Incidence and types of arrhythmias after mediastinal manipulation during transhiatal esophagectomy

Background. Transhiatal esophagectomy (THE) is a common operative procedure for carcinoma esophagus. Complications of this procedure include arrhythmias and hypotension during blunt dissection of the esophagus from posterior mediastinum. In the literature, exact incidence and type of arrhythmias have not been reported. We employed Holter monitoring during mediastinal manipulation in patients undergoing THE, for this purpose. Methods. This prospective study was carried out in 20 consecutive American Society of Anesthesiologists grade I-II patients undergoing THE. Anesthetic technique included induction with thiopentone and maintenance with morphine, vecuronium, and isoflurane. In addition to routine parameters, Holter monitoring was undertaken to record the exact incidence and types of arrhythmias. "Premanipulation" or control period included duration of 30 minutes preceding mediastinal manipulation, while "during manipulation" or study period included the duration of mediastinal manipulation. The incidence of arrhythmias was studied for 48 hours in the postoperative period. The Fisher exact test was applied to analyze incidence of arrhythmias and hypotension. Results. Out of 20 patients, only 2 had arrhythmias in the premanipulation period, while 13 had arrhythmias during the manipulation period (p < 0.01). During the manipulation period, arrhythmias included supraventricular ectopics and ventricular ectopics in 2 patients each and a combination of both in 9 patients. Arrhythmias were transient and had no correlation with either duration or degree of hypotension in all the patients. However, there was a linear relationship between hypotension and duration of mediastinal manipulation. Two patients (10%) had atrial arrhythmias in the postoperative period. Conclusions. In transhiatal esophagectomy, there is a significant incidence of both arrhythmias and hypotension during mediastinal manipulation. The incidence of arrhythmias can be minimized by limiting the duration of the manipulation. The incidence of postoperative arrhythmias was not significant.