title: Carotid endarterectomy significantly improves postoperative laryngeal sensitivity.
abstract: OBJECTIVE
  Iatrogenic injury of the vagus nerve or its branches during carotid endarterectomy (CEA) can result in globus sensation, dysphagia, and even vocal fold immobility. Knowledge of morphologic and functional laryngopharyngeal outcomes after CEA is poor. The present study was performed to determine potential iatrogenic damage to the laryngeal innervation after CEA. An area of particular interest was the supraglottic sensory threshold, which was examined by Fiberoptic Endoscopic Evaluation of Swallowing With Sensory Testing (FEESST; Pentax Medical Company, Montvale, NJ), a validated and safe method for the determination of the motor and sensory components of swallowing.
  
  
  METHODS
  FEESST was used preoperatively in 32 patients scheduled to undergo CEA and twice postoperatively to examine the motor and sensory components of swallowing. In this endolaryngeal examination, laryngopharyngeal sensory thresholds (in mm Hg) were defined as normal at <4.0 mm Hg air pulse pressure (APP), moderate deficit at 4.0 to 6.0 mm Hg APP, or severe deficit at >6.0 mm Hg APP, with a value >10.0 mm Hg APP indicating abolished laryngeal adductor reflex. Acoustic voice parameters were also analyzed for further functional changes of the larynx.
  
  
  RESULTS
  The mean ± standard deviation preoperative FEESST measures showed no significant differences (P = .065) between the operated-on side (6.73 ± 1.73 mm Hg) and the opposite side (5.83 ± 1.68 mm Hg). At 2 days postoperatively, the threshold increased (P = .001) to 7.62 ± 1.98 mm Hg on the operated-on side. A laryngopharyngeal mucosal hematoma on the operated side was endoscopically detectable in eight patients (30.8%); in these patients, we found a markedly elevated (P = .021) measure of 9.50 ± 0.93 mm Hg. On the opposite (nonoperated-on) side of the laryngopharynx, the thresholds remained at the same level as preoperatively over all assessments (P >.05), whereas the differences between the operated and nonoperated-on sides and the hematoma and nonhematoma groups were highly significant (P = .004 and P = .001, respectively). Surprisingly, the sensory threshold on the operated-on side (6.08 ± 2.02 mm Hg) decreased significantly at the 6-week follow-up, even in relation to the preoperative measure (P = .022). With the exception of one patient with permanent unilateral vocal fold immobility, no signs of nerve injury were detected.
  
  
  CONCLUSIONS
  In accordance with previous reports, injuries to the recurrent laryngeal nerve during CEA seem to be rare. In most patients, postoperative symptoms (globus, dysphagia, dysphonia) and signs fade within a few weeks without any specific therapeutic intervention. This study shows an improved long-term postoperative superior laryngeal nerve function with regard to laryngopharyngeal sensitivity.
authors.affiliation: Division of Phoniatrics, Speech and Swallowing, Department of Otorhinolaryngology, Medical University of Graz, Graz, Austria. Electronic address: georg.hammer@medunigraz.at.
authors.forename: Georg Philipp
authors.initials: GP
authors.lastname: Hammer
authors.affiliation: Division of Phoniatrics, Speech and Swallowing, Department of Otorhinolaryngology, Medical University of Graz, Graz, Austria.
authors.forename: Peter Valentin
authors.initials: PV
authors.lastname: Tomazic
authors.affiliation: Division of Phoniatrics, Speech and Swallowing, Department of Otorhinolaryngology, Medical University of Graz, Graz, Austria.
authors.forename: Sarah
authors.initials: S
authors.lastname: Vasicek
authors.affiliation: Division of Phoniatrics, Speech and Swallowing, Department of Otorhinolaryngology, Medical University of Graz, Graz, Austria.
authors.forename: Matthias
authors.initials: M
authors.lastname: Graupp
authors.affiliation: Division of Phoniatrics, Speech and Swallowing, Department of Otorhinolaryngology, Medical University of Graz, Graz, Austria.
authors.forename: Markus
authors.initials: M
authors.lastname: Gugatschka
authors.affiliation: Division of Vascular Surgery, Department of Surgery, Medical University of Graz, Graz, Austria.
authors.forename: Anneliese
authors.initials: A
authors.lastname: Baumann
authors.affiliation: Division of Vascular Surgery, Department of Surgery, Medical University of Graz, Graz, Austria.
authors.forename: Peter
authors.initials: P
authors.lastname: Konstantiniuk
authors.affiliation: Division of Vascular Surgery, Department of Surgery, Medical University of Graz, Graz, Austria.
authors.forename: Stephan Herwig
authors.initials: SH
authors.lastname: Koter
mesh_terms: D000162:Acoustics; D000368:Aged; D000369:Aged, 80 and over; D002340:Carotid Artery Diseases / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D003679:Deglutition; D003680:Deglutition Disorders / Q000209:etiology / Q000503:physiopathology; D055154:Dysphonia / Q000209:etiology / Q000503:physiopathology; D016894:Endarterectomy, Carotid / Q000009:adverse effects; D004945:Esophagoscopy; D005260:Female; D005336:Fiber Optic Technology; D006801:Humans; D007049:Iatrogenic Disease; D061224:Laryngeal Nerve Injuries / Q000209:etiology / Q000503:physiopathology; D007823:Laryngeal Nerves / Q000503:physiopathology*; D007830:Larynx / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D009043:Motor Activity; D011237:Predictive Value of Tests; D011312:Pressure; D011446:Prospective Studies; D020127:Recovery of Function; D012684:Sensory Thresholds; D013068:Speech Production Measurement; D013997:Time Factors; D016896:Treatment Outcome; D014833:Voice Quality