Analysis of Gait Characteristics Using Hip-Knee Cyclograms in Patients with Hemiplegic Stroke.

Gait disturbance is a common sequela of stroke. Conventional gait analysis has limitations in simultaneously assessing multiple joints. Therefore, we investigated the gait characteristics in stroke patients using hip-knee cyclograms, which have the advantage of simultaneously visualizing the gait kinematics of multiple joints. Stroke patients (n = 47) were categorized into two groups according to stroke severity, and healthy controls (n = 32) were recruited. An inertial measurement unit sensor-based gait analysis system, which requires placing seven sensors on the dorsum of both feet, the shafts of both tibias, the middle of both femurs, and the lower abdomen, was used for the gait analysis. Then, the hip-knee cyclogram parameters (range of motion, perimeter, and area) were obtained from the collected data. The coefficient of variance of the cyclogram parameters was obtained to evaluate gait variability. The cyclogram parameters differed between the stroke patients and healthy controls, and differences according to stroke severity were also observed. The gait variability parameters mainly differed in patients with more severe stroke, and specific visualized gait patterns of stroke patients were obtained through cyclograms. In conclusion, the hip-knee cyclograms, which show inter-joint coordination and visualized gait cycle in stroke patients, are clinically significant.

Reducing lesion incidence in pork carcasses by heating foot-and-mouth disease vaccine before injection.

OBJECTIVE: This study was conducted to investigate the effect of heating of foot-and-mouth disease (FMD) vaccine before injection, on the incidence of lesions at the injection site (pork butt), amount of discarded meat, and economical benefit. METHODS: In total, 101,086 piglets raised in 30 farms, were vaccinated in the neck with 2 mL of FMD vaccine at 56 d and 84 d of age using a commercial syringe. The heat treatment group (48,511 pigs) was injected with the FMD vaccine after it had been heated in a water bath at 40°C for 20 min. After slaughter, the incidence of lesions on the pork butt was inspected, and the subsequent amount of discarded meat was recorded. RESULTS: Heat treatment of FMD vaccine reduced the incident rate of lesions on the pork butt (p<0.01). Overall, 17.81% of the pigs in the heat treatment group had lesions, while the incident rate in the control group was 21.70%. The amount of discarded meat per head of total pigs and per head of pigs with lesions were significantly lower in the heat treatment group than the control group (p<0.01). Thus, the proportion of discarded meat to dressed carcass was lower in the heat treatment group (0.249%) compared with the control group (0.338%) (p<0.01). Farms that rear 1,000 sows can gain 1,863,289 KRW (1,600 USD) in one year when they adopt heat treatment of FMD vaccine before injection. CONCLUSION: Heat treatment of FMD vaccine using simple heat equipment (water bath) can be effective in reducing lesions caused by FMD vaccination and increase the economic benefits in pig farms.

Robotic versus laparoscopic intersphincteric resection for low rectal cancer: comparison of the operative, oncological, and functional outcomes.

BACKGROUND: Robotic surgery was developed to overcome the limitations of laparoscopic surgery and is increasingly used to treat low rectal cancer. In this study, we compared the operative, oncological, and functional outcomes of low rectal cancer patients who underwent robotic or laparoscopic intersphincteric resection (ISR). METHODS: Prospectively collected data from low rectal cancer patients who underwent laparoscopic or robotic ISR between September 2006 and August 2011 were retrospectively compared. The functional outcomes of patients followed up for ≥ 12 months after ileostomy closure were evaluated via questionnaire. RESULTS: Forty-four and 26 patients underwent robotic and laparoscopic ISR, respectively. The robotic group patients had a higher body mass index (BMI; 21.42 ± 3.13 vs. 24.13 ± 3.33 kg/m(2); p = 0.001), more advanced clinical N stage (p = 0.029), lower cancer location (3.71 ± 0.89 vs. 3.24 ± 0.78 cm; p = 0.023), more frequent chemoradiotherapy (26.9 vs. 54.5 %; p = 0.025), and longer operation time (286.77 ± 51.46 vs. 316.43 ± 65.11 min; p = 0.038). However, no intergroup differences were observed in the pathological details (except the number of retrieved lymph nodes), postoperative morbidity, 3-year overall survival, recurrence-free survival (RFS), local RFS, and functional outcomes. CONCLUSIONS: Robotic and laparoscopic ISR yielded similar operative, oncological, and functional outcomes in patients with low rectal cancer, despite differences in unfavorable outcome-affecting factors, including BMI, clinical N stage, cancer location, and chemoradiotherapy frequency. A randomized trial will provide more solid methodology for investigating the potential benefits of robotic ISR.

