楯谷 一郎

Objective: The application of the da Vinci Surgical System in neurosurgery is limited due to technical difficulties requiring precise maneuvers and small instruments. This study details the advantages and disadvantages of robotics in neurosurgery and the reachable range of the transoral approach to lesions of the skull base and upper cervical spine.Methods: In a cadaver study, the da Vinci Xi robot, lacking haptic feedback, was utilized for sagittal and coronal approaches on 5 heads, facilitating dura suturing in 3, with a 30°-angled drill for bone removal.Results: Perfect exposure of all the nasopharyngeal sites, clivus, sellar, and choana, including the bilateral eustachian tubes, was achieved without any external incisions using this palatal split approach of transoral robotic surgery. The time required to perform a single stitch, knot, and complete single suture in robotic suturing of deep-seated were significantly less compared to manual suturing via the endonasal approach.Conclusion: This is the first report to show the feasibility of suturing the dural defect in deep-seated lesions transorally and revealed that the limit of reach in the coronal plane via a transoral approach with incision of the soft palate is the foramen ovale. This preclinical investigation also showed that the transoral robotic approach is feasible for lesions extending from the sellar to the C2 in the sagittal plane. Refinement of robotic instruments for specific anatomic sites and future neurosurgical studies are needed to further demonstrate the feasibility and effectiveness of this system in treating benign and malignant skull base lesions.

Transoral robotic surgery (TORS), introduced by Weinstein et al. in 2005, has been widely adopted as a minimally invasive procedure, particularly for the treatment of patients with early stage oropharyngeal cancer. TORS is typically performed using the da Vinci Surgical System, similar to robot-assisted surgeries for other malignancies. The main difference between TORS and these other robot-assisted surgeries is that it is performed through the natural orifice of the mouth, which limits the surgical working space, and that it progresses from the lumen of the pharynx to the deeper tissues. The advantages of TORS are mainly due to the benefits of using the da Vinci Surgical System, such as three-dimensional high-definition images, magnification, multiple forceps articulation, tremor-stabilization function and motion scale function. To date, many big data and meta-analyses have shown that TORS is superior to conventional surgeries, such as open surgery, in terms of oncological outcomes, post-operative functionality and quality of life. In Japan, TORS is expected to spread across the country, as it has been covered by health insurance since April 2022. This review highlights the procedures of TORS, its unique aspects, its unparalleled advantages as a minimally invasive surgery for treating laryngeal and pharyngeal cancers, and its current status in Japan.

There are many methods and types of equipment for measuring the nasal airway, but there is no consensus regarding the results of various clinical studies on nasal obstruction. In this review, we discuss the two major methods of objectively assessing the nasal airway: rhinomanometry and acoustic rhinometry. The Japanese standard of rhinomanometry in Japanese adults and children was established by the Japanese Standardization Committee on Rhinomanometry in 2001 and 2018, respectively. However, the International Standardization Committee has proposed different standards because of differences in race, equipment, and social health insurance systems. The standardization of acoustic rhinometry in Japanese adults is making progress in several Japanese institutes, but the international standardization of acoustic rhinometry has not yet begun. Rhinomanometry is the physiological expression of nasal airway breathing, whereas acoustic rhinometry is the anatomic expression. In this review, we introduce the history and methods of the objective assessment of nasal patency and the physiological and pathological issues regarding nasal obstruction.

BACKGROUND: Endoscopic laryngopharyngeal surgery (ELPS) is a minimally invasive transoral surgery for superficial pharyngeal and laryngeal cancer, but dysphagia occasionally occurs post-treatment. We investigated dysphagia following ELPS and its risk factors. METHODS: Of the 145 patients who underwent ELPS, 92 were evaluated in this study using the Hyodo score, Functional Outcome Swallowing Scale, Eating Assessment Tool-10 along with the total scores for the three items of the method of intake, time, and food preoperatively and on postoperative 1, 3, and 6 months. We examined the 6-month trends of these values. Furthermore, the fasting period post-surgery, the need for swallowing rehabilitation by a speech therapist, and postoperative pneumonia episodes were set as outcomes reflecting the short-term swallowing function. We determined the associations between these outcomes and patient background factors. RESULTS: Postoperatively, the Hyodo score worsened at 1 month but recovered at 3 months. The Hyodo scores of all patients who underwent postcricoid ELPS did not worsen. The diameter of the resected specimen (DRS) was significantly associated with the need for swallowing rehabilitation and postoperative fasting time. A DRS ≥ 35 mm was considered the threshold for the need of swallowing rehabilitation, postoperative pneumonia, and prolonged postoperative fasting time. CONCLUSION: ELPS exerts a temporal and limited impact on the swallowing function, which recovers within 3 months in every swallowing evaluation. This necessitates additional care during the treatment of patients with mucosal defects ≥ 35 mm, owing to the significant association between the DRS and short-term swallowing function.

