Higher Rate of Benign Hemorrhage Seen with Thrombectomy for Acute Stroke

Mechanical thrombectomy with self-expanding retrievable stents may result in subarachnoid hemorrhage in as many as 1 out of every 6 acute stroke patients, though the complication does not appear to affect clinical outcomes, according to a small study published online January 3, 2013, ahead of print in Stroke.

Researchers led by Woong Yoon, MD, PhD, of Chonnam National University Hospital (Gwangju, South Korea), looked at 74 consecutive patients with acute ischemic stroke who underwent mechanical thrombectomy with a Solitaire stent (ev3/Covidien, Irvine, CA) as first-line treatment. All patients underwent nonenhanced CT scans before and after endovascular therapy with follow-up MRI if intracranial lesions were detected on CT.

Twelve patients (16.2%) showed a subarachnoid hemorrhage, either pure (n = 4) or mixed (hemorrhage and contrast extravasation; n = 8). Five of the 12 hemorrhages disappeared on 24-hour follow-up CT. Roughly half of the patients with and without subarachnoid hemorrhages were treated with IV thrombolysis prior to mechanical thrombectomy, and there was no difference between the 2 groups in the prevalence of intracranial atherosclerosis.

No Effect on Clinical Outcomes

One-third of patients with subarachnoid hemorrhage (n = 4) received rescue angioplasty after failure of mechanical thrombectomy compared with 9.7% of those without hemorrhage (P = 0.05). Intracranial stenting was not used in any patient.

Patients with subarachnoid hemorrhage exhibited no postprocedural neurological deterioration or associated symptomatic parenchymal hemorrhage. Recanalization rates and clinical outcomes were similar between the 2 groups (table 1).

Table 1. Clinical Outcomes After Mechanical Thrombectomy^a

^a P = NS for all comparisons.
Abbreviation: NIHSS, National Institutes of Health Stroke Scale.

Overall, 1 patient had symptomatic hemorrhage, 3 died during 3-month follow-up, and 31 (42%) showed good clinical outcome (modified Rankin Scale score of 0-2) at 3 months.

While noting that previous studies may have underreported the incidence of subarachnoid hemorrhage because of a lack of routine follow-up CT, the authors conclude that “isolated [subarachnoid hemorrhage], unrelated to parenchymal hemorrhage, was not uncommon after primary mechanical thrombectomy with a Solitaire device.”

They attribute this to several possible mechanisms, including:

• Angiographically occult extravasation of blood or contrast into the subarachnoid space during stent retrieval
• Vessel injury during rescue angioplasty
• Disruption of cerebral microvascular permeability barriers

Whatever the cause, though, “[t]his study showed that [subarachnoid hemorrhage] after thrombectomy with a Solitaire stent had a benign prognosis,” the authors stress. “The procedure did not cause neurological deterioration, regardless of whether a hemorrhage or contrast extravasation had occurred.”

Radiographically Positive, Clinically Benign

In an e-mail communication with TCTMD, Elad I. Levy, MD, of the University at Buffalo (Buffalo, NY), noted that in general, “it is not uncommon to see contrast staining consistent with subarachnoid hemorrhage after intra-arterial stroke interventions.” He agreed with the authors that the etiology of such staining can be multifactorial, “including disruption of microvascular permeability barrier secondary to ischemia, contrast toxicity, as well as direct vessel damage due to thrombectomy manipulations. We have noted in our practice that most of these cases have a benign course, with contrast staining resolving in the next 24 to 48 hours.”

Philip M. Meyers, MD, of Columbia University Medical Center (New York, NY), concurred that a small amount of bleeding after stroke revascularization is not uncommon. “The ones that are serious, that often will have a negative effect on outcome, are when there’s a greater volume of subarachnoid or parenchymal hemorrhage, which they didn’t find in this study,” he told TCTMD in a telephone interview. “We frequently see a little bit of hemorrhage on the brain scans of stroke victims, and sometimes it has to do with what medications they were given as much as any procedure that’s been performed.”

“The most important message,” Dr. Levy stressed, “is that the majority of these radiographically positive findings are clinically benign. Endovascular stroke interventions are typically performed when patients have severe neurologic deficits.  Recent SWIFT and TREVO2 trials have clearly demonstrated clinical benefit of stent-retrievers over earlier mechanical thrombectomy devices.”

Dr. Meyers agreed, noting that the key unanswered question is whether mechanical devices such as stent-retrievers actually improve patient outcomes. Studies from the upcoming International Stroke Conference, February 6 to 8 in Honolulu, Hawaii, will address this issue, he noted.

 

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Source:
Yoon W, Jung MY, Jung SH, et al. Subarachnoid hemorrhage in a multimodal approach heavily weighted toward mechanical thrombectomy with Solitaire stent in acute stroke. Stroke. 2013;Epub ahead of print.

 

 

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