A new self-convertible inferior vena cava filter:in vivo experimental evaluation / 中国组织工程研究

BACKGROUND:An inferior vena cava filter is an effective tool to prevent fatal pulmonary embolism. The existing filters have some shortcomings that limit their clinical application. OBJECTIVE:To evaluate the feasibility and capture efficiency of a new self-convertible inferior vena cava filter (SCF)in vivo. METHODS:L-lactide and ε-caprolactone were fused and polymerized to act as a degradable deformable switch of the filter. Medical stainless steel wire as the metal structure of the filter was combined with the degradable deformable switch to make the SCF. Eight SCFs were implanted into the inferior vena cava of eight adult Beagle dogs. The inferior vena cava angiography was performed to evaluate the release process, morphology and location of the filter. Venous angiography was performed 2 weeks later to evaluate the morphology and location of the filter and inferior vena cava patency. Detection of pulmonary embolism or other complications was performed at autopsy. RESULTS AND CONCLUSION:Eight SCFs were successfully implanted and positioned accurately with no tilt, and they were converted successfully at 2 weeks after the implantation, as assessed by the venous angiography. One of the eight SCFs migrated to the orifice of the right atrium, and caused asymptomatic inferior vena cava obstruction. The remaining SCFs were normally positioned with no tilt and local lesion or obstruction after deformation. No marked filling defect in the trunk of the pulmonary artery was shown by the pulmonary artery angiography. The autopsy report revealed that the filter arm had been endothelialized, and the inferior vena cava that was in contact with the filter arm had no obvious stenosis. Mild intimal hyperplasia, less than 1 mm in thickness, was found in the bottom of the filter arm, but it did not cause a stenosis in the lumen. No vena cava perforation, retroperitoneal hemorrhage, and injury of the surrounding viscera were found. Overall, the design of the SCF is feasible.

A new self-convertible inferior vena cava filter:in vitro experimental evaluation / 中国组织工程研究

BACKGROUND: Inferior vena cava filter is an effective way to prevent fatal pulmonary embolism. The existing filters have some shortcomings that limit the clinical application. OBJECTIVE:To evaluate the feasibility and capture efficiency of a new self-convertible inferior vena cava filter(SCF)in vitro. METHODS: The biodegradable switch was constructed of a copolymer of ε-caprolactone and L-lactide (75%/25%, PCLA75). The biodegradable switch bound together with the apices of the convertible struts to make the self-convertible filter. The deformability and capture efficiency of the filter were tested in an in-vitro flow model with three different diameters (22, 25, 28 mm). A total of 15 filters were implanted both in the vertical and horizontal positions, and the tilt angle of the filter was tested after release. To accelerate switch degradation, a lipase perfusate was injected into the flow model and refreshed every 8 hours until conversion. RESULTS AND CONCLUSION: (1) All the filters were successfully implanted without tilting, both in the vertical and horizontal positions in the three different diameter models. (2) All the 15 SCFs were converted successfully without tilting, structural damage, and displacement. (3) The capture efficiency of the SCF had significant difference between the different diameter of the models, the size of the embolus and the position of the two models (P < 0.001). The mean capture efficiency was 82.5%, and the capture efficiency exhibited a downward trend with the increase of pipe diameter, the decrease of emboli size, and the position of pipeline changing from vertical to horizontal. All these results show that the SCF is feasible and highly efficient.

Excimer laser atherectomy combined with drug-eluting balloon angioplasty for the treatment of chronic ischemia of lower limbs: preliminary results in three patients / 介入放射学杂志

Objective To evaluated the safety and feasibility of excimer laser atherectomy (ELA) combined with drug-eluting balloon angioplasty in treating chronic ischemia of lower limbs.Methods ELA combined with paclitaxel-eluting balloon angioplasty was adopted to treat chronic ischemia of lower limbs caused by arteriosclerosis occlusive disease of lower extremity in three patients.All three patients had arteriosclerosis occlusive disease of superficial femoral artery;in two of them the disease was primary occlusive lesion and in another patient the disease was in-stent re-occlusion lesion after sten implantation.Results After the treatment,the blood flow in the diseased arteries was unobstructed,the blood supply of the lower limbs was obviously improved.No procedure-related complications occurred.Two weeks after the treatment,no recurrence of ischemic symptoms was observed,the blood flow in superficial femoral artery kept unobstructed.The patients recovered smoothly.Conclusion For the treatment of chronic ischemia of lower limbs,which are caused by the primary arteriosclerosis occlusive disease of lower extremity or by the in-stent re-occlusion lesion after sten implantation,ELA combined with paclitaxel-eluting balloon angioplasty is clinically safe and feasible,although its long-term effect needs to be clarified with more studies.

