JP2019017728A - Blood flow control system and treatment method - Google Patents

Abstract

To provide medical equipment capable of properly detecting an object and grasping treatment intensity by the detection of the object, capable of detecting occurrence of an ischemic state, capable of being placed in an artery for a long term, and being suitable for treatment and prevention of DCI and other disease.SOLUTION: A blood flow control system 10 of the invention comprises: a blood flow control body 11 capable of adjusting a blood flow rate by adjusting a blockage degree of a blood vessel; and a blood pressure measurement part 12 for measuring blood pressure on an artery downstream side relative to a position of the blood flow control body.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a blood flow control system and a treatment method.

  Subarachnoid hemorrhage (hereinafter sometimes abbreviated as “SAH”) is an acute disease that causes arterial hemorrhage in the subarachnoid space mainly due to sudden rupture of a cerebral aneurysm. Although it is counted as one of the strokes along with cerebral infarction and stroke, the mortality rate is high (about 40%) compared to the other two, and even if it does not die, the case of leaving severe disability (about 30 %) Is a serious disease. Furthermore, since it develops at a relatively young age (median age of onset is 50s), there are impacts on society and the economy such as the loss of labor caused by death and disability, and long-term care costs due to long life expectancy. Very big.

When aneurysmal subarachnoid hemorrhage is diagnosed, a ruptured aneurysm is usually repaired within 24 hours (craniotomy clipping or endovascular coiling). After the operation, the patient enters the intensive care unit, where the whole body is managed and strict complications are monitored. On average, ICU stays for two weeks.
During this time, various complications can occur, and among them, the syndrome called delayed cerebral ischemia (hereinafter referred to as “DCI”) worsens the prognosis of patients with SAH. This is an abnormal cerebral vasospasm and accompanying cerebral ischemic symptom that occurs at a site unrelated to the aneurysm, peaking 7 days after the onset of subarachnoid hemorrhage, and in the worst case, leads to cerebral infarction.

  As a result, even if the initial treatment of a ruptured aneurysm is successful, the patient's life prognosis and functional prognosis are ultimately deteriorated due to cerebral infarction. Although the mechanism of this DCI has not been fully elucidated, it is considered that the automatic adjustment of blood flow in the cerebral blood vessels, vasospasm, etc. are related. It is widely considered important to release the spasm and maintain cerebral blood flow (hereinafter referred to as “CBF”).

In addition to such aneurysmal SAH, SAH also occurs due to cerebrovascular failure due to head trauma. In that case as well, it is known that there is a risk of DCI.
The fifth to fifteenth day after the onset of SAH is called the spasm phase, which is a period during which the risk of DCI is high. Indeed, more than 70% of SAH patients have various degrees of vasospasm, and about 36% reach DCI.

  Various drugs and techniques have been tried for this purpose, but the only scientifically proven effectiveness is the preventive administration of the oral Ca antagonist, Nimodipine. Although the arterial dilatory action of Ca antagonists is thought to antagonize vasospasm, the currently used dose of nimodipine is also known to be insufficient to provide sufficient vasodilation. However, it is known that increasing the oral dose of nimodipine or intravenous administration will increase the blood concentration, leading to systemic hypotension and eventually lowering CBF, which is rather harmful. The doses of Ca antagonists cannot be administered and their effectiveness is limited.

  In addition, as a rescue treatment for DCI that has already developed, arterial administration of vasodilators such as nicardipine, nimodipine, and fasudil hydrochloride, and physical vasodilation with PTA balloons are also performed. Thus, since the spasm period lasts for several days to 10 days or more, the effectiveness of temporary improvement is limited, and such rescue treatment may be repeated every day. On the other hand, continuous administration of these vasodilators is difficult to perform because it causes a drop in blood pressure.

Thus, there is a need for medical devices, treatment methods, and prevention methods for the treatment and prevention of DCI, but no satisfactory one has been proposed yet.
One of the diseases in which cerebral blood flow is very important is ischemic cerebral infarction, which is one of strokes. Cerebral infarction is a disease in which cerebral arteries are blocked by cerebral arteries embolized by a thrombus derived from the heart or the like, or an arteriosclerotic plaque is locally broken, causing peripheral brain tissue to become ischemic. It is important to reperfuse the disrupted blood flow before cerebral tissue falls into an irreversible infarction, and thrombolytic therapy with intravenous tissue plasminogen activator (tPA) as a treatment for acute cerebral infarction Is done. In recent years, standard treatment is changing so that treatment aiming at earlier reperfusion such as mechanical thrombectomy using an intravascular treatment device such as a stent retriever can be performed.
However, there are only a limited number of patients that can be used for intravenous tPA injection or thrombus recovery. Most estimates apply to less than 30% of all cerebral infarction patients, and most patients have no treatment.
In addition, there is no further treatment means for cases of unsuccessful and insufficiently successful thrombus recovery therapy.

  As a prior art, Patent Document 1 describes a medical device including a balloon that inhibits blood flow by being expanded, and a catheter having a sphygmomanometer on the distal end side of the balloon. The medical device described in Patent Document 1 is intended to increase blood flow in the brain or the like by being inserted into an artery and inhibiting the blood flow of the artery.

US Pat. No. 6,592,557

  However, the medical device described in Patent Document 1 includes a sphygmomanometer on the distal end side of the balloon that inhibits blood flow, and can only measure blood pressure upstream of the balloon. When the blood flow is inhibited for a long time, there is a risk of excessive blood flow restriction downstream of the balloon, and there is a risk of ischemia in the organ on the downstream side. Since measurement cannot be performed, it is impossible to detect that an ischemic state occurs. Therefore, when the risk of ischemia is taken into consideration, there is a problem that the medical device described in Patent Document 1 can only be performed for about 1 hour at maximum. Since brain tissue is vulnerable to ischemia and irreversible infarction occurs after several hours of blood flow, use for 1 hour or less is extremely insufficient as a treatment for cerebral ischemia. As for DCI, vasospasm, often referred to as spasm, is common on the 5th to 15th days after the onset of SAH, and the risk of DCI is high. Therefore, it is necessary to be a medical device that can increase cerebral blood flow. In addition, for the treatment of ischemic brain diseases other than DCI, such as cerebral infarction, the brain tissue will not be completely infarcted (depending on the development of collateral circulation, etc. for a maximum of 24 hours) over a long period of time. There is a need to continue to increase cerebral blood flow.

  Further, as a result of the study by the present inventors, the blood pressure upstream from the aortic occlusion does not necessarily correlate with the occlusion of the aorta. The flow state cannot be grasped, and an adverse event due to excessive blood flow inhibition may occur. The long-term treatment is likely to have a stronger negative effect.

  Therefore, an object of the present invention is to enable more accurate detection of a subject and accurate grasp of the treatment intensity thereby, and to detect the occurrence of an ischemic state downstream from the occluded part. It is an object of the present invention to provide a medical device and a treatment method suitable for treatment and prevention of diseases exhibiting cerebral ischemia including DCI and cerebral infarction, which can be placed.

