GPR40 deficiency is associated with hepatic FAT/CD36 upregulation, steatosis, inflammation, and cell injury in C57BL/6 mice.

G-protein-coupled receptor 40 (GPR40) is highly expressed in pancreatic islets, and its activation increases glucose-stimulated insulin secretion from pancreas. Therefore, GPR40 is considered as a target for type 2 diabetes mellitus (T2DM). Since nonalcoholic fatty liver disease (NAFLD) is associated with T2DM and GPR40 is also expressed by hepatocytes and macrophages, it is important to understand the role of GPR40 in NAFLD. However, the role of GPR40 in NAFLD in animal models has not been well defined. In this study, we fed wild-type or GPR40 knockout C57BL/6 mice a high-fat diet (HFD) for 20 wk and then assessed the effect of GPR40 deficiency on HFD-induced NAFLD. Assays on metabolic parameters showed that an HFD increased body weight, glucose, insulin, insulin resistance, cholesterol, and alanine aminotransferase (ALT), and GPR40 deficiency did not mitigate the HFD-induced metabolic abnormalities. In contrast, we found that GPR40 deficiency was associated with increased body weight, insulin, insulin resistance, cholesterol, and ALT in control mice fed a low-fat diet (LFD). Surprisingly, histology and Oil Red O staining showed that GPR40 deficiency in LFD-fed mice was associated with steatosis. Immunohistochemical analysis showed that GPR40 deficiency also increased F4/80, a macrophage biomarker, in LFD-fed mice. Furthermore, results showed that GPR40 deficiency led to a robust upregulation of hepatic fatty acid translocase (FAT)/CD36 expression. Finally, our in vitro studies showed that GPR40 knockdown by siRNA or a GPR40 antagonist increased palmitic acid-induced FAT/CD36 mRNA in hepatocytes. Taken together, this study indicates that GPR40 plays an important role in homeostasis of hepatic metabolism and inflammation and inhibits nonalcoholic steatohepatitis by possible modulation of FAT/CD36 expression.

Fenestrated Endovascular Aortic Aneurysm Repair as a First Line Treatment Option to Treat Short Necked, Juxtarenal, and Suprarenal Aneurysms.

OBJECTIVES: The outcomes of fenestrated endovascular aneurysm repair (FEVAR) as a first line strategy is reported. METHODS: All consecutive patients treated with FEVAR for short neck, juxtarenal, or suprarenal aortic aneurysms under the guidance of the senior author within the period January 2010 to December 2014 were included. Data were collected from a prospectively maintained database. Analyzed outcomes included technical success, defined by successful stent graft implantation with patent stented target vessels and no Type I/III endoleak, operative mortality and morbidity, target vessel patency, endoleak, re-intervention, and death. Survival, target vessel stent patency, and re-intervention during follow up were calculated by Kaplan-Meier analysis. RESULTS: A total of 281 patients (245 male, mean age 72.1 ± 7.7 years) were treated. The mean aneurysm diameter was 60.2 ± 9.3 mm and median proximal neck length 2 mm (range 0-10 mm). Technical success was 96.8% (272/281). Technical failure included one intra-operative death due to embolization and cardiac arrest, one open conversion due to iliac rupture, and seven target vessel complications. The thirty day mortality was 0.7% (2/281). Mean follow up was 21 ± 15.9 months. Estimated survival at 1 and 3 years was 94.7% ± 1.6% and 84.6% ± 3.0%, respectively. Estimated freedom from re-intervention at 1 and 3 years was 96.1% ± 1.4%, and 90% ± 2.7%. Estimated target vessel stent patency at 1 and 3 years was 98.6% ± 0.5%, and 98.1% ± 0.6%, respectively. Mean aneurysm sac diameter decreased from 60.2 ± 9.3 mm pre-operatively to 53.2 ± 12.8 mm (p < .001). CONCLUSIONS: FEVAR as a first line strategy was associated with high technical success and a low operative mortality rate. Efficacy and durability in the mid-term appear very good, with significant regression of aneurysm sac diameter, high target vessel patency, and acceptable rate of re-intervention.

