Can Tonsillar Retractor-Induced Tongue Edema Be a New Complication in Pediatric Patients Undergoing Tonsillectomy Detected by Ultrasonography? A Prospective, Case-Controlled, Observational Study.

BACKGROUND: Tonsillectomy is one of the most common surgical procedures in pediatric patients. The tonsillar retractor, which is routinely used during a tonsillectomy, applies high pressure to the patient's tongue and can lead to various complications. AIMS: This study aimed to explore tongue edema induced by the pressure applied by tonsillar retractor, using ultrasonography in pediatric patients undergoing tonsillectomy surgeries. MATERIALS AND METHODS: Sixty-one patients were included in the study. The tonsillectomy group included 31 patients who underwent tonsillectomy surgery, while the control group included 30 patients who underwent inguinal hernia and circumcision surgery. Submental coronal plane ultrasonography examinations of the tongue were performed twice for each patient. In the tonsillectomy group, the first examination of tongue area (TA1) was done immediately after intubation but before the placement of tonsillar retractor. The second examination (TA2) was done at the end of the tonsillectomy surgery after the removal of the tonsillar retractor but before extubation. In the control group, the first examination (TA1) was done immediately after intubation, whereas the second examination (TA2) was done at the end of the surgery before extubation. These results were compared with those for the control group. RESULTS: Groups were similar in terms of demographics and intubation duration. Groups did not significantly differ in terms of TA1 (P = .212), but they significantly differed in terms of TA2 (P = .000). They also significantly differed in terms of tongue edema defined as TA2 - TA1 (P = .000). CONCLUSIONS AND SIGNIFICANCE: Tonsillar retractor does cause tongue edema in tonsillectomy surgeries. This tongue edema seems to be a result of the pressure applied by the tonsillar retractor. This study is the first to demonstrate the possible role of ultrasonography examination in determining the tonsillar retractor-induced tongue edema in pediatric patients.

Very-Low Energy Monopolar Reduces Post-Tonsillectomy Hemorrhage Versus Standard Energy Techniques.

OBJECTIVES/HYPOTHESIS: To compare rates of post-tonsillectomy hemorrhage (PTH) between a very-low energy transfer monopolar technique (VLET) and standard energy techniques. STUDY DESIGN: Retrospective controlled cohort study. METHODS: All tonsillectomies performed by practice physicians during the period January 1, 2010 to August 31, 2019 were identified. Three groups were created based on surgeon technique utilization: the study group (VLET) and two control groups (exclusive standard energy monopolar [Standard]; exclusive "hot" technique without exclusive monopolar use [Mixed "Hot"]). Each group's PTH occurrences requiring surgical intervention (PTHRSI) were identified and rates compared. RESULTS: During the study period 11,348 tonsillectomies were performed (4,427 Standard, 1,374 VLET, 5,547 Mixed "Hot"), and 167 (1.47%) PTHRSI events identified (14 primary (<24 hours), 153 secondary (>24 hours), 12 repeat (>1PTHRSI/patient). Compared to the Standard group secondary and total PTHRSI rates (1.47%, 1.60%), the Mixed "Hot" group experienced similar rates (1.57%, P = .54; 1.68%, P = .64), but the VLET group experienced significantly lower rates (0.15%, P = .0026, adjusted odds ratio [OR] 0.114 [0.028-0.469]; 0.22%, P = .0016, adjusted OR 0.155 [0.048-0.494]). Age was a significant risk factor for both secondary and total PTHRSI (P = .0025, P = .0024, adjusted OR 1.02/year [1.01-1.03]). No significant difference in rate of primary PTHRSI was seen collectively or in any age group. The <12VLET Group experienced 0 episodes of secondary PTHRSI and a total PTHRSI rate of 0.09% in 1060 tonsillectomies. CONCLUSIONS: Standard energy techniques had an adjusted odds ratio over 8-fold higher for secondary PTHRSI and over 6-fold higher for total PTHRSI compared to the minimized energy transfer VLET technique. LEVEL OF EVIDENCE: 3 Laryngoscope, 131:2505-2511, 2021.

Delayed onset of tooth decay in a routine pediatric adenotonsillectomy.

