[Off-pump coronary artery bypass grafting for octogenarians with acute coronary syndrome].

In recent years, experiences with performing off-pump coronary artery bypass (OPCAB) has increased dramatically. Many early reports suggest that this approach may improve outcome by lowering postoperative complications. The benefit of this procedure to elderly patients seems appealing but is not well studied. We sought to review our experience with OPCAB in octogenarians with acute coronary syndrome (ACS) to better define the potential benefit of this approach in this high-risk group of patients. Until March 2003, OPCAB was performed in 21 octogenarians (10 men and 11 women with mean age of 82.9 +/- 2.8 years) with ACS at the department of cardiovascular surgery of National Kanazawa Hospital. Two had myocardial infarction and 3 unstable angina. Mean left ventricular ejection function was 41.2%. 14 patients had a history of previous cerebral infarction. All procedures were completed without hemodynamic deterioration and conversion to on-pump coronary artery bypass grafting (CABG). There was no operative mortality and no occurrence of major complications such as low output syndrome, re-exploration for bleeding, cerebral infarction, perioperative myocardial infarction, and mediastinitis. And no further deterioration of organ function occurred in patients with preexisting central nervous system dysfunction or kidney. Peak CK-MB concentrations after surgery were within normal limits. This study demonstrates that CABG can be performed safely on high-risk ACS patients 80 years of age and older without the use of cardiopulmonary bypass. OPCAB may be the operation of choice for octogenarians with ACS requiring surgical myocardial revascularization.

[Off-pump coronary artery bypass grafting for unstable angina pectoris combined with hypothyroidism and chronic renal failure; report of a case].

Coronary artery bypass grafting for patients with ischemic heart disease and hypothyroidism contains many controversies, and chronic renal failure causes perioperative water-electrolyte balance disorders. We experienced a case of unstable angina pectoris combined with hypothyroidism and chronic renal failure successfully treated by off-pump coronary artery bypass grafting (OPCAB). A 68-year-old man with a history of hypothyroidism and chronic renal failure was hospitalized with chest pain. Cardiac catheterisation revealed a 90% stenosis of segment 3, 11 and right ventricular (RV) branch, 75% stenosis of segment 6 and 50% stenosis of segment 5. His thyroid function was normal with orally administered levothyroxine. OPCAB was performed safely with hemodialysis until a day before operation and hemofiltration from a day after operation, and postoperative course was uneventful.

[Off-pump Cx grafting for unstable angina with left main trunk lesion].

Recently, off-pump coronary artery bypass grafting (OPCAB) has been rediscovered and spread to avoid the deleterious effect of cardiopulmonary bypass. In OPCAB, surgical exposure of Cx grafting site often threats the hemodynamic stability. We retrospectively analysed the 13 patients with acute coronary syndrome due to LMT lesion who underwent emergent OPCAB to accomplish the safe Cx grafting. We assessed the intraoperative hemodynamic changes and early results of OPCAB through the use of new devices and techniques. Myocardial tissue oxygen saturation was measured by near-infra red spectroscopy during OPCAB. All procedures were completed without hemodynamic deterioration and conversion to cardiopulmonary bypass. No hospital deaths or complications were noted. The early patency rate was 100 percent and perioperative maximal CK-MB was 16.6 +/- 4.7 IU/l. Concomitant use of ischemic preconditioning and KATP opener, oxidative radical scavenger, PD III inhibitor, ameliorated ischemic cardiac dysfunction during occlusion of the coronary artery and improved the postischemic functional recovery. These results suggest that intra-operative compound management may decrease the risk of Cx grafting of OPCAB.

[The role of ischemic preconditioning in off-pump CABG: is it really necessary to accomplish scrupulous ischemic preconditioning?].

In an attempt to avoid the deleterious effect of cardiopulmonary bypass, off-pump coronary artery bypass grafting has been rediscovered and spread. We often accomplish the ischemic preconditioning (IP) in off-pump CABG. IP is the phenomenon in which sublethal episode of myocardial ischemia result in increased tolerance to a later, potentially lethal, episode of ischemia. To evaluate the cardioprotective effect of IP and an ATP-sensitive potassium channel (KATP) opener, oxidative radical scavenger, 43 clinical cases were examined. The myocardial tissue oxygen saturation was measured by near-infra red spectroscopy during IP. Twelve cases were subjected to accomplish simple IP (5 min x twice), and 29 cases received pharmacological IP (administrated allopurinol preoperatively and nicorandil intraoperatively; 3 min x once). The result showed that the tissue oxygen of pharmacological IP group is superior to that of simple IP group. The concomitant use of IP and KATP opener, oxidative radical scavenger both ameliorated cardiac dysfunction during the ischemia in anastomotic occlusion of the coronary artery, and improved the postischemic functional recovery. These results suggest that we would be able to decrease both duration and the number of times of IP by using KATP opener and oxidative radical scavenger.

