Shoma Sugawara

Angioscopy and OCT in repeated in-stent restenosis in saphenous vein graft.

The morphological characteristics of in-stent restenosis (ISR) that occur in multiple layers of stents (stent in stent) are not well described. We used multimodality imaging in a 69-year-old man in whom repeated episodes of restenosis developed in a 9-year-old saphenous vein graft (SVG) to the left

“Intracoronary Whirling Current Phenomenon” and Thrombus Formation After Sirolimus-Eluting Stent Implantation Visualized by Optical Coherence Tomography

We present a case of imaged “intracoronary whirling current phenomenon.” A 60-year-old Japanese man was treated with 2 sirolimus-eluting stents (SES; 3.0×18 and 3.5×33 mm) in the right coronary artery (RCA) for chronic total occlusion in October 2007. After percutaneous coronary intervention, he was taking 200 mg of aspirin and 200 mg of ticlopidine. However, he had recurrent transient ischemic chest pain beginning at 7 months. A second coronary angiography at 8 months after SES implantation showed reocclusion at a site just proximal to the SES. A repeat percutaneous coronary intervention was performed for RCA chronic total occlusion (Figure 1). After crossing the guide wire to the distal portion of the RCA, the target lesion was dilated using a 1.25×10 mm balloon catheter. After minimum balloon dilatation, optical coherence tomography (OCT) was performed to evaluate in-stent reocclusion from the distal portion to the proximal portion (Figure 2). Two different types of tissue coverage (may be consistent with thrombus formations of different ages) were observed in the stent reocclusion.1 Moreover, in the patent distal portion of the RCA, an intracoronary whirling current …

Peripheral vasodilatory dysfunction in adult patients with congenital heart disease and severely elevated pulmonary vascular resistance.

Several studies have demonstrated that pulmonary vascular abnormalities precede alterations in aortic circulation downstream in animal models of heart failure. The relationship between increased pulmonary vascular resistance (PVR) and agonist-induced limb vasodilatory response remains unknown in patients with congenital cardiovascular shunt lesions (CSL). The authors hypothesized that patients with CSL and severely elevated PVR will show a defective vasomotor response in the peripheral vascular bed. To examine this hypothesis we measured forearm blood flow (FBF) responses to the endothelium-dependent vasodilator acetylcholine and the endothelium-independent vasodilator sodium nitroprusside. The values for these FBF responses were compared with PVR in adult patients with CSL (n = 20) and healthy age- and sex-matched controls (n = 15). When patients with CSL were divided into 2 subgroups by median value of PVR, in the lower PVR subgroup, acetylcholine-induced FBF changes were selectively and significantly lower than in the healthy control group (p < 0.05). In the higher PVR subgroup, FBF responses to both acetylcholine and sodium nitroprusside were significantly blunted compared to healthy controls (both p<0.01). In addition, when FBF changes above baseline for each dose of acetylcholine and sodium nitroprusside were cumulated and used as acetylcholine response and sodium nitroprusside response, the sensi tivity and specificity for identifying patients with Eisenmengers type of CSL was 100% and 80% by acetylcholine response, and 67% and 80% by sodium nitroprusside response, respec tively. In conclusion, adult CSL patients with elevated PVR and severe pulmonary arterial hypertension showed generalized vasodilator dysfunction in the forearm vasculature. This result suggests that upper limb resistance vessel dysfunction may be an indicator for advanced stage of adult patients with CSL.

Chronic thrombus occlusion after bare metal stenting in a patient with acute coronary syndrome visualized by optical coherence tomography

We present a case of chronic thrombus occlusion visualized by optical coherence tomography (OCT) in a patient following bare metal stent (BMS) implantation. A 74-year-old Japanese man was treated with single BMS implantation for acute coronary syndrome. The second follow-up angiography demonstrated no restenosis at the BMS site in the convalescent phase before discharge. A third coronary angiography at 6 months after BMS implantation showed sub-total occlusion at a site just proximal to the BMS. OCT was performed to evaluate in-stent restenosis. OCT demonstrated an organized thrombus-like image containing a micro-channel in the target lesion. Repeat percutaneous coronary intervention (PCI) was performed with a distal protection device and we were able to aspirate some tissue from the culprit lesion. Pathological examination of this tissue revealed an organized fibrin thrombus with angiogenesis. Phosphotungstic acid hematoxylin staining and CD68 immunological staining were positive in this tissue. Moreover, immunological staining for CD34 was positive in the micro-channel of this tissue, suggesting chronic build up. This case demonstrated that chronic, organized thrombus formation is a possible cause of restenosis after BMS implantation in the convalescent phase, and that OCT is a useful modality to discriminate thrombus formation from regular neo-intimal hyperplasia in in-stent restenosis lesions.

Late stent thrombosis after discontinuation of dual anti-platelet therapy in off-label use of paclitaxel-eluting stent visualized by optical coherence tomography—3-vessel OCT study

We observed late stent thrombosis image by optical coherence tomography (OCT) in vessels with off-label paclitaxel-eluting stents (PES) implantation. A 59-year-old Japanese man was treated with a single on-label PES for chronic coronary artery disease in the left circumflex artery. After 9 months, he was implanted with two linked PESs in the left anterior descending artery (LAD) and a single PES in the right coronary artery (RCA). He was examined for suspicion of a colon tumor by fiberscope after discontinuation of dual anti-platelet therapy without consultation. He complained of chest pain and was transferred to our center. Emergency coronary angiography demonstrated thrombotic total occlusion of the proximal LAD in the two linked PESs. After thrombus aspiration therapy, OCT was performed to evaluate the stents in the 3 vessels. The off-label two linked PESs demonstrated the same average neo-intimal hyperplasia (NIH) thickness and percentage of uncovered stent struts compared with the on-label PES in the RCA by visualized OCT image. However, the heterogeneity of NIH in the LAD stent was significantly higher than the stents in the other two vessels. The implantation of the two linked off-label and the heterogeneity of NIH may increase hyperplatelet coagulability more than on-label single PES use.

Serial endovascular assessment of polytetrafluoroethylene-covered stent: Capabilities and limitations of intravascular imaging modalities affected by a temporal factor

A 47-year-old male who previously underwent coronary bypass graft surgery was transferred to our hospital for treatment of bare metal in-stent restenosis (ISR) of severely calcified left main (LM) coronary lesion. During a repeat coronary intervention, LM coronary perforation occurred after rotational atherectomy followed by balloon dilatation. Hemostasis was successfully achieved by implantation of a single polytetrafluoroethylene (PTFE)-covered stent. Although intravascular ultrasound (IVUS) and optical coherence tomography (OCT) were documented, any additional information was not obtained except stent expansion. Routine 6-month follow-up angiography revealed no findings of restenosis. Three representative imaging modalities, IVUS, OCT, and angioscopy were applied to visualize and differentiate any structures within the PTFE-covered stent. Intravascular findings included, (1) vascular structures outside the covered stent could be observed sufficiently by both IVUS and OCT at this time that could not be seen at all just after implantation, (2) neointimal hyperplasia distributed dominantly at both stent edges, and (3) in-stent micro thrombi still existed even 6 months after implantation. Intravascular findings of PTFE-covered stent may vary between the observational periods. Furthermore, vascular healing process of this special stent may be different from those of non-covered mesh stents. <Learning objective: Even with the use of IVUS and OCT, it may be difficult to evaluate apposition of PTFE-covered stent just after implantation. However, it could be visualized as being sufficiently similar to the other common stents at 6-month follow-up. Unique longitudinal NIH distribution (bilateral edge dominant) was evaluated, and existence of micro thrombi within PTFE-covered stent even at 6 months.>.