The common equipment for interventional treatment of peripheral vascular diseases should include catheter, guide wire, balloon dilation catheter, endovascular stent and stent graft, filter and various puncture instruments.
Catheter
There are many kinds of catheters for interventional diagnosis and treatment of peripheral vascular diseases, which can be divided into diagnostic catheter and therapeutic catheter.
Diagnostic catheter can be divided into selective catheter and non selective catheter.
Among them, the commonly used non selective angiography catheters are: pigtail catheter with multi lateral holes and straight head catheter with multi lateral holes. The maximum flow rate can reach 20-25ml / s. Selective angiographic catheters have different shapes according to the requirements of different parts. For example, the catheters commonly used in several branches of the aortic arch are headhunter I, II, III and Simmon I, II and III; RDC and Simmon I, II and III catheters are used for renal artery and vein; cobra is used for iliac artery and vein 1. Type Ⅱ and type Ⅲ catheters and SHK type catheters were used.
Most of the selective contrast catheters have no side holes, and the maximum flow rate is 7-8 ml / s. The selection of catheters used in the treatment of different external vascular sites is basically the same as the selective angiographic catheter mentioned above. In addition, there is a thrombolytic catheter for the treatment, which is designed with multi lateral holes. The length of the perfusion section can reach 7.cm, which can directly penetrate into the thrombus for local perfusion therapy.
There is also a guiding catheter which can be used for auxiliary diagnosis and treatment. It is a coaxial inner core design. Its wall is thin and the cavity is large, which is convenient for other instruments to pass through the cavity. The outer diameter can reach 7-9f. Its supporting force is also strong, the head end is visible and easy to locate. Because the head end can be designed into different shapes, it can be used in different vascular parts, such as head and neck artery, renal artery, iliac artery and multi-purpose type.
Guide wire
The guide wire is the "forerunner" to enter the human peripheral blood vessels. Its function lies in: ① introduction; ② support; ③ opening; ④ exchange.
At present, the surface of the guide wire is generally covered with hydrophilic membrane to ensure its lubrication and penetration in the vascular cavity. It is often divided into ordinary (soft) guide wire, hard guide wire and special micro guide wire. Among them, the common (soft) guide wire is commonly used for radiography and treatment, with a diameter of 0.035in (0.89mm), with certain hardness and torsion control force, and the length can be 145cm, 180cm and 260cm.
Its front end can be designed as a soft head with different length (2-locm) to reduce the damage to the inner wall of blood vessel. The diameter of the guide wire is 0.035in (0.89mm) and 0.038in (0.97mm), and its length is 90cm, 180cm and 260cm. The head end is a soft head design (3-7cm long), which can be curved or straight.
The micro guide wire is mainly used in renal artery and head and carotid artery angioplasty. It is made of super elastic memory metal material with strong supporting force. It is easy to pass through the narrow section of blood vessel without damaging the inner wall of blood vessel. Most of them are 0.018in (0.46mm) in diameter and 300cm in length.
Balloon catheter
It is used for PTA treatment of peripheral vessels. According to the size of the balloon diameter, it can be divided into ultra-small balloon (diameter 2-5mm), ordinary balloon (diameter 5-lomm) and super large balloon (diameter ≥ 12mm).
At present, because of the ultra-thin balloon design, 5-8mm diameter balloon can pass through 5F catheter sheath, and 9-10mm diameter balloon can pass through 6F catheter sheath. In practice, the choice of balloon diameter is mostly determined by the size of the vascular diameter of the treatment site (normal) and the nature of the eye and mortar. PTA treatment follows the principle of expanding from small to large in order to improve the safety of PTA treatment, especially for larger diameter vessels (aorta, vena cava and iliac artery and vein).
If pre dilation is needed in special high stenosis sites (such as carotid artery and renal artery), balloon catheter with diameter of 3-4mm should also be selected for expansion; when post expansion is required after stent implantation, balloon catheter with similar size to normal diameter should be selected. For example, the balloon size range of aortic PTA treatment was 10-16mm, carotid artery 8-lomm, subclavian artery 8-lomm, renal artery 5-7mm. Iliac artery 8-12 mm, femoral artery 6-7 mm, popliteal artery 4-5 mm. Superior inferior vena cava was 16-24mm, iliac vein was 10-12mm, femoral vein was 8-lomm, and hepatic vein was 10-12mm.
For the selection of balloon length, if the lesion segment is short (length ≤ 4. OCM), the balloon with the length of 4.0-6.ocm should be selected for one-time expansion. If the diseased segment is longer, the balloon should be selected to expand according to the actual conditions. In order to improve the effect of PTA, a certain range should be overlapped when the adjacent parts are expanded.
Endovascular stent
Endovascular stents were selected according to the location, diameter and length of the lesion. When using endovascular stent in important branch or branch position, the larger mesh should be selected as far as possible, such as the bifurcation of internal and external iliac artery, the branch of vertebral artery near subclavian artery and the place where hepatic vein converges into inferior vena cava. The diameter of the stent should be about 10% larger than the normal diameter of the implanted site or imm. In this way, the stent can effectively keep the lumen unobstructed with good radial expansion force.
The length of stent should be 1 cm across both ends of the lesion. If the lesion segment is longer and more than one stent is needed, the adjacent two stents should overlap 0.5-1.cm.
