Endovascular aortic repair (EVAR) has been the main treatment means for abdominal aortic aneurysm.It has become an expert consensus that in the case of abdominal aortic aneurysm that is complicated by iliac aneurysm,the preservation of internal iliac artery is necessary because it can prevent the occurrence of gluteal muscle ischemnia,sigmoid ischemia,male sexual dysfunction and other complications.In recent years,with the continuous updating of the endovascular devices it has become possible to retain the internal iliac artery in the performance of EVAR.At present,the reconstruction of internal iliac artery in EVAR includes a variety of techniques,including intraluminal iliac branched device (IBD) technique,sandwich technique,common iliac artery covered-stent bell-bottom (BBT) technique,external iliac artery-internal iliac artery intraluminal shunt technique (reverse chimney technique),and spring coil embolism technique.This article aims to make a summary of all the above mentioned techniques.

BACKGROUND:Degradable polymer materials initiate the degradation process immediately after implantation. How to regulate the degradation of these materials is rarely reported at present. OBJECTIVE:To study the effect of ultrasonic wave on control ing the degradation of polymer materials. METHODS:The sample is made ofε-caprolactone/L-lactide copolymer, and its core was coated with low density polyethylene on the surface with the fol owing four different methods. (1) The core surface was firstly covered with CaCl 2 powder, and then coated with polyethylene. (2) The core was firstly coated with polyethylene and coarsened for 3 hours. (3) The core surface was firstly covered with CaCl 2 powder, and then coated with polyethylene, and coarsened for 3 hours. (4) The core was directly coated with polyethylene. The four kinds of specimens obtained were embedded in pork for ultrasonic bombardment experiment in vitro. RESULTS AND CONCLUSION:In the specimens prepared with methods 1 and 4, the lyophobic layer could protect core materials before ultrasonic treatment, and no absorption peak was found at 631 nm. After ultrasonic treatment, the lyophobic layer was destroyed, toluidine blue dye was released, leading to change the color of immersion solution and increase the absorption peak at 631 nm. In the specimens prepared with methods 2 and 3,the lyophobic layer cannot exhibit the protection effects, the absorption peak was found at 631 nm. Under electron microscope, the appearance of the specimens in four groups was changed obviously. It is feasible to control the starting of the degradation by coating the degradable copolymer with LDPE and using ultrasonic as a trigger.

Objective To evaluate the feasibility of endovascular aortic repair (EVAR) under local anesthesia without using any contrast agent for abdominal aortic aneurysm in patients with high allergic risk to contrast agent.Methods Under local anesthesia and with no use of any contrast,percutaneous EVAR was performed in a patient with abdominal aortic aneurysm who carried high allergic risk to contrast agent.Results Percutaneous EVAR was successfully accomplished.Postoperative follow-up MRI examination showed that the abdominal aortic aneurysm was completely isolated with no endoleak.The blood flow was unobstructed in the covered stent,and bilateral renal arteries were well visualized.Conclusion For the treatment of abdominal aortic aneurysm in patients who are highly allergic to contrast agent and who have contraindications to general anesthesia,percutaneous EVAR performed under local anesthesia and using no contrast agent is safe and effective.Strict observation of indications and sufficient preoperative evaluation of clinical conditions is the key to ensure a successful operation.

About 25%-40% of ischemic stroke is in the posterior circulation, in which 20% of posterior circulation stroke is caused by vertebral artery stenosis. Patients with symptomatic vertebral artery stenosis have a high risk of recurrent stroke. At present, the treatments of vertebral artery stenosis include medication, open surgery and interventional therapy. In this paper, the endovascular treatment of vertebral artery stenosis is reviewed, especially the progress of endovascular treatment is expounded, in order to promote the development of its treatment.

