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Makoto Hirose

Publications and source records attributed to Makoto Hirose.

At least 19 recordsLinked to original sources
PubMed2006

Method analysis for optimal continuous imaging using intravascular optical coherence tomography.

OBJECTIVES: Optical coherence tomography(OCT)is a high-resolution imaging method that can clearly visualize vessels through the displacement of blood with flushing agents. Continuous imaging methods have not been established. This study investigated optimal methods for continuous OCT imaging. METHODS: Thirty-four arteries with stent implantation (24 peripheral and 10 coronary arteries)in 14 pigs were examined using OCT with a motorized pullback device. Two imaging methods (flush alone by liquid substance and flush with occlusion) were compared. Adequate image acquisition was defined as the entire circumferential intimal layer being detectable within continuous segments. To investigate factors that could influence image quality, stented regions were divided into 4-5 mm segments. RESULTS: The flush with occlusion method provided better OCT images compared to flush alone (flush with occlusion: 60.9%, flush alone: 8.7%, p = 0.0002). Using the flush with occlusion method, the rate of adequate image acquisition was 64.4% and visualization of > 75% intimal circumference was 83.5%. Intravascular ultrasound could detect all stented regions. Segmental analyses found more adequate images were detected in smaller vessels (adequate segment: 3.8 +/- 0.4 mm, inadequate segment: 4.2 +/- 0.8 mm, p < 0.0001) or with centered image wire position (adequate segment: center 35%, inadequate segment: center 14%, p = 0.003). In addition, side branches did not affect image quality. CONCLUSIONS: To acquire continuous OCT images, the flush with occlusion method was more effective compared to flush alone. Moreover, image quality is affected by vessel size and imaging wire position. These results suggest that optimized OCT imaging can provide continuous vessel detection.

Animals↗
PubMed2005

[Skull metastasis of hepatocellular carcinoma: case report].

We report a case of skull metastasis from a hepatocellular carcinoma (HCC). A 68-year-old male with hepatitis C virus-associated cirrhosis and HCC presented with painless subcutaneous mass in the left frontotemporal region. Radiologically, skull X-ray showed an osteolytic lesion, and non-contrast CT displayed a hyperdense tumor that homogeneously enhanced on contrast CT. Cerebral angiography demonstrated a hypervascular mass with the feeding arteries from the external carotid artery. The tumor was shown as an iso-intensity mass with flow voids on T1WI, as iso- to hypo- intensity on T2WI and FLAIR images, and as hypo-intensity on DWI. The lesion was markedly enhanced by Gd-DTPA. Previous reports have described a low incidence of skull metastasis in HCC patients. However, the incidence is gradually increasing due to the prolonged survival rates of HCC patients, indicating the significance of the disease as a differencial diagnosis for skull tumors. Recent reports describe characteristic MRI findings of skull metastasis from HCC (hypointensity on T2WI with flow void); however, owing to the rarity of this disease, more studies are needed to establish the typical MRI pathognomonic findings.

Aged↗
PubMed2004

Relation of final lumen dimensions in saphenous vein grafts after stent implantation to outcome.

Larger final lumen dimensions after percutaneous coronary interventions in native coronary arteries lead to lower restenosis rates. We sought to determine the impact of stent expansion, as assessed by intravascular ultrasound, on clinical results of stent implantation in saphenous vein grafts (SVGs). We identified 226 consecutive patients who underwent intravascular ultrasound-guided stenting of 234 de novo SVG lesions. Patients were divided into 2 groups based on the final stent cross-sectional area (CSA): group I (stent CSA <100% of the reference lumen CSA, n = 176 patients, 182 lesions) and group II (stent CSA >/=100% of the reference lumen CSA, n = 50 patients, 52 lesions). Baseline patient characteristics were similar between the 2 groups with the exception of smaller lesions in group II. More aggressive stent expansion (group II) was associated with (1) increased rates of in-hospital non-Q-wave myocardial infarction (29% vs 17%, p = 0.05), (2) any myocardial infarction (26% vs 8%, p = 0.003) at 1-year follow-up, and (3) no improvement in target vessel revascularization at 1 year (31% vs 26%, p = 0.3). Aggressive stent expansion in SVG lesions resulted in higher myocardial infarction rates and, unlike native arteries, no improvement in target vessel revascularization rate at 1 year. A less aggressive stent implantation strategy in SVGs than in native coronary lesions appears prudent.

