The use of the pump catheter "Impeller" for patients with acute heart failure refractory to drug therapy such as cardiogenic shock has begun to spread mainly in facilities that actively engage in cardiovascular emergency. It has less burden on the heart and body than conventional treatment devices, can assist blood circulation, and is expected to further improve the survival rate of patients with cardiogenic shock.
The Impeller is the world's smallest heart pump and was introduced in Japan in September 2017 (application for approval in 2011, approval in September 2016). It was launched in Germany in 2004 and in the United States in 2008, and has been used overseas for more than 10 years. The impeller consists of a pump catheter placed in the left ventricle and a control device to assist blood circulation (Fig. 1). It is indicated for patients with acute heart failure due to cardiogenic shock who are resistant to drug therapy. Cardiogenic shock is a disease in which a decrease in the pumping function of the heart causes organ failure due to the inability to supply sufficient blood and oxygen to the whole body, resulting in death if left untreated. It usually occurs with heart failure. Cardiogenic shock occurs in 10% of heart failure, of which 50% are said to die.
The insertion method is to insert a pump catheter transdermally and transvascularly without opening the chest and place it in the left ventricle (Fig. 2). The impeller in the pump rotates at high speed to draw blood from the suction part at the tip of the catheter in the left chamber and send it to the discharge part located in the aorta, enabling antegrade auxiliary circulation. That is, instead of the heart, blood circulation is temporarily performed to promote recovery of cardiac function.
There are two types of products introduced in Japan: the "Impeller 2.5" (pump diameter 4.0 mm) with a maximum circulation assist amount of 2.5 L / min and the "Impeller 5.0" (7.0 mm) with a maximum circulation aid of 5 L / min. .. 2.5, which can be placed percutaneously, is often used in AMIs and the like. Since the 5.0 has a thick catheter, it is necessary to surgically attach an artificial blood vessel to the insertion site, but the circulating blood volume comparable to that of the left ventricular ventricular assist device (LVAD) can be obtained. It is expected to be used for patients waiting for a heart transplant in the future. Basically, it is used for 3 to 5 days as a guide for patients with high urgency such as a significant decrease in blood pressure.
So far, IABP (intra-aortic balloon pumping) and PCPS (percutaneous cardiopulmonary support) have been used for cardiogenic shock. However, PCPS, which is used especially in severe heart failure, has a great burden on the heart because it is retrograde to the original blood flow direction. In addition, there is an extracorporeal / implantable ventricular assist device that can perform anterograde blood transfer, but it is highly invasive, such as the need for thoracotomy, and it is difficult to handle emergency cases. The impeller can be said to be an auxiliary circulation device that solves these problems.
According to a survey by the Impeller Subcommittee of the Ventricular Assist Device Society Association, which consists of 10 related academic societies and study groups, 392 cases of impeller usage were counted from October 2017 to January 2019. It has been implemented. As a breakdown of diseases, it is used for myocarditis / cardiomyopathy (172 cases, 44% in total), AMI (161 cases, 41%), etc. (Table).
In early October 2017, the first case in Japan of treatment for acute heart failure using an impeller was performed at Osaka University. The patient had dilated cardiomyopathy in her 50s (male) and presented with aggravated acute heart failure refractory to drug treatment. Therefore, treatment with impeller was performed, and marked improvement in hemodynamics was observed.
Regarding the use of the impeller, there is a heart team consisting of cardiovascular surgery, cardiovascular physicians, intensive care physicians, etc., which is the core facility of the Cardiovascular Surgery Specialist Certification Organization, and a system for assisted circulation treatment is in place. Implementation facility certification standards such as are set. The impeller can be used after the facility has been certified and the staff has undergone prescribed training. As of July 2019, there are 133 implementation facilities. The number of impeller implementation facilities has increased sharply at this point, and it is believed that these preparations have been made at the facilities that wish to implement them.
The insurance reimbursement price of the impeller is 2.59 million yen per bottle. The medical fee (technical fee) is 11,000 points on the first day and 3,680 points on the second and subsequent days (as of the end of September 2019).
Figure 1. Impeller pump catheter and controller
Figure 2. Shamer of the pump part of the impeller placed in the left ventricle
Blood is pumped from the left ventricle by a motor, and blood is pumped from the discharge part in the aorta (provided by Nippon Aviomed).
Table. Impeller usage
(Materials of the Impeller Subcommittee of the Ventricular Assist Device Society Council)
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