Insights into the source-specific health risk of ambient particle-bound metals in the Pearl River Delta region, China.

Quantification of source-specific health risks of PM2.5 plays an essential role in health-oriented air pollution control. However, there is limited evidence supporting the source-based risk apportionment of particle-bound metals. In this study, source-specific cancer and non-cancer risk characterization of 12 particle-bound metals was performed in the Pearl River Delta (PRD) region, China. A combination of health risk assessment model and receptor-based source apportionment modeling with positive matrix factorization (PMF) was applied for characterizing the spatial-temporal patterns for inhalation health risks of particle-bound metals in three main city clusters, inland area and coastal area in the region from December 2014 through July 2016. Results showed that the carcinogenic risk of particle-bound metals for adults (4.13 × 10-5) was higher than that for children (9.53 × 10-6) in the PRD region. The highest and significant non-carcinogenic risk was found in the northwest city cluster. Industrial emission (63.3%) were the dominant contributors to the cancer risk, while the main contributors to the non-cancer risk were the vehicle emission source (33.2%) in the dry season and industrial emission (30.8%) in the wet season. Our results provide important evidence for spatial source-specific health risks with temporal characteristics of particle-bound metals in most densely populated areas in the southern China, and suggest that reduction of industrial and vehicle emissions could facilitate more cost-effective PM2.5 control measures to improve human health.

Linkage between Particulate Matter Properties and Lung Function in Schoolchildren: A Panel Study in Southern China.

While several scientific studies have linked PM2.5 to decreased lung function, there is still some degree of uncertainty regarding which particulate physicochemical properties are most harmful. We followed a panel of 57 healthy schoolchildren (857 person-days) to investigate the associations between a wide variety of PM2.5 and lung function in Heshan, China in 2016 for three periods. We monitored the daily concentrations of mass, chemical composition, size, number, surface area, and volume of particulate mixture. Associations of lung function with various particle metrics were estimated using generalized estimating equations and unconstrained distributed lag models. Random forest model was used to compare the relative importance of exposure metrics. Immediate (lag 0) associations of PM2.5 and carbonaceous aerosols with reduced FEV1 and MMEF, and accumulation-mode particles with FEV1 were found. Slightly delayed (lag 1, 2) effects on PEF were particularly prominent for Aitken-mode particles. Possible cumulative (lags 0-2) effects of PM2.5 and carbonaceous aerosols on PEF and Aitken-mode particles on FEV1, MMEF, and PEF were observed. This study provides comprehensive evidence that the physicochemical properties of particulate mixtures are associated with reduced lung function in children. Organic carbon (OC) may be an important risk factor for the decreased lung function related to PM exposure.

[Variety of the Composition and Sources of VOCs During the Spring Festival and Epidemic Prevention in the Pearl River Delta].

Volatile organic compounds (VOCs) are the key precursors of the ozone (O3) formation processes in the troposphere and are important control objects for the coordinated governance of O3 and PM2.5. The Spring Festival of 2020 was affected by the novel coronavirus (COVID-19) pneumonia epidemic:companies stopped work and production, and traffic was restricted, providing scientific experimentation opportunities for pollutant emission reduction research. This study analyzed the variety of the composition, chemical reaction activity, and sources of VOCs in the Pearl River Delta during the Spring Festival and the epidemic control period, using real-time online monitoring data of VOCs obtained at four sites(Guangzhou, Dongguan, Zhongshan, and Duanfen)in the Pearl River Delta from January 1, 2020 to February 29, 2020. The results showed that during the Spring Festival and the epidemic control period, the average of φ (VOCs) in the Pearl River Delta was 15.89×10-9, and the maximum hourly average concentration was 45.43×10-9, values that were 44% and 60% lower, respectively, than those before the Spring Festival holiday. Among the VOCs component concentration decreases, the aromatic hydrocarbon component decreased the most, and the decrease in the urban area of the Pearl River Delta (74%) was significantly greater than that in the suburban area (56%). As a result, the contribution rate of aromatic hydrocarbons to the total VOCs was reduced to less than 10%. The analysis of the·OH reaction activity of VOCs(L·OH)and ozone formation potential(OFP)showed that the L·OH and OFP of VOCs decreased significantly in the Pearl River Delta during the Spring Festival and the epidemic control period. Compared with those before the Spring Festival holiday, the total L·OH and total OFP decreased by an average of 60% and 63% in the urban area of the Pearl River Delta, respectively. Additionally, the atmospheric oxidation had also been significantly reduced, which showed a 28% decrease in ρ(Ox). The ratio of toluene/benzene showed that the influence of industrial sources had almost disappeared during the Spring Festival and the epidemic control period, and the total points of the representative components of industrial-related solvent-use sources such as toluene, ethylbenzene, and m/p-xylene dropped by 72% to 91%. The results of this study suggest that solvent-use sources and vehicle exhaust emission sources are the current sources of VOCs that need to be paid attention to in the prevention and control of O3 pollution in the Pearl River Delta region, and the impact of petrochemical sources cannot be ignored in the work of further reducing the background concentration of O3.

