Operation time and clinical outcomes for open infrarenal abdominal aortic aneurysms to remain stable in the endovascular era.

Objective: Endovascular aortic repair (EVAR) has become a routine procedure worldwide. Ultimately, the increasing number of EVAR cases entails changing conditions for open surgical repair (OSR) regarding patient selection, complexity, and surgical volume. This study aimed to assess the time trends of open abdominal aortic aneurysm (AAA) repair in a high-volume single center in Austria over a period of 20 years, focusing on the operation time and clinical outcomes. Materials and methods: A retrospective analysis of all patients treated for infrarenal AAAs with OSR or EVAR between January 2000 and December 2019 was performed. Infrarenal AAA was defined as the presence of a >10-mm aortic neck. Cases with ruptured or juxtarenal AAAs were excluded from the analysis. Two cohorts of patients treated with OSR at different time periods, namely, 2000-2009 and 2010-2019, were assessed regarding demographical and procedure details and clinical outcomes. The time periods were defined based on the increasing single-center trend toward the EVAR approach from 2010 onward. Results: A total of 743 OSR and 766 EVAR procedures were performed. Of OSR cases, 589 were infrarenal AAAs. Over time, the EVAR to OSR ratio was stable at around 50:50 (p = 0.488). After 2010, history of coronary arterial bypass (13.4% vs. 7.2%, p = 0.027), coronary artery disease (38.1% vs. 25.1%, p = 0.004), peripheral vascular disease (35.1% vs. 21.3%, p = 0.001), and smoking (61.6% vs. 34.3%, p < 0.001) decreased significantly. Age decreased from 68 to 66 years (p = 0.023). The operation time for OSR remained stable (215 vs. 225 min, first vs. second time period, respectively, p = 0.354). The intraoperative (5.8% vs. 7.2%, p = 0.502) and postoperative (18.3% vs. 20.8%, p = 0.479) complication rates also remained stable. The 30-day mortality rate did not change over both time periods (3.0% vs. 2.4%, p = 0.666). Conclusion: Balanced EVAR to OSR ratio, similar complexity of cases, and volume over the two decades in OSR showed stable OSR time without compromise in clinical outcomes.

The Femoral Vein as a Long-Term Aorto-Iliac Graft for Aortic Infection and Aortitis.

BACKGROUND: Reconstruction of the aorto-iliac segment with femoral vein (FV) as substitute for infected synthetic grafts or mycotic aneurysms constitutes the most sustainably convenient alternative. The aim of this study was to evaluate the long-term outcome of up to 16 years of follow-up, analysing the morphologic adaption of the FV with special emphasis on the distal and proximal anastomoses. METHODS: We conducted a retrospective study of 22 patients with 109 computed tomography angiograms (CTAs) treated between August 2001 and January 2020 in case of aortic infection/aortitis. Morphologic changes like anastomotic dilatation/stenosis as well as changes of FV wall thickness were retrospectively analysed in pre- and postoperative CTAs. RESULTS: Elective procedure was done in 17/22 (77%) cases, and 5/22 (23%) patients required emergent surgery. The median follow-up was 91.5 months (P25;P75 = 21;117). Cross-sectional diameter of proximal (20.38 ± 3.77 vs 22.04 ± 3.97 mm, p = 0.007) and distal anastomoses (13.05 ± 4.23 vs 14.61 ± 5.19 mm, p = 0.05) increased significantly, as well as the proximal and distal anastomotic areas (3.36 ± 1.29 vs 4.32 ± 1.63 mm2, p = 0.04 and 0.99 ± 0.48 vs 1.25 ± 0.72 mm2, p = 0.023, respectively). Venous wall thickness was significantly reduced at the anastomotic site (1.74 ± 0.46 vs 1.24 ± 0.31 mm, p = 0.001). The upper thigh diameter did not differ before and after harvesting of the FV (161.6 ± 29.1 vs. 178.2 ± 23.3 mm, p = 0.326, respectively). CONCLUSION: This long-term CTA follow-up study showed that the FV wall becomes thinner at the anastomotic site, and the anastomoses dilate with time without rupture. The FV is a durable conductor after replacement of the aorto-iliac segment due to aortic infection. Further CTA studies from more centres are warranted to evaluate the risk of vein rupture.

