Moving Forward with Dysphagia Care: Implementing Strategies during the COVID-19 Pandemic and Beyond.

Growing numbers of SARS-CoV-2 cases coupled with limited understanding of transmissibility and virulence, have challenged the current workflow and clinical care pathways for the dysphagia provider. At the same time, the need for non-COVID-19-related dysphagia care persists. Increased awareness of asymptomatic virus carriers and variable expression of the disease have also focused attention to appropriate patient care in the context of protection for the healthcare workforce. The objective of this review was to create a clinical algorithm and reference for dysphagia clinicians across clinical settings to minimize spread of COVID-19 cases while providing optimal care to patients suffering from swallowing disorders. Every practitioner and healthcare system will likely have different constraints or preferences leading to the utilization of one technique over another. Knowledge about this pandemic increases every day, but the algorithms provided here will help in considering the best options for proceeding with safe and effective dysphagia care in this new era.

Implementation of an interdisciplinary tracheostomy care protocol to decrease rates of tracheostomy-related pressure ulcers and injuries.

OBJECTIVES: Tracheostomy-related pressure injuries (TRPI) have been demonstrated to occur in approximately 10% of tracheostomy patients. In this study, we present TRPI outcomes after implementation of a standardized tracheostomy care protocol. METHODS: A tracheostomy care protocol was developed by an interdisciplinary quality improvement program and implemented on July 1, 2016. The protocol was designed to minimize factors that contribute to the development of TRPI. Rates of TRPI over the subsequent 20 months were compared to the year before implementation. RESULTS: 9 out of 85 patients (10.6%) developed TRPI in the pre-protocol cohort compared to 0 of 137 (0%) in the post-protocol cohort, which was a statistically significant decrease by Fisher's exact test with a p-value of 0.0001. Pearson's correlation coefficient demonstrated a negative correlation between age and post-operative day of diagnosis (r = -0.641, p = 0.063), indicating that older patients develop TRPI more quickly. CONCLUSIONS: Interdisciplinary peri-operative tracheostomy care protocols can be effective in decreasing rates of TRPI.

Airway Complications Following Vocal Fold Injection Augmentation: A Case Series and Review of Literature.

OBJECTIVE: This case series seeks to describe three specific airway complications following vocal fold injection augmentation procedures, involving carboxymethylcellulose gel. The literature review focused on adverse events linked to carboxymethylcellulose within the field of otolaryngology as well as beyond. STUDY DESIGN: Case series. METHODS: This series reviews the management of three patients who suffered severe airway complications following vocal fold injection augmentations from December 2020 to August 2021 RESULTS: All three of these patients received the RENÚ brand carboxymethylcellulose injection material. All three patients developed respiratory distress and stridor shortly following the injections, two before leaving the operating room and the third in the postanesthesia care unit. Both patients re-intubated in the operating room were found to have supraglottic edema upon direct laryngoscopy. All three patients required prompt re-intubation, and one patient required a temporary tracheostomy. None of these three patients were known to have a history of angioedema or anaphylaxis. CONCLUSIONS: Vocal fold injection augmentation has long been considered a safe and effective means to improve glottic closure and treat dysphonia in patients with anatomic deficiencies of the vocal folds. While the listed ingredients are consistent between Prolaryn (Merz Pharmaceuticals, Raleigh, NC) and RENÚ (Inhealth Technologies, Carpinteria CA), studies directly comparing the two materials have only been performed in animals. This case series recognizes an important cluster of complications worth further study and postmarket surveillance.

Airway Management in Singers: A Cross-sectional Survey.