Intrathoracic aneurysm of the innominate and right subclavian arteries: report of a case.

Aneurysms of the innominate and subclavian arteries are uncommon but associated with high mortality rates. We report herein the case of a 45-year-old man who presented with facial anhidrosis that developed several years after blunt thoracic trauma, in whom an aneurysm involving the innominate and subclavian arteries was revealed by preoperative examinations. Resection of the aneurysm and reconstruction from the ascending aorta to both the subclavian and common carotid arteries using a bifurcated graft was successfully performed without brain perfusion. Although the left posterior cerebral artery, which was not manipulated during surgery, became occluded, it was recanalized by thrombolysis. The patient was discharged in good health and has remained well since.

Hybrid revascularization feasibility in minimally invasive direct coronary artery bypass grafting combined with percutaneous transluminal coronary angioplasty in patients with acute coronary syndrome and multivessel disease.

OBJECTIVES: We reviewed early and midterm outcome of 11 multivessel-disease acute coronary syndrome patients treated by hybrid revascularization, i.e., initial coronary angioplasty followed by minimally invasive direct coronary artery bypass grafting. We evaluated procedural efficacy and applicability. METHODS: Beginning in August 1997, hybrid revascularization was conducted in 11 multivessel-disease acute coronary syndrome patients--9 men and 2 women with a mean age of 70.3 +/- 9.3 years. Occlusion or stenosis of the target coronary artery was treated by interventional cardiologic techniques and minimally invasive direct coronary artery bypass grafting, and the early and midterm outcome evaluated. Coronary angiography was conducted in all cases at 2 weeks, 6 months, 1 and 3 years postoperatively to evaluate anastomosis and restenosis in treated coronary vessels. RESULTS: Initial intervention succeeded in patients with minimal residual stenosis. Subsequent minimally invasive direct coronary artery bypass grafting involved no complications. Coronary angiography early postoperatively, 6 months, 1 and 3 years later showed grafts patent without stenosis. Percutaneous transluminal coronary angioplasty was reconducted on restenotic lesions in 3 patients, 1 of whom required 3 procedures. CONCLUSIONS: Hybrid revascularization appears safe and effective in coronary revascularization, at least over the short term. Several patients underwent angioplasty for restenosis within 3 years after initial procedure. Overall acceptance of this hybrid method depends on long-term functional success of the 2 procedures. Its major limitation is restenosis of angioplasty sites and the need for repeat procedures.

Rupture of pseudointima in an implanted vascular prosthesis: immunohistological study of plasminogen activators and matrix metalloproteinases.

We investigated late-onset anastomotic stenosis in an implanted prosthetic graft. Rupture of the pseudointima and hemorrhaging from the vasa vasorum were observed at the border of the collagenous tissue and fibrin layer. An immunohistological study showed that the fibrin layer was positive for tPA, but weakly positive for PAI-1. Some neutrophils and monocyte/macrophages in the fibrin layer were immunostained for tPA, uPA, uPAR, and MMP-1, -2 and -3. Some spindle-shaped cells surrounding the graft were immunostained for uPA, uPAR, MMP-1, -2, -3, -7 and -9, and TIMP-1 and -2. The endothelial cells of some microvessels were positive for MMP-1 and -2, and tPA. Some multi-nucleated giant cells were immunostained for MMP-7 and-9, tPA, PAI-1, uPA, and uPAR. Overexpressed MMPs and PAs possibly caused instability of the pseudointima.

Plasminogen activators, matrix metalloproteinases and their inhibitors in implanted vascular prostheses.

OBJECTIVES: To examine the role of plasminogen activators (PAs) and matrix metalloproteinases (MMPs) in the healing of prosthetic grafts. METHODS: Thirty explanted grafts (16 Dacron and 14 PTFE) were studied immunohistochemically using antibodies to PAs, MMPs, and their inhibitors. The percentages of immunostain-positive multinucleated giant cells (MGC) were related to duration of implantation (early vs late), type of lesion (stenosis vs false aneurysm), graft material (Dacron vs PTFE), and graft status (occluded vs patent). RESULTS: All specimens were positive for PAs and MMPs. There were no significant differences in the percentages of MGCs positive for PAs, MMPs, or tissue inhibitor type 2 of MMP (TIMP-2) between the groups. The percentage of TIMP-1 in the aneurysm group (mean, 26%) was significantly lower than that of the stenosis group (mean, 46%) (p<0.05). CONCLUSION: After the implantation of a vascular prosthesis, PAs and MMPs are expressed in cell migration, proliferation and matrix construction. Under-expression of TIMP-1 may be related to the formation of an anastomotic aneurysm.

