Thoracic epidural anesthesia in elderly patients undergoing cardiac surgery for mitral regurgitation feasibility study

The Editor, In contrast to coronary artery bypass grafting (CABG), surgical correction of mitral valve regurgitation (MR) poses the following additional problems: A difficult hemodynamic stability achievement (especially after general anesthesia and epidural anesthesia induction); B higher risk to develop sudden perioperative dismal left ventricular function; C greater risk of bleeding; D need for postoperative anticoagulation; and E extensive myocardial manipulation and cardiac troponin release especially in the case of mitral valve (MV) replacement compared to MV repair. 1 As demonstrated by Stenseth et al., thoracic epidural (TEA) may improve the left ventricular load condition decreasing the systemic resistance by the sympathetic blockade. 2 In the present study, we tested the feasibility of high TEA in 30 elderly patients undergoing mitral valve surgery for primary MR. Inclusion criteria were elective median sternotomy for MR correction with or without CABG, tricuspidal surgery, Maze procedure, age >65 years, and normal coagulation profile. In the recovery room, an 18-G epidural catheter was inserted between T2-T5 under sterile conditions by loss of resistance to air. Induction of thoracic epidural anesthesia was achieved in the operating room after general anesthesia induction with a bolus of 0.1-0.2 ml/kg of lidocaine 2%. Regional anesthesia was maintained by a continuous epidural infusion of 0.2% ropivacaine and 1 mcg/ml sufentanyl at an infusion rate between 2 and 6 ml postoperatively. GA was induced with fentanyl (10-20 mcg/kg), propofol (2 mg/kg) and rocuronium 0.6 mg/kg and maintained with continuous infusion of propofol 50-100 mcg/kg/min, desflurane and fentanyl as required. Standard cardiopulmonary bypass (CPB) technique was used. Intraoperative and postoperative data are presented in Table 1. The epidural catheter was removed on the third postoperative day. Postoperatively, nine patients (30%) needed inotropic drugs or vasoconstrictors for weaning from CPB. In particular, one experienced left ventricular failure after CPB weaning, two patients had severe right ventricular failure, and one developed oliguric acute renal failure requiring institution of renal replacement therapy. All patients were discharged from the hospital. Postoperative mechanical ventilation was less than 24 hours in 27 patients (90%). Postoperative pain control was satisfactory in all patients. The median (interquartile) length of ICU was 1 day (1-4). The median (interquartile) length of hospital stay was 7 days (5-8). To avoid hypotension and inadequate coronary perfusion, the induction of TEA was performed in the operating room, after general anesthesia induction, with the first bolus administered to get the epidural peak effect at the time of skin incision. Epidural hematoma remains the most feared complication of the neuraxial procedures, especially in patients undergoing cardiac surgery. In the present study, the recommendations of the American Society of Regional Anesthesia and Pain Medicine 3 were strictly followed. Pain control was excellent after surgery. In conclusion, TEA can provide a reliable postoperative analgesia, good hemodynamic stability and low rate of intraoperative and postoperative cardiovascular complications in elderly patients undergoing cardiac surgery for primary MR. Further prospective randomized controlled studies are needed to confirm a "therapeutic role" of TEA in this setting.Table 1: Intra-operative data