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.

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.

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.

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 17-mm St. Jude Medical Regent valve is a valid option for patients with a small aortic annulus.

BACKGROUND: When aortic valve replacement is performed in patients with a small aortic annulus, prosthesis-patient mismatch is of concern. Such prosthesis-patient mismatch may affect postoperative clinical status and survival. We investigated the outcomes of isolated aortic valve replacement performed with a 17-mm mechanical prosthesis in patients with aortic stenosis. METHODS: Twenty-three patients with aortic stenosis (mean age, 74.6 +/- 6.3 years) underwent isolated aortic valve replacement with a 17-mm St. Jude Medical Regent prosthesis. Mean body surface area was 1.41 +/- 0.13 m(2). Preoperative echocardiography yielded a mean aortic valve area of 0.36 +/- 0.10 cm(2)/m(2), a mean left ventricular-aortic pressure gradient of 68.4 +/- 25.3 mm Hg, and a mean left ventricular mass index of 200 +/- 69 g/m(2). RESULTS: There was no operative mortality, and there were no valve-related events. Echocardiography at 14.0 +/- 10.0 months after aortic valve replacement showed a significant increase in the mean effective orifice area index (0.95 +/- 0.24 cm(2)/m(2)), decrease in the mean left ventricular-aortic pressure gradient (17.4 +/- 8.2 mm Hg), and decrease in the mean left ventricular mass index (124 +/- 37 cm(2)/m(2)). Prosthesis-patient mismatch (effective orifice area index < 0.85 cm(2)/m(2)) was present in 8 patients at discharge. In these patients as well as in those without prosthesis-patient mismatch, the left ventricular mass index decreased remarkably during follow-up. CONCLUSIONS: Aortic valve replacement with a 17-mm Regent prosthesis appears to provide satisfactory clinical and hemodynamic results in patients with a small aortic annulus. Remarkable left ventricular mass regression during follow-up was achieved irrespective of the effective orifice area index at discharge.

Influence of patent false lumen on long-term outcome after surgery for acute type A aortic dissection.

OBJECTIVE: The fate of the dissected distal aorta after surgery for acute type A aortic dissection has not been fully understood. We assessed the influence of a residual patent false lumen on long-term outcomes. METHODS: Two hundred eighteen patients underwent emergency surgery for DeBakey type I or IIIb retrograde acute type A aortic dissection (1997-2006). Aortic arch replacement was performed in selected patients whose entry site was in or extended into the aortic arch. In-hospital mortality was 7.3% (16/218), and 193 survivors (mean age 62 years) underwent enhanced computed tomography within 1 month after the operation. These patients were divided into two groups according to the status of the false lumen, whether patent (n = 124) or thrombosed (n = 69). In each group, segment-specific aortic growth rate, distal reoperation, and late survival were examined. RESULTS: Growth rate was determined in 139 (72.0%) patients who underwent serial computed tomography. Average growth rate in the patent group was greater than that in the thrombosed group (aortic arch [1.1 vs -0.41 mm per year; P = .005], proximal descending aorta [1.9 vs -0.71 mm per year; P <.001], and distal descending aorta [1.3 vs -0.70 mm per year; P = .002]). However, growth was slow (<1 mm per year) in about 50% of patients in the patent group. There was no significant difference in distal reoperation or late survival between the two groups. CONCLUSIONS: The patent false lumen influences postoperative aortic enlargement. However, with careful follow-up, a favorable prognosis is expected even for patients with a residual patent false lumen.

Risk factors for prolonged mechanical ventilation following surgery for acute type a aortic dissection.

BACKGROUND: The aim of this study was to identify predictors of prolonged mechanical ventilation (PMV) following surgery for acute type A aortic dissection (AAAD) and to assess the influence of this complication on clinical outcomes. METHODS AND RESULTS: A total of 243 patients underwent emergency surgery for AAAD in the period of 1997-2006. Ten patients died within 48 h after surgery. The remaining 233 patients were divided into 2 groups according to the duration of mechanical ventilation; less than 48 h (group A: n=149) or 48 h or longer (group B; n=84). Multivariate analysis was used to identify predictors of PMV. Short and late outcomes were compared between groups. Multivariate analysis showed that shock (systolic BP <90 mmHg; p=0.007), postoperative renal dysfunction (creatinine >2.0 mg/dl; p=0.016), coronary artery bypass grafting (CABG) (p=0.017), and limb ischemia (p=0.044) were independent predictors of PMV. There was no significant difference in in-hospital mortality (group A, 2.7% vs group B, 3.6%) or 5-year survival (group A, 85.9% vs group B, 76.8%). CONCLUSIONS: Shock, limb ischemia, CABG, and postoperative renal dysfunction increase the risk for PMV. Knowing the predictors of PMV should help optimize postoperative management of these patients.

Postinfarction heart rupture of posterior wall repaired by covering patch.

A 46-year-old man underwent emergency surgery for heart rupture after acute infarction of the posterior wall. Echocardiography revealed limited myocardial thinning, so rather than sutureless repair, a covering patch was used in view of the risk of recurrent rupture. Postoperative echocardiography showed the myocardial thinning had progressed to a wide defect, and computed tomography demonstrated that the covering patch had prevented a repeat rupture.

Chronic type A aortic dissection associated with Listeria monocytogenes infection.

