On 5 February 1986, a committee meeting was held at Hilltop Congress Hall of Tokyo University to establish Japanese Society for Angioscopy and Laser Angioplasty. The members of the committee were Drs. Hitoshi Koyanagi, Syoichi Takekawa, Syunichi Hoshino, Masayoshi Okada, Komei Sugimoto, and Yasumi Uchida (myself). I was recommended as the representative of this society. On 26 September 1987, the first annual meeting of this society was held at the Hilltop Congress Hall. Dr. George Abela was invited as a guest speaker on laser angioplasty of the peripheral artery. On 17 September 1988, the second annual meeting, too, was held successfully at the same Hall. Since then, the meeting was held in Autumn every year. Since 1991, proceedings of the meeting were published in English every year. In 1998, the name of this society was changed to Japanese Association for Cardioangioscopy, and Dr. Uchida was elected as the president. In 2007, Dr. Kyoichi Mizuno was elected as the next president. During the past 29 years, angioscopy was applied clinically not only to coronary artery but also to cardiac chambers and valves, peripheral vessels and great vessels, and many hitherto unrecognized mechanisms of vascular disease were discovered. Many valuable papers were published in famous journals not only in Japan but also in abroad. Angioscopy and cardioscopy both conventional and fluorescent are now directed to cellular and molecular imaging of cardiovascular diseases, and also for guidance of intravascular and intracardiac surgery. This imaging technique will further contribute to diagnosis and evaluation of medical and surgical therapies of cardiovascular diseases.

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Recently, much attention has been paid to treat with the patients of intermittent claudication for minimal invasive method in the field of cardiovascular surgery. Earlier, there were only two methods of drug therapy and surgical therapy for cardiovascular diseases. However, there are some other kinds of methods such as balloon, atherectomy, laser, and stenting methods. Here, it is very important to check the vascular disease with angioscopic guidance. So, we have developed for long time, until angioscopy is available for clinical use. It was important to see clearly the inside of the vessels removing blood. So, we made a new flush channel of 1 mm inside the angioscope, with an outer diameter of 2.8 mm. With this angioscope, it was possible to check the inside of the vessels before and after laser therapy. The procedures and techniques are important for recognition of improvement before and after surgical therapy.

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Although long-term rather than short-term efficacy of new coronary stents is very important for patients, it is usually evaluated by the one-year results of randomized comparison trials. When Cypher-sirolimus-eluting stent (C-SES) was compared with Endeavor-zotarolimus-eluting stent (E-ZES), one-year results was significantly better for C-SES; however, the 5-year results was significantly better for E-ZES due to the higher event rate in C-SES after one year. Although the angioscopic images of those stents at one year demonstrated better neointimal coverage in E-ZES than in C-SES and suggested higher risk of complications in C-SES than in E-ZES, many interventionists preferred C-SES than E-ZES in the real world. A major mechanism of very-late drug-eluting stent (DES) failure has been regarded as neoatherosclerosis or atherosclerosis progression. Therefore, the formation of yellow plaque and its disruption may be the mechanism from the angioscopic viewpoint. C-SES is known to accelerate the formation of yellow plaque and E-ZES is known to reduce the yellow color by the formation of thick white neointima, while new DES like Xience-everolimus-eluting stent does not change the yellow color of the original vessel wall. We believe the information coming from the imaging studies should be paid more attention when we speculate the long-term outcome of new stents until the real long-term outcome data become available.

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In the era of drug-eluting stents, in-stent restenosis remains a major concern in patients with coronary artery disease. Recently, in-stent restenotic tissue patterns on optical coherence tomography (OCT) have been reported. However, the characteristics of restenotic tissue in hemodialysis patients have not been fully investigated. In the present study, we observed eight in-stent restenotic lesions in eight hemodialysis patients who underwent percutaneous coronary intervention with coronary angioscopy (CAS) and OCT examination. Two lesions (one lesion with a bare metal stent and one lesion with an everolimus-eluting stent) showed a layered restenotic tissue on OCT and white or light yellow neointima on CAS. One lesion treated with a sirolimus-eluting stent showed a restenotic lesion with red mural thrombus on CAS and OCT. Other five lesions showed lipid-laden neointima on OCT, including two lesions with yellow neointima on CAS that were suggestive of lipid-rich neointima, and three lesions that were suggestive of neointimal calcification on CAS. We suggest the discrepancy between the angioscopic and OCT findings might be explained by the presence of neointimal calcifications containing lipidic components. Patients undergoing hemodialysis potentially have an increased risk of progressive calcified atherosclerosis. Our findings suggest rapid progression of neointimal calcification inside the stent might have occurred especially in hemodialysis status.

