291 research outputs found

    Sustainable Recycling of Insoluble Rust Waste for the Synthesis of Iron-Containing Perovskite-Type Catalysts

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    Insoluble rust waste from the scraping of rusted iron-containing materials represents a cheap, eco-friendly, and available source of iron. LaFeO3 perovskite-type powders were successfully prepared by solution combustion synthesis using rust waste from an electricity transmission tower manufacturer. Solution combustion synthesis enabled introduction of this insoluble iron precursor directly into the final product, bypassing complex extraction procedures. Catalytic activity in the propylene oxidation of the waste-derived LaFeO3 with stoichiometric Fe/La ratio was almost identical to the commercial iron nitrate-derived LaFeO3 , thus demonstrating the viability of this recycling solution. The amount of waste iron precursor was varied and its effect on the powder properties was investigated. A lesser stoichiometric amount of precursor produced a LaFeO3 -La2O3 binary system, whereas a higher stoichiometric amount led to a LaFeO3 -Fe2O3 binary system. Catalytic activity of iron-rich compositions in the propylene oxidation was only slightly lower than the stoichiometric one, whereas iron-poor compositions were much less active. This eco-friendly methodology can be easily extended to other iron perovskites with different chemical compositions and to other iron-containing compounds

    Cost analysis in oral cavity and oropharyngeal reconstructions with microvascular and pedicled flaps.

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    Reconstructive surgery of the head and neck region has undergone tremendous advancement over the past three decades, and the success rate of free tissue transfers has risen to greater than 95\%. It must always be considered that not all patients are ideal candidates for free flap reconstruction, and also that not every defect strictly requires a free flap transfer to achieve good functional results. At our institution, free flap reconstruction is first choice, although we use pedicled alternative flaps for most weak patients suffering from severe comorbidities, and for pretreated patients presenting a second primary or a recurrent cancer. From July 2006 to May 2010, 54 consecutive patients underwent soft tissue reconstruction of oral cavity and oropharyngeal defects. We divided the cohort in three groups: Group 1 (G1): 16 patients in good general conditions that received free radial forearm flap reconstruction; Group 2 (G2): 18 high-risk patients that received a reconstruction with infrahyoid flap; Group 3 (G3): 20 patients that received temporal flap (10 cases) or pectoral flap (10 cases) reconstruction. We must highlight that pedicled alternative flaps were used in elderly, unfavourable and weak patients, where usually the medical costs tend to rise rather than decrease. We compared the healthcare costs of the three groups, calculating real costs in each group from review of medical records and operating room registers, and calculating the corresponding DRG system reimbursement. For real costs, we found a statistically significant difference among groups: in G1 the average total cost per patient was € 22,924, in G2 it was € 18,037 and in G3 was € 19,872 (p = 0.043). The amount of the refund, based on the DRG system, was € 7,650 per patient, independently of the type of surgery. Our analysis shows that the use of alternative non-microvascular techniques, in high-risk patients, is functionally and oncologically sound, and can even produce a cost savings. In particular, the infrahyoid flap (G2) ensures excellent functional results, accompanied by the best economic savings in the worst group of patients. Our data reflect a large disconnection between the DRG system and actual treatment costs.Abstract available from the publisher

    Effectiveness and pitfalls of elective neck dissection in N0 laryngeal cancer

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    The aim of the study was to evaluate the efficacy and potential pitfalls of selective neck dissection of levels II-IV in controlling occult neck disease in clinically negative neck (cN0) of patients with laryngeal squamous cell carcinoma. Charts of 96 consecutive cN0 laryngeal cancer patients undergoing 122 neck dissections at the University of Florence from January 2000 to December 2004 were reviewed. N0 neck was defined with contrast enhanced computed tomography scan. Occult neck disease rate was 12.5%, involvement per level was: 47.6% at level II, 38.1% at level III, 9.5% at level IV. Six patients developed neck recurrence (6.25%) after selective neck dissection of levels II-IV within the first two years after treatment. In conclusion, selective neck dissection of levels II-IV is effective in N0 laryngeal squamous cell carcinoma; posterior limits of surgical resection are missing therefore if post-operative radiation is required, the field should be extended beyond the dissected levels. The low incidence of occult neck disease indicates the need to refine treatment strategy, restricting elective neck dissection only to supraglottic T2 with epilaryngeal involvement, supraglottic T3-4 and glottic T4 tumours, and considering a "wait and see" protocol implemented with imaging techniques and cytological assessments for other lesions

    Tobacco exposure and complications in conservative laryngeal surgery.

