title: Peripheral baroreflex and chemoreflex function after eversion carotid endarterectomy.
abstract: OBJECTIVE
  This study assessed the long-term effect of the eversion technique for carotid endarterectomy (e-CEA) on arterial baroreflex and peripheral chemoreflex function.
  
  
  METHODS
  The study included 13 patients who underwent, between 2001 and 2006, bilateral e-CEA and 16 who underwent bilateral standard CEA (s-CEA) to eliminate the complicating effects of intact contralateral carotid sinus function. Exclusion criteria were age >70 years, diabetes mellitus, chronic pulmonary disease, ischemic cardiac disease or medical therapy with β-blockers, cardiac arrhythmia, neurologic deficits, carotid restenosis, and previous neck or chest surgery or irradiation. Young and aged-matched healthy individuals were recruited as controls. All patients underwent standard cardiovascular reflex tests, including lying-to-standing, orthostatic hypotension, deep breathing, and Valsalva maneuver. Autonomic cardiovascular modulation was indirectly evaluated by spectral analysis of heart rate variability and systolic arterial pressure variability. The chemoreflex sensitivity to hypoxia was obtained during classic rebreathing tests from the slopes of the linear regression of minute ventilation (VE) vs arterial oxygen saturation measured by pulse oximetry (SpO2%) and partial pressure of end-tidal oxygen (PetO2).
  
  
  RESULTS
  Patients (16 men; age, 62.4 ± 8.0 years) were enrolled after a mean interval of 24 ± 17 months from the last CEA. All were asymptomatic, and results of standard tests were negative. Residual baroreflex performance was documented in both patient groups, although reduced, compared with young controls. Notably, baroreflex sensitivity (msec/mm Hg) was better maintained after e-CEA than after s-CEA at rest (young controls, 19.93 ± 9.50; age-matched controls, 7.75 ± 5.68; e-CEA, 13.85 ± 14.54; and s-CEA, 3.83 ± 1.15; analysis of variance [ANOVA], P = .001); and at standing (young controls, 7.83 ± 2.55; age-matched controls, 3.71 ± 1.59; e-CEA, 7.04 ± 5.62; and s-CEA 3.57 ± 3.80; ANOVA, P = .001). Similarly, chemoreflex sensitivity to hypoxia was maintained in both patient groups, which did not differ from each other, and was reduced compared with controls (controls vs patient groups ΔVE/ΔSpO2: -1.37 ± 0.33 vs -0.33 ± 0.08 and SpO2% -0.29 ± 0.13 L/min; P = .002; ΔVE/ΔPetO2: -0.20 ± 0.1 vs -0.01 ± 0.0 and -0.07 ± 0.02 L/min/mm Hg; P = .04, ANOVA with least significant difference correction for multiple comparisons).
  
  
  CONCLUSIONS
  Our data show that e-CEA, even when performed on both sides, preserves baroreflexes and chemoreflexes and, therefore, does not confer permanent carotid sinus denervation. Also, e-CEA does not increase long-term arterial pressure variability, and this suggests that perioperative hemodynamic derangements can be attributed to the temporary effects of surgical trauma.
authors: Vascular Surgery, Vita-Salute San Raffaele University, Milan, Italy. max_marrocco@yahoo.com
authors: Massimiliano M
authors: MM
authors: Marrocco-Trischitta
authors: George
authors: G
authors: Cremona
authors: Daniela
authors: D
authors: Lucini
authors: Maria Grazia
authors: MG
authors: Natali-Sora
authors: Marco
authors: M
authors: Cursi
authors: Domenico
authors: D
authors: Cianflone
authors: Massimo
authors: M
authors: Pagani
authors: Roberto
authors: R
authors: Chiesa
mesh_terms: D000368:Aged; D000704:Analysis of Variance; D062186:Arterial Pressure; D017704:Baroreflex; D001944:Breath Tests; D002346:Carotid Sinus / Q000294:innervation*; D016893:Carotid Stenosis / Q000097:blood / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery*; D002628:Chemoreceptor Cells / Q000378:metabolism*; D016894:Endarterectomy, Carotid / Q000009:adverse effects / Q000379:methods*; D005260:Female; D006334:Heart Function Tests; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D010092:Oximetry; D010100:Oxygen / Q000097:blood; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D010100:Oxygen