Association of abnormal-glucose tolerance during pregnancy with exposure to PM2.5 components and sources.

Maternal exposure to PM2.5 has been associated with abnormal glucose tolerance during pregnancy, but little is known about which constituents and sources are most relevant to glycemic effects. We conducted a retrospective cohort study of 1148 pregnant women to investigate associations of PM2.5 chemical components with gestational diabetes mellitus (GDM) and impaired glucose tolerance (IGT) and to identify the most harmful sources in Heshan, China from January 2015 to July 2016. We measured PM2.5 using filter-based method and analyzed them for 28 constituents, including carbonaceous species, water-soluble ions and metal elements. Contributions of PM2.5 sources were assessed by positive matrix factorization (PMF). Logistic regression model was used to estimate composition-specific and source-specific effects on GDM/IGT. Random forest algorithm was applied to evaluate the relative importance of components to GDM and IGT. PM2.5 total mass and several chemical constituents were associated with GDM and IGT across the early to mid-gestation periods, as were the PM2.5 sources fossil fuel/oil combustion, road dust, metal smelting, construction dust, electronic waster, vehicular emissions and industrial emissions. The trimester-specific associations differed among pollutants and sources. The third and highest quartile of elemental carbon, ammonium (NH4+), iron (Fe) and manganese (Mn) across gestation were consistently associated with higher odds of GDM/IGT. Maternal exposures to zinc (Zn), titanium (Ti) and vehicular emissions during the first trimester, and vanadium (V), nickel (Ni), road dust and fossil fuel/oil combustion during the second trimester were more important for GDM/IGT. This study provides important new evidence that maternal exposure to PM2.5 components and sources is significantly related to elevated risk for abnormal glucose tolerance during pregnancy.

Size-segregated deposition of atmospheric elemental carbon (EC) in the human respiratory system: A case study of the Pearl River Delta, China.

It has increasingly become apparent in recent years that atmospheric elemental carbon (EC) is potentially a more sensitive indicator of human health risks from ambient aerosol exposure compared to particulate mass. However, a comprehensive evaluation of the factors affecting EC exposure is lacking so far. To address this, we performed measurements of size-segregated EC in Guangzhou, China, followed by an estimation of deposition in the human respiratory system. Most ambient EC was in the fine mode suggesting significant cloud processing, and ~40% was deposited in the human respiratory tract, with predominant deposition in the head region (47%), followed by the pulmonary (30%) and tracheobronchial (23%) regions. A significant fraction (36%) of deposited EC were coarse particles indicating the need to consider coarse-mode EC in future health effect studies. Infants and children exhibited greater vulnerability to EC exposure than adults, and the deposition amount varied linearly with breathing rate, a proxy for physical exertion. The nature of breathing was found to constrain EC inhalation significantly, with oronasal breathing associated with lower total deposition and nasal breathing leading to lower deposition in the tracheobronchial and pulmonary regions. Overall, these observations strengthen the need to include EC as an additional air quality indicator.

