首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
Purpose: To provide follow-up data on endovascular intervention for venous stenoses in the pelvis. Methods: Between 1985 and 1995, 35 patients presented with 42 stenoses of the pelvic veins after operative thrombectomy and creation of an arteriovenous fistula, combined with intraoperative venous angioscopy. All patients underwent angioplasty and, if unsuccessful, percutaneous insertion of an endovascular stent (n = 7). Results: Angioplasty with and without endovascular stenting was technically successful in 34 of 35 patients (97%). Average length of the stenoses was 20.6 mm (range 10–90 mm), average diameter before dilation 4.1 mm (range 2–6 mm), and average diameter after dilation 10.1 mm (range 5–18 mm). Intraoperative angioscopy showed pathologic findings (intimal laceration or residual thrombotic material) in 14 patients. After an average follow-up period of 4.13 years, 24 (69%) patients had patent veins. The difference in the primary patency rate between patients with angioscopically abnormal veins (6 of 14 patients, corresponding to a patency rate of 43%) and patients with angioscopically normal veins after thrombectomy (18 of 21 patients, corresponding to a patency rate of 86%) was statistically significant (p < 0.01, log rank test). Conclusions: Percutaneous transluminal angioplasty and/or stenting are good treatment modalities for pelvic vein stenosis following surgical thrombectomy. Angioscopically abnormal veins have a poorer long-term patency, regardless of the type of intervention.  相似文献   

2.
We describe a technique that extracted a ruptured angioplasty balloon which had become entrapped by a calcified left common iliac artery stenosis. The balloon catheter had been advanced crossover from the right and could not be retracted directly into a sheath across the aortic bifurcation. Therefore, a guidewire was inserted through the balloon catheter and captured by a loop snare advanced from the left femoral artery. The loop snare was also used to free the balloon wings from the stenosis. The balloon was then pulled into a 10 Fr sheath and removed as a unit with the sheath.  相似文献   

3.
Purpose: Magnetic resonance (MR)-guided percutaneous vascular interventions have evolved to a practical possibility with the advent of open-configuration MR systems and real-time tracking techniques. The purpose of this study was to assess an MR-tracking percutaneous transluminal angioplasty (PTA) catheter with regard to its safety profile and functionality. Methods: Real-time, biplanar tracking of the PTA catheter was made possible by incorporating a small radiofrequency (RF) coil in the catheter tip and connecting it to a coaxial cable embedded in the catheter wall. To evaluate potentially hazardous thermal effects due to the incorporation of the coil, temperature measurements were performed within and around the coil under various scanning and tracking conditions at 1.5 Tesla (T). Catheter force transmission and balloon-burst pressure of the MR-tracking PTA catheter were compared with those of a standard PTA catheter. The dilatative capability of the angioplasty balloon was assessed in vitro as well as in vivo, in an isolated femoral artery segment in a swine. Results: The degree of heating at the RF coil was directly proportional to the power of the RF pulses. Heating was negligible with MR tracking, conventional spin-echo and low-flip gradient-echo sequences. Sequences with higher duty cycles, such as fast spin echo, produced harmful heating effects. Force transmission of the MR-tracking PTA catheter was slightly inferior to that of the standard PTA catheter, while balloon-burst pressures were similar to those of conventional catheters. The MR-tracking PTA catheter functioned well both in vitro and in vivo. Conclusion: The in vivo use of an MR-tracking PTA catheter is safe under most scanning conditions.  相似文献   

4.
We implanted stents in three patients who had traumatic abdominal aortic dissections, complicated by right limb ischemia in one case. The circulating false channel extended to the left iliac artery in one case and to both iliac arteries in the last case. Diagnosis and radiological follow-up included ultrasound, computed tomography, and arteriography. Two patients were treated with Wallstents, one with a Palmaz stent. The occlusion of the false channel was obtained in all patients without any significant residual stenosis. No early or late complication was noted in any of the patients. The longest follow-up was 2 years. We conclude that stent placement is an efficient method for the treatment of noniatrogenic inframesenteric aortic dissections. Received: 0/00/00/Accepted: 0/00/00  相似文献   

