Carotid artery stenting without post-stenting angioplasty in patients with high risk for reperfusion injury (technical modification)

Background Cerebral Hyper perfusion Syndrome (CHS) is an ominous complication that can follow extracranial carotid artery revascularization. The most dangerous consequence of CHS is Hyperperfusion-Induced Cerebral Hemorrhage (HICH), which boasts a staggering mortality of 75%. The pathophysiology of HICH is thought to be disruption of cerebral autoregulation mechanisms in hypo-perfused brains, leading to a disastrous cerebral blood flow rise. Several risk factors have been reported for HICH, such as: Hypertension, Severe carotid artery stenosis (>90%), Poor collaterals, Contralateral carotid disease, and recent cerebrovascular events. Even though strict blood pressure control is the only established method of prevention of CHS, new evidence suggests that staged carotid artery stenting (CAS) can also offer additional preventive benefits by facilitating gradual reconstitution of cerebral blood flow. In this retrospective study, we examined the efficacy of a staged CAS approach. We performed stent alone without performing an angioplasty in the initial session, making use of the stent's radial force to gradually restore blood flow. Follow-up angiographic evaluation was used to identify candidates for a second-stage angioplasty. Results Retrospective analysis was done in high-risk patients with extracranial carotid artery stenosis who underwent carotid artery stenting (CAS) without post-stenting angioplasty. The study evaluated the effectiveness of stent self-expansion in re-establishing cerebral perfusion and the clinical evidence of hyperperfusion or hypoperfusion. Follow-up cerebral angiography detected those patients requiring additional treatment with angioplasty. After deployment of stent without immediate post-angioplasty, a residual stenosis of <30% was seen in 10 cases (29.41%). Permissive residual stenosis of 30% to 50% was allowed to avoid the risk of reperfusion injury in the other 24 cases (70.59%). After 1 month follow-up, 44.12% (15/34) of cases required second-stage angioplasty and 55.88% (19/34) of cases were successfully treated with stenting alone, with a decrease in stenosis to <30%. Interestingly, 13/19 (68.4%) of them belonged to the permissive stenosis group. That was, however, statistically non-significant (Chi2 =0.1, p=0.755). Conclusion As a safeguard against the hyperperfusion syndrome, the carotid stent's self-expanation criteria can be used to progressively restore blood flow to the hypoperfused brain.