Endoscopic Sinus Surgery Techniques Research Articles

Endoscopic endonasal trans-cribriform approachfor drainage of frontal lobe abscess in invasivemucormycosis – A case report

Abstract Introduction:Mucormycosis is a belligerent fungal infection that can cause fatal complications. Patients at risk arethose with poorly controlled diabetes mellitus, and similar immunosuppressed states. Tissue invasion and infarctionsecondary to angioinvasion are the pathognomonic features of the disease. The management of brain abscesseshas become increasingly complicated requiring close collaboration between various departments encompassinginfectious disease specialists, neurologists, radiologists and neurosurgeons. ENT surgeons are seldom involved inthe management of brain abscesses, but with the advancements in Endoscopic Sinus Surgery techniques, ENTsurgeons are now treating the skull base, meningeal and brain pathologies.Methods:A case report of a 36-year-old male with complaints of headache, left-sided facial pain, difficultyin opening left eye for 10 days, with a history of one episode of generalized seizure that lasted for 4 min,recently detected type 2 diabetic mellitus. Local examination revealed left-sided nasal crusting and an old palataldefect. KOH mount was positive for mucorales. CT scan PNS revealed left-sided maxillary, ethmoidal, sphenoidalfrontal sinusitis with erosion of left lamina papyracea, left extraconal and intraconal involvement with erosion ofleft cribriform plate. MRI brain revealed additional hyperdensities in both medial frontal, and parietal lobe withdiffusion restriction. The patient underwent left-sided endoscopic sinus surgery with endoscopic endo- nasal trans-cribriform drainage of frontal lobe abscess, with retro bulbar Amphotericin B injection, with a neurosurgical team onstandby in the event of unexpected complications. The eschar and pus drained from the frontal lobe abscess wassent for histopathological examination, culture and sensitivity. The patient was extubated, and the postoperativeperiod was uneventful.

A Study on the Possibility of Endoscopic Modified Lothrop Procedure Using Imaging Measurements

Background and Objectives Endoscopic modified Lothrop procedure (EMLP) is indicated after the failure of standard endoscopic sinus surgery techniques to alleviate frontal sinus disease. Three parameters, such as nasal beak thickness (NBT), accessible dimension of frontal recess (AD), and distance of frontal sinus (DFS), are important in the preoperative evaluation and selection of patients for EMLP. The purpose of this study is to apply the parameters to determine the feasibility of EMLP for the Korean population.Subjects and Method Sinus CT was performed on a total of 233 people, and a study was conducted using 466 bilateral sides with the following parameters: 1) NBT 2) the distance from the posterior margin of nasal beak to the anterior margin of skull base (DNBSB) 3) the right and left AD and 4) the right and left DFS. If the values of NBT, AD, and DFS of the study group were less than 10 mm, greater than 5 mm and 7 mm, respectively, they were considered candidates for the EMLP.Results DNBSB, NBT, AD, and DFS were 6.97±1.96 mm, 7.01±1.58 mm, 7.16±2.40 mm, and 9.47±2.91 mm, respectively. Parameters except DNBSB showed significant differences in male and female. The feasibility of EMLP was 75.36% for male and 57.89% for female, with 68.24% overall.Conclusion The overall feasibility of EMLP was 68.24% for the study group, where feasibility was lower for female than for male.

