Pei-Lei Zhang

Endovascular Reconstruction with the Willis Covered Stent for the Treatment of Large or Giant Intracranial Aneurysms

Background: The purpose of this study was to evaluate the feasibility, safety and efficacy of endovascular treatment of large or giant intracranial aneurysms with the Willis covered stent. Methods: Nineteen patients, each with a large or giant intracranial aneurysm, were treated with the Willis covered stent. Of these 19 aneurysms, 6 were giant and 13 were large; 18 were located in the cranial internal carotid artery and 1 in the vertebral artery. Results of the procedure, technical events and complications were recorded. Clinical and imaging follow-ups were performed at 3 and 6–12 months after the procedure. Results: Placement of Willis covered stent was successful in all patients. Complete aneurysm exclusion was achieved in 13 of the 19 aneurysms immediately after the procedure. No mortality or morbidity developed during the treatment or the follow-up period. During the follow-up period, complete aneurysm exclusion was achieved in 18 of the 19 patients; 11 aneurysms were totally involuted, 3 decreased to 25% of the original diameter, 4 decreased to 50% and 1 remained unchanged. Nine patients experienced full recovery, 9 improved and 1 was unchanged. No obvious in-stent stenosis was noted. Conclusions: Endovascular treatment of large or giant intracranial aneurysm with the Willis covered stent is feasible, safe and efficacious in selected cases. Endoleak is a frequent issue after initial covered stent placement, but can be eliminated or dramatically reduced to minimal endoleak by additional covered stent placement and/or balloon reinflation. Minor endoleak is likely to spontaneously resolve over time.

Treatment of traumatic internal carotid artery pseudoaneurysms with the Willis covered stent: a prospective study.

PURPOSE To evaluate the efficacy of the Willis covered stent in the treatment of traumatic pseudoaneurysms of the internal carotid artery (ICA). MATERIALS Thirty-eight patients with traumatic head and neck injury underwent angiography. We evaluated 14 delayed pseudoaneurysms in 13 patients who underwent angiography after treatment with the Willis covered stent. Prospective data on the technical success, initial and final angiographic results, mortality, morbidity, and final clinical outcome were analyzed immediately after the procedure, at the time of discharge from the hospital, at 3 months, 6 months, and 12 months after the procedures, and yearly thereafter. RESULTS The Willis covered stent placement was successful in all 14 pseudoaneurysms. The initial angiographic results showed complete exclusion in 9 patients with 10 aneurysms (71.4% [95% confidence interval {CI}: 44-98%]) and incomplete exclusion in 4 patients. The angiographic follow-up (mean, 15 months [95% CI: 9-20 months]; range, 3-36 months) findings exhibited a complete exclusion in 12 patients with 13 aneurysms (92.9% [95% CI: 77-108%]) and an incomplete exclusion in 1 patient and maintained patency of the ICA in all patients. The clinical follow-up (mean, 20 months [95% CI: 14-27 months]) findings demonstrated full recovery (11 patients), symptom improvement (1 patient), or no change in the symptoms (1 patient). No procedure-related complications or deaths occurred during follow-up. CONCLUSION Treatment with the Willis covered stent provides a viable approach for patients with traumatic pseudoaneurysms of the ICA, maintaining patency of the ICA and thus leading to excellent clinical results. An expanded clinical experiences and a larger sample are needed.

Application of the Willis covered stent in the treatment of aneurysm in the cisternal segment of the internal carotid artery: a pilot comparative study with midterm follow-up.

Purpose: To compare the use of the Willis stent-graft versus coil embolization for complicated aneurysms in the cisternal segment of the internal carotid artery (ICA). Methods: Thirty-four patients (19 women; mean age 46.7±16.8 years, range 3–79) with 36 complicated aneurysms were treated either by Willis covered stents (n=19) or by coil embolization (n=17). Follow-up angiography was performed to investigate aneurysm recurrence, endoleak, and parent artery stenosis. Kaplan-Meier curves were constructed to compare the freedom from recurrence and parent artery stenosis rates in both groups. Clinical follow-up data were retrospectively analyzed and categorized as fully recovered, improved, unchanged, or worsened. Results: In the covered stent group, total exclusion was immediately achieved in 13 aneurysms; there were 5 minor endoleaks and 1 delivery failure. In the patients treated with coil embolization, total/near-total occlusion was achieved in 7 aneurysms, subtotal in 8, and partial in 2. Acute thrombosis occurred in 1 patient in each group, while 1 patient experienced recurrent hemorrhage after embolotherapy. Follow-up angiography (mean 14.3±9.4, range 3–31) revealed that 16 aneurysms were completely isolated in the stent-graft group, with only 2 mild in-stent stenoses. Eighteen months after the procedure, Kaplan-Meier analysis showed recurrence-free rates of 93.3% and 50% for the stent-graft versus coil groups, respectively; freedom from parent artery stenosis was 87.5% and 100%. Symptoms were fully eliminated in 9 patients in each group; they were improved in 3 and 5, unchanged in 2 and 2, and worsened in 1 and 0, respectively, at the end of the follow-up period. Conclusion: Willis stent-graft application is an alternative to treat complicated aneurysms in the cisternal segment of the ICA. In the case of a tortuous parent artery or potential side branch coverage, however, it is still not a first choice therapy.

