Taisuke Konishi

Left coronary ostial obstruction after aortic valve replacement with a supra-annular aortic valve

We report a rare case of left coronary ostial obstruction after aortic valve replacement with a Top Hat supra-annular aortic valve, which was diagnosed with intraoperative transesophageal echocardiography and successfully treated with an unplanned coronary bypass. The patient was a 76-year-old woman (height 143 cm, weight 44 kg) with aortic stenosis and regurgitation. A 19-mm Top Hat valve was implanted in the supra-annular position because of a small aortic annulus. There was a possibility that the high profile of this prosthesis might block the left coronary ostium. There may be a problem with the use of this prosthesis in patients with small and rigid aortic roots with little compliance. Although the Top Hat valve has a great advantage for small aortic annuli, care in its use should be taken due to possible interference with the coronary ostia.

Excision after chemoradiotherapy of invasive thymoma extending into the right atrium: report of a case.

We report a case of invasive thymoma with intracardiac extension, resulting from the progression of intracaval growth, in a 56-year-old woman. Initially, the patient received two courses of chemotherapy, but the tumor showed only a modest response; however, subsequent radiotherapy reduced the tumor size further and the intracardiac lesion disappeared, making it possible to excise the tumor without cardiopulmonary bypass. Thus, when a thymoma does not respond well, we recommend radiotherapy as another treatment option, because its effects may allow for less invasive and more complete tumor excision.

Endovascular Repair of a False Aneurysm Developing from IgG4-Related Periaortitis during Corticosteroid Therapy.

Immunoglobulin G4 (IgG4)-related disease is a systemic autoimmune disease that can affect various organs. Corticosteroid therapy is generally an effective treatment; however, IgG4-related aortic lesions pose a risk of aortic rupture related to corticosteroid use. Here, we report a case of IgG4-related periaortitis complicated with a false aneurysm during corticosteroid therapy. Although endovascular repair was successfully performed, autoimmune pancreatitis and sclerosing cholangitis emerged after surgery. The multiple lesions associated with IgG4-related disease were resolved through continuous corticosteroid therapy. Our case suggests that both appropriate surgical intervention and continuous corticosteroid therapy are essential for the treatment of IgG4-related periaortitis.

Reducing the dose of contrast medium in angiography by use of a highly sensitive receiver and synchrotron radiation system.

OBJECTIVE Contrast medium causes side effects such as contrast-induced nephropathy, and the dose of contrast medium is a risk factor in their occurrence. To reduce doses of contrast medium, we developed an angiographic system with high definition and high sensitivity and reviewed its effectiveness. The system entails synchrotron radiation, which is characterized by high photon density and straightness of beam that together result in high resolution, and a high-gain avalanche rushing amorphous photoconductor receiver, which is 100 times more sensitive than conventional charge-coupled device cameras. MATERIALS AND METHODS Diluted contrast medium was administered, and angiography of rat hindlimbs was performed with synchrotron radiation and the high-gain photoconductor receiver. The difference in gray-scale value between the background and contrast medium was calculated. Images were evaluated by counting of arteries. RESULTS The difference in contrast at low levels was detected with the high-gain photoconductor receiver but not with the charge-coupled device camera. The photon density of synchrotron radiation with the high-gain photoconductor receiver was one-fifth that with the charge-coupled device camera. The high-gain photoconductor receiver had approximately 5 times the sensitivity of the charge-coupled device camera. CONCLUSION Use of the synchrotron radiation and high-gain photoconductor receiver makes it possible to perform angiography with an extremely low concentration of contrast medium.

Development of FOP-HARP imaging device

The high-gain avalanche rushing amorphous photoconductor (HARP) camera tube achieves ultrahigh-sensitivity by using the avalanche multiplication. The applications of this tube extend beyond broadcasting into other fields. It is attracting a great deal of attention especially for radiation diagnosis, such as synchrotron radiation microangiography, because it can obtain high-resolution and high-contrast images with a low dose of radiation. However, in the present system, a fluorescent screen and the photoconductive film of the HARP tube are connected optically by a lens-coupling method, and low light throughput remains a big problem. To improve the light throughput by using a fiber-coupling method, we applied a fiber-optic plate (FOP) to the substrate of a HARP tube. The FOP consists of three types of glass that have differing hardnesses and elastic coefficients that make it difficult to flatten the FOP surface enough to form the HARP film. We thus introduced a new mechanical polishing method and succeeded in realizing avalanche multiplication in the FOP-HARP tube. The results of shooting experiments by applying the FOP-HARP to the microangiography showed that a spatial resolution of over 20 line pairs/mm was obtained. Moreover, rat femoral arteries of 150-200 μm in diameter could be visualized as motion pictures with a one-fourth lower concentration of contrast material than that needed for ordinary microangiography. Another potential application of the FOP-HARP is an ultrahigh-sensitivity nearinfrared (NIR) image sensor made by fiber-coupling with an image intensifier (I.I.). The image sensor provides highquality images and should be a powerful tool for NIR imaging.

