title: Ipsilateral Pupillary Dilation Following Carotid Endarterectomy: A Temporary and Benign Phenomenon.
abstract: BACKGROUND
  Cases of post carotid endarterectomy (CEA) Horner's syndrome have been reported, with symptoms attributed to manipulation of the sympathetic plexus situated along the carotid artery; however, these patients presented with the typical constricted pupil. We report the first 3 cases to our knowledge of mydriasis following CEA.
  
  
  METHODS
  We present 3 cases of CEA followed by immediate postoperative development of ipsilateral mydriasis. The patients were otherwise at their neurologic baseline and the mydriasis resolved over the ensuing few days.
  
  
  CONCLUSIONS
  We suggest that these cases are secondary to an ischemic phenomenon, specifically to parasympathetic structures such as the ciliary ganglion and/or oculomotor nerve, resulting in autonomic dysfunction manifested by pupillary dilation. A similar finding of mydriasis occurring subsequent to other carotid pathology has been reported, with ischemia to parasympathetic structures also proposed as the underlying etiology. Although pupillary dilation often represents a worrisome neurosurgical sign indicating herniation, it should be recognized that after CEA this finding may be a transient, benign occurrence.
authors.affiliation: Department of Neurosurgery, University of California at San Diego, San Diego, California.
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: Steinberg
authors.affiliation: Department of Neurosurgery, University of California at San Diego, San Diego, California.
authors.forename: Bob S
authors.initials: BS
authors.lastname: Carter
authors.affiliation: Department of Neurosurgery, Stanford University School of Medicine, Stanford, California.
authors.forename: Marco B
authors.initials: MB
authors.lastname: Lee
authors.affiliation: Department of Neurosurgery, Stanford University School of Medicine, Stanford, California.
authors.forename: Gary K
authors.initials: GK
authors.lastname: Steinberg
mesh_terms: D000368:Aged; D017536:Carotid Artery, Common / Q000000981:diagnostic imaging / Q000601:surgery; D002343:Carotid Artery, Internal / Q000000981:diagnostic imaging / Q000601:surgery; D016893:Carotid Stenosis / Q000000981:diagnostic imaging* / Q000601:surgery*; D004106:Dilatation; D016894:Endarterectomy, Carotid / Q000009:adverse effects* / Q000639:trends; D006801:Humans; D008297:Male; D008875:Middle Aged; D015878:Mydriasis / Q000000981:diagnostic imaging* / Q000209:etiology*
keywords: Carotid endarterectomy; Mydriasis; Nerve ischemia