Classification of Chimney EVAR-Related Endoleaks: Insights from the PERICLES Registry

Juxtarenal aortic aneurysms (JAAs) pose significant challenges for endovascular aneurysm repair (EVAR). A short or absent infrarenal neck typically excludes standard EVAR as a viable or reasonable treatment option. In this context, the use of chimney grafts (chEVAR) is gaining in popularity and applicability. These grafts are designed to course in the aortic lumen outside the main stent-graft to maintain normal perfusion to the involved target branches. As such, they may represent a promising and less resource-intensive option for management of JAAs. However, this technical strategy is not without challenges of its own, particularly the inevitable creation of \u201cgutters\u201d that result from the interaction of the chimney graft with the main aortic stent-graft. These gutters can become a conduit for type Ia endoleak formation, hence they represent the Achilles\u2019 heel of chEVAR. Current reports point to a relatively wide-ranging incidence (0%\u201313%) of type Ia endoleaks related to chEVAR. The PERICLES Registry collected the global transatlantic experience of 13 European and US vascular centers reporting 517 patients with complex aneurysms treated with EVAR and chimney parallel grafts. Overall, 6% of PERICLES chEVAR patients had a type Ia endoleak at completion angiography, but the rate of persistent endoleaks was only 2.9% at a mean 17.1 months of follow-up. Close review of the postoperative computed tomography angiograms of these persistent endoleak patients revealed distinct types and patterns of chEVAR-related type Ia endoleaks and form the basis of a new classification proposed herein. It is hoped that these observations will lead to development of new treatment algorithms for effective management of chimney-related endoleaks and, in some cases, to prevent them from occurring in the first place

Karyological diversification in the genus lyciasalamandra (Urodela: Salamandridae)

We performed the first cytogenetic analysis on five out of the seven species of the genus Lyciasalamandra, including seven subspecies, and representatives of its sister genus Salamandra. All the studied species have a similar karyotype of 2n = 24, mostly composed of biarmed elements. C-bands were observed on all chromosomes, at centromeric, telomeric and interstitial position. We found a peculiar taxon-specific NOR configuration, including either heteromorphic and homomorphic NORs on distinct regions of different chromosomes. Lyciasalamandra a. antalyana and L. helverseni showed two homomorphic NORs (pairs 8 and 2, respectively), while heteromorphic NORs were found in L. billae (pairs 6, 12), L. flavimembris (pairs 2, 12), L. l. luschani (pairs 2, 12), L. l. basoglui (pairs 6, 12), L. l. finikensis (pairs 2, 6) and S. lanzai (pairs 8, 10). Homomorphic NORs with an additional supernumerary site were shown by S. s. salamandra (pairs 2, 8) and S. s. gigliolii (pairs 2, 10). This unexpected highly variable NOR configuration is probably derived from multiple independent NOR translocations and paracentric inversions and correlated to lineage divergence in Lyciasalamandra. These results support the taxonomic validity of the studied taxa and are consistent with a hypothesized scenario of synchronous evolution in the genus

The Gore Hybrid Vascular Graft in renovisceral debranching for complex aortic aneurysm repair

Objective This study reports our initial experience with the Gore Hybrid Vascular Graft (GHVG; W. L. Gore & Associates, Flagstaff, Ariz) for staged hybrid open renovisceral debranching and endovascular aneurysm repair in patients affected by thoracoabdominal aortic aneurysms and pararenal abdominal aortic aneurysms (PAAAs). Methods Between December 2012 and December 2013, we analyzed outcomes of 13 patients who underwent open surgical debranching of renovisceral vessels for thoracoabdominal aortic aneurysm and PAAAs. All patients were considered at high risk for conventional surgery. Inclusion criterion was treatment by open surgical debranching of at least one visceral artery (renal artery, superior mesenteric artery [SMA], or celiac trunk [CT]) using the GHVG. In a second step, the aortic stent graft was implanted to exclude the aneurysm. If required, parallel grafts to the remaining visceral arteries were deployed in the same procedure. One patient had a symptomatic descending thoracic aortic aneurysm and another had a ruptured PAAA. Perioperative measured outcomes were immediate technical success rate, mortality, and morbidity. Median follow-up was 24.8 months (range, 0-15; mean, 8.2; standard deviation, 4 months). Results All open surgical debranching of renovisceral vessels were completed as intended. GHVG was used to revascularize 20 visceral vessels in 13 patients with a mean of 1.54 vessels per patient. Six renal arteries (30%; 2 right and 4 left), 9 SMAs (45%), and 5 CTs (25%) were debranched. In nine of 13 (66%) patients, other renovisceral arteries were addressed with chimney/periscope, Viabahn Open Revascularization Technique, and end-to-side anastomosis. Two of 13 patients (15%) died of bowel ischemia. Neither patient had GHVG revascularization to the SMA or CT. Perioperative complications occurred in three patients (23%; 1 renal hematoma, 1 respiratory insufficiency, and 1 small-bowel ischemia related to a SMA GHVG thrombosis). At 24 months, estimated survival was 85%, and estimated primary and secondary patency were 94% and 100%, respectively. Conclusions This limited series extracted from a more consistent hybrid procedure experience showed a mortality rate similar to most recent reports. Technical feasibility and the short-term patency rate of the GHVG for renovisceral debranching during staged hybrid open and endovascular procedures were satisfactory. Use of GHVGs may represent a useful revascularization adjunct to minimize visceral ischemia in these challenging patients