The Effectiveness and Feasibility of Endovascular Coil Embolization for Very Small Cerebral Aneurysms: Mid- and Long-Term Follow-Up

BACKGROUND Endovascular embolization for very small cerebral aneurysms (VSCAs) is still controversial. We report our experience with endovascular coil embolization for these lesions and assess the feasibility and effectiveness. METHODS We conducted a review of our experience with endovascular treatment of a series of 19 patients with 20 VSCAs, located at the supraclinoid segment of the internal cranial artery (ICA) in seven, the cavernous ICA segment in three, the anterior communicating artery in five, vertebral artery-posterior inferior cerebellar artery in two, bifurcation of the middle cerebral artery in one, the pericallosal artery in one, and the P2 segment in one. The World Federation of Neurosurgical Societies classification before treatment was grade I in 14 patients and grade II in five patients. The strategy of endovascular treatment included coil occlusion, balloon-assisted coiling, and stent-assisted coiling. Occlusion rate was divided into (1) total/near total, occlusion rate 95-100%; (2) subtotal, occlusion rate 80-95%; and (3) partial, occlusion rate<80%. Clinical outcome of patients with ruptured aneurysm was ascertained according to the Glasgow Outcomes Scale. RESULTS All patients were successfully treated with coil embolization; immediate angiography determined occlusion of the aneurysm, including total occlusion in five, subtotal occlusion in nine, and partial occlusion in six. During 1-2 years of follow-up, all aneurysms were confirmed as complete occlusion by control angiography. No recurrence or coil compaction occurred. No rehemorrhage or ischemic stroke occurred. CONCLUSION Endovascular coil embolization for VSCAs is effective and feasible. Initial subtotal or partial aneurysm occlusion might progress to total occlusion.

Infrapopliteal angioplasty with a long over-the-wire (OTW) balloon in the treatment of severe limb ischemia in diabetic patients: a retrospective study.

Background: The use of short balloons in the treatment of infrapopliteal arterial occlusive disease in diabetic patients often has a poor clinical outcome. Purpose: To retrospectively evaluate the safety and efficacy of a long over-the-wire (OTW) balloon as a primary percutaneous transluminal angioplasty (PTA) treatment for diabetic infrapopliteal severe limb ischemia. Material and Methods: Infrapopliteal PTA with a long OTW balloon was performed between April 2007 and March 2008 in 34 patients (53 limbs), including a total of 119 lesions. Patient age was 71.8±7.4 years. All patients had limb ischemic symptoms. Angiography was retrospectively analyzed, and every lesion categorized and classified according to its length and severity. The mean follow-up period was 7.4±2.6 months. Lower-limb magnetic resonance angiography (MRA) was performed every 3 months during follow-up, and clinical data were collected. Results: Altogether, 92% of patients were successfully treated. Ankle-brachial index (ABI) and transcutaneous oxygen tension (TcPO2) improved from 0.50±0.18 and 18.85±12.08 mmHg, respectively, before the procedure to 0.81±0.12 and 39.85±12.67 mmHg, respectively, after the procedure. At the end of follow-up, 29 patients had maintained a stable outcome. Five patients had symptom recurrence, and three of them underwent a second PTA. Two major amputations and four minor amputations were performed, with a 94% limb salvage rate and 59% patency rate. Conclusion: Infrapopliteal PTA with a long OTW balloon was feasible, with encouraging midterm outcome, in the treatment of severe limb ischemia in diabetic patients in this single-center case series. Further research is warranted to evaluate long-term outcome.

Runoff detected by magnetic resonance angiography as an indicator for better recanalization outcomes in below-the-knee chronic total occlusions in diabetic patients.