Adenotonsillectomy is a common pediatric surgical procedure with a well-defined safety profile. Major complications from this procedure include bleeding/hemorrhage, infection, pain leading to dehydration, and airway obstruction or edema. Though rare, oral endotracheal intubation and oral retractor placement may result in injuries to the teeth and the surrounding soft tissue. We describe a rare case of delayed tooth decay in a 3-year-old female following an otherwise routine adenotonsillectomy.

Complications associated with PlasmaBlade TnA during tonsillectomy and adenoidectomy from 2010 to 2020: A MAUDE study.

PURPOSE: The pulsed-electron avalanche knife (PEAK) PlasmaBlade TnA (Medtronic, n.d.) is a relatively new electrosurgical technology that is used widely in head and neck surgery (Medtronic Manuals, n.d.). This study aims to summarize device malfunctions, patient complications, and subsequent interventions related to PEAK PlasmaBlade TnA during tonsillectomy and adenoidectomy. MATERIALS AND METHODS: The US Food and Drug Administration's Manufacture and User Facility Device Experience database was queried for reports of PlasmaBlade TnA adverse events from June 6, 2009, to August 30, 2020. Data were extracted from reports pertaining to tonsillectomy with or without adenoidectomy. RESULTS: 128 reports were identified, from which 163 adverse events were extracted. Of these, 23 (14.6%) were related to patients, and 140 (85.4%) were related to device malfunction. The most frequently reported patient-related adverse event was a burn injury (17 [73.9%]). The most common device malfunctions were dislodgment of device component (39 [27.9%]), followed by tip ignition (32 [22.9%]), damaged tip or wire during operation (28 [20%]), and melted device (24 [17.1%]). CONCLUSIONS: PEAK PlasmaBlade TnA have demonstrated utility in tonsillectomy with or without adenoidectomy but are associated with adverse events. Interventions aimed at improving both physician and patient education may help reduce adverse events attributed to improper use. Further study is needed to clarify optimal approaches to education.

David Alexander Draffin: An Irish ENT Surgeon and Inventor.

David Alexander Draffin was an Irish ENT surgeon and inventor of the internationally famous ENT instrument used in tonsillectomy, which carries his name and is called Draffin's rods. His story is not as well-known as his eponymous ENT instrument and this article attempts to shed a light into his life. He studied in Queen's University in Belfast and was a medical officer in World War II. During that time, he demonstrated great courage and spirit. On his return from the war, he worked in many hospitals as an ENT surgeon and published multiple articles. His career was an unconventional one though, since due to multiple extracurricular activities he never became a consultant! He was actually struck off the medical register for drink-driving charges just a little before his early death. His life was evidence of his bravery, innovative spirit and mischief and his legacy shaped the way tonsillectomies are done to this day.

Randomized controlled study comparing tonsillectomy safety and patient satisfaction outcomes between HARMONIC ACE® + shears and monopolar diathermy in an adult population - A pilot study.

PURPOSE: Various types of the harmonic scalpel blades have been used for tonsillectomy since the early 2000s with varying successes. The HARMONIC ACE® + 23 cm shears is a relatively new blade which has not been studied in an adult population yet. METHODOLOGY: A randomized controlled pilot study was performed comparing the HARMONIC ACE® + 23 cm shears (HS) and monopolar electrocautery (EC) tonsillectomy in 20 patients. Intraoperative blood loss, pain control, return to normal diet and activity as well as patient satisfaction outcomes were compared between these two arms. RESULTS: The operative time was comparable. Compared to the EC arm, there was less intraoperative bleeding, lower risks of delayed haemorrhage and readmission in the HS arm. Post-operative pain scores and use of analgesia were similar. There was earlier return to normal diet and activity in the HS arm compared to the EC arm. More patients in the HS arm recommended using HARMONIC ACE® + 23 cm shears compared to those in the EC arm. This is a non-inferiority study which suggests that the HARMONIC ACE® + 23 cm shears is comparable to monopolar electrocautery in terms of efficacy and post-operative complication rates with better patient satisfaction outcomes. The main weakness of the study is a small study population. CONCLUSION: This is the first reported study comparing the use of the HARMONIC ACE® + 23 cm shears with monopolar cautery in tonsillectomy. A prospective adequately powered study validated by objective outcome measures would be useful to verify the findings from this pilot study.

Surgical Team Exposure to Cautery Smoke and Its Mitigation during Tonsillectomy.

