[Role of new devices for angioplasty in the unprotected left main coronary artery]

OBJECTIVES

Angioplasty for the unprotected left main trunk remains controversial, but new procedures and devices such as directional coronary atherectomy and stenting have improved the results. We compared the results of angioplasty with the inflexible balloon and new devices.

METHODS

The procedures were performed in 239 consecutive lesions in 160 patients between April 1986 and March 2000. This study excluded emergency cases and repeat angioplasty cases, and included 120 initial and elective cases. Initial and long-term results were compared between the balloon group (n = 29) and the new device group (n = 91).

RESULTS

Lesion success rate was lower in the balloon group (90% vs 100%, p < 0.05), but there were no significant differences in in-hospital results including cardiac death (0% vs 0%), noncardiac death (0% vs 3.3%), Q-wave myocardial infarction (0% vs 2.2%), non-Q wave myocardial infarction (3.4% vs 6.6%), bypass surgery (0% vs 0%) and repeat angioplasty (6.9% vs 1.1%). Quantitative angiography showed significant improvements in minimal lumen diameter (mean 2.17 vs 3.16 mm, p < 0.001) and percentage diameter stenosis (mean 31% vs 13%, p < 0.001) in the new device group after the procedures. The minimum lumen diameter remained larger at 3 (p < 0.001) and 6 months (p < 0.05) in the new device group. Therefore, angiographic restenosis rate was higher in the balloon group (55% vs 21%, p < 0.005). Five-year survival rate showed no significant difference between the groups (75.0% vs 83.8%).

CONCLUSIONS

New devices significantly improved the minimal lumen diameter after angioplasty for unprotected left main trunk disease, and lead to significant improvement of restenosis rate at follow-up.

Initial and long-term results of directional coronary atherectomy in unprotected left main coronary artery

Angioplasty in the unprotected left main coronary artery (LMCA) has been controversial. Recently, several studies have suggested that new procedures and devices such as directional coronary atherectomy (DCA) and stents may change this situation. Although there are many reports of unprotected LMCA stenting, there are few reports of DCA of this lesion. Therefore, initial and long-term results were evaluated in 101 patients who underwent DCA for unprotected LMCA in our hospital. Emergency procedures were performed in 15 patients and electively in 86 patients. Scheduled angiographic follow-up was routinely performed, and all patients were clinically followed for >4 months after DCA. Technical success was achieved in 99%, and in-hospital outcomes were cardiac death (2%), noncardiac death (4%), Q-wave myocardial infarction (1%), non-Q-wave myocardial infarction (8.9%), coronary artery bypass grafting (0%), and repeat angioplasty (4%). In-hospital results varied considerably, depending on presentation. In-hospital mortality was significantly higher in the emergency, left ventricular ejection fraction < or =35%, and high-risk surgical subgroups. The angiographic restenosis rate was 20.4% at follow-up, and its predictor was postminimal lumen diameter by multivariate analysis. Mean clinical follow-up was 2.8 years; estimated 1- and 3-year survival rates were 87% and 80.7%, respectively. The cardiac survival rate of the low-risk surgical subgroup was significantly higher than that of the high-risk surgical subgroup (p <0.05). Thus, our data show that DCA can be performed safely and effectively in unprotected LMCA with an acceptable low restenosis rate and high survival rate.

[Predictors of prognosis after angioplasty in the unprotected left main coronary artery]

OBJECTIVES

The short-term and long-term predictors of outcome after coronary angioplasty in the unprotected left main coronary artery were investigated.

METHODS

The procedure was performed in 122 consecutive patients for de novo lesions without myocardial infarction in our hospital between April 1986 and October 1998, including 16 emergency cases. Procedures were directional coronary atherectomy (73 patients), balloon angioplasty (31 patients), and stent implantation (18 patients). There were 101 males and mean age was 68 +/- 10 years. Follow-up angiography was performed in 98% of discharged patients, and all patients were clinically followed up for more than 1 year. Clinical and angiographic predictors of in-hospital and long-term outcome were evaluated.

RESULTS

The in-hospital mortality was 5.7% (7 of 122 patients). Multivariate analysis revealed that more patients were admitted as emergency cases (57% vs 10%, p = 0.0088), with left ventricular ejection fraction < or = 35% (57% vs 22%, p = 0.029) and renal failure (43% vs 3%, p = 0.0004) finally died. Mean follow-up period was 3.5 years. Estimated survival rate was 77.1%, and cardiac-death free survival rate was 81.0% at 5 years by the Kaplan-Meier method. Univariate analysis showed that the predictors of cardiac death were emergency angioplasty, renal failure, decreased left ventricular ejection fraction, multivessel disease and unstable angina and/or congestive heart failure. Cox's regression model showed that renal failure (p = 0.0004) and multivessel disease (p = 0.0075) were significant predictors of long-term prognosis.

CONCLUSIONS

Renal failure was the strongest predictor of outcome after unprotected left main coronary artery angioplasty.

Initial and 6-month results of biodegradable poly-l-lactic acid coronary stents in humans

BACKGROUND

Although metallic stents are effective in preventing acute occlusion and reducing late restenosis after coronary angioplasty, many concerns still remain. Compared with metallic stents, poly-l-lactic acid (PLLA) stents are biodegradable and can deliver drugs locally. The aim of this study was to evaluate the feasibility, safety, and efficacy of the PLLA stent.

