Salvage transorbital approach for the endovascular treatment of carotid cavernous fistulas

Purpose

Carotid cavernous fistulas (CCFs) are abnormal connections between the cavernous sinus (CS) and carotid arteries. In direct CCFs, a transarterial route is often the preferred vascular access; in case of indirect CCFs, the complex anatomy of the feeder vessels and their extra-intracranial anastomosis makes the transarterial embolization challenging and often ineffective. The aim of this study was to review our experience with the transorbital approach to treat patients affected by CCF who have already experienced an endovascular failure procedure, in order to assess this salvage technique feasibility, by analyzing possible risks and complications.

Methods

We performed a retrospective study of all patients affected by CCFs who underwent transorbital embolization between February 2017 and February 2019 at our institution.

Results

All patients (3 cases) tolerated both the retrograde embolization and the direct surgical approach with clinical improvement; the closure of the fistula was complete and verified intraoperatively by angiography. Esthetic result was acceptable in all cases with reduction of the proptosis and the intraocular pressure, and increased visual acuity. There were no complications or clinical recurrence.

Conclusion

Transorbital approach for the endovascular treatment of CCFs is a feasible and safe salvage procedure, which can find indication after other endovascular access failures.

     

Iatrogenic intracranial pseudoaneurysms: neuroradiological and therapeutical considerations, including endovascular options

Abstract Intracranial pseudoaneurysms represent a potentially fatal complication of intracranial surgery. Our purpose is to describe their neuroradiological characteristics, prognostic features and possible treatment. Eight cases of postsurgical intracranial pseudoaneurysms have been observed at our institution since 1988. Four were observed following transsphenoidal (TS) surgery and four after pterional craniotomies. Two types of iatrogenic pseudoaneurysms were observed: “fusiform”, probably due to weakening of the adventitia during surgical peeling of the tumour from the artery (three cases) and “saccular”, occurring after a more focal or complete laceration of the vessel (five cases), more often after TS surgery. A thorough preoperative neuroradiological examination may identify anatomical conditions at risk for development of this severe complication. Postoperative neuroradiological follow-up is mandatory in cases in which unusual bleeding has occurred during the perioperative period, but absence of bleeding does not exclude the possible devel opment of a pseudoaneurysm. Endovascular treatment of pseudoaneurysms represents a safe and durable procedure, specifically in those cases in which damage to the carotid siphon occurred during TS surgery.     

Melanoma cell therapy: Endothelial progenitor cells as shuttle of the MMP12 uPAR-degrading enzyme

The receptor for the urokinase-type plasminogen activator (uPAR) accounts for many features of cancer progression, and is therefore considered a target for anti-tumoral therapy. Only full length uPAR mediates tumor progression. Matrix-metallo-proteinase-12 (MMP12)-dependent uPAR cleavage results into the loss of invasion properties and angiogenesis. MMP12 can be employed in the field of “targeted therapies” as a biological drug to be delivered directly in patient''s tumor mass. Endothelial Progenitor Cells (EPCs) are selectively recruited within the tumor and could be used as cellular vehicles for delivering anti-cancer molecules. The aim of our study is to inhibit cancer progression by engeneering ECFCs, a subset of EPC, with a lentivirus encoding the anti-tumor uPAR-degrading enzyme MMP12. Ex vivo manipulated ECFCs lost the capacity to perform capillary morphogenesis and acquired the anti-tumor and anti-angiogenetic activity. In vivo MMP12-engineered ECFCs cleaved uPAR within the tumor mass and strongly inhibited tumor growth, tumor angiogenesis and development of lung metastasis.The possibility to exploit tumor homing and activity of autologous MMP12-engineered ECFCs represents a novel way to combat melanoma by a “personalized therapy”, without rejection risk.The i.v. injection of radiolabelled MMP12-ECFCs can thus provide a new theranostic approach to control melanoma progression and metastasis.     

Extracellular acidity,a “reappreciated” trait of tumor environment driving malignancy: perspectives in diagnosis and therapy

Tumors are ecosystems which develop from stem cells endowed with unlimited self-renewal capability and genetic instability, under the effects of mutagenesis and natural selection imposed by environmental changes. Abnormal vascularization, reduced lymphatic network, uncontrolled cell growth frequently associated with hypoxia, and extracellular accumulation of glucose metabolites even in the presence of an adequate oxygen level are all factors contributing to reduce pH in the extracellular space of tumors. Evidence is accumulating that acidity is associated with a poor prognosis and participates actively to tumor progression. This review addresses some of the most experimental evidences providing that acidity of tumor environment facilitates local invasiveness and metastatic dissemination, independently from hypoxia, with which acidity is often but not always associated. Clinical investigations have also shown that tumors with acidic environment are associated with resistance to chemotherapy and radiation-induced apoptosis, suppression of cytotoxic lymphocytes, and natural killer cells tumoricidal activity. Therefore, new technologies for functional and molecular imaging as well as strategies directed to target low extracellular pH and low pH-adapted tumor cells might represent important issues in oncology.     

Ring-Opening polymerization of cycloolefins with catalysts derived from ruthenium and iridium

An investigation was carried out on the polymerization of norbornene, cyclopentene and cyclooctene by the following iridium and ruthenium compounds: chlorobis(cyclooctene)iridium ( 1 ), carbonylchlorobis(cyclooctene)iridium ( 2 ), trifluoroacetatobis(cyclooctene)iridium ( 3 ), chloroiridic(IV) acid ( 4 ), dichloro(2,7-dimethylocta-2,6-diene-1,8-diyl)-ruthenium ( 5a ), and bis(trifluoroacetato)-(2,7-dimethylocta-2,6-diene-1,8-diyl)ruthenium ( 5b ). All the above catalysts were found to be very active for the polymerization of norbornene via ring-opening. Iridium catalysts were practically inactive for the polymerization of cyclopentene and cyclooctene, but gave copolymers of norbornene with cyclopentene and cyclooctene via ring-opening. The ruthenium catalysts displayed no activity for the polymerization of cyclopentene and cyclooctene, but it was found that after treatment with H₂ they became active for the polymerization of cyclopentene. The results obtained from the reaction of norbornene and aliphatic olefins suggest that the above catalysts act by metathesis. The particular features of these catalysts were examined.     

Polymerization of propadiene by some η-allylic derivatives of rhodium(III)

An investigation has been carried out on the polymerization of propadiene (allene) by several η-allylic derivatives of rhodium(III). Polymers of a high structural regularity were obtained, along with liquid oligomers, at ca. 70°C. The results are compared with those obtained using complexes of rhodium(I) as catalysts. The catalytic cycle is interpreted on the basis of the formation of a complex of rhodium(III) in the initiation and of a complex of rhodium(I) in the termination.