Mouth Gag Research Articles

Comparison of Post-Tonsillectomy Hemorrhage rate in patients undergoing two commonly used Tonsillectomy Methods.

Objective: To compare the cold steel method and bipolar diathermy in tonsillectomies in terms of post-tonsillectomy hemorrhage. Study Design: Randomized Controlled Trial. Setting: Department of ENT, Head & Neck Surgery, Ayub Teaching Hospital, Abbottabad. Period: 29th October 2020 to 1st June 2022. Methods: A total of 102 patients of both genders with ages 3 to 59 years undergoing tonsillectomy were included. Patients undergoing antiplatelet therapy, experiencing bleeding diathesis, possessing a high anesthetic risk, having uncontrolled medical conditions, suffering from anemia, or currently dealing with acute infections were not included in the study. Patients were divided into two groups A & B. Group A patients were operated by the Cold steel method and Group B were operated by Bipolar diathermy. All the surgeries were performed by the same surgical team. Both tonsils were fully exposed by Boyl Devi's mouth gag under general anesthesia. Complete removal of both tonsils was done with the Cold steel method in group A and by using Bipolar diathermy in group B. Post-operative hemorrhage (occurring 24 hours after surgery) without the necessity to return to the operation theatre for intervention was assessed. Results: The mean age of patients in group A was 20.0 ± 13.83 years and in group B was 19.12 ± 13.17 years. The majority of the patients 79 (77.45%) were between 3 to 30 years of age. Out of 102 patients, 63 (61.76%) were males and 39 (38.24%) were females with male to female ratio of 1.6:1. Frequency of secondary hemorrhage in Group A (cold steel method) was found in 01 (1.96%) while in Group B (bipolar diathermy) was 06 (11.76%) (p-value = 0.050). Conclusion: This study concluded that the frequency of post-tonsillectomy hemorrhage is higher in patients operated by bipolar diathermy as compared to the cold steel method.

Validating the Modified Small Double Opposing Z-Plasty for Palatal Lengthening in Primary Palatoplasty.

To appraise the degree of intraoperative palatal lengthening with the modified Furlow small double-opposing Z-plasty (sDOZ). Retrospective single-surgeon (R.D.) study. Nonsyndromic children (n = 167) with Veau types I to IV cleft palates who underwent primary sDOZ palatoplasty. Intraoperative measurements of palatal lengths and widths were collected using calipers, paper rulers, and metal rulers before the administration of local anesthetic solution and before the removal of the mouth gag (initial and final palatal dimensions, respectively). Assessment of the intraoperative percentage change (difference between final and initial values) in surface palatal length, straight palatal length, and soft palatal length. Bivariate and multivariate analyses were performed to identify independent predictors (sex, age at surgery, Veau, Kernahan/ Stark, and Randall classifications, widest cleft width, presence of lateral relaxing incision, type of coverage with buccal fat flap, and postoperative complications) of soft palatal lengthening. Surface palatal, straight palatal, and soft palatal lengths had an intraoperative increase of 8%, 14.7%, and 27.7%, respectively. The degree of intraoperative soft palatal lengthening significantly varied among Veau cleft types (I = II < III = IV). Veau type III and cleft lip/palate were independent positive predictors (P < .001) of soft palatal lengthening, while other tested variables were not correlated (P > .05) with this outcome. Overall intraoperative palatal lengthening occurs with the modified sDOZ palatoplasty, with differences within the spectrum of cleft palate deformity.

Standing gustatory papillae biopsy procedure for antemortem diagnosis of equine grass sickness.

