Facial Soft-tissue Mobility: Baseline Dynamics of Patients with Unilateral Facial Paralysis.

BACKGROUND: The aims of this observational study were 2-fold: (1) To demonstrate a method and measures to quantify impaired facial soft-tissue movements in patients with facial paralysis; and (2) To quantify the differences in magnitude and velocity of facial soft-tissue movements between patients with facial paralysis and control participants. METHODS: The study sample that addressed both aims consisted of 20 adults with acute, unilateral, flaccid facial paralysis who presented at the onset of their paralysis, and a control group of 20 healthy adults. Dynamic 3D facial movement data were collected from each participant during 11 facial animations. To compare the movements between the patients and control participants, dynamic modeling comparisons of mean facial movements were computed as well as plots of movement vectors for each animation, in addition, measures of maximum displacement, movement velocity, and asymmetry were computed. RESULTS: Dynamic 3D modeling of critical facial landmarks provided precise profiles of zone-specific asymmetries and customized reporting that highlighted areas of importance for individual patients. The dynamic 3D movement data confirmed that the nonparalyzed side of patients' faces had abnormal directional movements. As expected, the controls had significantly higher excursive facial movements during all animations except during gentle eye closure, which was greater for the patients and the controls had significantly greater movement velocity than the patients. The patients had significantly greater asymmetry for all the animations, and the hierarchy of the asymmetry was such that maximum smile > lip purse > grimace > cheek puff. CONCLUSION: Dynamic 3D modeling appeared to be an effective tool to provide precise profiles of zone-specific asymmetries and customized reports for patients with facial paralysis.

Quantifying Soft Tissue Shape and Symmetry: Patients with Cleft Lip/Palate and Facial Paralysis.

BACKGROUND: The objective of this study was to demonstrate simple three-dimensional analyses of facial soft tissue shape and asymmetry. METHODS: There were 2 study samples: one retrospective comprised patients with repaired cleft lip and palate (CL/P) and control subjects; and the other prospective comprised patients with unilateral facial paralysis (FP) and control subjects. The data collected were digitized three-dimensional facial landmarks. Scores for shape and asymmetry of subjects' faces and for different facial regions were generated using Procrustes methods. Pivotal bootstrap methods and analysis of variance were used to test for significant differences in the scores between the patients and controls, and plots of the scores were generated to compare differences among the subjects. RESULTS: (1) Shape scores: The CL/P patients demonstrated significant overall and regional facial differences (P ≤ 0.01). The patients were further from the control mean, especially those with unilateral CL/P. Patients with FP demonstrated significant differences (P ≤ 0.05) for the lower face only. (2) Asymmetry scores: CL/P and FP patients demonstrated significant overall and regional facial differences (CL/P, P ≤ 0.0001; FP, P ≤ 0.01). CL/P and FP patients were more asymmetric and were further from the control mean, and patients with unilateral CL/P were more asymmetric than the bilateral CL/P patients. CONCLUSION: Clinicians can use the analyses to isolate differences and/or changes in the face due to shape or asymmetry, or a combination of both; based on the score plots, the extent of the shape and asymmetry differences can be compared among subjects and the extent of changes due to surgery measured.

Worldwide Testing of the eFACE Facial Nerve Clinician-Graded Scale.

BACKGROUND: The electronic, clinician-graded facial function scale (eFACE) is a potentially useful tool for assessing facial function. Beneficial features include its digital nature, use of visual analogue scales, and provision of graphic outputs and scores. The authors introduced the instrument to experienced facial nerve clinicians for feedback, and examined the effect of viewing a video tutorial on score agreement. METHODS: Videos of 30 patients with facial palsy were embedded in an Apple eFACE application. Facial nerve clinicians were invited to perform eFACE video rating and tutorial observation. Participants downloaded the application, viewed the clips, and applied the scoring. They then viewed the tutorial and rescored the clips. Analysis of mean, standard deviation, and confidence interval were performed. Values were compared before and after tutorial viewing, and against scores obtained by an experienced eFACE user. RESULTS: eFACE feedback was positive; participants reported eagerness to apply the instrument in clinical practice. Standard deviation decreased significantly in only two of the 16 categories after tutorial viewing. Subscores for static, dynamic, and synkinesis all demonstrated stable standard deviations, suggesting that the instrument is intuitive. Participants achieved posttutorial scores closer to the experienced eFACE user in 14 of 16 scores, although only a single score, nasolabial fold orientation with smiling, achieved statistically significant improvement. CONCLUSIONS: The eFACE may be a suitable, cross-platform, digital instrument for facial function assessment, and was well received by facial nerve experts. Tutorial viewing does not appear to be necessary to achieve agreement, although it does mildly improve agreement between occasional and frequent eFACE users.

