Incisional Negative Pressure Wound Therapy After Revascularisation Surgery in Patients with Peripheral Arterial Disease: A Randomised Trial (PICO-Vasc Study).

OBJECTIVE: This study assessed the potential benefits of using incisional negative pressure wound therapy (iNPWT) for patients undergoing revascularisation due to peripheral arterial disease. METHODS: A prospective randomised controlled trial was conducted to compare the inguinal application of iNPWT vs. standard surgical dressings. Patients were enrolled from February 2021 to November 2022. A total of 133 groin incisions were randomised (66 intervention group, 67 control group). The randomisation sequence was carried out by permuted blocks and allocation assigned by opening opaque envelopes once the revascularisation procedure had finished. Wound healing and complication rates were assessed at post-operative days 5, 14, and 30. Primary and secondary endpoints were: 30 day post-operative surgical site infection (SSI) and surgical site occurrence (SSO) rates, defined as a surgical wound complication other than a SSI. Post-operative SSI was defined according to the US Centers for Disease Control and Prevention criteria. SSO included: wound dehiscence, seroma or lymphocele, haematoma, and lymphorrhagia. The study was registered at ClinicalTrials.gov database (NCT04840576) and reported according to the CONSORT guidelines. RESULTS: iNPWT did not modify the 30 day inguinal SSI and SSO rates (16.7% vs. 20.9% and 37.9% vs. 44.8%; p = .53, relative risk [RR] 0.999, 95% confidence interval [CI] 0.52 - 1.88 and p = .42, RR 1.29, 95% CI 0.89 - 1.86, respectively). It reduced the early SSO rate (19.7% vs. 35.8%; p = .044, RR 1.45, 95% CI 1.047 - 2.013) and post-operative seroma rate (4.6% vs. 19.4%; p = .014, RR 1.73, 95% CI 1.296 - 2.397). CONCLUSION: There were no differences in SSI and SSO rates, although statistically significant reductions in early SSO rates and seroma were found in the intervention group.

Poly(caprolactone)-Based Coatings on 3D-Printed Biodegradable Implants: A Novel Strategy to Prolong Delivery of Hydrophilic Drugs.

Implantable devices are versatile and promising drug delivery systems, and their advantages are well established. Of these advantages, long-acting drug delivery is perhaps the most valuable. Hydrophilic compounds are particularly difficult to deliver for prolonged times. This work investigates the use of poly(caprolactone) (PCL)-based implant coatings as a novel strategy to prolong the delivery of hydrophilic compounds from implantable devices that have been prepared by additive manufacturing (AM). Hollow implants were prepared from poly(lactic acid) (PLA) and poly(vinyl alcohol) (PVA) using fused filament fabrication (FFF) AM and subsequently coated in a PCL-based coating. Coatings were prepared by solution-casting mixtures of differing molecular weights of PCL and poly(ethylene glycol) (PEG). Increasing the proportion of low-molecular-weight PCL up to 60% in the formulations decreased the crystallinity by over 20%, melting temperature by over 4 °C, and water contact angle by over 40°, resulting in an increased degradation rate when compared to pure high-molecular-weight PCL. Addition of 30% PEG to the formulation increased the porosity of the formulation by over 50% when compared to an equivalent PCL-only formulation. These implants demonstrated in vitro release rates for hydrophilic model compounds (methylene blue and ibuprofen sodium) ranging from 0.01 to 34.09 mg/day, depending on the drug used. The versatility of the devices produced in this work and the range of release rates achievable show great potential. Implants could be specifically developed in order to match the specific release rate required for a number of drugs for a wide range of conditions.

Evaluation of bariatric surgery patients at the emergency department of a tertiary referral hospital.

OBJECTIVE: To describe the profile of the bariatric surgery patients that were admitted to the Emergency Department (ED). METHOD: A retrospective review of the reasons why bariatric surgery patients go to our ED. We analyzed the first 30 days after the surgery. We evaluated the number and indications of admissions, the examinations ordered, and final diagnosis and destination of the patients. RESULTS: From January 2010 to July 2012, 320 patients underwent bariatric surgery at our Institution. Fifty three patients (16.6%) were admitted to the ED at least once. We found 58 admissions (1.1 admissions by patient). Patients who had duodenal switch and Roux-en-Y gastric bypass were the most representative (74%). The main indications for admission were abdominal pain (50%), and problems related to the surgical wounds (22.4%). Blood test was the most performed examination (75.9%). The most frequent final diagnosis was unspecific abdominal pain in 27 cases (46.6%), and complications of the surgical wound in 10 patients (17.2%). Nineteen patients (35.84%) were admitted to the surgical ward from the ED, and 5 of them required surgical revision (9.4%). Multivariate analyses showed that the type of surgery was the only predictor variable for the ED admission. CONCLUSIONS: Attending ED after bariatric surgery is not common, and less than a third of the patients required hospital admission. Just a small percentage of the examinations showed any pathological value. Readmission rate is very low. Surgical procedure is the only predictor for ED admission.

