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Background: Chronic thromboembolic pulmonary hypertension (CTEPH) is a progressive disorder with a poor prognosis. Recently, balloon pulmonary angioplasty (BPA) has been reported to be an effective treatment for inoperable patients with CTEPH. However, this catheter-based treatment has potentially life-threatening vascular complications. To improve the efficacy and safety of BPA, we assessed the morphological evaluation of organised thrombus and the vascular injury by BPA procedure., Methods: In this study, we assessed the morphology of organised thrombi and the vascular injury observed by angioscopy during BPA in 28 lesions from nine CTEPH patients., Results: Angioscopy visualised various forms of organised thrombi such as 'Mesh', 'Slit', 'Flap' and 'Mass' and allowed for a detailed evaluation of organised thrombus that was difficult to do by conventional contrast angiography. In addition, after balloon dilation for BPA, angioscopy revealed a haemorrhage due to a vessel wall injury caused by wiring and/or ballooning., Conclusions: Assessment of organised thrombus and vascular injury by angioscopy might contribute to improving the treatment of the patients with CTEPH., (Copyright © 2018 Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ). Published by Elsevier B.V. All rights reserved.)

: We here report the angioscopic assessment of inoperable peripheral chronic thromboembolic pulmonary hypertension in an 81-year-old man who was previously diagnosed with the disease. To assess the pathological morphology of the web lesion, pouch defect and band lesion, we used two types of angioscopic catheter: blood flow-maintaining type and blood flow-blocking type. Angioscopy revealed a heterogeneous thrombus that contained white organized thrombus, red fragile thrombus and yellowish thrombus. After three sessions of balloon pulmonary angioplasty, his pulmonary arterial pressure decreased and his symptom of dyspnea on exertion and desaturation were improved. Angioscopy displayed various forms of organized thrombus, and also allowed the detailed observation of lesions that were difficult to be observed by angiography.

Caveolin-1 (CAV1) and Cavin-1 are components of caveolae, both of which interact with and influence the composition and stabilization of caveolae. CAV1 is associated with pulmonary arterial hypertension (PAH). Bone morphogenetic protein (BMP) type 2 receptor (BMPR2) is localized in caveolae associated with CAV1 and is commonly mutated in PAH. Here, we show that BMP/Smad signaling is suppressed in pulmonary microvascular endothelial cells of CAV1 knockout mice. Moreover, hypoxia enhances the CAV1/Cavin-1 interaction but attenuates the CAV1/BMPR2 interaction and BMPR2 membrane localization in pulmonary artery endothelial cells (PAECs). Both Cavin-1 and BMPR2 are associated with the CAV1 scaffolding domain. Cavin-1 decreases BMPR2 membrane localization by inhibiting the interaction of BMPR2 with CAV1 and reduces Smad signal transduction in PAECs. Furthermore, Cavin-1 knockdown is resistant to CAV1-induced pulmonary hypertension in vivo. We demonstrate that the Cavin-1/Caveolin-1 interaction attenuates BMP/Smad signaling and is a promising target for the treatment of PAH. Cavin-1 and BMPR2 competitively interact with the Caveolin-1 scaffolding domain that modulate BMP/Smad signal transduction in pulmonary artery endothelial cells and these interactions are involved in the development of pulmonary hypertension. [ABSTRACT FROM AUTHOR]

Chronic thromboembolic pulmonary hypertension is caused by incomplete resolution and organization of thrombi. Blood flow dynamics are involved in thrombus formation; however, only a few studies have reported on pulmonary artery blood flow dynamics in patients with chronic thromboembolic pulmonary hypertension. Furthermore, the effects of treatment interventions on pulmonary artery blood flow dynamics are not fully understood. The aim of the study was to evaluate pulmonary artery blood flow dynamics in patients with chronic thromboembolic pulmonary hypertension before and after pulmonary endarterectomy and balloon pulmonary angioplasty, using computational fluid dynamics. We analyzed patient-specific pulmonary artery models of 10 patients with chronic thromboembolic pulmonary hypertension and three controls using computational fluid dynamics. In patients with chronic thromboembolic pulmonary hypertension, flow velocity and wall shear stress in the pulmonary arteries were significantly decreased, and the oscillatory shear index and blood stagnation volume were significantly increased than in controls. Pulmonary endarterectomy induced redistribution of pulmonary blood flow and improved blood flow dynamics in the pulmonary artery. Balloon pulmonary angioplasty improved pulmonary blood flow disturbance, decreased blood flow stagnation, and increased wall shear stress, leading to vasodilatation of the distal portion of the pulmonary artery following balloon pulmonary angioplasty treatment. [ABSTRACT FROM AUTHOR]