METHODS AND RESULTS

Fifteen patients electively underwent PLLA Igaki-Tamai stent implantation for coronary artery stenoses. The Igaki-Tamai stent is made of a PLLA monopolymer, has a thickness of 0.17 mm, and has a zigzag helical coil pattern. A balloon-expandable covered sheath system was used, and the stent expanded by itself to its original size with an adequate temperature. A total of 25 stents were successfully implanted in 19 lesions in 15 patients, and angiographic success was achieved in all procedures. No stent thrombosis and no major cardiac event occurred within 30 days. Coronary angiography and intravascular ultrasound were serially performed 1 day, 3 months, and 6 months after the procedure. Angiographically, both the restenosis rate and target lesion revascularization rate per lesion were 10.5%; the rates per patient were 6.7% at 6 months. Intravascular ultrasound findings revealed no significant stent recoil at 1 day, and they revealed stent expansion at follow-up. No major cardiac event, except for repeat angioplasty, developed within 6 months.

CONCLUSIONS

Our preliminary experience suggests that coronary PLLA biodegradable stents are feasible, safe, and effective in humans. Long-term follow-up with more patients will be required to validate the long-term efficacy of PLLA stents.

[Breast cancer at the site of an implanted pacemaker]

We report here an 81-old-female patient who had a permanent pacemaker implanted in the right chest and who developed breast cancer near the site of the implanted generator. The cancer was diagnosed as stage I adenocarcinoma and radical mastectomy preserving pectoral muscles was indicated. During temporary pacing via the femoral approach, the pacemaker lead was transferred to the left subclavicular area crossing before the sternum and the generator was reimplanted in the left chest without use of lead extension kit. After reimplantation of the generator, radical mastectomy was performed. Clinical course was uneventful after the operation without infection or pacing failure. For the patient who needs surgical procedure in the site of implanted pacemaker generator, this technique of reimplantation is one of the useful choices.

Catheter-based reperfusion of unprotected left main stenosis during an acute myocardial infarction (the ULTIMA experience). Unprotected Left Main Trunk Intervention Multi-center Assessment

The ULTIMA registry was a prospective, multicenter, international registry of 277 patients who underwent percutaneous coronary interventions of unprotected left main trunk stenosis. The 40 patients who underwent an emergency percutaneous left main intervention for acute myocardial infarction are the focus of this study. We compared the results of primary angioplasty with primary stenting, characterizing both the short-term (in-hospital) and long-term (12-month) outcomes. Of the 40 patients, 23 underwent primary angioplasty, whereas 17 underwent primary stenting. The angiographic success rate was an 88% for the cohort. The in-hospital death or coronary artery bypass grafting rate was 65% for the entire group, 74% for the percutaneous transluminal coronary angioplasty group (PTCA), and 53% for the stent group (p = 0.2). The in-hospital death rate was 55% for the entire cohort, 70% for the PTCA group, and 35% for the stent group (p = 0.1). The 12-month rate of death or bypass surgery was 83% and 58% for the PTCA and stent groups, respectively (p = 0.047). The 12-month survival rate was 35% and 53% for the PTCA and stent groups, respectively (p = 0.18). Bypass surgery was required in 6 patients in the PTCA group and 2 patients in the stent group (p = 0.07). Patients undergoing percutaneous interventions for unprotected left main myocardial stenosis during an acute myocardial infarction are critically ill; an initial percutaneous revascularization approach appears feasible and may be the preferred revascularization strategy. Primary stenting was associated with improved clinical outcomes.

Initial and long-term results of angioplasty in unprotected left main coronary artery

Angioplasty of the unprotected left main coronary artery (LMCA) has been controversial. Although recent single-center studies suggest that new devices may change the situation, many questions and problems remain. Therefore, the results of unprotected left main coronary angioplasty of 175 procedures in 107 patients were analyzed to evaluate its feasibility and effectiveness. The treatment of the initial 107 cases included balloon angioplasty (39 cases, 36%), directional coronary atherectomy (53 cases, 50%), and stents (15 cases, 14%). They were divided into 3 major subgroups: (1) acute group (n = 14), in which LMCA angioplasty was performed in patients with acute myocardial infarction; (2) emergency group (n = 10); and (3) elective group (n = 83). In-hospital mortality was higher in the acute (35.7%) and emergency (40.0%) groups than in the elective group (3.6%; p <0.0001). Angiographic follow-up was routinely performed and the restenosis rate including in-hospital restenosis was 70% in the acute group, 37.5% in the emergency group, and 40% in the elective group (p = NS). The mean clinical follow-up period was 2.9 years, and the estimated 5-year survival rates of the acute and emergency groups were 50% and 48.2%, respectively. However the 5-year survival rate of the elective group was higher than that seen in the acute or emergency group (77.5%; p <0.05). Repeat LMCA angioplasty was performed in 37 of 68 patients with 8.8% mortality (38.5% of acute and emergency cases and 1.8% of elective cases). The results indicated that elective unprotected LMCA angioplasty is relatively feasible and effective under scheduled angiographic follow-up.

