Recanalized thrombus treated with bioresorbable vascular scaffold: insights from optical coherence tomography

Optical coherence tomography characterization of spontaneous recanalized coronary thrombus - Single center experience

Introduction: Recanalized thrombus is an under diagnosed clinical entity. Aim was to investigate the utility of optical coherence tomography (OCT) in identifying spontaneously recanalized thrombi (SRCT) for management in clinical practice. Methods: This was a retrospective study analyzing 2678 coronary angiograms over a 4-year period which included intravascular imaging guidance in 75.8% of the percutaneous coronary interventions (PCI). Angiographic suspicion of SRCT has hazy appearance seen in 34 patients. Results: Eight patients (7 males and 1 female) were confirmed with SRCT on OCT and two underwent intravascular ultrasound (IVUS). Median age was 52 years (range 33-67 years). Based on clinical symptoms, diagnosis was STEMI-2, NSTEMI-1, unstable angina-3 and chronic stable angina-2. Angiographic patterns were veiled/hazy appearances in 3; braided in 2; pseudo dissection in 2; and near occlusion in 1 patient. OCT findings displayed multiple small cavities, signal-rich with high backscattering and thin septa with smooth inner borders dividing the lumen and intercommunications. Presence of multiple holes conferred typical "Swiss cheese" or 'lotus root' like appearance, characteristic of recanalized thrombi. SRCT lesion length was (median interquartile ranges [IQR], 16.5[12.07-21.5] mm) and minimal luminal area (median [IQR], 1.77 [0.93-3.26] mm²) with significant stenosis (median [IQR], 74.0[67.0-81.0] %). Minimum/maximum number of channels were (median [IQR], 2.0[2.0-2.0]) and (median [IQR], 4.50[4.0-6.75]) respectively. Lipid rich plaque was predominant. IVUS demonstrated echo-lucent channels with small cavities. All but one patient underwent PCI. Conclusion: Intravascular imaging by OCT delineates the characteristics of recanalized thrombi and distinguishes ambiguous lesions. Majority of the lesions involving SRCT were significant both symptomatic and stenosis severity wise on OCT requiring PCI.

Refractory hypertension secondary to renal artery stenosis with a honeycomb-like structure

Background

A honeycomb-like structure (HLS) is a rare abnormality characterized by a braid-like appearance. Angiograph and intravascular examination, including coherence tomography and intravascular ultrasound (IVUS), can further confirm the multiple intraluminal channels or honeycomb structure, which can also be described as looking like ‘swiss cheese’, a ‘spider web’ or a ‘lotus root’. Previous studies have mostly reported this abnormality in coronary arteries, with a few cases in renal arteries. More information about the characteristics and development of HLS is needed.

Case presentation

A 69-year-old Han man with resistant hypertension received abdominal enhanced computerised tomography and was revealed to have left renal artery stenosis with the possibility of left renal infarction. Renal artery angiography confirmed a 95% stenosis located in the proximal segment of the left renal artery, and the middle segment was blurred with multi-channel-like blood flow. Further IVUS was performed and identified multiple channels surrounded by fibrous tissue. It was a rare case of HLS in the renal artery secondary to the thrombus, with organisation and recanalisation. Balloon dilatation and stent implantation at the proximal segment of the left renal artery were performed successfully. Blood pressure was well controlled after the procedure.

Conclusions

The IVUS findings are helpful for forming interventional therapeutic strategies for HLS lesions in the renal artery.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-021-02428-1.

Anatomical features and clinical outcome of a honeycomb-like structure in the coronary artery: reports from 16 consecutive patients

BACKGROUND

Recanalization of thrombus in coronary artery tree is defined as a honeycomb-like structure. However, the anatomic features and appropriate treatment of honeycomb-like structure still remain largely unclear.

METHODS AND RESULTS

Between 2014 July and 2017 December, 17 honeycomb-like structure in 16 patients based on optical coherence tomography and intravascular ultrasound were included. Fractional flow reserve was measured for patients who had thrombolysis in myocardial infarction flow grade 3. Angiographic and optical coherence tomography/intravascular ultrasound-derived variables were studied. Clinical events (until to 2018 December) were collected. Honeycomb-like structures mostly involved left anterior descending artery (68.8%) and localized at proximal-mid (88.2%) segment of vessels. Eight patients had a side branch ≥ 2 mm in diameter taking from honeycomb-like structure. Only one patient had a normal fractional flow reserve. Fifteen patients underwent implantation of a stent. Stent implantation was associated with side branch compromise or closure (4 in each). Of 4 patients with side branch closure, all had a creatine kinase myocardial band > 5 times increase in hospital, with 3 deaths and 1 target lesion revascularization during follow-up.

CONCLUSIONS

Despite the presence of recanalization, most honeycomb-like structure lesion have a positive fractional flow reserve. Further study is required to address how to protect a large side branch taking from honeycomb-like structure.

Role of Intravascular Imaging for the Diagnosis of Recanalized Coronary Thrombus

INTRODUCTION

Recanalized thrombus (RCT) of coronary arteries is frequently unrecognized in interventional cardiology practice. Intravascular imaging conclusively establishes its diagnosis, which otherwise is often misdiagnosed as fresh thrombus, spontaneous coronary artery dissection, or severe calcification based on angiography, alone. We hereby report our experience of 10 RCT patients, who had the intravascular imaging-guided diagnosis, followed by the successful percutaneous coronary intervention (PCI).

METHODS

It was a retrospective analysis of 10 patients, who had angiographic haziness of the target lesion during PCI, which were found to be RCT on intravascular imaging. Either optical coherence tomography (OCT) or intravascular ultrasound (IVUS) was performed to characterize RCT in 9 and 1 patient, respectively.

