37 research outputs found
Treatment of post-resuscitation cicatricial tracheal stenosis after suffering severe COVID-19 associated pneumonia: A report of 11 cases
No full textObjective: Despite the full range of anti-epidemic measures, the rapidly mutating SARS-CoV-2 continues to spread worldwide, causing respiratory and pulmonary pathologies. So far, there are no generally accepted clinical guidelines for treating post-resuscitation cicatricial tracheal stenosis (CTS) after COVID-19 associated pneumonia. This study sought to evaluate the clinical outcomes of surgical treatment and perioperative management of patients who developed CTS. Methods: A cohort of eleven working-age patients (eight women and three men) with CTS were treated surgically after undergoing invasive artificial ventilation ranging from 5 to 130 days. Along with scarring changes in the tracheal wall, tracheomalacia was noted in five (55.6%) individuals. Circumferential tracheal resection (CTR) with subsequent anastomosis, tracheolaryngeal reconstruction, and endoscopic methods were modalities used to restore airway patency. In cases of CTR combined with tracheoesophageal fistula (TEF), CTR was performed with dissection of the pathological stoma. Results: In 80% of the cases, CTS was located at the larynx and cervical trachea level. All patients managed to restore adequate breathing through their natural airways with preserved vocal function. No lethal outcomes were observed in the post-op period. Patient outcomes after CTR were considered excellent in nine patients who continued an active lifestyle and went straight to work. One patient, after laryngotracheoplasty and tracheal stenting, is at the final stage of treatment. Conclusions: These patients are at high risk of developing CTS and require dynamic monitoring. CTR allows early rehabilitation of patients with the best functional outcome. If CTR is contraindicated, laryngotracheoplasty also allows adequate debridement of the tracheobronchial tree and respiratory support
Performing a radical trachelectomy with uterine transposition in a patient with stage IB2 cervical cancer: A case report
No full textWe describe a case of a woman with invasive IB2 cervical cancer who desired to maintain fertility and required complex treatment. The suggested surgical approach with uterine transposition improves the existing radical trachelectomy procedure. Oncologic outcomes are encouraging, and no perioperative complications were noted. This report may represent a “milestone” in fertility-sparing surgeries, supporting the feasibility and safety of the opted method in stage IB2 cervical cancer with tumors about or smaller than 2 cm
The equilibrium of martensite shear stress at phase transitions in TiNi-based alloy
Get PDFThermoelastic martensitic transformations play a fundamental role in the shape memory effect and related phenomena. Owing to their unique crystallographic and thermomechanical behaviour, martensitic transformations have generated considerable research in the areas of crystallography, thermodynamics and mechanical behaviour. In the area of thermodynamics a theoretical approach is now added which provides the basis for thermoelastic behaviour through consideration of the Gibbs energy change. In this paper, the interrelation of internal elastic stresses and martensite shear stresses in phase transitions has been defined. A thermoelastic stress equilibrium equation for a wide range of martensitic transformation temperatures has been presented. On the basis of the calculations made, an estimation of dislocation defects formation energy for the TiNi-based alloy has been made. For TiNi-based composition made of TN-10 brand alloy, commercially produced for medical goals, the energy of vacancy formation is about 0.06 kcal/mol. The study and calculations are shown to make clear, using a new approach, the considering of phase transitions in terms of external and internal stresses
Combination of solid and porous nitinol implants in surgical treatment of extensive post-excision thoracic defects in cancer patients
No full textInfluence of Silver Addition on Structure, Martensite Transformations and Mechanical Properties of TiNi–Ag Alloy Wires for Biomedical Application
No full textThe microstructural and functional behavior of TiNi-based wires with a silver content of 0–1.5 at.% was evaluated. The concentration range for Ag doping determined for the TiNi wires with potential for the medical industry was 0–0.2 at.%. Microstructure analysis of TiNi wires with different silver contents at room temperature indicated a multiphase structural state. Various internal structures with tangled grain boundaries were formed by intense plastic deformation. The nanocrystalline structure and phase state of wire with the minimum silver content (0.1 at.% Ag) provide full shape recovery, the greatest reversible strain, and optimal strength and ductility. TiNi ingots with a high Ag content (0.5–1.5 at.%) cracked under minimum load due to excess silver that crystallized along the grain boundaries and broke cohesion bonds between the TiNi grains
The equilibrium of martensite shear stress at phase transitions in TiNi-based alloy
No full textThermoelastic martensitic transformations play a fundamental role in the shape memory effect and related phenomena. Owing to their unique crystallographic and thermomechanical behaviour, martensitic transformations have generated considerable research in the areas of crystallography, thermodynamics and mechanical behaviour. In the area of thermodynamics a theoretical approach is now added which provides the basis for thermoelastic behaviour through consideration of the Gibbs energy change. In this paper, the interrelation of internal elastic stresses and martensite shear stresses in phase transitions has been defined. A thermoelastic stress equilibrium equation for a wide range of martensitic transformation temperatures has been presented. On the basis of the calculations made, an estimation of dislocation defects formation energy for the TiNi-based alloy has been made. For TiNi-based composition made of TN-10 brand alloy, commercially produced for medical goals, the energy of vacancy formation is about 0.06 kcal/mol. The study and calculations are shown to make clear, using a new approach, the considering of phase transitions in terms of external and internal stresses
Structure, biocompatibility and corrosion resistance of the ceramic-metal surface of porous nitinol
No full textOne of the key aspects of the biochemical compatibility of medical alloys is the surface corrosion resistance in living organisms. This study discusses the structure of the ceramic-metal surface layer of a porous nickel-titanium alloy (nitinol) and the corrosion resistance in simulated physiological liquids. The structure of the protective layer and glass-ceramic non-metallic inclusions in the surface of the porous alloy have been studied. The formation of the surface ceramic-metal layer and crystallization of various glass-metal-ceramic phases as a result of chemisorption from reaction gases and epitaxial growth from the gas phase during the self-propagating high-temperature synthesis are observed
Sparing Surgery for the Successful Treatment of Thyroid Papillary Carcinoma Invading the Trachea: A Case Report
No full textPublished reports on salvage treatment for trachea reconstruction after total thyroidectomy or partial tracheotomy are available, some of them using structures of the trachea itself, auricular cartilage, a musculocutaneous flap, or other methods. In our report, we emphasize the importance of a search for a new material and approach for sparing surgery. The purpose of this article is to describe a case of a successful sparing surgery in a patient with advanced thyroid papillary carcinoma invading the trachea. After total thyroidectomy in 2012, partial resection of the trachea was performed in 2014. The lesion defect was 5.5 × 2.3 cm in size, located between 4 (2nd–6th) tracheal cartilaginous rings and involving about a semicircumference. It was reconstructed with the aid of the knitted TiNi-based mesh endograft, which has been prefabricated in the sternocleidomastoid muscle and further covered with the skin draped over the wound. The tracheostoma was fully closed 6 weeks after the surgery. There were neither side effects nor complications. This kind of tracheal surgery for extensive lesions demonstrates good functional and cosmetic outcomes