Since the present invention increases the overall cerebral blood flow, DCI has the effect of physically expanding and treating blood vessels that have fallen into spasm due to increased cerebral blood flow. Also, for cerebral infarction, an increase in antegrade blood flow promotes the natural reopening of blocked blood vessels, and a decrease in antegrade blood flow even in partially open vessels. The effect of reducing the brain tissue that falls into the infarction, even if the blood vessels are not open at all, by amplifying the blood flow from the collateral circulation path, the peripheral region (penumbra region) that is not completely in the cerebral infarction is prolonged. It has the effect of earning time until natural resumption, and can be expected to reduce the final cerebral infarction.
Other diseases that can be expected to have a therapeutic effect by increasing cerebral blood flow include transient ischemic attack (TIA), a condition before cerebral infarction, moyamoya disease, and cerebral artery bypass surgery. Can be widely applied to ischemic brain diseases such as carotid endarterectomy (CEA) and carotid stenting (CAS), and cerebrovascular dementia.

  As a result of intensive studies to solve the above problems, the present inventors have found that it is better to increase the blood flow of the brain for the treatment of cerebral ischemic symptoms, and that the blood flow of the aorta is far from the left subclavian artery. Finding that it is possible to increase the blood flow of the brain when partially inhibited, and that the occurrence of an ischemic state can be detected by measuring the blood pressure downstream from the site of inhibition when partially inhibiting the blood flow of the artery, The present invention has been completed.

That is, this invention is the following (1)-(10).
(1) A blood flow control system including a blood flow control body capable of adjusting a blood flow volume by adjusting a degree of occlusion of a blood vessel, and a blood pressure measurement unit that measures blood pressure downstream of the blood flow control body.

(2) The blood flow control system according to (2), wherein the blood flow control body increases the blood flow in the brain by decreasing the blood flow to the downstream side of the artery.
(3) The blood flow control system according to (1) or (2), comprising adjustment means capable of adjusting a degree of occlusion of a blood vessel by the blood flow control body based on blood pressure information measured by the blood pressure measurement unit. .
(4) The blood flow control system according to any one of (1) to (3), further including a second blood pressure measurement unit that measures blood pressure upstream of the blood flow control body.
(5) The adjustment means adjusts the degree of occlusion of blood vessels by the blood flow control body based on blood pressure information from the blood pressure measurement unit and second blood pressure information from the second blood pressure measurement unit. (4) The blood flow control system.
(6) The blood according to any one of (1) to (5), further comprising notification means for notifying that the degree of occlusion of the blood vessel by the blood flow control body needs to be adjusted based on blood pressure information from the blood pressure measurement unit Flow control system.
(7) The blood flow control system according to any one of (1) to (6), which is a catheter including the blood flow control body and the blood pressure measurement unit.

(8) A blood flow control system including a blood flow control body capable of adjusting a blood flow volume by adjusting a degree of occlusion of a blood vessel, and a blood pressure measurement unit that measures blood pressure downstream of the blood flow control body. A method of treatment comprising adjusting an arterial blood flow by adjusting a degree of occlusion of a blood vessel by the blood flow control body while measuring blood pressure by the blood pressure measuring unit.

(9) The treatment method according to (8), wherein the blood flow volume in the brain is increased by the blood flow control body by decreasing the blood flow volume downstream of the artery from the blood flow control body.
(10) Adjusting the blood flow of the artery by adjusting the degree of occlusion of the blood vessel by the blood flow control body while measuring the blood pressure by the second blood pressure measurement unit located upstream of the blood flow control body. The method of (8) or (9).

  According to the blood flow control system of the present invention, a medical device suitable for treatment or prevention of ischemic brain disease, which can detect the occurrence of a downstream ischemic state and can be placed in an artery for a long period of time. Can be provided.

It is the schematic diagram by which the blood flow control system of one Embodiment of this invention was arrange | positioned in the human body. It is a schematic diagram of the preferable aspect of the blood flow control system of FIG. It is the schematic diagram by which the blood flow control system of another embodiment of this invention was arrange | positioned at the human body. It is a schematic diagram of the preferable aspect of the blood flow control system of FIG. It is the schematic diagram by which the catheter of one Embodiment of this invention was arrange | positioned in the human body. It is the schematic diagram by which the catheter of one Embodiment of this invention was arrange | positioned in the human body. It is the schematic diagram by which the catheter of one Embodiment of this invention was arrange | positioned in the human body. It is a schematic diagram of the catheter of one Embodiment of this invention. It is explanatory drawing of the cerebral blood flow adjustment system 50 of one Embodiment of this invention. It is a schematic diagram which shows an example of a blood flow control body. It is a schematic diagram which shows an example of a blood flow control body. It is a schematic diagram which shows an example of a blood flow control body. It is a schematic diagram which shows an example of a blood flow control body. It is a schematic diagram which shows an example of a blood flow control body. It is a schematic diagram which shows an example of a blood flow control body. It is a schematic diagram which shows an example of a blood flow control body. It is a schematic diagram which shows an example of a blood flow control body. It is a schematic diagram which shows an example of a blood flow control body. It is a schematic diagram which shows an example of a blood flow control body. It is a schematic diagram which shows an example of a blood flow control body. It is a schematic diagram which shows an example of a blood flow control body. It is a schematic diagram which shows an example of a blood flow control body. It is a graph which shows the relationship between arterial area obstruction | occlusion degree, the blood pressure above the ligation part of an aorta, the blood pressure below the ligation part of an aorta, and the blood flow volume of a head. It is a graph which shows the relationship between aortic area obstruction | occlusion degree (%), the blood pressure above the ligation part of the aorta, the blood pressure below the ligation part of the aorta, the cardiac output, and the pulmonary artery pressure (mmHg).

(Embodiment 1)
Hereinafter, the blood flow control system and the treatment method of the present invention will be described more specifically with reference to the drawings.
A blood flow control system according to the present invention includes a blood flow control body capable of adjusting a blood flow volume by adjusting a degree of occlusion of a blood vessel, and a blood pressure measurement unit that measures blood pressure downstream of the blood flow control body. Have.
The treatment method of the present invention comprises a blood flow control body capable of adjusting the blood flow volume by adjusting the degree of occlusion of the blood vessel, and a blood pressure measurement section for measuring blood pressure downstream of the blood flow control body from the artery. The blood flow volume of the artery is adjusted by adjusting the degree of occlusion of the blood vessel by the blood flow control body while measuring the blood pressure by the blood pressure measuring unit using the flow control system.

  FIG. 1 shows a schematic diagram in which a blood flow control system 10 according to an embodiment of the present invention is arranged on a human body 1. In FIG. 1, a human body 1 has an aorta 3 connected to a heart 2. In the aorta 3, the brachiocephalic artery 4, the left common carotid artery 5, and the left subclavian artery 6 are branched in order from the side close to the heart 2. The brachiocephalic artery 4 is further branched into a right subclavian artery 4a and a right common carotid artery 4b. When the relative position in the aorta 3 is expressed, the side closer to the heart 2 is defined as the upstream side, and the far side is defined as the downstream side.

