A surgical case of prosthetic valve endocarditis with a difficult diagnosis.

Early diagnosis and treatment of prosthetic valve endocarditis (PVE) is important because it has a high mortality rate. We report a case of PVE which was difficult to diagnose. A 36-year-old man, who had undergone an aortic valve replacement (AVR) 7 years prior, was hospitalized with a high fever of unknown origin. We could not detect a stuck valve, vegetations or abscesses using echocardiography, and the peak aortic transvalvular pressure gradient had increased to 81 mmHg. We suspected PVE and initiated intravenous antibiotic therapy immediately. On day 5, echocardiography demonstrated an abnormal shadow directly under the prosthesis, and we definitively diagnosed PVE and performed an operation. Intraoperatively, the prosthesis was not vegetative, but the left ventricular outflow tract was filled with vegetation that was nearly obstructing it. After dissecting the infectious focus, we performed a re-AVR. Postoperative echocardiography showed that the peak left ventricular aortic pressure gradient decreased to 30 mmHg. Obstructive vegetation is difficult to diagnose by preoperative echocardiography.

Clinical management of lower limb ischemia secondary to a persistent sciatic artery aneurysm: report of a case.

A persistent sciatic artery (PSA) is a rare congenital malformation, frequently complicated by atherosclerotic changes such as aneurysmal formation. Optimal treatment is dependent on the individual situation. We report a case of a PSA aneurysm complicated by lower limb ischemia. Graft interposition with distal balloon angioplasty and thrombectomy from the posterior transgluteal approach was performed successfully, without any complications.

Safe approach for redo coronary artery bypass grafting--preventing injury to the patent graft to the left anterior descending artery.

OBJECTIVE: In redo coronary artery bypass grafting (CABG), repeat median sternotomy is a routine approach when the graft to the left anterior descending artery (LAD) is occluded. However, it is important to avoid injury to the patent graft to LAD during repeat sternotomy. We retrospectively reviewed our cases to assess our combined strategy for a safer redo CABG. METHODS: The study group comprised 19 patients (18 men and 1 woman; mean age 67.7 ± 6.9 years) who underwent redo CABG operations from January 2000 to August 2008. All patients had undergone median sternotomy during previous surgery (13 ± 6 years before repeat CABG). Eighteen patients had previous graft occlusion, and 6 had developed new coronary artery disease. Five patients had patent left internal thoracic artery (LITA) and 8 had patent saphenous vein graft (SVG). We attempted to avoid median sternotomy when patients had patent graft to LAD. RESULTS: Median sternotomy (on-pump cardiac arrest) was performed on 13 patients with occluded graft to LAD. For those with the patent graft to LAD, left thoracotomy (on-pump beating) on 4 patients, and 2 patients underwent off-pump CABG via the subxiphoid approach. The mean number of bypass grafts was 2.6 ± 1.2. Internal thoracic arteries, radial arteries, saphenous vein graft, and gastroepiploic arteries were all selected as conduits. The ascending aorta, descending aorta, and previous SVG graft were used as the proximal anastomosis site. There was no graft injury, and 1 patient died as a result of ventricular tachycardia. CONCLUSION: According to the circumstances, conduits and a proximal anastomosis should be selected. For redo CABG patients who have a patent graft to LAD, it is important to choose the optimal approach to avoid injury to the previous patent graft.

Edaravone reduces mitochondrial damage due to reperfusion injury following leg ischemia in rats.

PURPOSE: Free radicals have been implicated in reperfusion injury. It was shown that the free radical scavenger edaravone might suppress reperfusion injury in rat extremities. The present study aimed to elucidate how edaravone suppresses reperfusion injury, focusing on its effect on the mitochondrial structure and glycogen storage in the lower extremity muscles. METHODS: Sixteen male Lewis rats (mean [± SD] weight 497±32 g) were divided into two groups and injected with either 3.0 mg/kg of edaravone (edaravone group, n=8 rats) or the same dose of saline (control group, n=8 rats) into the peritoneal cavity. The rat reperfusion injury models were created by clamping the bilateral common femoral arteries for 5 h, then declamping. The muscles were harvested more than 5 h after the start of reperfusion. The mitochondrial damage, defined as mitochondrial swelling, was examined using a transmission electron microscope at ×30,000 original magnification (n=3 for each rat). Glycogen storage, defined as a positive periodic acid-Schiff stain area, was examined using computerized densitometry (n=5 sections for each rat). RESULTS: The mitochondria in the control group demonstrated marked swelling (mean mitochondrial size = 0.169±0.059 µm(2)). However, the mitochondria in the edaravone group had significantly less swelling (mean mitochondrial size = 0.102±0.036 µm(2); P<0.01). The mean percentage of positive periodic acid-Schiff stain was also significantly higher in the edaravone group than in the control group (51.7±6.8% versus 7.3±2.1%; P<0.01). CONCLUSION: The results suggested that edaravone reduces mitochondrial damage due to reperfusion injury, resulting in a high level of glycogen storage.

