Carotid Stent Cell Design May Affect Outcomes

SAN DIEGO – The 30-day periprocedural outcomes in patients who underwent carotid artery stenting with closed-cell design stents were not significantly inferior to outcomes of those treated with carotid endarterectomy, a large meta-analysis demonstrated.

However, patients who underwent carotid endarterectomy (CEA) had significantly better 30-day periprocedural outcomes, compared with those who underwent carotid artery stenting (CAS) with open-cell design stents.

Doug Brunk/IMNG Medical Media

"A number of randomized clinical trials and meta-analyses have consistently showed the higher risk of periprocedural stroke in patients undergoing stenting when compared to endarterectomy," Dr. Mohammed A. Almekhlafi said at the annual meeting of the Society of Neurointerventional Surgery. "One of the factors that has been implicated as a determinant of periprocedural neurological events is the stent cell design. The small free-cell area between the struts of a closed-cell stent theoretically provides better scaffolding of the vessel wall and superior plaque stabilization compared to the larger uncovered gaps in open-cell stents."

Dr. Almekhlafi, an interventional neurology fellow at the University of Calgary (Alta.), and his associates set out to investigate the impact of stent cell design on the outcome of randomized controlled trials comparing CAS vs. CEA. The stent cell design was divided into closed (meaning all stent struts are interconnected) or open (meaning not all stent-struts are interconnected). The primary outcome was a composite of the 30-day risk of stroke or death.

The final analysis included 4,949 patients from nine randomized clinical trials. Of these, 807 underwent CAS with closed-cell stenting, 1,657 underwent CAS with open-cell stenting, and 2,485 underwent CEA.

Dr. Almekhlafi reported that the primary outcome was significantly lower among patients in the CEA arm, compared with those in the CAS open-cell design arm (odds ratio, 1.84; P = .003). The primary outcome was lower among patients in the CEA arm, compared with those in the CAS closed-cell design arm, although this difference did not reach statistical significance (OR, 1.54; P = .29).

When the researchers limited their analysis to risk of 30-day periprocedural stroke, this outcome remained nonsignificant among patients in the CEA arm, compared with those in the CAS closed-cell design arm (OR 2.92; P = .22). However, the risk of 30-day periprocedural stroke remained significantly higher among patients in the CAS open-cell design arm, compared with those in the CEA arm (OR, 1.97; P = .0007).

"Uncertainty still exists regarding the impact of stent characteristics on CAS outcome," Dr. Almekhlafi said. "The size of the emboli might also be relevant."

He acknowledged certain limitations of the study, including the fact that trials included in this analysis did not randomize patients to open vs. closed stents, and that trials using the closed-design stents recruited fewer patients than did those using open-cell stents.

Dr. Almekhlafi said that he had no relevant financial disclosures to make.

SAN DIEGO – The 30-day periprocedural outcomes in patients who underwent carotid artery stenting with closed-cell design stents were not significantly inferior to outcomes of those treated with carotid endarterectomy, a large meta-analysis demonstrated.

However, patients who underwent carotid endarterectomy (CEA) had significantly better 30-day periprocedural outcomes, compared with those who underwent carotid artery stenting (CAS) with open-cell design stents.

Doug Brunk/IMNG Medical Media

"A number of randomized clinical trials and meta-analyses have consistently showed the higher risk of periprocedural stroke in patients undergoing stenting when compared to endarterectomy," Dr. Mohammed A. Almekhlafi said at the annual meeting of the Society of Neurointerventional Surgery. "One of the factors that has been implicated as a determinant of periprocedural neurological events is the stent cell design. The small free-cell area between the struts of a closed-cell stent theoretically provides better scaffolding of the vessel wall and superior plaque stabilization compared to the larger uncovered gaps in open-cell stents."

Dr. Almekhlafi, an interventional neurology fellow at the University of Calgary (Alta.), and his associates set out to investigate the impact of stent cell design on the outcome of randomized controlled trials comparing CAS vs. CEA. The stent cell design was divided into closed (meaning all stent struts are interconnected) or open (meaning not all stent-struts are interconnected). The primary outcome was a composite of the 30-day risk of stroke or death.