  The blood flow control system 10 includes a blood flow control body 11 that can be provided downstream of the left subclavian artery 6 in the aorta 3 and a blood pressure that can be provided downstream of the aorta 3 relative to the blood flow control body 11. And a measurement unit 12. The blood flow control system 10 of this embodiment shown in FIG. 1 is an example in which a blood flow control body 11 and a blood pressure measurement unit 12 are inserted into the aorta 3 respectively.

  Not limited to the first embodiment, the blood flow control body 11 of the present invention may have any form as long as it adjusts the degree of occlusion of the aorta 3. The degree of occlusion means the degree of occlusion, and the occlusion is a state in which the blood vessel is occluded compared to a state in which no artificial manipulation is applied due to the presence of a foreign substance in the blood vessel or stenosis of the blood vessel. Say. An example of the blood flow control body 11 is one whose volume can expand and contract within the aorta 3. In this example, the degree of occlusion of the aorta 3 can be adjusted by expanding and contracting the volume of the blood flow control body 11 in the aorta 3. Another example of the blood flow control body 11 will be described in detail later. Blood is pumped from the heart and flows through the blood vessels. If the flow of blood is partially inhibited in the middle of the blood vessel, the blood flow is reduced downstream from the inhibited portion, and the blood flow in the other channels. Will increase. Therefore, it is considered that the blood flow control body of the present invention can increase the blood flow volume of the artery upstream of the blood flow control body and increase the blood flow volume toward the brain. Therefore, since it is important that the blood flow can be partially inhibited in the middle of the artery, the blood flow control body of the present invention can exert the effect of the present invention in any form as long as the degree of occlusion of the artery can be adjusted. There is expected.

  The blood pressure measurement unit 12 measures the blood pressure of the aorta 3 on the downstream side of the blood flow control body 11. In a preferred embodiment of the blood flow control system 10, the degree of occlusion by the aorta 3 by the blood flow control body 11 is adjusted based on blood pressure information measured by the blood pressure measurement unit 12. Another example of the blood pressure measurement unit 12 will be described later.

  The blood flow control body 11 and the blood pressure measurement unit 12 are attached to, for example, a catheter and held at a predetermined position in the aorta 3 as described in a preferred embodiment described later. But the blood flow control body 11 and the blood pressure measurement part 12 are not limited to what is attached to a catheter.

  The effect of the blood flow control system 10 of this embodiment shown in FIG. 1 will be described. The blood flow control system 10 of the present embodiment adjusts the degree of occlusion of the aorta 3 by the blood flow control body 11, thereby reducing the blood volume downstream from the brachiocephalic artery 4 and the left common carotid artery 5 connected to the brain. Can be reduced. As a result, the blood flow amount from the brachiocephalic artery 4 and the left common carotid artery 5 located upstream of the blood flow control body 11 toward the brain can be increased.

  According to the blood flow control system 10 of the present embodiment, when cerebral ischemia occurs, the blood flow control body 11 and the blood pressure measurement unit 12 are inserted into the blood vessel from the artery of the upper limb, for example, and the left subclavian in the aorta 3 is inserted. It arrange | positions downstream from the artery 6, and the blood flow control body 11 partially occludes the aorta 3 in the position. Thereby, a part of blood flow toward the lower body can be distributed to the upper body and the head. Specifically, according to the knowledge of the present inventors, for example, data has been obtained that the blood flow of the upper body could be increased by 27% simply by cutting the blood flow of the lower body by 7%. This is an example and there are individual differences.) The progression of ischemic brain disease can be prevented or treated by allocating part of the blood flow toward the lower body and increasing the cerebral blood flow.

  Moreover, since the blood flow control body 11 of the blood flow control system 10 partially occludes the aorta 3, the blood pressure of the head can be increased. It is possible to increase the dose of a Ca antagonist that is a therapeutic agent for DCI that could not be administered at a dose. Therefore, since the arterial dilating action of this Ca antagonist can be effectively utilized, DCI vasospasm can be suppressed in this respect.

  Furthermore, the blood flow control body 11 is placed in the aorta to adjust the cerebral blood flow during the spasm stage after the onset of SAH while observing the nerve findings, and the blood flow control body 11 can be removed after the spasm stage has elapsed. As a result, the risk of DCI can be reduced.

  In addition, by measuring the blood pressure with the blood pressure measurement unit 12 downstream of the aorta 3 relative to the blood flow control body 11, an accurate blood flow state downstream of the blood flow control body 11 can be grasped, and the blood of the organ Flow obstruction can be prevented.

  When the aorta 3 is partially occluded by the blood flow control body 11 of the blood flow control system 10, it is important to measure the blood pressure downstream of the blood flow control body 11. According to the knowledge of the present inventors, the blood pressure upstream of the blood vessel occlusion portion by the blood flow control body 11 does not necessarily correlate with the occlusion state of the blood vessel. Therefore, even if the blood pressure upstream of the occluded portion of the blood vessel is measured, the accurate blood flow state of the target cannot be grasped, and an adverse event due to excessive blood flow inhibition may occur. On the other hand, the blood flow control system 10 of this embodiment measures blood pressure by the blood pressure measurement unit 12 on the downstream side of the blood flow control body 11. Since the blood pressure downstream of the blood flow control body 11 is correlated with the occlusion state of the aorta 3 by the blood flow control body 11 and the cerebral blood flow compared to the upstream side, the blood pressure measurement unit 12 measures the blood pressure. Therefore, the accurate blood flow state of the subject can be grasped, and the treatment intensity can be evaluated.

A preferred embodiment of the blood flow control system 10 will be described with reference to FIG. 2. Adjustment capable of adjusting the degree of occlusion of blood vessels by the blood flow control body 11 based on blood pressure information measured by the blood pressure measurement unit 12. Means 13 may be included. This adjusting means may be manual or may be a device that automatically adjusts by various control methods based on blood pressure information.
The adjustment means 13 can adjust the degree of occlusion of blood vessels by the blood flow control body 11, and can adjust the blood flow and blood pressure appropriately.

When another preferred embodiment of the blood flow control system 10 is described with reference to FIG. 2, it is notified that the degree of occlusion of the blood vessel by the blood flow control body 11 needs to be adjusted based on blood pressure information from the blood pressure measurement unit 12. Notification means 14 can further be provided.
By receiving the notification from the notification means 14 and adjusting the degree of occlusion of the blood vessel by the blood flow control body 11, the degree of occlusion can be adjusted appropriately when adjustment is necessary.

  In the blood flow control system 10, the adjusting means 13 and the notification means 14 described above may have only one or both of them.

