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Biomedical subjects

K Kosuga

Publications and source records attributed to K Kosuga.

At least 37 records · Page 2Linked to original sources
PubMed1995

[Simultaneous operation for annulo-aortic ectasia, mitral regurgitation, and tricuspid regurgitation in a patient with Marfan syndrome--report of a case].

A 57-year-old man with manifestations of Marfan syndrome was referred for detail examination of cardiac murmur to our hospital. Cardioangiography showed moderate aortic valve regurgitation (2/4), and severe mitral valve regurgitation (3/4), in addition to aneurysmal dilatation of the aortic root. Moderate tricuspid valve regurgitation (2/4) was also detected by Doppler echocardiography. Aortic root replacement with the Cabrol technique, mitral valve replacement with a St. Jude Medical valve, and repair of the tricuspid valve with the bicuspidalization technique were simultaneously performed in this patient. His postoperative recovery was uneventful. In this study, we discuss about the indications of simultaneous aortic root replacement and mitral valve replacement in a patient with Marfan syndrome.

Aorta↗
PubMed1995

[Reconstructive surgery for acquired mitral regurgitation].

Between December, 1967, and July, 1994, 96 patients underwent repair of the mitral valve for acquired mitral valve regurgitation. According to Carpentier's classification, mitral valve pathology resulting in valve regurgitation was classified into three types; 4 patients assigned to type I, 63 type II, and 29 type III. The operative mortality rate was 1.0%. Follow-up data were available in 95 patients from 0.5 year to 25.3 years (mean average 8.8 years). The late mortality rate were not different between patients with valve pathology of type I, II and those with valve pathology of type III. Thromboembolism occurred on three patients for an embolic rate of 0.4% per patient-years. Twenty-eight patients required reoperation for residual MR and dehiscence of suture lines (type II; 10 cases, reoperation-free rate at 20 years, 83.2%) or recurrent MR due to progression of valve deformity (type III, 18 cases, reoperation-free rate at 20 years, 14.8%). These results demonstrate that patients with type I and II valve are good candidates for MVP, and that high incidence of reoperation for recurrent MR may limit the application of MVP to selected patients with type III valve.

Adolescent↗
PubMed1995

[Use of inferior epigastric artery for coronary artery bypass grafting].

The usefulness of the free inferior epigastric artery (IEA) as a coronary bypass graft was studied. Among 149 patients for coronary bypass grafting (CABG) between October 1992 and December 1994, the free IEA was used in 12 patients. The mean number of distal anastomosis was 3.7 per patient. The mean distal size of the IEA was 1.3 mm in diameter and the mean length was 9.4 cm. The IEA graft was anastomosed to the obtuse marginal branch in 5, to the diagonal branch in 4, and the right ventricular branch in 3. The proximal anastomosis of the IEA was constructed to the ascending aorta in three and to the saphenous vein (SVG) or to the internal thoracic artery (ITA) in 4 or 5, respectively. Postoperative angiogram demonstrated patent graft in ten and occluded graft in two in whom the size of IEA was less than 1.0 mm in distal diameter and the IEA was anastomosed to the aorta or to the SVG. The IEA was considered to be useful alternative arterial graft when it was used as "interposed graft" of which proximal anastomosis was made to the ITA and size-matching of the graft to the coronary artery was appropriate. The long-term patency of the graft can determine the true efficacy of the IEA for CABG.

Aged↗
PubMed1995

Long-term results after conservative aortic valve repair for aortic regurgitation with ventricular septal defect.

Aortic valve repair was performed in 61 patients having aortic regurgitation (AR) associated with ventricular septal defect (VSD). Preoperative regurgitation was classified according to the Sellers' classification and grade I was in 3 patients, grade II in 19, grade III in 34, and grade IV in 5 patients. Forty-six patients underwent only plication of aortic valve, and in 15 patients the commissuroplasty was added to reinforce the free edge of the cusp. Furthermore, aortoplasty (aortic annuloplasty) was performed in 11. Actuarial survival rate and freedom from reoperation rate were 91.6% and 87.2%, respectively at 10 years after the initial repair. The rate of freedom from deterioration for 22 patients showing grade I or II of AR before the initial operation was 86.4% at 1 year, 76.7% at 5 and 10 years, while the rate for 36 patients with grade III or more severe AR was 91.7% at 1 year, 77.4% at 5 years and 63.9% at 10 years. The rate at 10 years after operation between the two groups was different significantly (p < 0.05). Twenty among 22 patients having grade I or II of AR before operation were in NYHA class I, while 23 of 30 survivors with grade III or IV of AR were in class I, 6 in class II, and 1 in class III. Eight patients received reoperation and four of them underwent repeated conservative aortic valve repair, and one received aortic valve replacement at reoperation. Five of 7 survivors with reoperation improved in NYHA class I and 2 in class II. These results suggested that careful follow-up was required especially for the first 10 years after the initial operation in patients showing preoperative severe AR and receiving aortic repair.