OBJECTIVES: To assess the exposure of surgical personnel to known carcinogens during pediatric tonsillectomy and adenoidectomy (T&A) and compare the efficacy of surgical smoke evacuation systems during T&A. STUDY DESIGN: Prospective, case series. SETTING: Tertiary children's hospital. SUBJECTS AND METHODS: The present study assessed operating room workers' exposure to chemical compounds and aerosolized particulates generated during T&A. We also investigated the effect of 3 different smoke-controlling methods: smoke-evacuator pencil cautery (SE), cautery with suction held by an assistant (SA), and cautery without suction (NS). RESULTS: Thirty cases were included: 12 in the SE group, 9 in SA, and 9 in NS. The chemical exposure levels were lower than or similar to baseline background concentrations, with the exception of methylene chloride and acetaldehyde. Within the surgical plume, none of the chemical compounds exceeded the corresponding occupational exposure limit (OEL). The mean particulate number concentration in the breathing zone during tonsillectomy was 508 particles/cm3 for SE compared to 1661 particles/cm3 for SA and 8208 particles/cm3 for NS cases. NS was significantly different compared to the other two methods (P = .0009). CONCLUSIONS: Although the exposure levels to chemicals were considerably lower than the OELs, continuous exposures to these chemicals could cause adverse health effects to surgical personnel. These findings suggest that the use of a smoke-evacuator pencil cautery or an attentive assistant with handheld suction would reduce exposure levels to the aerosolized particles during routine T&A, compared to the use of cautery without suction.

Adolescents and Adults Undergoing Temperature-Controlled Surgical Instruments vs Electrocautery in Tonsillectomy: A Systematic Review and Meta-analysis of Randomized Clinical Trials.

Importance: Several temperature-controlled surgical instruments (TCSIs) have been used in tonsillectomy. However, to our knowledge, a meta-analysis of the differences between modern TCSIs and electrocautery (EC) has not been conducted. Objective: To compare TCSIs with EC with regard to the intraoperative and postoperative parameters of tonsillectomy. Data Sources: PubMed (MEDLINE), Embase, and the Cochrane Library were searched independently by 2 authors for relevant articles. Study Selection: A literature search identified randomized clinical trials comparing the outcomes of TCSIs vs EC. The search keywords were harmonic scalpel, ultracision, PlasmaBlade, coblation, radiofrequency ablation, and tonsillectomy. Studies of adult and adolescent patients were included. Data Extraction and Synthesis: Data from each study were extracted. A random-effects model was used in the pooled analysis. Main Outcomes and Measures: Four outcomes were analyzed: postoperative pain level on days 1, 2, 7, and 14 after surgery; postoperative bleeding; operative time; and intraoperative blood loss. Results: This meta-analysis included 11 studies with a total of 629 unique patients. (Mean ages ranged from 16 to 55 years.) The studies were further categorized by the methods of comparison. Five articles used between-participant comparisons, and 6 used within-participant comparisons (of the left vs right sides of the participant's body). The pooled results of the studies with between-participant measures showed that postoperative pain scores were lower in the TCSI group on the first day (standardized mean differences [SMD], -0.41 [95% CI, -0.77 to -0.06]) and seventh day (SMD, -0.76 [95% CI, -1.47 to -0.04]). The pooled results of the studies with within-participant measures showed that the postoperative pain scores were lower in the TCSI group on the first day (SMD, -0.37 [95% CI, -0.63 to -0.12]) and second day (SMD, -0.60 [95% CI, -1.10 to -0.10]). The pooled analysis of overall bleeding, major bleeding, minor bleeding, primary bleeding, and secondary bleeding in both the types of studies with between-participant measures and those with within-participant measures showed no significant differences between the TCSI and EC groups. Intraoperative blood loss and operative time were not significantly different between the groups. Conclusions and Relevance: Compared with EC, TCSIs were associated with significantly reduced pain on the first day after tonsillectomy, per this meta-analysis. The rates of overall bleeding, primary bleeding, secondary bleeding, major bleeding, and minor bleeding between TCSIs and EC were comparable. Intraoperative blood loss and operative time also showed no significant intergroup differences. Surgeons may consider using these modern instruments according to personal experiences, preferences, and cost-effectiveness criteria.

