[Early Structural Valve Deterioration of Bioprosthetic Mitral Valve in a Dialysis Patient].

Choice of prosthetic valve during valve replacement in dialysis patients is still controversial. There is a known risk of early structural valve deterioration of bioprosthesis in dialysis patients, whereas mechanical prosthesis is associated with a higher risk of bleeding and thrombotic events. A 68-year-old dialysis-dependent woman, who had undergone bioprosthetic mitral valve replacement at the age of 66, was admitted to our hospital because of general malaise and hypotension during dialysis. Echocardiography revealed severe mitral stenosis and regurgitation due to restricted motion and dense calcification in prosthetic valve leaflets, which indicated early structural valve deterioration. Redo mitral valve replacement using a mechanical valve was performed, and the patient gradually recovered. However, she eventually died of intracranial hemorrhage three months after the surgery.

[Mitral Valve Replacement and Cardiac Resynchronization Therapy for Mitral Regurgitation with Left Ventricular Noncompaction:Report of a Case].

Left ventricular noncompaction (LVNC) is a rare congenital abnormality resulting from an arrest of the normal process of myocardial compaction. LVNC has been known as a disease of infants, however, some surgical cases of LVNC in adult have been reported. A 61-year-old man who was diagnosed as dilated cardiomyopathy due to LVNC was admitted to our hospital because of dyspnea. Echocardiography revealed severe mitral regurgitation and diffuse left ventricular hypokinesis, and the hypokinetic wall consists of a thin compacted epicardial layer and a thicker noncompacted endocardial layer. Mitral valve replacement using a mechanical valve and cardiac resynchronization therapy were performed. The patient was easily weaned from cardiopulmonary bypass with medium-dose inotropic support and scheduled intra-aortic balloon pumping( IABP). Postoperative course was uneventful, and he was discharged in good condition on the 29th postoperative day.

[Endovascular Repair of Infected Thoracic Aortic Aneurysm whose Shape Changed during Treatment of Infection].

We report a successful case of infected thoracic aortic aneurysm treated by endovascular repair. An 82-year-old woman, presenting with intermittent back pain and low-grade fever, was transferred with the diagnosis of infected thoracic aortic aneurysm. High inflammatory reaction and a thickened aortic wall around the aneurysm confirmed the diagnosis. We performed infection control first because enhanced computed tomography (CT) scanning revealed aneurysm was a low-density mass, which denied aortic pseudoaneurysm or rupture. After administration of broad-spectrum antibiotics, low-grade fever was relieved and inflammatory reactions were decreased. CT performed on the 11th hospital day showed the low-density mass was decreased in size. However, CT performed on the 35th hospital day revealed penetrating atherosclerotic ulcer( PAU) into the low-density mass, which was consistent with saccular aortic aneurysm. The patient underwent thoracic endovascular aortic repair( TEVAR). Postoperative course was uneventful and she was discharged on 22nd postoperative day. Oral administration of antibiotics was continued for 6 months after discharge. Eight months after TEVAR, CT revealed disappearance of the aneurysm. The patient showed no recurrence of infection at 5 years of follow-up.

[Stanford type B aortic dissection associated with coarctation of the aorta].

We report a rare case of type B aortic dissection associated with coarctation of the aorta. A 35-year-old man had sudden dyspnea and severe back pain. Computed tomography revealed aortic coarctation at the distal aortic arch, and aortic dissection below the coarctation. The diameter of proximal descending aorta was enlarged to 52 mm. We electively performed excision of aortic coarctation and descending aortic graft replacement. Coarctation of the aorta has a poor prognosis, The risk of aortic rupture due to aortic dissection is very high, and the histological abnormality is also pointed out. Therefore we should perform aggressive surgical treatment.

[Reconstruction of the posterior mitral annulus using a crescent-shaped collar; a novel technique for mitral valve replacement in the severely calcified annulus; report of a case].

A 74-year-old female who had been on hemodialysis for 4 years developed congestive heart failure. Severe mitral valve stenosis and tricuspid regurgitation were thought to be causes of her heart failure. She underwent a replacement of severely calcified mitral valve and an annuloplasty of tricuspid valve. We excised both mitral leaflets, however, just a 21 mm sizer could pass through the annulus. Because posterior annular calcification was so severe we could not palace sutures. Therefore, we placed noneverted horizontal mattress sutures from the left ventricle to the atrium on the anterior annulus, and everted horizontal mattress sutures on the posterior left atrial wall. A crescent-shaped felt patch was sutured to the posterior left atrial wall for annular reconstruction. Then the prosthetic valve was fixed onto this felt patch, resulting a 25 mm ATS valve was seated successfully at a supraannular position. Although the patient died from a sepsis on postoperative day 14, the prosthetic valve functioned normally without any perivalvular leakage.

