Long-term night-to-night variability of sleep-disordered breathing using a radar-based home sleep apnea test: a prospective cohort study.

STUDY OBJECTIVES: Night-to-night variability of sleep-disordered breathing limits the diagnostic accuracy of a single measurement. Multiple recordings using a reliable, affordable method could reduce the uncertainty and avoid misdiagnosis, which could be possible with radar-based home sleep apnea testing (HSAT). METHODS: We recruited consecutive patients with suspected sleep-disordered breathing and performed contactless radar-based HSAT with automated scoring (Sleepiz One; Sleepiz AG, Zurich, Switzerland) over 10 nights. During the first night, patients were simultaneously measured with peripheral arterial tonometry. RESULTS: Twenty-four of the 28 included patients could achieve a minimum of 4 measurements. The failure rate was 16% (37 of 238 measurements). The apnea-hypopnea index (AHI) and oxygen desaturation index were consistently lower with radar-based HSAT compared with peripheral arterial tonometry. The variability of the AHI was considerable, with a standard error of measurement of 5.2 events/h (95% confidence interval [CI]: 4.6-5.7 events/h) and a minimal detectable difference of 14.4 events/h (95% CI: 12.7-15.9 events/h). Alcohol consumption partially accounted for the variability, with an AHI increase of 1.7 events/h (95% CI: 0.6-2.8 events/h) for each standard drink. Based on a single measurement, 17% of patients were misdiagnosed and 32% were misclassified for sleep-disordered breathing severity. After 5 measurements, the mean AHI of the measured nights stabilized with no evidence of substantial changes with additional measurements. CONCLUSIONS: Night-to-night variability is considerable and stable over 10 nights. HSAT using radar-based methods over multiple nights is feasible and well tolerated by patients. It could offer lower costs and allow for multiple-night testing to increase accuracy. However, validation and reducing the failure rate are necessary for implementation in the clinical routine. CLINICAL TRIAL REGISTRATION: Registry: ClinicalTrials.gov; Name: Recording of Multiple Nights Using a New Contactless Device (Sleepiz One Connect) in Obstructive Sleep Apnea; URL: https://clinicaltrials.gov/study/NCT05134402; Identifier: NCT05134402. CITATION: Tschopp S, Borner U, Caversaccio M, Tschopp K. Long-term night-to-night variability of sleep-disordered breathing using a radar-based home sleep apnea test: a prospective cohort study. J Clin Sleep Med. 2024;20(7):1079-1086.

Treatment of Residual Palatal Collapse in Hypoglossal Nerve Stimulation Using a Palatal Device.

Hypoglossal nerve stimulation (HNS) has increasingly become an alternative therapy for obstructive sleep apnea patients with CPAP intolerance. Stimulation of the hypoglossal nerve during sleep enhances airway patency and alleviates collapse. Suboptimal responses to HNS often stem from insufficient palatal coupling and residual velar collapse. Combining palatal devices, such as Velumount®, with HNS represents a simple and cost-effective strategy to treat residual palatal collapse. Patients desiring conservative treatment for residual palatal obstruction under HNS may consider this combined approach. Laryngoscope, 134:3412-3414, 2024.

Tonsil volume and outcome of radiofrequency uvulopalatoplasty with or without tonsillectomy in adults with sleep-disordered breathing.

PURPOSE: Predictors for the outcome of uvulopalatopharyngoplasty with and without tonsillectomy (UPPP ± TE) in sleep-disordered breathing have not been fully established. This study investigates tonsil grade, volume, and preoperative examination in predicting radiofrequency UPP ± TE outcomes. METHODS: All patients undergoing radiofrequency UPP with tonsillectomy if tonsils were present between 2015 and 2021 were retrospectively analyzed. Patients underwent a standardized clinical examination, including Brodsky palatine tonsil grade from 0 to 4. Preoperatively and 3 months after surgery, sleep apnea testing was performed using respiratory polygraphy. Questionnaires were administered assessing daytime sleepiness using the Epworth Sleepiness Scale (ESS) and snoring intensity on a visual analog scale. Tonsil volume was measured intraoperatively using water displacement. RESULTS: The baseline characteristics of 307 patients and the follow-up data of 228 patients were analyzed. Tonsil volume increased by 2.5 ml (95% CI 2.1-2.9 ml; P < 0.001) per tonsil grade. Higher tonsil volumes were measured in men, younger patients, and patients with higher body mass indices. The preoperative apnea-hypopnea index (AHI) and AHI reduction strongly correlated with tonsil volume and grade, whereas postoperative AHI did not. The responder rate increased from 14% to 83% from tonsil grade 0 to 4 (P < 0.01). ESS and snoring were significantly reduced after surgery (P < 0.01), but the reduction was not influenced by tonsil grade or volume. No other preoperative factor other than tonsil size could predict surgical outcomes. CONCLUSIONS: Tonsil grade and intraoperatively measured volume correlate well and predict the reduction of AHI, while they are not predictive of ESS and snoring response after radiofrequency UPP ± TE.