Diagnosing equine grass sickness (EGS) requires histopathological evidence of chromatolysis and/or neuronal loss in peripheral autonomic ganglia. Previous investigators performed postmortem biopsies of gustatory papillae located on the tongue and found chromatolytic subgemmal neurons in all 13 EGS horses. The present study aimed to design a standardized lingual biopsy sampling method through a transbuccal approach in healthy standing horses and assess the quality of the obtained samples, to allow antemortem diagnosis of EGS in clinical cases. 6 healthy horses. A transbuccal approach was performed bilaterally in 6 healthy standing horses. After having reached a deep level of sedation, horses were placed in stocks and a Günther mouth gag was inserted. Local anesthesia followed by a vertical full thickness incision was performed on both cheeks. Foliate papillae biopsies were carried out using an arthroscopic rongeur inserted through each incision site under oral endoscopic control. Tongue movements were restricted with diazepam. Histological assessment of taste buds and subgemmal plexi neurons was performed using H&E-stained longitudinal sections. The procedure was well tolerated in all horses. Minor complications observed were a transient facial paralysis, some incisional fluid collection, and abscesses. Ten samples (10/12) were suitable for assessment of neuronal perikarya. This procedure was safe for subgemmal plexus biopsy in healthy standing horses. The obtained samples were adequate as long as they were neatly cut lengthwise for inclusion. The technique was also used for 2 clinical cases and revealed the complete absence of neuronal perikarya, confirming chronic EGS.

Choice of Surgeons in Retractors used in Cleft Lip and Palate Surgery: An Original Research.

To ensure optimal exposure and enable precise tissue manipulation, cleft lip and palate abnormalities require surgical repair utilizing retractors. Different retractors may affect surgical outcomes; however, this is not yet evident. Examining surgeon preferences for retractors in cleft lip and palate surgery and assessing their impact on patient outcomes were the goals of this study. The patients who underwent primary cleft lip and palate repair were retrospectively analyzed. This study evaluated three widely used retractors: the Langenbeck, Gelpi, and Moult Mouth Gag retractors. This study looked at demographic information, surgical results (including scarring, aesthetic outcomes, and wound healing issues), and surgeon preferences for retractors. The study identified differences in surgical outcomes related to various retractor types. Both Group A (Langenbeck retractor) and Group B (Gelpi retractor) demonstrated similar favorable results, such as little wound healing issues, less scarring, and pleasing cosmetic results. The wound healing issues, scarring, and cosmetic outcomes were all worse in Group C (Moult Mouth Gag retractor). Retractors were not always preferred by surgeons doing cleft lip and palate surgery. The type of retractor had an impact on the surgical results; the Moult Mouth Gag retractor performed less well than the Langenbeck and Gelpi retractors. These results highlight the value of using evidence-based criteria to select retractors more effectively and enhance surgical methods for better patient outcomes in cleft lip and palate repair.

The Value of the Endoscope-Holding Arm in Transoral Pharyngeal Surgery.

Transoral pharyngeal surgery is mainly feasible with the use of a microscope or robotic systems. Data about alternative methods, with lower costs and easier availability, are sparse. We intended to examine to what extent the endoscope-holding arm is a suitable alternative to the microscope or robotic systems. We retrospectively reviewed subjects who underwent pharyngeal tumor resection with the endoscope-holding arm in our university department. We identified 13 subjects who underwent transoral pharyngeal surgery between November 2020 and November 2023. Most subjects presented with an oropharyngeal tumor (6/11 in the lateral wall or tonsil; 4/11 in the tongue base). The oropharyngeal lateral wall or tonsillar tumors were exposed with a standard mouth gag. The tongue-base tumors or hypopharyngeal tumors were exposed with an operating laryngoscope. Advantages over the microscope included an angled view. Advantages over robotic systems included haptic feedback and a faster setup. Advantages over both the microscope and robotic systems included lower costs and easier availability. Visualization with the endoscope was sufficient and similar to that of the microscope. Bimanual action was possible with surgical forceps and a monopolar electrode. Transoral pharyngeal surgery was feasible with the endoscope-holding arm. The endoscope-holding arm could be a cost-efficient alternative to the microscope or robotic systems.

Retrospective computed tomography analysis of endotracheal tube constriction and mispositioning in cats and dogs