From the point of view of stent types, it can be divided into self tensioning stent, balloon expanding stent and temperature memory alloy stent. The metal materials of the bracket are stainless steel, tantalum and nickel titanium alloy.
At present, all kinds of vascular stents made of NiTi alloy are the most popular
① Bard's products include Luminex stent, conformax stent and fluent stent for arteriovenous fistula and aneurysm.
② Cordis products, such as smart self expanding stent, Palmaz ball expanding bracket and smart control self expanding stent, etc.
③ German optimed products, such as sinus compliant stent, sinus aortic stent (diameter 18-28mm), sinus-c arotid carotid stent and sinus TIPSS 40. Bracket, etc.
④ The products of American cook company, such as Z-type stainless steel self expanding stent (mainly used for vena cava system), stent Zilver stent (mainly used for renal artery and carotid artery), and zenith stent graft system covered with polyester fiber membrane for the treatment of thoracic and abdominal aortic aneurysm.
⑤ Boston products include stainless steel self expanding Wallstent for iliac, femoral and tips treatment and Wallcraft for peripheral arteriovenous fistula and aneurysm repair.
⑥ Ev3 products, such as prolege self expanding nitinol stent (carotid artery, subclavian artery and iliac artery), para mount ball expandable stent for renal artery, and intracoil wound self expanding stent mainly used for lower extremity popliteal artery.
Venous filter
Venous filter is a kind of metal device designed to prevent pulmonary embolism caused by continuous detachment of embolus in vena cava system. There are many kinds of filters to choose. The selection of filters should be based on the shape of vena cava, the size of diameter, the location of thrombosis, the course of thrombosis and the age of patients.
In the case of inferior vena cava, it is usually placed below the opening of the lowest renal vein. If there is thrombus in the inferior vena cava at the level of renal vein or 3-4 cm below it, the filter should be placed above the renal vein level. If in the superior vena cava, the filter should be placed in the small section between the cephalic brachial vein joining the superior vena cava to the superior vena cava and the right atrium.
If both iliac and femoral veins have thrombus or occlusion, one side of internal jugular vein or anterior cubital vein can be selected. If the time of thrombus formation is short (1-2 weeks), it is estimated that the thrombolytic effect is good and the patient's age is younger, the temporary filter should be used. If the deep venous thrombosis of the following limbs has a wide range and a long time of thrombosis, it is not easy to dissolve the thrombus in a short time and the patient is older, permanent filter can be considered.
In addition, the diameter of the vena cava measured after angiography must be referred to when selecting the filter. At present, the commonly used filters are mostly suitable for the case of the diameter of the vena cava ≤ 28mm. For the diameter of the vena cava more than 28mm, there are three kinds of filters that can be selected in China at present: anther permanent filter (the maximum diameter is 34 mm), the trap ease permanent filter (the maximum diameter is 30 mm) and bird's nest permanent filter.
The types of imported filters commonly used in China are as follows:
① Gunther Tulip, a product of cook company in the United States, is recyclable and can be implanted through jugular vein and femoral vein. It is designed for permanent implantation and can be recovered through jugular vein within LOD after implantation. Because it is made of non-magnetic material, it is suitable for MRI examination. Bird's nest filter is a multi-layer reticular filtration system composed of stainless steel wire. It can be inserted into the jugular and femoral veins with good fixation effect. It can be used for the vena cava with a diameter of 40mm.
② The trap ease permanent filter and opt ease temporary filter are produced by cordis company. All of them were made of nickel titanium alloy, and the maximum diameter of the vena cava was 30mm. At present, the external diameter of the permanent vena cava filter is the thinnest (6F). It can be released through the jugular, brachial and femoral veins. The lower end of the optease filter (femoral vein) has a recovery hook, which can be recovered through the femoral vein pathway within 2 weeks after implantation. It is suitable for MRI examination.
③ Simon nitinol permanent filter 13, produced by bard company, USA, is suitable for those whose diameter of vena cava is less than 28mm. In the stenotic vessels, it can be adjusted into spider shape to capture thrombus, which can be input by jugular, femoral and cubital veins, but the filters placed through the femoral, cervical and anterior cubital veins should not be mixed. The filter is non-magnetic and does not affect the MRI examination. When the temporary filter is recovered, a long sheath or guide catheter with a diameter of 8-10f should be selected, and a special recovery hook, such as a gooseneck trap or a self-made trapper made by the guide wire, should be used to recover the temporary filter.
Puncture needle
Vascular puncture is the first step to complete interventional angiography and interventional therapy, and it is also the necessary guarantee of Seldinger technology.
The puncture needle generally includes ordinary puncture needle and special puncture needle. The common puncture needle is divided into single wall puncture needle and cannula puncture needle. Generally, the needle length is 7.ocm, the needle diameter is 18-19g, and 0.015in-0.038in guide wire can be inserted. The single wall puncture needle is made of stainless steel with a single component, and the needle tip is inclined. It is mainly used for the puncture of the anterior wall of blood vessels. The trocar needle is composed of an outer sleeve and a needle core. At present, most of the needle cores are hollow needles with sharp needle tip and exposed outside the outer sleeve. The outer sleeve is made of plastic. The puncture needle is inserted into the vascular lumen, the needle core is removed, the outer sleeve is left in the lumen, and the guide wire is sent along the outer tube lumen. It is often used for puncture of common parts of peripheral artery and vein.