Extent of lymphadenectomy for esophageal cancer / 中华胃肠外科杂志

Esophageal cancer is a common malignant tumor in China. For resectable ones, surgery is still the primary treatment. At present, the extent of lymph node dissection remains controversial. Extended lymphadenectomy makes metastatic lymph nodes more likely to be resected, which contributed to pathological staging and postoperative treatment. However,it may also increase the risk of postoperative complications and affect prognosis. Therefore, it is controversial how to balance the optimal extent/number of dissected lymph nodes for radical resection with the lower risk of severe complications. In addition, whether the lymph node dissection strategy should be modified after neoadjuvant therapy needs to be investigated, especially for patients who have a complete response to neoadjuvant therapy. Herein, we summarize the clinical experience on the extent of lymph node dissection in China and worldwide, aiming to provide guidence for the extent of lymph node dissection in esophageal cancer.

Characterization of diurnal variations of PM2.5 acidity using an open thermodynamic system: A case study of Guangzhou, China.

Aerosol acidity has significant implications for atmospheric processing, and high time-resolution measurements can provide critical insights into those processes. This paper reports diurnal variations of aerosol acidity characterized using an open thermodynamic system in Guangzhou, China. Hourly measurements of PM2.5-associated ionic species and related parameters were carried out during June-September 2013 followed by application of the Extended Aerosol Inorganic Model in open mode to estimate aerosol pH. The model-estimated aerosol pH was 2.4 ±â€¯0.3, and the pH diurnal profile exhibited peaks in the early morning (6 a.m.) and troughs in the afternoon (2 p.m.) that appeared to be constrained by liquid water content (LWC) and free H+. A linear regression model was developed to predict aerosol pH, which performed strongly with 4 variables during daytime (NH4+, Na+, SO42- and RH; R2 = 0.95) and 3 during nighttime (NH4+, SO42- and RH; R2 = 0.91). The effect of aerosol acidity on the partitioning of HNO3, HCl and NH3 was studied based on theoretical considerations and measurement data. The fractions in particulate phase for acidic compounds correlated strongly with pH (R2 = 0.64-0.69) while that for NH3, interestingly, was weak (R2 = 0.17). Analytical expressions were developed to explain these observations and it was concluded that the partitioning of HCl and HNO3 was more sensitive to pH compared to that of NH3. These results are significant in terms of potential atmospheric depletion rates of HCl and HNO3 in the region and stress the need for future studies in this direction.

Clinical application of Neuroform Atlas stent-assisted coiling in the treatment of unruptured wide-neck intracranial aneurysms / 北京大学学报(医学版)

OBJECTIVE@#To assess the safety and efficacy of Neuroform Atlas stent used in treatment of unruptured wide-neck intracranial aneurysms.@*METHODS@#Clinical data of 62 patients with unruptured wide-neck intracranial aneurysms undergoing Neuroform Atlas stent-assisted coiling from August 2020 to September 2021 were retrospectively analyzed. There were 64 aneurysms in those 62 patients. Among them, 25 aneurysms were located at the bifurcation of M1 segment on middle cerebral artery, 16 at the anterior communicating artery, 10 at the C7 segment of internal carotid artery, 5 at the C6 segment of internal carotid artery, 4 at the apex of basilar artery, 3 at the A3 segment of anterior cerebral artery, and 1 at the M2 segment of middle cerebral artery. All the patients underwent Neuroform Atlas stent-assisted coiling, including 49 patients with single stent assisted coiling and 15 patients with dual stents assisted coiling (14"Y"style and 1"X"style). After the procedure, the immediate DSA was performed to evaluate the status of aneurysm occlusion and the parent artery patency. The clinical follow-up was performed 3 months after the operation and evaluated based on the modified Rankin Scale(mRS).DSA image was reviewed at 6 months after operation and Raymond grading scale was used to assess the status of aneurysm occlusion and the parent artery patency.@*RESULTS@#A total of 62 patients with 64 aneurysms were all achieved technical success(100%).The immediate post-procedural Raymond scale was assessed, including Raymond Ⅰ in 57 aneurysms(89.1%, 57/64), Raymond Ⅱ in 6 aneurysms(9.3%, 6/64) and Raymond Ⅲ in 1 aneurysm(1.6%, 1/64). The peri-procedural complications rate was 4.8%(3/62), 2 patients developed intraoperative thrombosis and 1 patient suffered from local subarachnoid hemorrhage. Among them, 55 patients obtained 3 months clinical follow-up after operation and all the patients had good outcomes (mRS≤2), 50 patients with 52 aneurysms were followed up with DSA 6 months after operation, including Raymond Ⅰ in 45 aneurysms(86.5%, 45/52), Raymond Ⅱ in 4 aneurysms(7.7%, 4/52) and Raymond Ⅲ in 3 aneurysms(5.8%, 3/52).@*CONCLUSION@#Neuroform Atlas stent for the treatment of unruptured wide-neck intracranial aneurysms has high safety and good efficacy, and has its advantages over other traditional stents.