MODERN METHODS OF DIAGNOSTICS AND TREATMENT OF CHRONIC MAXILLARY SINUSITIS

The objective of the present study was to compare the efficacy of traditional and endoscopic surgical treatments for maxillary sinusit. Materials and methods: The present study is based on a comparison of the results of the radical maxillary sinusotomy and endoscopic endonasal approach sanation in 206 patients with sinusitis. The patients were divided into 2 comparable groups. The diagnosis was established on the basis of complaints, endoscopy of the nasal cavity and CT scan of the paranasal sinuses. We have developed a scale for assessing clinical effectiveness of surgery the criteria of which were: 1) intraoperative and postoperative complications; 2) relapse diseases. Clinical efficacy was defined as "unsatisfactory" in the event of a relapse of the disease, the presence of complications in the early postoperative period. "Satisfactory" - if available complications and with an increase in the length of stay patients in the hospital by 6-30%, "good" – in absence of complications, recurrence of the disease and reducing the length of the patient's stay in hospital. Results: Clinical efficacy in the 1nd group was higher in 62.4% - "good", in 23% - "satisfactory" and in 14.6% - "unsatisfactory" clinical efficacy. Clinical efficacy in the 2nd group was higher in 82.3% - "good", in 14,2% - "satisfactory" and in 4.5% "unsatisfactory" clinical efficacy. Conclusion: Endoscopic sinus surgery at allows to reduce complications in comparison with radical maxillary sinusotomy. The endoscopic sinus surgery technique is characterized by low trauma and the physiological principle of influencing the sinus, allows for constant visual control both during the intervention and in the postoperative period, and reduces the time of inpatient treatment compared to radical maxillary sinusectomy.

Three-Dimensional Printed Models to Accelerate Resident Surgical Learning Curve for Standard Endoscopic Sinus Surgery Techniques.

Background: Endoscopic sinus surgery presents significant visuospatial challenges to surgical trainees. We tested the utility of novel 3D printed models to simulate sinus surgery tasks to improve endoscopic skillsets in resident trainees. Methods: This was a prospective quality improvement study of 10 ENT residents (PGY1-5). Participants rotated through 4 stations with different 3D simulation training modules designed to enhance endoscopic skillsets in the axial, sagittal and coronal planes (e.g., straight forceps to grasp a bead from a ledge, angled instruments to cannulate openings). Participants completed a self-assessment survey on the subjective sinus surgical skills using a visual analog scale before and after tasks. Two- tailed paired T-tests were used to analyze the data. Results: All residents rated their post-intervention "overall sinus surgery skills" higher than pre-intervention. They rated simulations to provide more significant utility as an adjunct to surgical education after the intervention. All but one participant reported improved spatial awareness working with the endoscopes and surgical instruments. There was subjectively improved proficiency in using 0-degree and angled endoscopes as well as cutting, grasping, and curved instruments after the intervention. The simulations led to subjective improvements in spatial awareness, bimanual dexterity, and increased confidence in selecting correct surgical instruments. Conclusion: Our set of novel 3D printed models to improve sinus surgery skillset was well accepted by the resident cohort. The 3D models can serve as an adjunct tool to traditional residency education.

Online workshops on the teaching and practice of endoscopic sinus surgery techniques during the COVID-19 pandemic

Online workshops on the teaching and practice of endoscopic sinus surgery techniques during the COVID-19 pandemic

A Case of Endoscopic Reduction of Isolated Maxillary Sinus Posterior Wall Fracture Using Foley Catheter

The surgical goal for reduction of maxillofacial fracture has been focused on the reconstruction of facial buttresses. If there is fracture-displacement at non-buttress area, it close observation used to be the choice of treatment. It is not easy to have access to the posterior part of maxilla with conventional approach. But with the endoscopic sinus surgery technique, posterior wall of maxillary sinus is easily approachable and can be manipulated. This report presents a case of a 38-year-old male with isolated posterior wall of maxillary sinus fracture. Inward comminuted fracture-displacement of the posterior wall of maxillary sinus with retroantral fat and soft tissue was herniated into the maxillary sinus and extruded out through the natural ostium of maxillary sinus. Using endoscopic approach and Foley catheter inflation, the maxillary sinus posterior wall was successfully repaired without complications. This report thus suggests endoscopic approach with the Foley catheter for the posterior maxillary sinus wall fracture.

Long-Term Follow-Up After Maxillary Sinus Balloon Sinuplasty and ESS.

