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1.  Helical computed tomography scanning of the larynx and upper trachea in rabbits 
Background
Computed tomography (CT) is used to evaluate the human tracheobronchial tree because of its unsurpassed ability to visualize the airway and surrounding structures. To establish an ideal animal model for studying subglottic stenosis, we assessed the size and morphology of the normal rabbit’s laryngotracheal airway by helical CT. We measured luminal dimensions at the levels of the arytenoid and cricoid cartilages and the first, third, and eighth tracheal rings. At all levels, the axial slices were used to calculate the maximum anteroposterior (AP) dimension, transverse dimension, and cross-sectional areas. We measured the tracheal length from the cricoid to the third and eighth tracheal rings on sagittal reformation. We assessed the hyoid, thyroid, cricoid, arytenoid, and tracheal rings for the presence of calcific or soft tissue densities. We also addressed the presence or absence of pre-epiglottic and paraglottic fat.
Results
The mean AP tracheal dimension ± standard deviation (SD) was 8.6 ± 0.5 mm at the arytenoid level, 8.2 ± 0.7 mm at the cricoid level, and 7.7 ± 0.2 mm at the first tracheal ring level. The transverse tracheal dimension ±SD was 5.3 ± 0.1 mm at the arytenoid level, 5.5 ± 0.5 mm at the cricoid level, and 6.1 ± 0.6 mm at the first tracheal ring level. The mean tracheal area ±SD was 35.7 ± 2.2 mm2 at the arytenoid level, 35.8 ± 5.1 mm2 at the cricoid level, and 39.2 ± 4.3 mm2 at the first tracheal ring level. The tracheal length ±SD was 10.7 ± 2.3 mm from the cricoid to the third tracheal ring and 19.1 ± 1.14 mm to the eighth tracheal ring. There was complete calcification of the hyoid in all rabbits. Only two rabbits showed complete thyroid, arytenoid, or tracheal ring calcification. The remaining airway components were otherwise either uncalcified or partially calcified. The uvula, epiglottis, aryepiglottic fold, vallecula, piriform sinus, true/false vocal cords, and pre-epiglottic/paraglottic fat were not seen in any rabbit.
Conclusions
Helical CT investigation provides good, highly definitive anatomic details of the larynx and trachea in rabbits. Such results may be used in further evaluation of the normal airway and in cases of subglottic stenosis.
doi:10.1186/s13028-015-0157-4
PMCID: PMC4590308  PMID: 26427598
Helical computed tomography; Trachea; Subglottis; Rabbits
2.  The Anatomical Relationship Between Recurrent Laryngeal Nerve and First Tracheal Ring in Males and Females 
Objectives
Despite the modern advances in thyroid surgery, recurrent laryngeal nerve (rln) paralysis is still a critical problem. In order to decrease the rate of this complication, rln anatomy has been studied intensively. In our study, we aimed to recognize the relationship of rln and landmarks of the first tracheal ring.
Methods
Eighty-six female and 18 male patients who were undergone total thyroidectomy were included in this study. Trachea vertical height (tvh), right recurrent laryngeal nerve height (rrh), left recurrent laryngeal nerve height (lrh), right recurrent laryngeal nerve to trachea anterior face median raphe distance (rrd), left recurrent laryngeal nerve to trachea anterior face median raphe distance (lrd), right recurrent laryngeal nerve respect to trachea ratio (rrtr), and left recurrent laryngeal nerve respect to trachea ratio (lrtr) parameters of all patients were measured and compared in males and females using independent t-test and measurements on both right and left sides were compared statistically without sex discrimination.
Results
There were no significant differences between groups in tvh, rrh, rrd, lrd, rrtr, and lrtr parameters. Lrh parameter was significantly higher in males than in females (P<0.04). Comparison of right and left sides revealed that lrh was significantly higher than rrh (P<0.001), lrd was significantly higher than rrd (P<0.001), and rrtr was significantly higher than lrtr (P<0.001).
Conclusion
In this study, we have shown that in all cases the rln was located around the lower half of trachea vertical length and at this level left rln was located significantly deeper than the right side.
doi:10.21053/ceo.2015.01746
PMCID: PMC5327592  PMID: 27337947
Recurrent Laryngeal Nerve; Thyroidectomy; Intraoperative Complications; Trachea; Anatomy
3.  Relationship Between Preepiglottic Space Invasion and Lymphatic Metastasis in Supracricoid Partial Laryngectomy With Cricohyoidopexy 
Objectives
The aim of this study was to determine the role of preepiglottic space (PES) invasion in lymph node metastasis and prognosis in patients undergoing supracricoid partial laryngectomy (SCPL) with cricohyoidopexy (CHP).
Methods
A retrospective review of 42 previously untreated patients with squamous cell carcinoma of the larynx that underwent surgery was performed. The mean age of the subjects was 61.3 years, and the male-to-female ratio was 38:4. Regarding their pathological stages, there were 3, 8, 22, and 9 cases of stage T1 to T4, respectively. Concerning the disease stage of the cervical lymph nodes, there were 30, 5, 6, and 1 cases with N0 to N3, respectively.
Results
The PES invasion rate was 23.8% (10/42). Significant correlations were found between PES invasion and cervical lymph node metastasis (P=0.002). Seven of the 10 patients (70.0%) with PES invasion had cervical lymph node metastasis, whereas only 5 of the 32 patients (15.6%) without any evidence of PES invasion had lymph node metastasis. There was also a significant correlation of PES invasion with age (P=0.002) and T stage (P=0.030). However, there was no significant relationship between gender, primary tumor site, anterior commissure invasion, subglottic extension, paraglottic space invasion and PES invasion. There was a 5-year disease-specific survival of 70%. PES invasion served as a statistically significant prognostic factor for disease-specific survival (P=0.004). Cervical nodal metastasis (P=0.003) and subglottic extension (P=0.01) were also statistically significant prognostic factors associated with disease-specific survival.