(Embodiment 2)
In FIG. 3, the schematic diagram of the blood-flow control system 20 of another embodiment of this invention is shown. In FIG. 3, the same members as those in FIG. The blood flow control system 20 shown in FIG. 3 is provided on the downstream side of the left subclavian artery 6 in the aorta 3 and provided on the downstream side of the aorta 3 relative to the blood flow control body 11. And a second blood pressure measurement unit 15 provided on the upstream side of the aorta 3 with respect to the blood flow control body 11.

  The blood flow control system 20 of the present embodiment shown in FIG. 3 is different from the blood flow control system 10 of the embodiment shown in FIG. 1 in that it has a second blood pressure measurement unit 15. About the control body 11 and the blood-pressure measurement part 12, it can be set as the same structure. Therefore, regarding the blood flow control body 11 and the blood pressure measurement unit 12 in the blood flow control system 20 according to the present embodiment, the description overlapping with that explained in the blood flow control system 10 according to the previous embodiment is omitted.

  The second blood pressure measurement unit 15 of the blood flow control system 20 of the present embodiment is inserted into the aorta 3 from, for example, the artery of the upper limb, and is disposed on the upstream side of the left subclavian artery 6. The blood pressure of the aorta 3 on the upstream side is measured. In a preferred embodiment of the blood flow control system 20, the blood flow control body 11 controls the aorta 3 based on the blood pressure information from the blood pressure measurement unit 12 and the second blood pressure information from the second blood pressure measurement unit 15. It is possible to adjust the degree of occlusion. Another example of the second blood pressure measurement unit 15 will be described later.

The second blood pressure measurement unit 15 is attached to a catheter and held at a predetermined position in the aorta 3 as an example, as will be described in a preferred mode described later. But the 2nd blood-pressure measurement part 15 is not limited to what is attached to a catheter.
The effect of the blood flow control system 20 of this embodiment shown in FIG. 3 will be described. Similar to the blood flow control system 10, the blood flow control system 20 of the present embodiment includes a blood flow control body 11 and a blood pressure measurement unit 12. Therefore, the blood flow control system 20 of the present embodiment has all the effects exhibited by the blood flow control system 10 described above having the blood flow control body 11 and the blood pressure measurement unit 12.

  The blood flow control system 20 not only measures blood pressure on the downstream side of the blood flow control body 11 by the blood pressure measurement unit 12 but also measures the blood pressure when the blood flow control body 11 partially occludes the aorta 3. The blood pressure can be measured upstream of the blood flow control body 11 by the second blood pressure measurement unit 15. Therefore, a more accurate blood flow state on the upstream side of the artery than the blood flow control body 11 can be grasped, and the treatment intensity can be more accurately evaluated.

A preferred embodiment of the blood flow control system 20 will be described with reference to FIG. 4. Of the blood pressure measurement unit 12 and the blood pressure measurement unit 15, the blood pressure measurement unit is preferably based on at least blood pressure information measured by the blood pressure measurement unit 12. The blood pressure control unit 11 can adjust the degree of occlusion of the blood vessel based on blood pressure information measured by both the blood pressure measuring unit 12 and the blood pressure measuring unit 15. This adjusting means may be manual or may be a device that automatically adjusts by various control methods based on blood pressure information.
The adjustment means 16 can adjust the degree of occlusion of blood vessels by the blood flow control body 11 and can adjust the blood flow rate and blood pressure appropriately.

Another preferred embodiment of the blood flow control system 20 will be described with reference to FIG. 4. Among the blood pressure measurement unit 12 and the blood pressure measurement unit 15, blood pressure information measured by at least the blood pressure measurement unit 12, preferably the blood pressure measurement unit 12. And a blood pressure measurement unit 15 may further include notification means 17 for notifying that the degree of occlusion of the blood vessel by the blood flow control body 11 needs to be adjusted based on blood pressure information from both.
In the blood flow control system 20, the adjusting means 16 and the notification means 17 described above may have only one or both of them.

  The blood flow control system 10 shown in FIG. 1 can be a catheter 30 including a blood flow control body 11 and a blood pressure measurement unit 12, as shown in FIG. The catheter 30 shown in FIG. 5 is an example having the blood pressure measurement unit 12 on the distal end side of the catheter 30 relative to the blood flow control body 11 since it is inserted into the aorta from the artery of the upper limb. In the case of a catheter inserted into the aorta from the artery of the lower limb, a structure in which the blood pressure measuring unit 12 is provided on the proximal end side of the catheter 30 with respect to the blood flow control body 11 can be used.

In addition, as shown in FIG. 6, the blood flow control system 20 shown in FIG. 3 has a more specific preferred embodiment, as shown in FIG. 6, a blood flow control body 11, a blood pressure measurement unit 12, and a second blood pressure measurement unit 15. It can be set as the catheter 40 provided with. Since the catheter 40 shown in FIG. 6 is inserted into the aorta from the artery of the upper limb, the blood pressure measurement unit 12 is provided on the distal end side of the catheter 40 relative to the blood flow control body 11. In addition, the second blood pressure measurement unit 15 is provided on the proximal end side of the catheter 40. The catheter can be inserted from the artery of the lower limb into the aorta. In this case, the blood pressure measuring unit 12 is provided on the proximal end side of the catheter 60 with respect to the blood flow control body 11 as in the catheter 60 shown in FIG. In addition, the second blood pressure measurement unit 15 is provided on the distal end side of the catheter 60 with respect to the blood flow control body 11.
A more specific example of the catheter 40 shown in FIG. 6 will be described below as a third embodiment.

(Embodiment 3)
A catheter 40 as an embodiment of the blood flow control system of the present invention will be described with reference to FIG. FIG. 8 is a schematic view of the vicinity of the distal end of the catheter 40. The catheter 40 has three independent lumens 111, 112, 115 in the catheter body 118. The lumen 111 includes a balloon 111 a and is a lumen for inflating and deflating the balloon 111 a in the vicinity of the distal end of the catheter body 118. Lumen 112 and lumen 115 are lumens for measuring arterial pressure. The lumen 112 is arranged so that the arterial pressure can be measured on the distal end side of the catheter body 118 relative to the balloon 111a of the lumen 111. The lumen 115 is arranged on the proximal end side of the catheter body 118 relative to the balloon 111a of the lumen 111 so that the arterial pressure can be measured.

  In the catheter 40, the lumen 111 having the balloon 111a corresponds to the blood flow control body 11 of the blood flow control system 20 shown in FIG. 3 when the catheter 40 is inserted from the artery of the upper limb into the aorta. The lumen 115 corresponds to the second blood pressure measurement unit 15 of the blood flow control system 20, and the lumen 115 corresponds to the second blood pressure measurement unit 15 of the blood flow control system 20. That is, the catheter 40 in FIG. 8 is obtained by forming the blood flow control system 20 shown in FIG. 3 in the form of a catheter. When the catheter 40 is inserted from the artery of the lower limb into the aorta, the lumen 112 corresponds to the second blood pressure measurement unit 15 of the blood flow control system 20, and the lumen 115 is the blood pressure measurement unit 12 of the blood flow control system 20. It corresponds to. Therefore, as shown in FIG. 8, the catheter 40 having both the lumen 112 and the lumen 115 is used when the catheter 40 is inserted from the artery of the upper limb into the aorta or from the artery of the lower limb into the aorta. Can be used.