5.
Purpose: To evaluate in a porcine model of acute deep vein thrombosis (DVT) the efficacy of dalteparin and antithrombin with respect to heparin for local adjuvant therapy during selective thrombolysis, and the utility of nitroglycerin and iloprost as heparin supplements. Methods: DVT was induced in both hind limbs using a previously described technique (n = 20). Thirty minutes later, the animal was heparinized (2500 IU IV), and bilateral sequestrated thrombolysis was performed using 8 mg alteplase: both external iliac veins were endoluminally occluded with Swan-Ganz catheters, and a multi-sideport infusion wire coaxially introduced through each catheter and advanced into the ipsilateral popliteal vein. In the control limbs, tissue plasminogen activator (tPA) 8 mg was injected as 0.8-ml boluses at 3-min intervals for 2 hr as a 0.25-mg/ml solution containing heparin 50 IU/ml (n = 20). On the contralateral side, heparin was substituted with either dalteparin 50 IU/ml (n = 5) or antithrombin 12.5 IU/ml (n = 5), or supplemented with either nitroglycerin 0.075 mg/ml (n = 5) or iloprost (150 ng/ml) (n = 5). Blood samples were taken at predetermined intervals to measure the activated partial thromboplastin time (aPTT), prothrombin time (PT), and fibrinogen concentration. At autopsy, the thrombus mass in the iliofemoral veins was measured, and the extent of residual thrombosis in the venous tributaries graded at four sites. Results: Bilateral thrombolysis was successfully completed in all animals. The median thrombus mass in the iliofemoral veins after thrombolysis was 0.48 g (range 0.06–1.58 g), 0.95 g (0.59–1.29 g), 0.74 g (0.52–0.96 g), and 0.29 g (0.0–0.77 g) for dalteparin, antithrombin, iloprost, and nitroglycerin respectively, as compared with 0.53 g (0.18–0.88 g) (p = 0.69), 0.97 g (0.46–1.15 g) (p = 0.69), 0.53 g (0.48–1.10 g) (p = 0.69), and 0.18 g (0.13–1.04 g) (p = 0.5) for the respective controls. Likewise, the severity of residual thrombosis in the venous tributaries was not affected by the constituents of adjuvant therapy. Nitroglycerin induced a small drop in blood pressure, which was transient. The temporal change in aPTT was similar in all four groups. Invariably PT progressively shortened during thrombolysis (p = 0.0001); this effect was somewhat blunted with antithrombin. Fibrinogen levels demonstrated a time-dependent increase (p = 0.004) that was not influenced by the adjuvant therapy used. Conclusions: Dalteparin or antithrombin demonstrated no appreciable advantage over heparin as local adjuvant therapy for selective venous thrombolysis. Supplementation of heparin with iloprost or nitroglycerin also had virtually no effect on thrombolytic efficacy.  相似文献   

6.
Purpose: To determine the effectiveness of using Dacron-covered stents to treat access-related venous stenoses and occlusions. Methods: Twenty-two Dacron-covered stents were placed in 20 patients: in the basilic or axillary vein (n = 2), cephalic vein (n = 3), subclavian vein (n = 5), and at the venous anastomosis of the polytetrafluoroethylene (PTFE) implant graft (n = 10). Results: Initial technical success was 100%. The cumulative primary and secondary patency rates were 57% and 83% at 6 months, 29% and 64% at 12 months, and 29% and 53% at 18 months. A statistically significant difference in the stent patency was revealed by comparing the patients with stents in the subclavian vein and patients with upper arm stents. The secondary patency rates of the upper arm stents were 73% after 6, 12, and 18 months. Conclusions: Percutaneous placement of Dacron-covered stents is a safe and effective procedure for salvage of a dialysis fistula. First results are promising, with a tendency to prolongation of the time interval between reinterventions.  相似文献   