Conclusion
The PES invasion was significantly related to the cervical lymph node metastasis and prognosis in patients undergoing SCPL with CHP.
doi:10.3342/ceo.2014.7.3.205
PMCID: PMC4135157  PMID: 25177437
Laryngeal neoplasms; Laryngectomy; Lymphatic metastasis; Neoplasm invasiveness; Prognosis
4.  Autologous Cricoid Cartilage as a Graft for Airway Reconstruction in an Emergent Technique - A Case Report 
Introduction:
Laryngotracheal stenosis can be caused after traumatic injuries to the neck from the subglottic larynx to the trachea. Patients with laryngotracheal stenosis often need a tracheotomy and occasionally may become tracheotomy dependent. Different procedures have been described for the management of these lesions. Management options include techniques of endoscopic dilation, laser resection, laryngo-fissure, and an innovative array of plastic reconstructions with or without the use of stents.
Case Report:
This paper presents airway reconstruction in a young patient with severe subglottic stenosis due to a blunt trauma to the neck, who was treated using particles of an autologous fractured cricoid cartilage as the source for airway augmentation. An incision was made in the anterior midline of the cricoid lamina and deepened through the scar tissue to the posterior cricoid lamina. Then two lateral incisions (right & left) were made in the cricoid lamina and fractured cartilage particles and the scar tissue were removed via these two lateral incisions. The mucosal lining at the right and left of the midline incision, after debulking, were sutured to a lateral position. Thereafter three cartilage particles were used to reconstruct the anterior cricoid lamina and augment the lumen.
Conclusion:
It is worth to mention that an autologus cartilage graft can be used for certain cases with traumatic airway stenosis. Further follow up and more patients are needed to approve this method of reconstructive surgery in emergent situations.
PMCID: PMC4881886  PMID: 27280104
Airway trauma; Autologus Cricoid Cartilage; Reconstruction
5.  Extramedullary Plasmacytoma of the Larynx: A Case Report of Subglottic Localization 
Case Reports in Otolaryngology  2012;2012:437264.
Extramedullary plasmacytoma (EMP) is a rare neoplasm of plasma cells, described in soft tissue outside the bone marrow. EMP of the larynx represents 0.04 to 0.45% of malignant tumors of the larynx. A male of 57 years old presented with hoarseness, dyspnea, and biphasic stridor of 2 months. The indirect laryngoscopy (IL) revealed severe edema of the posterior commissure and a polypoid mass in the right posterior lateral subglottic wall. A biopsy of the subglottic mass was performed by a direct laryngoscopy (DL). The histopathologic diagnosis was EMP CD138+, therefore radiotherapy was given at 54 Gy in 30 sessions. The patient had an adequate postoperative clinical course and a new biopsy was performed having tumor-free margins. All laryngeal lesions should be biopsied prior to treatment to determine an accurate diagnosis to guide a proper management of the condition. Radiation therapy to the EMP is considered the treatment of choice, having local control rates of 80% to 100%. The subglottis is the least accessible area of view and the least frequent location of a laryngeal mass, nevertheless the otolaryngologist should always do a complete and systematic exam of the larynx when a tumor is suspected, to detect diagnoses such as a subglottic plasmacytoma.
doi:10.1155/2012/437264
PMCID: PMC3469077  PMID: 23082263
6.  Assessment of difficult laryngoscopy by electronically measured maxillo-pharyngeal angle on lateral cervical radiograph: A prospective study 
Saudi Journal of Anaesthesia  2010;4(3):158-162.
Background:
Difficult airway continued to be a major cause of anesthesia-related morbidity and mortality. Successful airway management depends on direct laryngoscopy and tracheal intubation. Difficult laryngoscopy is a resultant of incomplete structural arrangements during the process of head positioning. Through clinical history, examination of the patients along with craniofacial indices alerts the anesthetist for difficult laryngoscopy. But it does not predict all causes of difficult laryngoscopy during pre-anesthetic evaluation. The maxillo-pharyngeal angle, an upper airway anatomical balance, was proposed for better understanding the pathophysiology of difficult laryngoscopy. In our study we have assess difficult laryngoscopy by electronically measuring maxillo-pharyngeal angles on a lateral cervical radiograph. This angle is normally greater than 100°. Less than 90° angle suggests either impossible or difficult direct laryngoscopy when all known craniofacial indices were within the normal range. Cervical radiographic assessment is a simple, economical, and non-invasive predictive method for difficult laryngoscopy. It should be used routinely along with other indices as pre-anesthetic airway assessment criteria to predict the difficult laryngoscopy.
Context:
Difficulties with airway management continue to be a major cause of anesthesia-related morbidity, mortality, and litigation. Pre-operative assessment of difficult laryngoscopy by the simple and non-invasive radiological method can help to prevent them.
Aims:
To assess the difficult laryngoscopy pre operatively by a simple and non invasive radiological method by electronically measuring maxillo-pharyngeal angle on a lateral cervical radiograph and it’s correlation with Cormack and Lehane grading.
Settings and Design:
This is a controlled, nonrandomized, prospective, cohort observation study.
Patients and Methods:
The 157 adult consented patients of ASA grade I to III of either sex, scheduled for elective surgery under general anesthesia with endo-tracheal intubation, were studied. The patients with identified difficult airway indices were excluded from the study. The maxillo-pharyngeal angle was electronically measured on a lateral cervical radiograph and was correlated with ease or difficulty of laryngoscopy under general anesthesia. Their degree of laryngeal exposure according to Cormack and Lehane classification grade was also noted.
Statistical Analysis used:
We performed univariate analyses to evaluate the association between the covariates and direct laryngoscopy.
Results:
In 148 patients (94.28%), the maxillo-pharyngeal angle was more than 100°, in 7 patients (4.45%) it was less than 90°, and in 2 patients (1.27%) the M-P angle was less than 85° with normal craniofacial indices. When the MP angle was less than 90°, the direct laryngoscopy was difficult which could be compared with to Cormack and Lehane classification grade III and IV.
Conclusions:
Lateral cervical radiographic assessment should be used as pre-anesthetic airway assessment criteria to predict the difficult laryngoscopy as it is a simple, safe and non-invasive method.
doi:10.4103/1658-354X.71572
PMCID: PMC2980661  PMID: 21189852
Maxillo-pharyngeal angle; laryngoscopy; cervical radiograph; electronic measurement of angle; Cormack and Lehane grade
7.  Clinically Correlated Anatomical Basis of Cricothyrotomy and Tracheostomy 
Objective
Cricothyrotomy and tracheostomy are performed by physicians in various disciplines. It is important to know the comprehensive anatomy of the laryngotracheal region. Hemorrhage, esophageal injury, recurrent laryngeal nerve injury, pneumothorax, hemothorax, false passage of the tube and tracheal stenosis after decannulation are well known complications of the cricothyrotomy and tracheostomy. Cricothyrotomy and tracheostomy should be performed without complications and as quickly as possible with regards the patients' clinical condition.
