Katsuhisa Onoguchi

Hemodynamic evaluation of 19-mm Carpentier-Edwards pericardial bioprosthesis in aortic position

BACKGROUND The aortic Carpentier-Edwards pericardial bioprosthesis offers good long-term clinical outcomes with a low rate of structural deterioration. However, little in vivo hemodynamic data is available for this bioprosthesis. METHODS To determine the hemodynamic performance of the 19-mm Carpentier-Edwards pericardial valve, both cardiac catheterization and dobutamine stress echocardiography were electively performed in 10 patients. The mean age at the study was 71.6 +/- 4.4 years and the mean body surface area was 1.39 +/- 0.11 m2. The peak-to-peak gradient, instantaneous peak gradient, mean gradient, and valve orifice area were measured by standard cardiac catheterization. The Doppler-derived gradients and valve orifice area were also measured both at rest and during dobutamine infusion. RESULTS The average peak-to-peak gradient, instantaneous peak gradient, mean gradient, and valve orifice area measured by catheterization were 13.0 +/- 5.4 mmHg, 28.5 +/- 7.7 mmHg, 12.0 +/- 4.9 mmHg, and 1.55 +/- 0.45 cm2, respectively. The peak and mean Doppler gradients, and valve orifice area by resting echocardiography were 27.7 +/- 9.5 mmHg, 12.3 +/- 4.8 mmHg, and 1.39 +/- 0.26 cm2, respectively. At a dosage of 10 microg/kg/min of dobutamine, the mean Doppler gradient rose mildly to 22.2 +/- 4.8 mmHg, while the cardiac output increased from 4.49 +/- 0.44 to 6.64 +/- 0.87 L/min. The valve orifice area during the 10 microg/kg/min dobutamine infusion (1.55 +/- 0.25 cm2) was significantly larger than its value at rest (p < 0.05). CONCLUSIONS With acceptable hemodynamic performance, use of the aortic 19-mm Carpentier-Edwards pericardial valve is a reliable option for elderly patients with a small annulus.

Right atrial myxoma complicated with pulmonary embolism

A 25-year-old woman was admitted to our hospital with chest pain and dyspnea, and was diagnosed as having a right atrial myxoma complicated with pulmonary embolism. An emergency operation was performed with cardiopulmonary bypass. A papillary pedunculated tumor was found having a narrow-based attachment to the free atrial wall. After the tumor was carefully removed together with the atrial wall around the attachment, pulmonary embolectomy was performed. Several fragments of the tumor were removed, and sufficient back-flow from the pulmonary artery was established. The postoperative course was uneventful. However, a non-perfused area was observed in the left lower lung on pulmonary hemodynamic scintigraphy at 3 months after the operation. Long-term observation is required due to the high risk for metastasis and recurrence, and further surgical treatment remains the most appropriate treatment option. A second operation may be needed to prevent progression in complications.

Congenital mitral regurgitation from absence of the anterolateral papillary muscle

A 21-year-old woman had congenital mitral regurgitation. Echocardiography showed absence of the anterolateral papillary muscle and corresponding marginal chordae. This rare abnormality was corrected by anterolateral commissural annuloplasty and insertion of artificial chordae to prevent prolapse of the anterior leaflet. Postoperatively, there was no regurgitation, and an appropriate mitral valve area was achieved.

Cardioscopic guidance of linear lesion creation for radiofrequency ablation

BACKGROUND The broad use of catheter ablation of atrial fibrillation is limited by the difficulty inherent in creating transmural linear lesions under fluoroscopy. Therefore, we evaluated cardioscopy as a more accurate method of guiding the catheter for the placement of linear lesions. METHODS Nineteen swine underwent endocardial ablation to create linear conduction block lesions in the right atrium under cardioscopy (group I, n = 13) or fluoroscopy (group II, n = 6). In both groups, the linear lesion was created between the superior and inferior vena cava, perpendicular to hexapolar electrodes placed on the epicardial surface. Each swine received two pairs of epicardial hexapolar electrodes: one pair to measure the conduction delay time across the ablated line and another pair for pacing. The time spent to complete the ablation, number of trials and effective ablations, ratio of effective ablations to trials, length of the lesion, conduction delay under pacing, and postmortem pathology were compared between the two groups. RESULTS Statistically significant differences were found for the time required for ablation, ratio of effective ablation to total number of trials, and conduction delay. Histologic analysis revealed more homogenous, continuous lesions in group I. CONCLUSIONS Cardioscopy facilitated the placement of a conduction block line more efficiently than ablation performed under fluoroscopy. Landmarks of tissue relevant to ablation are readily visualized by cardioscopy. Moreover, cardioscopy can be useful for the development of a guiding catheter for the ablation of atrial fibrillation.

Patient-prosthesis mismatch may be irrelevant after aortic valve replacement with the 19-mm Perimount pericardial bioprosthesis in patients aged 65 years or older.

