Hiroyuki Hiramatsu

Usefulness of three-dimensional computed tomography of the larynx for evaluation of unilateral vocal fold paralysis before and after treatment: technique and clinical applications

Laryngoplasty is well-known technique for unilateral vocal fold paralysis (UVFP). However, operation result are sometimes not as good as expected before surgery. Three-dimensional Computed tomography (3DCT) is useful for visualizing complicated intralaryngeal structures. Moreover, 3DCT is suited for analyzing the movement of the vocal fold and arytenoid cartilage because the technique is based on actual data from live patients. We have been used 3DCT of the Larynx for evaluation of UVFP before and after treatment. We uncovered some new findings about UVFP and reasons of unsatisfactory outcomes after operation. Technique and clinical applications of 3DCT for UVFP are outlined in this paper.

Characterization of arytenoid vertical displacement in unilateral vocal fold paralysis by three-dimensional computed tomography

The paralyzed arytenoid is not immobile and is subjected to passive movement during phonation. If anatomical changes during inspiration and phonation are compared by three-dimensional computed tomography (3D CT), it is possible to observe vertical movement of the paralyzed arytenoid. Our aim was to use 3D CT to examine the characteristics of 3D arytenoid movement in unilateral vocal fold paralysis (UVFP). This is a prospective study. A total of 61 patients (18 females and 43 males) with UVFP who had undergone 3D CT imaging between April 2005 and January 2007 were included. Cricoid and arytenoid cartilage was imaged by 3D CT. We detected the movements of the paralyzed side when comparing inspiration and phonation. The degree of cranial displacement of the paralyzed arytenoids was classified into three grades (I for mild to III for severe). The mean flow rate (MFR) was calculated for each grade. By comparing the MFR of each grade with the normal control group, we determined whether cases would worsen according to grade. Passive gliding movement of the paralyzed arytenoids was found in 90.7% of cases. In all cases, the paralyzed arytenoids were displaced cranially compared to the unaffected side. MFR worsened significantly as the grade became more severe. We believe that the passive gliding movements observed when comparing inspiration and phonation are characteristic of paralysis. Even in mild cases, the paralyzed arytenoids are passively displaced cranially during phonation, and the degree of this displacement is one indicator that can be used to evaluate the severity of UVFP.

New approach to diagnose arytenoid dislocation and subluxation using three-dimensional computed tomography

Understanding the complex three-dimensional (3D) arrangement of the arytenoid cartilage is necessary for diagnosing arytenoid dislocation (AD) and arytenoid subluxation (AS). We examined the 3D arrangements of AD and AS (AD/AS) cases by region and considered their new diagnoses. This retrospective study included 2 patients with AD, 10 with AS, and 23 with unilateral vocal fold paralysis (UVFP) for comparison. The etiologies were intubation-induced and idiopathic. We classified the AD/AS position into four joint regions: mediocaudal, laterocaudal, mediocranial, and laterocranial. We generated 3D computed tomography (3DCT) images during rest and phonation to analyze functional movements. We attempted to compare the endoscopic findings and 3DCT images of patients with UVFP and AD/AS. To examine the joint status, we especially focused on the position and movements of the muscular process (MP) on the joint because the arytenoid facet is mainly located on the back of the MP. We were able to obtain endoscopic and 3DCT findings characteristic of each AD/AS region. The dislocated MPs were localized to the mediocaudal, mediocranial, and laterocranial regions. Two AD cases were diagnosed due to complete separation of the joint surfaces during rest and phonation. The finding of MPs displacing partially outside the cricoid facet is common to both severe UVFP and AS. The most important differentiation point was that the MP in UVFP cases was located on both the medial and lateral side regions of the joint, but that of AS was on one side region only. Furthermore, no cases of passive gliding movements characteristic of UVFP that have been described previously by us were observed in AD/AS cases. AD can be diagnosed by findings of complete joint separation. AS can be diagnosed based on positions and movements distinct from those of UVFP.

Therapeutic effects of a new photosensitizer for photodynamic therapy of early head and neck cancer in relation to tissue concentration.

