title: Post-Carotid Endarterectomy Hypertension. Part 1: Association with Pre-operative Clinical, Imaging, and Physiological Parameters.
abstract: OBJECTIVE
  Post-endarterectomy hypertension (PEH) is a well recognised, but poorly understood, phenomenon after carotid endarterectomy (CEA) that is associated with post-operative intracranial haemorrhage, hyperperfusion syndrome, and cardiac complications. The aim of the current study was to identify pre-operative clinical, imaging, and physiological parameters associated with PEH.
  
  
  METHODS
  In total, 106 CEA patients undergoing CEA under general anaesthesia underwent pre-operative evaluation of 24 hour ambulatory arterial blood pressure (BP), baroreceptor sensitivity, cerebral autoregulation, and transcranial Doppler measurement of cerebral blood flow velocity (CBFv) and pulsatility index. Patients who met pre-existing criteria for treating PEH after CEA (systolic BP [SBP] > 170 mmHg without symptoms or SBP > 160 mmHg with headache/seizure/neurological deficit) were treated according to a previously established protocol.
  
  
  RESULTS
  In total, 40/106 patients (38%) required treatment for PEH at some stage following CEA (26 in theatre recovery [25%], 27 while on the vascular surgical ward [25%]), while seven (7%) had SBP surges > 200 mmHg back on the ward. Patients requiring treatment for PEH had a significantly higher pre-operative SBP (144 ± 11 mmHg vs. 135 ± 13 mmHg; p < .001) and evidence of pre-existing impairment of baroreceptor sensitivity (3.4 ± 1.7 ms/mmHg vs. 5.3 ± 2.8 ms/mmHg; p = .02). However, PEH was not associated with any other pre-operative clinical features, CBFv, or impaired cerebral haemodynamics. Paradoxically, autoregulation was better preserved in patients with PEH. All four cases of hyperperfusion associated symptoms were preceded by PEH. Length of hospital stay was significantly increased in patients with PEH (p < .001).
  
  
  CONCLUSIONS
  In this study, where all patients underwent CEA under general anaesthesia, PEH was associated with poorly controlled pre-operative BP and impaired baroreceptor sensitivity, but not with other peripheral or central haemodynamic parameters, including impaired cerebral autoregulation.
authors.affiliation: Department of Vascular Surgery, Leicester Royal Infirmary, Leicester, UK. Electronic address: jeremy.newman@dgh.nhs.uk.
authors.forename: J E
authors.initials: JE
authors.lastname: Newman
authors.affiliation: Department of Vascular Surgery, Leicester Royal Infirmary, Leicester, UK; Department of Cardiovascular Sciences and NIHR Biomedical Research Unit in Cardiovascular Disease, University of Leicester, Leicester, UK.
authors.forename: M J
authors.initials: MJ
authors.lastname: Bown
authors.affiliation: Department of Vascular Surgery, Leicester Royal Infirmary, Leicester, UK; Department of Cardiovascular Sciences and NIHR Biomedical Research Unit in Cardiovascular Disease, University of Leicester, Leicester, UK.
authors.forename: R D
authors.initials: RD
authors.lastname: Sayers
authors.affiliation: Department of Anaesthesia, Leicester Royal Infirmary, Leicester, UK.
authors.forename: J P
authors.initials: JP
authors.lastname: Thompson
authors.affiliation: Department of Cardiovascular Sciences and NIHR Biomedical Research Unit in Cardiovascular Disease, University of Leicester, Leicester, UK.
authors.forename: T G
authors.initials: TG
authors.lastname: Robinson
authors.affiliation: University College London Institute of Cardiovascular Science and NIHR University College London Hospitals Biomedical Research Centre, London, UK.
authors.forename: B
authors.initials: B
authors.lastname: Williams
authors.affiliation: Department of Cardiovascular Sciences and NIHR Biomedical Research Unit in Cardiovascular Disease, University of Leicester, Leicester, UK.
authors.forename: R
authors.initials: R
authors.lastname: Panerai
authors.affiliation: University College London Institute of Cardiovascular Science and NIHR University College London Hospitals Biomedical Research Centre, London, UK.
authors.forename: P
authors.initials: P
authors.lastname: Lacy
authors.affiliation: Department of Vascular Surgery, Leicester Royal Infirmary, Leicester, UK; Department of Cardiovascular Sciences and NIHR Biomedical Research Unit in Cardiovascular Disease, University of Leicester, Leicester, UK.
authors.forename: A R
authors.initials: AR
authors.lastname: Naylor
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D017704:Baroreflex; D001783:Blood Flow Velocity; D016893:Carotid Stenosis / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D002560:Cerebrovascular Circulation; D015331:Cohort Studies; D016894:Endarterectomy, Carotid / Q000009:adverse effects*; D005260:Female; D006801:Humans; D006973:Hypertension / Q000209:etiology*; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000209:etiology*; D012307:Risk Factors
keywords: Baroreceptor sensitivity; Carotid endarterectomy; Cerebral autoregulation; Hypertension