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Biomedical subjects

K Kawachi

Publications and source records attributed to K Kawachi.

At least 109 records · Page 6Linked to original sources
PubMed1994

Long-term outcome of myocardial revascularization in patients with Kawasaki coronary artery disease. A multicenter cooperative study.

The long-term outcome of myocardial revascularization by coronary artery bypass grafting in patients with severe coronary obstruction caused by Kawasaki disease is largely unknown. A multicenter follow-up study was performed in 1991. A total of 168 patients with Kawasaki disease (127 male [75.6%] and 41 female patients [24.4%]) who had undergone coronary bypass grafting were enrolled. Obstructive coronary artery disease affected the left main trunk in 11.8%, the right coronary artery in 77.6%, the left anterior descending in 87.6%, and the left circumflex in 25.9%. Old myocardial infarction was noted in 46.0% of the patients. Fifty-four patients (32%, 12.4 +/- 9.8 years) underwent bypass grafting with saphenous vein grafts alone. The remaining 114 patients (68%, 9.8 +/- 7.1 years) received at least one internal thoracic artery graft to the left anterior descending coronary artery. Gastroepiploic artery grafts were used in 12 patients. There were no significant differences between the saphenous vein and internal thoracic artery groups in the mean age at operation (12.4 versus 9.8 years), female ratio (22% versus 25%), the number of patients over 20 years of age (9.3% versus 9.6%), previous history of infarction (51.9% versus 41.2%), impaired left ventricular function (ejection fraction < 0.5) (13.0 versus 11.4%), left main trunk disease (11.1% versus 10.5%), the number of vessels involved (2.2 +/- 0.8 versus 2.0 +/- 0.6 per patient), or the mean number of grafts used (1.7 +/- 0.7 versus 1.7 +/- 0.7 per patient). The operative death rate was also the same in the two groups (1.9% versus 0%), but the late cardiac death rate was significantly higher in the saphenous vein graft group (13.0%) than in the internal thoracic artery group (0.9%) (p < 0.003). Actuarial analysis showed a significantly higher survival in the internal thoracic artery group (98.7% +/- 1.2% versus 81.6% +/- 7.0%, p < 0.05) at 90 months after the operation. Late death was strongly related to the absence of an internal thoracic artery graft (p < 0.003) and to the age at the time of operation (p < 0.05). The actuarial patency rate was significantly higher for arterial grafts (77.1% +/- 1.1%, n = 151) than for vein grafts (46.2% +/- 6.3%, n = 126) 85 months after the operation (p < 0.003). Arterial grafts were used for the non-left anterior descending coronary arteries in only 41 of 155 grafts (26.5%); in contrast, vein grafts were used in 85 of 133 grafts (63.9%) (p < 0.005 to 0.001).(ABSTRACT TRUNCATED AT 400 WORDS)

Actuarial Analysis↗
PubMed1994

[The relationship between postoperative changes of exercise capacity and pulmonary blood flow in the residual lung after lobectomy of the lung].

The purpose of this study is to investigate a relationship between the postoperative change of exercise capacity judged by the change of peal oxygen consumption and the pulmonary blood flow of the residual lung after lobectomy. Twenty eight patients undergoing lobectomy for lung cancer received an exercise tolerance test and 99mTc-MAA perfusion lung scans before and after lobectomy. The change rate in the peak level of oxygen consumption (peak VO2) did not differ depending on the number of resected sub-segments. A good correlation was found between the reduction of perfusion ratio of the lung of the operated side (delta Q) and that of the peak level of oxygen consumption (delta peak VO2) (r = 0.74, p < 0.01). A reduction in delta Q and delta peak VO2 was remarkable in patients with postoperative respiratory complications such as atelectasis and pulmonary air leakage. These results indicate that the perfusion lung scans at rest before and after surgery would be able to predict the change of exercise capacity after lobectomy.

Adult↗
PubMed1994

[Percutaneous transluminal angioplasty for stenosis of coronary artery bypass grafts: a comparison of arterial grafts versus vein grafts with regard to restenosis and re-do CABG].

