Intraoperative carcinoid syndrome during small-bowel neuroendocrine tumour surgery

Only few descriptions of intraoperative carcinoid syndrome (ioCS) have been reported. The primary objective of this study was to describe ioCS. A second aim was to identify risk factors of ioCS. We retrospectively analysed patients operated for small-bowel neuroendocrine tumour in our institution between 2007 and 2015, and receiving our preventive local regimen of octreotide continuous administration. ioCS was defined as highly probable in case of rapid (<5 min) arterial blood pressure changes ≥40%, not explained by surgical/anaesthetic management and regressive ≥20% after octreotide bolus injection. Probable cases were ioCS which did not meet all criteria of highly-probable ioCS. Suspected ioCS were detected on the anaesthesia record by an injection of octreotide due to a manifestation which did not meet the criteria for highly-probable or probable ioCS. A total of 81 patients (liver metastases: 59, prior carcinoid syndrome: 49, carcinoid heart disease: 7) were included; 139 ioCS occurred in 45 patients: 45 highly probable, 67 probable and 27 suspected. ioCs was hypertensive (91%) and/or hypotensive (29%). There was no factor, including the use of vasopressors, significantly associated with the occurrence of an ioCS. All surgeries were completed and one patient died from cardiac failure 4 days after surgery. After preoperative octreotide continuous infusion, ioCS were mainly hypertensive. No ioCS risk factors, including vasopressor use, were identified. No intraoperative carcinoid crisis occurred, suggesting the clinical relevance of a standardized octreotide prophylaxis protocol.