The aim of this controlled follow-up study was to compare the need for revision surgery, long-term efficacy, and satisfaction in chronic rhinosinusitis patients who had undergone maxillary sinus operation with either balloon sinuplasty or traditional endoscopic sinus surgery (ESS) technique. Thirty-nine ESS patients and 36 balloon patients of our previously described cohort, who had been primarily operated in 2008 to 2010, were contacted by phone. Symptoms, satisfaction, and need for revision surgery were asked. In addition, we collected data of patients who had undergone primary maxillary sinus balloon sinuplasty in the Helsinki University Hospital during the years 2005 to 2019. As a control group, we collected data of patients who had undergone primary maxillary sinus ESS at 3 Finnish University Hospitals, and 1 Central Hospital in years 2005, 2008, and 2011. Altogether, 77 balloon patients and 82 ESS patients were included. The mean follow-up time was 5.3 years in balloon group and 9.8 years in ESS group. Revision surgery was performed on 17 balloon patients and 6 ESS patients. In the survival analysis, the balloon sinuplasty associated significantly with a higher risk of revision surgery compared to ESS. According to the phone interviews, 82% of ESS patients and 75% of balloon patients were very satisfied with the primary operation. Although the patient groups expressed equal satisfaction and change in symptoms after the operations, the need for revision surgery was higher after balloon sinuplasty than after ESS. This should be emphasized when counselling patients regarding surgical options.

Advances in Endoscopic Sinus Surgery Technique: The Impact of Technological Breakthroughs

Messerklinger initially characterized sinonasal mucociliary clearance patterns in the 1950’s using India ink particles and hypothesized that inflammatory disease within the sinuses, as well as anatomic variants, could obstruct mucus outflow. He introduced use of the endoscope for diagnostic evaluation, as well as surgical principles known as the Messerklinger technique [1]. In the following 70 years his technique, known as Endoscopic Sinus Surgery (ESS), was refined and popularized by Stammberger, Kennedy, and others [2,3]. Both emphasized the preservation of normal anatomic structures and re-establishment of natural mucociliary clearance patterns. Towards that end, Kennedy viewed the surgery as a functional and minimally invasive procedure, adding the term “functional” to ESS, with the procedure now widely known as Functional Endoscopic Surgery (FESS) [4]. Since then, minimally invasive endoscopic techniques have been further refined by a multitude of talented multi-disciplinary physicians, too numerous to name here [5].

"M" line: New anatomical landmark for the maxillary sinus natural ostium.

Describe a reliable anatomical landmark that can be used to locate the maxillary sinus natural ostium (MSNO) during endoscopic surgery, even if the uncinate process is preserved. Descriptive anatomical. An anatomical and radiological study was performed to evaluate the consistency of the landmark, denominated "M" line. Dissections were performed in 57 cadaver heads (114 sides). In addition, 73 computerised tomography (CT) scans (146 sides) of patients with chronic inflammatory sinonasal disease were analysed using a three-dimensional (3D) reconstruction computer program. The "M" line crossed the MSNO in 112 dissected sides (98.2%) and 140 sides at CT 3D reconstruction (95.9%). The "M" line is a reliable anatomical landmark for predicting MSNO location. As such, it could improve and facilitate endoscopic sinus surgery, using traditional, minimally invasive or uncinate preserving techniques.

The early history and development of functional endoscopic sinus surgery.

The concept of endoscopic diagnosis and procedures on the nasal cavity had been investigated for several decades in Europe in the early part of the twentieth century. It was Prof Walter Messerklinger and his assistant, Heinz Stammberger, with US colleague, David Kennedy, who brought the science and technique of functional endoscopic sinus surgery to the wider world. The author, an English-speaking surgeon, was present at this movement from the commencement of its propagation, and has recorded the remarkable ascendency of this technique throughout the world. The technique revolutionised the diagnosis and management of intranasal, sinus and intracranial conditions.

Survey of anesthesiologists on anesthetic maintenance techniques and total intravenous anesthesia for endoscopic sinus surgery.

