Treatment of distal internal carotid artery aneurysm with the willis covered stent: a prospective pilot study.
ABSTRACT To evaluate the flexibility and efficacy of the Willis covered stent in the treatment of distal internal carotid artery (DICA) aneurysms.
The study was approved by the authors' institutional review board, and the research was conducted by the authors' institution and the MicroPort Medical Company (Shanghai, China). Thirty-one patients with 33 DICA aneurysms were considered for treatment with a Willis covered stent. The angiographic assessments were categorized as complete or incomplete occlusion. The data on technical success, initial and final angiographic results, mortality, morbidity, and final clinical outcome were collected, and follow-up was performed at 1, 3, 6, and 12 months and yearly after the procedures.
Navigation and deployment of the covered stents were successful in 97.6% (41 of 42; 95% confidence interval [CI]: 93%, 102%) of the attempted stent placement procedures. The initial angiographic results showed a complete occlusion in 23 patients with 25 aneurysms (of 32 aneurysms, 78.1% [95% CI: 63%, 93%]) and an incomplete occlusion in seven patients with seven aneurysms (21.9%). The angiographic follow-up (mean, 14 months [95% CI: 12, 15 months]) findings exhibited a complete occlusion in 27 patients with 29 aneurysms (of 31 aneurysms, 93.5% [95% CI: 84%, 103%]) and an incomplete occlusion in two aneurysms (6.5%), with a mild in-stent stenosis in two patients. The clinical follow-up (mean, 27 months [95% CI: 23, 30 months]) demonstrated that 15 patients experienced a full recovery and 14 patients improved.
The preliminary results demonstrate good flexibility and efficacy of the Willis covered stent in the treatment of DICA aneurysms in selected patients; longer follow-up and expanded clinical trials are needed.
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ABSTRACT: This study proposes an anatomically based nomenclature for the internal carotid artery (ICA) that can be applied by all disciplines. In 1938, Fischer published a seminal paper describing five segments of the ICA that were designated C1 through C5. These segments were based on the angiographic course of the intracranial ICA rather than its arterial branches or anatomic compartments. Subsequent attempts to apply modern nomenclature to these numerical segments failed to recognize Fischer's original intent of describing patterns of arterial displacement by tumors and, therefore, resulted in a nomenclature that was anatomically inaccurate. Fischer's system was further limited, because segments were numbered opposite the direction of blood flow and the extracranial ICA was excluded. The authors propose a new classification, which includes the entire ICA, uses a numerical scale in the direction of blood flow, and describes the segments of the ICA according to a detailed understanding of the anatomy surrounding the ICA and the compartments through which it travels. Twenty cadaveric specimens with intravascular injection of silicone rubber were used for microscopic dissection and 20 dry skulls were inspected. Histological sections in critical areas were examined. The authors' classification has the following seven segments: C1, cervical; C2, petrous; C3, lacerum; C4 cavernous; C5, clinoid; C6, ophthalmic; and C7, communicating. This classification is practical, accounts for new anatomic information and clinical interests, and clarifies all segments of the ICA.Neurosurgery 04/1996; 38(3):425-32; discussion 432-3. · 2.53 Impact Factor
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ABSTRACT: Our objective was to evaluate the sensitivity of transcranial Doppler (TCD) sonographic monitoring during permanent balloon occlusion of the internal carotid artery (ICA) in predicting hemodynamic ischemia. Thirty-two consecutive patients underwent controlled therapeutic balloon occlusion of the ICA. Selection criteria included assessment of the circle of Willis by compression angiography, clinical tolerance during a 20-minute test occlusion, and TCD monitoring of the ipsilateral middle cerebral artery. The mean blood flow velocity (MBFV) (n = 32) and pulsatility index (PI) (n = 28) were recorded. In 25 patients, MBFV changes upon motor stimulation were recorded before and after ICA occlusion. Twenty-eight (88%) of the patients had no complications. Three patients suffered delayed symptoms 30 minutes to 20 hours after balloon detachment. Two of these patients recovered spontaneously within 1 day, the other improved after extracranial/intracranial (EC/IC) bypass surgery. One patient, who did not tolerate the test occlusion, suffered a hemodynamic stroke despite EC/IC bypass before permanent balloon occlusion. No embolic complications occurred. The mean MBFV reduction was 20% (range, 0% to 55%); the mean PI reduction was 20% (range, 0% to 56%). No complications occurred in patients who had mild MBFV and PI reduction (30% or less, n = 21). All three patients with severe MBFV or PI reduction (> 50%) had neurologic symptoms. Among those with moderate MBFV or PI reduction (30% to 50%, n = 8), symptoms developed in only one patient who had moderate reduction of both MBFV (33%) and PI (38%). Motor vasoreactivity showed wide variation and was markedly reduced in two symptomatic patients. TCD monitoring reflects changes in cerebral hemodynamics after therapeutic balloon occlusion of the ICA. MBFV and PI reductions under 30% are highly predictive of clinical tolerance. A reduction of more than 50% may be a critical threshold for the occurrence of symptoms; in such cases, EC/IC bypass should be considered before proceeding with permanent balloon occlusion.American Journal of Neuroradiology 04/1998; 19(3):577-82. · 3.17 Impact Factor
- Radiology 12/1997; 205(2):307-14. · 6.34 Impact Factor