Tasuku Shoji

Atrial activation during chronic atrial fibrillation in patients with isolated mitral valve disease

BACKGROUND A computerized 32-channel mapping system has been developed to investigate the characteristics of the atrial activation sequence. The system is capable of displaying sequential atrial maps and provides a rapid and dynamic means of verifying the activation sequence of atrial fibrillation. METHODS Using this system, we performed intraoperative atrial activation mapping in 10 patients with chronic atrial fibrillation who were undergoing isolated mitral valve operations. RESULTS Regular and repetitive activation (cycle length ranged from 131 to 228 milliseconds) originated in the left atrium in all 10 patients. Two patterns of repetitive activation in 2 patients and three patterns in 1 patient appeared alternately during the observation period in the left atrium. In contrast to the repetitive activation in the left atrium, the activation sequence of the right atrium was extremely complex and chaotic. In 7 of the 10 patients, the same pattern of right atrial activation was never repeated during the observation period. In 2 patients, revolution of repetitive activation in the right atrium sporadically appeared, but the pattern of activation immediately deteriorated to a complex and chaotic pattern. In 1 patient, repetitive activation emerged from the low lateral portion of the right atrium. Because our mapping technique was limited by the number of available atrial electrodes, discrete reentrant circuits or ectopic foci could not be demonstrated in the present study. However, the activation sequences during chronic atrial fibrillation suggested that (1) the left atrium would act as an electrical driving chamber for atrial fibrillation in the majority of the patients and (2) atrial activation patterns are different in each case. CONCLUSIONS Computerized intraoperative mapping should guide surgeons in determining the appropriate surgical procedure and facilitate operation for chronic atrial fibrillation associated with mitral valve disease.

Successful Combined Operation for Mitral Stenosis and Atrial Fibrillation

Simultaneous surgical treatment of mitral stenosis and atrial fibrillation was performed. The patients postoperative course was uneventful, the rhythm changed to sinus rhythm, and the patient was discharged on the 21st postoperative day in stable condition.

A rupture of lung metastasis of hepatocellular carcinoma causing haemothorax

A 67 year old male with non‐resectable hepatocellular carcinoma (HCC) in both lobes and liver cirrhosis was treated with transcatheter arterial embolization and regional chemotherapy. He was doing well for 18 months. He was readmitted for fever, chest pain and multiple pulmonary metastases. During interleukin‐2 therapy, he suddenly developed dyspnoea and palpitation, and was in shock. Left‐sided haemothorax was confirmed by draining 3 L of fresh blood. In spite of intensive care, he died within 36 h. Autopsy showed that the haemothorax was caused by rupture of one of the metastases in the upper lobe of the left lung, and that the primary HCC was totally necrotic. Survey of the literature failed to find a report of fatal bleeding from a lung metastasis of HCC.

Laser vascular welding in biologic grafts

This study evaluated the possibility and efficacy of laser welding in biologic vascular grafts. Grafts were anastomosed to 21 canine peripheral (femoral and/or carotid) arteries or coronary arteries with a Nd-YAG laser using the contact method. The laser welds were fashioned using 1-1.5 W power for 1-3 sec. The grafts used were heparinized canine carotid artery cross-linked with polyepoxy compounds. The welding was a success in 92% (22/24) of the peripheral artery and 83% (5/6) of the coronary artery procedures. The early patency rate was 100%. The anastomotic sites were strong enough to withstand high pressure (more than 300 mmHg of arterial pressure). Histologic examination was performed on days 0 and 3, 1 week, 3 weeks, or more than 1 month postoperatively to compare the progression of healing. The laser welded sites had a smooth external surface and minimal damage of the internal layer, with minimal inflammatory response and no pathologic granulation. The welded sites fused strongly after 1 postoperative week. In conclusion, an Nd-YAG laser, using a contact method, could successfully weld peripheral and coronary arteries to biologic vascular grafts.

