Effect of Hyaluronic Acid and Pluronic-F68 on the Surface Properties of Foam as a Delivery System for Polidocanol in Sclerotherapy.

The use of foams to deliver bioactive agents and drugs is increasing in pharmaceutics. One example is the use of foam as a delivery system for polidocanol (POL) in sclerotherapy, with the addition of bioactive compounds to improve the delivery system being a current subject of study. This work shows the influence of two bioactive additives on the structure and stability of POL foam: hyaluronic acid (HA) and Pluronic-F68 (F68). HA is a natural non-surface-active biopolymer present in the extracellular matrix while F68 is a surface-active poloxamer that is biocompatible with plasma-derived fluids. Both additives increase the bulk viscosity of the sample, improving foam stability. However, HA doubled and F68 quadruplicated the foam half lifetime of POL. HA reduced the size and polydispersity of the bubble size distribution and increased the surface elasticity with respect to POL. Both facts have a positive impact in terms of foam stability. F68 also altered bubble structure and increased surface elasticity, again contributing to the enhancement of foam stability. The surface characterization of these systems is important, as in foam sclerotherapy it is crucial to assure the presence of POL at the surface of the bubbles in order to deliver the sclerosant agent in the target vein.

Revascularización infragenicular con aloinjerto arterial criopreservado / Below-the-knee revascularisation with a cryopreserved arterial allograft

Objetivo. Valorar los resultados preliminares obtenidos en nuestro servicio en revascularización infragenicular con aloinjerto arterial criopreservado (AAC) en caso de ausencia de injerto autólogo. Pacientes y métodos. Entre junio de 2001 y agosto de 2005, realizamos ocho procedimientos en ocho pacientes (dos mujeres y seis varones) con una edad media de 73 años (rango: 55-82 años). En dos casos los injertos fueron compuestos AAC-segmento venoso residual. En otros dos casos se emplearon dos AAC. Las indicaciones para intervenir fueron isquemia crítica (siete) e infección protésica (uno). En cinco casos había al menos una revascularización previa. Los AAC se obtuvieron de donante cadáver. La anastomosis distal se realizó sobre poplítea (dos), arteria tibial (cinco) o arteria perimaleolar (uno). En todos los casos se descartó la existencia de segmento venoso autólogo suficiente mediante eco-Doppler. El seguimiento fue clínico y ecográfico. Resultados. Durante el primer mes se produjeron una rotura de AAC y una trombosis precoz, ambas con reparación satisfactoria. Durante un seguimiento medio de 14 meses (rango: 1-46 meses), cuatro injertos sufrieron un fallo primario: dos trombosis, una estenosis y una degeneración aneurismática. Ello derivó en una amputación mayor, una trombectomía y una sustitución del injerto. La permeabilidad global fue del 75% (6/8) y la salvación de extremidad del 87,5% (7/8). Una paciente falleció a los cuatro y otro a los 46 meses, ambos con injerto permeable. Conclusión. A pesar de ser una serie pequeña, los AAC pueden ser una opción en las revascularizaciones infrageniculares en caso de ausencia de injerto autólogo suficiente para ésta

Aim. To assess our preliminary results of infrapopliteal bypass grafting performed with cryopreserved arterial allografts (CAA) in case of absence of alternate autologous veins. Patients and methods. Between June 2001 and August 2005, eight procedures were performed in eight patients (two female and six male), with a mean age of 73 years (range: 55-82 years). In two cases a composite CAA-residual vein bypass was realized. In another two cases two segments of CAA were used. Indications for operation were critical leg ischaemia in seven cases and infection in the other. In five cases, there was at least one previous revascularization on the same limb. CAA were obtained from cadaveric donors in a multidisciplinary organs explant program. Distal anastomosis was to the bellow knee popliteal artery in two cases, to a tibial artery in five cases and to a perimaleolar artery in one case. In all cases we searched for the existence of alternate autologous vein with Doppler scan. The surveillance was clinic and with Doppler scan. Results. During follow-up (mean: 14 months; range: 1-46 months), four grafts failed. These failures were two thrombosis, one stenosis and one aneurysmatic degradation. Due to this, a major amputation and a CAA-prosthetic replacement were performed. The global patency rate was 75% (6/8) and the limb salvage rate was 87.5% (7/8). One patient died at four month after procedure, with patent bypass. Conclusion. Even knowing that this is a small group of patients, we think CAA could be an option in infrapopliteal bypass surgery in case of absence of autologous vein