An Experimental Anatomic Investigation For The Source And Disposition Of Blood Supply To The Porcine Diaphragm

BackgroundDiseases of esophagus are one of the most common digestive tract disease in our country,specially that the carcinoma of esophagus has a high rate of occurrence in many regions of our country,now many benign and malignat or the congenital and postnatal diseases of the esophagus require effective and physiological reconstruction of the esophagus, which comprises the excision of the pathologic segment of the esophagus and the reconstruction of the remaining segment in enough length, reconstruction of the esophagus is one of the most important part of the esophageal surgery besides the excision of pathological part, the rectification of abnormity and the recovery of the trauma,and also the only way to restore the continuity of esophagus.otherwise,reconstruction of the esophagus is important to the survival of the patients with esophageal diseases,only renconstructing esophagus can nomal way of foodintake via mouth be restored,thus ensuring more physiological and effective intake of nutrition.then appears the topic of substitute for the esophagus which is researched in the realm of esophageal surgery in a long time,effective reconstruction of esophagus requires ideal substitute for the esophagus,in the history of modern esophageal surgery,medical workers of thoracic surgery had beening serching for the ideal esophageal substitute, carrying out many animal experiment research for it,and getting many sensible and inspirative results,the artificial esophagus is just the hot topic of one of them. Theoretically,ideal esophageal substitute should have these characteristics: (1)Because that esophageal substitute must be used in the clinical surgery of surgery,it should has extensive and reliable source,so this should be the most important respect of the research for the application of esophageal substitute;(2)Although theoretically the artifical esophagus mainly as a stretch for remaining esophageal segment and a passage for the food,it would disturb nomal physiological functions of the body if we design a tubiform subject that totally be deprived of the esophageal physical characteristics and physiological functions purely for this aim. So esophageal substitute require the similar physical characteristics and the correspondence with the anatomical and physiology characteristics of the thoracic cavity in the most extent; (3) Esophageal substitute as an organic graft may induce rejection in different degrees,which is a keypoint for the success of the surgery of esophageal reconstruction,so histocompatibility is the most important topic for all kinds of researched esophageal substitute,otherwise,it can not be consolidated to the autologous tissue and achieve biological fixation, finally,it would desquamate inevitably,Obviously in this aspect, autologous organs or autologous tissue flaps have great advantages; (4) Esophageal substitute should persist in the body in a long time after being implanted,now most researched esophageal substitute of artificial materials or biotype compound materials have properties of self-degradation,this requires that these materials and its degradation product don't have toxicity,and don't have obvious carcinogenicity after long time of persistence in the body;(5)Affected by modus operandi,the body condition of the patients and the physico-chemical property of esophageal substitute itself,the implanting of esophageal substitute main render all kinds of complications in different extent which may be an important factor restricting the research of it and its clinical application;(6)esophageal substitute must be connected to the stomach,which is a environment of high degree of acidity, and must be repeatedly impacted by gastric juice and alimentary bolus.because it's proximal to the important organs like heart and lung,thus its rupture or erosion would lead to infection of the thoracic and mediastinal organs,so it should be more resist to the erosion. According to above principles,people have devised many kinds of esophageal substitute and have done substantial animal experiments for it in the past 50 years,and have gained much significant advancement.In summary,the great variety of esophageal substitutes can be classified into two categories:(1)artificial esophagus;(2) autoallergic tissue or organs.The so-called artificial esophagus is a kind of tubeform equipment which made up by biomedicine project, tissue engineering and biomaterial technology to substitute the functions of esophagus and can induce the regeneration of newly born esophagus and its remodeling or functional reconstruction.The research of artificial esophagus begun in 1952,Beman used a special polyethylene pipe to repair the defect of the esophagus in their experiment,which open up the research of artificial esophagus,then appeared all kinds of materials of artificial esophagus to be used in the animal experiment,according to different kinds of materials to be constructed,it can be classified as artificial synthetic material esophagus,biotype composite material esophagus,biotype artificial esophagus,and tissue project artificial esophagus.In recent