A. Koempel, K. Hirose, T.I. Abelson, J.S. Reilly, S.P. Cook, et al., Safety and efficacy of powered intracapsular tonsillectomy in children: a multi-center retrospective case series, Int. J. Pediatr. Otorhinolaryngol. 69 (2005) 21–26. [8] F. Celenk, Y.A. Bayazit, M. Yilmaz, Y.K. Kemaloglu, K. Uygur, A. Ceylan, et al., Tonsillar regrowth following partial tonsillectomy with radiofrequency, Int. J. Pediatr. Otorhinolaryngol. 72 (2008) 19–22. [9] C.M. Mixson, P.M. Weinberger, M.B. Austin, Comparison of microdebrider subcapsular tonsillectomy to harmonic scalpel and electrocautery total tonsillectomy, Am. J. Otolaryngol. 28 (2007) 13–17. [10] C.S. Derkay, D.H. Darrow, C. Welch, J.T. Sinacori, Post-tonsillectomy morbidity and quality of life in pediatric patients with obstructive tonsils and adenoid: microdebrider vs electrocautery, Otolaryngol. Head Neck Surg. 134 (2006) 114–120. [11] T.Y. Colen, C. Seidman, J. Weedon, N.A. Goldstein, Effect of intracapsular tonsillectomy on quality of life for children with obstructive sleep-disordered breathing, Arch. Otolaryngol. Head Neck Surg. 134 (2008) 124–127. [12] D.E. Tunkel, K.S. Hotchkiss, K.A. Carson, L.M. Sterni, Efficacy of powered intracapsular tonsillectomy and adenoidectomy, Laryngoscope 118 (2008) 1295– 1302. [13] C. Guilleminault, R. Peraita, M. Souquet, W.C. Dement, Apneas during sleep in infants: possible relationship with sudden infant death syndrome, Science 190 (1975) 677–679. [14] N.A. Goldstein, V. Pugazhendhi, S.M. Rao, J. Weedon, T.F. Campbell, A.C. Goldman, et al., Clinical assessment of pediatric obstructive sleep apnea, Pediatrics 114 (2004) 33–43. [15] B.K. Reilly, J. Levin, S. Sheldon, K. Harsanyi, M.E. Gerber, Efficacy of microdebrider intracapsular adenotonsillectomy as validated by polysomnography, Laryngoscope 119 (2009) 1391–1393. [16] L. Brodsky, Modern assessment of tonsils and adenoids, Pediatr. Clin. North Am. 36 (1989) 1551–1569. [17] S.V. Jacob, A. Morielli, M.A. Mograss, F.M. Ducharme, M.D. Schloss, R.T. Brouillette, Home testing for pediatric obstructive sleep apnea syndrome secondary to adenotonsillar hypertrophy, Pediatr. Pulmonol. 20 (1995) 241–252.
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[18] M.S. Schechter, Technical report: diagnosis and management of childhood obstructive sleep apnea syndrome, Pediatrics 109 (2002) e69. [19] R.T. Brouillette, S.V. Jacob, K.A. Waters, M. Morielli, M. Mograss, F.M. Ducharme, Cardiorespiratory sleep studies for children can often be performed in the home, Sleep 19 (1996) S278–S280.
[20] J.S. Kemp, Omigosh, not home sleep studies! J. Pediatr. 142 (2003) 364– 365. [21] L.A. D’Andrea, Diagnostic studies in the assessment of pediatric sleep-disordered breathing: techniques and indications, Pediatr. Clin. North Am. 51 (2004) 169– 186.
