Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Toshinori Kubota is active.

Publication


Featured researches published by Toshinori Kubota.


Otology & Neurotology | 2014

Feasibility and Advantages of Transcanal Endoscopic Myringoplasty

Takatoshi Furukawa; Tomoo Watanabe; Tsukasa Ito; Toshinori Kubota; Seiji Kakehata

Objective When performing transcanal myringoplasty under a microscope, the total circumference of the perforation can be difficult to confirm in patients where the external ear canal is narrow and/or protruded. In such patients, a retroauricular incision approach is usually used. However, we have developed a transcanal endoscopic myringoplasty procedure, and the microscopic and endoscopic views are compared herein for the first time. The feasibility and advantages of transcanal endoscopic myringoplasty were examined. Study Design A prospective case series. Setting Tertiary referral center. Patients Transcanal endoscopic myringoplasty was performed on 25 ears in 21 patients with chronic otitis media between September 2011 and December 2012. Intervention Microscopic and endoscopic views were compared for each patient. The 2 fields of views were both recorded and evaluated to determine the advantages and disadvantages of microscopes and endoscopes. Myringoplasty was performed using an endoscopic technique while comparing views as necessary. Results Endoscopic views revealed the entire tympanic membrane in a single field with clear visualization of the perforation edges even when the ear canal was curved. This clear visualization facilitated reliable refreshing of the perforation edges and grafting. The anterior edge of the perforation was not visible under microscopy in 5 of 25 ears. Under an endoscopic wide view, the tympanic cavity was observable through the perforation, and the orifice of the tube, ossicular chain, and tympanic isthmus were visible especially with large perforations. Transcanal endoscopic myringoplasty was successfully performed with a simple underlay technique or with an intracanal incision in cases of marginal perforation. Conclusion Comparison of microscopic and endoscopic views revealed superior visualization and operability of the endoscopic approach as opposed to transcanal simple underlay myringoplasty. Transcanal endoscopic myringoplasty does not require surgical exposure such as a retroauricular skin incision to get an anterior view. Our results demonstrated that transcanal endoscopic myringoplasty can be performed, regardless of the perforation size and the narrowness and/or protrusion of external ear canal.


Otology & Neurotology | 2014

Extension of indications for transcanal endoscopic ear surgery using an ultrasonic bone curette for cholesteatomas.

Seiji Kakehata; Tomoo Watanabe; Tsukasa Ito; Toshinori Kubota; Takatoshi Furukawa

Background One-handed endoscopic procedures have, up until now, limited the indications for transcanal endoscopic ear surgery (TEES) in cholesteatoma surgery. However, the development of electrically powered instruments has opened the door to such one-handed endoscopic procedures in restricted surgical spaces. Objective We examined the feasibility of using one such powered instrument, the ultrasonic bone curette (UBC) in TEES for cholesteatoma surgery. The UBC offers several advantages, including nonrotational motion and the combination of both suction and irrigation in a single handpiece. Study Design A prospective case series. Setting Tertiary referral center. Patients TEES was performed on 43 cases of primary cholesteatoma between September 2011 and December 2012, including 14 cases extending to the antrum. Intervention Zero-, 30-, or 70-degree angled rigid endoscopes with an outer diameter of 2.7 mm (Karl Storz) were used together with a high-definition video system. A Sonopet UBC (Stryker) was used to cut bony tissue. The nonrotational motion of the UBC prevents injury to the tympanomeatal flap and other soft tissue, which may result with standard drills. Transcanal endoscopic retrograde mastoidectomy on demand was performed to access the pathologies in the attic and antrum. Results A minimum attico-antrotomy was performed using the UBC, removing only the bony tissue necessary to visualize the pathology. The cholesteatoma was completely removed from the antral mucosa under clear endoscopic visualization in 13 of 14 cases. After removal of the cholesteatoma, the canal wall was reconstructed using cartilage taken from the tragus. This procedure resulted in greater mastoid preservation. Conclusion The transcanal endoscopic approach to the antrum using the UBC proved to be less invasive and more functional. The UBC contains both a suction and irrigation system in a single handpiece, and this UBC is an appropriate cutting tool that extends the indications for TEES.