Inhalational anesthesia and total intravenous anesthesia (TIVA) are techniques used for maintenance of general anesthesia for endoscopic sinus surgery (ESS). Growing evidence exists that TIVA may be associated with decreased bleeding and improved surgical fields, yet data suggest it is used in a minority of sinus surgery cases. The objective of this study was to investigate perceptions and approaches to anesthetic maintenance techniques in ESS among anesthesia providers. A total of 719 anesthesiology residents, faculty, and certified registered nurse anesthetists (CRNAs) at 3 tertiary academic centers in the United States were invited to participate in a survey of considerations and practice patterns for inhalational anesthesia and TIVA for ESS. Responses were received from 200 participants (28%). Sixty-five percent of respondents reported a lack of familiarity with current literature on TIVA for ESS. Many considered factors other than surgical field visualization when choosing a maintenance technique. Most were comfortable with performing TIVA but stated they would participate in additional training. The majority of anesthesiology providers were unaware of the existing literature demonstrating advantage in improved surgical visualization with TIVA. Many used a combination of inhaled and intravenous anesthetics for maintenance. These findings suggest that future opportunities may exist to develop education, training, and practice approaches specific to anesthetic techniques for ESS.

Simultaneous endoscopic endonasal sinus surgery and sinus augmentation with immediate implant placement: A retrospective clinical study of 23 patients

ObjectiveThe aim of this study was to evaluate the efficacy of simultaneous endoscopic endonasal sinus surgery and sinus augmentation with immediate implant placement. Patients and methodsThe study patients (n = 23) were partially or completely edentulous in the posterior maxilla and required maxillary sinus augmentation. All included patients had a sinus pathology confirmed clinically and radiographically. The technique of simultaneous endoscopic endonasal sinus surgery and sinus augmentation was used in 15 patients, with eight endonasal sinus surgery procedures being performed 2–3 months before sinus augmentation. Where possible, implants were placed during the same surgical procedure (with a ridge bone height of at least 4 mm). ResultsThere were no any major intraoperative complications. Implants placed in the reconstructed areas were shown to integrate normally, and postoperative occlusal function and aesthetics were favorable. Of the 95 implants placed in these 23 patients, two failed to osseointegrate. ConclusionThe method of simultaneous endoscopic endonasal sinus surgery and sinus augmentation with immediate implant placement leads to a reduction in postoperative complications, significantly shortening the rehabilitation period for patients with maxillary sinus diseases and insufficient bone tissue.

Optimization of the Surgical Field in Endoscopic Sinus Surgery: an Evidence-Based Approach.

The advent of endoscopic sinus surgery (ESS) has enabled the development of minimally invasive surgical procedures in Rhinology. However, proficiency with ESS techniques can still be hampered by poorly controlled bleeding limiting visibility of the surgical field (VSF). This can lead to increased operating time and, more importantly, increased risk of major and minor complications. To optimize the VSF and mitigate the risk of complications, many strategies have been explored. This is a narrative review of the relative risks and benefits of pre- and intra-operative interventions aimed at optimizing intraoperative conditions during ESS. The value of these interventions is determined based on their impact on intraoperative blood loss, time of surgery, and the VSF, and weighed against their adverse event profile. This review provides a comprehensive overview of the evidence relating to the safety and efficacy of interventions used to improve intraoperative conditions during ESS.

The Validity of Training Endoscopic Sinus and Skull Base Surgery Techniques on the Experimental Head Model.