Adolescent↗
PubMed1994

Preferential inhibition of inducible nitric oxide synthase by ebselen.

Ebselen, 2-phenyl-1,2-benzisoselenazole-3(2H)-one can preferentially inhibit the activity of inducible nitric oxide (NO) synthase with little inhibition of endothelial constitutive NO synthase within a certain concentration range. This suggests that ebselen deserves further in vivo studies to examine its possible application to the therapy of septic shock where inducible NO synthase is responsible for vasodilation.

Amino Acid Oxidoreductases↗
PubMed1994

Tricuspid valve replacement with the St. Jude Medical valve.

A study was conducted on 20 patients who underwent tricuspid valve replacement (TVR) with the St. Jude Medical (SJM) valve. Isolated TVR was performed on 9 patients, and additional mitral, or mitral and aortic valve replacements were performed on 11 patients. Four patients (20%) died in the early postoperative period, but there were no deaths related to the SJM valve in the tricuspid position. The mean follow-up period of the 16 survivors was 74.4 months, and there have been no deaths during the follow-up period. The postoperative actuarial survival rate was 80%, 10 years after surgery. Three patients, representing 0.25%/patient-months, developed valve thrombosis, the valve thrombosis-free rate being 72.8%, 10 years after surgery, while entrapment of a leaflet by endothelial pannus was found in one patient, representing 0.08%/patient-months. Thus, the incidence of all prosthetic valve-related complications was 0.34%/patient-months, and the postoperative complication-free rate was 65.3%, 10 years after surgery. The medium-term follow-up study of TVR with the SJM valve revealed no prosthetic valve-related deaths and a relatively low incidence of prosthetic valve-related complications. However, as with other mechanical valves, valve thrombosis was a major risk posed by the SJM valve in the tricuspid position.

Actuarial Analysis↗
PubMed1994

Limited effectiveness of FK506 administration for ongoing rejection in heterotopic rat heart transplantation.

A comparison was made of the histological findings for myocardial tissue of heterotopic transplanted rat hearts administered with FK506. ACI rats were used as donors and Lewis rats as recipients. FK506 was used for 6 days except for group I (control group). Group II received 0.32 mg/kg/day of FK506 from the day of operation while group III was given the same dosage from the 4th day after transplantation. Group IV was given 1.28 mg/kg/day of the agent from the day of grafting and group V received the same dose from the 4th postoperative day. The graft survival time was longer for all groups given FK506, but was significantly longer only for groups administered with FK506 from the day of operation. Histological studies performed 10 and 20 days after transplantation showed that a moderate rejection was seen in about half of the grafts receiving FK506 from the 4th day after grafting. An ultrastructural study of these cases showed that infiltrating large lymphocytes still remained in the interstitial tissues and that the cytoplasmic organelles of the myocytes had been focally destroyed. These results suggest that, although FK506 suppressed any further rejection, the effect might be limited and the myocardial changes of the cardiac graft might persist even after administration for ongoing rejection.

Animals↗
PubMed1994

Aortic root replacement with a composite graft: results of 69 operations in 66 patients.

