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Dive into the research topics where Kazunori Futai is active.

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Featured researches published by Kazunori Futai.


Otology & Neurotology | 2006

Comparison of intratympanic and intravenous dexamethasone treatment on sudden sensorineural hearing loss with diabetes.

Seiji Kakehata; Akira Sasaki; Kasumi Oji; Kazunori Futai; Shuji Ota; Kimitoshi Makinae; Hideichi Shinkawa

Objective: The purpose of this study was to evaluate the efficacy of intratympanic administration of dexamethasone (IT-DEX) treatment on sudden sensorineural hearing loss (SSNHL) patients with diabetes by comparing the results with intravenous administration of dexamethasone (IV-DEX) treatment. Study Design: Comparative study. Setting: University hospital and affiliated hospital. Patients: Ten sequential SSNHL patients with diabetes receiving IT-DEX and 21 sequential SSNHL patients with diabetes receiving IV-DEX. Patients with low tone hearing loss were excluded. Intervention: In the IT-DEX group, two methods were applied to deliver DEX (4 mg/ml): injection through a perforation made by laser-assisted myringotomy or through a tympanostomy tube. IT-DEX administration was performed on 8 sequential days. In the IV-DEX group, DEX was administrated intravenously starting from an amount of 8 mg/d followed by taped doses for 10 days. Main Outcome Measures: Preprocedure and postprocedure hearing levels and complications. Results: In the IT-DEX group, the average hearing level before the treatment was 79 dB. Overall, all 10 patients showed improvement of more than 10 dB in the pure-tone audiogram, with a mean improvement of 41 dB. Seven patients (70%) demonstrated successful results, and four recovered completely. In the IV-DEX group, 14 (67%) of the 21 patients showed improvement of more than 10 dB with a mean improvement of 25 dB. Thirteen patients (62%) demonstrated successful results. Free blood sugar during and after the IT-DEX treatment remained below the pretreatment levels, whereas four patients in the IV-DEX group demonstrated worsening of the hyperglycemia. Conclusion: IT-DEX treatment is at least as effective as IV-DEX treatment for SSNHL patients with diabetes.


Otology & Neurotology | 2006

Endoscopic transtympanic tympanoplasty in the treatment of conductive hearing loss: early results.

Seiji Kakehata; Kazunori Futai; Akira Sasaki; Hideichi Shinkawa

Objective: We describe our initial experience with endoscopic transtympanic tympanoplasty and evaluate whether this approach is adequate and minimally invasive in the treatment of conductive hearing loss. Study Design: Prospective trial. Setting: University hospital. Patients: Nine patients underwent endoscopic transtympanic tympanoplasty, with an average follow-up period of 17 months. Presurgical diagnosis was made by transtympanic endoscopy through a perforation made by OtoScan laser-assisted myringotomy in the outpatient clinic. Methods: With clean endoscopic visualization, ossiculoplasty was performed by inserting a trimmed tragal cartilage through the myringotomy perforation made by laser-assisted myringotomy. Two types of ossiculoplasty were performed: columella reconstruction and interposition. The tympanic membrane was covered with a chitin membrane or sealed with a small piece of perichondrium from the tragal cartilage. Main Outcome Measures: Perioperative and postoperative complications and preoperative and postoperative hearing. Results: Endoscopic transtympanic tympanoplasty with columella and endoscopic transtympanic tympanoplasty with interposition were performed in seven and two patients, respectively. Insertion of the cartilage was performed without conversion to a conventional otomicroscopic technique. The average hearing level before the operation was 59 dB. After the endoscopic transtympanic tympanoplasty, the average improved to the level of 27 dB, with an average air-bone gap of 11 dB. The myringotomy perforation was closed within 2 to 3 weeks. Conclusion: As opposed to conventional methods, this procedure does not require surgical exposure such as otosclerosis drilling and skin incision, and avoids the substantial risk of unnecessary injury to the chorda tympani. Endoscopic transtympanic tympanoplasty for a disrupted ossicular chain is an adequate and minimally invasive procedure and should prove to be a useful surgical procedure in future endoscopic tympanoplasty.


Laryngoscope | 2004

Office‐Based Endoscopic Procedure for Diagnosis in Conductive Hearing Loss Cases Using OtoScan Laser‐Assisted Myringotomy

Seiji Kakehata; Kazunori Futai; Reiko Kuroda; Hideichi Shinkawa

Objectives/Hypothesis: In conductive hearing loss (HL), even though preoperative examinations including audiometry, tympanometry, and computed tomography (CT) scan are applied, exploratory tympanotomy is necessary to make an exact diagnosis of ossicular interruption and stapes fixation. Precise preoperative diagnosis would be useful for patient counseling, surgical indications, and planning. The advantages of office‐based OtoScan laser‐assisted myringotomy (LAM), which makes a circular and non‐hemorrhagic perforation, prompted us to investigate other uses of LAM in addition to ventilation and drainage of the tympanic cavity. To make presurgical diagnosis in conductive HL, endoscopes with an outer diameter of 1.7 or 1.9 mm were used to inspect the middle ear pathology through perforations with a diameter of 2 mm made by LAM.