Methods
A total of 40 cadaver necks were dissected in this study. The trachea and larynx and the relationship between the trachea and larynx and the surrounding structures was investigated. The tracheal cartilages and annular ligaments were counted and the relationship between tracheal cartilages and the thyroid gland and vascular structures was investigated. We performed cricothyrotomy and tracheostomy in eleven cadavers while simulating intensive care unit conditions to determine the duration of those procedures.
Results
There were 11 tracheal cartilages and 10 annular ligaments between the cricoid cartilage and sternal notch. The average length of trachea between the cricoid cartilage and the suprasternal notch was 6.9 to 8.2 cm. The cricothyroid muscle and cricothyroid ligament were observed and dissected and no vital anatomic structure detected. The average length and width of the cricothyroid ligament was 8 to 12 mm and 8 to 10 mm, respectively. There was a statistically significant difference between the surgical time required for cricothyrotomy and tracheostomy (p < 0.0001).
Conclusion
Tracheostomy and cricothyrotomy have a low complication rate if the person performing the procedure has thorough knowledge of the neck anatomy. The choice of tracheostomy or cricothyrotomy to establish an airway depends on the patients' clinical condition, for instance; cricothyrotomy should be preferred in patients with cervicothoracal injury or dislocation who suffer from respiratory dysfunction. Furthermore; if a patient is under risk of hypoxia or anoxia due to a difficult airway, cricothyrotomy should be preferred rather than tracheostomy.
doi:10.3340/jkns.2010.47.3.174
PMCID: PMC2851084  PMID: 20379468
Anatomy; Cricothyrotomy; Tracheostomy
8.  Early Glottic Cancer: Role of MRI in the Preoperative Staging 
BioMed Research International  2014;2014:890385.
Introduction. Clinical staging is the most important time in management of glottic cancer in early stage (I-II). We have conducted a prospective study to evaluate if magnetic resonance imaging (MRI) is more accurate than computed tomography (CT) about tumoral extension, to exactly choose the most appropriate surgical approach, from organ preservation surgery to demolitive surgery. Materials and Methods. This prospective study was conducted on 26 male patients, with suspected laryngeal neoplasia of glottic region. The images of MRI and CT were analyzed to define the expansion of glottic lesion to anterior commissure, laryngeal cartilages, subglottic and/or supraglottic site, and paraglottic space. The results of MRI and CT were compared with each other and with the pathology report. Results. CT accuracy was 70% with low sensitivity but with high specific value. MRI showed a diagnostic accuracy in 80% of cases, with a sensitivity of 100% and high specificity. Statistical analysis showed that MRI has higher correlation than CT with the pathology report. Conclusion. Our study showed that MRI is more sensitive than CT in the preoperative staging of early glottic cancer, to select exactly the eligible patients in conservative surgery of the larynx, as supracricoid laryngectomy and cordectomy by CO2 laser.
doi:10.1155/2014/890385
PMCID: PMC4150401  PMID: 25197667
9.  The relationship between hyoid and laryngeal displacement and swallowing impairment 
Objectives
Reduced range of hyoid and laryngeal movement is thought to contribute to aspiration risk and pharyngeal residues in dysphagia. Our aim was to determine the extent to which movements of the hyoid and larynx are correlated in the superior and anterior directions in swallowing, and whether movement range is predictive of penetration-aspiration or pharyngeal residue.
Design
Prospective, single-blind study of penetration-aspiration and pharyngeal residue with objective frame-by-frame measures of hyoid and laryngeal excursion from videofluoroscopy.
Setting
Tertiary hospital and rehabilitation teaching hospital.
Participants
28 participants referred for videofluoroscopy: 13 females, aged 57-77; 15 males aged 54-70. Individuals with known neurodegenerative diseases or prior surgery to the neck were excluded. Each swallowed three boluses of 40% w/v thin liquid barium suspension.
Outcomes
Two speech-language pathologists independently rated penetration-aspiration, vallecular and pyriform sinus residue. Cervical spine length, hyoid and laryngeal displacement were traced frame-by-frame. Predictive power was calculated.
Results
Cervical spine length was significantly greater in males. Hyoid displacement ranged from 34-63% of the C2-4 distance. Arytenoid displacement ranged from 18-66%, with significantly smaller anterior displacement in males. Positive hyoid-laryngeal movement correlations in both axes were the most common pattern observed. Participants with reduced displacement ranges (≤ first quartile) and with abnormal correlation patterns were more likely to display penetration-aspiration. Those with reduced anterior hyoid displacement and abnormal correlation patterns had a greater risk of post-swallow pharyngeal residues.
Conclusions
It is difficult for clinicians to make on-line appraisals of the extent to which hyoid and laryngeal movement may be contributing to functional swallowing consequences during videofluoroscopy. This study suggests that it is most important for clinicians to discern whether reduced anterior displacement of these structures is contributing to a patient's swallowing impairment. Measures of structural displacement in thin liquid swallowing should be corrected for variations in participant height. Reductions in anterior hyoid and laryngeal movement below the first quartile boundaries are statistically associated with increased risk for penetration-aspiration and post-swallow residues.
doi:10.1111/j.1749-4486.2010.02219.x
PMCID: PMC3757521  PMID: 21414151
10.  Role of Anterior Neck Soft Tissue Quantifications by Ultrasound in Predicting Difficult Laryngoscopy 
Background
The aim of this study was to determine if ultrasound (US) measurements of anterior neck soft tissue thickness at hyoid bone (DSHB), thyrohyoid membrane (DSEM), and anterior commissure (DSAC) levels can be used to predict difficult laryngoscopy.
Material/Methods
We included 203 patients age 20–65 years scheduled to undergo general anesthesia in this prospective observational study. Correlation analysis and receiver operating characteristic curve (ROC) analysis were used to determine the roles of screening tests [interincisor gap (IIG), thyromental distance (TMD), modified Mallampati score (MMS)] and US measurements (DSHB, DSEM, DSAC) in predicting difficult laryngoscopy.
