Kazuma Shimura

Surgical Treatment of an Aortoesophageal Fistula Caused by Stent Implantation for Esophageal Stenosis: Report of a Case

An aortoesophageal fistula is uncommon, but almost always fatal. We report a case of an aortoesophageal fistula that developed after stent dilation for an esophageal stricture caused by benign esophagitis. As soon as esophageal hemorrhaging was identified by endoscopy, the patient was transferred to the operating theater; however, the uncontrollable and massive bleeding resulted in pulseless shock. The digestive surgeon put side-clamps on the descending aorta and esophagus and transferred the patient to our hospital. We identified an aortoesophageal fistula, 3.0 mm in diameter, in the descending aorta, and performed a graft replacement of the descending aorta and esophagectomy. It was immediately evident that the edge of the stent had been sticking into the aortic wall, which had caused the fistula. To our knowledge, this is the first report of successful surgical treatment of an aortoesophageal fistula caused by esophageal stent dilatation.

Assessment of the St. Jude Medical Regent Prosthetic Valve by Continuous-Wave Doppler and Dobutamine Stress Echocardiography

BACKGROUND The St. Jude Medical (SJM) Regent prosthetic valve (St. Paul, MN), a recently developed mechanical valve, is an improvement on the conventional SJM valve, having a wider valve area than the SJM HP valve. We evaluated this mechanical valve by Doppler echocardiography and dobutamine stress echocardiography (DSE). METHODS The functions of the SJM Regent valve were evaluated by continuous-wave Doppler echocardiography and DES in 58 cases of aortic valve replacement during a stable postoperative period. RESULTS The peak pressure gradient of the replaced valves sized 17, 19, 21, and 23 mm was 27.5 +/- 11.1, 20.0 +/- 9.8, 15.6 +/- 5.7, and 14.3 +/- 9.1, mm Hg respectively, and the effective orifice area index was 0.97 +/- 0.32, 1.01 +/- 0.29, 1.09 +/- 0.30, and 1.41 +/- 0.54 cm(2)/m(2), respectively, with prosthesis-patient mismatch (PPM) found in 1, 3, 2, and 0 cases for the 17-, 19-, 21- and 23-mm valves, respectively, with a total incidence of 10.3%. In 20 cases, the peak pressure gradient and the effective orifice area index were significantly increased during DSE compared with those at rest. CONCLUSIONS Although the PPM incidence was 6.6%, it was deemed from the data of DSE and clinical symptoms that there were no clinical issues for such cases of PPM in the early and intermediate phases after operation. Particularly, the effectiveness of the 17- and 19-mm valves in patients with a small aortic annulus was demonstrated, confirming the satisfactory functions of the SJM Regent prosthetic valve.

Cardiac Angiosarcoma with Cardiac Tamponade Diagnosed as a Ruptured Aneurysm of the Sinus Valsalva

Primary cardiac angiosarcoma is a rare, diagnostically elusive disease with a poor prognosis. In this report, we describe the case of a 56-year-old woman with a right atrial angiosarcoma. The patient presented with impending cardiac tamponade caused by right atrial perforation, but was misdiagnosed as a ruptured aneurysm of the sinus valsalva based on findings of a continuous murmur and an aorta to right atrium shunt by echocardiography. In the emergent operation that ensued, we found a right atrial perforation and a right coronary artery fistula to the right atrium. Coronary artery fistula is a rare complication of primary cardiac angiosarcoma, and a continuous murmur is also extremely rare as a clinical finding of angiosarcoma. We report the case and review the literature.

Arrhythmia and sleep-disordered breathing in patients undergoing cardiac surgery

BACKGROUND Recently, the role of sleep-disordered breathing (SDB) in cardiovascular disease has attracted attention. In this study, we investigated the influence of SDB on postoperative arrhythmias after cardiac surgery. METHODS AND RESULTS In 89 patients undergoing cardiac surgery, postoperative portable monitoring for SDB and Holter electrocardiography were performed. The primary end-points were the apnea-hypopnea index (AHI) and occurrence of arrhythmia. The secondary end-points were: (1) patient background factors; (2) average heart rate; (3) maximum heart rate (total, daytime, and nighttime); (4) minimum heart rate (total, daytime, and nighttime); (5) minimum SaO(2) during sleep; and (6) an independent predictor for arrhythmia. Twenty-six patients (29.2%) had an AHI≥15 and they were classified into the SDB group, while patients with an AHI<15 formed the non-SDB group (70.8%). Although there was no significant difference in atrial fibrillation, frequent nocturnal premature ventricular contractions were significantly more common in the SDB group (19.2%) than the non-SDB group (3.2%) (p=0.01). Maximum daytime and nighttime heart rates were also significantly higher in the SDB group. AHI was a significant predictor for frequent nocturnal premature ventricular contractions. CONCLUSIONS This study showed that SDB is common among patients undergoing cardiac surgery, and that SDB might be closely associated with arrhythmia in these patients.