ObjectiveTo discover the prevalence of endotracheal tube (ETT) constriction and rostral and caudal mispositioning in anaesthetized cats and dogs, and to identify associated risk factors. Study designRetrospective analysis. AnimalsA total of 146 cats and 670 dogs. MethodsComputed tomography images of the head/neck/thorax from orotracheally intubated cats and dogs were visually assessed for constriction or mispositioning of the ETT. If constriction was present, measurements of the cross-sectional area (CSA) of the ETT lumen at constricted and un-constricted locations were compared. Location and cause of constriction were noted and the expected increase in resistance to gas flow was calculated. Animal information was collected from clinical records. Normality of continuous variables was assessed via the Shapiro–Wilk test. Chi-square tests examined associations between variables. Kendall’s tau-b test was performed between measured ETT size and degree of constriction. ResultsThe ETT extended rostrally beyond incisors in 52% of cases; the connector was within the oral cavity in 19% of cases. The ETT extended beyond the first rib in 25.5% of cases. The prevalence of ETT constriction was 22.7%. Median reduction in CSA was 7.68% (0.14–64.19%). Median increase in resistance assuming laminar and turbulent flow was 16.5% (0.3–680%) and 21% (0.3–1200%), respectively. The most common cause of constriction was the presence of a radiotherapy mouth gag. Significant associations existed between presence of constriction and rostral mispositioning, and caudal mispositioning and extreme brachycephaly. Increased severity of constriction was more likely in smaller ETT. Conclusions and clinical relevanceConstriction and mispositioning of ETT occurred very commonly in this population. Checking the ETT within the oral cavity for constriction and mispositioning is recommended. Radiotherapy mouth gags increase the risk of ETT compression. Smaller ETT are at greater risk of severe constriction. Brachycephalic dogs are at particular risk of caudal mispositioning.

Near-Field LED Illumination Strategies for Tonsillectomy and Adenoid Surgery.

Objective: Perform a pilot feasibility study to demonstrate viability, quality, and safety advantages of light-emitting diode (LED) illumination when performing tonsillectomy. Study Design: Prospective cohort. Setting: Children's Hospital and Community Multispecialty Hospital. Methods: We tested a commercially available LED light, held in position with a minimally modified mouth gag, for off-label use in a "cavernous wound." We assessed surgeons', residents', and nurses' perceptions of function, safety, as well as preferences compared to headlights. Results: The light was used in 30 cases. Noted advantages over traditional lighting methods included superior brightness, stability and consistency of illumination, and the ability for others to assist more quickly. The inability to adjust brightness and/or the angle of light was an observed disadvantage. A small oral cavity or large tonsillar pillars creating a shadow required the temporary addition of a headlight. However, LED light use was not discontinued. Surgeons and residents reported a preference for not wearing a headlight, and nurses expressed concerns about headlight cleanliness. Conclusion: LED lighting technology demonstrated utility for teaching surgeons, residents, and nurses, and was perceived as safe. Additional specifications may make the light applicable to a wider variety of cases and could potentially mitigate headlight use during procedures of the oral cavity and oropharynx.Level of Evidence: 4.

A novel chairside technique to assess the interocclusal clearance and abutment axial walls during tooth preparation.

The importance of a judicious and unerring abutment tooth preparation in the field of prosthodontics has always been paramount. It is not uncommon for many clinicians to face challenges during laboratory fabrication of fixed prostheses, caused due to inappropriate occlusal clearance and over axial wall taper of the abutment tooth. With evolving technologies and methods, the modus operandi for attaining such tooth preparation is varying; however, every technique has its own shortcomings. The technique mentioned in the article is cost-effective as it uses modified Heister mouth gag forceps to achieve the desired objective of evaluating the prepared abutment morphology three-dimensionally with minimum chairside time.

Assessment of intracranial pressure with ultrasonographic measurement of optic nerve sheath diameter on patients undergoing suspension direct laryngoscopy.

The study aims to examine the effect on intracranial pressure by calculating the optic nerve sheath diameter (ONSD) using ultrasound in patients who underwent suspension direct laryngoscopy. Thirty-three patients who underwent suspension direct laryngoscopy were included in this prospective observational study. ONSD measurement was performed using a high-frequency linear probe. The ONSD basal (T0) value was determined using ultrasound in the supine position before the induction. Ultrasonography was used to record ONSD in the Boyce Jackson position (T1) just before inserting the laryngeal blade, in the Boyce Jackson position just before removing the laryngeal blade (T2), and in the supine position (T3) just before extubation. A statistically significant rise (p < 0.001) was seen between the patients' baseline ONSD values and the values at T1, T2, and T3. The optic nerve sheat diameter level recorded prior to withdrawing the laryngeal blade (T2) was considerably greater than the ONSD level calculated instantly before insertion of the laryngeal blade (T1) (p < 0.001). The ONSD value prior to extubation (T3) following the removal of the laryngeal blade was considerably smaller than the ONSD value prior removing the laryngeal blade (T2) (p < 0.001). This study found that when the laryngeal blade is mounted during the suspension direct laryngoscopy surgery, there is a significant increase in ultrasonographically measured ONSD and increased the ONSD even further during the time the mouth gag was remained in situ. This is the first research to indicate that measuring ONSD with ultrasonography during suspension direct laryngoscopy raises intracranial pressure.