[Aneurysm of the membranous ventricular septum with ventricular septal defect, mitral and tricuspid insufficiency]

A seventy-year-old man was admitted at our hospital because of dyspnea. Echocardiogram and left ventriculogram showed an aneurysm formation of the membranous ventricular septum and small left-to-right shunt through ventricular septum defect and also severe mitral and tricuspid insufficiency. Operation was performed after medical therapy for congestive heart failure. During operation, mitral leaflets showed no organic lesions nor prolapse, but the annulus was dilated. The cause of mitral insufficiency, we thought, might be congenital, and the annulus dilatation was caused of mitral insufficiency, we thought, might be congenital, and the annulus dilatation was caused to produce tricuspid insufficiency secondary. The ventricular septal communication became small (diameter; 5 mm) and was associated with aneurysm formation of the remaining portion of the membranous septum. And the aneurysm, protruding to the septal leaflet of tricuspid valves, enhanced tricuspid insufficiency. It was reported by many authors that the aneurysm formation was related to spontaneous closure of ventricular septal defect. Patients with small ventricular septal defect, without any symptoms, must be followed intensively, or they might get cardiac complications, such as arrhythmia, right ventricular outflow obstruction, tricuspid insufficiency, and so on.

Contemporary percutaneous treatment of unprotected left main coronary stenoses: initial results from a multicenter registry analysis 1994-1996

BACKGROUND

Coronary artery bypass surgery (CABG) has been considered the therapy of choice for patients with unprotected left main (ULMT) coronary stenoses. Selected single-center reports suggest that the results of percutaneous intervention may now approach those of CABG.

METHODS AND RESULTS

To assess the results of percutaneous ULMT treatment from a wide variety of experienced interventional centers, we requested data on consecutive patients treated after January 1, 1994, from 25 centers. One hundred seven patients were identified who were treated either electively (n=91) or for acute myocardial infarction (n=16). Of patients treated electively, 25% were considered inoperable, and 27% were considered high risk for bypass surgery. Primary treatment included stents (50%), directional atherectomy (24%), and balloon angioplasty (20%). Follow-up was 98.8% complete at 15+/-8 months. Results varied considerably, depending on presentation and treatment. For patients with acute myocardial infarction, technical success was achieved in 75%, and survival to hospital discharge was 31%. For elective patients, technical success was achieved in 98.9%, and in-hospital survival was strongly correlated with left ventricular ejection fraction (P=.003). Longer-term event (death, infarction, or bypass surgery) -free survival was correlated with ejection fraction (P<.001) and was inversely related to presentation with progressive or rest angina (P<.001). Surgical candidates with ejection fractions > or = 40% had an in-hospital survival of 98% and a 9-month event-free survival of 86+/-5%, whereas patients with ejection fractions < 40% had 67% and 22+/-12% in-hospital and 9-month event-free survivals, respectively. Nine hospital survivors (10.6%) experienced cardiac death within 6 months of hospital discharge.

CONCLUSIONS

While results for selected patients appear promising, until early post-hospital discharge cardiac death can be better understood and minimized, percutaneous revascularization of ULMT stenosis should not be considered an alternative to bypass surgery for most patients. When percutaneous revascularization of ULMT is required, directional atherectomy and stenting appear to be the preferred techniques, and follow-up angiography 6 to 8 weeks after treatment is probably advisable.

Effectiveness of tranilast on restenosis after directional coronary atherectomy

Tranilast is an antiallergic drug used widely in Japan that also inhibits the migration and proliferation of vascular smooth muscle cells. This pilot study was undertaken to determine the effectiveness of tranilast on restenosis after successful directional coronary atherectomy. After the procedure, 40 patients (56 lesions, tranilast group) were treated with oral tranilast for 3 months, and 152 patients (188 lesions, control group) did not receive tranilast. Angiographic and clinical variables were compared between the two groups. The minimal lumen diameter was significantly larger in the tranilast group than in the control group at both 3-month (2.08 vs 1.75 mm, p = 0.004) and 6-month follow-up (2.04 vs 1.70 mm, p = 0.003). The diameter stenosis in the tranilast group was smaller than that in the control group both 3 months (28% vs 40%, p = 0.0007) and 6 months (30% vs 43%, p = 0.0001) after the procedure, with a lower restenosis rate (percent diameter stenosis > or =50) in the tranilast group at 3 months (11 % vs 26%, p = 0.03). The number of clinical events over the 12-month period after the procedure was significantly reduced by tranilast administration (p = 0.013). These findings suggest that the oral administration of tranilast strongly prevents restenosis after directional coronary atherectomy.

Hemodynamic performance of the St. Jude Medical Hemodynamic Plus valve

The hemodynamic performance of the St. Jude Medical Hemodynamic Plus valve (HP) for a small aortic annulus was compared to that of the standard St. Jude Medical valve (SJM). Doppler echocardiographic parameters were evaluated in patients undergoing aortic valve replacement with either a 19 mm HP (HP19, n = 7), a 21 mm HP (HP21, n = 8), a 19 mm SJM (SJM19, n = 16), or a 21 mm SJM (SJM21, n = 34). The peak and mean pressure gradients and peak flow velocity were significantly (p < 0.05) lower in both patients with the HP21 and those with the HP19 than patients with the SJM21 and those with the SJM19, respectively. The echocardiographic parameters of the patients with the HP19 corresponded closely to those of patients with the SJM21. The left ventricular mass index regressed markedly in patients with the HP19 during the late postoperative period. The results suggested that the hemodynamic performances of certain sizes of the HP were superior to those of the same size SJMs and were considered to be equivalent to those of the next size larger SJM.