Stenoses of ten arterial grafts and thirty-four venous grafts from previous coronary artery bypass grafting (CABG) were treated with percutaneous transluminal angioplasty. In all ten arterial grafts, stenosis occurred at the distal coronary anastomotic site (A-d). In vein grafts, stenosis occurred at the proximal aortic anastomotic site (V-p) in 10, at the graft body (V-b) in 9 and the distal coronary anastomotic site (V-d) in 10 vessels. The initial success rates of angioplasty were 89% (A-d), 100% (V-p), 89% (V-b) and 100% (V-d). The time period between CABG and angioplasty was significantly shorter for A-d (4 +/- 3.8 months) and V-d (8.1 +/- 9.9 months) groups than for V-p (56.9 +/- 35.7 months) or V-b (45.9 +/- 48.6 months) groups. The restenosis rates following angioplasty were 0% (A-d), 50% (V-p), 50% (V-b) and 0% (V-d). Repeat CABG surgery was required for restenosis in 2 patients of group V-p and V-b. Our experience suggests that angioplasty can be performed with a high success rate for stenosis at the distal anastomosis of either arterial or vein grafts after CABG.

Anastomosis, Surgical↗
PubMed1994

Hemodynamic assessment during exercise after left ventricular aneurysmectomy.

The exercise hemodynamics of eight patients who underwent cardiac catheterization were assessed at rest and during exercise, before and after left ventricular aneurysmectomy by the classical technique. Left ventricular end-diastolic volume increased before operation and then significantly decreased after the operation (p < 0.05). The ejection fraction increased from 0.27 before the operation to 0.46 after the operation (p < 0.01). The cardiac index, which was low before operation, increased within the normal range after operation. Mean systolic circumferential tension also decreased significantly (p < 0.01) after the operation. Thus, the indexes at rest showed improvement. Left ventricular end-diastolic pressure showed a decreasing tendency after the operation both at rest and during exercise in comparison with that before the operation. However, the difference was not significant. The stroke work index increased significantly during exercise after the operation (p < 0.05). Before the operation, the stroke work index did not increase despite the elevation of left ventricular end-diastolic pressure; however, after the operation, the stroke work index increased during exercise without much increase of left ventricular end-diastolic pressure. This indicated improvement in the Frank-Starling curve and recovery of preload reserve by the resection of the left ventricular aneurysm. Thus, an important factor for demonstrating improvement in postoperative cardiac function was clarified through its relation to exercise load.

Cardiac Output↗
PubMed1994

[Allograft (homograft) valve surgery: current status in Japan].

The advance of cryopreservation techniques has dramatically increased the durability of human allograft valves, resulting in the wide-spread use of allograft valves in many western countries except Japan. The superiority of the allograft valve to other prosthetic valves has become apparent in some specific situations such as active endocarditis, small aortic root and hemorrhagic conditions. In this manuscript, we described the setting-up of the cryopreservation laboratory, quality control and the clinical use of allograft valves in our institute. The authors believe that surgeons should have an option of utilizing allograft valves in selected patients in Japan.

Adult↗
PubMed1994

[Coronary artery bypass surgery-redo operation particularly in patients with a functioning ITA graft or with a patent atheromatous vein graft].

An experience with redo-CABG in 20 patients is described. The incidence of reoperation in patients undergoing primary CABG in our hospital was 1.4%, relatively low even in Japanese population. The low incidence of redo-CABG in our hospital depends on the relatively short period of follow-up of 14 years, the prevalence of interventional cardiology and the early routine use of ITA grafts. The main cause of reoperation was the failure of a SVG to the LAD in 70 to 80% of the cases. The most important and difficult decision-making in redo-CABG is the selection of surgical approaches and cardioprotective methods in patients with a patent functioning ITA graft, and the management of an atherosclerotic patent SVG. Surgical strategies in these situations are discussed.

Adult↗
PubMed1993

A pathohistological and biochemical study of arteriosclerosis in the internal thoracic artery, a vessel commonly used as a graft in coronary artery bypass surgery.

Pathohistological and biochemical studies were conducted on the severity of arteriosclerosis in the internal thoracic artery (ITA), an artery commonly used for coronary artery bypass grafting (CABG). For the pathohistological examination, 26 bilateral ITAs and 13 left anterior descending coronary arteries (LADs) obtained in full length from 13 autopsy cases, none of which had died of arteriosclerotic heart disease, were used. The ratio of the thickness of the intima to that of the media (R) was used as the index for arteriosclerosis. ITAs and LADs were classified as grades I to IV according to the value of R. The R of the ITAs was approximately 1/10 that of the LADs (P < 0.01). Most ITAs showed a low arteriosclerotic grade, with no variation in arteriosclerosis along their length and a low R in all segments. No difference was found between right and left ITAs. Biochemical examination was conducted on 12 ITAs and 11 LADs, obtained from 12 different and unselected autopsy cases. The lipid content in the vascular wall was determined to evaluate the severity of arteriosclerosis, with the following results: Total cholesterol, 5.5 +/- 1.8 and 17.8 +/- 13.6 micrograms/mg wet weight (P < 0.05); triglyceride, 90.4 +/- 90.3 and 114.4 +/- 117.2 micrograms/mg wet weight (n.s.); and phospholipid, 7.4 +/- 3.9 and 11.2 +/- 3.9 micrograms/mg wet weight (P < 0.05), respectively, for the ITAs and LADs. These findings thus demonstrate that arteriosclerosis of the ITA in Japanese people is very mild, compared to that of the LAD in the same individuals.

