Application Of Rapid Proto-typing Technology In The Treatment Of Aortic Dissection

Objectives:Obtaining the image data of patients with aortic dissection by the means of CT angiography, and designing and making aortic dissection model which is same with the structure of patients in short time through three-dimensional printing technology to prove the feasibility of using rapid proto-typing technology and medical image data to make aortic dissection model which is same with the structure of humans quickly. Preoperative analysis was made on the design of the model, patients’ sickness was fully understood, and a surgery plan was formulated before operationto evaluate operation risks and to guide the treatment of aortic dissection.Methods:Carry out CTA scanning on the aorta of the patient with aortic dissection to obtain original DICOM data, and process the original data by adopting Mimics 16.0 software on the basis of original CTA data, set up gray threshold to distinguish different tissues, and cut aorta through built-in editing tools of software by adopting region growing algorithm, then conduct three-dimensional reconstruction of aorta. After the smooth modification on the surface of model, remove the hollow aortic dissection model, thicken aortic wall to 1.5mm and output STL files. And then transfer the files into rapid prototyping machine, sinter and mold ABS powders after setting parameters to create a model of aortic dissection with the same size of real structure. Analysis was made on rapid proto-typing model, patients’ sickness was fully understood, and a surgery plan was made, simulated operation was also carried out before operation to make full preparations for surgery.Results:Obtain image data of patients with aortic dissection through CTA scanning, and then process the data by adopting MIMICS 16.0 software to output STL files, which can guide three-dimensional printer to accurately print aortic dissection model with the same size of real structure. This study carried out rapid prototyping technology on 16 patients with aortic dissection, and made analysis on these rapid prototyping models, conducted "individualized" surgical treatment on patients, obtaining good operation effect. The average extracorporeal circulation time at first-stage thoracotomy was (171 ±9.2) minutes, myocardial blocking time (88±9.3) minutes, and circulation arrest time (39±6) minutes. The drainage volume after 24 hours was (619±217) ml. the blood transfusion volume of intraoperation and postoperation is (2299±506) ml. At the second-stage endovascular treatment, the blood flow slowed down significantly at false lumen, but increased obviously at true lumen after surgery. New angiography after endovascular exclusion showed:proximal stents were anchored firmly, every cut was isolated successfully, only allowing a small amount of blood flow going into false lumen through the permeable membrane of stunts, true lumen was enlarged significantly.Conclusions:The aortic dissection model made by adopting rapid prototyping technology can directly and accurately reflect the anatomical structure of aortic dissection, making the preoperative preparation more adequate, reducing intraoperative bleeding and shortening operation time, thus improve the efficiency and precision of aortic dissection operation, and in the meanwhile guide the accurate proximal anchoring of stents in blood vessel lumens. Rapid prototyping technology finds good application andex tensive prospects in the treatment of aortic dissection.