Clinical impact of manual scoring of peripheral arterial tonometry in patients with sleep apnea.

PURPOSE: The objective was to analyze the clinical implications of manual scoring of sleep studies using peripheral arterial tonometry (PAT) and to compare the manual and automated scoring algorithms. METHODS: Patients with suspected sleep-disordered breathing underwent sleep studies using PAT. The recordings were analyzed using a validated automated computer-based scoring and a novel manual scoring algorithm. The two methods were compared regarding sleep stages and respiratory events. RESULTS: Recordings of 130 patients were compared. The sleep stages and time were not significantly different between the scoring methods. PAT-derived apnea-hypopnea index (pAHI) was on average 8.4 events/h lower in the manually scored data (27.5±17.4/h vs.19.1±15.2/h, p<0.001). The OSA severity classification decreased in 66 (51%) of 130 recordings. A similar effect was found for the PAT-derived respiratory disturbance index with a reduction from 31.2±16.5/h to 21.7±14.4/h (p<0.001), for automated and manual scoring, respectively. A lower pAHI for manual scoring was found in all body positions and sleep stages and was independent of gender and body mass index. The absolute difference of pAHI increased with sleep apnea severity, while the relative difference decreased. Pearson's correlation coefficient between pAHI and oxygen desaturation index (ODI) significantly improved from 0.89 to 0.94 with manual scoring (p<0.001). CONCLUSIONS: Manual scoring results in a lower pAHI while improving the correlation to ODI. With manual scoring, the OSA category decreases in a clinically relevant proportion of patients. Sleep stages and time do not change significantly with manual scoring. In the authors' opinion, manual oversight is recommended if clinical decisions are likely to change.

The Otoprotective Effect of Ear Cryotherapy: Systematic Review and Future Perspectives.

This systematic review investigates ear cooling and cryotherapy in the prevention and treatment of inner ear damage and disease, within the context of animal models and clinical studies. A literature search was carried out in the databases Pubmed and Cochrane Library. Ten studies were identified concerning the otoprotective properties of cryotherapy. Nine of these were rodent in vivo studies (mice, rats, gerbils, guinea pigs). One study involved human subjects and investigated cryotherapy in idiopathic sensorineural hearing loss. The studies were heterogeneous in their goals, methods, and the models used. Disorder models included ischemia and noise damage, ototoxicity (cisplatin and aminoglycoside), and CI-electrode insertion. All ten studies demonstrated significant cryotherapeutic otoprotection for their respective endpoints. No study revealed or expressly investigated otodestructive effects. While limited in number, all of the studies within the scope of the review demonstrated some degree of cryotherapeutic, otoprotective effect. These promising results support the conducting of further work to explore and refine the clinical applicability and impact of cryotherpeutics in otolaryngology.

Home sleep apnea testing with peripheral arterial tonometry to assess outcome in upper airway stimulation.

