Initial Experience with the Contour Device in the Treatment of Ruptured Intracranial Wide-necked Bifurcation Aneurysms: A Single-operator, Multicenter Study.

Background: Intrasaccular flow diverters are a new modality in the treatment of intracranial aneurysms. The Contour device has been designed to offer a variety of advantages over existing endovascular treatment options for wide-necked bifurcation aneurysms. There is no available literature describing its use in treating ruptured aneurysms. Objective: To assess the safety, outcome, and efficacy of the Contour device as a primary modality in treating ruptured intracranial aneurysms. Materials And Methods: A retrospective analysis of 14 aneurysms in 13 patients treated with the Contour device was studied. Data pertaining to demographics, clinical presentation on arrival, aneurysmal characteristics, and follow-up outcome was collected. The Hunt-Hess scale and modified Rankin scale were used to grade severity of clinical presentation. Results: Of the 14 aneurysms treated, one was unruptured and 13 were ruptured. Six middle cerebral artery aneurysms, six anterior communicating artery, one basilar top and one distal anterior cerebral artery aneurysm were treated. Coiling was required in two patients due to the large size of their aneurysms. No thromboembolic complications or intraoperative rupture was reported following device placement. Two patients required antiplatelet therapy for 6 weeks. A median follow-up at 3 months revealed stable placement of the device within the aneurysm and no sign of residual aneurysm or rebleed. Conclusion: Initial experience with Contour in treating ruptured aneurysms has shown favorable immediate and short-term follow-up outcome. However, long-term follow-up studies are required to assess its safety and long-term efficacy.

Enantioselective Total Synthesis of (+)-Eucophylline.

The total enantioselective synthesis of (+)-eucophylline 1 was achieved using as a key-structural motif a chiral piperidinone bearing the natural product all-carbon quaternary stereocenter. The elaboration of the latter is based on two strategies relying on the free-radical carbo-cyanation and sulfonyl-cyanation respectively of enantiopure substituted cyclopropenes and cyclobutenes. Co- or Ni-boride reduction of the nitrile functional group along with the cyclopropane and cyclobutane ring-opening then led to the formation of the chiral piperidinone ring. Further elaboration of the latter into the key 1-azabicyclo[3.3.1]nonane motif followed by its coupling with a 2-cyanoaniline allowed the formation of the tetrahydrobenzo[b][1,8]-naphthyridine skeleton of 1, which was finally accessible in 17 steps and 5.9 % overall yield from 1,1-dibromobutene.

REtrospective Multicenter INdian Study of Derivo Embolization Device (REMIND): Periprocedural Safety.

PURPOSE: The treatment of aneurysms with characteristics such as complex morphology, fusiform, blister-like, wide neck, or large size has been revolutionized with the introduction of flow diverters. Though flow diverters have several advantages over coiling, they also have certain important disadvantages such as the lack of immediate protection against rupture, the risk of ischemic stroke, the need for antiplatelet therapy, and long latency for complete effect. The Derivo Embolization Device (DED) is a second-generation self-expanding device that is claimed to be less thrombogenic than conventional devices. We retrospectively evaluated the periprocedural safety and risks associated with the DED across 5 centers in India. MATERIALS AND METHODS: This is a multicentric, retrospective, observational study of DED, conducted at 5 high volume endovascular therapy centers in India from May 2018 to June 2020. Periprocedural demographic, clinical, and angiographic data were collected from a retrospective review of patient charts. RESULTS: A total of 96 patients, including 56 (58.3%) females, aged between 16-80 years (60±12.7 years) harboring 106 aneurysms were studied. Seven (7.3%) were noted to harbor multiple aneurysms: 6 had 3 aneurysms each, while 1 patient had 5 aneurysms. The following aneurysm characteristics were noted: average size, 9.8±8.2 mm; average neck size, 6.9±8.5 mm; wide-necked (>4 mm), 63 (59.4%); giant (>25 mm), 8 (7.5%); and anterior circulation location, 98 (92.5%). Eighteen (17%) of these were ruptured. Additional balloon angioplasty was performed in 5 (5.2%) patients. Intraprocedural problems were encountered in 3 (3.1%), of which only 1 had clinical implications, the device fish-mouthing with stent thrombosis resulting in a malignant middle cerebral artery territory infarction. The modified Rankin scale at 3 months was worse in 1 patient. CONCLUSION: DED is a newer generation flow diverter stent with a low periprocedural complication rate.

