Multi-loop traction device facilitates gastric endoscopic submucosal dissection: ex vivo pilot study and an inaugural clinical experience

Background Endoscopic submucosal dissection (ESD) is technically difficult and requires considerable training. The authors have developed a multi-loop traction device (MLTD), a new traction device that offers easy attachment and detachment. We aimed to evaluate the utility of MLTD in ESD. Methods This ex vivo pilot study was a prospective, block-randomized, comparative study of a porcine stomach model. Twenty-four lesions were assigned to a group that undertook ESD using the MLTD (M-ESD group) and a group that undertook conventional ESD (C-ESD group) to compare the speed of submucosal dissection. In addition, the data of consecutive 10 patients with eleven gastric lesions was collected using electronic medical records to clarify the inaugural clinical outcomes of gastric ESD using MLTD. Results The median (interquartile range) speed of submucosal dissection in the M-ESD and C-ESD groups were 141.5 (60.9–177.6) mm2/min and 35.5 (20.8–52.3) mm2/min, respectively; submucosal dissection was significantly faster in the M-ESD group (p < 0.05). The rate of en bloc resection and R0 resection was 100% in both groups, and there were no perforation in either group. The MLTD attachment time was 2.5 ± 0.9 min and the MLTD extraction time was 1.0 ± 1.1 min. Clinical outcomes of MLTD in gastric ESD were almost the same as those of ex vivo pilot study. Conclusions MLTD increased the speed of submucosal dissection in ESD and was similarly effective when used by expert and trainee endoscopists without perforation. MLTD can potentially ensure a safer and faster ESD.

Safety and Efficacy of an Atraumatic Uterine Cervical Traction Device: A Pilot Study

Introduction: Alignment of the uterine cervix with the vaginal canal is often required during insertion of an intrauterine contraceptive device (IUD). Currently available instruments are traumatic tenacula, which can cause pain and bleeding and represent an obstacle for certain patients to pursue their medical follow-up. A novel investigational cervical vacuum tenaculum, enables atraumatic traction of the cervix using a semi-circular suction pad, designed to conform to the anatomical shape of the external cervical os. Suction is generated by manually pulling out a sliding tube in a vacuum chamber.Methods: We performed a single arm non-comparative pilot study to assess the safety and efficacy of the cervical vacuum tenaculum in 13 women receiving an IUD. Data on procedural efficacy, safety, patient-reported pain scores at specific time points during IUD insertion procedure and patient satisfaction were collected prospectively.Results: Insertion of IUD was successful with use of the study device in 7 of the 13 enrolled patients (54%). No bleeding or only limited ecchymosis were caused by the device. No adverse events were reported. Participants reported very little pain (mean Visual Analog Scale &lt;10) when applying the device. Participants who achieved IUD insertion with the device reported strong overall satisfaction with the procedure.Conclusions: The suction-based atraumatic tenaculum can be used to manipulate the cervix during IUD insertion with satisfactory efficacy and safety. The results of this pilot study support further studies of this device in larger populations comparing with standard single-tooth tenaculum.Clinical Trial Registration:ClinicalTrials.gov, identifier: NCT 04441333.

The Expression of MMP-2 on the Pressure Side During Tooth Movement

Objectives: To explore the effects of matrix metalloproteinase-2 (MMP-2) on the development of orthodontic root resorption in rats and to provide a theoretical basis for prevention and treatment of root resorption in clinical diagnosis.Methods: Thirty-five 6-8-week-old male SD rats were randomly divided into 7 groups, each with 5 rats weighing approximately 200 g±20 g. An orthodontic traction device was applied between the right first molar and the maxillary incisor in the experimental rats, and a mesial tractive force of 60 g was applied. Five rats were used for the control group without orthodontic applications. After 0, 1, 3, 5, 7, 14, and 21 days, the maxillae were abducted, and immunohistochemical analysis was performed. We used hematoxylin eosin staining to observe root resorption. The expression of MMP-2 was also assessed by immunohistochemical staining. SPSS17.0 statistical software was used to process the data.Results: Forcing 3 d was observed in the formation of bone resorption lacunae, which were confined to the cementum. After that, it becomes more serious. The most serious damage in 7 days. In 14 d, root absorption was relieved, and osteogenic cells aggregated at the root absorption site. Root resorption lacuna visible dentin repair phenomenon. With the extension of the force application time, the expression of MMP-2 was raised gradually, reached the peak at 7 d, and then gradually declined, 21d tends to be stable, but still stronger than controls.Conclusion: MMP-2 is involved in the metabolism of extracellular matrix in the process of root absorption.

The stress-strain state of the trailer seat-coupling device simulation

The article deals with the issues of modeling the stress-strain state of a traction device designed for towing a heavy semi-trailer, on which the equipment of the base station of a mobile transport and reloading rope complex is placed. The main design loads are defined. Geometric and computational finite element models are constructed, taking into account the features of the metal structure. The method of gluing elements of the grid model is applied. On the basis of the performed calculations, conclusions are drawn about the compliance of the developed structure with the requirements of strength.