Results
There were 28 out of 203 patients categorized as difficult laryngoscopy. DSHB, DSEM, DSAC, and MMS were greater in the difficult laryngoscopy group (P<0.0001). There was a strong positive correlation between DSEM and DSHB (r=0.74); moderate positive correlations between DSEM and DSAC (r=0.60), DSHB and DSAC (r=0.69); small positive correlations between MMS and DSHB (r=0.32), MMS and DSEM (r=0.27), MMS and DSAC (r=0.32), all P values ≤0.0001; very small positive correlation between TMD and IIG (r=0.18, P=0.0089); small negative correlation between IIG and MMS (r=−0.27, P=0.0001); and very small negative correlations between MMS and TMD (r=−0.20, P=0.004), IIG and DSAC (r=−0.18, P=0.011), IIG and DSHB (r=−0.15, P=0.034). The areas under the ROC curve (AUCs) of MMS, DSHB, DSEM, and DSAC were significantly larger compared with the reference line (P<0.0001).
Conclusions
Anterior neck soft tissue thicknesses measured by US at hyoid bone, thyrohyoid membrane, and anterior commissure levels are independent predictors of difficult laryngoscopy. Combinations of those screening tests or risk factors with US measurements might increase the ability to predict difficult laryngoscopy.
doi:10.12659/MSM.891037
PMCID: PMC4247231  PMID: 25403231
Airway Management; Anesthesia; Critical Care; Laryngoscopy; Ultrasonography
11.  Canine location in different maxillomandibular relationships in Egyptians and Saudis 
The Saudi Dental Journal  2010;23(1):37-42.
The standards or proportions commonly used as guides for the selection of maxillary anterior teeth for a removable prosthesis have been developed mainly on Caucasian populations with normal ridge relationships.
Purpose
This study was conducted to determine the canine position in relation to commissures in different maxillomandibular relationships among Egyptian and Saudi populations.
Material and methods
Two hundred subjects participated in this study, 100 from each population. The location of the corners of the mouth for each subject was marked on the buccal surface of a screen previously constructed on the maxillary cast and transferred to the casts. The distances between the corners of the mouth and the canines’ distal aspect were measured on the casts. The measurements were subdivided according to their relation to the commissures: at commissures, medial to commissures, or distal to commissures. The data were then statistically analyzed.
Results
Coincidence between the canine distal aspects and commissures was recorded only within 8% of both Egyptian and Saudi populations. Additionally, within the Egyptian population, coincidence was recorded only at Class-I ridge relationship.
Conclusion
Commissures are not a reliable landmark for determination of the distal aspect of the canine distal aspects of both Egyptian and Saudi populations.
doi:10.1016/j.sdentj.2010.09.004
PMCID: PMC3723365  PMID: 23960500
Canine relationship; Maxillomandibular; Egyptian; Saudi
12.  Effects of Different Annuloplasty Rings on Anterior Mitral Leaflet Dimensions 
OBJECTIVE
To assess the effects of annuloplasty rings (ARs) on anterior mitral leaflet (AML) dimensions.
METHODS
Sixteen radiopaque markers were sutured evenly spaced over the surface of the AML in 57 sheep. Size 28 mm Cosgrove (n=11), rigid saddle-shaped AR (RSAR) (n=12), Physio (n=12), IMR-ETlogix (n=10) and GeoForm (n=12) rings were implanted in a releasable fashion. Under acute open-chest conditions, 4-D marker coordinates were measured using biplane videofluoroscopy with the AR inserted and after AR release. Septal-lateral and commissure-commissure dimensions were calculated from opposing marker pairs on the septal-lateral and commissure-commissure aspect of the AML at end-diastole (ED) and end-systole (ES). To assess changes in AML shape, a “planarity index” was assessed by calculating the root mean square values as distances of the 16 AML markers to a best fit AML plane at ES.
RESULTS
At ED, AML septal-lateral and commissure-commissure dimensions did not change with Cosgrove compared to Control, while RSAR, Physio, IMR-ETlogix and GeoForm reduced AML commissure-commissure, but not septal-lateral AML dimensions. At ES, the septal-lateral AML dimension was smaller with IMR-ETlogix and GeoForm, but did not change with Cosgrove, RSAR and Physio. AML shape was unchanged in all five groups.
CONCLUSIONS
With no changes in AML planarity, the 4 complete, rigid rings (RSAR, Physio, IMR-ETlogix, and GeoForm) reduced the AML commissure-commissure dimension at ED. IMR-ETlogix and GeoForm decreased the septal-lateral AML dimension at ES, probably due to inherent disproportionate downsizing. These changes in AML geometry could perturb the stress patterns, which in theory may affect repair durability.
doi:10.1016/j.jtcvs.2009.12.014
PMCID: PMC2864008  PMID: 20412950
13.  Middle Frontal Horizontal Partial Laryngectomy (MFHPL): A Treatment for Stage T1b Squamous Cell Carcinoma of the Glottic Larynx Involving Anterior Vocal Commissure 
PLoS ONE  2013;8(1):e52723.
Objective
The therapeutic effect of middle frontal horizontal partial laryngectomy (MFHPL) in treating stage T1b squamous cell carcinoma of the glottic larynx involving anterior vocal commissure (AVC) was compared with that of the anterior frontolateral vertical partial laryngectomy (AFVPL). The feasibility and practical significance of MFHPL in clinical application was discussed in the present study.
Methods
From January 1996 to January 2010, a total of 65 patients diagnosed with stage T1bN0M0 glottic laryngeal cancer were treated with MFHPL or AFVPL. The postoperative complications, glottic reconstruction, recurrence rate, voice quality and survival rates were evaluated and compared between two treatments.
Results
AFVPL and MFHPL were performed in 34 and 31 patients, respectively. Flexible fiberoptic laryngoscopy revealed that in the MFHPL-treated patients the reconstructed glottis was spacious and symmetric. In contrast, AFVPL treatment resulted in irregular glottic area with poor symmetry and tubular glottis. The incidence of postoperative laryngeal stenosis significantly differed between the MFHPL- and AFVPL-treated groups (P = 0.025). No significant difference was detected in the 3- and 5-year overall- or tumor-free survival rates between two treatments. The Voice Handicap Index (VHI) and maximum phonation time (MPT) after surgery were 51.0±12.99 and 12.42±3.44 sec in the AFVPL-treated group; while in the MFHPL-treated patients they were 31.81±7.48 and 7.65±1.98 sec, respectively. Both differences in VHI (P = 0.012) and MPT (P = 0.024) were significant between two treatments.
