Kensaku Hasegawa

Usefulness of chest CT scan for head and neck cancer

OBJECTIVE Chest computed tomography (CT) is not performed routinely or worldwide as the initial diagnostic procedure for patients with head and neck cancer (HNC). The significance of the chest CT scan for HNC diagnosis has not been thoroughly defined. The present study reports findings in an effort to broaden the acceptance and application of CT for HNC. METHODS Using medical records, we assessed initial chest CT scans of the patients with new-onset HNC between April 2004 and March 2010. The results were classified into three groups: nodules ≥ 1 cm, small nodules (< 1 cm) that were indeterminate and normal lungs without nodules. Lung nodules that increased in size and/or number at follow-up were regarded as malignant. First, the sensitivity of X-ray and CT for detection of lung nodules in patients with HNC was compared. Second, the nodules were estimated to be malignant or not malignant by follow-up chest CT. Third, statistical analyses were performed to determine the association between variables and distant lung metastases in patients with head and neck squamous cell carcinoma. RESULTS In total, 332 patients underwent a chest CT scan as part of the initial examination. Lung nodules were detected on the initial chest CT in 77 patients: in contrast, lung nodules were detected on the initial chest X-ray in only five patients. On initial chest CT scans, lung nodules ≥ 1 cm were observed in 10 patients, small solitary lung nodules were observed in 67 patients, and lungs without nodules were observed in 255 patients. Lung nodules were detected in 77 (23.2%) patients, 25 (32.5%) of whom had malignant lung nodules. Moreover, in 18/67 patients (26.9%), small lung nodules initially classified as indeterminate were determined as malignant at follow-up. However, 30/255 patients (11.8%) without nodules at initial diagnosis developed lung nodules at follow-up. T3 or T4 disease (P = 0.006), N2 or N3 disease (P < 0.001) and stage 3 or 4 disease (P = 0.001) individually and significantly correlated with the development of lung metastases. In addition, lung nodules in initial CT scans (P = 0.004) and other distant metastases (P < 0.001) were significant predictors for the development of lung metastases at follow-up. CONCLUSION Initial chest CT scan is recommended for patients with advanced HNC. Further, patients with advanced HNC with or without lung nodules, as detected on initial chest CT scans, should be followed up with additional scanning.

Analysis of human glottal velocity using hot-wire anemometry and high-speed imaging.

Objectives: The aim of this study was to analyze glottal velocity and glottal opening and closure. For this purpose, we developed a miniature, flexible, hot-wire probe that can make truly instantaneous measurements of the human larynx in vivo. Methods: A miniature hot-wire tip was inserted into a flexible transnasal endoscope. Fiberscopic examination was performed transnasally so that we could observe glottal vibration using high-speed imaging. The tip of the hot-wire probe was placed just above the glottis. The position of the probe was carefully monitored and checked with another flexible endoscope. Results: Changes in velocity were recorded periodically. The velocity was higher in close proximity to the vocal folds. High-speed motion pictures were taken at a rate of 2,000 frames per second with an auxiliary light source. Conclusions: Quantitative analysis of glottal velocity is required to improve our understanding of the relationship between laryngeal physiology and acoustics in humans. To solve the problem of synchronization inaccuracy, glottal velocity was captured instantaneously in the high-speed imaging systems processor memory.

Sequential multipoint motion of the tympanic membrane measured by laser Doppler vibrometry: preliminary results for normal tympanic membrane.

Background Numerous studies have reported sound-induced motion of the tympanic membrane (TM). To demonstrate sequential motion characteristics of the entire TM by noncontact laser Doppler vibrometry (LDV), we have investigated multipoint TM measurement. Materials and Methods A laser Doppler vibrometer was mounted on a surgical microscope. The velocity was measured at 33 points on the TM using noncontact LDV without any reflectors. Measurements were performed with tonal stimuli of 1, 3, and 6 kHz. Amplitudes were calculated from these measurements, and time-dependent changes in TM motion were described using a graphics application. Results TM motions were detected more clearly and stably at 1 and 3 kHz than at other frequencies. This is because the external auditory canal acted as a resonant tube near 3 kHz. TM motion displayed 1 peak at 1 kHz and 2 peaks at 3 kHz. Large amplitudes were detected in the posterosuperior quadrant (PSQ) at 1 kHz and in the PSQ and anteroinferior quadrant (AIQ) at 3 kHz. The entire TM showed synchronized movement centered on the PSQ at 1 kHz, with phase-shifting between PSQ and AIQ movement at 3 kHz. Amplitude was smaller at the umbo than at other parts. In contrast, amplitudes at high frequencies were too small and complicated to detect any obvious peaks. Conclusion Sequential multipoint motion of the tympanic membrane showed that vibration characteristics of the TM differ according to the part and frequency.

