Coronary angiography and percutaneous coronary intervention in the porcine model: a practical guide to the procedure

Coaxial bioprinting of a stentable and endothelialized human coronary artery-sized in vitro model

Atherosclerosis accounts for two-thirds of deaths attributed to cardiovascular diseases, which continue to be the leading cause of mortality. Current clinical management strategies for atherosclerosis, such as angioplasty with stenting, face numerous challenges, including restenosis and late thrombosis. Smart stents, integrated with sensors that can monitor cardiovascular health in real-time, are being developed to overcome these limitations. This development necessitates rigorous preclinical trials on either animal models or in vitro models. Despite efforts being made, a suitable human-scale in vitro model compatible with a cardiovascular stent has remained elusive. To address this need, this study utilizes an in-bath bioprinting method to create a human-scale, freestanding in vitro model compatible with cardiovascular stents. Using a coaxial nozzle, a tubular structure of human coronary artery (HCA) size is bioprinted with a collagen-based bioink, ensuring good biocompatibility and suitable rheological properties for printing. We precisely replicated the dimensions of the HCA, including its internal diameter and wall thickness, and simulated the vascular barrier functionality. To simplify post-processing, a pumpless perfusion bioreactor is fabricated to culture a HCA-sized model, eliminating the need for a peristaltic pump and enabling scalability for high-throughput production. This model is expected to accelerate stent development in the future.

Ultrasound-guided femoral approach for coronary angiography and interventions in the porcine model

Coronary angiography and percutaneous coronary intervention (PCI) procedural details in swine are similar to those performed to humans, since their heart and coronary anatomy closely resembles. However, only a few detailed descriptions of the procedure are available, containing notable differences. We present a feasible and reproducible protocol for percutaneous coronary interventions in porcine experimental models, utilizing ultrasound-guided femoral approach. Nine female pigs were studied to explore the feasibility of superficial femoral arterial (SFA) access for coronary angiography and provisional PCI, as well as the most suitable guiding coronary catheters and angiographic projections for the above interventions. Experiments were performed under general anesthesia, using ultrasound-guided puncture of the SFA to gain arterial access. The Amplatzer AR1^® catheter, and the Right Coronary Bypass^® catheter were used for the selective engagement of the right and the left coronary artery, respectively. Successful arterial access and subsequent cardiac catheterization were performed in all pigs. Only one animal required a second puncture for femoral artery access. None of the 9 animals presented any significant tachycardia or hypotensive episode. One animal developed an access site-related complication following the first catheterization procedure. During follow-up, 100% success of SFA catheterization was achieved using the same ultrasound-guided technique. The ultrasound-guided superficial femoral artery access for coronary angiography and provisional interventions in porcine models is a quick and safe alternative to the carotid artery approach. The RCB and AR1 catheters may be the best choice for the quick and easy selective coronary engagement of the right and left ostia, respectively.

Percutaneous Ultrasound-Guided Carotid Access and Puncture Closure with Angio-Seal in Horses

Simple Summary

Endovascular surgery is a type of image-guided minimally invasive surgery that aims to solve different types of pathologies from inside the blood vessel. This technique requires access to a peripheral vessel (vein or artery) and the navigation through the vascular system to reach the operating site, using different catheters. In horses, the main indication for endovascular therapy involves access to the common carotid artery for different purposes. Traditionally, this was performed by open dissection of the neck to reach and incise the common carotid artery, followed by vascular suture of the vessel and skin closure when the procedure was over. However, this can also be performed by percutaneous puncture of the artery, using ultrasound to guide the needle to its adequate position in the artery, as has been reported in experimental horses. Along with that, in human medicine, commercial closure systems are used to seal these arterial punctures and avoid some complications (mainly haematomas and haemorrhages). We describe our experience in a series of 11 clinical cases in which this minimally invasive way of access was used, and the puncture site was sealed with one of these devices (AngioSeal arterial closure system), reporting its first use in horses. In all cases, the artery was effectively accessed, and the planned procedure could be performed. Our haematoma/bleeding rate (16.66%) was lower than in other studies using the same type of access, even considering two failures due to incorrect use of the device. However, further studies comparing AngioSeal use to simple manual compression would be necessary to be able to recommend their routine use in horses.

Abstract

Background: There are different indications for endovascular surgery in horses, mainly the treatment of guttural pouch mycosis. Traditionally, these procedures are carried out by open arteriotomy of the common carotid artery (CCA), although less invasive percutaneous ultrasound-guided carotid access (PUGCA) has been described in experimental horses. In human medicine, commercial closure systems are used to seal these arterial puncture sites and reduce complications. The aims of this study are to retrospectively describe our experience with PUGCA in clinical cases and to report, for the first time, the use of the commercial vascular closure device Angio-Seal after PUGCA in horses. Methods: Retrospective study of clinical case records. Collected parameters, including the feasibility of the PUGCA and variables related to the safety and efficacy of the use of the Angio-Seal. Results: Twelve PUGCA procedures in 11 horses were included. In all cases, the artery was effectively accessed, and the planned procedure could be performed. In two cases, haematoma/bleeding due to incorrect use of the Angio-Seal was recorded. This complication rate (16.66%) was lower than that obtained in other studies using PUGCA in horses, but where the puncture was sealed by manual compression only. Main limitations: A control group of clinical cases with PUGCA but without using Angio-Seal is not available. Conclusions: Clinical data confirm previous experimental results, which showed that PUGCA is safe and effective in horses. The Angio-Seal system, regardless of possible complications due to incorrect use, can be used safely and effectively in horses. Further studies comparing arterial access site management using manual compression or Angio-Seal would be necessary to state if its routine use in horses is advisable.

Strut protrusion and shape impact on endothelial shear stress: insights from pre-clinical study comparing Mirage and Absorb bioresorbable scaffolds

Protrusion of scaffold struts is related with local coronary flow dynamics that can promote scaffold restenosis and thrombosis. That fact has prompted us to investigate in vivo the protrusion status of different types of scaffolds and their relationship with endothelial shear stress (ESS) distributions. Six Absorb everolimus-eluting Bioresorbable Vascular Scaffolds (Absorb, Abbott Vascular) and 11 Mirage sirolimus-eluting Bioresorbable Microfiber Scaffolds (Mirage, Manli Cardiology) were implanted in coronaries of eight mini pigs. Optical coherence tomography (OCT) was performed post-scaffold implantation and obtained images were fused with angiographic data to reconstruct the three dimensional coronary anatomy. Blood flow simulation was performed and ESS distribution was estimated for each scaffold. Protrusion distance was estimated using a dedicated software. Correlation between OCT-derived protrusion and ESS distribution was assessed for both scaffold groups. A significant difference was observed in the protrusion distances (156 ± 137 µm for Absorb, 139 ± 153 µm for Mirage; p = 0.035), whereas difference remained after adjusting the protrusion distances according to the luminal areas. Strut protrusion of Absorb is inversely correlated with ESS (r = −0.369, p < 0.0001), whereas in Mirage protrusion was positively correlated with EES (r = 0.192, p < 0.0001). Protrusion distance was higher in Absorb than in Mirage. The protrusion of the thick quadratic struts of Absorb has a tendency to lower shear stress in the close vicinity of struts. However, circular shape of the less thick struts of Mirage didn’t show this trend in creating zone of recirculation around the struts. Strut geometry has different effect on the relationship between protrusion and shear stress in Absorb and Mirage scaffolds.