A data-driven Bayesian network for probabilistic crash risk assessment of individual driver with traffic violation and crash records.

In recent years, individual drivers' crash risk assessments have received much attention for identifying high-risk drivers. To this end, we propose a probabilistic assessment method of crash risks with a reproducible long-term dataset (i.e., traffic violations, license, and crash records). In developing this method, we used 7.75 million violations and crashes of 5.5 million individual drivers in Seoul, South Korea, from June 2013 to June 2017 (four years). The stochastic process of the Bayesian network (BN), whose structure is optimized by tabu-search, successfully evaluates individual drivers' crash and violation probability. In addition, the cluster analysis classifies drivers into five distinctive groups according to their estimated violation and crash probabilities. As a result, this study found that the estimated average crash rate within a cluster converges with the actual crash rate by the proposed framework without privacy issues. We also confirm that violation records and expected crash probability are strongly correlated, and there is a direct relationship between a driver's previous violations and crash record and the future at-fault crash. The proposed assessment method is valuable in developing proactive driver education programs and safety countermeasures, including adjusting the penalty system and developing user-based insurance by recognizing dangerous drivers and identifying their properties.

Multiple membership multilevel model to estimate intersection crashes.

Numerous studies have developed intersection crash prediction models to identify crash hotspots and evaluate safety countermeasures. These studies largely considered only micro-level crash contributing factors such as traffic volume, traffic signals, etc. Some recent studies, however, have attempted to include macro-level crash contributing factors, such as population per zone, to predict the number of crashes at intersections. As many intersections are located between multiple zones and thus affected by factors from the multiple zones, the inclusion of macro-level factors requires boundary problems to be resolved. In this study, we introduce an advanced multilevel model, the multiple membership multilevel model (MMMM), for intersection crash analysis. Our objective was to reduce heterogeneity issues between zones in crash prediction model while avoiding misspecification of the model structure. We used five years of intersection crash data (2009-2013) for the City of Regina, Saskatchewan, Canada and identified micro- and macro-level factors that most affected intersection crashes. We compared the fitting performance of the MMMM with that of two existing models, a traditional single model (SM) and a conventional multilevel model (CMM). The MMMM outperformed the SM and CMM in terms of fitting capability. We found that the MMMM avoided both the underestimation of macro-level variance and the type I statistical error that tend to occur when the crash data are analyzed using a SM or CMM. Statistically significant micro-level and macro-level crash contributing factors in Regina included major roadway AADT, four legs, traffic signals, speed, young drivers, and different types of land use.

Effect of saphenous vein diameter and reflux time on stump length after cyanoacrylate closure.

Cyanoacrylate closure (CAC) has recently been introduced for the treatment of incompetent saphenous veins. The purpose of the present study is to investigate the correlation of the saphenous vein diameter and reflux time (RT) with the stump length after CAC. A retrospective review was performed using prospectively collected data of CAC patients. The pre-operative saphenous vein diameter and RT were measured. The stump length was measured immediately after the procedure and at 1 week. Pearson's correlation analysis was applied to determine the correlation between the saphenous vein diameter or RT and stump length. A total of 32 saphenous veins were closed in 21 patients, 15 of whom were female. The mean age was 56.9±12.6 years (range, 31-73 years). Complete closure was achieved in all patients. The pre-operative mean diameter was 7.0±2.2 mm. The mean stump lengths were 26.1±10.2 and 28.1±13.6 mm on post-operative days 0 and 7, respectively (P=0.002). The Pearson coefficients for the correlation between the saphenous vein diameter and stump length on post-operative days 0 and 7 were 0.528 (P=0.005) and 0.177 (P=0.430), respectively. Furthermore, the Pearson coefficients for the correlation between the RT and stump length on post-operative days 0 and 7 were -0.215 (P=0.282) and 0.019 (P=0.938), respectively. In conclusion, CAC is effective modality for the treatment of saphenous vein insufficiency. The stump length increased with the diameter of the saphenous veins, while the RT had no marked effect on the stump length. Therefore, the glue injection should be initiated from the instructed position to avoid glue extension into deep veins and to prevent elongating the stump length.

