Eiji Moriyama

Hyperthermia for Brain Tumors: Improved Delivery with a New Cooling System

Hyperthermia has emerged as an adjunct to other forms of brain tumor therapy. Interstitial microwave irradiation is an effective method of inducing localized brain hyperthermia. One of the problems with this technique, however, is the overheating of tissue adjacent to the antenna. In this study, a cooling system for the interstitial microwave antenna was developed for the purpose of providing uniform and accurate heating by the elimination of overheating. The ability to generate more uniform hyperthermic fields was evaluated in normal monkey brains. Six monkeys under general anesthesia and controlled respiration underwent parietooccipital craniectomies 4 x 4 cm in size. The antenna cooling system was constructed of a silicone tube 5.0 mm in outer diameter. Silicone-coated interstitial microwave antennae 1.5 mm in diameter were used. A single antenna or a square array (1.6 cm on a side) of 4 antennae was inserted into the brain with the coupled system to a depth of 2 cm. The brain tissue was heated by 2450-MHz microwave irradiation. Temperature distributions were mapped using nonperturbing thermocouples. These thermal profiles were compared with those generated without the cooling system. In the experiments with the single antenna, the antenna cooling system eliminated the overheating and rapid radial falloff in temperature, without a reduction of the hyperthermic field. In the four-antennae experiments using the cooling system, the thermal field was dramatically flattened with minimal reduction in size; however, the area maintained at a therapeutic temperature range (42-45 degrees C) was significantly enlarged by the cooling system.(ABSTRACT TRUNCATED AT 250 WORDS)

Progress in the management of patients with aneurysmal subarachnoid hemorrhage: A single hospital review for 20 years: Part I: Younger patients

BACKGROUND This study was carried out to clarify if there has been any improvement in the outcome of patients with aneurysmal subarachnoid hemorrhage during the past 20 years. Because elderly patients have apparently poorer prognoses than younger patients, patients older than 70 years were analyzed separately in the following article. METHODS Five hundred seventy-one patients with aneurysmal subarachnoid hemorrhage, under 70 years, who were consecutively admitted to Kagawa Prefectural Central Hospital from July 1972 to December 1992, were reviewed. These patients were divided into four groups according to the time of admission. The ultimate outcome was evaluated by means of Glasgow Outcome Scale 6 months after the ictus. RESULTS Changes in treatment protocol in this period included the induction of early surgery and the invention of a variety of modalities for the treatment of cerebral vasospasm. This resulted in a distinct increase in patients who actually underwent direct aneurysm clipping. Outcome has been significantly improved during this period, especially in patients with Hunt and Kosnik grade III (p<0.05, chi2). Patients in good clinical condition at follow-up (Glasgow Outcome Scale: good recovery) increased from 8.7% to 60.7%. Mortality decreased from 28.7% to 10.7%. CONCLUSIONS Current therapeutic modalities have significantly improved the outcome of patients with aneurysmal subarachnoid hemorrhage. Rebleeding before early surgery remains as a major cause of unfavorable outcome and further progress on this subject is mandatory.

Management of patients with aneurysmal subarachnoid homorrhage: Progress and current problems.

香川県立中央病院に脳神経外科が開設された1972年7月以来, 1994年6月までの22年間に治療した615人の70歳未満のクモ膜下出血患者の治療成績を分析した.これらの患者を治療方針の変化に伴い, 時期別に4群に分けて検討した.この期間中の治療方針の最大の変化は, 待機手術から早期手術への移行であり, 平均手術時期はHunt and Kosnik gradeI-II患者で, Day 17.5からDay 1.5 (発症日 : Day0), gradeIII患者では, Day11.5からDay0.8と発症から手術までの時間が有意に短縮していた.これに伴いgrade III患者では手術施行率が, 71%から97.5%と増加し, 最終的な転帰も有意に改善していた.Grade I-II患者では手術施行率は待機手術が主流であった時代と変化がないものの, やはり転帰の改善が見られた.従来は手術の対象となることが少なかったgrade IVについても, 積極的な早期手術によって転帰の改善が認められた.現在の治療上の最大の問題点は, 急性期手術準備中の再出血であり, これらの患者の転帰は有意に不良であった.種々の脳血管攣縮対策により, 重篤な脳血管攣縮の発生は減少しており, 現在では死亡原因としてではなく神経脱落症状の原因として重要であった.