The Emerging Role of Peri-Operative Methadone for the Management of Post-Operative Pain for Patients Undergoing Oesophagectomy: A Narrative Review

Background: Oesophageal cancer is a diagnosis carrying significant morbidity and mortality. Gold standard treatment is resection; however, this requires a complex operation. Despite progression to minimally invasive approaches, post-operative pain is a significant issue. Methadone is emerging as an additive intraoperative analgesic across specialities, with a single intra-operative dose seen to improve post-operative pain and reduce post-operative opioid use. This is promising for oesophagectomy patients, where pain is a significant issue; however, it remains poorly characterised. Aim: This paper aimed to assess the literature surrounding intra-operative methadone (IOM) in oesophagectomy, then broadly consider related evidence to consider how it may be applicable to patients undergoing oesophagectomy for oesophageal cancer. Methods: The search assessed existing evidence for efficacy and safety of IOM for patients undergoing oesophagectomy for oesophageal cancer. Of 1856 studies, only one fit inclusion criteria. Following this, the search was broadened to assess IOM use in related surgical contexts, deriving applicability to oesophagectomy. Results: There is very limited evidence for IOM use in oesophagectomy. Several papers explore its use in other intraabdominal and intrathoracic procedures. This evidence may be leveraged for oesophagectomy patients. There remain several safety concerns, most notably respiratory and cardiac risks. Further, several knowledge gaps remain. Conclusions: Overall, IOM represents a promising analgesic option. Unfortunately, current evidence is limited, predominantly derived from non-generalisable studies. This paper provides an up-to-date review of evidence, highlighting clear gaps. It is clear oesophagectomy patients are a vulnerable group who would benefit from improved pain and post-operative quality of life. As such, further focused research should be done to evaluate the role of IOM in oesophagectomy for oesophageal cancer.