Fenestrated Thoracic Endovascular Aortic Repair Using Physician Modified Stent Grafts for Acute Type B Aortic Dissection with Unfavourable Landing Zone.

OBJECTIVES: The aim was to evaluate the early results of fenestrated thoracic endovascular aortic repair (fTEVAR) using physician modified stent grafts (PMSGs) to revascularise aortic branches for acute type B aortic dissection (ABAD) with unfavourable proximal landing zone. METHODS: Twenty consecutive patients who underwent fenestrated TEVAR using PMSGs between November 2015 and December 2016 were retrospectively reviewed. Pre-, intra-, and post-operative clinical data were recorded. RESULTS: The median patient age was 53 years (range, 18-83 years), and 16 of the 20 (80%) patients were men. Indications were complicated ABAD with unfavourable proximal landing zones, including inadequate proximal landing zone (n = 4), retrograde dissection extending to the left subclavian artery (LSA) (n = 13), and retrograde haematoma involving the LSA (n = 3). Twenty PMSGs (Medtronic Valiant stent grafts, n = 4; Relay thoracic stent grafts, n = 10; Ankura thoracic stent grafts, n = 6) were deployed. One LSA fenestration was created in 19 patients, and one LSA fenestration combined with a left common carotid artery (LCCA) scallop was created in one patient. Branch stents consist of a covered stent for the LSA (n = 7), an uncovered stent for the LSA (n = 14), and an uncovered stent for the LCCA (n = 1). The median duration for stent graft modifications was 40 min (range 30-60 min). The mean interval between symptom onset and treatment was 5 ± 3 days (range, 1-10 days). The initial technical success rate was 90% (18 of 20). Partial coverage of the LCCA in one patient resolved after uncovered chimney stent implantation in the LCCA. Type III endoleak between the LSA covered stent and the PMSG occurred in this patient 1 week post fTEVAR and resolved after re-intervention with deployment of an Amplatzer occluder device across the site of the leak. A chimney stent was deployed to solve the misalignment of the LSA in another patient. The mean operation time was 101 ± 48 min, and fluoroscopy time was 24 ± 16 min. There were no in hospital deaths and no peri-operative neurological complications. The median length of stay was 9 ± 6 days (range, 5-26 days). One patient had a left brachial artery (LBA) pseudoaneurysm at the puncture site that required open repair. One patient presented renal deterioration post-operatively and recovered uneventfully after conservative therapy. All patients survived at a mean follow-up of 6.95 months (range, 2-14 months). During follow-up, no post-operative complications occurred and all target vessels remained patent. No fenestration related Type I or III endoleaks were observed. CONCLUSIONS: fTEVAR using PMSGs may be a viable alternative for patients who present with ABAD without healthy proximal landing zones and who are unable to wait for a custom made fenestrated device.

Clinical features and prognosis of patients with acute aortic dissection in China.

Objective To evaluate the clinical features, risk factors, and prognostic significance of different Stanford types of acute aortic dissection (AAD). Methods We retrospectively analyzed the clinical data and prognostic predictors in 105 patients with AAD (37 with Stanford type A and 68 with Stanford type B) at Tianjin Medical University General Hospital and Tianjin 4th Central Hospital from January 2014 to November 2015. Results Patients with Marfan syndrome and bicuspid aortic valve constituted 24.3% and 8.1%, respectively, of patients with type A AAD; these proportions were significantly higher than those of patients with type B AAD (7.4% and 0.0%, respectively). The proportion of iatrogenic causes of type A AAD (8.1%) was significantly higher than that of type B AAD (0.0%). Computed tomography angiography showed that the proportion of involvement of the aortic arch and pericardial effusion (86.5% and 18.9%, respectively) in patients with type A AAD were higher than those in patients with type B AAD (23.5% and 5.9%, respectively). Endovascular treatment was performed in a higher proportion of patients with type B than A AAD (70.6% vs. 5.4%, respectively). Conclusion Systolic blood pressure, pericardial effusion, periaortic hematoma, conservative treatment, and open surgery were independent predictors of increased mortality in patients with AAD.

Quantum dot conjugates for targeted silencing of bcr/abl gene by RNA interference in human myelogenous leukemia K562 cells.

Quantum dots (QDs) have been receiving a lot of attention recently for their unique fluorescence properties that can be used in drug discovery and bioimaging applications. We have in this article focused particularly on QDs and used it as a transfection vector as well as a fluorescence label for the RNA interference research. The siRNAs were designed to knock down the bcr/abl oncogene in leukaemia K562 cells. EDAC used as a cross-linker, COOH-functionalized QDs were conjugated with NH2-modified siRNAs to generate QD-siRNA conjugates. We also demonstrated their application to the K562 cells. Using such constructs, the delivery and transfection of siRNAs could be monitored by the presence of fluorescent QDs in the conjugates. QDs not only exhibited superior photostability for labeling cells but also worked as a good vector that remarkably increased the transfection efficiency of siRNAs into the cells. Cell proliferation was examined by the MTT assay and cell apoptosis by FACS. Our data have shown that the QD-siRNA conjugates could efficiently inhibit the viability of K562 cells and induced their apoptosis. In summary, QDs can be considered strong tools for the functional analysis of RNAi.