title: Vagus-preserving technique during minimally invasive esophagectomy: the effects on cardiac parameters in a swine model.
abstract: BACKGROUND
  Cardiac complications are an important cause of morbidity and mortality observed after esophageal resections. We examined whether an high intrathoracic vagotomy during abdominothoracic esophagectomy would have an effect on intraoperative and early postoperative cardiac function in the setting of a minimally invasive resection. Two hypotheses were generated for this study: (1) Vagotomy would cause cardiac changes, and (2) vagus-preserving esophagectomy would prevent cardiac problems during resection and in the early postoperative phase.
  
  
  RESULTS
  Thirty male pigs were operated on while cardiac parameters (heart rate [HR], cardiac index [CI], preload recruitable stroke work [PRSW], contractility speed [dp/dtmax], relaxation speed [dp/dtmin], and relaxation time [tau]) were monitored using a conductance catheter and the thermodilution method. Animals were randomized into 4 groups (each n = 7): (1) control, thoracoscopy only, (2) thoracoscopy with vagotomy, (3) esophageal resection with vagotomy, and (4) esophageal resection with vagus nerve preservation. To evaluate the first hypothesis, we compared groups 1 and 2; to evaluate the second hypothesis, we compared groups 3 and 4. HR, CI, PRSW, dp/dtmax, and tau were different in the 2 groups without resection (area under the curve; each P < .05). Vagotomy with esophagectomy resulted in nonsignificant differences between groups 3 and 4. The requirement for metoprolol administration to avoid severe tachycardia was greater in the groups that underwent vagotomy (P < .05; Fisher's exact test).
  
  
  CONCLUSIONS
  An high intrathoracic vagotomy results in loss of vagal tone and a greater rate of tachycardia during thoracoscopy and esophagectomy. There were no differences, however, in cardiac dynamics between the esophagectomy groups. Thus, vagal injury is not the sole reason for cardiac dysfunction after esophagectomy.
authors.affiliation: Department of General, Visceral and Vascular Surgery, Medical Faculty of the Humboldt University, Charité - Campus Benjamin Franklin, Berlin, Germany. Electronic address: urte.zurbuchen@charite.de.
authors.forename: Urte
authors.initials: U
authors.lastname: Zurbuchen
authors.affiliation: Department of General and Visceral Surgery, Asklepios Klinik Altona, Hamburg, Germany.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Schwenk
authors.affiliation: Department of General, Visceral, Thoracic and Vascular Surgery, Klinikum Bremerhaven, Bremerhaven, Germany.
authors.forename: Tido
authors.initials: T
authors.lastname: Junghans
authors.affiliation: Department of General, Visceral, Thoracic, and Vascular Surgery, Medical Faculty of the Humboldt University, Charité - Campus Mitte, Berlin, Germany.
authors.forename: Diethelm
authors.initials: D
authors.lastname: Modersohn
authors.affiliation: Department of General, Visceral, Thoracic, and Vascular Surgery, Medical Faculty of the Humboldt University, Charité - Campus Mitte, Berlin, Germany.
authors.forename: Oliver
authors.initials: O
authors.lastname: Haase
mesh_terms: D000818:Animals; D016629:Esophagectomy / Q000379:methods*; D006339:Heart Rate; D007431:Intraoperative Complications / Q000209:etiology* / Q000517:prevention & control; D007432:Intraoperative Period; D008297:Male; D011184:Postoperative Period; D012372:ROC Curve; D011897:Random Allocation; D013552:Swine; D013610:Tachycardia / Q000209:etiology* / Q000517:prevention & control; D013906:Thoracoscopy / Q000379:methods*; D014628:Vagotomy / Q000009:adverse effects*