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The Studies On Biology Character About Chitosan Tube And Lung Tissue Flap With Inner Chitosan Stand Reparing Partial Esophageal Defection

Posted on:2009-02-09Degree:DoctorType:Dissertation
Country:ChinaCandidate:G ChenFull Text:PDF
GTID:1114360275959570Subject:Chest science
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IntroductionDisease of esophagus is one of frequent diseases of digestive trace in china.Esohpagus should be reconstructed after resection in order to revive the digestive tract's succession.Suitable surrogate should be selected,people have studied a series of materials:artificial esophagus,biology composite,tissue-engineering,and can not find an ideal material.We think the chitosan tube stand is an ideal one,because it can be absobed as a biology material.The present study is its manufacture method and biology characters,and the effect on esophagus repairing.In animal clinical experiment,pleural cavity is exposed for the operation,the negative pressure of thoracic carvity will vanish and breath is confined,mediastinal swaying,tracheal intubation and mechanical ventilation are need.Otherwise,the animal's breath failure lead to death.it will affect the progression of animal experiment.People often use dog and pig in experiments,can not find the rabbit as chest-operation model.As a new model,we use tracheal intubation through mouth and mechanical ventilation in general anesthesia.Tissue engineering is becoming a cross science,and it is a combination of life science and engineering.The stand materials should have good stereochemical structure, biocompatibility,biology degradation and plasticity.The chitosan tube has above-mentioned characters and profit for growth and distribution of cell.At present, the chitosan rebuild technology is approving,and is made into lamellar,film,tubiform, studing on medical domain.We study the preparative method and biology characters of chitosan stand.Esohpagus should be reconstructed after resection in order to revive the digestive tract's succession.At present,the surrogate for esophageal reconstruction has autologous tissue and artificial esopahgus.The ideal surrogate should be easy to obtain, avirulent no reject reaction,no carcinogenicity and absobability.However which reconstruction,cicatride hyperplasy and narrow preventation is a keypoint.We repair the partial esophageal defection with lung tissue flap,putting the chitosan tube stand inner,prevent from narrow and study the feasibility.Materials and methodsUsing 10 health Japanese white rabbits,weigh about 3 kg,male or female,20%urethane (5ml/kg) is intraperitoneal injected and Ket amine is musle injected(1mg/kg), 1%procaine is aspersed on the pars laryngea pharyngis,and next step is tracheal intubation by the mouth and mechanical ventilation,next is chest-operation.the tracheal intubation is canceled after chest is closed and general anaesthesia awake;first,add acetic acid solution into chitosan and get 6%chitosan acetic acid hydrosol,and get the tube by membrane making way and make it take off in sodium hydroxide and get kinds of tubes.Them are scaned by electron microscope and the internal structure is observed,Cut the tube into many segmentations and imbed in rat tela,in different time (1,4,8weeks) observing the biological histocompatibility and vivo-degradation by the eye and light microscope;fifteen rabbits were divided into two groups,include 10 in experiment group and 5 in control group.Esophagus defect was repaired with pulmonary flap having chitosan stent in experimental group and with no stent in control group.The gross appearance histological apearance and were observed at 2,4,8weeks,barium X-ray films is observed at 10 weeks after operation.Results10 white rabbits,3 of them is stopped in the experiment because of tracheal intubation failure;2 of them is death,5 of them is succeed in model establishment;the surface of chitosan tube is smooth and the tenacity is good,and after absorbing the water,it will be soft,a good tissue histocompatibility,with the time passing,is absorbed and degraded by tissue;10 rabbits survived for over two weeks,lung tissue flap healed with esophageal defection,squamous metaplasia was found on the surface of lung tissue flap.At 10 weeks after operation,;barium meal examination found barium is fluent through the esophageal and no narrow or backstreaming,the creeping is good.DiscussionGeneral pig and dog or monkey are used to form the chest-operation model. When the experiment is early stage,small animal is economic,gentle,easier to be managed than the big ones,it need not more people and money.First,we should ensure the survive of animal,it need a successful anesthesia.We must be familiar with the rabbit's throat anatomy,can complete the tracheal intubation through mouth,control anesthesia depth,normalize the operation,ensure the nutrition,the model many been formed;Chitin is a high polumer material,which is only one with cation and is biodegradable in the natural world,dis-acetyl product is chitosan,pure chitosan is white or grey.Chitosan is utilized generally in clinic,which is made into film and used in artificial dressing and antistik film after operation,it can be used in tissue engineering vassular research,it can be used in chondral reconstruction and tissue restoration,cell growth.Chitosan is biomaterial,asepsis,no adverse reaction,can be degraded with time passing in tissue.There are many methods in chitosan tube manufacture,general it need low temperature lyopyilization,equipment is complex, need more money.This method is simple and reliable,economic,suitable for small amount;Esophagus resection and reconstruction is important in esophagus surgery, scholars always search for it and improve original esophagus repairing methods. Repairing esophagus defection with lung tissue flap is a new method.We make chitosan into tube stand,which has a good tissue compatibility and degradation characters,it can effectually prevent from cicatricle shrink and narrow.After narrow stage,it can be degraded,and the product is asepsis,harmless,no adverse reaction,an ideal biology degradation material.We should study the operation method with lung tissue flap,which is a new in all over the world.It can reconstruct esophagus in thoracic cavity,need not open the abdomen and blood wessel shunt.So it is a simple method and a small wound.Conclusions:after tracheal intubation by the mouth,rabbit chest-operation model with establishment is a feasible method;it gives a new kind of way to prepare chitosan tube and approve the biological degradation;It is a feasible method to repair the esophageall defect with pulmonary tissue flap,with the inner chitosan stent preventing from the narrow.
Keywords/Search Tags:rabbit, tracheal intubation, animal model, chitosan, biomacromolecule materials, tube stand, biological degradation, lung issue flag, chitosan stand, esophagus reconstruction
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