Authors: Shiho Wakasa, Hiroya Hayashi, Takanori Yamazaki...

KEY CLINICAL MESSAGE

Contrast defects in veins are often diagnosed as benign thrombi, but depending on the patient's background it is necessary to differentiate between tumor thrombi. It is difficult to differentiate between these using contrast-enhanced CT alone, but with angioscopy it is easy to visually distinguish between a benign and tumor thrombi.

ABSTRACT

Contrast-enhanced computer tomography (CT) performed on a male patient being treated for de-differentiated chondrosarcoma revealed contrast defects in the pulmonary artery and right femoral vein, and a diagnosis of pulmonary artery thromboembolism and venous thromboembolism was made, and oral anticoagulant therapy was started. However, a follow-up CT showed that the contrast defect had extended to the inferior vena cava. Observation using an angioscope revealed that it was not a benign thrombi but a tumor.

PubMed: 37780915
DOI: 10.1002/ccr3.7975

Authors: X Chaufour, A K Deva, K Vickery...

PURPOSE

Nosocomial transmission of viral hepatitis and retrovirus infection has been reported. The expected risk is greatest for the hepatitis B virus (HBV). The duck HBV (DHBV) has similar biologic and structural characteristics to HBV and has been adopted as a suitable model for disinfectant testing.

METHODS

Angioscopic examination of the external jugular vein was performed on DHBV-infected ducks. After use, the instrument was air dried for 3 minutes. Samples were obtained by flushing the channel with 5 mL of phosphate buffered saline solution. The samples were collected immediately after drying (control), after flushing with 5 mL of water, after glutaraldehyde disinfection for 5, 10, and 20 minutes, and after ethylene oxide gas sterilization. Angioscopes were either precleaned or uncleaned before disinfection/sterilization. Residual infectivity was assessed with inoculation of samples into the peritoneal cavity of day-old ducks (n = 231).

RESULTS

DNA analysis results of liver samples showed that all 38 control ducks became infected. The frequency of DHBV infection was reduced to 93% (14 of 15) by flushing the angioscope with 5 mL of sterile water. No transmission occurred after the use of any of the properly precleaned and disinfected/sterilized angioscopes. However, after the use of the uncleaned angioscopes, the transmission rate was 90% (9 of 10) and 70% (7 of 10) after 5 and 10 minutes of contact time, respectively, in 2% glutaraldehyde. Even after the recommended 20 minutes of contact time, there was still 6% (2 of 35) transmission. After ethylene oxide sterilization, two of the recipient ducklings (2 of 35) were infected with DHBV.

CONCLUSION

There was no disease transmission after reuse of disposable angioscopes adequately cleaned before disinfection or sterilization. However, if the angioscopes are inadequately cleaned, DHBV can survive despite glutaraldehyde disinfection or ethylene oxide sterilization. This contrasts with previous in vitro and in vivo data with solid surgical instruments. It is postulated that the presence of a narrow lumen or residual protein shielding within the lumen may compromise effective inactivation of hepadnaviruses on angioscopes, with the potential risk for patient-to-patient transmission.

Topics: Angioscopes; Angioscopy; Animals; Cross Infection; DNA, Viral; Disease Models, Animal; Disinfection; Ducks; Hepatitis B Virus, Duck; Jugular Veins; Liver; Sterilization

PubMed: 10436447
DOI: 10.1016/s0741-5214(99)70138-2

Authors: Yuji Hoshino, Hiroyoshi Yokoi

BACKGROUND

Venous stenting is increasingly used to manage femoro-ilio-caval venous outflow obstruction/stenosis due to post-thrombotic syndrome. Although the safety, efficacy, and long-term patency of venous stents have been reported, re-interventions due to stent occlusion and in-stent restenosis (ISR) have also been reported. The mechanism of ISR and the in-stent neointimal growth after venous stenting remains unclear. We performed angioscopy to evaluate intraluminal details after venous stenting, allowing real-time direct visualization of the vessel lumen.