A Novel Low Recurrence Surgical Approach for Medulloblastoma Excision: A Study of 58 cases.

AIM: Telovelar and transvermian approaches for medulloblastoma excision have high complication and recurrence rates. This study aims to describe a novel surgical approach to decrease such rates. MATERIAL AND METHODS: A retrospective review was performed. The novel technique was performed in similar conditions for all patients. It involves early intra-operative identification of the superior part of the floor of the fourth ventricle, so that the inferior part of the tumour can be viewed directly and excised thoroughly. Importance was given to the pattern of tumour growth and CSF flow dynamics. RESULTS: A total of 58 patients underwent this surgery between February-2006 and May-2016. Mean age was 13.2 years (Range - 6 months to 55 years). Follow-up ranged from 1 to 11 years. 49 patients (84.4%) who were under the age of 3 years were administered craniospinal radiation as well as chemotherapy, while 9 patients (15.6%) over the age of 3 years were administered only chemotherapy. Total excision could be performed in 50 cases (86.2%) and subtotal excision ( 90% excision) in 8 cases (13.8%). The tumour recurred in only 1 patient (1.72%). The complications included akinetic mutism (8.6%), meningitis (8.6%), 6th and 7th nerve paresis/palsy (5.17%), and chest infection (3.44%). Death occurred in 2 patients (3.44%), causes of death were unrelated to surgery. CONCLUSION: This study highlights the possible benefits of this novel approach to medulloblastoma excision by decreasing recurrence and complication rates and increasing rates of total excision. However, studies with large cohorts need to be performed to evaluate its efficacy.

Mechanistic Perspectives in the Regioselective Indole Addition to Unsymmetrical Silyloxyallyl Cations.

Our investigations on the reaction mechanism to account for regioselectivity on the addition of indoles to unsymmetrical silyloxyallyl cations are reported. Using both experimental and computational methods, we confirmed the significance of steric effects from the silyl ether group toward directing the inward approach of indoles, leading to nucleophilic attack at the less substituted electrophilic α'-carbon. The role of residual water toward accelerating the rate of reaction is established through stabilization of the participating silyloxyallyl cation.

Ruptured Posterior Circulation Aneurysms with Bilateral Internal Carotid Artery Occlusion: Surgical Nuance.

BACKGROUND: Craniotomy and surgical clipping is the standard modality of treatment in patients of cerebral aneurysms. However, the surgical clipping of aneurysm may pose serious difficulties in the case of a bilateral carotid artery occlusion. The endovascular treatment has shown promising results in this disease. METHODS: A retrospective study of all patients of posterior circulation aneurysms in the background of carotid occlusive disease at our department was performed. The aim of this study was to describe the clinical, radiological characteristics, and the treatment of this rare entity. RESULTS: Four patients were treated from January 2009 to October 2015. The mean age of our patients was 34 years with ages that ranged from 17 to 45 without any gender predominance. The mean period between onset of symptoms and diagnosis was 6 weeks. Angiographic localization of the disease was observed in all patients. All patients were treated by endovascular techniques. The postoperative course has been satisfactory with a complete neurological recovery in all patients. CONCLUSIONS: Rupture of posterior circulation aneurysms in the setting of bilateral internal carotid artery occlusion is extremely rare. Treatment is exclusively endovascular intervention. The functional outcome of ruptured posterior circulation aneurysms in setting of bilateral carotid occlusive disease is particularly favorable with good neurological recovery.

