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Biomedical subjects

Soichiro Kitamura

Publications and source records attributed to Soichiro Kitamura.

At least 19 recordsLinked to original sources
PubMed2007

Is extracorporeal life support contraindicated in elderly patients?

BACKGROUND: Extracorporeal life support (ECLS) using percutaneous extracorporeal membrane oxygenation (ECMO) is now considered an important means of resuscitation for patients suffering from refractory cardiogenic shock. The indications for the use of ECLS have yet to be established, however, and its use for elderly patients is still controversial. We retrospectively evaluated the impact of ECLS on the survival of patients with cardiogenic shock to determine the validity of using ECLS in elderly patients (> or = 75 years of age). METHODS: Between 2000 and 2004, 91 patients were emergently placed on percutaneous ECMO. The patients were divided into two groups by age (group 1, n = 79: less than 75 years; group 2, n = 12: 75 years or older), which were compared for clinical outcome. Logistic regression analysis of the variables was performed to identify predictors of ability to be weaned from ECLS. RESULTS: Weaning from ECLS was achieved in 50 patients in group 1 (63.3%) and 6 patients in group 2 (50%; p = 0.37). Thirty-five patients in group 1 (44.3%) and 5 patients in group 2 (41.7%) were discharged from the hospital (p = 0.86). Logistic regression analysis revealed that patients with a body surface area of more than 1.50 m2, patients with cardiomyopathy, and patients who underwent interventions under ECMO support were more likely to be successfully supported by ECMO. CONCLUSIONS: Extracorporeal life support using percutaneous ECMO systems provides excellent cardiac support. It is also effective in resuscitating elderly patients, yielding hospital survival similar to that for younger patients.

Adolescent↗
PubMed2006

Graft design strategies with optimum antegrade bypass flow in total arterial off-pump coronary artery bypass.

OBJECTIVE: In arterial conduits, graft flow is one of the major determinants of long-term patency. We sought to delineate the effect of strategy for graft arrangement and design to three-vessel disease by evaluation of the dominant flow direction in each segment of a bypass graft. MATERIALS AND METHODS: We reviewed coronary angiograms of 1571 bypass grafts in 395 patients who underwent total arterial off-pump coronary revascularization without aortic manipulation for three-vessel disease since December 2000. The graft flow graded as A (antegrade), B (competitive), C (reverse), and O (no flow=occlusion). The current arrangement and design has been introduced since March 2003, and consists of the in-situ left internal thoracic artery (ITA) to the anterior descending artery and the composite I-graft of the right ITA and radial artery to the left circumflex (LCX) and right coronary artery (RCA) territories. Either clockwise or counterclockwise orientation, the I-graft was chosen to achieve a sufficient antegrade flow. Group I consisted of 181 patients with a single in-situ ITA as a composite Y-graft. Group II consisted of 214 patients with bilateral in-situ ITAs, which subdivided into Subgroup II-A consisted of 80 patients with bilateral in-situ ITAs until February 2003, and Subgroup II-B consisted of 134 patients with bilateral in-situ ITAs since March 2003. RESULTS: The number of distal anastomoses was 3.52+/-0.63 in Group I, and 4.36+/-0.83 in Group II, respectively (p<0.0001). The overall graft patency rate was 98.6% (1549/1571), and there was no significance different between the groups. The rate of grade A in Group II was 863/933 (92.5%) and was significantly higher (p=0.049) than that of Group I 572/638 (89.7%). The rate of functioning bypass in Subgroup II-B was (95.8%) 568/593, and was significantly higher (p=0.03) than that in Subgroup II-A (92.4%) 314/340. In Subgroup II-B, 233/268 (86.9%) of the conduits had completely grade A bypass flow, and this ratio was significantly higher (p=0.04) than that in Subgroup II-A (79.4%) 127/160. CONCLUSION: Usage of bilateral ITAs and selecting the orientation of the I-graft to LCX and RCA branches provide maximal distal anastomotic sites with satisfactory graft patency rate, and simultaneously minimized the incidence of reverse and competitive flow.

Aged↗
PubMed2006

Redo off-pump coronary bypass grafting with arterial grafts for Kawasaki disease.

