Suguru Kubota

Left lobectomy might be a risk factor for atrial fibrillation following pulmonary lobectomy

OBJECTIVE To identify risk factors for atrial fibrillation (AF) following lobectomy for a pulmonary malignant tumour. METHODS The outcomes of patients who underwent lobectomy from February 2005 to September 2010 were analysed with respect to the development of postoperative AF. RESULTS Among 186 patients, 20 developed AF and these had significantly higher preoperative B-type natriuretic peptide (BNP) than those without AF. A significantly high incidence of AF following pulmonary lobectomy was demonstrated in the group of patients who were male, underwent a thoracotomy, had a high preoperative value of BNP and underwent a left lobectomy. Multivariate analysis revealed that left lobectomy is the only independent risk factor. The area under the receiver-operating characteristic curve for BNP to predict postoperative AF following a left lobectomy for a pulmonary malignant tumour was 0.82 (95% confidence interval 0.70-0.93; P<0.05). A BNP level of 24.1 pg/ml had a sensitivity of 90.9% and a specificity of 56% for predicting postoperative AF following left lobectomy for a pulmonary malignant tumour. CONCLUSIONS Left lobectomy is the only independent risk factor for postoperative AF. Elevated BNP is the risk factor for postoperative AF in patients undergoing left pulmonary lobectomy.

Repair of False Para-anastomotic Aortic Aneurysms Using an Endovascular Stent Graft Technique in a Patient with Severe Pulmonary Disease: Report of a Case

Abstract Conventional surgery for para-anastomotic aortic aneurysms is technically challenging, and is associated with high morbidity and mortality. This report describes the case of a patient with severe pulmonary diseases in whom false para-anastomotic aortic aneurysms were successfully repaired using an endovascular stent graft technique.

Surgical experience of the thoracic aortic aneurysm due to Takayasu’s arteritis

We have treated 10 patients with thoracic aortic aneurysms due to Takayasus arteritis during the last 15 years and presented surgical results. In the surgical treatment of thoracic aortic aneurysm due to Takayasus arteritis, therapeutic strategy is different from that for atherosclerotic aneurysm and should be determined by the location and the extent of aneurysmal lesions and the degree of inflammation. Palliative procedure, which was taken to reduce surgical risk, has failed to prevent the recurrence of aneurysmal formation or to minimize surgical risk in the later period. Radical surgical treatment for thoracic aortic aneurysms is highly recommended if technically possible. Penoperative steroid therapy to control the degree of inflammation, appropriate strategy for multiple or extensive lesions and progress in the organ protection method that enabled radical treatment, all these will contribute to the improvement of surgical results.

Slope in preload recruitable stroke work relationship predicts survival after left ventriculoplasty and mitral repair in patients with idiopathic cardiomyopathy

BACKGROUND Left ventriculoplasty (LVP) and mitral valve plasty (MVP) are sometimes effective for patients with idiopathic dilated cardiomyopathy (DCM) who are not eligible for heart transplantation. Strict patient selection is warranted for these controversial procedures. METHODS AND RESULTS The subjects were 18 patients with idiopathic DCM and mitral regurgitation who had not been indicated for heart transplantation due to either older age or patient refusal, and who underwent LVP and MVP. Their mean age was 57±14 years and 50% were dependent on catecholamine infusion. The preload recruitable stroke work (PRSW) relationship and its slope (Mw) were estimated by a single-beat technique using transthoracic echocardiography. There were one 30-day mortality and six (33%) hospital deaths due to heart failure. The one-year survival rate was 50%. Left ventricular end-diastolic dimension (LVDd) decreased from 77±11 to 68±11mm (p=0.001) whereas the ejection fraction did not change. Preoperative Mw was significantly higher in one-year survivors than that in non-survivors (54±17ergcm(-3)10(3) vs. 31±10ergcm(-3)10(3), p=0.005). Preoperative LVDd was not different between the groups. The cut-off value of 42ergcm(-3)10(3) for Mw predicted one-year survival with high sensitivity (100%) and specificity (77%). CONCLUSIONS Mw, the slope in the PRSW relationship, may predict survival after LVP and MVP in patients with idiopathic DCM.

