George Endo

Inhibition of Development of Abdominal Aortic Aneurysm by Glycolysis Restriction

Objective—The mechanisms underlying abdominal aortic aneurysm development remain unknown. We hypothesized that acceleration of glucose metabolism with the upregulation of glucose transporters is associated with abdominal aortic aneurysm development. Methods and Results—Enhanced accumulation of the modified glucose analogue 18 fluoro-deoxyglucose by positron emission tomography imaging in the human abdominal aortic aneurysm was associated with protein expressions of glucose transporters-1 and -3, assessed by Western blot. The magnitude of glucose transporter-3 expression was correlated with zymographic matrix metalloproteinase-9 activity. Intraperitoneal administration of glycolysis inhibitor with 2-deoxyglucose significantly attenuated the dilatation of abdominal aorta induced by periaortic application of CaCl2 in C57BL/6J male mice or reduced the aneurysmal formation in angiotensin II-infused apolipoprotein E knockout male mice. In monocytic cell line induced by phorbol 12-myristate 13-acetate or ex vivo culture obtained from human aneurysmal tissues, 2-deoxyglucose abrogated the matrix metalloproteinase-9 activity and interleukin-6 expression in these cells/tissues. Moreover, 2-deoxyglucose attenuated the survival/proliferation of monocytes and the adherence of them to vascular endothelial cells. Conclusion—This study suggests that the enhanced glycolytic activity in aortic wall contributes to the pathogenesis of aneurysm development. In addition, pharmacological intervention in glycolytic activity might be a potential therapeutic target for the disorder.

Clinical Outcome of Aortic Valve Replacement With 16-mm ATS-Advanced Performance Valve for Small Aortic Annulus

BACKGROUND Various surgical techniques have been proposed to treat small aortic annulus. We have used small-diameter mechanical valves for small aortic annulus. The present study examined aortic valve replacement with small diameter mechanical valves to determine their effectiveness. METHODS The study included 67 patients who underwent elective, isolated aortic valve replacement with ATS-Advanced Performance (AP) valves (ATS Medical, Inc, Minneapolis, MN) within our department. The patients were divided into two groups; patients receiving the 16-mm AP valve (16-mm group) and those receiving valves 18-mm AP or larger (>16-mm group). RESULTS The mean age of the 16-mm group was significantly higher than that of the >16-mm group. Body surface area was significantly smaller in the 16-mm group than the >16-mm group. We found no significant differences in preoperative conditions between the groups. The effective orifice area index of the mechanical valve was lower in the 16-mm group (0.87+/-0.06 vs 1.12+/-0.13 cm2/m2, p<0.0001). Six patients (40%) in the 16-mm group fell into the category of prosthesis-patient mismatch cases. Although the postoperative pressure gradient was higher in the 16-mm group (33.7+/-12.5 vs 23.16+/-8.78, p<0.01), left ventricular mass index and left ventricular ejection fraction at early and at late follow-up improved from the preoperative period in both groups. We found no significant differences in incidence of postoperative complications, including death. CONCLUSIONS We believe aortic valve replacement with small-diameter mechanical valves (the ATS-AP valves) in patients with a small annulus provides satisfactory remote prognosis. The use of mechanical valves in elderly patients is considered acceptable with strict clinical monitoring to prevent thromboembolism and anticoagulation therapy-induced complications.

A safe automatic driving method for a continuous flow ventricular assist device based on motor current pulsatility: in vitro evaluation.

We previously reported that detection of two specific points (the t-point and the s-point) in the relationship between pump speed and Motor Current Amplitude index (ICA) indicates the safe driving range for a continuous-flow ventricular assist device (CFVAD). During the first stage of the present experiment, the characteristic curves relating pump speed and ICA were determined by varying preload (left atrial pressure: −6 to 30 mm Hg), afterload (total circuit resistance: 890 to 3,180 dyne · sec · cm−5), and contractility of the left ventricle (total circuit flow: 0.5 to 2.1 L/min). These data showed that an ICA value of 0.18 was always located between the t- and s-points. During the second stage of the experiment, we developed an automatic driving program to control pump speed by maintaining ICA at 0.18. This program was able to drive the CFVAD, without exhibiting regurgitant flow or sucking, under various driving conditions in the mock circulation. Pump speed stabilized within 1 minute after varying the drive conditions. This sensorless method of driving the CFVAD by using a target ICA proved feasible and effective for safe automatic control, within our mock circulation.

Aortic Pseudoaneurysm due to Simple Vertebral Compression Fracture Treated with Conservative Management

Blunt aortic injures are rarely associated with minimal trauma. We present a 78-year-old man with an aortic pseudoaneurysm resulting from a simple vertebral compression fracture, which was conservatively managed. He was diagnosed with a compression fracture from a minor fall 10 days previously, and fortuitously he visited the hospital after which follow-up computed tomography (CT) for previous multiple aortic surgeries was performed. The enhanced CT revealed a pseudoaneurysm on the abdominal aorta, which was bleeding from a pinhole perforation. He was conservatively treated and follow-up CT 9 months later revealed that the pseudoaneurysm had disappeared.

Two Dehiscences of the Aortic Valve Commissure and Cusp with Progressive Acute Aortic Regurgitation

A 54-year-old female with acute heart failure due to aortic regurgitation (AR) was admitted to our hospital. Following admission, her condition worsened progressively; thus, surgery was performed prematurely. During surgery, two dehiscences were visualized in the aortic valve commissure between the right and left cusps and the upper part of the left coronary artery ostium. However we scheduled aortic valve replacement (AVR) at first, we made the shift to perform the aortic root replacement for reinforcement of the aortic wall around the left coronary artery ostium. We describe a rare case of two dehiscences at the aortic root, which is the first report.