Percutaneous endovascular thrombosuction for acute lower limb ischemia: a 5-year single center experience.

AIM: The aim of this paper was to report a 5-year single center experience with the use of percutaneous endovascular thrombosuction (PET) for acute lower limb ischemia (ALLI). METHODS: All patients that underwent PET for ALLI within the period January 2009-December 2013 in our institution were included. Data were collected retrospectively. RESULTS: A total of 262 patients (132 female, mean age 74.5±11 years) were treated. Level of severity of ALLI preoperatively was stratified as class I (viable) in 76% (199/262) of patients, class IIa (threatened marginally) in 19.4% (51/262), and class IIb (threatened immediately) in 4.6% (12/262). Initial technical success was 91% (237/262). Additional PTA was performed in 29.8% (78/262) of patients, and PTA with stenting in 27.5% (72/262). Open surgery due to technical failure of PET was required in 4.2% (11/262) of patients. Thirty-day mortality was 4.6% (12/262). Perioperative complications occurred in 9.2% (24/262). Thirty-day amputation rate was 3.8% (10/262). The mean duration of follow-up was 26.2±16 months. Estimated cumulative survival was 84.2±2.5% at 1 year, and 73.7±3.6% at 3 years. Estimated freedom from amputation during follow-up was 92.4±1.8% at 1 year, and 91.2±2% at 3 years. Estimated freedom from reintervention was 90.4±2% at 1 year, and 80±3.7% at 3 years. CONCLUSION: PET in selected patients with ALLI provides high initial technical success, low mortality and morbidity rates, and favorable early and mid-term limb salvage rates.

Editor's Choice - Ten-year Experience with Endovascular Repair of Thoracoabdominal Aortic Aneurysms: Results from 166 Consecutive Patients.

OBJECTIVE: To present a 10 year experience with endovascular thoracoabdominal aortic aneurysm (TAAA) repair using fenestrated and branched stent grafts. MATERIALS AND METHODS: Consecutive patients with TAAA treated with fenestrated and branched stent grafts within the period January 2004-December 2013. Data were collected prospectively. RESULTS: 166 patients (125 male, 41 female, mean age 68.8 ± 7.6 years) were treated. The mean TAAA diameter was 71 ± 9.3 mm. Types of TAAA were: type I, n = 12 (7.2%), type II, n = 50 (30.1%), type III, n = 53 (31.9%), type IV, n = 41 (24.8%), and type V, n = 10 (6%). Fifteen (9%) patients had an acute TAAA (11 contained rupture, 4 symptomatic). One hundred and eight (65%) patients were refused for open surgery earlier. Seventy eight (47%) patients had previously undergone one or more open/endovascular aortic procedures. Technical success was 95% (157/166). Thirty day operative mortality was 7.8% (13/166), with an in hospital mortality of 9% (15/166). Peri-operative spinal cord ischemia (SCI) was observed in 15 patients (9%), including permanent paraplegia in two (1.2%). Mean follow up was 29.2 ± 21 months. During follow up 40 patients died, two of them probably from aneurysm related cause. Re-intervention, mostly by endovascular means, was needed in 40 (24%) patients. Estimated survival at 1, 2, and 5 years was 83% ± 3%, 78% ± 3.5%, and 66.6% ± 6.1%, respectively. Estimated target vessel stent patency at 1, 2, and 5 years was 98% ± 0.6%, 97% ± 0.8%, and 94.2% ± 1.5%, respectively. Estimated freedom from re-intervention at 1 and 3 years was 88.3% ± 2.7%, and 78.4% ± 4.5%, respectively. CONCLUSIONS: Endovascular repair of TAAA with fenestrated and branched stent grafts in high volume centers appears safe and effective in the mid-term in a high risk patient cohort. A considerable reintervention rate should be acknowledged, however.

