Yasuhiko Nakajima

Morphological investigation of the neuroprotective effects of graded hypothermia after diverse periods of global cerebral ischemia in gerbils

Hypothermia is known to be the most effective method to protect the neuronal damage induced by ischemia. In the present study, we investigated the histopathological consequences of hippocampal CA1 pyramidal neurons as well as the glial reactions in the hippocampus, after diverse periods of ischemic insult at graded intra-ischemic hypothermia ranging from 32 to 20 degrees C. Gerbils were exposed to forebrain ischemia by clamping the bilateral common carotid arteries for 5-120 min depending upon the temperatures. The morphological study was performed 7 days after ischemia or sham-operation. Histopathological evaluation of delayed neuronal death (DND) was performed by Cresyl violet (CV) staining and MAP2 immunoreactivity. Glial reactions were examined by GFAP immunostaining and isolectin B4 histochemistry, corresponding to astrocytes and microglia, respectively. The forebrain ischemia at 32 degrees C for 10 min and at 28 degrees C for 20 min did not induce DND in the CA1 region. However, the ischemia at 32 degrees C for 20 min and at 28 degrees C for 30 min caused extensive degeneration of CA1 pyramidal neurons as observed in normothermic ischemic animals. Under the condition of deep hypothermia, the ischemia for 60 min at 24 degrees C and for 120 min at 20 degrees C which were the longest durations of each temperature within the limitation of the animal survival following 7 days, induced no DND in CA1 pyramidal neurons. The reactive changes of astrocytes were observed not only in ischemic animals with DND, but also in ischemic animals without DND. Computer image analysis showed that the area fraction of GFAP-positive structures in the CA1 region was significantly increased in both ischemic cases with and without DND compared with each sham group. In contrast, the distribution of activated microglia was much more restricted to the CA1 region and they were always accompanied by DND at 7 days postischemia. The present results demonstrate the remarkable neuroprotective effect of deep hypothermia that has been widely used in cardiovascular surgeries as the cerebroprotective strategy during total circulatory cessation. The findings also suggest that even under the condition of hypothermia, glial reactions may play an important role in neuronal survival and death after ischemia.

Unruptured Aneurysm of the Sinus of Valsalva Into the Pulmonary Artery

Congenital aneurysms of the sinus of Valsalva are rare lesions. Because the aortic root is central, the aneurysm can rupture into any cardiac chamber, and virtually all combinations of sinus and chamber fistulas have been described. Rupture into the pulmonary artery, however, is very rare. We encountered a 14-year-old boy with conal ventricular septal defect and right coronary cusp prolapse with an unruptured aneurysm of the sinus of Valsalva into the pulmonary artery.

Supravalvular Stenotic Mitral Ring with Ventricular Septal Defect

Abstract Background: Supravalvular mitral ring is exceedingly uncommon. Methods: We report a 4‐year‐old girl with supravalvular stenotic mitral ring and ventricular septal defect (VSD). The VSD was closed by a Dacron patch and the supravalvular ring was excised. For treatment of supravalvular mitral ring with obstruction, surgical resection is commonly performed. Results: There are no reports of long‐term follow‐up after resecting the supravalvular mitral ring. Conclusion: In our case, no mitral stenosis was evident on postoperative echocardiogram performed 3 years after surgery.

Clinical significance of reverse redistribution phenomenon after coronary artery bypass grafting

The reverse redistribution (RR) phenomenon is a decrease in thallium 201 uptake during redistribution compared with 201Tl uptake immediately after exercise. We evaluated RR in 23 patients after coronary artery bypass grafting. Postoperative RR was present in 48% and was significantly more common in patients with a history of myocardial infarction (62%). The patients were classified according to the presence (+) or absence (-) of RR. An analysis of left ventricular wall motion showed significant improvement after coronary artery bypass grafting in the RR+ group (n = 12) but not in the RR- group (n = 11). Quantitative myocardial viability was evaluated using the defect volume ratio, mean defect severity, and defect severity index. The preoperative defect volume ratio was higher in the RR+ group than in the RR- group (p < 0.05). In the RR- group, no improvement in these indices was observed after operation. In contrast, the RR+ group showed significant improvement in all three indices (p < 0.05). These results indicate that after coronary artery bypass grafting, an adequate blood supply to the remaining myocardium may induce RR. This phenomenon, therefore, may be a significant indicator of postoperative myocardial viability.