The aim of this study was to better understand the usual learning curve in acquiring endonasal endoscopic sinus and skull base surgery (ESSBS) techniques during the novice training on the lamb's head model. Ten novices were asked to perform 10 bilateral dissections on the particular lamb's head each. The dissections were uniform, consisted of 10 well-defined steps, beginning from the simple removal of the inferior turbinate, and ending with more complicated procedures like cerebrospinal fluid leak repair, Draf 3 procedure for the frontal sinus and elevation of the nasal septal flap. The dissections have been supervised by experienced surgeons. A set of standard ESSBS instruments and 0° and 45° endoscopes have been used under the navigational system. The time required to complete each step has been measured in minutes. In general and quite expectedly, time rates have been obviously lowering as the number of the dissections performed has been growing in each of the participants. Training of the endonasal ESSBS techniques on the lamb's head proved to be useful for novices in getting basic surgical skills in the field. Because of the high degree of anatomic similarity and high level of the anatomic dimensions congruency between the lamb's head and human head (sheep's head has bigger dimensions!) it proved to be an essential preparation for the human cadaveric dissection. The median values of the time rates having been needed to complete the particular of the 10 steps in the last novices' dissections could be accepted as an orientation, just suggesting that once the time needed to complete 1 of the 10 steps has been and achieved by the particular novice, this could be an approximate sign of the maturity for the exercises on human cadaver head.

Evolving trends in sinus surgery: What is the impact of balloon sinus dilation?

Balloon dilation (BD) represents a minimally invasive alternative to endoscopic sinus surgery (ESS). Although BD was introduced in 2006, distinct Current Procedural Terminology (CPT) codes were not available until 2011, making prior analysis of population-based trends difficult. Our objectives were to evaluate these trends and compare any changes to the use of traditional ESS techniques. Geographic trends also were evaluated. Medicare Part B national datasets encompassing procedures from 2011 to 2015 were obtained. ESS CPT codes (frontal sinusotomy, maxillary antrostomy with/without tissue removal, sphenoidotomy) and BD codes were searched to determine temporal trends in their use. Additionally, state carriers were individually evaluated for geographic trends. National use of BD increased greater than five-fold (39,193 from 7,496 among Medicare patients), whereas the use of ESS increased by only 5.9%. This increase in BD was observed across all sites, including the sphenoid (7.0x), maxillary (5.1x), and frontal (4.7x) sinuses. In the most recent year for which data was available (2015), a significantly greater portion of sinus procedures in these sites utilized BD in the South (42.1%) compared to the Northeast (30.6%), West (29.5%), and Midwest (25.3%) regions (P < 0.0001). The performance of BD has increased markedly in recent years. Because the use of ESS codes remain stable, observed BD trends are unlikely to be due simply to greater familiarity with newer CPT coding. The reasons for the striking increase in BD popularity are speculative and beyond the scope of this analysis, but further study may be needed. NA. Laryngoscope, 128:1299-1303, 2018.

Fabrication and validation of a low-cost, medium-fidelity silicone injection molded endoscopic sinus surgery simulation model

Develop a low-cost, medium-fidelity model for education in endoscopic sinus surgery techniques. Establish face and content validity of the model based on the feedback of otolaryngology faculty including fellowship-trained rhinologists. Survey. A novel silicone injection molded sinus model was constructed. Three fellowship-trained rhinologists and four general otolaryngologists were recruited to perform seven tasks and provide feedback of the model's performance via a 22-question Likert survey. Those surveyed strongly agreed the sinus model is useful for basic endoscopic skill acquisition such as camera skills (86%), hand-eye coordination (100%), nasal endoscopy skills (100%). Ratings of the model for training the specific tasks were consistently high. Neutral or lower were received for inferior turbinoplasty (14%), frontal balloon task (14%), understanding the ethmoid bulla (29%), and advanced sinus techniques (57%). All faculty strongly agreed they would be interested in using the model to train residents. Simulation models have proven efficacy in endoscopic skill and procedural training. The group developed a novel low-cost, medium-fidelity sinus training model utilizing three-dimensional modeling and printing. Testing of this model revealed high ratings for both face and construct validity for a range of endoscopic procedures. Strong interest in using this model for resident training was unanimous among all survey participants. NA Laryngoscope, 127:781-786, 2017.

Defining appropriateness criteria for endoscopic sinus surgery during management of uncomplicated adult chronic rhinosinusitis: a RAND/UCLA appropriateness study.

