Early- and long-term outcomes after surgery for acute type a aortic dissection in patients aged 45 years and younger.

BACKGROUND: Acute type A aortic dissection (AAAD) is rare in young people. The early- and long-term outcomes after surgery for AAAD in patients aged ≤ 45 years was investigated. METHODS AND RESULTS: Subjects were 355 patients who had undergone emergency surgery for AAAD. The patients were grouped as those aged ≤ 45 years (n=30; mean age, 38.3 years; younger group) and those aged > 45 years (n = 325; mean age, 65.3 years; older group). Clinical and prognostic variables were compared between the groups. Male sex, Marfan syndrome, and severe aortic regurgitation were more prevalent in the younger group. In-hospital mortality (16.7% vs. 8.6%, P = 0.15) and postoperative patency of the distal aorta (90.8% vs. 59.1%, P < 0.01) were more frequent in the younger group. The leading causes of late death were aortic rupture in the younger group (75.0%) and malignancy in the older group (27.5%). Although actuarial survival at 10 years was similar (64.5% vs. 62.5%), freedom from aortic reoperation at 10 years was decreased in the younger group (49.4% vs. 85.0%, P = 0.012). A distal aorta > 45 mm (P<0.001), Marfan syndrome (P < 0.01), and age ≤ 45 years (P = 0.045) were shown to be independent risk factors for reoperation. CONCLUSIONS: Early- and long-term surgical outcomes are not better for patients ≤ 45 years, and the risk for reoperation is high in this group. Careful follow up is important in young patients with AAAD.

Impact of concomitant cardiac procedure on coronary artery surgery in hemodialysis-dependent patients.

OBJECTIVE: Coronary artery bypass grafting (CABG) in hemodialysis-dependent patients is associated with high mortality and morbidity rates. This retrospective study was undertaken to identify the risk factors for in-hospital mortality for hemodialysis-dependent patients. METHODS: Subjects included 87 consecutive hemodialysis-dependent patients (81 men and 6 women), aged 47-82 years (mean age, 65 years), who underwent CABG. Operative procedures included CABG alone (n=77) and CABG with valve replacement, repair, or the Dor procedure (n=10). Thirty-one perioperative risk factors were subjected to univariate and multivariate analyses to identify the risk factors for hospital death. RESULTS: The overall in-hospital mortality rate, including operative death, was 14.9% (13/87). Univariate analysis showed the following 7 risk factors to be statistically significant predictors of hospital death: age > or = 70 years, a concomitant cardiac procedure, left ventricular ejection fraction <30%, left ventricular end-systolic volume index >70 ml/m2, a left main lesion, emergency/urgent surgery, and anemia (hemoglobin <10 mg/dl) (p<0.05 for each predictor). Multivariate logistic regression analysis confirmed that a concomitant cardiac procedure (chi-squared = 17.080, p=0.013) and age > or = 70 years (chi-squared = 9.112, p=0.019) are statistically significant independent risk factors for hospital death. CONCLUSION: A concomitant cardiac procedure and age > or = 70 years were identified as significant independent risk factors for hospital mortality after CABG for hemodialysis-dependent patients. These preoperative risk factors may help in predicting operative risks and improving clinical outcomes in hemodialysis-dependent patients undergoing CABG.

On the Way to Experimental Test of the Time Reversal Invariance in the Nuclear Reactions.

Time (T) violation can be related with charge-parity (CP) violation through the CPT theorem. The CP violation was discovered experimentally in the K0-meson decays about 35 years ago. The T violating interaction related with the CP violation violates parity as well. However, an extension of the theory beyond the locality of the interactions might violate the CPT theorem. The result of the CPLEAR experiment [1], which has given direct evidence of T violation in the elementary-particle phenomena, could be considered under assumption of the CPT invariance.

Off-pump coronary artery bypass grafting attenuates proinflammatory markers.

