Tracheal stents are an important form of treatment for benign or malignant central airway obstruction.However,the mechanical behavior of current tracheal stents is significantly different from that of the native trach...Tracheal stents are an important form of treatment for benign or malignant central airway obstruction.However,the mechanical behavior of current tracheal stents is significantly different from that of the native trachea,which leads to a variety of serious complications.In this study,inspired by the structure of the native trachea,a wavy non-uniform ligament chiral tracheal stent is proposed,in which J-shaped stress-strain behavior and negative Poisson's ratio response are achieved by replacing the tangential ligament of tetrachiral and anti-tetrachiral hybrid structure with a wavy non-uniform ligament.Through the combination of theoretical analysis,finite element analysis and experimental tests,a wide range of desired J-shaped stress-strain curves are explored to mimic the native porcine trachea by tailoring the stent geometry.Besides,the negative Poisson’s ratio and auxetic diameter curves versus axial strain of the stent are also studied in detail,thus contributing to the enhancement of cross-section ventilation and reducing the migration of the stent.This novel tracheal stent with a unique microstructure shows a potential to perfectly match the physiological activities of the native trachea and thereby reduce potential complications.展开更多
BACKGROUND Meckel’s diverticulum is a common congenital malformation of the small intestine,with the three most common complications being obstruction,per-foration,and inflammation.To date,only a few cases have been ...BACKGROUND Meckel’s diverticulum is a common congenital malformation of the small intestine,with the three most common complications being obstruction,per-foration,and inflammation.To date,only a few cases have been reported world-wide.In children,the clinical symptoms are similar to appendicitis.As most of the imaging features are nonspecific,the preoperative diagnosis is not precise.In addition,the clinical characteristics are highly similar to pediatric acute appendicitis,thus special attention is necessary to distinguish Meckel’s diver-ticulum from pediatric appendicitis.Patients with poor disease control should undergo laparoscopic exploration to avoid serious complications,including intestinal necrosis,intestinal perforation and gastrointestinal bleeding.CASE SUMMARY This report presents three cases of appendicitis in children combined with intestinal obstruction,which was caused by fibrous bands(ligaments)arising from the top part of Meckel's diverticulum,diverticular perforation,and diver-ticular inflammation.All three patients,aged 11-12 years,had acute appendicitis as their initial clinical presentation.All were treated by laparoscopic surgery with a favorable outcome.A complete dataset including clinical presentation,dia-gnostic imaging,surgical information,and histopathologic findings was also provided.CONCLUSION Preoperative diagnosis of Meckel’s diverticulum and its complications is challenging because its clinical signs and complications are similar to those of appendicitis in children.Laparoscopy combined with laparotomy is useful for diagnosis and treatment.展开更多
The liver has eight segments, which are referred to by numbers or by names. The numbering of the segments is done in a counterclockwise manner with the liver being viewed from the inferior surface, starting from Segme...The liver has eight segments, which are referred to by numbers or by names. The numbering of the segments is done in a counterclockwise manner with the liver being viewed from the inferior surface, starting from Segment Ⅰ(the caudate lobe). Standard anatomical description of the liver segments is available by computed tomographic scan and ultrasonography. Endoscopic ultrasound(EUS) has been used for a detailed imaging of many intra-abdominal organs and for the assessment of intra-abdominal vasculature. A stepwise evaluation of the liver segments by EUS has not been described. In this article, we have described a stepwise evaluation of the liver segments by EUS. This information can be useful for planning successful radical surgeries, preparing for biopsy, portal vein embolization, transjugular intrahepatic portosystemic shunt, tumour resection or partial hepatectomy, and for planning EUS guided diagnostic and therapeutic procedures.展开更多
Background: Although many authors advise to postpone surgical intervention until skeletal maturity is reached, the Langenskiöld procedure—entailing physiolysis and the release of Vickers’ ligament—is a kno...Background: Although many authors advise to postpone surgical intervention until skeletal maturity is reached, the Langenskiöld procedure—entailing physiolysis and the release of Vickers’ ligament—is a known procedure in case of Madelung’s deformity in children. Although advised in textbooks and recent reviews, the results and late sequelae of this procedure have been poorly documented. The aim of this study is to portray the late effects of this procedure for three patients and emphasize a very careful patient selection. Methods: A retrospective study was performed of the medical records of three patients who underwent a Langenskiöld procedure with release of Vickers’ ligament for Madelung’s deformity of the wrist. They were recalled for function evaluation and their results are presented in the current study. Results: We report the long term results of three patients (five wrists) who underwent a Langenskiöld procedure with release of Vickers’ ligament in detail. Mean follow-up was twelve years (range: 11 - 14 years). In all of the operated wrists severe pain recurred due to destruction of the distal radio-ulnar joint. Further salvaging surgeries were necessary, some with highly dissatisfying results. Conclusions: Based on our experience we advise not to perform this procedure until further studies have proven its effectiveness and clear indications. Other techniques are available for later correction of Madelung’s deformity, with similar results on pain relief, wrist function and cosmetics. However, we will advocate conservative treatment until skeletal maturity is reached.展开更多
基金supported by the National Key Research and Development Program of China(No.2020YFC1107103)the National Natural Science Foundation of China(No.51821093)the Research Project of Public Welfare Technology Application of Zhejiang Province,China(No.LGF21H010006).