Facial mimetic, cosmetic, and functional standardized assessment of the facial artery musculomucosal (FAMM) flap.

OBJECTIVE: To objectively assess donor site morbidity after harvesting the facial artery musculomucosal flap. Use of the FAMM-flap in oral cavity reconstruction remains sporadic. This case series describes our newly developed standardized assessment of this flap in a floor of mouth (FOM) reconstructive setting. METHODS: Standardized postoperative assessment of the FAMM flap for donor site wound complications, functional, facial mimetic and oncologic outcomes. RESULTS: There were no wound complications. Oral competence remained intact, tongue mobility was good to excellent, average word articulation score was 98%, and mimetic function excellent in all patients. Three patients experienced ipsilateral upper lip anesthesia, and five patients were noted to have slight dysfunction of the orbicularis oris resulting in a loss of lip height at rest. CONCLUSION: The FAMM flap is a reliable option for reconstruction of ablative defects of the FOM, and should be considered a workhorse flap for oral cavity defects. Unlike the submental island flap, a complete level I dissection may be concurrently performed without compromising the vascular supply to the FAMM flap.

Bilateral Facial Paralysis: A 13-Year Experience.

BACKGROUND: Bilateral facial palsy is a rare clinical entity caused by myriad disparate conditions requiring different treatment paradigms. Lyme disease, Guillain-Barré syndrome, and leukemia are several examples. In this article, the authors describe the cause, the initial diagnostic approach, and the management of long-term sequelae of bilateral paralysis that has evolved in the authors' center over the past 13 years. METHODS: A chart review was performed to identify all patients diagnosed with bilateral paralysis at the authors' center between January of 2002 and January of 2015. Demographics, signs and symptoms, diagnosis, initial medical treatment, interventions for facial reanimation, and outcomes were reviewed. RESULTS: Of the 2471 patients seen at the authors' center, 68 patients (3 percent) with bilateral facial paralysis were identified. Ten patients (15 percent) presented with bilateral facial paralysis caused by Lyme disease, nine (13 percent) with Möbius syndrome, nine (13 percent) with neurofibromatosis type 2, five (7 percent) with bilateral facial palsy caused by brain tumor, four (6 percent) with Melkersson-Rosenthal syndrome, three (4 percent) with bilateral temporal bone fractures, two (3 percent) with Guillain-Barré syndrome, one (2 percent) with central nervous system lymphoma, one (2 percent) with human immunodeficiency virus infection, and 24 (35 percent) with presumed Bell palsy. Treatment included pharmacologic therapy, physical therapy, chemodenervation, and surgical interventions. CONCLUSIONS: Bilateral facial palsy is a rare medical condition, and treatment often requires a multidisciplinary approach. The authors outline diagnostic and therapeutic algorithms of a tertiary care center to provide clinicians with a systematic approach to managing these complicated patients.

Use of the submental vessels for free gracilis muscle transfer for smile reanimation.