STUDY OBJECTIVES: To determine whether home sleep apnea testing with peripheral arterial tonometry (HSAT-PAT) can be used in upper airway stimulation to evaluate therapy success. METHODS: Data analysis from 50 consecutive patients receiving upper airway stimulation was performed. Baseline values were measured by polysomnography and HSAT-PAT. Follow-up was performed during and after titration (3-6 months) by polysomnography and HSAT-PAT and after 1 year by HSAT-PAT only. Primary outcome measures were reduction in the apnea-hypopnea index and oxygen desaturation index. In addition, an analysis of night-to-night variability for HSAT-PAT was performed. RESULTS: All 50 patients completed their posttitration visit (3-6 months) and 41 patients completed the 1-year follow-up. In HSAT-PAT after 1 year, the mean apnea-hypopnea index (desaturation 3%) was reduced from 29.5 ± 17.1 events/h to 19.9 ± 13.1 events/h (P < .01) and the oxygen desaturation index (desaturation 4%) was reduced from 17.8 ± 12.6 events/h to 10.2 ± 8.3 events/h (P < .01). Therapy adherence after 1 year was high (6.6 ± 1.9 hours per night) and led to improvement in daytime sleepiness, meaning a reduction in the Epworth Sleepiness Scale score from 12.8 ± 5.4 to 5.9 ± 4.0 (P < .01). Analysis of night-to-night variability showed similar apnea-hypopnea index values between the 2 nights. CONCLUSIONS: Upper airway stimulation was able to reduce the apnea-hypopnea index and oxygen desaturation index after 1 year, as assessed by full-night efficacy studies with HSAT-PAT. In addition, improvements in self-reported outcome parameters were observed. The importance of publishing the scoring criteria is highlighted and whether data are based on full-night efficacy studies or a selected period of time from a sleep study. This is a prerequisite for comparing data with other trials in the emerging field of upper airway stimulation. CITATION: Hinder D, Schams SC, Knaus C, Tschopp K. Home sleep apnea testing with peripheral arterial tonometry to assess outcome in upper airway stimulation. J Clin Sleep Med. 2022;18(9):2197-2205.

Evaluation of a nasopharyngeal stent in patients with obstructive sleep-related breathing disorders.

OBJECTIVE: This study was performed to evaluate the therapeutic effect and diagnostic value of a novel nasopharyngeal stent (Nastent; Corinium Medical Equipment Ltd., Cirencester, UK). The Nastent is designed to stent palatal collapse in patients with sleep-related breathing disorders. METHODS: The study was conducted from 2018 to 2019. Patients who did not qualify for continuous positive airway pressure therapy underwent split-night examination with an inserted Nastent for the first half of the night. The next morning, drug-induced sleep endoscopy (DISE) was performed. RESULTS: Of the 122 enrolled patients, 21 were excluded because of Nastent intolerance (n = 14) or technically invalid examinations (n = 7). Among the remaining 101 patients, in correlation with DISE, the apnea-hypopnea index was significantly reduced in patients with palatal obstructions, mainly in those with anteroposterior collapse patterns. The Nastent did not influence retrolingual or multilevel obstructions. Using a 40% reduction of the apnea-hypopnea index by the Nastent as a cut-off value, 85.7% of soft palate obstructions were detected compared with DISE. CONCLUSIONS: The Nastent is a viable tool to reduce palatal obstructions, although it is not readily tolerated. It may also be helpful for diagnosis of sleep-related breathing disorders when DISE is unavailable.

Night-to-night variability in obstructive sleep apnea using peripheral arterial tonometry: a case for multiple night testing.

STUDY OBJECTIVES: Night-to-night variability of obstructive sleep apnea severity is considerable and may depend on the diagnostic modality used. We investigated the night-to-night variability using peripheral arterial tonometry (PAT). METHODS: Home sleep apnea testing was performed in 51 patients during 3 consecutive nights using PAT. Patients referred to our sleep clinic were screened and prospectively recruited for this study. All recordings were automatically and manually scored according to the PAT scoring guidelines. RESULTS: No systematic differences in PAT-derived apnea-hypopnea index (pAHI) were found between the nights. The night-to-night variability was comparable between manually and automatically scored data. pAHI varied in 35% of patients more than 10 events/h between the nights. The obstructive sleep apnea severity of 24% of patients was misclassified when using 1 night compared to the average of all nights. On average, pAHI varied by 57% from night to night. The variability of pAHI could partially be explained by the variability of time spent in the supine position with more time supine leading to a higher pAHI. On measuring a subsequent night, 12-14% of patients spontaneously fulfilled the commonly accepted criteria for treatment success without any intervention. CONCLUSIONS: With repeated recordings of PAT, we found no first night effect. However, there is considerable night-to-night variability similar to values found for polysomnography, which can partially be explained by the variability of time spent in the supine position. Obstructive sleep apnea severity was frequently misclassified due to the night-to-night variability. Our findings make a strong case for multiple testing in the diagnostic work-up of obstructive sleep apnea patients. CITATION: Tschopp S, Wimmer W, Caversaccio M, Borner U, Tschopp K. Night-to-night variability in obstructive sleep apnea using peripheral arterial tonometry: a case for multiple night testing. J Clin Sleep Med. 2021;17(9):1751-1758.