A case of strut fracture of the new Björk-Shiley mital valve prosthesis

We treated a 61-year-old Japanese man with a strut fracture of the new Björk-Shiley mitral valve. This fracture occurred about two months after mitral valve replacement. Emergency reoperation was performed as soon as the chest X-ray showed the fracture, despite the presence of cardiopulmonary shock. He died on the 3rd postoperative day. Similar reported cases of literature are reviewed.

Congenital aortic regurgitation caused by a rudimentary noncoronary cusp: Report of a case

A 14-year-old asymptomatic boy was admitted to our department for investigation of a diastolic murmur which had been discovered by his family doctor during a routine examination. Echocardiography showed aortic regurgitation with dilatation of the left ventricle. Inspection of the aortic valve at the time of operation revealed normal left and right cusps with a rudimentary noncoronary cusp. An aortic commissuro-plication was performed and a new bicuspid aortic valve successfully reconstructed. His postoperative course was uneventful and he has been well and leading an active life since his discharge from hospital.

Peritoneovenous shunting for intractable cirrhotic and cancerous ascites using different types of shunting tubes

A total oftwenty six peritoneovenous shuntings were performed in our department between 1978 and 1984, on twelve cirrhotic and ten cancerous patients with intractable ascites, using Pudenz, LeVeen or Denver type shunting tubes. Reduced ascites was noted postoperatively with statistical significance in both the cirrhotic group (p<0.05) and the cancerous group (p<0.01), of whom eight cirrhotic and seven cancerous patients exhibited an abdominal girth reduced by 9.7cm (a 10.9 per cent reduction) in two weeks. A larger urinary output was noted in 13 patients, with a mean increase of 587 ml/day compared with the pre-shunting output. These patients lost a mean weight of 6.13 kg in two weeks, while the non-reduced ascites group gained weight. The post-shunting serum albumin level was higher in the reduced ascites group. The mean functioning periods of the shunts were 5.1 and 2 months, respectively for the cirrhotic and cancerous patients whose shunts were patent. The patients’ outcome was shown to depend on the disease itself, with the exception of one patient who died of disseminated intravascular coagulopathy following shunting. In comparing several types of shunting systems, the Denver-type was proven as being the most unlikely to plug or malfunction because of its simpler structure.

Surgical laser ablation of a pediatric idiopathic ventricular tachycardia

A pediatric patient with medically refractory idiopathic ventricular tachycardia was successfully treated by surgical laser ablation. Application of laser on the normothermic beating heart enables continuous electrophysiological assessment. The histopathology of idiopathic ventricular tachycardia and the advantages of laser ablation are presented.

Continuous and stable recording of the his bundle electrogram during open heart operations

We describe a method for continuously recording the stabilized His bundle electrogram from the aortic root during open heart surgical procedures. This simple technique was useful in all surgical procedures for the oblation of supraventricular tachyarrhythmias in the region around the atrioventricular conduction system.

Histopathological study of regenerative mechanism after partial hepatectomy of the liver cirrhosis induced by thioacetamide administration.

Thioacetamide投与ラット硬変肝を用い2/3の肝切除後における細胞,細胞外基質と増殖因子の動態について形態学的,免疫組織化学的に観察し検討した.肝切除の7日後に類洞の開大とKupffer細胞の増殖,3週後に類洞の狭小化,5週後には類洞の再開大とKupffer細胞の減数をみた.肝細胞のBrdU摂取率(LI)の最高値は正常肝で22.0±3.0%を示したが,硬変肝では12.3±1.7%にとどまった.S期細胞の分布は正常肝で辺縁部と中心部に差異があり,硬変肝では偽小葉内に不規則な局在を示した.増殖因子のbFGF, EGFは硬変肝で不均一に分布し,TGFβ1は硬変肝では持続的な局在を示した.細胞外基質ではI・III・IV型コラーゲン,ラミニン,フィブロネクチンの局在に肝切除前後で著変を認めなかった.以上より,硬変肝では細胞外基質に著変はなく血行動態の変化による増殖因子の非効率的供給とTGFβ1等の増殖抑制因子の持続的存在により,肝細胞の増殖能が減弱していると考えられた.