23.1.1 Clinical Presentation

An 80-year-old female with a past medical history of hypertension, diabetes mellitus type II, kidney tumor, atrial fibrillation, and peripheral arterial disease was transferred to the hospital after she became suddenly unresponsive, was unable to speak, and experienced a right-sided weakness. She received tissue plasminogen activator 3 hours following symptom onset.

At presentation, the patient’s Glasgow Coma Scale was 6, withdrawing bilaterally to pain, less on the right side, and was not opening her eyes to verbal stimulus. The National Institutes of Health Stroke Scale (NIHSS) score was 19. She was intubated in the emergency department.

23.1.2 Imaging Workup and Investigations

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  Noncontrast computed tomography (NCCT), performed at 4 hours 50 minutes, demonstrated no signs of stroke (Fig. 23.1a).

  
  
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  CT angiography showed suspected left M2 occlusion (Fig. 23.1b).

  
  
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  Perfusion imaging was not conducted as patient was taken for mechanical thrombectomy.

  

23.1.3 Diagnosis

Left M2 occlusion in the setting of atrial fibrillation.

23.1.4 Treatment

23.1.5 Progress

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  Postprocedure, the patient was moving all four extremities with mild weakness on the right side. She was extubated on the following day. Aphasia gradually improved and the patient was oriented to herself and to place.

  
  
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  NCCT at 24 hours showed no signs of acute infraction.

  
  
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  The patient was started on aspirin 81 mg.

  
  
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  The patient was discharged to a skilled nursing facility.

23.1.6 Discussion

Mechanical thrombectomy underwent rapid development in the past few years after being proven superior to medical treatment for the management of ischemic stroke. MERCI retriever was one of the first devices to be used for that purpose. ^{1 ,​ 2} The distal access catheter (DAC) is the largest catheter that can be easily tracked into an anterior intracranial vessel, such as the M1 or A1 segments. Multiple studies evaluated the utility of DAC in different endovascular procedures, including embolization of cerebral aneurysms, arteriovenous malformation, and mechanical thrombectomy. ^{1 ,​ 3 ,​ 4 ,​ 5 ,​ 6 ,​ 7 ,​ 8 ,​ 9 ,​ 10 ,​ 11 ,​ 12 ,​ 13} The use of DAC during mechanical thrombectomy was originally developed to compliment the MERCI retriever and facilitate faster and safer deployment, distal support, trackability and accessibility to cerebral arterial clots at the time of thrombectomy, with the goal of achieving a higher clot retrieval rate. ³ The principle is to provide distal support to the microcatheter and align the pulling force on the clot in line with the vessel toward the DAC, thereby achieving safer and more effective clot retrieval.

The same concept of distal access with a large-bore catheter was originally provided by aspiration catheters, like the Penumbra, until DACs facilitated the application of a very similar principle to stent retrievers. ¹⁴ In our case, a Sofia catheter was used as DAC to facilitate Trevo access for clot retrieval. The advantage of having a large inner lumen and shorter length is to increase the effective flow rate out of the catheter according to the Hagen Poiseuille equation. ³ Kalia et al compared the use of DAC with the largest Penumbra reperfusion catheter. They found that DAC had 1.5 times greater flow when compared to Penumbra, which may be related to the lumen diameter and shorter length of the DAC. ³ Currently, DAC catheters are used alone as aspiration catheters or in conjunction with stent retrievers to improve access to tortuous anatomy or aid retrieval with joint aspiration.