Inertial measurement unit sensor-based gait analysis in adults and older adults: A cross-sectional study.

BACKGROUND: Gait assessment has been used in a wide range of clinical applications, and gait velocity is also a leading predictor of disease and physical functional aspects in older adults. RESEARCH QUESTION: The study aim to examine the changes in IMU-based gait parameters according to age in healthy adults aged 50 and older, to analyze differences between aging patients. METHODS: A total of 296 healthy adults (65.32 ± 6.74 yrs; 83.10 % female) were recruited. Gait assessment was performed using an IMU sensor-based gait analysis system, and 3D motion information of hip and knee joints was obtained using magnetic sensors. The basic characteristics of the study sample were stratified by age category, and the baseline characteristics between the groups were compared using analysis of variance (ANOVA). Pearson's correlation analysis was used to analyze the relationship between age as the dependent variable and several measures of gait parameters and joint angles as independent variables. RESULTS: The results of this study found that there were significant differences in gait velocity and both terminal double support in the three groups according to age, and statistically significant differences in the three groups in hip joint angle and knee joints angle. In addition, it was found that the gait velocity and knee/hip joint angle changed with age, and the gait velocity and knee/hip joint angle were also different in the elderly and adult groups. CONCLUSIONS: We found changes in gait parameters and joint angles according to age in healthy adults and older adults and confirmed the difference in gait velocity and joint angles between adults and older adults.

Computer modeling for the prediction of thoracic aortic stent graft collapse.

OBJECTIVE: To assess the biomechanical implications of excessive stent protrusion into the aortic arch in relation to thoracic aortic stent graft (TASG) collapse by simulating the structural load and quantifying the fluid dynamics on the TASG wall protrusion extended into a model arch. METHODS: One-way coupled fluid-solid interaction analyses were performed to investigate the flow-induced hemodynamic and structural loads exerted on the proximal protrusion of the TASG and aortic wall reconstructed from a patient who underwent traumatic thoracic aortic injury repair. Mechanical properties of a Gore TAG thoracic endoprosthesis (W. L. Gore and Assoc, Flagstaff, Ariz) were assessed via experimental radial compression testing and incorporated into the computational modeling. The TASG wall protrusion geometry was characterized by the protrusion extension (PE) and by the angle (θ) between the TASG and the lesser curvature of the aorta. The effect of θ was explored with the following four models with PE fixed at 1.1 cm: θ = 10 degrees, 20 degrees, 30 degrees, and 40 degrees. The effect of PE was evaluated with the following four models with θ fixed at 10 degrees: PE = 1.1 cm, 1.4 cm, 1.7 cm and 2.0 cm. RESULTS: The presence of TASG wall protrusion into the aortic arch resulted in the formation of swirling, complex flow regions in the proximal luminal surface of the endograft. High PE values (PE = 2.0 cm) led to a markedly reduced left subclavian flow rate (0.27 L/min), low systolic perfusion pressure (98 mm Hg), and peak systolic TASG diameter reduction (2 mm). The transmural pressure load across the TASG was maximum for the model with the highest PE and θ, 15.2 mm Hg for the model with PE = 2.0 cm and θ = 10 degrees, and 11.6 mm Hg for PE = 1.1 cm and θ = 40 degrees. CONCLUSIONS: The findings of this study suggest that increased PE imparts an apparent risk of distal end-organ malperfusion and proximal hypertension and that both increased PE and θ lead to a markedly increased transmural pressure across the TASG wall, a load that would portend TASG collapse. Patient-specific computational modeling may allow for identification of patients with high risk of TASG collapse and guide preventive intervention. CLINICAL RELEVANCE: A potentially devastating complication that may occur after endovascular repair of traumatic thoracicaortic injuries is stent graft collapse. Although usually asymptomatic, stent graft collapse may be accompanied by adverse hemodynamic consequences. Numerous anatomic and device-related factors contribute to the development of collapse, but predictive factors have not yet been clearly defined. In the present study, we assessed the relevant hemodynamics and solid mechanics underlying stent graft collapse using a computational fluid-structure interaction framework of stent graft malapposition. Our findings suggest that both increased stent graft angle and extension into the aortic arch lead to a markedly increased transmural pressure across the stent graft wall, portending collapse. Patient-specific computational modeling may allow for identification of patients at high risk for collapse and aid in planning for an additional, prophylactic intervention to avert its occurrence.

