VIABAHN® Stent Graft Implantation for Iatrogenic Arteriovenous Fistula and Pseudoaneurysm of the Deep Femoral Artery

Femoral arteriovenous access is most commonly used in endovascular diagnosis and treatment. Complications arising during femoral arteriovenous access include hematoma, retroperitoneal hemorrhage, pseudoaneurysm, and arteriovenous fistula. A 66-year-old woman diagnosed with paroxysmal atrial fibrillation was treated with catheter ablation. This patient had a high femoral artery bifurcation, and we punctured the femoral vein by the conventional Merkmal method, which led to a femoral vein puncture through the deep femoral artery. The next day, echography revealed a pseudoaneurysm communicating with the deep femoral artery. We performed a thrombin injection without complication, and the pseudoaneurysm was occluded. However, echography three days after thrombin embolization showed a recurrence of the pseudoaneurysm and an arteriovenous fistula connecting to the common femoral vein. The first choice for the treatment of pseudoaneurysms and arteriovenous fistula is surgical treatment, but in addition to the lack of vascular surgery in our hospital, the patient did not want an invasive treatment and strongly preferred to be treated with a catheter. We performed endovascular treatment by VIABAHN® stent graft insertion. VIABAHN® stent graft was implanted at the deep femoral artery, and the patient was discharged without complications. VIABAHN® stent graft placement in the deep femoral artery sealed the entrance of the pseudoaneurysm and the arteriovenous fistula at once, which simultaneously treated both the pseudoaneurysm and AV fistula, and helped avoid the use of an invasive surgical procedure.

A novel therapeutic approach for coronary inflammation and lymphatic vessels using non-invasive low-intensity pulsed ultrasound in a porcine model with DES-induced coronary hyperconstricting responses

Background

The coronary adventitia harbors lymphatic vessels (LVs). We previously demonstrated that coronary adventitial inflammation and LV dysfunction play important roles in the pathogenesis of coronary artery spasm, including drug-eluting stent (DES)-induced coronary hyperconstricting responses, in pigs and humans. However, a direct therapeutic approach to the coronary adventitia remains to be developed.

Purpose

In this study, we aimed to examine whether our novel and non-invasive therapy with low-intensity pulsed ultrasound (LIPUS) ameliorates DES-induced coronary hyperconstricting responses, and if so, what mechanisms are involved.

Methods

An everolimus-eluting stent (EES) was implanted into the left anterior descending (LAD) coronary artery in normal male pigs. They were randomly assigned to the LIPUS or the sham therapy groups. After EES implantation, in the LIPUS group, LIPUS (32 cycles, 193 mW/cm2) was applied to the heart at 3 different levels (proximal and distal stent edges and middle portion of the stent) through X-ray fluoroscopy for 20 min at each level for every other day for 2 weeks (6 days in total) (Fig. 1A, B). The sham therapy group was treated in the same manner but without LIPUS. At 4 weeks after the procedure, we performed coronary angiography to examine coronary vasoconstricting responses to intracoronary serotonin in vivo. Finally, stented coronary vessels were harvested for immunohistochemistry of vasa vasorum (vWF), LVs (LYVE-1), vascular inflammation (CD68-positive macrophages and IL-1β expression), vascular endothelial growth factor A (VEGF-A, angiogenesis marker), VEGF-C and VEGF receptor 3 (VEGFR3, lymphangiogenesis markers).

Results

Coronary vasoconstricting responses to intracoronary serotonin at the DES edges in the LAD were significantly enhanced in the sham group but were significantly suppressed in the LIPUS group, while those responses were comparable at the non-DES implanted left circumflex (LCx) coronary artery between the 2 groups (Fig. 1C, D). In addition, in vivo lymph transport speed was significantly faster in the LIPUS group than in the sham group (Fig. 1E–G). In histological analysis, the number of LVs was significantly increased in the LIPUS group compared with the sham group, whereas those of CD68 and IL-1β expressions were significantly reduced in the LIPUS group compared with the sham group. In contrast, the density of vasa vasorum was comparable between the 2 groups. Mechanistically, the extents of VEGF-C and VEGFR3 expressions were increased in the LIPUS group, whereas that of VEGF-A was comparable between the 2 groups (Fig. 1G–K). Importantly, there were significant correlations among the LV-related changes and enhanced coronary vasoconstricting responses.

