Comparison of polyvinyl alcohol copolymer with detachable balloons for the embolisation of direct carotid cavernous fistula: a single-centre experience.

OBJECTIVES: To characterise the safety, efficacy and cost of direct carotid-cavernous fistula (CCF) treatment using polyvinyl alcohol copolymer or detachable balloons. METHODS: We reviewed retrospectively patients with direct CCFs treated with either a detachable balloon or polyvinyl alcohol copolymer at our hospital from 2005 to 2015 and identified 94 patients with 105 CCFs. All patients had follow-up angiograms. The CCF occlusion rate, procedure complication rate, treatment expense and operation time were recorded. RESULTS: With a mean of 5.4 months of angiographic follow-up, the complete occlusion rate and recanalisation rate of the polyvinyl alcohol copolymer group was not significantly different from that of the detachable balloon group. The treatment expense was much higher and the operation time was much longer in the polyvinyl alcohol copolymer group than the detachable balloon group (P < 0.001). CONCLUSIONS: Embolisation of CCF with polyvinyl alcohol copolymer is as safe and effective as detachable balloon but has a much higher cost and longer operation time. KEY POINTS: • Carotid-cavernous fistula results from a damaged carotid artery. • Detachable balloons have been used with success for many years. • Some reported excellent outcomes after embolisation with polyvinyl alcohol copolymer. • Treatment expense is much higher in the polyvinyl alcohol copolymer group.

Preliminary clinical assessment of polyvinyl alcohol-tetrahydroxyborate hydrogels as potential topical formulations for local anesthesia of lacerations.

OBJECTIVES: The aim of this study was to assess a novel semisolid material as a potential topical drug delivery system for acute laceration. The objectives were to correlate physical characterization data using rheologic studies and to compare with clinical assessment of performance in an emergency department (ED). METHODS: Polyvinyl alcohol (PVA) hydrogels, cross-linked using tetrahydroxyborate (THB), were characterized using texture profile analysis. Formulation samples were applied to acute lacerations presented to the ED and factors, such as in vivo residency time and cohesive removal, were assessed. RESULTS: Viscosity was shown to be related to mechanical characteristics, whereas adhesiveness depended on the THB concentration. Residence in, and clean removal from, lacerations was evaluated on 29 patients. Formulation F3 (10.0% PVA, 2.5% w/w THB) displayed the most appropriate characteristics for clinical use by scoring highest in qualitative assessments. Other formulations exhibited difficulties in application and removal due to excessive adhesiveness. The release of a model local anesthetic drug was proportional to the concentration of drug incorporated, but was not substantially affected by small changes in the formulation constituents. CONCLUSIONS: Using a combination of pharmaceutical evaluation and clinical assessment, it was shown that cross-linked PVA semisolids are a suitable formulation for drug administration to acute lacerations, with potential for induction of anesthesia prior to wound repair.