Application of Rotarex catheter system in femoropopliteal artery stenosis accompanied with thrombosis / 北京大学学报(医学版)

OBJECTIVE@#To evaluate the effectiveness and safety of Rotarex catheter system in treating femoropopliteal artery stenosis accompanied with thrombosis.@*METHODS@#From Jun. 2017 to Dec. 2019, the clinical data of 32 femoropopliteal artery stenosis accompanied with thrombosis cases treated with Rotarex catheter system were retrospectively analyzed. There were 23 males and 9 females aged from 50 to 89 years and the mean age was (70.7±10.3) years. Six cases had acute course of disease (≤2 weeks), 17 cases had subacute course of disease (>2 weeks, ≤3 months), and 9 cases had chronic course of disease (>3 months). Mean lesion length was (23.4±13.7) cm, mean occlusion length was (19.9±13.3) cm, and in-stent occlusion 7 cases. The superficial femoral artery (SFA) was involved in 13 cases, the popliteal artery (PA) was involved in 8 cases, and both SFA and PA were involved in the other 11 cases. All the cases were treated with Rotarex catheter system. When necessary, suction with large lumen catheter was enabled. Residual stenosis was treated with percutaneous transluminal angioplasty (PTA). Drug-coated balloon (DCB) was only used in patients with financial status, and stent was used only when it was necessary. Heparin was used for 24 h after procedures, and after that, antiplatelet agents were used. Doppler ultrasonography was taken during the followed-up.@*RESULTS@#Technical success was 100%, and mean procedure time was (107.4±21.5) min. 8F (1F≈0.33 mm) and 6F Rotarex catheter were used in 27 and 5 cases respectively. In 27 cases, forward flow was obtained immediately after debulking with Rotarex catheter, and in the other 5 cases, suction with large lumen catheters were used. PTA was used in all 32 cases. DCB were used in 8 cases, of which 4 were used in in-stent stenosis. Twelve cases were implanted stents. There were no perioperative deaths. The only one procedure related complication was distal embolism. We took out the thrombus with guiding catheter. In all cases, mean hospital stay were (4.6±1.5) d. The ankle brachial index increased from 0.32±0.15 to 0.86±0.10 after treatment (t=-16.847, P < 0.001). The Rutherford stages decreased significantly (Z=-4.518, P < 0.001). All the patients were followed up for 6.0-36.0 months, and the median time was 16.0 months. 2 cases stopped antiplatelet agents, which resulted in acute thrombosis. Another percutaneous mechanical thrombectomy and PTA were taken in one of them. Two cases died of cardiovascular disease during the follow-up, and no amputation was observed. Target lesion restenosis occurred in 7 cases during the follow-up, and target lesion revascularization (TLR) was taken in two of them.@*CONCLUSION@#In treating femoropopliteal artery stenosis accompanied with thrombosis, Rotarex catheter can remove thrombus effectively, and that can expose underlying lesions and reduce stent use and complications rates. It is a safe and effective method.

Radiofrequency obliteration of varicose veins of lower extremity guided by combined venography and ultrasonography / 北京大学学报(医学版)

