Microguidewire Stiffness [Neurosurgery Wiki]

This page is read only. You can view the source, but not change it. Ask your administrator if you think this is wrong.
===== Microguidewire Stiffness =====

**Definition:**  
Microguidewire stiffness refers to the **degree of resistance a microguidewire offers to bending or deformation**. It is a critical property influencing its **navigability, pushability, and support** during endovascular procedures, especially in neurointervention.

**Clinical relevance:**  
  * **High-stiffness** wires improve support and penetration power but may increase the risk of vessel trauma.  
  * **Low-stiffness** wires are more flexible and atraumatic but may lack support and can prolapse in tortuous anatomy.  
  * The choice of stiffness must balance **trackability**, **safety**, and **device compatibility**.

**Determinants of stiffness:**  
  * Core material (e.g., stainless steel, nitinol)  
  * Tapered design and distal profile  
  * Surface coating (hydrophilic vs. hydrophobic)  
  * Inner construction (solid core vs. coiled)

**Related terms:**  
  * [[trackability]]  
  * [[pushability]]  
  * [[torque response]]  
  * [[steerability]].

===== Experimental in vitro bench studies =====


In a [[Experimental]] [[in vitro]] [[bench]] study using [[silicone]] [[vascular]] [[model]]s  
Sakuta et al.  
from UCLA, Los Angeles & Jikei Univ, Tokyo (neurotrauma/neuroendovascular labs)  
published in the [[Interventional Neuroradiology Journal]]
to assess whether stiffer microguidewires improve catheter [[trackability]] and reduce kickback during navigation in [[tortuous]] intracranial [[vessel]]s.  
Increased microguidewire stiffness reduces required pushing force and diminishes wire kickback, thus improving catheter deliverability
((Sakuta K, Hanaoka Y, Ghovvati M, Molaie A, Imahori T, Fukuda KA, Tateshima S, Kaneko N. [[Microguidewire stiffness]] for [[microcatheter]] and [[aspiration]] [[catheter]] [[navigation]] in [[tortuous vessel]]s. Interv Neuroradiol. 2025 Jun 30:15910199251352883. doi: 10.1177/15910199251352883. Epub ahead of print. PMID: 40589194.)).

=== Critique ===

1. **Methodology strength:** Controlled in‑vitro design with reproducible silicone models is well‑suited to isolate stiffness effects.  
  
2. **Stiffness [[quantification]]:** Using Stryker Synchro Select wire variants (Soft, Standard, Support) provides relevant clinical-grade comparison. 
However, the exact mechanical differences (e.g. bending modulus) are not detailed.  
  
3. **Force & kickback [[metrics]]:** Objective measurements strengthen the analysis, but data on statistical significance, sample size, or measurement error is missing from abstract.  
  
4. **Model [[limitation]]s:** Silicone vasculature lacks tissue compliance, blood flow dynamics, and vessel elasticity—factors that could affect real‑world performance.  
  
5. **Clinical [[correlation]]:** Results support anecdotal practice (stiffer wires help), but no in‑vivo or patient outcome data. Potential trade‑offs—like vessel trauma or perforation risk—are not addressed.  
  
6. **[[Bias risk]]:** Industry‑sponsored use of proprietary wires may introduce bias; disclosure is absent.

=== Verdict ===  

**Score:** 6.5 / 10  

**Strengths:** Experimental rigor, objective metrics, direct relevance to endovascular technique.  

**Weaknesses:** Limited external validity, incomplete statistical detail, no safety assessment.  

=== Takeaway for neurosurgeons ===  
Stiffer microguidewires can ease catheter navigation in highly tortuous intracranial vessels by reducing kickback and required push forces. Use these findings to inform wire selection—balancing navigability with safety in complex anatomies.

=== Bottom line ===  
This [[in vitro]] [[study]] confirms that guidewire [[stiffness]] improves [[tractability]] and decreases kickback during [[catheter]] delivery through [[tortuous]] vascular segments. [[Clinical validation]] and [[safety]] profiling remain essential before changing practice.

==== Citation ====

Corresponding author: Kenichi Sakuta, e‑mail coverage not listed in abstract/public data.