Comparison of Traditional Upper Airway Surgery and Upper Airway Stimulation for Obstructive Sleep Apnea.

OBJECTIVE: To compare patients with moderate-severe obstructive sleep apnea (OSA) undergoing traditional single and multilevel sleep surgery to those undergoing upper airway stimulation (UAS). STUDY DESIGN: Case control study comparing retrospective cohort of patients undergoing traditional sleep surgery to patients undergoing UAS enrolled in the ADHERE registry. SETTING: 8 multinational academic medical centers. SUBJECTS AND METHODS: 233 patients undergoing prior single or multilevel traditional sleep surgery and meeting study inclusion criteria were compared to 465 patients from the ADHERE registry who underwent UAS. We compared preoperative and postoperative demographic, quality of life, and polysomnographic data. We also evaluated treatment response rates. RESULTS: The pre and postoperative apnea hypopnea index (AHI) was 33.5 and 15 in the traditional sleep surgery group and 32 and 10 in the UAS group. The postoperative AHI in the UAS group was significantly lower. The pre and postoperative Epworth sleepiness scores (ESS) were 12 and 6 in both the traditional sleep surgery and UAS groups. Subgroup analysis evaluated those patients undergoing single level palate and multilevel palate and tongue base traditional sleep surgeries. The UAS group had a significantly lower postoperive AHI than both traditional sleep surgery subgroups. The UAS group had a higher percentage of patients reaching surgical success, defined as a postoperative AHI <20 with a 50% reduction from preoperative severity. CONCLUSION: UAS offers significantly better control of AHI severity than traditional sleep surgery. Quality life improvements were similar between groups.

Tonsil size and outcome of uvulopalatopharyngoplasty with tonsillectomy in obstructive sleep apnea.

OBJECTIVES/HYPOTHESIS: To investigate the relationship of tonsil volume and grade on outcomes of uvulopalatopharyngoplasty (UPPP) with tonsillectomy in patients with obstructive sleep apnea (OSA). STUDY DESIGN: Retrospective cohort analysis. METHODS: Data of 70 consecutive patients undergoing UPPP with tonsillectomy between 2015 and 2018 were analyzed. Patients with an apnea-hypopnea index (AHI) <10/hr or concomitant surgery other than nasal surgery were excluded. Tonsil volume was measured intraoperatively. Preoperatively and 3 months after surgery we assessed the AHI using respiratory polygraphy, daytime sleepiness using the Epworth Sleepiness Scale (ESS), and a visual analog scale for the snoring index (SI). RESULTS: Tonsil grade and volume both showed a significant correlation with preoperative AHI. Postoperative AHI was not significantly different between grades and volume. The AHI reduction after surgery increased significantly with larger volume and higher tonsil grade. For all grades, the postoperative ESS was significantly reduced compared to the preoperative value, but was not significantly correlated with tonsil volume. Preoperative and postoperative SI was not significantly correlated between tonsil grade or volume. In all grades, SI was significantly reduced after surgery. CONCLUSIONS: In our study, we found that large tonsils are responsible for higher preoperative AHI values, and their removal leads to greater reduction of initial AHI. However, the postoperative effect on daytime sleepiness and snoring reduction is not significantly correlated with tonsil size and volume, indicating that these parameters are mainly influenced by other factors. The knowledge of the significance of tonsil size and volume is important for ear, nose, and throat physicians when counseling OSA patients. LEVEL OF EVIDENCE: 2c Laryngoscope, 129:E449-E454, 2019.

Contribution of Hyoid and Tonsillar Procedures to Outcome in Multilevel Surgery for Obstructive Sleep Apnea Syndrome.