An unusual case of benign thyroid tumour consisting of epithelial and nonepithelial components.

An encapsulated tumour consisting of follicular epithelial cells, fat-laden round cells and spindle cells was found in the right lobe of the thyroid gland of a 66-year-old woman. The follicular epithelial cells had oxyphilic cytoplasm in which numerous mitochondria were densely packed. The fat-laden round cells were indistinguishable from mature fat cells by light microscopy. However, they were immunohistochemically negative for S-100 protein and epithelial markers, and lacked a continuous basement membrane. The spindle cells embedded in the collagenous matrix possessed well-developed rough endoplasmic reticulum, most of which contained variably sized, non-membrane-bound lipid droplets. Bundles of thin filaments were occasionally observed in the cytoplasm. Some spindle cells were immunoreactive for PCNA and alpha-smooth muscle actin. There was no striking nuclear atypia of the tumour cells and no capsular or vascular invasion by these components. The tumour can be classified as a benign mixed tumour.

Graft replacement of the dissecting aneurysm originating in the suprarenal abdominal aorta. A case report.

Spontaneous dissection originating in the suprarenal aorta is very rare. We successfully treated a patient with this type of aneurysm by a safe and reliable operative method. During aortic clamping, the visceral organs were perfused with oxygenated blood. And for reconstruction of visceral arteries, a graft with multiple branches was used. In spite of renal dysfunction before surgery and aortic clamping time extending for 40 minutes, the patient recovered almost uneventfully, and postoperative angiography confirmed good patency of the graft.

An immunohistochemical analysis of implanted woven Dacron and expanded polytetrafluoroethylene grafts in humans.

An immunohistochemical analysis was performed to clarify the healing process in implanted vascular grafts in human. Eight woven Dacron grafts and 6 expanded polytetrafluoroethylene grafts were obtained following redo surgery, limb amputation, and autopsy. The implantation periods ranged from 5 days to 148 months. The antibodies used for the analysis were specific to alpha-actin (smooth muscle cells), macrophages, von Willebrand factor (endothelial cells), fibrin, elastin, collagen types 1-5, CD3 (T cells), and CD20 (B cells). At 5 and 24 days after implantation, thrombi containing red blood cells and fibrin covered the anastomotic lines and some of the luminal surfaces of the grafts. Macrophages were scattered throughout the thrombi. At 11-148 months after implantation, either a single layer of endothelial cells or a thin layer of fibrin covered the anastomotic segments of the grafts, and smooth muscle cells and collagen fiber were seen forming anastomotic intimal hyperplasia (AIH). The AIH in the grafts at 94 and 148 months after implantation was almost the same thickness and length a that in the grafts at 11-36 months after implantation Apart from the anastomotic segments, a connective tissue matrix containing collagen fibers covered the luminal surfaces, and some thrombi were noted. Most of the collagen present was type 3, in addition to some type 1, 4, and 5 collagen. No type 2 collagen was noted. Some elastin was also detected in the AIH but not in the midportion of the grafts. Some macrophages and T cells were noted in the perigraft tissues.

Pathological study of implanted dacron grafts in surgery of thoracic aortic aneurysms.

We studied woven dacron grafts that had been implanted in 5 patients of thoracic aortic aneurysms. In addition to usual stains, immunocytochemical analysis was performed using monoclonal antibodies to the muscle actin (HHF35) and to the macrophage (HAM56). In the graft of 5 and 24 days implantation, thin thrombi containing red cells and fibrin covered the luminal surface in some places, and macrophages came into the thrombi. In the grafts of 12 and 38 months implantation, intimal hyperplasia of 0.2-1.0 mm thickness was seen at the anastomotic segments with the accumulation of smooth muscle cells. Except for the anastomotic segments, connective tissue matrix with collagen fibers covered the luminal surface, and in some hollows of the graft crimps, old and fresh thombi were seen in layers. Organizing thrombi of 1.0 mm thickness attached where the branched graft was anastomosed to the main graft. Anastomotic intimal hyperplasia in the graft of 148 month implantation was 0.4-1.0 mm in thickness and 5-10 mm in length, and aside from the intimal hyperplasia, an endothelial lining did not cover the luminal surface of the graft. In the thoracic aorta, woven dacron graft implantation did not cause a critical stenosis with the intimal hyperplasia. The mural thrombi formed at the branched graft, however, threatened to result in graft occlusion or embolization.