OBJECTIVE@#To explore the technical details and short-term effects of radiofrequency obliteration of varicose veins of lower extremities guided by combined venography and ultrasound.@*METHODS@#Thirty-seven patients with varicose veins of lower extremities were treated with radiofrequency obliteration using Olympus Celon RFiTT® under combined guidance of venography and ultrasound. The indications included varicose veins of lower extremities and reflux of the great saphenous vein confirmed by ultrasound. The contraindications included deep vein thrombosis, cardiac pacemaker, severe cardio- and cerebrovascular diseases or coagulation disorders. Under ultrasound guidance, the saphenous vein around knee level was punctured using a 21G needle, and a 7F sheath was introduced. Through the sheath a venography was made, and an Olympus Celon ProCurve radiofrequency catheter was inserted and advanced to the great saphenous vein under road map, and the catheter tip was positioned at the point 2 cm below the sapheno-femoral junction. The swelling anesthesia was made under ultrasound guidance. Then the radiofrequency obliteration was performed with pressing of the treatment section. The venography was repeated to ensure optimal outcomes. If necessary the radiofrequency obliteration could be repeated once to twice. After that the superficial varicose veins were stripping by small incisions under local anesthesia. After operation, medical decompression stocking was utilized immediately and sustained for three months. The clinical data, intraoperative radiation dose, exposure time and short-term effects were retrospectively analyzed.@*RESULTS@#After the operation, all the patients walked out of the operating room by themselves. The success rate of operation was 100%. The intraoperative radiation dose was 1.78-10.12 mGy (mean 6.56 mGy), and the exposure time was 61-448 s (mean 161 s). By 3 months follow-up, the symptoms were alleviated in all the 37 patients, and the occlusion rate was 100%. No complications such as skin burns, ecchymosis and deep venous thrombosis were found.@*CONCLUSION@#The short-term effects of radiofrequency obliteration using Olympus Celon RFiTT® system in a manner of twice fixed point followed by once reciprocating radiofrequency were satisfactory. Radiofrequency obliteration of great saphenous veins guided by venography and ultrasound has not only the advantages of minimal trauma and rapid recovery, but also the advantages of accurate location, exact effect and avoidance of complications.

Application of Rotarex mechanical thrombectomy system in acute lower limb ischemia / 北京大学学报(医学版)

OBJECTIVE@#To evaluate the effectiveness and safety of Rotarex mechanical thrombectomy system in treating acute lower limb ischemia.@*METHODS@#From December 2017 to December 2019, the clinical data of 23 acute lower limb ischemia cases treated with Rotarex mechanical thrombectomy system were retrospectively analyzed. There were 14 males and 9 females from 53- to 84-year-old patients and the mean age was (69.1±9.1) years. Duration of symptoms was 6 hours to 14 days (median time 7 days). In the study, 8 acute thromboembolism cases and 15 acute thrombosis cases were included (In which, there was one thromboangiitis obliterans case and two in-stent restenosis cases). In 5 cases, the lesions were located above the groin; in 16 cases, the lesions were located below the groin, and in the other 2 cases, the lesions were located both above and below the groin. All the cases were treated with Rotarex mechanical thrombectomy system. When residual stenosis was greater than 50%, percutaneous transluminal angioplasty (PTA) was used, and stent was used only when it was necessary. Heparin was used 24 h after the procedure, and after that, antiplatelet agents were used in acute thrombosis cases, and oral anti-coagulants were used in acute thromboembolism cases. Doppler ultrasonography was taken during the follow-up.@*RESULTS@#In all the 23 cases, there were 22 successful cases and 1 unsuccessful case, the mean procedure time was (68.2±15.6) min. Percutaneous transluminal angioplasty was used in 18 cases, 7 of which were implanted stents (3 stents were implanted in iliac artery and 4 in superficial femoral artery). There were 3 procedure related complications. The first one was arterial wall injury which resulted in contrast medium extravazation, and in this case, we solved it with prolonged balloon inflation. The second one was distal embolism. We took out the thrombus with guiding catheter. The last one was acute occlusion in a stent, and thrombectomy was applied urgently, and the result was good. Mean hospital stay were (3.6±1.7) days. The ankle brachial index (ABI) increased from 0.25±0.10 to 0.85±0.16 after treatment (t=12.901, P < 0.001). All the patients were followed up for 4.0-28.0 months, and the median time was 12.0 months. One patient stopped antiplatelet agents, which resulted in acute thrombosis 2 months later. Another percutaneous mechanical thrombectomy and PTA were taken. In the failed case, the patient suffered amputation above the knee 3 months later and in another case, the patient died of heart failure 8 months after the procedure. Two target lesion restenosis occurred during the follow-up. Because the patients' symptom was not sever, no procedure was taken.@*CONCLUSION@#Percutaneous mechanical thrombectomy using Rotarex catheter is safe and effective in treating acute lower limb ischemia. For one side, it can restore blood flow to the affected limbs quickly, and for the other, it has the characteristics of minimally invasive and good repeatability. So it should be considered that this me-thod can be widely used for acute lower limb ischemia.