Complications and side effects after barbed pharyngoplasty: a systematic review.

Recently, the use ofbarbed pharyngoplasty (BP) has become widespread in snoring and obstructive sleep apnoea (OSA) palatal surgery, but there are no studies regarding the short- and long-term complications resulting from these different techniques. This systematic review aimed to report the complications and side effects of different BP techniques. An electronic search was performed on PubMed/MEDLINE, Google Scholar, and Ovid databases. The PRISMA statement was followed. Databases were searched from inception through September 2, 2021. We included 14 prospective clinical studies consisting of 769 patients aged 23 to 81years. The associated intra-operative complications of BP were as follows: partial thread extrusion (2.9%), self-limited bleeding (2.9%), broken needle (1.0%), and suture rupture (1.0%). Short-term complications were as follows: thread/knot extrusion (12.4%), dysphagia (5.6%), bleeding (1.5%), velopharyngeal insufficiency (1.5%), anterior pharyngoplasty dehiscence (1.2%), tonsillar haemorrhage (1.0%), excessive postnasal discharge (1.0%), barbed suture failure (0.5%), acute infection (0.2%), mucosal granulomas (0.2%), chipped tooth caused by mouth gag displacement (0.2%), and fibrous scar (0.2%). Long-term complications were as follows: foreign body sensation (7.8%), sticky mucus in throat (5.9%), dysphagia (3.6%), rhinolalia (3.1%), throat phlegm (1.1%), nose regurgitation (0.8%), dry throat (0.6%), and throat lump (0.3%). BP is a safe technique free of significant side effects and major complications. However, in this review, patients undergoing BP were very heterogeneous in terms of characteristics of patientschosen and severity of diseases, surgical technique used (myoresective vs non-myoresective), time of follow-up, and mono level vs multilevel surgery. More studies on a larger scale with long-term follow-up are needed to confirm these promising results.

Evaluation of the association between nasopharyngeal depth and respiratory complications after cleft palate surgery in children between 9 and 18 months old

Background: Considering the incidence of respiratory complications after cleft lip and palate surgery and its significance in the survival of children undergoing the mentioned surgery, the present study was performed to evaluate the association between the nasopharyngeal depth and the incidence of respiratory complications after cleft palate surgery.Materials and Methods: The present cross-sectional study was performed on 222 children who aged 9–18 months and were the candidates for cleft palate surgery. After performing general anesthesia and implanting mouth gag and before surgery, the nasopharyngeal depth and the cleft palate width were measured with a calibrated ruler and an ophthalmic caliper, respectively. At the end of the surgery and after extubation, the incidence of respiratory complications such as respiratory distress, laryngospasm, bronchospasm, and need for intubation was recorded.Results: The nasopharyngeal depth in children with respiratory complications with a mean of 7.57 ± 3.12 mm was significantly less than that of children without respiratory complications with a mean of 10.82 ± 2.14 mm (P < 0.001). The nasopharyngeal depth of ≤8 mm with a sensitivity of 80% and a specificity of 89.60% had a significant predictive value in the incidence of respiratory complications (P < 0.001).Conclusion: According to the results of the present study, it seems that the nasopharyngeal depth of ≤8 mm can make the incidence of respiratory complications more likely. Therefore, considering the simplicity and convenience of measuring the nasopharyngeal depth and the cleft palate width, it is suggested to perform further studies to evaluate the anatomy of palate before this surgery using the employed method and address its association with respiratory complications.

Evaluation of a new laryngoscope blade (Manipal throat packing blade) for throat pack insertion.