BACKGROUND: Free muscle transfer is an important in dynamic facial reanimation; however, suitable donor vessels in this population can be inadequate. In this case series, the submental vessels were used as donors to free gracilis muscle in vessel-depleted patients. METHODS: Five patients underwent free gracilis muscle transfer for smile reanimation, 2 with a prior failed free gracilis transfer, 2 with vascular anomalies, and 1 with previous distal ligation of the facial vessels. The submental artery was used as a donor in all cases, and the submental vein was used in 3 cases. RESULTS: There were no complications or flap failure. Postoperative arterial and venous blood flow was confirmed in all patients using Doppler color flow imaging above and below the anastomoses. CONCLUSION: The submental vessels are suitable for microvascular anastomosis for free flaps having short pedicles, such as the free gracilis muscle flap, in the vessel-depleted hemiface. © 2016 Wiley Periodicals, Inc. Head Neck 38: First-E2503, 2016.

Decision management in transoral robotic surgery: Indications, individual patient selection, and role in the multidisciplinary treatment for head and neck cancer from a European perspective.

BACKGROUND: Transoral robotic surgery (TORS) has become an accepted first-line treatment for T1 and T2 head and neck squamous cell carcinoma (HNSCC). The growing popularity of this procedure is the result of mounting skepticism as to the survival and quality of life (QOL) benefits of primary chemoradiation over definitive surgery, the rising incidence of human papillomavirus (HPV)-positive oropharyngeal squamous cell carcinoma (OPSCC) in progressively younger patients, and the advantages of TORS over transoral laser microsurgery (TOLM) and open surgery. METHODS: The authors use their experience and data gained from the TORS-based management of >100 patients to establish a systematic approach to the use of TORS in HNSCC. RESULTS: This approach is constructed on a framework which goal is to select the primary treatment option that is most likely to reduce morbidity while preserving function and maintaining oncologic safety. CONCLUSION: A consensus regarding the indications of TORS and its role in the multidisciplinary management of HNSCC is to be established. © 2015 Wiley Periodicals, Inc. Head Neck 38: E2190-E2196, 2016.

Long-term vestibulocochlear functional outcome following retro-sigmoid approach to resection of vestibular schwannoma.

The objective of this study was to evaluate long-term vestibulocochlear functional outcomes of patients operated for unilateral vestibular schwannoma via the retro-sigmoid approach. Patients who underwent vestibular schwannoma resection via retro-sigmoid approach between 2004 and 2008 at our institution, without prior surgical or radio-surgical therapy were considered to be eligible for this study. Preoperative auditory and vestibular symptoms were assessed retrospectively. Postoperative symptoms were prospectively assessed using a standardised questionnaire, pure tone audiometry, video-oculography, and rotary chair testing. Out of a total of 203 patients, 120 were eligible for this study, of whom 64 responded to follow-up requests and could be enrolled. Serviceable hearing was reported in 42 patients (66 %) preoperatively and was maintained in 18 (43 %) postoperatively. While no significant change in rate of tinnitus and balance impairment between pre- and postoperative periods was detected, vertigo decreased significantly (40 to 28 %, p < 0.001). Postoperative video-oculography demonstrated vestibular paresis in 80 %. Rotary chair testing demonstrated normal or central compensation in 84 %. Absence of central compensation was associated with postoperative balance disturbance (p = 0.035). Increasing tumour size and patient age, also decreasing quality of preoperative hearing were independent factors predictive of a postoperative non-serviceable hearing (p = 0.020, p = 0.039 and p = 0.002, respectively). Resection of vestibular schwannoma via the retro-sigmoid approach is associated with improvement in postoperative vertiginous symptoms. Absence of central compensation leads to increased postoperative balance disturbances. Preservation of serviceable postoperative hearing is associated with good preoperative hearing status, younger age, and smaller tumours.

Silver nitrate mimicking a foreign body in the pharyngeal mucosal space.