The prevalence of patient–prosthesis mismatch (PPM) and its influence on clinical midterm results were examined in elderly patients whose activity was supposed to be less than that of younger patients. We evaluated valve function and the effects of PPM on the midterm results of the 19-mm Carpentier–Edwards Perimount (CEP) pericardial aortic valve in patients aged 65 years or older. Between August 1996 and May 2005, 51 patients underwent aortic valve replacement with the 19-mm CEP valve. The mean follow-up was 2.4 ± 1.8 years, involving a total of 134.4 patient-years. The mean age and body surface area at operation were 74.0 ± 5.0 years and 1.41 ± 0.14 m2. There were two (3.9%) operative deaths. Three patients (5.9%) underwent enlargement of their small aortic annuli. The actuarial survival rate at 8 years, including operative mortality, averaged 90.2% ± 4.7%. The freedom from thromboembolism, reoperation, and valve-related mortality averaged 75.0% ± 21.7%, 97.8% ± 2.2%, and 95.3% ± 3.2%, respectively, at 8 years. High preoperative peak and mean transvalvular pressure gradients were significantly improved after the operation (peak, 93 ± 35 versus 28 ± 12 mmHg; mean, 58 ± 19 versus 17 ± 7 mmHg, respectively; P < 0.01). The mean left ventricular mass index was reduced from 192 ± 44 to 142 ± 46 g/m2 at late follow-up (P < 0.01). The prevalence of PPM was low (17.6%) when an indexed effective orifice area of less than 0.85 cm2/m2 was taken as the definition of PPM. The clinical results, postoperative pressure gradients, and reduction in left ventricular mass index were not different between the PPM and no-PPM groups. The 19-mm CEP valve produced satisfactory midterm clinical outcomes in patients aged 65 years or older whose activity was supposed to be less than that of younger patients, regardless of the presence or absence of PPM. Moderate PPM was rare and it did not adversely impact on the midterm results. The application of annulus enlargement could be limited to the small number of patients for whom the 19-mm CEP valves are not able to be inserted.

Chronic dissecting aneurysm of the thoracic aorta following minor blunt trauma.

A 64-year-old man admitted for treatment of a thoracic aneurysm had experienced severe back pain 10 years earlier after falling heavily on his forearms. From the night following the fall, hoarseness and pleuritic chest wall pain continued for about 3 months. Preoperative imaging showed a chronic dissecting aneurysm near the aortic isthmus. The patients history suggested that the fall 10 years before surgery was the most likely cause.

Aortic valve repair with autologous pericardium for traumatic aortic valve regurgitation

We present a case of successful aortic valve repair for traumatic aortic valve regurgitation. A 26-year-old male who had a history of motor-cycle accident months prior to admission, was referred to our hospital for surgical treatment of severe aortic valve regurgitation. Intraoperative inspection revealed a tear in noncoronary cusp, with otherwise preserved valvular anatomy. Aortic valvuloplasty was successfully performed with closure using an autologous pericardium patch. Intraoperative transesophageal echocardiogram confirmed absence of residual regurgitation.

Jaundice After Surgery for an Aortic Arch Aneurysm

A 57-year-old patient who developed hyperbilirubinemia after surgery for an aortic arch aneurysm subsequently suffered pseudomonas sepsis. Low-volume biliary drainage from the common bile duct was colorless. A disturbance in the livers excretory system caused jaundice. Sepsis and jaundice were resolved when hepatic excretory function recovered.

Improved hemostasis with the combination of a heparin-coated circuit and aprotinin prime during open-heart surgery: potentiating effect on platelet preservation

Aprotinin administration with or without a heparin-coated circuit is expected to modulate subclinical plasma coagulation and fibrinolysis and platelet function during cardiopulmonary bypass. We studied the effect of the application of both, either one, or neither of an aprotinin prime (100 million KIU) and heparin-coated circuit in 32 consecutive patients undergoing coronary artery bypass surgery randomly divided into four groups of 8 patients each. Aprotinin was not used with the non-heparin-coated circuit in the control group. Levels of fibrinopeptide A were significantly lower in the heparin-coated circuit groups (P<0.05–0.01), irrespective of an aprotinin prime. D-dimer levels in the control group were significantly higher than in the other groups (P<0.05–0.01). The preservation rates of platelet count and function (acceleration of coagulation by platelet activating factor) in the control group were significantly lower than in the other three groups (P<0.05–0.01). Platelet preservation in the aprotinin plus heparin-coated group was significantly better than in the aprotinin only and the heparin-coated only groups (P<0.05). The amount of mediastinal drainage and the units of blood transfusion were significantly reduced in the two aprotinin groups, irrespective of heparin-coated use (P<0.01). The values in the aprotinin plus heparin-coated group were significantly less than the values in the heparin-coated only group (P<0.05). The heparin-coated circuit was beneficial for suppressing subclinical plasma coagulation and fibrinolysis and for preserving platelets. Addition of the minimal-dose aprotinin prime further preserved about a further reduction in postoperative blood loss and blood requirements.

One-Staged Surgical Treatment for Multiple Aortic Aneurysms.

1986年1月から1991年12月までの6年間に当科で施行した真性大動脈瘤手術数は214例であり, うち15例 (7%) に重複大動脈瘤を認め, 9例に対し一期的手術を施行した. 補助手段は一時的バイパス4例, 遠心ポンプ4例, 部分体外循環1例で, 入院死および遠隔死を認めず経過は良好であった. 一過性の腎機能障害を一時的バイパス群に認め, 本症例の場合の補助手段としては, 至適灌流量が調節可能な遠心ポンプや部分体外循環が有効と考えられた. 一方, 二期的手術としての初回手術を6例に施行し, うち1例は二期的に他部位の手術を行った. 二期的手術としての初回手術を行い, 残存瘤を外来にて観察中の5例中1例に, 破裂によると思われる突然死を認めた. 重複大動脈瘤症例では全身的な血管病変の存在が予想されるが, risk factor や補助手段を考慮した上での一期的手術は十分可能であり, とくに胸部下行と胸腹部, 腹部などの合併の場合, 手術視野の点などからもほぼ安全に一期的手術が可能であり, 選択されうる術式と考えられる.