RESULTS

The mean age was 53 ± 13.1 years, comprising 9 men and 1 woman. Six patients had acute coronary syndrome, while four had chronic stable angina. Coronary angiography revealed ≥ 70% angiographic stenosis, with intracoronary haziness/filling defects which were linear, spiral or braided in appearance. OCT findings in 9 patients include signal-rich, high backscattered septa dividing the lumen into multiple small cavities communicating with each other, giving a "Swiss cheese" or "honeycomb" appearance. Intravascular ultrasound (IVUS) findings in one patient showed multiple cavities filled with blood speckling consistent with recanalized thrombus. All patients underwent successful PCI with image-guided optimization.

CONCLUSION

With the increasing use of intravascular imaging during PCI, RCT is frequently identified. OCT remains the investigation of choice to differentiate it from other similar entities on angiography.

Differential Diagnosis, Clinical Characteristics, and Interventions of Braid-Like Coronary Artery: Case Series Analysis Based on Optical Coherence Tomography

Aim

Based on optical coherence tomography (OCT), we aimed to determine the diagnosis, clinical characteristics, and interventions of braid-like coronary arteries, which are rare and tend to be diagnosed as a woven coronary artery (WCA) anomaly.

Methods and Results

We identified braid-like lesions on coronary angiography (CAG) in 7 patients (6 men; median age 47 years; age range 26 to 57 years). All patients were heavy smokers. Four patients were diagnosed with an old myocardial infarction and the other 3 with unstable angina. The braid-like lesions were located in the left anterior descending arteries in 2 patients and in the right coronary arteries in the other 5. TIMI grade 2 flow was observed in all involved vessels. OCT findings of all lesions were consistent with recanalization of organized thrombi, which consisted of septa that divided the lumen into multiple small cavities communicating with each other. No separate three-layered structure could be defined. Based on the significance of the stenosis and its related symptoms, drug-eluting stents were implanted in all of the lesions. All patients experienced symptomatic improvement after the intervention and were followed up event-free for 12 months.

Conclusions

Braid-like coronary arteries are likely to undergo recanalization of organized thrombi rather than WCA according to our OCT findings. The majority of cases affect men who smoke heavily. Percutaneous stent implantation may be beneficial in selected patients when feasible.

Optical Coherence Tomography for In Vivo Identification, Characterization and Optimal Treatment of Spontaneous Recanalization of Coronary Thrombus

BACKGROUND/AIM

Spontaneous recanalization of coronary thrombus (SRCT) is a rare in vivo appearance, with a nonspecific angiographic aspect. The aim of this study was to investigate the importance of optical coherence tomography (OCT) use for SRCT identification, characterization of pathogenic mechanisms and optimal treatment.

PATIENTS AND METHODS

We retrospectively analyzed all patients with angiographic suspicion of SRCT who underwent coronary angiography for suspected coronary artery disease and afterward investigated by OCT imaging.

RESULTS

We identified 28 cases with angiographic suspicion of SCRT (0.41% of CA) and confirmed it in 4 patients (0.05% of CA). OCT provided insight about the underlying SRCT mechanism: possible complicated atherosclerotic plaques in two cases and, respectively, spontaneous coronary artery dissection in other two cases. OCT provided accurate lesion assessment and offered optimal PCI materials selection.

CONCLUSION

Besides providing the diagnosis, OCT also improved characterization of SRCT pathogenic mechanisms, in the four confirmed SRCT cases, supporting the role of coronary wall in situ complications, namely dissection of an atherosclerotic plaque or spontaneous dissection of a normal coronary wall.

A patient with multiple Swiss cheese aspect coronary lesions: optical coherence tomography to guide coronary angioplasty

Although spontaneous recanalization of coronary thrombi has been reported pathologically, it is rarely recognized in clinical practice. We presented a rare case of recanalized thrombi of the right coronary artery and distal left anterior descending artery in a patient with an anterior ST segment elevation myocardial infarction treated with primary percutaneous intervention of the proximal left anterior descending artery. Optical coherence tomography aspect of right coronary artery was consistent with a 'Swiss cheese' appearance that represented recanalization of organized thrombi. Optical coherence tomography has been essential to discriminate the underlying mechanism and may provide useful information for an appropriate treatment approach.

Honeycomb-like structure in the right coronary artery treated with a drug-eluting stent: a case report and literature review

A honeycomb-like structure (HLS) is a rare entity encountered in catheterization laboratories. The etiology of HLS remains elusive. Moreover, no treatment guideline or consensus for HLS has been proposed. However, with more frequent adoption of intravascular imaging modalities, the number of cases of HLS is rising. We herein present a case of HLS and summarize previous reports in the literature with the aim of providing useful information for interventional cardiologists and promoting further research.

ST-segment elevation myocardial infarction – ideal scenario for bioresorbable vascular scaffold implantation?

Bioresorbable vascular scaffolds (BVS) represent a breakthrough technology for percutaneous coronary intervention (PCI). In this context, because of the unique properties of bioresorbable devices, ST-segment elevation myocardial infarction (STEMI) may represent the ideal scenario for BVS implantation. Consistently, 57% of physicians declare they currently use BVS in this group of patients. However, continuous and growing evidence on the good performance of these devices has been actually shown only in small studies with short- and mid-term follow-up. For these reasons, we need data from sufficiently large observational studies, with long-term follow-up, to confirm that BVS can deliver the same results as 2nd-generation drug-eluting stents when using an appropriate implantation technique. In this review, we discuss the potential advantages of BVS implantation in STEMI patients, together with the most recent evidence from clinical studies, highlighting safety and procedural concerns.