Nikolaos Daskalakis

The - Not So - Solid 5.5 cm Threshold for Abdominal Aortic Aneurysm Repair: Facts, Misinterpretations, and Future Directions.

Abdominal aortic aneurysms (AAAs) represent a focal dilation of the aorta exceeding 1.5 times its normal diameter. It is reported that 4–8% of men and 0.5–1% of women above 50 years of age bear an AAA. Rupture represents the most disastrous complication of aneurysmal disease that is accompanied by an overall mortality of 80%. Autopsy data have shown that nearly 13% of AAAs with a maximum diameter ≤5 cm were ruptured and 60% of the AAAs >5 cm in diameter never ruptured. It is therefore obvious that the “maximum diameter criterion,” as a single parameter that fits all patients, is obsolete. Investigators have begun a search for more reliable rupture risk markers for AAA expansion, such as the level and change of peak wall stress or AAA geometry. Furthermore, it is becoming more and more evident that intraluminal thrombus (ILT), which is present in 75% of all AAAs, affects AAA features and promotes their expansion. Though these hemodynamic properties of AAAs are significant and seem to better describe rupture risk, they are in need of specialized equipment and software and demand time for processing making them difficult in use and unattractive to clinicians in everyday practice. In the search for the addition of other risk factors or user-friendly tools, which may predict AAA expansion and rupture, the use of the asymmetrical ILT deposition index seems appealing since it has been reported to identify AAAs that may have an increased or decreased growth rate.

Totally Percutaneous Endovascular Aneurysm Repair Using the Preclosing Technique: Towards the Least Invasive Therapeutic Alternative.

Endovascular aneurysm repair (EVAR) offers a minimally invasive approach for the treatment of abdominal aortic aneurysms, whereas arterial closure devices have made totally percutaneous EVAR feasible. This is a retrospective analysis of patients undergoing EVAR in a single institution, between May 2011 and October 2014 using surgical or percutaneous access. Hemostasis after percutaneous access was achieved with 2 Perclose ProGlide suture-mediated devices and a preclosing technique. Technical success, local complications, procedural times, length of hospitalization, and need for analgesics are recorded and compared between groups. Among 82 patients/164 groins, 120/164 (73%) groins underwent percutaneous and 44/146 (27%) surgical access. An average 2.2 devices per access site was used. Technical success was 95% (114/120). Local complications (3.3% vs. 11.4%, P=0.05), procedural times (90 vs. 112 min, P=0.05), hospitalization (2 vs. 5 d, P<0.001), and postoperative analgesics (0.7 vs. 4.4 g IV paracetamol, P=0.01) were significantly reduced after percutaneous access which overall seems safe and effective to perform EVAR.

Ozone and carbon monoxide budgets over the Eastern Mediterranean.

The importance of the long-range transport (LRT) on O3 and CO budgets over the Eastern Mediterranean has been investigated using the state-of-the-art 3-dimensional global chemistry-transport model TM4-ECPL. A 3-D budget analysis has been performed separating the Eastern from the Western basins and the boundary layer (BL) from the free troposphere (FT). The FT of the Eastern Mediterranean is shown to be a strong receptor of polluted air masses from the Western Mediterranean, and the most important source of polluted air masses for the Eastern Mediterranean BL, with about 40% of O3 and of CO in the BL to be transported from the FT aloft. Regional anthropogenic sources are found to have relatively small impact on regional air quality in the area, contributing by about 8% and 18% to surface levels of O3 and CO, respectively. Projections using anthropogenic emissions for the year 2050 but neglecting climate change calculate a surface O3 decrease of about 11% together with a surface CO increase of roughly 10% in the Eastern Mediterranean.

Drivers of Air Quality in the East Mediterranean

Due to its location and the particularly warm and sunny climate, the East Mediterranean is receptor and chemical cooker of transported air pollution. Main local anthropogenic sources in the region are from traffic, combustion and energy generation concentrated in the large urban agglomerations in the region. These megacities local pollution emissions are added to high background regional air pollutant levels that are due to long range transport from upwind pollution or dust sources and to interactions of transported air masses with regional natural and anthropogenic emissions. Air quality in the East Mediterranean is strongly affected by sources other than the local anthropogenic sources. Thus, inter-country influences and natural contributions need to be documented. Improvement in air quality in the East Mediterranean requires coordinated effort between the countries surrounding the basin as well as the upwind located countries since their emissions affect the basin via long range transport and chemical aging of air masses. Our results clearly demonstrate significant imports of pollutants to the boundary layer via long range transport within the free troposphere followed by subsidence to the boundary layer. The impact of hot spot emissions in the area and its evolution in a warmer climate are evaluated and discussed.