Evaluation of the effect of Boyle-Davis mouth gag on intracranial pressure in patients undergoing adenotonsillectomy by using ultrasonographic optic nerve sheath diameter measurement.

OBJECTIVE: We aimed to evaluate the effect of an increase in intracranial pressure (ICP) due to sympatho-adrenergic response caused by mouth gag and tongue depressor during adenotonsillectomy by measuring the optic nerve sheath diameter (ONSD) by ultrasonographic method. METHODS: Forty patients (age range 3-12 years) who underwent adenotonsillectomy were included in the study. All patients underwent surgery under general anesthesia with endotracheal intubation. Boyle-Davis mouth gag was used during the procedure. ONSD measurement was performed and a high-frequency linear probe. All ONSD measurements were performed by a single investigator experienced in the use of ultrasound. Ultrasonographically measured ONSD before induction was accepted as baseline (T0) value. Immediately after insertion of the mouth gag (T1), just before removal of the mouth gag (T2), and just before extubation (T3), ultrasonographic measurements of ONSD were recorded. RESULTS: When patients' baseline ONSD values were compared with the values obtained in T1, T2, T3, and a statistically significant increase was detected. The ONSD value measured before removing the mouth gag (T2) was significantly higher than the ONSD value measured immediately after the insertion of the mouth gag (T1). The ONSD value measured just before extubation (T3) and after removal of the mouth gag was significantly lower than the ONSD value (T2) measured just before removal of the mouth gag. When heart rate, mean arterial pressure (MAP), peripheral oxygen saturation (SpO2) values of T0, T1, T2, T3 were compared, any statistically significant difference was not observed. When end-tidal carbon dioxide level (etCO2) and peak inspiratory pressure (PIP) values of T1, T2, T3 were compared, any statistically significant difference was not observed. CONCLUSION: This study showed that the Boyle-Davis mouth gag used during the adenotonsillectomy operation resulted in a significant increase in the diameter of the optic nerve sheath measured ultrasonographically and increased the ONSD even further during the time the mouth gag was remained in situ. In children with intracranial pathologies who will undergo adenotonsillectomy or those with increased ICP-related risk factors, the risks that may arise from the effect of the Boyle-Davis mouth gag on ICP should be considered.

Rare electrosurgical complications in tonsillectomy: Analysis of national adverse event reporting.

OBJECTIVES: To identify U.S. Food and Drug Administration (FDA)-reported adverse events related to electrosurgical devices during tonsillectomy and characterize the most common devices and patient/provider sequelae. STUDY DESIGN: Retrospective analysis of FDA database of device-related adverse events. METHODS: Data were extracted from the OpenFDA database for all adverse events reported for electrosurgical devices used in tonsillectomies from January 2008 to December 2017. Adverse events were classified by device, event type, etiology, complication severity, and patient disposition. RESULTS: Six hundred fifty-two adverse events were identified, with 195 events (30%) leading to known bodily injury to patient/provider. Device failure was the most common adverse event (202 events, 31%), followed by burns in 187 patient (98% of burns) and three provider events (2%). Burn injuries occurred most frequently with coblation devices (78 events, 42% of burns), monopolar electrocautery (48 events, 25%), and electrosurgical generators (23 events, 13%). Burn injuries most commonly occurred in the oral cavity (144 events, 76% of burn events) and were most commonly first-degree (28 events, 15%). Complications related to burns were managed conservatively for 36% of burn events (68 events), and secondary surgery was rarely required (8 events, 4%). Postoperative bleeding (173 events, 26%; 3 deaths) and intraoperative fire (73 events, 11%) were also reported. Device failures caused significant OR delay or cancellation in 17% of occurrences (35 events). CONCLUSION: Numerous complications may occur with various devices used during tonsillectomy and can result in significant patient/provider harm and sequelae. Surgeons must understand the nature of such complications to facilitate safe perioperative care and inform preoperative patient discussions. LEVEL OF EVIDENCE: NA Laryngoscope, 130:1138-1143, 2020.

The cheek expander enables tonsillectomy with a wide view and working space.