Contents lists available at ScienceDirect
International Journal of Pediatric Otorhinolaryngology journal homepage: www.elsevier.com/locate/ijporl
Polysomnography outcomes for partial intracapsular versus total tonsillectomy§,§§ Jason Mangiardi a,1, Katharina D. Graw-Panzer b, Jeremy Weedon c, Theresa Regis a, Haesoon Lee b, Nira A. Goldstein a,* a
Division of Pediatric Otolaryngology, State University of New York Downstate Medical Center, 450 Clarkson Avenue, Box 126, Brooklyn, NY 11203, United States Division of Pediatric Pulmonology, State University of New York Downstate Medical Center, 450 Clarkson Avenue, Box 49, Brooklyn, NY 11203, United States c Scientific Computing Center, State University of New York Downstate Medical Center, 450 Clarkson Avenue, Box 7, Brooklyn, NY 11203, United States b
A R T I C L E I N F O
A B S T R A C T
Article history: Received 2 July 2010 Received in revised form 30 August 2010 Accepted 3 September 2010 Available online 28 September 2010
Objective: To demonstrate similar improvement in pediatric sleep-disordered breathing (SDB) as determined by polysomnography (PSG) with microdebrider-assisted partial intracapsular tonsillectomy and adenoidectomy (PITA) versus Bovie electrocautery complete tonsillectomy and adenoidectomy (T&A). Methods: In this retrospective cohort study, 30 children found to have SDB by PSG who have undergone either PITA (15 participants) or T&A (15 participants) as treatment were evaluated with standardized history and physical examination and unattended home overnight PSG. Results: Median change in apnea–hypopnea index (AHI) was 1.7 ( 4.9 to 29.8) for the PITA group and 2.3 ( 10.9 to 64.1) for the T&A group, although there was substantially more variability in the T&A group. A mixed linear model evaluating the relation of surgical group with change in AHI demonstrated no significant differences in group means (F[1,13] = 0.31, P = .590) but the variances differed significantly (residual likelihood ratio chi-square = 5.24, df = 1, P = .022). Five of 15 (33%) PITA patients and 4 of 15 (27%) T&A patients had postoperative AHI scores of 5; this difference was not statistically significant (Fisher exact test P = 1.000). There was no significant interaction or substantial confounding effect of age, sex, race, preoperative tonsil size, preoperative AHI, or body mass index in the model relating surgery type to reduction of postoperative AHI to 5. Conclusions: Our study demonstrates no clinically or statistically significant differences in PSG and clinical outcomes between PITA and T&A for treatment of pediatric SDB in otherwise healthy children. ß 2010 Elsevier Ireland Ltd. All rights reserved.
Keywords: Sleep-disordered breathing Obstructive sleep apnea Tonsillectomy Polysomnography
1. Introduction Pediatric sleep-disordered breathing (SDB) is a continuum of pathology including primary snoring, increased upper airway resistance syndrome and obstructive sleep apnea (OSA) with OSA being the most severe form [1]. Estimates place the prevalence of pediatric SDB at 1–3% of the preschool and school-age populations [2]. Treatment of SDB with tonsillectomy and adenoidectomy (T&A) is successful in resolution of abnormal polysomnographic
§ Presented at the American Society of Pediatric Otolaryngology Annual Meeting, May 2, 2010; Las Vegas, NV, United States. §§ Trial Registration: clinicaltrials.gov Identifier: NCT00887471. * Corresponding author at: Department of Otolaryngology, State University of New York Downstate Medical Center, 450 Clarkson Avenue, Box 126, Brooklyn, NY 11203, United States. Tel.: +1 718 270 1638; fax: +1 718 270 3924. E-mail address: [email protected] (N.A. Goldstein). 1 Current address: New York Otolaryngology Group, 501 Seaview Avenue, Staten Island, NY 10305, United States.
0165-5876/$ – see front matter ß 2010 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.ijporl.2010.09.003
indices in 80% of otherwise healthy children [3,4]. However, standard methods of tonsillectomy are riddled with postoperative complications including high risks of bleeding, burdensome postoperative pain and significant delays in return to regular activity. Recently, some centers have advocated partial intracapsular tonsillectomy and adenoidectomy (PITA) as treatment for pediatric SDB [5,6]. In the PITA procedure, only part of the tonsil is removed with the extent of dissection varying by surgeon. This allows the remainder of the tonsil to serve as a ‘‘biologic dressing’’ over the tonsillar fossa musculature. Advocates of this method cite lower postoperative pain rates because of decreased thermal injury to the underlying musculature with a correspondingly improved rate of return to regular activity [5]. However, opponents worry that the residual tonsil tissue could regrow leading to a recurrence in symptoms. Symptomatic tonsillar regrowth with microdebriderassisted PITA has been found to be less than 1% [7] and higher with other PITA techniques [8]. Studies regarding the postoperative hemorrhage rate and regrowth potential of PITA patients are