years,with the development of materialogia and tissular project,the materials that used to construct the artificial esophagus have gotten great improvement,many kinds of materials for artificial esophagus not only have the function of inducing the epithelium mucosae and smooth muscle cell and any other structure of the newly born esophagus to crawl and grow along,but also have the biodegradability within some time,but the artificial materials have all kinds of deficiency and contraindication in different extent, they have led to all kinds of complications in the animal experiments,especially the previously used bracket-type artificial esophagus which don't have cell,namely the artificial polymers and bio-composite material artificial esophagus,because that totally man-made materials have weak histocompatibility with human body,the tissue of blood vessel,nerve and other tissue can not grow into them,thus the newly born esophageal tissue can not crawl onto them,at the same time,they may even lead to the overgrowth of the granulation tissue or Inflammatory reaction,the incidence of the common complications like fistula and abscission of the anastomotic stoma, stenosis of the anastomotic stoma so on is very high,so research of these materials only stay at the period of animal experiment,their clinical application are severely suspended.Hower,the biotype and tissue project materials have many advantages in these aspects,especially the tissue-project artificial esophagus which is developed under the context of the hot topic of tissue-project technology,if we inplant some amount of in vitro fractional cultivated cell or bone marrow stem cell after induced onto the bracket-type materials that have superior histocompatibility,and let it grow into a tubeform "newly born esophagus",it can grow into tubeform structure that have the similar hierarchical structure with the esophagus,However,there exist great difficulty to obtain the tissue-project material in abundance now,so it can even hardly be used in the large sample animal experiments,but it offer a promising topic in the research of aritificial esophagus.At present, the esophageal substitute used in the clinic are the autologous tubeform organs such as stormach,colon or dissociate jejunum,whose anatomical position relation with esophagus determine that using them to reconstruct the esophagus must alter the structure of the alimentary tract in great extent,and the operation must be undertaken via thoracic and abdominal cavity at the same time,which may be a massive trauma to the body and a great interference,besides the common complication of anastomotic stoma fistula and stenosis,the complication of necrosis,reflux,digestive function disorder,dystrophia and so on can always happen,so people have being trying best to search for more suitable autologous tissue to substitute them,for the aim of restructing the esophagus most effectively the minimal trauma and interference.The autologous pedicled tissue flaps that proximal to esophagus have exclusive advantage in this aspect,which can not be compared by other artificial materials.In principle,this kind of autologous esophageal substitute tissue should have the features of good bloodflow,high physical strength,some compatibility and homology with the esophageal mucous membrane,enough surface area to be rolled into tubeform,at the same time,the procedures of dissociation and acquisition of it should be simple and not a great interference to the function of the body.At present,we have done many clinical and animal experiment researches of autologous pedicled tissue flap such as pedicled lung tissue flap,myocutaneous flap,latissimus colli myocutaneous flap,periosteal intercostal muscle myocutaneous flap and so on,however,for the restriction of the shape,anatomy and blood supply of the tissue flaps,they are always used to reconstruct cervical segment of the esophagus and not suitable for the reconstruction of thoracic segment of esophagus.on the other hand,the present researched autologous tissue flaps are restricted to be functioned as the repair for the defect or stenosis of esophageal segment,instead of the totally substitution of the pathological esophageal segment.In view of these,this research proposes the idea that rolling the autologous diapharagm flap into tubeform to reconstruct the esophagus by substitution,the laminar structure,large surface area,and location in the thoracic cavity of the esophagus determines that it can not only be used to totally substitute for certain length of esophagus, but also be applied to reconstruct the thoracic segment of esophagus,besides these,the pedicled diaphragm flap has many other advantages,so it should be researched in-depth.Applying a kind of tissue flap to be rolled into tubeform for the substitution of requires massive and enough length of it,and this would inevitablely make a long longitudinal anastomotic stoma in its axis of ordinates,therefore, this requires that all the part of the tissue flap has affluent blood supply and can resist adequate stress force to ensure its viability and extensibility,thus avoiding the post-operation occurance of the anastomotic stoma fistula, these should be based on the