Recent Advances in Polymers as Matrices for Drug Delivery Applications.

Polymeric-based drug delivery systems have become versatile and valuable candidates in sectors such as pharmaceuticals, health, medicine, etc [...].

Antibacterial Aerogels-Based Membranes by Customized Colloidal Functionalization of TEMPO-Oxidized Cellulose Nanofibers Incorporating CuO.

An innovative colloidal approach is proposed here to carry out the customized functionalization of TEMPO-Oxidized Cellulose Nanofibers (CNF) incorporating non-noble inorganic nanoparticles. A heterocoagulation process is applied between the delignified CNF and as-synthetized CuO nanoparticles (CuO NPs) to formulate mixtures which are used in the preparation of aerogels with antibacterial effect, which could be used to manufacture membranes, filters, foams, etc. The involved components of formulated blending, CNF and CuO NPs, were individually obtained by using a biorefinery strategy for agricultural waste valorization, together with an optimized chemical precipitation, assisted by ultrasounds. The optimization of synthesis parameters for CuO NPs has avoided the presence of undesirable species, which usually requires later thermal treatment with associated costs. The aerogels-based structure, obtained by conventional freeze-drying, acted as 3D support for CuO NPs, providing a good dispersion within the cross-linked structure of the nanocellulose and facilitating direct contact of the antibacterial phase against undesirable microorganisms. All samples showed a positive response against Escherichia coli and Staphylococcus aureus. An increase of the antibacterial response of the aerogels, measured by agar disk diffusion test, has been observed with the increase of CuO NPs incorporated, obtaining the width of the antimicrobial "halo" (nwhalo) from 0 to 0.6 and 0.35 for S. aureus and E. coli, respectively. Furthermore, the aerogels have been able to deactivate S. aureus and E. coli in less than 5 h when the antibacterial assays have been analyzed by a broth dilution method. From CNF-50CuO samples, an overlap in the nanoparticle effect produced a decrease of the antimicrobial kinetic.

Nanocellulose from Spanish Harvesting Residues to Improve the Sustainability and Functionality of Linerboard Recycling Processes.

The hornification processes undergone by the fibers in the paper industry recycling processes lead to the loss of properties of the final products, which exhibit poor mechanical properties. Among the most promising solutions is the reinforcement of secondary fibers with cellulose nanofibers. The present work addresses two important issues: the efficient production of cellulose nanofibers from scarcely exploited agricultural wastes such as horticultural residues and vine shoots, and their application as a reinforcement agent in recycled linerboard recycling processes. The effect of the chemical composition and the pretreatment used on the nanofibrillation efficiency of the fibers was analyzed. Chemical pretreatment allowed a significantly higher nanofibrillated fraction (45−63%) than that produced by mechanical (18−38%), as well as higher specific surface areas (>430 m2/g). The application of the nanofibers as a reinforcing agent in the recycled linerboard considerably improved the mechanical properties (improvements of 15% for breaking length, 220−240% for Young's modulus and 27% for tear index), counteracting the loss of mechanical properties suffered during recycling when using chemically pretreated cellulose nanofibers from horticultural residues and vine shoots. It was concluded that this technology surpasses the mechanical reinforcement produced by conventional mechanical refining used in the industry and extends the number of recycling cycles of the products due to the non-physical modification of the fibers.

Operational Variables on the Processing of Porous Titanium Bodies by Gelation of Slurries with an Expansive Porogen.

Colloidal processing techniques, based on the suspension of powders in a liquid, are very versatile techniques to fabricate porous structures. They can provide customized pores, shapes and surfaces through the control of operational parameters, being the base of the alternative additive manufacture processes. In this work disperse and stable titanium aqueous slurries has been formulated in order to process porous materials by the incorporation of methylcellulose (MC) as a gelation agent and ammonium bicarbonate as an expansive porogen. After casting the slurries and heating at mild temperatures (60-80 °C) the methylcellulose gels and traps the gas bubbles generated by the ammonium bicarbonate decomposition to finally obtain stiff porous green structures. Using an experimental design method, the influence of the temperature as well as the concentration of gelation agent and porogen on the viscosity, apparent density and pore size distribution is analyzed by a second-order polynomial function in order to identifying the influence of the operating variables in the green titanium porous compact. After sintering at 1100 °C under high vacuum, titanium sponges with 39% of open porosity and almost no close porosity were obtained.

Capability of core-sheath polyvinyl alcohol-polycaprolactone emulsion electrospun nanofibrous scaffolds in releasing strontium ranelate for bone regeneration.