Open surgical repair for a ruptured abdominal aortic aneurysm with a horseshoe kidney.

Horseshoe kidney is a congenital anomaly characterized by medial fusion of the bilateral kidneys. Treatment for an abdominal aortic aneurysm (AAA) with a horseshoe kidney is a technical challenge because of the complex anatomy. We report a successful open surgical repair for a ruptured AAA with a horseshoe kidney. An aortic grafting was performed with division of the renal isthmus through a transperitoneal approach. In the case of a ruptured AAA, quick open surgery is the most reliable treatment. If a horseshoe kidney coexists, transperitoneal approach with division of the renal isthmus provides good surgical field for an aortic grafting.

Bilateral subdural hematoma following aortic root and subtotal aortic arch replacement

We report herein a case of subdural hematoma following aortic root and subtotal aortic arch replacement with selective cerebral perfusion in a 78-year-old woman. Her level of consciousness gradually deteriorated on postoperative day (POD) 2. Subdural hematoma, including fresh bleeding in bilateral frontal and parietal regions, was detected on brain computed tomography (CT) on POD 3. No head injury had been sustained previously. As the brain was not under pressure and disturbance of consciousness improved the next day, she was observed conservatively with follow-up brain CT. The subdural hematoma disappeared within about 2 months. The patient recovered completely and was discharged without sequelae.

Radiopaque Ruler-Guided Frozen Elephant Trunk Technique

Frozen elephant trunk (FET) technique combines open surgery and endovascular repair for extensive thoracic aortic aneurysms. When a FET is inserted into the descending thoracic aorta, it is difficult to confirm its proper positioning. Here we report a radiopaque ruler-guided FET technique. On the basis of preoperative computed tomography, we create a roadmap which shows the relationship between the descending thoracic aorta and vertebrae. During surgery, a radiopaque ruler placed beneath the patients back provides the accurate target position under fluoroscopy. Our technique is effective to prevent spinal cord injury because it avoids an overly deep implantation of a FET.

Right atrial myxoma with a large tumor embolus in the left pulmonary artery

Cardiac myxoma, the most common primary cardiac tumor, usually develops in the left atrium. Right atrial myxomas are rare, especially those accompanied by pulmonary tumor embolism. We describe a case of a right atrial myxoma with a large tumor embolus in the left pulmonary artery. A 74-year-old man was referred to our hospital for the treatment of a right atrial tumor. Upon echocardiography, the right atrial tumor was revealed to have a mobile and tail-like surface projection. In addition, computed tomography showed that an embolus was wedged into the left pulmonary artery. We performed an emergency surgery to remove both the right atrial tumor and the pulmonary embolus. Histopathological examination revealed them both to be myxoma. Right atrial myxoma with a large pulmonary tumor embolus is a serious condition and emergency surgery to remove both cardiac tumors and pulmonary emboli should be performed to avoid the risk of sudden death.

Fatal Gastrointestinal Bleeding Probably Caused by an AortoduodenalFistula Following Surgical Repair of an Inflammatory Abdominal AorticAneurysm during Postoperative Steroid Therapy

We describe a case of fatal gastrointestinal bleeding probably caused by an aortoduodenal fistula following open surgical repair of an inflammatory abdominal aortic aneurysm (AAA) during postoperative steroid therapy. A 71-year old man underwent a graft replacement for an inflammatory AAA. Prolonged elevated C-reactive protein and newly emerged ascites after surgery were improved by oral administration of predonine. The steroid therapy had been continued until 5 months after surgery, when he suffered from fatal gastrointestinal bleeding. We speculated that the gastrointestinal bleeding was caused by an aortoduodenal fistula and discuss the etiology of this condition.