Predictors for etiology of acute LVO

All fevers are not the same. The etiology determines the treatment.

Etiology of acute LVO

RBC clot

Fibrin/ hard Clot

ICAD with acute occlusion

Mechanical thrombectomy technique

aspiration; stent retriever; combination of both

Is there a way to determine etiology prior to procedure to optimize mechanical thrombectomy?

Methodology

• Retrospective study
• Inclusion criteria: acute stroke due to LVO treated by mechanical thrombectomy
• Exclusion criteria: failure to recanalize the target vessel
• Study period: April 2018 - June 2021
• Samples studied: 82

ICAD-related LVO was diagnosed if the final angiography after mechanical thrombectomy showed fixed focal stenosis or a clear tendency for reocclusion.

Thromboembolic LVO was diagnosed when there was no or minimal stenosis with sufficient blood flow and no tendency to reocclusion after recanalization.

• Red clot was diagnosed if the retrieved material was predominantly soft and rich in RBC
• White Clot was diagnosed if the retrieved content was hard and rich in fibrin

• Demographic characteristics, relevant clinical parameters, risk factors, imaging characteristics (MRI), angiographic features, and morphology of retrieved clots were compared between the ICAD-related LVO and thromboembolic LVO
• Parameters were compared using the Chi-Square/Fisher exact test for non-parametric variables, and t-test used for continuous variables
• Logistic regression analysis was used to investigate the strength of the variable association.

Results - Demographic

Results – LVO location

Results - SWI

A total of 30 clots retrieved during mechanical thrombectomy were studied and compared with SWI blooming on MRI.

Results – Clot sign (SWI)

Results – Length of clot on SWI

Results – Cut off clot length

ROC curve – Clot Length

ROC analysis demonstrated an AUC of 0.816 (95 % CI, 0.695–0.904; P = 0.0001)

 

• SWI Clot length cut off – 9.17 mm (Youden index)
• Sensitivity of 62.5 % (95 % CI, 35.4–84.8)
• Specificity of 93.2 % (95 % CI, 81.3-98.6)

Clot length cut off

Results – Watershed infarcts

Results – Need for adjunct therapy

To conclude

Limitations

• Retrospective study
• Fixed focal stenosis on final angiogram was diagnosed as ICAD LVO. Theoretically possible to have residual clot or dissection manifesting as focal stenosis
• clot assessment due to clot loss in suction and failure of retrieval in failed mechanical thrombectomy
• Clot histopathology not available due to practical limitation

Future direction

• Apply etiology-specific MT technique and its impact on clinical outcomes
• IDEAL TIME TO OPTIMISE ETIOLOGY-SPECIFIC MT TECHNIQUE