Clinical Outcomes of Radiofrequency Ablation for Unilateral and Bilateral Varicose Veins.

BACKGROUND: Approximately 20% of varicose vein are bilateral. Patients prefer a simultaneous bilateral procedure instead of 2 separate unilateral procedures. There is currently little evidence comparing bilateral and unilateral varicose vein surgeries. OBJECTIVE: To report the clinical outcomes of unilateral and bilateral radiofrequency ablation (RFA) for varicose veins. MATERIALS AND METHODS: The authors retrospectively collected data on clinical outcomes of patients who underwent RFA. They investigated clinical, etiologic, anatomic, and pathophysiologic (CEAP) score, venous clinical severity score (VCSS), and quality of life (QoL) score. RESULTS: Radiofrequency ablation was performed in 546 limbs in 385 patients. Women comprised 60.4% of the patients. The mean age was 52.3 ± 11.6 years (range, 19-84). The occlusion rate after 2 years was 94.5%. Clinical outcomes of CEAP score, VCSS, and QoL scores improved significantly from 2.15 ± 0.45, 2.70 ± 2.04, and 6.91 ± 6.69 at baseline to 2.10 ± 0.32, 0.63 ± 0.04, and 3.38 ± 4.74 at the study end, respectively. The preoperative and postoperative differences in CEAP score for unilateral and bilateral RFA were 0.02 ± 0.21 and 0.13 ± 0.49, respectively (p = .073). Those of VCSS for unilateral and bilateral RFA were 1.87 ± 1.50 and 4.01 ± 2.93, respectively (p < .001). CONCLUSION: Good clinical outcomes were shown after RFA with respect to CEAP, VCSS, and QoL scores. The simultaneous bilateral RFA can be performed with effectiveness.

Cross-classified multilevel models for severity of commercial motor vehicle crashes considering heterogeneity among companies and regions.

This study analyzes 86,622 commercial motor vehicle (CMV) crashes (large truck, bus and taxi crashes) in South Korea from 2010 to 2014. The analysis recognizes the hierarchical structure of the factors affecting CMV crashes by examining eight factors related to individual crashes and six additional upper level factors organized in two non-nested groups (company level and regional level factors). The study considers four different crash severities (fatal, major, minor, and no injury). The company level factors reflect selected characteristics of 1,875 CMV companies, and the regional level factors reflect selected characteristics of 230 municipalities. The study develops a single-level ordinary ordered logit model, two conventional multilevel ordered logit models, and a cross-classified multilevel ordered logit model (CCMM). As the study develops each of these four models for large trucks, buses and taxis, 12 different statistical models are analyzed. The CCMM outperforms the other models in two important ways: 1) the CCMM avoids the type I statistical errors that tend to occur when analyzing hierarchical data with single-level models; and 2) the CCMM can analyze two non-nested groups simultaneously. Statistically significant factors include taxi company's type of vehicle ownership and municipality's level of transportation infrastructure budget. An improved understanding of CMV related crashes should contribute to the development of safety countermeasures to reduce the number and severity of CMV related crashes.

Ultrasound fusion imaging with real-time navigation for the surveillance after endovascular aortic aneurysm repair.

Ultrasound can be an effective alternative to computed tomography for surveillance following endovascular aneurysm repair (EVAR). Recently, ultrasound fusion imaging with the real-time navigation system was introduced. Here we described 3 patients who underwent post-EVAR surveillance using this novel technique. Complete coregistration was achieved in all patients. The origin of left renal artery was selected for the target of coregistration. Ultrasound fusion imaging was useful to differentiate the confusing lesion and to evaluate the complete resolution of endoleak and newly developed delayed endoleak. Ultrasound fusion image with real-time navigation system can be a feasible imaging tool for post-EVAR surveillance.

Anatomic and clinical risk factors for pulmonary embolism in patients with deep venous thrombosis of the lower extremity.

