The present invention relates to a medical fluid injection device for a decompression neuroplasty and a method for injecting a medical fluid. The medical fluid injection device comprises: a cannula which includes a penetration pipe a trocar and an approaching needle which are inserted into the penetration pipe of the cannula and a catheter which is inserted into the penetration pipe of the cannula, and which discharges a medical fluid, injected from the outside, toward a target location via a discharge path in a state in which a front end of the catheter is set so as to protrude from the cannula. The medical fluid injection device enables the cannula to be accurately located at a target location inside a spine by using the approaching needle, thereby improving accuracy of a medical procedure. In particular, medical fluid discharge holes formed in the catheter are opened in a side direction of the catheter, and thus cross sections of flow of a medical fluid passing through the discharge holes can be extended. Accordingly, the medical fluid can be rapidly injected and can be widely spread, thereby enabling a medical procedure to be conveniently and rapidly performed. Furthermore, the flexible catheter inserted into the cannula can sufficiently extend from a rear of the cannula. Additionally, a syringe is connected to the catheter rather than the cannula so as to inject the medical fluid. Accordingly, the cannula is prevented from moving during a medical procedure, thereby enabling performance of a medical procedure to be less stressful and safe.본 발명은 감압신경성형술용 약액주입장치 및 약액주입방법에 관한 것이다. 상기 약액주입장치는, 관통로를 갖는 캐뉼러와 상기 캐뉼러의 관통로에 끼워지는 트로카 및 어프로치니들과 상기 캐뉼러의 관통로 내부로 삽입되되 그 선단부가 캐뉼러의 외부로 돌출되도록 세팅된 상태로, 외부로부터 주입된 약액을 분출통로를 통해 목표지점으로 분출하는 카테터를 포함한다.상기 약액주입장치는, 어프로칭니들을 이용해 캐뉼러를 척추 내부의 목표지점에 정확하게 위치시킬 수 있으므로 그만큼 시술의 정밀성이 뛰어나며, 특히 카테터에 형성한 약액 분출구멍을 카테터의 측방향으로 개방시켜 분출구멍을 통과하는 약액의 유동단면적을 확장할 수 있어 약액의 주입속도가 빠르고 약액이 넓게 퍼질 수 있으므로 간편하고 신속한 시술을 수행할 수 있게 하고, 또한, 캐뉼러의 내부에 끼워진 연질 카테터를 캐뉼러의 후방으로