International Journal of Pediatric Otorhinolaryngology | 2015

Transcanal endoscopic ear surgery for pediatric population with a narrow external auditory canal

Tsukasa Ito; Toshinori Kubota; Tomoo Watanabe; Kazunori Futai; Takatoshi Furukawa; Seiji Kakehata

OBJECTIVES To retrospectively determine the size of the external auditory canal (EAC) in a pediatric population and to describe our experience with transcanal endoscopic ear surgery (TEES) in this pediatric population which had been successfully treated for middle ear disease using TEES. METHODS We analyzed 31 patients ranging in age from 2 to 13 years old (median: 7.6 years) with middle ear disease who underwent TEES between November 2011 and August 2014. Sixteen of these patients had surgery for cholesteatomas; 11 for chronic otitis media; and 4 for malformation of the middle ear. A preoperative CT scan was performed to evaluate the middle ear disease. Transcanal endoscopic tympanoplasty was performed using a rigid endoscope with a 2.7mm outer diameter. Transcanal endoscopic atticoantrotomy was also performed, as necessary, on some patients to access pathologies in the antrum. The values of anterior-posterior diameters and superior-inferior diameters of the bony parts of EAC were measured retrospectively based on the preoperative CT scan data. RESULTS TEES was successfully performed in all 31 pediatric patients without resorting to a retroauricular incision. Twenty-seven patients were evaluated for postoperative hearing levels which were found to fall within an acceptable range and for postoperative air-bone gap (ABG) by pure tone audiometry with a resulting mean of 8.6dB. The smallest anterior-posterior diameters of the external ear canal ranged from 3.2 to 7.1mm (5.0±1.0mm) and the smallest superior-inferior diameters ranged from 3.4 to 10.3mm (5.9±1.3mm). CONCLUSION TEES can be used to safely and effectively treat middle ear disease even in the pediatric population in its narrow EAC.


Otolaryngology-Head and Neck Surgery | 2009

Treatment of auricular hematoma by OK-432

Toshinori Kubota; Nobuo Ohta; Shigeru Fukase; Yoshihisa Kon; Masaru Aoyagi

Objectives: Intralesional injection therapy with OK-432 was developed as a therapy for operatively difficult lymphangioma (cystic hygroma) and is currently becoming a first-choice treatment for this disease. The aim of this article was to evaluate the outcome and complications of the treatment of patients with auricular hematoma by OK-432 therapy. Study Design: Case series with planned data collection. Setting: Yamagata University School of Medicine. Subjects and Methods: We tried this therapy in 21 patients with auricular hematoma between January 2001 and February 2009. We injected OK-432 solution into the lesion with a 27-gauge needle to prevent the leak of the agent out of the hematoma. We performed this treatment on an outpatient basis without hospitalization. Results: Disappearance or marked reduction of the lesion were observed in all patients who had this therapy, and local scarring and deformity of the auricle did not occur in any patients. As for side effects, local pain at the injection site and fever (37°C-38°C) were observed in a few of the patients who had this therapy, but such problems resolved within a few days. Conclusion: These results may allow us to speculate that intralesional injection therapy with OK-432 is simple, easy, safe, and effective and can be used as a substitute for surgery in the treatment of auricular hematoma.


International Journal of Otolaryngology | 2013

Clinical and Pathological Characteristics of Organized Hematoma

Nobuo Ohta; Tomoo Watanabe; Tsukasa Ito; Toshinori Kubota; Yusuke Suzuki; Akihiro Ishida; Masaru Aoyagi; Atsushi Matsubara; Kenji Izuhara; Seiji Kakehata

Objective. To study the clinical and pathological characteristics of patients with organized hematoma with malignant features in maxillary sinuses. Subjects and Methods. This was a retrospective study of five patients who were treated surgically for organized hematoma. The preoperative CT and MRI findings were studied clinically. The expressions of CD31, CD34, and periostin in surgical samples were investigated by immunohistochemistry. Results. The clinical features of organized hematoma, such as a mass expanding from the maxillary sinus with bone destruction, resembled those of maxillary carcinoma. However, CT and MRI provided sufficient and useful information to differentiate this condition from malignancy. Surgical resection was the first-line treatment because of the presence of a firm capsule. Characteristic histopathological findings were a mixture of dilated vessels, hemorrhage, fibrin exudation, fibrosis, hyalinization, and neovascularization. The expressions of periostin, CD31, and CD34 were observed in organized hematoma of the maxillary sinus. Conclusion. The expressions of periostin, CD31, and CD34 were observed in organized hematoma of the maxillary sinus. Organized hematoma is characterized pathologically by a mixture of bleeding, dilated vessels, hemorrhage, fibrin exudation, fibrosis, hyalinization, and neovascularization. CT and MRI show heterogeneous findings reflecting a mixture of these pathological entities.