PURPOSE: Iliac vein compression is a known culprit of deep vein thrombosis (DVT). In contrast, the compression may prevent the pulmonary embolism (PE). The aim of this study was to evaluate the anatomic and clinical risk factors of PE in patients with lower extremity DVT. METHODS: PE was evaluated using chest computed tomography in patients with lower extremity DVT. The patients were classified into group I (DVT without PE) and group II (DVT with PE) and analyzed to clarify the anatomic and clinical risk factors associated with PE in patients with DVT. As the anatomic factor, the shortest length between the common iliac artery (CIA) and spinal body (SB) was measured. Statistical analyses utilized the multivariable logistic regression model, and receiver operating characteristic (ROC) curve analysis. RESULTS: We examined 114 patients (age; 62.7 ± 16.9 years, 41.7% men) with DVT with/without PE. The prevalence of concurrent DVT with PE was 52.6%. Blood tests showed no difference between the 2 groups. Of all the assessed patients' characteristics, only infection was significantly and independently associated with PE (P = 0.04). The shortest length between CIA and SB was 6.7 ± 3.5 mm in group I and 11.3 ± 3.7 mm in group II (P < 0.001). ROC curve analysis showed that 7.6 mm was the cut-off value for the anatomic risk of PE. CONCLUSION: Infection was significantly associated with concurrent DVT and PE. The shortest length between CIA and SB (<7.6 mm) may prevent PE in patients with DVT.

The Usefulness of Duplex Ultrasound for Hemodialysis Access Selection.

PURPOSE: A native vessel is preferable to an artificial graft for dialysis access. Duplex ultrasound (DUS) is noninvasive, cost-effective modality to evaluate the vessels for dialysis. The purpose of this study was to compare the rates of utilization of native vessels after preoperative imaging with DUS and contrast venography (CV). MATERIALS AND METHODS: A retrospective review was performed on patients who received an arteriovenous fistula (AVF) or arteriovenous graft (AVG) between June 2006 and July 2010. Patients were classified into 3 groups. In group 1, CV was used to evaluate the vessel. Both DUS and CV were used in group 2. In group 3, only DUS was used. The frequency of utilization of a native vessel was analyzed in each group. The chi-square test was used for statistical analysis. RESULTS: During the study period, 173 patients received an AVF or AVG. Eighty-nine patients were male. The mean age was 60.6±14.6 years. A native vessel was used in 56/81 patients (69.1%) and 74/81 patients (91.4%) in groups 1 and 3, respectively (P<0.001). In group 2, all patients underwent access procedures using native vessels. AVG was initially planned for 2 patients in group 2 after vessel evaluation using CV, but a native vessel was successfully used because DUS identified optimal vessels for AVF. The 1-year primary patency rate was similar in 3 groups. CONCLUSION: Preoperative DUS is safe and easy to use for vessel evaluation, and can be used as a primary imaging modality for creation of access.

Measuring of Abdominal Aortic Aneurysm with Three-Dimensional Computed Tomography Reconstruction before Endovascular Aortic Aneurysm Repair.

PURPOSE: Conventional computed tomography (CT) is the gold standard method for case planning for endovascular aortic aneurysm repair (EVAR). However, aortography with a marking catheter is needed for measuring the actual length of an aneurysm. With advances in imaging technology, a 3-dimensional (3D) workstation can obviate the need for the aortography. The objective of this study was to determine whether a 3D workstation could obviate the need for aortography for EVAR. MATERIALS AND METHODS: One vascular surgeon and 1 interventional radiologist retrospectively assessed axial CT scans and reformatted the 3D CT scans by using the iNtuition workstation (TeraRecon Inc., San Mateo, CA, USA) for 25 patients who underwent EVAR. Four measurements of diameter and length were obtained from each modality. The actual length of an aneurysm for the proper graft was decided by 2 observers by reviewing the aortography with a marking catheter. RESULTS: The measurements from the 2 modalities were reproducible with intraobserver correlation coefficients of 0.89 to 1.0 for conventional CT and 0.98 to 1.0 for 3D workstation. Interobserver correlation coefficients were 0.29 to 0.95 for conventional CT and 0.85 to 0.99 for the 3D workstation. The length of the aneurysm for proper main graft coincided in 18 and 14 patients according to the conventional CT scan and in 21 and 18 patients according to the 3D workstation, respectively. CONCLUSION: The interobserver agreement in planning EVAR was significantly better with the iNtuition 3D workstation. But aortography with a marking catheter may still be needed for selecting the proper graft.