OBJECTIVE: Cardiac surgery with cardiopulmonary bypass (CPB) has been considered the main causative factors of postoperative inflammatory reactions. The aim of this study was to compare surrogate markers of the proinflammatory response in patients who underwent coronary artery bypass grafting (CABG) with or without CPB. METHODS AND RESULTS: Twenty patients undergoing first-time CABG were enrolled in the study, 10 with and 10 without CPB. Blood samples were drawn at the following times: at the anesthetic induction, the end of surgery, and thereafter at 12 and 24 hours postoperatively. Neutrophil elastase, interleukin (IL)-6 , and serum soluble Fas were chosen to evaluate the extent of the systemic inflammatory response. The groups were similar in terms of age, gender ratio, number of grafts per patient. There were no operative mortality or serious postoperative complications. Two of each group received blood transfusion postoperatively. Neutrophil elastase showed a significantly higher value in the on-pump group compared with the off-pump group at the end of surgery. Soluble Fas level showed a higher value at the end of surgery compared with baseline, while it had no significant changes in the off-pump patients. IL-6 levels in the on-pump group were consistently higher compared to the off-pump group but showed no statistically significant differences between the groups. CONCLUSION: Compared with off-pump CABG, on pump CABG induced higher serum levels of proinflammatory markers including neutrophil elastase and soluble Fas.

Pitfalls of sutureless repair of a blow-out type left ventricular free wall rupture.

A 55-year-old man was admitted for acute myocardial infarction. Cardiac catheterization revealed total occlusion of the left circumflex artery. During catheterization, he suffered cardiogenic shock. Percutaneous cardiopulmonary support was established, and the patient was transferred to the operating room. A blow-out left ventricular free wall rupture (LVFWR) with an epicardial tear, 1 mm in diameter, was found, and sutureless repair with a collagen hemostat (TachoComb) was performed. However, on postoperative day 7, echocardiography revealed an echo-free space resembling a pseudoaneurysm. A second operation was performed immediately for impending re-rupture. An epicardial tear, 2 x 10 mm in diameter, was found at the previous bleeding point where hemostasis had been achieved with only one sheet of TachoComb. The defect was closed with mattress sutures buttressed with Teflon felt. We conclude that even if the risk of re-rupture is low, sutureless repair with a collagen hemostat alone should be avoided in treating blow-out LVFWR.

Aortobronchial fistula resulting from a mycotic pseudoaneurysm after treatment of an aortoesophageal fistula due to a thoracic aortic aneurysm.

A 58-year-old man was admitted for an aortoesophageal fistula (AEF) resulting from a thoracic aortic aneurysm. He underwent immediate in-situ prosthetic graft replacement, primary esophageal repair and wrapping of the aneurysm. Postoperative upper gastrointestinal endoscopy and computerized tomography (CT) findings were unremarkable. He was discharged on postoperative day (POD) 25. Three months after surgery, he was readmitted with complaints of worsening cough and hemoptysis. CT showed a thrombosed aneurysm adjacent to the left bronchus. Aortobronchial fistula due to mycotic pseudoaneurysm was suspected. The patient underwent immediate resection of the infected graft and prosthetic graft replacement positioned to avoid the infected area. The graft was wrapped with omentum. On POD 7, pleural empyema developed, and esophagography revealed a residual leak. Staged reconstruction of the esophagus was performed successfully. We conclude that even if the fistulous opening is small, simultaneous esophageal resection should be performed during the initial treatment of AEF.

Platelet dysfunction in acute type A aortic dissection evaluated by the laser light-scattering method.