The new C3 Gore Excluder stent-graft: single-center experience with 100 patients.

OBJECTIVES: To present results from the first 100 patients treated with the new C3 Gore Excluder stent-graft in a single institution. METHODS: All patients treated with the C3 Excluder stent-graft between August 2010 and July 2013 in our institution were included. Patient demographics, treatment indication, need for intraoperative stent-graft repositioning, immediate technical success, survival, endoleak and migration rate, and need for reintervention during follow-up were analyzed. RESULTS: A total of 100 patients (86% male, mean age 71.1 ± 9.3 years) were enrolled. Elective abdominal aortic aneurysm (AAA) was the most common indication for treatment (n = 90), followed by common iliac artery aneurysm (n = 5), ruptured AAA (n = 2), type Ia endoleak (n = 1), and type IV endoleak (n = 1) after prior EVAR, and penetrating aortic ulcer (n = 1). Technical success was achieved in 98 patients. In two patients a small type I endoleak persisted at completion angiography, but had disappeared at the first control computed tomography angiogram. Stent-graft repositioning after initial deployment was required in 49 patients, almost equally distributed for level and contralateral gate reorientation. Exact positioning of the proximal trunk was achieved in 98 patients, with the remaining two cases within 5 mm of the intended location. Adverse events related to repositioning maneuvers were noticed in two cases. Mean follow-up duration was 12.2 ± 9.4 months (range 0-36 months). Eight patients died, none from aneurysm related causes. Cumulative patient survival was 96.2 ± 2.1% at 1 year, and 84 ± 6.1% at 2 years, respectively. No migration, or type I or III endoleak was detected during follow-up. Estimated freedom from reintervention was 96 ± 2.4% at 1 year, and 91 ± 5.2% at 2 years, respectively. CONCLUSIONS: The new C3 Excluder stent-graft provides excellent short-term outcomes and offers important advantages in terms of stent-graft repositioning to achieve high proximal deployment accuracy. Longer follow-up is required to confirm improved long-term outcome compared with the previous generation Excluder stent-graft.

Category effects: is top-down control alone sufficient to elicit the mismatch negativity (MMN) component?

This study investigated whether the mismatch negativity (MMN) event-related brain potential (ERP) could be evoked by purely top-down, attentional control. An infrequently occurring tone was designated as a target prior to presenting a randomized sequence of five equi-probably occurring tones. MMN elicitation to the tones categorized as "high", "medium", or "low" frequency, and designated as the target, would indicate that the change detection process can be driven solely by top-down control. However, MMNs were not elicited by the categorized tones. Only the N2b and P3b attention-driven target detection components were elicited. These results suggest that top-down factors alone cannot generate mismatch negativity. Standard formation by stimulus-driven factors is required.

Ground-level ozone differentially affects nitrogen acquisition and allocation in mature European beech (Fagus sylvatica) and Norway spruce (Picea abies) trees.

Impacts of elevated ground-level ozone (O(3)) on nitrogen (N) uptake and allocation were studied on mature European beech (Fagus sylvatica L.) and Norway spruce (Picea abies [L.] Karst.) in a forest stand, hypothesizing that: (i) chronically elevated O(3) limits nutrient uptake, and (ii) beech responds more sensitively to elevated O(3) than spruce, as previously found for juvenile trees. Tree canopies were exposed to twice-ambient O(3) concentrations (2 × O(3)) by a free-air fumigation system, with trees under ambient O(3) serving as control. After 5 years of O(3) fumigation, (15)NH(4)(15)NO(3) was applied to soil, and concentrations of newly acquired N (N(labelled)) and total N (N(total)) in plant compartments and soil measured. Under 2 × O(3), N(labelled) and N(total) were increased in the bulk soil and tended to be lower in fine and coarse roots of both species across the soil horizons, supporting hypothesis (i). N(labelled) was reduced in beech foliage by up to 60%, and by up to 50% in buds under 2 × O(3). Similarly, N(labelled) in stem bark and phloem was reduced. No such reduction was observed in spruce, reflecting a stronger effect on N acquisition in beech in accordance with hypothesis (ii). In spruce, 2 × O(3) tended to favour allocation of new N to foliage. N(labelled) in beech foliage correlated with cumulative seasonal transpiration, indicating impaired N acquisition was probably caused by reduced stomatal conductance and, hence, water transport under elevated O(3). Stimulated fine root growth under 2 × O(3) with a possible increase of below-ground N sink strength may also have accounted for lowered N allocation to above-ground organs. Reduced N uptake and altered allocation may enhance the use of stored N for growth, possibly affecting long-term stand nutrition.

