Impact of uncertainty induced by fatality function on future tropical cyclone risk assessment.

Tropical cyclones (TCs) are among the deadliest extreme events occurring under a warming climate. Future TC risk assessment depend on TC projection from climate models and impact function relating TC to its possible consequence. Few studies have explored the uncertainty of impact function in future TC risk assessment compared to uncertainty in future TC characteristics. In this study, we investigate the uncertainty in TC fatality risk assessment induced by geographic and TC category-dependence of fatality function. We focus on all provinces in the mainland of China with historically recorded TC-induced fatalities and examine their TC fatality risks by assessing the difference in the annual average fatalities between current and future climate conditions. Synthetic TCs derived from four climate models and fatality functions parameterized from three grouped historical TC disaster datasets are used to observe the uncertainty induced by climate model and fatality function. Results show that the changes in the TC frequency, wind, TC-induced rainfall intensity, and exposure due to climate change in each province are dependent on the climate models. And the changes in the annual average fatality of each province are dependent on both the climate models and fatality functions. Climate models play a dominant role in determining the spatial pattern of future risk, while the fatality functions can alter the direction and magnitude of the risk change for certain provinces. Our results highlight the role of fatality function in detecting future TC risk under climate change, and inspire further TC impact studies that consider the heterogeneity of both climate conditions and geographical locations.

Vulnerability to typhoons: A comparison of consequence and driving factors between Typhoon Hato (2017) and Typhoon Mangkhut (2018).

Typhoon disasters have caused casualties, property loss, and other negative impacts to social and economic development. Vulnerability is an important component of typhoon risk. However, little is known about the contributions of vulnerability factors and their interaction effects on typhoon-induced losses at a fine scale. Focusing on the vulnerability measures of Typhoon Hato in 2017 and Typhoon Mangkhut in 2018, this study aims to quantify the contribution and interactive effects of physical and socioeconomic factors on vulnerability based on the GeoDetector method and determine the factors that account for most of the change in vulnerability. The results show that from Typhoon Hato in 2017 to Typhoon Mangkhut in 2018, the vulnerability of the economy and houses decrease on average. Rain intensity and wind intensity are the dominant factors of disaster loss for Typhoon Hato and Typhoon Mangkhut, respectively. Vegetation cover and landform explain vulnerability better than average slope in most instances. For different loss types, the dominant socioeconomic vulnerability factor is different. For both typhoons, emergency transfer has a higher determining power (q) ranking for the population vulnerability, while the percentage of the GDP made up of primary industry have higher q ranking for economic vulnerability. The dominant interaction effects between two vulnerability factors differ depending on the typhoon and loss type but show a nonlinear enhancement effect in most cases. Moreover, changes in the maximum 4-hour accumulated rainfall account for most of the change in vulnerability between Hato and Mangkhut. Overall, the results can be conducive to understanding the complexity of vulnerability to typhoons and provide a reference for possible indicators for vulnerability assessment models, and determining the reasons for changes in vulnerability can be constructive to the formulation of specific policies for disaster prevention and mitigation.

Analysis and experimental demonstration of propagation features of radially polarized specific non-uniformly correlated beams.

With the development of the unified theory of coherence and polarization, the novel physical properties generated by different correlation structures of vector partially coherent beams (PCBs) have attracted much attention. Recently, a new class of structured beams have been proposed [Opt. Lett.45, 3824 (2020)10.1364/OL.397316], called vector specific non-uniformly correlated beams. These beams combine non-uniform polarization and non-uniform correlation, and they exhibit propagation features not seen in conventional vector PCBs. In this Letter, we continue the analysis of the previous work, taking radially polarized Hermite non-uniformly correlated (RPHNUC) beams as an example, and focus on the physical interpretation of the peculiar propagation features of such beams. We verify the predicted behavior of RPHNUC beams through experiment.

Second-order statistical properties of conjugate mode "double-H" partially coherent beams in turbulence.