Audiology and Neuro-otology | 2011

Daily Short-Term Intratympanic Dexamethasone Treatment Alone as an Initial or Salvage Treatment for Idiopathic Sudden Sensorineural Hearing Loss

Seiji Kakehata; Akira Sasaki; Kazunori Futai; Rei Kitani; Hideichi Shinkawa

Objective: Intratympanic (IT) steroid therapy has been proposed as an alternative treatment option for patients with idiopathic sudden sensorineural hearing loss (ISSNHL). However, the number and frequency of IT treatments and drug delivery methods remain to be determined. The purpose of this study was to evaluate the efficacy of daily short-term IT dexamethasone (DEX) treatment alone in ISSNHL patients using laser-assisted myringotomy (LAM) for the drug delivery route as an initial and/or salvage treatment. Study Design: Retrospective study. Setting: University hospital. Patients: Seventy-six ISSNHL patients receiving IT DEX. Patients with low-tone hearing loss, unilateral or bilateral fluctuating hearing loss or contralateral hearing loss were excluded. Intervention: DEX (4 mg/ml) was injected through a perforation made by LAM. IT DEX administration was performed on 8 sequential days. Main Outcome Measures: Pre- and postprocedure hearing levels. The average hearing level was determined by 5 frequencies (250, 500, 1000, 2000 and 4000 Hz). Results: Nineteen out of 76 patients fit the criteria for initial treatment in the study (group I), while 24 patients, who had failed systemic therapy, received salvage treatment (group S). The mean age of the patients in groups I and S was 56.2 years with a range from 31 to 73 years of age and 46.0 years with a range from 11 to 76 years of age, respectively. The mean number of days from onset of symptoms to IT therapy in groups I and S was 4.8 days with a range of 1–23 days and 15.3 days with a range of 6–28 days, respectively. In group I, 18 of the 19 patients (95%) showed improvement of more than 10 dB in the pure-tone audiogram, with a mean improvement of 40 dB. Twelve patients (63%) recovered completely and 16 patients (84%) demonstrated successful results with an improvement of more than 30 dB. In group S, 14 of the 24 patients (58%) showed improvement of more than 10 dB with a mean improvement of 16 dB. Two (8%) of the 7 patients (29%) with successful results recovered completely. Conclusions: Daily short-term IT DEX administration using LAM for ISSNHL patients without concurrent therapy showed a high response rate and high cure rate and proved to be an alternative therapeutic option to high-dose systemic steroids as a first- and/or second-line treatment.


Otology & Neurotology | 2008

Autologous serum eardrops therapy with a chitin membrane for closing tympanic membrane perforations.

Seiji Kakehata; Yuki Hirose; Rei Kitani; Kazunori Futai; Shin-ichiro Maruya; Kenji Ishii; Hideichi Shinkawa

Objective Office treatment for chronic tympanic membrane (TM) perforations has limitations, and alternative methods to myringoplasty are sometimes needed. Serum lacks antigenicity and contains a large variety of growth factors known to modulate proliferation of various tissues to promote wound healing effects. Our purpose was to evaluate the feasibility of autologous serum eardrops therapy with a chitin membrane for closing TM perforations. Intervention In the outpatient clinic, the perforation margin was cauterized with silver nitrate, and the perforation was covered with a chitin membrane. Patients were instructed to apply autologous serum eardrops daily. Patients were examined every 2 weeks, and the procedure was repeated. Results We treated 19 sequential patients with chronic TM perforation in 1 ear between October 2005 and September 2007. Closure of the TM was achieved in 11 (58%) of 19 ears, and reduction of the perforation size was observed in 2 ears (11%). Closure rates for small, medium, and large perforations were 57 (8 of 14), 0 (0 of 1), and 75% (3 of 4), respectively. Closure rates for perforations attributable to intratympanic dexamethasone treatment, after myringoplasty and chronic otitis media were 67 (2 of 3), 67 (2 of 3), and 54% (7 of 13), respectively. Time for closure took from 15 to 175 days, with an average of 68 days (5.9 clinic visits). During autologous serum eardrop therapy with a chitin membrane, no remarkable side effects in the treated ears were observed. Measurement of the concentration of the epidermal growth factor, transforming growth factor &bgr;1, fibronectin, and interleukin 6 in the serum showed no decrease in 14 days, suggesting activity remained stable in that period. Conclusion Autologous serum eardrops therapy with a chitin membrane, which requires no surgical intervention, was found to be a promising office-based technique for the closure of chronic TM perforations because of its ease, safeness, and feasibility. However, additional studies are needed to independently analyze the specific benefits of the serum drops and the chitin membrane.


Otology & Neurotology | 2005

Evaluation of attic retraction pockets by microendoscopy.