Conclusions
MFHPL was comparable to AFVPL with respect to postoperative complications, recurrence rate and survival rates, but possessed advantages over AFVPL in terms of the incidence of laryngeal stenosis and voice quality. Our study indicated that MFHPL has a potential value in clinical practice of treating stage T1b squamous cell carcinoma of the glottic larynx involving AVC.
doi:10.1371/journal.pone.0052723
PMCID: PMC3541376  PMID: 23326350
14.  Anatomic Consideration of Stitch Depth in Tricuspid Valve Annuloplasty  
Acta Cardiologica Sinica  2015;31(3):232-234.
Background
The durability of De Vega’s tricuspid valve annuloplasty might be related to tension of the annulus and could be reinforced by increasing stich depth. However, depth of stitches to date has not been addressed in the literature. Thus, it is important to better understand the anatomical distance between the tricuspid valve annulus and the right coronary artery.
Methods
From 1998 to 2009, we measured the distances between TV annulus and RCA (TRD) on 46 explanted human hearts during heart transplantation. Five points were measured from the anterior/septal leaflet commissure to the posterior/septal leaflet commissure clockwise. Statistical significance was tested in the analyses.
Results
We found the TRD were independent from sex, age, body weight, and etiology. With a minimum of 10 mm at the posterior/septal leaflet commissure, the distances increased counterclockwise to the maximum of 20 mm at the anterior/septal leaflet commissure.
Conclusions
Stitch depth within 10 millimeter will not injure the right coronary artery in making De Vega’s tricuspid annuloplasty.
PMCID: PMC4805006  PMID: 27122875
De Vega’s tricuspid valve annuloplasty
15.  Long-Range Optical Coherence Tomography of the Neonatal Upper Airway for Early Diagnosis of Intubation-related Subglottic Injury 
Rationale: Subglottic edema and acquired subglottic stenosis are potentially airway-compromising sequelae in neonates following endotracheal intubation. At present, no imaging modality is capable of in vivo diagnosis of subepithelial airway wall pathology as signs of intubation-related injury.
Objectives: To use Fourier domain long-range optical coherence tomography (LR-OCT) to acquire micrometer-resolution images of the airway wall of intubated neonates in a neonatal intensive care unit setting and to analyze images for histopathology and airway wall thickness.
Methods: LR-OCT of the neonatal laryngotracheal airway was performed a total of 94 times on 72 subjects (age, 1–175 d; total intubation, 1–104 d). LR-OCT images of the airway wall were analyzed in MATLAB. Medical records were reviewed retrospectively for extubation outcome.
Measurements and Main Results: Backward stepwise regression analysis demonstrated a statistically significant association between log(duration of intubation) and both laryngeal (P < 0.001; multiple r2 = 0.44) and subglottic (P < 0.001; multiple r2 = 0.55) airway wall thickness. Subjects with positive histopathology on LR-OCT images had a higher likelihood of extubation failure (odds ratio, 5.9; P = 0.007). Longer intubation time was found to be significantly associated with extubation failure.
Conclusions: LR-OCT allows for high-resolution evaluation and measurement of the airway wall in intubated neonates. Our data demonstrate a positive correlation between laryngeal and subglottic wall thickness and duration of intubation, suggestive of progressive soft tissue injury. LR-OCT may ultimately aid in the early diagnosis of postintubation subglottic injury and help reduce the incidences of failed extubation caused by subglottic edema or acquired subglottic stenosis in neonates.
Clinical trial registered with www.clinicaltrials.gov (NCT 00544427).
doi:10.1164/rccm.201501-0053OC
PMCID: PMC4731717  PMID: 26214043
optical coherence tomography; neonate; diagnostic imaging; intubation injury; subglottic stenosis
16.  A comparison of McCoy, TruView, and Macintosh laryngoscopes for tracheal intubation in patients with immobilized cervical spine 
Saudi Journal of Anaesthesia  2014;8(2):188-192.
Background:
Cervical spine immobilization results in a poor laryngeal view on direct laryngoscopy leading to difficulty in intubation. This randomized prospective study was designed to compare the laryngeal view and ease of intubation with the Macintosh, McCoy, and TruView laryngoscopes in patients with immobilized cervical spine.
Materials and Methods:
60 adult patients of ASA grade I-II with immobilized cervical spine undergoing elective cervical spine surgery were enrolled. Anesthesia was induced with propofol, fentanyl, and vecuronium and maintained with isoflurane and nitrous oxide in oxygen. The patients were randomly allocated into three groups to achieve tracheal intubation with Macintosh, McCoy, or TruView laryngoscopes. When the best possible view of the glottis was obtained, the Cormack-Lehane laryngoscopy grade and the percentage of glottic opening (POGO) score were assessed. Other measurements included the intubation time, the intubation difficulty score, and the intubation success rate. Hemodynamic parameters and any airway complications were also recorded.
Results:
TruView reduced the intubation difficulty score, improved the Cormack and Lehane glottic view, and the POGO score compared with the McCoy and Macintosh laryngoscopes. The first attempt intubation success rate was also high in the TruView laryngoscope group. However, there were no differences in the time required for successful intubation and the overall success rates between the devices tested. No dental injury or hypoxia occurred with either device.
Conclusion:
The use of a TruView laryngoscope resulted in better glottis visualization, easier tracheal intubation, and higher first attempt success rate as compared to Macintosh and McCoy laryngoscopes in immobilized cervical spine patients.
doi:10.4103/1658-354X.130705
PMCID: PMC4024674  PMID: 24843330
Anesthesia: general; cervical immobilization; equipments: Macintosh laryngoscope; McCoy laryngoscope; TruView laryngoscope; technique: tracheal intubation
17.  Effect of Cricoid Pressure on Laryngeal View During Macintosh, McGrath MAC X-Blade and GlideScope Video Laryngoscopies 
Objective
Cricoid pressure is useful in fasted patients requiring emergency intubation. We compared the effect of cricoid pressure on laryngeal view during Macintosh, McGrath MAC X-Blade and GlideScope video laryngoscopy.