OBJECTIVE: To review and establish current practices regarding airway management in vocal professionals undergoing surgery. STUDY DESIGN: Cross-sectional survey SETTING: The setting included practitioners that treat vocal professionals across international sub-specialty societies. SUBJECTS AND METHODS: A twenty-one-item survey was sent to practitioners that routinely treat vocal professionals including the American Broncho-Esophagological Association, European Laryngological Society, and 2017 Fall Voice Conference attendees. It included questions regarding the respondents' demographics, preferences for airway control in non-laryngeal and laryngeal surgery, and peri-operative management. RESULTS: Total respondents (n = 163): 82.8% were Laryngologists, 4.3 % were General Otolaryngologists, 3.1% were Head & Neck Oncologists, and 6.8% were Speech-Language Pathologists. One hundred twenty-five of the participants (76.7%) classified their experience with vocal professionals as 'extensive' or 'often.' For non-laryngeal surgery, there was a tendency towards laryngeal mask airway (53.1%) over endotracheal intubation (46.9%). For professional singers, a smaller endotracheal tube was recommended. Size varied based on sex. For males, 88.5% recommended a tube ≤7.0 in non-singers; 98.2% recommended a tube ≤7.0 in singers. In females 76.1% recommended a tube ≤6.0 for non-singers; 94.6 % recommended a size ≤6.0 in a female singer. For laryngeal surgery, 14% of providers personally intubated patients over 90% of the time. Of the providers who work with trainees, 60.5% did not allow resident intubation. CONCLUSION: Objective data regarding precautions in airway management of professional voice users is scarce. This is the largest survey to date on current practices. Survey results indicate that smaller ETTs are preferred for singers, and that more experienced practitioners are preferred for the intubation.

Risk factors for developing subglottic and tracheal stenosis from the medical intensive care unit.

Objective: Endotracheal intubation is a common procedure in the medical intensive care unit (MICU), but it carries risk of complications including, but not limited to, subglottic stenosis (SGS) and tracheal stenosis (TS). Current literature suggests identifiable risk factors for the development of airway complications. This study is a comprehensive evaluation of potential risk factors in patients who developed SGS and TS following endotracheal intubation in our MICU. Methods: Patients intubated in our MICU were identified from 2013 to 2019. Diagnoses of SGS or TS within 1 year of MICU admission were identified. Data extracted included age, sex, body measurements, comorbidities, bronchoscopies, endotracheal tube size, tracheostomy, social history, and medications. Patients with prior diagnosis of airway complication, tracheostomy, or head and neck cancer were excluded. Univariate and multivariate logistic regressions were performed. Results: A total of 136 patients with TS or SGS were identified out of a sample of 6603 patients intubated in the MICU. Cases were matched to controls who did not develop airway stenosis based on identical Charlson Comorbidity Index scores. Eighty six controls were identified with a complete record of endotracheal/tracheostomy tube size, airway procedures, sociodemographic data, and medical diagnosis. Regression analysis showed that SGS or TS were associated with tracheostomy, bronchoscopy, chronic obstructive pulmonary disease, current tobacco use, gastroesophageal reflux disease, systemic lupus erythematosus, pneumonia, bronchitis, and numerous medication classes. Conclusion: Various conditions, procedures, and medications are associated with an increased risk of developing SGS or TS. Level of evidence: 4.

Low Pressure Low Frequency Jet Ventilation: Techniques, Safety and Complications.

OBJECTIVE: Manual jet ventilation is a specialized oxygenation and ventilation technique that is not available in all facilities due to lack of technical familiarity and fear of complications. The objective is to review our center's 15 year experience with low pressure low frequency jet ventilation (LPLFJV). METHODS: Retrospective review of procedures utilizing LPLFJV from 2005 to 2019 were performed collecting patient demographic, surgery type and complications. Fisher exact test, Chi square, and t-test were used to determine statistical significance. RESULTS: Four hundred fifty-seven patients underwent a total of 891 microlaryngeal surgeries-279 cases for voice disorders, 179 for lesions, and 433 for airway stenosis. The peak jet pressure for all cases did not exceed 20 psi and average peak pressure for the last 100 procedures in this case series was 14.9 ± 4.6 psi. The average lowest oxygen saturation for all cases was 95% ± 0.6%. Brief intubation was required in 154 cases (17%). Surgical duration was significantly longer for cases requiring intubation P < .001. The need for intubation was not associated with smoking or cardiopulmonary disease, but was strongly associated with body mass index (BMI). Intubation rates were 7% for normal weight (BMI < 25, N = 216), 13% for overweight (BMI 25-30, N = 282), 24% for obese (BMI 30-40, N = 342), and 37% for morbidly obese (BMI > 40, N = 52) patients. Three patients developed respiratory distress in the recovery unit and 2 patients required intubation. CONCLUSION: LPLFJV assisted by intermittent endotracheal intubation is an exceedingly safe and effective intraoperative oxygenation and ventilationmodality for a broad variety of laryngeal procedure.

Healthcare disparities for the development of airway stenosis from the medical intensive care unit.

