This report documents two rare cases we encountered in which paraplegia developed as a postoperative complication following elective operations for an unruptured abdominal aortic aneurysm (AAA). Case1: A 80-year-old man receiving dialysis therapy was found to have 75% occlusion of the left anterior descending branch by preoperative coronary arteriography but, as the cardiac function was satisfactory, replacement of the aneurysm with a tube graft was performed through a retroperitoneal approach for treatment of the AAA. Symptoms of paraplegia developed immediately following the operation and a diagnosis of anterior spinal artery syndrome was made based on the postoperative MRI findings. Case 2: A 62-year-old man underwent a coronary artery bypass operation (3 sites in 2 branches) using the bilateral internal thoracic artery with the breast beating prior to elective surgery for an unruptured AAA, and subsequently underwent an aneurysm replacement with a Y-graft through a midline incision. At the same time, the celiac artery and superior mesenteric artery cure found to be stenotic at their roots were also bypassed via vascular prostheses to the right arm of the Y-graft. Paraplegia was evident after emerging from anesthesia. In both cases, there were complicating coronary arterial lesions and significant atherosclerotic changes in the thoracic descending aorta. A CT scan demonstrated an artery coursing from the iliolumbar artery, a branch of the internal iliac artery, to the spinal cord in Case 2, indicating that intraoperative clamping of the internal iliac artery might have caused the paraplegia. In patients with marked arteriosclerosis of the thoracic descending aorta, there is the possibility of occlusion of spinal root arteries originating from that affected region. Blood supply to the spinal cord via a collateral vascular route is important in such cases.

This study compared the hemodynamic performance of the Carpentier-Edwards PERIMOUNT Magna bioprosthesis (Magna) with the Carpentier-Edwards PERIMOUNT bioprosthesis (CEP) for aortic valve stenosis (AS). Between January 2005 and May 2010, 164 patients underwent aortic valve replacement for AS with either the Magna (n=68) or the CEP (n=96) at our institute. Patients undergoing a concomitant mitral valve procedure were excluded from this study. The 21-mm Magna and CEP prostheses were the most frequently used during this period. Transthoracic echocardiography was postoperatively performed within 2 weeks. The peak velocity (PV) of the Magna was significantly lower than that of the CEP (2.59±0.36 vs. 2.75±0.47 m/s ; p=0.022). The mean pressure gradient (PG) was not significantly different. For the 19-mm prostheses, the mean PG and PV of the Magna were significantly lower than those of the CEP [16.4±4.5 vs. 19.7±6.4 mmHg ; p=0.034 (PG) and 2.70±0.36 vs. 3.03±0.49 m/s ; p=0.008 (PV)]. The effective orifice area (EOA) of the Magna was larger than that of the CEP [19 mm : 1.29±0.18 vs. 1.11±0.24 cm² (p=0.007) ; 21 mm : 1.46±0.23 vs. 1.42±0.18 cm² (p=0.370) ; and 23 mm : 1.70±0.34 vs. 1.52±0.25 cm² (p=0.134)]. In this study, the EOA of the Magna was approximately 80% of that described in the manufacture's description. Patient-prosthesis mismatch (PPM ; EOA index≤0.85 cm²/m²) was seen in 26.8% of patients with the Magna and in 47.2% of patients with the CEP (p=0.018). Severe PPM (EOA index≤0.65 cm²/m²) was not seen in any patients with the Magna. The EOA of the 19-mm Magna was significantly larger and the mean PG was lower than those of the 19-mm CEP. Compared with the CEP, the Magna significantly reduced the incidence of PPM, and had superior hemodynamic performance.

Acute aortopulmonary artery fistula is a rare but potentially fatal disorder. We encountered a case in which this disorder was successfully treated by urgent total arch graft replacement and repair of the left pulmonary artery. A 74-year-old man was referred to Shizuoka City Hospital with a 2-day history of worsening dyspnea and thoracic aortic aneurysm. The patient had a history of hypertension and dyslipidemia. Physical examination showed diastolic hypotension, marked peripheral coldness, and systolic murmur. Arterial blood gas analysis showed severe metabolic acidosis with base excess of −16 mmol/l. Contrast-enhanced computed tomography (CT) revealed an aortic arch aneurysm on the lesser curvature, almost obstructing the left pulmonary artery. A Swan-Ganz catheter study confirmed severe low-output syndrome and uncompensated congestive heart failure. After amelioration of critically ill conditions with dopamine, milrinone, and carperitide, oxymetry revealed significant left-to-right shunt with Qp/Qs＝3.2 at the pulmonary artery level. Acute aortopulmonary artery fistula was diagnosed and urgent surgery was planned. Transesophageal echocardiography showed systolic shunt flow from the aneurysm into the left pulmonary artery. Surgery was performed through a median sternotomy. Aortic arch graft replacement with a 24-mm Dacron graft and repair of the left pulmonary artery with an equine pericardial patch were accomplished under hypothermic circulatory arrest and selective antegrade cerebral perfusion. Flooding of pulmonary circulation until circulatory arrest was prevented by manual control through the main pulmonary artery incision. Postoperative recovery was uneventful, and the patient is doing well at one year postoperatively.

The 76-year-old woman underwent double bioprosthetic valve replacement for aortic and mitral valve regurgitation without any postoperative complication. About 33 months later, the patient complained of sudden dyspnea and was diagnosed with mechanical hemolytic anemia, severe aortic regurgitant jet collision with stent post (SP) at mitral position and acute heart failure. The cause of mechanical hemolysis was suspected to be a collision of the regurgitant jet due to structural valve deterioration (SVD) with the SP because of the absence of any paravalvular leak (PVL). The externally-mounted bioprosthetic aortic valve was replaced and the inadequate projection of the SP in left ventricular outflow tract was recognized simultaneously. The patient fully recovered from heart failure and hemolytic anemia after surgery. Early SVD of externally-mounted bioprosthetic valves has often been reported, and the eccentric regurgitant jet due to SVD may collide with any sub-valvular structures. We report a rare case of hemolytic anemia due to SVD.