  In addition, in the catheter 40 of FIG. 8, the aspect which does not have any one of the lumen | rumen 115 and the lumen | lumen 112 is equivalent to what made the blood-flow control system 10 shown in FIG. 1 the form of a catheter. The following description using the catheter 40 of FIG. 8 includes both an aspect having both the lumen 115 and the lumen 112 and an aspect not having any one of the lumen 115 and the lumen 112. .

  The distance between the balloon 111a and the distal end of the catheter 40 is not particularly limited, but is preferably at least 5 cm apart. An arterial pressure transducer can be connected to the lumen 112 and the lumen 115 to continuously record the arterial pressure at the opening of the lumen 112 and the arterial pressure at the opening of the lumen 115.

  Further, by recording the pressure difference between the arterial pressure at the opening of the lumen 112 and the arterial pressure at the opening of the lumen 115, it is possible to know the extent to which the expansion of the balloon 111a inhibits the aortic blood flow.

  The position of the opening of the lumen 112 is not particularly limited, but when the catheter 40 is inserted from the artery of the upper limb into the aorta, the lumen 112 is preferably located at least 4 cm away from the balloon because the lumen 112 is located downstream of the balloon 111a. . This is because the blood flow passing through the aorta is temporarily accelerated at the blood vessel stenosis due to the expansion of the balloon 111a, decelerates as a turbulent flow downstream of the balloon 111a, and then returns to a stable flow. At this time, a phenomenon occurs in which the blood pressure is suddenly lost on the downstream side of the balloon 111a and then recovered several cm later. Therefore, the lumen 112 for measuring pressure avoids measuring a temporary decrease in blood pressure due to turbulent flow by being present at a position sufficiently away from the balloon 111a that causes the most narrowed portion of the blood vessel. It is possible to prevent overestimation of the effect of blocking the balloon 111a. According to the results of the blood flow simulation, the distance required for the pressure loss to recover and stabilize again under physiological conditions is about 4 cm, and thus is preferably at least 4 cm, more preferably 5 cm from the balloon 111a. As described above, the opening of the lumen 112 for measuring the arterial pressure is provided on the downstream side.

  The position of the opening of the lumen 115 is not particularly limited. However, when the catheter 40 is inserted from the artery of the lower limb into the aorta, the lumen 115 is preferably located at least 4 cm away from the balloon because the lumen 115 is located downstream of the balloon 111a. . The reason for this is the same as described in the above paragraph, in which, when the catheter 40 is inserted from the artery of the upper limb into the aorta, it is preferable that the position of the opening of the lumen 115 be at least 4 cm away from the balloon 111a. Therefore, an opening of the lumen 115 for measuring the arterial pressure is provided on the downstream side, preferably at least 4 cm, more preferably 5 cm or more from the balloon 111a.

When the catheter 40 of this embodiment is inserted from the artery of the upper limb, the balloon 111a expanded in the aorta receives a blood flow and is strongly pulled in the distal direction. This becomes a force pulling the catheter 40, and stress may be applied to a portion where the aortic wall and the catheter 40 are in contact with each other, which may cause blood vessel damage. To prevent this, (A) Change the catheter material of the contact part (for example, the material of the catheter or catheter tube is polyurethane, silicon, polyethylene, Teflon (registered trademark), polytetrafluoroethylene, polyvinyl chloride, or these (B) Change the thickness or shape of the catheter at the contact area, (C) Change the contact area with a small-diameter balloon. It is preferable to reduce the stress on the blood vessels and enable long-term indwelling by using one or a combination of two or more measures such as mounting and expanding as a cushion.
Similarly, it is preferable to fix the catheter 40 without obstructing the above-described arterial pressure measurement or the like at the portion where the catheter 40 has come out of the body so that the catheter 40 is not drawn into the blood vessel.

  When the catheter is inserted from the artery of the lower limb, the balloon expanded in the aorta can receive a blood flow and be strongly flowed in the peripheral direction. This becomes a force that pushes back the catheter, which may cause the catheter shaft to be bent and the entire catheter to come out of the blood vessel. In order to prevent this, the rigidity of the catheter shaft is increased so as not to bend. Further, it is preferable to fix the entire catheter to the lower limb etc. outside the blood vessel so that the position does not shift in the long axis direction.

  The known balloon catheter is usually used for the purpose of expanding a stenotic lesion, and there is no usage like the catheter 40 of the present embodiment in which the balloon catheter is held in the lumen with an expansion less than the diameter of the lumen. It was. The catheter 40 of this embodiment is also novel in this respect.

  According to the literature, it is known that patients with DCI in SAH patients are about 27% lower in CBF than patients without DCI. Therefore, if an increase in cerebral blood flow of about 20-30% is obtained, it is expected to have an inhibitory effect on DCI. In order to examine the preferable degree of occlusion (the degree of occlusion is expressed as a percentage) with the catheter 40 of this embodiment, the relationship between the degree of occlusion and cerebral blood flow was examined for healthy pigs. The effect of increasing flow was seen, and no obvious adverse phenomenon was seen up to 70%. On the other hand, when the degree of occlusion of the aorta approaches 100%, the increase in blood pressure in the upper limbs, the decrease in blood pressure in the lower limbs, and the increase in the afterload on the heart increase rapidly. Therefore, it is preferable to adjust the degree of occlusion of the aorta so as to be within the range of the degree of occlusion that has an effective therapeutic effect and falls within a load acceptable to the human body.

Next, how to use the catheter 40 will be described.
Following normal arterial catheterization procedures, insert into the artery from the left or right brachial artery or left and right iliac arteries and advance to the part of the descending aorta after the left subclavian bifurcation under fluoroscopy. At this site, a lumen 111 having a balloon is injected with a mixture of physiological saline and contrast medium, and the balloon 111a is slowly expanded. When the catheter 40 is inserted into the artery from the left or right brachial artery, if the expansion of the balloon 111a creates a significant blood flow limitation, the blood pressure measured at the distal side, ie, lumen 112, begins to decrease, the central side, That is, the blood pressure measured by the lumen 115 increases. When the catheter is inserted into the artery from the left and right iliac arteries, the blood pressure measured on the peripheral side, that is, the lumen 115 starts to decrease, and the blood pressure measured on the central side, that is, the lumen 112, increases. The expansion of the balloon 111a can be adjusted by using the blood pressure on the downstream side of the balloon 111a and, if necessary, the blood pressure on the upstream side as an index.