Aged↗
PubMed2004

Luminal narrowing due to intramural hematoma shift from left anterior descending coronary artery to left circumflex artery.

This case report demonstrates subacute luminal narrowing 20 days after balloon angioplasty in the left anterior descending coronary artery due to an intramural hematoma. Stenting was performed and resulted in side-branch compromise caused by squeezing the hematoma from the left anterior descending coronary artery into the left circumflex artery. Another stent was deployed to treat the stenosis in the left circumflex artery.

Adult↗
PubMed2004

[Transient abnormalities associated with status epilepticus on diffusion-weighted MR imaging].

We report on two patients with transient abnormalities on MRI during status epilepticus(SE). Diffusion-weighted MR imaging(DWI) and T2-weighted and fluid-attenuated inversion recovery (FLAIR) MR images showed cortical and thalamic hyperintensity with swelling of the cortex. The lesions did not respect vascular territories. We also observed an increased signal in the ipsilateral middle cerebral artery on magnetic resonance angiography(MRA), and leptomeningeal enhancement on postcontrast MRI. Follow-up imaging revealed that the abnormal findings resolved within a few weeks, although a residual area of increased T2 signal intensity persisted. These findings suggest the presence of reversible cytotoxic and vasogenic edema induced by seizure. We conclude that this disorder should be taken into consideration in the differential diagnosis of other conditions, including ischemic stroke.

Aged↗
PubMed2004

[Solitary subependymal giant cell astrocytoma: a forme fruste of tuberous sclerosis complex?].

Subependymal giant cell astrocytoma (SEGA) is usually associated with tuberous sclerosis (TS) and believed to originate from subependymal nodules. We report a rare case of SEGA in a patient lacking symptoms of TS. Radiological findings, including CT and MRI, were characteristic of SEGA, but the preoperative diagnosis was difficult due to the fact that no other features of TS were present. TS has been classically characterized by the clinical presence of Vogt's triad of seizure, facial angiofibroma and mental retardation, however, few cases present with all of these manifestations. In 1998, Roarch et al. proposed new clinical diagnostic criteria for the TS complex based on the clinical and radiographic features of TS. According to these criteria, our case is classified as a "possible" TS complex. There have been previous reports of SEGAs without any obvious features of TS, but it is still controversial as to whether these reports represent a forme fruste of TS. To determine a strict diagnosis of SEGA, additional genetic studies are needed. The possibility of SEGA should be considered whenever an intraventricular tumor near the foramen of Monro is found, regardless of other clinical features of TS.

Adult↗
PubMed2004

[Minimal change nephrotic syndrome].

In minimal change nephrotic syndrome (MCNS), selective proteinuria is associated with structural alterations of the glomerular epithelial cells, such as effacement of the foot process. Although the pathogenesis of MCNS has not been completely clarified, clinical and experimental observations suggest that it results from T cell dysfunction in the pathogenesis. Recently, it has been proposed that the occurrence of MCNS has been associated with type 2 Th (Th2) lymphocyte-dependent conditions and some vascular permeability factors, which are induced by T cell disorder. In general, MCNS has the good long-term outcome with sustained remission and preserved renal function, because almost cases are responsible for the treatment. However, some patients show frequent relapses or resistance to this treatment and need large doses of immunosuppressive agents for a long time. Therefore, we should be care for the complications associated with prolonged these therapies.

Drug Hypersensitivity↗
PubMed2004

[Significance of point of no return in therapeutic strategy for treatment of renal osteodystrophy; from histopathological findings].