Selective use of preoperative chemoradiotherapy for T3 rectal cancer can be justified: analysis of local recurrence.

BACKGROUND: Preoperative chemoradiotherapy (CXRT) is performed to reduce local recurrence and improve the rate of radical resection for rectal cancer. Currently, it is recommended for all suspected T3 rectal cancers. However, the survival benefit of this procedure is controversial, and complications of RT are often overlooked. The present study was designed to assess the validity of our institutional policies regarding selective use of preoperative CXRT for T3 rectal cancer. METHODS: From September 2006 to May 2010, we retrospectively analyzed data for patients with pathologic T3 rectal cancer, especially those with follow-up for more than 18 months. Patients who underwent RT pre-/postoperatively were excluded. Patients who fulfilled these criteria but did not undergo RT or had incurable distant metastasis were also excluded. RESULTS: Of the 319 patients who underwent surgery for rectal cancer, 183 were diagnosed with T3 cancer. After excluding 58 patients, the final sample included 125 subjects with a mean follow-up of 26.0 months. In all, 94 patients had a follow-up of more than 18 months. Four patients had local recurrences, and the cumulative local recurrence rate was 3.4 % at 18 months and 5.6 % after 2 years. All four had low rectal cancer (mean distance 4.5 ± 1.9 cm). Three were diagnosed as N0 and one as N1. The mean disease-free period was 15.0 months. The distance between the tumor and the anal verge was the only significant risk factor for local recurrence. CONCLUSIONS: In this study, the oncologic outcome for T3 rectal cancer without preoperative CXRT was acceptable in terms of local recurrence. Selective use of preoperative CXRT for T3 rectal cancer needs to be further evaluated prospectively.

Endovascular repair of ruptured abdominal aortic aneurysm does not confer survival benefits over open repair.

OBJECTIVE: Endovascular repair of ruptured abdominal aortic aneurysm (rAAA) is being increasingly performed despite lack of good evidence for its superiority. Other reported studies suffer from patient selection and publication bias with limited follow-up. This study is a single-center propensity score comparing early and midterm outcomes between open surgical repair (OSR) and endovascular repair of rAAA (REVAR). METHODS: A retrospective review from January 2001 to November 2010 identified 312 patients who underwent rAAA repairs. Thirty-one patients with antecedent AAA repair and three with incomplete records were excluded, leaving 37 REVARs and 241 OSRs. Propensity score-based matching for sex, age, preoperative hemodynamic status, surgeon's annual AAA volume, and preoperative cardiopulmonary resuscitation was performed in a 1:3 ratio to compare outcomes. Thirty-seven REVARs were matched with 111 OSRs. Late survival was estimated by Kaplan-Meier methods. RESULTS: Operative time and blood replacement were higher with OSR. Overall complication rates were similar (54% REVAR vs 66% OSR; P = .23), except for higher incidences of tracheostomies (21% vs 3%; P = .015), myocardial infarction (38% vs 18%; P = .036), and acute tubular necrosis (47% vs 21%; P = .009) with OSR. Operative mortality rates were similar (22% REVAR vs 32% OSR), with an odds ratio of 0.63 for REVAR (95% confidence interval = [0.24, 1.48]; P = .40). No differences in the incidences for secondary interventions for aneurysm- or graft-related complications were noted (22% REVAR vs 22% OSR; P = .99). Kaplan-Meier estimates of 1-, 2-, and 3-year survival rates were also similar (50%, 50%, 42% REVAR vs 54%, 52%, 47% OSR; P = .66). CONCLUSIONS: REVAR for rAAA does not seem to conclusively confer either acute or late survival advantages. Routine use of REVAR should be deferred until prospective, randomized trial data become available.

Delayed open conversions after endovascular abdominal aortic aneurysm repair.