Methods
After obtaining approval from the Human Research Ethics Committee and written informed consent from patients, we enrolled 120 patients (American Society of Anesthesiologists I–II, age 18–65 years) undergoing elective surgery that required endotracheal intubation in this prospective randomised study. Patients were divided into three groups (Macintosh, McGrath MAC X-Blade and GlideScope).
Results
Demographic and airway variables were similar in the groups. Cormack-Lehane grades were improved or unchanged on using cricoid pressure in Macintosh and McGrath MAC X-Blade groups. However, laryngeal views worsened in 12 patients (30%), remained unchanged in 26 patients (65%) and improved in 2 patients (5%) in the GlideScope group (p<0.001). Insertion and intubation times for Macintosh and McGrath MAC X-Blade video laryngoscopes were similar. Insertion times for GlideScope and Macintosh video laryngoscopes were similar, but were longer than those for the McGrath MAC X-Blade video laryngoscope (p=0.02). Tracheal intubation took longer with the GlideScope video laryngoscope than with the other devices (p<0.001 and p=0.003). Mean arterial pressures after insertion increased significantly in Macintosh and GlideScope groups (p=0.004 and p=0.001, respectively) compared with post-induction values. Heart rates increased after insertion in all three groups compared with post-induction values (p<0.001). Need for optimisation manoeuvres and postoperative minor complications were comparable in all three groups.
Conclusion
Although all three devices are useful for normal or difficult intubation, cricoid pressure improved Cormack-Lehane grades of Macintosh and McGrath MAC X-Blade video laryngoscopes but statistically significantly worsened that of the GlideScope video laryngoscope.
doi:10.5152/TJAR.2017.57778
PMCID: PMC5772416
Macintosh; McGrath MAC X-Blade; GlideScope; cricoid pressure; laryngeal view; intubation; Cormack-Lehane
18.  Real-Time Subglottic Stenosis Imaging Using Optical Coherence Tomography in the Rabbit 
Importance
Subglottic stenosis (SGS) is a severe, acquired, potentially life-threatening disease that can be caused by endotracheal tube intubation. Newborns and neonates are particularly susceptible to SGS owing to the small caliber of their airway.
Objective
To demonstrate optical coherence tomography (OCT) capabilities in detecting injury and scar formation using a rabbit model. Optical coherence tomography may provide a noninvasive, bedside or intensive care unit modality for the identification of early airway trauma with the intention of preventing progression to SGS and can image the upper airway through an existing endotracheal tube coupled with a small fiber-optic probe.
Design
Rabbits underwent suspension laryngoscopy with induction of of SGS via epithelial injury. This model was used to test and develop our advanced, high-speed, high-resolution OCT imaging system using a 3-dimensional microelectromechanical systems-based scanning device integrated with a fiber-optic probe to acquire high-resolution anatomic images of the subglottic epithelium and lamina propria.
Setting
All experiments were performed at the Beckman Laser Institute animal operating room.
Intervention or Exposure
Optical coherence tomography and endoscopy was performed with suspension laryngoscopy at 6 different time intervals and compared with conventional digital endoscopic images and histologic sections. Fifteen rabbits were killed at 3, 7, 14, 21, and 42 days after the induction of SGS. The laryngotracheal complexes were serially sectioned for histologic analysis.
Main Outcome and Measure
Histologic sections, endoscopic images, and OCT images were compared with one another to determine if OCT could accurately delineate the degree of SGS achieved.
Results
The rabbit model was able to reliably and reproducibly achieve grade I SGS. The real-time OCT imaging system was able to (1) identify multiple structures in the airway; (2) delineate different tissue planes, such as the epithelium, basement membrane, lamina propria, and cartilage; and (3) detect changes in each tissue plane produced by trauma. Optical coherence tomography was also able demonstrate a clear picture of airway injury that correlated with the endoscopic and histologic images. With subjective review, 3 patients had high correlation between OCT and histologic images, 10 demonstrated some correlation with histologic images, and 2 showed little to no correlation with histologic images.
Conclusions and Relevance
Optical coherence tomography, coupled with a fiber-optic probe, identifies subglottic scarring and can detect tissue changes in the rabbit airway to a depth of 1 mm. This technology brings us 1 step closer to minimally invasive subglottic airway monitoring in the intubated neonate, with the ultimate goal of preventing SGS and better managing the airway.
doi:10.1001/jamaoto.2013.2643
PMCID: PMC3893145  PMID: 23681033
19.  Orotracheal intubation of morbidly obese patients, comparison of GlideScope® video laryngoscope and the LMA CTrach™ with direct laryngoscopy 
Background:
Morbidly obese patients are at increased risk of difficult mask ventilation and intubation as well as increased risk of hypoxemia during tracheal intubation. Recently, new video-assisted intubation devices have been developed. The GlideScope® videolaryngoscope and LMA CTrach™ (CT) allows continuous video-endoscopy of the tracheal intubation procedure.
Objective:
this study is to determine whether the GlideScope® videolaryngoscope (GVL) and the LMA CTrach™ (CT) provide the best airway management, measured primarily in intubation difficulty scale (IDS) scores, time and numbers of intubation attempts, and improvement in the intubation success rate of morbidly obese patients when compared with the direct Macintosh laryngoscope (DL).
Materials and Methods:
After Ethics’ Committee approval, 90 morbidly obese patients (BMI > 35 kg/m2) scheduled for general, gynecological, and bariatric surgery were included in this prospective study. Patients were randomly assigned in three groups: tracheal intubation using direct laryngoscopy (DL), GlideScope® videolaryngoscope (GVL) or the LMA CTrach™ (CT). Characteristics and consequences of airway management were evaluated. The primary outcome was the intubation difficulty scale score (IDS), Secondary outcomes were theintubation time, overall success rate, number of attempts, Cormack–Lehane grade, subjective difficulty of intubation, desaturation and upper airway morbidity.
Results:
Difficulty in facemask ventilation was similar in the three groups. IDS scores were significantly lower with GVL and CT than with DL. The mean TTI was 14 s faster in patients intubated with the GVL (86 s, IQR: 68-115) compared with DL (100 s, IQR; 80-150), and was 34 s faster when compared with CT (120 s, IQR; 95-180). The success rate of tracheal intubation was lower with the DL (80%) compared with the GVL (100%) or the CT (100%). Six cases of failed intubation occurred in group DL, four patients from the six patients were intubated successfully with GVL, and two patients were intubated with the CT. Both the GVL and the CTimproved the Cormack and Lehane view obtained at laryngoscopy, compared with the DL. Significantly high percent of patients in DL (43%) and CT (27%) required optimization maneuvers (external laryngeal pressure) compared with GVL (0%). In the CT group, 30% of the patients required laryngeal mask manipulation (for view optimization) compared with (0%) in GVL and CT groups.