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difficult to perform given the large sample sizes required to show any substantial difference between PITA and T&A children. The largest, a retrospective study of 870 children from 3 different medical centers, reported a postoperative hemorrhage rate (95% CI) of 0.5% (0, 1.4), readmission rate (95% CI) of 0.7% (0, 1.9) and a regrowth rate (95% CI) of 0.46% (0.009, 0.9) over a mean follow-up of 1.2 years [7]. The rates of bleeding and readmission were significantly lower than those in a comparison group of 1121 children undergoing conventional T&A. Retrospective comparisons between differing techniques for PITA have shown microdebrider-assisted procedures preferable to electrocautery and harmonic scalpel techniques in the domains of postoperative pain and return to normal diet and activity [9]. Prospective studies have shown improved median days to regular activity (2.5 versus 4 days for microdebrider-assisted PITA versus electrocautery tonsillectomy respectively) and median days to last pain medication dose (4 versus 6.5 days) [10]. Two studies have evaluated SDB-related quality of life in otherwise healthy children undergoing PITA using the validated quality of life survey, the OSA-18. Colen et al. [11] reported large and significant improvements in both the total and individual domain scores for 50 children with SDB (42% with positive preoperative polysomnography [PSG]) at 3-months and 1-year after surgery and Tunkel et al. [12] reported similar findings for 14 children, all with positive preoperative PSG, at 5–10 weeks after surgery. The improvements in OSA-18 scores in both studies were similar to studies reporting changes in quality of life in children undergoing conventional T&A. Since its first description in children in 1975, the gold standard for evaluation of OSA has been PSG [13,14]. There are two previous studies evaluating PSG outcomes in otherwise healthy PITA patients. In the uncontrolled before-after study by Tunkel et al. [12] described above, 14 children with moderate OSA (apnea– hypopnea index [AHI] between 5 and 20) demonstrated significant improvement in AHI on laboratory-based PSG and 13 of 14 patients had complete cure of their OSA (AHI 1) with one patient having mild residual OSA (AHI > 1 and < 5) at a follow-up of 5–10 weeks after surgery. Reilly et al. [15] performed a retrospective review of 26 children treated by microdebrider tonsillectomy and electrodessication adenoidectomy who had both pre- and postoperative laboratory-based PSG. The authors found statistically significant improvements in both AHI and AI at mean follow-up of <2 years, with complete resolution of OSA (AHI 1) in 50% and persistent mild residual OSA (AHI > 1 and <5) in 50%. The current study aims to further validate PITA as a treatment modality for pediatric SDB by demonstrating similar home PSG outcomes between PITA and T&A at one to 6-year follow-up. 2. Methods 2.1. Participants This is a retrospective cohort study of children with SDB who have undergone either PITA or T&A as treatment. The protocol was approved by the Institutional Review Boards of the State University of New York Downstate Medical Center and the Long Island College Hospital and informed consent was obtained from the parents or legal guardians of the participants. Between July 2003 and January 2008, 149 children underwent PITA while 455 underwent T&A by the senior investigator at the Long Island College Hospital or the University Hospital of Brooklyn in Brooklyn, NY. PITA was offered as an alternative to T&A to all the parents of children with SDB but no history of recurrent tonsillitis. The potential benefits of PITA as well as the potential risk of tonsil regrowth were explained and the procedure was chosen by the parent or caretaker. The medical records of the 149 children who underwent PITA were reviewed to
identify children with positive preoperative PSG (laboratorybased, home or nap). All patients with positive studies were offered participation. Of these, 15 completed all aspects of the study. PITA participants were randomly 1–1 matched by age, sex, time since procedure and PSG results (AHI within 5) to 15 children who underwent T&A. Children with recurrent tonsillitis, craniofacial syndromes, neuromuscular disorders and sickle cell disease were excluded. 2.2. Interventions All participants underwent a standardized history and physical examination, by either the primary investigator or first author, and home overnight PSG. The history determined the presence of snoring, apneic pauses, restless sleep, frequent awakenings, neck extension, enuresis for children 4 years of age and older, daytime sleepiness, behavior/learning problems, and mouthbreathing. The physical examination included height, weight, tonsil size and the presence of mouthbreathing, hyponasality, and adenoid facies (open mouth, long face, mandibular hypoplasia). BMI was calculated by dividing the child’s weight in kilograms by the square of the height in meters and compared to standard percentiles for age and sex. Tonsil size was graded as the reduction in pharyngeal luminal diameter: 1+, 0–25%; 2+, 26–50%; 3+, 51– 75%; and 4+, 76–100% as described by Brodsky [16]. The patient’s office and hospital charts were reviewed to record the preoperative symptoms and physical examination findings. Entry and preoperative symptom scores were calculated as the sum of all positive history items divided by the total number of items with valid responses. Due to the sequential nature of the study, examiners were not blinded to the type of surgery performed. Unattended home overnight PSG was performed. Studies consisted of respiratory rate, pulse rate, pulse oximetry, inductive plethysmography of the chest and abdomen and the mathematical sum of the 2 for respiratory effort, and oronasal airflow from a loose mask or nasal cannula. Obstructive apnea was defined as the cessation of oronasal airflow with continued respiratory effort for at least 2.5 times the typical breath interval, and