  Therefore, when the catheter 40 is inserted into the artery from the artery of the upper limb, specifically, the left or right upper arm artery, the blood pressure measured by the lumen 112 downstream of the balloon 111a becomes a predetermined value. Thus, the degree of occlusion is adjusted by adjusting the degree of expansion of the balloon 111a. If necessary, the degree of expansion of the balloon 111a so that the blood pressure measured with the lumen 112 on the downstream side of the balloon 111a and the blood pressure measured with the lumen 115 on the upstream side of the balloon 111a have predetermined values, respectively. The degree of occlusion is adjusted by adjusting.

  Further, when the catheter 40 is inserted into the artery from the lower limb artery, specifically, the left and right iliac arteries, the balloon 111a has a predetermined value so that the blood pressure measured by the lumen 115 on the downstream side of the balloon 111a becomes a predetermined value. The degree of occlusion is adjusted by adjusting the degree of expansion. If necessary, the degree of expansion of the balloon 111a so that the blood pressure measured by the lumen 115 on the downstream side of the balloon 111a and the blood pressure measured by the lumen 112 on the upstream side of the balloon 111a have predetermined values, respectively. The degree of occlusion is adjusted by adjusting.

  The catheter 40 according to the present embodiment is inserted from the artery of the upper limb so that the catheter 40 and the balloon 111a are placed in the forward direction with respect to the blood flow, and blood expected when an obstruction is placed in the aorta. The displacement of the balloon position due to the flow, the bending of the catheter, the floating of the balloon, etc. can be minimized.

  By placing a balloon 111a as an obstruction at a site downstream of the left subclavian artery 6 of the aorta, it is possible to modify the physiological hemodynamics of the human body and dissociate the blood pressure between the upper limb and the lower limb. That is, the blood volume toward the trunk organ and the lower limbs through the descending aorta can be decreased and the blood pressure can be decreased, the blood volume toward the brain and the upper limb can be increased and the blood pressure can be increased.

  By using this device as a prophylaxis after the onset of DCI or before the onset in SAH patients, it is possible to increase CBF, antagonize spasm and prevent cerebral infarction. Increased cardiac output by large volume infusions and cardiotonic drugs as in the prior art, and increased blood pressure by pressor drugs affect the whole body, and increased renal blood flow compensates for increased urine output. The effect does not last. On the other hand, since the catheter 40 of this embodiment increases only the blood flow of the head and decreases the renal blood flow, the compensation effect is not exhibited and the effect can be maintained. Furthermore, since only the blood pressure in the head can be selectively increased, high-capacity Ca antagonists can be administered without worrying about the deterioration of cerebral perfusion due to low blood pressure, and pharmacotherapy that is currently effective It is possible to maximize the effect. In addition, the increase in blood pressure that occurs as a physiological response for brain protection during the occurrence of cerebral ischemia is only a burden for organs other than the brain, but this device increases blood pressure in the head and increases blood pressure outside the head. The pressure load can be reduced by lowering.

  Since the risk of DCI lasts from several days to 10 days or more, after insertion of the catheter 40 of this embodiment, the transition of cranial nerve findings and the blood pressure on the central and peripheral sides of the balloon are observed, and the size of the balloon is determined. By adjusting, the degree of obstruction is changed, and the treatment effect is adjusted until the spasm phase is completed (about 10 days), and then removed.

An example of a cerebral blood flow adjustment system using the catheter 40 of the present embodiment will be described.
FIG. 9 is an explanatory diagram of the cerebral blood flow adjustment system 50. In FIG. 9, the catheter 40 can have the same configuration as that described above with reference to FIG. 8, and the same reference numerals are given in FIG. 9. Therefore, in the following description, a duplicate description of the catheter 40 is omitted.

  The cerebral blood flow adjustment system 50 includes a sensor 51 connected to the lumen 112 of the catheter 40 and a sensor 52 connected to the lumen 115. The sensors 51 and 52 are, for example, arterial pressure transducers. The arterial pressure information from the sensors 51 and 52 is input to the adjustment device 53.

The adjustment device 53 includes a comparison unit 531, a calculation unit 532, and an adjustment unit 533. The comparison unit 531 compares the target value of the arterial pressure in the lumen 112 with the actual value of the arterial pressure in the lumen 112 output by the sensor 51. In addition, the target value of the arterial pressure in the lumen 115 is compared with the actual value of the arterial pressure output by the sensor 52.
The calculation unit 532 obtains an appropriate degree of occlusion of the artery from the comparison result by the comparison unit 531.
The adjusting unit 533 outputs a signal for adjusting the expansion rate of the balloon 111 a based on the degree of occlusion of the artery obtained by the calculating unit 532. The signal output from the adjusting means 533 is input to the pump 54 for adjusting the expansion rate of the balloon 111a. The pump 54 expands and contracts the balloon 111a to adjust the degree of occlusion.

  Although the cerebral blood flow adjustment system 50 in FIG. 9 has the adjustment device 53, the adjustment device 53 may not be provided, and the occlusion degree may be manually adjusted instead of the adjustment device 53.

  The catheter 40 of this embodiment showed the example which has the balloon 111a as a blood flow control body in the lumen | rumen 111. FIG. The blood flow control body is not limited to the balloon 111a. Examples of blood flow control bodies are shown in FIGS. These blood flow control bodies can be used by being attached to the distal end portion of the catheter, or can be used separately from the catheter.

  The blood flow control body 11A shown in FIG. 10 has the same structure as described above with reference to FIG. 8, and is a balloon whose tip is expanded in the blood vessel to limit the cross-sectional area of the aorta. The degree of occlusion can be adjusted by changing the degree of expansion of the balloon.

  The blood flow control body 11B shown in FIG. 11 has a basket or umbrella-like structure that expands in the direction perpendicular to the axis by shortening the tip in the axial direction. The degree of occlusion can be adjusted by changing the degree of expansion of the basket or umbrella.

  The blood flow control body 11C shown in FIG. 12 has a structure in which a tip is attached to a self-expanding umbrella-like structure. This is placed in the blood vessel, and the degree of occlusion is adjusted depending on how much the umbrella-like structure is extracted from the catheter 40 or the like.

  The blood flow control body 11D shown in FIG. 13 is a network structure having a self-expanding tip. This is placed in the blood vessel, and the degree of occlusion is adjusted depending on how much of the network structure is taken out from the catheter 40 or the like.

  The blood flow control body 11E shown in FIG. 14 is a balloon whose tip is expanded in the axial direction into the blood vessel. Even if the cross-sectional area does not expand in the radial direction of the axis as in the balloon of FIG. 10, the blood flow control body 11E becomes more effective in restricting blood flow as the balloon expands in the axial direction. Adjust the degree of occlusion with.

  The blood flow control body 11F shown in FIG. 15 is a coil of shape memory alloy that forms a disk shape when the distal end portion is deployed in a blood vessel. The degree of occlusion is adjusted because the size of the disk changes depending on how long the coil extends from the lumen opening.