Augmentation Index Is Elevated in Aortic Aneurysm and Dissection

BACKGROUND The augmentation index, the ratio of the ejection pressure from the heart to the reflection pressure from the arterial system, has recently been recognized as one of the indexes of left ventricular afterload. We studied it in patients with aortic aneurysm and dissection, using carotid artery diameter waveform obtained from an echo-tracking system. METHODS Forty-six patients were divided into the following three groups based on pathology: group A, 21 patients with thoracic aortic aneurysm; group B, 15 patients with chronic aortic dissection; and group C, 10 patients without any aortic diseases. Using an echo-tracking system on the carotid artery, we measured stiffness parameter beta, arterial compliance, and the augmentation index. RESULTS There was no significant difference in stiffness parameter beta and arterial compliance among the three groups. The augmentation index was significantly higher in groups A and B than group C (22 +/- 10%, 22 +/- 13% vs 8 +/- 17%; p = 0.012). Female (p = 0.028) and heart rate (p = 0.005) were significantly associated with the augmentation index and the significance of aortic diseases was marginal (p = 0.056). CONCLUSIONS The carotid augmentation index is elevated in patients with aortic aneurysm and dissection.

Thymic carcinoma with tumor thrombus into the superior vena cava

Tumor thrombus into the vena cava have been reported in cases with renal cell carcinoma, thyroid tumor and in those with thymoma. These tumors are frequently invasive and continuous from the main tumor that shows direct vessel wall invasion. Here, we report a case of thymic carcinoma with superior vena cava syndrome, which was caused by a tumor thrombus in the superior vena cava without vessel wall invasion. The main mediastinal tumor did not show innominate vein invasion, and the superior vena cava syndrome was a result of separate tumor thrombus that was free of vessel wall invasion. The tumor thrombus could be removed through a simple venotomy. To prevent stenosis in the superior vena cava and the left innominate vein, we used a pericardial patch to close the venotomy site.

Measured Tube Technique for Ensuring the Correct Length of Slippery Artificial Chordae in Mitral Valvuloplasty

Mitral valvuloplasty using Gore-Tex (W.L. Gore & Associates, Inc, Flagstaff, AZ) as artificial chordae is often associated with difficulties in determining the length of the artificial chordae, as well as preventing knot slippage, especially for patients with broad anterior leaflet prolapse. We describe a simple technique that enables surgeons to easily determine the correct length of the artificial chordae and tie slippery knots without using a specific device.

Effects of Surgical Ventricular Reconstruction and Mitral Complex Reconstruction on Cardiac Oxidative Metabolism and Efficiency in Nonischemic and Ischemic Dilated Cardiomyopathy