Adult↗
PubMed1993

Exercise coronary flow reserve of bilateral internal thoracic artery bypass grafts.

We attempted to quantify the exercise coronary flow reserve in 20 patients with bilateral internal thoracic artery grafts to the left coronary arteries (group I) who had complete revascularization. The coronary sinus blood flow was measured by the continuous thermodilution method both at rest and during exercise (50 W for 8 to 9 minutes) approximately 1 month after the operation. These results were compared with 30 patients treated with an internal thoracic artery and saphenous vein grafts to the left coronary arteries (group II) and 9 patients with saphenous vein grafts alone to the left coronary arteries (group III). There were no differences among the three groups in age, sex, number of vessels involved, heart rate, double products, left ventricular (LV) end-diastolic pressure, LV ejection fraction, LV end-diastolic volume, or LV mass at the time of study. None of the 59 patients in the study had abnormally enlarged LV end-diastolic volume or increased LV mass. The postoperative coronary sinus blood flow per 100 grams of LV mass at rest was similar among the three groups (73.0 +/- 28.4 mL/min per 100 g LV mass in group I, 73.4 +/- 31.1 mL/min per 100 g LV mass in group II, and 75.9 +/- 28.5 mL/min per 100 g LV mass in group III [not significant]) and significantly (p < 0.01) increased by exercise, although the differences between groups during exercise were not significant (158.9 +/- 45.9, 153.5 +/- 72.1, and 148.3 +/- 60.0 mL/min per 100 g LV mass, respectively [not significant]).(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Pressure↗
PubMed1993

Lower extremity ischemia secondary to internal thoracic-coronary artery bypass grafting.

Vascular complications associated with the use of the internal thoracic artery as a conduit for coronary artery bypass are infrequent. However, acute limb-threatening ischemia can occur after the use of the internal thoracic artery for myocardial revascularization when this vessel forms an important collateral to an obstructed aortoiliac artery system. Although this is a rare complication, the consequences are devastating. Due to the risk of peripheral vascular insufficiency, we now perform simultaneous revascularization of the myocardium and the lower extremity when an internal thoracic artery that appears to be a major collateral to the ipsilateral aortoiliac system is used.

Acute Disease↗
PubMed1993

Hypothermic ventricular fibrillation with pulsatile coronary perfusion during repair of ventricular septal perforation following infarction.

Emergency or urgent surgery for ventricular septal perforation (VSP) following acute myocardial infarction still carries a high operative mortality rate. Hypothermic fibrillatory arrest studies without aortic cross-clamping and using continuous pulsatile coronary flow were performed to improve this result. Of 19 patients suffering from VSP, 12 underwent hypothermic (mean(s.d.) blood temperature 23.5(1.7) degrees C) ventricular fibrillation with concomitant pulsatile systemic and continuous coronary perfusion (group 1), and seven underwent deep hypothermic cardioplegic ischaemic arrest with systemic pulsatile perfusion alone (group 2). The two groups were comparable in terms of age, sex, location of infarction, number of coronary arteries involved, interval between infarction and surgery, and preoperative maximum enzyme levels and haemodynamics. Pulsatile flow with a mean(s.d.) pulse pressure of 48(13) mmHg was produced by an intra-aortic balloon pumping device in both groups. Operative exposure in the two groups was comparable. In group 1, mean(s.d.) cardiac output in the early postoperative period (within 3 h of procedure) was significantly higher than in group 2 (4.2(0.9) versus 2.6(0.7)lmin-1m-2, P < 0.01). The 30-day operative mortality rate was significantly lower in group 1 (8% (80% confidence interval 1-29%)) than in group 2 (57% (80% confidence interval 28-83%)) (P < 0.05). On the basis of these results, hypothermic fibrillatory arrest with continuous pulsatile coronary perfusion can be recommended for myocardial protection during surgery for VSP associated with severe heart failure or cardiogenic shock.

