CT and MR anatomy of the larynx and hypopharynx.

Imaging of the larynx and hypopharynx is frequently requested to assess the extent of neoplasms beyond the field of view of endoscopic evaluation. The combination of optical and cross-sectional imaging allows tumors to be classified according to AJCC/UICC guidelines. A thorough understanding of laryngeal and hypopharyngeal anatomy is crucial to guide the radiological eye along the possible pathways of the spread of diseases and to guide differential diagnoses. Computed tomography (CT) has been the first cross-sectional imaging technique used to evaluate the larynx and hypopharynx; its spatial resolution combined with volumetric capability and the use of injectable contrast medium made CT the working horse in the assessment of neoplastic and inflammatory diseases. In the last two decades, magnetic resonance (MR) supported CT in the most challenging cases, when the optimal contrast resolution due to the multisequence portfolio is needed to assess the neoplastic involvement of laryngeal cartilages, paraglottic space(s), and extra laryngeal spread. The aim of this paper is to give a comprehensive radiological overview of larynx and hypopharynx complex anatomy, combining in vivo images, anatomical sections, and images of ex vivo specimens.

Cone-beam computed tomography airway measurements: Can we trust them?

INTRODUCTION: Pharyngeal airway space (PAS) assessment has been used in the past for a better understanding of orthodontic and surgical outcomes; however, this analysis could be unreliable. Our objective was to evaluate possible changes in the PAS reading in the same patient from their consecutive cone-beam computed tomography (CBCT) scans. METHODS: We evaluated a total of 27 patients' CBCT scans obtained at 2 time points with the use of a standardized acquisition protocol. The mean age at T0 was 31 years (range 17-62 years) and the follow-up records (T1) were taken after 4-6 months. Dolphin Imaging software was used to measure the volumes of the nasopharynx, oropharynx, and hypopharynx. We also evaluated the craniocervical position with the use of a lateral cephalogram. RESULTS: The variables exhibited high intraclass correlation coefficients (ICCs) when measuring the same CBCT scan twice (T0 and T0). However, The ICC between the measurements performed on the first and second CBCT scans (T0 and T1) showed that the only variable with high reproducibility between the 2 scans was cranial base, with an ICC >0.97. Average differences of 682.1 mm3, 2255.3 mm3, and 517.4 mm3 were found for the nasopharynx, oropharynx, and hypopharynx, respectively. Regarding the cephalometric angles, average differences between T0 and T1 scans were 0.6°, 2.7°, and 0.4° for OPT.CVT, OPT.SN, and cranial base, respectively. CONCLUSIONS: Different CBCT exams with equal scanning and patient positioning protocols can result in different 3D PAS readings. A more careful interpretation of CBCT volumetric data to achieve adequate conclusions of the clinical outcomes is necessary.

Can anatomical assessment of hypopharyngolarynx in awake patients predict obstructive sleep apnea?

OBJECTIVES/HYPOTHESIS: To assess the relationships between laryngeal and hypopharyngeal morphology and obstructive sleep apnea-hypopnea syndrome (OSAHS) in awake patients. STUDY DESIGN: Prospective study. METHODS: Awake flexible fiberoptic laryngoscopy and sleep studies were performed in 80 patients for snoring or OSAHS suspicion. Endoscopic videos were reviewed by two examiners to assess morphological characteristics of hypopharynx and larynx using a standardized examination of appearance, shape and position of epiglottis, shape of retropharyngeal-epiglottic aerospace (RPEA), modified Cormack-Lehane score, and length ratios of the hypopharynx and epiglottis. The multivariate logistic regression model was used to assess independent predictors of moderate/severe OSAHS. RESULTS: The interrater agreements were moderate for epiglottis appearance (κ = 0.52), epiglottis form (κ = 0.66), and epiglottis position (κ = 0.49), but fair for the shape of RPEA (κ = 0.26) and modified Cormack-Lehane scoring (κ = 0.38). The presence of a mega-epiglottis was significantly correlated with the severity of OSAHS (P < .05). By multivariate logistic regression analysis, independent predictors of moderate/severe obstructive sleep apnea were mega-epiglottis (adjusted odds ratio [aOR]: = 4.78, 95% confidence interval [CI]: 1.23-18.56, P = .024), modified Cormack-Lehane score of 2 (aOR: 15.3, 95% CI: 1.8-130.3, P = .012), or modified Cormack-Lehane score of 3 (aOR: 10.03, 95% CI: 1.3-78.2, P = .03) and aging (aOR = 1.07, 95% CI: 1.01-1.14, P = .025). CONCLUSIONS: Routine flexible fiberoptic laryngoscopy performed by otorhinolaryngologists in awake patients may help to detect some predictors of OSAHS such as presence of mega-epiglottis, and modified Cormack-Lehane score of 2 or more. Investigation of sleep disorders should be proposed in these patients. LEVEL OF EVIDENCE: 2 Laryngoscope, 129:2782-2788, 2019.