BACKGROUND/OBJECTIVE: In multilevel surgery for obstructive sleep apnea (OSA), the contribution of distinct operative steps is still unclear. The aim of the present study is to retrospectively compare different combinations of multilevel surgeries in order to estimate the contribution of hyoid and tonsillar procedures to the outcome. METHODS: A total of 45 patients were selected in a retrospectively matched case-control study from a database of patients who underwent surgery for OSA at our institution: group A (n = 15) had hyoid suspension, tonsillectomy, and radiofrequency-assisted uvulopalatoplasty (RAUP); group B (n = 15) had hyoid pharyngoplasty with resection of the hyoid body and preepiglottic fat tissue, tonsillectomy, and RAUP; and group C (n = 15) had hyoid suspension and RAUP but no tonsillectomy, because the tonsils had already been removed. The apnea-hypopnea index (AHI) was defined as the primary outcome measure. RESULTS: The postoperative AHI significantly improved in groups A and B, in which all patients had a tonsillectomy. However, the improvement in the patients of group C, who had no tonsillectomy, was not significant (p = 0.08). CONCLUSION: The patients having undergone multilevel surgery without tonsillectomy showed significantly poorer postoperative results, suggesting that the effectiveness of hyoid procedures at the level of the hypopharynx may be limited. However, removal of the tonsils is a major predictive factor for postoperative success.

Long-term compliance of the Velumount® palatal device.

OBJECTIVES: The aim of this study was to investigate the long-term compliance of the Velumount® palatal device. METHODS: This was a cohort study: 46 patients who received a Velumount device three years previously were enrolled. A questionnaire was sent to all patients. The data of 43 patients (93%) could be evaluated. RESULTS: Seventeen (40%) patients used the Velumount device regularly (>5 nights per week). However, 24 (56%) abandoned its use, 1 (2%) used it only occasionally (1-2 nights/week) and 1 (2%) used it only on special occasions. The main reasons for discontinuing Velumount were gag reflex (36%) and foreign body sensation (20%). CONCLUSIONS: The long-term compliance of the Velumount is 40%. Those patients who tolerate Velumount well use it regularly at least 5 nights per week. The Velumount palatal device is a valuable treatment option in counseling for patients with primary snoring or mild obstructive sleep apnea.

Statistical model for postoperative apnea-hypopnea index after multilevel surgery for sleep-disordered breathing.

The objective of the study was to formulate a statistical model for postoperative apnea-hypopnea index (AHI) 3 and 12 months after multilevel surgery using the predictors preoperative AHI, body mass index (BMI) and age. The study design was a prospective cohort study. Data of 144 patients were collected prospectively 3 and 12 months after multilevel surgery for obstructive sleep apnea syndrome (OSAS) or upper airway resistance syndrome with excessive daytime sleepiness. The primary endpoint postoperative AHI and the secondary endpoint success according to the Sher criteria (postoperative AHI <20 h and >50% reduction of preoperative AHI) were modeled with multiple linear and logistic regression using the predictors preoperative AHI, BMI, age and the indicator whether the patient had undergone a tonsillectomy. Preoperative AHI and tonsillectomy had a highly significant positive influence on postoperative AHI after 3 months, whereas the influence of preoperative BMI was only marginally significant but numerically rather large. Age was not a significant decisive factor. The success according to the Sher criteria was highly significantly determined by the circumstance whether the patient had undergone a tonsillectomy, but not by the other predictors preoperative BMI or age. The responder rate with and without tonsillectomy was 58 and 19%, respectively. The odds ratio to be a responder if a tonsillectomy was conducted was 5.7. This study provides statistical models predicting postoperative AHI and success according to the Sher criteria after multilevel surgery for OSAS.

Therapy of snoring and obstructive sleep apnea using the Velumount palatal device.

OBJECTIVES: The aim of the present study is to investigate the efficacy of the Velumount device. METHODS: In a prospective cohort study 40 patients were examined with and without Velumount. The apnea-hypopnea index and average esophageal pressure were measured using nocturnal manometry of the upper airways, combined with respiratory polygraphy. The snoring index (1-10) and daytime sleepiness using the Epworth Sleepiness Scale were assessed by means of a questionnaire. RESULTS: Using Velumount the snoring index was reduced from on average 8.4 (SD +/- 1.3) to 3.7 (SD +/- 2.5), the Epworth Sleepiness Scale score from on average 7.9 (SD +/- 4.4) to 3.8 (SD +/- 3.4) and esophageal pressure from on average 14.8 cm H(2)O (SD +/- 6.7) to 11.2 cm H(2)O (SD +/- 6.4). In patients (n = 25) with obstructive sleep apnea, the average apnea-hypopnea index was 24.3 (SD +/- 10.1) without and 13.6 (SD +/- 12.2) with Velumount. All changes were highly significant. CONCLUSIONS: The Velumount device is effective for the treatment of snoring and obstructive sleep apnea. The effect is similar to that reported from uvulopalatopharyngoplasty.