Purpose: To compare the feasibility and efficacy of recanalizing below-the-knee (BTK) chronic total occlusions (CTOs) between patients with good or poor distal runoff based on magnetic resonance angiography (MRA) scans. Methods: Two hundred long-segment BTK CTOs in 171 limbs of 113 diabetic patients (58 men; mean age 69.8±1.9 years) were divided into good distal runoff (GDR: 119 lesions, 98 limbs) or poor distal runoff groups (PDR: 81 lesions, 73 limbs) based on baseline MRA findings. After angioplasty, modified thrombolysis in myocardial ischemia (mTIMI) grades and ankle-brachial index (ABI) were used to assess immediate outcomes. Regularly scheduled duplex or MRA imaging was performed in follow-up. The restenosis and limb salvage rates were compared. Results: The success rates were 93.3% and 87.7% in the GDR and PDR groups, respectively (p=0.21); subintimal angioplasty was more common in the PDR group (93.0% vs. 63.1%, p<0.01). Completion angiography indicated an mTIMI grade 3 blood flow in 71.2% lesions in the GDR patients and in 52.1% in the PDR (p=0.01) group. Improvement in the ABI was greater in the GDR limbs (p<0.001 vs. PDR). Mean imaging follow-up was 10.8±6.9 months in the GDR group and 11.1±6.6 months in the PDR group. Kaplan-Meier analysis showed a better restenosis-free rate in the GDR group (80.6% vs. 61.7%; p=0.02) at 12 months and for lesions with mTIMI grade 3 flow (p<0.01). At 24 months, Kaplan-Meier analysis revealed a better limb salvage rate in the GDR group (84.2% vs. 54.6%; p=0.02). Conclusion: Distal runoff detected using MRA could be a predictor for successful intraluminal recanalization, better distal tissue perfusion, improved long-term patency, and better limb salvage for patients with BTK CTOs.

Safety, feasibility, and mid-term follow-up of Willis stent graft placement in the treatment of symptomatic complicated intra- or extra-cranial aneurysms: a multicenter experience.

Abstract We report the technical success rate and mid-term follow-up results after deploying stent-grafts to treat a cohort of patients with symptomatic complicated intra- or extracranial aneurysms (SCIEAs). This study was a retrospective review of 58 patients (39 male; mean age 40.4 ± 12.3 years) with 60 SCIEAs treated by 67 Willis covered stents at three medical centers in China between April 2005 and January 2010. The locations of the SCIEAs were as follows: Intracranial internal carotid artery (ICA) in 54 patients, extracranial ICA in one, intracranial vertebral artery (VA) in three and extra-cranial VA in two. Surgery was successful in 59 (98.3%) SCIEAs. Total exclusion was immediately achieved in 48 SCIEAs, and minor endoleaks were present in 11. Acute thrombosis occurred in two patients and hemorrhage in one. Follow-up angiography (mean 13.8 ± 8.9 months) revealed that 49 of 52 (94.2%) aneurysms were completely isolated, with mild in-stent stenosis in only two patients and in-stent occlusion in one patient. Willis stent-graft application is an alternative therapy to treat SCIEAs in either intra- or extracranial ICAs or VAs. In the case of a tortuous intracranial ICA or potential side branch coverage, however, it is still not a first choice.

Batroxobin for Prevention of Restenosis in Diabetic Patients After Infrapopliteal Arterial Angioplasty: A Small Randomized Pilot Trial

BACKGROUND We designed a small randomized clinical trial to prospectively test the hypothesis that batroxobin is more effective than aspirin alone to prevent restenosis in patients with diabetes undergoing angioplasty of infrapopliteal arteries. METHODS After a successful angioplasty, a total of 52 diabetic patients with symptomatic infrapopliteal obstructions were randomized to either the treated group (n = 26) or the control group (n = 26). Patients in the treated group received 5 IU batroxobin through an intravenous drip once every alternate day, for a total of six doses. The primary end point was restenosis and reocclusion, which was documented by magnetic resonance angiography or duplex scanning at 12-month follow-up. The clinical symptoms relief and ankle-brachial index (ABI) were compared before and after the procedure, and during follow-up. Kaplan-Meier curves were constructed to evaluate restenosis or reocclusion-free, limb salvage, and amputation-free rates. RESULTS Restenosis and reocclusion occurred in 22.0% and 34.5% lesions in the treated and the control group, respectively (p = 0.0307). Statistical differences were observed between the ABI before the angioplasty procedure(p < 0.05) and the ABI at the 12-month follow-up (p = 0.0094) of the two groups. Clinical symptoms improvement and tissue healing occurred in 23 and 19 patients in the batroxobin group and the control group, respectively (p = 0.0544). Twelve months after angioplasty, Kaplan-Meier analysis showed that the restenosis and reocclusion-free rate was 74.0% and 54.8%, the limb salvage rate was 96.2% and 92.3%, and the amputation-free rate was 84.6% and 84.6%, in the treated and control group, respectively. CONCLUSION This pilot trial revealed that batroxobin usage was effective in preventing restenosis and reocclusion after infrapopliteal arterial angioplasty, and it might provide better clinical symptoms relief; however, it did not report preferable limb salvage or amputation-free rates.