Group 14 metallated 6-amino-1-azafulvene dimers : evidence for a double intramolecular nitrogen-tin interaction

The structures of group 14 C-metalated 6-amino-1-azafulvene dimers have been investigated in solution and in the solid state by NMR spectroscopy. For one of these compounds, 5,10-bis(dimethylamino)-3,8-bis(trimethylstannyl)-5H,10H-dipyrrolo[1,2-a: 1\u27,2\u27-d]-pyrazine (2c), the molecular structure in the solid state has been determined by X-ray diffractometry. The two tin centers have a distorted-trigonal-bipyramidal co-ordination geometry with the more electronegative N ligand at a pseudoaxial position, resulting in one of the longest known Sn - N interactions: 3.101 (5) A°. Moreover, the temperature-dependent 13C CP-MAS NMR spectrum of this compound shows an appreciable narrowing of the Me3Sn signal between 296 and 333 K. By comparison with nonmetalated analogs or with isomer 5c, the nonreactivity of compound 2c toward hydrolytic decomposition into corresponding 5-(trimethylstannyl)-pyrrole-2-carbaldehyde (3c) may be the result of stabilization of the dimeric form 2c by a double Sn - N interaction. In silicon and germanium analogs (2a, 2b) the Si(Ge) - N interaction is weaker

Collected world experience about the performance of the snorkel/chimney endovascular technique in the treatment of complex aortic pathologies: The PERICLES registry

Objectives: We sought to analyze the collected worldwide experience with use of snorkel/chimney endovascular aneurysm repair (EVAR) for complex abdominal aneurysm treatment. Background: EVAR has largely replaced open surgery worldwide for anatomically suitable aortic aneurysms. Lack of availability of fenestrated and branched devices has encouraged an alternative strategy utilizing parallel or snorkel/chimney grafts (ch-EVAR). Methods: Clinical and radiographic information was retrospectively reviewed and analyzed on 517 patients treated by ch-EVAR from 2008 from 2014 by prearranged defined and documented protocols. Results: A total of 119 patients in US centers and 398 in European centers were treated during the study period. US centers preferentially used Zenith stent-grafts (54.2%) and European centers Endurant stent-grafts (62.2%) for the main body component. Overall 898 chimney grafts (49.2% balloon expandable, 39.6% self-expanding covered stents, and 11.2% balloon expandable bare metal stents) were placed in 692 renal arteries, 156 superior mesenteric arteries (SMA), and 50 celiac arteries. At a mean follow-up of 17.1 months (range: 1-70 months), primary patency was 94%, with secondary patency of 95.3%. Overall survival of patients in this high-risk cohort for open repair at latest follow-up was 79%. Conclusions: This global experience represents the largest series in the ch-EVAR literature and demonstrates comparable outcomes to those in published reports of branched/fenestrated devices, suggesting the appropriateness of broader applicability and the need for continued careful surveillance. These results support ch-EVAR as a valid off-the-shelf and immediately available alternative in the treatment of complex abdominal EVAR and provide impetus for the standardization of these techniques in the future

The bicoid mRNA localization factor Exuperantia is an RNA-binding pseudonuclease.

This is the author accepted manuscript.Final version available from Nature Research via the DOI in this record.Anterior patterning in Drosophila is mediated by the localization of bicoid (bcd) mRNA at the anterior pole of the oocyte. Exuperantia (Exu) is a putative exonuclease (EXO) associated with bcd and required for its localization. We present the crystal structure of Exu, which reveals a dimeric assembly with each monomer consisting of a 3'-5' EXO-like domain and a sterile alpha motif (SAM)-like domain. The catalytic site is degenerate and inactive. Instead, the EXO-like domain mediates dimerization and RNA binding. We show that Exu binds RNA directly in vitro, that the SAM-like domain is required for RNA binding activity and that Exu binds a structured element present in the bcd 3' untranslated region with high affinity. Through structure-guided mutagenesis, we show that Exu dimerization is essential for bcd localization. Our data demonstrate that Exu is a noncanonical RNA-binding protein with EXO-SAM-like domain architecture that interacts with its target RNA as a homodimer.This project received funding from the Max Planck Gesellschaft, the European Research Council under the European Union's Seventh Framework Programme (FP7/2007-2013), ERC grant agreement no. 310957 and the Deutsche Forschungsgemeinschaft (SFB860 to K.K. and H.U., and BO3588/2-1 to F.B.)

RS12. Sustained Late Branch Patency and Low Incidence of Persistent Type Ia Endoleaks Following Snorkel/chimney EVAR Shown in the Updated PERICLES Registry

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