[Results of endovascular repair of TAAA in the first 50  patients]. / Bericht über die ersten 50 endovaskulären thorako-abdominellen Behandlungen mit Seitenarmprothesen.

BACKGROUND: Developments with fenestrated and branched stent grafts have opened the way to treat complex aortic aneurysms involving the visceral arteries. First reports on endovascular treatment of thoracoabdominal aneurysms have demonstrated the feasibility of the technique. METHODS: A literature review and results of first 50  patients treated with a custom-made Zenith device with fixed branches are presented. Most of the patients were refused open surgery mainly for the extent of the disease combined with co-morbidity, which included in most patients a combination of several risk factors. Mean aneurysm size was 71 mm and extent of the aneurysm was type  I (n = 9), type  II (n = 13), type  III (n = 19), and type  IV (n = 9), respectively. RESULTS: Primary and primary assisted technical successes in our series were 88 % (44 / 50) and 92 % (46 / 50), respectively. One patient died on day  1 from an intraoperative aneurysm rupture. In two patients a renal artery was lost, one due to rupture and one due to malpositioning of the bridging stent graft. In a fourth patient, a celiac artery could not be catheterised and was lost. Finally, in two more patients, catheterisation of in total three renal arteries proved impossible. This was solved by a retrograde approach for two renal arteries via laparotomy in one patient, and a spleno-renal bypass in the other patient. Thirty-day mortality was 8 %. Estimated survival at 6  months, 1  year, and 2  years was 91.2 %, 79.8 %, and 69.7 %, respectively. Freedom of reintervention of all kinds at 1 and 2  years was 81.9 % and 73.7 %, respectively. CONCLUSION: Results of fully endovascular repair of thoracoabdominal aneurysms in a high-risk cohort are promising. A learning curve should be expected. Although longer term results need to be awaited, it is likely that endovascular repair of thoracoabdominal aneurysms will become a preferential treatment option for many patients in the future.

First experience with the new repositionable C3 excluder stent-graft.

AIM: The Gore Excluder device is a modern third generation device that performs well. Nevertheless, the proximal deployment was not as accurate and controlled as with some other modern devices. Therefore a new deployment system was developed. This system allows to reconstrain the graft after initial deployment, with the purpose to reposition the graft for both level or orientation. METHODS: The new system was used in 25 patients with an infrarenal abdominal aortic aneurysm. In 72% of cases the system was used to achieve a better proximal position or to facilitate catheterization of the contralateral limb. Surprisingly, the option to orientate the graft was used most. RESULTS: The new deployment system worked well, and all grafts were easily repositioned to the intended final position. Additional cuffs were not required in any of the patients. Surgical mortality was nil. All patients left the hospital in good condition. There were no type I endoleaks at completion angiography neither at first computed tomography scanning. CONCLUSION: With the new deployment system it is possible to reposition the Excluder to achieve optimal fixation and sealing. A global registry has been set into place to report real life results including longer term performance of the graft.

Diagnosis of American foulbrood in honey bees: a synthesis and proposed analytical protocols.