Endovascular therapy for complex subclavian artery occlusive diseases / 介入放射学杂志

Objective To discuss the key points of endovascular therapy for complex subclavian artery occlusive diseases. Methods During the period from January 2012 to December 2013, a total of 92 patients with complex subclavian artery occlusive disease were admitted to Xuanwu Hospital of Capital Medical University, Beijing, China. The clinical data were retrospectively analyzed. The features of the lesions, the success rate of endovascular therapy, the use of combined approaches, the relief of symptoms after treatment, etc. were evaluated. Results The complex subclavian artery occlusive diseases could be divided into three types. Type Ⅰ: long segment of the left subclavian artery was occluded; type Ⅱ: ostial stenosis or occlusion of the right subclavian artery; and type Ⅲ: subclavian artery stenosis or occlusion was associated with the ostial disorder of the vertebral artery, or the opening of vertebral artery was affected by the subclavian artery stenosis or occlusion. The technical success rate was 82.6%. Combination use of femoral artery and brachial artery approach was employed in 27.2% of patients, which had improved the technical success rate. After the treatment the symptom improvement rate was 81.6%. Conclusion Upper limb artery approach can improve the re-canalization rate of left subclavian artery with long segment occlusion, and can ensure the accurate positioning of stent at the site of right subclavian artery opening. During the procedure of endovascular intervention for subclavian artery occlusion disease, attention should be paid to the protection of the vertebral artery.

Totally laparoscopic bypass surgery for aortoiliac occlusive disease in China / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Totally laparoscopic aortic surgery is still in its infancy in China. One of the factors preventing adoption of this technique is its steep learning curve. The objective of this study was to evaluate the feasibility and safety of laparoscopic surgery for aortoiliac occlusive disease (AIOD).</p><p><b>METHODS</b>From November 2008 to November 2012, 12 patients were treated for severe AIOD with a totally laparoscopic bypass surgery at our university hospital. The demographic data, operative data, postoperative recovery data, morbidity and mortality were analyzed and compared with those of conventional open approach.</p><p><b>RESULTS</b>Twelve totally laparoscopic aortic surgery procedures, including two iliofemoral bypasses (IFB), three unilateral aortofemoral bypasses (UAFB), and seven aortobifemoral bypasses (ABFB), were performed. Conversion to open procedures was required in three patients. The mean operation time was 518 (range, 325-840) minutes, mean blood loss was 962 (range, 400-2500) ml, and mean aortic anastomosis time was 75 (range, 40-150) minutes. Compared with conventional open approach for aortofemoral bypasses performed concomitantly during this period, laparoscopic patients required fewer narcotics and a shorter in-hospital stay and earlier recovery. Postoperative complications developed in four patients, including a single patient with transient left hydronephrosis, ischemic colonic fistula and pneumonia, residual aortic stenosis proximal to the anastomotic site, and asymptomatic partial left renal infarction. All patients recovered and were discharged on postoperative Days 7-14 except one patient that died of respiratory failure on Day 46. All grafts were patent with follow-up imaging performed by Duplex examination, with a mean follow-up time of 10.7 (range, 2-61) months.</p><p><b>CONCLUSION</b>Totally laparoscopic bypass surgery is a feasible and safe procedure for AIOD, but attention needs to be paid to improve laparoscopic skills of vascular surgery in order to minimize morbidity during the learning curve of this advanced procedure.</p>

Preliminary evaluation of clinical effects of below-knee arterial bypass on diabetic lower limb ischemia / 中华外科杂志