Appropriate indications for endoscopic sinus surgery (ESS) for chronic rhinosinusitis (CRS) are currently poorly defined. The lack of clear surgical indications for ESS likely contributes to the large geographic variation in surgical rates and contributes to reduced quality of care. The objective of this study was to define appropriateness criteria for ESS during management of adult patients with uncomplicated CRS. The RAND/UCLA appropriateness methodology was performed. An international, multi-disciplinary panel of 10 experts in CRS was formed and completed two rounds of a modified Delphi ranking process along with a face-to-face meeting. A total of 624 clinical scenarios were ranked, 312 scenarios each for CRS with and CRS without nasal polyps. For adult patients with uncomplicated CRS with nasal polyps, ESS can be appropriately offered when the CT Lund-Mackay score is ≥ 1 and there has been a minimum trial of a topical intranasal corticosteroid plus a short-course of systemic corticosteroid with a post-treatment total SNOT-22 score ≥ 20. For adult patients with uncomplicated CRS without nasal polyps, ESS can be appropriately offered when the CT Lund-Mackay score is ≥ 1 and there has been a minimum trial of a topical intranasal corticosteroid plus either a short-course of a broad spectrum/culture-directed systemic antibiotic or the use of a prolonged course of systemic low-dose anti-inflammatory antibiotic with a post-treatment total SNOT-22 score ≥ 20. This study has developed and reported of list of appropriateness criteria to offer ESS as a treatment option during management of uncomplicated adult CRS. The extent or technique of ESS was not addressed in this study and will depend on surgeon and patient factors. Furthermore, these criteria are the minimal threshold to make ESS a treatment option and do not imply that all patients meeting these criteria require surgery. The decision to perform ESS should be made after an informed patient makes a preference-sensitive decision to proceed with surgery. Applying these appropriateness criteria for ESS may optimize patient selection, reduce the incidence of unwarranted surgery, and assist clinicians in providing high quality, patient-centered care to patients with CRS.

Face, content, and construct validation of a low-cost, non-biologic, sinus surgery task trainer and knowledge-based curriculum.

The purpose of this study was to evaluate face and content validity of a low-cost, low-technology, non-biologic endoscopic sinus surgery (ESS) task trainer and knowledge-based curriculum followed by construct validation of the task trainer. A sinus surgery task trainer and curriculum were developed. Attending otolaryngologists were surveyed regarding the utility of the task trainer and curriculum. A cross-sectional construct validation study was performed including medical students, residents, and attending otolaryngologists. Nine tasks were performed on the task trainer and graded using a global rating scale (GRS). Predictors of task trainer performance were evaluated, and spatial performance was measured. Regression analyses were performed to assess main associations. All attending physicians (n = 7) agreed that the task trainer accelerates the learning curve and incorporates essential ESS techniques and that the knowledge-based curriculum describes anatomical and technical knowledge germane to ESS. Twelve medical students, 9 otolaryngology residents, and 5 attending otolaryngologists completed task trainer testing. GRS score varied by level of training after adjusting for potential confounders (slope = 2.63; p = 0.001). There was evidence of an association between a history of video gaming (slope = 1.33; p = 0.077), sports experience (slope = 2.08; p = 0.033), and sinus surgery simulation (slope = 2.72; p = 0.023) with GRS score, although not statistically significant. This study demonstrated validity of a knowledge-based sinus surgery curriculum and low-cost, sinus task trainer supporting use in early training. Participants with prior video gaming, sports participation, and sinus surgery simulation experience perform better at baseline on the task trainer.

Surgical Treatment of Oroantral Communications.