Objective To investigate the safety and feasibility of carotid endarterectomy (CEA) combined with carotid artery stent angioplasty (CASA) in treating tandem stenosis of carotid artery. Methods The clinical data of 9 patients with tandem stenosis of carotid artery, who were treated at authors' hospital during the period from January 2013 to October 2014, were retrospectively analyzed. The patients included 7 males and 2 females, with a mean age of (66.0 ±4.2) years. The disease course ranged from 2 months to 36 months, with a mean of 7 months. Clinically, all patients had cerebral ischemia symptoms. Transient ischemia attack was seen in 5 patients and history of cerebral infarction was present in 2 patients. Coronary artery disease was found in 2 patients, hypertension in 6 patients and lower limb ischemia in one patient. After receiving adequate antiplatelet therapy, CEA and CASA were carried out in all patients. Results The technical success rate was 100%, postoperative residual stenosis was less than 30%, no death occurred in perioperative period. After the treatment, the clinical symptoms were improved in all 9 patients;no new stroke or cerebral hemorrhage occurred. After the treatment, 2 patients developed cerebral hyperperfusion-related symptoms such as headache and dizziness, which were much relieved at the time of discharge. The patients were followed up for 4-19 months, with a mean of (10.5±6.2) months. No recurrence of symptoms was observed . In one patient , transcranial Doppler ultrasound performed at 6 months after treatment showed that the carotid artery became moderate restenosis (50%-70%). No death occurred. Conclusion For the treatment of tandem stenosis of carotid artery, CEA combined with CASA is safe and effective, although larger sample and long-term follow-up studies are still needed to further confirm the effect.

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Objective:To detect the characteristics of vascular remodeling after carotid balloon injury model in rats using ultrasound biomicroscopy(UBM), and to discuss the application value of UBM technique by comparing ultrasonic characteristics with histopathological results.Methods:Carotid balloon injury was performed in 10-week-old SD rats(11 female and 11 male) by 2F Fogarty balloon catheter. The left common carotid artery(CCA) was injured and the right side in the same animal was used as an uninjured control. Arterial structures and hemodynamics were evaluated pre-procedure and post-procedure at 7, 14 days.The intima-media thickness(IMT) inner diameter, outer diameter, lumen area, vessel area, peak systolic velocity, end diastolic velocity of CCA were measured by UBM, and the vascular resistance index, shear stress and blood flow were calculated to evaluate the vascular hemodynamics. The histological data were obtained by H&E staining in cross-sections at 14 days after balloon injury. The characteristics of arterial structure and hemodynamic changes at various time points were compared, the structural changes of CCA between injured and control side after injury were compared. The Spearman correlation and linear regression were used to test the correlation between ultrasonic and histological measurements 14 days after balloon injury.Results:①Compared with pre-procedure, the IMT at 14 days after balloon injury was increased, the inner diameter was decreased, the shear stress in ultrasound was increased(all P<0.05). H&E staining histological test showed that IMT and neointima area in male rats were larger than those of female rats (all P<0.001). ②After carotid balloon injury, the lumen area decreased, but the CCA underwent compensatory positive remodeling and the vessel area increased. ③Significant correlations were demonstrated between UBM and histology in IMT, inner diameter, outer diameter and vessel area of CCA( rs=0.819, 0.965, 0.896, 0.955; all P<0.001). The vessel area value measured by UBM was larger than that of histology( P=0.006). Conclusions:The CCA of rats can be showed clearly by UBM in males and females. The arterial structure cab be measured by UBM accurately with good correlation with histology, as did arterial hemodynamic parameters, which may be benefit for the study in carotid balloon injury model of rats.