<p><b>OBJECTIVE</b>To evaluate medium-long term patency of below-knee bypass on patients who suffered from diabetic lower limb ischemia.</p><p><b>METHODS</b>Clinical and follow-up data of 51 patients was retrospectively analyzed who underwent 56 below-knee bypass because of diabetes from November 2001 to December 2006. There were 35 male and 16 female with an average age of 68 years. They endured 26 months ischemic time lag in average, and had suffered from diabetes for 11 years. All of the patients were performed bypass to below-knee (posterior tibial, anterior tibial or peroneal) arteries. Kaplan-meier method was applied. The subgroups of different operative methods and different out-flow vessels were compared by Log-rank tests.</p><p><b>RESULTS</b>An average follow-up time of 23 months was achieved, and lost-follow-up rate was 15%. The total 1- and 5-year primary patent rates were 68% and 54% respectively, secondary patent rate were 70% and 60% respectively, limb salvage rates were 69% and 65%, survival rates were 82% and 60%. One year (3 years) of patent rate(s) of operative method subgroups of femoral-popliteal-infrageniculate bypass with composite grafts, femoral/popliteal-infrageniculate bypass with artificial grafts and femoral/popliteal-infrageniculate bypass with autologous veins were 70% (50%), 33% (33%) and 70% (70%) respectively. One year (4 years) of patent rate(s) of out-flow vessel subgroups of posterior tibial artery, anterior tibial artery and peroneal artery were 65% (60%), 80% (53%) and 77% (66%) respectively. However, both subgroups did not show any statistic differences by log-rank tests.</p><p><b>CONCLUSIONS</b>Partial or whole autologous veins as bypass grafts should be chosen when infrageniculate bypass is considered in diabetic patients. Considerable patent rates are acceptable no matter what kinds of out-flow vessels are chosen.</p>

Treatment of severe cerebral ischemia in Takayasu's disease with arterial reconstruction / 中华外科杂志

<p><b>OBJECTIVE</b>To evaluate the effect of surgical bypass and to explore the role of transcranial doppler (TCD) during the bypass operation.</p><p><b>METHODS</b>From March 2003 to February 2008, sixteen patients (4 male and 12 female) with mean age of 32 years old and mean disease course of 7.5 years were treated by surgical procedures. The main clinical presentations were dizziness, headache, vertigo, and visional dysfunction. Variated degree of artery stenoses in the 4 arteries (bilateral carotid and vertebral arteries) were revealed by color doppler ultrasonography and DSA. Eight patients underwent aorto-bi-subclavian arteries prosthetic graft bypass. Three patients underwent aorto-bi-subclavian artery prosthetic graft bypass and graft-unilateral carotid artery bypass with autologous great saphenous vein. Three patients underwent aorta-unilateral subclavian artery-unilateral carotid artery prosthetic graft bypass. Two patients underwent aorta carotid artery bypass with autologous great saphenous vein, of which one patient underwent aortocoronary artery bypass simultaneously. Cerebral blood supply was monitored in 14 patients with transcranial doppler. Unilateral subclavian carotid and femoral carotid artery shunt was used respectively to avoid cerebral ischemia during operation in 2 patients.</p><p><b>RESULTS</b>Symptoms and signs of cerebral ischemia improved in all patients with effective rate of 100% apart from deflected tongue-protrusion in 3 patients which recovered in 2 weeks after operation. All patients survived and no symptoms recurred at the end of a 2.2 year's follow-up. Unfortunately, two patients developed aneurysm at the anastomosis within 4 years after operation.</p><p><b>CONCLUSIONS</b>Arterial reconstruction is an effective method for Takayasu's disease with severe cerebral ischemia. TCD monitoring plays an important role during the bypass operation. It can help to determine the revision of blood pressure and prevent postoperative brain reperfusion injury.</p>

Transplantation of autologous bone marrow mononuclear cells for patients with lower limb ischemia / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Many treatment options for lower limb ischemia are difficult to apply for the patients with poor arterial outflow or with poor general conditions. The effect of medical treatment alone is far from ideal, especially in patients with diabetic foot. A high level amputation is inevitable in these patients. This study aimed to explore the effect of transplantation of autologous bone marrow mononuclear cells on the treatment of lower limb ischemia and to compare the effect of intra-arterial transplantation with that of intra-muscular transplantation.</p><p><b>METHODS</b>In this clinical trial, 32 patients with lower limb ischemia were divided into two groups. Group 1 (16 patients with 18 affected limbs) received transplantation of autologous bone marrow mononuclear cells by intra-muscular injection into the affected limbs; and group 2 (16 patients with 17 affected limbs) received transplantation of autologous bone marrow mononuclear cells by intra-arterial injection into the affected limbs. Rest pain, coldness, ankle/brachial index (ABI), claudication, transcutaneous oxygen pressure (tcPO(2)) and angiography (15 limbs of 14 patients) were evaluated before and after the mononuclear cell transplantation to determine the effect of the treatment.</p><p><b>RESULTS</b>Two patients died from heart failure. The improvement of rest pain was seen in 76.5% (13/17) of group 1 and 93.3% (14/15) of group 2. The improvement of coldness was 100% in both groups. The increase of ABI was 44.4% (8/18) in group 1 and 41.2% (7/17) in group 2. The value of tcPO(2) increased to 20 mmHg or more in 20 limbs. Nine of 15 limbs which underwent angiography showed rich collaterals. Limb salvage rate was 83.3% (15/18) in group 1 and 94.1% (16/17) in group 2. There was no statistically significant difference in the effectiveness of the treatment between the two groups.</p><p><b>CONCLUSIONS</b>Transplantation of autologous bone marrow mononuclear cells is a simple, safe and effective method for the treatment of lower limb ischemia, and the two approaches for the implantation, intra-muscular injection and intra-arterial injection, show similar results.</p>