Effects of minimal-dose aprotinin on coronary artery bypass grafting

OBJECTIVE

To evaluate the effects of minimal-dose aprotinin in patients undergoing coronary artery bypass grafting, we conducted a prospective randomized study.

METHODS

A total of 167 patients were randomized to receive no aprotinin treatment (control, n = 57), minimal-dose aprotinin (1.0 x 10(6) KIU; n = 55), or low-dose aprotinin (2.7 +/- 0.5 x 10(6) KIU; n = 55). Blood loss and transfusion requirements, parameters of clotting and fibrinolysis, renal function, and early graft patency rates were assessed.

RESULTS

Postoperative blood loss and transfusion requirements were significantly (p = 0.01) lower in both the minimal-dose and low-dose groups than in the control group. The increase in D-dimer level after cardiopulmonary bypass was significantly (p < 0.05) less marked in the low-dose group than in the control group. The alpha 2-plasmin inhibitor and plasminogen activator inhibitor-1 levels were significantly (p < 0.05) greater in the minimal-dose and low-dose groups than in the control group after bypass, suggesting the prevention of fibrinolysis by both aprotinin doses. No statistically significant differences in postoperative renal function and early vein graft patency rates were noted (control group, 93.8%; minimal-dose group, 95.5%; low-dose group, 92.3%; p = 0.25).

CONCLUSIONS

Aprotinin was not associated with a significant increase in the prevalence of renal dysfunction or early vein graft occlusion. Minimal-dose aprotinin inhibited enhanced fibrinolytic activity and reduced blood loss and transfusion requirements after bypass equivalently to low-dose aprotinin. The dose of 1 x 10(6) KIU added to the pump prime may be acceptably effective in reducing blood loss in patients undergoing primary coronary operations.

[Combined superior-transseptal approach to left atrial myxoma]

A 60-year-old woman was referred to our hospital for treatment of an intracardiac tumor Echocardiography revealed a 47 x 30 mm tumor in the left atrium which had a short stalk attached to the atrial septum. At operation, a large left atrial myxoma was extirpated using a combine superior transseptal approach. Through this incision, exposure of the left atrial myxoma and it stalk was excellent and removal of the myxoma was easily performed with minimal minpulation. Postoperative arrhythmias related to the operative procedures were not observed. The patient recovered uneventfully. The operative technique and indications of the combined superior transseptal approach to the left atrium are discussed in this paper.

Aortic root replacement for annuloaortic ectasia in Shprintzen-Goldberg syndrome: a case report

Annuloaortic ectasia due to Shprintzen-Goldberg syndrome (SGS) is reported. A 10-year-old boy was admitted to our hospital for evaluation of chest pain. On admission, he was diagnosed as SGS on the basis of his various anomalies. Two-dimensional echocardiography showed a bicuspid aortic valve and marked annular dilatation, Doppler flow studies revealed severe aortic regurgitation, and retrograde aortography showed severe aortic regurgitation with annular dilatation. Successful aortic root replacement was performed; subsequent histologic examination of the ascending aorta demonstrated cystic medial necrosis. In conclusion, SGS is a generalized connective tissue dysplasia, with clinical manifestations of cardiovascular lesions similar to those in Marfan syndrome. Aortic root replacement was successfully performed; however, recurrence of aortic aneurysms outside of the ascending aorta should be carefully observed. Surgical treatment for cardiovascular disorders may be necessary to save the life of patients with SGS.

Operation for type B aortic dissection using hypothermic selective cerebral perfusion

A 56-year-old man who had a huge type B dissecting aortic aneurysm extending from the distal arch to the thoracoabdominal aorta underwent replacement of the descending thoracic and thoracoabdominal aorta under hypothermic circulatory arrest with selective cerebral perfusion. The intercostal arteries at the T-8 to T-11 level were preserved with beveled distal anastomosis, and the celiac artery and the intercostal arteries at the T-5 and T-6 levels were reconstructed. The patient recovered uneventfully and is presently doing well 1 year after the operation.

Coronary artery revascularization concomitant with vascular surgery

Patients with vascular disease and coronary disease are usually treated initially by coronary artery bypass grafting (CABG), and vascular surgery is generally performed later. In this study we assessed the feasibility of combined CABG and vascular surgery in a single operation. Between 1988 and 1995, 16 patients received combined operations for vascular and cardiac lesions and the clinical results were assessed. There were no operative or hospital deaths. The mean time for operation was 421 min and the duration of the stay in the intensive care unit (ICU) was a mean of 3.6 days. In one patient with an ischemic left leg, the left internal thoracic artery (ITA) had become a collateral source of the ischemic leg, and the need for preoperative angiography of the ITA in such patients was indicated. The combined operation clearly takes longer than either vascular surgery or CABG alone, but the length of the postoperative intensive care unit stay was essentially the same as that after a single operation and the patient was still managed safely after the combined operation. In patient requiring both operations, the combined procedure therefore appears to be safe and to have a good clinical outcome.

Mitral valve repair for mitral regurgitation with ventricular septal defect in children

BACKGROUND

We examined the results of intermediate and long-term follow-up of 25 patients aged 3 months to 11 years (mean, 2.6 +/- 2.3 years) who initially underwent conservative mitral valve repair for mitral regurgitation associated with ventricular septal defect between April 1973 and March 1991.