OBJECTIVE: Secondary interventions after endovascular aneurysm repair (EVAR) remain a concern. Most are simple catheter-based procedures, but in some instances, open conversions (OCs) are required and carry a worse outcome. We reviewed our experience to characterize these OCs. METHODS: A retrospective review was conducted of all patients who underwent an OC after a previous EVAR for an aneurysm-related indication from 2001 to 2010. Clinical outcomes are reported. RESULTS: Data were reviewed for 44 patients (77% men) with a mean age of 74 years (range, 55-90 years). The average time from EVAR to the first OC was 45 months (range, 2-190 months). In six patients (14%), the initial EVAR was at another institution. The endografts used were Ancure in 16, Excluder in 13, AneuRx in eight, Zenith in three, Lifepath in one, Renu in one, and undetermined in two. Twenty-two patients had previously undergone a total of 32 endovascular reinterventions before their index OC. Indications for OC were aneurysm expansion in 28 (64%), rupture in 12 (27%), and infection in four (9%). The endograft was preserved in situ in 10 patients (23%). Explantation was partial in 18 (41%) or complete in 16 (36%). Endograft preservation was used for type II endoleak in all but one patient by selective ligation of the culprit arteries (lumbar in four, inferior mesenteric artery in five, and middle sacral in one). Proximal neck banding was performed in one type Ia endoleak. Overall morbidity was 55%, and mortality was 18%. No deaths occurred in a subgroup of patients who underwent endograft preservation with selective ligation of culprit vessels for type II endoleak. Intraoperative complications included bowel injury in two, bleeding in two, splenectomy in one, and ureteral injury in one. At a mean follow-up of 20 months, two patients underwent additional procedures after the index OC: one after endograft preservation and one after partial explantation. None of the patients who underwent elective OC with endograft preservation required subsequent endograft explantation. CONCLUSIONS: Most OCs after EVAR are associated with significant morbidity and mortality, except when electively treating an isolated type II endoleak with ligation of branches and preservation of the endograft.

Evolution of treatment for traumatic thoracic aortic injuries.

OBJECTIVE: To review the evolution of traumatic thoracic aortic injury (TTAI) treatment at a single institution. METHODS: Retrospective analysis of all patients included in an institutional trauma registry and vascular surgery database who underwent treatment of TTAI between January 1999 and January 2011. RESULTS: Ninety-one patients (69 males) were treated for TTAI. The mean age was 38.5 years (range, 16-79 years). Forty-one patients underwent open repair (OR) and 50 thoracic endovascular repair (TEVAR), 37 with thoracic stent grafts (TSG) alone, 11 with infrarenal aortic extender cuffs (AEC), and two with a combination of TSG and AEC. OR was performed exclusively until 2004; the last one was performed in January 2007. All TTAIs have since been treated with TEVAR. The left subclavian artery (LSA) was fully covered in 10 patients (20%) and partially covered in eight patients, with revascularization in only two cases. The use of AEC and avoidance of LSA coverage increased after 2007. Baseline characteristics and injury severity scores were similar between groups. The mortality rate was higher in the OR group (19.5% vs 6.0%; P = .06), although it did not reach statistical significance. The overall incidence of morbidities was similar between the two groups (42% OR vs 50% TEVAR). Two patients developed paraplegia (4.4%) after OR compared with none after TEVAR. In the TEVAR group, a pseudoaneurysm, an iliac artery thrombosis, and a retroperitoneal hematoma developed in one patient each. Overall, eight patients (16%) developed stent graft-related complications (SRC), with two developing early (within 30 days) complications. All complications were related to poor apposition, requiring 10 reinterventions. Four patients underwent open conversions with no mortality. Nine out of 10 SRCs were associated with the use of thoracic stent graft malapposition. No patient treated with AEC had endoleaks or SRC. CONCLUSIONS: TEVAR for TTAI has superior survival outcomes and has replaced OR. SRC requiring reintervention is associated with malapposition and the use of TSG. Until TTAI-specific endografts become available, use of AEC may minimize malapposition and reduce reinterventions. Routine overstenting of the LSA is not necessary and may increase SRC.

Indeterminate pulmonary nodules in rectal cancer: a recommendation for follow-up guidelines.