Core-sheath nanofibrous scaffolds from polyvinyl alcohol (PVA)-strontium ranelate (SrR)-Polycaprolactone (PCL) were prepared by water in oil electrospinning method. Thus, PCL (the oil phase) was used as the shell part and a mixture of PVA and SrR (the water phase) was inserted in the core. The amounts of SrR was varied from 0 to 15 wt.% Mussel-inspired dopamine-gelatin coating was done on the nanofibrous to improve their hydrophilicity and cellular attachment. The effect of the SrR content on morphology, mechanical, physicochemical, in vitro release behaviors, and biological properties as well as in vivo bone regeneration was investigated. Morphological observations revealed that continuous nanofibers with a core/shell structure were successfully obtained and the fibers diameter increased as the SrR content rose. X-ray diffraction (XRD) analysis revealed that SrR was molecularly distributed in the nanofibers and increasing the amount of the SrR decreased the crystallinity of the nanofibers. Moreover, the SrR release was regulated through the mechanism of Fickian diffusion and it was assumed as fast as possible in the samples with higher SrR content. The mesenchymal stem cell culturing showed improved cell proliferation by adding SrR and accelerating the expression of ALP, Runx2, Col I, and OCN genes. Besides, the SrR-loaded nanofibers improved bone formation of calvarial defects in a rat model as revealed by in vivo investigations.

Controlled SrR Delivery by the Incorporation of Mg Particles on Biodegradable PLA-Based Composites.

Among several ions playing a vital role in the body, Sr2+ and Mg2+ are involved in the mechanism of bone formation, making them especially useful for bone tissue engineering applications. Recently, polylactic acid (PLA)/Mg composites have emerged as a promising family of biomaterials due to their inherent biocompatibility and biodegradability properties. In these composites, polymer and bio-metal have a synergetic effect-while the PLA inhibits the Mg fast reactivity, Mg provides bioactivity to the inert polymer buffering the medium pH during degradation. Meanwhile, the typical form of administrating Sr2+ to patients is through the medication strontium ranelate (SrR), which increases the bone mineral density. Following this interesting research line, a new group of composites, which integrates Mg particles and SrR charged onto halloysite nanotubes (HNT) in a polymeric matrix, was proposed. PLA/Mg/SrR-HNT composites have been processed following a colloidal route, obtaining homogenous composites granulated and film-shaped. The drug delivery profile was evaluated in terms of in vitro lixiviation/dissolution paying special attention to the synergism of both ions release. The combination of two of the most reported ions involved in bone regeneration in the composite biomaterial may generate extra interest in bone healing applications.

[Anaemia, iron, transfusion and therapeutic alternatives. A review from a surgical perspective]. / Anemia, hierro, transfusión y alternativas terapéuticas. Revisión desde una perspectiva quirúrgica.

Anemia is very common entity or comorbidity in surgical patients. Its management involves a multidisciplinary approach with the aim of optimizing the available therapeutic resources with individualized care for each clinical situation. Rational use of blood transfusions, iron therapy (oral and intravenous), erythropoiesis stimulating agents and other therapeutic alternatives by physicians must achieve maximal benefit with minimal complications for our patients. This review article summarizes the main characteristics of anemia, iron metabolism, erythropoiesis and therapeutic alternatives from a surgical perspective in the light of present knowledge.

Effect of SrR delivery in the biomarkers of bone regeneration during the in vitro degradation of HNT/GN coatings prepared by EPD.

Among strontium-based drugs, the Strontium ranelate (SrR) is a divalent strontium salt of ranelic acid which has an overall effect over the bone microarchitecture improvement. However, some findings reveal that the SrR affects in an opposite manner to the cell proliferation and osteoblastic differentiation, based on its concentration. Consequently, its release should be controlled. The incorporation of Halloysite nanotubes (HNT) as nanocarriers of SrR, into gelatine (GN) coatings, tailors the release of this anabolic bone-forming and anti-catabolic agent to stimulate bone growth. In fact, as-prepared GN/HNT-SrR coatings release 100 % SrR in phosphate buffered saline (PBS) within 21 days, and cellular studies of the nanocomposite coatings (MTT, Alkaline Phosphatase activity (ALP) and Calcium deposition assay) confirm the valuable bio-performance of these composite coatings to enhanced bone regeneration. In the present manuscript, suspensions with HNT/GN weight ratio of 0.5 are formulated to coat AISI 316 L stainless steel foils by Electrophoretic Deposition (EPD). Zeta potential determination is used to stablish the drug loading (HNT-SrR) by electrostatic interaction, as well as to optimize the dispersion of bare HNT and HNT SrR-loaded in a GN aqueous solution. Polyethilenimnine (PEI) is used as stabilizer to buffer the suspension media, assure cargo-drug dispersion and sequential release, while the thermal gelling of the suspension controls and step up the coating formation during EPD.