We present an analysis of the propagation properties of a recently introduced class of conjugate mode partially coherent beams (called "double-H" beams) in a turbulent atmosphere using the extended Huygens-Fresnel integral. We investigate how the phase constant φ0 between the modes plays a role in controlling the evolution of the intensity distribution and resisting the degradation effects of the atmosphere. Our results indicate that this new class of structured beams provides a new degree of freedom for controlling the shape of the beams and improves turbulence resistance, with potential application in free-space optical communications.

Factors contributing to spatial-temporal variations of observed oxygen concentration over the Qinghai-Tibetan Plateau.

Oxygen (O2) is the most abundant molecule in the atmosphere after nitrogen. Previous studies have documented that oxygen concentration remains nearly constant (20.946%) at all altitudes. Here we show for the first time that oxygen concentration varies significantly from earlier consensus and shows strong spatial and seasonal differences. Field observations on the Qinghai-Tibetan Plateau (QTP) indicate oxygen concentration of 19.94-20.66% (2018, n = 80), 19.98-20.78% (2019, n = 166) and 19.97-20.73% (2020, n = 176), all statistically different from earlier reports (p < 0.001) and are lower than the nearly constant. The mean oxygen concentration in summer (20.47%) is 0.31% higher than that of winter (20.16%) (n = 53) at identical locations in 2019, sampled in the Qilian Mountains, northwest QTP. We used LMG (The Lindeman, Merenda and Gold) method to estimate the relative contributions of altitude, air temperature and vegetation index (Fractional Vegetation Cover, FVC and Leaf Area Index, LAI) to oxygen concentration, which are 47%, 32% and 3% (FVC, R2 = 82%); 45%, 30% and 7% (LAI, R2 = 82%), respectively. These findings provide a new perspective for in-depth understanding on population risk in high altitude regions in the context of global climate change, to ensure the health and safety of residents and tourists in high altitude regions and promoting the stability, prosperity and sustainable development of high-altitude regions worldwide.

An Immunological Hypothesis of Fu's Subcutaneous Needling Acupuncture.

Fu's subcutaneous needling (FSN) is a novel acupuncture approach. Although it has been popularized and widely used by acupuncture practitioners, theoretical research on its mechanism of action remains lacking. This study establishes an immunological hypothesis for the efficacy of FSN basis existing knowledge in biomedical science, histology and physiology, and traditional acupuncture mechanisms. The theoretical inference indicates that FSN treatment may affect the body's immune system through subcutaneous connective tissue, similar to triggering a cobweb-like system. This article also proposes possible clinical implications of this theory, which require further studies to validate.

How earthquake-induced direct economic losses change with earthquake magnitude, asset value, residential building structural type and physical environment: An elasticity perspective.

Diagnosing all components of risk is essential in earthquake loss attribution science, but quantitative estimates on how sensitive the earthquake-induced direct economic losses (DELs) are to changes in hazard, exposure and vulnerability is rarely known. Here the relationship between earthquake DELs and earthquake magnitude (Ms), asset value exposure (K), proportion of non-steel-concrete residential buildings (H) and physical environment instability (E) is quantified using the concept of economic elasticity. Earthquake disaster event-based DEL records over the period from 1990 to 2016 for the mainland of China are fitted to a regression model. Elasticity values for Ms, K, H and E are 7.63, 0.75, 4.92 and 0.91, respectively, indicating that on average, DEL changes are more sensitive to changes in Ms and H-a 13% increase in Ms or a 20% increase in H would double earthquake DELs, while it may take a 133% increase in K or a 110% increase in E to cause the same economic losses. In turn, this suggests that human factors-decreasing H and K-could be efficient ways to reduce earthquake risk, while these two factors will become increasingly relevant for risk assessment in the future with continued economic growth. The elasticity estimate results could be used for studying future change in earthquake risks and for supporting disaster risk reduction strategies.

Emerging Trends and New Developments in Disaster Research after the 2008 Wenchuan Earthquake.