detailed research of the anatomic structure of it,especially its blood supply and correlated accessory structure,then we can find feasibility in theory according to it,and carry out the research animal experiment,which would promote its clinical application finally.Taiwan scholar Hung-chi Chen used to apply the tensor fasciae latae flap and radial forearm flap to substitute for the pathological segment of esophagus by shaping them into tubeform in some patients under special circumstances,however,the blood supply and other correlated anatomic information of this two kind of myocutaneous flaps used to be sufficiently clarified in the preciously researches,so it can be used in the clinic directly.In previous researches,the diaphragm is seldom researched as a kind of tissue flap, and its blood supply and correlated structures are never systematically researched accordingly,the objective of this study aims at this,we would provide definite evidence to the construction of the animal model for the operation of using the diaphragm to substitute for the esophagus by the experiment anatomical research of the diaphragm and thoracic segment esophagus of the experimental animal,thus providing satisfactory theoretical foundation for the animal experiment of this method of operation.ChapterⅠThe application of arterial contrast radiography technology in the anatomical research of diaphragmatic blood supply ObjectiveTo demonstrate the feasibility and validity of the application of gelatin-lead oxide and sodium methoxycellulose-lead oxide contrast radiography technology in the research of the pocine diaphragmatic blood supply by the animal experiment,and to contrast the use of three common magistral formulas of contrast radiography in the establishment of the three-dimension visualized model of the opacification diaphragmatic arteries,thus ultimately providing a favourable method of investigating the diaphragmatic blood supply of the experimental animal,then finally supply vascular anatomy evidences for the operation of using diaphragm as substitute for the esophagus.Method1. Experimental animals and their grouping:12 hybrid Landraces are divided into three groups,and given a number in series.Group NO.1 comprises NO.1-6 specimen,and were perfused in the magistral formula of gelain(5%)-lead oxide(25g/100ml of distilled water);group NO.2 comprises NO.7-9 specimen, and were perfused in the magistral formula of gelain(5%)-lead oxide(50g/100ml of distilled water);group three comprises NO.10-12 specimen, and were perfused in the magistral formula of sodium methoxycellulose (12%)-lead oxide(25g/100ml of distilled water).2. empirical method:(1)The experimental animal were anesthetized and rendered arterial cannulation via common carotid artery using lactoprene cannula,then they were injected liquemine via vein for the anticoagulation and received bloodletting,then we used iso-osmia kcl solution to flush their blood vessel,all the pretreated specimens were placed into the water tank that hold warm of 40℃;(2)we prepared constrast medium in all the three kinds of magistral formulas,then we used suitable method to perfuse via common carotid artery cannula, and we try the best to perfuse the artery of the specimens in the one-time;(3)then we used the 16-row spiral CT(GE Lights Speed,16pro) machine to scan the specimens in series without interval and in slices within 24 hours,and get the original tomoscan images in DICOM format,which were directed into GE Adw4.3 workstation to be reconstructed using the method of VR and MIP by the software package of 3D reconstruction;then we used the DicomWork1.3.5 software to analayze the original tomoscan images and investigated the homogeneity of the constrast medium,and also analysed the 3D reconstruction images,investigating the display and reconstruction effect of the diaphragmatic arteries;(4)finally,we isolated the diaphragm specimen in intergrity,and investigated the braching of the diaphragmatic arteries on the diaphragm.Result1. The infused dose of contrast medium of the three groups of specimens:group NO.1:25-35ml/kg of body weight(NO.4 specimen had a arteriorrhexis and leakage in the process of perfusion,its result was not counted);group NO.2:21-23ml/kg of body weight; group NO.3:17-21 ml/kg of body weight.2. The situation of the perfusion:the group NO.1 and 2 were perfused very well,except that several specimens get problem of the blockage and arteriorrhexis,the process of perfusion was smooth in gross;but the process of perfusion of group NO.3 was very difficult,which experienced many times of blockage of the tunnel,and received several times of cannulation.3. Analysis of the original tomoscan images:images of group NO.1 showed that the visualized arteries had small amount of radiation-form constructed defect,the order of magnitude is about 4491-4645HU,and the CV of the CTm is amount to5.92-7.79%;its arteries are perfused full and continusous,the borderline of them are smooth and without defect and interruption, so the quality of the images is grossly very well; images of group N0.2 showed that the visualized arteries had very intensive radiation-form constructed defect,the magnitude of the CT-M is amount to 6583-6714HU,and