Lignin and Cellulose Blends as Pharmaceutical Excipient for Tablet Manufacturing via Direct Compression.

Extensive efforts are being made to find alternative uses for lignin (LIG). In the present work the use of this biopolymer as excipient to prepare tablets was studied. For this purpose, LIG was combined with microcrystalline cellulose (MCC) and used as excipients to prepare directly compressed tablets containing a model drug, tetracycline (TC). The excipients contained different concentrations of LIG: 100%, 75%, 50%, 25% and 0% (w/w). Two different compression forces were used (two and five tonnes). When formulations were prepared using LIG as the only excipient, tablets were formed, but they showed lower densities and crushing strength than the ones obtained with only MCC or LIG/MCC blends. Moreover, tablets prepared using five tonnes of compression force showed TC releases ranging from 40% to 70% of the drug loading. On the other hand, the tablets prepared using two tonnes of compression force showed a faster and more efficient TC release, between 60% and 90%. The presence of LIG in the tablets modified significantly the release profile and the maximum amount of TC released. Finally, a DPPH (2,2-diphenyl-1-picrylhydrozyl) assay was performed to confirm that the presence of LIG provided antioxidant properties to the formulations. Accordingly, LIG has potential as a pharmaceutical excipient.

Rapidly growing vegetables as new sources for lignocellulose nanofibre isolation: Physicochemical, thermal and rheological characterisation.

Rapidly growing vegetables could be an abundant and cheap sources of lignocellulose biomass for lignocellulose nanofibre (LCNF) production. The aim of this work is to study the feasibility of using Chamaecytisus proliferus and Leucaena leucocephala for LCNF isolation by mechanical, enzymatic and TEMPO-mediated oxidation pre-treatments. Characterisation of the nanofibres shows that there are significant differences in the production of LCNF depending on the raw material and pre-treatment used. XRD and FTIR analysis show that homogenisation has a strong negative effect on the crystallinity index; however, the higher lignin content of tagasaste (10%) protects the fibre, causing a smaller decrease in crystallinity. The thermal stability of LCNF is also affected by the high lignin content in the case of tagasaste, which exhibited maximum degradation temperatures of 340-315°C, that were higher than those for leucaena (330-310°C). A strong shear thinning behaviour was observed in most of the LCNF, which revealed a great degree of interconnectivity in the gel like-network.

[Intravenous iron]. / Hierro intravenoso.

Parenteral iron is a useful and safe therapeutic measure to treat anaemia, and is a proven clinical alternative to blood transfusion. This review article summarises the main characteristics of the different formulations of parenteral iron, their advantages, indications, dosages and adverse effects. Moreover, we analyse some of the most important published articles on parenteral iron therapy in General Surgery and other surgical specialties, as well as providing information about new formulations that will soon be available.

Aortic dissection after open repair of an infrarenal aortic aneurysm.

INTRODUCTION: A case of thoracic-abdominal dissection after open surgical exclusion of an infrarenal aortic aneurysm is presented. CASE PRESENTATION: A 62-year-old woman was diagnosed with an infrarenal abdominal aortic aneurysm with a rapid increase in maximal diameter. She underwent surgery for aneurysm exclusion by an end-to-end aortoaortic bypass with Dacron collagen (Intervascular; WL Gore & Associates Inc, USA). After 15 days, she was admitted to the emergency department with intense epigastric and lumbar pain. Computed tomography angiography with contrast revealed an aortic dissection with origin in the proximal bypass anastomosis and cranial extension to the thoracic aorta. The true lumen at the level of the eighth thoracic vertebra was practically collapsed by the false lumen. The celiac trunk, and the mesenteric and renal arteries were perfused by the true lumen. After the acute phase of the aortic dissection, surgical repair was planned. Two paths of false lumen were found - one at the thoracic aorta and the second in the proximal bypass anastomosis. Surgical repair comprised two approaches. First, a Valiant Thoracic stent graft (Medtronic Inc, UK) was implanted distal from the left subclavian artery, expanding the collapsed true lumen and covering the false and dissected lumen. Second, an infrarenal Endurant abdominal stent graft (Medtronic Inc) was implanted. This second device was complemented with an aortic infrarenal extension using a Talent abdominal stent graft (Medtronic Inc) in the infrarenal aortic neck to achieve a hermetic seal. The postoperative clinical course was uneventful, and her symptoms were completely resolved in six months. CONCLUSION: Arteritis must be taken into account in young patients with high inflammatory markers. Covered stents and endoprosthetic devices seem to be effective methods to seal the dissected lumen.