OBJECTIVES: Platelet dysfunction contributes to bleeding tendency in acute type A aortic dissection. Particle counting by new laser light-scattering methods more accurately quantifies changes in the number of different-sized platelet aggregates than do conventional optical density methods. We studied platelet aggregation kinetics and patterns of aggregation deficiency in acute-phase aortic dissection with laser light scattering. METHODS: Blood from 20 acute type A aortic dissection patients undergoing surgery was sampled during acute (9.1 +/- 6.8 hours from onset) and chronic (postoperative day 20, control) phases of aortic dissection. Platelet count and aggregability were assessed by optical density and laser light-scattering methods after aggregation was induced (addition of 2.0 microg/mL collagen to samples). RESULTS: Optical density showed significant reduction in acute-phase platelet aggregation (acute vs chronic: 65 +/- 27% vs 77 +/- 17%, P <.03). Laser light scattering showed significant reduction in medium (25-50 microm) and large (50-70 microm) but not small aggregate (9-25 microm) generation (acute vs chronic: small, 1.2 +/- 0.6 x 10(7) vs 1.5 +/- 1.0 x 10(7), NS; medium, 0.6 +/- 0.3 x 10(7) vs 1.1 +/- 0.5 x 10(7), P <.001; large, 1.4 +/- 1.2 x 10(7) vs 2.6 +/- 1.7 x 10(7), P <.001). Acute- versus chronic-phase platelet counts were significantly decreased (1.7 +/- 0.1 x 10(5)/microL vs 3.6 +/- 0.3 x 10(5)/microL, P <.001). CONCLUSIONS: Platelet aggregation is suppressed in acute-phase aortic dissection. This suppression does not occur in the initial phase of small aggregate formation; rather, it occurs during the conglomeration of small aggregates into larger aggregates.

Coronary malperfusion due to type A aortic dissection: mechanism and surgical management.

BACKGROUND: Coronary malperfusion associated with aortic dissection is relatively rare, but when it occurs, it is fatal to the patient. To salvage such moribund patients, aggressive coronary revascularization concomitant with aortic repair is essential. We review the surgical results and mechanism of malperfusion in a group of 12 patients with coronary malperfusion caused by type A aortic dissection, and we discuss our surgical approach. METHODS: Between March 1990 and March 2003, 12 patients (6.1%) from a total of 196 consecutive patients with acute type A aortic dissection undergoing surgery suffered coronary malperfusion associated with the dissection. There were 4 men and 8 women (mean age, 60.8 +/- 8.3 years). Nine patients had acute myocardial infarction due to dissection before surgery, and 3 patients suffered coronary malperfusion after aortic declamping. RESULTS: Hospital mortality rate was 33.3% (4 patients). The mortality rate was higher than that in patients without coronary malperfusion (33.3% vs. 8.2%, p = 0.019). Three patients could not be weaned from cardiopulmonary bypass, and 1 patient died of heart failure in the intensive care unit. Involved coronary arteries included the right coronary artery (8 patients), left coronary (2 patients), and both (2 patients). Mechanisms of coronary obstruction were compression (2 patients), coronary dissection (7 patients), and coronary disruption (3 patients). Coronary artery bypass grafting was performed concomitant with aortic repair. CONCLUSIONS: Acute type A aortic dissection with coronary involvement is associated with high mortality rate, aggressive coronary revascularization and early aortic repair with simple techniques are necessary to salvage these critically ill patients.

Off-pump coronary artery bypass in patients with Takayasu's disease.

We report 2 patients with ostial stenoses of coronary arteries and heavy aortic calcification caused by Takayasu's disease in which severe angina was successfully relieved by off-pump coronary artery bypass grafting. In one case, visceral arteries such as the right gastroepiploic artery, the superior mesenteric artery, and the splenic artery were used as proximal blood sources of saphenous vein grafts. In another case, an aortic connector system was employed for proximal anastomoses of saphenous vein grafts. The use of off-pump coronary artery bypass grafting techniques should be considered in surgical coronary revascularization in patients with Takayasu's disease, thus leading to wide-spreading indication for the surgery.

Evaluation of recurrent nerve paralysis due to thoracic aortic aneurysm and aneurysm repair.

