Off-Pump Coronary Artery Bypass Grafting for an Unstable Angina Pectoris Complicated by Heparin-Induced Thrombocytopenia Diagnosed after Introducing Hemodialysis / 日本心臓血管外科学会雑誌

<p>A 53-year-old man was urgently hospitalized with chronic renal failure, congestive heart failure, pulmonary edema, and pneumonia. He received respiratory support and dialysis after hospitalization in the intensive care unit. Coronary arteriography revealed an old myocardial infarction and unstable angina (triple vessel disease). Surgery was planned. However, after dialysis under heparin administration, clot formation was noted in the dialyzer. Serological tests confirmed the presence of antibodies to heparin-platelet factor 4 complex ; accordingly, heparin-induced thrombocytopenia (HIT) was diagnosed. Coronary artery bypass surgery should preferably be performed early in the case of coronary artery disease. However, surgery during the acute phase of HIT when antibodies to heparin-platelet factor 4 complex (HIT antibodies) are present is associated with a very high risk of developing thromboembolism. There is no criterion regarding the optimal timing for surgery when HIT antibodies are present. Therefore, clinicians are often confused about this. In cases where the platelet count, D-dimer level, fibrinogen degradation product (FDP) level, and fibrinogen level improve, thrombin production due to HIT antibodies is thought to decrease. We considered that the improvement in these values suggests that the number of HIT antibodies decreases and thus HIT antibody activity would be reduced. We evaluated the platelet count, D-dimer level, FDP level, and fibrinogen level over time and accordingly determined the optimal timing for surgery. In the present case, argatroban administration was started after HIT developed, and the platelet counts increased gradually ; the D-dimer and FDP levels decreased, whereas there were no significant changes in the fibrinogen levels. Although HIT antibodies were still present, we performed off-pump coronary artery bypass grafting under the administration of argatroban when the platelet count, D-dimer, and FDP values improved. The patency of coronary bypass grafts was confirmed postoperatively ; the patient did not develop thromboembolism during the perioperative period and was discharged without complications. When HIT antibodies are present, an improvement in platelet count, D-dimer, and FDP values is thought to be useful in determining the optimal timing of surgery.</p>

Successful Treatment of a Rapidly-Expanding Infected Thoracic Aortic Aneurysm with <i>Streptococcus pneumonia</i> / 日本心臓血管外科学会雑誌

An 83-year-old woman who had an attack of fever, fatigue, and lumbar pain was hospitalized as an emergency. Detailed investigations revealed that she had urinary infection, infectious spondylitis, and bacteremia with <i>Streptococcus pneumonia</i>, for which she received antimicrobial therapy. After 12 days in hospital, enhanced computed tomography showed that the aortic arch had expanded, with fluid collection. Though there had been no imaging findings by computed tomography scan on admission. We thought this was an infected thoracic aortic aneurysm with <i>Streptococcus pneumonia</i>, and continued to administer the antibiotic drugs for infection control. After 14 days in hospital, she developed hoarseness and complained of severe back pain. Emergency computed tomography scan showed that the aortic arch had further expanded to 66 mm in size and that much more fluid had collected. We decided it was an impending rupture of the rapidly-expanding infected thoracic aortic aneurysm, and we then performed an emergency operation. The infected portion of the thoracic aorta was resected. The ascending, arch, and descending portions of the aorta were replaced with rifampicin-bonded synthetic graft, and then omental wrapping was performed. Antimicrobial administration was continued after surgery. The postoperative course was uneventful. The infection was successfully controlled. She was discharged without complications. No signs of recurrent infection have been observed for 1 year and 6 months after operation.

A Case of Left Ventricular Rupture during Mitral Valve Reconstruction / 日本心臓血管外科学会雑誌

Left ventricular rupture is one of the critical complications that can occur during cardiac surgeries, often during a mitral valve replacement. We report a case in which we encountered a left ventricular rupture during a mitral valve reconstruction after completing use of a cardiopulmonary bypass. A 58-year-old man was found to have a cardiac murmur during a health check-up, and visited a nearby hospital where he was given a diagnosis of severe mitral valve regurgitation due to a prolapsed mitral valve by an echocardiographic examination. Under a median sternotomy, a cardiopulmonary bypass was established, and we reconstructed chordae tendineae with Gore-Tex suture and placed an annuloplasty ring to repair the mitral valve. Weaning from the cardiopulmonary bypass was simple, but bleeding inside the pericardium increased during the following hemostasis and we found an oozing area in the left ventricular posterior wall, which was diagnosed as a left ventricular rupture. The patient was placed back on cardiopulmonary bypass, and we closed the ruptured area by tucking it with felt strips while the heart was beating and reinforced it with a fibrin sheet, PGA sheet, and fibrin glue. We then inserted IABP. The hemodynamic condition was stable afterwards and IABP was removed on the 7th day. The patient developed an atrial flutter on the 13th day, which was drug resistant, and we performed a radiofrequency ablation. The patient fully recovered and was discharged on the 44th postoperative day. Considering factors such as excess resection of papillary muscle, failure of mitral loop due to a resection of papillary muscle, excess resection of annulus tissue, excess traction of papillary muscle, damage to the left ventricular inner wall by suction tubes, or excess load on the left ventricle when removing a cardiopulmonary bypass as possible causes, we think very careful maneuvers are required and important even in a mitral valve reconstruction.

Three Cases of Right Atrial Separation for Chronic Atrial Fibrillation with Atrial Septal Defects / 日本心臓血管外科学会雑誌

Atrial fibrillation is common in adults with atrial septal defect. A right atrial separation procedure was performed for the ablation of atrial fibrillation during the concomitant repair of atrial septal defect. The operation was performed under cardiopulmonary bypass. A Y-shape incision was made in the right atrium, followed by cryoablation of the tricuspid annulus and the atrial septum. After the operation, all three patients recovered and maintained a normal sinus rhythm during follow-up periods of 12, 4, and 1 months. This is a simple and effective procedure for the elimination of chronic atrial fibrillation associated with atrial septal defects in adults.