Emergency off-pump complete arterial revascularization in a patient with dextrocardia.

We describe complete emergency arterial coronary artery bypass grafting performed on the beating heart of a 73-year-old man with situs inversus totalis and triple-vessel disease. The right internal mammary artery was anastomosed to the left anterior descending artery in situ. The first and second obtuse marginal branches of the circumflex coronary and the posterior descending branch of the right coronary artery were sequentially revascularized using the left internal mammary and radial arteries in situ. The only abnormality was that the position of the heart mirrored that of a normal heart. Beating heart surgery appears to be as safe in patients with dextrocardia as in the general population. However, the position of the surgeon must be reconsidered for optimal handling of stabilizers and to facilitate access to anastomosis sites. Understanding mirror-image coronary arterial anatomy is important for successful surgical outcomes among patients with dextrocardia.

Cardioprotective effects of tetrahydrobiopterin in cold heart preservation after cardiac arrest.

BACKGROUND: It has recently been shown that tetrahydrobiopterin (BH4), an essential cofactor of nitric oxide synthase (NOS), reduces ischemia-reperfusion myocardial injury. The aim of this study was to determine if supplementation with BH4 after cardiac arrest followed by cold heart preservation would exert a cardioprotective effect against ischemia-reperfusion injury. MATERIALS AND METHODS: Isolated perfused rat hearts were subjected to 4 degrees C cold ischemia and reperfusion. Hearts were treated with cold cardioplegic solution with or without BH4 just before ischemia and during the first 5 min of reperfusion period. Effects of BH4 on left ventricular function, myocardial contents of high-energy phosphates, and nitrite plus nitrate were measured in the perfusate, before ischemia and after reperfusion. Moreover, the effect of BH4 on the cold-heart preservation followed by normothermic (37 degrees C) ischemia was determined. RESULTS: BH4 improved the contractile and metabolic abnormalities in reperfused cold preserved hearts that were subjected to normothermic ischemia. Furthermore, BH4 significantly alleviated ischemic contracture during ischemia, and restored the diminished perfusate levels of nitrite plus nitrate after reperfusion. CONCLUSION: These results demonstrated that BH4 reduces ischemia-reperfusion injury in cold heart preservation. The cardioprotective effect of BH4 implies that BH4 could be a novel and effective therapeutic option in the preservation treatment of donor heart after cardiac arrest.

Malignant fibrous histiocytoma of the heart complicated by factor XI deficiency in a Jehovah's Witness patient.

We describe a 16-year-old girl with malignant fibrous histiocytoma (MFH) of the heart complicated by factor XI deficiency. The preoperative diagnosis was left atrial myxoma. We decided to perform the operation owing to a normal bleeding time. Operative findings suggested a malignant tumor. The patient was a Jehovah's Witness, and extensive excision was not performed because blood transfusion was not allowed. We resected as much of the tumor and left atrial appendage as possible. The pathologic diagnosis was MFH. Excessive bleeding was not observed during the operation. Bleeding time helps to determine whether a surgical procedure is indicated in patients with factor XI deficiency.

Diaphragmatic plication in adult patients with diaphragm paralysis after cardiac surgery.

OBJECTIVE: We investigated the benefit of diaphragmatic plication for weaning from mechanical ventilation in these adult patients. PATIENTS AND METHODS: Four patients underwent diaphragmatic plication for difficulty of weaning from mechanical ventilation due to diaphragmatic paralysis. They were all men with an average age of 70.5 +/- 6.3 years. Three of the patients had undergone cardiac surgeries for coronary artery bypass grafting and one patient ascending aortic replacement for pseudoaneurysm after coronary revascularization. Right diaphragmatic plication (muscle sparing procedure) was performed between 30 to 61 days after cardiac surgery. RESULTS: The mean forced tidal volume improved dramatically from 216 to 415 ml after plication in all patients, and it was possible to discontinue mechanical ventilation from 2 to 12 days after plication. One patient with obstructive respiratory dysfunction died from aspiration pneumonia 15 days after plication. However, postoperative tidal volume in this patient improved to 420 ml and he was able to be weaned from ventilatory support five days after plication. The other three patients were discharged between 26 to 58 days after plication and continue to do well without symptoms. CONCLUSION: Diaphragmatic plication is a useful procedure for treatment of diaphragmatic paralysis in adults as well in children.

Type B dissection complicated with subacute visceral ischemia.