Infrainguinal Endovascular Recanalization: Risk Factors for Arterial Thromboembolic Occlusions and Efficacy of Percutaneous Aspiration Thrombectomy

PURPOSE To investigate factors predictive of thromboembolic occlusions and evaluate the efficacy of percutaneous aspiration thrombectomy (PAT) for infrainguinal thromboembolic occlusions in patients undergoing endovascular recanalization (EVR). MATERIALS AND METHODS In this single-center retrospective study, 23 patients who underwent PAT for thromboembolism during EVR and 237 patients who underwent successful EVR without thromboembolic occlusions (control group) were enrolled. Immediate posttreatment and follow-up outcomes between groups were compared. Multivariate analysis was performed to identify factors predictive of thromboembolic occlusions. Technical success of PAT was defined as achievement of < 30% residual stenosis and restoration of modified thrombolysis in myocardial infarction grade 3 flow. RESULTS The technical success rate was 95.7% in the PAT group. After intervention, ankle brachial index (ABI), restoration of blood flow, and improvement in dorsal/plantar arterial pulse score showed no significant differences between the PAT and control groups. During follow-up, no significant differences were observed between groups in improvement of sustained ABI and maximum walking distance, ulcer healing, restenosis/occlusion and limb salvage rates, and pain relief in patients with critical ischemia. Stenosis greater than 90% with lesion occlusion (odds ratio, 12.891; 95% confidence interval, 1.676-99.161; P = .014) and intraluminal angioplasty (odds ratio, 18.423; 95% confidence interval, 2.408-140.942; P = .005) were associated with a high incidence of thromboembolism. CONCLUSIONS Stenosis greater than 90% with lesion occlusion and intraluminal angioplasty may be factors predictive of thromboembolic occlusions. PAT is a safe and effective treatment for thromboembolism during infrainguinal arterial EVR.

Treatment of complex ruptured anterior communicating arterial aneurysms by endovascular coil embolisation of the anterior communicating artery

Purpose. The current study evaluates the feasibility and safety of coil embolisation of the anterior communicating artery (ACoA) for the treatment of complicated anterior communicating arterial aneurysms (ACoAAs). Methods and materials. Five patients presented with a subarachnoid haemorrhage caused by a ruptured ACoAA. The ACoAA morphologies were well defined by three-dimensional digital subtraction angiography (3D-DSA) and magnetic resonance angiography (MRA). Two of the ACoAAs were tiny (<3 mm in diameter), and the remaining three ACoAAs were small (3–5 mm in diameter). All of the aneurysms were localised to the ACoA. The projection of the aneurysm dome was defined as being oriented superiorly or posteriorly in all five aneurysms. We performed a superselective catheterisation of each aneurysm, and we subsequently performed coil embolisation with balloon, stent or microcatheter assistance. Angiography and clinical follow-up occurred 3–6 months after the procedure. Clinical follow-up data were collected and retrospectively analysed, and patient responses were categorised as fully recovered, improved, unchanged or aggravated. Results. All five patients with ACoAA were treated successfully using coil embolisation. In three patients, both the aneurysm sac and the ACoA were embolised using coils, and in two patients, only the ACoA was embolised. Acute angiography showed occlusion of the aneurysm and ACoA. Follow-up angiography confirmed complete occlusion of the aneurysm sac, and no ACoAA recurrence was detected in any of the patients. In clinical follow-up visits, none of the patients had haemorrhaged or had a stroke. Conclusion. Combined coil embolism of the aneurysm sac and the ACoA could be a feasible and safe method for the treatment of complicated ACoAAs without bilateral aplasia of the A1 segment.