Two-dimensional and three-dimensional assessment of the upper airway / Evaluación bidimensional y tridimensional de la vía aérea superior

The aim of this study was to validate and correlate the two-dimensional (2D) with the three-dimensional (3D) measures of the upper airway assessment. Lateral cephalograms and cone beam CT of 100 adult subjects were used to perform a 2D and 3D assessment of the upper airway. Spearman correlation coefficient was used to determine whether there was correlation between variables. Additionally, specificity, sensitivity, negative predictive value and positive predictive value was calculated for the 2D assessment of the upper airway. Correlation between all two and three dimensional variables was found. In the nasopharynx and oropharynx, a weak correlation (r <0.51) was found; in the oropharynx a moderate one (0.50

El objetivo de este estudio fue validar y correlacionar las medidas bidimensionales (2D) con las medidas tridimensionales (3D) de la evaluación de las vías aéreas superiores. Se realizaron cefalogramas laterales y cone beam CT en 100 sujetos adultos para realizar una evaluación 2D y 3D de la vía aérea superior. Se utilizó el coeficiente de correlación de Spearman para determinar si había correlación entre las variables. Además, para la evaluación 2D de la vía aérea superior, se calculó la especificidad, sensibilidad, valor predictivo negativo y valor predictivo positivo. Se encontró correlación en todas las variables entre dos y tres dimensiones. En la nasofaringe y la orofaringe, se encontró una correlación débil (r <0,51) mientras que en la orofaringe moderada (0,50

Impact on the upper airway space of different types of orthognathic surgery for the correction of skeletal class III malocclusion: A systematic review and meta-analysis.

OBJECTIVE: This study is aimed at assembling, through a systematic review and meta-analysis, scientific evidence related to the effects of mandibular setback (MdS) surgery and bimaxillary surgery for the correction of Class III malocclusion on the cross-sectional area (CSA) and volume of the upper airway as assessed using CT. METHODS: An electronic search was conducted on Cochrane Library, EMBASE, PubMed, Scopus and Web of Science up to June 20, 2016. The inclusion criteria were prospective or retrospective studies, with the aim of comparing the impact on the upper airway space of orthognathic surgery for the treatment of the skeletal class III malocclusion. The methodological index for non-randomized studies (MINORS) was chosen as the evaluation instrument and Revman5.3 was used for the meta-analysis. RESULTS: A total of 1213 studies were retrieved, of which only 18 met the eligibility criteria. The results of meta-analysis showed that the mean decrease in the upper airway volume after MdS surgery was 3.24 cm3 [95%CI (-5.25,-1.23), p = 0.85]; the mean decrease in minimum CSA after a combined surgery of maxillary advancement with mandibular setback (MdS + MxA) was 27.66 mm2 [95%CI (-52.81,-2.51), p = 0.51], but there was no significant decrease in upper airway volume (mean 0.86 cm3); comparison between MdS + MxA and isolated MdS showed significant differences in the CSA of the posterior nasal spine plane (PNS) and epiglottis plane (EP); statistically significant differences in nasopharynx volume (P < 0.0001) and upper airway total volume (P = 0.002) were observed, but no statistically meaningful variations existed in oropharynx volume (P = 0.08) and hypopharynx volume (P = 0.64). CONCLUSION: The results of this study suggest that bimaxillary surgery promotes less decrease on the upper airway than mandibular setback surgery alone for the correction of the skeletal class III malocclusion.

Histoanatomical characteristics to increase the success in transoral surgery for hypopharyngeal cancer.