METHODS

Ten angioscopic procedures in four patients with post-thrombotic syndrome were performed. All evaluated vessels were stented iliac veins, and their native pathology was chronic post-thrombotic occlusion. Nine procedures in three patients underwent serial evaluation of the neointimal changes after stent implantation to study the natural time course of neointimal proliferation/coverage over the stent. The serial follow-up angioscopic evaluations were performed at the end of the venous stent deployment procedure, and at 6 months, 12 months, and 24 months. One procedure was performed 1 month after the stent implantation to evaluate ISR, which was observed at the first month of routine stent surveillance. A 5.7F angioscope was used to visualize the target veins. Continuous irrigation was used to displace blood and clear the visual field.

RESULTS

At 6 months after stent implantation, stent struts were covered by a thin neointima in two of the three patients. The struts were partially covered in one patient, but there was little neointimal growth overall. Neointimal coverage increased over time, and at 12 months stent struts in 2 patients were almost completely covered. There was no significant change between the 12 and 24 months after stent implantation. In the ISR case, angioscopy demonstrated an overgrown thickened neointima, and the stent struts were fully embedded and invisible in the entire stented area. No thrombus and no webs or trabeculae were found in the area evaluated as an ISR lesion.

CONCLUSIONS

At 6 months after stent placement, the stent struts were almost covered by a neointima. The stent struts were completely covered 1 year after stent implantation. Neointimal coverage was unchanged from the 1-year follow-up to the 2-year follow-up, suggesting that neointimal proliferation proceeded gradually with subsequent neointimal remodeling up to 1 year. The cause of ISR might be the overgrown thickened neointima rather than the formation of thrombosis.

Topics: Humans; Angioscopy; Neointima; Drug-Eluting Stents; Angioscopes; Stents

PubMed: 35931362
DOI: 10.1016/j.jvsv.2022.05.017

Authors: V M Srinivasan, T T Lazaro, A Srivatsan...

BACKGROUND AND PURPOSE

Visualization in neuroendovascular intervention currently relies on biplanar fluoroscopy and contrast administration. With the advent of endoscopy, direct visualization of the intracranial intravascular space has become possible with microangioscopes. We analyzed the efficacy of our novel microangioscope to enable direct observation and inspection of the cerebrovasculature, complementary to a standard fluoroscopic technique.

MATERIALS AND METHODS

Iterations of microangioscopes were systematically evaluated for use in neurodiagnostics and neurointerventions in both live animal and human cadaveric models. Imaging quality, trackability, and navigability were assessed. Diagnostic procedures assessed included clot identification and differentiation, plaque identification, inspection for vessel wall injury, and assessment of stent apposition. Interventions performed included angioscope-assisted stent-retriever thrombectomy, clot aspiration, and coil embolization.

RESULTS

The microangioscope was found helpful in both diagnosis and interventions by independent evaluators. Mean ratings of the imaging quality on a 5-point scale ranged from 3.0 (clot identification) to 4.7 (Pipeline follow-up). Mean ratings for clinical utility ranged from 3.0 (aspiration thrombectomy) to 4.7 (aneurysm treatment by coil embolization and WEB device).

CONCLUSIONS

This fiber optic microangioscope can safely navigate and visualize the intravascular space in human cadaveric and in vivo animal models with satisfactory resolution. It has potential value in diagnostic and neurointerventional applications.

Topics: Angioscopes; Angioscopy; Animals; Embolization, Therapeutic; Endovascular Procedures; Fluoroscopy; Humans; Intracranial Aneurysm; Neuroendoscopy; Rabbits; Swine

PubMed: 33361372
DOI: 10.3174/ajnr.A6900

Authors: Masami Nishino, Yasuyuki Egami, Hiroaki Nohara...