Objectives/hypothesis: To identify sociodemographic factors associated with the development of airway stenosis (AS) among intubated medical intensive care unit (MICU) patients. Study design: Retrospective cohort study. Methods: A retrospective review of adult MICU intubated patients from 2013 to 2019 at a single academic institution was performed. Univariate and multivariate analysis with logistic regression examined associations between the development of AS and subsite abnormalities such as posterior glottic stenosis (PGS), subglottic stenosis (SGS), tracheal stenosis (TS), vocal fold immobility (VFI), and posterior glottic granuloma (PGG) with age, body mass index (BMI), height, weight, race, ethnicity, sex, rurality, Appalachian status, length of admission, distance to hospital, and median household income. Results: Of an overall sample of 6603 MICU patients, 449 intubated patients were included in the study, and 204 patients were found to have AS. AS was statistically associated with decreased driving distance to the hospital and increases in BMI. PGS was statistically associated with increases in age. TS was statistically associated with increases in admission duration and not having residence status in Appalachia. VFI was statistically associated with decreases in driving distance to the hospital and not having residence status in Appalachia. Additionally, black patients had a higher odds of developing VFI compared to Caucasian patients. Conclusion: AS is associated with sociodemographic factors such as age, BMI, shorter distance to hospital, admission duration, and no Appalachian status. These data demonstrate the need to further investigate the impact of social determinants of health on airway pathology and outcomes. Level of evidence: 4.

National Database Outcomes of Esophageal Dilations.

OBJECTIVES/HYPOTHESIS: To better assess rates of postoperative complications and mortality following esophageal dilation, and to identify factors associated with adverse outcomes. STUDY DESIGN: Observational, retrospective cohort study. METHODS: We queried a national database of insurance claims for Current Procedural Terminology (CPT) codes representing esophageal dilation performed between 2011 and 2017. Patients aged 18 to 100 who were continuously enrolled with their insurance provider were included. Demographic information, additional CPT codes, concomitant diagnoses, and anticoagulant medication data were collected for all patients included. Postoperative mortality was assessed and International Classification of Diseases (ICD)9/10 codes for complications, including esophageal perforation, hemorrhage, mediastinitis, and sepsis were flagged. RESULTS: We identified 202,965 encounters for esophageal dilation. Of these procedures, 193 were performed on a patient who underwent percutaneous endoscopic gastrostomy (PEG) during the study period and was analyzed separately. Another 244 dilations were excluded due to repeat entries. Of the remaining 202,528 procedures remaining, 42,310 were repeat dilations in the same patient. Data analysis was confined to each patient's initial dilation. 160,218 initial dilations remained. Of these, 62,107 were performed on male patients and 98,111 were performed on female patients. The average age was 57.7 years. There were 12 mortalities within 30 days postoperatively, representing 0.0075% of all dilations. Esophageal perforation and esophageal hemorrhage were the most common reported complications, with 139 and 110 occurrences, respectively. The overall per-dilation complication rate was 0.215%. CONCLUSIONS: Evidence from a national insurance claim database suggests that esophageal dilation is a safe procedure with a low rate of serious complications and a 30-day all-cause mortality rate of less than 1 per 10,000 dilations. LEVEL OF EVIDENCE: 4 Laryngoscope, 131:2436-2440, 2021.

Thick Silicon Double-Sided Strip Detectors for Low-Energy Small-Animal SPECT.

This work presents characterization studies of thick silicon double-sided strip detectors for a high-resolution small-animal SPECT. The dimension of these detectors is 60.4 mm × 60.4 mm × 1 mm. There are 1024 strips on each side that give the coordinates of the photon interaction, with each strip processed by a separate ASIC channel. Our measurement shows that intrinsic spatial resolution equivalent to the 59 µm strip pitch is attainable. Good trigger uniformity can be achieved by proper setting of a 4-bit DAC in each ASIC channel to remove trigger threshold variations. This is particularly important for triggering at low energies. The thick silicon DSSD (Double-sided strip detector) shows high potential for small-animal SPECT.

Cost Analysis of Channeled, Distal Chip Laryngoscope for In-office Laryngopharyngeal Biopsies.