Objective:To investigate the clinical characteristics and surgical treatment experience of carotid body tumor (CBT).Methods:The clinical data of 12 patients with CBT admitted to the Department of Vascular Surgery, Xuanwu Hospital, Capital Medical University from March 2013 to August 2020 were analyzed retrospectively. Among them, there were 6 males and 6 females, aged 31-83 years, with a median age of 57 years. Among the 12 patients, 2 patients were not treated surgically. The body mass index (BMI), tumor side, maximum diameter of tumor, and tumor classification, operation time, intraoperative bleeding volume, postoperative drainage volume and time, postoperative hospital stay and postoperative complications of patients undergoing surgery were recorded.Results:BMI of the 12 patients was 17.19-29.07 kg/m 2, with an average of (24.05±3.95) kg/m 2. Among the 12 patients, there were 4 tumors on the left side, 6 tumors on the right side and 2 patients had bilateral tumors. The maximum diameter of the tumor was 1.7-8.7 cm, with an average of (4.05 ± 1.89) cm. Among the 2 patients with bilateral tumors, 1 patient underwent staged resection within 9 months and 1 patient only removed the larger tumor. A total of 10 patients underwent surgical resection. All excised tumors were confirmed histopathologically to be paraganglioma. The average operation time and the amount of bleeding was(164.73 ± 74.39)min and 341.82 mL respectively. The drainage time was 1-3 d, with an average of (1.73 ± 0.65) d. The cumulative drainage volume was 22-237 mL, with an average of (77.18 ± 57.47) mL. Classification of 11 surgically resected tumors: 3 patients (3/11, 27.3%) were Shamblin Ⅰ, 7 patients (7/11, 63.6%) were Shamblin Ⅱ and 1 patient (1/11, 9.1%) were Shamblin Ⅲ. There were 1 patient of hematoma and 1 patient of acute cerebral infarction after operation. One patient with decrease in muscle strength of right limb, other surgical patients complained no complications such as stroke and cranial nerve injury when discharged. Patients undergoing surgery were hospitalized for 8-20 days, with an average of (13.36 ± 3.61) d. Conclusions:CBT is a rare paraganglioma in clinic. Surgical resection is an effective method to treat CBT. Careful operation should be carried out to avoid serious complications such as wound hematoma, cranial nerve injury and ischemic stroke.

Objective o investigate the clinical efficacy of atherectomy in the treatment of Tosaka class Ⅲ in-stent restenosis in the femoropopliteal artery. Methods From June 2013 to December 2015, 33 restenotic lesions after femoropopliteal artery stenting were retrospectively analyzed by clinical information including technical success rate, incidence of complications, improvement of postoperative symptoms and objective indicators, and target vessel patency. Results To January 2016, twenty-eight cases were followed up. The average follow-up time was 17. 9 months. Five cases were lost. The follow-up rate was 84. 9％. The technical success rate was 100％. The patency rate was 79. 9％ at 6 months and 65. 8％ at 1 year after surgery. Conclusions Atherectomy is safe and effective for treatment of Tosaka classⅢin-stent restenosis in femoropopliteal artery with good short-term and medium-term efficacy.

Objective To explore the clinical effectiveness and safety of selective usage of embolic protection device to prevent distal embolization during SilverHawk atherectomy for atherosclerotic femoropo-pliteal artery disease. Methods From Jan 2014 to December 2015, 45 femoropopliteal artery atherosclerot-ic patients were treated with SilverHawk atherectomy and selective embolic protection device (EPD). The indication for EPD was instent restenosis, highly calcified lesion, suspicious of thrombosis, ulcerated le-sion, and single below-the-knee runoff. All cases who met the indication were treated with atherectomy and EPD, and those who did not meet the indication were treated with or without EPD according to the patient's choice. The embolic related complications were analyzed. Results Twenty three out of 45 patients who met the EPD indication were all treated with SilverHawk atherectomy under EPD protection, filter captured deb-ris in 17 patients (73. 9％) of the patients. The other 22 patients who did not meet the indication were di-vided into 2 groups according to the patient's choice of EPD usage, 11 were treated by atherectomy with EPD and 11 without EPD. One case out of 11 unindicated patients without EPD suffered a tibioperoneal trunk embolization and restored with catheter aspiration. For 1/11 (9. 1％) unindicated cases with EPD protec-tion, the filter captured embolization. There was a significant difference of distal embolization rate between the indicated and unindicated patients (χ2 =19. 368,P =0. 000). All filters were retrieved successfully without any distal embolization and any complications except arterial spasm occurred in 2 patients and re-stored well with nitroglycerin. Conclusions It is safe and effective for selective usage of embolic protection device to prevent distal embolization during SilverHawk atherectomy for atherosclerotic femoropopliteal artery disease.