Silver nitrate is sometimes used as a means of chemical cauterization for control of minor bleeding and management of hypergranulation tissue following bedside head and neck procedures. There are only few reports available on the imaging appearance of silver nitrate and its potential to mimic a foreign body. We report a case of a patient presenting with dysphagia, odynophagia, and fever following dental work who had a peritonsillar incision and drainage for treatment of a deep neck space infection. During the procedure, silver nitrate was applied to halt the bleeding. Patient was subsequently transferred to another institution. Since the patient was not showing significant clinical improvement on antibiotic therapy, a computed tomography (CT) scan was performed demonstrating a hyperdense structure lodged in the pharyngeal mucosal space in the oropharynx and soft palate that was mistaken for a foreign body such as bone. Silver nitrate can have density similar to bone but does not have the normal architecture of bone with cortex and marrow on CT. Familiarity with the appearance of silver nitrate on CT, lack of bone architecture, and proper documentation and communication of the use of silver nitrate to the consultant radiologist and medical personnel could help avoid misdiagnosis and potentially unnecessary surgical exploration.

A new technology for applanation free corneal trephination: the picosecond infrared laser (PIRL).

The impact of using a Femtosecond laser on final functional results of penetrating keratoplasty is low. The corneal incisions presented here result from laser ablations with ultrafast desorption by impulsive vibrational excitation (DIVE). The results of the current study are based on the first proof-of-principle experiments using a mobile, newly introduced picosecond infrared laser system, and indicate that wavelengths in the mid-infrared range centered at 3 µm are efficient for obtaining applanation-free deep cuts on porcine corneas.

Reduction of thermocoagulative injury via use of a picosecond infrared laser (PIRL) in laryngeal tissues.

The carbon dioxide (CO2) laser is routinely used in glottic microsurgery for the treatment of benign and malignant disease, despite significant collateral thermal damage secondary to photothermal vaporization without thermal confinement. Subsequent tissue response to thermal injury involves excess collagen deposition resulting in scarring and functional impairment. To minimize collateral thermal injury, short-pulse laser systems such as the microsecond pulsed erbium:yttrium-aluminium-garnet (Er:YAG) laser and picosecond infrared laser (PIRL) have been developed. This study compares incisions made in ex vivo human laryngeal tissues by CO2 and Er:YAG lasers versus PIRL using light microscopy, environmental scanning electron microscopy (ESEM), and infrared thermography (IRT). In comparison to the CO2 and Er:YAG lasers, PIRL incisions showed significantly decreased mean epithelial (59.70 µm) and subepithelial (22.15 µm) damage zones (p < 0.05). Cutting gaps were significantly narrower for PIRL (133.70 µm) compared to Er:YAG and CO2 lasers (p < 0.05), which were more than 5 times larger. ESEM revealed intact collagen fibers along PIRL cutting edges without obvious carbonization, in comparison to diffuse carbonization and tissue melting seen for CO2 and Er:YAG laser incisions. IRT demonstrated median temperature rise of 4.1 K in PIRL vocal fold incisions, significantly less than for Er:YAG laser cuts (171.85 K; p < 0.001). This study has shown increased cutting precision and reduced lateral thermal damage zones for PIRL ablation in comparison to conventional CO2 and Er:YAG lasers in human glottis and supraglottic tissues.

A comparison of hearing results following stapedotomy under local versus general anesthesia.

Advances in operative technique, instrumentation, and prosthesis design in otosclerosis surgery continue since Shea performed the first successful surgery. This is the first analysis to specifically compare post-operative hearing outcomes following stapedotomy surgery performed under local versus general anesthesia. Hearing outcomes were further stratified by comparing conventional perforator and Er:YAG laser ablation perforation techniques. Pre- and post-operative audiograms were retrospectively analyzed together with the method of anesthesia and the perforation technique for all patients with otosclerosis who underwent stapedotomy between 1998 and 2007. Pre-operative individual standard audiometry frequency thresholds (IFTs), air (AC) and bone conduction pure tone averages (PTA), and air bone gaps (ABG) were compared against post-operative results. Differences between pre- and post-operative PTAs and ABGs were compared between patients who received stapedotomy under local versus general anesthesia, as well as for patients who underwent conventional versus Er:YAG laser ablation perforations. Eighty-six patients were identified of which 24 % (n = 21) received local and 76 % (n = 65) received general anesthesia. Post-operative audiograms were available for 84 and 48 patients, respectively. Significant improvements were seen across all groups for standard 4-frequency AC-PTA and ABG and for IFTs up to 3 kHz. No significant difference was seen for IFTs between 4 and 6 kHz. A significant decline in post-operative hearing thresholds was seen at 8 kHz. Significant improvements in PTA and ABG were seen for all groups. There was a trend toward general compared to local anesthesia post-operative hearing results furthermore in combination with conventional perforation technique then with laser technique.