Conclusion:
The GlideScope® videolaryngoscope and the LMA CTrach™ reduced the difficulty, improved laryngoscopic views and overall success rate of tracheal Intubationto a similar extent compared with the Macintosh laryngoscope in morbidly obese patients. The GVL improved intubation time for tracheal intubation compared with the CT and DL but no patient became hypoxic with CT because of prolonged intubation time.
doi:10.4103/0259-1162.108304
PMCID: PMC4173448  PMID: 25885612
GlideScope® videolaryngoscope; LMA CTrach™; Macintosh laryngoscope; morbid obese patients; tracheal intubation
20.  Surgical treatment of postintubation tracheal stenosis: Iranian experience of effect of previous tracheostomy 
Background
Postintubation tracheal stenosis remains the most common indication for tracheal surgery. In the event of a rapid and progressive course of the disease after extubation, surgical approaches such as primary resection and anastomosis or various methods of tracheoplasty should be selected. We report our experience with surgical management of moderate to severe postintubation tracheal stenosis. We also compared intraoperative variables in postintubation tracheal stenosis between those with and without previous tracheostomy.
Methods
Over a 5-year period from June 2005 to July 2010, 50 patients aged 14–64 years with moderate (50%–70% of the lumen) to severe (>70%) postintubation tracheal stenosis underwent resection and primary anastomosis. Patients were followed up to assess the surgical outcome. To study the effect of previous tracheostomy on treatment, surgical variables were compared between patients with previous tracheostomy (group A, n = 27) and those without previous tracheostomy (group B, n = 23).
Results
Resection and primary anastomosis was performed via either cervical incision (45 patients) or right thoracotomy (five patients). In two patients with subglottic stenosis, complete resection of the tracheal lesion and anterior portion of cricoid cartilage was performed, and the remaining trachea was anastomosed to the thyroid cartilage using a Montgomery T-tube. There was only one perioperative death in a patient with a tracheo-innominate fistula. The length of the resected segment, number of resected rings, and subsequent duration of surgery were significantly greater in group A compared with group B (P < 0.05). Six months after surgery, the outcome was satisfactory to excellent in 47 (95.9%) patients.
Conclusion
This surgical approach leads to highly successful results in the treatment of moderate to severe postintubation tracheal stenosis. In addition, previous tracheostomy might prolong the duration of surgery and increase the need for postoperative interventions due to an increase in the length and number of resected tracheal segments. Therefore, in the event of emergency tracheostomy in postintubation tracheal stenosis, insertion of the tracheostomy tube close to the stenotic segment is recommended.
doi:10.2147/IJGM.S27559
PMCID: PMC3273371  PMID: 22319246
trachea; tracheostomy; tracheal stenosis; intubation; tracheal resection
21.  Supracricoid partial laryngectomy with crico-hyoido-epiglottopexy for glottic carcinoma with anterior commissure involvement 
SUMMARY
Glottic cancers discovered at an early stage (T1-T2) can be treated with either radiotherapy or surgery. The aim of our study is to analyse survival and functional results of supra-cricoid partial laryngectomy (SCPL) with crico-hyoido-epiglottopexy (CHEP) as surgical treatment for glottic carcinoma with anterior commissure involvement. We performed a retrospective study (1996-2013) which included patients who underwent SCPL-CHEP for glottic squamous cell carcinoma with involvement of the anterior commissure. Before surgery, all patients underwent staging including head, neck and chest CT-scan with contrast injection as well as suspension laryngoscopy under general anaesthesia. A total of 53 patients were included. The median follow-up period was 124 months. Tumour resection was complete in 96.2% of cases. The overall, specific and recurrence-free survival rates at 5 years were, respectively, 93.7%, 95.6% and 87.7%. The average period of hospitalisation was 18 days. The average time elapsed before decannulation and before restoration of oral feeding were 15 and 18 days, respectively. SCPL-CHEP is an important option for laryngeal surgical preservation. It allows adequate disease control as well as good functional results as long as the indications are well respected and the surgical techniques are mastered.
doi:10.14639/0392-100X-1002
PMCID: PMC5463507  PMID: 28516961
Glottic cancer; Anterior commissure; Partial laryngectomy; Survival; Functional results
22.  Traditional transcutaneous approaches in head and neck surgery 
The treatment of laryngeal and hypopharyngeal malignancies remains a challenging task for the head and neck surgeon as the chosen treatment modality often has to bridge the gap between oncologically sound radicality and preservation of function. Due to the increase in transoral laser surgery in early tumor stages and chemoradiation in advanced stages, the usage of traditional transcutaneous approaches has decreased over the recent past. In addition, the need for a function-sparing surgical approach as well as highest possible quality of life has become evident. In view of these facts, rationale and importance of traditional transcutaneous approaches to the treatment of laryngeal and hypopharyngeal malignancies are discussed in a contemporary background.
The transcutaneous open partial laryngectomies remain a valuable tool in the surgeon's armamentarium for the treatment of early and advanced laryngeal carcinomas, especially in cases of impossible laryngeal overview using the rigid laryngoscope. Open partial laryngetomies offer superior overview and oncologic safety at the anterior commissure, especially in recurrencies. In select advanced cases and salvage settings, the supracricoid laryngectomy offers a valuable tool for function-preserving but oncologically safe surgical therapy at the cost of high postoperative morbidity and a very demanding rehabilitation of swallowing.
In hypopharyngeal malignancies, the increasing use of transoral laser surgery has led to a decline in transcutaneous resections via partial pharyngectomy with partial laryngectomy in early tumor stages. In advanced stages of tumors of the piriform sinus and the postcricoid area with involvement of the larynx, total laryngectomy with partial pharyngectomy is an oncologically safe approach. The radical surgical approach using circumferent laryngopharyngectomy with/without esophagectomy is indicated in salvage cases with advanced recurrences or as a primary surgical approach in patients where chemoradiation does not offer sufficient oncologic control or preservation of function.