OBJECTIVE: Given that financial considerations play an increasingly prominent role in clinical decision-making, we sought (1) to determine the cost-effectiveness of in-office biopsy for the patient, the provider, and the health-care system, and (2) to determine the diagnostic accuracy of in-office biopsy. STUDY DESIGN: Retrospective, financial analyses were performed. METHODS: Patients who underwent in-office (Current Procedural Terminology Code 31576) or operative biopsy (CPT Code 31535) for laryngopharyngeal lesions were included. Two financial analyses were performed: (1) the average cost of operating room (OR) versus in-office biopsy was calculated, and (2) a break-even analysis was calculated to determine the cost-effectiveness of in-office biopsy for the provider. In addition, the diagnostic accuracy of in-office biopsies and need for additional biopsies or procedures was recorded. RESULTS: Of the 48 patients included in the current study, 28 underwent in-office biopsy. A pathologic sample was obtained in 26 of 28 (92.9%) biopsies performed in the office. Of these patients, 16 avoided subsequent OR procedures. The average per patient cost was $7000 and $11,000 for in-office and OR biopsy, respectively. Break-even analysis demonstrated that the provider could achieve a profit 2 years after purchase of the necessary equipment. CONCLUSION: In-office laryngopharyngeal biopsies are accurate and, overall, more cost-effective than OR biopsies. Purchase of the channeled, distal chip laryngoscope and biopsy forceps to perform in-office biopsies can be profitable for a provider with a videolaryngoscopy tower. In-office biopsy should be considered the initial diagnostic tool for suspected laryngopharyngeal malignancies noted on videolaryngoscopy.

Impact of vocal fold augmentation and laryngoplasty on dyspnea in patients with glottal incompetence.

OBJECTIVES/HYPOTHESIS: Given that the vocal folds are active organs of respiration, reports of dyspnea in the context of glottic insufficiency are not uncommon. We hypothesize that improved glottal closure via framework surgery or vocal fold augmentation improves dyspnea symptoms. STUDY DESIGN: Retrospective review. METHODS: Charts of patients undergoing procedures to correct glottal insufficiency, either via vocal fold augmentation (VFA) or medialization laryngoplasty (ML) between December 2012 and September 2015 were reviewed (n = 189). Modified Borg Dyspnea Scale (MBDS) and Modified Medical Research Council Dyspnea Scale (MMRCDS) data were collected before and after intervention. Age, body mass index (BMI), and sex, as well as pulmonary and cardiac comorbidities were considered. Subgroup analysis was performed on individuals with subjective dyspnea prior to intervention. RESULTS: For the entire cohort, differences in the MMRCDS and MBDS were not statistically different pre- and postintervention (P = .20 and P = .12, respectively). Patients with BMI <30 experienced more improvement on the MBDS (P = .03). Both the MMRCDS and MMBDS improved post-procedure (P = .001 and P = .001, respectively) in patients reporting dyspnea prior to intervention. CONCLUSIONS: Patients with glottic insufficiency and dyspnea prior to intervention to improve glottic closure had a significant reduction in dyspnea following treatment. Conversely, subjects without complaints of dyspnea prior to intervention had variable outcomes with regard to dyspnea symptoms. Additionally, based on data from the entire cohort, VFA or ML did not worsen dyspnea symptoms. These data may assist in counseling and/or selection of patients considered for procedures to improve glottic closure. LEVEL OF EVIDENCE: 4. Laryngoscope, 128:427-429, 2018.

Prevalence of Voice Disturbances in the Pediatric Craniofacial Patient Population.

OBJECTIVE: To report on the prevalence of voice disturbances in the pediatric craniofacial population and to prove that the pediatric Voice Handicap Index (pVHI) is a useful questionnaire for this unique population. STUDY DESIGN: Case series with chart review. SETTING: Tertiary care center. SUBJECTS: Pediatric patients seen by a pediatric otolaryngologist in a craniofacial clinic. METHODS: Consecutive patients (N = 366) seen by a single pediatric otolaryngologist in a craniofacial clinic from July 2011 to September 2012 were included. Any patient specifically referred for airway problems or voice difficulties completed a pVHI questionnaire. Patients each underwent an evaluation including flexible fiberoptic laryngoscopy and videostroboscopy. Voice disturbance was further characterized into dysphonia, hypernasality, or hyponasality. RESULTS: Of all the patients evaluated, 280 (77%) were specifically referred for airway problems or voice disturbance. Of those referred, 39 (10.7%) were found to have an organic vocal fold pathology causing dysphonia, as seen on the videostroboscopic examination; 53.7% of these lesions were attributable to potential iatrogenic causes. Hypernasality and hyponasality were seen in 116 (31.7%) and 78 (21.3%) patients, respectively. The pVHI was 3.95, 26.3, 11.34, and 10.53 for those with no voice disturbance, dysphonia, hypernasality, and hyponasality, respectively. CONCLUSION: Pediatric patients with craniofacial disorders have a higher prevalence of dysphonia than the general pediatric population. The majority of causes of dysphonia in these patients are possibly iatrogenic in origin. The pVHI serves as a useful questionnaire in this unique patient cohort to quantify the disability from not only dysphonia but also hypernasality and hyponasality.