Risk Factors for Abdominal Aortic Aneurysm in the Korean Population.

BACKGROUND: Ultrasound screening shows a clinical benefit in reducing abdominal aortic aneurysm (AAA)-related mortality. However, its cost-effectiveness remains unclear. Understanding the relationship between risk factors and AAA is important to maximize the benefit of AAA screening. However, risk factors for AAA have not been reported in Korea. The purpose of this study is to determine the prevalence of, and risk factors for, AAA among the Korean population. METHODS: The study population consisted of patients >50 years of age who consented for AAA screening. Screening was performed as follows for all participants: collection of demographic information, including risk factors, physical examination, and ultrasound screening. We measured the maximal diameter of the aorta from the outer to outer layer at 5 levels: suprarenal, renal, and infrarenal aorta, and bilateral common iliac arteries. AAA was defined as maximal aortic diameter >3 cm. The risk factors and risk ratio for AAA were determined. Chi-square test and a logistic regression model were used for statistical analysis. All P-values <0.05 were considered significant. RESULTS: A total of 2,035 participants were enrolled. Among them, 908 (44.6%) were men and 1,127 (55.4%) were women. Mean age was 66.9 ± 10.3 years (range 23-95). AAA was detected in 18 of 908 (2.0%) men and 4 of 1,127 (0.4%) women. The presence of an AAA was significantly correlated with male sex (P < 0.001), advanced age (P = 0.01), smoking (P < 0.001), alcohol consumption (P < 0.01), and the presence of pulmonary disease (P = 0.01). Multivariate analysis revealed that smoking was the only significant risk factor for AAA. CONCLUSIONS: The prevalence of AAA was 2.0% in men and 0.4% in women. Male sex, old age, smoking, alcohol use, and pulmonary disease are possible risk factors for AAA in the general Korean population. Smoking is the strongest risk factor for the development of AAA.

Prevalence and risk factors for atherosclerotic carotid stenosis and plaque: A population-based screening study.

Atherosclerotic carotid stenosis (ACS) is a major cause of ischemic stroke. Screening for asymptomatic ACS is important to identify the patients who require longitudinal surveillance, medication, or endovascular surgery. The aim of this study was to assess the prevalence and risk factors for ACS and carotid plaque (CP) in Korea using a population-based screening study.We recruited participants during visits to several community welfare centers in Korea. The baseline characteristics of the study population were collected. All patients underwent duplex ultrasonography to examine their bilateral carotid arteries. ACS was defined as the presence of plaque with ≥50% vessel diameter reduction and peak systolic velocity (PSV) ≥125 cm/s or PSV ratio ≥2.0. CP was defined as the presence of plaque with <50% vessel diameter reduction. The Mann-Whitney test, χ test, Fisher exact test, and logistic regression were used in the statistical analysis.A total of 3030 participants were enrolled in this study (male 43.7% and female 56.3%). The prevalence of ACS and CP was 1.1% and 5.7%, respectively. Significant risk factors for CP included age ≥80 years (odds ratio [OR], 8.11; 95% confidence interval [CI], 3.45-18.93), male sex (OR, 2.16; 95% CI, 1.29-3.61), hypertension (OR, 1.72; 95% CI, 1.21-2.45), and hyperlipidemia (OR, 1.84; 95% CI, 1.30-2.62). The presence of ACS was significantly associated with age (OR, 1.07; 95% CI, 1.03-1.12), hypertension (OR, 3.16; 95% CI, 1.34-7.46), and being an ex-smoker (OR, 6.81; 95% CI, 1.66-27.93) or current smoker (OR, 6.97; 95% CI, 1.78-27.31) after adjusting for confounding factors.This population-based screening study revealed that ACS was uncommon and had a prevalence of 1.1% in the study population. Age, hypertension, and smoking were risk factors for ACS. Further investigations into the prevalence and risk factors of ACS are required, as are studies on the cost-effectiveness of a national screening program.

National trends for open and endovascular repair of aneurysms in Korea: 2004-2013.

