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  • Author or Editor: Masao Tsuji x
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Yoji Tamura, Teppei Uesugi, Adam Tucker, Tohru Ukita, Masao Tsuji, Hiroji Miyake and Toshihiko Kuroiwa

Colloid cysts of the third ventricle presenting with acute obstructive hydrocephalus due to intracystic and intraventricular hemorrhage are extremely rare. The authors report a case of a 43-year-old man with a hemorrhagic colloid cyst that was treated using endoscopic surgery. A small colloid cyst of the third ventricle was initially diagnosed in the patient, and he was treated conservatively at that time. On admission to the authors' institution he presented with sudden headache onset without neurological deficits. Computed tomography and MRI demonstrated a round hemorrhagic mass lesion in the third ventricle with bilateral intraventricular hemorrhage. Endoscopic resection was performed using a flexible videoscope. Only partial removal of the cyst was performed because of a tough cyst wall with highly viscous, hemorrhagic cystic contents. Histological examination revealed a typical colloid cyst wall and hemorrhage mixed within a mucinous substance. Postoperative serial neuroimaging demonstrated a gradual reduction in the residual cyst size and normalization in the lateral ventricle size.

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Shuji Kazuki, Tomio Ohta, Ryusuke Ogawa, Masao Tsuji, Yoji Tamura, Yasushi Yoshizaki and Takashi Takase

✓ The authors investigated selective intra- and extraluminal effects of endothelin (ET) on perfused basilar and extracranial arteries and also studied the interaction between ET and extraluminal oxyhemoglobin (oxyHb). The basilar, mesenteric, and femoral arteries were isolated from 23 Japanese White rabbits. After isolation of the intra- and extraluminal sides of the preparation, 3 × 10−10 to 3 × 10−8 mol/L of ET was administered intra- or extraluminally. After extraluminal pretreatment with 10−5 mol/L oxyHb, 10−5 mol/L NG-monomethyl-l-arginine (l-NMMA), or 10−6 mol/L indomethacin, 10−10 to 10−8 mol/L of ET was administered intra- or extraluminally. Arterial contraction was evaluated by measuring the increase in the perfusion pressure gradient with a differential pressure gauge. Both intra- and extraluminal ET (10−9 to 3 × 10−8 mol/L) showed potent and dose-dependent vasoconstricting effects on basilar arteries (p < 0.01). The effect of ET on the basilar arteries was significantly greater than on the femoral or mesenteric arteries (both p < 0.01). The effect of intraluminal ET was enhanced by extraluminal oxyHb (p < 0.05) and l-NMMA (p < 0.01), but not by extraluminal indomethacin. Extraluminal oxyHb did not potentiate the contraction induced by extraluminal ET. These results indicate that the sensitivity of the basilar artery to intraluminal ET is greater than that of the femoral or mesenteric artery. Endothelin may act as a potent vasoconstrictor intra- as well as extraluminally under conditions such as subarachnoid hemorrhage in which oxyHb is present in the extraluminal space and endothelium-derived relaxing factors are inhibited.

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Yoji Tamura, Toshihiko Kuroiwa, Yoshinaga Kajimoto, Yoshihito Miki, Shin-Ichi Miyatake and Masao Tsuji

✓Several neurosurgical studies have provided descriptions of the utility of fluorescence-guided tumor resection using a microscope. However, fluorescence-guided endoscopic detection of a deep-seated brain tumor has not yet been reported. The authors report their experience with an endoscopic biopsy procedure for a malignant glioma within the third ventricle using a 5–aminolevulinic acid (5-ALA)–induced protoporphyrin IX fluorescence imaging system. A 5-ALA–induced fluorescence image of an intraventricular tumor is barely visible with the typical fluorescence endoscopic system used in other clinical fields because the intensity of excitation light at wavelengths of 390 to 405 nm through a cutoff filter is too weak to delineate a brain tumor.

The technique described in this study made use of a laser illumination system with a high-powered output that delivered a violet-blue light at wavelengths of 405 nm. In addition, a common ultraviolet cutoff filter was fitted between the endoscope and the high-sensitivity camera to block the backscattered excitation light. A 5-ALA–induced fluorescence endoscopy performed using this system allowed the intraventricular tumor to be clearly visualized as a red fluorescent lesion. Several biopsy specimens obtained from the fluorescent lesion provided a definitive histological diagnosis. The results indicate that this endoscopic system is useful in detecting an intraventricular fluorescent tumor.