Worldwide, American foulbrood (AFB) is the most devastating bacterial disease of the honey bee (Apis mellifera). Because the distinction between AFB and powdery scale disease is no longer considered valid, the pathogenic agent has recently been reclassified as one species Paenibacillus larvae, eliminating the subspecies designations Paenibacillus larvae subsp. larvae and Paenibacillus larvae subsp. pulvifaciens. The creamy or dark brown, glue-like larval remains of infected larvae continue to provide the most obvious clinical symptom of AFB, although it is not conclusive. Several sensitive and selective culture media are available for isolation of this spore-forming bacterium, with the type of samples that may be utilized for detection of the organism being further expanded. PCR methods for identification and genotyping of the pathogen have now been extensively developed. Nevertheless, biochemical profiling, bacteriophage sensitivity, immunotechniques and microscopy of suspect bacterial strains are entirely adequate for routine identification purposes.

Spatiotemporal maturation of the central and lateral N1 components to tones.

This paper examines maturational changes in the spatiotemporal features of central and lateral N1 components of the auditory evoked potentials (AEPs) to tone stimuli presented with a long stimulus onset asyncrony (SOA; 4200 ms) using the scalp current density (SCD) technique. A group of typically developing children ranging from 6 to 12 years of age and a group of adults were studied. Recently studies have begun to explore the topography of these components in children. These studies, however, often used rapidly presented stimuli and did not elicit observable central N1s in the younger children. Our stimuli elicited both central and lateral N1s. Peak latencies of both components decreased with age. Peak amplitude also decreased with age for the lateral N1 but not for the central N1. Consequently, the difference between the lateral N1 and the central N1 amplitudes (or the ratio of lateral N1 amplitude to central N1 amplitude) also decreased with age, dramatically altering the morphology of the elicited AEP waveforms. Topography of the lateral N1 did not change with age. The location of maximal activation for the central N1 appeared to move more medially with age but this 'apparent' movement is probably due to the decreasing impact of the partially overlapping lateral N1 component whose amplitude is significantly smaller in adults than in children.

[Endovascular therapy of renal artery stenosis: technical results with the Palmaz-Corinthian stent]. / Endovaskuläre Therapie der Nierenarterienstenose: Technische Ergebnisse mit dem Palmaz-Corinthian-Stent.

OBJECTIVE: To evaluate the technical performance and delivery characteristics of the Palmaz-Corinthian stent for endovascular therapy of atherosclerotic renovascular disease. METHODS: 61 patients underwent implantation of 76 Palmaz-Corinthian (PC) stents in 72 arteries. 50 original PC and 26 PC stents with the modified IQ-design were employed. The indications comprised primary stenting of ostial (n = 49) or truncal (n = 1) stenosis or occlusion (n = 3), and selective stenting following complicated (dissection, n = 4) or unsuccessful (n = 8) angioplasty. The remaining stents were placed in patients with recurrent stenosis (n = 5) or acute aortic dissection (n = 2) involving the renal artery. Mean severity and length of stenosis were 81.3% and 9.8 mm, respectively. 39 lesions were rated eccentric or calcified. Data on technical success, complication rate, delivery characteristics and ease of placement compared to standard renal stents were retrieved from a prospective multicenter registry. RESULTS: Stent delivery was successful in all patients, major complications were not reported. Stent placement was suboptimal in 7 of 72 cases: 4 stents were located too distally in the renal artery, necessitating proximal coaxial overstenting in 2 cases. The distal part of the stenosis was incompletely covered and the orifice of a segmental branch inappropriately overstented in one case each. One stent was dislodged from the balloon, resulting in stent protrusion in the aortic lumen. Significant residual stenosis after stenting was not observed. Overall stent deliverability, trackability and potential repositioning inside the stenosis were rated positive, radio-opacity was rated superior for the IQ design. CONCLUSION: Technical performance and delivery characteristics of the Palmaz-Corinthian stent have been significantly improved compared to the Palmaz design, allowing mostly correct placement in renal artery stenoses with a low complication rate.