OBJECTIVES: We sought to clarify the relationship between the outcome of recurrent laryngeal nerve paralysis with the characteristics of the thoracic aortic aneurysm and the surgical procedure used in each patient. METHODS: Nine patients who developed recurrent nerve paralysis (nonsurgical paralysis) due to a thoracic aortic aneurysm alone and 14 patients who underwent artificial vessel replacement for thoracic aortic aneurysm and developed recurrent nerve paralysis postoperatively (surgical paralysis) were evaluated. RESULTS: In the patients with nonsurgical paralysis, the aneurysms were similar in size to those of other patients who underwent surgery of the thoracic aorta and were invariably located near the aortic arch. Aneurysm shape was not associated with nerve paralysis. Surgical paralysis was alleviated in two patients. Surgical paralysis was observed in 9% of those who underwent surgery of the thoracic aorta. Vocal cord mobility recovered in 4 of the 11 patients with surgical paralysis who underwent follow-up. Symptoms were alleviated by rehabilitation in many patients who did not recover vocal cord mobility. The positions of the artificial vessel anastomoses are thought to be closely related to the outcome of paralysis. CONCLUSION: Recurrent nerve paralysis reduced not only the patient's quality of life but also survival by leading to disorders including aspiration pneumonia. Therefore, early rehabilitation should be performed, and surgical treatment should be considered, if necessary, for patients with recurrent nerve paralysis.

The outcome and criteria for mitral valve surgery in patients with ischemic mitral regurgitation.

OBJECTIVES: Mitral valve surgery for the correction of mitral regurgitation (MR) in patients with ischemic heart disease has been associated with poor prognosis. The criteria for selecting an appropriate surgical procedure are not clearly defined. The objectives of this study were to clarify the criteria for mitral valve manipulation and the outcome in patients with ischemic MR. METHODS: Twenty patients with ischemic MR were proposed for surgery. Ten of them (group A) had grade II MR and underwent isolated coronary artery bypass grafting (CABG). The remaining 10 patients with grade III or more MR underwent both CABG and mitral valve repair (group B). Postoperative left ventricular function and outcome were compared. RESULTS: Preoperative left ventricular end-systolic volume index (LVESVI) in group A was significantly smaller, while preoperative ejection fraction (EF) was almost equal between the groups. EF demonstrated a significant improvement in group A postoperatively, but no changes in group B. Two of group B died following surgery. The other patients were successfully treated with surgery which diminished MR. Congestive heart failure (CHF) developed in 2 patients of group B during follow-up and in none of group A. The 5-year freedom from CHF and the 5-year survival rate in group A were significantly greater than those in group B. CONCLUSIONS: Deterioration of mitral valve function, which necessitated mitral valve repair, was more frequent in the impaired and enlarged hearts. Although mitral repair was beneficial for diminishing MR and New York Heart Association, postoperative course in patients with ischemic MR depended on the preoperative LVESVI.

Infected left atrial myxoma with mitral valve endocarditis.

We report a rare case of infected left atrial myxoma associated with mitral valve endocarditis. The tumor and a small amount of vegetative growth on the anterior mitral leaflet were surgically excised. Subsequent antibiotic therapy may have prevented the infection from recurring. Histological findings showed myxoma cells embedded in mucinous stroma at the tumor base and an organized thrombus with bacterial colonization at the tumor tip.

Cardiac surgery in patients aged 80 years and older.