  The blood flow control body 11G shown in FIG. 16 is a two-layer funnel-shaped structure with a tip portion having a hole in a slope, and one of the two-layer stack is rotated with respect to the other one. The degree of occlusion is adjusted by changing the opening area of the hole in the slope by rotating it relatively around the axis at a predetermined angle.

  The blood flow control body 11H shown in FIG. 17 is a band or clip that narrows the blood vessel wall from the outside, and adjusts the degree of occlusion by changing the degree of the band or clip sandwiching the blood vessel wall.

  The blood flow control body 11I shown in FIG. 18 creates an intramural hematoma by injection into the aorta media, and narrows the inner wall by thickening the aortic wall. The degree of occlusion is adjusted by adjusting the amount of medicinal solution to be injected.

  The blood flow control body 11J shown in FIG. 19 narrows the aortic wall by hooking two ridge-like wires from the catheter or the like to the aortic wall in the aorta and then pulling back to the catheter or the like. The degree of occlusion is adjusted by adjusting the degree to which the wire is pulled back.

  The blood flow control body 11K shown in FIG. 20 increases the blood resistance by installing a helical structure in a blood vessel. The spiral structure can be accommodated in, for example, a catheter, and adjusts the blood resistance and adjusts the degree of occlusion according to the length of the catheter from the catheter into the blood vessel.

  The blood flow control body 11L shown in FIG. 21 has a hollow cylindrical structure in which two ring-shaped members are cylindrical ends and the waistline is covered with a film in a blood vessel, and one ring-shaped member is the other ring. The aortic lumen is narrowed by rotating the cylindrical member relatively around the central axis and twisting the film. The degree of occlusion is adjusted by adjusting the degree of twist.

  In the blood flow control body 11M shown in FIG. 22, a valve structure having one or more rotatable blades is placed inside the aorta inside the cylindrical member, and the inclination of the blades is received by receiving an external signal. The degree of occlusion is adjusted by adjusting.

  Next, the blood pressure measurement unit of the catheter 40 of this embodiment will be described. In the example described above, the blood pressure measuring unit has a hollow lumen 112 opened to the arterial pressure measuring unit, filled with physiological saline or the like, and connected to an external arterial pressure transducer. Is measuring. The blood pressure measurement unit of the catheter 40 of the present embodiment is not limited to the lumen 112. For example, the blood pressure can be measured by arranging an optical fiber of a fiber optic distribution type intravascular pressure distribution measurement system.

The catheter 40 of the present embodiment already described is an example in which the blood flow control body is provided in the same catheter as the blood pressure measurement unit. But the catheter as a blood flow control system of this invention may be the structure which incorporates either a blood flow control body or a blood-pressure measurement part. In this case, the other blood flow control body or blood pressure measuring unit that is not built in one catheter may be built in another catheter, or arranged in the aorta as an independent structure. Also good.

Furthermore, neither the blood flow control body nor the blood pressure measurement unit is built in the catheter, and each may be disposed in the aorta as a separate structure. It can be understood from the embodiments of the present invention described with reference to FIGS. 1 to 4 that such a configuration is included in the present invention.
When the blood flow control body and the blood pressure measurement unit of the blood flow control system of the present invention are not built in the same instrument and are separated and placed in the aorta, the degree of freedom of the blood pressure measurement unit is increased. For example, the blood flow control body may be disposed at a predetermined position of the aorta downstream of the left subclavian artery 6, and the blood pressure measurement unit may be disposed in the aorta downstream of the blood flow control body. Alternatively, it may be placed in the femoral artery. Further, the second blood pressure measurement unit may be disposed in the aorta upstream of the blood flow control body, may be disposed in the radial artery, the brachial artery, or may be disposed in the carotid artery.

  In the blood flow control system of the present invention, as a structure when the blood flow control body is not built in the catheter, the blood flow control body is placed in a manner to be fixed to the aorta wall with a nail or the like from the inside, a signal from the outside, etc. May be a device that adjusts the degree of occlusion, or may be a device that is located outside the aorta and that adjusts the degree of occlusion by receiving a signal from the outside.

  Using healthy pigs, we obtained quantitative data on the effects of partial ligation of the descending aorta on the circulatory dynamics.

1) The target healthy pig (with a body weight of around 25 kg) was subjected to descending aortic stenosis according to the following procedure.
After induction anesthesia with ketamine hydrochloride (400-800 mg / animal, im, ketalal intramuscular injection 500 mg, Daiichi Sankyo Propharma Co., Ltd.), the tracheal cannula was intubated into the respiratory tract, and a coma ventilator (PRO) -45Va, artificial respiration was performed by Acoma Medical Industry Co., Ltd.

  2) The ventilator was set to breathing rate 10-20 strokes / min and Tidal Volume 5-15 mL / kg / stroke. Maintenance of anesthesia is performed with a mixed animal (Air: O 2 = 3: 0.2 as a guide) and 0.5 to 3% isoflurane (isoflurane inhalation anesthesia solution “Pfizer”) using an anesthetic machine for animals (NS-5000A, Acoma Medical Industry Co., Ltd.) Mylan Pharmaceutical Co., Ltd.) was inhaled, and the amount of gas was adjusted as appropriate to maintain a constant depth of anesthesia.

3) The skin of the head was incised, and an intracranial pressure measuring tube was inserted.
4) Incision of the inguinal region, the right femoral artery and the right femoral vein are exposed, a sheath introducer is inserted, and an angiographic JR catheter for blood pressure measurement is inserted from the artery, and a site about 10 cm below the ligature Detained at. From the vein, a Swanganz catheter was advanced to the pulmonary artery and placed.
5) The right lateral position was held, the chest side wall between the 4th and 5th ribs was opened, and electromagnetic blood flow meters were attached to the ascending aorta base and descending aorta.

6) After confirming the aortic arch, the lower descending aorta about 5 cm after the subclavian artery bifurcation was removed.
7) A vascular tape was wound around the exfoliated part, and the descending aorta was gradually narrowed.
8) The descending aortic stenosis was performed according to the following standard by measuring the circumference of the vascular tape around the aorta and calculating the aorta cross-sectional area calculated from the circumference.
40%, 50%, 60%, 70%, 80%, 90%, 100%, 0%

9) For each degree of stenosis, after 5 minutes have passed since stenosis, the following items were recorded.
Arterial pressure (upper and lower stenosis)
・ Cardiac output, descending artery blood flow (by electromagnetic blood flow meter)
・ Central venous pressure (CVP), pulmonary artery pressure (PAP), pulmonary artery wedge pressure (PCWP)

The recording results are shown in FIGS.
In FIG. 23, the horizontal axis is the aortic area occlusion rate, the left vertical axis is the blood pressure above the ligation part of the aorta (mmHg) and the blood pressure below the aortic ligation part (mmHg), and the right vertical axis is the head It is a graph made into the blood flow volume (increase% from a reference value). In the figure, the bar graph is the blood flow of the head (% change from the reference value), the line graph sBP1 is the blood pressure above the ligation part of the aorta, and the line graph sBP2 is the blood pressure below the ligation part of the aorta is there.