obstructive hypopnea was defined as a decrease in amplitude of oronasal airflow of at least 50% with no decrease in respiratory effort for the same duration with at least 4% desaturation. PSG was considered positive for OSA when the number of obstructive apneas plus hypopneas per hour of sleep (AHI) was >5, the number of apneas per hour of sleep (apnea index, AI) was >1, or the minimum oxygen saturation was less than 92% [14]. This definition of a positive PSG was used as these are the traditional criteria for which surgical treatment is recommended. The pre- and postoperative sleep studies were analyzed by a pediatric pulmonologist blinded to treatment group and to pre- or postoperative signs and symptoms. Unattended home PSG has been found to be accurate and practical in the routine evaluation of pediatric OSA [17]. It is advantageous in that it allows children to sleep in their own environment, leading to longer sleep duration, higher sleep efficiency, and fewer laboratory-induced arousals. Home sleep study also increases patient compliance and retention through all aspects of the study. 2.3. Statistical methods Patients who enrolled and completed the study, patients who withdrew and patients not offered enrollment were compared in terms of age at surgery, current age, time since surgery, preoperative AHI and preoperative lowest oxygen saturation using the Kruskal–Wallis test and in terms of age, race and surgical group using the generalized Fisher exact test.
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The relationship of surgical group with AHI change was evaluated by constructing a mixed linear model (MLM). The dependent variable was the logarithm of the ratio of postoperative AHI score to preoperative AHI score; this transformation was chosen in order to minimize skew of model residuals. Surgical group was introduced as a fixed factor; subject pairs constituted levels of a random (blocking) factor. Variance was estimated separately for each surgical group; a residual likelihood ratio test was conducted to test differing variance between groups. Two outlying change scores were excluded from inferential analysis. A similar analysis was constructed for symptom change score, but this time the dependent variable was a simple preoperative minus postoperative difference score; no cases were excluded. The relationship of surgical group with postoperative AHI 5 was evaluated by exact conditional logistic regression, predicting AHI 5 from surgical group with subject pairs as strata. A similar model was used to determine if any of the following covariates were predictive of postoperative AHI 5: age, sex, race, preoperative tonsil size, preoperative AHI and entry percentile BMI category. A P value < .05 was considered statistically significant. SAS Release 9.2 (SAS Institute, Cary NC) and LogXact Release 7 (Cytel Corp., Cambridge MA) software were used. 3. Results Review of surgical case logs identified 45 patients with positive PSG who had undergone PITA and 101 with positive PSG who had undergone T&A. Of these 15 PITA patients entered and completed the study and 15 matched T&A patients entered and completed the study. An additional 8 patients (7 PITA, 1 T&A) were enrolled but withdrew prior to completion. One additional T&A patient completed the study but was not included because his matched PITA patient withdrew. There was no significant difference in age at surgery (P = .453), current age (P = .508), sex (P = .951), race (P = .495), time since surgery (P = .541), preoperative AHI (P = .407) and preoperative lowest oxygen saturation (P = .681) among patients who completed the study, patients who withdrew, and patients who were not offered enrollment. PITA patients were significantly more likely to withdraw than T&A patients (P < .001). Patient demographics for the 15 PITA and 15 T&A patients that completed the protocol are presented in Table 1. Mean (SD) age at surgery was 5.33 (3.65) years for the PITA patients and 6.15 (3.29) years for the T&A patients. 80% of the PITA patients were male as compared to 47% of the T&A patients. BMI was measured only at entry into the study due to a large number of missing heights and weights in the patients’ charts at the time of surgery. 67% of the PITA patients and 71% of the T&A patients were overweight or obese. Time between surgery and study entry was about 4 years for both groups. History and physical examination findings are presented in Table 2. Data are missing for some of the preoperative measures due to incomplete information in the patients’ charts. All patients snored preoperatively while snoring was found in 73.3% of the PITA patients and 40.0% of the T&A patients at study entry. Apneic pauses were reported for 80.0% of the PITA patients and 93.3% of the T&A patients preoperatively and 0% of the PITA patients and 14.3% of the T&A patients at study entry. Preoperative tonsil size was 3+ or 4+ for about 80% of patients in both groups. Residual 1+ tonsils were found for 33.3% of the PITA patients and 13.3% of the T&A patients at study entry. The mean (SD) symptom change score was 0.38 (0.31) for the PITA patients and 0.44 (0.28) for the T&A patients (P < .001 for both). No significant difference was found between groups in either mean (F[1,14] = 0.24, P = .630) or variance (chi-square = 0.116, df = 1, P = .733). Preoperative studies consisted of 5 overnight laboratorybased studies, 3 overnight home studies, and 7 nap studies for
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Table 1 Patient demographics.