OBJECTIVES The aim of this study was to investigate the effects of surgical ventricular reconstruction (SVR) on cardiac efficiency as a surrogate marker for cardiac function and oxidative metabolism in patients with severe heart failure. BACKGROUND Our new integrated overlapping left ventriculoplasty, modified SVR, combined with mitral complex reconstruction, reduce left ventricular (LV) volume associated with improvement of symptoms of heart failure. METHODS Twelve consecutive patients with end-stage heart failure due to nonischemic dilated cardiomyopathy (DCM) (n = 6) and ischemic dilated cardiomyopathy (ICM) (n = 6) who underwent SVR were studied. Myocardial oxidative metabolism per gram of tissue was estimated by monoexponential clearance of (11)C-acetate positron emission tomography (K(mono)). Forward stroke volume at the LV outflow tract was measured by echocardiography. Cardiac efficiency was estimated by the ratio of external work (stroke volume at the LV outflow tract index × systolic blood pressure × heart rate) to K(mono) before and 1 month after SVR. RESULTS After SVR, medians of New York Heart Association functional class significantly improved from 3 to 1.5 (p < 0.01) in both DCM and ICM patients. End-systolic and end-diastolic volume and LV mass significantly decreased in both groups. Stroke volume at the LV outflow tract increased from 43 ± 8 ml to 52 ± 11 ml (p = 0.028) in DCM patients, but not in ICM patients (49 ± 21 ml to 59 ± 26 ml, p = 0.12). K(mono) × LV mass, as an index of global LV oxidative metabolism, decreased in DCM patients (13.6 ± 1.9 g/min vs. 8.6 ± 1.5 g/min, p = 0.03) and ICM patients (12.0 ± 3.4 g/min vs. 9.2 ± 1.0 g/min, p = 0.06). As a result, cardiac efficiency increased in all patients with DCM (3.34 ± 0.46 × 10E6 vs. 4.74 ± 0.88 × 10E6 mm Hg·ml·min/m(2), p = 0.03) and in 5 of 6 patients with ICM (4.54 ± 1.66 × 10E6 vs. 5.99 ± 2.11 × 10E6 mm Hg·ml·min/m(2), p = 0.12). CONCLUSIONS Combined surgery with SVR and mitral complex reconstruction reduced LV volume in association with improvement of cardiac efficiency in patients with severe heart failure.

Aortic Valve Replacement Through Left Thoracotomy After Esophageal Operation

A 67-year-old man was referred for aortic valve surgery due to aortic valve regurgitation. He underwent an aortic valve replacement through a left thoracotomy, since he had a history of esophageal surgery with substernal gastric tube reconstruction and lymph node dissection through a right thoracotomy 14 years ago. The aortic valve was successfully replaced with excellent visualization using vacuum-assisted venous drainage on a cardiopulmonary bypass. Although exposing the aortic valve through a left thoracotomy is difficult, the application of vacuum-assisted venous drainage helps visualize the aortic valve in this approach.

Left-ventricular electromechanical delay is prolonged in patients with postoperative atrial fibrillation

OBJECTIVE Although several risk factors for postoperative atrial fibrillation (AF) have been proposed, it remains the most common complication after cardiac surgery, even in low-risk patients. There is still no single reliable and reproducible parameter for predicting AF, and no standardized recommendation exists for this issue. Electromechanical delay (excitation-contraction coupling delay) is the time delay from the electrical activation to the actual systolic motion, and it reflects abnormality in calcium-handling proteins, which is considered one mechanism of postoperative AF. We hypothesized that left-ventricular electromechanical delay (LVEMD) is correlated to postoperative AF and serially examined it by echocardiography. METHODS We prospectively included 16 patients with relatively low risk for AF, who underwent cardiac surgery. The inclusion criteria were younger than 80 years, an ejection fraction greater than 45%, a left-atrial dimension less than 50mm, and a brain natriuretic peptide (BNP) value less than 250 pg ml⁻¹. Postoperative AF for 10 postoperative days was monitored by 24-h electrocardiogram. The LVEMD was assessed by pulse-wave tissue Doppler echocardiography before and 1, 3, and 7 days after the operation. Serum BNP, adrenalin, and noradrenalin levels were also examined at the same time. RESULTS Postoperative AF was detected in six (37.5%) patients. There was no significant difference in heart rate, QRS duration, and serum hormones between the non-AF (n = 10) and AF (n = 6) groups. Although the preoperative LVEMD was comparable, that on postoperative day 1 of the AF group was significantly longer than that of the non-AF group (in the septal wall, 174 ± 50 vs 101 ± 36 ms, p = 0.020; in the lateral wall, 195 ± 71 and 111 ± 37 ms, p = 0.029). A LVEMD on postoperative day 1 greater than 150 ms well predicted postoperative AF (sensitivity, 75% and 75%; specificity, 100% and 86%, in septal and lateral LVEMDs, respectively). CONCLUSIONS LVEMD is prolonged in patients with postoperative AF. This could be a new predicting parameter for AF in low-risk patients.