The introduction of endovascular aneurysm repair has led to a dramatic decline in open aneurysm repair. The aim of this report was to evaluate Korean national trends for the treatment of aneurysms. A serial, cross-sectional study of time trends of patients who underwent aneurysm repair between 2004 and 2013 was conducted. Data from the Health Insurance Review and Assessment Service were used to evaluate the trends of aneurysm repair in the Korean population and to analyze the trends of open and endovascular aneurysm repair among Medicare beneficiaries. A linear-by-linear association was performed to determine alterations in the rates at which these aneurysm repair techniques were performed. A total of 32,130 patients underwent aneurysm repair between 2004 and 2013. The proportion of patients who underwent open repair decreased from 94.0% in 2004 to 54.9% in 2013; whereas the proportion of patients who underwent endovascular repair increased from 6.0% in 2004 to 45.1% in 2013. During the study period, the number of patients undergoing endovascular repair of aortic aneurysms significantly increased from 82 to 1,396 (relative risk, 16.17; 95% confidence interval: 12.94-20.21). Endovascular repair of abdominal aortic aneurysms (AAAs)overtook open repair between 2010 and 2011. The frequency of open aneurysm repair increased 1.2-fold, with an overall downward trend. The prevalence of endovascular repair markedly increased 15.3-fold. These findings indicated that, in Korea, the endovascular repair of AAAs overtook open repair as the most common technique between 2010 and 2011.

National trends in carotid endarterectomy and stenting in Korea from 2004 to 2013.

Stroke imposes a substantial clinical and socioeconomic burden. Carotid endarterectomy (CEA) or carotid artery stenting (CAS) are proven procedures in stroke prevention for the lesions of extracranial carotid disease. Although several studies have addressed national trends regarding carotid revascularization in Western countries, limited data is available with respect to the Korean population. The aim of the present study was to identify the national trend in carotid revascularization in Korea over the previous decade. A serial, cross-sectional study was conducted with the use of time trends to analyze patients undergoing carotid revascularization using CEA and CAS between 2004 and 2013. Health Insurance Review and Assessment Service data was used. The present study endeavored to analyze trends in the number of CEA and CAS procedures for the treatment of extracranial carotid disease in Medicare beneficiaries. A linear-by-linear association was performed to determine the changes of carotid revascularization for the aforementioned period. A total of 23,142 patients received carotid revascularization between 2004 and 2013. CEA was performed in 4,012 and CAS in 19,130 patients. The rate of total carotid revascularization per 1,000,000 Medicare beneficiaries substantially increased during the study period from 22 procedures in 2004 to 57 in 2013 (risk ratio (RR), 2.59; 95% confidence interval (CI), 1.58-4.24; P=0.001). CAS increased from 18 procedures in 2004, to 45 in 2013 (RR, 2.50; 95% CI; 1.45-4.32; P=0.001). In addition, the number of CEA procedures performed per 1,000,000 Medicare beneficiaries increased from four procedures in 2004, to 11 in 2013 (RR, 2.75; 95% CI, 0.88-8.64; P=0.08). In conclusion, total carotid revascularization increased by 255% during the previous 10 years in Korea. This increase predominantly resulted from the 249% increase of CAS. The number and population-based rates of carotid revascularization remained low, as compared with Western countries.

Intraoperative indocyanine green angiography for the objective measurement of blood flow.

PURPOSE: Intraoperative assessment of tissue perfusion is important to predict wound healing or improvement of symptoms in patients with peripheral arterial disease (PAD) or vascular trauma. There is no widely accepted standard for intraoperative measurement of tissue perfusion. Here, we report the use of indocyanine green (ICG)-based angiography to determine the blood flow in patients with PAD and vascular trauma. METHODS: The SPY fluorescent imaging system was utilized. A dose of 3-5 mL of ICG (2.5 mg/mL) was injected intravenously followed by a 10 mL normal saline flush. The SPY imaging system was used to quantitatively assess perfusion. During the study period, the SPY imaging system was applied in 4 patients with PAD and one patient with vascular trauma. RESULTS: In 3 patients with PAD associated with an ischemic wound, complete wound healing was achieved with the indication of viable tissue by the SPY system. In one patient with severe claudication in both lower extremities, the ICG angiography was used to determine the increased blood flow after revascularization. In the case of vascular trauma, this imaging system enabled the delineation of viability of the injured tissue. CONCLUSION: ICG angiography can determine the surface tissue viability in PAD patients. In cases of severe vascular trauma,the SPY system can be used to determine tissue perfusion. Further study is warranted to define the definite utility of this technology to assess perfusion, response to revascularization, and potentially, to predict the likelihood of wound healing.

