Unexpected difficult extubation of double lumen bronchial intubation: a case report

Background The anesthetist and other members of the perioperative team need to be extremely cautious for successful completion of any surgery. If the final step of any general anesthetic-extubation is not sufficiently well planned, it can lead to critical airway incidents during the extubation and hinder transportation of the patient to the post-anesthesia care unit. Case presentation A 48-year-old female underwent video-assisted thoracoscopic surgery (VATS) combined with left lower lobectomy. The distal end of the left branch of the tracheal tube was lodged by surgical sutures. In this case, the respiratory physician burned the sutures using an argon electrode, after discussion with the thoracic surgery experts. Conclusions Teamwork is essential when caring for a patient with a shared airway. The anesthetist and surgeon must communicate well with each other to achieve optimal surgical outcomes. Importantly, testing the patency of the ETT prior to extubation should be a regular procedure, which is practical significance to guide safe extubation.

Smart surgical sutures using soft artificial muscles

Wound closure with surgical sutures is a critical challenge for flexible endoscopic surgeries. Substantial efforts have been introduced to develop functional and smart surgical sutures to either monitor wound conditions or ease the complexity of knot tying. Although research interests in smart sutures by soft robotic technologies have emerged for years, it is challenging to develop a soft robotic structure that possesses a similar physical structure as conventional sutures while offering a self-tightening knot or anchor to close the wound. This paper introduces a new concept of smart sutures that can be programmed to achieve desired and uniform tension distribution while offering self-tightening knots or automatically deploying secured anchors. The core technology is a soft hydraulic artificial muscle that can be elongated and contracted under applied fluid pressure. Each suture is equipped with a pressure locking mechanism to hold its temporary elongated state and to induce self-shrinking ability. The puncturing and holding force for the smart sutures with anchors are examined. Ex-vivo experiments on fresh porcine stomach and colon demonstrate the usefulness of the new smart sutures. The new approaches are expected to pave the way for the further development of smart sutures that will benefit research, training, and commercialization in the surgical field.

Toughen and Strengthen Alginate Fiber by Incorporation of Polyethylene Glycol Grafted Cellulose Nanocrystals

Alginate fibers have great potential in many applications, such as medical dressings, surgical sutures, and masks, etc. owing to their good biocompatibility and other properties. However, for alginate fibers prepared by wet spinning, the fibers have disadvantages such as low strength, poor toughness, and brittleness. Herein, a simple, scalable, and cost-effective blending spinning strategy was developed to produce the alginate composite fibers with excellent mechanical properties. Cellulose nanocrystals (CNCs) were incorporated directly in the wet spinning solution to improve its strength, wherein the CNCs were prepared from waste cotton fabrics. Polyethylene glycol (PEG) molecular chain was grafted onto the CNC surface to be used as a plasticizer while increasing the dispersibility of CNCs in alginate matrix. It was worth noting that modification of alginate fibers with PEG grafted cellulose nanocrystals (CNC-g-PEG) enhanced the tensile strength and elongation at break, simultaneously. In addition, the CNC-g-PEG modified alginate fibers exhibited improved salt tolerance and reduced water absorbency. This work may make high-value utilization of waste cotton fabrics, and pave the way for the development of high-performance, green alginate fibers.

Symplectic Integration for Multivariate Dynamic Spline-Based Model of Deformable Linear Objects

Deformable Linear Objects (DLOs) such as ropes, cables, and surgical sutures have a wide variety of uses in automotive engineering, surgery, and electromechanical industries. Therefore, modeling of DLOs as well as a computationally efficient way to predict the DLO behavior are of great importance, in particular to enable robotic manipulation of DLOs. The main motivation of this work is to enable efficient pre- diction of the DLO behavior during robotic manipulation. In this paper, the DLO is modeled by a multivariate dynamic spline, while a symplectic integration method is used to solve the model iteratively by interpolating the DLO shape during the manipulation process. Comparisons between the symplectic, Runge-Kutta and Zhai integrators are reported. The presented results show the capabilities of the symplectic integrator to overcome other integration methods in predicting the DLO behavior. Moreover, the results obtained with different sets of model parameters integrated by means of the symplectic method are reported to show how they influence the DLO behavior estimation.

