Jeanwan Kang

Outcomes following endovascular abdominal aortic aneurysm repair (EVAR): an anatomic and device-specific analysis.

OBJECTIVE We performed a device-specific comparison of long-term outcomes following endovascular abdominal aortic aneurysm repair (EVAR) to determine the effect(s) of device type on early and late clinical outcomes. In addition, the impact of performing EVAR both within and outside of specific instructions for use (IFU) for each device was examined. METHODS Between January 8, 1999 and December 31, 2005, 565 patients underwent EVAR utilizing one of three commercially available stent graft devices. Study outcomes included perioperative (< or =30 days) mortality, intraoperative technical complications and need for adjunctive procedures, aneurysm rupture, aneurysm-related mortality, conversion to open repair, reintervention, development and/or resolution of endoleak, device related adverse events (migration, thrombosis, or kinking), and a combined endpoint of any graft-related adverse event (GRAE). Study outcomes were correlated by aneurysm morphology that was within or outside of the recommended device IFU. chi2 and Kaplan Meier methods were used for analysis. RESULTS Grafts implanted included 177 Cook Zenith (CZ, 31%), 111 Gore Excluder (GE, 20%), and 277 Medtronic AneuRx (MA, 49%); 39.3% of grafts were placed outside of at least one IFU parameter. Mean follow-up was 30 +/- 21 months and was shorter for CZ (20 months CZ vs 35 and 31 months for GE and MA, respectively; P < .001). Overall actuarial 5-year freedom from aneurysm-related death, reintervention, and GRAE was similar among devices. CZ had a lower number of graft migration events (0 CZ vs 1 GE and 9 MA); however, there was no difference between devices on actuarial analysis. Combined GRAE was lowest for CZ (29% CZ, 35% GE, and 43% MA; P = .01). Graft placement outside of IFU was associated with similar 5-year freedom from aneurysm-related death, migration, and reintervention (P > .05), but a lower freedom from GRAE (74% outside IFU vs 86% within IFU; P = .021), likely related to a higher incidence of graft thrombosis (2.3% outside IFU vs 0.3% within IFU; P = .026). The differences in outcome for grafts placed within vs outside IFU were not device-specific. CONCLUSION EVAR performed with three commercially available devices provided similar clinically relevant outcomes at 5 years, although no graft migration occurred with a suprarenal fixation device. As anticipated, application outside of anatomically specific IFU variables had an incremental negative effect on late results, indicating that adherence to such IFU guidelines is appropriate clinical practice.

Infrapopliteal balloon angioplasty for the treatment of chronic occlusive disease

OBJECTIVE There is little documentation of the effectiveness of percutaneous balloon angioplasty (PTA) of infrapopliteal vessels for the treatment of chronic lower extremity ischemia. This study reviewed our recent experience with infrapopliteal PTA in a large series of patients to determine its effectiveness as a treatment modality. METHODS All patients undergoing primary infrapopliteal PTA from March 2002 to June 2006 were included. Primary study end points were primary patency, assisted patency, limb salvage, and patient survival assessed by Kaplan-Meier life-table analysis. Factors predictive of PTA failure and patient longevity were evaluated by multivariate methods. RESULTS There were 155 PTAs undertaken in 144 patients (70% men; mean age, 74 years), with critical limb ischemia (86%), diabetes (66%), and renal insufficiency (45%). Infrapopliteal lesions were classified as TransAtlantic Inter-Society Consensus A (7%), B (18%), C (39%), and D (35%). PTA was confined to the infrapopliteal segment in 40 (26%), and 115 (74%) underwent multilevel treatment. Five patients (3%) received stents. Technical success was 95%. The 30-day mortality was 2%, and major morbidity was 3%. The mean follow-up was 22 months (range, 0-54 months). The 40-month actuarial primary patency was 62% (standard error, 5%), with assisted patency (infrapopliteal re-PTA, 25 [16%]) of 90%. Interval conversion to bypass surgery occurred in seven (5%). Nonhealing ulcers occurred in 118 patients (76%), of which 76 (64%) healed during follow-up. Of the 42 unhealed ulcers, 15 (13%) required major amputations for a 40-month limb salvage of 86.2%. Multivariate predictors that were negative for primary patency included 0/1 vessel runoff (P = .01), critical limb ischemia (P = .002), and dialysis (P = .03). Negative predictors of limb salvage included dialysis (P = .007) and failure to improve runoff to the foot (P = .006). At 40-months, patient survival was 54%, with negative predictors including severe pulmonary disease (P = .01), coronary artery disease (P = .04), and renal insufficiency (P < .001). CONCLUSIONS Infrapopliteal angioplasty can be performed safely with favorable results in patients with limited longevity. Primary patency is related to disease extent. Secondary interventions may be necessary to maintain clinical success. These data indicate that PTA should be considered as initial therapy for infrapopliteal occlusive disease in patients with lower extremity ischemia.