On the tenth anniversary of the 2008 Wenchuan Earthquake, investigating the evolution of disaster science is worthwhile and can be used to improve the future execution of disaster risk management. Based on more than 55,786 articles on the relative topic of "Disaster" derived from the Web of Science Core Collection from 1999⁻2017, this study employs CiteSpace and Google Earth to identify and visualize the spatial distribution of publications, bursts of keywords and categories, highly cited references, and interdisciplinary levels and then identify the emerging trends of disaster research over the past 20 years. The results show that the earthquake indeed jumpstarted a massive wave of disaster research around the world and increased international cooperation over the last decade. However, in terms of both the quantity and quality of publications in disaster research fields, China is lagging behind the U.S. and European countries. Moreover, although designing disaster prevention and mitigation strategies is a new popular field of disaster science, geological environment changes and geologic hazards triggered by earthquakes are more popular research topics than disaster emergency and recovery. In addition, the transdisciplinary level of disaster science increased after the earthquake. This interdisciplinary characteristic of disaster science gradually increased in popularity, which demonstrates that people can learn from catastrophes. These emerging trends could serve as a scientific basis to clearly understand disaster science progress over the last 20 years and provide a reference for rapidly identifying frontier issues in disaster science.

Historical Earthquakes and Their Socioeconomic Consequences in China: 1950⁻2017.

Understanding the spatiotemporal pattern of historical earthquake disasters and resultant socioeconomic consequences is essential for designing effective disaster risk reduction measures. Based on historical earthquake disaster records, this study compiles a Chinese earthquake disaster catalog (CH-CAT) that includes records of 722 earthquake disasters that occurred during 1950⁻2017 in the mainland of China. This catalog includes more complete data records than other existing global earthquake databases for China as a whole. Statistical results demonstrate that the number of earthquake disasters and the resultant direct economic losses (DELs) exhibit significant increasing trends (p < 0.01) over the studied 68-year period. Earthquake-induced deaths vary greatly between individual years and exhibit no significant trend. The Qinghai-Tibet seismic zone is the area with the highest frequency of earthquake disasters and the largest accumulated DELs, whereas the North China seismic zone is associated with the highest number of deaths. Among the 722 earthquake disasters, nearly 99.0% of deaths and 95.0% of DELs are attributable to 1.8% and 3.9% of the earthquake disasters, respectively. Approximately 54.2% of recorded earthquake disasters have earthquake magnitude (Ms) values between 5.0 and 5.9, while earthquake disasters with Ms greater than or equal to 7.0 account for 88.5% of DELs and 98.8% of deaths. On average, earthquake-induced DELs and deaths increase nonlinearly with increasing Ms per earthquake. DELs have a positive correlation with deaths and casualties on a logarithmic scale. This study further discusses that during different stages of socioeconomic development, changes in both exposure and vulnerability may be the major factors leading to change differences in earthquake-induced socioeconomic consequences. This study is a beneficial supplement to the global earthquake database and is useful for calibrating global or regional empirical loss models.

Development of an Asset Value Map for Disaster Risk Assessment in China by Spatial Disaggregation Using Ancillary Remote Sensing Data.

The extent of economic losses due to a natural hazard and disaster depends largely on the spatial distribution of asset values in relation to the hazard intensity distribution within the affected area. Given that statistical data on asset value are collected by administrative units in China, generating spatially explicit asset exposure maps remains a key challenge for rapid postdisaster economic loss assessment. The goal of this study is to introduce a top-down (or downscaling) approach to disaggregate administrative-unit level asset value to grid-cell level. To do so, finding the highly correlated "surrogate" indicators is the key. A combination of three data sets-nighttime light grid, LandScan population grid, and road density grid, is used as ancillary asset density distribution information for spatializing the asset value. As a result, a high spatial resolution asset value map of China for 2015 is generated. The spatial data set contains aggregated economic value at risk at 30 arc-second spatial resolution. Accuracy of the spatial disaggregation reflects redistribution errors introduced by the disaggregation process as well as errors from the original ancillary data sets. The overall accuracy of the results proves to be promising. The example of using the developed disaggregated asset value map in exposure assessment of watersheds demonstrates that the data set offers immense analytical flexibility for overlay analysis according to the hazard extent. This product will help current efforts to analyze spatial characteristics of exposure and to uncover the contributions of both physical and social drivers of natural hazard and disaster across space and time.

[An analysis of hypoglycemic agents used among patients with type 2 diabetes in Beijing communities].