文摘Tracheal stents are an important form of treatment for benign or malignant central airway obstruction.However,the mechanical behavior of current tracheal stents is significantly different from that of the native trachea,which leads to a variety of serious complications.In this study,inspired by the structure of the native trachea,a wavy non-uniform ligament chiral tracheal stent is proposed,in which J-shaped stress-strain behavior and negative Poisson's ratio response are achieved by replacing the tangential ligament of tetrachiral and anti-tetrachiral hybrid structure with a wavy non-uniform ligament.Through the combination of theoretical analysis,finite element analysis and experimental tests,a wide range of desired J-shaped stress-strain curves are explored to mimic the native porcine trachea by tailoring the stent geometry.Besides,the negative Poisson’s ratio and auxetic diameter curves versus axial strain of the stent are also studied in detail,thus contributing to the enhancement of cross-section ventilation and reducing the migration of the stent.This novel tracheal stent with a unique microstructure shows a potential to perfectly match the physiological activities of the native trachea and thereby reduce potential complications.
文摘BACKGROUND Meckel’s diverticulum is a common congenital malformation of the small intestine,with the three most common complications being obstruction,per-foration,and inflammation.To date,only a few cases have been reported world-wide.In children,the clinical symptoms are similar to appendicitis.As most of the imaging features are nonspecific,the preoperative diagnosis is not precise.In addition,the clinical characteristics are highly similar to pediatric acute appendicitis,thus special attention is necessary to distinguish Meckel’s diver-ticulum from pediatric appendicitis.Patients with poor disease control should undergo laparoscopic exploration to avoid serious complications,including intestinal necrosis,intestinal perforation and gastrointestinal bleeding.CASE SUMMARY This report presents three cases of appendicitis in children combined with intestinal obstruction,which was caused by fibrous bands(ligaments)arising from the top part of Meckel's diverticulum,diverticular perforation,and diver-ticular inflammation.All three patients,aged 11-12 years,had acute appendicitis as their initial clinical presentation.All were treated by laparoscopic surgery with a favorable outcome.A complete dataset including clinical presentation,dia-gnostic imaging,surgical information,and histopathologic findings was also provided.CONCLUSION Preoperative diagnosis of Meckel’s diverticulum and its complications is challenging because its clinical signs and complications are similar to those of appendicitis in children.Laparoscopy combined with laparotomy is useful for diagnosis and treatment.
文摘The liver has eight segments, which are referred to by numbers or by names. The numbering of the segments is done in a counterclockwise manner with the liver being viewed from the inferior surface, starting from Segment Ⅰ(the caudate lobe). Standard anatomical description of the liver segments is available by computed tomographic scan and ultrasonography. Endoscopic ultrasound(EUS) has been used for a detailed imaging of many intra-abdominal organs and for the assessment of intra-abdominal vasculature. A stepwise evaluation of the liver segments by EUS has not been described. In this article, we have described a stepwise evaluation of the liver segments by EUS. This information can be useful for planning successful radical surgeries, preparing for biopsy, portal vein embolization, transjugular intrahepatic portosystemic shunt, tumour resection or partial hepatectomy, and for planning EUS guided diagnostic and therapeutic procedures.
文摘Background: Although many authors advise to postpone surgical intervention until skeletal maturity is reached, the Langenskiöld procedure—entailing physiolysis and the release of Vickers’ ligament—is a known procedure in case of Madelung’s deformity in children. Although advised in textbooks and recent reviews, the results and late sequelae of this procedure have been poorly documented. The aim of this study is to portray the late effects of this procedure for three patients and emphasize a very careful patient selection. Methods: A retrospective study was performed of the medical records of three patients who underwent a Langenskiöld procedure with release of Vickers’ ligament for Madelung’s deformity of the wrist. They were recalled for function evaluation and their results are presented in the current study. Results: We report the long term results of three patients (five wrists) who underwent a Langenskiöld procedure with release of Vickers’ ligament in detail. Mean follow-up was twelve years (range: 11 - 14 years). In all of the operated wrists severe pain recurred due to destruction of the distal radio-ulnar joint. Further salvaging surgeries were necessary, some with highly dissatisfying results. Conclusions: Based on our experience we advise not to perform this procedure until further studies have proven its effectiveness and clear indications. Other techniques are available for later correction of Madelung’s deformity, with similar results on pain relief, wrist function and cosmetics. However, we will advocate conservative treatment until skeletal maturity is reached.
