Perioperative Analgesia for Patients Undergoing Open Liver Resection: Epidural or Paravertebral?

Abstract

Open liver resection is a painful surgery, and patients clearly benefit from regional anesthesia for pain management in the perioperative period. However, it is still unclear which regional block technique is superior in these patients. Epidural Analgesia in Open Liver Resection Although simple liver resection is increasingly done laparoscopically, patients with large liver masses or previous abdominal surgery often undergo an open liver resection. This requires a long right subcostal incision, the associated pain of which may carry significant morbidity in the post-operative period. The best-studied regional technique in abdominal as well as thoracic procedures is thoracic epidural block. Decreasing nociceptive input via epidural analgesia reduces activation of sympathetic outflow, thus reducing surgical stress, which negatively impacts many organ systems (1). Epidural analgesia decreases pain-related tachycardia and hypertension, which could cause perioperative myocardial ischemia. Furthermore, thoracic and upper abdominal nociceptive input activates reflex inhibition of diaphragmatic excursion and increased expiratory intercostal and abdominal muscle tone, leading to increased atelectasis and risk of pneumonia. One study of 915 major abdominal surgical patients revealed that epidural analgesia both decreased pain scores in the first three postoperative days and decreased rates of respiratory failure (2). Interestingly, a handful of studies have also documented a positive impact of epidural analgesia on the coagulation profile, which prevents post-operative thromboembolic complications (1). Other benefits include a decrease in stress-induced gastrointestinal disruption and immunosuppression. Moreover, in patients undergoing open liver resection, epidural technique resulted not only in improved analgesia, but also in decreased postoperative morphine consumption (3), the latter of which is an additional benefit of epidural analgesia, given the potentially deleterious side effects associated with intravenous (IV) opioids (i.e., respiratory depression, decreased gastrointestinal motility). Indeed, epidural analgesia was sufficient for 80% of patients undergoing open liver resection in another study, with only 20% of patients requiring additional analgesia with IV opioids (4).