Surgical revascularization for coronary artery lesions secondary to Kawasaki disease is relatively uncommon. The late stenosis of the saphenous vein graft is the problem to be solved. We report a case of redo off-pump coronary bypass grafting in a 35-year-old man, 20 years after bypass grafting using a saphenous vein graft. Off-pump total arterial revascularization was performed uneventfully. The procedure comprised grafting of bilateral internal thoracic arteries to left anterior descending branch and obtuse marginal branch, and radial artery to AV branch and posterior descending branch. Off-pump total arterial revascularization is a safe and less invasive procedure at the time of redo operation, even for patients with Kawasaki disease.

Adult↗
PubMed2006

Transplantation of mesenchymal stem cells attenuates myocardial injury and dysfunction in a rat model of acute myocarditis.

Acute myocarditis is a non-ischemic inflammatory disease of the myocardium for which there is currently no specific treatment. We have previously shown that mesenchymal stem cells (MSC) can ameliorate heart injury during acute ischemia and in dilated cardiomyopathy; however, the therapeutic potential in acute myocarditis is unclear. In this study, we investigated the ability of MSC to attenuate myocardial injury and dysfunction during the acute phase of experimental myocarditis. Ten-week-old male Lewis rats were injected with porcine myosin to induce myocarditis. Cultured MSC (3x10(6) cells/rat) were injected intravenously 7 days after myosin injection. At 3 weeks, myosin injection resulted in severe inflammation and significant deterioration of cardiac function. MSC transplantation attenuated increases in CD68-positive inflammatory cells and monocyte chemoattractant protein-1 (MCP-1) expression in myocardium, and improved cardiac function in this model. Furthermore, myocardial capillary density was higher in myocarditis tissue, and was further increased by MSC transplantation. In vitro, cultured adult rat cardiomyocytes were injured in response to MCP-1, whereas this effect was attenuated by MSC-derived conditioned medium, suggesting cardioprotective effects of MSC acting in a paracrine manner. MSC transplantation attenuated myocardial injury and dysfunction in a rat model of acute myocarditis, at least in part through paracrine effects of MSC.

Acute Disease↗
PubMed2006

Impact of blockade of histamine H2 receptors on chronic heart failure revealed by retrospective and prospective randomized studies.

OBJECTIVES: The goal of this work was to determine whether the blockade of histamine H2 receptors is beneficial for the pathophysiology of chronic heart failure (CHF). BACKGROUND: Because CHF is one of the major life-threatening diseases, we need to find a novel effective therapy. Intriguingly, our previous study, which predicts the involvement of histamine in CHF, suggests that we should test this hypothesis in patients with CHF. METHODS: We selected 159 patients who received famotidine among symptomatic CHF patients for the retrospective study. We blindly selected age- and gender-matched CHF patients receiving drugs for gastritis other than histamine H2 receptor blockers as a control group. For the prospective study, 50 symptomatic CHF patients were randomly divided into 2 groups. One group received famotidine of 30 mg/day for 6 months, and the other group received teprenone. RESULTS: In the retrospective study, famotidine of 20 to 40 mg decreased both left ventricular end-diastolic and end-systolic lengths (LVDd and LVDs, respectively) and the plasma B-type natriuretic peptide (BNP) levels (182 +/- 21 vs. 259 +/- 25 pg/ml, p < 0.05) with unaltered fractional shortening (FS). In a randomized, open-label study, compared with teprenone, famotidine of 30 mg prospectively decreased both New York Heart Association functional class (p < 0.05) and plasma BNP levels (183 +/- 26 pg/ml vs. 285 +/- 41 pg/ml, p < 0.05); this corresponded to decreasing both LVDd (57 +/- 2 mm vs. 64 +/- 2 mm, p < 0.05) and LVDs (47 +/- 2 mm vs. 55 +/- 2 mm, p < 0.05) with unaltered FS (15 +/- 1% vs. 17 +/- 1%). The frequency of readmission because of worsening of CHF was lower in the famotidine group (4% and 24%, p < 0.05). On the other hand, teprenone had no effects on CHF. CONCLUSIONS: Famotidine improved both cardiac symptoms and ventricular remodeling associated with CHF. Histamine H2 receptor blockers may have therapeutic benefits for CHF.

Aged↗
PubMed2006

Beraprost sodium enhances neovascularization in ischemic myocardium by mobilizing bone marrow cells in rats.