OBJECTIVE Talaporfin sodium (Laserphyrin, Meiji Seika, Tokyo, Japan) is a second-generation photosensitizer developed in Japan. It is characterized by both mild and short-term skin photosensitivity. The objective of this study was to evaluate the efficacy and the pharmacokinetic characteristics in tumor tissues in patients with head and neck cancer. METHODS (1) Four hours after administration intravenous injection of talaporfin sodium (40 mg/m(2)), 100mg tissue specimens were taken from the central part of the tumor. The samples were analyzed by reverse phase liquid chromatography and concentrations were measured. (2) Four hours after intravenous injection of talaporfin sodium (40 mg/m(2)), we gave 60-150 J/cm(2) of 664 nm laser irradiation with a diode laser (PD laser, Panasonic, Japan). Biopsies were performed at 4 weeks and at 3 months after treatment and periodically thereafter to confirm the treatment efficacy of photodynamic therapy (PDT). RESULTS Of the 14 patients who grope informed consent, more than 1 microg/g of talaporfin sodium was found in the tumor tissues in 13. Moreover, in 9 patients, tumor-to-normal-tissue ratios ranged from 2.32:1 to 5.69:1, which indicates that more than double the amount of talaporfin sodium was maintained within the tumor than in normal tissues. We have enrolled 22 patients with head and neck cancer with no clinically recognizable metastases after obtaining written informed consent to participate in this study. PDT using talaporfin sodium exhibited the equivalent efficacy to that of conventional PDT using hematoporphyrin derivative (HpD). CONCLUSIONS The results using a combination of talaporfin sodium and PD laser achieved a primary treatment outcome equivalent to that of conventional PDT. This method has also proven to be advantageous because of the reduced incidence of side effects such as photosensitivity and local edema.

Efficacy of total intravenous anesthesia without intubation for laryngeal framework surgery

Conclusion. Total intravenous anesthesia (TIVA) without intubation has the advantages of both conventional general anesthesia and local anesthesia. It is useful in laryngeal framework surgery because intraoperative voice monitoring while the patient remains awake is required. Objective. In laryngeal framework surgery, it is desirable to monitor the voice during surgery. However, surgery is conducted under general anesthesia, although such a procedure renders the patient unable to phonate during surgery. We conducted TIVA without intubation, allowing patients to breathe spontaneously while undergoing operation, and succeeded in intraoperative voice monitoring with satisfactory postoperative voice production. Subjects and methods. The subjects were 21 patients who underwent surgery. For TIVA, propofol and pentazocine were used as a sedative and analgesic, respectively. A bispectral index (BIS) monitor was used to measure the depth of the anesthesia. Before the vocal folds were to be rotated, propofol administration was interrupted to arouse and instruct the patient to phonate. Guided by the phonation, the vocal folds were correctly positioned. Then propofol administration was resumed, and the wound was closed. Results. The BIS value during continued administration of propofol was around 60, but exceeded 90 in all patients within 233.6±64.5 s after cessation. They clearly remembered the conversation they had with us during surgery.

Three-dimensional laryngeal model for planning of laryngeal framework surgery

Conclusion. The three-dimensional prototype model was useful for planning of laryngeal framework surgery. Objective: To discuss the usefulness of a three-dimensional laryngeal model for laryngeal framework surgery. Materials and methods. A three-dimensional laryngeal model was created based on the postoperative helical computed tomography (CT) data of the larynx (case 1) which underwent lateral cricoarytenoid muscle (LCA) pull surgery. LCA pull surgery is a kind of arytenoid adduction for unilateral vocal cord paralysis. A three-dimensional model of case 1 larynx was prototyped using a selective laser sintering method. In case 1, the patients voice did not improve after LCA pull surgery. The three-dimensional model revealed that the original surgical procedure was not appropriate to obtain optimal arytenoid adduction. According to the analysis of this three-dimensional model, we changed the surgical approach and performed this new refined LCA pull surgery on another patient with unilateral vocal cord paralysis (case 2). Results. We were able to pull LCA precisely in case 2. Three-dimensional CT of case 2 after refined LCA pull surgery allowed the correct pulling of LCA and complete adduction of arytenoid. The postoperative voice improved remarkably.

Direct pull of lateral cricoarytenoid muscle for unilateral vocal cord paralysis

Conclusion. Lateral cricoarytenoid muscle-pull surgery (LCA pull) is a safe and effective method for the treatment of unilateral vocal cord paralysis. Objective. To evaluate the results of an improved method of LCA pull for unilateral vocal cord paralysis. Material and methods. Thirteen patients with unilateral vocal cord paralysis underwent LCA pull between April 2003 and January 2004. A small window was made in the posterior lower part of the thyroid cartilage and 2–3 mm in a cranial direction to the lower edge of the thyroid cartilage. The inner perichondrium was carefully removed to expose the LCA muscle. A 4-0 nylon suture placed through the LCA muscle was pulled to adduct the arytenoid and was tied to the anterior lower part of the thyroid cartilage. All cases were treated by LCA pull alone. In all cases, the maximum phonation time was measured and an auditory evaluation was performed using the grade, roughness, breathiness, asthenia and strain scale. The airflow rate was measured in five cases. Results. Vocal improvement was obtained in 11/13 cases (85%). One of the unimproved cases had cricoarytenoid joint ankylosis. No complications were observed.