OBJECTIVE: Tonsillectomy is the most commonly performed otolaryngological surgeries. Although a surgical method had been established, obtaining a clear surgical field still remains problematic, and injury to the corners of the mouth may occur. For safer tonsillectomy, we use a cheek expander coupled with a Davis mouth gag. The devise retract both corners of the mouth to a wide lateral position. We report here our investigation in the application of a cheek retractor for tonsillectomy and also report the advantages of this device. METHODS: A series of 13 tonsillectomies (7 adults and 6 children) using the cheek retractor from November 2017 to March 2018 were enrolled for this study. The cheek retractor was applied after the Davis mouth-opening device was in place. We measured the oral angle diameter before and after placement of the cheek retractor. RESULTS: This devise increases the width of the visual field 1.6 times and provides a good surgical field. In addition, this device covers the mouth fully and safely, so no lip injury develops CONCLUSION: The cheek retractor is useful for improving the narrow working space in tonsillectomy.

Massive pneumomediastinum with subcutaneous emphysema after elective adenotonsillectomy in children: Involvement of the Boyle-Davis mouth gag.

Adenotonsillectomy, a very common surgical procedure in otorhinolaryngology, is considered easy and safe surgery. However, clinicians should be aware of some less common but potentially life-threatening complications. This report discusses subcutaneous emphysema with pneumomediastinum following elective adenotonsillar surgery in children. The Boyle-Davis mouth gag seemed to play a part in the pathogenic mechanism of this rare complication in this case. Better insights in the mechanism of this severe complication of adenotonsillectomy may contribute to the prevention of this complication.

Surgeons' preferences and anxiety levels in paediatric adenotonsillectomy: European perspective.

OBJECTIVE: This study assessed the preferences of surgeons regarding surgical modalities used for adenotonsillectomy, and determined anxiety levels related to the adenotonsillectomy procedure. METHODS: A 10-question survey created by the authors was administered to 413 ENT specialists attending the 4th Congress of Otorhinolaryngology Head and Neck Surgery, held in October 2017 in Barcelona, Spain. RESULTS: Cold knife dissection was the preferred surgical modality for both adenoidectomy and tonsillectomy. Most participants reported encountering one to five patients with post-tonsillectomy bleeding throughout their entire career. The mean anxiety levels during surgery and the 10-day post-operative period were 3.39 ± 2.14 and 4.18 ± 2.63, respectively (p < 0.05). There was a significant negative correlation between anxiety level and surgeon's experience (p < 0.05). CONCLUSION: Cold dissection is still the preferred surgical modality for adenotonsillectomy, while both suture ligation and electrocautery are used for haemostasis. Paediatric adenotonsillectomy is likely to generate anxiety in ENT surgeons, and the possibility of secondary post-tonsillectomy bleeding increases the anxiety levels of surgeons in the post-operative period.

Wound healing after tonsillectomy - a review of the literature.

OBJECTIVE: To summarise the available literature related to wound healing post tonsillectomy, including the stages of healing, experimental models for assessing healing (in animals and humans) and the various factors that affect wound healing. METHODS: A search of the English literature was conducted using the Ovid Medline database, with the search terms 'tonsillectomy' or 'tonsil' and 'wound healing'. Thirty-one articles that objectively assessed tonsillectomy wound healing were included for analysis. RESULTS: The majority of assessments in humans investigating tonsillectomy wound healing involve serial direct clinical examinations of the oral cavity. Many patient and surgical factors have been shown to affect wound healing after tonsillectomy. There is some research to suggest that the administration of adjunctive treatment in the post-operative period may be beneficial to tonsillectomy wound healing. CONCLUSION: Wound healing post tonsillectomy has been poorly researched. Having a better understanding of the process of wound healing would allow surgeons to potentially prevent, anticipate and manage complications from the surgery that arise as part of the healing process.

Use of the EndoMaster robot-assisted surgical system in transoral robotic surgery: A cadaveric study.

BACKGROUND: The EndoMaster is a novel robot-assisted surgical system originally designed for endoscopic resection of gastrointestinal polyps and tumours. It incorporates two robotic arms (a grasper and a probe for monopolar diathermy) into the end of a flexible endoscope, creating improved manoeuvrability, with two arms allowing for 9 degrees of movement and triangulation; this enables fine manipulation and dissection of tissues. METHODS: The EndoMaster was used in two human cadavers to perform 4 radical tonsillectomies to evaluate its performance in transoral robotic surgery (TORS). RESULTS: The EndoMaster allowed for good visualization of the surgical field and its compact form factor allowed for quick docking and avoided the problem of clashing of the working arms. CONCLUSION: The EndoMaster system shows promising potential for use in TORS. Further refinements to movements of the effector arms are required.