Beraprost sodium, an orally active prostacyclin analogue, has vasoprotective effects such as vasodilation and antiplatelet activities. We investigated the therapeutic potential of beraprost for myocardial ischemia. Immediately after coronary ligation of Sprague-Dawley rats, beraprost (200 microg/kg/day) or saline was subcutaneously administered for 28 days. Four weeks after coronary ligation, administration of beraprost increased capillary density in ischemic myocardium, decreased infarct size, and improved cardiac function in rats with myocardial infarction. Beraprost markedly increased the number of CD34-positive cells and c-kit-positive cells in plasma. Also, four weeks after coronary ligation of chimeric rats with GFP-expressing bone marrow, bone marrow-derived cells were incorporated into the infarcted region and its border zone. Treatment with beraprost increased the number of GFP/von Willebrand factor-double-positive cells in the ischemic myocardium. These results suggest that beraprost has beneficial effects on ischemic myocardium partly by its ability to enhance neovascularization in ischemic myocardium by mobilizing bone marrow cells.

Animals↗
PubMed2006

Immunohistological findings for an extracardiac conduit in Fontan pathway constructed with pedicled autologous pericardium.

Although autologous pericardium has been used in pedicled fashion for various reconstructive procedures in congenital cardiovascular surgery with the expectation that it will be able to grow and remain viable after implantation, no clinical study has evaluated the histological characteristics of implanted pedicled pericardium long after previous implantation. We describe herein histological findings of pedicled pericardium, which had been used for three years as an extracardiac conduit in Fontan pathway. A four-year-old boy with a history of Fontan operation using pedicled autologous pericardial roll required conduit replacement three years after the previous operation, and resected pericardial tissue was examined immunohistologically. Staining for CD34 revealed abundant microvasculature, suggesting preservation of viability. Staining for factor VIII demonstrated the presence of endothelium on the luminal surface of the conduit. Elastica-van Gieson staining revealed a band of elastic tissue, which is generally found not in the native pericardium but in the vascular wall structures. These findings suggested that the pedicled pericardium thus appeared to have remained viable and might have differentiated to resemble tissue of the vascular wall after having been used in Fontan pathway.

Child, Preschool↗
PubMed2006

The impact of mitral valve surgery combined with maze procedure.

OBJECTIVE: Recent studies indicated that successful maze procedure for atrial fibrillation (AF) adjunct to mitral valve surgery provided a lower incidence of stroke and recurrence of AF. The purpose of this study is to review the 13-year experience of these combined procedures and to identify the risk factors and late outcomes of successful maze procedures compared to failed maze procedures. METHODS: At a single institution, 521 consecutive patients underwent combined maze procedures with mitral valve replacements or valvuloplasties. Three kinds of maze techniques were primarily used: Cox-maze III, Kosakai maze, and cryo-maze procedure. Three months after the operation, 394 patients were in sinus rhythm (Group S) while the remaining 116 patients were in continuous or intermittent AF (Group F), excluding 11 early death patients. Risk factors for Group F were determined by the analysis of all patient demographics. Survival, freedom from stroke, cardiac events, and AF recurrence were analyzed. RESULTS: The proportion of the patients without any other simultaneous procedures was greater in Group S (41% vs 29%, P = 0.02). The distributions of mitral valve surgery and maze procedure techniques were similar in these two groups. A left atrium larger than 70 mm [hazard ratio (HR) = 2.6; 95% confidence interval range 1.04-6.3, P = 0.043], preoperative AF history longer than 10 years (HR = 8.2; 4.5-15.1, P < 0.001) and f-wave voltage in V1 smaller than 0.1 mV (HR = 6.2; 5.0-15.2, P < 0.001) were determined to be risk factors for unsuccessful maze procedures. All the results of Cox proportional hazards models showed superiority in Group S; actuarial survival rates (HR = 2.7; 1.04-7.0, P = 0.035), freedoms from stroke (HR = 3.0; 1.1-8.1, P = 0.003) and cardiac events (HR = 4.3; 2.9-6.1, P < 0.001). Freedom from AF recurrence rate was 98.4% at 5 years and 81.0% at 12 years in Group S, and 73.0% and 60.1% in overall patients. CONCLUSIONS: Patients with successful maze procedures resulted in higher survival rate, greater freedom from stroke and cardiac events. The large left atrium, small f-wave, and long AF duration were significant risk factors for failed maze procedures, suggesting that earlier surgical interventions would result in superior results in mitral valve surgery combined with maze procedure.

Adult↗
PubMed2006

Hemiarch replacement during pregnancy (19 weeks) utilizing normothermic selective cerebral perfusion.

