C-C coupling between trinitrothiophenes and triaminobenzenes: zwitterionic intermediates and new all-conjugated structures.

The reactions of 1,3,5-triaminobenzene derivatives with 2,3,4-trinitrothiophene and 2-bromo-3,4,5-trinitrothiophene gave new all-conjugated compounds bearing both an electron-withdrawing and an electron-donor moiety on the same unit. The reactions with 2,3,4-trinitrothiophene offered evidence, by NMR spectroscopy at low temperature, of the formation of new labile Wheland-Meisenheimer intermediates whereas at room temperature stable unexpected products derived from the attack of the nucleophile at C-4 with replacement of the nitro group were isolated. Their formation caused, in turn, the obtainment of a salt between 1-nitroso-2,4,6-triaminobenzenes and 2,4-dinitrothiophen-3-ol. The reactions with 2-bromo-3,4,5-trinitrothiophene produced in good yields the SNAr substitution product with the displacement of the bromide. All the new coupling products obtained are of applicative interest, considering the increasing concern for highly conjugated π-systems in solar energy conversion or optoelectronic devices.

Value and limitations of chimney grafts to treat arch lesions.

AIM: The endovascular debranching with chimney stents provides a minimally invasive alternative to open surgery with readily available devices and has extended the option of endoluminal therapy into the realm of the aortic arch. But a critical observation at the use of this technique at the aortic arch is important and necessary because of the lack of long-term results and long term patency of the stents. Our study aims to review the results of chimney grafts to treat arch lesions. METHODS: A systematic health database search was performed in December 2014 according to the Prisma Guidelines. Papers were sought through a meticulous search of the MEDLINE database (National Library of Medicine, Bethesda, MA) using the Pubmed search engine. RESULTS: Twenty-two articles were eligible for detailed analysis and data extraction. A total of 182 patients underwent chimney techniques during TEVAR (Thoracic Endovascular Aneurysm Repair). A total of 217 chimney grafts were implanted: 36 to the IA, 1 to the RCCA, 91 to the LCCA and 89 to the LSA. The type of stent-graft used for TEVAR was described in 132 patients. The type and name of chimney graft was described in 126 patients. In 53 patients information was limited to the type. Primary technical success, defined as a complete chimney procedure was achieved in 171 patients (98%). In 8 patients it was not clearly reported. The overall stroke rate was 5.3%. The overall endoleak rate, in those papers were it was clearly reported, was 18.4% (31 patients); 23(13,6%) patients developed a type IA endoleak, 1 patient (0.6%) developed type IB endoleak and 7 patients (4.1%) developed a type II endoleak CONCLUSION: The total endovascular aortic arch debranching technique represent a good option to treat high-risk patients, because it dramatically reduces the aggressiveness of the procedure in the arch. Many concerns are still present, mainly related to durability and material interaction during time. Long-term follow-up is exceptionally important in light of the interactions of the stents, the thoracic endograft, the aortic arch, and every variation in systolic and diastolic pressure. Actually this technique has acceptable short and mid-term results. Long term data are available just from a very small number of patients and more data from a wider number are needed in order to embrace this method as a safe one.

Case report of an endovascular repair of a residual type A dissection using a not CE not FDA-approved Najuta thoracic stent graft system.

This report describes an endovascular repair of a residual type A dissection using a medical device that is not marked by european conformity (CE) or Food and Drug Administration (FDA).The patient underwent ascending aortic surgery for acute type A dissection. The 2-year angio-computed tomography demonstrated patency of the residual false lumen with evolution into a 6 cm aneurysm, the extension of the dissection from the aortic arch to the aortic bifurcation with thrombosis of the right common iliac artery. There was no CE- or FDA-marked medical device indicated for this case or any other acceptable therapeutic alternative.We used the Najuta thoracic stent graft and successfully handled the pathology in a multiple-phase treatment.Technology is evolving with specific grafts for the ascending and fenestrated grafts for the aortic arch. In this single case the Najuta endograft, in spite of the periprocedural problems, was a valid therapeutic option.