OBJECTIVES/HYPOTHESIS: Transoral laser microsurgery (TLM) for hypopharyngeal cancer results in a lower incidence of complications than conventional open surgery. However, additional knowledge regarding the histoanatomical characteristics of the hypopharynx is necessary to prevent severe complications during TLM. The purpose of this study is to investigate the histoanatomical characteristics of the hypopharynx for TLM. STUDY DESIGN: Histoanatomical study. METHODS: Whole organ serial sections of three hypopharynges and larynges from autopsy cases were subjected to hematoxylin & eosin and Elastica van Gieson staining. Surgical histoanatomy of the hypopharynx was observed with each section, and the histoanatomical characteristics directly related to TLM performance were examined microscopically. RESULTS: The histological structures of muscle layers showed obvious differences between each hypopharyngeal subsite. The posterolateral wall had two kinds of pharyngeal elevator muscles. These fasciae were connected to the perichondrium of the thyroid cartilage. The anterolateral wall between the superior horn and the lamina of the thyroid cartilage had no muscle layer. The superior laryngeal artery and the internal branch of the superior laryngeal nerve run into the larynx and hypopharynx at that site. The inner perichondrium of the thyroid cartilage was present beneath the mucosa. The dihedral angle of the anterior piriform fossa had a deep propria mucosa and paraglottic space. The postcricoid wall consisted of a multilayered structure, including cricoid cartilage covered with laryngeal muscles and mucosa. CONCLUSION: A precise understanding of the histoanatomical characteristics of the hypopharynx increases the success of TLM, decreases complication rates, and improves laryngeal preservation. LEVEL OF EVIDENCE: N/A. Laryngoscope, 126:1783-1789, 2016.

Effects of Le Fort I Osteotomy on the Nasopharyngeal Airway-6-Month Follow-Up.

PURPOSE: The literature discussing the impact of a single Le Fort I osteotomy on nasopharyngeal airways is limited. This study assessed the volumetric changes in the nasopharyngeal airway after a single Le Fort I osteotomy and explored the correlation between these changes and 3-dimensional surgical movements of the upper jaw. MATERIALS AND METHODS: This retrospective study was conducted in 40 patients who had undergone a single Le Fort I (maxillary advancement with or without impaction) to correct Class III malocclusion with maxillary hypoplasia. Preoperative (T1) and 6-month postoperative (T2) cone-beam computed tomographic (CBCT) scans of these patients were used for analysis. Maxillary surgical movements and volumetric changes in the nasopharyngeal airway were measured. The reproducibility of the measurements was evaluated using paired t tests and intraclass correlation coefficients. The Wilcoxon test and Pearson correlation coefficient were applied to evaluate the volumetric changes in the nasopharyngeal airway space and assess the correlations of these changes to the maxillary surgical movements. RESULTS: Six patients were excluded from the study owing to major differences (>5°) in their head and neck posture between the T1 and T2 CBCT scans. The errors of the repeated measurements were insignificant (P > .05), with a high level of agreement (r = 0.99; P < .05) between the repeated digitization of the landmarks. There was a statistically significant impact of a Le Fort I osteotomy on the right maxillary sinus (decreased by 17.8%) and the lower retropalatal space (expanded by 17.3%; P < .05). The correlation between the change in airway volume and the magnitude of surgical maxillary movements was moderate (r = .4). Similarly, there was a moderate correlation between changes in the upper nasopharynx and those in the hypopharynx. CONCLUSION: The single Le Fort I osteotomy was found to increase the retroglossal airway volume. This could be important for the treatment of obstructive sleep apnea in patients with maxillary deficiency. A long-term follow-up assessment of a larger sample with a functional assessment of airway would be beneficial to confirm these findings.

Visual evaluation of the larynx and hypopharynx during esophagogastroduodenoscopy: a safety and feasibility study.

BACKGROUND: The larynx and hypopharynx are common sites for head and neck cancer, which shares many risk factors with upper digestive tract disease. Patient survival with malignancies depends on stage at the time of diagnosis. Endoscopic screening of the hypopharynx is neither routinely performed in clinical practice nor has it been evaluated in a formal study. METHODS: This is a prospective pilot study of patients undergoing routine EGD. Demographic data were collected from patients prior to the procedure. All patients in the study underwent an EGD and prior to performing the standard portion of the EGD procedure, the endoscopist evaluated the larynx and hypopharynx with both white light endoscopy (WLE) and narrow band imaging (NBI). Details of the procedure, including ability to see all anatomic structures, time spent, complications, and findings, were recorded. RESULTS: A total of 111 patients were included in the study. The exam of the laryngopharynx was completed in 87% of patients (97/111). Reasons for incomplete exam included intubated patients (2/14), inadequate sedation (9/14), and inability to see the entire hypopharynx (3/14). The mean time of the WLE was 20.2 s, while the NBI evaluation took 15.6 s for a mean and 35.8 s for the entire exam of the larynx and hypopharynx. Minor procedural complications occurred in 3/11 (2.7%) of the patients and included hypotension, tachycardia, and hypoxia. There were 6 patients who had hypopharyngeal abnormalities seen on both WLE and NBI (5.4%) and were subsequently referred to otolaryngology. Of the six referrals, one patient had a vocal cord biopsy showing leukoplakia, while the others were deemed normal anatomic variants. CONCLUSIONS: Evaluation of the hypopharynx can be accomplished by gastrointestinal endoscopists at the time of EGD in the vast majority of patients in a safe manner while adding only about 35 s to the overall exam time.