Surgical treatment of complications associated with the angio-seal vascular closure device: report of three cases.

The Angio-Seal arterial closure device consists of several bioabsorbable components and is used for hemostasis of arterial puncture sites. We report 3 cases of hemorrhagic and ischemic complications related to Angio-Seal use. Two cases were treated successfully by surgical removal of the device. In the third case surgical removal of the device failed and additional intervention was necessary. The unique structure of the Angio-Seal and the most likely cause of failure should be considered when treating device-related complications.

Surgical approach to left subclavian artery aneurysm in Marfan syndrome.

We present a case of left subclavian artery aneurysm in a 48-year-old man with Marfan syndrome. Aneurysmectomy and interposition with an artificial graft were successfully performed through an infraclavicular incision by dividing the clavicle at its midshaft. The clavicle bone was reconstructed with a steel plate, and the postoperative course was uneventful. Because the arterial wall is fragile in cases of connective tissue disorders such as Marfan syndrome, our surgical approach was considered to be helpful for gentle maneuvering in an adequate operative field.

Which valve and which size should we use in the valve-on-valve technique for re-do mitral valve surgery?

The valve-on-valve (VOV) technique is that a mechanical valve is implanted on the sewing cuff of the previous bioprosthesis after removing degenerated leaflets. We conducted an in vitro study to determine the size-match of the valves for VOV technique. The Carpentier-Edwards pericardial (CEP) valve and Mosaic valve were used. We measured the inner diameter of the bioprosthesis after removing the leaflets. We investigated five mechanical mitral valves and two mechanical aortic valves (inverted use). The mitral valves used in this study were the ATS valve (ATS), the CarboMedics standard valve (CMS), the CarboMedics OptiForm valve (CMO), the On-X valve, and the St Jude valve (SJM). Two aortic mechanical valves, CarboMedics and St Jude Regent valves, were investigated for inverted use. After removing the tissue leaflets, the inner diameter of the Mosaic valve was 3 mm smaller than that of the CEP valve even in the same catalogue labeling size. The outer diameters of the housing of the ATS, CMS, CMO, On-X, and SJM valves of the same catalogue size (25 mm) were 25.7, 25.8, 22.0, 25.0, and 23.2 mm, respectively. SJM and CMO valves are the favorite mechanical valve for the VOV technique in terms of the profile and size-match.

Modification of the Bentall operation using the proximal double sewing technique without excision of leaflets.

We present a report on reinforcement of the proximal anastomosis during the Bentall operation. The aortic wall was excised with a 5-mm remnant, and aortic valve leaflets were preserved. Interrupted horizontal mattress sutures (2-0 Polyestel) reinforced with pledgets were placed. The composite graft was placed at the intraannular position inside of the preserved leaflets. The aortic valve leaflets were then pasted to the sewing cuff with fibrin glue. A running suture with 4-0 monofilament was placed between the remnant of the aortic wall and the peripheral side of the sewing cuff wrapped with native aortic valve leaflets.

Beneficial effects of mini-cardiopulmonary bypass on hemostasis in coronary artery bypass grafting: analysis of inflammatory response and hemodilution.

We compared the inflammatory response, hemodilution, and blood loss in patients who underwent mini-cardiopulmonary bypass (CPB) or conventional CPB during coronary artery bypass grafting (CABG). Ninety-eight consecutive patients with ischemic heart disease were randomly assigned to mini-CPB (n = 34) or conventional CPB (n = 64). Interleukin (IL) -8 and neutrophil elastase levels were measured before and after surgery. Hemodilution during CPB, blood loss during and after surgery were also evaluated. Compared with the conventional group, the mini-CPB group had lower levels of IL-8 on postoperative day 1 (8.3 +/- 6.4 vs. 19 +/- 11 pg/mL, p = 0.016) and of neutrophil elastase on postoperative days 1 (127 +/- 52 vs. 240 +/- 100 microg/L, p = 0.013) and 2 (107 +/- 17 vs. 170 +/- 45 micro/L, p = 0.0001). The mini-CPB group also has less blood loss during (620 +/- 595 vs. 978 +/- 658 mL, p = 0.012) and after the operation (578 +/- 310 vs. 1,002 +/- 651 mL, p = 0.0034) and a hemodilution ratio of 14 +/- 2 vs. 25% +/- 3%, p < 0.0001. Thus, mini-CPB attenuated the inflammatory response and hemodilution, resulting in blood conservation in patients undergoing CABG.

Simple method of left ventricular assist system exchange from a BVS-5000 to a Toyobo: case report of a patient with fulminant myocarditis.

We implanted a BVS-5000 biventricular assist system in a 29-year-old woman in cardiogenic shock due to fulminant myocarditis. Exchange of the left ventricular assist system (LVAS) from the BVS-5000 to a Toyobo LVAS and weaning from the right ventricular assist system were performed successfully without cardiopulmonary bypass. This simple, less invasive method may be useful for patients requiring LVAS exchange for long-term ventricular support.

Minimal cardiopulmonary bypass attenuates neutrophil activation and cytokine release in coronary artery bypass grafting.