Otology & Neurotology | 2014

Safety of ultrasonic bone curette in ear surgery by measuring skull bone vibrations.

Tsukasa Ito; Hideyuki Mochizuki; Tomoo Watanabe; Toshinori Kubota; Takatoshi Furukawa; Takuji Koike; Seiji Kakehata

Hypothesis Mastoidectomy using an ultrasonic bone curette (UBC) is as safe for the inner ear as a mastoidectomy using a high-speed drill. Background Transcanal endoscopic ear surgery (TEES) is a minimally invasive, secure, and functional technique, which has been performed using high-speed drills. We have started to use a UBC instead of the high-speed drill because a UBC allows for simultaneous bone cutting, irrigation, and aspiration. These features of the UBC make it an excellent candidate for use in one-handed TEES, but the safety of the UBC still needs to be confirmed. We thus measured skull vibrations caused by the UBC to estimate the effects of UBC on the inner ear. Methods Eight patients with cholesteatoma underwent mastoidectomy using a Sonopet UST-2001 UBC (Stryker, MI, USA) and 2 high-speed drills (drills A and B). Skull vibrations were measured using polyvinylidene difluoride film taped to the forehead as a piezoelectric vibration sensor. The recorded data were transformed to the power spectrum in the frequency domain by fast Fourier transform. The mean and peak values of vibrations were analyzed in four frequency bands: 200 to 500 Hz, 500 to 2,000 Hz, 2,000 to 8,000 Hz, and 8,000 Hz to 20 kHz. Results Both the mean values and the peak values of skull vibrations caused by the UBC were significantly smaller than those values obtained for drill B between 500 and 8,000 Hz, (p < 0.05). No significant differences were found among the 3 instruments below 500 Hz or above 8,000 Hz. Conclusion Skull vibration levels generated by the UBC were found to be comparable or even lower than those levels associated with conventional high-speed drills. These findings indicated that the UBC can be safely applied to TEES without the risk of harmful effects on the inner ear.


Otology & Neurotology | 2015

The efficacy of color mapped fusion images in the diagnosis and treatment of cholesteatoma using transcanal endoscopic ear surgery.

Tomoo Watanabe; Tsukasa Ito; Takatoshi Furukawa; Kazunori Futai; Toshinori Kubota; Masafumi Kanoto; Yuuki Toyoguchi; Takaaki Hosoya; Seiji Kakehata

Objective To assess the efficacy of color mapped fusion images (CMFIs) in preoperatively evaluating the anatomic location of cholesteatomas and determining whether a patient is indicated for transcanal endoscopic ear surgery. Study Design Prospective case study. Setting A single university hospital. Patients Ninety-two patients scheduled for middle ear cholesteatoma surgery. Intervention Imaging analysis was first performed using echo planar diffusion-weighted imaging (EPI) for the first patient group with mixed results. Imaging analysis was then performed using 1-mm thin-slice non-EPI combined with magnetic resonance cisternography in a second group. The resulting image was then processed using color mapping to create a CMFI that enhanced cholesteatoma visualization. A second non-EPI was also performed on the third group, incorporating a T1-weighted image (T1WI) to reduce false-positives. Main Outcome Measure(s) Preoperative findings from EPI, non-EPI/CMFIs, and non-EPI/T1WI-enhanced CMFIs were compared with intraoperative findings. The positive predictive value and negative predictive value were also evaluated for each group. Results Both the positive predictive value and negative predictive value obtained from the CMFIs were high in all areas of the middle ear, and CMFI facilitated accurate detection of the anatomic location of cholesteatomas of 3 mm or larger. The incidence of false-positives was further reduced in the final 18 patients by performing T1WI to distinguish between cholesteatomas and cholesterin granulomas. Conclusion CMFI combined with T1WI is a reliable diagnostic modality for evaluating the anatomic location of cholesteatomas 3 mm or larger and determining whether transcanal endoscopic ear surgery is indicated for treatment in such cases.