OBJECTIVES: Intraoperative cone beam computed tomography (CBCT) imaging has the potential to facilitate the surgical procedure. The current preliminary retrospective chart review investigated the benefits of intraoperative CBCT during laryngoplasty. METHOD: This study examined 26 cases that underwent intraoperative CBCT imaging during laryngoplasty, with one patient who counted twice due to first and revision surgery. The visual quality of structures of interest (glottal shape, thyroid cartilage, arytenoid cartilage, and implants) was determined using intraoperative CBCT during laryngoplasty. Each patient also underwent an aerodynamic assessment. RESULTS: CBCT provided unique information, such as surgical landmarks in severe scarring, the subglottal shape, and the rotation angle of the arytenoid cartilage during arytenoid adduction. Nonetheless, 26.9% (7 of 26) of cases were affected by motion artifact, due to the long acquisition time. When motion artifact-negative cases were evaluated, 100% of glottal shape and more than 89% of thyroid cartilage were well visualized. All arytenoids were well-visualized in patients ≥ 50 years of age and without motion artifact, while CBCT failed to visualize the arytenoids in 2 of 4 patients who were < 50 years, due to the lack of calcifications. After medialization surgery, the yields of improved maximal phonation times (MPTs) in the motion artifact-negative and -positive groups were 8.7 sec and 3.4 sec, respectively (p = 0.032; Welch's t test). This comparison indicates intraoperative CBCT would contribute in MPT improvement, if CBCT is taken in measurable quality. CONCLUSION: The potential benefits of intraoperative CBCT during laryngoplasty were demonstrated. A corollary, prospective study is warranted to further confirmation.

INTRODUCTION: Radiation-induced carotid artery stenosis (RI-CS) is known as one of long-term side effects of radiotherapy for head and neck cancer (HNC). However, the clinical time course after irradiation has been poorly understood. We aimed to investigate the natural history of radiation-induced carotid atherosclerosis, comparing the patients who received radiotherapy for HNC with the patients who were treated without radiotherapy. METHODS: The patients who received treatment of HNC at Department of Otolaryngology, Head and Neck Surgery of Kyoto University Hospital, from November 2012 to July 2015 were enrolled. The patients were assigned into the RT group and the control group, depending on whether radiotherapy was planned or not. Annual carotid ultrasound was performed from the enrollment to 5 years. The increase of mean intima-media thickness (IMT) at common carotid artery from the enrollment (Δmean IMT) was evaluated. RESULTS: Fifty-six patients in the RT group and 25 patients in the control group were enrolled. From 5-year follow-up data, the significant higher increase of Δmean IMT was consistently observed in the RT group than in the control group after 2 years. The RT group presented a 7.8-fold increase of mean IMT compared to the control group (0.060 mm per year in the RT group and 0.008 mm per year in the control group). Cumulative incidence curves obtained from the analysis of all vessels revealed that the RT group presented higher incidence of Δmean IMT ≥0.25 mm than the control group (p < 0.01). In the RT group, the patients with mean IMT ≥1.0 mm at enrollment exhibited significantly higher incidence of Δmean IMT ≥0.25 mm than the patients with mean IMT <1.0 mm (p < 0.01). DISCUSSION: Radiotherapy for HNC induces continuous carotid mean IMT progression. The irradiated carotid arteries with mean IMT ≥1.0 mm before radiotherapy presented earlier IMT progression than those with mean IMT <1.0 mm.

OBJECTIVES: The success of type 2 thyroplasty (TP2) for adductor spasmodic dysphonia (AdSD) depends on the selection of optimally sized titanium bridges, which requires accurate assessment of intraoperative vocal changes. While this procedure has traditionally been performed according to the laryngologist's experience, the most appropriate method for voice monitoring and selection of titanium bridge size remains to be determined. This study aimed to investigate evaluation parameters useful for voice monitoring, as these may allow less experienced surgeons to perform TP2 properly. METHODS: In this prospective study, voice monitoring was performed in 18 patients with AdSD patients undergoing TP2. Evaluations were performed preoperatively, intraoperatively, 13 weeks postoperatively, and 52 weeks postoperatively using GRBAS (grade, roughness, breathiness, asthenia, and strain), as well as perceptual judgment and acoustic analyses. RESULTS: Preoperative and intraoperative assessments of the G, R, B, and S parameters, perceptual judgment, and harmonic-to-noise ratio (HNR) were in moderate or better agreement. Intraoperative and 13- or 52-week postoperative measurements of the R, B, and G parameters and strangulation, tremor, and HNR were also in high agreement. When two different sizes of titanium bridges were compared (unselected vs. selected), ratings for G, R, S, strangulation, tremor, jitter, shimmer, HNR, standard deviation of F0, and degree of voice breaks were better for the selected width than the unselected width. CONCLUSION: The candidate items for intraoperative voice monitoring during TP2 for AdSD are G, R, strangulation, tremor, and HNR. The use of these items may help to ensure successful TP2 and contribute to the advancement of laryngeal framework surgery. LEVEL OF EVIDENCE: Level 4.