7.
Purpose: To assess the technical success, initial clinical outcome, and intermediate follow-up of the Memotherm nitinol self-expanding stent in aortic bifurcation reconstruction. Methods: Thirty-three patients (13 male, 20 female), mean age 64 years, were treated, who had symptoms classified by the Surgical Vascular Society/International Society of Cardiovascular Surgery (SVS/ICVS) classification as grade 2 in 11 (33%), grade 3 in 19 (58%) and grade 4 in 3 (9%) patients. Lesions were classified according to severity and type. Indications for placement of a Memotherm nitinol self-expanding stent were failed angioplasty in 14 (42%), chronic occlusions in 12 (37%), and complex stenoses in seven (21%) patients. Results: Sixty-seven stents were technically successfully placed in 66 aorto-iliac segments in 33 patients, with one major complication. Initial clinical outcome was improvement in 25 (81%), no change in four (13%), and a worsening in two (6%) patients by Rutherford criteria. Mean early ankle/brachial pressure index (ABI) gain was 0.27 for occlusions and 0.05 for stenoses. Clinical follow-up was obtained in all patients, with retrospective angiographic follow-up in 28 (85%) at a mean of 16 months (range 12–26 months). The decrease in ABI and the decrease in angiographic luminal diameter at follow-up was determined as the “late loss.” The mean ABI late losses were −0.06, 0.00, and 0.09, and the mean angiographic late losses were 6.7%, 10% and 14% for occlusions, stenoses, and normal segments respectively. Primary clinical patency was 96%, primary angiographic patency was 89%, and secondary angiographic patency was 93%. Conclusion: The high technical success of stent placement, the low complication rates for aortic bifurcation reconstruction using the Memotherm self-expanding stent, and high clinical and angiographic patency maintained at intermediate follow-up support their use in aortic bifurcation reconstruction.  相似文献   

8.
Purpose: To develop an animal model of acute deep vein thrombosis (DVT). Methods: In part I of the study nine juvenile domestic pigs were used. Each external iliac vein was transluminally occluded with a balloon catheter. Thrombin was infused through a microcatheter in one leg according to one of the following protocols: (1) intraarterial (IA): 1250 U at 25 U/min in the common femoral artery (n= 3); (2) intravenous (IV): 5000 U in the popliteal vein at 500 U/min (n= 3), or at 100 U/min (n= 3). Saline was administered in the opposite leg. After the animals were killed, the mass of thrombus in the iliofemoral veins was measured. The pudendoepiploic (PEV), profunda femoris (PF), and popliteal veins (PV) were examined. Thrombosis in the tributaries of the superficial femoral vein (SFVt) was graded according to a three-point scale (0, +, ++). In part II of the study IV administration was further investigated in nine pigs using the following three regimens with 1000 U at 25 U/min serving as the control: (1) 1000 U at 100 U/min, (2) 250 U at 25 U/min, (3) 250 U at 6.25 U/min. Results: All animals survived. In part I median thrombus mass in the test limbs was 1.40 g as compared with 0.25 g in the controls (p= 0.01). PEV, PFV and PV were thrombosed in all limbs infused with thrombin. IV infusion was more effective in inducing thrombosis in both the parent veins (mass 1.32–1.78 g) and SVFt (++ in 4 of 6 legs), as compared with IA infusion (mass 0.0–1.16 g; SFVt ++ in 1 of 3 legs). In part II thrombus mass in axial veins ranged from 1.23 to 2.86 g, and showed no relationship with the dose of thrombin or the rate of infusion. Tributary thrombosis was less extensive with 250 U at 25 U/min than with the other regimens. Conclusion: Slow distal intravenous thrombin infusion in the hind legs of pigs combined with proximal venous occlusion induces thrombosis in the leg veins that closely resembles clinical DVT in distribution.  相似文献   

9.
A transjugular central venous catheter was inadvertently sutured to the wall of the right atrium in a 63-year-old female during coronary bypass surgery. Using two nitinol Goose Neck snares via a transfemoral and a transjugular approach the catheter was severed into two pieces and retrieved percutaneously.  相似文献   

10.
Purpose: To examine the extent of the changes in the intrarenal spectral waveform patterns after percutaneous transluminal angioplasty (PTA) and whether there is a correlation with the angiographic and clinical results. Methods: In 44 patients with 68 PTAs we analyzed the intrarenal spectral waveform regarding the existence of a tardus–parvus pattern before and after PTA. Results: In 51 of the 60 cases with a tardus–parvus pattern prior to PTA, a complete normalization of the spectral waveform was noted. There was no correlation between the Doppler result after PTA and the angiographic and clinical result. In contrast there was a significant correlation between the Doppler result before PTA and the clinical outcome: patients with a normal intrarenal spectral waveform before PTA showed no improvement in their arterial hypertension. Conclusion: Our results indicate that a patient with a normal spectral waveform analysis does not response to PTA. However, there is still an unpredictable clinical response even if a patient has an abnormal intrarenal spectral waveform prior to PTA and a complete normalization after PTA.  相似文献   