Age at surgery, y n Mean (SD) Range Sex, no. (%) n Male Female Race, no. (%) n White Black Hispanic Asian Postoperative BMI percentile, no. (%) n Underweight, <5th percentile Healthy, 5th & <85th percentile Overweight, 85th & <95th percentile Obese, 95th percentile Time since surgery, y n Mean (SD) Range
PITA
Total T&A
15 5.33 (3.65) 1.31–13.92
15 6.15 (3.29) 1.07–12.38
15 12 (80.0) 3 (20.0)
15 7 (46.7) 8 (53.3)
15 2 (13.3) 12 (80.0) 0 1 (6.7)
15 2 (13.3) 11 (73.3) 2 (13.3) 0
9 0 3 (33.3) 3 (33.3) 3 (33.3) 15 4.04 (1.39) 1.63–5.72
14 1 3 3 7
(7.1) (21.4) (21.4) (50.0)
15 3.84 (1.85) 0.90–6.26
Abbreviations: PITA, partial intracapsular tonsillectomy and adenoidectomy; Total T&A, total tonsillectomy and adenoidectomy.
the PITA patients and 9 overnight laboratory-based studies, one overnight home study and 5 nap studies for the T&A patients. All postoperative studies were home overnight studies. Mean sleep time was shorter in the preoperative studies for both groups because a large number of patients had nap PSG (Table 3). Median preoperative AHI was 8.3 for the PITA patients and 10.9 for the T&A patients, while median postoperative AHI was 5.9 for the PITA patients and 8.1 for the T&A patients (Table 3). Postoperative AHIs were generally higher than expected from previous literature that reported values using laboratory-based PSG. Lowest oxygen saturation improved in both groups postoperatively. Although median AHI change score was very similar between groups, there was substantially more variability of the response in the T&A group. The MLM showed that the group mean change in AHI did not differ significantly (F[1,13] = 0.31, P = .590), but the variances differed significantly between groups (chi-square = 5.24, df = 1, P = .022). Adjusting for subject pairings, the mean decline in AHI was estimated at 27% for the PITA patients (P = .036) and 36% for the T&A patients (P = .085). Although the mean change was greater for the T&A patients, the P value is larger because of the greater variability in scores for the T&A patients. Five of 15 (33%) PITA patients and 4 of 15 (27%) T&A patients had a postoperative AHI 5; this difference was not statistically significant (Fisher exact test P = 1.000). There was no significant interaction or substantial confounding effect for age, sex, race, preoperative tonsil size, preoperative AHI, and postoperative body mass index category in the model relating surgery type to reduction of postoperative AHI to 5. Improvement in PSG indices was lower than expected in both groups. All children with AHI > 5 were recommended to have repeat overnight laboratory PSG. Only 2 patients (1 PITA patient [AHI 15.4], 1 T&A patient [AHI 12.6]) complied as the other patients were symptomatically improved. These 2 patients had normal laboratory-based studies (AHI 0.9 and 1.6, respectively). One PITA patient with a higher postoperative AHI than on entry (change in AHI = 3.8) underwent a completion tonsillectomy with resultant resolution of his symptoms.