Transoral radical tonsillectomy and retropharyngeal lymph node dissection with a flexible next generation robotic surgical system.

BACKGROUND: The purpose of this study was to describe the use of a novel flexible, single-arm robot in performing a transoral radical tonsillectomy and retropharyngeal lymph node dissection. METHODS: A 63-year-old man with a T1N2bM0 (American Joint Committee on Cancer seventh edition classification) squamous cell carcinoma (SCC) of the left tonsil underwent a transoral robotic radical tonsillectomy and retropharyngeal lymph node dissection, followed by a left selective neck dissection of levels I to IV. RESULTS: The tonsillar tumor was removed completely with a negative margin that was followed by a dissection and removal of a retropharyngeal lymph node, completed with primary closure of the site. A left selective neck dissection was then performed. The patient was tolerating an oral diet on postoperative day 1 and had no robotic or surgically related complications at 30-day follow-up. CONCLUSION: It is feasible and safe to use this novel, flexible, single-arm robot in performing a transoral robotic radical tonsillectomy and retropharyngeal lymph node dissection.

Indirect visualisation of the upper pole during tonsillectomy.

BACKGROUND: During tonsillectomy, one of the key concerns is establishing adequate haemostasis. Intra-operative haemorrhage from the upper pole of the tonsil fossae can be a challenge to deal with because of an inability to clearly visualise bleeding points. Laryngeal mirrors are readily available in an ENT operating theatre and routinely used for indirect visualisation of the post-nasal space during adenoidectomy. OBJECTIVE: This paper describes a technique, utilising a laryngeal mirror placed within the tonsil fossa (after having removed the palatine tonsil), to visualise the upper pole and any bleeding points. RESULTS AND CONCLUSION: Laryngeal mirrors can be used with case to inspect the tonsil fossa post-tonsillectomy for bleeding points which may not be directly visible, so that these can be cauterised.

Utilization and trends in surgical instrument use in pediatric adenotonsillectomy.

OBJECTIVE: Examine trends in surgical instrument usage for pediatric adenotonsillectomy. METHODS: An online survey asking questions about current and previous surgical instrument use was created by the authors and distributed to 517 members of the American Society of Pediatric Otolaryngology in October 2015. The survey was designed to assess trends in the use of surgical instruments in pediatric adenotonsillectomy by comparing the results of our 2015 survey to data from a previously published 2005 study. RESULTS: 133 surveys were returned. The most common instruments for total tonsillectomy in 2015 were monopolar electrocautery (57.0%) and coblation (22.7%). The most common subtotal tonsillectomy instruments in 2015 were microdebrider with monopolar electrocautery (41.3%) and coblation (37.0%). The most common adenoidectomy instruments in 2015 were monopolar electrocautery alone (41.3%), coblation (15.1%), and microdebrider with electrocautery (15.1%). CONCLUSION: As compared to our 2005 study, our 2015 study demonstrates that the instrument choice for total tonsillectomy, sub-total tonsillectomy, and adenoidectomy have shifted away from cold techniques toward monopolar electrocautery and coblation.

Coblation versus other surgical techniques for tonsillectomy.