Aged↗
PubMed1993

[Cardiac function following left ventricular aneurysm repair--comparison between patch reconstruction and direct closure methods].

Left ventricular function was compared between two groups of patients who underwent patch reconstruction or direct closure of the ventricular wall following resection of a post-infarction left ventricular aneurysm (LVA). There were 15 and 9 patients in the respective groups. Coronary artery bypass grafting was additionally performed in 8 patients (53%) in the patch reconstruction group and 5 patients (56%) in the direct closure group. The size of the patch used for patch reconstruction (including the suture line) was 57 +/- 19% of the resected area. Before and 1-2 months after surgery, equilibrium RI angiography and cardiac catheterization were performed to assess the following hemodynamic parameters: ejection fraction (EF) at rest and during exercise, left ventricular end-diastolic pressure (LVEDP), left ventricular end-diastolic volume index (LVEDVI), cardiac index (CI) and mean pulmonary artery pressure (m-PAP). Preoperatively, there were no differences in each parameter between the two groups. Postoperatively, there were significant improvements in the EF at rest and during exercise (p < 0.01), LVEDVI (p < 0.01) and the LVEDP (p < 0.05). However there no significant changes in CI or m-PAP following the operation. There were also no significant differences observed in the postoperative values between the two groups. However, based upon postoperative left ventriculograms, patch reconstruction was significantly superior to direct closure for reconstruction of a septal aneurysm.

Aged↗
PubMed1993

[Comparison of various methods to close the stump of the main bronchus after pneumonectomy].

In 58 patients who underwent pneumonectomy, the stumps of the main bronchus were sutured manually (by the Sweet method in 13, the Overholt method in 12, and the modified Overholt method in 8) or with machines (TA-30 + S method in 15, TA-30 + O method in 10), and the methods to close the stump were evaluated according to the outcome and postoperative endoscopic findings. Cancer was positive at the stump in 3, and rupture of the membranous portion was observed in 1 in the mechanical suture group. Bronchial fistula was observed in 2 (12%) of the 25 patients in the mechanical suture group but in none of the 33 patients in the manual suture group. The line of closure of the bronchial stump observed by endoscopy was perpendicular to the crest at the tracheal bifurcation in patients sutured by the Sweet or TA-30 + S method, angulated in a chevron shape in many of those sutured by the Overholt method and those sutured by TA-30 + O method, and parallel to the crest in part of those sutured by Overholt method and those sutured by modified Overholt method. The mucosa at the stump was uneven in many patients who showed chevron shaped closure lines. By the modified Overholt method, the wall of the main bronchus could be resected more extensively, the mucosa at the stump was smooth, and the airway lumen showed no marked deformation.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1993

[Aortic valve replacement and coronary artery bypass grafting in a patient with a porcelain aorta due to aortitis syndrome].

Clamping a calcified aorta during cardiac operation increases the risk of cerebral embolism by aortic debris. We operated upon a 61-year-old female with severe angina pectoris due to aortic regurgitation and bilateral coronary calcific ostial stenosis associated with porcelain aorta secondary to aortitis syndrome. At operation, cardiopulmonary bypass was begun with profound hypothermia. Using an occlusion balloon catheter inflated in the ascending aorta, the calcified aorta was incised with scissors. However accidentally the balloon was ruptured by intimal calcification of the ascending aorta, and cardiopulmonary bypass was discontinued for 11 minutes under 20 degrees C hypothermia. Extensive removal of the intimal calcification of the ascending aorta was performed with care and then, the aorta was clamped. Aortic valve replacement and triple coronary bypass operation (SVG to LAD, SVG to LCX, GEA to RCA) were performed. The proximal anastomoses of the SVGs were made on the decalcified aortic wall. The postoperative course was uneventful and aortography revealed neither dissection nor dilatation of the ascending aorta following extensive decalcification procedure of the ascending aorta, and the 3 grafts were all patent. From the experience, we learned that extensive removal of calcification of the aorta can be successfully performed in porcelain aorta due to aortitis syndrome. For CABG in aortitis syndrome, the use of ITA is rarely possible, but the GEA may be a versatile graft.

Aorta↗
PubMed1993

[Cell viability assessment of cold-preserved (4 degrees C) and cryopreserved (-196 degrees C) allograft valves by flowcytometric analysis].