METHODS

The preoperative degree of mitral regurgitation was 2+ in 3, 3+ in 17, and 4+ in 5 patients, and the major causes of mitral regurgitation were annular dilatation and prolapse of the anterior leaflet. Annuloplasty was performed in all except 2 patients, suturing of the cleft was done in 3 patients, and posterior mitral leaflet advancement was done in 2 patients. In addition, the papillary muscle was incised and adhesive chordae were removed in 1 patient, and adhesive fused chordae were detached from a leaflet in 1 other patient.

RESULTS

There were no early deaths. Two patients with residual mitral regurgitation with or without mitral stenosis underwent reoperation for mitral valve replacement 2 months and 6 years after the mitral repair, respectively. Late death occurred in 2 patients, and the actuarial survival rate was 92.0% at 15 years after operation. The freedom from reoperation was 91.3% at both 10 and 15 years after the initial operation. Postoperative color Doppler flow imaging was performed in 22 of the 23 survivors, and results showed no mitral regurgitation in 4, mild regurgitation in 14, and moderate regurgitation in 4 patients. Four patients presently have mitral stenosis, with a mean transmitral pressure gradient greater than 10 mm Hg. The residual lesion of moderate mitral regurgitation with or without mitral stenosis developed in 6 of 11 patients in whom bilateral mitral annuloplasty was applied after the initial operation. Nineteen of the 22 survivors without reoperation were in New York Heart Association class I, and 3 were in class II.

CONCLUSIONS

Clinical improvement was observed after conservative mitral repair in most pediatric patients with ventricular septal defect. However, careful follow-up for growth potential still appears to be needed to detect changes in mitral regurgitation and the development of mitral stenosis after valve repair, especially after bilateral annuloplasty.

[Surgical treatment for active infective endocarditis]

Between April 1975 and December 1995, 33 patients with active infective endocarditis underwent surgical treatment at our hospital. The location of diseased valve was shown as ; 18 in aortic, 11 in mitral, and 4 in aortic and mitral position. Of these, 14 patients had an annular abscess or mycotic aneurysm. All patients achieved antibiotic therapy previously, and predominant indication for operation was congestive heart failure. All patients underwent valve replacement. The reconstructive procedures for 14 patients with paravalvular involvement were as follows ; direct closure : 5 cases, direct closure+tilted prosthesis technique : 5 cases, and another 4 cases were, patch closure of VSP resulting from a septal abscess, patch closure+translocation, translocation, and reconstruction of annulas with pericardial patch. There were five (15.2%) operative and hospital deaths and actuarial survival rate was 81% and 61% at 5 and 10 years after operation. Including one who died early after operation, there were 5 cases with postoperative paravalvular leakage and its main cause were persistent infection. In conclusion, it considered that the principles of treating active infective endocarditis is to decide the optimal timing for operation, debride the infected tissue, and close the defect completely.

[Acute aortic dissection complicated with acute myocardial infarction--a case report of successful operation for the case of DOA]

A 61-year-old woman who suddenly manifested chest and back pain was admitted after the diagnosis of acute type A dissection complicated with acute inferior myocardial infarction at another hospital. While being transported to our hospital by ambulance, her ECG repeatedly demonstrated ventricular fibrillation of cardiac arrest. She was in the state of dead on arrival (DOA) when arrived at our hospital. ECG demonstrated complete A-V block and cardiac arrest alternately. However, soon after right ventricular pacing was done, her blood pressure increased and she recovered consciousness. We therefore performed an emergency operation. We performed reconstruction of the ascending aorta and right coronary bypass grafting, since she had aortic dissection and conus brach avulsion. The postoperative course was uneventful.

Valve detachment after aortic valve replacement--a successfully reoperated case with the Cabrol technique

A 50-year-old Japanese male was admitted with a 1 month history of progressive shortness of breath, palpitations, and intermittent low-grade fever. On admission, a musical diastolic murmur (sea-gull murmur) was heard on the 3rd left sternal border. Blood studies showed an accelerated erythrocyte sedimentation rate, and positive C-reactive protein. Retrograde aortography revealed severe aortic regurgitation. At the operation, the aortic wall was remarkably thickened, and the aortic valve commissures between the right and left coronary cusps and between the left and non-coronary cusps had completely detached from the aortic wall. The aortic valve was replaced with a St Jude Medical valve using pledgeted sutures. Histologic studies of the aorta and aortic valve revealed no evidence of any pathologic changes. Echocardiography performed 82 days after aortic valve replacement showed severe paravalvular leakage and valve detachment. At the reoperation, the prosthetic valve was detached from the extremely edematous and fragile native aortic annulus. There was no vegetation or abscess formation. Aortic root replacement with the Cabrol technique was performed using a composite graft in which the prosthetic valve was placed 1 cm above the proximal extremity to reduce the tension on the suture line and the aortic annulus. Histologic study of the aorta after the reoperation showed non-specific inflammatory disease. The patient, who received steroid therapy, has recovered without any signs of graft detachment or pseudoaneurysm formation.