A 20-year-old woman with Marfan syndrome in the 19 weeks of pregnancy was admitted for a dissecting aneurysm of the ascending aorta to the proximal arch. She wanted to continue with pregnancy. A cardiotocography and a trans-esophageal echo probe which allowed visualization of the fetal heart contraction were attached on the abdomen. A cardio-pulmonary bypass was established via the right axillar and femoral arteries with bicaval drainage. The aortic isthmus and arch branches were clamped. After opening the ascending aorta, selective cerebral perfusion was initiated by quick cannulation into the left carotid and left subclavian arteries. Peripheral pressure was maintained above 80 mmHg with the flow of the selective cerebral perfusion at 1.0 L/min and flow from the femoral artery at 3.5L/min. Hemi-arch replacement was performed using a Dacron graft. The body temperature passively descended to 35 degrees C. She normally delivered a healthy female baby after 37 weeks' of gestation.

Adult↗
PubMed2006

Monolayered mesenchymal stem cells repair scarred myocardium after myocardial infarction.

Mesenchymal stem cells are multipotent cells that can differentiate into cardiomyocytes and vascular endothelial cells. Here we show, using cell sheet technology, that monolayered mesenchymal stem cells have multipotent and self-propagating properties after transplantation into infarcted rat hearts. We cultured adipose tissue-derived mesenchymal stem cells characterized by flow cytometry using temperature-responsive culture dishes. Four weeks after coronary ligation, we transplanted the monolayered mesenchymal stem cells onto the scarred myocardium. After transplantation, the engrafted sheet gradually grew to form a thick stratum that included newly formed vessels, undifferentiated cells and few cardiomyocytes. The mesenchymal stem cell sheet also acted through paracrine pathways to trigger angiogenesis. Unlike a fibroblast cell sheet, the monolayered mesenchymal stem cells reversed wall thinning in the scar area and improved cardiac function in rats with myocardial infarction. Thus, transplantation of monolayered mesenchymal stem cells may be a new therapeutic strategy for cardiac tissue regeneration.

Animals↗
PubMed2006

Determinants of rapid progression of aortic root dilatation and complications in Marfan syndrome.

BACKGROUND: Progressive aortic dilatation has prognostic significance in the Marfan syndrome. METHODS: To identify which patients were at high risk of rapid progression, we echocardiographically studied 43 patients (age 22 +/- 14 years) with the mean follow-up period of 5.2 +/- 3.2 years. Aortic diameters, left ventricular (LV) size, fractional shortening, and the severity of aortic and mitral regurgitation were assessed. Transmitral peak early and atrial flow velocities, their ratio and the deceleration time of peak early velocity were also obtained. RESULTS: Mean annual increases of aortic diameters were 0.4 +/- 0.3 mm at the annulus, 1.5 +/- 1.3 mm at the sinuses of Valsalva, 0.7 +/- 0.6 mm at the supraaortic ridge and 0.4 +/- 0.4 mm at the proximal ascending aorta. Patients were divided into 2 groups according to the aortic growth rate at the sinuses of Valsalva level: rapid (R, >3% per year, 15 patients) or slow (S, < or =3% per year, 28 patients) progression groups. Measured variables did not show significant differences between the 2 groups except older age, higher blood pressure and more severe aortic regurgitation in group R. Multiple regression analysis identified prolonged deceleration time as the most important variable predicting aortic complications. Aortic dissection occurred more frequently in group R (7 patients, 47%) than in group S (0%, P < 0.001). CONCLUSIONS: Marfan patients at older age, with higher blood pressure, and with significant aortic regurgitation were at high risk of progression of aortic dilatation, with the most remarkable increase at the sinuses of Valsalva. Prolonged deceleration time may relate to an increased risk for aortic complications.

Adolescent↗
PubMed2006

Suppressive effect of phosphodiesterase type 4 inhibition on systemic inflammatory responses after cardiopulmonary bypass.