Point of no return implies a stage at irreversible to medical treatment of secondary hyperparathyroidism, clinically equivalent to intact PTH levels are more than 500 pg/mL in Japan. Most of glands resected by parathyroidectomy indicate nodular hyperplasia, increased parathyroid cell proliferation. Down-regulation of calcium sensing receptors and vitamin D receptors in nodular parathyroid cells become a cause of resistance to medical treatment. Most of nodular glands are more than 500 mg in weight, predictable to existence at estimated volume and gland color signals by ultrasonographic method. New options both parathyroid injection therapy using ethanol and active vitamin D, and calcimimetic agent have a potential to change point of no return in therapeutic strategy for secondary hyperparathyroidism.

Biomarkers↗
PubMed2004

Impact of HMG-CoA reductase inhibitors for non-treated coronary segments.

BACKGROUND: HMG-CoA reductase inhibitors (statin) have been reported to decrease coronary artery events in several angiographic studies. However, the mechanism by which statin achieve this is still unclear. The purpose of this study was to identify the effect of statin on coronary plaque using serial intravascular ultrasound analysis. METHODS AND RESULTS: In this study, 48 patients with 48 lesions were divided into the prescribed group (statin group, n = 22) or the non-prescribed group (control group, n = 26) after successful coronary artery stenting. IVUS images were obtained at consecutive 5 mm segments, 5 mm from the proximal stent edge, immediately after stenting and at 6 months follow up. External elastic membrane volume (EEMV), lumen volume (LV) and plaque volume (PV) were measured using Simpson's method. The control group revealed no significant serial change in EEMV, PV, and LV during 6 months. On the other hand, the statin group revealed significant reductions of PV (35.5 +/- 12.7 mm3 vs 30.9 +/- 15.6 mm3, p = 0.001), resulting in increase of LV (47.7 +/- 19.8 mm3 vs 52.5 +/- 22.2 mm3, p = 0.003) without EEMV change (82.8 +/- 21.8 mm3 vs 83.9 +/- 25.7 mm3, p = NS). Although percent EEMV and percent LV changes showed no differences between the two groups, a larger percent PV change was observed in the statin group compared to the control group (control; 5.8 +/- 20.3% vs statin; -20.4 +/- 21.8%, p = 0.02). CONCLUSION: The results of this study suggest that statin administration for 6 months reduces coronary plaque without positive vessel remodeling.

Aged↗
PubMed2004

The impact of IVUS guided bare metal stent implantation for non-small vessel.

UNLABELLED: Previous studies have shown larger target vessel or greater stent area contribute to reduced restenosis rate. Thus, intravascular ultrasound (IVUS)-guided bare metal stent (BMS) implantation for selected lesions might achieve drug-eluting stent-like outcomes. The aim was to examine the long-term outcomes of BMS using IVUS-guided optimization. METHODS: Consecutive 103 coronary artery lesions suitable for IVUS were enrolled. Using IVUS, final stent balloon size selected was 90 percent of media-to-media diameter at the lesion or distal reference. The balloon size was listed as follows: group A (3.0-3.5 mm, n = 15), group B (3.5-3.75 mm, n = 64), and group C (3.75-4.5 mm, n = 24). RESULTS: At post-intervention, average stent area increased by the balloon size (A: 7.2 +/- 1.4 mm2, B: 8.9 +/- 1.5 mm2, and C: 12.1 +/- 2.0 mm2, respectively p < 0.001). At 6 month follow up, the average lumen area increased by balloon size (A: 4.1 +/- 1.7 mm2, B: 5.7 +/- 1.2 mm2, and C: 8.1 +/- 2.0 mm2, respectively p < 0.001). Accordingly, group B and C revealed lower restenosis, compared to group A (A: 46.7%, B: 10.9%, C: 8.3%, A vs B: p = 0.001; C vs A: p = 0.015). Moreover, target lesion revascularization was less in group B and C than group A (A 26.6%, B 3.1%, C 0%, A vs B: p = 0.011; C vs A: p = 0.017). CONCLUSIONS: For non-small vessels, IVUS-guided BMS implantation showed less restenosis and target lesion revascularization compared to small vessels, mainly due to larger initial gain. These study results suggest that IVUS-guided optimal BMS implantation for selected lesions might result in favorable long-term outcomes similar to those seen using drug-eluting stents. For a decade, coronary stenting has become a standard therapy for coronary artery disease due to favorable long-term outcomes and simple treatment procedure. Furthermore, for the last two years, drug-eluting stents (DES), releasing antiproliferative agents from bare metal backbone, revealed the restenosis rates less than half of those seen using conventional bare metal stents (BMS). While target lesions especially suitable for DES continue to be identified, earlier BMS studies showed that larger target vessel or greater stent area contributed to less restenosis. Thus, optimal IVUS-guided BMS implantation for selected lesions might achieve DES-like long-term outcomes. This study was designed to examine the long-term outcomes of BMS with intravascular ultrasound (IVUS)-guided optimization, using coronary angiography and IVUS data.