Outcome of functional endonasal sinus surgery with and without CT-navigation.

INTRODUCTION: Computer-assisted surgery (CAS) has found widespread use in functional endonasal sinus surgery (FESS) over the past few years. The present study investigates if CAS leads to a better outcome in FESS. MATERIAL AND METHODS: All patients who underwent endonasal sphenoethmoidectomy were enrolled in a prospective, non-randomized case-control study. The procedures were done without CAS (group A) in 2003 and with CAS (group B) in 2004, using a Stryker navigation unit. Sixty-two patients (113 sphenoidectomies) were included in group A and 61 patients (109 sphenoidectomies) in group B. The underlying disease was recurrent chronic sinusitis or polyposis nasi in all patients except for inverted papilloma in one patient from group A and in two patients from group B. The follow-up period was 12 months. Symptom scores were assessed preoperatively and at 12 months postoperatively, using a questionnaire. A CT-scan was obtained in all patients preoperatively and at 6 months postoperatively. RESULTS: No significant difference was found between group A and B, neither with respect to symptom scores at 12 months postoperatively, nor in postoperative CT-scans. The operation strategy did not change by the introduction of CAS. The frontal sinuses were entered in group A and B in 59% and 64% of the patients, respectively. All parameters improved significantly postoperatively, compared to the preoperative values. As far as complications are concerned, two anterior orbital injuries and one retrobulbar haematoma occurred in group A and one postoperative lacrimal stenosis in group B. CONCLUSIONS: CAS does not lead to a better clinical outcome in FESS. Our data suggest that the rate of complications may be reduced using CAS. However, studies with a much larger number of patients would be necessary in order to definitely answer the question of whether CAS reduce complications in FESS.

Comparison of various methods of electromyographic monitoring of the recurrent laryngeal nerve in thyroid surgery.

In the present study, 3 types of electrodes for recurrent laryngeal nerve (RLN) monitoring are compared: 1) intralaryngeal surface electrodes attached to a conventional endotracheal tube, 2) monopolar needle electrodes placed on the vocal cords by direct laryngoscopy, and 3) bipolar needle electrodes inserted intraoperatively through the cricothyroid ligament. Data were collected from stimulation of 21 RLNs in 16 patients undergoing thyroid surgery. The reliability in terms of distinct electromyographic (EMG) potentials following stimulation of the RLN was 100% with monopolar and bipolar needle electrodes and 76% with intralaryngeal surface electrodes. The mean (+/-SD) amplitudes of the EMG potentials were 1.61 +/- 1.6 mV, 2.37 +/- 1.8 mV, and 0.35 +/- 0.4 mV for the monopolar endolaryngeal, bipolar transligament, and intralaryngeal surface electrodes, respectively. The advantages and disadvantages of each type of electrode are discussed.

Monopolar electrocautery in adenoidectomy as a possible risk factor for Grisel's syndrome.

OBJECTIVES/HYPOTHESIS: Grisel syndrome is a nontraumatic atlantoaxial subluxation after an inflammatory process in the upper cervical region. It results from a peripharyngeal infection as well as a rare complication following adenotonsillectomy. After the introduction of monopolar suction electrocautery in adenoidectomy, an increased incidence of Grisel's syndrome has been observed. The purpose of the study was to evaluate monopolar suction electrocautery as a possible risk factor. STUDY DESIGN: Retrospective chart review along with current measurements of monopolar and bipolar electrocautery during adenoidectomy. METHODS: The charts of 1431 consecutive cases of adenoidectomy were reviewed before (n = 710) and after (n = 721) the introduction of monopolar suction electrocautery for intraoperative hemostasis. Moreover, energy of delivered current of electrocautery was measured in 30 pediatric patients during adenoidectomy. RESULTS: Three cases of Grisel's syndrome occurred as a postoperative complication in 721 adenoidectomies (0.4%) after the introduction of monopolar suction electrocautery. In contrast, no Grisel's syndrome was observed in 710 procedures before the use of monopolar electrocautery. Current measurements demonstrate an almost fourfold higher level of electrical energy using monopolar electrocautery compared with bipolar coagulation for bleeding control in adenoidectomy. CONCLUSION: Monopolar suction cautery in adenoidectomy may be considered as a risk factor for Grisel's syndrome.