In cases with impending reconstruction, fasciocutaneous free flaps (anterolateral thigh flap, radial forearm flap) seem to offer superior results to enteric flaps in cases where the cervical esophagus is not involved leading to better voice rehabilitation with fewer complications and postoperative morbidity. In salvage situations, the Gastroomental Free Flap has proven to be a valuable tool.
In conclusion, the choice of a surgical treatment modality is influenced by the patient's anatomy, tumor size and location as well as the surgeon's personal expertise.
doi:10.3205/cto000088
PMCID: PMC3544212  PMID: 23320058
23.  Is there a correlation between right bronchus length and diameter with age? 
Journal of Thoracic Disease  2013;5(3):306-309.
Objective
Right main bronchial anatomy knowledge is essential to guide endoscopic stent placement in modern era. The aim is to describe right bronchial anatomy, cross-area and its relation with the right pulmonary artery and patient’s age.
Methods
One hundred thirty four cadaveric specimens were studied after approval by the Research and Ethics Committee at the University of São Paulo Medical School and Medical Forensic Institute of São Paulo. All necropsies were performed in natura after 24 hours of death and patients with previous pulmonary disease were excluded. Landmarks to start measurement were the first tracheal ring, vertex of carina, first right bronchial ring, and right pulmonary artery area over the right main bronchus. After mobilization, the specimens were measured using a caliper and measurement of distances was recorded in centimeters at landmarks points. All the measures (distances, cross sectional area and planes) were performed by three independent observers and recorded as mean, standard error and ranges. Student t test was used to compare means and linear regression was applied to correlate the measurements.
Results
From 134 specimens studied, 34 were excluded (10 with previous history of pulmonary diseases, surgery or deformities and 24 of female gender). Linear regression showed proportionality between tracheal length and right bronchus length; with the area at first tracheal ring and carina and also between the cross sectional area at these points. Linear regression analysis between tracheal length and age (R=0.593 P<0.005), right bronchus length and age (R=0.523, P<0.005), area of contact between right bronchus and right pulmonary artery and age (R=0.35, P<0.005).
Conclusions
We can conclude that large airways grow progressively with increasing age in male gender. There was a direct correlation between age and tracheal length; as has age and right bronchus length. There was a direct correlation between age and the area of the right bronchus covered by the right pulmonary artery.
doi:10.3978/j.issn.2072-1439.2013.03.12
PMCID: PMC3698291  PMID: 23825764
Anatomy; right bronchus; trachea; gender; age; human
24.  Inter-Racial, Gender and Aging Influences in the Length of Anterior Commissure-Posterior Commissure Line 
Objective
The length of anterior-posterior commissure (AC-PC) in racial groups, age, gender of patients with deep brain stimulation (DBS) and pallidotomy were investigated.
Methods
From January 1996 to December 2003, 211 patients were treated with DBS and pallidotomy. There were 160 (76%) Caucasians, 35 (17%) Hispanics, 12 (5%) Asians and 4 Blacks (2%). There were 88 males and 52 females in DBS-surgery group and 44 males, 27 females in pallidotomy group. Mean age was 58 year-old. There were 19 males and 19 females and mean age was 54.7 years in the control group. Measurements were made on MRI and @Target software.
Results
The average AC-PC distance was 24.89 mm (range 32 to 19), which increased with aging until 75 years old in Caucasian and also increased with aging in Hispanic, but the AC-PC distance peaked at 45 years old in Hispanic. The order of AC-PC distance were 25.2±2 mm in Caucasian, 24.6±2.24 mm in Asian, 24.53 mm in Black, 23.6±1.98 mm in Hispanic. The average AC-PC distance in all groups was 24.22 mm in female who was mean age of 56.35, 25.28 mm in male who was mean age of 60.19 and 24.5±2 mm in control group that was excluded because of the difference of thickness of slice. According to multiple regression analysis, the AC-PC distance was significantly correlated with age, race, and gender.
Conclusion
The AC-PC distance is significantly correlated with age, gender, and race. The atlas of functional stereotaxis would be depended on the variation of indivisual brain that can influenced by aging, gender, and race.
doi:10.3340/jkns.2008.43.2.79
PMCID: PMC2588230  PMID: 19096609
Pallidotomy; Anterior commissure; Posterior commissure
25.  A comparative study to find out the relationship between the inner inter-canthal distance, interpupillary distance, inter-commissural width, inter-alar width, and the width of maxillary anterior teeth in Aryans and Mongoloids 
Background
One of the most confusing and difficult aspects of complete denture prosthodontics is the selection of appropriately sized maxillary anterior denture teeth. Various guidelines have been suggested for determining the size of anterior teeth, but different opinions have been reported regarding their significance. In the study reported here, the relationships between facial measurements and the width of maxillary anterior teeth in two ethnic groups, namely Aryans and Mongoloids, were determined.
Objective
The aims of the study were to determine the inner inter-canthal distance (ICAD), inter-pupillary distance (IPD), inter-commissural width (ICOW), inter-alar width (IAW), and the combined width of maxillary anterior teeth (CW) in Aryans and Mongoloids and to determine the relationships between these measurements.
Materials and methods
Impressions of the teeth of 170 dentulous subjects (85 males and 85 females) were made with alginate then Type IV gypsum product was poured in. Measurements of the cast maxillary anterior teeth at their widest dimension (contact areas) were made with the Boley gauge. ICAD, IPD, ICOW, and IAW distances were also measured with a Boley gauge.
Results
For all 170 subjects, 85 Aryans and 85 Mongoloids, Pearson’s correlation coefficient (r) for IAW, IPD, ICOW, ICAD, and CW was calculated. In Aryans, highly significant (P<0.001) but weak correlations were found between CW and IAW, IPD, and ICOW. In Mongoloids, a highly significant (P<0.001) and weak correlation was found only between CW and IPD.
Conclusion
Within the limitations of this study, the results suggest that the IAW, IPD, and ICOW for Aryans and IPD for Mongoloids can be used as a preliminary method for determining the width of the maxillary anterior teeth in edentulous patients.
doi:10.2147/CCIDE.S87837
PMCID: PMC4772945  PMID: 26955292
maxillary anterior denture teeth; facial measurements; maxillary anterior teeth width; Nepal

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