[Cone-beam computed tomography evaluation of upper airway change in skeletal Class III patients after orthodontic-mandibular setback surgery].

OBJECTIVE: To evaluate the short-term and long-term effects of pharyngeal airway in mandibular prognathism patients after the combined orthodontic and orthognathic treatment. METHODS: The sample included 28 skeletal Class III patients (13 males, 15 females) who had undergone mandibular setback surgery and orthodontic treatment. Cone-beam CT was taken one week before treatment (T0), 6 months (T1) and 3 years after surgery (T2). Raw data were reconstructed into three-dimensional model. Sagittal and transversal measurements, cross sectional areas, partial and total volumes were computed. RESULTS: Six months after surgery, oropharyngeal volume [(9 021 ± 4 263) mm³], hypopharyngeal volume [(9 236 ± 5 963) mm³] and total volume [(28 619 ± 9 854) mm³] decreased significantly (P < 0.05). Three years after surgery, only sagittal diameters [(15.9 ± 3.5) mm] and cross sectional areas [(996 ± 398) mm²] in the first cervical vertebra plane came back to the original levels (P > 0.05). CONCLUSIONS: The pharyngeal airway space decreased after orthodontic-orthognathic therapy in the short term and it increased in some areas in the long term.

Pharyngeal airway space in subjects with class II and class III facial deformities / Espacio de la vía aérea faríngea en sujetos con deformidad facial clase II y clase III

Facial deformities are related to morphological differences and the mandible position shows differences in maxillomandible relation. The aim of this research was to compare the pharyngeal airway space (PAS) in subjects with class II and class III facial deformities We included 28 adult subjects with skeletal characteristics associated to class II or class III according to the SNA angle and dental overjet; subjects with facial asymmetry and other facial deformities and subjects with facial trauma or facial surgery history were excluded. Cone beam computed tomography was realized (CBCT) to asses the nasopharynx, oropharynx, hypopharynx, as well as the distance measured between the mandible genial spine and hyoid bone; data analysis were realized by descriptive analysis and statistical analysis using t test with 0.05 to show statistical differences. Class II subjects presented minor values in all of the measurements; in the oropharynx and the hypopharynx we observed the most important differences, with nasopharynx showing statistically significant differences (p<0.05). In conclusion class II subjects presented a minor pharyngeal airway space and it is suggested that this information should be used in the diagnosis process and prior to surgical treatment.

Las deformidades faciales son asociadas a diferencias en la posición mandibular evidenciando diferencias en la relación maxilomandibular. El objetivo de esta investigación fue comparar el espacio aéreo faríngeo en sujetos con deformidad facial clase II y clase III. Se incluyeron 28 sujetos con características esqueletales asociadas a clase II o clase III seguidos de la evaluación del angulo SNA y el resalte dentario; se excluyeron los sujetos con asimetría facial y otras deformidades faciales y sujetos con historia de trauma facial o historia de cirugía facial; se realizó la tomografía computadorizada cone beam para evaluar el área de nasofaringe, orofaringe, hipofaringe y la distancia entre la espina geni mandibular y el hueso hioides; los datos se analizaron con estadística descriptiva y la prueba t usando un valor de 0,05 para establecer significancia estadística. Se observó que los sujetos de clase II presentaron valores menores a los sujetos clase III en todas las mediciones realizadas; en el área de orofaringe e hipofaringe se observaron las diferencias mas importantes, estadísticamente significativas (p<0,05). Se puede concluir que los sujetos con deformidad facial clase II presentan un espacio de vía aérea faríngea más estrecho y se sugiere que este temática sea resuelta en la etapa de diagnóstico previo a la selección de tratamientos quirúrgicos o no quirúrgicos.

Pharyngeal airway space, hyoid bone position, and head posture after bimaxillary orthognathic surgery in Class III patients: long-term evaluation.