The Accuracy of the Laryngopharyngeal Reflux Diagnosis: Utility of the Stroboscopic Exam.

OBJECTIVE: To determine the prevalence and also accuracy of the laryngopharyngeal reflux (LPR) referring diagnosis and to determine the most useful clinical tool in arriving at the final diagnosis in a tertiary laryngology practice. STUDY DESIGN: Case series with planned data collection. SETTING: Six tertiary academic laryngology practices. SUBJECTS AND METHODS: We collected referring diagnosis and demographic information, including age, sex, ethnicity, referring physician, and whether or not patients had prior flexible laryngoscopy for 1077 patients presenting with laryngologic complaints from January 2010 and June 2013. Final diagnosis after the referred laryngologist's examination and the key diagnostic test used was then recorded. RESULTS: Of 1077 patients, 132 had a singular referring diagnosis of LPR. Only 47 of 132 patients (35.6%) had LPR confirmed on final primary diagnosis. Transnasal flexible laryngoscopy confirmed this in 27 of 47 (57.4%) patients. Eighty-five of 132 (64.4%) had a different final diagnosis than LPR. Sixty-five of 85 (76.5%) of these alternative pathologies were diagnosed with the aid of laryngeal stroboscopy. CONCLUSIONS: LPR appears to be an overused diagnosis for laryngologic complaints. For patients who have already had transnasal flexible laryngoscopic exams prior to their referral, laryngeal stroboscopy is the key diagnostic tool in arriving at the correct diagnosis.

Management of airway compromise following thyroid cyst hemorrhage after thrombolytic therapy.

The risk of hemorrhage after therapeutic administration of tissue plasminogen activator (tPA) is well known. Cases of postadministration hemorrhage have been reported within many organ systems. We present a case of a 62-year-old female with undiagnosed thyroid goiter who received tPA for acute ischemic stroke and developed acute airway compromise. The surgical airway response team was called due to inability to ventilate or intubate. An incision into the mass during attempted tracheotomy released colloid and blood, decompressing the airway and facilitating ventilation and intubation. Hemithyroidectomy for mass removal was delayed for 3 days to allow normalization of post-tPA coagulopathy.

The Safety of Antithrombotic Therapy During In-office Laryngeal Procedures-A Preliminary Study.

INTRODUCTION: In-office laryngeal procedures present an alternative to the risks and costs associated with general anesthesia. However, the inherent control afforded by the operative theater is decreased potentially increasing the risk of complications. Many patients undergoing these procedures have traditional surgical risk factors, such as antithrombotic (AT) medical therapy. We sought to quantify complication rates for in-office procedures as a function of AT therapy. METHODS: A retrospective review of 127 diverse, in-office laryngeal procedures was performed and patients were then stratified based on AT medication status and type of procedure. The primary dependent variables were intraoperative and postoperative complications. Additionally, in those patients undergoing procedures with the goal of voice improvement, Voice Handicap Index (VHI)-10 scores were used to quantify the success of the procedure as a function of AT therapy. RESULTS: Of the 127 procedures, 27 procedures (21.2%) involved patients on some form of AT agent that was not ceased for the procedure. Across all patients, no intraoperative complications were encountered, irrespective of therapeutic status. Three postoperative complications were noted; all in patients not on AT therapy. A statistically significant improvement in VHI-10 scores was noted across all patients, irrespective of AT status. CONCLUSIONS: AT medications do not appear to increase the risk of complications associated with in-office laryngeal procedures. Furthermore, AT therapy seemed to have no negative impact on the voice outcomes of patients undergoing procedures for voice improvement.

Antiplatelet and anticoagulation therapy in microlaryngeal surgery.

