Dilation of the Internal Carotid Artery at the Entrance to the Carotid Canal following Carotid Artery Stenting Predicts Postprocedural Hyperperfusion

Experience of Staged Angioplasty to Avoid Hyperperfusion Syndrome for Carotid Artery Stenosis

Hyperperfusion syndrome (HPS) after carotid artery stenting (CAS) may cause hemorrhagic or ischemic events leading to serious sequelae. We previously reported the staged angioplasty (SAP) to prevent HPS. In the present study, we analyzed our treatment results of SAP to know its effectiveness and problems. The study included 43 patients scheduled for SAP in whom preoperative single photon emission computed tomography (SPECT) showed severely impaired cerebral blood flow (CBF). The analyzed subjects were 38 males and 4 females, mean age was 73 ± 8.5 years old. SAP was indicated for the patients whose CBF ratio in the affected/unaffected hemisphere (asymmetry index) was below 0.8, and cerebrovascular reactivity measured by acetazolamide challenge was below 10%. First, percutaneous transluminal angioplasty (PTA) was performed. If PTA was successful, CAS was performed 2 weeks later. If PTA was not successful due to inadequate dilatation or extensive dissection, a stent was placed. SPECT was performed immediately after PTA and CAS to confirm the presence or absence of hyperperfusion phenomenon (HPP) indicating radiologic hyperperfusion. In 39 of 43 patients (91%), SAP was successfully performed and HPP was not observed. On the other hand, in the other four patients (9%), immediate stent placement was added due to inadequate dilatations in three patients and vascular dissection in one. Among 43 candidates for SAP, 41 patients (95.4%) had favorable course, but one hemorrhagic and one ischemic complications were observed after PTA. SAP was a relatively simple procedure, and its clinical results seemed acceptable.