Background: Long-term survival is increasingly common following oesophageal resection. Gastric conduits are associated with adverse gastrointestinal symptoms, which may significantly impact quality-of-life(QoL). Improving understanding of gastric conduit physiology is vital to improve outcomes in survivorship.
Methods: Patients ≥2years post oesophagectomy were recruited for high fidelity nuclear scintigraphy emptying studies with a tailored protocol: 90-minutes static emptying, 15-minutes mobilisation then further imaging. QoL questionnaires were completed. A subset underwent dynamic MRI, and controls were recruited.
Results: 57 patients, 44(88%)men, were recruited median(IQR) 24-months(24-29.5) post oesophagectomy, along with 12-controls. Oesophagectomy types included 2-stage&3-stage, and all included a pyloric relaxing procedure. Conduit emptying half-time was 178-minutes(61.5-458). 90-minutes post semi-solid meal, median emptying was 21%(8-48). Post mobilisation(115-minutes), emptying increased to 53.4%(33.4-80.6)p<0.0001. Conduit emptying was observed to be vastly different to the physiological emptying in controls. There was no correlation between increased emptying half times with symptoms of dysphagia(p=0.213), reflux(p=0.859), dumping(p=0.208) or regurgitation(p=0.057). In patients emptying halftime≥250minutes, 16(73%) have no reflux. Dynamic MRI(n=18) successfully delineated gastric wall contractions(peristaltic frequency 5-waves/90 seconds, GMI35.45mm2/sec(17.3-47.5) but didn't demonstrate an association between emptying and peristalsis(r=0.33,p=0.19). Increased Sigstad scores demonstrated significant, inverse correlation to seven of eight SF-36 QoL domains.
Conclusions: Conduit emptying is vastly different to normal gastric emptying, and emptying studies need to be interpreted with specialised reference ranges. Patients with severely abnormal gastric emptying are frequently asymptomatic. Gravity-mediated drainage appears a key mechanism in a significant proportion of patients. Gastric peristalsis isn’t associated with improved conduit emptying. This provides a substantially different paradigm of conduit function.