Tomoo Watanabe

The University of Electro-Communications, Edo, Tōkyō, Japan

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Publications (12)9.83 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: 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. Prospective case study. A single university hospital. Ninety-two patients scheduled for middle ear cholesteatoma surgery. 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. 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. 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. 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.
    11/2014;
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    ABSTRACT: 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. A prospective case series. Tertiary referral center. Transcanal endoscopic myringoplasty was performed on 25 ears in 21 patients with chronic otitis media between September 2011 and December 2012. 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. 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. 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: official publication of the American Otological Society, American Neurotology Society [and] European Academy of Otology and Neurotology 04/2014; 35(4):e140-5. · 1.44 Impact Factor
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    ABSTRACT: Mastoidectomy using an ultrasonic bone curette (UBC) is as safe for the inner ear as a mastoidectomy using a high-speed drill. 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. 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. 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. 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: official publication of the American Otological Society, American Neurotology Society [and] European Academy of Otology and Neurotology 12/2013; · 1.44 Impact Factor
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    ABSTRACT: 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. 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. A prospective case series. Tertiary referral center. TEES was performed on 43 cases of primary cholesteatoma between September 2011 and December 2012, including 14 cases extending to the antrum. 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. 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. 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.
    Otology & neurotology: official publication of the American Otological Society, American Neurotology Society [and] European Academy of Otology and Neurotology 10/2013; · 1.44 Impact Factor
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    ABSTRACT: 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.
    International Journal of Otolaryngology 01/2013; 2013:539642.
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    ABSTRACT: Immunoglobulin G4 (IgG4)-related sclerosing sialadenitis is a recently recognized disease entity characterized by high serum IgG4 concentration and IgG4-producing plasma cell expansion in affected organs, which show fibrotic or sclerotic changes. However, little is known about the roles of CD4+ and CD8+ T cells or interleukin (IL)-17 in this disease. The purpose of this study was to evaluate the characteristics of CD4+ and CD8+ T cells and IL-17 in patients with IgG4-related sclerosing sialadenitis. A retrospective clinical study at the Yamagata University School of Medicine. The patient group consisted of six males and four females with an average age of 57.9 years (range, 38 to 73years). Subsets of T helper (Th)1, Th2, T cytotoxic type (Tc)1, and Tc2 cells from patients with IgG4-related sclerosing sialadenitis were examined by using intracellular cytokine flow cytometry. Expression of IL-17 in the patients' lesions was also investigated immunohistochemically. Six patients with IgG4-related sclerosing sialadenitis with high ratios of IgG4/IgG and prominent infiltration of IgG4-positive plasmacytes in the involved salivary glands had systemic complications, including pancreatitis, retroperitoneal fibrosis, and/or inflammatory pseudotumor of the lung after the initial swelling of the salivary glands. Populations of Th1 and Tc1 cells were significantly greater in IgG4-related sclerosing sialadenitis than in the controls (P < .05), but Th2 and Tc2 cell populations were not significantly increased. Expression of IL-17 was observed in the lesions of affected patients. Increases in Th1 and Tc1 cell populations and IL-17 expression might be involved in the mechanism of pathogenesis of IgG4-related sclerosing sialadenitis. Laryngoscope, 2012.
    The Laryngoscope 07/2012; 122(10):2169-74. · 1.98 Impact Factor
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    ABSTRACT: The efficacy of combined high-dose steroid and PGE1 treatment initiated immediately after the onset of sudden deafness was analyzed with the outcome of 174 patients begun on treatment within 7 days of the onset of sudden deafness. Four potential prognostic factors (days from onset to treatment, age, initial hearing level, presence of vertigo) and hearing outcome were examined with a multiple logistic regression analysis. Days from onset to treatment and age significantly correlated with hearing improvement. The efficacy of the treatment of patients begun on treatment within 3 days of the onset was significantly better than that of patients on treatment 4-7 days after the onset (p < 0.001). In the examination of patients younger than 50 years, the efficacy of the treatment of patients begun on treatment within 3 days of the onset didn't differ significantly from that of patients on treatment 4-7 days after the onset. On the other hand, in the examination of patients aged 50 years and older, the efficacy of the treatment of patients begun on treatment within 3 days of the onset was significantly better than that of patients on treatment 4-7 days after the onset (p < 0.001). These results suggest that significant efficacy may be expected from the combined high-dose steroid + PGE1 treatment, if its use is started within 7 days of the onset of sudden deafness, and started within 3 days of the onset of sudden deafness in patients 50 years old and older.
    Nippon Jibiinkoka Gakkai Kaiho 05/2012; 115(5):540-5.
  • The Laryngoscope 01/2012; 122(1):131-3. · 1.98 Impact Factor
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    ABSTRACT: 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.
    Case reports in otolaryngology. 01/2012; 2012:634949.
  • Practica Otologica, Supplement 01/2011; 130:31-34.
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    ABSTRACT: Liposarcoma most commonly arises in the retroperitoneum and lower extremities. Liposarcoma of the head and neck region is a rare and potentially life-threatening malignancy. Those originating in the right retrocervical space cause special diagnostic and therapeutic difficulties. In present report, a case of differentiated liposarcoma of the right cervical region with intestinal carcinoid is reported. The tumor continued to grow slowly over 3 years before a definitive diagnosis was established. Extended extirpation of the tumor and modified radical neck dissection, postoperative radiotherapy followed by chemotherapy were performed and proved to be efficacious in that no recurrence was observed for 2 years. Recommendations for earlier and correct diagnosis and treatment of this rare neoplasm are discussed.
    Auris, nasus, larynx 10/2010; 38(3):421-5. · 0.58 Impact Factor
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    ABSTRACT: Our results confirmed that OK-432 therapy is simple, easy, safe, and effective and can be used as a substitute for surgery in the treatment of benign neck cysts. In OK-432 therapy, inflammatory cytokines may play important roles in shrinkage of the cystic spaces. The aim of this study was to evaluate the outcome and mechanism of action of OK-432 therapy in benign neck cysts. We tried OK-432 therapy in 83 patients with benign neck cysts between April 1997 and August 2009. We aspirated as much of the fluid content of each cystic lesion as possible, and then replaced the volume of aspirated fluid with about half the volume of OK-432 solution. We evaluated the mechanism of action of OK-432 in 43 of the patients. The intracystic fluid in the cysts was aspirated before and after OK-432 therapy, and cytokine production in each aspirate was analyzed by ELISA. Disappearance of the lesion was observed in 63 of 83 patients (76%). Marked reduction was observed in 13 of the 83 patients (16%). Partial reduction was observed in two patients (2%) and no response was seen in five (6%). Local discomfort at the injection site and low-grade fever were side effects observed in half of the patients, but such problems resolved within a few days. No local scarring or deformity of the injected sites occurred in any patient. We performed OK-432 therapy on an outpatient basis without hospitalization. Levels of various cytokines, including tumor necrosis factor, interleukin-8, interleukin-6, interferon gamma, and vascular endothelial growth factor, were significantly elevated in each aspirate after OK-42 therapy.
    Acta oto-laryngologica 05/2010; 130(11):1287-92. · 0.98 Impact Factor

Publication Stats

20 Citations
9.83 Total Impact Points

Institutions

  • 2013
    • The University of Electro-Communications
      Edo, Tōkyō, Japan
  • 2010–2013
    • Yamagata University
      • Department of Otolaryngology, Head and Neck Surgery
      Ямагата, Yamagata, Japan