Intracranial Hemorrhage Complicating Carotid Artery Stenting and Carotid Endarterectomy

Abstract

See related article, pages 2782–2787. There are now 2 options for revascularization of patients with significant carotid artery stenosis, carotid artery stenting (CAS), approved by the Food and Drug Administration in May for conventional risk patients, and carotid endarterectomy (CEA). In this issue of Stroke , McDonald et al1 utilize International Classification of Diseases 9th revision codes from the National Inpatient Sample (NIS) hospital discharge database to study intracranial hemorrhage (ICH), mortality, and discharge disposition after CAS or CEA during 2001 to 2008. This database study illustrates both the power and the weaknesses of such a large retrospective review. With 229 000 patients in a study, infrequent events can be detected in numbers adequate to yield statistically significant group differences. Such is the case with the ICH rates for asymptomatic patients after the procedure. Fortunately, in such patients ICH appears to be a rare event after either CAS or CEA, with rates <1%. For symptomatic patients, the NIS database rate of ICH was of concern and higher after CAS at 4.4% ICH vs 0.8% ICH after CEA. Weaknesses of a retrospective database review include diagnostic imprecision and limited capability to describe important baseline differences between groups. For example, in the NIS database 136 (41%) of the ICH are attributed to International Classification of Diseases 9th revision code 430, subarachnoid hemorrhage (SAH). However, documented cases of SAH after CAS and CEA are rare and proportionately much less …