National trends for the treatment of peripheral arterial disease in Korea between 2004 and 2013.

PURPOSE: Peripheral arterial disease (PAD) has been a major public health issue in the elderly. Advances in endovascular surgery have led to a substantial shift in the management of PAD. Although the nationwide trend of PAD treatment in the Western countries was reported, limited data have been available on this in Korea. This study examined the national trend in the treatment of PAD in Korea over the past decade. METHODS: Health Insurance Review and Assessment Service data were used. We sought to analyze trends in the open and endovascular surgery for the treatment of PAD in Medicare beneficiaries between 2004 and 2013. We also analyzed trends in each types of surgery in the lower extremity. A linear-by-linear association was performed to determine the changes of PAD treatment for this period. RESULTS: The rate of open surgery per 100,000 Medicare beneficiaries decreased significantly from 8 procedures in 2004 to 6 in 2013. At the same time, endovascular surgery increased from 23 procedures in 2004 to 59 in 2013. Endovascular surgery in the lower extremity increased more than twofold, while the open surgery decreased by 39%. The rate of balloon angioplasty among endovascular surgery was increased by almost threefold, while the bypass surgery using artificial graft decreased by half. CONCLUSION: Endovascular surgery is now performed more commonly than open surgery for PAD treatment. Balloon angioplasty increased by almost threefold, while the bypass surgery using artificial graft decreased by about 50%.

Effect of Diameter of Saphenous Vein on Stump Length after Radiofrequency Ablation for Varicose Vein.

PURPOSE: Radiofrequency ablation (RFA) has gained popularity for treatment of varicose veins. The diameter of the saphenous vein should be considered before RFA because occlusion of the vein may differ depending on its diameter. Until now, however, there have been few data about the correlation between the diameter of the saphenous vein and the stump length after RFA. The purpose of our study was to investigate its correlation. MATERIALS AND METHODS: A retrospective review was performed from prospectively collected data of RFA patients between March 2009 and December 2011. Preoperatively, the saphenous vein diameter was measured. Ablation was initiated 2 cm distal from the junction. Postoperatively, stump length was measured at 1 week and 6 months. After 2 years, we measured the length from the saphenofemoral junction to the leading point of occlusion for great saphenous vein, and length from the saphenopopliteal junction to the leading point of occlusion for small saphenous vein. The paired t-test, independent t-test, and correlation analysis were used for statistical analysis. P-value <0.05 was considered statistically significant. RESULTS: During the study period, RFA was performed in 201 patients. Endovenous heat-induced thrombosis developed in 3 patients (1.5%). After 2 years, the stump length was obtained in 74 limbs. The mean diameter and stump length of the saphenous vein were 6.7±1.8 mm and 12.5±8.5 mm, respectively. Correlation analysis showed that the Pearson correlation coefficient of these factors was -0.017. CONCLUSION: There was no correlation between the diameter of saphenous vein and stump length.

The comparison of monitored anesthesia care with dexmedetomidine and spinal anesthesia during varicose vein surgery.