Seiji Kakehata; Koji Hozawa; Kazunori Futai; Hideichi Shinkawa

Attic retraction pockets (RPs) are one of the important sequelae of otitis media with effusion and are classified on the basis of the findings of otoscopy or otomicroscopy. It is unclear when and how RPs turn into cholesteatomas. We compared the findings of RPs obtained with the use of a microendoscope with those from an otomicroscope to determine the extension of RPs. Study Design: Comparative study. Patients: Twenty-seven attic RPs (Tos type III or IV) and 10 precholesteatomas previously classified under an otomicroscope were reexamined. Main Outcome Measures: A high-resolution, fine, rigid microendoscope with an outer diameter of 1.0 mm was used to observe the extension of a retraction. In addition, to confirm the extent of the RP, computed tomography (CT) scans using water as the contrast media were performed in representative cases. Results: Endoscopy with the microendoscope revealed that in 59%, the RP was deeper than indicated by the initial otomicroscopic estimation, suggesting that the extension of the RP was underestimated. The findings of water-enhanced CT scans were comparable with the endoscopic findings. The bottom was observable with the microendoscope and the otomicroscope in 20 (74%) and 11 (41%) of 27 RPs, respectively. Seven ears had a deeper RP, which extended beyond the incudomallear joint. Of the 10 precholesteatoma cases, in which the bottoms were not visible with an otomicroscope or conventional endoscopes, the microendoscope revealed the bottom in 5 (50%). Conclusion: On the basis of the observations of our study, we suggest that reexamination of cases of RP classified as Tos type III or IV, preferably with a microendoscope, if available, and assessment of the depth of the RP using water-enhanced CT, would be useful and that careful follow-up is necessary for deep RPs because of a potential risk of development into cholesteatoma.


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.


Otology & Neurotology | 2015

The Efficacy of Color-Mapped Diffusion-Weighted Images Combined With CT 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 a color-mapped diffusion-weighted image combined with a computed tomography scan (CMDWI-CT) in preoperatively evaluating the anatomical location of cholesteatomas and determining whether a patient is indicated for transcanal endoscopic ear surgery (TEES) to reduce intraoperative switching to microscopic ear surgery (MES). Study Design: Prospective case study. Setting: A single university hospital. Patients: Fifty-five patients scheduled for middle ear cholesteatoma surgery. Intervention: The CMDWI-CT is produced in a multistep process. A color-mapped fusion image (CMFI) is created by performing MR cisternography on a 1-mm thin-slice nonecho planar diffusion-weighted imaging (non-EPI DWI) and then by performing color mapping on the resulting image to enhance cholesteatoma visualization. False positives are reduced by taking a T1-weighted image (T1WI), whereas false negatives are further reduced by preoperative endoscopic examination. As cholesteatomas are difficult to locate on a CMFI in the temporal bone region, we stripped out the MR cisternography data from the CMFI and then fused the CMFI to the initial computer tomography (CT) scan to create a CMDWI-CT. This CMDWI-CT better clarifies the cholesteatoma position within temporal bone. Main Outcome Measure(s): CMDWI-CT preoperative findings were compared with intraoperative findings. The positive predictive value and negative predictive value were also evaluated depending on the cholesteatoma location. Results: CMDWI-CT facilitated accurate detection of the cholesteatoma anatomical location in the temporal bone region which was reflected in positive predictive and negative predictive values of over 90% for all areas of the middle ear. Conclusion: CMDWI-CT is a reliable diagnostic modality for evaluating the anatomical location of cholesteatomas that seem as high-signal regions on a CMFI and for determining whether TEES is indicated for treatment in such patients.


Journal of Japan Society for Head and Neck Surgery | 2016

The clinical experience of cone-beam CT for presurgical evaluation of sio-nasal diseases

Nobuo Ohta; Yasuhiro Abe; Yusuke Suzuki; Toshinori Kubota; Kazunori Futai; Seiji Kakahata; Hiroshi Ogawa; Yoshitaka Okamoto

The clinical experience of cone-beam CT for presurgical evaluation of sio-nasal diseases : Nobuo Ohta1), Yasuhiro Abe2), Yusuke Suzuki2), Toshinori Kubota1), Kazunori Futai1), Seiji Kakahata2), Hiroshi Ogawa3) and Yoshitaka Okamoto4). 1)Department of Otolaryngology, Yamagata City Hospital, 2)Department of Otolaryngology Head and Neck Surgery, Yamagata University Faculty of Medicine, 3)Department of Otolaryngology, Aizu Medical Center, Fukushima Medical University, 4)Department of Otolaryngology, Head and Neck Surgery, Chiba Graduate School University


Tohoku Journal of Experimental Medicine | 2006

Leupeptin, a Calpain Inhibitor, Protects Inner Ear Hair Cells from Aminoglycoside Ototoxicity

Junko Momiyama; Toshimitsu Hashimoto; Atsushi Matsubara; Kazunori Futai; Atsushi Namba; Hideichi Shinkawa

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