Obstruction of mechanical valve prostheses: clinical diagnosis and surgical or nonsurgical treatment

Twenty patients underwent nonsurgical and/or surgical treatment for obstruction of mechanical prosthetic valves. The obstructed prosthetic valve was in the aortic position in 11 patients, in the mitral position in 5, and in the tricuspid position in 4. Twelve patients had a bileaflet valve (3 aortic, 5 mitral, 4 tricuspid), and 8 had a tilting disk valve (all aortic). The diagnosis of prosthetic valve obstruction was made by cineradiography and echocardiography. Thrombolytic therapy was instituted in a series of our 10 most recent patients (11 cases), except for one patient with acute renal failure, regardless of the position of the obstructed prosthetic valve. Successful thrombolysis was achieved in 6 cases (54.5%). Six patients required surgical treatment subsequent to either failed or incomplete thrombolysis, and one patient died of congestive heart failure 1 month after surgery. Nonfatal neurologic events occurred in 2 cases (18.2%). A total of 16 patients underwent surgical treatment. Two (12.6%) of the 16 patients died of causes unrelated to the operative procedures before discharge from the hospital. These results suggest that thrombolytic therapy appears to be an attractive nonsurgical alternative for valve thrombosis when the patient's clinical condition is not critical, and thus surgical treatment should only be performed in an emergency on seriously ill patients.

Effect of the addition of albumin to crystalloid cardioplegic solutions on myocardial metabolism in infants undergoing open heart surgery

The effect of the addition of albumin to crystalloid cardioplegic solutions was investigated in infants who underwent open heart surgery. The patients were divided into four groups according to whether or not they received a composition of crystalloid cardioplegic solutions containing albumin. Cardioplegic solution (Kurume solution) without albumin was administered to 12 patients (group 1); Kurume solution with 1% albumin to 10 patients (group 2); GIK solution without albumin to 10 patients (group 3); and GIK solution with 1% albumin to 15 patients (group 4). All patients had a ventricular septal defect and underwent closure of the defect with Dacron double velours through either the tricuspid or pulmonary valve. Our results showed that the percent oxygen extraction in group 2 was significantly greater than that in group 1, while the value in group 4 was less than that in group 3 at 5 min after reperfusion. No significant differences were seen between groups 1 and 2, or between groups 3 and 4, regarding the value for creatine kinase muscle-brain (MB) for any measurements during reperfusion. However, regarding the percent lactate and the malondialdehyde extraction values, significant differences between the groups with and without albumin were noted 5 min after reperfusion. These results did not completely support the addition of albumin to crystalloid cardioplegic solutions to help preserve myocardial aerobic metabolism in infants; however, such an addition might contribute to the preservation of myocardial lactate utilization while also helping to inhibit lipoperoxide metabolism immediately after reperfusion.

Reconstruction of the mitral annulus with porcine pericardium--report of a case with mitral annular disruption due to staphylococcal endocarditis

A 60-year-old man was admitted to our hospital for investigation of dyspnea and disorientation with right hemiplegia. Echocardiography showed thickened mitral valve leaflets with vegetations and severe mitral regurgitation. Blood cultures grew Staphylococcus aureus. During the operation, perforation and destruction of the mitral valve leaflets and vegetations were confirmed. Debridement of the infected tissues resulted in segmental disruption of the posterior mitral fibrous annulus. Reconstruction of the mitral annulus with porcine pericardium treated with glutaraldehyde and mitral valve replacement were successful. The patient's postoperative course was complicated with metastatic cerebral and splenic abscesses. After splenectomy on the 8th postoperative day, he gradually recovered without major neurologic sequelae. We believe that reconstruction of the mitral valve annulus with pericardium, especially autologous pericardium, is reliable and useful for the treatment of patients with disruption of the mitral valve annulus.

Aortic valve replacement for aortic regurgitation due to Kawasaki disease. Report of two cases

Two cases of severe aortic regurgitation due to Kawasaki disease are reported. Both patients were diagnosed as having Kawasaki disease in their infancy, and were followed up by a pediatrician. Aortic regurgitation was detected 18 months in one case and 36 days in the other case after onset of the illness. With the passage of time, the aortic regurgitation increased and aortic valve replacement was scheduled in both patient at the age of 13. On admission, two-dimensional echocardiography showed thickening of the aortic cusps, and severe aortic regurgitation was detected by color flow Doppler studies. Successful aortic valve replacement was performed, and histological studies of the cusps showed sequelae of valvulitis. In conclusion, aortic regurgitation is a rare complication of Kawasaki disease, and the aortic valve function, especially occurrence of aortic regurgitation, should be carefully observed in patients with a past history of Kawasaki disease.

Lysophosphatidylcholine inhibits endothelium-dependent hyperpolarization and N omega-nitro-L-arginine/indomethacin-resistant endothelium-dependent relaxation in the porcine coronary artery

BACKGROUND

Oxidized LDL and lysophosphatidylcholine (LPC) have been reported to inhibit the endothelium-dependent relaxation (EDR) mediated by nitric oxide. Recently, a new vasorelaxing factor, endothelium-derived hyperpolarizing factor (EDHF), which hyperpolarizes and relaxes the porcine coronary artery in the presence of N omega-nitro-L-arginine (NNA) and indomethacin (IM), has been reported. We examined whether LPC also inhibits both the EDHF-mediated relaxation and membrane hyperpolarization of the porcine coronary artery.

