The Design Of An Individualized Covered Stent In The 3D Printing Technique For The Accurate Treatment Of Stanford A Type Aortic Arch Dissection

Background Aortic dissection(AD)is a rare and severe cardiovascular acute disease characterized by sudden onset,rapid progression of the disease,and high mortality in the acute phase.The rate of untreated Standford type A aortic dissection is as high as 80%.As the aorta's anatomy changes,there are many branch vessels,and the disease itself has complex factors,so there are many difficulties in the treatment.Aortic arch replacement is an important part of the treatment of Standford type A aortic dissection.The purpose of surgical treatment is to replace the diseased aortic arch and its branch vessels with artificial blood vessels to ensure systemic blood supply.In the classic surgery,the stent graft was placed in the descending aorta,and the full-aortic arch was replaced with a four-armed artificial blood vessel.The distal end of the artificial vessel was anastomosed to the proximal descending aorta,and each branch was anastomosed to each branch of the aortic arch.Traditional surgical bleeding,revealing difficulties,and many complications.The extracorporeal circulation technology of deep hypothermic circulatory arrest is a necessary condition for the development of total aortic arch replacement.The surgery involves anesthesia,CT,echocardiography,operating room,and extracorporeal circulation.A new technique for the treatment of Stanford type A aortic dissection with a three-branch aortic arch stent graft followed.Intraoperative stent graft,a kind of artificial blood vessel coated with polyester of Ni Ti memory metal stent,is used for surgical treatment of aortic arch dissection.To a certain extent,the treatment of the aortic arch dissection is simplified.Because each patient's aortic arch and BT,LCCA,LSA three branches of the blood vessels anatomy,size,there are differences,there are three branch stents fixed position,can not be applied to each case,making the stent can not be completely and BT,LCCA,LSA three branches Perfect match,prone to residual leakage,false cavity does not close,the stent shift and fall off,resulting in a new sandwich,and even increase the difficulty of surgery.It is impossible to cope with the anatomical variation of the bow.In order to avoid the related risks and improve the deficiencies of the threebranch aortic arch stent graft surgery,an individualized combination stent technique has been developed to treat the aortic arch dissection.The use of single branch stent grafts and branching intravascular stents to reconstruct the aortic arch,that is,individual combined stent graft reconstruction aortic arch surgery,the technique is relatively more flexible in the choice of surgical methods and indications,can be applied to almost all types Aortic arch dissection patients.However,this type of surgery requires the exploration of the internal structure of the aorta during surgery to accurately determine the internal structure of the aorta,and then the suture of the aortic cavity stent can be performed.This increases the operation time and difficulty to a certain extent,making the operation Increased risk.In view of the problems in the above mentioned surgical methods,we use 3D printing technology to replicate the lesion model and carry out surgery planning.We can fully understand the patient's disease anatomy before surgery,and design individual stent grafts for accurate treatment of Stanford A.The aortic arch section provides a new idea.That is,using individual stent grafts to reconstruct the aortic arch and its branch vessels.Objectives The 3D printing technique was used to replicate the lesion model and the aortic dissection model was accurately measured.The spatial anatomy of the three branches of BT,LCCA,LSA and the aortic arch was obtained.Surgical planning was performed.Individual stent grafts were designed to reconstruct the aortic arch.Precise treatment of Stanford A aortic dissection and evaluation of clinical efficacy,and compared with the traditional aortic total arch replacement and "nose like" stent surgery.Methods From January 2007 to December 2016,40 patients with Stanford A aortic dissection received surgery.The patients were divided into group A(n=25)undergoing total aortic arch replacement plus "nose like" stenting and group B(n=15)undergoing individualized stent graft surgery.There was no significant difference in gender,age,and condition between the two groups(P>0.05).All patients underwent aortic CTA and echocardiography before surgery.After follow-up,aortic CTA and echocardiography were performed.Results Cardiac blockade time,stop circulation time,extracorporeal circulation time and intraoperative blood loss were lower in group B than in group A(t=-5.248-40.868,all P<0.05).There was no significant difference in the incidence of transient brain injury and operative mortality between the two groups.The two groups recovered well after short-term follow-up.Conclusions Preoperative surgical planning using 3D printing technology and intraoperative design of individual stent grafts for the treatment of Stanford A aortic dissection compared with currently applied aortic total arch replacement plus "nose-like" stent technique for aortic arch surgery Simplified,greatly reducing the risk of surgery for the treatment of most patients with Stanford A aortic dissection,its long-term effect still needs further observation.