The Influence of Simvastatin on NGAL, Matrix Metalloproteinases and Their Tissue Inhibitors in Human Intraluminal Thrombus and Abdominal Aortic Aneurysm Tissue.

OBJECTIVE/BACKGROUND: Matrix metalloproteinases (MMPs) play a pivotal role in the development and progression of abdominal aortic aneurysms (AAAs). The action of MMPs depends on a balance between tissue inhibitors of MMPs (TIMPs) and compounds that may prolong protease activity, such as neutrophil gelatinase-associated lipocalin (NGAL). METHODS: The study was designed to analyse gene expression and protein concentration of MMPs, TIMPs, and NGAL in AAA walls and intraluminal thrombi (ILTs) of patients on simvastatin (n = 10) and not on statins (n = 10). The patients were matched by age, sex, and AAA diameter. Expression of MMP2, MMP9, TIMP1, TIMP2, and NGAL was investigated by real time polymerase chain reaction, and MMP2, MMP9, MMP9/TIMP1, MMP9/TIMP2, and MMP9/NGAL protein levels by enzyme-linked immunosorbent assay. RESULTS: MMP2 and MMP9 protein and mRNA levels were comparable in the simvastatin and non-statin groups (p > .05); however, there was a significant decrease in TIMP1 mRNA in AAA tissue (p = .04). Moreover, a significant increase in MMP9/TIMP2 complex concentration in ILTs of patients on simvastatin was noted (median 94.71 ng/mL in the simvastatin group vs. 36.80 ng/mL in the non-statin group; p = .01). No significant difference was observed for NGAL mRNA or protein content in AAA and ILT. CONCLUSION: Simvastatin treatment in patients with AAAs may influence the concentration of proteases and their inhibitors (TIMPs) in aneurysmal wall tissue and ILTs. Thus, further studies should be undertaken to understand the different influence of statin therapy on the components of the MMP/TIMP system in AAAs and ILTs.

Endovascular repair of thoracoabdominal aortic aneurysms with a novel multibranch stent-graft design: preliminary experience.

AIM: The aim of this paper was to report our preliminary experience in outcome, safety and mid-term results in the treatment of thoracoabdominal aortic aneurysms (TAAA) with a novel multibranchstentgraft (E-xtra DESIGN ENGINEERING, JOTEC, Germany). METHODS: Eight patients (mean age 66 years, 2 female) with TAAA (Crawford type I: 2 cases, type III: 3 cases, type IV: 3 cases), mean aneurysm diameter 61 mm, growth over 5 mm per year were treated. Implantation was performed under general anesthesia and surgical exposition of the common femoral artery. Brachial access was percutaneous in 5/8 patients. Balloon-expandable (Advanta V12) bridging stent-grafts were employed and lined with self-expanding nitinol stents. All patients except type IV TAAA received a spinal drainage catheter. RESULTS: The device was successfully deployed in 8/8 patients. 29/32 visceral branches were engaged. One stenosed celiac trunk was left untreated without further consequences, two renal arteries which could not be cannulated were revascularized with iliorenal bypass. One patient needed surgical revision of groin hematoma, one patient suffered from permanent protopathic sensory deficit. No renal complications occurred. Since the primary implantation was deliberately kept short and amount of contrast agent was minimised, four patients needed a secondary percutaneous procedure (Palmaz stent implantation for type I endoleak, re-PTA or additional bridging stent-graft implantation for type III endoleak). The assisted primary success rate was 8/8. Mean follow-up was 18 months. Success was stable in 7/8 patients, one patient shows type V endoleak with 5mm sac expansion. No mortality or complication occurred during follow-up. CONCLUSION: The JOTEC E-xtra DESIGN ENGINEERING multibranch stent-graft is a promising new candidate for endovascular TAAA treatment with sufficient safety and efficacy. Its short delivery time suggests its use in patients with rapid aneurysm growth or high anxiety.