Combined catheter embolization and femorofemoral bypass for pseudoaneurysm of the right external iliac artery: Report of a case

Performing direct surgery for postoperative hemorrhage caused by intraperitoneal arterial injury is very difficult. We report herein the case of a 52-year-old woman who developed sudden right lower abdominal pain after numerous laparotomies and radiotherapy for advanced uterine cancer. A diagnosis of pseudoaneurysm of the right external iliac artery was made, and an emergency catheter embolization and femorofemoral bypass was successfully performed under local anesthesia. The patient was able to walk the next day. To the best of our knowledge, this is the first report of such a combined procedure in the literature.

Bilateral main bronchial compression caused by the ductal ligament

Several authors have reported cases of respiratory distress resulting from bronchial compression due to a hypertensive pulmonary artery in the setting of a large left-to-right shunt. However, respiratory distress due to bilateral main bronchial compression due to an enlarged pulmonary artery suspended posteriorly by the ductal ligament following repair of a ventricular septal defect is extremely rare. In this report, we advocate the necessity of dividing the ductal ligament in some patients with large left-to-right shunts when there are episodes of idiopathic respiratory distress before operation.

Invagination induced by a long intestinal tube: Report of a case

Invagination induced by a long intestinal tube is rarely encountered. We report herein one such case of a 62-year-old man who was successfully treated by laparoscopically reducing the invagination, then performing partial resection of the small intestine.

Thrombomodulin Concentration in Patient Undergoing Surgery for Abdominal Aortic Aneurysm.

近年, 血中トロンボモジュリンは血管内皮細胞の障害程度を示す新しい分子マーカーとして注目されている. われわれは腹部大動脈瘤手術中の血管内皮障害を調べる目的で血中トロンボモジュリンを測定したので報告する. 対象は腎動脈下の腹部大動脈瘤に待機的手術を施行した9例で, 性別は全例男性, 年齢は46～74歳 (平均64.9歳) であった. 血中トロンボモジュリンの測定は手術前, 大動脈遮断直前, 大動脈遮断解除直後, 大動脈遮断解除1時間後, 3時間後, 18時間後に, 一側の大腿静脈より採血し, EIA法にて行った. トロンボモジュリンは大動脈遮断直前には術前より有意に低下したが, 遮断解除3時間後に増加し, 術前値との有意差は消失し, 以後とくに有意な変化は認められなかった. これらの結果から, 腹部大動脈瘤手術中は血中トロンボモジュリン値が増加するような血管内皮障害は発生していないと考えられた.

The Physical Effects of Body Movement on Axillary-to-Femoral Artery Graft.

われわれはEPTFE人工血管を用いた右腋窩-大腿動脈バイパス術後, 右肋骨弓の尾側で非吻合部の人工血管断裂をきたした症例を経験した. この発生原因の一つとして, 体幹運動による人工血管への物理的負荷を考慮し, 健常者において実験を行った. 直立基本肢位にて, 右鎖骨中央より右ソケイ靱帯中央までの距離を測定し, この距離を3等分するようにマーカーを描いたものを基本位モデルとした. 次に, 各部位の距離が最長となる体位をそれぞれの部位での伸展位モデル, 最短となる体位を同様に屈曲位モデルとし, 各モデル間での各部位の距離の変化率 (%) を算出し検討した. 伸展位では中部で有意に伸展しており, 屈曲位では下部が有意に短縮していた. 腋窩-大腿動脈術後のグラフトでは, 体幹運動により, 中部および下部にて伸展, 屈曲の物理的負荷がかかるものと考えられ, この負荷により遠隔期に人工血管の断裂をきたす可能性が疑われた.