Coil Embolisation of Post Traumatic Giant Supraclinoid Pseudoaneurysm Presenting as Carotid Cavernous Fistula.

This report documents the occurrence, diagnosis and treatment of a 29 year-old male patient who presented with progressive swelling of the left eye with associated progressive loss of vision, three months after sustaining a closed head injury in a road traffic accident. Magnetic resonance imaging (MRI) showed a large, ill-defined lesion in the left supraclinoid and paraclinoid region with variable contrast enhancement. A four vessel Digital Subtraction Angiography (DSA) showed a large, supra-clinoid pseudoaneurysm which had ruptured inferiorly into the roof of cavernous sinus, forming direct carotid cavernous fistula (CCF) which lead to dilatation of the superior ophthalmic vein and subsequent peri-orbital oedema and chemosis of conjunctiva. Complete obliteration of the indirect CCF was achieved by coiling of the aneurysm alone. During follow up, patient reported a significant improvement in vision and follow up DSA after one year shows no recurrence with this technique.

Enantioselective Functionalization of Enamides at the ß-Carbon Center with Indoles.

We report an enantioconvergent approach for the functionalization of enamides at the ß-carbon atom, which involves a chiral Brønsted acid induced tautomerization of 2-amidoallyl into 1-amidoallyl cations. These putative reactive intermediates were produced by ionization of racemic α-hydroxy enamides with a chiral Brønsted acid and captured with substituted indoles in a highly regio- and enantioselective manner.

Visible-Light-Mediated Addition of Phenacyl Bromides onto Cyclopropenes.

Visible-light-promoted addition of α-bromoacetophenones onto the cyclopropene π-system in the presence of the fac-Ir(ppy)3 catalyst was shown to afford the corresponding 1(4H)-naphthalenones. The syn-carboarylation of the cyclopropene is followed by a cyclopropane ring opening under the basic conditions, allowing the formation of two C-C bonds and the generation of 1(4H)-naphthalenones bearing an all-carbon benzylic quaternary stereocenter.

Regioselective Functionalization of Enamides at the α-Carbon via Unsymmetrical 2-Amidoallyl Cations.

A new method to functionalize enamides via an intermediacy of unsymmetrical 2-amidoallyl cations is reported. Generated under mild Brønsted acid catalysis, these reactive species were found to undergo addition with various nucleophiles at the less substituted α-carbon to produce highly substituted enamides in high yields with complete control of regioselectivity.

Free-Radical Carbocyanation of Cyclopropenes: Stereocontrolled Access to All-Carbon Quaternary Stereocenters in Acyclic Systems.

Free-radical carbocyanation of cyclopropenes offers straightforward access to tetrasubstituted cyclopropanes in satisfying yields with moderate diastereoselectivity. The incorporation of various functional groups on the cyclopropane ring allows a subsequent base-mediated ring-opening reaction leading to functionalized acyclic systems having an all-carbon quaternary stereocenter.

Functionalization of Silyldienol Ethers at the γ-Position via 2-Silyloxypentadienyl Cations.

This report describes Brønsted acid catalyzed de novo synthesis of silyldienol ethers bearing tetrasubstituted double bonds via an intermediacy of 2-silyloxypentadienyl cations. The reactivity of these novel cationic intermediates could be modulated and harnessed toward direct nucleophilic additions regioselectively at the γ-position to produce highly functionalized silyldienol ethers with tunable control of the resulting double bond geometry.

Malignant fibrous histiocytoma of the skull base: A neurosurgical nuance.

A 69-year-old male, treated for colonic carcinoma 15 years back, presented to our services with status epilepticus. He had complaints of headache and vomiting for 7 days prior to presentation. Computed tomography and magnetic resonance imaging of the brain revealed heterogeneous, lobulated and osteolytic tumor involving middle and posterior cranial fossa. Excision of the tumor was planned in two stages. Middle fossa component was removed through right temporobasal approach. Histopathology was suggestive of malignant fibrous histiocytoma. Patient succumbed to pneumonia and septicemia in the postoperative period. Pathology, clinical features and therapeutic challenges of this clinical entity have been briefly reviewed.