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Table 2 Preoperative and postoperative clinical assessment. PITA Variable History Snoring Apnea Restless sleep Frequent awakenings Neck extension Enuresis Daytime sleepiness Behavior problems Mouthbreathing Physical examination Tonsil size 4+ 3+ 2+ 1+ 0 Mouthbreathing Hyponasality Adenoid facies
Total T&A
Preop, n
Preop, no. (%)
Postop, n
Postop, no. (%)
Preop, n
Preop, no. (%)
Postop, n
Postop, no. (%)
15 15 14 13 14 10 13 9 15
15 12 10 9 7 5 1 7 14
(100.0) (80.0) (71.4) (69.2) (50.0) (50.0) (7.7) (77.8) (93.3)
15 15 15 15 14 13 15 15 15
11 0 7 1 4 3 2 5 5
(73.3) (0) (46.7) (6.7) (28.6) (23.1) (13.3) (33.3) (33.3)
15 15 14 13 14 14 13 11 14
15 14 14 7 9 8 7 5 10
15 14 15 15 14 15 15 15 15
6 2 10 4 1 1 5 7 3
(40.0) (14.3) (66.7) (26.7) (7.1) (6.7) (33.3) (46.7) (20.0)
5 8 2 0 0 10 0 5
(33.3) (53.3) (13.3) (0) (0) (71.4) (0) (55.6)
0 0 0 5 10 2 2 2
(0) (0) (0) (33.3) (66.7) (13.3) (13.3) (13.3)
0 0 0 2 13 2 0 1
(0) (0) (0) (13.3) (86.7) (13.3) (0) (6.7)
15
14 4 9
15
15
15 15 15
PITA
Symptom score
*
(100.0) (93.3) (100.0) (53.8) (64.3) (57.1) (53.8) (45.5) (71.4)
14 10 12
15 8 4 3 0 0 7 1 1
(53.3) (26.7) (20.0) (0) (0) (50.0) (10.0) (8.3)
15 15 15
Total T&A
n
Preop, mean (SD)
Postop, mean (SD)
Change, mean (SD)
n
Preop, mean (SD)
Postop, mean (SD)
Change, mean (SD)
15
0.69 (0.19)
0.31 (0.26)
0.38 (0.31)
15
0.73 (0.18)
0.30 (0.22)
0.44 (0.28)
Abbreviations: PITA, partial intracapsular tonsillectomy and adenoidectomy; Total T&A, total tonsillectomy and adenoidectomy; Preop, preoperative; Postop, postoperative. * Sum of all positive history items divided by total number of items with valid responses. There was no significant difference between groups in either mean (F[1,14] = 0.24, P = .630) or variance (chi-square = 0.116, df = 1, P = .733).
4. Discussion Current literature establishes a strong argument for PITA procedures based on reduced perioperative morbidities and complications along with postoperative quality of life considerations. Tunkel et al. [12] and Reilly et al. [15] also demonstrated significant improvement in PSG indices in children undergoing PITA. Our study endeavored to compare clinical and PSG outcomes between PITA and T&A. Although this study was not designed as an equivalence study and sample size is insufficient to make a definitive statement, there is little evidence in terms of either clinical or statistical significance in these data to suggest that PITA might be an inferior procedure. Success of surgery was not influenced by the patient’s age, tonsil size, severity of the AHI or BMI. There are a few notable limitations to the study. The complexity of patient enrollment and the staged nature of the study prohibited interviewer blinding to procedure type. However, the pulmonologist evaluating the sleep studies was
blinded to the patient’s history and procedure type. There was also a risk of selection bias. To investigate this potential bias, we compared the groups offered enrollment, those who dropped out and those who completed the study. We found no difference in preoperative data between these groups. Refusals to participate were rare, however, drops-outs were more common. The most common reasons for dropping out were difficulty in arranging a visit for completing the standardized history and physical examinations or completing home PSG. BMI was measured only at entry and may not have been reflective of the patient’s preoperative status as an average of 4 years had elapsed between surgery and entry into the study. Preoperative PSG consisted of overnight laboratory, overnight home and nap studies as these were what were available to the patients based on the treating institution and their insurance status. The distribution of studies was not that different for the 2 groups and the AHI for nap and home studies should approximate those of laboratory-based studies [18].
Table 3 Preoperative and postoperative polysomnography results. PITA (n = 15)
Total T&A (n = 15)
Variable
Preop, mean (SD) Median, range
Postop, mean (SD) Median, range
Change, mean (SD) Median, range
Preop, mean (SD) Median, range
Postop, mean (SD) Median, range
Change, mean (SD) Median, range
Sleep time (min.)