OBJECTIVES/HYPOTHESIS: Indications for antiplatelet and anticoagulation use are expanding. There is no evidence to direct therapeutic management in patients undergoing microlaryngeal surgeries. Our aim was to compare bleeding complications between microlaryngeal surgeries performed for patients preoperatively taken off and maintained on antiplatelet and/or anticoagulation therapy. STUDY DESIGN: Retrospective cohort study. METHODS: Patients undergoing microlaryngeal surgeries (2008-2009) on baseline antiplatelet and/or anticoagulation therapy were identified. Records were reviewed to determine whether therapy was stopped preoperatively. The primary outcome, bleeding complication, was compared between those taken off and maintained on therapy. Patient characteristics, surgical data, and outcomes were assessed. RESULTS: Of 287 microlaryngeal surgeries, 26% were performed for patients on antiplatelet (23%) and/or anticoagulation (3%) therapy. There was no difference in bleeding complications between patients' naïve to and on baseline antiplatelet or anticoagulation therapy [naïve: 3.8% vs. on: 5.3%, P = 0.58] and no thromboembolic events. Among surgeries performed for patients on baseline antiplatelet therapy, 35% preoperatively stopped therapy. No observed difference in bleeding complications was observed between those taken off or maintained on therapy [off: 8.0% vs. on: 4.9%, P = 0.63]. Of 3% of surgeries performed for patients on warfarin, no bleeding complications occurred, even among the 8/10 with therapeutic international normalized ratios. CONCLUSIONS: Perioperative management decisions regarding antiplatelet and anticoagulation therapy are becoming more common. Results suggest that antiplatelet therapy can be maintained during microlaryngeal surgery without increasing bleeding risk. Further prospective research is required to confirm findings and rigorously investigate the safety of continuing warfarin and other anticoagulation therapy in these surgeries. LEVEL OF EVIDENCE: 4.

Extracellular and intracellular melanin in inflammatory middle ear disease.

OBJECTIVES/HYPOTHESIS: Melanin is a pigmented polymer with a known role in dermal solar protection. In vertebrates, melanogenesis has been reported in leukocyte populations, suggesting a potential role in innate immunity. In this study, we report the novel finding of melanin associated with chronic inflammation and speculate on its potential role in the middle ear and mastoid. STUDY DESIGN: Retrospective review of case series. METHODS: Medical records of six patients who demonstrated melanin in the ear were reviewed. RESULTS: Six patients from 1 to 63 years of age were identified with extracellular melanin and melanin-laden histiocytes within the middle ear and/or mastoid air cells at time of surgery. Concurrent intraoperative findings included cholesteatoma (n = 3), chronic suppurative otitis media (n = 2), and coalescent mastoiditis (n = 1). Histologically, extracellular melanin and melanin-laden histiocytes were identified by Fontana-Masson stain; absence of melanocytes was confirmed by the absence of Melan-A staining. One patient had a positive stain for CD163 (a marker for macrophages). CONCLUSION: This case series is the first demonstration of melanin within middle ear mucosa without melanocytes in immediate proximity or metastatic melanocytic lesions. Melanin's presence in the setting of inflammation suggests that there may be a heretofore unreported link between the pigmentary and immune systems in the middle ear. LEVEL OF EVIDENCE: 4.

Clinical testing of an alternate method of inserting bone-implanted fiducial markers.

BACKGROUND: Deep brain stimulation (DBS) surgery utilizes image guidance via bone-implanted fiducial markers to achieve the desired submillimetric accuracy and to provide means for attaching microstereotactic frames. For maximal benefit, the markers must be inserted to the correct depth since over-insertion leads to stripping and under-insertion leads to instability. PURPOSE: The purpose of the study was to test clinically a depth-release drive system, the PosiSeat™, versus manual insertion (pilot hole followed by manual screwing until tactile determined correct seating) for implanting fiducial markers into the bone. METHODS: With institutional review board approval, the PosiSeat™ was used to implant markers in 15 DBS patients (57 fiducials). On post-insertion CT scans, the depth of the gap between the shoulder of the fiducial markers and the closest bone surface was measured. Similar depth measurements were performed on the CT scans of 64 DBS patients (250 fiducials), who underwent manual fiducial insertion. RESULTS: Median of shoulder-to-bone distance for PosiSeat™ and manual insertion group were 0.03 and 1.06 mm, respectively. Fifty percent of the fiducials had the shoulder-to-bone distances within 0.01-0.09 mm range for the PosiSeat group and 0.04-1.45 mm range for the manual insertion group. These differences were statistically significant. CONCLUSIONS: A depth-release drive system achieves more consistent placement of bone-implanted fiducial markers than manual insertion.