AIM To demonstrate the feasibility and effectiveness of modeling and 3D printing of polyether ether ketone (PEEK) extravascular stent for the treatment of nutcracker syndrome.
METHODS Firstly, the arteries and the left renal vein (LRV) were reconstructed and 3D printed based on the patient’s computational tomography (CT) imaging data. Secondly, the extravascular stent was carefully designed according to the three-dimensional digital models of arteries and veins. Afterwards, the stent was 3D printed using PEEK material. Finally, the 3D printed PEEK external vascular stent was placed on the 1:1 arteriovenous model in order to do preoperative planning. The t test was adopted to compare and analyze the pre- and postoperative examination data of patients.
RESULTS The mean diameter of LRV at the stenotic area measured on the preoperative CT image was (2.81 ± 1.67) mm and that measured on the 3D digital model was (2.85 ± 1.59) mm, which gave the absolute value of error as (0.17 ± 0.21) mm. From the clinical perspective, the examination outcomes revealed that there were significant differences between pre- and postoperative results in the diameter of LRV at stenotic area (P＜0.01), the ratio of diameter of LRV at the hilum area to the stenosis (P< 0.01) and the blood flow velocity at LRV hilum (P< 0.05). In addition, of the 37 patients, 22 had symptoms completely resolved after surgery, 15 had obvious relief, and no patients had any complications. CT images showed the stent was stable and there was no displacement.
CONCLUSION The process of Modeling and 3D printing of the PEEK extravascular stent for the treatment of nutcracker syndrome is feasible and effective.
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