Most osteomalacia-inducing tumors (OITs) are phosphaturic mesenchymal tumors (PMTs) that secrete fibroblast growth factor 23 (FGF23). These tumors usually occur in the bone and soft tissues, and intracranial OITs are rare. Therefore, intracranial OIT is difficult to diagnose and treat. This paper presents a case of intracranial OIT and shows a review of previous cases. A 45-year-old man underwent nasal cavity biopsy and treatment with active vitamin D3 and neutral phosphate for hypophosphatemia. Amplification of FGF23 mRNA level within the tumor was detected. Subsequently, the surgical specimen was diagnosed with a PMT and was considered the cause of the patient's osteomalacia. The patient was referred to a neurosurgery department for the excision of the intracranial tumor extending to the nasal cavity. After tumor removal, the serum levels of FGF23 and phosphorus were normalized as compared to preoperative those. The patient remains disease-free, without additional treatment, approximately 10 years after surgery, with no tumor recurrence. As per the literature, intracranial OITs usually occur in patients aged 8-69 years. Bone and muscle pain are major complaints. Approximately 60% of the patients reported previously had symptoms because of intracranial tumors. In some cases, it took several years to diagnose OIT after the onset of the osteomalacia symptoms. Laboratory data in such cases show hypophosphatemia and elevated FGF23 levels. Because FGF23 levels are associated with the severity of osteomalacia symptoms, total tumor resection is recommended. PMT and hemangiopericytoma (HPC) are histologically similar, but on immunochemistry, PMT is negative for signal transducer and activator of transcription 6 (STAT6), whereas HPC is positive. FGF23 amplification is seen in PMTs but not in HPCs. Therefore, the analysis of FGF23 and STAT6 was helpful in distinguishing PMTs from HPCs. In cases of hypophosphatemia and osteomalacia without a history of metabolic, renal, or malabsorptive diseases, the possibility of oncogenic osteomalacia should be considered.

38歳男性。全身の骨痛、歩行・起立障害を主訴に前医を受診した。腫瘍性骨軟化症(TIO)が疑われ、精査加療目的に当院へ紹介となった。FGF23の全身静脈サンプリングと68Ga-DOTATOC-PET/CTにより右鼻腔内の腫瘤がTIOの原因腫瘍であると診断し、内視鏡下に右鼻腔腫瘍摘出術が施行された。その結果、病理組織学的に鼻腔原発リン酸塩尿性間葉系腫瘍と診断され、術後5日で全身の骨痛は完全消失し、立位保持・歩行ともに可能となった。術後1年経過現在、腫瘍の再発や骨痛の再燃はなく、FGF23も正常範囲内である。

PURPOSE: Auditory-perceptual evaluation is essential for the assessment of voice quality. The Consensus Auditory-Perceptual Evaluation of Voice (CAPE-V) provides a standardized protocol and assessment form for clinicians to analyze the voice quality and has been adapted into several different languages. The aims of this study were to develop the Japanese version of the CAPE-V and to investigate its reliability and validity. METHOD: The Japanese CAPE-V consisted of the same three speech contexts (vowels, sentences, and conversation) as developed in the original English version. The sentences were designed according to the concepts of the original version and reviewed by Japanese phoneticians. To validate the usefulness of the Japanese CAPE-V, voices of 173 Japanese-speaking subjects (76 subjects with dysphonia and 97 without voice complaints) were evaluated by five experienced judges, according to the Japanese CAPE-V as well as the GRBAS (Grade, Roughness, Breathiness, Asthenia, Strain) scale. RESULTS: The Japanese CAPE-V provided a high interrater reliability (intraclass correlation coefficients [ICCs] > .85 for all the parameters) as well as a high intrarater reliability (ICCs > .85 for all the parameters). In addition, overall severity, roughness, and breathiness in the Japanese CAPE-V were highly correlated with the corresponding dimensions in the GRBAS scale, having Spearman correlation coefficients greater than .8. CONCLUSION: This study demonstrated the reliability and validity of the newly developed Japanese CAPE-V as an auditory-perceptual evaluation instrument.