Conclusion

These results provide the first evidence that the LIPUS therapy ameliorates DES-induced coronary hyperconstricting responses in pigs in vivo through structural and functional alterations of LVs (Fig. 1L).

Figure 1

Funding Acknowledgement

Type of funding source: None

Development of a Shock-Wave Catheter Ablation System for Ventricular Tachyarrhythmias: Validation Study in Pigs In Vivo

Background

Although radiofrequency catheter ablation is the current state‐of‐the‐art treatment for ventricular tachyarrhythmias, it has limited success for several reasons, including insufficient lesion depth, prolonged inflammation with subsequent recurrence, and thromboembolisms due to myoendocardial thermal injury. Because shock waves can be applied to deep lesions without heat, we have been developing a shock‐wave catheter ablation (SWCA) system to overcome these fundamental limitations of radiofrequency catheter ablation. In this study, we evaluated the efficacy and safety of our SWCA system for clinical application to treat ventricular tachyarrhythmia.

Methods and Results

In 33 pigs, we examined SWCA in vivo for the following 4 protocols. First, in an epicardial substrate model (n=8), endocardial SWCA significantly decreased the sensing threshold (pre‐ versus postablation: 11.4±3.8 versus 6.8±3.6 mV; P<0.05) and increased the pacing threshold (pre‐ versus postablation: 1.6±0.8 versus 2.0±1.1 V; P<0.05), whereas endocardial radiofrequency catheter ablation failed to do so. Second, in a myocardial infarction model (n=3), epicardial SWCA of the border zone of the infarcted lesion was as effective as ablation of the normal myocardium. Third, in a coronary artery application model (n=10), direct application of shock waves to the epicardial coronary arteries caused no adverse effects in either the acute or chronic phase. Fourth, with an epicardial approach (n=8), we found that 90 shots per site provided an ideal therapeutic condition to create deep lesions with less superficial damage.

Conclusions

These results indicate that our new SWCA system is effective and safe for treatment of ventricular tachyarrhythmias with deep arrhythmogenic substrates.

2381Low-intensity pulsed ultrasound ameliorates DES-induced coronary adventitial inflammation and hyperconstricting responses in pigs in vivo - A novel non-invasive therapy for coronary inflammation

Background

We previously demonstrated that coronary adventitial inflammation plays important roles in the pathogenesis of coronary artery spasm, including drug-eluting stent (DES)-induced coronary hyperconstricting responses, in pigs and humans. Indeed, the coronary adventitia has recently attracted much attention as the important site for vascular inflammation. However, a direct therapeutic approach to the coronary adventitia remains to be developed. We have developed a non-invasive low-intensity pulsed ultrasound (LIPUS) therapy for angina, which exerts anti-inflammatory effects through improved coronary microcirculation.

Purpose

In this study, we aimed to examine whether our LIPUS therapy ameliorates DES-induced coronary hyperconstricting responses in pigs in vivo, and if so, what mechanisms are involved.

Methods

An everolimus-eluting stent (EES) was implanted into the left anterior descending (LAD) coronary artery in normal male pigs. They were randomly assigned to the LIPUS or the sham therapy groups. After EES implantation, in the LIPUS group, LIPUS (32 cycles, 193 mW/cm2) was applied to the heart at 3 different levels (proximal and distal stent edges and middle portion of the stent) through X-ray for 20 min at each level for every other day for 2 weeks (6 days in total) (Figs. 1A, 1B). The sham therapy group was treated in the same manner but without LIPUS. At 4 weeks after the procedure, we performed coronary angiography to examine coronary vasoconstricting responses to intracoronary serotonin in vivo. Finally, stented coronary vessels were harvested for immunohistochemistry of vasa vasorum, lymphatic vessels (LYVE-1), sympathetic nerve fibers (SNF), vascular inflammation (macrophages and IL-1β expression), Rho-kinase expression and activity as evaluated by phosphorylated myosin phosphatase target subunit-1 (pMYPT-1).

Results

Coronary vasoconstricting responses to intracoronary serotonin were significantly enhanced in the sham therapy group but were significantly suppressed in the LIPUS group at the DES edges in the LAD, whereas those responses were comparable at the non-DES implanted segments in the left circumflex (LCx) coronary arteries between the 2 groups. (Figs. 1C, 1D). Furthermore, in vivo lymph transport speed was significantly faster in the LIPUS group than in sham group (Figs. 1E–1G). Histological analysis showed that except vasa vasorum formation, the number of lymphatic vessels, adventitial inflammatory cells infiltration, Rho-kinase expression and activity were all significantly enhanced in the sham therapy group and were significantly suppressed in the LIPUS group (Figs. 1G–1K).