295.8 (188.6) 404, 51–558 11.3 (10.0) 8.3, 3.4–44.1 88.0 (9.3) 93,67–95 Preop AHI 5, No. (%)a 1 (6.7)
499.0 (146.1) 529, 92–668 7.5 (4.3) 5.9, 3.5–16.0 92.3 (4.1) 95, 82–95 Postop AHI 5, No. (%)a 5 (33.3)
–
297.6 (166.4) 328, 67–604 16.8 (16.6) 10.9, 1.7–67.0 87.7 (9.4) 90 (62–95) Preop AHI 5, No. (%)a 2 (13.3)
509.4 (139.6) 560, 94–651 8.8 (4.7) 8.1, 2.5–18.5 90.3 (7.5) 95, 70–95 Postop AHI 5, No. (%)a 4 (26.7)
–
AHI Lowest Saturation (%)
Result
3.8 (8.5) 1.7, 4.9 to 29.8* –
8.0 (18.7) 2.3, 10.9 to 64.1* –
Abbreviations: PITA, partial intracapsular tonsillectomy and adenoidectomy; Total T&A, total tonsillectomy and adenoidectomy; Preop, preoperative; Postop, postoperative; AHI, apnea–hypopnea index. * No significant difference in group means (F[1,13] = 0.31, P = .590) but variances between groups differed significantly (residual likelihood ratio chi-square = 5.24, df = 1, P = .022). a Difference between groups is not statistically significant (exact test, P = 1.000).
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The sample size also limits the study as it was not powered to detect small differences between the groups and was specifically not designed as an equivalence study; such a study would require a much larger sample, particularly considering the strict matching to which we aspired. There were two main barriers to this type of expansion. First, the cost of obtaining the postoperative PSG is significant. Second, we offered participation to all patients who met our inclusion criteria over a 4 1/2-year period. To substantially increase our patient population would require adding a second surgeon or expanding the time period covered by the study. Adding a second surgeon was not possible without adding an additional clinical site and would limit standardization of the surgery and PSG performed. Patients lost to follow up are a significant problem in a transient urban population and would only have been worsened by expanding the time criteria of the study. Our study was also limited by the use of unattended home PSG instead of laboratory-based PSG. Home PSG was used because it is less expensive, more convenient for patients, and less disruptive of normal sleep. Although two small studies have shown good sensitivity and specificity for home PSG in otherwise healthy children in comparison to laboratory PSG [19], the American Academy of Pediatrics guidelines cautions that the equipment used in these studies was relatively sophisticated and not commercially available and the authors studied a very selected patient population [18]. Additional investigators have cautioned that home PSG has not been adequately validated in children [20,21]. In our study, postoperative AHIs were generally higher than expected, only about 30% of children in both groups had a postoperative AHI 5, and none had AHI < 1, the most stringent definition for cure. Our resolution rate was much lower than rates reported in studies using laboratory-based PSG and calls into question the validity of home PSG. The two children with abnormal postoperative home PSGs who had subsequent laboratory PSG had normal studies. Since both groups had home postoperative PSG, any variability in measurement should have affected both groups equally. It is unlikely that there was an inherent severity of SDB in this patient population. The senior author has performed the identical T&A procedure and published laboratory-based PSG results on a very similar patient population in the past with a 90% rate of resolution of abnormal PSG findings (defined as AHI 5) after T&A at an average follow-up of 8 months [14]. 34% of the patients in the prior study were obese as compared to 42% of the patients in the current study. It was our intent to compare the long-term outcomes between PITA and T&A and the mean time between surgery and postoperative PSG was 4 years. It is possible that the surgical efficacy of both procedures waned over time, but our study was not designed to evaluate time-related changes. In spite of these limitations, our results demonstrate minimal differences in PSG and clinical outcomes between PITA and T&A for treatment of pediatric SDB at relatively long-term follow-up. Our patients were otherwise healthy so the results may not be extrapolated to children with complicated OSA from craniofacial or neuromuscular disorders. Although reduction in perioperative morbidity may be especially beneficial in children with underlying medical problems, the increased scarring associated with conventional tonsillectomy that is not found after PITA may improve the pharyngeal hypotonia in children with underlying neuromuscular disorders. About 70% of our patients were overweight or obese and BMI did not appear to be a confounder. PITA does appear to be as effective as T&A in overweight or obese children. Ideally, our study should be repeated in a larger sample size using pre- and postoperative laboratory-based PSG preferably in a blinded, prospective, randomized fashion with outcomes assessed over time. Special populations of children with complicated OSA