Background and aims:Insertion of a throat pack using a Macintosh laryngoscope after placing an oral Ring, Adair and Elwyn (RAE) tube fixed to the lower lip in the midline invariably results in the lateral movement of the tongue or the tube requiring repositioning. The aim was to design a laryngoscope blade that would produce minimal movement of the endotracheal tube or the tongue during the insertion of throat pack and compare it with the Macintosh laryngoscope blade.Material and Methods:A laryngoscope blade similar to the Doughty’s blade of Boyle Davis mouth gag with a groove in the center of the blade was initially designed. This was made of polyvinyl chloride to enable 3-D printing. Specifications given were modified after trial and error including addition of a flange. A bench study was then done to compare the Macintosh blade with the Manipal blade with and without flange. Forty anesthesia postgraduates and staff familiar with airway management inserted throat pack with each blade in random order in a manikin already intubated with an oral RAE tube and their impressions were noted.Results:The RAE tube remained in the midline after throat packing in 97.5 and 95% with Manipal blade with and without flange as compared to 52.5% with Macintosh blade. Ease of use was affected by the lack of sturdiness of the new blades. The light was good. Most people found both blades better or the same as the Macintosh blade.Conclusion:The Manipal laryngoscope blade with and without flange are both associated with the minimal lateral movement of the endotracheal tube and are easy to use. Their sturdiness must be improved.

A Novel Custom Fabricated Teeth Guard for Boyle Davis Mouth Gag- A Feasibility Study

A Novel Custom Fabricated Teeth Guard for Boyle Davis Mouth Gag- A Feasibility Study

Peri operative airway and respiratory complications in children undergoing cleft lip and palate repair at a tertiary institute: An observational study

Introduction: Airway related problems have always been a major concern in paediatric patients more so in patients presenting with cleft lip/palate. Objective: Our aim was to determine the incidence of various types of perioperative airway and respiratory complications in children undergoing cleft lip and palate repair and their management at our tertiary care centre. Methodology: This prospective observational study was conducted over a period of 18 months in 50 ASA I and II paediatric patients (age group new born to 12 years) undergoing cleft lip/palate surgery. Complications during induction, intubation and postoperative period were noted. Results: Difficult laryngoscopy in 10% (n=5) patients & difficult intubation in 4% (n=2) patients were noted. No incidences of failed intubation were seen. Tube disconnection (n=1) and tube repositioning (n=2) after mouth gag placement. Desaturation occurred in 4% (n=2) patients, one during difficult intubation and one after mouth gag placement. One patient had laryngospasm during intubation. One patient had an episode of post extubation breath holding spell. One patient had tongue fall postoperatively. Conclusion: Airway and respiratory complications can be encountered during cleft lip and palate surgeries. Preoperative assessment and identifying any airway problems, congenital anomalies and comorbid conditions is important. Adequate preparation for difficult airway should be done before induction of anaesthesia to avoid morbidity and mortality. Intraoperative airway complications due to the shared airway have to be anticipated. Postoperative airway obstruction may be encountered and has to be treated prophylactically.

Substantiation of application of pneumoexercise machine mouth gag in patients with chewing muscle hypertonus

The hypertone of chewing muscles is the leading reason of development of pain of non-odontogenic character in maxillofacial area. This pathology is rather widespread, at the same time has permanent character and is characterized average or heavy degree of expressiveness of clinical symptoms. Muscular pains considerably reduce working capacity and worsen quality of life of patients. Treatment of a hypertone of chewing muscles is relevant in stomatology. For clear understanding of genesis of development of muscular frustration in work the anatomy of a temporal and mandibular joint and chewing muscles is in detail presented systems. Modern methods of treatment of a hyper tone of chewing muscles include correction of occlusion that doesn’t eliminate a painful symptom; orthopedic and orthodontic treatment with application a cap. However, application of above-mentioned methods is rather effective, there is no exact understanding of the mechanism of their action. At some patients the temporary improvement of a state is noted, – gets the chronic sluggish long course of development of a disease which doesn’t give in by any known methods subsequently from others. Dentists perfectly understand this fact, at the same time the disappointment from the treatment comes in spite of the fact that all efforts were bent on improvement of knowledge in the field of factors predictors of development of pathology, modern methods of diagnostics and treatment of muscular frustration. In this work the use of the pneumoexercise machine mouth gag as the device relaxing muscles and separating device on the one hand, and possibilities of his use as a stimulator of process of the return development of the available already structural and functional changes of muscle tissue with another is proved. Accurate indications and contraindications to use of this device are submitted. It is recommended to use the device as the low-invasive method which isn’t leading to irreversible consequences. Further need of development of practical recommendations on uses of the pneumoexercise machine mouth gag as is obvious to patients and their parents, and to dentists in the medical and preventive purposes.

