[Endovascular management of symptomatic carotid stenosis combined with kinking].

OBJECTIVE: To study the necessity, feasibility, security of carotid angioplasty and stenting (CAS) for symptomatic carotid stenosis combined with kinking. METHODS: Twelve patients with symptomatic carotid stenosis and kinking demonstrated by digital subtraction angiography (DSA) received CAS from December 2003 to December 2009. There were 9 male and 3 female patients, age ranged from 59 to 77 years (mean 69.3 years). All the patients' clinical, imaging, intervention and follow up data were collected and analyzed. RESULTS: All CAS procedures were successfully performed with 14 self-expandable stents placed. The mean degree of stenosis was reduced from 85.6% before stenting to 11.2% after stenting, the angle of kinking, according to Metz' category, were improved from less than 90° to more than 120° in each case. No perioperative procedure related stroke and transient ischemic attack (TIA) occurred. The clinical symptoms and signs of cerebral ischemia were improved or disappeared for all patients. During follow-up of these 12 patients for 6 to 72 months, one patient experienced ipsilateral carotid territory TIA and another patient experienced contralateral carotid territory TIA. DSA follow up of 5 patients demonstrated 1 case with in-stent restenosis and arterial kinking remote to the stent of internal carotid artery. CAS were performed again and CT angiography follow up demonstrated no kinking and restenosis 2 years after the intervention. Duplex scan of the other 7 patients demonstrated neither kinking nor restenosis. CONCLUSIONS: CAS seems to be feasible and safe for the patients with symptomatic kinking and stenosis, and maybe helpful to lower the risk of cerebral ischemia, but further study is needed.

[Endovascular treatment of micro-intracranial aneurysms: adverse factors of micro-catheterization and its relevant managements].

OBJECTIVES: To investigate adverse factors that may hinder successful placement and stabilization of the microcatheter during endovascular therapy of micro-intracranial aneurysms (≤ 3 mm in maximum diameter), and to explore the relevant managements. METHODS: Forty-six patients with fifty-one micro-intracranial aneurysms treated by endovascular therapy from June 2001 to October 2009 were retrospectively analyzed for their intervention data. RESULTS: Adverse factors of optimal micro-catheterization mainly included, tortuosity of the proximal vessels (PVs) and the parent artery (PA), relative large gap in diameter among the PVs, the PA and the microcatheter, relative large divergence in direction among the PVs, the PA and the aneurysm dome, and stent deployed in the PA. CONCLUSIONS: Carefully considering the direction of the PVs and the PA, the aneurysm's location and dome orientation, choosing the microcatheter and microwire after balancing among their physical properties, as well as utilizing balloon and/or stent assistance, can facilitate micro-catheterization during endovascular treatment of micro-intracranial aneurysms.

[Endovascular treatment of ruptured and unruptured intracranial very small aneurysms].

OBJECTIVE: To evaluate the feasibility and safety of endovascular treatment of ruptured and unruptured intracranial very small aneurysms (< or = 3 mm in maximal diameter). METHODS: Forty-eight intracranial very small aneurysms in 44 patients treated with endovascular therapy from June 2001 to August 2009 were reviewed retrospectively in clinical, imaging, interventional and follow-up data. Among 44 patients, there were 20 males and 24 females with a mean age of 57.8 years old. The Hunt-Kosnik grade was as follows: Grade 0 (n = 11); Grades I & II (n = 23); Grades III & IV (n = 9); and ungraded (n = 1). The sizes of 48 aneurysms were not more than 3 mm in maximal diameter. The locations of aneurysms were as follows: ACoA (n = 11), MCA (n = 8), PCoA (n = 14), ICA (n = 12), pericallosal artery (n = 1), VA (n = 1) and PICA (n = 1). Thirty-nine aneurysms were embolized with coil, of which 13 with stent assistance and 6 by balloon remodeling technique. The other 9 aneurysms underwent sole stent placement in parent artery. RESULTS: Among 39 coiling aneurysms, 100% occlusion was achieved in 9 aneurysms, 90% in 20, 80% in 9 and less than 80% in 1 respectively. Only one aneurysm ruptured during coiling. Two patients had transient hemiparesis and one patient had ataxia caused by bilateral cerebellar infarction postoperatively. All patients were clinically followed up for 4-90 months and no recurrent hemorrhage occurred. Thirteen patients received repeat angiography at 4-72 months post-treatment. And no radiological re-growth was detected. CONCLUSION: Endovascular treatment of ruptured and unruptured intracranial very small aneurysms seems to be technically feasible, relatively safe and practically effective.

[Changes of nitric oxide and endothelin serum level after carotid balloon denudation or stent assisted angioplasty: an experimental and clinical observation].