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should also be studied including those with craniofacial abnormalities, neuromuscular disease, hypotonia, Down and other syndromes, sickle cell disease, obesity and children under 2. 5. Conclusions Our results demonstrate similar clinical and unattended home PSG outcomes between PITA and T&A in otherwise healthy children with SDB. Success of surgery was not influenced by the patient’s age, tonsil size, sleep study indices or BMI. Conflict of interest statement None of the authors of this manuscript have any financial or non-financial competing interests to disclose. Acknowledgments This study was supported by a 2006 American Society of Pediatric Otolaryngology Research Grant. The study sponsor had no role in study design, collection, analysis and interpretation of data, writing of the manuscript, and decision to submit the manuscript for publication. We thank Kevin Cary and Advanced Sleep and Breathing for performing the home polysomnography. Results of this study are posted in the ClinicalTrials.gov public trials registry. References [1] M.G. Greene, J.L. Carroll, Consequences of sleep-disordered breathing in childhood, Curr. Opin. Pulm. Med. 3 (1997) 456–463. [2] N.J. Ali, D.J. Pitson, J.R. Stradling, Snoring, sleep disturbance, and behaviour in 4–5 year olds, Arch. Dis. Child. 68 (1993) 360–366. [3] S.E. Brietzke, D. Gallagher, The effectiveness of tonsillectomy and adenoidectomy in the treatment of pediatric obstructive sleep apnea/hypopnea syndrome: a meta-analysis, Otolaryngol. Head Neck Surg. 134 (2006) 979–984. [4] A.J. Lipton, D. Gozal, Treatment of obstructive sleep apnea in children: do we really know how? Sleep Med. Rev. 7 (2003) 61–80. [5] P.J. Koltai, C.A. Solares, J.A. Koempel, K. Hirose, T.I. Abelson, P.R. Krakovitz, et al., Intracapsular tonsillar reduction (partial tonsillectomy): reviving a historical procedure for obstructive sleep disordered breathing in children, Otolaryngol. Head Neck Surg. 129 (2003) 532–538. [6] P.J. Koltai, C.A. Solares, E.J. Mascha, M. Xu, Intracapsular partial tonsillectomy for tonsillar hypertrophy in children, Laryngoscope 112 (2002) 17–19. [7] C.A. Solares, J.A. Koempel, K. Hirose, T.I. Abelson, J.S. Reilly, S.P. Cook, et al., Safety and efficacy of powered intracapsular tonsillectomy in children: a multi-center retrospective case series, Int. J. Pediatr. Otorhinolaryngol. 69 (2005) 21–26. [8] F. Celenk, Y.A. Bayazit, M. Yilmaz, Y.K. Kemaloglu, K. Uygur, A. Ceylan, et al., Tonsillar regrowth following partial tonsillectomy with radiofrequency, Int. J. Pediatr. Otorhinolaryngol. 72 (2008) 19–22. [9] C.M. Mixson, P.M. Weinberger, M.B. Austin, Comparison of microdebrider subcapsular tonsillectomy to harmonic scalpel and electrocautery total tonsillectomy, Am. J. Otolaryngol. 28 (2007) 13–17. [10] C.S. Derkay, D.H. Darrow, C. Welch, J.T. Sinacori, Post-tonsillectomy morbidity and quality of life in pediatric patients with obstructive tonsils and adenoid: microdebrider vs electrocautery, Otolaryngol. Head Neck Surg. 134 (2006) 114–120. [11] T.Y. Colen, C. Seidman, J. Weedon, N.A. Goldstein, Effect of intracapsular tonsillectomy on quality of life for children with obstructive sleep-disordered breathing, Arch. Otolaryngol. Head Neck Surg. 134 (2008) 124–127. [12] D.E. Tunkel, K.S. Hotchkiss, K.A. Carson, L.M. Sterni, Efficacy of powered intracapsular tonsillectomy and adenoidectomy, Laryngoscope 118 (2008) 1295– 1302. [13] C. Guilleminault, R. Peraita, M. Souquet, W.C. Dement, Apneas during sleep in infants: possible relationship with sudden infant death syndrome, Science 190 (1975) 677–679. [14] N.A. Goldstein, V. Pugazhendhi, S.M. Rao, J. Weedon, T.F. Campbell, A.C. Goldman, et al., Clinical assessment of pediatric obstructive sleep apnea, Pediatrics 114 (2004) 33–43. [15] B.K. Reilly, J. Levin, S. Sheldon, K. Harsanyi, M.E. Gerber, Efficacy of microdebrider intracapsular adenotonsillectomy as validated by polysomnography, Laryngoscope 119 (2009) 1391–1393. [16] L. Brodsky, Modern assessment of tonsils and adenoids, Pediatr. Clin. North Am. 36 (1989) 1551–1569. [17] S.V. Jacob, A. Morielli, M.A. Mograss, F.M. Ducharme, M.D. Schloss, R.T. Brouillette, Home testing for pediatric obstructive sleep apnea syndrome secondary to adenotonsillar hypertrophy, Pediatr. Pulmonol. 20 (1995) 241–252.
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