Oroantral communication (OAC) can be defined as a pathologic space created between the maxillary sinus and the oral cavity.This communication and subsequent formation of a chronic oroantral fistula is a common complication often encountered by oral and maxillofacial surgeons.Although various techniques have been proposed in published studies, long-term successful closure of oroantral fistulas is still one of the most difficult problems confronting the surgeon working in the oral and maxillofacial region.The decision of which treatment modality to use is influenced by many factors, such as the amount and condition of tissue available for repair, the size and location of the defect, the presence of infection, the time to the diagnosis of the fistula. To evaluate an alternative technique for the treatment of oro-antral fistula, using a combined therapeutic ear nose and throat/intraoral approach. Twelve consecutive patients affected by complicated OAC were included in this study.The protocol consisted of: clinical, endoscopic, and radiological preoperative evaluation (panoramic tomogram and computed tomography); systemic antibiotic and steroid therapy for 2 weeks before surgery; one-stage surgical procedure consisting of Functional Endoscopic Sinus Surgery technique associated with the closure of the OAC by a titanium mesh and a mucoperiosteal flap; postoperative antibiotic and cortisone-based therapy.A titanium mesh was used to obtain an optimal support and stabilization of soft tissues.Follow-up consisted of weekly clinical evaluation during the first month, a clinical evaluation at 1, 3, 6, 12, 24 months and a nasal endoscopy at 3, 8, 24 weeks after surgery. A second surgical step took place to remove the mesh, after a period of healing, which went from 6 to 18 months. Samples were harvested from the surgical site after mesh removal for histological analysis. At 1 month follow-up, in 10 patients of 12, the Valsalva manoeuvre was negative, same result at the 3rd month follow-up, although in 11 of 12 patients. In 5 of 12 patients, the mesh was exposed. The histological analysis confirmed the formation of a pseudo-periosteum layer.One patient failed because the mesh lost its stability. The patient was operated again 8 months later and new mesh was fixed into place. The current study showed that one-stage, combined endoscopic and intraoral approach represents a feasible and minimally invasive procedure for the long-term effective treatment of chronic complicated OACs.The main advantage of the use of a titanium mesh to guide the regeneration is that it assures a predictable healing, mechanic scaffold, tissues stability and allows a possible following oral rehabilitation.

Defining appropriateness criteria for endoscopic sinus surgery during management of uncomplicated adult chronic rhinosinusitis: a RAND/UCLA appropriateness study.

Appropriate indications for endoscopic sinus surgery (ESS) for chronic rhinosinusitis (CRS) are currently poorly defined. The lack of clear surgical indications for ESS likely contributes to the large geographic variation in surgical rates and contributes to reduced quality of care. The objective of this study was to define appropriateness criteria for ESS during management of adult patients with uncomplicated CRS. The RAND/UCLA appropriateness methodology was performed. An international, multi-disciplinary panel of 10 experts in CRS was formed and completed two rounds of a modified Delphi ranking process along with a face-to-face meeting. A total of 624 clinical scenarios were ranked, 312 scenarios each for CRS with and CRS without nasal polyps. For adult patients with uncomplicated CRS with nasal polyps, ESS can be appropriately offered when the CT Lund-Mackay score is ≥ 1 and there has been a minimum trial of a topical intranasal corticosteroid plus a short-course of systemic corticosteroid with a post-treatment total SNOT-22 score ≥ 20. For adult patients with uncomplicated CRS without nasal polyps, ESS can be appropriately offered when the CT Lund-Mackay score is ≥ 1 and there has been a minimum trial of a topical intranasal corticosteroid plus either a short-course of a broad spectrum/culture-directed systemic antibiotic or the use of a prolonged course of systemic low-dose anti-inflammatory antibiotic with a post-treatment total SNOT-22 score ≥ 20. This study has developed and reported of list of appropriateness criteria to offer ESS as a treatment option during management of uncomplicated adult CRS. The extent or technique of ESS was not addressed in this study and will depend on surgeon and patient factors. Furthermore, these criteria are the minimal threshold to make ESS a treatment option and do not imply that all patients meeting these criteria require surgery. The decision to perform ESS should be made after an informed patient makes a preference-sensitive decision to proceed with surgery. Applying these appropriateness criteria for ESS may optimize patient selection, reduce the incidence of unwarranted surgery, and assist clinicians in providing high quality, patient-centered care to patients with CRS.