OBJECTIVE: To observe the changes of nitric oxide (NO) and endothelin (ET) serum level in the Guangxi BA-MA minipigs whose carotid arteries were injured by balloon denudation and in the patients with carotid stent assisted angioplasty. METHODS: Twelve Guangxi BA-MA minipigs were chosen. High fat/cholesterol feeding and endovascular balloon denudation were used to create a carotid artery atherosclerotic stenosis animal model. Blood samples were collected from peripheral veins before starting the procedure, and again, at 2 and 3 weeks after the procedure, respectively. Serum NO and ET concentrations of blood samples were tested. Nineteen patients with carotid artery stenosis who underwent stent assisted angioplasty were randomly selected, and their serum NO and ET were tested using the same methods as above. RESULTS: In the animal group, there was a significant decrease of mean NO concentration at 2 weeks after carotid injury (t-test, P < 0.05), however, no significant change of ET was observed. A very significant increase of ET was observed at 3 weeks after the procedure (t-test, P < 0.01). In the patient group, there were no significant differences among serum NO or ET concentration of peripheral vein blood before, immediately after, and 6 h after the endovascular treatment. CONCLUSIONS: In this study, a decrease of NO concentration and an increase of ET concentration of peripheral vein blood are found in BA-MA minipigs after carotid arteries are injured by balloon denudation, which might be a cue for the formation of atherosclerosis. However, no significant changes are observed in this group of patients who underwent carotid angioplasty treatment. Therefore, further studies are needed.

[Evaluation of cerebral hemodynamics in geriatric carotid stenosis pre- and post-carotid artery stenting].

OBJECTIVES: To explore influencing factors of regional cerebral blood flow (rCBF) in geriatric carotid stenosis, and to analyze changes of rCBF and clinical symptoms after carotid stenting. METHODS: During August 2005 and April 2008, 68 geriatric patients of carotid stenosis having SPECT examination in our hospital were retrospectively studied, whose diagnosis was approved by angiography. Correlated rCBF was compared separately in different stenotic degrees of carotid stenosis, in unilateral or bilateral stenosis, accompanied with vertebrobasilar stenosis (VBS) or not, with collateral circulation or not, before and after carotid stenting. RESULTS: When patients of unilateral carotid stenosis were grouped by different clinical factors, cases of patients with reduced rCBF were compared using chi(2) test: the P value was 0.046 and 0.020 when comparing group of stenotic degree 90% - 99% with group 70% - 89% and group 50% - 69%; the P value was 0.927 between group accompanied with VBS and group without; the P value was 0.222 between group with collateral circulation and group without. When comparing reduced rCBF cases between unilateral and bilateral carotid stenosis, the P value was 0.046. After carotid stenting, 76% of patients had their rCBF improved, and also the scores of presenting symptoms evaluated by modified Rankin scale were elevated from 1.4 +/- 0.7 on admission to 0.4 +/- 0.3 postoperatively (P < 0.001). CONCLUSIONS: The research indicates that higher stenotic degree and bilateral carotid stenosis may cause rCBF decrease in geriatric carotid stenosis. Carotid stenting may improve rCBF and change clinical symptoms significantly.

[Clinical study and numerical simulation of hemodynamics in the tortuosity of internal carotid artery].

OBJECTIVES: To establish a theoretical model for the tortuosity of internal carotid artery and summarize the hemodynamic rule of blood flow in a tortuous artery. To explore the relationship of cerebral ischemia and tortuous internal carotid artery. METHODS: Taking the internal carotid artery as a prototype, a geometric model of a tortuous artery was constructed according to the normal physiological and anatomical parameters of internal carotid artery. The boundary conditions and calculation conditions of blood flow are proposed. The numerical simulation of the blood flow in the tortuous artery is carried out with finite element method. Hemodynamic parameters of internal carotid artery were measured in 15 cases with the tortuosity of internal carotid artery and in 15 cases of normal control group. Blood pressure was measured by microcatheter connecting a pressure transducer at internal carotid artery, pre-tortuous and post-tortuous artery. The diameter and length of the above artery were measured and calculated by DSA machine. RESULTS: Numerical simulation results indicated pressure drop of blood flow and elongated length of artery is increased with diminution of the angle of tortuous artery. Clinical measurement data disclosed the same trend in the same curve as numerical simulation. CONCLUSION: The elongation and tortuosity of internal carotid artery results in decrease of blood pressure in the distal segment of tortuous internal carotid artery, kinking of internal carotid artery may be one of factors related to attack of cerebral ischemia on certain conditions.

[Management of elderly patients with symptomatic vertebrobasilar insufficiency].

OBJECTIVE: To evaluate the feasibility, safety and short-term efficacy of stent-assisted angioplasty and/or drug therapy for elderly patients with symptomatic vertebrobasilar insufficiency. METHODS: Elderly patients (> or = 60 years old) with symptomatic vertebrobasilar stenosis (> or = 50%) demonstrated by cerebral angiography were treated with drug therapy and some with endovascular stenting further from April 2001 to June 2006. The clinical, imaging, intervention and follow-up data were collected and analyzed. RESULTS: Eighty-one elderly patients were chosen for study, including 68 males and 13 females. The mean age is 70 years (60 - 87 years); stroke rate of 4.9% (4/81) and stroke-related mortality rate of 2.5% (2/81) were found in this group during hospitalization and follow-up (mean 28.1 months), and symptoms resolved or improved clinically in 66 (81.5%). Fifty-two balloon expandable stents were placed in 48 (59.3%) patients of this group with a technical success rate of 98.1% and the mean degree of stenosis was reduced from (82.4 +/- 13.1)% to (6.4 +/- 3.2)% (t = 22.4, P = 0.00). CONCLUSIONS: Appropriate management including endovascular stenting and/or drug therapy may improve short-term outcomes of elderly patients with symptomatic vertebrobasilar insufficiency; meanwhile, stent-assisted angioplasty is technically feasible and relatively safe.