Brønsted acid catalyzed α'-functionalization of silylenol ethers with indoles.

A new method which enables carbon-carbon bond formation at the α'-position of silylenol ethers by using catalytic amounts of pyridinium triflate is reported. This chemistry successfully produces, structurally challenging, highly substituted indole-containing silylenol ethers in excellent yields with complete regiocontrol, presumably through silyloxyallyl cation intermediates. Despite the use of Brønsted acid, the silylenol ether moiety does not undergo protodesilylation, thus underscoring the very mild reaction conditions.

Cooperative benzylic-oxyallylic stabilized cations: regioselective construction of α-quaternary centers in ketone-derived compounds.

We describe a novel reactivity of benzylic-stabilized oxyallyl cations towards regioselective construction of carbon quaternary centers. These synthetically useful intermediates were readily generated upon ionization of aryl substituted α-hydroxy methylenol ethers with catalytic, mild Brønsted acid. The emerging unsymmetrical oxyallyl cations were then directly captured by indoles and other nucleophiles with exquisite control of regioselectivity, predictably at the electrophilic carbon bearing the alkyl substituent to produce highly functionalized, value-added enol ethers.

One-pot asymmetric synthesis of seven-membered carbocycles cyclohepta[b]indoles via a sequential organocatalytic Michael/double Friedel-Crafts alkylation reaction.

A new method has been developed for the enantioselective synthesis of highly functionalized cyclohepta[b]indoles with high enantioselectivity (up to 96% ee). The process combines an enantioselective organocatalytic Michael addition and a highly efficient double Friedel-Crafts reaction sequence in one pot with good yields and stereoselectivity. The structures and absolute configurations of the products were confirmed by X-ray analysis.

One-pot organocatalytic enantioselective domino double-Michael reaction and Pictet-Spengler-lactamization reaction. A facile entry to the "inside yohimbane" system with five contiguous stereogenic centers.

An expedited method was developed for the enantioselective synthesis of dodecahydrobenz[a]indolo[3,2-h]quinolizine containing five contiguous stereogenic centers with high enantioselectivities (>99% ee). The methodology comprises a domino organocatalytic double Michael reaction and Pictet-Spengler-lactamization reaction. The structures and absolute configurations of the appropriate products were confirmed by X-ray analysis.

Organocatalytic asymmetric anti-selective Michael reactions of aldehydes and the sequential reduction/lactonization/Pauson-Khand reaction for the enantioselective synthesis of highly functionalized hydropentalenes.

A new method has been developed for the enantioselective synthesis of highly functionalized hydropentalenes bearing up to four stereogenic centers with high stereoselectivity (up to 99% ee). This process combines an enantioselective organocatalytic anti-selective Michael addition with a highly efficient one-pot reduction/lactonization/Pauson-Khand reaction sequence. The structures and absolute configurations of the products were confirmed by X-ray analysis.

Epidermoid cyst inside anterior sacral meningocele in an adult patient of Currarino syndrome manifesting with meningitis.

The Currarino triad, also known as the "Currarino Syndrome", is a rare complex of congenital caudal anomalies including three main features; a sacral bony deformity, anorectal malformations, and a presacral mass. We present an extremely uncommon case of Currarino syndrome in adulthood presenting with repeated episodes of meningitis. Magnetic resonance imaging of spine was suggestive of caudal regression. Cord was low lying, conus ending at L3 level with evidence of tethering at that level. A large cyst was noted in the sacral canal extending forwards in the pelvis through the widened sacral foramina on right side. She was operated through a posterior approach, via sacral laminectomy. Dura was opened in the midline, large silvery white epidermoid tumor was found completely occupying the anterior sacral meningocele. The case and relevant literature is discussed.