Background: Balloon pulmonary angioplasty (BPA) is used for treatment of inoperable chronic thromboembolic pulmonary hypertension (CTEPH) and residual pulmonary hypertension after pulmonary endarterectomy (PEA) to improve hemodynamics, right ventricular function, and exercise capacity. However, the effectiveness and safety of guide extension catheters for BPA treatment in patients with CTEPH have not been demonstrated. Methods: We retrospectively analyzed 91 lesions in 55 sessions of 28 patients with CTEPH who underwent BPA using a guide extension catheter. The purpose (backup, coaxial, and extension), efficacy, and safety of the guide extension catheters were explored. The efficacy of the guide extension catheter was assessed based on the success of the procedures and safety was evaluated based on procedure-related complications. Results: Regarding the intended use, a guide extension catheter was used to strengthen the backup force of the guiding catheter in 52% of cases, extend the tip of the catheter in 38% of cases, and maintain the coaxiality of the guiding catheter in 10% of cases. Procedural success was achieved in 92.7% of 55 sessions and in 95.6% of 91 lesions. Complex lesions had a lower success rate than simple lesions (p = 0.04). Regarding safety concerns, complications were observed in 5 of 55 sessions (9.1%) and 6 of 91 lesions (6.6%). Only one case of pulmonary artery dissection using a guide extension catheter was reported. Except for this one case, extension catheter-related complications were not observed. Conclusions: A guide extension catheter can be used safely in BPA procedures with anatomically complex pulmonary artery branches and complex lesions by increasing backup support. [ABSTRACT FROM AUTHOR]

Background: Balloon pulmonary angioplasty (BPA) is an effective treatment for inoperable chronic thromboembolic pulmonary hypertension (CTEPH). The purpose of this study is to evaluate the therapeutic effect and safety of the non-slip element percutaneous transluminal angioplasty (NSE PTA) scoring balloons in BPA. Methods: 108 pulmonary artery branches in 14 CTEPH patients who underwent BPA using NSE PTA scoring balloon (the NSE PTA group) or plain balloon (the POBA group) and pressure gradient evaluation were analyzed. We compared the improvement of the pressure ratios after BPA (Δ Pressure ratio) of both groups. Results: There was no significant difference in the Δ Pressure ratios of the two groups (0.241 ± 0.196 POBA, 0.259 ± 0.177 NSE PTA, p = 0.63). No complications occurred in the NSE PTA group, while 3 episodes of hemoptysis were seen in the POBA group. This, however, was not found to be significant (p = 0.27). In the cases where balloon-to-vessel ratio exceeded 1.0 (n = 35), multivariate analysis showed that the use of NSE PTA scoring balloon and pressure ratio before BPA were significantly correlated with Δ Pressure ratio (β coefficient: 0.047, 95% CI: 0.0016 to 0.093, p = 0.043 and β coefficient: −0.60, 95% CI: −0.78 to −0.42, p < 0.01, respectively). Conclusions: Although NSE PTA scoring balloon was safe, there was no significant pressure gradient improvement with NSE PTA scoring balloon compared to conventional BPA. Nevertheless, the NSE PTA scoring balloon showed effective blood-flow improvement in the case of large balloon-to-vessel ratio. [ABSTRACT FROM AUTHOR]

Background: Chronic thromboembolic pulmonary hypertension (CTEPH) is a progressive disease with poor prognosis. The mechanisms of CTEPH have not been well-known. Recently, balloon pulmonary angioplasty (BPA) has been widely spread for the treatment of inoperable CTEPH. However, the efficacy of BPA for the pulmonary blood flow dynamics is still unclear. In this study, we evaluated pulmonary blood flow dynamics in the patients with CTEPH before and after BPA using computational fluid dynamics (CFD). Methods: We analyzed the patients-specific models of the pulmonary arteries with 4 normal patients and 4 CTEPH patients before and after BPA using CFD. Flow stream patterns, velocity magnitude, wall shear stress (WSS) and oscillatory shear index (OSI) were calculated during one cardiac cycle. Results: In the patients with CTEPH, flow velocity and WSS in the pulmonary arteries were significantly decreased compared with normal subjects (16.7±4.0 vs 9.9±3.3 cm/s, P<0.001, 12.9±3.0 vs 6.9±1.9 dynes/cm2, P<0.001, respectively). BPA significantly increased flow velocity in the distal portion of pulmonary artery (23.4±5.8 vs 9.9±3.3 cm/s, P<0.001), and also improved WSS in the both of proximal and distal portion (proximal: 1.4±0.3 vs 2.9±0.6 dynes/cm2; P<0.001, distal: 30.4±8.5 vs 6.9±1.9 dynes/cm2; P<0.001, respectively). The area of OSI distribution and stagnated blood flow were decreased after BPA compared with before BPA. These results suggest that BPA recover the pulmonary blood flow dynamics, and might improve the thrombogenicity and endothelial function. Conclusion: In the analysis using CFD, flow velocity and WSS was decreased in the pulmonary artery of the patients with CTEPH, suggesting that this stagnation of blood flow plays a role in the pathogenesis and progression of CTEPH. BPA improved the stagnation of blood flow and WSS. Recovery of pulmonary blood flow dynamics might decrease thrombogenicity and lead to vascular endothelial function recovery. [ABSTRACT FROM AUTHOR]