BACKGROUND: Incidental visualization of indeterminate pulmonary nodules is considered a clinical dilemma. METHODS: We identified patients for inclusion in this study by searching for the term "indeterminate nodules" in the radiology database of rectal cancer patients who underwent surgery. Patients with definite metastatic disease were excluded. RESULTS: In total, 224 patients underwent chest computerized tomography (CT) and 59 of these patients had indeterminate pulmonary nodules detected more than twice by CT scan. Six patients (10.2%) were confirmed to have metastatic lesions on follow-up evaluation. Pulmonary nodule size (P=0.028), pathologic N status (P=0.049), positive nodal status (P=0.036) and the number of positive lymph nodes (P=0.033) were significant risk factors for pulmonary metastasis. In the pulmonary metastasis group, the patients who had received adjuvant oxaliplatin-based (FOLFOX4) chemotherapy had longer intervals to developing metastasis compared to patients who had not received it. CONCLUSIONS: It is not necessary to perform excessive surveillance routinely for all rectal cancer patients who have indeterminate pulmonary lesions. Intensive follow-up chest CT or other invasive diagnostic modalities should be considered only in patients with pulmonary nodules larger than 5.7 mm or positive nodal status. In addition, patients receiving adjuvant FOLFOX4 chemotherapy should be followed-up for longer periods.

Robotic versus conventional laparoscopic surgery for rectal cancer: a cost analysis from a single institute in Korea.

BACKGROUND: Since its introduction, robotic surgery has been applied actively in several fields of minimally invasive surgery, and its use in the field of colorectal surgery is also increasing. In the studies to date, feasibility and safety have been the main focus, but the economics involved are important to examine. We compared the economics of robotic surgery with those of laparoscopic surgery for rectal cancer. MATERIAL AND METHODS: We analyzed the clinical characteristics, total hospital charges, payments, operating room costs, and hospital profits for patients who underwent robotic and laparoscopic resection of rectal cancer at Korea University Anam Hospital between July 2007 and August 2010. RESULTS: From July 2007 and August 2010, 154 robot-assisted and 150 laparoscopic rectal surgeries were performed. The patient demographics were similar in the two groups with the exception of tumor location (6.7 vs 8.7 cm distal to the anal verge; p = 0.043), preoperative chemoradiotherapy (22.7 vs 8 %; p = 0.001), and operative time (285.2 vs 219.7 min; p = 0.018). Postoperative course and complications were also similar in the two groups. The total hospital charges in U.S. dollars ($14,647 vs $9,978; p = 0.001) and payments made by patients ($11,540 vs $3,956; p < 0.001) were significantly higher in the robotic group. Hospital profit was significantly lower in the robotic group than in the laparoscopic group ($689 vs $1,671; p < 0.001). CONCLUSIONS: Robot-assisted surgery is more expensive than laparoscopic surgery for rectal cancer. Considering that robotic surgery can be applied more easily for low-lying cancers, the cost-effectiveness of robotic rectal cancer surgery should be assessed based on oncologic outcomes and functional results from future studies.

Aneurysm of a 32-year-old aortorenal saphenous vein bypass graft.

We report the case of an incidentally discovered aneurysm of a previous saphenous vein bypass graft performed 32 years earlier for a renal artery aneurysm. The patient is a 52-year-old man who initially suffered from symptoms of hypertension and left-sided back pain. Saphenous vein bypass grafting was performed with aneurysm resection. Thirty-two years after surgery, the patient underwent a magnetic resonance imaging scan for back pain, hip pain, and anemia, discovering a 1.8-cm focal aneurysm at the site of the previous bypass. The patient underwent a repeat aortorenal bypass with an 8-mm flanged Dacron graft with excision of the existing aneurysmal saphenous vein graft.

Development of Models to Estimate Total Soil Carbon across Different Croplands at a Regional Scale Using RGB Photography.

A quick, accurate and cost-effective method for estimating total soil carbon is necessary for monitoring its levels due to its environmentally and agronomically irreplaceable importance. There are several impediments to both laboratory analysis and spectroscopic sensor technology because the former is both expensive and time-consuming whereas the initial cost of the latter is too high for farmers to afford. RGB photography obtained from digital cameras could be used to quickly and cheaply estimate the total carbon (TC) content of the soil. In this study, we developed models to predict soil TC contents across different cropland types including paddy, upland and orchard fields as well as the TC content of the soil combined from all the aforementioned cropland types on a regional scale. Soil colour measurements were made on samples from the Chungcheongnam-do province of South Korea. The soil TC content ranged from 0.045% to 6.297%. Modelling was performed using multiple linear regression considering the soil moisture levels and illuminance. The best soil TC prediction model came from the upland soil and gave training and validation r2 values of 0.536 and 0.591 with RMSE values of 0.712% and 0.441%, respectively. However, the most accurate equation is the one that produces the lowest RMSE value. Hence, although the model for the upland soil was the most stable of all, the paddy soil model which gave training and validation r2 values of 0.531 and 0.554 with RMSE values of 0.240% and 0.199%, respectively, was selected as the best soil TC prediction equation of all due to its comparatively high r2 value and the lowest RMSE of all equations.