Use of a microsecond Er:YAG laser in laryngeal surgery reduces collateral thermal injury in comparison to superpulsed CO2 laser.

Despite causing significant thermocoagulative insult, use of the carbon dioxide (CO2) laser is considered gold standard in surgery for early stage larynx carcinoma. Limited attention has been paid to the use of the erbium:yttrium-aluminium-garnet (Er:YAG) laser in laryngeal surgery as a means to reduce thermal tissue injury. The objective of this study is to compare the extent of thermal injury and precision of vocal fold incisions made using microsecond Er:YAG and superpulsed CO2 lasers. In the optics laboratory ex vivo porcine vocal folds were incised using Er:YAG and CO2 lasers. Lateral epithelial and subepithelial thermal damage zones and cutting gap widths were histologically determined. Environmental scanning electron microscopy (ESEM) images were examined for signs of carbonization. Temperature rise during Er:YAG laser incisions was determined using infrared thermography (IRT). In comparison to the CO2 laser, Er:YAG laser incisions showed significantly decreased epithelial (236.44 µm) and subepithelial (72.91 µm) damage zones (p < 0.001). Cutting gaps were significantly narrower for CO2 (878.72 µm) compared to Er:YAG (1090.78 µm; p = 0.027) laser. ESEM revealed intact collagen fibres along Er:YAG laser cutting edges without obvious carbonization, in comparison to diffuse carbonization and tissue melting seen for CO2 laser incisions. IRT demonstrated absolute temperature rise below 70 °C for Er:YAG laser incisions. This study has demonstrated significantly reduced lateral thermal damage zones with wider basal cutting gaps for vocal fold incisions made using Er:YAG laser in comparison to those made using CO2 laser.

Laryngeal injuries following endotracheal intubation in ENT surgery: predictive value of anatomical scores.

Endotracheal intubation has been associated with a threefold higher incidence of laryngopharyngeal complaints following anesthesia in comparison to laryngeal mask airway. Such complaints, including hoarseness and sore throat, have been reported in up to 90% of patients within 24 h of extubation. The purpose of this study was to determine which preoperatively documented clinical and anatomic parameters are predictive of laryngo-pharyngeal trauma resulting from elective endotracheal intubation. Fifty-three patients undergoing ENT procedures requiring general anesthesia with endotracheal intubation were recruited. Pre and postoperative laryngostroboscopic examination was performed and findings correlated to preoperative clinical and anatomic parameters. Readily assessed anatomic parameters including height (>180 cm) and weight (>80 kg) correlated significantly to the Eckerbom grade of intubation-associated acute laryngeal injury (rs = 0.374; p = 0.006 and rs = 0.278; p = 0.044, respectively). The mandibular protrusion test also correlated significantly to the Eckerbom grade (rs = 0.462, p = 0.001) while the upper-lip-bite test showed significant correlation to impaired vocal fold oscillation (rs = 0.288, p = 0.036), with injury prediction sensitivities of 37.5 and 39.4%, respectively. No parameters correlated to subjective complaints (n = 5, 9.2%). This study provides suggestions on how to improve the classification of intubation-associated laryngeal injuries as well as providing the basis for larger clinical trials in other surgical subspecialties.

Bone ablation without thermal or acoustic mechanical injury via a novel picosecond infrared laser (PIRL).