OBJECTIVE: We studied disease and surgical outcomes in an 80-plus age group to determine the feasibility of cardiac surgery at this age. METHODS: Between January 1991 and August 2000, we statistically analyzed 19 variables in 62 consecutive cases of cardiac surgery in the 80-plus age group to predict in-hospital and long-term mortality. Cases were classified by disease type (ischemic heart disease (IHD), n = 39; valvular heart disease (VHD) n = 19; and mechanical complications associated with acute myocardial infarction, n = 4; and by surgical status (emergency, n = 6; urgent, n = 10; and elective, n = 46). We compared these with 370 patients 70 to 79 years undergoing similar procedures during the same interval. RESULTS: No significant difference was seen between groups in total in-hospital mortality--9.7% vs. 3.8%--or in-hospital mortality for IHD--2.6% vs. 4.2%--or VHD--10.5% vs. 2.8%. We found cardiopulmonary bypass time > 150 min. and dialysis to be independent risk factors for hospital death. Actuarial survival at 7.5 years overall was 39% in the 80-plus age group vs. 53% in the 70-79 age group for VHD and 38% in the 80-plus age group vs. 62% in the 70-79 age group. No significant difference was seen in survival between groups for IHD. Stroke proved to be an independent prognostic factor. CONCLUSIONS: Cardiac surgery is conducted feasibly in selected octogenarians, providing acceptable mortality and results similar to those achieved in those 70 to 79 years old.

Aortic connector for coronary revascularization in a patient with Takayasu's disease.

Takayasu's disease affects the aorta and its major branches including coronary arteries, some of which may require coronary artery bypass grafting (CABG). However, calcification of the aorta affected by Takayasu's disease often makes proximal anastomosis of a vein graft very difficult. In addition, since the major branches of the aortic arch are also frequently affected by it, the internal mammary arteries are unsuitable for use in CABG. We report a 60-year-old woman with stenosis of the left main coronary artery and heavy aortic calcification caused by Takayasu's disease whose severe angina was successfully relieved by off-pump CABG using mechanical aortic connectors for proximal vein graft anastomoses.

Use of a larynyngeal mask airway during aortic valve replacement.

We report the elective use of a laryngeal mask airway during cardiac surgery for congenital tracheal stenosis. A 53-year-old woman with severe aortic valve stenosis was scheduled for aortic valve replacement. During anesthesia induction, the anesthesiologists attempted conventional intubation but failed. Fiberoptic tracheal examination and computed tomography showed a tracheal stenosis with 5 mm minimal diameter. A laryngeal mask airway was used at the patient's rescheduled surgery. The laryngeal mask airway use did not lead any surgical complication. We concluded that the laryngeal mask airway may be considered as an alternative to conventional intubation in patients with tracheal stenosis.

A highly stable DC power supply for precision magnetic field measurements and other purposes.

A homogeneous magnetic field is essential for the (3)He neutron spin filter used to polarize neutron beams and analyze neutron spins in neutron scattering. The required spatial uniformity of the magnetic field is on the order of 10(-4)/cm or less. To measure such uniformity, one needs a DC current source with a current stability much better than 10(-4). However, laboratory DC power supplies, which are commonly used in many (3)He neutron spin filters, do not have such stabilities. To attain a highly stable current with a common laboratory DC power supply for every (3)He neutron spin filter, a simple feedback circuit has been developed to keep the output current stable up to 10(-6). Such a highly stable current or voltage from a common laboratory DC power supply can also be used for various other research applications.

A successful surgical case of an 80-year-old patient with type A acute aortic dissection complicated by preoperative multiple organ failure.

An 80-year-old woman was hospitalized in a state of shock accompanied by blood acidosis due to type A acute aortic dissection complicated by respiratory, liver, and kidney failure. A warning was given to her family that lack of intervention may possibly lead to an early death, and permission for the intervention was obtained. After undergoing a "less invasive quick replacement (LIQR)," a newly modified procedure that we had developed, the patient improved gradually, went home without any complications, and continues to be well. Emergency surgery for octogenarians remains controversial, particularly for patients with a preoperative, compassionate indication. Here, we report a survival case for an emergency operation using LIQR to treat an octogenarian diagnosed with type A acute aortic dissection complicated by multiple organs failure.

Efficacy of intraoperative epiaortic ultrasound scanning for preventing stroke after coronary artery bypass surgery.