Late collapse of a thoracic endoprosthesis.

Thoracic stent graft collapse is a rare complication of thoracic endovascular aortic repair that is mostly asymptomatic and occurs ≤ 3 months of the procedure. We describe the case of a 36-year-old man who presented with symptomatic endograft collapse 38 months after an initial thoracic endovascular aortic repair that was performed for traumatic aortic transection. He had sudden and complete loss of bilateral lower extremity motor and sensory functions (spinal cord ischemia) and anal sphincter tone. The patient was successfully treated with redo thoracic endovascular aortic repair, followed by open conversion and device explantation.

Comparison of modern open infrarenal and pararenal abdominal aortic aneurysm repair on early outcomes and renal dysfunction at one year.

OBJECTIVE: This study was conducted to review contemporary results of elective open infrarenal abdominal aortic aneurysm (IAAA) and pararenal abdominal aortic aneurysm (PAAA) repairs and determine predictors of death and acute and 1-year renal dysfunction (RD). METHODS: A retrospective review identified 432 consecutive patients undergoing open IAAA (233 patients) or PAAA (184 patients) repair between January 2000 and December 2007. Demographic, preoperative, intraoperative, and postoperative variables were collected. RD was defined as an increase in creatinine of ≥ 0.5 mg/dL from baseline. Multiple logistic regression models were used to identify predictors of mortality and RD. RESULTS: Mortality rates were similar between the groups (3.9% IAAA and 6.0% PAAA). Preoperative coronary artery disease (CAD), postoperative myocardial infarction, or pulmonary complications were all strong predictors of operative mortality in patients undergoing repair of PAAAs and IAAAs. However, neither PAAA nor baseline renal insufficiency was an independent predictor of death. Postoperative RD occurred in 32% of patients after PAAA repairs compared with 13% of patients after IAAA repairs (P < .001). The presence of PAAA, baseline hypertension, and hyperlipidemia all correlated positively with postoperative RD, while a trend was noted with baseline renal insufficiency (P = .09). At the 1-year follow-up, 5.1% of patients in the PAAA group had RD compared with none in the IAAA group. Similarly, the serum creatinine level was significantly higher in the PAAA group (1.4 mg/dL vs 1.2 mg/dL, PAAA and IAAA, respectively; P = .02) at 1 year. However, there were no instances of new-onset hemodialysis dependence at 1 year. Mean follow-up was 2.2 years overall. CONCLUSION: Open PAAA repair can be performed without a significant increase in mortality compared to open IAAA repair. Although the incidence of renal function deterioration after open PAAA repairs remains higher than with open IAAA repairs, the overall incidence remains low at 1-year follow-up.

Inflow thrombosis does not adversely affect thrombolysis outcomes of symptomatic iliofemoral deep vein thrombosis.

OBJECTIVE: The presence of popliteal or tibial vein clot is thought to adversely affect thrombolysis for iliofemoral deep vein thrombosis (DVT). We examined the effect of inflow thrombosis on functional and anatomic outcomes. METHODS: Data for 44 patients treated for symptomatic iliofemoral DVT between 2006 and 2009 were retrospectively reviewed. All patients were treated by pharmacomechanical thrombectomy with local lytic therapy. Catheter-directed lysis and vena cava filters were used sparingly. Univariate and multivariate logistic regression analyses were used. The independent variable used in the logistic regression model was symptom relief. RESULTS: Forty-four patients (mean age, 52.1 ± 15.8 years) presented with symptoms averaging 13.4 ± 9.9 days in duration. Twenty (45.4%) had symptoms for >14 days. Seventeen patients were treated in one session, but 27 patients required lytic infusion for residual thrombus. Iliac stenting was required in 49% of limbs. Successful lysis (>50%) was achieved in 91% of patients, and symptom resolution or improvement in 91%. All patients became ambulatory, with no or minimal limitation. No major systemic bleeding complications occurred. Freedom from DVT recurrence and reintervention was 84% at 24 months by life-table analysis. Preoperative ultrasound imaging showed 89% had popliteal and tibial clots. A thrombosed popliteal vein was accessed for treatment and was corroborated by venographic findings. One patient required simultaneous tibial lysis. At a mean follow up of 8.7 ± 6.3 months, 41 patients (93%) had no symptom recurrence, 82% had preserved valve function and no reflux on duplex imaging, with a mean CEAP class of 1.4 and Villalta score of 3.3. Inflow thrombus had no adverse effect on symptom relief, treatment duration, patency, CEAP class, or valve reflux. Interestingly, 90% of patients with initial popliteal thrombus had a patent popliteal vein on postlysis ultrasound imaging, and the presence of tibial thrombus on presentation was predictive of symptom relief with thrombolysis (odds ratio, 13.03; 95% confidence interval, 1.02-165.58; P = .048). CONCLUSIONS: Inflow thrombosis is common and does not preclude successful thrombolysis of iliofemoral DVT. Valve function is preserved on midterm follow-up, with maintained CEAP class and symptom relief.