The effect of perceptual grouping on the mismatch negativity.

The mismatch negativity (MMN) was used as a probe to evaluate changes, with age, of transient auditory memory. Subjects were 16 young (M = 23 years) and 16 old (M = 72 years) people. Standard auditory stimuli were presented in trains of eight tones (1000 Hz) with either a I-s or 8-s intertrain interval (ITI). Occasionally, the first stimulus of a train was replaced with a 1200 Hz tone (deviant). The MMN was recorded while subjects watched a silent movie and ignored the sounds. Both groups of subjects showed an MMN response to deviant stimuli under the 1-s ITI condition, but MMNs were only seen for some subjects under the 8-s ITI condition. After MMN recording, subjects performed a discrimination task to the tones used for recording MMNs. Accuracy for both groups was near 100% at both ITIs. These results suggest that generation of MMN is a function of the perceptual grouping of the acoustical stimuli and that the integrity of perceptual grouping may be maintained with increased age.

An event-related potential evaluation of involuntary attentional shifts in young and older adults.

Involuntary shifts in attention to irrelevant stimuli were studied in elderly and young volunteers during a dichotic-listening task. Event-related potentials and behavioral measures were recorded. Volunteers heard pairs of tones presented with 2 different stimulus onset asynchronies (SOAs). To-be-ignored tones were presented to the left ear, followed by to-be-attended tones to the right ear. Left-ear tones were a frequent standard (700 Hz) and an infrequent small (650 Hz) and large (500 Hz) deviant. Right-ear tones (1500 Hz) were presented with 2 equiprobable intensities. Volunteers responded to the lower intensity stimulus. Behavioral performance was impaired at the short SOA when to-be-ignored large deviants preceded to-be-attended targets, but more so for the elderly volunteers. Large deviants also elicited the mismatch negativity (MMN) and P3a for both age groups. It was concluded that the more impaired behavioral performance observed for the elderly was due to greater sensitivity to output from the MMN system by a frontal lobe system responsible for the maintenance of attentional focus.

Sacbrood virus of the honeybee (Apis mellifera): rapid identification and phylogenetic analysis using reverse transcription-PCR.

Sacbrood virus (SBV) infects larvae of the honeybee (Apis mellifera), resulting in failure to pupate and death. Until now, identification of viruses in honeybee infections has been based on traditional methods such as electron microscopy, immunodiffusion, and enzyme-linked immunosorbent assay. Culture cannot be used because no honeybee cell lines are available. These techniques are low in sensitivity and specificity. However, the complete nucleotide sequence of SBV has recently been determined, and with these data, we now report a reverse transcription-PCR (RT-PCR) test for the direct, rapid, and sensitive detection of these viruses. RT-PCR was used to target five different areas of the SBV genome using infected honeybees and larvae originating from geographically distinct regions. The RT-PCR assay proved to be a rapid, specific, and sensitive diagnostic tool for the direct detection of SBV nucleic acid in samples of infected honeybees and brood regardless of geographic origin. The amplification products were sequenced, and phylogenetic analysis suggested the existence of at least three distinct genotypes of SBV.

The detection of constancy amidst change in children: a dissociation of preattentive and intentional processing.

This study examined whether 7-9-year-old children preattentively build memories of constancy for individual stimulus features, and if these representations are affected by variability of other stimulus features. This was achieved by looking at the mismatch negativity (MMN) event-related potential to a duration deviant occurring in a stimulus environment in which one or two other features constantly changed. Performance data were also collected, to look at the correspondence between the effects of this manipulation on preattentive and intentional deviance detection. MMN data indicated that the children built a preattentive feature-based memory of constancy that was not affected by the number of varying features. In contrast, intentional deviance detection was considerably impaired by the introduction of feature variability. This dissociation is at variance with previous studies that usually report close association between MMN and behavior.

Mismatch negativity in children and adults, and effects of an attended task.