Figure 1

Conclusion

We were able to develop a non-invasive LIPUS therapy for coronary functional abnormalities caused by chronic adventitial inflammation in pigs in vivo, for which multiple beneficial effects appear to be involved (Fig. 1L).

Coronary Adventitial and Perivascular Adipose Tissue Inflammation in Patients With Vasospastic Angina

BACKGROUND

Recent studies suggested that perivascular components, such as perivascular adipose tissue (PVAT) and adventitial vasa vasorum (VV), play an important role as a source of various inflammatory mediators in cardiovascular disease.

OBJECTIVES

The authors tested their hypothesis that coronary artery spasm is associated with perivascular inflammation in patients with vasospastic angina (VSA) using ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography/computed tomography (PET/CT).

METHODS

This study prospectively examined 27 consecutive VSA patients with acetylcholine-induced diffuse spasm in the left anterior descending artery (LAD) and 13 subjects with suspected angina but without organic coronary lesions or coronary spasm. Using CT coronary angiography and electrocardiogram-gated ¹⁸F-FDG PET/CT, coronary PVAT volume and coronary perivascular FDG uptake in the LAD were examined. In addition, adventitial VV formation in the LAD was examined with optical coherence tomography, and Rho-kinase activity was measured in circulating leukocytes.

RESULTS

Patient characteristics were comparable between the 2 groups. CT coronary angiography and ECG-gated ¹⁸F-FDG PET/CT showed that coronary PVAT volume and coronary perivascular FDG uptake significantly increased in the VSA group compared with the non-VSA group. Furthermore, optical coherence tomography showed that adventitial VV formation significantly increased in the VSA group compared with the non-VSA group, as did Rho-kinase activity. Importantly, during the follow-up period with medical treatment, both coronary perivascular FDG uptake and Rho-kinase activity significantly decreased in the VSA group.

CONCLUSIONS

These results provide the first evidence that coronary spasm is associated with inflammation of coronary adventitia and PVAT, where ¹⁸F-FDG PET/CT could be useful for disease activity assessment. (Morphological and Functional Change of Coronary Perivascular Adipose Tissue in Vasospastic Angina [ADIPO-VSA Trial]; UMIN000016675).

Development of a novel shock wave catheter ablation system-A validation study in pigs in vivo

Aims

Although the radiofrequency catheter ablation (RFCA) is widely used for the treatment of tachyarrhythmias, it has three fundamental weaknesses as a thermal ablation system, including a limited lesion depth, myoendocardial injury linking to thromboembolism, and prolonged inflammation followed by subsequent recurrences. In order to overcome these limitations, we have been developing a shock wave (SW) catheter ablation (SWCA) system as a novel non-thermal therapy. In the present study, we validated our new SWCA system with increased SW intensity.

Methods and results

In a total of 36 pigs, we applied our new SWCA to ventricular muscle in vivo for the following protocols. (i) Epicardial approach (n = 17): The lesion depth achieved by the SWCA from the epicardium was examined. High intensity SW achieved 5.2 ± 0.9 mm lesions (35 applications), where there was a strong correlation between SW intensity and lesion depth (R = 0.80, P < 0.001, 54 applications). (ii) Endocardial approach (n = 6): The extent of endocardial injury with the two energy sources was examined by electron microscopy (8 applications each). Shock wave catheter ablation markedly reduced myoendothelial injury compared with RFCA (4.3 ± 1.2 vs. 79.6 ± 4.8%, P < 0.01). The electrophysiological effects on the SW lesions were also confirmed using three-dimensional mapping system. (iii) Time-course study (n = 6 each): The healing process after ablation therapy was examined. We found transient inflammatory responses and accelerated reparative process with preserved blood flow in the SWCA group.

Conclusion

These results indicate that our SWCA system is characterized, as compared with RFCA, by deeper lesion depth, markedly less myoendocardial injury and accelerated tissue repair process.