A previously healthy 77-year-old woman with a 4-week history of back pain and fever was admitted to our hospital for chronic type A aortic dissection. The aortic arch was enlarged to 7.5 cm in diameter, and the large dissecting aortic aneurysm involved all three branches of the aortic arch and compressed the trachea. Laboratory tests showed an increased C-reactive protein level (10.5 mg/dl). Blood cultures performed upon admission were negative. Progression of the symptoms suggested the possibility of impending aneurysm rupture. The patient underwent urgent total arch replacement, and cultures of samples obtained from the aortic wall during surgery were positive for Listeria monocytogenes. Two months after surgery, advanced rectal cancer was diagnosed. It is believed that the rectal cancer predisposed the patient to development of an arterial infection associated with L. monocytogenes.

Extracardiac aneurysm of the interleaflet triangle above the aortic-mitral curtain due to infective endocarditis of the bicuspid aortic valve.

A previously healthy 33-year-old man presented to our hospital with fever, left hemiparalysis, motor aphasia, and clouding of consciousness. Echocardiography revealed vegetation attached to the bicuspid aortic valve as well as an aneurysm originating below the annulus. Head computed tomography showed multiple infarctions. Under the diagnosis of infective endocarditis and perivalvular aneurysm, operation was performed because of the risk of further embolization. Operative findings showed an extracardiac aneurysm of the interleaflet triangle above the aortic-mitral curtain. Because there was no sign of active inflammation, the orifice was closed with an autologous pericardial patch, and the aortic valve was replaced with a mechanical valve. We should be aware of extracardiac aneurysm of the interleaflet triangle when dealing with infective endocarditis, which should be operated as soon as it is found because of the risk for extracardiac aneurysmal rupture.

Type B aortic dissection associated with Salmonella infection.

A 59-year-old man with a long history of hypertension and diabetes was admitted to our hospital with acute type B aortic dissection 14 days after the sudden onset of back pain. The dissecting descending thoracic aorta was enlarged to 5.2 cm in diameter, and laboratory tests showed an elevated white blood cell count (15530/mm3) and an increased C-reactive protein level (19.2 mg/dl). Computed tomography performed 2 days after admission revealed rapid growth of the aortic dissection. Blood cultures obtained upon admission were positive for Salmonella. Impending rupture of the aortic dissection complicated by Salmonella infection was strongly suspected, and the patient underwent emergency surgery consisting of debridement and prosthetic graft placement covered by an omental flap. In this case, it is believed that insidious Salmonella aortitis caused acute type B aortic dissection.

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.

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.

Anterolateral thoracotomy for distal aortic arch disease.

PURPOSE: Optimal exposure and antegrade arterial perfusion are keys to avoiding complications in the repair of distal aortic arch disease. To achieve these ends, we performed distal aortic arch repair through a left anterolateral thoracotomy while also using axillary artery perfusion. METHODS: From Mach 1998 to December 2004, 28 patients (23 men and 5 women, age 65.2 +/- 12.0 years) underwent a distal aortic arch repair through a left anterolateral thoracotomy. All cases had atherosclerotic aneurysms. Emergency surgery was performed in 1 of these cases (1/28, 3.6%) with an aortic rupture. The right axillary artery was used for arterial perfusion in all cases. RESULTS: No perfusion problems occurred during surgery, and the left anterolateral thoracotomy approach provided an excellent view of both the aortic arch and descending aorta. There was no hospital mortality. Morbidity included one incident of transient convulsion without computed tomographic evidence of an embolism and one incident of heart failure that required temporary mechanical support. No other significant event or morbidity occurred related to the surgical methods. There was no late death during the 1 to 81-month follow-up. CONCLUSION: A left anterolateral thoractomy provides an ideal view of distal aortic arch disease, and antegrade arterial perfusion is effective in the prevention of retrograde embolism. These results suggest this treatment modality to be a reliable alternative approach for the repair of distal aortic arch disease.

Perfusion through the dorsalis pedis artery for acute limb ischemia secondary to an occlusive arterial cannula during percutaneous cardiopulmonary support.

Percutaneous cardiopulmonary support (PCPS) is a powerful resuscitation tool for patients in cardiogenic shock. The femoral artery is generally used for arterial access; however, vascular complications, particularly in atherosclerotic arteries, can occur. Although such complications occur infrequently, they can be fatal. We describe the case of a 75-year-old woman who required extended PCPS for cardiogenic shock secondary to coronary spasm after on-pump beating coronary artery bypass grafting. Limb ischemia occurred because of an occlusive cannula, and distal perfusion with a 20G elastic intravenous catheter inserted into the dorsalis pedis artery resolved the ischemia. The catheter was connected to the side port of an oxygenator and provided distal limb perfusion during PCPS. This technique appears to be useful in treating limb ischemia and may have application in patients with arterial occlusive disease who are dependent on mechanical support.

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.

Successfully treated triple valve infective endocarditis: a case report.

A 45-year-old woman presented with triple valve infective endocarditis and ventricular septal defect. There were vegetations on the tricuspid valve, pulmonary valve, and aortic valve. She had multiple complications such as nephrotic syndrome, severe anemia, congestive heart failure, and convulsion. Her general condition was extremely poor. Intensive medical therapy, such as blood transfusion, mechanical ventilation, and continuous venovenous hemofiltration, allowed her to tolerate surgery. Triple valve replacement and ventricular septal defect closure was successfully performed without major complication. She was ambulatory at the time of discharge.

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.