Auris Nasus Larynx | 2016

Safety of heat generated by endoscope light sources in simulated transcanal endoscopic ear surgery

Tsukasa Ito; Toshinori Kubota; Akira Takagi; Tomoo Watanabe; Kazunori Futai; Takatoshi Furukawa; Seiji Kakehata

OBJECTIVE To determine whether heat generated by endoscope light sources during ear surgery is safe. METHODS Transcanal endoscopic ear surgery (TEES) was simulated using 2.7-mm or 4-mm endoscopes coupled to xenon or LED light sources and a 3D model of human temporal bone. The endoscope tip was fixed at the center of tympanic annulus. Light sources were tested at clinical (30% for xenon and 40% for LED) and 100% settings. Temperatures were measured using thermocouples attached to the endoscope tip and three points within the middle ear cavity: promontory, horizontal portion of the facial nerve and lateral semicircular canal. RESULTS Maximum temperatures measured within the middle ear cavity were below 31°C at clinical settings, while the temperatures rose to 44.1°C using a 4-mm endoscope with a xenon light source set at 100%. Temperatures measured at the tip were all safe at clinical settings, but rose dramatically to 110.1°C for the 4-mm endoscope with xenon at 100%. CONCLUSION Endoscopes can be safely used within the middle ear at clinical settings. However, operators should not exceed clinical settings, particularly with 4-mm endoscopes with a xenon light source, to ensure temperatures generated within the middle ear cavity are safe.


Laryngoscope | 2012

Treatment of thyroglossal duct cysts by Ok‐432

Nobuo Ohta; Shigeru Fukase; Tomoo Watanabe; Tsukasa Ito; Toshinori Kubota; Yusuke Suzuki; Masaru Aoyagi

INTRODUCTION Although surgery is the treatment of choice for thyroglossal duct cysts, it can give rise to complications, including nerve injury, cyst recurrence, wound infection, and cosmetic problems. Use of a nonsurgical procedure could prevent these complications. Although simple aspiration of otolaryngological cystic diseases is a noninvasive treatment, cyst recurrence is commonly observed despite repeated aspiration. Ogita et al. reported in 1987 that OK-432 therapy was effective for lymphangioma. OK-432 was originally developed as an immunotherapeutic agent for cancer, but it is widely accepted that it is very effective in reducing ascites and pleural effusion in patients with carcinomatous peritonitis and pleuritis. When it is injected into the peritoneal or pleural cavity, reduction of ascites and pleural effusion occurs and adhesion of the cavity develops. OK-432 therapy is also effective for lymphangioma, branchial cleft cysts, salivary mucocele, auricular hematoma, thyroid cysts, cervical lymphocele, and plunging ranula, but studies of the effectiveness of OK-432 in treating thyroglossal duct cysts have been rare. The purpose of this study was to investigate the effectiveness of OK-432 therapy in patients with thyroglossal duct cysts.


Case reports in otolaryngology | 2012

A Case of Sublingual Dermoid Cyst: Extending the Limits of the Oral Approach

Nobuo Ohta; Tomoo Watanabe; Tsukasa Ito; Toshinori Kubota; Yusuke Suzuki; Akihiro Ishida; Seiji Kakehata; Masaru Aoyagi

We present the case of a dermoid cyst with an oral and a submental component in a 21-year-old Japanese woman who presented with complaints of a mass in the oral cavity and difficulty in chewing and swallowing solid foods for about 2 years. MRI shows a 55 × 65 mm well-circumscribed cystic mass extending from the sublingual area to the mylohyoid muscle. Under general anesthesia and with nasotracheal intubation, the patient underwent surgical removal of the mass. Although the cyst was large and extending mylohyoid muscle, intraoral midline incision was performed through the mucosa overlying the swelling and the cyst was separated from the surrounding tissues with appropriate traction and countertraction and successfully removed without extraoral incision. Oral approach in surgical enucleation is useful procedure to avoid cosmetic problems in large and extending mylohyoid muscle cyst.

Collaboration


Dive into the Toshinori Kubota's collaboration.

Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Masaru Aoyagi

Tokyo Medical and Dental University

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Researchain Logo
Decentralizing Knowledge