Sequential motion of the ossicular chain measured by laser Doppler vibrometry

Abstract Objective: In order to help a surgeon make the best decision, a more objective method of measuring ossicular motion is required. Methods: A laser Doppler vibrometer was mounted on a surgical microscope. To measure ossicular chain vibrations, eight patients with cochlear implants were investigated. To assess the motions of the ossicular chain, velocities at five points were measured with tonal stimuli of 1 and 3 kHz, which yielded reproducible results. The sequential amplitude change at each point was calculated with phase shifting from the tonal stimulus. Motion of the ossicular chain was visualized from the averaged results using the graphics application. Results: The head of the malleus and the body of the incus showed synchronized movement as one unit. In contrast, the stapes (incudostapedial joint and posterior crus) moved synchronously in opposite phase to the malleus and incus. The amplitudes at 1 kHz were almost twice those at 3 kHz. Conclusions: Our results show that the malleus and incus unit and the stapes move with a phase difference.

Staged resection for vestibular schwannoma

Abstract Conclusion: Surgery remains the preferred option for large vestibular schwannoma (VS). The presence of unpredictable intraoperative difficulties may convince the operator to suspend the surgery to avoid risks to patient life. Additional surgeries may be mandatory and are better performed using a transcochlear approach. High rates of complications, poor facial nerve results, and a percentage of incomplete removals should be expected in such unfavorable cases. Objectives: To review the results for nine cases of huge VS treated by staged resection. Method: A retrospective case review was performed for all nine patients who underwent staged resection of VS at the Gruppo Otologico between 1984–2012. The decision to perform staged surgery was always made intra-operatively after encountering unpredicted difficulties. Results: The nine patients represented 0.3% of all patients who underwent VS surgery during the same period. Mean tumor size was 4.7 cm (range = 3.0–6.6 cm). Two cases required three surgeries, resulting in a total of 20 operations. In addition, two cases required pre-operative ventriculoperitoneal shunt and one required temporary tracheotomy. After the final stage of surgery, complete removal had been achieved in six of the nine patients. The facial nerve was never preserved anatomically.

A Case of Deep Cervical Abscess Caused Perforation at Gastroenterological Endoscopy

We reported a rare case of perforation of the piriform sinus caused by gastroenterological endoscopy examination, leding to deep cervical abscess. The patient was a 56-year-old man who complained of dyspnea, high-grade fever and neck pain after gastroenterological endoscopy examination. Computed tomography revealed a deep cervical abscess and obstruction of the airway. We immediately, performed drain-age under general anesthesia, and found a perforation at the piriform sinus. He was treated with frequent wound washing and the daily intravenously instillation of antibiotics for anaerobic bacteria, and was discharged 31 days after the operation. Early diagnosis and operation are important for the management of deep cervical abscess.

Laryngeal Carcinosarcoma Recurring with Innominate Artery Fistula: A Case Report

Innominate artery fistulas require a surgical procedure, although the prognosis is usually very poor because of complications such as re-bleeding and infection. A 50-year-old man presented with laryngeal carcinosarcoma (T1a, N0, M0). Partial laryngectomy was performed but there was a recurrence; therefore, total laryngectomy, total thyroidectomy, right radical neck dissection, left functional neck dissection, skin-combined resection and D-P flap were performed. On postoperative day 6, after intense coughing, copious hemorrhage from the tracheostoma was demonstrated. Immediately, bleeding was arrested by pressing the tracheostoma. Fistula of the innominate artery was then repaired using left great saphenous vein, but recurrent perforation of the innominate artery developed. Therefore, innominate artery transection and omentopexy were performed. These results demonstrate that in cases of trachea-innominate artery fistula, innominate artery transection should be performed first.

Melkersson-Rosenthal Syndrome; A Case Report

We report a case of Melkersson-Rosenthal syndrome. The case involved an eight-year-old girl. She had experienced left facial paralysis and its spontaneous regression two years before she first came to our clinic with left recurrent facial paralysis and lower lip swelling. Evoked electromyography revealed that the ratio between left and right was 5%. Recovery of facial nerve function was observed after administration of a steroid. Six months later, right facial paralysis occurred, but it disappeared after steroid therapy. Three years after her first visit, right facial paralysis recurred. Because lingua plicata was also exhibited, the diagnosis of Melkersson-Rosenthal syndrome was confirmed. Complete recovery from right facial paralysis was observed after steroid therapy. Although her mother had a history of sarcoidosis, the patients chest roentgenography, serum angiotensin converting enzyme level, and ophthalmological evaluation for uveitis revealed no signs of sarcoidosis.