Cardiac Lymphatic Dysfunction Causes Drug-Eluting Stent–Induced Coronary Hyperconstricting Responses in Pigs In Vivo

Objective—

We have previously demonstrated that coronary adventitial inflammation plays important roles in the pathogenesis of coronary vasomotion abnormalities, including drug-eluting stent (DES)–induced coronary hyperconstricting responses. Importantly, the adventitia also harbors lymphatic vessels, which may prevent inflammation by transporting extravasated fluid and inflammatory cells. We thus aimed to examine the roles of coronary adventitial lymphatic vessels in the pathogenesis of DES-induced coronary hyperconstricting responses in a porcine model in vivo.

Approach and Results—

We performed 2 experimental studies. In protocol 1, 15 pigs were divided into 3 groups with or without DES and with bare metal stent. Nonstented sites 20 mm apart from stent implantation also were examined. In the protocol 2, 12 pigs were divided into 2 groups with or without lymphatic vessels ligation followed by DES implantation at 2 weeks later (n=6 each). We performed coronary angiography 4 weeks after DES implantation, followed by immunohistological analysis. In protocol 1, the number and the caliber of lymphatic vessels were greater at only the DES edges after 4 more weeks. In protocol 2, coronary hyperconstricting responses were further enhanced in the lymphatic vessels ligation group associated with adventitial inflammation, Rho-kinase activation, and less adventitial lymphatic vessels formation. Importantly, there were significant correlations among these inflammation-related changes and enhanced coronary vasoconstricting responses.

Conclusions—

These results provide evidence that cardiac lymphatic vessel dysfunction plays important roles in the pathogenesis of coronary vasoconstrictive responses in pigs in vivo.

Renal Denervation Suppresses Coronary Hyperconstricting Responses After Drug-Eluting Stent Implantation in Pigs In Vivo Through the Kidney-Brain-Heart Axis

OBJECTIVE

Drug-eluting stent-induced coronary hyperconstricting responses remain an important issue. The adventitia harbors a variety of components that potently modulate vascular tone, including sympathetic nerve fibers (SNF) and vasa vasorum. Catheter-based renal denervation (RDN) inhibits sympathetic nerve activity. We, thus, examined whether RDN suppresses drug-eluting stent-induced coronary hyperconstricting responses, and if so, what mechanisms are involved.

APPROACH AND RESULTS

Protocol 1: pigs implanted with everolimus-eluting stents into the left coronary arteries underwent coronary angiography at 1 month after implantation for assessment of coronary vasomotion and adventitial SNF formation. Drug-eluting stent-induced coronary hyperconstricting responses were significantly enhanced associated with enhanced coronary adventitial SNF and vasa vasorum formation. Protocol 2: pigs implanted with everolimus-eluting stents were randomly assigned to the RDN or sham group. The RDN group underwent renal ablation. At 1 month, RDN significantly caused marked damage of the SNF at the renal arteries without any stenosis, thrombus, or dissections. Notably, RDN significantly upregulated the expression of α₂-adrenergic receptor-binding sites in the nucleus tractus solitarius, attenuated muscle sympathetic nerve activity, and decreased systolic blood pressure and plasma renin activity. In addition, RDN attenuated coronary hyperconstricting responses to intracoronary serotonin at the proximal and distal stent edges associated with decreases in SNF and vasa vasorum formation, inflammatory cell infiltration, and Rho-kinase expression/activation. Furthermore, there were significant positive correlations between SNF and vasa vasorum and between SNF and coronary vasoconstricting responses.

CONCLUSIONS

These results provide the first evidence that RDN ameliorates drug-eluting stent-induced coronary hyperconstricting responses in pigs in vivo through the kidney-brain-heart axis.

Increased Coronary Perivascular Adipose Tissue Volume in Patients With Vasospastic Angina

BACKGROUND

Recent studies have suggested that coronary perivascular adipose tissue (PVAT) impairs coronary vasomotion, so we examined whether PVAT is increased at the spastic coronary segment in patients with vasospastic angina (VSA).

METHODS AND RESULTS

PVAT volume in the left anterior descending (LAD) coronary arteries on CT coronary angiography was significantly increased in 48 VSA patients with LAD spasm compared with 18 controls (30.7±2.0 vs. 21.0±3.2 cm(3), P=0.01), whereas that of total epicardial adipose tissue was comparable between the 2 groups.

CONCLUSIONS

The results suggested an important role of PVAT in the pathogenesis of coronary spasm. (Circ J 2016; 80: 1653-1656).