OBJECTIVE: To compare the coverage rate of the hypoglycemic agents base on 2009 and 2012 versions of the national essential medicine list among patients with type 2 diabetes mellitus (T2DM) in Beijing communities. METHODS: A total of 900 patients with T2DM were enrolled in the study from four community health service centers in Beijing and followed up for one year. The following data were collected and analyzed, including patients characteristics, the proportion of patients with glycosylated hemoglobin A1c (HbA1c) less than 7% and the coverage rate of the hypoglycemic agents. RESULTS: (1) The coverage rate of using the hypoglycemic agents in 2012 version of the national essential medicine list was significantly higher than that in 2009 version (91.4% vs 42.9%, χ(2) = 481.09, P < 0.05). The coverage rates of the seven hypoglycemic agents in national essential medicine list were significantly different (χ(2) = 1519.65, P < 0.05) . The coverage rates of acarbose (48.9%), metformin(40.7%) and human insulin (31.1%) were higher than those of glimepiride (9.4%), glipizide (3.0%), glibenclamide (0.6%) and animal insulin (0.2%). (2) After one year follow-up, the proportion of the patients with HbA1c less than 7% was higher than that at the baseline(53.6% vs 32.3%, χ(2) = 77.26, P < 0.05). The coverage rate of using the hypoglycemic agents in 2012 version of the national essential medicine list was significantly higher than that in 2009 version (85.5% vs 37.4%, χ(2) = 376.367, P < 0.05). The coverage rates of acarbose (49.7%), metformin (36.3%) and insulin (30.4%) were still higher than those of glimepiride (6.3%), glipizide (2.2%) , glibenclamide (0.4%) and animal insulin(0.0%). CONCLUSION: The hypoglycemic agents in 2012 version of the national essential medicine list could meet the current need of the type 2 diabetes patients in Beijing communities better than those in 2009 version.

Local spatial and temporal factors influencing population and societal vulnerability to natural disasters.

The identification of societal vulnerable counties and regions and the factors contributing to social vulnerability are crucial for effective disaster risk management. Significant advances have been made in the study of social vulnerability over the past two decades, but we still know little regarding China's societal vulnerability profiles, especially at the county level. This study investigates the county-level spatial and temporal patterns in social vulnerability in China from 1980 to 2010. Based on China's four most recent population censuses of 2,361 counties and their corresponding socioeconomic data, a social vulnerability index for each county was created using factor analysis. Exploratory spatial data analysis, including global and local autocorrelations, was applied to reveal the spatial patterns of county-level social vulnerability. The results demonstrate that the dynamic characteristics of China's county-level social vulnerability are notably distinct, and the dominant contributors to societal vulnerability for all of the years studied were rural character, development (urbanization), and economic status. The spatial clustering patterns of social vulnerability to natural disasters in China exhibited a gathering-scattering-gathering pattern over time. Further investigations indicate that many counties in the eastern coastal area of China are experiencing a detectable increase in social vulnerability, whereas the societal vulnerability of many counties in the western and northern areas of China has significantly decreased over the past three decades. These findings will provide policymakers with a sound scientific basis for disaster prevention and mitigation decisions.

Berberine suppresses in vitro migration of human aortic smooth muscle cells through the inhibitions of MMP-2/9, u-PA, AP-1, and NF-κB.

Berberine, a type of isoquinoline alkaloid isolated from Chinese medicinal herbs, has been reported to have various pharmacological activities. Studies have demonstrated that berberine has beneficial effects on vascular remodeling and alleviates restenosis after vascular injury. However, its mechanism of action on vascular smooth muscle cell migration is not fully understood. We therefore investigated the effect of berberine on human aortic smooth muscle cell (HASMC) migration. Boyden chamber assay was performed to show that berberine inhibited HASMC migration dosedependently. Real-time PCR and Western blotting analyses showed that levels of matrix metalloproteinase (MMP)-2, MMP-9, and urokinase-type plasminogen activator (u-PA) were reduced by berberine at both the mRNA and protein levels. Western blotting assay further confirmed that activities of c-Fos, c-Jun, and NF-κB were significantly attenuated. These results suggest that berberine effectively inhibited HASMC migration, possibly by down-regulating MMP-2, MMP-9, and u-PA; and interrupting AP-1 and NF-κB mediated signaling pathways.