METHODS AND RESULTS

EDHF was evaluated as the bradykinin- or A23187-induced relaxation of the porcine coronary artery contracted by prostaglandin F2 alpha in the presence of NNA and IM. We also directly measured the membrane potential of the porcine coronary artery. The effects of LPC on both relaxation and membrane hyperpolarization were investigated. At concentrations of 0 to 20 mumol/L, LPC dose-dependently inhibited the NNA/IM-resistant EDR induced by bradykinin and A23187, and the relaxation was reversible after the absorption of LPC with albumin. LPC also inhibited the bradykinin- and A23187-induced hyperpolarization of the porcine coronary artery.

CONCLUSIONS

In the present study, LPC was found to inhibit not only nitric oxide-mediated but also EDHF-mediated relaxation of the porcine coronary artery. Our findings suggest a new regulatory mechanism in the atherosclerotic coronary artery.

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.

Beneficial effect of steroid on myocardial preservation in isolated rat hearts

Myocardial injury after heart storage has been known to contribute to an increase in myocardial calcium content or oxygen free radical production. The present experiment was designed to determine the inhibitory effect of steroid in the preservation solution on myocardial injury during simple immersion of isolated rat hearts. The experimental group was divided into 5 sub-groups according to the concentration of steroid added to the solution. Group I was stored in preservation solution containing no steroid. Groups II to V were stored in preservation solutions containing methylprednisolone in concentrations of 50 mg/L, 100 mg/L, 150 mg/L, and 200 mg/L, respectively. After the rat hearts were isolated, crystalloid cardioplegic solution at 4 degrees C was used for cardiac arrest, and the hearts were immersed in 4 degrees C Euro-Collins solution for 8 h. Hearts were then maintained under ischemic conditions at 25 degrees C for 15 min. After 60 min of reperfusion at 37 degrees C, cardiac function was measured and biochemical analyses of coronary effluent and myocardium were performed. The cardiac outputs in groups IV and V were significantly higher than those in groups I and II (p < 0.01). Creatine kinase-MB in coronary effluent in groups IV and V were significantly lower than those in groups I and II at 15, 30 and 60 min after reperfusion (p < 0.05). The level of arachidonic acid at 1 and 5 min, and the level of malondialdehyde at 5 min, after reperfusion in groups III, IV and V were significantly lower than those in groups I and II. Myocardial adenosine triphosphate was most preserved in group IV, and myocardial arachidonic acid, malondialdehyde, and calcium levels and water content in groups IV and V were lower than those in groups I and II. Ultrastructural observations also showed that myofilaments and mitochondria were well preserved in groups III, IV and V at 15 min after reperfusion compared with those in groups I and II. These results indicate that the addition of steroid to preservation solution might be effective in preventing myocardial injury during preservation of rat hearts, and the optimal concentration appears to range from 150 mg/L to 200 mg/L.

[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.

Aortic dissection after aortic valve replacement. Report of a case with an aortocameral fistula

A 58-year-old Japanese woman who had a history of aortic valve replacement for congenital bicuspid valve, was admitted for investigation of facial edema and of pulselessness of the right leg. Physical examination disclosed the patient suffering from a superior vena cava syndrome. On auscultation, a continuous murmur was heard at the left lower sternal border. Computed tomographic scans revealed aortic dissection extending from the ascending aorta to the bifurcation. Echocardiography showed an intimal flap in the dilated ascending aorta, but not abnormal blood flow from the aorta to the right atrium was detected. Cardiac catheterization and aortography, however, allowed a correct diagnosis of aortic dissection with fistula to the right atrium and with obstruction of the right common iliac artery. The patient received emergency aortic root replacement and reconstruction of the coronary arteries and then recovered uneventfully.

Long-term prognosis after thrombolytic therapy for acute myocardial infarction

In order to clarify the relationship between the patency of the infarcted arteries and subsequent long-term prognosis after thrombolytic therapy, we evaluated 116 patients with acute myocardial infarction treated with intracoronary (112 patients) or intravenous (four patients) urokinase. Patients treated with angioplasty after thrombolysis were excluded. The infarcted vessel was recanalized in 52 patients (patent group) and was not in the remaining 64 patients (occluded group). Five-year and 8-year follow up was conducted in 91% and 81% of the patients, respectively. The 1-, 5- and 8-year survival rate for the patent and occluded group was 91.8 and 80.9%, 80.8 and 79.2%, and 75.9 and 75.6%, respectively. The survival rate in the patent group tended to be higher than that in the occluded group up to 4 years. However, after 5 years, both groups showed similar survival rates. Therefore, reopening of the infarcted arteries with thrombolysis was not an independent predictor for late cardiac death (Cox regression analysis).

[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.

Long-term results of mitral valve repair for non-rheumatic mitral regurgitation

The durability of mitral valve repaired with reconstructive techniques is variable. If the durability continues to be good, mitral valve repair may be the procedure of choice in many patients with mitral regurgitation. Between December 1970 and June 1993, 54 patients had mitral valve repair for non-rheumatic mitral regurgitation. There were 38 men and 16 women with a mean age of 46.8 (range 19-68) years. The pathology which required surgical treatment was torn chordae in 38 patients, elongation of the chordae in five, valve prolapse without elongation or rupture of the chordae in six, infective endocarditis in three, and annular dilatation in two. Forty-four patients had triangular or quadrangular resection of the mitral leaflet, and seven had annuloplasty alone. Choral reconstruction was performed on three patients. There were no operative deaths. Five patients (9%) died late after operation. The actuarial survival rate and the valve-related death-free rate at 10 years were 83.9% and 90.0%, respectively. Seven patients (13%) required reoperation. Freedom from reoperation at 10 years was 84.5%. Improper evaluation of residual regurgitation during operation and suture dehiscence were the principal causes of reoperation. It was concluded that mitral valve repair for non-rheumatic mitral regurgitation showed low operative mortality and stable long-term results. It is suggested that intraoperative transoesophageal colour Doppler echocardiography provides accurate assessment of mitral valve competence and may be helpful in reducing the need for reoperation.