OBJECTIVE: (1) To determine the effect of bimaxillary orthognathic surgery on pharyngeal airway, hyoid bone, and craniocervical posture in Class III bimaxillary surgery patients. (2) To evaluate short-term and long-term results. (3) To compare short- and long-term values. MATERIALS AND METHODS: Twenty-six Class III adult patients treated with bimaxillary surgery were included in the study. Cephalometric records were taken before treatment (T1), before surgery (T2), and 5 months (T3), 1.4 years (T4), 3 years (T5), and 5 years (T6) postsurgery. RESULTS: No significant differences were identified in craniocervical angulation between time intervals. There was a significant superior movement of hyoid bone at postsurgery (T3; P < .05); however, adaptation occurred to the normal position in the long term. A nonsignificant decrease occurred at the oropharyngeal middle pharyngeal distance parameter; however, this was compensated with a significant increase between T5 and T6 (P < .001). A significant decrease was observed in the hypopharyngeal Go-P parameter between T3 and T1 (P < .01), but it recovered with a nonsignificant increase in the long term. A significant increase in nasopharyngeal area was observed between T3 and T1 (P < .05). The hypopharyngeal area significantly increased between T5 and T6, and PNS-R significantly increased between T3 and T1 (P < .05). CONCLUSION: The pharyngeal areas adversely affected after surgery recover at long-term follow-up; thus, adaptation occurs after bimaxillary surgery.

Pitfalls in the staging squamous cell carcinoma of the hypopharynx.

To accurately interpret pretreatment and posttreatment imaging in patients with hypopharyngeal squamous cell carcinoma (SCC), one must understand the complex anatomy of this part of the aerodigestive system. Common patterns of spread must be recognized, andpitfalls in imaging must be understood. This article reviews the epidemiology, anatomy, staging, treatment, and pitfalls in imaging of hypopharyngeal SCC.

Risk factors for decreased distance between internal carotid artery and pharyngeal wall.

OBJECTIVES: The risk of disastrous bleeding during pharyngeal surgery is increased in cases of an internal carotid artery (ICA) that is medially displaced due to its anomalous course. We attempted to assess the distance between the ICA and the pharyngeal wall (DIP) and to evaluate the predisposing factors associated with ICA variation. METHODS: The course of ICA was studied in 509 CT scans, and a retrospective chart review was performed. The course of ICA and DIP were evaluated at each level of the pharynx: nasopharynx (NP), oropharynx (OP), and hypopharynx (HP). RESULTS: The mean DIP value was greatest (15.8±4.6mm) at NP, decreased at OP (15.8±4.6mm), and was shortest at HP (13.5±6.0mm). DIP was significantly shorter in females compared with males at all three pharyngeal levels. Age was inversely correlated with DIP at NP and OP. Tortuous ICA was most common (51.4%), followed by straight (41.2%), kinking (6.9%), and coiling (0.5%) types. DIP was longest in the straight type and decreased as the curvature of ICA increased. The most common ICA type differed between younger (<60 years; 56.2% having the straight type) and older groups (≥60 years; 66.2% having the tortuous type). Females older than 60 years displayed a higher incidence of kinking ICA compared with males. CONCLUSIONS: Hypopharynx, old age, female gender, and tortuous or kinking ICA types were risk factors for a decreased distance between the ICA and the pharyngeal wall. Meticulous examination of the pharyngeal wall should therefore be performed prior to pharyngeal surgery in patients with these associated risk factors.

[Hypopharynx and larynx cancers: propositions for the selection and the delineation of peritumoral microscopic disease volumes (lymph nodes excluded)]. / Cancer de l'hypopharynx et du larynx : proposition de sélection et délimitation des volumes cibles microscopiques péri-tumoraux (aires ganglionnaires exclues).

This article reviews the concept of selectivity in peritumoral microscopic disease to be included in the Clinical Target Volume (CTV) for elective treatment for larynx and hypopharynx squamous cell carcinoma (50 Gy or 54-60 Gy for SIB-IMRT), using the local tumoral spread. The objective of the present article is to present the different delineations of the target volumes, required for an appropriate application of 3-DCRT and IMRT (supraglottic larynx, vocal cord, subglottic larynx, pyriform sinus, lateral and posterior pharyngeal wall and postcricoid pharynx). These propositions are for the delineation of microscopic peritumoral target volumes when external beam irradiation is required. CTVs are illustrated on CT sections.

Two- and three-dimensional evaluation of the upper airway after bimaxillary correction of Class III malocclusion.

