Tomonori Ooka

Bioprosthetic replacement of the ascending thoracic aorta: what are the options?

Increasing patient age and improved durability of latest generation bioprostheses have stimulated the use of bioprosthetic devices in the setting of ascending aortic replacement as an alternative to mechanical valved conduits or aortic valve-sparing procedures. We performed an English literature review to assess different surgical options that have been described for bioprosthetic replacement of the ascending aorta. Reported options include: (1) composite valved conduits using a stented bioprosthesis; (2) composite valved conduits using a stentless bioprosthesis; (3) total xenopericardial valved conduits. Composite valved grafts using stented bioprostheses offer a safe and durable option for bioprosthetic replacement of the ascending aorta. Other options are of more recent use and await medium-term results.

Coil Embolization of Symptomatic Persistent Sciatic Artery Aneurysm: A Case Report

Persistent sciatic artery is a rare congenital vascular anomaly of the lower extremity. This artery is predisposed to atherosclerosis or aneurysm formation. Persistent sciatic artery aneurysm often causes limb-threatening ischemia owing to its thrombosis or its mural thrombus. We report a case of successful transcatheter coil embolization for persistent sciatic artery aneurysm. An 89-year-old woman presented to our hospital, suffering from severe ischemia of the right leg and a pulsatile mass in the right buttock. Angiography and enhanced computed tomography revealed right persistent sciatic artery aneurysm with mural thrombus and complete occlusion of the distal end. After she underwent major amputation because of the advanced ischemia following unsuccessful thrombectomy, we performed coil embolization for the aneurysm successfully. Endovascular treatment including transcatheter embolization for persistent sciatic artery aneurysm is safe, effective, and less invasive than surgery. Its application gives various therapeutic options for the treatment of persistent sciatic artery aneurysm.

Surgical Strategy for Ischemic Mitral Regurgitation Adopting Subvalvular and Ventricular Procedures

PURPOSE The progression of left ventricular (LV) remodeling and subsequent mitral valve tethering impair the results of reduction annuloplasty for ischemic mitral regurgitation (MR). METHODS We studied 90 patients who underwent surgical repair of ischemic MR between 1999 and 2013 according to our surgical strategy adding submitral and ventricular procedures to annuloplasty as follows: annuloplasty alone (stage 1, n = 30), additional papillary muscle approximation (PMA) for progression of tethering (stage 2, n = 26), and additional left ventriculoplasty with PMA for progression of LV remodeling and tethering (stage 3, n = 34). RESULTS The preoperative New York Heart Association (NYHA) functional classes (2.5 ± 0.7, 3.1 ± 0.7 and 3.3 ± 0.7 for stages 1, 2 and 3, respectively, P <0.001), LV end-diastolic diameters (56 ± 7 mm, 66 ± 5 mm and 70 ± 7 mm, P <0.001), and LV ejection fractions (45 ± 12%, 32 ± 9% and 27 ± 9%, P <0.001) significantly differed among the stages. In contrast, the MR grades did not significantly differ (2.9 ± 0.8, 3.0 ± 1.0, and 2.9 ± 1.1, respectively; P = 0.93). Both the rates of cardiac-related survival and freedom from reoperation were comparable among the 3 groups (log-rank P = 0.92 and 0.58, respectively). CONCLUSION Additional submitral and ventricular procedures can compensate for the possible impairment of the outcomes after annuloplasty alone for ischemic MR in patients with severe LV remodeling and tethering.

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.

A semiquantitative analysis of reactive astrogliosis demonstrates its correlation with the number of intact motor neurons after transient spinal cord ischemia

OBJECTIVE We evaluated the relationship between reactive astrogliosis and delayed motor neuron death after transient spinal cord ischemia in rabbits using a semiquantitative analysis of glial fibrillary acidic protein expression. METHODS Spinal cord ischemia was induced by means of balloon occlusion of the infrarenal aorta for 15 minutes at 39 degrees C in 18 New Zealand white rabbits. At 1, 3, and 7 days after reperfusion, 6 animals at each time point were killed, and the spinal cord was removed for histologic and immunohistochemical study. The variables analyzed were (1) neurologic function (Johnson score) at every 24 hours after reperfusion, (2) the number of intact motor neurons and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick-end labeling-positive positive neurons, and (3) expression of glial fibrillary acidic protein in the gray and white matter, which was expressed as the percentage of stained area. RESULTS All animals presented delayed motor neuron death. The number of intact neurons decreased correlatively with neurologic function. No obvious terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick-end labeling-positive cells were observed. Glial fibrillary acidic protein expression increased with time in both the gray and white matter, representing the development of reactive astrogliosis. Significant correlation was found between glial fibrillary acidic protein expression and the number of intact motor neurons on the third day in both the gray (r(2) = 0.726, P = .031) and white (r(2) = 0.927, P = .002) matter. CONCLUSIONS Reactive astrogliosis 3 days after transient spinal cord ischemia correlates with the number of intact motor neurons. Our method for semiquantitative analysis of reactive astrogliosis is simple and reproducible and seems useful for such experimental studies.

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.

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.

Volume-rendering and endocardial views of partially unroofed coronary sinus with 64-slice multidetector CT

We diagnosed unroofed coronary sinus preoperatively by the 3D volume rendering and endocardial views with 64-slice MDCT, and those clearly showed the defect of the roof of the coronary sinus and the relationship with the surrounding structure. MDCT is a good non-invasive tool for the evaluation of unroofed coronary sinus, and the reconstructed endocardial view is useful for preoperative surgical planning.