Cardiopulmonary bypass (CPB) induces excessive production of endogenous proinflammatory mediators such as cytokines and elastase, which are responsible for the subsequent development of systemic inflammatory response syndrome (SIRS). In this study, we investigated the protective effect of rolipram against SIRS after CPB. Rats were divided into three groups (n = 5 in each): control (C), rolipram (R), and sham (S). Rats in groups C and R underwent CPB for 60 min followed by 60 min of observation, while those in group S were observed for 120 min without CPB. In group R, 40 microg/kg/min of rolipram was intravenously administered throughout the experiment. CD11b expression on neutrophils was analyzed using flow cytometry. Serum concentrations of tissue necrosis factor alpha (TNF-alpha), interleukin 1beta (IL-1beta), macrophage inflammatory protein 2 (MIP-2), and elastase were also determined. CD11b expression at the end of the experiment was unchanged from the initial value in group R, whereas that in group C increased to almost double, and that in group S also showed a slight increase (P < 0.01). Serum TNF-alpha levels in groups R and S were lower than those observed in group C (P < 0.05). Serum IL-1beta and MIP-2 levels in groups C and R tended to be higher than those in group S, although the difference was not statistically significant. Regarding elastase, group R showed a significantly lower value than group C and a higher value than group S (P < 0.05). Phosphodiesterase type 4 inhibition seems to suppress CPB-induced SIRS through the regulation of proinflammatory mediators in this rat model.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed2006

Surgical outcome of aortic arch repair for patients with Takayasu arteritis.

BACKGROUND: Takayasu arteritis can cause segmental dilatation or stenosis of the aorta and its major branches, and surgical treatment of it is still difficult. Our objective was to review late results of aortic arch repair for patients with Takayasu arteritis. METHODS: Between 1987 and 2003, 21 patients underwent aortic arch repair under circulatory arrest. Diagnosis was performed by pathologic study of specimens for all patients. Total aortic arch repair was performed in 12 patients with separated branched grafts and in 2 patients with the island technique. Selective cerebral perfusion was used in 12 patients and retrograde cerebral perfusion in 2 patients in this type of surgery. Hemiarch replacement using retrograde cerebral perfusion was performed in 7 patients. Craniocervical vascular stenosis was found in 7 patients and aneurysm in 5 patients. The elephant trunk technique was used in 10 patients. The follow-up period was 6.2 +/- 4.2 years. RESULTS: There was one hospital death due to renal failure, and two late deaths, both of which were sudden. Late in follow-up, a patient who had undergone hemiarch replacement 12 years previously required total aortic arch repair for dilatation of the distal arch. Three patients required thoracoabdominal aortic repair and one patient descending aortic repair for residual aortic dilatation late in follow-up. Postoperative spinal infarction occurred in one patient who underwent hemiarch replacement. CONCLUSIONS: Surgical and late outcomes of aortic arch repair under circulatory arrest appear favorable, though late dilatation of the residual aorta is a matter of concern.

Acute Kidney Injury↗
PubMed2006

Prediction and incidence of atrial fibrillation after aortic arch repair.

BACKGROUND: Although atrial fibrillation is often associated with increased morbidity after open heart surgery, neither the incidence nor the clinical consequences of atrial fibrillation after aortic surgery has been well investigated. The goal of this study was to elucidate the risks for incidence of postoperative atrial fibrillation after aortic arch repair. METHODS: From January 1993 to February 2004, 483 patients with atherosclerotic aortic arch aneurysm (n = 327) or aortic dissection (n = 156) underwent total aortic arch repair. All patients operated on as elective, urgent, or emergency aortic arch repair were included. One hundred sixteen patients received surgery on an emergency basis because of rupture or acute type A dissection. Twenty-four patients had atrial fibrillation preoperatively. Potential predictors of postoperative atrial fibrillation were estimated by a logistic regression model. RESULTS: The incidence of postoperative, new onset of atrial fibrillation was 52.7% (242 of 459). The length of postoperative hospital stay was longer in patients with postoperative atrial fibrillation (48 +/- 52 days) than in patients without it (35 +/- 29 days; p = 0.001). The length of intensive care unit stay was also longer in patients with postoperative atrial fibrillation (12.1 +/- 23.2) than in patients without it (6.2 +/- 8.8; p = 0.002). Advanced age (p = 0.007; odds ratio = 1.34; 95% confidence interval: 1.14 to 1.62, per 10 years) was the only risk factor that correlated with postoperative new onset of atrial fibrillation. CONCLUSIONS: Atrial fibrillation was not uncommon after aortic arch repair. Advanced age was the only preoperative risk factor for postoperative atrial fibrillation.

Age Factors↗
PubMed2006

Intermediate results of the double-switch operations for atrioventricular discordance.