A 63-year old man presented with back pain and abdominal pain that worsened after eating. Contrast-enhanced computed tomography revealed type B aortic dissection. Arteriography 20 days after dissection revealed celiac trunk stenosis and the superior mesenteric artery did not arise from the true lumen. Saphenous vein bypass grafting from the right common iliac artery to the superior mesenteric and gastroduodenal arteries was performed. The postoperative course was uneventful and the abdominal symptoms completely disappeared.

Two cases of ventricular tachycardia with congenital left ventricular malformation in an adult.

Two patients without any risk factors for coronary artery disease presented with symptomatic, recurrent, nonsustained ventricular tachycardia. They were found to have a postero-lateral left ventricular aneurysm and diverticulum. Coronary angiography revealed normal coronary arteries. The 12-lead electrocardiogram showed sinus rhythm with frequent premature ventricular contractions. Their nonsustained ventricular tachycardias were reproduced by programmed electrical stimulation and was unresponsive to procainamide, mexiletine, and disopyramide. Aneurysmal resection and cryoablative surgery were performed. The pathological examination of the aneurysmal wall revealed focal defect of muscle fibers in case 1. On the other hand, the wall of case 2 was formed by all three cardiac layers. After surgery, ventricular programmed stimulation was negative, and premature ventricular contraction had disappeared.

Acute postoperative paraplegia complicating with emergency graft replacement of the ascending aorta for the type a dissection.

Postoperative paraplegia complicating with type A dissection is extremely rare. We describe a case of acute paraplegia after emergency graft replacement of the ascending aorta for type A dissection. A 63 year-old hypertensive man presented to hospital with chest pain. A chest computed tomography demonstrated an aortic dissection of the ascending aorta with mild pericardial effusion. Under deep hypothermic circulatory arrest with concomitant antegrade selective cerebral perfusion, the ascending aorta was replaced. The patient regained consciousness six hours after operation, however, he was complicated with paraplegia. All sensation was lost below the level of Th12. The cause of the paraplegia was assumed to be a thrombotic occlusion of costal arteries, which originated from the false lumen. Spinal fluid was drained for three days. Hyperbaric oxygenation therapy was started four days after onset of paraplegia. Fortunately, our patient recovered gradually, and he was doing well and was walking independently at one-year follow-up. (Ann Thorac Cardiovasc Surg 2003; 9: 330-3)

Off-pump redo coronary artery bypass grafting via left thoracotomy.

OBJECTIVE: We evaluated the usefulness of off-pump coronary artery bypass grafting (CABG) via left thoracotomy (LT) in redo coronary revascularization. METHODS: Over the past 23 years, 21 patients (2.3%) underwent redo coronary revascularization in our hospital. The period between the first and the redo surgeries was 9.1+/-4.4 years. They were divided into two groups according to the method of surgical approach in the redo CABG: re-median sternotomy group (RMS group, n=12) and LT group (n=9). RESULTS: In the RMS group, five of 12 patients suffered prolonged postoperative respiratory failure with ventilatory support, and the RMS patients stayed in the hospital for a significantly longer period of time than the LT patients. Four patients (19.0%, 4/21), who were all in the RMS group, died during the hospitalization. In the LT group, there were no hospital deaths and no cases of respiratory failure. CONCLUSION: Redo CABG via LT provided acceptable and satisfactory surgical results. As it is expected that the number of emergency reoperative surgical cases will increase, the LT approach may be useful for rapid exposure of the target coronary artery without causing significant myocardial damage.

Successful management in the case of mesenteric ischemia complicated with acute type a dissection.

We report a case of acute type A dissection with ischemic enterocolitis due to blood flow insufficiency in the superior mesenteric artery. A 67 year-old man, with medicated ischemic heart disease and hypertension, presented to another hospital with chest pain radiating to the back and epigastrium. Contrast-enhanced computed tomography revealed a type A dissecting aneurysm, that extended from the ascending aorta to the left common iliac artery, with a 50-mm diameter in the ascending aorta. Celiac trunk and left renal artery arose from the false lumen, and the superior mesenteric artery (SMA) was compressed by the thrombosed false lumen. Symptoms of acute mesenteric ischemia clearly developed. Then, a large amount of tarry stool (melena) was discharged. First, an emergency saphenous vein bypass was performed from the common iliac artery to the superior mesenteric artery at the orifice of the ileocolic artery where it was free from dissection. Then total arch replacement was performed using cardiopulmonary bypass. The patient's postoperative course was uneventful, and the abdominal symptoms completely disappeared. This case demonstrates that prompt surgical relief of ischemia in major organs is important to save lives in the cases of acute aortic dissection with ischemic complications.