Surgical and endovascular treatment of severe complications secondary to noncirrhotic portal hypertension: experience of 56 cases.

BACKGROUND: Major complications of noncirrhotic portal hypertension (NCPH) include bleeding esophagogastric varices, hypersplenism, ascites, and bowel ischemia under acute circumstances. The aim of this article is to determine the outcomes of surgical and endovascular treatments for severe complications from NCPH. METHODS: From January 2000 to June 2011, 56 patients with symptomatic NCPH underwent open surgery or endovascular thrombolysis. The medical records were retrospectively reviewed. Of the 56 patients, there were 39 males and 17 females. The mean age was 21 years, ranging from 2 to 54 years. Forty-one of them were diagnosed to have prehepatic portal vein obstruction (PHPVO), 9 had Budd-Chiari syndrome (BCS), and 6 had noncirrhotic portal fibrosis (NCPF). All patients were symptomatic from 5 days to 14 years (mean 25 months). Portosystemic shunt (PSS) was primarily performed in 49 patients. Shunts were as follows: 35 mesocaval; 7 splenorenal; 4 portocaval; 2 paraumbilical-jugular; and 1 portal to right atrial. Esophagogastric devascularization was performed in 3 patients, but was converted to mesocaval shunt later in 2. The remaining 4 patients with acute superior mesenteric vein (SMV) and portal vein thrombosis were treated with endovascular catheter-directed thrombolysis. Warfarin was prescribed to all the patients for at least 6 months. Mean follow-up was 57 months, ranging from 2 to 125 months. The outcomes, focusing on 30-day mortality, recurrent bleeding, and hypersplenism, were recorded. RESULTS: In the 49 patients undergoing primary PSS, the shunts remained patent and there was no recurrent variceal bleeding during the follow-up. All 3 patients with esophagogastric devascularization had recurrent variceal bleeding at 8, 13, and 24 months postoperatively. Two of them were converted to mesocaval shunt, and 1 died before redo operation. Thrombolysis in all 4 patients with acute SMV and portal thrombosis was technically successful. Three of the 4 survived without complications and 1 died from small bowel infarction due to recurrent thrombosis 40 days later. In the 47 patients with hypersplenism, mean platelet counts increased from 43×10(9)/L to 239×10(9)/L 2 weeks after surgery. Ascites in 30 of the 31 patients disappeared within 2 months after PSS. There was no postoperative encephalopathy, and perioperative 30-day mortality was 0%. CONCLUSIONS: PSS can be employed to treat bleeding esophagogastric varices and severe hypersplenism secondary to NCPH. Post-PSS encephalopathy is less of a concern in NCPH patients with normal liver function. Endovascular catheter-directed thrombolysis via superior mesenteric artery is a useful alternative treatment for acute portal and/or mesenteric venous thrombosis.

The return period analysis of natural disasters with statistical modeling of bivariate joint probability distribution.

New features of natural disasters have been observed over the last several years. The factors that influence the disasters' formation mechanisms, regularity of occurrence and main characteristics have been revealed to be more complicated and diverse in nature than previously thought. As the uncertainty involved increases, the variables need to be examined further. This article discusses the importance and the shortage of multivariate analysis of natural disasters and presents a method to estimate the joint probability of the return periods and perform a risk analysis. Severe dust storms from 1990 to 2008 in Inner Mongolia were used as a case study to test this new methodology, as they are normal and recurring climatic phenomena on Earth. Based on the 79 investigated events and according to the dust storm definition with bivariate, the joint probability distribution of severe dust storms was established using the observed data of maximum wind speed and duration. The joint return periods of severe dust storms were calculated, and the relevant risk was analyzed according to the joint probability. The copula function is able to simulate severe dust storm disasters accurately. The joint return periods generated are closer to those observed in reality than the univariate return periods and thus have more value in severe dust storm disaster mitigation, strategy making, program design, and improvement of risk management. This research may prove useful in risk-based decision making. The exploration of multivariate analysis methods can also lay the foundation for further applications in natural disaster risk analysis.