Endovascular treatment of extracranial vertebral artery aneurysm and aberrant right subclavian artery aneurysm.

We report an endovascular approach that used to treat a symptomatic extracranial vertebral artery aneurysm associated to an asymptomatic aberrant right subclavian artery aneurysm. A 54-year-old man presented with neck pain, vertigo and loss of balance. The computed tomography (CT) scan demonstrated a left extracranial vertebral artery aneurysm that compressed and eroded the C5 vertebra associated to an aberrant right subclavian artery aneurysm. Endovascular exclusion of the vertebral aneurysm using a covered stent and a hybrid treatment of the aberrant subclavian artery aneurysm were performed. The 13th month follow-up CT scan confirmed the stent-grafts and supra-aortic vessels patency. The endovascular treatment represents a good option for these complex pathologies with excellent immediate results, reduces the complication rate and the hospital stay if compared to open repair. Long-term follow-up is necessary. To our knowledge this is a unique case in the literature.

Percutaneous endovascular aneurysm repair with the ultra-low profile Ovation Abdominal Stent-Graft System.

AIM: Aim of the study was to report our single-center experience of the ultra-low profile OvationTM Abdominal Stent-Graft System with totally percutaneous endovascular aneurysm repair (PEVAR). METHODS: Between December 2010 and March 2013 we electively treated 35 patients (male: 89%, mean age: 73±7 years) with abdominal aortic aneurysm (AAA) using bilateral PEVAR with the OvationTM endograft. Most (77%) cases were characterized by challenging femoral artery anatomy. Patients returned for follow-up visits at 1, 3, 6 months and annually thereafter. RESULTS: Technical success was 97.1%. One type Ia endoleak was identified on final angiography, which was treated with an extension cuff. No groin complications were observed, including lymphocele, hematoma, pseudoaneurysm, dehiscence, or wound infection. Mean follow-up was 10 months (range 1-24 months). No death was registered. One type Ia endoleak was identified at the 12-month follow-up, which resolved with placement of a Palmaz balloon-expandible stent. No type II, III, or IV endoleaks were identified. No migration, AAA enlargement, AAA rupture, or conversion to open surgery was reported. Two patients (5.7%) developed monolateral iliac limb occlusion at 58 and 72 days of follow-up, respectively. In one case a limb kinking was observed and treated with iliac kissing stent. The other limb occlusion was due to external iliac artery severe stenosis and was treated with thrombolysis and iliac artery stenting. CONCLUSION: PEVAR with the OvationTM endograft is feasible and safe in patients with unfavorable anatomy.

Endovascular stenting of the ascending aorta for type A aortic dissections in patients at high risk for open surgery.

BACKGROUND: Open repair is the gold standard for type A aortic dissection (TAAD). Endovascular option has been proposed in very limited and selected TAAD patients. We report our experience with endovascular TAAD repair. METHODS: Inclusion criteria were: (1) entry tear in the ascending aorta; (2) proximal landing zone of at least 2 cm; (3) distance between entry tear and brachio-cephalic trunk of at least 0.5 cm; (4) no signs of cardiac tamponade or severe aortic regurgitation and (5) no signs of aortic branches ischaemia. Patients with cardiac revascularisation from ascending aorta were excluded. RESULTS: From April 2009 to June 2012, 37 patients with TAAD were admitted to our hospital. As many as 28 underwent surgical repair and 9 were considered at high surgical risk in a multidisciplinary meeting. Four met our inclusion criteria for an endovascular approach. Two of them had previous ascending aortic repair for TAAD and one had aortic valve replacement. Technical success was achieved in 100% of the patients. No mortality was registered during a median follow-up of 15 months (range 4-39 months), no migration of the graft and complete false lumen thrombosis of the ascending aorta in three patients. CONCLUSION: Endovascular treatment of TAAD is challenging but feasible in a selected subset of patients. Further research remains mandatory.