A Surgical Approach for Aortic Valve Replacement in a Patient with a Functional Right Internal Thoracic Artery Graft Located Close to the Posterior of the Sternum / 日本心臓血管外科学会雑誌

A 78-year-old woman who had undergone triple coronary bypass grafting with the right internal thoracic artery (RITA) to the left anterior descending artery 8 years previously was referred to our hospital because of heart failure due to progressive aortic valve stenosis. Coronary angiography showed that all of the coronary grafts were patent, and multidetector-row computed tomography demonstrated the functional RITA graft located close to the posterior of the sternum at the level of the second costal cartilage. To prevent injury of the RITA graft, we initially performed an inverted-L-shaped partial sternotomy extended to the right second intercostal space. After institution of peripheral cardiopulmonary bypass, we performed careful removal of adhesions along the posterior of the sternum under decompressed conditions and accomplished resternotomy safely. The patent internal thoracic artery grafts were never dissected and the patient was cooled to a rectal temperature of 22°C. After aortic crossclamping, myocardial arrest was obtained with systemic hyperkalemia by instilling 40 mEq of potassium chloride into the cardiopulmonary bypass circuit and we successfully performed aortic valve replacement. This method is an alternative approach for re-do cardiac surgery after previous bypass grafting in patients with a functional RITA graft located close to the posterior of the sternum.

Mid-Term Results of Entry Closure for Chronic Type B Dissecting Aortic Aneurysm / 日本心臓血管外科学会雑誌

We performed entry closure for the chronic type B dissecting aneurysms by open surgical procedure or endovascular stent-graft placement. The purpose of this study is to evaluate the mid-term results of these patients with respect to mortality, morbidity, change of aneurysm diameter and outcome of the false lumen. From 1996 to 2003, entry closure was performed on 8 patients with chronic dissecting aortic aneurysm with an entry site in the descending aorta and visceral arteries that originated from the true lumen. The study population consisted of 4 men and 4 women with a mean age of 63.8±10.9 years. One patient had a DeBakey type III a and 7 patients had a DeBakey type III b dissecting aneurysm. Five patients underwent surgical entry closure and 3 patients underwent endovascular stent-graft placement. The mean follow-up period was 40±29 months. No operative mortalities, complications of paraplegia or visceral ischemia occurred. A leak was identified in 3 patients, 1 patient underwent an open repair with descending aortic replacement and 1 patient required additional stent-grafting. In the follow-up period, 1 patient died of cancer, but there were no dissection-related mortalities or re-operations for increase in size. With the exception of 1 case with a graft replacement, complete thrombosis of the thoracic aortic false lumen was achieved in 6 cases. There were no significant differences in the pre- and postoperative aortic diameter. Overall, complete thrombosis of the thoracic aortic false lumen was achieved with a high rate of success without a dissection-related mortality. Long-term follow-up, however, is necessary because a reduction in size did not occur in some cases.

A Case of Combined Valvular Disease with Tricuspid Valve Stenosis / 日本心臓血管外科学会雑誌

A 63-year-old woman was admitted to our hospital for combined valvular disease with tricuspid valve stenosis. Aortic and mitral valves were replaced with artificial valves and tricuspid valve were replaced with a biological valve. We chose artificial valves for the aortic and mitral valves because the patient was younger than 70, while a biological valve was used for the tricuspid valve to avoid possible thromboembolism. The postoperative course was excellent. We propose that it is better to use a biological valve for the tricuspid valve, even if artificial valves are used in other sites.

An Alternative to Total Arch Replacement for Type A Aortic Dissection / 日本心臓血管外科学会雑誌

The total arch replacement protocol using the open-style stent-graft placement is frequently performed for type A aortic dissection to obtain complete closure of entry sites. However the open-style stent-graft placement must be carefully planned when the entry site is in the descending aorta and extends beyond the level of the tracheal bifurcation, because spinal cord ischemia can be caused due to occlusion of lower thoracic intercostal arteries. We report an alternative to total arch replacement for type A aortic dissection with entry in the ascending aorta and aneurysmal re-entry in the descending aorta, beyond the level of the tracheal bifurcation. We inserted a guide-wire from the dissected area of the aortic arch towards the normal region beyond the re-entry in the descending aorta, with confirmation by direct ultrasonography and already incised half, introduced a graft into the descending aorta using the wire as a guide and performed anastomosis at the level of the transverse aortotomy in the inclusion method. This operation has the advantage of preventing spinal cord ischemia because the re-entry site in the descending aorta is confirmed by direct ultrasonography and the distal anastomosis does not reach the lower thoracic intercostal arteries. In this method, by which the prosthesis is introduced through the descending aorta and anastomosed in the inclusion method, is not needed troublesome treatment in the descending aorta and less invasive than conventional single-stage total arch replacement and applicable with the great safe for aortic dissection that had shown difficulty in application of open-style stent-graft placement.

Postoperative Hemodynamic Performance after Aortic Valve Replacement Using the Carpentier-Edwards Pericardial Valves / 日本心臓血管外科学会雑誌

Postoperative hemodynamic performance after aortic valvular replacement using the Carpentier-Edwards pericardial valve of 19-mm (group A, 10 cases) or 21-mm (group B, 5 cases) was compared with that using the 19-mm St. Jude Medical hemodynamic plus (group C, 13 cases). We evaluated hemodynamic performance by measuring the peak pressure gradient via aortic valve using Doppler echocardiography. Preoperative peak pressure gradients were 80±18.5mmHg in A, 81.6±17.5mmHg in B and 87±36.3mmHg in C. Valvular replacement obviously improved the hemodynamic performance by decreasing the postoperative peak pressure gradient to 24.2±7.3mmHg in A, 14.2±6.2mmHg in B and 26.7±19.0mmHg in C, though no statistically significant difference was present among the three groups. We also applied the dobutamine stress test for 5 cases in group A, 4 in B and 4 in C, who could receive the additional examination. The amount of dobutamine given was 8.2±1.6μg/kg/min in A, 7.2±2.0μg/kg/min in B and 7.7±1.5μg/kg/min in C. Before administration of dobutamine, the peak pressure gradient was 18.1±4.3mmHg in A, 14.2±6.2mmHg in B and 20.9±5.7mmHg in C. Although administration of dobutamine increased the peak pressure gradient to 41.1±15.0mmHg in A, 32.2±9.8mmHg in B and 46.8±14.4mmHg in C, there was no significant difference among the groups. The Carpentier-Edwards pericardial valve of 19-mm and 21-mm thus provided satisfactory valvular function compared with the 19-mm St. Jude Medical in terms of hemodynamics. Therefore, it is concluded that the Carpentier-Edward pericardial valve is a reliable alternative for elderly patients.