Magnetic compression anastomosis to restore biliary tract continuity after obstruction following major abdominal trauma:A case report

BACKGROUND The combination of magnetic compression anastomosis(MCA)and endoscopy has been used to treat biliary stricture after liver transplantation.However,its use for the treatment of complex biliary obstruction after major abdominal trauma has not been reported.This case report describes the successful use of MCA for the treatment of biliary obstruction resulting from major abdominal trauma.A 23-year-old man underwent major abdominal surgery(repair of liver rupture,right half colon resection,and ileostomy)following a car accident one year ago.The abdominal drainage tube,positioned at the Winslow foramen,was draining approximately 600-800 mL of bile per day.During the two endoscopic retrograde cholangiopancreatography procedures,the guide wire was unable to enter the common bile duct,which prevented placement of a biliary stent.MCA combined with endoscopy was used to successfully achieve magnetic anastomosis of the peritoneal sinus tract and duodenum,and then a choledochoduodenal stent was placed.Finally,the external biliary drainage tube was removed.The patient achieved internal biliary drainage leading to the removal of the external biliary drainage tube,which improved the quality of life.CONCLUSION Magnetic compression technique can be used for the treatment of complex biliary obstruction with minimal operative trauma.

Novel magnetic compression technique for the treatment of postoperative anastomotic stenosis in rectal cancer:A case report

BACKGROUND The treatment of postoperative anastomotic stenosis after excision of rectal cancer is challenging.Endoscopic balloon dilation and radial incision are not effective in all patients.We present a new endoscopy-assisted magnetic compression technique(MCT)for the treatment of rectal anastomotic stenosis.We successfully applied this MCT to a patient who developed an anastomotic stricture after radical resection of rectal cancer.A 50-year-old man had undergone laparoscopic radical rectal cancer surgery at a local hospital 5 months ago.A colonoscopy performed 2 months ago indicated that the rectal anastomosis was narrow due to which ileostomy closure could not be performed.The patient came to the Magnetic Surgery Clinic of the First Affiliated Hospital of Xi'an Jiaotong University after learning that we had successfully treated patients with colorectal stenosis using MCT.We performed endoscopy-assisted magnetic compression surgery for rectal stenosis.The magnets were removed 16 d later.A follow-up colonoscopy performed after 4 months showed good anastomotic patency,following which,ileostomy closure surgery was performed.CONCLUSION MCT is a simple,non-invasive technique for the treatment of anastomotic stricture after radical resection of rectal cancer.The technique can be widely used in clinical settings.

Treatment of anastomotic stricture after rectal cancer operation by magnetic compression technique:A case report

BACKGROUNDThe treatment of postoperative anastomotic stenosis(AS)after resection of colorectalcancer is challenging.Endoscopic balloon dilation is used to treat stenosisin such cases,but some patients do not show improvement even after multipleballoon dilations.Magnetic compression technique(MCT)has been used for gastrointestinalanastomosis,but its use for the treatment of postoperative AS aftercolorectal cancer surgery has rarely been reported.CASE SUMMARYWe report a 72-year-old man who underwent radical resection of colorectal cancerand ileostomy one year ago.An ileostomy closure was prepared six months ago,but colonoscopy revealed a narrowing of the rectal anastomosis.Endoscopic balloondilation was performed three times,but colonoscopy showed no significantimprovement in stenosis.The AS was successfully treated using MCT.CONCLUSIONMCT is a minimally invasive method that can be used for the treatment of postoperativeAS after colorectal cancer surgery.

Magnetic compression anastomosis for sigmoid stenosis treatment:A case report

BACKGROUND Endoscopic balloon dilation is a minimally invasive treatment for colorectal stenosis.Magnetic compression anastomosis can be applied against gastrointestinal anastomosis.When combined with endoscopy,it offers a unique approach to the recanalization of colorectal stenosis.CASE SUMMARY We have reported here the case of a 53-year-old female patient who underwent a descending colostomy due to sigmoid obstruction.Postoperative fistula restoration was not possible in her due to sigmoid stenosis.Accordingly,endoscopicassisted magnetic compression anastomosis for sigmoid stenosis was performed,and the sigmoid stenosis was recanalized 15 d after the surgery.Subsequently,a reduction colostomy was successfully performed after 10 d.CONCLUSION This case report proposes a novel minimally invasive treatment approach for colorectal stenosis.

