[Review of studies on the biomechanical modelling of the coupling effect between stent degradation and blood vessel remodeling].

The dynamic coupling of stent degradation and vessel remodeling can influence not only the structural morphology and material property of stent and vessel, but also the development of in-stent restenosis. The research achievements of biomechanical modelling and analysis of stent degradation and vessel remodeling were reviewed; several noteworthy research perspectives were addressed, a stent-vessel coupling model was developed based on stent damage function and vessel growth function, and then concepts of matching ratio and risk factor were established so as to evaluate the treatment effect of stent intervention, which may lay the scientific foundation for the structure design, mechanical analysis and clinical application of biodegradable stent.

Review of studies on the biomechanical modelling of the coupling effect between stent degradation and blood vessel remodeling / 生物医学工程学杂志

The dynamic coupling of stent degradation and vessel remodeling can influence not only the structural morphology and material property of stent and vessel, but also the development of in-stent restenosis. The research achievements of biomechanical modelling and analysis of stent degradation and vessel remodeling were reviewed; several noteworthy research perspectives were addressed, a stent-vessel coupling model was developed based on stent damage function and vessel growth function, and then concepts of matching ratio and risk factor were established so as to evaluate the treatment effect of stent intervention, which may lay the scientific foundation for the structure design, mechanical analysis and clinical application of biodegradable stent.

Gastroduodenal stenting with Niti-S stent: long-term benefits and additional stent intervention.

BACKGROUND AND AIM: Self-expandable metallic stents have mainly been used for the palliation of malignant gastric outlet obstruction (GOO). However, their use in long-term survivors and the feasibility, safety and benefit of additional intervention for stent dysfunction remain controversial. The present study examined the long-term benefits of endoscopic gastroduodenal stenting. METHODS: We reviewed 61 patients treated with Niti-S stents at several hospitals and estimated the efficacy of stent intervention, stent patency, eating period and factors related to poor effectiveness. RESULTS: All 61 first stent interventions and 14 additional stent interventions (11 second interventions and 3 third interventions) were successfully carried out. Clinical success rates were 83.6% and 85.7%, and median stent patency was 214 days and 146 days (P = 0.47), respectively. Fifty patients could be treated with a first stent only, and 11 patients received additional stents. At the time of study termination or death, 70.0% of the former group and 63.6% of the latter group maintained oral intake (P = 0.71), and each 86% and 100% among the group could maintain oral intake for a period exceeding half of their remaining lives after first stent intervention. Karnofsky performance status ≤50 (P = 0.03), ascites (P = 0.009), and peritoneal dissemination (P = 0.001) appeared to be factors related to poor effectiveness. CONCLUSIONS: Despite the presence of factors related to poor effectiveness, endoscopic gastroduodenal stenting would be the first treatment of choice for GOO and provide long-term benefits. If stent dysfunction occurs, additional stent intervention enables continued oral intake safely.

Research progress in biomechanics of in-stent restenosis / 医用生物力学

Stent intervention has become one of the most effective ways in treating cardiac and cerebral vascular stenosis. However, postoperative in-stent restenosis remains a major unsettled issue. The occurrence of in-stent restenosis is related not only to the mismatch between stent and artery, as well as the stress induced by mechanical support of the stent struts on arterial wall, but also to the intimal hyperplasia induced by the hemodynamic change. Recent literatures on biomechanics of the stented artery were reviewed in this paper. In particular, from the view of solid mechanics and hemodynamics, the research progress of stented artery in biomechanical simulation was given detailed discussion; moreover, the biomechanical factors associated with in-stent restenosis were analyzed and summarized. Numerical simulation is a good method for investigating the relationship between stent intervention and in-stent restenosis, and it also provides a scientific guideline for the design of stent structure and clinical procedure of stent intervention.

Clinical application of expandable stent for benign and malignant esophageal obstruction / 中国微创外科杂志

Objective To study the clinical application of self-expanding nitinol stent in benign and malignant esophageal obstruction as well as in postoperative anastomotic stenosis and anastomotic leakage. Methods 22 cases of benign or malignant esophageal stenosis were treated by placing metallic stents inserted into the stenosis segment through per-oral intubation under the fluoroscopic guidance. Results The degreee of dysphagia was improved, Stooler′s staging of dysphagia was down from 3.1 preoperatively to 1.2 postoperatively. 2 cases of anastomotic leakage and 1 case of esophagorespiratory fistula were cured. All have been followed up for one to twelve months. 3 cases died with carcinoma cachexia and one succumbed to severe hemorrahage of digestive tract. The other 18 cases are still followed up. Conclusions Placement of esophageal expandable stent is one of the ideal methods to treat benign and malignant esophageal stenosis and anastomotic leakage. It can also play an important role in the improvement of the patients' life quality and prolongation of life.