Attention has been shown to modulate the amplitude of the mismatch negativity (MMN) elicited by a small deviation in auditory stimuli in adults. The present study examined the effects of attention and deviant size on MMN amplitude in children. Children and adults were presented with sequences of tones containing standards (1000 Hz) and three deviants varying in degree of deviance from the standard (1050, 1200, and 1500 Hz). Tones were presented in three conditions: (1) while participants ignored them; (2) while participants listened to them and responded to all three deviants; and (3) while participants again ignored them. We found that the MMNs elicited by the hard deviant (1050 Hz) were larger when the children were actively discriminating the stimuli than when they were ignoring them. However, the MMNs elicited by the easy and medium deviants (1500 and 1200 Hz, respectively) in the children and by all three deviants in the adults were not affected by attention.

Associated deficits in mismatch negativity generation and tone matching in schizophrenia.

OBJECTIVE: Schizophrenia is associated with deficits in mismatch negativity (MMN) generation and in the ability to match two tones following brief delay. Both deficits reflect impaired early cortical processing of auditory information. However, the relationship between deficits in MMN generation and tone matching performance in schizophrenia has not been established. METHODS: MMN and tone matching performance was evaluated in 12 schizophrenic subjects and 12 similar aged controls. A pitch separation known to produce non-ceiling performance in patients (5% Deltaf) was used. Narrow band filtering of MMN data was used to enhance signal-to-noise ratio. RESULTS: Schizophrenic subjects showed impairments in both MMN generation and tone matching performance. The two deficits were significantly correlated across subjects. In addition, decreased MMN amplitude and poorer tone matching performance correlated with increased severity of negative symptoms. CONCLUSIONS: These findings support the concept that similar neurophysiological mechanisms underlie MMN and tone matching deficits in schizophrenia. Further, they indicate that increased sensitivity to environmental change may be related to social withdrawal and other negative symptoms in schizophrenia.

Aortic aneurysm size and graft behavior after endovascular stent-grafting: clinical experiences and observations over 3 years.

PURPOSE: To assess the long-term safety and efficacy of aortic endografts in terms of clinical outcome, continuing aneurysm exclusion, and changes of aneurysm size and graft configuration. METHODS: Between August 1994 and July 1997, 190 patients (176 men; mean age 68.7 years, range 40-87) with aortic and aortoiliac aneurysms were treated with endovascular stent-grafts (Stentor, Vanguard, and EGS) in a tertiary care municipal hospital setting. Follow-up involved clinic visits every 3 to 6 months with contrast-enhanced computed tomography (CT), color duplex, and plain abdominal radiographs at regular intervals; angiography was used selectively. All data were collected prospectively and entered into a computerized database. RESULTS: Implantation was possible in 188 (98.9%) patients. Early conversion to open surgical repair was required in 14 (7.4%) patients. Primary endoleaks were detected in 32 (16.8%) patients. Perioperative mortality was 0.53% (1/190). During follow-up, 17 (8.9%) additional patients were converted to open repair over a mean 20.9 months. Thirty-seven secondary procedures to treat endoleaks and pelvic outflow occlusions were performed in 30 (15.8%) patients. Changes in stent configuration suggestive of endograft disintegration were observed in 31 (29.8%) of 104 abdominal radiographs. Intraluminal layering of thrombus was seen on contrast-enhanced CT images in 20 patients. A significant trend (chi(2)4 = 12.34, p < 0.025) toward aneurysm enlargement was seen in patients with persistent endoleaks at a mean 18-month follow-up. CONCLUSIONS: Although endoleaks after aortic stent-graft placement tend to cause ongoing aneurysm growth, we have also observed aneurysm shrinkage despite ongoing endoleak. The presence or absence of an endoleak in itself may be a poor predictor of successful stent-graft therapy. Lifelong surveillance is needed to assure successful aneurysm exclusion and stability or shrinkage of the aneurysm sac. Technical improvements in stent materials and design are necessary to guarantee long-term stability and safety of the device.