[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.

Total aortic replacement in a patient with mega aorta syndrome--a case report

A 64-year-old woman without manifestations of Marfan syndrome was referred for the close investigation of a pulsatile abdominal mass. Computed tomographic scans and magnetic resonance images revealed aneurysmal dilatation of the entire aorta, including the ascending aorta and extending to the bifurcation of the aorta, as well as tortuousness of the thoracoabdominal and abdominal aorta. Digital subtraction angiography also showed aneurysmal dilatation of the entire aorta and trivial aortic regurgitation. However, aortic annular dilatation was not found by echocardiography or aortography. The entire aorta was replaced in two stages. First, graft replacement of the ascending aorta, except for the sinus segment, and the aortic arch was performed using an elephant trunk technique under hypothermic cardiopulmonary bypass with selective cerebral perfusion. Twelve weeks later, the remaining aorta, including the descending aorta and extending to the common iliac artery on the right side, and to the common femoral artery on the left side, was replaced with a partial cardiopulmonary bypass using femoral artery and vein cannulation. We believe that patients with mega aorta syndrome are best treated by total aortic replacement. The results in the present case indicate that the elephant trunk technique is useful for extensive aortic replacement in stages, and greatly facilitates the second stage operative procedures.

Nucleotide sequence of a cDNA for mouse squalene epoxidase

A full-length cDNA encoding mouse squalene epoxidase was isolated by screening a mouse liver cDNA library with the rat squalene epoxidase gene as a probe. The cDNA had an open reading frame for a 572 amino acid polypeptide with a calculated molecular mass of 63.8 kDa. The predicted amino acid sequence of the mouse enzyme contained an FAD-binding motif, and was 93% identical to that of the rat enzyme. The former is one amino acid shorter than the latter. Blotting analyses showed that the mRNA is 2.8 kb in size and that a single copy of the gene is present in the mouse genome.

Changes in the mononuclear cell subpopulations of rat cardiac transplant recipients administered FK506 for the treatment of ongoing rejection

The inhibitory effect of ongoing rejection and the changes that occurred in mononuclear cell subpopulations were compared between four groups of rats treated with FK506 or steroids. Group 1 was given no immunosuppressive drugs, group 2 was given FK506 from the day of grafting, group 3 was commenced on FK506 on the 4th day after grafting, and group 4 was commenced on methylprednisolone (MP) on the 4th day after grafting. The graft survival times in groups 2 and 3 were significantly longer than those in groups 1 and 4, and there were fewer CD3+ and CD4+ T lymphocytes in the peripheral blood in the groups treated with immunosuppressive drugs than in group 1. In group 4, the levels in both the peripheral blood and thymus were significantly lower than those in the groups treated with FK506 despite the fact that graft rejection occurred soon after the discontinuation of steroid administration. Moreover, the levels of interleukin-2 receptors and macrophages in groups 2, 3, and 4 were significantly lower than that in group 1 postoperatively; however, the number of macrophages in groups 2 and 3 was significantly lower than that in group 4 on the 10th day after transplantation. The findings of this study demonstrated that FK506, even if administered after rejection has begun, might inhibit the subsequent extensive allograft rejection more specifically and effectively than steroids, and that the measurement of a marker for macrophages in the peripheral blood could be useful for the detection of rejection following allograft transplantation in rats.

Identification of two splice isoforms of mRNA for mouse hepatocyte nuclear factor 4 (HNF-4)

Hepatocyte nuclear factor 4 (HNF-4) is a liver-enriched transcription factor involved in the expression of many liver-specific genes. In the preceding communication (Hata, S., Tsukamoto, T. and Osumi, T. (1992) Biochim. Biophys. Acta 1131, 211-213), we reported the presence of two isoforms of mRNA for HNF-4 in rat liver and kidney. The longer isoform contained a segment of 30 bases which was not present in the shorter one. As an initial step to determine whether or not other mammals have these mRNA isoforms, we isolated a cDNA for mouse HNF-4 using the rat HNF-4 gene as a probe. The cDNA had an open reading frame for a 465 amino acid polypeptide. The deduced amino acid sequence was remarkably conserved between mouse HNF-4 and rat HNF-4 (99.6% identical). Moreover, like the cDNA for the larger rat isoform, the mouse cDNA contained an extra segment of 30 bp in the coding region near the C-terminus. Blotting analyses showed that the mRNA is about 3.7 kb in size and that a single copy of the gene is present in the mouse genome. Next we carried out the polymerase chain reaction (PCR) using primers located just upstream and downstream of the extra segment. Two PCR products were amplified from a mouse liver cDNA library. Determination of their nucleotide sequences proved that they exactly corresponded to the two rat isoforms. Finally, we amplified a DNA fragment (1.1 kb in size) from mouse genomic DNA using the same PCR primers as above. Its nucleotide sequence unequivocally confirmed that different splice donor sites were used to generate the two isoforms.

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.