Hirokazu Hattori

Posture of patients with sleep apnea during sleep

The relationship between sleep apnea syndrome (SAS) and posture during sleep has been noted and the beneficial effect of an optimal posture on sleep apnea has been empirically indicated. We investigated this effect in a group of subjects that included obese patients and found that the apnea-hypopnea index (AHI) may be normalized in the lateral position, even among patients severely affected with apnea. Among those with intermediate or lower AHI values, sleeping in a lateral position markedly improved the symptoms, with AHI even approaching the normal range in many patients. A tendency was noted for AHI to rise regardless of posture but in proportion to the increase in body mass index (BMI). In other words, the improvement due to changes in posture became increasingly insignificant with increase in BMI.

Obesity and obstructive sleep apnea syndrome

We investigated the influence of obesity on upper airway obstruction, especially the relationship between obesity and the type of obstruction. The site of obstruction was identified by means of endoscopic examination and dynamic MRI during sleep. Many obese patients have the circumferential type of obstruction.

Two cases of sleep apnea syndrome caused by primary hypothyroidism.

Two cases of sleep apnea syndrome caused by primary hypothyroidism are reported. The first patient was a 66-year-old man who complained of sleep apnea; his apnea-hypopnea index (AHI) was 50.8, as assessed by all-night monitoring. Hypothyroidism was subsequently suspected when he showed delayed recovery from general anesthesia following surgery involving uvulopalatopharyngoplasty. Hypothyroidism was diagnosed on the basis of blood tests His snoring and apnea improved after 2 months of levothyroxine sodium administration and the AHI fell from 50.8 to 13.0. The second patient was a 73-year-old man with an AHI of 41.3, as assessed by all-night monitoring. Hypothyroidism was diagnosed on the basis of blood tests and was suspected because of his slow speech. He was similarly treated with levothyroxine sodium. The AHI did not decrease after 4 months of treatment. His desaturation rate (rate of O2 saturation < 90%) improved however, from 56.6% to 31.9%, and the symptoms of hypothyroidism also improved markedly. In both patients, elevated creatine phosphokinase, a dull facial expression, peripheral edema and slow speech were recognized, and these symptoms were suggestive of hypothyroidism. The type of sleep apnea was mainly obstructive in both patients.

Obstructive sleep apnea syndrome in children.

Obstructive sleep apnea syndrome (OSAS) in children is often caused by obstruction of the upper airway due to hypertrophy of the adenoids and palatine tonsils. Between October 1988 and December 1991, 50 children (34 males, 16 females) visited our department due to attacks of sleep apnea and underwent adenotomy or adeno-tonsillectomy. Respiratory monitoring during sleep was performed before and after operation, and the usefulness of the surgery was evaluated. Before operation, 27/ 50 children (54.0%) were diagnosed as having OSAS. Their age distribution showed peaks at the ages of 4 and 5 years and the male:female ratio was 2:1. Concerning the degree of improvement in clinical symptoms after surgery, marked effects were observed in 40/50 patients (80.0%), moderate effects in 7 (14.0%) and slight effects in 3 (6.0%). Concerning the degree of improvement in the apnea index after surgery in the 27 patients with OSAS, marked effects were observed in 22 patients (81.50%), moderate effects in 2 (7.4%), slight effects in 1 (3.7%) and no change in 2 (7.4%).

Application of lingual tonsillectomy to sleep apnea syndrome involving lingual tonsils.

In sleep apnea syndrome, surgical treatment is applied in obstructive-type cases and some mixed-type cases. If the obstructive part is in the root of the tongue, forward transfer of the tongue, lingual tonsillectomy and laser midline glossectomy are applied. In this study, we demonstrate the surgical technique of lingual tonsillectomy using an ultrasonic coagulating dissector (SonoSurg) with a blade tip shape developed in our department. We conclude that lingual tonsillectomy using SonoSurg, which we have frequently used, should be the first choice of treatment for snoring and sleep apnea caused by hypertrophy of the lingual tonsils from the viewpoints of effectiveness, prevention of hemorrhage, safety and handling.

Development of new blades of ultrasonic surgical system (SonoSurgR) for tonsillectomy and nasal conchotomy

Abstract In the otolaryngological field, SonoSurg R (Ultrasonic Surgical System, developed by Olympus Corporation in Japan) has never been used because the shape of the tips is too large for ENT-Head and Neck Surgery use. SonoSurg R is an ultrasonic surgical device with 47000 Hz vibration and 75 μm amplitude. An ultrasonic vibration at the tip of the SonoSurg R blade can cut the tissue continuously with low tissue damage. SonoSurg R has hemostasis and coagulation performance by frictional heat on the side of the blade. Coagulation will finish with a low temperature, less than 80 °C, and causes few lateral tissue damages. In this paper, we presented the advantages and disadvantages of a SonoSurg R knife blade and a spatula blade that we newly developed for tonsillectomy and nasal conchotomy. SonoSurg R needs no protective glasses, has strong stop-bleeding and high-coagulation ability, has few lateral tissue damage, and has no muscle twitch. Fine SonoSurg R blades with 3.8 mm diameter as newly developed by us are more useful for our ENT-Head and Neck Surgical field surgery. SonoSurg R has a few disadvantages in that the blades are somewhat costly and the sheath heats up with continuous use.