Long-term sac behavior after endovascular abdominal aortic aneurysm repair with the Excluder low-permeability endoprosthesis.

PURPOSE: Sac regression is a surrogate marker for clinical success in endovascular aneurysm repair (EVAR) and has been shown to be device-specific. The low porosity Excluder endograft (Excluder low-permeability endoprosthesis [ELPE]; W. L. Gore & Associates Inc, Flagstaff, Ariz) introduced in 2004 was reported in early follow-up to be associated with sac regression rates similar to other endografts, unlike the original Excluder which suffered from sac growth secondary to fluid accumulation in the sac. The purpose of this study was to determine whether this behavior is durable in mid-term to long-term follow-up. METHODS: Between July 2004 and December 2007, 301 patients underwent EVAR of an abdominal aortic aneurysm (AAA) with the ELPE at two institutions. Baseline sac size was measured by computed tomography (CT) scan at 1 month after repair. Follow-up beyond 1 year was either with a CT or ultrasound scan. Changes in sac size ≥5 mm from baseline were determined to be significant. Endoleak history was assessed with respect to sac behavior using χ(2) and logistic regression analysis. RESULTS: Two hundred sixteen patients (mean age 73.6 years and 76% men) had at least 1-year follow-up imaging available for analysis. Mean follow-up was 2.6 years (range, 1-5 years). The average minor-axis diameter was 52 mm at baseline. The proportion of patients with sac regression was similar during the study period: 58%, 66%, 60%, 59%, and 63% at 1 to 5 years, respectively. The proportion of patients with sac growth increased over time to 14.8% at 4-year follow-up. The probability of freedom from sac growth at 4 years was 82.4%. Eighty patients (37.7%) had an endoleak detected at some time during follow-up with 29.6% (16 of 54) residual endoleak rate at 4 years; 13 of the residual 16 endoleaks were type II. All patients with sac growth had endoleaks at some time during the study compared with only 18% of patients with sac regression (P < .0001). CONCLUSION: A sustained sac regression after AAA exclusion with ELPE is noted up to 5-year follow-up. Sac enlargement was observed only in the setting of a current or previous endoleak, with no cases of suspected hygroma formation noted.

A multicenter experience of the management of collapsed thoracic endografts.

OBJECTIVES: Thoracic endograft collapse after thoracic endovascular aortic repair (TEVAR) is a potentially devastating complication. This study evaluates the management of thoracic stent graft collapse. METHODS: A multicenter review of thoracic stent graft collapse was performed from 2005 to 2009. Diagnosis and preoperative planning was performed by computed tomography angiography (CTA). Outcome measures included success of endovascular salvage, postoperative complications, and conversion to open repair. RESULTS: Eleven patients (10 men) with thoracic endograft collapse were identified. Mean age was 41.2 years old (range, 21-66 years). Indications for the index TEVAR were traumatic aortic transections in 8 patients and acute type B dissections in 3 patients. All were initially treated with the TAG endoprosthesis (Gore and Associates, Flagstaff, Ariz). The median duration from initial repair to diagnosis of collapse was 9 days (range, 1 day-38 months). All collapses were initially treated by endovascular means using another TAG device in 7 patients, a Talent (Medtronic, Santa Rosa, Calif) thoracic stent graft in 3 patients, and a Palmaz (Cordis Endovascular, Warren, NJ) stent in 1 patient. In 1 patient, the secondary TAG did not resolve the collapse and required a Palmaz stent placement. Technical success rate was 91%, while re-expansion of the collapsed endograft was achieved in all patients. Early and late complications were observed in 3 patients. Delayed (>30 days) open conversion with device explantation was performed for an aortoesophageal fistula, physiological aortic coarctation, and prevention of a recurrent collapse in 1 patient each. There were no perioperative deaths or recurrent collapses. CONCLUSION: Endograft collapse can be successfully managed by endovascular techniques in most cases. Redo-TEVAR using high radial force devices should be considered the initial treatment of choice. Late endograft-related complications after treatment of collapsed endografts are not uncommon and can be safely managed by open conversion.