Aged↗
PubMed2003

Optimal final lumen area and predictors of target lesion revascularization after stent implantation in small coronary arteries.

Despite similar early clinical events, patients who undergo treatment of small vessels are at an increased risk for target lesion revascularization (TLR) after coronary artery stenting. We sought to determine predictors of TLR after stent implantation in small coronary arteries. We identified 423 consecutive patients who underwent intravascular ultrasound (IVUS)-guided small vessel stenting procedures in 465 coronary lesions with an angiographic reference vessel diameter of <2.75 mm. Patients were divided into 2 groups based on a final IVUS lumen area of < or =6.0 mm2 (n=345 lesions, group I) and >6.0 mm2 (n=115, group II). Baseline patient characteristics and in-hospital outcomes were similar between the 2 groups, except for a higher rate of restenotic lesions in group I and bifurcation lesions in group II. Group I had higher TLR rates at 1 year compared with group II patients (39% vs 26%, p = 0.02). The TLR rate appeared to decrease with greater stent expansion, especially at >90% of the reference vessel area, as assessed by IVUS. By multivariate analysis, an IVUS final stent area of < or =6 mm2, diabetes, absence of prior myocardial infarction, and history of intervention were independent predictors of 1-year TLR in this population. Final stent area of >6.0 mm2 and greater stent expansion were associated with a decrease in TLR. Therefore, there does not appear to be any "downside" to aggressive stent implantation strategies in small vessels. In contrast, IVUS allows maximization of final lumen dimensions to minimize clinical restenosis.

Aged↗
PubMed2003

Correlation of coronary arterial remodeling determined by intravascular ultrasound with angiographic diameter reduction of 20% to 60%.

Negative remodeling is commonly observed in stenotic coronary lesions. It is unknown whether negative remodeling is an early or late event. This study was designed to elucidate when negative remodeling occurs in the development of coronary stenosis. Remodeling was assessed by preintervention intravascular ultrasound in 104 native coronary lesions with intermediate stenosis (20% to 60% of diameter stenosis measured by quantitative coronary angiography). Positive remodeling was defined as lesion external elastic membrane (EEM) cross-sectional area (CSA) greater than the proximal reference, intermediate remodeling as lesion EEM CSA between those of the proximal and distal references, and negative remodeling as lesion EEM CSA less than the distal reference. Positive, intermediate, and negative remodeling were observed in 18%, 32%, and 50%, respectively, of lesions with intermediate stenosis. Lesions with negative and intermediate remodeling had more hard plaque compared with those with positive remodeling (79% vs 70% vs 42%, p = 0.02). Calcium was more frequent in lesions with negative and intermediate remodeling than in those with positive remodeling (52% vs 55% vs 16%, p = 0.01). Lesions with negative remodeling had smaller EEM CSA (11.5 +/- 5.2 vs. 13.7 +/- 3.4 vs 14.5 +/- 5.6 mm(2), p = 0.03) and less plaque (7.9 +/- 4.6 vs 10.8 +/- 3.4 vs 10.8 +/- 4.9 mm(2), p = 0.004) compared with positive and intermediate remodeling lesions, although lumen CSA (3.7 +/- 1.7 vs 2.8 +/- 0.8 vs 3.6 +/- 1.3 mm(2), p = 0.1) and area stenosis (57 +/- 15% vs 59 +/- 14% vs 56 +/- 10%, p = 0.7) were similar. Negative remodeling is frequently observed in lesions with intermediate stenosis. This suggests that negative remodeling occurs early in lesion formation.