Application of Rotarex mechanical thrombectomy system in treating in-stent restenosis of lower extremity arteriosclerosis obliterans / 北京大学学报(医学版)

OBJECTIVE@#To evaluate the role of Rotarex mechanical thrombectomy system in treating instent restenosis of peripheral artery disease (PAD).@*METHODS@#The clinical data of 7 in-stent restenosis (ISR) cases of lower extremity PAD from June 2017 to Dec 2018 were retrospectively analyzed. There were 5 males and 2 females and the mean age was (70.0±7.6) years from 59.0 to 76.0 years. All the cases were treated by Rotarex mechanical thrombectomy system. In the 7 cases, time interval from the previous stent implantation to ischemia recurrence was 1.0 to 72.0 months, and the median time was 6.0 months. The period from ischemia recurrence to endovascular therapy was 3 days to 2 years, and the median time was 62 days. Rotarex mechanical debulking catheter and percutaneous transluminal angioplasty (PTA) were used in all the cases, and the stent was used only when it was necessary. Anticoagulation was used for 24 hours after procedures and then antiplatelet agents were used as usual. Doppler ultrasonography was taken during the followed-up.@*RESULTS@#All the 7 cases were successful in technology, 3 of which were implanted with new stents for the fracture of the old ones. while for the other four cases, no new stent was implanted. The ankle-brachial index (ABI) increased from 0.31±0.08 to 0.86±0.08 after treatment (t=-12.84, P < 0.001). Thrombectomy was applied urgently in one case because of acute thrombosis in the stent, and the result was good. There was no other complications in hospital. All the patients were followed up for 5.0-22.0 months, and the median time was 14.0 months. No death and amputation occurred during the follow-up. One patient stopped antiplatelet agents because of gastrointestinal bleeding, which resulted in acute thrombosis. in-stent restenosis reappeared in 3 cases.@*CONCLUSION@#Debulking using Rotarex catheter is safe and effective in treating in-stent restenosis of PAD, especially in reducing stents implantation, but is not good at dealing with old thrombus and proliferating intima, and can do nothing about fractured stents and hyperplasia of intima, so it needs to be combined with stents and drug coated balloons.

Hybrid treatment for symptomatic long-segment chronic internal carotid artery occlusion without stump / 北京大学学报(医学版)

OBJECTIVE@#To summarize the preliminary experience of hybrid operation for the treatment of symptomatic long-segment chronic internal carotid artery occlusion (CICAO) without stump.@*METHODS@#Clinical data of 12 patients of symptomatic long-segment CICAO without stump undergoing hybrid operation treatment from July 2015 to December 2017 were retrospectively analyzed. The safety and efficacy of hybrid operation for the treatment of symptomatic long-segment CICAO without stump were preliminarily assessed. CICAO was defined as occlusion time being more than 4 weeks. The primary outcome was defined as any stroke (including ischemic or hemorrhagic) or deaths from any cause after hybrid operation within 30 days. The secondary outcome was defined as successful revascularization and occurrence of >50% in-stent restenosis during the follow-up period.@*RESULTS@#In this group, the symptomatic long-segment CICAO of 11 patients were successfully recanalized. Technical success rate was 91.7% (11/12). The main complication rate was 8.3% (1/12). This patient encountered iatrogenic internal carotid artery cavernous sinus fistula caused by micro-guide wire in the midway of the hybrid operation, the proximal segment of this internal carotid artery was ligated and the iatrogenic internal carotid artery cavernous sinus fistula disappeared in the following digital subtraction angiography image. No patient encountered hemorrhagic stroke and ischemic stroke. No death complications occurred. In this group 10 patients of them were followed up. The follow-up period ranged from 10 to 32 months [mean, (19±9) months]. During the follow-up period, 1 patients developed in-stent restenosis and improved after reoperation of percutaneous transluminal angioplasty by the right size balloon without stenting treatment.@*CONCLUSION@#Hybrid operation for the treatment of highly screened patients with symptomatic long-segment CICAO without stump is safe and effective, could reduce the incidence of complications and improve procedural success rate.

