Nandakumar Nagaraja MD, MS

Endovascular interventions for acute ischemic stroke can result in complications such as arterial perforation, dissection, subarachnoid hemorrhage or intraparenchymal hematoma. It is important to know the magnitude of these risks related to the procedure and their clinical implications. It helps in the decision making process when discussing with the family to obtain consent for the procedure and be prepared to manage these complications if it occurs.

Yoon and colleagues performed a retrospective analysis of 74 acute ischemic stroke patients who underwent multimodal endovascular intervention weighted toward mechanical thrombectomy with a Solitaire stent. They evaluated for the incidence, clinical implications and prognosis of SAH after the procedure. All patients had a baseline CT and multimodal MRI prior to the procedure; immediate post procedure and 24hr CT scan; and 24 hr MRI to evaluate for blood on GRE in patients who had hyperdense lesion in the post procedure CT scan.

12 (16.2%) patients had SAH; 4 pure SAH and 8 mixed SAH with contrast extravasation. SAH in 5 patients (3 pure and 2 mixed) disappeared on 24 hr imaging. There was no significant difference between the SAH group and the control group for baseline characteristics including demographics, risk factors and stroke etiology. Baseline NIHSS was 12. Half the patients had received iv t-PA and 30-41% of the patients had mechanical clot disruption with IA urokinase in each group. Patients who had angioplasty had higher rates of SAH (33.3%) compared to control group (9.7%), p=0.05. The authors’ consider this to be due to small vessel rupture from mechanical stretch during stent retrieval. There was no significant difference in the clinical outcome between the two groups for recanalization status, SICH, mortality, discharge NIHSS and 3 months mRS assessment and therefore the SAH post procedure was considered to be clinically benign.

Some patients who develop SAH post procedure may not have grossly evident neurological deficits and the symptoms if present may be masked from the deficits of acute ischemic stroke. A significant proportion of the patients could develop cognitive impairment which may be subtle and not detected with routine assessment. The AHA/ASA guidelines for management of aneurysmal SAH recommend a comprehensive evaluation of cognitive, behavioral and psychosocial function after discharge. Though the SAH is due to the procedure and not aneurysmal in this study it may be useful to obtain detailed neuropsychological assessment in these patients after discharge.