Between December 1973 and December 1992, 66 patients underwent aortic root replacement at our hospital. The mean age of the patients was 42.5 years (range, 20 to 71 years); 44 patients were male and 22 were female. Of the 66 patients, 34 (51.5%) had clinical stigmata of Marfan's syndrome. The aortic pathology requiring aortic root replacement was annuloaortic ectasia in 59 patients, aortic dissection in 5, and progressive dilatation of the ascending aorta after aortic valve replacement in 2. Twelve of the 59 patients with annuloaortic ectasia also had aortic dissection. The operative techniques used were the Bentall technique in 36 operations, the Cabrol technique in 21, the aortic button technique in 3, and other miscellaneous techniques in 9. The hospital mortality rate for the primary operation was 10.6% (7 patients), and the late mortality rate was 20.3% (12 patients). Four of the late deaths were related to the graft valve prosthesis, and 6 were related to the progression of aneurysmal diseases on the remaining aorta. The survival rate was 71.0% at 10 years. Pseudoaneurysm at the suture lines was detected in 7 patients, 6 of whom had been treated with the Bentall technique, and 5 patients also had Marfan's syndrome. No patients having aortic root replacement with the Cabrol technique have required reoperation for pseudoaneurysms.(ABSTRACT TRUNCATED AT 250 WORDS)

Actuarial Analysis↗
PubMed1994

Structure and function of nitric oxide synthases.

Nitric oxide (NO), which accounts for the biological activity of endothelium-derived relaxing factor, is now thought to play a variety of roles in the nervous system and in immunologic reactions. NO is synthesized from L-arginine by nitric oxide synthase (NOS). There are three isoforms of NOS; type I (neuronal), type II (inducible), and type III (endothelial). The fundamental structure of the three isoforms, which contain calmodulin-, FMN-, FAD-, and NADPH-binding domains, is the same. Calmodulin is already bound to inducible NOS without requiring Ca2+, while the others are Ca2+/calmodulin-dependent. Endothelial NOS is bound to membranes by N-myristoylation, while the other isoforms are soluble. The human endothelial NOS gene has been cloned. It has several highly repetitive regions which could provide potential sites for DNA polymorphism. It might be of interest to examine the relationship between such polymorphism and cardiovascular disorders.

Amino Acid Oxidoreductases↗
PubMed1994

Surgical treatment for acute aortic dissection and coexistent degenerative aortic aneurysm. Report of three cases.

Acute aortic dissection occurring in an aorta previously afflicted with degenerative, atherosclerotic is unusual. We report three cases with acute aortic dissection (DeBakey type III-b) occurring in an aorta which had a preexistent degenerative aortic aneurysm. Two of the three patients had acute aortic dissection originating from the distal end of the degenerative aneurysm, and the remaining one had the acute aortic dissection and degenerative aneurysm at different segments of the aorta. Since the risk of rupture is likely to be much higher in the patients with coexistence of acute aortic dissection and degenerative aortic aneurysm, compared with patients with DeBakey type III acute aortic dissection alone, we believe that a prompt and aggressive surgical approach is essential to prevent rupture, and that digital subtraction angiography (DSA) is more helpful in making a correct diagnosis and in helping to decide surgical procedures and supportive methods than other noninvasive diagnostic procedures.

Acute Disease↗
PubMed1994

The St. Jude medical prosthesis in the mitral position.

To study the long-term results of the St. Jude medical prosthesis in the mitral position, 520 patients were evaluated who had undergone mitral valve replacement with St. Jude medical (SJM) prosthesis. Eighteen patients or 3.5% died in the early postoperative period (within 30 days after operation). The total follow-up was 2872 patient-years and late deaths occurred in 23 cases. Postoperative cerebral embolism occurred in six, bleeding complication in five, and thrombosed valve in two patients. Postoperative anti-coagulant therapy was initiated with both dipyridamole (300 mg/day) and warfarin potassium. After discharge from our hospital the patients underwent routine examination of their thrombo-tests or prothrombin times at least every 2-3 months, and the major thromboembolic or bleeding complication rate was 0.45%/100 patient-years. In a period of 12 years, severe hemolysis following implantation was seen in seven patients. The cause of this hemolysis was perivalvular leakage in two patients but there were no leakages in the other five patients, although preoperative moderate to severe liver dysfunction was noted. Ninety-three percent of the patients were followed up, and their postoperative New York Heart Association functional classes were I or II in 88.6% of the cases. Their clinical results after mitral valve replacement with SJM prosthesis in the anti-anatomical position showed excellent durability and a low incidence of valve-related complications.

Adolescent↗
PubMed1994

False aneurysm of the ascending aorta with fistula to the right atrium. Noninvasive diagnosis by computed tomographic scan and two-dimensional echocardiography with successful repair.