The return periods and risk assessment of severe dust storms in Inner Mongolia with consideration of the main contributing factors.

This study presents a methodology for return period analysis and risk assessment of severe dust storm disaster. Meteorological observation data, soil moisture data, and remote sensing data from 30 meteorological stations in Inner Mongolia (western China) from 1985 to 2006 were used for the study. A composite index of severe dust storm disaster (Index I (SDS)) based on the influence mechanisms of the main contributing factors was developed by using the analytic hierarchy process and the weighted comprehensive method, and the hazard risk curves (i.e., the transcendental probability curves of I (SDS)) for the 30 stations were established using the parameter estimation method. We then analyzed the risk of the occurrence of severe dust storm under different scenarios of 5-, 10-, 20-, and 50-year return periods. The results show that the risk decreased from west to east across Inner Mongolia, and there are four severe dust storm occurrence peak value centers, including Guaizihu, Jilantai, Hailisu, and Zhurihe-Erenhot. The severity of dust storms in seven places will be intolerable in the 50-year return period scenario and in three places in the 20-year return period scenario. These results indicate that these locations should concentrate forces on disaster prevention, monitoring, and early warning. The I (SDS) was developed as an easily understandable tool useful for the assessment and comparison of the relative risk of severe dust storm disasters in different areas. The risk assessment was specifically intended to support local and national government agencies in their management of severe dust storm disasters in their efforts to (1) make resource allocation decisions, (2) make high-level planning decisions, and (3) raise public awareness of severe dust storm risk.

[Investigation of endovascular aneurysm repair of complex abdominal aortic aneurysm in high-risk patients].

OBJECTIVE: To evaluate the results of a variety of alternative endovascular techniques applied to patients with complicated abdominal aortic aneurysm complex abdominal aortic aneurysm (cAAA) and unsuitable for open surgery. METHODS: From January 2001 to December 2010, charts of all patients having an abdominal aortic aneurysm (AAA) were reviewed. Endovascular aneurysm repair (EVAR) was done in 138 patients, in which 9 patients were defined as cAAA such as juxta-renal AAA, short or angulated AAA neck, AAA with bilateral iliac artery aneurysms. There were 8 male and 1 female patients, aged from 26 to 87 years with a mean of 67 years. All these patients at high risk for open surgery were offered a modified EVAR technique including fenestrated technique, scallop technique, chimney technique, balloon assisted U-turn stenting and reverse-U stent-graft in 2, 5, 1 and 1 patients respectively. RESULTS: All techniques were successful and without severe postoperative complications. An intraoperative endoleak was found in 4 patients and was corrected immediately. One patient with type I and III endoleaks underwent dilatation with a compliant balloon. Two patients with type I endoleak underwent coil embolization (1 patient) and bare stent (1 patient). During follow-up, one patient with a type II endoleak who demonstrated no increase in sac diameter during follow-up was observed. Mean follow-up was 25.9 months (ranging from 4 to 79 months). No rupture occurred and 8 aneurysms shrink significantly. In 7 patients, critical vessels (renal and mesenteric arteries) were protected during the initial procedure and remained patent except in one patient who was performed reverse "U" stent graft with thrombosis in hypogastric artery. CONCLUSION: High-risk patients with cAAA inappropriate for traditional EVAR can be successfully treated by using simple ancillary endovascular techniques with acceptable short or mid-term results.

[Surgical treatment for popliteal artery occlusive disease].