Mechanical thrombectomy treatment in patients with acute ischemic stroke: a single center study / 北京大学学报(医学版)

OBJECTIVE@#To evaluate the effectiveness and safety of mechanical thrombectomy treatment in patients with acute ischemic stroke (AIS),and to explore influential factors of the clinical prognosis preliminarily.@*METHODS@#Clinical data of 26 patients with acute cerebral arterial occlusion treated with mechanical thrombectomy in Peking University Third Hospital from January 2014 to June 2017 were retrospectively collected. The immediate effects of the 26 patients in this group after mechanical thrombectomy treatment were analyzed,The national institutes of health stroke scale (NIHSS) scores between preoperative and at discharge of the 26 patients in this group were compared,and modified Rankin scale (mRS) scores of 90 days post operation were analyzed to assess the prognosis of the 26 patients in this group.@*RESULTS@#(1)In this group, 23 patients (88.5%) achieved vascular recanalization evaluated by thrombolysis in cerebral ischemia scale scores [thrombolysis in cerebral ischemia scale (TICI) scores, 3/2b grades were recognized as vascular recanalization], 19 patients of them reached TICI grade 3 and 4 atients reached TICI grade 2b. In this group 3 patients (11.5%) encountered symptomatic intracranial hemorrhage, 2 patients of them recovered after cerebral hemorrhage absorbed and 1 patient died of massive cerebral hemorrhage. In this group 4 patients (15.4%) died after mechanical thrombectomy treatment,2 patients died of hernia of the brain caused by severe cerebral edema, 1 patient died of symptomatic intracranial hemorrhage and 1 patient died of extensive subarachnoid hemorrhage. (2)The assessment of NIHSS scores at discharge(5.3±2.1)showed significantly lower than those preoperatively(12.6±4.2), P<0.01,and in this group 12 patients (46.2%) achieved favourable prognosis (defined as mRS scores 0-2), 6 patients of them reached mRS 0 score,4 patients reached mRS 1 score and 2 patients reached mRS 2 scores.@*CONCLUSION@#Mechanical thrombectomy with stent retriever contributed to a high rate of vascular recanalization and favourable prognosis,but some patients had poor prognosis, suggesting that we should screen the enrolled patients strictly.

Cerebral hyper perfusion syndrome after carotid artery stenting / 北京大学学报(医学版)

OBJECTIVE@#To explore the risk factors, clinical characteristics, precaution and treatment of hyper perfusion syndrome (HPS) after carotid artery stenting (CAS).@*METHODS@#From September 2014 to March 2018, the clinical data of 226 patients with severe carotid stenosis (70%-99%) treated with carotid artery stenting (CAS)at Department of Interventional Radiology and Vascular Surgery, Peking University Third Hospital, were analyzed retrospectively．Five of them developed HPS after CAS．The relationship between the clinical baseline data, imaging characteristics, perioperative management and HPS were assessed.@*RESULTS@#In this group, 5 patients of them (2.21%, 5/226) developed HPS after CAS, and 2 patients of them (0.88%, 2/226) were hyper perfusion induced intracranial hemorrhage (HICH). The 5 patients consisted of 4 men and 1 woman whose age ranged from 58 to 74 years. The symptoms of HPS occurred within 4 hours to 3 days after CAS. Among the 5 cases, the clinical manifestations were that 2 cases with headache, 1 case with delirium,1 case with hemiparesis of left limbs, and 1 case with coma(died ultimately).The main manifestations of case 1 and case 2 were headache in the frontal parietal temporal region of the operative side, accompanied by nausea and vomiting. The symptoms were relieved after blood pressure lowering treatment and mannitol dehydration. The main manifestations of case 3 were excitement and delirium. The symptoms were relieved by a small dose of sedatives, also with blood pressure lowering treatment and mannitol dehydration. The initial symptoms of case 4 were excitement and delirium, accompanied by mild headache of the operative side, and hemiplegia of the contralateral limb occurred within a short time. The main manifestation of case 5 was severe headache and went into deep coma within a short time. This patient died of massive cerebral hemorrhage ultimately.@*CONCLUSION@#HPS is an uncommon but serious complication after CAS. Improving our understanding and heightening vigilance of HPS is necessary. The earlier diagnosis, the earlier treatment.