Management of difficult, severe and recurrent Budd-Chiari syndrome / 中华外科杂志

<p><b>OBJECTIVE</b>To investigate the management of complicated, severe or recurrent Budd-Chiari syndrome.</p><p><b>METHODS</b>From February 2004 to August 2007, 28 patients with complicated, severe or recurrent Budd-Chiari syndrome were treated. In this series, 16 patients relapsed after treated with percutaneous transluminal angioplasty or stent deployment, 2 cases relapsed after surgery; and the other 10 were under severe conditions and hard to treat, including malignancy of the inferior vena cava and right atrium. Meso-cavo-atrial shunt was carried out in 10 cases, meso-cavo-jugular shunt in 6 (capitis medusa was used in one case), cavoatrial shunt in 2 and cavo-jugular shunt in 1, mesocaval shunt in 2, and radical or extended radical correction in 7.</p><p><b>RESULTS</b>One patient (3.6%) died in 24 hours after operation. Graft infection occurred in 1 case. Excellent, good, fair, poor and death rate were 22.2%, 55.5%, 14.8%, 3.7% and 3.7%, respectively, the overall effective rate was 92.5%.</p><p><b>CONCLUSION</b>To select personalized treatment according to the disease status brings hopes to difficult, severe, recurrent Budd-Chiari syndrome.</p>

Surgical treatment of 82 patients with diabetic lower limb ischemia by distal arterial bypass / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Diabetic lower limb ischemia is a serious complication of diabetes mellitus. This study was conducted to investigate the effectiveness of distal arterial bypass treatment in diabetic patients with lower limb ischemia.</p><p><b>METHODS</b>From July 2000 to July 2004, 96 lower limbs of 82 diabetic patients (type 2) with severe lower limb ischemia were treated in Xuan Wu Hospital. Arterial bypass with femoro-popliteal polytetrafluoroethylene (PTFE) and graft-tibial autologous grafts was performed on 31 limbs (32.3%). Popliteal-tibial artery bypass alone was performed on 22 limbs (22.9%). Combined iliac artery stenting, femoro-popliteal artery PTFE graft bypass, and graft-tibial artery autologous graft bypass was performed on 12 limbs (12.5%), and femoro-tibial artery graft bypass was performed on 10 limbs (10.4%). Popliteal-tibial-pedal artery graft bypass was performed on 7 limbs (7.3%).</p><p><b>RESULTS</b>Arterial grafts in 92 limbs of 79 patients were patent on discharge. Three patients with 4 ischemic limbs (3.7%) died of respiratory failure 12 hours, 3 days and 7 days after operation respectively. Early operation success rate was 96.3% (79/82). Graft patency rate of patients on discharge was 95.8% (92/96). The short-term total effectiveness rate was 83.3% (80/96). Foot ulcer healing rate was 35.7% (10/28). 97.4% (75/77) patients were followed up for a mean of 13.5 months. The long-term total effective rate was 80.7% (71/88). The total amputation rate was 4.5% (4/88). Mortality was 4.5%. The total graft patency rate was 90.9% (80/88).</p><p><b>CONCLUSION</b>In the treatment of diabetic foot, distal lower limb arterial bypass can help to avoid amputation or lower the amputation level, and may promote foot ulcer healing and improve patient's quality of life.</p>

Clinical analysis of vascular reconstruction in 56 cases of lower extremity ischemia suffering from infrapopliteal arterial occlusion / 中华外科杂志

<p><b>OBJECTIVE</b>To summarize therapeutic efficacy of vascular reconstruction in treating infrapopliteal arterial occlusion.</p><p><b>METHODS</b>Retrospective analysis of vascular reconstruction of lower extremity was made in 56 cases suffering from popliteal arteries or 3 branches of popliteal arteries (anterior tibial, posterior tibial, peroneal artery) between July 2001 and August 2005 in our hospital. According to the level of lower extremity arterial occlusion, a composite grafts which consisting of a combined proximal PTFE prosthesis grafts with autogenous vein grafts were used to establish the sequential vascular reconstruction for multilevel and multistage arterial occlusive disease.</p><p><b>RESULTS</b>The mean follow-up period after operation was 17 months. The primary graft patency rates in this series was 67.3%, the secondary graft patency rate was 78.8%.</p><p><b>CONCLUSIONS</b>The treatment of composite sequential bypass is a practical means for multilevel arterial occlusive disease suffering from femoral-infrapopliteal arteries, which effectively resolves the insufficiency supply of autogenous vessel grafts and the problem of bad patency rate for vascular reconstruction with prosthetic grafts alone in arterial occlusion suffering from infrapopliteal arteries.</p>

