| Objectives A novel pancreaticojejunostomy(PJ)device was designed by CT scanning data,manufacture method,product material,and clinical use.This novel device was manufactured by 3D-printing,and its feasibility and safety were verified by performance testing and the vivo experiments in large animals.The aim of this research was to explore the clinical application value of the novel PJ device.Methods Part 1.72 cases of hospitalized patients with the head of pancreatic or periampullary tumors were collected from January 2017 to January 2018.All cases received enhanced CT scanning of upper abdomen.Reference to the left margin of portal vein,the anterior and posterior diameters of pancreatic neck,the upper and lower diameters of pancreatic neck,and the diameters of pancreatic duct were measured on the cross-sectional,coronal and sagittal scanning images.The pancreas and lesions were reconstructed by computer software at preoperation,then saved as stl.format and printed by 3D printer.The upper and lower diameters,anterior and posterior diameters,and the diameter of anastomotic pancreatic duct were measured directly during the operation and compared with preoperative ones.The similarity of 3D printing models was compared during the operation.The accuracy of 3D reconstruction was calculated according to the intraoperative measurement results.Polylactic acid(PLA)was used as the material of PJ device and the shape was designed by computed software.The mechanical properties,surface microstructures,molecular structure analysis and material identification,the relationship between physical properties and temperature,and crystalline morphology analysis of the novel 3D device materials were carried out.Part 2.18 Bama minipigs were selected as the experimental animals.In the first stage,the preoperative CT scan of upper abdomen was performed to acquire image data,and the normal model of pancreas and surrounding tissues was constructed by 3D reconstruction software.The animal model of pancreatic duct dilation was established artificial.Peripheral blood was collected as a reference for normal indicators.In the second stage,CT scan was performed again at preopation.The 3D printing device was manufactured according to the measurement data of pancreatic neck and pancreatic duct.All minipigs were randomly divided into two groups with 9 cases in each group.The novel device was using in the experimental group,and manual suture method was used in control group.The operative time,PJ time,intraoperative bleeding and postoperative complications were compared between two groups.4 weeks after PJ,CT scan was performed again in the third stage and the healing of anastomotic site was observed grossly.The specimen of anastomotic site and peripheral blood were collected,the inflammatory cytokines IL-1??IL-6?IL-10?TNF-?were detected by HE staining,immunohistochemistry,ELISA and QPCR.To compare the effects of different PJ methods on local and systemic inflammatory reaction,and to evaluate the safety and advantages of the novel PJ device.SPSS 22.0 statistical software was used for statistical analysis.Results Part 1.According to the requirements of PJ and the characteristics of PLA material,the design of 3D printing bioabsorbable device(3DP-BPD)consists of three parts: hollow stent,supporting plate and nut.The average diameter of pancreatic duct was(2.09±1.32)mm,the average diameter of upper and lower neck of pancreas was(21.12±2.33)mm,and the diameter of anterior and posterior pancreatic duct was(14.96±1.98)mm from 72 patients CT information.The individualized anastomotic device and the pancreas model were successfully reconstructed and printed.The coincidence rate of upper and lower diameters,anterior and posterior diameters was 92.6% and 99.36% respectively.The size of pancreatic duct stent matches the size of main pancreatic duct.It was highly similar between printing models and real organs.Compared with the resected specimens,the coincidence rate of left and right diameters was 98.53%,and that of upper and lower diameters was 98.78%.The tensile strength and Young's modulus of PLA samples are higher than those of silica gel.Microscopically,the front view is arranged in a grid pattern,the plane distribution is uniform,and the side view is arranged in layers,with uniform and compact arrangement,no voids or impurities.There was no significant difference between PLA 3D printing device and wire on the average melting temperature,decomposition temperature and final temperature(P > 0.05).It was stable in the human body with the average temperature of 37?.The infrared spectra of the device were consistent with the characteristic spectra of PLA in the sample bank.The X-ray diffraction peaks of PLA printed samples are identical with those of wires.After 3D printing,there is no significant effect on the structure of PLA,but the amorphous ratio is slightly higher than that of reference samples.Part 2.Pancreatic CT scan was performed 4 weeks after the ligation of pancreatic duct.The images showed that the main pancreatic duct located at the distal end of the ligation line was dilated to more than 1.5 mm.The mean diameter of the upper and lower neck of the pancreas was(15.2±2.2)mm,the anterior and posterior pancreas was(11.6±1.3)mm,and the pancreatic duct was(2.5±0.5)mm.Compared with the actual measurement results during the operation,the coincidence rate of the upper and lower diameters of the pancreatic neck and the anterior and posterior diameters was 93.7 ± 4.4%)and 93.5 ± 4.6%).The coincidence rate of the diameter of the pancreatic duct was 92.6±3.4%)with no statistical difference(P > 0.05).The total operation time of the experimental group(novel device)and the control group(manual suture)were(132.8±11.6)min and(147.3±10.1)min respectively.The average time of the device anastomosis was(6.0±1.2)min and the average time of manual anastomosis was(11.6±2.6)min).The results were statistically different(Ps<0.05).There was no significant difference between the two groups in intraoperative bleeding,anesthesia recovery time,postoperative activity time and eating time(P > 0.05).In the experimental group Postoperative complications included intestinal obstruction in 1 case,abdominal infection in 1 case,and no death.The total incidence of complications was 22.2%.In the control group,intestinal obstruction occurred in 2 cases,including 1 case of death and 1 case of biochemical leakage.There was no significant difference between the two groups(P > 0.05).After PJ,the anastomotic site healed well in both groups.There was no significant difference in CT images,grossly observation,local and systemic inflammatory reaction of the anastomotic site between the two groups.The 3D reconstruction model is consistent with the standard appearance.Conclusions Thin-slice CT scan provided clear images for 3D reconstruction of pancreas and individualized PJ device data collection.As the raw material of PJ device,PLA meets the clinical requirements in terms of its own performance and product function,even after 3D printing.Ligation of pancreatic neck is an excellent method to create a pancreatic duct dilatation model in large animals.It is safe and feasible to use PLA to make the novel device for PJ.This device decreased the operation time of PJ,simplified the procedure of PJ,and reduce the incidence of complications.It may have a certain clinical application prospect. |
PDF Full Text Request