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    Smoking is an important risk factor in the development of head and neck cancer. However, little is known about its effects on postoperative complications in head and neck cancer surgery. We performed a retrospective analysis on 535 consecutive laryngeal cancer patients submitted to open partial laryngectomy at the Otolaryngology-Head and Neck Surgery Department of Florence University to evaluate a possible correlation between smoking and surgical complications. Patients were grouped in non smokers and smokers and evaluated for airway, swallowing, local and fistula complications by multivariate analysis: 507 (95\%) patients were smokers, 69\% presented supraglottic, 30\% glottic and 1\% transglottic cancer. The most common operation was supraglottic horizontal laryngectomy in 58\%, followed by supracricoid partial laryngectomy in 27\% and frontolateral hemilaryngectomy in 15\% of cases. The incidence of overall complications was 30\%, airway complications representing the most frequent (14\%), followed by swallowing (7\%), local (6\%) and fistula complications (3\%). Smokers developed more local complications (p = 0.05, univariate, p = 0.04, multivariate analysis) and pharyngocutaneous fistula (p = 0.01, univariate, p = 0.03, multivariate analysis)

    Spontaneous internal carotid artery rupture during neck dissection in osteogenesis imperfecta patient.

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    Several connective tissue disorders are associated with vascular wall abnormalities, including spontaneous dissection of the cervical arteries. Osteogenesis imperfecta (OI) is a hereditary disorder, with rare neurovascular complications, which potentially lead to life-threatening events.We presented a case of spontaneous internal carotid artery (ICA) rupture that occurred in a 52-year-old-woman, suffering from OI type I, and who underwent a bilateral modified radical neck dissection (mRND) plus total thyroidectomy for a T4aN1b thyroid cancer. During mRND, an ICA's spontaneous rupture occurred.Histopathologic report suggested a structural defect of the arterial wall without cancer infiltration. The patient did not experience any neurologic complications.Head and neck surgeons have to be aware about early clinical recognition of possible cervical vascular abnormalities, in patients with connective tissue disorders, potentially responsible for dramatic vascular rupture during cervical surgical procedures

    Infrahyoid fascio-myocutaneous flap as an alternative to free radial forearm flap in head and neck reconstruction.

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    The use of microvascular free flaps is currently the favored method for the reconstruction of defects after resection of head and neck cancer. The flap most commonly used for head and neck reconstruction is the free radial forearm flap, but the less popular infrahyoid flap represents a good alternative in selected cases. This flap has proven to be helpful in the reconstruction of a wide range of moderate-sized head and neck defects.We reviewed a series of 13 patients with defects resulting from cancer of the head and neck, who underwent infrahyoid flap reconstruction as an alternative to free radial forearm flap. The series includes 12 squamous cell carcinomas arising from the oral cavity and oropharynx, and 1 Merkel cell carcinoma of the submental skin. In the harvesting of the flap, the technical modifications recently suggested by Dolivet et al were used in all cases. Furthermore, another technical change has been introduced so creating a new infrahyoid facio-myocutaneous flap (IHFMCF). The surgical technique is described in detail.No total or partial flap necrosis was experienced. All reconstructions healed quickly without wound complications and with good functional results. The healing process in the donor site was excellent in every case with good aesthetic results.The IHFMCF is a versatile, reliable, and convenient flap suitable for repairing small and medium-sized defects of the oral cavity and oropharynx and obviates the need for a microvascular reconstruction

    Palliative combined treatment for unresectable cutaneous basosquamous cell carcinoma of the head and neck.

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    A case is presented of a patient with a skin basosquamous cell carcinoma of the frontal region infiltrating the cerebral tissue and with a widespread unresectable regional metastatic ulceration of the left parotid region. The patient underwent combined palliative treatment: surgical coverage of the ulceration by means of a pectoralis mayor flap transposition and radiotherapy. After 18 months of follow-up, no signs of tumour progression were noted, the patient is currently free from pain, no increase in trismus was seen, and a slight gain in weight was recorded. Unresectable cancer is mainly treated by concurrent chemoradiation; radiotherapy, however, is contraindicated in deep neoplastic ulcerations with exposure of large vessels. The data reported suggest that surgical coverage of an unresectable neoplastic ulcer is feasible, and combined with early administration of radiation permits a palliative approach in an otherwise untreatable condition.Abstract available from the publisher

    Oral cavity reconstruction with the masseter flap.

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    The purpose of this report is to highlight how an unusual, outdated, unpopular and overlooked reconstructive method such as the masseter flap can be a reliable, straightforward and effective solution for oral reconstruction in selected cases. We report the transposition of the masseter crossover flap in two previously pre-treated patients presenting a second primary oral squamous cell carcinoma; excellent functional results with satisfactory cosmetic appearance were obtained in both cases. In the literature, only 60 cases of oral cavity and oropharyngeal reconstructions using the masseter flap have been reported. The possible clinical utility of this flap, even in modern head and neck reconstructive surgery, is presented and discussed. We believe that the masseter flap should enter in the armamentarium of every head and neck surgeon and be kept in mind as a possible solution since it provides an elegant and extremely simple procedure in suboptimal cases for microvascular reconstruction
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