Clinical and anatomic outcomes after carotid endarterectomy

OBJECTIVE The purpose of this study was to examine 30-day and long-term outcomes after carotid endarterectomy (CEA) in a contemporary series and to identify variables associated with stroke and death after CEA. METHODS This was a retrospective review of patients undergoing an isolated CEA at a single institution between January 1989 and December 2005. Primary study end points were 30-day and long-term overall stroke, ipsilateral stroke, and death. Secondary end points were recurrent stenosis (>70% stenosis) and reintervention. Kaplan-Meier analysis was used to create survival curves for the long-term study end points. Multivariate models were created to identify variables associated with the study end points. RESULTS During the study period, 3014 CEAs were performed on 2644 patients (mean age, 71.0 ± 8.9 years; 60.9% male; 33.5% symptomatic; 37% primary closure), with mean follow-up of 7.0 years. The 30-day ipsilateral stroke, death, and combined ipsilateral stroke/death rates were 1.3%, 1.1%, and 2.2%, respectively. Previous ipsilateral CEA or neck dissection for cancer (hazard ratio [HR], 3.68; P = .0081) and symptomatic disease (HR, 2.45; P = .0071) were predictive of 30-day ipsilateral stroke. Stroke-free survival was 93.8% at 4 years and 86.9% at 10 years. Diabetes (HR, 1.94; P < .0001), symptomatic disease (HR, 1.75; P < .0001), female gender (HR, 1.34; P = .035), and increasing age (HR, 1.02; P < .0001) were predictors of long-term overall stroke. Ipsilateral stroke-free survival was 97.6% at 5 years and 94.6% at 10 years, respectively. Contralateral occlusion (HR, 2.06; P = .025) and symptomatic disease (HR, 1.87; P = .003) were predictors of ipsilateral stroke, whereas antilipid therapy was protective (HR, 0.65; P = .049). Overall survival was 70.1% at 5 years and 42.2% at 10 years, with no difference between symptomatic and asymptomatic patients. Although a variety of comorbidities were associated with inferior late survival, as anticipated, female gender (HR, 0.89; P = .016) and lipid-lowering therapy (HR, 0.69; P < .0001) were protective. Reintervention was 3.4% at 5 years and 6.6% at 10 years, with primary closure (vs patch angioplasty/eversion) increasing the risk of reintervention (HR, 1.72; P = .007). CONCLUSIONS CEA has favorable perioperative and long-term clinical and anatomic outcomes with respect to its goal of stroke prevention for symptomatic and asymptomatic patients. Adjuvant medical therapy (antilipid) has increased overall and ipsilateral stroke-free survival.

A risk prediction model for determining appropriateness of CEA in patients with asymptomatic carotid artery stenosis.