BACKGROUND AND OBJECTIVE: A precise means to cut bone without significant thermal or mechanical injury has thus far remained elusive. A novel non-ionizing ultrafast pulsed picosecond infrared laser (PIRL) may provide the solution. Tissue ablation with the PIRL occurs via a photothermal process with thermal and stress confinement, resulting in efficient material ejection greatly enhanced through front surface spallation photomechanical effects. By comparison, the Er:YAG laser (EYL) ablates via photothermal and cavitation-induced photomechanical effects without thermal or acoustic confinement, leading to significant collateral tissue injury. This study compared PIRL and EYL bone ablation by infrared thermography (IRT), environmental scanning electron microscopy (ESEM), and histology. STUDY DESIGN: Prospective, comparative, ex vivo animal model. SETTING: Optics laboratory. SUBJECTS AND METHODS: Ten circular area defects were ablated in ex vivo chicken humeral cortex using PIRL and EYL at similar average power (~70 mW) under IRT. Following fixation, ESEM and undecalcified light microscopy images were obtained and examined for signs of cellular injury. RESULTS: Peak rise in surface temperature was negligible and lower for PIRL (1.56 °C; 95% CI, 0.762-2.366) compared to EYL ablation (12.99 °C; 95% CI, 12.189-13.792) (P < .001). ESEM and light microscopy demonstrated preserved cortical microstructure following PIRL ablation in contrast to diffuse thermal injury seen with EYL ablation. Microfractures were not observed. CONCLUSION: Ablation of cortical bone using the PIRL generates negligible and significantly less heat than EYL ablation while preserving cortical microstructure. This novel laser has great potential in advancing surgical techniques where precision osseous manipulation is required.

Heat generation during ablation of porcine skin with erbium:YAG laser vs a novel picosecond infrared laser.

IMPORTANCE: Despite significant advances in surgery, most surgical tools remain basic. Lasers provide a means of precise surgical ablation, but their clinical use has remained limited because of undesired thermal, ionizing, or acoustic stress effects leading to tissue injury. A novel ultrafast, nonionizing, picosecond infrared laser (PIRL) system has recently been developed and is capable, in theory, of ablation with negligible thermal or acoustic stress effects. OBJECTIVE: To measure and compare heat generation by means of thermography during ablation of ex vivo porcine skin by conventional microsecond-pulsed erbium:YAG (Er:YAG) laser and picosecond infrared laser (PIRL). DESIGN AND SETTING: This study was conducted in an optics laboratory and used a pretest-posttest experimental design comparing 2 methods of laser ablation of tissue with each sample acting as its own control. INTERVENTION: Ex vivo porcine skin was ablated in a 5-mm line pattern with both Er:YAG laser and PIRL at fluence levels marginally above ablation threshold (2 J/cm² and 0.6 J/cm², respectively). MAIN OUTCOMES AND MEASURES: Peaks and maxima of skin temperature rises were determined using a thermography camera. Means of peak temperature rises were compared using the paired sample t test. Ablation craters were assessed by means of digital microscopy. RESULTS Mean peak rise in skin surface temperature for the Er:YAG laser and PIRL was 15.0°C and 1.68°C, respectively (P < .001). Maximum peak rise in skin surface temperature was 18.85°C for the Er:YAG laser and 2.05°C for the PIRL. Ablation craters were confirmed on digital microscopy. CONCLUSIONS AND RELEVANCE: Picosecond infrared laser ablation results in negligible heat generation, considerably less than Er:YAG laser ablation, which confirms the potential of this novel technology in minimizing undesirable thermal injury associated with lasers currently in clinical use.

A novel tool in laryngeal surgery: preliminary results of the picosecond infrared laser.

OBJECTIVES/HYPOTHESIS: Conventional lasers ablate tissue through photothermal, photomechanical, and/or photoionizing effects, which may result in collateral tissue damage. The novel nonionizing picosecond infrared laser (PIRL) selectively energizes tissue water molecules using ultrafast pulses to drive ablation on timescales faster than energy transport to minimize collateral damage to adjacent cells. STUDY DESIGN: Animal cadaver study. METHODS: Cuts in porcine laryngeal epithelium, lamina propria, and cartilage were made using PIRL and carbon dioxide (CO2) laser. Lateral damage zones and cutting gaps were histologically compared. RESULTS: The mean widths of epithelial (8.5 µm), subepithelial (10.9 µm), and cartilage damage zones (8.1 µm) were significantly lower for cuts made by PIRL compared with CO2 laser (p < 0.001). Mean cutting gaps in vocal fold (174.7 µm) and epiglottic cartilage (56.3 µm) were significantly narrower for cuts made by PIRL compared with CO2 laser (P < 0.01, P < 0.05). CONCLUSION: PIRL ablation demonstrates superiority over CO2 laser in cutting precision with less collateral tissue damage.

