自體動靜脈瘻管(arteriovenous fistula, AVF)為洗腎病患中，最常使用之血管通路，因其具有較長的使用時間以及較少的併發症。然而AVF術後成熟化的過程中，常因紊流產生的內皮細胞增生、過小的初始靜脈直徑或靜脈不適當的扭轉，使得通過的血流量不足，導致成熟化失敗。而紊流被認為是不當的動靜脈吻合角度所產生。目前治療AVF狹窄的方式之一，是透過植入金屬支架對狹窄處進行擴張。但治療完成後，支架會永久留在血管中，可能引起血栓或造成限縮可下針進行血液透析區域等不良影響。
本研究將透過3D列印機製作靜脈瘻管塑形模具，配合聚乳酸(polylactic acid, PLA)支架、鎂合金支架與人工血管進行血管塑形實驗，以驗證是否能達到控制動靜脈吻合角度及避免靜脈不適當扭轉的目的。實驗結果顯示，PLA支架配合內徑為6 mm、彎曲角度為40°之模具，以加熱塑形之實驗流程進行實驗，能將人工血管內徑擴張至4.520.05 mm且彎曲角度達36.371.2°。鎂合金支架配合內徑為6 mm、彎曲角度為50°之模具進行塑形實驗，能將人工血管擴張至內徑4.480.04 mm，且彎曲角度達35.020.79°。本研究設計之靜脈瘻管塑形模具，配合具有良好生物相容性及可降解性之支架(PLA、鎂合金)能將靜脈瘻管塑形至利於成熟化之幾何形狀(內徑>4 mm、彎曲角度介於30°~46.5°)，達到加速動靜脈瘻管成熟及提升成熟化比例之目的，且支架在完成協助動靜脈瘻管成熟化之目的後，將降解並為人體吸收，避免未來可能引起血栓或其他不良影響。

Arteriovenous fistula (AVF) is the most commonly used vascular pathway for hemodialysis, due to its longer duration of use and fewer complications. However, in the process of AVF maturation, endothelial hyperplasia caused by turbulent blood flow, too small initial vein diameter and improper twisting of the vein often result in insufficient blood flow rate and failure of maturation. However, the flow disturbance is considered caused by improper arteriovenous anastomotic angle (AV angle). One of the current ways to treat AVF stenosis is to implant a metal stent to dilate the narrow part of AVF. However, after the treatment, the stent will remain permanently in the AVF, and may cause thrombosis or shrinkage of the hemodialysis area.
In this study, the 3D printing equipment will be used to make a venous fistula shaping mold, and the blood vessel shaping experiment will be performed with polylactic acid (PLA) stent, magnesium alloy stent and artificial blood vessel, so as to verify if the goal of this study, to control the AV angle and avoid improper twisting of the vein, can be achieved. The experimental results showed that the experiment was carried out on the PLA stent with the heating and shaping process and the shaping mold with an inner diameter 6 mm and a bending angle of 40° could dilate the inner diameter of the artificial blood vessel to 4.520.05 mm and bend the angle of the artificial blood vessel to 36.371.2°. When the experiment was carried out on the magnesium alloy stent with the shaping mold with an inner diameter 6 mm and a bending angle of 50° could dilate the inner diameter of the artificial blood vessel to 4.480.04 mm and bend the angle of the artificial blood vessel to 35.020.79°. The venous fistula shaping mold combined with good biocompatible and biodegradable stents (PLA and magnesium alloy), both developed in this study, can shape the venous fistula to a geometric shape, inner diameter >4 mm, bending angle between 30° and 46.5°, conducive to AVF maturation, so as to accelerate the maturation of arteriovenous fistula and increase the success rate of maturation. In addition, after completing the purpose of assisting the maturation of arteriovenous fistula, the stent will be degraded and absorbed by the human body to avoid thrombosis or other adverse effects in the future.

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