Objective: The benefit of carotid endarterectomy (CEA) over medical therapy in patients with asymptomatic carotid artery stenosis is predicated upon a life expectancy of at least 5 years after the procedure. The goal of this study was to create a scoring system for prediction of 5-year survival after CEA that can be used to triage patients with ACAS. Methods: All patients who underwent CEA for severe asymptomatic carotid stenosis from 1989 to 2005 were identified. Long-term survival was determined by a review of hospital records and the social security death index. Because all patients had at least 5-year follow-up, a logistic regression of predictors of survival at 5 years was performed and the odds ratios associated with particular significant comorbidities were used to create a scoring system to predict survival. The scoring system was then validated within the cohort using the Hosmer-Lemeshow Test and a derivation/validation receiver operating characteristic (ROC) curve. Results: There were 2004 CEA performed in 1791 patients. The average follow-up was 130 ± 49 months. The clinical profile of the cohort data included 84% hypertension, 56% coronary artery disease (CAD), 24% diabetes, and 71% on statins. The 30-day stroke rate was 1.1% and the death rate was 0.7%. The actual 5-year survival was 73%. Logistic regression yielded the following predictors of mortality: age (by decade) (odds ratio [OR] = 1.8, P < 0.0001), CAD (OR = 1.5, P = 0.0007), chronic obstructive pulmonary disease (OR = 2.5; P < 0.0001), diabetes (OR = 1.7, P < 0.0001), neck radiation (OR = 2.6, P = 0.005), no statin (OR = 2.1, P < 0.0001), and creatinine more than 1.5 (OR = 2.6, P < 0.0001). These variables were then assigned a hierarchal point scoring system in accordance with the OR value. The 5-year survival based on the scoring system was as follows: 0 to 5 points = 92.5%, 6 to 8 points = 83.6%, 9 to 11 points = 63.7%, 12 to 14 points = 46.5%, and more than 15 points = 33.8%. The Hosmer-Lemeshow test validated the scoring system (P = 0.26) and there was no difference in the ROC curves (C statistic = 0.74 vs 0.73). Conclusions: This validated scoring system can be a useful tool for determining which patients are likely to benefit most from CEA based on the probability of long-term survival. Given that the 5-year survival of patients in the medical arm of the asymptomatic CEA trials was 60% to 70%, it is reasonable to conclude that patients who score 0 to 8 points are excellent candidates for CEA whereas most patients with ≥12 points should be managed with medical therapy alone.

The effects of systemic hypothermia on a murine model of thoracic aortic ischemia reperfusion

INTRODUCTION Hypothermia is widely used to mediate ischemia-reperfusion injury associated with repair of the thoracoabdominal aorta. Experiments were designed in a murine model of thoracic aortic ischemia-reperfusion (TAR) to evaluate the effect of moderate systemic hypothermia on neurologic function, spinal cord morphology, and indices of inflammation in critical organs. METHODS C57BL/6 mice were subjected to TAR under hypothermic (34 degrees C) or normothermic (38 degrees C) conditions, followed by 24 or 48 hours of normothermic reperfusion. Neurologic functions were assessed during reperfusion. Spinal cords were examined at 24 and 48 hours after reperfusion, and the degree of injury qualified by counting the number of viable motor neurons within the anterior horns. Keratinocyte chemokine, interleukin-6, and myeloperoxidase levels were measured from lung, liver, and kidney at 24 and 48 hours. RESULTS Normothermic TAR resulted in a dense neurologic deficit in all mice throughout the reperfusion period. Mice subjected to TAR under hypothermic conditions had transient, mild neurologic deficit during the initial periods of reperfusion. Between 24 and 48 hours, delayed paralysis developed in half of these mice, whereas the other half remained neurologically intact. Spinal cord histology showed a graded degree of injury that correlated with neurologic function. There was no correlation between markers of inflammation in various organs and neurologic outcomes following TAR. CONCLUSION Systemic moderate hypothermia was protective against immediate paralysis after TAR in all cases and was associated with delayed paralysis in 50% of mice. This study suggests that delayed-onset paralysis may be the result of a local insult, rather than a systemic inflammatory event, precipitating spinal cord injury.