BACKGROUND: Since 1987, anatomic biventricular repair using the double-switch operations has been our principal choice for patients with atrioventricular discordance. These alternative procedures have the theoretical advantage of using the anatomic left ventricle to support the systemic circulation. METHODS: A total of 45 patients underwent the double-switch operation. Their ages ranged from 6 months to 21 years. Associated malformations included pulmonary atresia in 27, pulmonary stenosis in 11, and Ebstein's malformation in 5. An atrial switch plus an arterial switch procedure was performed in 7, and an atrial switch plus a Rastelli-type ventriculoarterial switch procedure in 38. Follow-up ranged from 6 months to 15 years. RESULTS: Early mortality was 8.9% (n = 4). In the latter half of the series (n = 23, since 1994), there was no early death. Six patients died late. Actuarial survival at 5 and 10 years was 83.6% and 77.6%, respectively. Six patients required conduit replacement, and 2 required revision of an intraatrial baffle for pulmonary venous channel obstruction and infection, respectively. Freedom from reoperation was 95.3% at 5 years and 76.2% at 10 years. Freedom from arrhythmia was 88.8% at 5 years and 78.4% at 10 years. The systemic ventricular ejection fraction was 0.568 +/- 0.103 at 1 year (n = 39), 0.555 +/- 0.105 at 5 years (n = 17), and 0.539 +/- 0.098 at 10 years (n = 12). CONCLUSIONS: The surgical results of the double-switch operations have been improving. Intermediate follow-up suggests that these alternative procedures are a reasonable option for patients with atrioventricular discordance.

Adolescent↗
PubMed2006

Surgical management of distal arch aneurysm: another approach with improved results.

BACKGROUND: Surgical treatment for distal arch aneurysm carries the risk of stroke. Although left thoracotomy has been used for repair of distal arch aneurysm as a standard approach, we have performed total arch replacement under deep hypothermia with circulatory arrest through a midsternotomy for this subset of aneurysms. METHODS: From January 1998 to February 2003, 119 patients underwent elective total arch replacement (mean age, 72.3 +/- 6.0 years) for distal arch aneurysm under deep hypothermia with circulatory arrest. Antegrade selective cerebral perfusion was used for brain protection. Arch vessels were independently reconstructed using quadrifurcated grafts. Concomitant procedures included tricuspid annuloplasty in 1 patient, aortic valve operations in 2, sinotubular junction plication in 6, and coronary artery grafting in 22. RESULTS: The early mortality rate was 0.84% (1 of 119). The mean duration of circulatory arrest was 67.1 +/- 19.7 minutes. Perioperative stroke rate was 0.84% (1 of 119). This stroke occurred 9 days postoperatively in an 81-year-old man with a history of cerebral infarction. Other complications were reexploration for bleeding in 1 patient (0.84%) and respiratory failure in 6 (5.0%). CONCLUSIONS: This operative approach for distal arch aneurysm featured a low mortality rate and low risk of perioperative stroke. Concomitant cardiac surgery could be performed routinely in standard fashion. Distal arch aneurysms that do not involve a large segment of the descending thoracic aorta can thus be repaired with low mortality and few cerebral complications through a midsternotomy.

Aged↗
PubMed2006

Functional angiographic evaluation of individual, sequential, and composite arterial grafts.

BACKGROUND: To help optimize graft arrangement, we examined the effects of target vessel characteristics, conduit type, and interactions between the target vessels on the occurrence of flow reversal or occlusion. METHODS: The postoperative angiograms of 458 patients after total arterial revascularization with an off-pump, no aortic manipulation technique beginning in December 2000 were reviewed. Reverse flow was defined as the lack of opacification of a distal anastomotic site during graft angiography, but clear retrograde graft opacification during native coronary angiography. We analyzed characteristics of the target coronary branches, and bypass conduits. The potential interactions between coronary branches and sequential anastomoses were categorized as those with two 75% stenotic branches (situation 1); one 75% stenotic branch at the end of the graft and a 99% to 100% stenotic branch at the middle of the graft (situation 2); and a composite Y (or K) graft with one end to a 75% stenotic branch and the other to a 99% to 100% stenotic branch (situation 3). RESULTS: A total of 18 bypasses (1.1%) were occluded while reverse flow was found in 4.5% (74 of 1,627). In a multivariate analysis of the 521 bypass conduits having more than two distal anastomoses, the predictors of reverse flow or occlusion were a right coronary artery target with 75% or less stenosis (p = 0.006), more than three distal anastomoses with a conduit (p = 0.005), situation 1 (p = 0.04), situation 2 (p < 0.0001), and situation 3 (p < 0.0001). CONCLUSIONS: Interactions between coronary branches and graft arrangement play important roles in flow distribution. Graft arrangement should be adjusted for each patient to minimize reverse flow.

Aged↗