11.
Purpose: To evaluate the effectiveness of ultrasound thrombolysis in occluded hemodialysis access shunts using an in vitro model. Methods: Thrombosed hemodialysis accesses were simulated by clotted bovine blood in a flow model (silicone tubing; inner diameters 4, 6, and 9 mm). After retrograde and antegrade sheath placement (7 Fr), mechanical thrombolysis was performed using an ultrasound probe (Acolysis, Angiosonics, Morrisville, NC, USA). The tip of the device measured 2.2 mm in diameter. During sonication, the catheter was moved slowly back and forth using an over-the-wire system. Thirty complete occlusions [tubing diameters 4 mm (n = 12), 6 mm (n = 12), 9 mm (n = 6)] were treated. Initial thrombus weights were 3.5 (± 0.76) g, 7.7 (± 1.74) g, and 19.4 (± 2.27) g for the three diameters. Maximum sonication time was 15 min for each probe. Results: With this device, we were able to restore a continuous lumen in all 12 occluded 4∼mm silicone tubes. No wall-adherent thrombi remained after sonication for 3.5–9.6 min. In hemodialysis access models with diameters of 6 mm, thrombus fragments persisted in 25% (3/12 accesses). These were located in the medial portion of the access loop and near to the puncture sites. However, flow was re-established after 5.0–13.0 min of treatment in all settings. Mechanical dissolution of thrombus material failed in five of six access models with diameters of 9 mm, even though ultrasound energy was applied for the maximum of 15 min. Conclusion: In a clotted hemodialysis shunt model, successful ultrasound thrombolysis was limited to small access diameters and small amounts of thrombus.  相似文献   

12.
> Purpose: To evaluate complications and their predictors in percutaneous transluminal angioplasty (PTA) of lower-limb arteries. Methods: Complications in 410 angioplasty procedures in 295 consecutive patients (192 claudicants and 103 suffering from chronic critical ischemia) were prospectively analyzed. Results: The total complication rate was 10.5% (43/410). There were 21 major complications (5%), eight of which required surgical treatment, including four hematomas, two arteriovenous fistulae, and two pseudoaneurysms at the puncture site, two retroperitoneal hematomas, and 11 thrombotic/thromboembolic complications. There were significantly more complications with treatment of occlusions compared with stenoses (18% vs 7%, p= 0.002). Women had significantly more bleeding complications than men (15% vs 6%, p= 0.032). The 30-day mortality rate in patients with critical ischemia was 10%. Conclusion: In lower-limb PTA a few target lesion- and patient-related determinants of complications could be identified. In patients with critical ischemia, the 30-day mortality was rather high and mainly due to associated coronary and cerebrovascular diseases.  相似文献   

13.
Endovascular Treatment of Chronic Mesenteric Ischemia: Report of Five Cases   总被引:3,自引:0,他引:3  
Purpose: To evaluate the midterm results of percutaneous transluminal angioplasty (PTA) and stent placement in stenotic and occluded mesenteric arteries in five consecutive patients with chronic mesenteric ischemia. Methods: Five patients with 70%–100% obliterations of all mesenteric vessels resulting in chronic mesenteric ischemia (n= 4) and as a prophylactic measure prior to abdominal aortic aneurysm repair (n= 1) underwent PTA of celiac and/or superior mesenteric artery (SMA) stenoses (n= 2), primary stenting of ostial celiac occlusions (n= 2), and secondary stenting of a SMA occlusion (n= 1; recoil after initial PTA). All patients underwent duplex ultrasonography (US) (n= 3) and/or angiography (n= 5) during a median follow-up of 21 months (range 8–42 months). Results: Clinical success was obtained in all five patients. Asymptomatic significant late restenoses (n= 3) were successfully treated with repeat PTA (n= 2) and stenting of an SMA occlusion (n= 1; celiac stent restenosis). Recurrent pain in one patient was interpreted as secondary to postsurgical abdominal adhesions. Two puncture-site complications occurred requiring local surgical treatment. Conclusions: Endovascular techniques may be attempted prior to surgery in cases of stenotic or short occlusive lesions in patients with chronic mesenteric ischemia. Surgery may still be preferred in patients with long occlusions and a low operative risk.  相似文献   

