[Abstract]Esophageal stricture is a common esophageal lesion in adults and children, and endoscopic dilatation is currently the standard treatment. However, high recurrence rate and frequent dilations have become a major problem in patients. Esophageal stents provide sustained dilation therapy but can lead to serious complications such as displacement, perforation, and bleeding, necessitating removal. Biodegradable stents, with the advantage of both dilation and self-degradation, are promising potential solutions to this problem. Currently, biodegradable materials are mainly categorized into metals and polymers, leading to the development of magnesium alloy esophageal stents and polymer esophageal stents. Among polymer stents, PLLA stents and SX-ELLA stents have been put into clinical application. In recent years, with the advancement of 3D bioprinting technology, the personalized fabrication of biodegradable stents has become feasible. In this paper, we will outline the current research status and progress of biodegradable magnesium alloy stents and polymer stents, introduce the new process of constructing esophageal stents by 3D bioprinting technology, focus on the clinical research of SX-ELLA stents in pediatric and adult patients. We will also analyze the existing problems with biodegradable stents and the directions for future development.
Abstract： Objective To explore the association between transforming growth factor-β receptor typeⅡ (TGFBR2) gene rs6785358 and rs764522 polymorphisms and rheumatic heart disease (RHD) in Chinese Han People. Methods The research design was a case-control study. A total of 207 patients who were hospitalized in Nanjing First Hospital Affiliated to Nanjing Medical University between October 2008 and January 2011 with RHD served as RHD group while 225 age and gender matched healthy adults as control group. Polymerase chain reaction-restriction length polymorphism (PCR-RFLP) technique was used to determine TGFBR2 gene rs6785358 and rs764522 polymorphisms. Results The frequencies of genotype AA, AG and GG of rs6785358 in RHD group and control group were 72.0%, 25.1%, 2.9% and 68.9％, 28.0％, 3.1％,respectively. There was no significant difference in the distribution of genotype frequencies for rs6785358 between RHD group and control group（χ2=0.50，P=0.78）. The frequencies of allele A and G of rs6785358 in RHD group and control group were 84.5％, 15.5％ and 82.9％, 17.1％,respectively. There was no significant difference in the distribution of allele frequencies for rs6785358 between RHD group and control group（χ2=0.43，P=0.51）. The frequencies of genotype CC, CG and GG of rs764522 in RHD group and control group were 77.3%, 21.3%, 1.4% and 75.6％, 21.3％, 3.1％, respectively. There was no significant difference in the distribution of genotype frequencies for rs764522 between RHD group and control group（χ2=1.33，P=0.51）. The frequencies of allele C and G of rs764522 in RHD group and control group were 87.9％, 12.1％ and 86.2％, 13.8％,respectively. There was no significant difference in the distribution of allele frequencies for rs764522 between RHD group and control group（χ2=0.55，P=0.46）. Further analysis by sex stratification showed that no statistical significance was detected in the distribution of genotype and allele frequencies for rs6785358 or rs764522 between RHD patients and controls. Conclusion TGFBR2 gene rs6785358 and rs764522 polymorphisms are not associated with RHD in Chinese Han people.
ObjectiveTo evaluate the effectiveness of cervical disc replacement for cervical myelopathy. MethodsBetween October 2006 and October 2008, 20 patients (26 segments) with cervical myelopathy underwent single-level (14 segments) or bi-level (6 segments) cervical disc replacement. There were 8 males and 12 females with an average age of 46 years (range, 26-65 years). The disease duration ranged 2-18 months (mean, 7 months). The effectiveness was evaluated using visual analogue scale (VAS) score, cervical range of motion (ROM), and the Odom et al. criteria. Heterotopic ossification (HO), osteophyte formation, and prosthesis loosening were observed. ResultsAll incisions healed by first intention, with no severe complication. Twenty patients were followed up 30-48 months (mean, 34 months). At 28 months after operation, according to Odom et al. criteria, the results were excellent in 17 cases and good in 3 cases. The VAS scores of the neck, shoulder, and upper limb were significantly improved when compared with preoperative scores (P lt; 0.05). At 30 months after operation, X-ray films showed that 20 replaced segments were mobile and ROM was (10.6 ± 4.5)°, showing no significant difference (P gt; 0.05) when compared with that of upper adjacent segment (10.8 ± 3.7)° and lower adjacent segment (7.5 ± 4.2)°. HO occurred in 10 cases (13 segments). No displacement, subsidence, or loosening occurred except 1 case of retrodisplacement of the prosthesis. ConclusionCervical disc replacement can obtain good effectiveness. It can maintain normal cervical ROM and physiological curvature. But it needs further long-term follow-up to evaluate the function and the influence on the adjacent segments.