In this report, we describe a case of isolated left-sided SAH 6 days after ipsilateral CEA surgery. No evidence of intraparenchymal hemorrhage or other explanation for the SAH was found. SAH as a manifestation of CHS after CEA is an extremely rare complication; Ogasawara et al. report a 0% incidence of SAH in the CEA (n = 1596) subgroup of their retrospective review of 4494 patients (Ogasawara et al.2007), whereas McDonald et al. report it as being the least common form of CHS in 203 post-CEA patients (McDonald et al.2011). To our knowledge, there are only 2 previous cases that report this phenomenon (Bodenant et al.2010); (Dalton1992).
In 1992 SAH was described in a 62-year old Caucasian woman 5 days post-CEA surgery with no neurological deficits (Dalton1992). In 2010 a 74-year old male who presented with left-sided hemiplegia, left visual and sensory neglect, fluctuant altered consciousness and partial motor seizure 9 days following a right CEA was reported (Bodenant et al.2010). Neuroimaging confirmed a frontal SAH but was negative for aneurysms and vascular malformations. In contrast to our patient, that patient developed vasospasm in the middle cerebral artery. In both these cases, as in our patient, the likely source of the hemorrhage was rupture of small dilated, cortical vessels experiencing elevated flow and pressures following restoration of normal ICA flow.
Post-operative hypertension has been identified as one of the most important risk factors predisposing to CHS in post-CEA patients (Lieb et al.2012; Ogasawara et al.2007; van Mook et al.2005), and Bouri et al. report reduced odds for intracranial hemorrhage when systolic blood pressure is maintained at <140 – 160 mmHg post-operatively (Bouri et al.2011). Our patient was difficult to maintain normotensive in the post-operative period, and presented with blood pressures of 230/170 mmHg, which likely contributed to development of CHS and the subsequent SAH. A recent study reinforces the importance of treating hypertension to minimize neurological deficits (Wellman & Koide2013), supporting the strict blood pressure control the patient underwent.
An isolated cerebral hemisphere, whose perfusion is dependent solely upon the ipsilateral carotid artery, is also a risk factor for CHS (Moulakakis et al.2009; Moulakakis et al.2012). While our patient did not have an incomplete Circle of Willis, he had bilateral carotid stenosis, and his CTA showed severe right ICA narrowing, which has been associated with an increased likelihood of developing CHS (Pyysalo et al.2011), likely through disruption of auto-regulatory mechanisms. However, on the other hand, a recent paper earlier this year has found that the degree of contralateral stenosis was not significant in the development in cerebral hyper-perfusion. These results indicate that further research has to be done in the field of contralateral stenosis (Maas et al.2013).
The risk of significant vasospasm developing from a cortical SAH in this clinical context is minimal, and was not a significant management concern in this case. If concern is higher, due to a significant hemorrhagic component in the basal cisterns, consideration may be given to the use of nimodipine, and longer inpatient monitoring, with cerebrospinal fluid drainage as indicated. Anticonvulsants (used to treat his presumed seizures at onset) are important to ensure adequate seizure control because the spikes in systolic blood pressure during seizure activity can further worsen the established CHS (Connolly et al.2012).
This case demonstrates the importance of aggressively controlling hypertension in patients after their CEA surgery. The presence of one or more risk factors for CHS demands particular vigilance and outpatient blood pressure monitoring on discharge. The case also highlights a rare presentation of CHS. Appropriate aggressive management of this complication through blood pressure reduction, seizure control and antispasmodic therapy (if indicated) decrease the risk of mortality and neurological deficits (Pyysalo et al.2011).
Informed consent was obtained from the patient for the publication of this report and any accompanying images.