14.
Purpose: To compare angiographic and intravascular ultrasound (IVUS) data before and after balloon angioplasty (PTA) of the femoropopliteal artery. Methods: Qualitative and quantitative analyses were performed on corresponding angiographic and IVUS levels obtained from 135 patients. Results: IVUS detected more lesions, calcified lesions, and vascular damage than angiography. Sensitivity of angiography was good for the presence of a lesion (84%), moderate for eccentric lesions (53%) and for vascular damage (52%), and poor for calcified lesions (30%). The increase in angiographic diameter stenosis was associated with a decrease in lumen area and increase in percentage area stenosis on IVUS. Conclusions: Angiography is less sensitive than IVUS for detecting lesion eccentricity, calcified lesions, and vascular damage. Presence of a lesion and amount of plaque were underestimated angiographically. Only before PTA was good agreement found between angiographic diameter stenosis and lumen size on IVUS.  相似文献   

15.
Purpose: To evaluate the efficacy of covered stents for the treatment of transjugular intrahepatic portosystemic shunt (TIPS) obstruction in human subjects with identified or suspected biliary fistulae. Methods: Five patients were treated for early failure of TIPS revisions. All had mid-shunt thrombus, and four of these had demonstrable biliary fistulae. Three patients also propagated thrombus into the native portal venous system and required thrombolysis. TIPS were revised in four patients using a custom-made polytetrafluoroethylene (PTFE)-covered Wallstent, and in one patient using a custom-made PTFE-covered Gianturco Z-stent. Results: All identified biliary fistulae were successfully sealed. All five patients maintained patency and function of the TIPS during follow-up ranging from 2 days to 21 months (mean 8.4 months). No patient has required additional revision. Thrombosis of the native portal venous system was treated with partial success by mechanical thrombolysis. Conclusion: Early and recurrent failure of TIPS with mid-shunt thrombosis, which may be associated with biliary fistulae, can be successfully treated using covered stents. Stent-graft revision appears to be safe, effective, and potentially durable.  相似文献   

16.
Purpose: To assess the incidence of infections and its influence on the survival of radiologically inserted Hickman catheters (HCs) in patients with hematologic disorders and to determine factors associated with premature HC removal. Methods: Survival and complications of 175 HCs in 115 patients were studied retrospectively. To describe the data the Kaplan-Meier method and the log-rank test were used, using the date of HC removal due to HC-related infection as endpoint. A stratified Cox regression model was used to determine explanatory factors. Results: Seventy (40%) HCs were removed prematurely because of proven or probable HC-related infections. The incidence of infection leading to HC removal was 4.78 per 1000 catheter-days for proven HC infections. Univariate analysis revealed that acute myeloid leukemia, acute lymphocytic leukemia, or treatment for these diseases, gender, each subsequent catheter in the same patient and insertion site increased the risk of premature removal of the catheter due to infection. Conclusion: Infection is a major problem in patients with HCs. Unfortunately, the factors associated with increased infection rates that were found in this study cannot be influenced. Further studies are necessary to determine the role of environmental conditions in a radiology suite in relation to the risk of developing a catheter-related infection.  相似文献   

17.
Purpose: To evaluate the efficacy of the placement of covered metallic stents for palliation of gastrointestinal anastomotic strictures secondary to recurrent gastric cancer. Methods: Under fluoroscopic guidance, placement of one or two self-expandable covered metallic stents was attempted perorally in 11 patents (aged 48–76 years) with anastomotic stenoses due to recurrent gastric malignancies. The strictures involved both the afferent and efferent loops in three patients. All patients had poor peroral food intake with severe nausea and vomiting after ingestion. The technical and clinical success was evaluated. Results: Placement of the covered stent was technically successful in 13 of 15 (87%) attempts in ten patients. After the procedure, 9 of 11 (82%) patients overall were able to ingest at least a liquid diet and had markedly decreased incidence of vomiting. During the follow-up of 2–31 weeks (mean 8.5 weeks) there were no major complications. Conclusion: These preliminary results suggest that flexible, covered stents may provide effective palliation of malignant anastomotic stricture secondary to recurrent gastric cancer.  相似文献   