OBJECTIVE: The aim the study was to evaluate area and volumetric changes in the upper airway after bimaxillary correction of Class III malocclusion by the means of computer tomography (CT), and to compare these to the changes in linear measurements from lateral cephalograms. STUDY DESIGN: This was a prospective clinical trial. Lateral cephalograms and CT scans of 10 Class III patients were evaluated 1 week before and 6 months after surgery. Wilcoxon matched pairs signed ranks test was used to determine the differences in measurements pre- and postoperatively. Spearman's rank correlation was used to test the association between the CT and cephalometric measurements. RESULTS: CT measurements: The oropharyngeal and hypopharyngeal volumes increased by 3.98 +/- 4.18 cm(3) (P = .015) and 2.51 +/- 1.92 cm(3) (P = .021), respectively. The total volume of the posterior airway space increased, but the increase was not statistically significant. After surgery no change in the cross-sectional area of the upper airway was recorded at the retropalatal, oropharyngeal, or hypopharyngeal levels. Cephalometric measurements: The nasopharyngeal space increased 4.08 +/- 5.07 mm (P = .039) and the tongue increased in length by 4.84 +/- 5.93 mm (P = .22). No correlation was found between the measurements on CT scans and corresponding measurements on the lateral cephalograms. CONCLUSIONS: Bimaxillary surgery for correction of Class III malocclusion did not cause decrease of the posterior airway space. Three-dimensional imaging techniques are preferable to 2-dimensional lateral cephalograms for evaluation of the upper airway after orthognathic procedures.

Imaging of the larynx and hypopharynx.

The purpose of this article is to review currently used imaging protocols for the evaluation of pathologic conditions of the larynx and hypopharynx, to describe key anatomic structures in the larynx and hypopharynx that are relevant to tumor spread and to discuss the clinical role of Computed Tomography (CT), Magnetic Resonance Imaging (MRI) and PET CT in the pretherapeutic workup and posttherapeutic follow-up of patients with squamous cell carcinoma of this region. A detailed discussion of the characteristic neoplastic submucosal invasion patterns, including extension to the preepiglottic space, paraglottic space and laryngeal cartilages and the implications of imaging for tumor staging and treatment planning is provided. The present article also reviews less common tumors of this region, such as chondrosarcoma, lymphoma, minor salivary gland tumors and lipoma. As the majority of non-neoplastic conditions do not require imaging the role of CT and MRI is discussed in some particular situations, such as to delineate cysts and laryngoceles, abscess formation in inflammatory conditions, to evaluate laryngeal and hypopharyngeal involvement in granulomatous and autoimmune diseases, and to evaluate the extent of laryngeal fractures due to severe blunt trauma.

Nutritional support during radiotherapy for head and neck cancer: the role of prophylactic feeding tube placement.

Significant weight loss and resultant malnutrition in patients undergoing radiotherapy for head and neck carcinomas are recognized and preventable clinical concerns. Morbidity related to weight loss during treatment may include dehydration, hospitalization, compromised treatment efficacy, and reduced quality of life and may impact survival. Malnutrition effects on wound healing may prolong recovery following treatment and increase the risk of morbidity for those undergoing subsequent salvage surgery. Multiple interventions have been implemented to help ameliorate the impact of treatment on weight loss and nutritional status, including the use of percutaneous endoscopic gastrostomy (PEG) tubes. The value of prophylactic PEG tube placement at treatment initiation increasingly is being recognized, and evidence suggests that patients experience better outcomes. Criteria for patient selection have not been defined completely, and a great deal of variation in clinical practice exists, contributing to underuse of this supportive intervention. According to a literature review, patients who require therapeutic PEG tube placement in response to significant weight loss during treatment suffer greater morbidity than patients who receive PEG tubes prophylactically. Understanding patient-, tumor-, and treatment-related risk factors to systematically identify patients most likely to benefit from prophylactic PEG tube placement is an important aspect of nursing care.

Head torsion technique for detailed observation of larynx and hypopharynx.

We introduce here an easy but effective method for detailed observation of the larynx and hypopharynx. During the endoscopic observation, the patient's head is turned to one side. Anatomical structures on the same side of the endolarynx, such as the laryngeal ventricle and inferior surface of the vocal fold, are easily observed. In addition, observation of the opposite side of the hypopharynx also becomes easier. Such head turning is also useful in patients with an oblique larynx, in whom the epiglottis obstructs insertion of the endoscope. This is a simple but very effective technique for laryngeal and hypopharyngeal observation.