Takeki Ohashi

Inhibition of Na+/H+ exchanger attenuates neutrophil-mediated reperfusion injury

BACKGROUND The effect of Na+/H+ exchange inhibition in neutrophil-induced reperfusion injury was investigated using a new amiloride analogue, 5-methyl-N-isobutyl amiloride (MIA). METHODS Rat neutrophils were separated using Percoll gradient. Luminol chemiluminescence intensity of isolated neutrophils was depressed by MIA in a dose-dependent manner. RESULTS The effect of MIA on neutrophil-induced reperfusion injury was evaluated in Langendorff-perfused rat hearts subjected to 30 minutes of normothermic ischemia. Postischemic left ventricular developed pressure recovery was depressed by the reperfusion with neutrophils (60% +/- 7% to 33% +/- 26%) and was reverted by MIA pretreatment (86% +/- 17%, p < 0.05). MIA also improved percent recovery of coronary flow (51% +/- 2% to 70% +/- 13%), reduced creatine kinase (0.28 +/- 0.1 to 0.085 +/- 0.03 IU.L-1.g-1 dry wt), and lactate dehydrogenase leakage (10.6 +/- 3.8 to 5.16 +/- 1.3 IU.L-1.g-1 dry wt) significantly. The incidence of reperfusion-induced ventricular fibrillation also was reduced by MIA. CONCLUSIONS The inhibition of Na+/H+ exchange shows a protective effect against neutrophil-induced reperfusion injury possibly by inhibiting the activation of neutrophils.

Ventricular Septal Perforation Caused by Right-Sided Infective Endocarditis Associated With Giant Vegetation

A 71-year-old man presented with general fatigue associated with syncope and fever, and was admitted to our hospital and treated with antibiotics for pneumonia. On day 10 after admission, cardiac echocardiography showed a ventricular septal perforation and giant vegetation floating in the right ventricle near the tricuspid valve, which had not been detected at the time of admission. An emergency operation (including vegetation excision, debridement, ventricular septal perforation patch closure, and tricuspid valve replacement) was performed. A permanent pacemaker was implanted on postoperative day 34, and the patient was discharged without any complications. A culture of the excised vegetation and blood culture revealed methicillin-susceptible Staphylococcus aureus. There has been no previous report of a presenting ventricular septal perforation caused by right-sided infective endocarditis.

Congenital pericardial defect with ruptured acute type A aortic dissection

We report 2 cases of congenital pericardial defect with ruptured acute type A aortic dissection. Case 1: An 83-year old man presented with sudden chest and back pain, and computed tomography (CT) showed acute aortic dissection with left pleural massive effusion. Because of his unstable haemodynamic condition with low blood pressure, an emergency operation was performed. We observed small amounts of bloody pericardial effusion, massive left-sided bloody pleural effusion and a partial left-sided pericardial defect of the pulmonary artery. The ascending aorta was replaced. The postoperative course was uneventful. Case 2: A 79-year old man presented with fainting followed by cardiac arrest and was resuscitated. Chest CT showed acute aortic dissection and massive haemothorax. Emergency operation was attempted, but was given up. We observed partial left-sided pericardial defect of the pulmonary artery. Further, we reviewed 6 cases of congenital pericardial defect with ruptured acute aortic dissection, including our 2 cases. In all the cases, the patients did not develop cardiac tamponade but had massive haemothorax due to congenital pericardial defects leading to confusion in diagnoses and surgical strategies. Therefore, it may be necessary to consider congenital pericardial defects before performing an operation in case of acute type A aortic dissection with massive haemothorax.

Cardiogenic shock without cardiac tamponade caused by a subepicardial hematoma after percutaneous coronary intervention

A 73-year-old man complaining of pain on effort was admitted to a hospital for a percutaneous coronary intervention (PCI) because of severe stenosis of the mid right coronary artery. During PCI, a coronary artery was ruptured, and the patient suddenly went into shock. Percutaneous pericardiocentesis was successfully performed, and cardiac tamponade was relieved. Despite the echocardiographic finding of no cardiac tamponade, the patient remained in the shock state. An emergency operation was performed. There was little pericardial effusion, but a large subepicardial and intramyocardial hematoma was present and was being compressed by the pericardium. Pericardial incision and off-pump coronary artery bypass grafting were performed. The patient was discharged on the 12th postoperative day. Decompression of the subepicardial hematoma by pericardiotomy ameliorated the condition of the patient, who was in cardiogenic shock. We thus report a rare case of subepicardial hematoma resulting in shock during PCI in which cardiac tamponade was not observed.