Application of Neuroform EZ stent in the treatment of severe intracranial arterial stenosis with complex symptomatic / 北京大学学报(医学版)

OBJECTIVE@#To assess the safety and efficacy of Neuroform EZ stent used in treatment of symptomatic complex severe intracranial atherosclerotic stenosis (ICAS).@*METHODS@#Clinical data of 18 patients with symptomatic complex severe ICAS undergoing Neuroform EZ stent angioplasty from January 2016 to December 2017 were retrospectively analyzed. All the lesions of the patients in this group were considered as complex ICAS, i.e. with severe tortuous access, long (>10 mm) or occlusive or bifurcation lesions, with concurrent aneurysms near the stenotic lesion. The primary outcome was defined as any stroke (including ischemic or hemorrhagic) or deaths from any cause after stenting procedure within 30 days. The secondary outcome was defined as successful revascularization and occurrence of >50% in-stent restenosis during the follow-up period.@*RESULTS@#All the 18 patients achieved technical success (100%) and mean stenosis rate was reduced from 85%±7% to 18%±6%. Of the 18 patients included, the 30-day stroke or death was 5.6% (1/18), which presented as basal ganglia region infarction in a patient with tandem lesions on the left vertebral artery. There was no hemorrhagic and death complications that occurred in the patients of this group. One concurrent aneurysm was embolized with micro coil (stent assisted) by stages after 1 month. In this group 12 patients were followed up with digital subtraction angiography (DSA) after hospital discharge. The follow-up period ranged from 8 months to 26 months [mean: (16±8) months]．During the follow-up period 2 patients in the 12 patients (2/12, 16.7%) developed in-stent restenosis (ISR) confirmed by DSA, and one of them was symptomatic restenosis and restored unobstructed blood flow after balloon angioplasty.@*CONCLUSION@#Neuroform EZ stent for the treatment of highly screened symptomatic complex severe ICAS is safe and effective. It has its advantages over traditional stent.

Construction of Transjugular Intrahepatic Portosystemic Shunt: Bare Metal Stent/Stent-graft Combination versus Single Stent-graft, a Prospective Randomized Controlled Study with Long-term Patency and Clinical Analysis / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Balanced adjustment of the portal vein shunt volume during a transjugular intrahepatic portosystemic shunt (TIPS) is critical for maintaining liver perfusion and decreasing the incidence of liver insufficiency. A stent-graft is proved to be superior to a bare metal stent (BMS) for the construction of a TIPS. However, the clinical results of the combination application of stents and stent-grafts have not been determined. This study aimed to compare the technique of using a combination of stents and stent-grafts with using a single stent-graft to construct a TIPS.</p><p><b>METHODS</b>From April 2011 to November 2014, a total of fifty patients were randomly assigned to a stents-combination group (Group I, n = 28) or a stent-graft group (Group II, n = 22). Primary patency rates were calculated. Clinical data, including the technical success rate, bleeding control results, incidence of encephalopathy, liver function preservation, and survival rate, were assessed.</p><p><b>RESULTS</b>Technically, the success rate was 100% for both groups. The primary patency rates at 1, 2, and 3 years for Group I were 96%, 84%, and 77%, respectively; for Group II, they were 90%, 90%, and 78%, respectively. The survival rates at 1, 2, and 3 years for Group I were 79%, 74%, and 68%, respectively; for Group II, they were 82%, 82%, and 74%, respectively. The incidence of hepatic encephalopathy was 14.3% for Group I and 13.6% for Group II. The Child-Pugh score in Group I was stable at the end of the follow-up but had significantly increased in Group II (t = -2.474, P = 0.022).</p><p><b>CONCLUSIONS</b>The construction of a TIPS with either the single stent-graft or BMS/stent-graft combination is effective for controlling variceal bleeding. The BMS/stent-graft combination technique is superior to the stent-graft technique in terms of hepatic function preservation indicated by the Child-Pugh score. However, considering the clinical results of the TIPS, the two techniques are comparable in their primary shunt patency, incidence of encephalopathy and patient survival during the long-term follow-up.</p>