Automation of the wet disinfection process during the production of suture threads from natural collagen, catgut

Surgical sutures are the simplest yet most used medical devices in modern healthcare, they are the preferred type because of its biocompatibility and ability to be resorbed. Bovine intestinal fibers are converted into catgut that serves as the starting material of absorbable surgical suture threads. The mechanical and control subsystems of industrial equipment were designed to automate disinfection of bovine intestinal fibers to increase efficiency during the wet process stage of disinfection without altering its fiber quality. A turbulent regime of the water and disinfectant mix was designed, implemented and validated, this automatic aeration system in the disinfection thank increased the process efficiency by reducing the time used to handle a load of fibers by 50%, and the working time of the personnel involved in the process was reduced from 220 to 20 minutes. Tests on the final product showed that LAL levels comply with what is established by the American Pharmacopoeia: USP <85> Bacterial Endotoxin Test and USP <161> Medical Devices - Bacterial and Pyrogen Endotoxin Test. These results indicate that the disinfected catgut using the proposed automated system complies with all mechanical quality control tests.

390 Characterisation of a Platelet Rich Fibrin Membrane and Formation of an Autologous Fibrin Mesh

Aim Platelet-rich fibrin (PRF) is a three-dimensional fibrin scaffold with associated platelets and leukocytes which releases high quantities of growth factors over a sustained period of time. PRF has shown promising clinical results in promoting wound healing and tissue regeneration. The aims of this feasibility study were to establish optimal spinning methods for production of PRF, to quantify the production of vascular endothelial growth factor (VEGF) by PRF and to explore new vehicles of clinical PRF delivery. Method Assessment of optimal production involved comparisons between Protocol 1 (EDTA bottle) and Protocol 2 (no additive) at three different centrifugation forces: 400g, 1000g and 1700g. VEGF production was analysed using ELISA with varied incubation periods and PRF plug segments. Novel methods for PRF delivery were explored using surgical sutures and a Zimmer® Skin Graft Mesher. Results Protocol 2 demonstrated shorter average time to blood draw (9.8s compared to 13.6s) and to centrifuge (25.5s compared to 33.1s) with a decreased range of values. All PRF segments exhibited a positive correlation between incubation time and amount of VEGF produced with the bottom segments producing on average more VEGF. A segment of the fibrin plug was successfully secured on a suture and meshed in a 1:1.5 ratio. Conclusions PRF production can be optimised using blood bottles with no additive and high centrifugation forces. VEGF production by PRF peaks at 120 hours with the bottom PRF segment exhibiting the highest rate of production. The first description of a PRF mesh enables new clinical applications.

Efficacy of a Novel Medical Adhesive for Sealing Lung Parenchyma: An in vitro Study in Rabbit Lungs

<b><i>Introduction:</i></b> During thoracic resection procedures, complete hemostasis and aerostasis are priorities. A persistent alveolar air leak is associated with increased morbidity and mortality rates. This study aimed to evaluate whether the novel medical adhesive VIVO (Adhesys Medical GmbH Aachen, Germany) is a reliable alternative sealing technique to routine surgical procedures. <b><i>Methods:</i></b> We conducted an in vitro animal study by analyzing 21 lungs of New Zealand (<i>n</i> = 19) and Chinchilla Bastard (<i>n</i> = 2) rabbits (age, 11–18 weeks; weight, 2,400–3,600 g). Three groups, each comprising 7 animals, were evaluated. VIVO (VIVO-group) was compared with standard surgical lung parenchymal lesion closure with a polypropylene suture (Suture-group) and TachoSil® (TachoSil-group). We adopted a stable, pressure-controlled ventilation protocol. After explantation, a surgical incision 0.5-cm deep and 1.5-cm wide was made in the lungs using a customized template. Air leak was measured quantitatively (mL/min) using a respirator and visualized qualitatively by 2 observers who made independent judgments. Next, the leak was closed using VIVO, suture, or TachoSil® as specified by the manufacturer. Subsequently, positive end-expiratory pressure (PEEP) and inspiratory pressure were gradually increased until a maximum of 15 and 30 mbar were attained, respectively. <b><i>Results:</i></b> At PEEPs of 8, 10, and 15 mbar, VIVO achieved complete sealing of the profound parenchymal defect in all (<i>n</i> = 7) lungs. After closure of the incision, we observed an air leak variation of 127 ± 114 mL/min (Suture-group), 31 ± 49 mL/min (VIVO-group), and 114 ± 134 mL/min (TachoSil-group). VIVO showed a significantly lower air leak than surgical sutures (<i>p</i> = 0.031) and TachoSil® (<i>p</i> = 0.046). <b><i>Conclusion:</i></b> VIVO offers sufficient closure of the lung parenchymal lesions. The novel adhesive enabled significantly better sealing with lower persistent air leakage than TachoSil® or surgical sutures. Further investigation using in vivo models is strongly encouraged to confirm our findings.