Emergency Pulmonary Embolectomy Using Minimally Invasive Cardiac Surgery

A 78-year-old man who had undergone operation for acute type A aortic dissection presented with dyspnea and shock. Chest computed tomography revealed pulmonary embolism. Minimally invasive cardiac surgery was performed through a right fourth intercostal skin incision using cardiopulmonary bypass through the right femoral artery and vein. The right pulmonary artery below the superior vena cava was incised vertically, and the thrombus was extracted directly by balloon catheter. The patient was weaned off cardiopulmonary bypass uneventfully. The postoperative course was also uneventful. In redo cardiac surgery, pulmonary embolectomy through minimally invasive right thoracotomy can be easily performed, with quick recovery.

Fistula between the Thoracic Duct and an Unusual Vessel Aneurysm Branching Off the Abdominal Aorta Revealed by Aneurysm Rupture: A Case Report

Fistulas between an aneurysm branching off the abdominal aorta and the thoracic duct are rare. We report a case of aneurysmal-thoracic duct fistula diagnosed by angiography when aneurysm ruptured, and we successfully treated by catheter embolization. A 42-year-old man was referred to our hospital with a chief complaint of sudden back and chest pain. Computed tomography showed both post-mediastinal and retroperitoneal hematomas, with the aneurysm from the aorta being connected to the thoracic duct. After confirming the aneurysmal-thoracic duct fistula by angiography, we performed embolization of the aneurysm. The patient has remained well for 3 postoperative months, to date.

Oblique venotomy with parallelogram anastomosis in sequential bypass grafting

The proximal vein graft is incised obliquely and anastomosed to the coronary artery to ensure that the proximal rim of the vein incision is adjusted to the lateral side of the coronary artery incision adjacent to the proximal rim. So the vein graft can be placed perpendicular to the coronary artery without kinking, and the anastomosis orifice can be made wider than those made with diamond anastomosis. Oblique venotomy with parallelogram anastomosis provides sufficient anastomotic flow, allows long incisions, and prevents kinking.

Mitral and tricuspid valve surgery for Coffin–Lowry syndrome

Coffin–Lowry syndrome is a rare X-linked disorder characterized by craniofacial and skeletal abnormalities, mental retardation, short stature, and hypotonia. An 18-year-old man with morphologic features characteristic of Coffin–Lowry syndrome was referred to our institution for valve disease surgery for worsening cardiac failure. Echocardiography showed severe mitral valve regurgitation associated with tricuspid valve regurgitation. Mitral valve implantation with a biological valve and tricuspid annular plication with a ring was performed. The ascending aorta was hypoplastic. Both the mitral papillary muscle originating near the mitral annulus and the chordae were shortened. The patient’s postoperative course was uneventful and his cardiac failure improved.

Clinical application of recombinant human SOD for the prevention of ischemia-reperfusion injury during open heart surgery

We have applied recombinant human superoxide dismutase (RH-SOD) to prevent ischemia reperfusion injury in the patients who received open heart surgery. Twenty-four patients were divided into 2 groups; group A had no treatment as control and group B received bolus injection of RH-SOD (35,000 IU/kg) into cardiopulmonary bypass 5 minutes before reperfusion. Arterial and coronary sinus blood was collected to measure chemiluminescence (ChL) value, SOD activity, lactate and pyruvate level, and several parameters of myocardial oxygen metabolism after reperfusion. Arterio-venous difference of ChL value showed the tendency of less ChL generation of the heart in group B compared with those in group A. But no other parameters showed significant difference between the two groups. Our data suggested that this way of the administration of RH-SOD failed to improve the myocardial protection during open heart surgery. Further investigation, such as dose response study, might be required to determine whether RH-SOD possess beneficial effects or not in the clinical setting.