18.
Four patients underwent endovascular treatment of vascular injuries complicating lumbar spinal surgery. In two patients with massive retroperitoneal hemorrhage, the extravasating lumbar arteries were successfully embolized with microcoils. Two patients with large iliac arteriovenous fistula (AVF) were treated, one with embolization using a detachable balloon and coils, which failed, and the other with placement of a stent graft after embolization of distal runoff vessels, which occluded the fistula. We conclude that acute arterial laceration or delayed AVF complicating lumbar spinal surgery can be managed effectively with selective embolization or stent-graft placement, respectively.  相似文献   

19.
Purpose: To compare the early andlong-term outcomes of subclavian artery angioplasty in patients with aortoarteritis and atherosclerosis. Methods: Sixty-one subclavian artery angioplasties were performed in 55 consecutive patients with aortoarteritis (n= 32) and atherosclerosis (n= 23) between 1986 and 1995. An arch aortogram followed by a selective subclavian artery angiogram was done to profile the site and extent of the lesion, its relation to the vertebral artery, and the distal circulation. Percutaneous transluminal angioplasty (PTA) was performed via the femoral route for 56 stenotic lesions and 5 total occlusions. Results: PTA was successful in 52 (92.8%) stenotic lesions and 3 (60%) total occlusions. Three patients (5.4%) had complications, that could be effectively managed nonsurgically. Compared with atherosclerosis, patients with aortoarteritis were younger (27.4 ± 9.3 years vs 54.5 ± 10.5 years; p < 0.001), more often female (75% vs 17.4%; p < 0.001), gangrene was uncommon (0% vs 17.4%; p < 0.05), and diffuse involvement was seen more often (43.8% vs 4.4%; p < 0.001). The luminal diameter stenoses were similar before PTA (88.6 ± 9.7% vs 89.0 ± 9.1%; p= NS). Higher balloon inflation pressure was required to dilate the lesions of aortoarteritis (9.9 ± 4.6 ATM vs 5.5 ± 1.0 ATM; p < 0.001). This group had more residual stenosis (15.5 ± 12.4% vs 8.3 ± 9.4%; p < 0.05) after PTA. There were no neurological sequelae, even in PTA of prevertebral lesions. On 3–120 months (mean 43.3 ± 28.9 months) follow-up of 40 patients, restenosis was more often observed in patients with aortoarteritis, particularly in those with diffuse arterial narrowing. These lesions could be effectively redilated. Clinical symptoms showed marked improvement after successful angioplasty. Conclusion: Subclavian PTA is safe and can be performed as effectively in aortoarteritis as in atherosclerosis, with good long-term results. Long-term follow-up shows that it provides good symptomatic relief.  相似文献   

20.
Purpose: To compare nonferromagnetic iliac artery prostheses in their suitability for patency monitoring with magnetic resonance angiography (MRA) using conventional angiography as a reference. Methods: In experiment 1, three Memotherm stents were inserted into the iliac arteries of each of six sheep: two “tandem” stents on one side and a single stent on the other side. In experiment 2, four prostheses (normal and low-porosity Corvita stent-grafts, Memotherm, ZA-stent) were inserted in each of 11 sheep. Patency was monitored before and 1, 3, and 6 months after insertion with 3D phase-contrast and two 2D time-of-flight sequences (TOF-1: TR/TE = 18/6.9, TOF-2: 13/2.5) with and without contrast at 1.5 T. On 206 coronal MIP images (72 pre-, 134 post-stenting), three readers analyzed 824 iliac segments (206 × 4) for patency and artifacts. Results: There was no difference in the number of artifacts between tandem and single iliac Memotherm stents. The ZA-stent induced significantly fewer artifacts than the other prostheses (p < 0.00001). With MRA, patency of the ZA-stent was correctly diagnosed in 88% of cases, which was almost comparable to nonstented iliac segments (95%), patency of the Memotherm stent in 59%, and of the Corvita stent-grafts in 57% and 55%. The TOF-2 sequence with contrast yielded the best images. Conclusion: MRA compatibility of nonferromagnetic prostheses depends strongly on the design of the device. MRA may be used to monitor the patency of iliac ZA-stents, whereas iliac Memotherm stents and Corvita stent-grafts appear to be less suited for follow-up with MRA.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号