Microcatheters and microwires:
Basics and distinguishing features
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Microcatheter |
Microwire
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• OD ≤ 3-F (1F=0,33mm)
• Coaxially inserted via a (guiding)catheter
• Navigated over a „microwire“
• Used for superselective catheterization
• Coils, particles, glue, chemo ect. may be applied
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• Diameter ≤ 0,018`` (0,01``= 0,25mm)
• Used for navigation of a microcatheter
• Shapeable ['ʃeɪpəbl] 可成形的 and steerable
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多微导管操作：分叉动脉瘤栓塞 |
术后 |
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微导丝引导微导管 |
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Microcatheter
Flexible
Easy to navigate, good trackability
Once in position stable
Good visibility of the tip
High ration of OD/ID (for larger particles, angio via microcath.)
Compatibility (Lipiodol, Glue,DMSO, alkohol)
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Nitinol slotted [ˈslɒtɪd] 开槽 tube |
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• Typically the shaft is braided ['breɪdɪd] 编织
– Tungston [ˈtʌŋstən] 钨 spiral
– Stainless steel spiral
– Nitinol slotted [ˈslɒtɪd] 开槽 tube
– Fiber braiding
• Catheter has different zones
– stiffer near the hub for a good pushability,
– flexible at the distal end
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• Fiber braided: keeps the shape after steam shaping – surface may be irregular
• Metal braided: more resistent to shaping - surface remains smooth
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surface may be irregular |
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surface remains smooth |
Hiro Kiyosue et al. AJNR Am J Neuroradiol 2005;26:2610-2616
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OD
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ID
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Braiding
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PSI max.
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Renegate
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2,4F/2,8F
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,021´´/ ,027´´
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fiber,platinum
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800
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Direxion
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2,4F/2,8F
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,021´´/ ,027´´
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Nitinol
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1200
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FasTracker
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2,8F
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,024´´
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300
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Progate
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2,0F/ 2,4F/
2,7F,/2,8F
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,019´´/,022´´/,025´´/,027´´
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Tungsten
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750 - 900
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Cantata
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2,5F/2,8F
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,021´´/,025´´
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steel
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1200
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Minimal lumen of the guiding catheter
for 2,5F: ,035 inch
for 2,8F: ,038 inch
Largest particles (non compressable)
for ,021´´ 500µm
for ,025´´ 700µm
For angio via the guiding catheter: Have at least 1-F size difference between the ID of the guiding catheter and the OD of the microcatheter
通过引导导管对血管造影：在I引导导管内径D与微导管外径（OD）之间至少有1-F大小的差异。
Larger / smaller inner lumen
Larger ID is good for:
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power CM injection (flow rates up to 5,3 ml/sec!!)
Braiding
length
CM
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Embol. with large particles
Smaller = adequat ID is needed for:
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Coilembolisation
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microcath. with an ID of ,027´´ does not accept 2mm or 3mm coils for a ,0165´´ ID
Renegate 可变 HIFLO ≠ Concerto [kənˈtʃɜrtoʊ] coil 2 or 3 mm
concerto coil
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EV3 concerto coil |
Medtronic Unveils Concerto 3D Detachable Coil |
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CONCERTO Coil Bead |
Medtronic launches Concerto 3D detachable coil system |
Compatibility
Lipiodol、DMSO、Chemo、Alcohol、Glue
starndard catheter hub
Micro guidewires
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Typically shapeable
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Preshaped (J-tip)
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Steel shaft, combination steel/nitinol, slotted nitinol hypertube
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Hydrophilic coating
Micro catheter -micro guidewires combination
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Micro wire should be ,03´´ smaller than the microcatheter
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Permanent flushing is recommended (hydrophilic coating!)
Selection of microcatheter and microwire
• There is no „best“ microcatheter and/or wire
• Material selection needs to be done according to the type of the procedure and the anatomy.
– Coilembolisation
– Particles
– Glue ect.
– Difficult anatomy
Limit your portfolio – know your material
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