PURPOSE: The purpose of this study was to investigate the effectiveness and safety of monitored anesthesia care (MAC) using dexmedetomidine for its sedative and analgesic effect during varicose vein surgery. METHODS: Forty-two patients, who underwent varicose vein surgery, were divided into the MAC group (n = 20) or the spinal anesthesia group (n = 22) for randomized clinical trial. In the MAC group, dexmedetomidine was administered by a loading dose of 1 µg/kg for 10 minutes, followed by a maintenance infusion of 0.2-1.0 µg/kg/hr. Ketamine was used for intermittent injection. In the spinal anesthesia group, midazolam was used for sedation. Intraoperative vital signs, the number of adverse events, and the satisfaction of patients and surgeons concerning the anesthetic condition were compared between the two groups. RESULTS: Systolic blood pressure was intraoperatively significantly different over time between the two groups. The groups had statistical differences in the change in heart rate with regard to time. In the postanesthetic care unit, patients and surgeons in the MAC group had a lower satisfaction score, compared to patients and surgeons in the spinal anesthesia group. However, in the recovery period, patients had a positive perception concerning MAC anesthesia. In addition, without significant adverse events, the MAC group had a shorter time to possible ambulation, which indicated an early recovery. CONCLUSION: We believe that MAC using dexmedetomidine in combination with ketamine may be an alternative anesthetic technique for varicose vein surgery with regard to a patient's preference and medical condition.

Simultaneous hybrid revascularization for symptomatic lower extremity arterial occlusive disease.

Multilevel revascularization, using a combination of endovascular and open (hybrid) surgery, is increasingly being used. Hybrid surgery allows complex anatomy to be treated by minimally invasive procedures in medically high risk patients. The aim of the present study was to report a novel hybrid surgery for lesions in the multilevel lower extremity arteries and to evaluate the clinical outcomes. Consecutive patients who presented at a single institution between March 2009 and Feburary 2012 were selected for inclusion in the study. The patients had disabling claudication or critical limb ischemia and underwent treatment for revascularization by open surgery or by a combination of open surgery and endovascular procedure. Retrospective analysis was conducted from a prospectively collected database. All procedures were performed by a vascular surgeon in an operating room. Postoperative surveillance in outpatient clinics was conducted at 3 and 6 months and every 6 months thereafter. A total of 76 patients were included in the study with a mean age of 67.1±11.3 years (range, 42-94 years) and the male to female ratio was 67:9. The most common indication for revascularization was Rutherford category IV (resting pain). The immediate technical success rate of hybrid surgery was 90.5%, with an overall limb salvage rate of 97.4%. The primary patency rates of the hybrid and open groups were 100 and 90.9%, respectively (P=0.441). Therefore, the results of the present study indicate that hybrid surgery is a feasible option for the treatment of multilevel peripheral arterial occlusive disease, showing favorable patency and limb salvage rates. These observations indicate that femoral endarterectomy plays a vital role in hybrid surgery.

Reconstruction of the internal iliac artery in patients with aneurysmal disease: Two case reports.

During the endovascular repair of aortoiliac aneurysm, bilateral internal iliac artery (IIA) occlusion may give rise to significant morbidities such as ischemia of buttock or sigmoid colon and erectile dysfunction. Open and endovascular approaches are used to maintain IIA circulation in such cases. The present report describes the cases of two patients who underwent external-to-internal iliac artery bypass surgery, one via a novel hybrid approach. The first patient had a right common iliac artery aneurysm without a sufficient distal landing zone for endovascular repair. The distal landing of the device was therefore placed in the right external iliac artery (EIA). The tortuous portion of the right EIA was excised and anastomosed in an end-to-end fashion. An external-to-internal iliac artery bypass was then performed. The second patient underwent endovascular repair of the IIA aneurysm with a Gore® Viabahn®-covered stent (W. L. Gore and Associates, Inc., Flagstaff, AZ, USA). This covered stent was anastomosed with the iliac bypass graft. Postoperative pelvic circulation was maintained. In conclusion, this strategy for maintaining IIA flow is a potential novel approach for future use.

Hypogastric Artery Transposition to Restore the Arterial Flow after Resection of the External Iliac Artery.

Tumors in the pelvic cavity frequently involve the iliac vessels. Common and external iliac arteries should be reconstructed to restore the flow to the lower extremity if the tumor directly invades these arteries. We report herein a 58-year-old female patient with a 10×11 cm, recurred uterine leiomyosarcoma. We performed en bloc resection of the tumor mass including the sigmoid colon, left ureter and 5 cm of the left external iliac artery. After complete resection, restoration of arterial flow to the lower extremity was made with a novel strategy of hypogastric artery transposition. There was no evidence of tumor recurrence or vascular insufficiency at 12 months after surgery.