Giant cavernous aneurysms occluded by aneurysmal thrombosis, calcification, parent artery occlusion: A case report and review of literature.

BACKGROUND: Patients with giant intracranial aneurysms (GIAs) are at a high risk of rupture, morbidity, and mortality even after surgical or endovascular treatment. We described a case of a spontaneously occluded GIA secondary to gradual growth of the GIA, continuously progressed aneurysmal thrombosis, complete aneurysmal calcification and complete occlusion of the parent artery-the right internal carotid artery (RICA). CASE SUMMARY: A 72-year-old female patient complained of sudden pain in her right eye upon admission to our hospital. She had been diagnosed with a GIA [30 mm (axial) × 38 mm (coronal) × 28 mm (sagittal)] containing an aneurysmal thrombus located in the cavernous sinus segment of RICA diagnosed by magnetic resonance imaging (MRI), enhanced MRI, and magnetic resonance angiography more than 14 years ago. Later, with slow growth of the cavernous carotid GIA, aneurysmal thrombosis progressed continuously, spontaneous occlusion of the RICA, complete aneurysmal calcification, and occlusion of the GIA occurred gradually. She had no history of subarachnoid hemorrhage but missed the chance for endovascular therapy at an early stage. As a result, she was left with severe permanent sequelae from the injuries to the right cranial nerves II, III, IV, V1/V2, and VI. CONCLUSION: The risk of rupture of the cavernous carotid GIAs was relatively low and possibly further be reduced by the stasis flow and spontaneous occlusion of the parent artery internal carotid artery (ICA) induced by the mass effect of the cavernous carotid GIAs and the extremely rare aneurysmal calcification. However, nowadays, it is advisable to recommend early endovascular treatment for the cavernous carotid GIAs to prevent injuries to the surrounding intracranial nerves and occlusion of the ICA, mainly caused by the mass effect of the cavernous carotid GIAs.

Secondary hierarchical complexity in double-stranded cluster helicates covered by NNNNN type pincer ligands.

We designed and synthesized a new tripyridine dipyrrolide pincer ligand, which could be doubly deprotonated to provide five-nitrogen-donor sites and then utilized to prepare a subnanometric chiral silver cluster. The cluster belongs to an S4 point group and shows a double-stranded helicate. DFT calculations were performed to analyze the electronic structure of the cluster. Interestingly, through hierarchical intercluster interactions, the cluster helicates evolve into complex secondary structures including a right-handed helix and a folded sheet, both of which are reminiscent of secondary structures of proteins, i.e., an α-helix and an antiparallel ß-sheet.