Decreased tissue levels of cyclophilin A, a cyclosporine a target and phospho-ERK1/2 in simvastatin patients with abdominal aortic aneurysm.

BACKGROUND: Cyclophilin A (CyPA), a cyclosporine A-binding protein, influences abdominal aortic aneurysm (AAA) formation and the ERK1/2 signalling pathway in animal and in vitro studies. Statins decrease CyPA in smooth muscle cells although their influence on CyPA in human AAA is unknown. MATERIAL AND METHODS: The study was performed on AAA wall-tissue samples obtained from 30 simvastatin-treated and 15 non-statin patients (2:1 case to control). The patients were matched by age, sex and AAA diameter. We investigated the gene expression of CyPA, its receptor extracellular matrix metalloproteinase inducer (EMMPRIN) by real-time RT-PCR. CyPA and EMMPRIN protein level and phosphorylated extracellular signal-regulated kinases 1 and 2 (ERK1/2) were measured by Western blot. RESULTS: The AAA wall tissue from simvastatin-treated patients had significantly lower CyPA gene expression and protein levels (P = 0.0018, P = 0.0083, respectively). Furthermore, phosphorylation of ERK1 and ERK2 was markedly suppressed in the simvastatin group (P = 0.0002, P = 0.0027, respectively). However, simvastatin did not influence EMMPRIN gene and protein expression. CONCLUSION: Simvastatin-treated patients with AAA exert lower CyPA messenger RNA (mRNA), as well as CyPA intracellular protein levels and a decreased amount of phospho-ERK1/2. Thus, the interference with signalling pathways leading to CyPA formation and ERK1/2 activation reveals a new anti-inflammatory role of statins in AAA.

Simvastatin decreases free radicals formation in the human abdominal aortic aneurysm wall via NF-κB.

OBJECTIVES: Statins have been reported to suppress the progression of abdominal aortic aneurysm (AAA). However, the effects of statins on inflammatory processes and free radicals generation are poorly understood. METHODS: Wall samples from 51 patients (simvastatin patients, n = 34; non-statin patients, n = 17; matched by sex, age and aneurysm size) subjected to elective open AAA repair were analysed. We examined the effects of simvastatin on lipid peroxidation (4-hydroxy-trans-2-nonenal (4-HNE)), hydrogen peroxide (H(2)O(2)), tumour necrosis factor alpha (TNF-α) concentration, superoxide dismutase (SOD) and catalase (CAT) activity as well as nuclear factor kappa B (NF-κB) pathway activation in human AAA wall samples. RESULTS: Treatment with simvastatin resulted in a decrease in 4-HNE and TNF-α concentration (median 4.18 µg/mg protein vs. 4.75, p = 0.012; median 10.33 pg/ml vs. 11.81, p = 0.026, respectively). CAT activity was higher in the simvastatin group (median 3.98 U ml vs. 3.19, p = 0.023). NF-κB expression was lower (p = 0.018) in the simvastatin group. However, simvastatin had little effect on H(2)O(2) concentration (p = 0.832) and SOD activity (p = 0.401). CONCLUSION: Simvastatin inhibits free radicals and TNF-α generation and improves antioxidant capacity of human AAA wall tissue, possibly through the suppression of NF-κB activity. This may be one possible explanation how statins can inhibit AAA oxidative stress.

Reproducibility of serial whole-brain MR spectroscopic imaging.