BACKGROUND

Coronary angioscopy (CAS) has 2 unique abilities: direct visualization of thrombi and plaque color. However, in the recent drug-eluting stent (DES) era, serial CAS findings after DES implantation have not been fully elucidated. We investigated the impact of CAS findings after implantation of a polymer-free biolimus A9-coated stent (PF-BCS) or durable polymer everolimus-eluting stent (DP-EES).

METHODS AND RESULTS

We investigated serial CAS and optical coherence tomography (OCT) findings at 1 and 12 months in 99 patients who underwent PF-BCS or DP-EES implantation. We evaluated factors correlated with angioscopic thrombi and yellow plaque, and the clinical impact of both thrombi and yellow plaque at 12 months (BTY). The BTY group included 17 (22%) patients. The incidence and grade of thrombi and yellow plaque decreased from 1 to 12 months. Although no patients had newly appearing thrombi at 12 months, 2 DP-EES patients had newly appearing yellow plaque at 12 months. Multivariable analysis revealed HbA1c, minimum stent area, and adequate strut coverage were significant factors correlated with 12-month angioscopic thrombi, and DP-EESs were significantly correlated with 12-month yellow plaque. However, BTY was not correlated with clinical events.

CONCLUSIONS

The management of diabetes, stent area, and adequate stent coverage are important for intrastent thrombogenicity and polymer-free stents are useful for stabilizing plaque vulnerability.

Topics: Humans; Drug-Eluting Stents; Aged; Male; Female; Middle Aged; Angioscopy; Tomography, Optical Coherence; Everolimus; Plaque, Atherosclerotic; Sirolimus; Percutaneous Coronary Intervention; Coronary Thrombosis; Coronary Artery Disease

PubMed: 38987207
DOI: 10.1253/circj.CJ-24-0255

Authors: William Y Shi, Arminder S Jassar

PubMed: 34926185
DOI: 10.21037/acs-2021-taes-21

Authors: Patrick Z McVeigh, Raphael Sacho, Robert A Weersink...

BACKGROUND

Endoluminal optical imaging, or angioscopy, has not seen widespread application during neurointerventional procedures, largely as a result of the poor imaging resolution of existing angioscopes. Scanning fiber endoscopes (SFEs) are a novel endoscopic platform that allows high-resolution video imaging in an ultraminiature form factor that is compatible with currently used distal access endoluminal catheters.

OBJECTIVE

To test the feasibility and potential utility of high-resolution angioscopy with an SFE during common endovascular neurosurgical procedures.

METHODS

A 3.7-French SFE was used in a porcine model system to image endothelial disruption, ischemic stroke and mechanical thrombectomy, aneurysm coiling, and flow-diverting stent placement.

RESULTS

High-resolution, video-rate imaging was shown to be possible during all of the common procedures tested and provided information that was complementary to standard fluoroscopic imaging. SFE angioscopy was able to assess novel factors such as aneurysm base coverage fraction and side branch patency, which have previously not been possible to determine with conventional angiography.

CONCLUSION

Endovascular imaging with an SFE provides important information on factors that cannot be assessed fluoroscopically and is a novel platform on which future neurointerventional techniques may be based because it allows for periprocedural inspection of the integrity of the vascular system and the deployed devices. In addition, it may be of diagnostic use for inspecting the vascular wall and postprocedure device evaluation.

Topics: Angioscopy; Animals; Disease Models, Animal; Endoscopy; Feasibility Studies; Neurosurgical Procedures; Stroke; Swine

PubMed: 24762703
DOI: 10.1227/NEU.0000000000000383

Review

Authors: Yasunori Ueda, Nobuyuki Ogasawara, Koushi Matsuo...

Although the concept of vulnerable plaque has become common, it is still impossible to predict effectively the onset of acute coronary syndrome (ACS). Thin-cap fibroatheroma (TCFA) is regarded as vulnerable from pathological studies and various diagnostic tools have tried to detect TCFA clinically but failed to predict ACS. Because there are so many silent plaque ruptures detected, it is supposed that many vulnerable plaques might have ruptured but not caused ACS. Some factor(s) other than the rupture of vulnerable plaque is required for the onset of ACS. "Vulnerable blood" may be one of them. The thrombogenic potential of blood (ie, vulnerable blood) may play an important and determinant role in the onset of ACS, the process of which will be discussed from the angioscopic point of view.