Mouth Gags: Advantages and Disadvantages.

Mouth gags have been in use since 1220 as a solution to the cumbersome limitations encountered when visibility and access to the oral cavity, pharynx, and larynx are needed. The instruments being used today range from the simple but effective design of the bite block to the sophisticated and intricate design of the Feyh-Kastenbauer. This article highlights the most frequently used well-designed mouth gags and the applications for which they provide the most benefit. Disadvantages and risks of their use are explored, especially those that clinicians should be aware of for patient and operator safety.

Pre-hospital management of childhood convulsions in Ilesa, South-west, Nigeria

Convulsion evokes a lot of fear in mothers and caregivers whenever it occurs. They even think that their child is dying. Many interventions are often carried out because of anxiety and limited knowledge. The aim of this study is to examine the interventions instituted by caregivers for children with convulsions before presentation in the hospital for treatment. We prospectively studied all the 276 children that presented to the emergency room with convulsion over a period of seven months and the care administered at home before presenting in the hospital was noted. One hundred and nine (39.5%) of the children had water poured on them during convulsion. Substances administered orally were; salt 32 (11.6%), onions 14 (5.1%), palm oil 3 (1.1%) and herbal concoctions 13 (4.7%), of which two contained cow urine. Metal spoons were used as mouth gag in 41 (14.9%) of subjects while 29 (10.5%) children had intramuscular (IM) injections given by health workers at home (eight) in various health centres (15) and hospitals (6). Other interventions were scarifications and drinking of their mothers’ urine. While 40 (14.5%) children had more than one treatment given to them before their arrival, 99 (35.9%) had no treatment given before their arrival. Caregivers continue to carry out various interventions at home for convulsions in children. Majority of the interventions are not beneficial while some are harmful. There is, therefore, need to continue to educate caregivers on the appropriate prehospital interventions of convulsions in children before presenting in the hospital. Key words: Convulsion, pre-hospital interventions.

Custom-Made Cleft Palate Models to Teach V-Y Pushback Palatoplasty.

We developed custom-made cleft palate (CP) models to teach V-Y pushback palatoplasty, with a focus on design and mucoperiosteal elevation.A model (23 cm wide, 30 cm long, and 13 cm high) was made using silicone (model 1; M1). On the palate of a skull model, 2 layers of colored rubber clay were applied to represent the superficial oral mucoperiosteum and deep nasal mucosa (model 2; M2). From the greater palatine foramen, threads of dental floss were inserted inside the clay, representing the greater palatine artery. In a workshop, a mouth gag was applied on M1, and participants designed 2-flap palatoplasty and 4-flap palatoplasty. On the palate of M2, incisions were made with a #15 blade. On M2, a mucoperiosteal flap (rubber clay over the hard palate) was elevated using a periosteal elevator, avoiding injury to the dental floss mimicking the greater palatine artery. Six participants were recruited for the workshop and were asked to rate their satisfaction with the outcome on a Likert scale.For CP design, participants answered that they had learned useful knowledge from this workshop, reflecting a significant improvement (4.0 ± 1.1 for incomplete CP, 4.2 ± 1.2 for complete CP). They became confident in this skill after the workshop (4.2 ± 0.8 for incomplete CP, 3.8 ± 0.8 for complete CP). For cleft mucoperiosteal flap elevation, they likewise learned useful knowledge (4.7 ± 0.5 for incomplete CP, 4.5 ± 0.5 for complete CP) and became confident in this skill (3.8 ± 0.8 for incomplete CP, 4.0 ± 0.6 for complete CP.)These models can be useful for V-Y pushback palatoplasty training for medical personnel.

