Different Vascular Responses to a Bare Nitinol Stent in Porcine Femoral and Femoropopliteal Arteries

Abstract

Nitinol stents are widely used for the treatment of peripheral arterial diseases in lower extremity arteries and have shown different clinical outcomes depending on implanted arterial segments. We aimed to compare histopathological responses to nitinol stents in femoral artery (FA) with those in femoropopliteal artery (FPA), which is markedly bended during knee flexion. A single nitinol stent was implanted in FA and FPA of 21 domestic swine. The stented vessels were angiographically assessed and then harvested for histopathology at 1 and 3 months after implantation. Angiographic late lumen loss was significantly greater in FPA than in FA at 3 months. Neointimal area decreased in FA and increased in FPA from 1 to 3 months. Compared with FA, peri-strut area of FPA showed more pronounced hemorrhage and fibrin deposition at 1 month and angiogenesis and inflammation at 1 and 3 months. Injury to internal elastic lamina or media was minimal in both FA and FPA at both time points. In conclusion, vascular responses to nitinol stents were different between FA and FPA with respect to time course of neointimal formation and progress of healing, suggesting that repetitive interaction between stent and vessel wall during dynamic vessel motion affected vascular responses.

Can a self‐expanding pediatric stent expand with an artery? Relationship of stent design to vascular biology

“…These criteria have been widely used in literature. High injury scores, particularly scores of 2–3, have been reported to yield thicker neointima formation in the porcine coronary arteries 22 . Because the force on each stented artery was a function of both the stent type as well as the diameter of the stented vessel, an attempt was made to correlate radial force with vascular injury and histopathology.…”

“…High injury scores, particularly scores of 2-3, have been reported to yield thicker neointima formation in the porcine coronary arteries. 22 Because the force on each stented artery was a function of both the stent type as well as the diameter of the stented vessel, an attempt was made to correlate radial force with vascular injury and histopathology. While the outward force of the stents did not correlate with the biological response, it was noted that smaller arteries in general had higher levels of injury and stenosis regardless of stent force.…”

Scientific and Regulatory Policy Committee Points to Consider for Medical Device Implant Site Evaluation in Nonclinical Studies

“…The most common ancillary imaging methods include high-resolution radiography (i.e., Faxitron), CT or microCT, magnetic resonance imaging (MRI) or microMRI, SEM, optical coherence tomography (OCT), fluoroscopy, and angiography. 15,23 , 34-41 Other imaging methods such as 3D electro-anatomical imaging may also be possible. The need to use an ancillary imaging method to support pathology evaluation of an implanted medical device should be determined on a case-by-case basis.…”

“…The most common ancillary imaging methods include high-resolution radiography (i.e., Faxitron), CT or microCT, magnetic resonance imaging (MRI) or microMRI, SEM, optical coherence tomography (OCT), fluoroscopy, and angiography. 15,23,[34][35][36][37][38][39][40][41] Other imaging methods such as 3D electro-anatomical imaging may also be possible.…”

Trans-radial versus trans-femoral approach for cerebral angiography: a meta-analysis of randomized controlled trials.

“…Percutaneous cerebral angiography is a standard approach used when diagnosing cerebrovascular diseases [1][2][3]. While the trans-femoral approach (TFA) is commonly used in a wide array of vascular interventional procedures [4][5][6][7], the trans-radial approach (TRA) has been adopted in place of the TFA in the cardiology field given that it results in lower rates of vascular complications and reduced bleeding, thereby improving patient safety outcomes and overall satisfaction [8][9][10]. The benefits associated with this approach have attracted interest in the use of the TRA when conducting cerebrovascular interventions [11].…”