We introduced cryopreservation technique to store the allograft valve and subsequently commenced the use of the cryopreserved aortic allograft valve for aortic valve replacement. For the clinical use of the allograft valve, it is essential to evaluate the cell viability. We assessed cell viability of the allograft valve by flowcytometry (FCM), using a fluorescein diacetate (FDA)-propidium iodide (PI) stain. Pulmonary allograft valves were harvested from the cadavers with a consent. Of the 9 valves collected and sterilized in 4 degrees C antibiotic solution for 48 hours, 4 valves were stored under refrigeration (cold-preserved), and the remaining 5 valves were cryopreserved. The warm ischemic time from cardiac death to valve preservation was 7.3 +/- 5.4 hours. The cold-preserved valves were stored at 4 degrees C in the nutrient medium (TC-199, calf serum and HEPES buffer). The cryopreserved valves were frozen by a programmable freezer to -80 degrees C in the same nutrient medium containing 10% dimethylsulfoxide (DMSO), and subsequently stored in liquid nitrogen (-196 degrees C). We assessed the cell viability of the allograft valve leaflet, before storage and at 2 weeks, 1 month and 2 months after the storage. Suspensions of the valve leaflet fibroblasts were double-stained with FDA (1 micrograms/ml) and PI (1 microgram/ml) for flowcytometric analysis of the viable cells (cells showing a chromatic response to FDA but no response to PI). In the cold-preserved group, percentage of the viable cell was 90.3 +/- 3.6% before storage, 62.0 +/- 3.0% after 1 month of storage, and 50.3 +/- 3.7% after 2 months of storage.(ABSTRACT TRUNCATED AT 250 WORDS)

Aortic Valve↗
PubMed1993

Dosimetry and measured differential W values of air for heavy ions.

Heavy-ion irradiation systems were designed and constructed at two cyclotron facilities in Japan for use in various fields of radiation physics and radiation biology. A 135 MeV/u carbon beam as well as 12 MeV/u carbon and helium-3 beams were first used in experiments. We have established a systematic method for heavy-ion dosimetry at both high and low incident energies involving measurements of fluences. We also obtained differential W values (w) of air for those beams by comparing the results of fluence measurement dosimetry with ionization chamber dosimetry. The differential W values of air were found to be 36.2 +/- 1.0, 34.5 +/- 1.0, and 33.7 +/- 0.9 eV for 6.7 MeV/u carbon ions, 10.3 MeV/u 3He ions, and 129.4 MeV/u carbon ions, respectively. The w value for high-energy heavy ions approaches the W value for high-energy electron or photon beams. In ionization chamber dosimetry for a heavy-ion beam, we found a track-size effect. A difference in the track sizes of heavy ions in the gas and solid phases affected the output current of the ion chamber in the case of high-energy heavy ions.

Carbon↗
PubMed1993

Successful repair and postoperative management of tetralogy of Fallot in a patient with maple syrup urine disease.

A case of tetralogy of Fallot with maple syrup urine disease (MSUD) treated surgically is reported. This 2-year-old female patient developed neurologic deterioration after intracardiac repair. Postoperative management, which included peritoneal dialysis, intravenous hyperalimentation, and early intestinal alimentation with branched-chain amino acid-free milk was successful. At the present time, two years after the operation, she is doing quite well with a special diet for MSUD. This is the first report on a patient with MSUD who underwent open heart surgery using a cardiopulmonary bypass, stressing the importance of postoperative management.

Cardiopulmonary Bypass↗
PubMed1993

[Successful surgical management for chronic sternal osteomyelitis and anterior mediastinal abscess after double valve replacement by total sternectomy and pectoralis major muscle flaps].

A 63-year-old woman underwent double (aortic and mitral) valve replacement in February, 1987. Thirty days later, purulent drainage developed at the sternotomy incision with high fever. Wound cultures revealed staphylococcus aureus. She was treated by local wound care with antibiotics. About one month later, she had a satisfactory wound healing. But three cutaneous fistulas with discharge emerged at the sternotomy incision in November (9 months later) and the cultures grew the same species. The fistulogram showed the communication between these tracts and the mediastinum. The diagnosis of chronic sternal osteomyelitis and anterior mediastinal abscess was made. At first the resection of the xiphoid process and the mediastinal drainage were carried out in March, 1988. Inspite of this procedure, she still had persistent purulent discharge. Then, en bloc excision of the infected sternum and the adjacent costal cartilage were performed in April. The defect was obliterated with the bilateral pectoralis major muscle flaps. After the radical operation, her wound was completely healed, even though the ventilatory support was needed for 24 days because of flail chest due to the anterior chest wall instability. Now she has been free from recurrence for four years. Total sternectomy and pectoralis major muscle plombage seem to be a very effective management in chronic sternal osteomyelitis.

Abscess↗