Clinical study of extrahepatic biliary adenoma

BACKGROUND Biliary adenomas that occur in the extrahepatic biliary tree are rare.It is difficult to distinguish it from cholangiocarcinoma or cholangiolithiasis by various imaging examinations,and it is very easy to be misdiagnosed.AIM To evaluate the cumulative experiences including clinical characteristics and treatments of nine patients diagnosed with extrahepatic biliary adenoma admitted to the First Affiliated Hospital of Xi’an Jiaotong University from 2016 to 2022.METHODS A total of nine patients were included in our study.The laboratory examinations,disease diagnosis,therapy and pathological characteristics,and follow-up of every patient were evaluated.RESULTS Our cohort consisted of six females and three males with an average diagnosis age of 65.1 years(range 46-87).Six extrahepatic biliary adenomas were located in the common bile ducts and three in the hepatic duct.On initial presentation,all of the patients have symptom of biliary origin,including obstructive jaundice(4/9,44.4%),abdominal pain(6/9,66.7%),and fever(3/9,33.3%).Preoperative imaging examination considered bile duct carcinoma in 6 cases and bile duct calculi in 3 cases.All the patients received surgical treatment and were confirmed by pathology as biliary adenoma.The symptoms improved significantly in all 9 patients after surgery.Seven of nine patients recovered well at follow-up without tumor recurrence.One patient died 2 mo after the surgery due to heart failure.One patient developed jaundice again 8 mo after surgery,underwent endoscopic retrograde cholangiopancreatography and biliary stent placement.CONCLUSION Benign extrahepatic biliary tumors are rare and difficult to diagnosis preoperatively.Intraoperative choledochoscopy and timely biopsy may offer great advantages.

Udwadia–Kalaba Equation for Constrained Mechanical Systems:Formulation and Applications

There are many achievements in the field of analytical mechanics, such as Lagrange Equation, Hamilton’s Principle, Kane’s Equation. Compared to Newton–Euler mechanics, analytical mechanics have a wider range of applications and the formulation procedures are more mathematical. However, all existing methods of analytical mechanics were proposed based on some auxiliary variables. In this review, a novel analytical mechanics approach without the aid of Lagrange’s multiplier, projection, or any quasi or auxiliary variables is introduced for the central problem of mechanical systems. Since this approach was firstly proposed by Udwadia and Kalaba, it was called Udwadia–Kalaba Equation. It is a representation for the explicit expression of the equations of motion for constrained mechanical systems. It can be derived via the Gauss’ s principle, d’Alembert’s principle or extended d’Alembert’s principle. It is applicable to both holonomic and nonholonomic equality constraints, as long as they are linear with respect to the accelerations or reducible to be that form. As a result, the Udwadia–Kalaba Equation can be applied to a very broad class of mechani?cal systems. This review starts with introducing the background by a brief review of the history of mechanics. After that, the formulation procedure of Udwadia–Kalaba Equation is given. Furthermore, the comparisons of Udwadia–Kalaba Equation with Newton–Euler Equation, Lagrange Equation and Kane’s Equation are made, respectively. At last, three di erent types of examples are given for demonstrations.

Correlation Between Energy Transfer Rate and Atomization Energy of Some Trinitro Aromatic Explosive Molecules

An assumptive theoretical relationship is suggested to describe the property of molecular atomization energy and energy transfer rate in the initiation of explosions. To investigate the relationship between atomization energy and energy transfer rate, the number of doorway modes of explosives is estimated by the theory of Dlott and Fayer in which the rate is proportional to the number of normal mode vibrations. It was evaluated frequencies of normal mode vibrations of eight molecules by means of density functional theory （DFT） at the b3p86/6-31G（d,p） level. It is found that the number of doorway modes shows a linear correlation to the atomization energies of the molecules, which were also calculated by means of the same method. A mechanism of this correlation is discussed. It is also noted that in those explosives with similar molecular structure and molecular weight, the correlation between the atomization energy and the number of doorway modes is higher.