OBJECTIVE: To investigate surgical procedures for popliteal artery occlusive disease. METHODS: The clinical data of 25 patients with popliteal artery occlusive disease from June 2007 to June 2008 was analyzed retrospectively. There were 18 male and 7 female with an average age of (53 ± 21) years. Eleven patients (11 limbs, 42.3%) were acute limb ischemia and 14 patients (15 limbs, 57.7%) were chronic limb ischemia. All patients were treated with surgical revascularization. Four limbs underwent thrombectomy. Nineteen limbs underwent endarterectomy with patch below knee. Three limbs underwent femoral-popliteal bypass with reversed saphenous vein or graft. Six of all the limbs underwent resection of the aberrant muscle when revascularization. RESULTS: Ischemic symptoms and claudication distance were improved in 24 patients (25 limbs). Postoperative ankle-branch index (ABI) was 0.75 ± 0.29, significantly higher than preoperative ABI 0.35 ± 0.20 (P < 0.01). Average follow up time was 10.2 months. I stage patency rate was 92.3%. Three patients were amputated postoperatively. The rate of limb salvage was 88.5% in this study. CONCLUSIONS: The cause of popliteal artery occlusive disease are diverse. Treatment for popliteal artery occlusive disease should depend on its etiology to make the outcomes be satisfied.

Revascularization for iliac-femoral artery pseudoaneurysm with greater saphenous vein.

OBJECTIVE: To investigate the role of revascularization procedures with autologous greater saphenous vein in surgical management of iliac-femoral artery pseudoaneurysm in parenteral drug abusers. METHODS: Twenty-one patients with iliac-femoral artery pseudoaneurysm caused by parenteral drug abuse from 2004 to 2007 were enrolled. Among them, 15 patients were male and 6 were female; their average age was 31.3 years. The size of pseudoaneurysms ranged from 3.0 cm to 7.5 cm. Common femoral artery and distal external iliac artery were often involved. We performed arterial reconstruction on these patients with autologous greater saphenous vein as a graft after excising iliac-femoral artery pseudoaneurysm through a single curved inguinal incision. All patients were followed up, and the complications were recorded. RESULTS: The surgical procedures were finished without intraoperative mortality or perioperative complications. All patients were free of claudication symptoms after the surgery except one case with preoperative popliteal artery stenosis. One case of infection and wound tissue fistula was found later. One case had inguinal incisional hematoma and another complained of numbness in thigh skin. CONCLUSIONS: The use of autologous greater saphenous venous grafts for arterial reconstruction after pseudoaneurysm excision in drug abusers is safe and effective. This technique offers more advantages than arterial ligation alone without revascularization. An optimal greater saphenous venous graft is a prerequisite for revascularization.

[Endovascular revascularization for lower extremity atherosclerosis obliterans in elderly patients:a report of 86 cases].

OBJECTIVE: To analyze the outcome and risk factors of endovascular revascularization of lower limb artery for elder patients. METHODS: From January 2006 to November 2008, 86 elder patients (98 ischemia limbs) underwent endovascular revascularization due to lower limb ischemia. Age of this group were 60 to 82 years old with a mean of (70 +/- 6) years old. Fifty-four limbs (55.0%) had severe intermittent claudication, 28 limbs (28.6%) had rest pain, 11 limbs (11.2%) had ulcer, and 5 limbs (5.1%) had gangrene. Sixty-six limbs were mono segment disease, including 25 aorta-iliac lesions, 33 femoral-popliteal lesions and 8 infra-popliteal lesions. Thirty-two limbs were multiple segment disease involving 2 or 3 segment lesions. Mortality, morbidity, primary patency, secondary patency and limb salvage were retrospectively analyzed. Risk factors on outcome were also evaluated. RESULTS: Ten limbs underwent angioplasty, while the rest 88 limbs underwent angioplasty plus primary stent implantation. The total operation success rate was 95.9%. Perioperative mortality within the first 30 d was 0. Perioperative morbidity within the first 30 d was 5 cases (5.1%), including 2 myocardial infarction, 2 major amputations and 1 irreversible contrast-induced nephropathy. Follow-up duration were 1 to 35 months with a mean of (18 +/- 10) months. Eighty-three (96.5%) patients had effectively follow-up. Mortality was 2.3% (2 cases died due to myocardial infarction). Primary patency rate was 83.7%, secondary patency rate was 94.9% and limb salvage rate was 95.9%. Risk factor analysis showed that diabetes mellitus, critical ischemia and multiple segment lesions were associated with worse patency. CONCLUSIONS: Endovascular treatment is effective, safe and repeatable revascularization for elder patients of Critical lower limb ischemia. Patients with diabetes mellitus, critical ischemia and multiple segment lesions should be paid more attention because their rather worse outcome.