Reconstruction of cheek defects: a review of current techniques.

PURPOSE OF REVIEW: The article discusses the fundamental principles of cheek reconstruction and summarizes recently published techniques and reviews in the field. RECENT FINDINGS: Reconstruction of the cheek is a complex endeavour. Patient, defect, and potential donor site factors must be carefully considered in the restoration of cheek form and function. Fortunately the surgeon, each with his or her own personal preferences and experience, has a wealth of techniques available from which to choose. New flaps and techniques are described including recent reviews of traditional techniques. Examples include a modification to the Mustardé flap, an axial pedicled flap from the radix nasi region, a technique of superficial musculoaponeurotic system plication to achieve primary closure of large defects, and reviews of the submental island flap, the subcutaneous cervicofacial flap, the medial sural artery perforator flap, and the anterolateral thigh flap. SUMMARY: Surgical innovation and conscientious assessments of traditional techniques continue to advance the field of cheek reconstruction towards improved aesthetic and functional outcomes.

Airway luminal diameter and shape measurement by means of an intraluminal fiberoptic probe: a bench model.

OBJECTIVE: To design and test a bench model of an intraluminal optical device capable of accurately measuring airway diameter. DESIGN: A fresh porcine trachea divided longitudinally and affixed to a linear translation stage was used to simulate 20 tracheal diameters (18.3-30.3 mm). Tungsten-halogen light was dispersed across the luminal surface by a diffraction grating. Determination of the wavelength of diffusely reflected light of peak intensity by spectrograph analysis then allowed for the calculation of an optical distance for each simulated tracheal diameter. The criterion standard was the distance as measured by the micrometer on the translation stage. Intraclass correlation (ICC) and Bland-Altman regression analysis (BARA) were performed between the optical and micrometer measurements. Subject Trachea from a newly exsanguinated pig. RESULTS: The ICC showed high correlation (0.994; 95% confidence interval [CI], 0.9860.998) (P < .001); BARA showed a small mean difference between the optical and micrometer measurements (0.052 mm; 95% CI, -0.867 to 0.762 mm) and no significant trend in bias for varying diameters (r = 0.581; 95% CI, 0.187-0.814) (P = .07). CONCLUSIONS: The determination of airway diameter by means of the reflection of nonionizing radiation from the luminal surface correlates closely to actual diameter as measured by a micrometer. This bench model may be used to develop a fiberoptic intraluminal probe capable of accurately profiling airway luminal diameter and shape during flexible or rigid bronchoscopy.

Surgical skill acquisition with self-directed practice using computer-based video training.

BACKGROUND: Computer-based video training (CBVT) provides flexible opportunities for surgical trainees to learn fundamental technical skills, but may be ineffective in self-directed practice settings because of poor trainee self-assessment. This study examined whether CBVT is effective in a self-directed learning environment among novice trainees. METHODS: Thirty novice trainees used CBVT to learn the 1-handed square knot while self-assessing their proficiency every 3 minutes. On reaching self-assessed skill proficiency, trainees were randomized to either cease practice or to complete additional practice. Performance was evaluated with computer and expert-based measures during practice and on pretests, posttests, and 1-week retention tests. RESULTS: Analyses revealed performance improvements for both groups (all P < .05), but no differences between the 2 groups (all P > .05) on all tests. CONCLUSIONS: CBVT for the 1-handed square knot is effective in a self-directed learning environment among novices. This lends support to the implementation of self-directed digital media-based learning within surgical curricula.