The relationship between body fat mass and erectile dysfunction in Korean men: Hallym Aging Study

The aim of this study was to assess the relationship between body fat mass (BFM) and erectile dysfunction (ED) in Korean men. This study was a cross-sectional study using data on 208 men (the mean age=67.4±8.2). ED was diagnosed by the International Index of Erectile Function (IIEF)-5 and body fat percentage (BF%) was quantified with bioelectrical impedance. BF% was divided into quintiles (quintile 1: ⩽20.5%, quintile 2: 20.6–23.2%, quintile 3: 23.3–25.8%, quintile 4: 25.9–28.8%, quintile 5: ⩾28.9%). Using subjects with quintile 3 of BF% as reference, the adjusted odds ratios of subjects with the lowest quintile of BF% and with the highest quintile were 9.29 (95% CI: 2.29–37.72) and 4.99 (95% CI: 1.37–18.09), respectively. This study showed that BFM and ED had a U-shaped relationship in Korean men. These findings suggest that not only obesity but also a low BFM may be a risk factor of ED in Asians.

Renal artery duplex ultrasound criteria for the detection of significant in‐stent restenosis

To define velocity criteria by ultrasonography for the detection of hemodynamically significant (>60%) renal artery in‐stent restenosis (ISR).

Enoxaparin Does Not Ameliorate Limb Ischemia-Reperfusion Injury

OBJECTIVE Since low molecular weight heparin has greater bioavailability and sustained serum levels in vivo than unfractionated heparin, it has been used to supplant unfractionated heparin to achieve therapeutic anticoagulation in humans. These studies were designed to determine whether treatment with enoxaparin could protect murine skeletal muscle from ischemia reperfusion injury. METHODS C57BL6 mice were divided into four groups. Sham control animals underwent 90 min of anesthesia alone. All other groups underwent 90 min of unilateral hindlimb ischemia. At the onset of reperfusion, animals received either normal saline (control and saline) or 4 mg/kg of enoxaparin subcutaneously twice daily. Groups were followed for 24 or 48 h reperfusion. Hindlimb skeletal muscle blood flow was measured by laser Doppler, and muscle was removed for histological and protein analysis. Tissue thrombosis was evaluated by thrombin antithrombin III (TAT III), local inflammation by measurement of proinflammatory cytokines (macrophage inflammatory protein-2: MIP-2, monocyte chemoattractant protein-1: MCP-1), and neutrophil infiltration by myeloperoxidase (MPO) using enzyme-linked immunosorbent assay. Plasma levels of Factor Xa were measured during reperfusion to confirm therapeutic levels of anticoagulation. Comparisons were calculated using analysis of variance. RESULTS At 24 h reperfusion, there was increased expression of MIP-2, MCP-1, MPO, and TAT III in saline and enoxaparin treated mice compared with control (*P < 0.05). By 48 h reperfusion, all parameters measured remained greater than control except for the enoxaparin treated mice whose TAT III levels were significantly less than untreated mice (P < 0.05). Despite documented therapeutic anticoagulation and decreased levels of markers of thrombosis in enoxaparin treated mice, there was no difference in tissue cytokines, inflammatory markers, degree of muscle fiber injury (31% +/- 8% versus 30% +/- 5%) or muscle flow between ischemia-reperfusion groups (2447 +/- 141 versus 2475 +/- 74 flux units) at 48 h reperfusion. CONCLUSIONS Post hoc administration of enoxaparin did not affect local tissue thrombosis, inflammatory markers, or muscle necrosis. This suggests that despite its potent in vivo activity, enoxaparin did not modulate skeletal muscle injury, thrombosis, or inflammatory following ischemia reperfusion. enoxaparin may not be useful in mediating skeletal muscle injury when administered in a clinically relevant scenario.