In FIG. 24, the horizontal axis is the aortic area occlusion rate, the left vertical axis is the blood pressure above the ligature of the aorta (mmHg) and the blood pressure below the aortic ligation (mmHg), and the right vertical axis is the heart rate. (/ min), pulmonary artery wedge pressure (mmHg), central venous pressure (mmHg). In the figure, the line graph sBP1 is the blood pressure above the ligature of the aorta, the line graph sBP2 is the blood pressure below the ligation of the aorta, the line graph HR is the heart rate (/ min), and the line graph PCWP is The pulmonary artery wedge pressure (mmHg), and the line graph CVP is the central venous pressure (mmHg).
Pulmonary artery wedge pressure PCWP is one of the indicators of heart failure. Central venous pressure is one of the indicators of effective circulating plasma volume.

  As shown in FIG. 23, the blood flow in the head increased from an occlusion rate of about 50% or more, and the effect of ligation of the aorta was observed. In addition, the blood pressure above the ligature of the aorta hardly changed even when the occlusion rate was increased up to about 70%. Therefore, it is understood that when only the blood pressure above the ligation part of the aorta is measured, it is difficult to adjust the degree of occlusion based on the blood pressure measurement value.

The blood pressure below the ligation part of the aorta is gradually decreased as the occlusion rate is increased, and the degree of occlusion can be adjusted based on the measured value of blood pressure.
When the occlusion rate was up to 70%, the blood pressure above the ligation part of the aorta hardly increased and the blood flow in the head increased. This phenomenon indicates that it is possible to treat or prevent ischemic brain disease by increasing the blood flow in the head with almost no risk of re-bleeding in the skull due to an increase in blood pressure.

  From FIG. 24, up to about 70% occlusion rate, no obvious adverse phenomenon was observed with respect to heart rate HR and pulmonary artery wedge pressure PCWP. This indicates that the ischemic brain disease can be treated or prevented by increasing the blood flow in the head without adversely affecting the cardiac function as the degree of obstruction is adjusted. Similarly, there was no significant change in central venous pressure CVP. This shows that even if there is a decrease in blood flow to the trunk lower limbs, a decrease in effective circulating plasma volume is not observed.

  The technology necessary for realizing the blood flow control system of the present invention is only a technology for manufacturing a large-diameter balloon catheter. Although it is used for different purposes, it is used for IABP balloons, some ablation balloons, and Inoue used for mitral valvuloplasty. Since it can be realized by diverting the technology of products that actually exist, such as balloons, the practical hurdles for manufacturing are not high. The effect of increasing cerebral blood flow can be said to be certain from the results of hydrodynamic simulations, animal experiment results, NeuroFlo data, and the like. In addition, many clinical trials, etc. that look at the effects of specific drugs on DCI use cerebral blood flow as a parameter, and there is a certain amount of cerebral blood flow increase directly linked to DCI treatment in this specialized field. Because there is a consensus (but there are few drugs that have the effect of increasing cerebral blood flow), we believe it is likely to be effective.

From a market perspective, it is said that approximately 30,000 patients with aneurysmal subarachnoid hemorrhage occur in Japan annually, and 115,000 in Japan, the United States, and Europe, and DCI merges with 36.5%. Therefore, 42000 SAH patients annually have DCI. The merger of DCI results in additional treatment for rescue, treatment of cerebral infarction, and extension of ICU duration, resulting in additional medical costs of $ 57,000 per person. In addition, if unfortunately it leads to cerebral infarction or death, there will be an economic loss of $ 228,000 per person, including potential loss due to life-long hospital visits, oral medicine, nursing care, rehabilitation, entrance to nursing care facilities, unemployment, etc. doing. If this is multiplied by the 42,000 mentioned above, DCI is actually incurring additional medical expenses of $ 5B in Japan, the US and Europe. At present, there is no treatment that has been confirmed to be effective as a treatment for DCI, but if this can be reduced, a very large economic effect can be expected. If a reimbursement price equivalent to that of a medical device with the same effect is attached, the price of the catheter is expected to be about $ 5,000, and the market size will reach up to $ 210M. Once validated, the indications for traumatic subarachnoid hemorrhage are expected to expand, in which case the market will reach a maximum of $ 1B.
In addition to DCI, cerebral infarction, transient cerebral ischemic attack (TIA), which is a condition before cerebral infarction, moyamoya disease, cerebral artery bypass surgery, carotid endarterectomy ( CEA)-Can be widely applied to ischemic brain diseases such as carotid artery stenting (CAS) and cerebrovascular dementia.

DESCRIPTION OF SYMBOLS 10,20 Blood flow control system 11 Blood flow control body 12 Blood pressure measurement part 13 Adjustment means 14 Notification means 30, 40, 60 Catheter

Claims (10)

  A blood flow control system comprising: a blood flow control body capable of adjusting a blood flow volume by adjusting a degree of occlusion of a blood vessel; and a blood pressure measurement unit that measures blood pressure downstream of the blood flow control body.   The blood flow control system according to claim 1, wherein the blood flow control body increases the blood flow in the brain by decreasing the blood flow downstream to the artery.   3. The blood flow control system according to claim 1, further comprising an adjusting unit capable of adjusting a degree of occlusion of a blood vessel by the blood flow control body based on blood pressure information measured by the blood pressure measuring unit.   The blood flow control system according to any one of claims 1 to 3, further comprising a second blood pressure measurement unit that measures blood pressure upstream of the blood flow control body.   The adjustment means can adjust the degree of occlusion of the blood vessel by the blood flow control body based on blood pressure information from the blood pressure measurement unit and second blood pressure information from the second blood pressure measurement unit. The blood flow control system according to claim 4.   The blood flow control according to any one of claims 1 to 5, further comprising notification means for notifying that the degree of occlusion of a blood vessel by the blood flow control body needs to be adjusted based on blood pressure information from the blood pressure measurement unit. system.   The blood flow control system according to any one of claims 1 to 6, which is a catheter including the blood flow control body and the blood pressure measurement unit.   Using a blood flow control system having a blood flow control body capable of adjusting the blood flow volume by adjusting the degree of occlusion of the blood vessel, and a blood pressure measurement unit for measuring blood pressure downstream of the blood flow control body from the artery, A treatment method comprising adjusting an arterial blood flow by adjusting a degree of occlusion of a blood vessel by the blood flow control body while measuring blood pressure by the blood pressure measuring unit.   The method according to claim 8, wherein the blood flow control body increases the blood flow of the brain by decreasing the blood flow downstream of the artery from the blood flow control body. The blood flow volume of the artery is adjusted by adjusting the degree of occlusion of the blood vessel by the blood flow control body while measuring the blood pressure by a second blood pressure measurement unit located upstream of the blood flow control body. The treatment method according to 8 or 9.