The minimal cardiopulmonary bypass (mini-CPB) circuit, a closed system with neither cardiotomy suction nor an open venous reservoir and thus no air-blood interface, reportedly reduces blood loss and inflammatory reactions associated with coronary bypass surgery. We evaluated the inflammatory reactions in patients in whom coronary bypass operations were performed with conventional CPB or mini-CPB (n=15 each). Interleukin (IL)-6, IL-8, and neutrophil elastase levels; the neutrophil count; and the C-reactive protein value were measured before and immediately after surgery and on postoperative days 1 and 2. In addition, intraoperative blood loss and the transfusion volume were evaluated in these groups. Neutrophil elastase levels were lower in the mini-CPB group than in the conventional group on postoperative days 1 (127 +/- 52 vs. 240 +/- 100 microg/l, P=0.013) and 2 (107 +/- 17 vs. 170 +/- 45 micro/l, P=0.0001), as was the IL-8 level on postoperative day 1 (8.3 +/- 6.4 vs. 19 +/- 11 pg/ml, P=0.016). The intraoperative blood loss and transfusion volumes were significantly lower in the mini-CPB group than in the conventional group (510 +/- 244 vs. 1046 +/- 966 ml, P=0.012, and 691 +/- 427 vs. 1416 +/- 918 ml, P=0.0033). Thus, mini-CPB appears to attenuate neutrophil activation and cytokine release after coronary bypass surgery and, in addition, has some beneficial effects on blood conservation.

Edaravone suppresses postoperative reperfusion injury in rat lower extremity: An immunohistological study.

PURPOSE: The present study evaluated whether the free radical scavenger edaravone (Radicut [Mitsubishi Pharma Co, Japan]) can suppress lower extremity postoperative reperfusion injury by evaluating muscle cell viability with immunohistological stain (cytochrome c oxidase stain). METHODS: Eight Lewis male rats (460 g to 510 g) were divided into two groups. In the control group, postoperative reperfusion injury models were created by clamping the bilateral common femoral arteries for 5 h and then releasing. In the other group, 9.0 mg/kg of edaravone was administered before clamping the bilateral common femoral arteries. After 5 h of reperfusion, the bilateral triceps muscles in both groups were stained with cytochrome c oxidase stain (each n=4 × 2). The positive areas of cytochrome c oxidase stain were measured and compared, using computerized densitometry (National Institutes of Health Image program, version 1.61). RESULTS: In the control group, the lower triceps muscles were not stained with cytochrome c oxidase. In the edaravone group, the lower triceps muscles were strongly stained with cytochrome c oxidase. The positive areas of cytochrome c oxidase stain were significantly greater in the edaravone group (133,000±12,000 µ(2)/mm(2), P<0.01) compared with the control group (8000±1300 µ(2)/mm(2)). CONCLUSION: The present study suggests that the preoperative administration of 9.0 mg/kg of edaravone may suppress postoperative reperfusion injury in a rat model.

Ruptured giant aneurysm of the ascending aorta caused by chronic aortic dissection.

A 55-year-old man developed acute chest pain and dyspnea. Computed tomography demonstrated a rupture of a giant aneurysm of the ascending aorta. The lesion was 14 cm in diameter--the largest ever reported-and resulted from chronic aortic dissection. The patient did not have aortic insufficiency or aortic dissection around the coronary ostium. Graft replacement of the ascending aorta was performed successfully under deep hypothermia with right hemisphere perfusion.

Long-term results of mitral valve replacement: biological xenograft versus mechanical valves.

We studied 279 patients who underwent mitral valve replacement at the Department of Thoracic and Cardiovascular Surgery, Hyogo College of Medicine, between November 1973 and December 1998. The patients were divided into two groups based on the type of replacement valve (154 patients in the biological xenograft group and 125 patients in the mechanical valve group), and the long-term results were compared. Clinically satisfactory results were obtained in both the biological xenograft group and the mechanical valve group according to the surgical results, long-term survival, and incidence of prosthetic valve endocarditis. At 15 years, fewer patients in the mechanical valve group than in the biological xenograft group were free of bleeding events (92.5 +/- 3.7% vs 100% P < 0.05). At 15 years, the biological xenograft group was lower than the mechanical valve group with respect to freedom from thromboembolism (72.2 +/- 4.6% vs 93.5 +/- 3.6% P < 0.01), freedom from valve failure (22.0 +/- 5.2% vs 87.0 +/- 4.1% P < 0.005) and freedom from cardiac events (16.5 +/- 3.9% vs 47.2 +/- 14.5% P < 0.01). Though it has previously been suggested that biological xenografts used in mitral valve replacement do not need anticoagulation, the current study suggests the need for anticoagulation with the use of biological xenografts. Mechanical valves require close monitoring of anticoagulation, but their use has decreased the incidence of valve failure and thromboembolism, as compared with the use of biological xenografts. Therefore, mechanical valves are currently the preferred choice for mitral valve replacement. We believe that biological xenografts are indicated only for the older patient (> or =65 years).