Evaluation of the effect of the mouth gag use on optic nerve sheath diameter of pediatric patients undergoing tonsillectomy or Adenotonsillectomy: An observational study

BackgroundA mouth gag is usually used during tonsillectomy and adenotonsillectomy surgeries, cleft palate repair, obstructive sleep apnea surgery, and intraoral tumor excision. The placement of the gag causes hemodynamic changes similar to laryngoscopy. The aim of this study was to evaluate the effect of mouth gag placement on the optic nerve sheath diameter (ONSD) of pediatric patients. The secondary aim was to assess the relationship between neck extension and changes in ONSD.MethodsThe trial was prospectively registered to the Australian New Zealand Clinical Trials Registry (Trial ID: ACTRN12618000551291) on 12.04.2018. This prospective, observational study was performed in a tertiary university hospital operating room between 01.05.2018–01.07.2018. Thirty-five children aged < 18 years, with ASA I status, who were scheduled for tonsillectomy and adenotonsillectomy surgeries were prospectively included in the study. Measurements of ONSD were performed (T0) after induction of anesthesia, (T1) after endotracheal intubation, (T2) after mouth gag placement, and (T3) 20 min after mouth gag placement. After the mouth gag was placed and the head was positioned for surgery, the degree of neck extension was calculated.ResultsAll participants completed the study. There were significant differences in ONSD values at time points T1, T2, and T3 (p < 0.001, CI: − 0.09,-0.05; p < 0.001, CI: − 0.09,-0.05; p < 0.001, CI: − 0.05,-0.02; respectively). The maximum increase in ONSD was after intubation (0.69 ± 0.06 mm) and immediately after mouth gag placement (0.67 ± 0.07 mm). ONSD values continued to increase 20 min after gag placement (0.36 ± 0.04). There was no relation between the degree of neck extension and ONSD values (β = 0.63, p = 0.715).ConclusionsThe use of a mouth gag causes significant increases in ONSD measurements of children. Therefore, attention to the duration of mouth gag placement should be considered during surgery.Trial registrationThe trial was prospectively registered to the Australian New Zealand Clinical Trials Registry (Trial ID: ACTRN12618000551291) on 12.04.2018.

0659 A Safe and Precise Tongue Base Surgery for Obstructive Sleep Apnea: Real-Time Intraoperative Ultrasound-Assisted Transoral Robotic Surgery

Abstract Introduction Lingual artery (LA) injury is a devastating complication of tongue base surgery. Compared with the anatomic findings of computed tomography angiography (CTA), intraoperative blade of mouth gag might change the thickness of base of tongue (BOT) and anatomy of LA. We aimed to investigate the position of LA in the BOT with intraoperative ultrasound (IOU) imaging during transoral robotic surgery (TORS), and evaluate the bleeding complications when assisted with / without IOU. Methods Adult obstructive sleep apnea (OSA) patients who received TORS in BOT resection were recruited since 2016. Assessment tools were pre-op over-night hospital polysomnography (PSG) and anatomy-based Friedman Staging System. Ultrasound imaging was utilized to identify anatomic parameters of LA in BOT, including distance to midline, arterial depth and diameter. Results Ninety-three OSA patients (82 male, 88.2%) were analyzed. The mean age was 42.2±10.0 years old and body mass index was 29.2±4.5 kg/m2. The average apnea hypopnea index (AHI) was 58.1±21.4 events/hour. There were 66 (71.0%), 24 (25.8%) and 3 (3.2%) patients in Friedman stages II, III and IV, respectively. Seventy patients underwent TORS with IOU had shorter operation time (191.7±3.8 minutes) than 23 patients without IOU (220.1±6.6 minutes), less total blood loss (11.3±10.8 versus 19.6±26.7 ml), and more BOT tissue reduction volume (7.1±2.5 versus 3.9±1.6 ml). Significant predictors of arterial depth were higher AHI level during rapid-eye-movement (REM) sleep stage (p=0.038), bigger tonsil size (p=0.034) and more elevated Friedman tongue position (p=0.012). Postoperative complication associated with LA injury was not found in the patients with use of IOU. Conclusion When tongue retracted with blade, the distance to midline and depth of LA were altered in BOT. With IOU assisted, surgeon could identify LA position confidently. It is expectable to maximize efficiency and minimize catastrophic bleeding complications when OSA patients received TORS in BOT resection. Support nil