Analysis of High-Pitched Phonation Using Three-Dimensional Computed Tomography

OBJECTIVES/HYPOTHESIS Our aim was to use three-dimensional computed tomography (3DCT) to examine arytenoid cartilage movement during a high-pitched tone task. STUDY DESIGN This was a prospective study. METHODS This study included 14 patients with male-to-female gender identity disorder who had undergone 3DCT imaging for surgical simulation between January 2007 and May 2008. First, to prove that the phonation condition was indeed one of the high-pitched phonation, we confirmed the rotational movement of the thyroid cartilage, horizontal gliding movement of the inferior horn, and vocal fold elongation on a high-pitched tone task. Next, we detected the arytenoid cartilage positions of the joint during a comparison of comfortable and high-pitched phonations. We measured the movement direction and movement distance of the arytenoid cartilage. RESULTS In all cases, the cricothyroid space became narrower (rotation movement), and we observed anterior gliding movement of the inferior horn. In all cases, elongation of the vocal folds by the high-pitched phonation was confirmed and the arytenoid cartilages were displaced both anteriorly and caudally from the position during comfortable phonation by the high-pitched tone task. CONCLUSIONS The arytenoid cartilages did not move posteriorly to elongate the vocal folds during high-pitched phonation. The arytenoid cartilages were pulled anteriorly and moved caudally because of tension associated with vocal fold elongation because of the task of high-pitched phonation. These results suggest that there are no movements at the cricoarytenoid joint that directly control the length of the vocal folds in accordance with pitch.

Analysis of pitch range after arytenoid adduction by fenestration approach combined with type I thyroplasty for unilateral vocal fold paralysis.

OBJECTIVE The purpose of this study was to determine the postoperative pitch range acquired in cases of unilateral vocal fold paralysis, as well as factors affecting outcomes. SUBJECTS AND METHODS We analyzed 39 cases of unilateral vocal fold paralysis for which surgery was performed between January 2006 and January 2009 and for which pitch ranges and the items listed below were measured preoperatively and 1 year postoperatively. Arytenoid adduction (AA) and type I thyroplasty were performed simultaneously in all cases regardless of preoperative severity. AA was performed by the fenestration approach as previously reported. In this procedure, the cricoarytenoid and cricothyroid joints are not released. Correlations between pitch range acquired postoperatively and the following items were examined: (1) pre- and postoperative maximum phonation time (MPT), (2) pre- and postoperative mean airflow rate (MFR), and (3) preoperative pitch range. Furthermore, patients were surveyed regarding their ability to sing after surgery, and the pitch range cutoff value dividing ability and inability to sing was calculated. RESULTS Pitch range increased significantly from 3±4.47 halftones (mean ± standard deviation) preoperatively to 17.5±5.80 halftones postoperatively. Preoperative MPT, MFR, and pitch range did not correlate with postoperative pitch range. Postoperatively, only MPT correlated with the width of postoperative pitch range. Twenty-three of 39 subjects (59%) responded that they were able to sing, and the pitch range cutoff value dividing the two groups was 22 halftones. CONCLUSION AA and type I thyroplasty significantly expanded postoperative pitch range. There was no correlation between preoperative severity and width of pitch range acquired postoperatively.

A case of high-pitched diplophonia that resolved after a direct pull of the lateral cricoarytenoid muscle.

Various approaches have been employed for the surgical treatment of unilateral vocal cord paralysis. Recently, we performed a direct pull of the lateral cricoarytenoid muscle in a case of high-pitched diplophonia with little difference between the right and left vocal cord levels and obtained favorable results. The patient was a 66-year-old male who consulted our hospital with chief complaints of husky voice and abnormal sensation in the pharyngolaryngeal region. Cerebellum/brainstem inflammation was diagnosed in February 2002 and appropriate treatment was instituted. Despite an improvement in the patients systemic condition, right vocal cord paralysis remained. Although there were no abnormalities in the vocal range for ordinary speech, diplophonia was noted at high pitches, and synchronization could not be observed using stroboscopy. Therefore, the patient was operated on in October 2002. The high-pitched diplophonia disappeared and stroboscopy revealed favorable mucosal waves at high pitches. Thus, direct pulling of the lateral cricoarytenoid muscle appears to be a useful procedure, even in a case of mild unilateral vocal cord paralysis.