PURPOSE: The aim of this study was to clarify the efficacy of intraoperative epiaortic ultrasound scanning (EAS) for preventing cerebral emboli following coronary artery bypass grafting (CABG). PATIENTS AND METHODS: The intraoperative EAS was used to evaluate the ascending aorta in 909 consecutive CABG patients. When the scanning documented more than 3 mm of atheromatous thickness or plaque in the ascending aorta, we never manipulated it. Therefore 196 patients (21.6%) underwent off-pump CABG using composite grafts (85 cases, 9.4%) or in situ grafts (111 cases, 12.2%) with no aortic manipulation. The ascending aorta was confirmed to be free from significant atheromatous plaque by the EAS in 713 patients (78.4%). On-pump CABG was performed using aortic cannulation and total aortic clamping in 429 patients (47.2%). Off-pump CABG with aortocoronary bypass grafts was performed using side-bite aortic clamping in 165 cases (18.2%) or the other anastomotic devices in 63 cases (6.9%). RESULTS: There were five hospital deaths (0.6%) but no postoperative strokes. Postoperative coronary angiography revealed 98.8% (1,659/1,680) of the patency of the bypassed grafts. CONCLUSIONS: It was suggested that the application of aortic clamping or cardiopulmonary bypass was not a risk factor of cerebral emboli when the ascending aorta was evaluated using the EAS. Furthermore, the application of aortic clamping with free grafts may provide eligible bypass graft patterns, leading to sufficient graft patency.

Early postoperative aortic rupture following surgery for acute type A aortic dissection.

We report our experience with patients who died of early aortic rupture following surgical treatment for acute type A aortic dissection in a consecutive series of 324 patients who underwent surgery for this condition between 1991 and 2007. In-hospital mortality rate was 9.9% (32/324), and seven patients (two men, mean age, 67 years) died of postoperative aortic rupture. Rupture sites were the proximal aorta in two and distal aorta in five patients. Surgical procedures included ascending aorta replacement in six and ascending aorta plus aortic arch replacement in one. The common characteristics of the two patients with proximal aortic rupture were preoperative aortic insufficiency, intraoperative bleeding from the proximal stump, and high blood pressure before the rupture. In contrast, the distal aortic ruptures occurred in patients with uncomplicated postoperative courses, with three distal aortic ruptures occurring on the inpatient ward. The only common characteristic of the distal aortic ruptures was residual patent false lumen (80%, 4/5 patients), the other patient had a large pre-existing aneurysm in the descending thoracic aorta. Careful postoperative management, including strict blood pressure control, is especially important in patients with residual patent false lumen following surgery for acute type A aortic dissection.

The efficacy of intravenous milrinone in left ventricular restoration.

PURPOSE: The aim of this study was to clarify the efficacy of intravenous milrinone in postoperative care for patients following left ventricular (LV) restoration (LVR). METHODS: Fourteen patients who had ischemic cardiomyopathy with an LV ejection fraction (LVEF) of less than 0.30 and an LV end-systolic volume index of more than 100 ml/m2 underwent coronary artery bypass grafting and concomitant LVR. The patients received perioperative management with continuous infusions of 0.5 microg/kg/min milrinone that were started at the induction of a cardiopulmonary bypass (CPB). The perioperative course and outcome of these patients were retrospectively compared with those of matched LVR patients (n = 14) without milrinone administration during perioperative management. RESULTS: The preoperative LV end-diastolic pressure (26.3 mmHg vs. 15.4 mmHg) and early diastolic filling velocity/atrial filling velocity ratio (4.1 vs. 2.1) in the milrinone patients were significantly worse than those in the control. Even though the preoperative LV function in each patient demonstrated to be extremely poor, the perioperative hemodynamic variables were stable. The administered doses of dobutamine (4.01 vs. 5.81 microg/kg/min) and epinephrine (0.017 vs. 0.038 microg/kg/min) at the end of CPB were significantly lower in the milrinone patients compared to control. CONCLUSION: In those patients who underwent LVR because of ischemic cardiomyopathy, the administration of milrinone achieved safe perioperative management for stable hemodynamics and reduced the postoperative doses of dobutamine and epinephrine.