Aged↗
PubMed2002

Short- and long-term outcomes of compromised side branches after Multi-Link stent implantation.

The Multi-Link stent is superior to other stents in terms of low rates of restenosis and target vessel revascularization. However, few data exist regarding short- and long-term outcomes for side branches after stenting. We evaluated short and long clinical outcomes and angiographic predictors of side-branch occlusion after the deployment of 137 Multi-Link stents. Thirty-four (25%) of the 137 side branches occluded immediately after stenting. We attempted reangioplasty for the side branches and our success rate was 85%. The incidence of side branches with intrinsic ostial disease was more than 50% before stenting and origination from the stented midsegment was a powerful angiographic predictor of side-branch occlusion. Side-branch patency is well maintained long-term. The incidence of restenosis within and near the stented segment of the parent vessel was 19%, and the incidence of target vessel revascularization was 15%. We recommend the use of Multi-Link stents regardless of the presence of side branches in the vicinity of the stenosis.

Aged↗
PubMed2002

Head-to-head comparison of fundamental, tissue harmonic and contrast harmonic imaging with or without an air-filled contrast agent, levovist, for endocardial border delineation in patients with poor quality images.

Recent developments in tissue harmonic imaging and intravenous contrast agents have enhanced left ventricular endocardial border delineation (EBD). In a total of 48 patients with poor quality images, apical 4- and 2-chamber views were obtained with fundamental, tissue harmonic and contrast harmonic imaging with or without intravenous Levovist, an air-filled contrast agent. The left ventricle (LV) was divided into 12 segments, and the EBD of each segment was scored: (1) not visible, (2) barely visible, (3) well delineated. The EBD index (EBDI), defined as the sum of the endocardial scores divided by 12 was obtained for each patient. Of a total of 576 LV segments, 231 were scored as 1 by fundamental imaging and that number decreased to 125 segments by tissue harmonic imaging and 116 segments by fundamental imaging with Levovist. The number of segments scored as 1 decreased to 38 segments by tissue harmonic imaging with Levovist, and to 29 segments by contrast harmonic imaging with Levovist. The EBDI by fundamental imaging was 1.85+/-0.29, which improved significantly with the addition of Levovist (2.10+/-0.36, p<0.001) and was nearly identical to that by tissue harmonic imaging (2.15+/-0.32, p=NS). Tissue and contrast harmonic imaging with Levovist further enhanced the EBDI (2.43+/-0.26, 2.51+/-0.27, respectively). Levovist enhances EBD, even in the fundamental mode, to the level obtained with tissue harmonic imaging. Tissue harmonic and contrast harmonic imaging are the best modalities for enhancing EBD after Levovist injection.

Aged↗
PubMed2002

Coronary artery spasm associated with a moderately severe atherosclerotic stenosis in the proximal LAD.

Treatment of coronary artery spasm can be difficult; up to 25% of patients continue to have episodes of chest pain despite maximal therapy with calcium antagonists and nitrates. We describe the case of a 42-year-old female with severe coronary artery spasm associated with a moderately severe atherosclerotic stenosis of the proximal left anterior descending coronary artery. We discuss the diagnostic value of intravascular ultrasound and treatment options for spasm associated with atherosclerotic plaques.

Adult↗