Topics: Acute Coronary Syndrome; Angioscopy; Coronary Thrombosis; Coronary Vessels; Humans; Rupture, Spontaneous

PubMed: 20118566
DOI: 10.1253/circj.cj-09-0795

Authors: W S Grundfest, F Litvack, T Sherman...

In this study, the development of intraoperative angioscopy, the value of the information obtained, and the problems encountered with the procedure are reported. Eight angioscopes, 1.5 to 2.8 mm in diameter, with a line resolution of greater than 0.4 mm at 5 mm, were used. One-hundred ten angioscopic investigations were performed in 46 patients; 24 at peripheral bypass surgery and 22 at coronary artery bypass surgery. These included 68 arteries, 28 new anastomoses, six old grafts, five laser angioplasties, and three in situ vein grafts. The most important finding was that angioscopic data provide information not available from probes or angiography. Angioscopic findings were responsible for a change in surgical procedures in 12 patients (26%) including three anastomotic revisions, three alterations in graft site placement, and two repeat thrombectomies. The most significant technical problems were lack of steerability and insufficient irrigation, which resulted in poor angiographic images. Further technical development is necessary before routine intraoperative angioscopy is practical. Nevertheless, if these problems are resolved, angioscopy will provide unique, high-resolution information which can directly alter surgical therapy.

Topics: Angioplasty, Balloon; Arteriovenous Shunt, Surgical; Coronary Artery Bypass; Coronary Disease; Embolism; Endoscopy; Fiber Optic Technology; Humans; Intraoperative Period; Laser Therapy; Postoperative Complications; Suture Techniques; Vascular Surgical Procedures; Videotape Recording

PubMed: 2931056
DOI: 10.1097/00000658-198509000-00018

Review

Authors: Yasumi Uchida

Angioscopy enables macroscopic pathological diagnosis of cardiovascular diseases from the inside. This imaging modality has been intensively directed to characterizing vulnerable coronary plaques. Scoring of plaque color was developed, and based on prospective studies; dark yellow or glistening yellow plaques were proposed as vulnerable ones. Colorimetry apparatus was developed to assess the yellow color of the plaques quantitatively. The effects of lipid-lowering therapies on coronary plaques were confirmed by angioscopy. However, since observation is limited to surface color and morphology, pitfalls of this imaging technology became evident. Dye-staining angioscopy and near-infrared fluorescence angioscopy were developed for molecular imaging, and the latter method was successfully applied to patients. Color fluorescence angioscopy was also established for molecular and chemical basis characterization of vulnerable coronary plaques in both in vitro and in vivo. Drug-eluting stents (DES) reduce coronary restenosis significantly, however, late stent thrombosis (LST) occurs, which requires long-term antiplatelet therapy. Angioscopic grading of neointimal coverage of coronary stent struts was established, and it was revealed that neointimal formation is incomplete and prevalence of LST is higher in DES when compared to bare-metal stent. Many new stents were devised and they are now under experimental or clinical investigations to overcome the shortcomings of the stents that have been employed clinically. Endothelial cells are highly anti-thrombotic. Neoendothelial cell damage is considered to be caused by friction between the cells and stent struts due to the thin neointima between them that might act as a cushion. Therefore, development of a DES that causes an appropriate thickness (around 100 μm) of the neointima is a potential option with which to prevent neoendothelial cell damage and consequent LST while preventing restenosis.

Topics: Acute Coronary Syndrome; Angioscopy; Coronary Disease; Coronary Vessels; Humans

PubMed: 21146367
DOI: 10.1016/j.jjcc.2010.11.001