The final analysis included 4,949 patients from nine randomized clinical trials. Of these, 807 underwent CAS with closed-cell stenting, 1,657 underwent CAS with open-cell stenting, and 2,485 underwent CEA.

Dr. Almekhlafi reported that the primary outcome was significantly lower among patients in the CEA arm, compared with those in the CAS open-cell design arm (odds ratio, 1.84; P = .003). The primary outcome was lower among patients in the CEA arm, compared with those in the CAS closed-cell design arm, although this difference did not reach statistical significance (OR, 1.54; P = .29).

When the researchers limited their analysis to risk of 30-day periprocedural stroke, this outcome remained nonsignificant among patients in the CEA arm, compared with those in the CAS closed-cell design arm (OR 2.92; P = .22). However, the risk of 30-day periprocedural stroke remained significantly higher among patients in the CAS open-cell design arm, compared with those in the CEA arm (OR, 1.97; P = .0007).

"Uncertainty still exists regarding the impact of stent characteristics on CAS outcome," Dr. Almekhlafi said. "The size of the emboli might also be relevant."

He acknowledged certain limitations of the study, including the fact that trials included in this analysis did not randomize patients to open vs. closed stents, and that trials using the closed-design stents recruited fewer patients than did those using open-cell stents.

Dr. Almekhlafi said that he had no relevant financial disclosures to make.

SAN DIEGO – The 30-day periprocedural outcomes in patients who underwent carotid artery stenting with closed-cell design stents were not significantly inferior to outcomes of those treated with carotid endarterectomy, a large meta-analysis demonstrated.

However, patients who underwent carotid endarterectomy (CEA) had significantly better 30-day periprocedural outcomes, compared with those who underwent carotid artery stenting (CAS) with open-cell design stents.

Doug Brunk/IMNG Medical Media

"A number of randomized clinical trials and meta-analyses have consistently showed the higher risk of periprocedural stroke in patients undergoing stenting when compared to endarterectomy," Dr. Mohammed A. Almekhlafi said at the annual meeting of the Society of Neurointerventional Surgery. "One of the factors that has been implicated as a determinant of periprocedural neurological events is the stent cell design. The small free-cell area between the struts of a closed-cell stent theoretically provides better scaffolding of the vessel wall and superior plaque stabilization compared to the larger uncovered gaps in open-cell stents."

Dr. Almekhlafi, an interventional neurology fellow at the University of Calgary (Alta.), and his associates set out to investigate the impact of stent cell design on the outcome of randomized controlled trials comparing CAS vs. CEA. The stent cell design was divided into closed (meaning all stent struts are interconnected) or open (meaning not all stent-struts are interconnected). The primary outcome was a composite of the 30-day risk of stroke or death.

The final analysis included 4,949 patients from nine randomized clinical trials. Of these, 807 underwent CAS with closed-cell stenting, 1,657 underwent CAS with open-cell stenting, and 2,485 underwent CEA.

Dr. Almekhlafi reported that the primary outcome was significantly lower among patients in the CEA arm, compared with those in the CAS open-cell design arm (odds ratio, 1.84; P = .003). The primary outcome was lower among patients in the CEA arm, compared with those in the CAS closed-cell design arm, although this difference did not reach statistical significance (OR, 1.54; P = .29).

When the researchers limited their analysis to risk of 30-day periprocedural stroke, this outcome remained nonsignificant among patients in the CEA arm, compared with those in the CAS closed-cell design arm (OR 2.92; P = .22). However, the risk of 30-day periprocedural stroke remained significantly higher among patients in the CAS open-cell design arm, compared with those in the CEA arm (OR, 1.97; P = .0007).

"Uncertainty still exists regarding the impact of stent characteristics on CAS outcome," Dr. Almekhlafi said. "The size of the emboli might also be relevant."

He acknowledged certain limitations of the study, including the fact that trials included in this analysis did not randomize patients to open vs. closed stents, and that trials using the closed-design stents recruited fewer patients than did those using open-cell stents.

Dr. Almekhlafi said that he had no relevant financial disclosures to make.