Preliminary in vivo evaluation of tissue engineered venous grafts fabricated based on endothelial progenitor cells / 中华外科杂志

<p><b>OBJECTIVE</b>To explore the feasibility of the tissue engineered venous grafts (TEVGs) constructed in vitro based on canine autologous bone marrow-derived endothelial progenitor cells (EPCs) and porcine decellularized aortic scaffolds implanted into the canine inferior vena cava.</p><p><b>METHODS</b>To draw out a volume of 8 - 12 ml of bone marrow from the canine (n = 8), to culture and expand EPCs in vitro using conditioned medium. After labeled with a red fluorescent dye PKH26-GL, the cells were seeded onto the luminal surface of decellularized porcine scaffolds with single, rotative method for 4 h. Following static culture for 24 - 72 h, the hybrids were implanted to replace autologous canine inferior vena cava about 4 cm long. Meantime one femoral artery-venous shunt about 1 cm long was performed. The non-seeded decellularized scaffolds (n = 4) were performed the same as control. Angiography was performed and the hybrids were explanted for morphology and labeled cells' immuno-fluorescence examinations at postoperative 10 d, 4 weeks and 12 weeks, respectively.</p><p><b>RESULTS</b>The patent number of experiment (control) group were 7/7 (2/4), 6/6 (2/2) and 4/4 (1/2) at postoperative 10 d, 4 weeks and 12 weeks, respectively. At 12 weeks, tightly confluence endothelial cells which covered the whole inner luminal surface of the explants were detected by immunohistochemistry of factor VIII and scanning electron microscopy, while fibrin-based pseudo-intima was detected on the inner luminal surface of matrix in the solo patent dog from the control group. Meanwhile, fibroblasts and alpha-actin positive cells in the matrices were found by transmission electron microscopy and alpha-actin immunohistochemistry. PKH26-GL labeled EPCs sustained on the luminal surface at a rather proportion accompanied by newly formed endothelial cells. However, the explants in both groups showed partial stenosis.</p><p><b>CONCLUSIONS</b>Such constructed tissue engineered venous graft based on canine autologous bone marrow-derived endothelial progenitor cells and porcine decellularized aortic matrices is promising and deserve to further improvement and testing.</p>

Challenges in management of cerebral ischemia due to Takayasu's arteritis / 中华外科杂志

<p><b>OBJECTIVE</b>To explore the management of cerebral ischemia caused by Takayasu's arteritis.</p><p><b>METHODS</b>One hundred and three cases treated from 1984 to 2003 were reviewed including 92 females. Seven cases underwent ascending aorta to bilateral internal carotid artery (ICA) bypass, 38 cases to the axillary artery with graft to single ICA bypass. Six cases underwent ascending aorta to axillary bypass with 3 graft to single ICA bypasses as the second stage surgery. Three cases underwent ascending aorta to right ICA bypass with 2 graft to left ICA bypasses as well as 6 subclavian to carotid bypass, PTA in 5 and stenting in 3 cases, etc.</p><p><b>RESULTS</b>Twenty-seven patients with less clinical severity received conservative therapy, 9 of them had mostly temporarily improvement, 15 had slight improvement or basically no change, 1 had hemiplegia and 2 died of stroke and myocardial infarction respectively. Surgically, the short-term effective rate was 87% and operative death 7.8%. Fifty-five patients were followed up, a mean follow-up time was 48 months, and the follow-up rate was 80.9%. The excellently, good, fair, no change and death rate were 36.4%, 38.2%, 20.0%, 3.6% and 1.8% respectively. All patients with PTA or stent had an immediate good response and all recurred within 3 to 5 months.</p><p><b>CONCLUSIONS</b>For treating severe cerebral ischemia caused by Takayasu's arteritis, the ascending aorta to axillary and single ICA reconstruction or the ascending aorta-bilateral axillary bypass for patients with subclavian steal syndrome is advocated; second stage operation from graft to contralateral ICA can be carried out if necessary.</p>