A 57-year-old Japanese man presented with symptoms of congestive heart failure 9 years after aortic valve replacement. On auscultation, a continuous murmur was heard at the left lower sternal border. Chest radiograph showed moderate cardiomegaly and a widened upper mediastinum. Computed tomographic scans showed a dilated ascending aorta, in which there was no intimal flap, and also showed a large mass which compressed the right atrium. Two-dimensional Doppler echocardiography revealed abnormal continuous blood flow directed from the dilated ascending aorta to the right atrium and no periprosthetic leak. At operation, a false aneurysm of the ascending aorta which originated from the aortotomy suture line and a fistula from the aorta to the right atrium were confirmed. The fistula was closed with pledgeted sutures, and the ascending aorta was replaced with a collagen-coated double woven velour dacron graft. The patient recovered uneventfully. Computed tomographic scan and two-dimensional echocardiography are complementary techniques for reliable non-invasive assessment of the complexity of an aortic aneurysm.

Aneurysm, False↗
PubMed1994

Surgical treatment of aneurysms of the aortic arch using a simplified selective cerebral perfusion technique.

Between April 1989 and October 1993, 35 patients underwent aortic arch reconstruction for aneurysms using cardiopulmonary bypass (CPB) with selective cerebral perfusion (SCP). Of the 35 patients, the initial 19 (Group P) consecutively received simplified SCP (partial brachiocephalic perfusion; PBP), and the next 16 (Group S) were consecutively treated with standard SCP. For cerebral protection, blood was supplied to the right axillary artery in Group P, and to the right axillary and the left common carotid arteries in Group S. The aneurysms was aortic dissection in 24 patients, and was secondary to arteriosclerosis in the remaining 11. Partial replacement of the aortic arch together with the ascending aorta was the most commonly performed procedure in both groups. The cardiopulmonary bypass time and the cardiac arrest time were not significantly different between the two groups. The overall cerebral perfusion time was significantly longer in Group S (100 min) than in Group P (65 min); however, when 2 patients with an accidental prolongation of the cerebral perfusion time in Group S were excluded, there was no significant difference in the cerebral perfusion time between the two groups. Early death occurred in 3 patients (15.8%) in Group P, and 2 patients (12.5%) in Group S, however, there were no deaths related to the selective cerebral perfusion technique, and there were no late deaths in either group. Cerebral complications were seen in 1 patient in each group (6.3% vs. 6.7%, not significant). These results suggest that the simplified SCP (PBP) under hypothermic CPB provides as satisfactory cerebral protection as standard SCP, so long as the patency of the circle of Willis is confirmed.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Coronary artery bypass grafting in elderly patients.

To determine the benefits of coronary artery bypass grafting (CABG) in elderly patients, we evaluated 37 patients more than 70 years old who underwent this surgical procedure and compared the results with those in 177 younger patients. Three-vessel lesions and left main lesion were seen in 78.4% and 48.6% of the elderly patients, respectively. Emergency or urgent surgery was performed on 19 patients and the number of distal anastomoses was 3.0 +/- 0.8 per patient. Left main lesion and emergency surgery were more common in elderly patients than in younger patients. Twelve patients received CABG with only a saphenous vein graft (SVG), while the remaining 25 patients had at least one arterial graft. The quality of the saphenous vein was poor to moderate in 50% of the elderly patients, while none of the arterial grafts showed significant sclerotic change. In 17 elderly patients, the ascending aorta showed sclerotic lesions and care was taken when completing proximal anastomoses of SVG to the aortic wall. After surgery, mechanical ventilation was required for an average of 29 h, which was longer than that in the younger patients. Postoperative low cardiac output, hypertension, and arrhythmia occurred in 6, 6 and 15 elderly patients, respectively. There were no early deaths, although there was one hospital death due to posttransfusion hepatitis. Thirty four elderly patients were classified as New York Heart Association functional class I or II during late follow-up maximum of 5 years) and only one had postoperative angina. The ascending aorta showed more sclerotic lesions, and the quality of the saphenous vein was worse, in the elderly patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1994

A study of reservoir implantation--especially with saphenous vein graft catheterization.