Effects of knee osteoarthritis severity on inter-joint coordination and gait variability as measured by hip-knee cyclograms.

Inter-joint coordination and gait variability in knee osteoarthritis (KOA) has not been well investigated. Hip-knee cyclograms can visualize the relationship between the hip and knee joint simultaneously. The aim of this study was to elucidate differences in inter-joint coordination and gait variability with respect to KOA severity using hip-knee cyclograms. Fifty participants with KOA (early KOA, n = 20; advanced KOA, n = 30) and 26 participants (≥ 50 years) without KOA were recruited. We analyzed inter-joint coordination by hip-knee cyclogram parameters including range of motion (RoM), center of mass (CoM), perimeter, and area. Gait variability was assessed by the coefficient of variance (CV) of hip-knee cyclogram parameters. Knee RoM was significantly reduced and total perimeter tended to be decreased with KOA progression. KOA patients (both early and advanced) had reduced stance phase perimeter, swing phase area, and total area than controls. Reduced knee CoM and swing phase perimeter were observed only in advanced KOA. Both KOA groups had a greater CV for CoM, knee RoM, perimeter (stance phase, swing phase and total) and swing phase area than the controls. Increased CV of hip RoM was only observed in advanced KOA. These results demonstrate that hip-knee cyclograms can provide insights into KOA patient gait.

Prior endovascular abdominal aortic aneurysm repair provides no survival benefits when the aneurysm ruptures.

OBJECTIVE: It has been proposed that prior endovascular abdominal aortic aneurysm (AAA) repair (EVAR) confers protective effects in the setting of ruptured AAA (rAAA). This study was conducted to compare outcomes of rAAA repairs in patients with and without prior EVAR. METHODS: A retrospective review identified 18 patients with (group 1) and 233 patients without (group 2) antecedent EVAR who presented with rAAA from January 2001 to December 2008. Patient characteristics and perioperative variables were noted and the outcomes were compared. Multiple logistic regression was used to identify factors contributing to morbidity and mortality and Kaplan-Meier analyses to estimate late survival rates. RESULTS: Baseline characteristics were similar between groups. Mean age was 78 years in group 1 and 74.8 years in group 2 (P=.17). Men comprised 83.3% of patients in group 1 and 77.3% in group 2 (P=.77). Hemodynamic instability at rAAA was noted with similar frequency between groups, 55.6% vs 52.6%, respectively (P=.99). Mean time from EVAR to rAAA was 4.0 years and from last follow-up computed tomography (CT) 1.2 years. The devices involved were Ancure (Guidant, Menlo Park, Calif) (9), AneuRx (Medtronic, Minneapolis, Minn) (5), Zenith (Cook Medical Inc, Bloomington, Ind) (3), and Excluder (W.L Gore, Flagstaff, Ariz) (1). Mean preoperative AAA size was 6.4 cm in group 1. All but 1 patient had an endoleak at the time of rupture. Of 14 patients with CT follow-up, only 3 patients had a known increase in size (≥5 mm) and only 3 were known to have an endoleak. Fifteen patients were treated by a single intervention, whereas 3 patients underwent multiple procedures. In group 2, open repair was performed in 218 patients and EVAR in 15. Morbidity (66.7% vs 56.7%) and in-hospital mortality (38.9% vs 36.9%) were nearly identical between groups. One-year survival rates (27.8% vs 48.2%; P=.15) were also similar. The mortality rates for EVAR for primary rAAA was 20% as compared to 38.1% for open repair for rAAAs (P=.27). CONCLUSION: rAAA remains a lethal problem in patients with and without prior EVAR alike. An existing endograft provides neither acute nor 1-year survival benefits after rAAA repairs. Prediction of patients at risk for rupture post-EVAR is difficult, as only a minority of patients had a known prior endoleak or sac enlargement.