The reproducibility of serial measurements using a volumetric proton MR Spectroscopic Imaging (MRSI) acquisition implemented at 3 Tesla and with lipid suppression by inversion-recovery has been evaluated. Data were acquired from two subjects at five time points, and processed using fully-automated procedures that included rigid registration between studies. These data were analyzed to determine coefficients of variance (COV) for each metabolite and for metabolite ratio images based on an individual voxel analysis, as well as for average and grey-matter and white-matter values from atlas-defined brain regions. The volumetric MRSI acquisition was found to obtain data of sufficient quality for analysis over 70 +/- 6% of the total brain volume, and spatial distributions of the resultant COV values were found to reflect the known distributions of susceptibility-induced magnetic field inhomogeneity. Median values of the resultant voxel-based COVs were 6.2%, 7.2%, and 9.7% for N-acetylaspartate, creatine, and choline respectively. The corresponding mean values obtained following averaging over lobar-scale brain regions within the cerebrum were 3.5%, 3.7%, and 5.2%. These results indicate that longitudinal volumetric MRSI studies with post-acquisition registration can provide an intra-subject reproducibility for voxel-based analyses that is comparable to previously-reported single-voxel MRS measurements, while additionally enabling increased sensitivity by averaging over larger tissue volumes.

Mapping of brain metabolite distributions by volumetric proton MR spectroscopic imaging (MRSI).

Distributions of proton MR-detected metabolites have been mapped throughout the brain in a group of normal subjects using a volumetric MR spectroscopic imaging (MRSI) acquisition with an interleaved water reference. Data were processed with intensity and spatial normalization to enable voxel-based analysis methods to be applied across a group of subjects. Results demonstrate significant regional, tissue, and gender-dependent variations of brain metabolite concentrations, and variations of these distributions with normal aging. The greatest alteration of metabolites with age was observed for white-matter choline and creatine. An example of the utility of the normative metabolic reference information is then demonstrated for analysis of data acquired from a subject who suffered a traumatic brain injury. This study demonstrates the ability to obtain proton spectra from a wide region of the brain and to apply fully automated processing methods. The resultant data provide a normative reference for subsequent utilization for studies of brain injury and disease.

Subclavian to carotid artery transposition: medial versus lateral approach.

INTRODUCTION: Subclavian to carotid transposition (SCT) is gaining importance as an adjunct for thoracic endovascular aortic repair (TEVAR). Two different anatomical approaches are described. We reviewed our experience with both approaches to evaluate the occurrence of complications and long-term outcome. MATERIALS/METHODS: We report the outcome of 150 SCTs carried between October 1979 and April 200710/79 at 2 university based tertiary care centers. Independent neurologic evaluation was performed. RESULTS: Lateral and medial approaches were used in 83 (55.4%) and 67 (44.6%) cases, respectively. The internal thoracic artery and the thyrocervical trunk were sacrificed more frequently when the lateral approach was used (1.5% vs 39.8%; p=0.0001 and 1.5% vs 49.4%; p=0.0001, respectively). The medial approach was associated with significantly less complications (8, 11.9%, compared to 24, 28.9%, p=0.012). Thirty day mortality was 0.7%. Median follow-up was 36 months (1-227), and no subclavian artery occlusions were identified. CONCLUSIONS: SCT is a durable procedure for the management of occlusive pathologies of the proximal subclavian artery occlusion. The medial approach is associated with significantly fewer complications.

Continuous beta-lactam antibiotic therapy in a double-lung transplanted patient with a multidrug-resistant Pseudomonas aeruginosa infection.

BACKGROUND: It is well known that the bactericidal effect of beta-lactam antibiotics is closely related to the time which the serum concentration of the antibiotic remains above the minimal inhibitory concentration of the target pathogen. Thus, the optimal administration of beta-lactam antibiotics would be the continuous infusion of the drug. METHODS: We present a case report with a critically ill double-lung transplanted patient with pneumonia due to a multidrug-resistant Pseudomonas aeruginosa who received continuously 8 g meropenem/24 hr. Based on a previous pharmacokinetic study showing that continuous infusion of meropenem is at least equivalent to intermittent administration this case report is reported to demonstrate the clinical efficacy of continuous infusion. RESULTS: C-reactive protein and pneumonia decreased rapidly when clinical conditions were improved significantly. Continuous administration of meropenem did not interfere with cyclosporine, no side effects were seen, and the patient's renal function was not impaired during the whole period of treatment. CONCLUSION: The continuous administration of beta-lactam antibiotics is a powerful application in critically ill patients to intensify antimicrobial therapy.