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Background: Aggressive lipid-lowering therapy by statins is recommended for the primary and secondary prevention of cardiovascular events in diabetes patients. Although atherosclerotic change has been shown to progress in pre-diabetic patients, the effect of statins in pre-diabetic patients is not well known.
Purpose: To compare the degree of atherosclerosis in pre-diabetic patients with and without statin therapy using coronary angioscopy.
Methods: This was a retrospective cross-sectional study. Twenty-eight pre-diabetic patients underwent angioscopic multi-vessel evaluation of the coronary arteries. The color grade of yellow plaque was defined as 1 (light yellow), 2 (yellow), or 3 (intense yellow) based on semiquantitative analysis of angioscopic findings. The number of yellow plaques (NYP) per vessel and the maximum yellow grade (MYG) were compared between patients with and without statin therapy (statin group and non-statin group, respectively).
Results: Baseline characteristics including serum levels of low-density lipoprotein cholesterol were similar between the two groups. Mean NYP and MYG were significantly lower in the statin group than in the non-statin group (2.03 ± 0.59 vs. 1.12 ± 0.73, P = 0.002; and 2.50 ± 0.71 vs. 1.72 ± 0.83, P = 0.019; respectively).
Conclusions: The coronary angioscopic findings in the present study suggest that statin therapy plays an important role in inhibiting atherosclerotic progression in pre-diabetic patients. From the viewpoint of preventive medicine, statins may be administered in the early stage of glucose metabolism disorder.

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Previous studies showed that intimal atherosclerotic change over stent was found, which is the so-called in-stent neoatherosclerosis. Previous studies with coronary imaging devices such as intravascular ultrasound and optical coherence tomography demonstrated that in-stent neoatherosclerosis was observed several years after stent implantation. However, a few cases of in-stent neoatherosclerosis observed by coronary angioscopy (CAS) have been reported. A 50-year-old male was treated with bare metal stent (BMS) implantation at proximal right coronary artery (RCA) for first acute myocardial infarction (AMI). Ten years later, he suffered from a second AMI. Emergency coronary angiography showed a de novo lesion of severe stenosis at mid RCA and mild restenosis of BMS which had been implanted at proximal RCA 10 years ago. Severe stenosis at mid RCA seemed to be the culprit lesion. At mid RCA of the culprit lesions, CAS showed that red thrombus was observed on yellow plaque without plaque rupture. Intravascular ultrasound (IVUS) showed luminal narrowing with attenuated plaque, with neither plaque rupture nor thrombus. Plaque erosion was the mechanism of occurrence of acute coronary syndrome. At mid and proximal portions in BMS, several yellow plaques were observed whose morphology was complex with irregular surface. Red thrombus stuck on yellow plaque stickily, not sticking out of the lumen. In BMS segment, IVUS showed neointimal proliferation with dissection over BMS, which part was low echoic plaque. CAS revealed yellow plaque and silent stent thrombus in the BMS segment implanted 10 years ago. These findings suggested neoatherosclerosis with high thrombogenity formed in neointima after BMS implantation.

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Femoral arteries are the most popular vessels of vascular access for angiography or percutaneous catheter intervention because of their diameter and accessibility. After the catheter procedures, hemostasis at the puncture site is achieved with conventional manual compression or by use of several vascular closure devices (VCDs) in recent years. However, the use of these devices infrequently results in lower limb ischemia as their major complications. We highlight a case of acute femoral artery occlusion caused by Angio-Seal ™ hemostatic device and angioscopic findings of the case. Angioscopy after revascularization by balloon angioplasty revealed a residual red and white thrombi and an inorganic pale mass protruding into the lumen. The color of the mass was considered strange in vivo. On the basis of angioscopic findings, it was speculated that collagen sponge of the Angio-Seal accidently penetrated in to the arterial wall and the collagen component in the lumen caused thrombotic occlusion. Interventional cardiologist should be aware that serious problems sometimes occur when VCDs are used.

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Several clinical studies have shown comparative outcomes of paclitaxel-eluting stent (PES), Zilver PTX and bare-metal stent (BMS), Zilver implanted into the superficial femoral artery. However, detailed process of vascular healing after implantation of the 2 different stents is little known. We assessed a total of 3 patients of successfully deployed 1 BMS and 2 PES who underwent angiographic and angioscopic follow-ups after 6 months of the intervention. The degree of neointimal stent coverage (NSC) was classified into presence of uncovered struts (grade 0), visible struts through a thin neointima (grade 1), or invisible struts with complete neointimal coverage (grade 2). Also, the existence of in-stent thrombus was also evaluated qualitatively using angioscopy. In a case of BMS, follow-up angiography confirmed stent patency. Angioscopy showed that stent struts were fully and homogeneously covered by proliferating white neointima (grade 2) without thrombus. One PES was angiographically patent but another showed diffuse restenosis. In a case without restenosis, angioscopy showed heterogeneous neointimal coverage within the PES segment. Although stent struts were clearly visible and neointimal coverage was absent (grade 0) at the proximal site, thick neointima covered stent and the struts were invisible (grade 2) at the mid and distal segments without thrombus. In a case of restenosis, angioscopy found thin and thick neointima (grade 1 and 2, respectively) as heterogeneous artery healing of the PES with no thrombus. This angioscopic observation revealed that heterogeneous growth of neointima in Zilver PTX, while Zilver showed homogenous healing at 6 months of their implantation.

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