the CV is between4.08% to5.71%;but the degree of satiation of the contrast medium in blood vessel was well,only several tiny vacuole shadows could be seen,so the quality of the image is grossly bad; images of group NO.3 showed that the visualized arteries had very small amount of radiation-form constructed defect,its order of magnitude is low,which is about 3870 to 4083HU,and the CV is about 1.74 to 2.43%.but the continuity and degree of satiation of the contrast medium in blood vessel was inferior,several decks of image had the defect of contrast medium and big bubble shadow,its borderline of the blood vessel is nevertheless smooth,so the quality of the image is bad, which is not suitable for the three-dimension reconstruction.4. Three-dimension reconstruction:if we reconstrut the visualized arteries exclusively at the threshold of over 1000HU,the quality of the image is superior,and the reconstruction image has great stereo feeling,and can be rotated,dissected,and magnified;if we reconstruct at the threshold of below 1000HU,the image of bone and soft tissue can be displayed,but the image of reconstruction has obvious arterial constructed defect,and it would be greatly affected by the shadow of soft tissue and calcification,which is not suitable for observation.images of reconstruction for the group NO.1 specimens have good quality,we can observe the source and course of the diaphragmatic arteries; images of reconstruction for the group NO.2 specimens have great amount of arterial constructed defect,its blood vessel is crude and spike-form; images of reconstruction for the group NO.3 specimens have bad quality,many arteries of it are missing and interrupted;the combination of the reconstruction method of VR and MIP can demonstrate the diaphragmatic arteries very well.5. The X-ray Photographs of the isolated diaphragm specimen:because the effect of the perfusion is bad in group NO.3 specimens,the arteries on the diaphragm specimen are visualized badly,except these, we can observe the diaphragmatic arteries' network allroundly and directly.Conclusion1. Contrast radiography technology is a favourable method to research the anatomy of the diaphragmatic arteries whose source is multiple.2. Using the magistral formula of gelain(5%)-lead oxide(25g/100ml of distilled water) for perfusion have favourable visualization and reconstruction effect for the porcine diaphragmatic arteries whose diameter are small,and the process of perfusion is easy to perform,it is the key point of successful anatomy of the diaphragmatic arteries in this experiment.3. As a simple and allround method of angiotomy, lead oxide contrast radiography technology should be preferably generalized to the angiotomy of the tissue flap.ChapterⅡAn experimental anatomic investigation for the source and disposition of blood supply to the porcine diaphragmObjectiveTo investigate the architecture of porcine diaphragm and the source and distribution of its arterial blood supply,and to discuss anatomical feasibility of the operation of using diaphragm as substitute for the esophagus,then providing the anatomical evidence for the establishment of the animal experiment model in depth.Methods(1) 6 anesthetized mongrel Landrace were cannulated via carotid artery,then sacrificed by arterial hemospasia and perfused with gelatin-lead tetraoxide mixture via arterial cannula.The perfused pigs were underwent successive CT scanning, then the acquired images were input to the computer software to perform the 3-dimensions reconstruction,then we could review the location of the diaphragmatic rete arteriosum,the source of each diaphragmatic arteries and their course,diameter, ramification etc under the 3D images.(2)The integrated diaphragms and their attachment were incised and underwent X-ray radiation after CT scaning, through which the distribution of diaphragmatic arteries and their blood-supply area, anastomosis with each other could be reviewed.(3) Dissections were performed to grossly observe and measure the diaphragms and their attachments.ResultThe morphous and arterial blood supply of porcine diaphragm is similar to that of human being.But there's some discrepancy on the location of the bulk of porcine diaphragm and its muscle fiber between human and swine,and the multiple blood supply of are mainly the musculophrenic artery, pericardiacophrenic artery, intercostal artery and phrenic artery,their trunks and major branches can be clearly disclosed by the 3D images, and the X-ray images disclosed that their distributions on the diaphragm are definitive,and their anastomosis with each other are extensive.ConclusionsThe porcine diaphragm's morphologic characteristics, architechture of muscle fiber,distribution of vascular and its anatomical position to the esophagus lays a good anatomical foundation for its feasibility of obtaining pedicle diaphragm flap to reconstruct the esophagus, phrenic arteries walk upwards along the muscle fibers of diaphragm crura,with definitive and extensive ramification,and be adjacent to the esophagus,so it is anatomical feasible to use it as pedicle,and it should be used as the optimal alternative for the operation of using pedicle diaphragm flap to reconstruct the esophagus.