BACKGROUND: Tonsillectomy is a very common operation and is performed using various surgical methods. Coblation is a popular method because it purportedly causes less pain than other surgical methods. However, the superiority of coblation is unproven. OBJECTIVES: To compare the effects of coblation tonsillectomy for chronic tonsillitis or tonsillar hypertrophy with other surgical techniques, both hot and cold, on intraoperative morbidity, postoperative morbidity and procedural cost. SEARCH METHODS: The Cochrane ENT Information Specialist searched the ENT Trials Register; Central Register of Controlled Trials (CENTRAL 2017, Issue 3); PubMed; Ovid Embase; CINAHL; Web of Science; ClinicalTrials.gov; ICTRP and additional sources for published and unpublished trials. The date of the search was 20 April 2017. SELECTION CRITERIA: Randomised controlled trials (RCTs) of children and adults undergoing tonsillectomy with coblation compared with any other surgical technique. This review is limited to trials of extracapsular (traditional) tonsillectomy and excludes trials of intracapsular tonsil removal (tonsillotomy). DATA COLLECTION AND ANALYSIS: We used the standard Cochrane methods. Our primary outcomes were: patient-reported pain using a validated pain scale at postoperative days 1, 3 and 7; intraoperative blood loss; primary postoperative bleeding (within 24 hours) and secondary postoperative bleeding (more than 24 hours after surgery). Secondary outcomes were: time until resumption of normal diet, time until resumption of normal activity, duration of surgery and adverse effects including blood transfusion and the need for reoperation. We used GRADE to assess the quality of the evidence for each outcome; this is indicated in italics. MAIN RESULTS: We included 29 studies, with a total of 2561 participants. All studies had moderate or high risk of bias. Sixteen studies used an adequate randomisation technique, however the inability to mask the surgical teams and/or provide adequate methods to mitigate the risk of bias put nearly all studies at moderate or high risk of detection and measurement bias for intraoperative blood loss, and primary and secondary bleeding. In contrast most studies (20) were at low risk of bias for pain assessment. Most studies did not report data in a manner permitting meta-analysis.Most studies did not clearly report the participant characteristics, surgical indications or whether patients underwent tonsillectomy or adenotonsillectomy. Most studies reported that tonsillitis (infection) and/or tonsillar hypertrophy (obstruction) were the indication for surgery. Seven studies included only adults, 16 studies included only children and six studies included both. Pain At postoperative day 1 there is very low quality evidence that patients in the coblation group had less pain, with a standardised mean difference (SMD) of -0.79 (95% confidence interval (CI) -1.38 to -0.19; 538 participants; six studies). This effect is reduced a SMD of -0.44 (95% CI -0.97 to 0.09; 401 participants; five studies; very low-quality evidence) at day 3, and at day 7 there is low quality evidence of little or no difference in pain (SMD -0.01, 95% CI -0.22 to 0.19; 420 participants; five studies). Although this suggests that pain may be slightly less in the coblation group between days 1 and 3, the clinical significance is unclear. Intraoperative blood loss Methodological differences between studies in the measurement of intraoperative blood loss precluded meta-analysis. Primary and secondary bleeding The risk of primary bleeding was similar (risk ratio (RR) 0.99, 95% CI 0.48 to 2.05; 2055 participants; 25 studies; low-quality evidence). The risk of secondary bleeding was greater in the coblation group with a risk ratio of 1.36 (95% CI 0.95 to 1.95; 2118 participants; 25 studies; low-quality evidence). Using the median of the control group as the baseline risk, the absolute risk in the coblation group was 5% versus 3.6% in the control group. The difference of 1.3% has a 95% CI of 0.2% lower in the coblation group to 3.5% higher. Secondary outcomes Differences in study design and data reporting precluded the identification of differences in the time to resumption of normal diet or activity, or whether there was a difference in the duration of surgery.Although we could not feasibly compare the costs of equipment or operative facility, anaesthetic and surgical fees across different healthcare systems we used duration of surgery as a proxy for cost. Although this outcome was commonly reported in studies, it was not possible to pool the data to determine whether there was a difference.Adverse events other than bleeding were not well reported. It is unclear whether there is a difference in postoperative infections or the need for reoperation. AUTHORS' CONCLUSIONS: The coblation technique may cause less pain on postoperative day 1, but the difference is small and may be clinically meaningless. By postoperative day 3, the difference decreases further and by postoperative day 7 there appears to be little or no difference. We found similar rates of primary bleeding but we cannot rule out a small increased risk of secondary bleeding with coblation. The evidence supporting these findings is of low or very low quality, i.e. there is a very high degree of uncertainty about the results. Moreover, for most outcomes data were only available from a few of the 29 included studies.The current evidence is of very low quality, therefore it is uncertain whether or not the coblation technique has any advantages over traditional tonsillectomy techniques. Despite the large number of studies, failure to use standardised or validated outcome measures precludes the ability to pool data across studies. Therefore, well-conducted RCTs using consistent, validated outcome measures are needed to establish whether the coblation technique has a benefit over other methods. In the included studies we identified no clear difference in adverse events. However, given the rarity of these events, randomised trials lack the power to detect a difference. Data from large-scale registries will provide a better estimate of any difference in these rare outcomes.