Intra-arterial infusion chemotherapy is commonly used to treat hepatocellular carcinomas (HCC) and metastatic liver cancer after hepatectomy or in unresectable patients, and it has been adopted at Kurume University Hospital as a treatment for HCC. As complications of reservoir implantation have been encountered, the implantation procedure needs improvement. Procedures were compared in a study with 109 patients who were available for follow-up observation among 116 patients who underwent reservoir implantation. Fifty-six of the patients received intraoperative implantation through the gastroduodenal artery (GDA catheterization), 31 received external catheterization (EXT catheterization) and 22 received catheterization using a saphenous vein graft (SVG catheterization). The complication rates were 75.0%, 9.7% and 13.9% and the one-year patencies were 44.1%, 70.6% and 79.4%, respectively. GDA catheterization was no better than the other two procedures and it had a higher incidence of complications and a lower patency. SVG catheterization achieved good patency, although it had a little higher incidence of complications than external catheterization. It was presumed to be a procedure that would ensure reservoir implantation even in patients with a winding or variation of hepatic artery.

Catheters, Indwelling↗
PubMed1994

Long-term results of valve replacement with the St. Jude Medical valve.

Between 1980 and 1992, 908 patients underwent single aortic (n = 178), single mitral (n = 577), or double aortic and mitral (n = 153) valve replacement with the St. Jude Medical valve at our hospital. There were 392 male patients and 516 female patients whose ages ranged from 1.2 to 74 years (mean, 52 years). The early mortality rate was 5.0% (45 patients). A 94% complete follow-up was accomplished for 863 patients who were discharged from the hospital (4682.3 patient-years). Sixty-nine of these patients died, for a late mortality rate of 8.0%. Fifty-two patients, including four patients (0.3%/100 patient-years) had anticoagulant-related hemorrhage, 4(0.1%/100 patient-years) had prosthetic valve endocarditis, 11 (0.2%/100 patient-years) had nonstructural valve dysfunction, and 16 (0.3%/100 patient-years) underwent reoperation. There were no structural valve failures in this series. The total number of valve-related deaths was 22. Of those patients who survived, 98% were in New York Heart Association functional class I or II at the date of the last follow-up. The probabilities of freedom from thromboembolism and anticoagulant-related hemorrhage at 10 years were 94% +/- 2% and 97% +/- 2% in aortic valve replacement, 89% +/- 2% and 98% +/- 4% in mitral valve replacement, and 89% +/- 6% and 92% +/- 6% in double valve replacement, respectively. Significant hemolysis related to the St. Jude Medical valve occurred in 8 of the 577 patients who received mitral valve replacement in our early experience, and modifying the valve orientation appeared to play an important role in reducing hemolysis. The event-free rate, including all complications and late deaths, at 10 years was 75% +/- 7%, 74% +/- 3%, and 81% +/- 6% in aortic valve replacement, mitral valve replacement, and double valve replacement, respectively. On the basis of these results, the St. Jude Medical valve seems to be an excellent mechanical valve in terms of durability and low thrombogenicity and remains our prosthetic valve of choice when valve replacement with a mechanical valve is indicated.

Adolescent↗
PubMed1994

[Surgical treatment for postinfarction ventricular septal perforation].

Between August 1981 and August 1992, operation for ventricular septal perforation (VSP) after acute myocardial infarction (AMI) was performed in 12 patients and the results were studied. During this period, medical treatment was attempted as a standard therapy for more than two weeks after AMI, followed by operation. However, only four patients received elective operation two weeks after the onset of AMI. Regarding the relationship between the preoperative circulatory status and timing of surgery, elective operative could not be performed in seven patients showing a pulmonary to systemic flow ratio (Qp/Qs) of more than 3.0, while four out of five patients with a ratio of less than 3.0 received operation more than two weeks after the onset of AMI. Two patients with severe right heart failure after the repair of VSP died on table without weaning from the pump. Ten operative survivors were weaned from the pump without any difficulty of hemostasis and intraaortic balloon pumping was removed after operation. However, three patients died of multiple organ failure which had been deteriorating before operation. Postoperative activity improved to New York Heart Association Functional Class I or II in six survivors for the late follow-up period. In the case of high Qp/Qs due to VSP, early operation is recommended to prevent multiple organ failure.

Aged↗