Stanford type A aortic dissection with intimal intussusception.

A 51-year-old man presented with acute chest pain and loss of consciousness. Computed tomography showed no intimal flap in the ascending aorta and clear dissection involving the aortic root and arch, as well as the descending aorta. At surgery, the intimal tear was found to be circumferential and dissection extended to the proximal aortic arch with intussusception of the intimal layer. Emergency graft replacement of the ascending aorta was performed successfully and his postoperative course was uneventful.

Experimental investigation of "hANP shot" using human atrial natriuretic peptide for myocardial protection in cardiac surgery.

BACKGROUND We investigated myocardial protection by human atrial natriuretic peptide (hANP) during cardiac surgery without cardioplegia and determined whether suppression of myocardial ischemic reperfusion injury by hANP allows intraoperative aortic cross-clamp time to be prolonged. METHODS AND RESULTS Thirty-two pigs were placed on cardiopulmonary bypass. Experimental pigs were divided into 4 groups: 15 min clamping; hANP 15 min clamping; 30 min clamping; and hANP 30 min clamping. In both hANP groups, a 100 μg dose of hANP was administered after clamping. Left ventricular function, premature ventricular contractions (PVCs), histopathological studies, 8-isoprostane, myocardial Ca(2+), and ATP concentrations were determined. Comparison of the myocardial contractile force indicator E(max), in the 30 min groups, showed a significantly higher recovery rate in the hANP than in the control group. PVC numbers were significantly lower in the hANP than in the control groups for both arrest durations. On microscopic examination, hANP reduced ischemic reperfusion injury in the 30 min groups. The myocardial ATP level was significantly higher in the hANP 30 min than in the control 30 min group. Increases in 8-isoprostane and myocardial Ca(2+) concentrations were significantly inhibited in both hANP groups. CONCLUSIONS This study demonstrated that hANP ameliorates ischemic reperfusion injury, improves postoperative myocardial contractility, and reduces reperfusion arrhythmias. We suggest that hANP allows aortic cross-clamping to be prolonged and thereby exerts a direct myocardial protective effect against cardiac arrest during cardiac surgery.

Ruptured Abdominal Aortic Aneurysm With Left-Sided Inferior Vena Cava

We present a case of ruptured abdominal aortic aneurysm with left-sided inferior vena cava. An 82-year-old man was admitted to our hospital with a sudden onset of severe abdominal pain and loss of consciousness. Computed tomography revealed rupture of an infrarenal abdominal aortic aneurysm and a left-sided inferior vena cava. At surgery, the inferior vena cava was found to cross anteriorly over the abdominal aorta at the usual level of the renal vein. Graft replacement was successfully performed, with careful mobilization and retraction of the inferior vena cava. The patient had an uneventful postoperative course without any deterioration of renal function.

Efficacy of neutrophil elastase inhibitor on type A acute aortic dissection.

BACKGROUND Surgery for type A acute aortic dissection (AAD) is associated with a high mortality and incidence of postoperative complications, including acute respiratory failure and coagulopathy. Aim of the study was to investigate the effects of sivelestat on pulmonary function and coagulopathy in patients undergoing surgery for AAD. METHODS Sixty patients undergoing emergency ascending replacement for AAD were divided into two groups. Group I was administered sivelestat intravenously from the beginning of surgery until extubation. Group II was not treated with sivelestat. The platelet count, antithrombin III (AT III) level, leukocyte count, C-reactive protein (CRP) level, prothrombin time (PT), activated partial thrombin time (APTT), and prothrombin time-international normalized ratio (PT-INR) were measured. RESULTS The postoperative decrease of AT III and the platelet count on admission to the intensive care unit (ICU) and 3 hours later were significantly less in group I. The leukocyte count and the values of CRP, PT, APTT, and PT-INR did not differ significantly between the groups. The duration of mechanical ventilation after surgery tended to be shorter in group I. CONCLUSIONS Sivelestat significantly reduced the postoperative decreases in AT III and platelet count in patients undergoing emergency surgery for AAD.

Intrathoracic left subclavian artery aneurysm: report of a case.

Aneurysms of the intrathoracic subclavian artery are extremely rare. A 74 year-old man was referred to our hospital with an abnormal chest X-ray film. Contrast computed tomography revealed an intrathoracic left subclavian artery aneurysm. Via left 4th posterolateral thoracotomy, the aneurysm was exposed under systemic deep hypothermia and circulatory arrest. The distal arch was replaced with a 26 mm single-branched graft and the left subclavian artery was reconstructed with a 10 mm graft.